cssi/SciSciGPT-SciSciNet huggingface dataset:
Clustering Time Series Data with Distance Matrices

Clustering is a frequently used method in unsupervised analysis of various data types including time series data. In this study, we first present a discrete k-median (DKM) method based on uncoupled bilinear programming algorithm and modify it for faster implementation, which becomes a variant of the Lloyds algorithm. We also introduce the fuzzy discrete k-median (FDKM) method which is the fuzzy version of the modified algorithm. The main draw for the these two efficient algorithms is that they do not require any input but a matrix of distances as a measure of dissimilarity between pairs of samples to avoid the complications that may arise from working with the actual domain that the data samples reside in. We also include a hiearchical cluster tree (HCT) method and partition around medoids (PAM) method, both of which can use the distance matrix for clustering. The output of all four methods are median samples, which define clusters by assigning each sample to the closest median sample using the distance matrix. We consider four different distance measures, rectilinear, Euclidean, squared-Euclidean and dynamic time warping (DTW) to create the distance matrix, and also mention how the calculation of the distance matrix can be extended to any kernel induced feature space. The main application domain in this study is time series data, where actual samples in the data set are better cluster representations than mean or median points whose components are independently calculated for each dimension of the domain. We present computational results on a public time series benchmark data set and a real life local field potential (LFP) recordings collected from a macaque monkey brain during a visuomotor task.
Using Diatomite to Enhance the Thermal Storage of Lunchbox

Most parents make their children packed lunches when they go to school and these packed lunches are usually put in thermal insulated containers or thermal lunchboxes. The insulating material used in these containers are usually insulating foams. However, the commonly used insulating lunchboxes could not preserve the temperature of the food. If the temperature of the food is not maintained properly, bacteria may inhabit the food which could lead to children having foodborne illnesses. Therefore, testing various kinds of containers with different insulating materials is essential (Chu, 2013). To look for another alternative insulating material for lunchboxes, this research will focus on the use of diatomite, an insulating material used in road pavements, in lunchboxes to preserve the temperature of the food. In the experiment, there were two set-ups, one with the diatomite insulated lunchbox and the commercially available insulated lunchbox. The insulating material used by the commercially available lunchbox is foam. Measurements of the temperature were obtained every thirty-six minutes using a thermometer. The means and the standard deviation of each lunchboxes were compared. T-Test was used to determine if there was a significant difference between the mean temperatures of the commercially available lunchbox and the lunchbox with diatomite.At alpha 0.05, it could possibly be concluded that there is a significant difference between the means of both lunchboxes. The mean of the diatomite insulated lunchbox is greater than the mean of the commercially available lunchbox. This shows that the diatomite insulated lunchbox tend to be more efficient in preserving the temperature of the food than that of the commercially available lunchbox. The study suggests that diatomite appears to be a more efficient substitute. Furthermore, the researchers recommend to use an advanced technology of thermometer in order to yield more accurate results and to prevent heat loss. The researchers also suggest to use different kinds of lunchboxes with different insulating materials.
Damage caused by women's lower self-efficacy on physics learning

Gender differences in conceptual test performance and course grades for introductory physics students are mainly associated with students' self-efficacy.
Enhancement of chemical oscillations by self-generated convective flows

Chemical feedback loops in fluids can produce not only chemical oscillations, but also density variations that generate solutal buoyancy forces, which in turn initiate fluid flow. Using analytical and computational models, we herein examine how the reaction-induced flows alter the chemical oscillations in a fluid-filled chamber whose top and bottom walls are coated with different enzymes. Due to this chemo-fluidic coupling, the systems form oscillating flow patterns, which combine the characteristic size of the buoyancy-driven convection rolls with the frequency of the chemical oscillations. With changes in the distance between the enzyme-coated walls, the convective flows not only enhance or suppress the chemical oscillations, but also substantially increase the amplitude and frequency of the oscillations and extend the regime of the oscillatory behavior. These design principles can facilitate the development of artificial biochemical networks that act as chemical clocks. Oscillating chemical reactions are ubiquitous in living systems. Here, the authors propose a mathematical model to study how chemically-driven density gradients produced by enzymatic reactions can trigger hydrodynamic instabilities coupling with chemical oscillations.
Selective autophagy of MHC-I promotes immune evasion of pancreatic cancer

Major histocompatibility complex class I (MHC-I) is a key molecule in anti-tumor adaptive immunity. MHC-I is essential for endogenous antigen presentation by cancer cells and subsequent recognition and clearance by CD8+ T cells. Defects in MHC-I expression occur frequently in several cancers, leading to impaired antigen presentation, immune evasion and/or resistance to immune checkpoint blockade (ICB) therapy. Pancreatic ductal adenocarcinoma (PDAC), a deadly malignancy with dismal patient prognosis, is resistant to ICB and shows frequent downregulation of MHC-I independent of genetic mutations abrogating MHC-I expression. Previously, we showed that PDAC cells exhibit elevated levels of autophagy and lysosomal biogenesis, which together support the survival and growth of PDAC tumors via both cell-autonomous and non-cell-autonomous mechanisms. In our recent study, we have identified NBR1-mediated selective macroautophagy/autophagy of MHC-I as a novel mechanism that facilitates immune evasion by PDAC cells. Importantly, autophagy or lysosome inhibition restores MHC-I expression, leading to enhanced anti-tumor T cell immunity and improved response to ICB in transplanted tumor models in syngeneic host mice. Our results highlight a previously unknown function of autophagy and the lysosome in regulation of immunogenicity in PDAC, and provide a novel therapeutic strategy for targeting this deadly disease.
Intrinsic Degradation of the Type-II Antitoxin ParD from Pseudomonas aeruginosa

Abstract Type-II Toxin Antitoxin (TA) systems are regulated by differential half-lives of the resulting non-secreted proteins, such that the neutralizing antitoxin undergoes continual degradation and replenishment to maintain neutralization of its cognate toxin. Antitoxin proteins are widely reported as labile, including upon purification and in vitro storage. During the course of studies on a ParDE TA system we noted a prevalent in vitro degradation of the ParD antitoxin. In efforts to combat this for practical use in assays, we characterized parameters impacting the degradation as well as the resulting products. These revealed a mechanism likely mediated by a serine or metal-dependent protease. Using Direct Infusion Mass Spectrometry, the cleavage products were identified as an essentially intact DNA binding region of the antitoxin and with the toxin binding domain completely removed. No other species were identified in the solution, such as a contaminant that may mediate such cleavage. Therefore, while our studies revealed viable strategies to mitigate the in vitro degradation they did not identify any protease, leaving open the possibility of a potential auto-catalytic proteolytic activity of the antitoxin proteins.
The roles of history, chance, and natural selection in the evolution of antibiotic resistance

History, chance, and selection are the fundamental factors that drive and constrain evolution. We designed evolution experiments to disentangle and quantify effects of these forces on the evolution of antibiotic resistance. Previously, we showed that selection of the pathogen Acinetobacter baumannii in both structured and unstructured environments containing the antibiotic ciprofloxacin produced distinct genotypes and phenotypes, with lower resistance in biofilms as well as collateral sensitivity to β-lactam drugs (Santos-Lopez et al., 2019). Here we study how this prior history influences subsequent evolution in new β-lactam antibiotics. Selection was imposed by increasing concentrations of ceftazidime and imipenem and chance differences arose as random mutations among replicate populations. The effects of history were reduced by increasingly strong selection in new drugs, but not erased, at times revealing important contingencies. A history of selection in structured environments constrained resistance to new drugs and led to frequent loss of resistance to the initial drug by genetic reversions and not compensatory mutations. This research demonstrates that despite strong selective pressures of antibiotics leading to genetic parallelism, history can etch potential vulnerabilities to orthogonal drugs.
Context Matters (But Some Contexts Matter More): Disentangling the Influence of Traditional Bullying Victimization on Patterns of Cyberbullying Outcomes

Data from the 2017 National Youth Risk Behavior Surveillance System, consisting of 14,765 students, ranging in age from 12 to 18 years, were used to investigate patterns of cyberbullying victimization, with particular focus on understanding the interplay between traditional bullying victimization and other relevant predictors of cyberbullying. Through a conjunctive analysis of case configurations (CACC), results from the current study show that (1) incidents of cyberbullying cluster significantly among specific situational profiles, which are defined by the unique combination of variable attributes; (2) students most likely to be cyberbullying victims have always experienced traditional bullying, but students least likely to experience cyberbullying victimization almost never experience traditional bullying; and (3) being a victim of traditional bullying can increase the chances of cyberbullying victimization by as much as 17% in some situational contexts, but can have almost no influence on cyberbullying victimization in others. Current findings are discussed in light of existing cyberbullying scholarship and recommendations for policy and future areas of research are offered.
Environmental Movements in the United States

Environmental movements have always been a core subject of research within environmental sociology (Dunlap & Catton, 1979). Once largely the near sole purview of environmental sociologists, organized and collective efforts at social change in the name of the environment are now a central object of inquiry among scholars interested in social movements, business organizations, civic participation, resource governance and other topics. The result has been a marked increase in sociological research on environmental movements over the past couple of decades.
A Comparison of Homeless Male Veterans in Metropolitan and Micropolitan Areas in Nebraska: A Methodological Caveat

This study explored differences between homeless male veterans in metropolitan and micropolitan cities in Nebraska on sociodemographic, housing, clinical, and psychosocial characteristics as well as health service use. A convenience sample of 151 homeless male veterans (112 metropolitan, 39 micropolitan) were recruited from Veterans Affairs facilities and area shelters in Omaha, Lincoln, Grand Island, and Hastings in Nebraska. Research staff conducted structured interviews with homeless veterans. Results showed that compared to homeless veterans in metropolitans, those in micropolitans were more likely to be White, unmarried, living in transitional settings, and were far more transient but reported greater social support and housing satisfaction. Veterans in micropolitans also reported more medical problems, diagnoses of anxiety and personality disorders, and unexpectedly, were more likely to report using various health services and less travel time for services. Together, these findings suggest access to homeless and health services for veterans in micropolitan areas may be facilitated through Veterans Affairs facilities and community providers that work in close proximity to one another. Many homeless veterans in these areas are transient, making them a difficult population to study and serve. Innovative ways to provide outreach to homeless veterans in micropolitan and more rural areas are needed.
TU-F-BRB-00: MRI-Based Motion Management for RT

The current clinical standard of organ respiratory imaging, 4D-CT, is fundamentally limited by poor soft-tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose-volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft-tissue contrast. MRI-based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR-based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D-MRI and MRI hybrid treatment machines (i.e. MR-linac or MR-Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI-based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR-based motion management methods and technologies, the state-of-the-art concerning MRI development and clinical application and the barriers to more widespread adoption. Learning Objectives: 1. Discuss the need of MR-based motion management for improving patient care in radiotherapy. 2. Understand MR techniques for motion imaging and tumor motion characterization. 3. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.
Unobserved Product Differentiation in Discrete Choice Models: Estimating Price Elasticities and Welfare Effects

Standard discrete choice models such as logit, nested logit, and random coefficients models place very strong restrictions on how unobservable product space increases with the number of products. We argue (and show with Monte Carlo experiments) that these restrictions can lead to biased conclusions regarding price elasticities and welfare consequences from additional products. In addition, these restrictions can identify parameters which are not intuitively identified given the data at hand. We suggest two alternative models that relax these restrictions, both motivated by structural interpretations. Monte-Carlo experiments and an application to data show that these alternative models perform well in practice.
Intracavity Laser Spectroscopy of NiCl System G: Identification of a [13.0] 2Π3/2 State

Abstract The (0,0) vibronic band of NiCl system G with a bandhead near 12 961 cm −1 was recorded at high resolution in absorption using intracavity laser spectroscopy (ILS). For the ILS absorption spectra, the NiCl molecules were produced in a nickel hollow cathode, operated with a small amount of CCl 4 , and line positions were referenced to iodine spectra. Fourier transform (FT) emission spectroscopy was used to record an extensive region of the spectrum used in a vibronic analysis of system G. For the FT spectra, excited NiCl molecules were produced in a high-temperature King-type carbon tube furnace. We show that this transition is the (0,0) vibronic band associated with a newly identified 2 Π 3/2 excited state and the X 2 Π 3/2 ground state. The molecular constants for the new 2 Π 3/2 electronic state are derived from the rotational analysis. Improved vibronic constants for the band are obtained from analysis of the FT spectra.
Comparison of variable region primary structures within an anti-fluorescein idiotype family.

Abstract Previous reports described the properties of a high affinity (Ka = 1.7 X 10(10) M-1) prototype anti-fluorescein monoclonal antibody 4-4-20, an intermediate affinity (Ka = 3.7 X 10(7) M-1) prototype 9-40, and Ig members of the 9-40 idiotype family (comprised of 3-24, 5-14, 5-27, 10-25 and 12-40). Although the seven monoclonal anti-fluorescein antibodies expressed similar active site structural determinants (idiotypes) as determined serologically, each was characterized by different affinities for fluorescein and fine specificity binding patterns. Partial heavy (H)- and light (L)-chain N-terminal amino acid sequence analyses revealed all antibodies (except 5-27) were composed of highly homologous VHIII(C) and V kappa II subgroup genes, respectively. Antibody 5-27 utilized a VHIII(B) and a V kappa V subgroup genes and shared low V-region sequence homology with 4-4-20, 9-40 and the remaining 9-40 idiotype family. In addition, complete 4-4-20, VH- and VL-region primary structures were determined to better understand antibody-antigen interactions. Antibody 4-4-20 utilized a VHIII(C) subgroup VH-gene, a truncated Sp2 D gene segment, JH4, a V kappa II subgroup VL-gene, and J kappa 1. Antibody 4-4-20 VH and VL complementarity-determining regions contained many basic and aromatic amino acid residues capable of interaction with fluorescein. Results are discussed in terms of idiotypic and fluorescein-binding characteristics as well as antibody structural and functional diversity in the immune response.
Convenient, simplified preparation of less commonly used media.

A method is described for the preparation of some less commonly used media. This approach should encourage use of these media.
Validation of a 3-factor scoring model for the Pittsburgh sleep quality index in older adults.

Study objectives The Pittsburgh Sleep Quality Index (PSQI) is widely used to assess subjective sleep disturbances in psychiatric, medical, and healthy adult and older adult populations. Yet, validation of the PSQI single-factor scoring has not been carried out. Design The PSQI was administered as a self-report questionnaire. Using a cross-validation approach, scores from the PSQI were analyzed with exploratory and confirmatory factor analyses. Setting San Diego, Denver, and Los Angeles community-based clinics. Participants Community-dwelling depressed and nondepressed adults older that 60 years of age (N = 417) Measurements and results Results yielded a 3-factor scoring model that obtained a measure of perfect fit and was significantly better fitted than either the original single-factor model or a 2-factor model. Components of the 3 factors were characterized by the descriptors sleep efficiency, perceived sleep quality, and daily disturbances. Conclusions These findings validate the factor structure of the PSQI and demonstrate that a 3-factor score should be used to assess disturbances in three separate factors of subjective sleep reports.
Tissue distribution and disposition of tin-protoporphyrin, a potent competitive inhibitor of heme oxygenase.

Tin(Sn)-protoporphyrin is a potent competitive inhibitor of heme oxygenase and can also suppress naturally occurring or experimentally induced hyperbilirubinemia in animals. In this study we examined the plasma clearance of Sn-protoporphyrin, its persistence in tissues and the time course of heme oxygenase inhibition up to 7 days after administration of doses up to 50 mumol/kg b.w. to adult male rats. After s.c. doses the metalloporphyrin was rapidly and almost completely absorbed. Initial plasma clearance was log-linear with a T 1/2 of approximately 3 h after either i.v. or s.c. administration. Levels of Sn-protoporphyrin in most tissues rose during the first 2 h and persisted for up to 7 days. Concentrations were highest in kidney and liver, were considerably lower in spleen, lung, intestine, adrenal and testes, and as Sn-protoporphyrin concentrations in plasma declined, concentrations in these tissues eventually exceeded simultaneous plasma concentrations. This suggests a varying degree of uptake and binding of the metalloporphyrin in these tissues. There was little or no uptake of Sn-protoporphyrin in heart, brain and red cells. Markedly decreased heme oxygenase activity in liver, kidney and spleen persisted as did Sn-protoporphyrin up to 7 days. The total amount of Sn-protoporphyrin present in tissues and excreta was a fairly constant fraction of the dose (approximately 50%) at time intervals up to 7 days after injection. These results indicate that single doses of Sn-protoporphyrin are rapidly cleared from plasma and persist in tissues and potently inhibit heme oxygenase activity for prolonged periods.
Bierce aboard the Beagle: Darwinian Discourse and Chickamauga

(2009). Bierce aboard the Beagle: Darwinian Discourse and Chickamauga. The Explicator: Vol. 67, No. 3, pp. 227-231.
Human mammary artery endothelial sparing with fibrous jaw clamping

Background. Temporary clamping of the internal mammary artery pedicle is required for visualization during coronary artery bypass grafting. A nylon fibril jaw surface has been developed for these clamps that exerts pressure only at discrete sites on the pedicle surface. The effect of this new jaw surface on endothelial cell function and integrity after compression is investigated in this study. Methods. Internal mammary artery specimens from 10 patients each were divided into three separate rings, and two of these rings were clamped for 30 minutes with either a smooth or fibrous jaw clamp. Isometric tensions were measured in organ chambers after contraction by relaxing the rings with the endothelium-dependent agent acetylcholine followed by the endothelium-independent agent sodium nitroprusside. The intimal surfaces of similar rings were silver stained to assess the percentage of intact endothelium. Results. Endothelium-dependent relaxation was spared after fibrous jaw clamping (75% versus 89%) but significantly impaired after smooth jaw clamping (25% versus 89%; p p Conclusions. Foam silicone with nylon fibrils on the jaw surface of internal mammary artery clamps preserves endothelial cell function and integrity. The remaining undamaged cells also may facilitate the subsequent regeneration of a confluent endothelial cell layer.
Primary Iron Overload in African Americans

Purpose To report African Americans with primary iron overload diagnosed during life and to study iron stores in African Americans undergoing autopsy. Patients and Methods We summarized information for 4 African-American patients diagnosed during life with iron overload not explainable by alcohol, blood transfusions, or ineffective erythropoiesis. We reviewed liver specimens and hospital records of 326 unselected adult African Americans who were autopsied, assessing Prussian blue-stained sections for hepatocelluar iron and measuring iron quantitatively in specimens that stained positively. We calculated the hepatic iron index (the hepatic iron concentration in μmol/g dry weight divided by the age in years). In autopsy subjects we corrected the index to account for iron administered by blood transfusion (the adjusted hepatic iron index). The hepatic iron index is useful for distinguishing primary iron overload from the moderate siderosis that may accompany alcoholic liver disease. The normal index is ≤1.0. An index ≥1.7 cannot be explained by alcohol effects and an index ≥1.9 indicates the magnitude of iron-loading found in Caucasian homozygous HLA-linked hemochromatosis. Results The 4 living patients, all males and 27 to 50 years of age, had elevated body iron burdens and one or more of the following: hepatomegaly, cirrhosis, cardiomyopathy, diabetes mellitus, and impotence. Hepatic iron indices were 2.3, 11.5, and 20.2 in the 3 whose liver iron concentrations were measured. Among the autopsy subjects, 4 (1.2%), 2 men and 2 women aged 50 to 63 years, had adjusted hepatic iron indices ≥1.9 (range 1.9 to 5.6). Conclusions Primary iron overload occurs in African Americans. Further studies are needed to define prevalence, pathophysiology and clinical consequences. Clinicians should look for this condition.
Molecular mechanics calculations on HIV-1 protease with peptide substrates correlate with experimental data

Molecular models of HIV-1 protease and 21 peptide substrates with single amino acid substitutions at positions from P4 to P3' were built and compared with kinetic measurements. The crystal structure of HIV-1 protease with a peptidic inhibitor was modified to model the peptide substrate Pro-Ala-Val-Ser-Leu-Ala-Met-Thr for the starting geometry. Models were built of two reaction intermediates, HIV protease with peptide substrate and with its tetrahedral intermediate. The energy minimization used a new algorithm that increased the speed and eliminated a cut-off for non-bonded interactions. After minimization the models for substrate and tetrahedral intermediate both had root mean square deviations of 0.48 A for all atoms of the HIV protease compared to the starting crystal structure. Differences in the model structures and interaction energies for HIV protease with different substrates were analyzed. The calculated interaction energies for the 21 HIV protease-tetrahedral intermediate models gave a correlation coefficient of 0.64 with the kinetic measurements. The eight substrates with changes in the P1 and P1' residues next to the scissile bond gave the highest correlation of 0.93, while the 14 substrates with changes in P2-P2' gave a correlation coefficient of 0.86. The catalytic mechanism and factors influencing the catalytic efficiency of the different substrates are discussed in relation to the models. The predictive ability of molecular mechanics calculations is discussed in the context of the statistical mechanics analysis of the differences in free energy.
Integrated concurrency analysis in a software development enviornment

The inherent difficulties of analyzing concurrent software make reliance on a single technique or a single monolithic tool unsatisfactory. A better approach is to apply multiple analysis and verification techniques by coordinating the activities of a variety of small tool components. We describe how this approach has shaped the design of a set of tool components to support concurrency analysis in the Arcadia-1 software development environment. Implementation and experience with key components is described.
The Matrix Metalloproteinase System: Changes, Regulation, and Impact throughout the Ovarian and Uterine Reproductive Cycle

The ovary and uterus undergo extensive tissue remodeling throughout each reproductive cycle. This remodeling of the extracellular environment is dependent upon the cyclic hormonal changes associated with each estrous or menstrual cycle. In the ovary, tissue remodeling is requisite for growth and expansion of the follicle, breakdown of the follicular wall during the ovulatory process, transformation of the postovulatory follicle into the corpus luteum, as well as the structural dissolution of the corpus luteum during luteal regression. In the uterus, there is extraordinary turnover of the endometrial connective tissue matrix during each menstrual cycle. This turnover encompasses the complete breakdown and loss of this layer, followed by its subsequent regrowth. With implantation, extensive remodeling of the uterus occurs to support placentation. These dynamic changes in the ovarian and uterine extracellular architecture are regulated, in part, by the matrix metalloproteinase (MMP) system. The MMP system acts to control connective tissue remodeling processes throughout the body and is comprised of both a proteolytic component, the MMPs, and a regulatory component, the associated tissue inhibitors of metalloproteinases. The current review will highlight the key features of the MMPs and tissue inhibitors of metalloproteinases, focus on the changes and regulation of the MMP system that take place throughout the estrous and menstrual cycles, and address the impact of the dynamic tissue remodeling processes on ovarian and uterine physiology.
A Direct Photoelectric Determination of Planck's " h "

Quantum theory was not originally developed for the sake of interpreting photoelectric phenomena. It was solely a theory as to the mechanism of absorption and emission of electromagnetic waves by resonators of atomic or subatomic dimensions. It had nothing whatever to say about the energy of an escaping electron or about the conditions under which such an electron could make its escape, and up to this day the form of the theory developed by its author has not been able to account satisfactorily for the photoelectric facts presented herewith. We are confronted, however, by the astonishing situation that these facts were correctly and exactly predicted nine years ago by a form of quantum theory which has now been pretty generally abandoned.
Trajectory Analysis and Staging Trades for Smaller Mars Ascent Vehicles

Mars ascent trajectories are calculated for small-scale vehicles that would improve the affordability of Mars sample return. Vehicle size, thrust levels, staging, and the importance of atmospheric drag are all taken into consideration. The high acceleration of conventional solid rockets requires a steep trajectory for drag avoidance, followed by a relatively large circularization burn, appropriate for a second stage. Lower thrust reduces total ∆v because reduced drag permits less steep trajectories that require small circularization burns. The results suggest the development of miniature liquid-propelled vehicles or advanced solid rockets having reduced thrust and multiple-burn capability.
Sublethal effects of a pure polychlorobiphenyl on mice

Abstract Sexually mature, weight-stable male mice were dosed by oral intubation with either 0, 200, 500, or 1000 mgm/kgm of 2,4,5,2′,4′,5′-hexachlorobiphenyl (PCB), dissolved in peanut oil, and housed for 28 days in groups of five in metabolic cages. Their food and water consumption, urine and fecal (dry) output, and body weights were not depressed or enhanced by the PCB treatment; nor were any neuromuscular deficiencies detected by rotarod tests. At the termination of the experiment, hematocrit values were not significantly changed. The wet weights (percentage of body weight) of whole brain, testes, and epididymal fat pads were not changed significantly in the PCB-treated animals. However, wet spleen weights of those animals receiving 500 mgm of PCB/kgm were significantly depressed and the wet kidney weights of animals receiving 500 and 1000 mgm of PCB/kgm were also decreased significantly. The wet and dry weights of livers were significantly elevated in animals treated with 500 and 1000 mgm of PCB/kgm. The average amount of PCB extracted from dry livers increased significantly with each higher dose of PCB administered. Linear regression analysis revealed a dose-related response in the amount of PCB sequestered in the liver. The polychlorinated biphenyl extracted from dry livers was confirmed, by mass spectral analysis, to be 2,4,5,2′,4′,5′-hexachlorobiphenyl. Concerning cytologic changes in hepatocytes, the mean cell volume, mean nuclear volume, and mean cytoplasmic volume of centrilobular hepatocytes treated with 200 mgm of PCB/kgm (and higher) were all significantly greater than these same parameters in the centrilobular hepatocytes of untreated animals. No cytologic volume changes were detected in the periportal hepatocytes. Morphometric analysis of electron micrographs (35,000x) from each of 11 mice (three mice given 200 mgm of PCB/kgm and four mice each given 0 or 1000 mgm of PCB/kgm) revealed that the number of lipid bodies and mitochondria per cell were significantly higher in the average centrilobular hepatocyte treated with 1000 mgm of PCB/kgm. The membrane surface areas (expressed as square microns) were also significantly elevated in the mitochondrial envelope, the mitochondrial cristae, and the smooth endoplasmic reticulum per centrilobular hepatocyte. The volumes (expressed as cubic microns) of numerous cytoplasmic components were significantly greater in the centrilobular hepatocytes treated with 1000 mgm of PCB/kgm; these include lipid bodies, secondary lysosomes, mitochondria, rough and smooth endoplasmic reticulum, and open cytoplasm. In conclusion, this study gives a detailed quantitative morphometric description of the way in which centrilobular hepatocytes adapt to the toxic effects of a persistent environmental contaminate, 2,4,5,2′,4′,5′-hexachlorobiphenyl.
Implications of early and guideline adherent physical therapy for low back pain on utilization and costs

Initial management decisions following a new episode of low back pain (LBP) are thought to have profound implications for health care utilization and costs. The purpose of this study was to evaluate the impact of early and guideline adherent physical therapy for low back pain on utilization and costs within the Military Health System (MHS). Patients presenting to a primary care setting with a new complaint of LBP from January 1, 2007 to December 31, 2009 were identified from the MHS Management Analysis and Reporting Tool. Descriptive statistics, utilization, and costs were examined on the basis of timing of referral to physical therapy and adherence to practice guidelines over a 2-year period. Utilization outcomes (advanced imaging, lumbar injections or surgery, and opioid use) were compared using adjusted odds ratios with 99% confidence intervals. Total LBP-related health care costs over the 2-year follow-up were compared using linear regression models. 753,450 eligible patients with a primary care visit for LBP between 18–60 years of age were considered. Physical therapy was utilized by 16.3% (n = 122,723) of patients, with 24.0% (n = 17,175) of those receiving early physical therapy that was adherent to recommendations for active treatment. Early referral to guideline adherent physical therapy was associated with significantly lower utilization for all outcomes and 60% lower total LBP-related costs. The potential for cost savings in the MHS from early guideline adherent physical therapy may be substantial. These results also extend the findings from similar studies in civilian settings by demonstrating an association between early guideline adherent care and utilization and costs in a single payer health system. Future research is necessary to examine which patients with LBP benefit early physical therapy and determine strategies for providing early guideline adherent care.
Wet Scrubber Analysis of Volatile Organic Compound Removal in the Rendering Industry

The promulgation of odor control rules, increasing public concerns, and U.S. Environmental Protection Agency (EPA) air regulations in nonattainment zones necessitates the remediation of a wide range of volatile organic compounds (VOCs) generated by the rendering industry. Currently, wet scrubbers with oxidizing chemicals are used to treat VOCs; however, little information is available on scrubber efficiency for many of the VOCs generated within the rendering process. Portable gas chromatography/mass spectrometry (GC/MS) units were used to rapidly identify key VOCs on-site in process streams at two poultry byproduct rendering plants. On-site analysis was found to be important, given the significant reduction in peak areas if samples were held for 24 hr before analysis. Major compounds consistently identified in the emissions from the plant included dimethyl disulfide, methanethiol, octane, hexanal, 2-methylbutanal, and 3-methylbutanal. The two branched aldehydes, 2-methylbutanal and 3-methylbutanal, were by far the most consistent, appearing in every sample and typically the largest fraction of the VOC mixture. A chlorinated hydrocarbon, methanesulfonyl chloride, was identified in the outlet of a high-intensity wet scrubber, and several VOCs and chlorinated compounds were identified in the scrubbing solution, but not on a consistent basis. Total VOC concentrations in noncondensable gas streams ranged from 4 to 91 ppmv. At the two plants, the odor-causing compound methanethiol ranged from 25 to 33% and 9.6% of the total VOCs (v/v). In one plant, wet scrubber analysis using chlorine dioxide (ClO2) as the oxidizing agent indicated that close to 100% of the methanethiol was removed from the gas phase, but removal efficiencies ranged from 20 to 80% for the aldehydes and hydrocarbons and from 23 to 64% for total VOCs. In the second plant, conversion efficiencies were much lower in a packed-bed wet scrubber, with a measurable removal of only dimethyl sulfide (20-100%).
Neighborhood context and the Hispanic health paradox: Differential effects of immigrant density on children׳s wheezing by poverty, nativity and medical history

Prior research suggests that immigrant enclaves provide respiratory health benefits for US Hispanic residents. We test if immigrant enclaves provide differential respiratory health benefits for Hispanic children in El Paso (Texas) based on individual-level factors. Results reveal that higher neighborhood immigrant density is associated with reduced odds of wheezing, but that the protective immigrant enclave effect is modified by poverty, general health status, body mass index (BMI), and caretaker nativity. Higher immigrant density is significantly more protective for poor children and those with foreign-born caretakers; conversely, it is significantly less protective for children in worse health and those with higher BMI. These findings foster a novel understanding of how immigrant enclaves may be differentially protective for Hispanic children based on individual-level factors.
Carbon budget of a marine phytoplankton-herbivore system with carbon-14 as a tracer1

Adult female and stage V Calanus pacificus were fed /sup 14/C-labeled phytoplankton in the laboratory in the form of monospecific cultures and natural populations. A carbon budget was constructed by following the /sup 14/C activity and the specific activity, over 48 h, in the phytoplankton, copepod, dissolved organic, dissolved inorganic, and fecal carbon compartments. The average incorporation of carbon into the copepod's body was 45% of the phytoplankton carbon available. Of the phytoplankton carbon, 27% appeared as dissolved organic carbon, 24% as dissolved inorganic carbon, and 3 to 4% in the form of fecal pellets. All of the tracer was recovered at the end of the experiments. The specific activity of the phytoplankton compartment was constant throughout each experiment. The other compartments had initial specific activities of zero, or close to zero, and increased throughout the experiment. In most experiments, the copepod specific activity equalled that of the phytoplankton at the end of 48 h, while the dissolved organic carbon, dissolved inorganic carbon, and fecal specific activities remained well below that of the phytoplankton.
The application of a simultaneous model for multisite exchange to solid-state NMR lineshapes

Abstract A multisite exchange treatment is developed to simulate NMR powder lineshapes in cases where motional processes of more than one type occur simultaneously. An example is presented where one type involves rotational diffusion, libration, or oscillation over a limited range whereas the other includes jumps of larger amplitudes between potential minima, the axis of motion being the same for both types. Restricted rotation of lower angular amplitude is conceived in terms of jumps between sites within one well with the amplitude of this restricted rotation being the key parameter which can be the same or different for each potential minimum. The second motional process of larger amplitude involves a series of jumps between sites in one well to sites in the other well. In the cases treated, the first process is always considered too fast to exhibit rate-dependent effects. One rate parameter is used for all jumps. This rate is always kept sufficiently large to keep the first process in the rapid exchange limit. At very large rates, both motions exhibit rate-independent effects. At slower rates, the rate dependence of the second process leads to conspicuous changes in the lineshape. The model sets an equal probability for all jumps and represents an alternative to the conventional treatment where one deals with the processes sequentially. The method is illustrated for the case of bisphenol-A polycarbonate (BPAPC), where results show an improvement over the previously published treatment based on a sequential approach.
A Simulator Study of T-tail Aircraft in Deep Stall Conditions

T tail aircraft in deep stall conditions in fixed- base cockpit simulation at large angle of attack
The perception of face gender: the role of stimulus structure in recognition and classification.

The perception of face gender was examined in the context of extending “face space” models of human face representations to include the perceptual categories defined by male and female faces. We collected data on the recognizability, gender classifiability (reaction time to classify a face as male/female), attractiveness, and masculinity/femininity of individual male and female faces. Factor analyses applied separately to the data for male and female faces yielded the following results. First, for both male and female faces, the recognizability and gender classifiability of faces were independent—a result inconsistent with the hypothesis that both recognizability and gender classifiability depend on a face’s “distance” from the subcategory gender prototype. Instead, caricatured aspects of gender (femininity/masculinity ratings) related to the gender classifiability of the faces. Second, facial attractiveness related inversely to face recognizability for male, but not for female, faces—a result that resolves inconsistencies in previous studies. Third, attractiveness and femininity for female faces were nearly equivalent, but attractiveness and masculinity for male faces were not equivalent. Finally, we applied principal component analysis to the pixel-coded face images with the aim of extracting measures related to the gender classifiability and recognizability of individual faces. We incorporated these model-derived measures into the factor analysis with the human rating and performance measures.
Interactions of antimicrobial peptides with Leishmania and trypanosomes and their functional role in host parasitism

Antimicrobial peptides (AMPs) are multifunctional components of the innate systems of both insect and mammalian hosts of the pathogenic trypanosomatids Leishmania and Trypanosoma species. Structurally diverse AMPs from a wide range of organisms have in vitro activity against these parasites acting mainly to disrupt surface-membranes. In some cases AMPs also localize intracellularly to affect calcium levels, mitochondrial function and induce autophagy, necrosis and apoptosis. In this review we discuss the work done in the area of AMP interactions with trypanosomatid protozoa, propose potential targets of AMP activity at the cellular level and discuss how AMPs might influence parasite growth and differentiation in their hosts to determine the outcome of natural infection.
Application of surface plasmon resonance for analysis of protein-protein interactions in the G protein-mediated signal transduction pathway.

Hundreds of extracellular stimuli are received by cells via the pathways consisting of three basic components: cell-surface receptors, heterotrimeric G proteins, and intracellular effector enzymes or ion channels. A number of additional molecules, including G protein-coupled receptor kinases (GRKs), phosducin and Ca2+-binding proteins modulate signal transduction through these cascades. Understanding how these universal pathways work requires a detailed analysis of the interactions between these proteins. The recently emerged technology of surface plasmon resonance (SPR) can study protein–protein interactions by measuring not only the equilibrium binding constants, but also the association and dissociation rates. This article reviews experimental design used by researchers to analyze different components of the G protein pathway by SPR and focuses on the insights this technique provides regarding the kinetics, structure–function aspects and regulation of specific molecular events in the cascade. Copyright © 2000 John Wiley & Sons, Ltd.
Design and development of portable biofeedback systems for use in oral dysphagia rehabilitation

The management of dysphagia presents a major problem in the comprehensive rehabilitation of stroke and head injury patients. Dysphagia is a disorder of the swallowing process. Oral dysphagia refers to abnormalities in the oral phase of the swallowing mechanism. The oral phase of the swallowing mechanism is important for the proper triggering of the swallowing reflex. Current techniques in oral dysphagia rehabilitation include oro-motor exercises using tongue depressors and mouth-care swabs. There is thus a need for a better therapeutic method for oral dysphagia. The purpose of this paper is to report the development of audio-visual biofeedback devices for treating oral dysphagia. Portable biofeedback devices rendering feedback of biomechanical parameters characterizing the oral phase were developed and evaluated in preliminary clinical trials. A patient progress index (PPI) was developed and used to quantify the overall patient progress. The devices demonstrated good patient acceptability.
Microprobe study of the effect of Li intercalation on the structure of graphite

The structural stability of graphite electrodes in Li-ion cells, which were cycled at room temperature and 60 °C was investigated. We observed gradual structural degradation of the graphite, which was most pronounced on the electrode surface but also extended into the bulk of the electrode. Graphite particles close to the Cu current collector remained almost unchanged, whereas those close to the electrode/electrolyte interface suffered significant structural damage. Structural degradation of the graphite led to an increased anode surface reactivity vs. the electrolyte. A thick layer of inorganic products from side reactions was observed on the disordered carbon areas of the anode.