Thomas Brown - US grants

IgA is the principal carrier of antibody activity in external secretions and is more resistant to degradation by common proteases than other classes of immunoglobulins. IgA has been shown to be involved in the protection of mucosal surfaces from infection and has been implicated in immunity to dental caries and may be involved in protection against forms of periodontal disease. IgA occurs in two subclasses, IgA1 and IgA2, and two molecular forms, monomer and polymer, which have unique distributions in serum and secretions. The IgA1 subclass (but not the IgA2 subclass) is susceptible to cleavage by highly specific microbial proteases whose only known substrate is human IgA1. Recent findings indicate that natural antibodies to certain antigens of Streptococcus mutans, the principal etiologic agent of dental caries, occur predominantly in the IgA1 subclass, while others occur predominantly in IgA2. It has also been found that ratios of IgA1/IgA2 may change during an active infection. The long term objectives of this application are to approach questions concerning the potential of IgA1 proteases to compromise IgA- mediated immunity. The subclass distribution of specific antibodies that occur in patients with localized juvenile periodontitis (LJP) and active caries by examining them before and at periods after treatment. The IgA subclass distribution of specific antibodies in parotid saliva will be determined for selected antigens of S. mutans and the principal suspected pathogen of LJP, Actinobacillus actinomycetemcomitans. Serum IgA antibodies will also be examined in LJP patients for subclass distribution and for polymer/monomer distribution, using high performance liquid chromatography, as a means of discovering their origin. A solid phase assay will be developed which will allow for rapid enumeration of IgA protease-producing colonies in microbial samples. Knowledge of the dynamics of the IgA subclass response in disease together with a means of enumeration of IgA1 protease producing microorganisms will lead to a greater understanding of the potential impact of proteases on IgA- mediated immunity.

In the last several years, prophylactic knee braces have been widely marketed as a means for reducing the high incidence of serious ligament injuries occurring in football and other sports. However, no scientific consensus yet establishes the efficacy of these devices. Field trails and laboratory experiments provide complementary information needed to resolve this issue. However, even if it can be proven that current knee braces are of some benefits, the empirical nature of their designs makes it unlikely that such devices are optimal. In fact, preliminary evidence from our laboratory and in the literature suggests distinctly different performance characteristics between existing braces. We suspect that prophylactic knee brace performance is sensitive to one more major design variables, and that these design variables can be most efficiently identified in a well- controlled laboartory model. We propose series of parametric laboratory trials to document how the degree of afforded ligament protection varies in accordance with realistic changes in the major design variables. We will pursue two specific aims. First, we will refine and further validate an existing laboratory surrogate knee model which has proven useful for comparative studies of several commerical braces. This surrogate knee model incorporates modularly-replaceable polymeric ligament analogs whose mechanical properties (stiffness and strength) approximate those of normal human ligaments; we have completed initial validation against cadaveric performance under dynamic valgus loading conditions. The surrogate model overcomes many of the difficulties inherent in cadaver material as a vehicle for brace testing. Our second specific aim is to use this surrogate model to document failure load changes and ligament strain changes accompanying parametric changes in the major design variables that characterize prophylactic knee braces. These parametric design variations are to be efficiently achieved by means of interchangeable component substitutions in a modular, five-piece generic knee brace model.

Aseptic necrosis of the femoral head is an often-disabling disease entity which can result from any of several forms of circulatory compromise to tenuously perfused weight-bearing bone. Preservation of the natural femoral head is an important goal, particularly in the younger adult patients for whom prosthesis loosening would be a strong likelihood. Presently, it is difficult to predict which infarcted femoral heads will suffer early or late collapse, and the relationship between involvement region and severity of symptoms is not well understood. We hypothesize, based on preliminary studies and data in the literature, that femoral heads with osteonecrosis of varying configurations not only have varying potential for collapse, but that collapse can be reliably predicted by appropriate mechanical models. Osteonecrosis generally involves structural comprise of affected bony regions due to the fact that the complex natural repair processes which accompany infarct revascularization tend to result in net resorption of necrotic trabeculae, prior to eventual trabecular reconstitution with newly deposited viable bone. We propose to use finite element analysis to study several aspects of the structural behavior of the weakened necrotic femoral head. A fully anatomic three-dimensional linearly elastic model is proposed (Specific Aim I) to estimate the stress aberrations associated with five general configurations of infarct development, and to estimate the mechanical consequences of core-drilling, bone grafting, and varus/derotation osteotomy for each of these infarct configurations. We propose also to exercise to three-dimensional elastic model for individual infarct configurations (Specific Aim II) detected in five specific patients using magnetic resonance imaging. To more closely explore the mechanisms of actual structural failure in the necrotic femoral head (Specific Aim III), we propose to build upon preliminary work a linear elastic fracture mechanics finite element algorithm that has proven capable of predicting crack propagation patterns similar to those seen clinically. Although the biomechanical aspects of osteonecrosis are presently not well understood, most current therapeutic measures are essentially mechanical in nature. The significance of the proposed work lies in helping better delineate the indications for surgical intervention, and in helping to more selectively identify which procedure is likely to be of greatest benefit for specific head involvement patterns.

peptidases; immunoglobulin A; child (0-11); periodontitis; Streptococcus mutans; lipopolysaccharides; parotid gland; oral bacteria; Actinobacillus; dental caries; microorganism immunology; immunoglobulin M; polymers; high performance liquid chromatography; human subject;

Despite the general belief that cartilage contact pressures are elevated near articular surface incongruities, there are no data which directly link the degree of geometric incongruity with the degree of pressure elevation. Nor are there data linking the degree of pressure elevation with the quality of defect repair. The governing hypothesis of our application is that the ability of hyaline cartilage to repair and/or avoid degeneration, due to local defect, progressively diminishes in accordance with the severity of elevations of contacts pressure (and/or pressure gradient) near the defect. To date, techniques have been lacking for measuring cartilage contact stresses at spatial resolutions appropriate for the high- gradient regions that often surround local incongruities. Recent success with digital image scanning of magnified Fuji-film recordings now makings such measurements feasible. After briefly expanding upon our preliminary studies to further document the reliability and precision of the new pressure mapping technique, we first propose (specific Aim 1) to perform in-vitro pressure mappings for three established human intra- articular fracture models (tibial plateau, acetabulum, and ankle). The objective of this part of the study is to show that despite substantial differences in the amount of geometric incongruity that can be tolerated clinically, these functions involve approximately equivalent local pressure elevations near their respective geometric tolerance limits. We also propose to study the influence of local pressure aberrations on the quality of cartilage repair, using a canine model with full-thickness circular defects in the femoral condyle. We will perform in-vitro pressure mapping studies (Aim 2) to determine the specific defect sizes necessary to achieve three specific levels of pressure elevation at the defect rim. We then will conduct a prospective in-vivo study (Aim 3), in which each of our three graded local pressure elevations is created in a group of eight dogs, all of which will be allowed to heal their defects over a ten-month period. The success of defect repair in these 24 dogs will be assessed by numerical histomorphic grading, supplemented by indentation testing.

The working hypothesis of this proposal is that certain forms of learning reflect changes in the strengths of synaptic connections between the critically-involved neurons. The synaptic hypothesis for learning has not yet been adequately tested in mammals, although there is plenty of indirect evidence. The phenomenon of long-term synaptic potentiation (LTP), first discovered in the hippocampus, is widely touted as the most promising candidate synaptic substrate for rapid forms of learning In vertebrates. LTP was recently discovered to occur in the amygdala, another temporal lobe brain structure. The amygdala and hippocampus have repeatedly been implicated in various mnemonic functions in man and other animals. Knowledge of the cellular neurophysiology of the hippocampus and the mechanisms underlying hippocampal LTP is beginning to emerge, but comparable information does not exist for the amygdala. The goal of this proposal is to understand the mechanisms underlying amygdaloid LTP at the level of cellular neurophysiology and to test the idea that this form of synaptic plasticity is in fact involved in a particular type of rapid Pavlovian conditioning. The mechanisms will be explored using cultured and acute amygdala brain slices (two preparations that this laboratory has been developing) in conjunction with high-resolution visualization and neurophysiological techniques (whose application to brain slices this laboratory has also helped to pioneer). The knowledge gained from these in vitro systems about the underlying mechanisms will be used in in vivo experiments designed to test the hypothesis that amygdaloid LTP participates in aspects of rapid fear conditioning. The information that will be provided is relevant not only to the synaptic hypothesis for learning. The amygdala has major significance for neurology and psychiatry. Further understanding of the cellular neurophysiology and pharmacology of this structure will be relevant to the cause or treatment of numerous human neuropsychological disorders--possibly including major and minor mood disorders, memory impairments, sexual dysfunctions, epilepsy and certain violent behaviors.

IgA is the principal carrier of antibody activity in external secretions and is more resistant to degradation by common proteases than other classes of immunoglobulins. IgA has been shown to be involved in the protection of mucosal surfaces from infection and has been implicated in immunity to dental caries and may be involved in protection against forms of periodontal disease. IgA occurs in two subclasses, IgA1 and IgA2, and two molecular forms, monomer and polymer, which have unique distributions in serum and secretions. The IgA1 subclass (but not the IgA2 subclass) is susceptible to cleavage by highly specific microbial proteases whose only known substrate is human IgA1. Recent findings indicate that natural antibodies to certain antigens of Streptococcus mutans, the principal etiologic agent of dental caries, occur predominantly in the IgA1 subclass, while others occur predominantly in IgA2. It has also been found that ratios of IgA1/IgA2 may change during an active infection. The long term objectives of this application are to approach questions concerning the potential of IgA1 proteases to compromise IgA- mediated immunity. The subclass distribution of specific antibodies that occur in patients with localized juvenile periodontitis (LJP) and active caries by examining them before and at periods after treatment. The IgA subclass distribution of specific antibodies in parotid saliva will be determined for selected antigens of S. mutans and the principal suspected pathogen of LJP, Actinobacillus actinomycetemcomitans. Serum IgA antibodies will also be examined in LJP patients for subclass distribution and for polymer/monomer distribution, using high performance liquid chromatography, as a means of discovering their origin. A solid phase assay will be developed which will allow for rapid enumeration of IgA protease-producing colonies in microbial samples. Knowledge of the dynamics of the IgA subclass response in disease together with a means of enumeration of IgA1 protease producing microorganisms will lead to a greater understanding of the potential impact of proteases on IgA- mediated immunity.

The requested electrochemical profiler/photovoltage spectroscopy unit brings new capabilities to the recently established optoelectronics facility at the Institute of Optics, for epitaxial growth, characterization and fabrication of III-V heterstructure optoelectronics devices. The profile/photovoltage instrumentation is required for many aspects of an extensive research program that includes the investigation of quantum well lasers and modulators grown on (111) substrates (for low threshold and higher modulation frequency lasers, and larger electro-optic effect), quantum well lasers with doped active regions (for higher gain), novel circularly symmetric surface emitting laser structures, pseudomorphic GaInAs quantum well lasers (for lasing in the wavelength range of 860 to 110 nm., a region previously inaccessible to high efficiency diode lasers), quantum well lasers structures with dry etched facets (to enable integration of diode lasers), fast electro-optic modulators (for high speed phase and intensity modulation of light), an innovative approach to the disordering of superlattices by impurity diffusions (using applied electric fields during annealing) and the use of such selectively disordered structures in planar optical structures (lasers, waveguides, gratings electro-optic modulators). These research programs compliment the ongoing effort in indirect bandgap semiconductors (isoelectronic impurity complexes in indirect bandgap semiconductors, low noise avalanche photodiodes and nonlinear optical interactions in silicon on insulator structures), also at the Institute of Optics. The facility for growth, characterization and device fabrication of optoelectronic III-V semiconductors presently includes a molecular beam epitaxy machine, Raman, photoluminescence and excitation spectroscopy, photolithography, chemically assisted ion beam etching and rapid thermal annealing. The electrochemical profiler and photovoltage spectroscopy unit will be used to measure carrier concentration and bandgap profiles in III-V and Si state of the art optoelectronic materials and devices.

The hippocampus is one of the most extensively studied brain regions. The popularity of this structure derives from four considerations-it is important in major clinical disorders; its architecture is convenient, relative to other cortical areas, for experimental analysis; it appears to play an essential role in "cognitive" forms of learning and/or memory; and its synapses exhibit long-term potentiation (LTP), currently the leading candidate mechanism for rapid learning in mammals. Within the hippocampus, the neurophysiology of synapses in region CA3 region is the least understood. The granule cells of the dentate gyrus provide an important synaptic input to region CA3. The granule cell's mossy-fiber (mf) synaptic input is unusual and interesting for several reasons-they are among the largest synapses in the brain; they contain dynorphin and high concentrations of zinc; and they display a form of LTP that is different from the kind that is most often studied in other regions of the hippocampus and neocortex. The induction of mf LTP is not dependent on activation of N-methyl-d-aspartate (NMDA) receptors. We now know that NMDA receptor-independent LTP is not unique to the mf synapses, but also exists in synapses of other brain regions, such las the amygdala. The mf synapses offer a number of unique experimental advantages, which we will develop and exploit. State-of-the-art experimental and analytical methods will be used to examine the microphysiology of mf synapses and to test several hypotheses about the mechanisms underlying mf LTP induction and expression. The methods include whole-cell recordings of synaptic currents; quantal analysis; optical measurements of synaptic microstructure, calcium transients, and vesicle recycling; and compartmental modelling of mf synapses and CA3 pyramidal neurons. The results will provide a firm understanding of synaptic signalling and plasticity in the mf synapses, furnishing a key piece in the larger puzzle of how the hippocampal circuitry processes and stores information. This knowledge will be relevant to other brain regions, where comparable experiments would be impracticable.

WPCf 2 B J d | x MACNormal p 5 X ` h p x (# % '0* , .81 3 5@8 : < : } D 4 P T I. A. 1. a.(1)(a) i) a) T 0 * * . , US X ` h p x (# % '0* , .81 3 5@8 : < : } D 4 P 0 * * . , US , 3 ' 1 Z MACNormal Hall 9311044 The Institute of Optics at the University of Rochester will purchase a pulsed laser system and an electron beam deposition unit that will be dedicated to support r esearch in engineering. The equipment will be used for several research projects, including in particular: 1)the fabrication and investigation of circularly symmetric grating, surface emitting semiconductor lasers, 2) new materials and epitaxial structures for advanced semiconductor lasers, 3) epitaxial layer disordering in III V Heterostructures, and 4) avalanche processes in semiconductors and gain coupled semiconductor lasers for applications in optoelectronics. ***

This is a Shannon award providing partial support for the research projects that fall short of the assigned Institute's funding range but are in the margin of excellence. The Shannon award is intended to provide support to test the feasibility of the approach; develop further tests and refine research techniques; perform secondary analysis of available data sets; or conduct discrete projects that can demonstrate the PI's research capabilities or lend additional weight to an already meritorious application. The abstract below is taken from the original document submitted by the principal investigator. DESCRIPTION: (Adapted from the Investigator's abstract): This once revised application seeks to determine the characteristics of the humoral and cellular immune response following oral immunization with avirulent Salmonella typhimurium (S. typhimurium) strains expressing Porphyromonas gingivalis (Pg) antigens. It focuses on the possible virulence factor hagB hemagglutinin. There are three Specific Aims. In Specific Aim 1, the optimum immunization regimens, that is the size, number and frequency of doses of the immunogen for priming and boosting will be determined. The kinetics and isotype distribution of antibodies in serum, saliva, bile, gut washes and feces will be measured. Responses will also be examined at the cellular level in spleen, gut lamina propria, and salivary glands using the ELISPOT assay. TH1 and Th2 cells in Peyer's patches and spleen will be determined by measuring cytokine profiles. Specific Aim 2 will examine the effect of copy number of the plasmid, pre-existing antibody to the carrier strain, fusion of antigens with mucosal adjuvants and presence of the Salmonella virulence plasmid in the carrier strain. Specific Aim 3 will determine the effects of immunization with cloned antigens in experimental in vitro and in vivo models. It is expected that these approaches will improve understanding of the mechanisms by which Pg causes disease, and will be useful in designing a potential vaccine.

DESCRIPTION: (Adapted from the Investigator's Abstract) Recent interest in the adaptive response of strain-sensitive musculoskeletal tissues has led to the development of various devices aimed at delivering well controlled mechanical stimuli to laboratory cell culture preparations. In many of these devices, the targeted cells are adhered to the surface of a compliant substrate membrane, which, in turn, undergoes cyclic transverse displacements, induced either by imposed pressure differentials or by direct platen contact. In such "cell stretching" systems, it is assumed that the induced substrate deformation is the dominant mechanical stimulus delivered to the target cells. However, almost no attention has been directed to the potentially severely confounding effects of reactive shear and/or normal stresses imparted to the adhered cells due to the coupled motion of the overlying fluid medium. The applicants have developed a preliminary finite element model of one representative, widely-used cell stimulus system. By means of a specially instrumented testing chamber, they have shown that the finite element formulation reasonably models the culture substrate's motions and deformation, both statically and under complex dynamic loading conditions. Detailed stress distribution data from that finite element model strongly suggest that there are many situations in contemporary cell culture practice wherein the cell strains induced by coupled motions of the nutrient medium may be of at least the same order of magnitude as the cell deformations induced by the input membrane strains. The preliminary finite element model appears to accurately simulate the major inertial effects present in the nutrient medium. However, as presently formulated, that model has no provision to estimate fluid shear stress, likely also an important stimulus for cellular mechano- transduction. For that reason, the investigator proposed (Aim 1) to amend their constitutive treatment of the nutrient medium - for simplicity, initially modeled as a very compliant hyperplastic continuum - to address the considerably more complex behavior of a Newtonian fluid. A set of physical validation experiments is planned, including both substrate and fluid kinematics (Aim 2). They then will use this physically validated finite element model plus a spatially refined near- surface model to identify specific experimental conditions under which the stress state of cells adhered to the membrane culture surface becomes appreciably influenced by the kinetics of the nutrient medium of the present system (Aim 3), as well as for several other mechano- stimulus system designs (Aim 4). Finally, for the present system at selected operation settings above and below the computed fluid-influence threshold(s), they will conduct cell culture experiments to detect differentials of biological response, monitoring cyclin D1 and DNA synthesis (Aim 5). If coupled nutrient medium motions can indeed induce biologically consequential reactive strains to cells in culture, then it is very important to identify the operational conditions under which such an effect occurs.

9419776 Rose Modern orders of mammals first appeared in the fossil record and began to diversify during the early Eocene age, 52-55 million years ago. This research will use the most extensive collection of early Eocene mammal skeletons in existence to present the first comprehensive overview of the skeletal anatomy and adaptations of early Eocene mammals. Locomotion and related behaviors of extinct fossil mammals will be determined through rigorous anatomical comparisons with modern mammals whose behavior has been documented. Quantitative image analyses of joint and bone shapes in modern mammals will identify skeletal structures that are associated with particular modes of locomotion. Those results will be used to infer the locomotor behavior of fossil mammals from their skeletal anatomy. Quantitative analysis of exceptionally well-preserved teeth and skulls from fossils closely-spaced throughout the 3 million year period will define the anatomy and relationships of fossil mammals and show how evolution proceeded during the Eocene increase in species diversity. This research will provide new data on the anatomy, adaptations, behavior, and evolution of the basal members of modern mammalian orders and their archaic contemporaries. It will lead to a broader understanding of community evolution through the recent history of mammals and insight into the stability of mammal communities over time.

DESCRIPTION (Adapted from investigator's abstract): The design of a vaccine as a means to control Porphyromonas gingivalis will require knowledge of how to induce immunity to the various virulence factors of this organism. In this study, oral immunization in mice with live avirulent Salmonella typhimurium strains expressing the clone P. gingivalis hemagglutinin Hag B, will be used to examine the induction of immunity to these organisms. The optimum immunization regimen and kinetics for primary immunization with avirulent Salmonella carriers expressing P. gingivalis antigens including such factors as dosage, number and frequency of doses will be examined. The optimum regimen and the kinetics for boosting will also be determined. The responses in serum, saliva, bile, vaginal and gut washes and in fecal samples will be measured with respect to magnitude, duration and isotypic distribution in these compartments. Immune responses at the single cell level in spleen, gut lamina propria and salivary glands will be assessed and selected samples will be examined for IgG subclass distribution. The impact on cell mediated immunity will be assess by enumerating antigen-specific Th1 and Th2 cells in Peyer's patch and spleen using cytokine-specific assays and the induction of delayed-type hypersensitivity. The parameters involving the vector and host immunity which affect the magnitude, duration and isotype distribution in serum and secretions of antibodies to the expressed foreign virulence antigen will also be investigated. These include the effect of plasmid copy number, preexisting immunity to the carrier strain, and the presence of the Salmonella virulence plasmid in the carrier strain. Finally, the Salmonella delivery system will be compared with systemic immunization, and oral immunization with the antigen coupled to an oral adjuvant (CTB), for magnitude, duration and isotype distribution. These studies will provide valuable information on the potential utility of the Salmonella delivery system for the induction of immunity to the cloned P. gingivalis HagB and should increase our understanding of the immune system and provide information that will be useful in designing vaccine strategies.

DESCRIPTION (Adapted from Applicant's Abstract): The perirhinal cortex (PR) and adjacent lateral amygdala (LA) are implicated in learning and emotion as well as certain disorders such as Alzheimer's disease, epilepsy, and schizophrenia. To understand the roles of these brain structures in learning and emotion, and the manner in which they might become compromised during aging or in disease states, one must know more about the properties of their neurons and synaptic interconnections. Preliminary data suggested a specific and testable working hypothesis about how the cellular and synaptic properties of neurons in PR and LA might combine to produce aspects of the emotional learning in which these brain regions are thought to participate. To evaluate and develop further the working hypothesis requires (i) collection of the requisite physiological and anatomical data describing the properties of PR and LA neurons; (ii) physiological and pharmacological characterization of their synaptic interconnections; and (iii) incorporation of these data into computational models. The experimental and modeling results will test certain cellular- and circuit-level mechanisms implicit in the working hypothesis. It is expected that the principles revealed in these computational models will generalize to other brain regions as well. This laboratory has already applied several useful and powerful methods to rat brain slices containing PR and LA-- including whole-cell recordings from visually preselected neurons, confocal microscopy, and serial anatomical reconstructions of recorded cells. These and additional proposed methodological advances will enable collection of the experimental data required to evaluate and extend the working hypothesis. The data will also furnish a quantitative baseline for evaluating aging-related neuronal changes in PR and LA, changes of the kind that could explain certain aging-related alterations in learning, memory, and mood seen in humans. Ultimately, the information gained by these studies should be pertinent to the prevention and/or treatment of age- or disease-related mental dysfunctions, including Alzheimer's disease, epilepsy, and schizophrenia.

DESCRIPTION (Adapted from applicant's abstract): Emotions play a tremendous role in our lives - creating priorities, shaping values, and guiding our most important choices. Recent studies demonstrate that learning and memory in humans is much more profoundly affected by emotion than was previously assumed. The long-term goal is to understand how the amygdala and related brain regions are involved in emotional learning and memory. This requires elucidating the necessary and modulatory structures involved in emotional learning. The model preparation for studying aversive Pavlovian learning entails conditioned enhancement of the rat eyeblink reflex. The short-latency (R1) electromyographic component of the blink reflex offers several advantages as an index of emotional learning. The proposed methods combine neurophysiology, neuroanatomy, behavior and computational modeling. A general working hypothesis has been developed, an associated computational model, and a behavioral paradigm for evaluating the role of the amygdala and perirhinal cortex in forming associations between a conditioned stimulus (CS) and an unconditioned stimulus (US) and for encoding the CS-US interval during aversive conditioning. The computational model is the first to show how certain temporal aspects of associative learning emerge from the cellular neurobiology and circuitry. The approach allows vertical integration, traversing several levels of organization - from synapses to circuits to behavior. The model serves as the current hypothesis and also as the theoretical glue that binds information within and among levels and helps us understand and test various proposed hypotheses. In pursuit of the goal of vertical integration, the system selected for study enables one to go back and forth between in vitro and in vivo analysis, and the technology to do so is available (although the present proposal is concerned with in vivo studies). One goal is to demystify some of the psychological components of certain disorders by understanding the circuitry involved in emotional learning and to develop testable hypothesis for explaining biological changes that occur during stressful situations. The information and technology should be relevant to insights into, and treatment of, both psychiatric and neurological disorders (anxiety, stress, panic, cognitive impairment, blepharospasm, and epilepsy). By design, the approach is extendible into aging-related problems.

During the last thirty years in the United States, significant environmental management decisions have required the participation of the public. The justification for requiring public input is most clear for actions by public agencies on public lands, but the condition of the environment necessarily affects everyone so we are all stakeholders in every environmental management decision. People's opinions about the consequences of environmental changes are important, and they are often legally required. But the consequences of environmental management are often complex, they are frequently only to be realized far into the future, and they are always somewhat uncertain. How, then, is the public to be meaningfully engaged in the environmental management decision process? How are alternative future states of the environment to be communicated? How can the public determine and express their preferences for these alternatives?

Many different "public participation" methods have been developed and tried with varying levels of success, ranging from the posting of notices and the publication of lengthy environmental impact statements to holding open meetings to implementing elaborate conflict resolution processes. Every method has advantages and disadvantages, and all have a legitimate role. One of the most important public participation methods is a formal values assessment--a systematic survey of relevant public preferences. Environmental values assessments typically present management alternatives, including processes and expected outcomes, to representative samples of the public who indicate their preferences, usually by assigning numerical ratings or rankings or by making choices. For this process to be meaningful, it is critical that the values and preferences expressed in the assessment are consistent with the values and preferences that would be elicited if the alternative environmental conditions represented were actually realized--the results of environmental values assessments must be valid. Among the most basic factors affecting the validity of environmental values assessments is the accuracy and completeness of the representation of alternatives. That is, the words, numbers, maps and/or pictures used to describe relevant environmental conditions must allow participants to correctly understand the alternatives at issue, and to ascertain how those conditions affect things that they value.

The proposed study investigates the validity of computer visualizations as a means for representing alternative environmental conditions in formal value assessments. Environmental visualization technology has advanced very rapidly, from crude schematics to cartoon-like images to photographic realism to "virtual reality." These representations can very efficiently be distributed to audiences world-wide over interactive computer networks, providing unprecedented opportunities for public participation. But the effects of these representations on public understanding and evaluations of environmental alternatives is not known. This study will inform environmental managers and assessment specialists of the advantages and limitations of computer visualizations, and help to insure that public input to environmental decisions is valid.

The proposal research is to investigate fundamental issues regarding long fiber Bragg gratings in two important areas: first, the stabilization of the fabrication process by a new approach for real-time adaptive grating writing, and second, the methodology of synthesis of long gratings based on inverse scattering method for optimum design. Both of these are important issues that are holding back progress in the field. The fiber Bragg gratings have a broad impact on optical communications, particularly on dispersion management, and optical pulse shaping.

UT M.D. Anderson Cancer Center proposes to continue its role as a research base in the Community Clinical Oncology Program (CCOP). The aim is to establish a national network of CCOPs by generating broad spectrum clinical protocols, encompassing both cancer control and therapeutic scientific questions, that can be implemented in a community environment and provide data of the highest quality through a solid infrastructure of data management and quality control mechanisms. M.D. Anderson Cancer Center has served as a CCOP Research Base since 1986 and has generated a full program of Phase II and Phase III treatment protocols. In the past five years, 1,416 CCOP and affiliate patients were placed on clinical trial protocols. During this period, 2,339 patients were treated on M.D. Anderson cancer control protocols. A major thrust in M. D. Anderson cancer control program is to develop programs in the areas of chemoprevention, identification of high-risk individuals, nursing research focusing on symptom management and compliance, and pain control. In order to facilitate the development of concepts and protocols in this area, major CCOP/M.D. Anderson committees have been developed, including a Chemoprevention Working Group, the Community Oncology Nurse Investigator Network, and a CCOP Pain Task Force. A major innovation has been the extension of M.D. Anderson cancer control studies in the area of lung and head and neck chemoprevention studies into the Intergroup mechanism, with participation by all major cooperative groups in these studies. In developing the clinical trial and cancer control research programs, a Data Management Core has been established with full range of data collection, and computerized data base-capabilities. A quality assurance program, including both ongoing quality control assessments and periodic on-site audits, has been developed. All CCOPs are reviewed annually for performance, and recommendations for improvement or remedial action are made as necessary. The inclusion of CCOP program in the M.D. Anderson Comprehensive Cancer Center research program has proven to be a valuable extension of the scientific mission of the Center and is now viewed as an integral part of its research capability.

DESCRIPTION (Adapted from Applicant's Abstract): The perirhinal cortex (PR) and adjacent lateral amygdala (LA) are implicated in learning and emotion as well as certain disorders such as Alzheimer's disease, epilepsy, and schizophrenia. To understand the roles of these brain structures in learning and emotion, and the manner in which they might become compromised during aging or in disease states, one must know more about the properties of their neurons and synaptic interconnections. Preliminary data suggested a specific and testable working hypothesis about how the cellular and synaptic properties of neurons in PR and LA might combine to produce aspects of the emotional learning in which these brain regions are thought to participate. To evaluate and develop further the working hypothesis requires (i) collection of the requisite physiological and anatomical data describing the properties of PR and LA neurons; (ii) physiological and pharmacological characterization of their synaptic interconnections; and (iii) incorporation of these data into computational models. The experimental and modeling results will test certain cellular- and circuit-level mechanisms implicit in the working hypothesis. It is expected that the principles revealed in these computational models will generalize to other brain regions as well. This laboratory has already applied several useful and powerful methods to rat brain slices containing PR and LA-- including whole-cell recordings from visually preselected neurons, confocal microscopy, and serial anatomical reconstructions of recorded cells. These and additional proposed methodological advances will enable collection of the experimental data required to evaluate and extend the working hypothesis. The data will also furnish a quantitative baseline for evaluating aging-related neuronal changes in PR and LA, changes of the kind that could explain certain aging-related alterations in learning, memory, and mood seen in humans. Ultimately, the information gained by these studies should be pertinent to the prevention and/or treatment of age- or disease-related mental dysfunctions, including Alzheimer's disease, epilepsy, and schizophrenia.

This GOALI award, co-funded by the Division of Materials Research and the Office of Multidisciplinary Activities of the Directorate for Mathematical & Physical Sciences, involves a collaboration between the University of Rochester and the Eastman Kodak Company. A new concept for photoresponsive polymers is described based on a process called Quantum Amplified Isomerization (QAI). QAI materials are defined as polymers that undergo electron transfer-initiated ion radical chain isomerization reactions upon absorption of light. QAI materials have the potential to overcome many of the known problems associated with existing photoresponsive polymers, while still retaining their primary advantages. Specifically, QAI materials are designed to produce many chemical tranformations per photon absorbed, with little or no accompanying dimensional changes. The primary research goals of this proposal are: (1) to obtain a predictive understanding of the fundamental ion radical chain reaction chemistry that forms the basis of QAI processes, (2) to test sensitization strategies for the efficient inititaion of QAI processes, (3) to use the insights from (1) and (2) to design and synthesize functionalized QAI polymers, and (3) to characterize key optical properties of new QAI materials.

This collaboration is in the fields of photochemistry and optical materials for communications, and involves a number of educational experiences, including on-site industrial research for the students and weekly group meetings among the academic and industrial co-PI's.

DESCRIPTION (adapted from the Investigator's abstract): Immunological control of microbial pathogens through vaccination is an effective way of dealing with many infectious diseases. Live avirulent Salmonella have been shown to be safe, effective delivery vehicles for a wide variety of recombinant antigens and induce systemic and mucosal immunity. The Principal Investigator has shown the feasibility of using Salmonella to effectively deliver a putative virulence factor HagB from Porphyromonas gingivalis resulting in systemic and mucosal immune responses. Many questions remain concerning the basic immunology of live oral vectors. Factors such as recombinant gene expression level and cellular localization can affect the characteristics of the immune response. The ability to control the characteristics of the immune response, the immunogenicity of the foreign antigen and the induction of memory are all desirable goals for the design of any vaccine. To address these questions three Specific Aims are proposed. Aim 1 will construct strains of S. typhimurium expressing variable levels of HagB, characterize the effects of expression level on vaccine viability and immunogenicity, evaluate the immune response parameters including the magnitude, duration and antibody isotype distribution in serum, saliva and vaginal washes, and examine the effects on IgG subclass distribution. Aim 2 proposes to construct strains of S. typhimurium which express HagB on their surface, to assess the effects of surface expression on membrane integrity, viability, growth rate, and immunogenicity, to evaluate the effects of surface expression on the magnitude, duration and antibody isotype distribution in serum, saliva and vaginal washes and to examine the effects on IgG subclass distribution. Aim 3 will compare differences in priming, boosting and long-term memory induction by strains expressing varying levels of HagB cytoplasmically, or surface localized HagB. In selected experiments, the immune responses and memory induction will be compared using another P. gingivalis potential virulence factor, HagA. These studies will aid in the current understanding of the effects of vaccine parameters on immunogenicity, the pattern of the immune response and factors which affect induction of long-term memory and recall.

0076322
Houde-Walter

The Institute of Optics at the University of Rochester is building an excitation spectroscopy laboratory for research in new optical sources utilizing nano-engineered optical materials. An optical parametric oscillator, monochromator and multiscaler will be used in four research programs and two undergraduate/graduate training labs. Energy transfer will be studied using excitation spectroscopy to refine laser rate equation models and help to determine the best host composition and doping levels in rare-earth doped nano-glasses. In a related teaching lab exercise, students will observe cooperative luminescence in Yb-doped glasses, as is currently practiced in optical amplifier research. In another project, radiative impurity complexes will be introduced into silicon-on-insulator (SOI) structures that exhibit enhanced absorption/emission via nanostructured surfaces. Excitation spectroscopy will be used to elucidate the microscopic processes that determine emission cross sections in the hybridized SOI structures. Photoluminescence (PL) spectroscopy will be used to explore phonon mode control in isotopically pure crystalline Si. The new lab will permit the excitation of high spatial densities of indirect excitons, which may result in coherent phonon emission. Group III-V quantum dots, as made by in-situ laser patterning during molecular-beam epitaxial (MBE) growth, will also be investigated. Resonant excitation will be used to probe quantum dots of very narrow size distributions and may indicate the limit of what might be eventually achieved with an ensemble of uniform features. In a related lab, undergraduate students will investigate the absorption spectra of bulk crystals with various bandgaps (Si or GaAs, GaP, and GaN or diamond) as well as quantum well and dot group III-V semiconductors grown in our MBE lab. Honors students will also be encouraged to use the new lab for independent projects during their senior year.
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The Institute of Optics at the University of Rochester, which grants Bachelors, Masters and doctoral degrees in Optical Science and Engineering, is building a new optical spectroscopy lab for research and training. New optical materials that utilize features on the nanometer (one billionth of
a meter) scale, will be emphasized. New training exercises that are closely related to this research will be offered to both undergraduate seniors and first-year graduate students. A tunable source and associated detection equipment will be used to probe the relationships between the microscopic components and their radiative efficiency. Improved knowledge and design of materials for many applications, including biomedical research and telecommunications, are expected. However, the overarching goal of this new laboratory is to reveal fundamental relations and elucidate hidden connections in the characterization and process parameters of new (or just useful) optical materials.
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DESCRIPTION (Adapted from the applicant's abstract): Disorders of the hip comprise a substantial fraction of the current musculoskeletal disease burden. Complex nonlinear mechanical phenomena pervade many aspects of the treatment of hip disease and injury, including total hip arthroplasty, intra-articular fractures, osteonecrosis, and developmental dysplasia. While bioengineering capabilities exist, in principle, to quantify key mechanical factors influencing treatment outcomes in these areas, contemporary clinical decision making still rests almost entirely on subjective empirical experience. This BRP brings together the capabilities of an experienced computational biomechanics research group, four senior orthopaedic hip surgeons, a veterinary research orthopaedist, and an industry-based materials scientist, in order to advance the state of the art in biomechanically grounded management of disorders and injuries of the human hip. The central focus of the research Partnership lays in applying nonlinear finite element formulations to address as-yet-unquantified mechanical phenomena that are clinically recognized as being crucial to patient outcome. Building on previous and ongoing finite element work, new computational formulations will be developed to tackle nonlinearities currently limiting the accuracy of numerical simulations in five clinically important areas of hip surgery. The first two areas involve leading complications of total hip arthroplasty. First, as regards abrasive wear of polyethylene, they propose to incorporate local directionality of femoral head counterface motion in computing wear rates with a sliding-distance-coupled contact finite element formulation. Second, as regards dislocation, they propose to introduce soft tissue tethering into a large-displacement sliding contact model of resistance to dislocation. The third area involves intra-articular fractures of the acetabulum: estimating residual cartilage contract stress elevations accompanying attempts at surgical restoration of articular surface congruity. The forth area involves osteonecrosis: computationally characterizing a new animal model (the emu) which unlike previous animal models progresses to human-like femoral head collapse, and using that model for in-vivo testing of computationally optimized placement of a novel head-preserving implant device. The fifth application area involves surgical management of developmental hip dysplasia: using novel mesh pre-processing techniques to quantify improvements of intra-articular contract stress achieved by pelvic osteotomies. This partnership proposes to bring together a critical mass of engineers and surgeons, to achieve clinically grounded advances in nonlinear numerical simulations of surgery of the hip.

The PIs propose to use paleobotanical and paleogeochemical data with a model developed for understanding modern controls on vegetation distribution to explore the fundamental mechanisms behind complex advance, retreat, and further advance of a boreal-tundra ecotone along the Brooks Range in Alaska. The paleobotanical evidence will be used to examine several different approaches to discern movements of the ecotone with a species-level resolution with the changes in climate variables (temperature, precipitation amount, and seasonality of precipitation). The analysis will provide independent climate and vegetation datasets. The climate dataset will be used to drive an ecosystem model to simulate changing vegetation under changing climate. The results of the study will provide a useful predictive capability for separating climate-induced changes from those caused by feedbacks in the climate-vegetation system when attempting predictions of boreal forest ecosystem responses to future climate change.

Studies of Earth's history show that climate is capable of changing rapidly (within a few years or decades) and dramatically (from glacial to interglacial conditions). The response of the Earth's ecosystems to such global-scale changes can be spatially complex. Paleoclimatic fluctuations are evident during the last glacial cycle (~12,000 and 110,000 years ago) when temperatures were generally cooler than present and were interrupted by 24 warm events during which temperature ranged from 15-20 degrees C.

Understanding the mechanisms and timing of such environmental change is particularly important for the Arctic, a region particularly sensitive to climate variability. Historically, data from the Greenland ice sheet has been the foundation for paleoclimatic reconstruction for the region. Still lacking, however, is an understanding of how northern ecosystems have responded to changes in climate.

This research will address this knowledge gap by providing the first continuous, high-resolution, multi-proxy record of paleovegetational and paleoclimatic change from the Arctic for the period ~22,000 to 50,000 years ago. A sediment core from Elikchan Lake in northeast Siberia will be recovered and analyzed for pollen and diatom remains as well as sediment geochemistry with sufficient temporal control to be compared to climate trends found in ice cores.

These new data will be used to define the number, magnitude, and timing of climatic fluctuations to assess the similarities and differences in the climate histories between the eastern (North Atlantic) and western (northeast Siberia) Arctic. Specifically, the research will: 1) evaluate computer simulations of past temperature in northern Asia as related to climatic and oceanic changes in the North Atlantic region; 2) explore the role of Siberia in transmitting climatic fluctuations originating in the North Atlantic to the North Pacific; and 3) examine the range of ecosystem responses to various climatic conditions and the potential importance of biofeedback to the climate system (e.g., whether changes in the distribution of boreal forests, a major methane source, can affect levels of methane in the atmosphere).

DESCRIPTION (provided by applicant): Osteolysis and aseptic loosening secondary to bearing surface wear remain the greatest limitation to longevity of contemporary total hip arthroplasty (THA). To-date, most effort in reducing wear has been focused on average or cohort-wide assessments, rather than on the small minority of patients at the high end of the wear spectrum who are at greatest risk for loosening. These outlier wear situations need to be much better understood if revision rates are to be lowered. Contemporary trends in THA design and surgeon preference attest that, to most of the orthopaedic community, 3rd body acceleration of polyethylene wear is only a nebulous theoretical abstraction. By contrast, there are immediate attractions (e.g., versatility, surgical convenience, economy of inventory) for adopting 3rd-body-prone design features, such as modularity and biological fixation. Since 3rd body debris seems likely to remain a fact of life for the foreseeable future - increasingly, if present trends continue - it seems reasonable to explore steps to reduce the harm it sometimes does. Understanding the mechanisms by which the damage occurs is necessary if surgeons and designers are to take action accordingly. Our central paradigm is that forestalling 3rd body acceleration of polyethylene wear depends on avoiding scratch production in kinetically critical femoral head regions. Using a new finite element formulation, supported by clinical wear rate measurements, we propose to elucidate direct mechanistic relationships between wear front abnormality, wear rate elevation, and localized femoral head roughening (Aim 1). We suspect that the primary determinant of the severity of wear acceleration due to a given debris burden lies in whether or not particulates are able to gain access to the bearing surface in such a manner as to scratch specific head regions upon whose roughness UHMWPE cup wear most sensitively depends. We propose to identify those most-critical head roughening regions (Aim 2), and to elucidate a novel mechanism - subluxation and fluid convection - by which 3rd body particles plausibly can gain access (Aim 3). We hope to demonstrate that this access route is amenable to influence by modification of surgical technique or by component design changes. Finally, while highly-crosslinked polyethylenes appear to offer dramatic performance improvement under relatively favorable tribologic conditions, it remains to be seen (Aim 4) how well that apparent improvement carries over into the adverse situation of 3rd body challenge.

Genetic mutation can be caused by external mutagenic agents such as chemical mutagens or radiation, or it can occur without the impact of external agents. Natural mutagenesis due to transposable elements is understood primarily from research in fruit flies; it results when a gene is affected by the movement of another gene causing a change in phenotype. Activity of a Mariner element was observable in Drosophila mauritiana as a high frequency of mosaicism or speckling in the eye controlled by the Mos1 gene (Hartl, 2001). Although it appears that many transposable elements have become silenced leaving an inactive sequence in the host genome, the mechanism of regulation is not understood. There are few models of natural mutagenesis apart from those in fruit flies.

The objective of this project is to develop a new genetic model for natural mutagenesis, focusing on understanding the mechanism by which multiple spontaneous mutations of pigmentation (black eye, golden eye, et al.) and patterning (striped eye) arose in a lineage of a moth, Heliothis virescens (Lepidoptera: Noctuidae). While there are many possible mechanisms for this phenomenon, this project will focus on one working hypothesis that each of the various phenotypes is controlled by mutation in a corresponding gene. Each putative gene will be purified while gathering physiological data on mechanisms of altered pigmentation so that the mutations and any novel genetic mechanism involved can be identified subsequently. This project bears the risks of disproving the stated hypothesis; however, in that case this approach will provide information applicable to an alternate hypothesis. The significance of discovering a new type of natural mutagenesis if present will be in advancing the basic science of eukaryotic genetics leading to scientific applications to benefit society. Examples of present and anticipated applications of understanding mutation include defense against genetic weapons and genetic control of mosquitoes and other pests.

DESCRIPTION (provided by applicant): Femoral head osteonecrosis remains a major unsolved problem in orthopedic surgery of the hip. Because total hip replacement often proves unsatisfactory for patients with this disorder, means are needed to forestall necrotic femoral head collapse. Much could be learned from an animal model reliably mimicking the human disorder's natural history of structural collapse. Existing quadrupedal models fail to replicate this key aspect of the pathogenesis, presumably owing to unduly benign biomechanical demand. Cryogenically-induced osteonecrosis in the emu, a large and very active biped, shows great promise for overcoming this difficulty. The central goal of the proposed work is to bring this new emu model optimally into concordance with human disorder. Aim 1 is to establish quantitative linkage between cryo-insult parameters and resulting distributions of osteocyte death. This will involve thermal finite element analysis of temperature fields produced by a specially developed cryo-insult probe, and prediction of corresponding patterns of osteocyte death. Validation will be provided by osteocyte death distributions resulting from corresponding insults delivered intraoperatively. Aim 2 is to quantify the functional similarity of femoral head mechanical load transmission in emus versus humans. In vivo joint loading of the emu hip will be determined from force plate and optoelectronic recordings. Bench tests will be performed to measure hip joint contact stress distributions, and to map cancellous bone stiffness distributions. A whole-gait-cycle structural finite element model of the emu femoral head will be developed, for comparison with corresponding data for the human. Aim 3 is to compare the pathogenesis of osteonecrosis in emus with that in a (non-collapsing) canine model. Parameters of interest include the speed and patterns of revascularization, cell types, histomorphometric alterations of the trabecular lattice, and mechanical compromise. Aim 4 is to correlate the speed and severity of collapse in the emu osteonecrosis model with quantifiable structural compromise. This will again involve the structural finite element model, coupled with CT-based assessments of bony structural degradation. At the project's conclusion, we expect to have filled a longstanding need in the field of osteonecrosis research: an animal model suitable for systematic study of human-implementable interventions to forestall femoral head collapse.

DESCRIPTION (provided by applicant): Three medial-temporal-lobe (MTL) structures--perirhinal cortex (PR), amygdala (AM), and hippocampus (HC)--are known to be critical for emotional and cognitive aspects of animal and human learning and memory. All three are also severely compromised in Alzheimer's disease (AD). Here we combine methods of behavioral and computational neuroscience to elucidate the manner in which performance declines within rat MTL circuits as a function of aging. Special focus is on PR/AM function because of the recognized importance of these two structures in emotional and cognitive aspects of learning and memory; because almost nothing is known about the functional consequences of aging associated changes in the cellular neurobiology of these structures, which we study in a separate but parallel in vitro research project; and because PR is one of the earliest brain regions to develop neurofibrillary tangles, which are characteristic of Alzheimer's disease. The role of PR/AM circuitry in aging-related performance decline has never been addressed. Our battery of conditioning procedures is designed to increase the performance demand on PR/AM circuits. I expect to create a set of more sensitive and circuit-specific Pavlovian measures of aging-related performance decline. The test battery will be combined with neurobiological manipulations to get a better understanding of normal PR function and its changes during aging. This theory-driven research should impact in three directions. First, it will furnish critical experimental data regarding normal PR/AM function that will test and/or be incorporated into our computational model of the neurophysiology of PR/AM-dependent fear conditioning. This is the only such model and we plan to develop it further. Second, the tests can be used to "time stamp" circuit-specific changes during aging. This information is needed to detect and understand the temporal and causal relationship between particular changes in cognition and specific modifications in the underlying neurobiology. Third, the overall results will furnish a better basis for evaluating therapeutic treatment effects. Based on the "calcium dysregulation" hypothesis for cognitive aging, a treatment strategy we shall explore involves pharmacologically altering a calcium-dependent potassium current that is thought to be altered in opposite directions by conditioning and aging.

The Department of Mathematical Sciences at Eastern New Mexico University provides 20 scholarships for students in the targeted areas of mathematical sciences, computer science, and electronics engineering technology. This project develops develop sustainable infrastructure and assessment-based methodologies for improving the graduation chances, employment opportunities, and quality of learning for the ENMU Department of Mathematical Sciences students.

The implementation of this program promotes success through the Department of Mathematical Sciences' dedication to student learning and its focus on student centered learning. The project provides a comprehensive, sustainable, assessment-based, academically progressive plan for project implementation. The project implementation plan includes recruitment, a candidate selection process, a retention-based educational process, work placement skills instruction, optional internship opportunities, and an internal and external dissemination plan.

The project makes effective use of existing ENMU support structures, creates new structures, and enhances existing structures to meet project needs. The project utilizes and enhances existing student support structures during the process of recruitment and admissions, tutoring, advising, retention, internship, and high-technology job placement of graduates. By using and enhancing existing ENMU resources, the quality and efficiency of the project increases, the sustainability of the project methodologies is improved, and it allows the CSEMS Principal Investigators to focus on other project functions. The program creates a Learning Community composed of CSEMS scholars and other Department of Mathematical Sciences students. The CSEMS Learning Community is implemented within the Eastern Learning Community program. Working together with instructors and other students in a collaborative learning environment enables students to make connections, form friendships, and accomplish their educational goals. The integration between courses and increased opportunities for interaction outside the classroom makes the learning communities a valuable learning experience for the CSEMS scholar.

DESCRIPTION (provided by applicant): Hypertension is a hallmark symptom of a common condition associated with pregnancy, preeclampsia. Maternal hypertension in preeclampsia often develops suddenly and severely. The only effective treatment of this disease is delivery of the fetus and more importantly, the placenta. Thus, the majority of preeclamptic patients must deliver prematurely. The cause of preeclampsia is unknown, but impaired development of the placenta is strongly associated with the condition. The placenta is composed of trophoblast cells. Early in pregnancy, trophoblast cells are proliferative. Upon encountering changes in the intrauterine environment, they differentiate to fulfill particular functions. One subset of trophoblasts acquires an invasive phenotype. Invasive trophoblasts are responsible for remodeling the maternal uterine arteries to obtain blood flow to the rest of the placenta and the growing fetus. In preeclampsia, the invasive trophoblasts fail to properly differentiate. Oxygen is one of the environmental cues postulated to trigger trophoblast differentiation. Previous studies suggest that tropoblast cell differentiation is inhibited by hypoxia, but the molecular mechanisms involved have not been identified. Mammalian cellular responses to low oxygen conditions can be mediated by the transcription factor Hypoxia Inducible Factors (HIFs). We hypothesize that HIFs mediate hypoxic inhibition of trophoblast differentiation. To address this hypothesis, we will determine the effect of hypoxia, HIF-1 alpha, and HIF-2 alpha expression on trophoblast differentiation. Trophoblast differentiation will be assayed by analyzing changes in transcription factor expression, endoreduplication, and invasiveness. The results of these experiments will elucidate if HIFs mediate trophoblast differentiation. Understanding how oxygen signaling mediates trophoblast differentiation will help identify altered mechanisms that could cause preeclampsia.

DESCRIPTION (provided by applicant): Intervertebral total disc replacement (TOR) implants potentially herald a paradigm shift in the management of degenerative disc disease. Preservation of motion may avoid adjacent-segment degeneration, a well-recognized complication effusion. Based on encouraging experience in Europe and now-concluding IDE trials, FDA approval is likely in early/mid 2005 for two leading designs: Charite III and ProDisc. As an alternative to fusion (approximately 330,000/year in the U.S.), an onrush of implantations of these devices seems imminent. The potential for late wear-related complications is concerning. Both devices involve metal-on-conventional-polyethylene bearings, and the TDR patient population is a decade younger than for THR/TKR. Moreover, owing to close proximity of the spinal cord, the potential consequences of implant failure are much more dire than for THR/TKR. It is crucial that the scientific community expeditiously confront the issue of TDR wear. A Bioengineering Research Partnership is proposed to provide a firm scientific basis for identifying and dealing with wear-related problems in TDR. Aim 1 is to develop techniques for TDR wear assessment in the pre-clinical phase. This will be done leveraging complementary numerical and physical techniques: sliding-distance-coupled finite element analysis (Iowa) and servo-controlled laboratory simulation (Leeds). Aim 2 is to implement a novel approach to in vivo TDR radiographic wear measurement (Iowa), using high-resolution digital image analysis to assess relative three-dimensional pose position of the implant's metallic end plates. After documenting accuracy/precision, the pose image analysis technique will be used to measure wear in one of the largest/longest-ongoing European TDR series (Munich). Aim 3 is to assess the functional biologic activity of TDR wear debris (Leeds). Morphologically realistic simulator-generated debris will be used to challenge cells in a culture preparation specifically tailored to reflect the local spinal environment, from which key metrics of the inflammatory/osteolytic cascade will be assayed.

DESCRIPTION (provided by applicant): Dislocation remains second only to aseptic loosing as a leading cause of failure in total hip arthroplasty (THA). To complement the limited capabilities for mechanistic investigation afforded by clinical registries or by laboratory experimental studies, an anatomically and kinetically realistic three-dimensional nonlinear finite element (FE) model of THA dislocation has been developed. The formulation builds on substantial previous FE work, to now also include implant interaction(s) with the surrounding anatomic bony surfaces and with the hip joint capsule. The pre-processing sequence is structured for efficient parametric variation of individual implant design parameters and of surgical positioning of the components. The capsule is materially represented in terms of a heterogeneous hyperelastic continuum sheath whose anatomy and mechanical properties are taken from earlier cadaver testing. Input kinematic and kinetic sequences are taken from earlier motion studies of (non-THA-implanted) subjects performing dislocation-prone challenge maneuvers. Corroborative pilot work experimentally with a servo-hydraulic loading system and a novel trans-pelvic THA implantation protocol has reproduced the computations in terms of impingement/dislocation behavior, including capsule compromise effects, of comparable quantitative magnitude. Pilot work computationally has shown that the stable range of motion and the moment developed to resist dislocation depend strongly upon (1) the overall degree of capsule mechanical degradation, (2) focal defects either of internal capsule substance continuity (e.g., incisions) or of external attachment integrity (e.g., detachment from bony insertions), and (3) technical specifics of surgical repair. Four hypotheses, with corresponding specific aims, are structured as an analytical framework for parametric study of the interactions between capsular integrity, dislocation motion challenge, implant design, and component surgical placement. Relevance: THA dislocation rates vary by about an order of magnitude (approximately 1% to 10%), depending on surgical approach, implant design, component placement/orientation, and mechanical competence of the capsule. The problem is particularly vexing for revision surgery (" 8% incidence), a growing proportion of many surgeons'practices and in which capsule compromise is commonplace. Surgeon awareness and interest in this area has increased greatly in recent years, with various capsule repair/reinforcement procedures showing promise, and with many new options arising in terms of implant design and control of component placement. Realistic finite element analysis is an ideal vehicle for systematically assessing the complex interactions of the many factors influencing dislocation propensity, toward the goal of reducing this troublesome complication.

[unreadable] DESCRIPTION (provided by applicant): Carpal tunnel syndrome (CTS) is among the most important of the family of musculoskeletal disorders caused by chronic peripheral nerve compression. Generically, mechanical insult to the median nerve is well recognized as the proximate cause. However, despite the existing large body of research in many disciplinary areas, objective characterization of the local biomechanical insult directly responsible for the disorder remains conspicuously absent. The central paradigm of the proposed research is that local mechanical stress on the median nerve can be meaningfully quantified. This mechanical stress is due to fluid pressure within the confines of the tunnel, and direct physical contact of the median nerve with adjacent anatomic structures. Both of these types of interactions can be quantified - in tandem - by finite element (FE) analysis, using an anatomically based, three-dimensional, fluid immersion multi-body contact formulation, which has been developed in preliminary work. The long-term goal of the study is to establish an objective mechanistic framework for linking CTS with quantifiable biomechanical influence factors. An interdisciplinary approach will be adopted, integrating research team member expertise in the areas of biomechanical stress analysis, hand surgery, and musculoskeletal magnetic resonance imaging (MRI). The project has three specific aims: (1) Refine and physically validate the numerical model, and use it to explore the relative importance of fluid pressure versus solid contact on median nerve stress in normal subjects and CTS patients. (2) Based on clinical measurement, systematically study the effects of individual anatomic and functional parameters on median nerve stresses, and perform logistic regression analysis to identify the most important influence factor(s) or group(s) of factors. (3) Test for association between FE-identified factors most predisposing to elevated median nerve mechanical stress, and the presence and severity of CTS symptoms, in an affected patient group and in a negative control group of matched normal subjects. [unreadable] [unreadable] [unreadable]

A Biomechanics and Imaging (B&I) Core is proposed to provide sophisticated technical support to all three CORT projects. Post-traumatic osteoarthritis (PTOA) results from mechanical insult to articular cartilage, and it is frequently evaluated based on a variety of imaging features. The members of the Core have an established history of developing mechanics and image analysis methodologies for quantifying particular observations of interest. The B&I Core will support the three CORT projects by achieving two specific aims. The first aim of the Core is to serve as a general technical resource comprised of advanced hardware, image analysis protocols, and personnel experienced in developing and conducting biomechanical and imaging studies. These general capabilities will be utilized as needed by the different CORT projects to support and complement both ongoing and newly evolving project activities. The second aim of the Core is to provide expert support in the areas of mechanics and image analysis which specifically enhances the work in the three CORT projects. These specialized activities can be broadly classified into four main types: computational mechanics/modeling; physical measurement and hardware design; quantitative MRI analysis; and quantitative evaluation of microscopic-level images. This variety of multidisciplinary activities best fits within the structure of a core that can support all three CORT projects simultaneously. The B&I Core provides an explicit point of overlap between the various aims of the three research projects, which allows for opportunities for the different projects to inform each other better than if the individual Core activities were segregated in the different projects. A combined mechanics and imaging core also facilitates development of unique multi-modal (e.g. stress analysis and imaging) and multi-scale (e.g. histological to clinical) imaging comparisons, which are critical to translating basic research into the clinical setting.

This S-STEM project supports scholarships for academically talented and financially needy students in mathematics, sciences and computing. This project builds on lessons learned from a previous CSEMS project to provide a learning environment producing highly qualified scholars who will contribute to a 21st century workplace. This project aggressively recruits scholars from area high schools, two-year colleges, and universities. In addition, the project supports a bridge program for scholars between the participating community colleges and the university. The project advertises the scholarships through brochures, posters, a website, and meetings with math and science teachers in regional high schools. The recruited student population has high financial need and includes a large percentage of underrepresented groups. An Advisory Committee of university and community college faculty from targeted disciplines selects the scholars each semester and serves as advisors for the scholars. The project creates community among the scholars through required participation in a tailored learning community and in a yearly one-hour project course where the scholars work for a mock company to produce a marketable product. Fields trips and speakers provide the scholars with exposure to industry professionals.

DESCRIPTION (provided by applicant): The majority of microorganisms in natural and biological ecosystems exist as biofilms, allowing them to better tolerate stresses and fluctuating environmental conditions. Dental plaque is a complex biofilm on the tooth surface that is subject to fluctuations in environmental factors in the oral cavity. Furthermore, oral biofilms on supragingival surfaces are in the constant presence of S-IgA antibodies;the principal mediator of host immunity in saliva. Little if any data exist on the influence of host immunity on oral biofilms except with respect to attachment. S-IgA can block adhesins, block cell-cell coadhesion, and interfere with nutrient transport systems. In turn, plaque microorganisms can produce specific IgA1 proteases that can cleave S- IgA1. We hypothesize that these interactions could affect not only initial attachment, but could also have a profound effect on the accumulation phase, and the ultimate architecture of the plaque biofilm. To address these gaps in knowledge we propose the following: Specific Aim 1, examine the effects of S-IgA on attachment, development, architecture and viability of biofilms of pioneer oral streptococci (Streptococcus sanguinis, S. oralis and S. gordonii) using a microplate-based biofilm assay, and by confocal laser scanning microscopy. Examine the effects of S-IgA concentration, and exposure to S-IgA during different developmental stages of biofilm formation on ultimate accumulation, architecture and viability. Specific Aim 2, compare the behavior of IgA1 protease-deficient mutants grown in the presence or absence of S-IgA. Compare the effects of intact S-IgA, purified S-IgA1 and Fab1 fragments derived from cleavage by IgA1 proteases on attachment, development, architecture and viability of biofilms of pioneer oral streptococci. Understanding the interplay of host immunity with oral microorganisms, particularly the pioneer colonizers, is critical to understanding how biofilms are formed and shaped in vivo. These interactions are an important consideration in the design of any immunological intervention, such as a vaccine. An understanding of the role of host immunity on biofilms formation might lead to salivary diagnostics that could predict susceptibility to development of pathogenic biofilms. PUBLIC HEALTH RELEVANCE: Understanding the interplay of host immunity with oral microorganisms, particularly those organisms which are involved in first establishing a plaque biofilm (the pioneer colonizers), is critical to understanding how biofilms are formed and shaped in vivo. These interactions are an important consideration in the design of any immunological intervention, such as a vaccine. An understanding of the role of host immunity on biofilm formation might also lead to salivary diagnostics that could predict susceptibility to development of pathogenic biofilms.

DESCRIPTION (provided by applicant): When present, 3rd body effects in total joint replacement can obviate many of the wear rate improvements otherwise associated with advanced bearing materials such as highly cross-linked polyethylenes. While long recognized as a potential clinical concern, the difficulties of quantifying 3rd body challenge unfortunately have kept it largely confined to the domain of nebulous conjecture. Consequently, attempts to reduce the genesis of 3rd bodies and/or to study their effects on implant performance have been sporadic, heterogeneous, and often of questionable grounding in clinical realism. Building on a series of recent studies which have helped clarify the mechanisms linking 3rd body challenge, implant surface damage, and wear rate acceleration, two new directions of translational research are now proposed. The first of these directions is to quantify the 3rd body generation propensity of major intra-operative procedural steps of THA implantation surgery. Such data should be helpful to highlight the relative deleteriousness of specific procedural stages, a necessary initial step toward conceiving and documenting effective technical improvements. The second research direction is to establish a clinically-grounded framework for a practicable consensus protocol for laboratory 3rd body wear testing. To gain widespread acceptance, such a protocol will need to involve a reliably quantifiable 3rd body challenge that causes clinically realistic counterface damage. And, it will need to have the ability to reproducibly deliver wear rate accelerations in a clinically realistic range, ideally with a monotonic, mechanistically-grounded dose/response relationship. The proposed work will involve interdisciplinary collaboration among research groups at the University of Iowa, the University of Leeds, and Ohio State University. Peri-prosthetic tissue and fluid specimens will be obtained at various stages intra-operatively during patient surgeries and in cadaver preparations, from which specimens the 3rd body debris will be isolated and quantitatively analyzed. Computational models of 3rd body-induced wear rate acceleration will be extended to account for morphologically identifiable femoral head scratch damage, with direct validation physically. A registry of scratch damage on retrieval femoral heads in constructs with documented 3rd body challenge will be compiled using novel 3-dimensional laser micrometry, providing an objective basis to document clinically representative scratch damage regimens, and ranges of severity. A laboratory protocol will be refined to generate (registry-consistent) femoral head scratching from polyethylene-embedded 3rd body debris, with the damaged heads then being applied in standardized laboratory wear testing. At the conclusion of the proposed work, we expect to have identified which steps of THA surgical implantation are most problematic in terms of 3rd body debris generation. And, we expect to have developed a mechanistically-grounded protocol for laboratory simulation of 3rd body wear rate acceleration, suitable as a conceptual platform for a consensus testing standard. PUBLIC HEALTH RELEVANCE: In patients with total hip replacements, small particles comprised of hard materials such as metal, bone cement, or bone sometimes are unintentionally present in the tissues or fluid surrounding the implant, for reasons not well understood. These particles, known as 3rd bodies, can find their way into the ball-in-socket mechanism of the implant itself, where they roughen the otherwise very smooth bearing surfaces, causing the implant to rapidly wear, leading to clinical failure. It is important to find ways to minimize these 3rd body particles, and to develop implants that are more resistant to 3rd body damage.

DESCRIPTION (provided by applicant): Many pregnancy-associated disorders, including IUGR and pre-eclampsia, stem from abnormal placental development. Evidence in humans as well as animal models suggests that babies born from these pregnancies are at increased risk of hypertension, cardiovascular diseases, diabetes, and stroke later in life. In the US alone, it is estimated that the combined short and long-term financial costs related to these pregnancies are approximately 7 billion dollars per year. Importantly, each of these defects appears to be specific to a particular cell layer in the placenta, implying that each one relates to specific cell lineage origins. For example, early onset IUGR is associated with defects in placental nutrient-transporting cells whereas pre-eclampsia is associated with defects in invasive trophoblast cells that fail to remodel maternal arteries. Previous studies have shown that oxygen is an important mediator of trophoblast differentiation. Hypoxia inducible factor-1 alpha (HIF-1a) is a critical component of the cellular oxygen-sensing machinery and is essential for placental formation and embryonic survival. Endogenous HIF-1a is active under low oxygen (hypoxic) conditions, but becomes rapidly inactivated at arterial levels of oxygen, which allows trophoblast differentiation to occur. Prolonged HIF-1a activity inhibits trophoblast differentiation in culture and is associated with pregnancy- associated disorders. In this proposal, we utilize novel approaches to target specific placental cell lineages in order to investigate the role of placental HIF-1a in controlling trophoblast differentiation. This study will provide novel gene targeting vehicles and evaluate the importance placental HIF-1a activity in regulating the development of the individual trophoblast lineages necessary for appropriate placental development and normal embryonic growth. The long term objective of our research program is to determine the oxygen signaling mechanisms that regulate trophoblast differentiation, placental development, embryogenesis and maternal well being.

Illumination with beams of light in unconventional polarization states departs from the usual, textbook description. Two popular examples of unconventional polarization states are radial and azimuthal polarizations (sometimes called Cylindrical Vector Beams). A wide variety of unconventional polarizations exist -- some have been well studied, while many remain unexplored. This research activity brings together three investigators that have been studying unconventional polarization states and their mathematical representation, the propagation and focusing of polarized light, and light scattering from small particles such as those found within biological cells.

This investigation makes use of a novel mathematical representation (complex-focus basis) for modeling optical focusing and scattering, the study of radial, azimuthal, and Full Poincare fields as representatives of a complex-focus basis, and the scattering of unconventional polarization states from mesoscopic particles, including cell organelles. In the process, we also address the formulation and testing of a theory of partially coherent unconventional polarization states, the coupling of unconventional polarization states to nanostructures, and develop numerically efficient theoretical models for coherent and partially coherent light propagation. We make use of the recently-introduced concept of stress- engineered optical elements to adapt an existing light scattering microscope to carry out polarization- sensitive scattering experiments. In the process, we are advancing optical physics by introducing new analytic tools for scattering analysis, a new experimental tool for rapid-acquisition pupil polarimetry, and find better ways to use polarization as a tool for improving projection imaging systems such as LCD projectors and semiconductor lithography systems.

Polarization--the vector nature of light--influences the scattering of light in profound ways, and is therefore fundamental to how we gain information about a scatterer from the scattered light. This has been used to good result in advancing cell identification for immune cell research, for example. Scattering is also important in the inspection processes that are used to guarantee high quality semiconductor circuits for computers and electronic devices. A better understanding of the physics of new polarization states will therefore have a broad impact on fields such as optical engineering and biomedical optics. The educational impact is seen annually through involvement by both undergraduates and graduate students, not merely as research assistants, but as students in training who are encouraged toward independent initiatives. Our role as educators at the Institute of Optics offers us a unique platform from which to take the results of the work, bring them into the classroom at the MS and BS levels, and to take the exciting features of polarized light with us on educational activities in area schools and science museums. Our presence at the Institute of Optics offers technology transfer to over 30 companies who are members of our Industrial Associates Program.

Polarized light (light with directional vibrations whose effects can sometimes be seen in changes in attenuation while rotating polarizing sunglasses) is everywhere--it is in the blue sky, the reflection from a pond, in light scattering from natural and manmade airborne particles, and in the display screens on our smartphones. The understanding and use of polarized light is central to both the science of light and to applications ranging from medicine to consumer electronics. For example, some of the triumphs of the computer information revolution have been built around manufacturing technologies that require almost unimaginable precision in measurements--many of which are light-based and use the polarization of light in ways that can be precisely controlled and measured. The proposed research uses the concept of an "unconventional polarization state" - a special form of light in which the polarization varies across the width of a laser beam - to explore fundamentally new ways of carrying out light-based measurements. In conjunction with some special optical devices, it is possible to use an ordinary camera to create a visual map of the polarization in a single image, something that ordinarily requires a sequence of four or more images and accompanying algorithms. These measurement methods will also spur new ways of thinking about how to execute the simultaneous measurement of sub-nanometer process errors in microelectronics manufacturing.

The multiple measurements required to characterize the polarization of an ultrafast laser pulse or individual photon require either a time-sequential operation or explicit division of the amplitude into different detector ports. While each of these has been used to good success, there is a need to truly extend polarization measurements in a way that the maximum amount of polarization information is extracted from each measured photon (in the case of low light levels) or each pulse (in the case of ultrafast pulse characterization). Because the method is extendable to the mapping of polarization over a sampled image field, it is possible to extend the concept to capture either angle- or frequency-resolved polarization information in a single image. The investigation also applies the new physics of unconventional polarization states to the now-famous physics of weak measurements by using unconventionally polarized light to measure two or more physical quantities in a single measurement. This concept will be tested by measuring nanoscale features in a microscope equipped with a liquid crystal controller that defines a field with arbitrary polarization, amplitude, and phase for focused beam scatterometry. The work is expected to impact allied areas of physics (through the introduction of new measurement methods), optical engineering (specifically, polarization engineering and image formation), biomedical optics (in medical imaging and spectroscopy), environmental science (through the use of polarimetric light scattering for aerosol characterization), and semiconductor inspection.