cssi/SciSciGPT-SciSciNet huggingface dataset:
Trophic effects of androgen: development and hormonal regulation of neuron number in a sexually dimorphic vocal motor nucleus.

In Xenopus laevis, the laryngeal motor nucleus (n. of cranial nerves IX-X) is part of a sexually differentiated, androgen sensitive neuromuscular system devoted to vocalization. Adult males have more n. IX-X neurons than females; however, during development of n. IX-X, the rate of neurogenesis does not appear to differ between the sexes. In this study, we explored the role of naturally occurring cell death in the development of this nucleus and asked whether cell death might be involved in establishing the sex difference in neuron number. Counts of n. IX-X neurons reveal that at tadpole stage 56, males and females have similar numbers of n. IX-X neurons, but by stage 64 male neuron numbers are greater. This sex difference arises owing to a greater net loss of neurons in females-males lose approximately 25% of their n. IX-X neurons between stages 56 and 64, while females lose approximately 47%. Sexual differentiation of n. IX-X neuron number coincides with a period of developmental cell death, as evidenced by terminal transferase-mediated dUTP nick-end labeling and the presence of pyknotic nuclei in n. IX-X. A role for gonadal hormones in controlling cell number was examined by treating tadpoles with exogenous androgen and determining the number of n. IX-X neurons at stage 64. Dihydrotestosterone (DHT) treatment from the beginning of the cell death period (stage 54) until stage 64 had no effect on the number of n. IX-X neurons in males but did significantly increase n. IX-X neuron number in females. This increase was sufficient to abolish the sex difference normally observed at stage 64. Although DHT induced increases in female neuron number, it did not induce increases in cell proliferation or addition of newly born neurons to n. IX-X. DHT may therefore have increased neuron number by protecting cells from death. We conclude that androgens can influence the survival of n. IX-X neurons during a period of naturally occurring cell death, and that this action of androgen is critical to the development of sex differences in n. IX-X neuron number.
Robust Reputation Protocol Design for Online Communities: A Stochastic Stability Analysis

This paper proposes a new class of incentive mechanisms aiming at compelling self-interested users in online communities to cooperate with each other by exchanging resources or services. Examples of such communities are social multimedia platforms, social networks, online labor markets, crowdsourcing platforms, etc. To optimize their individual long-term performance, users adapt their strategies by solving individual stochastic control problems. The users' adaptation catalyze a stochastic dynamic process, in which the strategies of users in the community evolve over time. We first characterize the structural properties of the users' best response strategies. Subsequently, using these structural results we design incentive mechanisms based on reputation protocols for governing the online communities, which can “manage” the long-run evolution of the community. We prove that by appropriately penalizing and rewarding users based on their behavior in the community, such incentive mechanisms can eliminate free-riding and ensure that the community converges to a desirable equilibrium selected by the community designer such that social welfare is maximized and in which users find it in their self-interest to cooperate with each other.
On the Reliability of Eyewitness Testimony: A Retrospective Review:

The debate between McCloskey and Egeth and Loftus concerning the usefulness of expert psychological testimony in court serves here as the springboard for an essay-review of a significant part of its context, a retrospective evaluation of Loftus's book Eyewitness Testimony. The partisanship evident in the book provides a case study of the unusual vulnerability of psychology, in policy contexts, to overgeneralization and underqualification of small average effects.
Atheoretical macroeconometrics: A critique

Abstract The spurious nature of the restrictions used to identify many macroeconometric models has led some researchers to advocate a style of econometric inquiry that is less dependent on prior theoretical restrictions of the sort that were central to the approach of the Cowles Commission. This development, which we call atheoretical macroeconometrics, is summarized and evaluated in the current paper. It is contrasted with an updated version of the Cowles Commission approach. We conclude that while some of the exercises of atheoretical macroeconometrics are valid, those that have attracted the most attention and appear the most innovative-exogeneity testing, impulse response analysis and policy analysis using estimated vector autoregressions - are based on incorrect analysis.
Interactive Visualization of Line Congruences for Spatial Mechanism Design

This paper presents a framework for generating, representing, and interacting with the line congruences associated with four general finite poses. These line congruences are the solution space of spatial 4C mechanisms which will guide a moving body through the four prescribed poses. Hence, the contributions of this paper are applicable to developing interactive tools for designing spatial 4C mechanisms for four pose motion generation. Moreover, the strategies employed to address this difficult interactive visualization challenge are presented. The goal here being to facilitate future works which address other interactive visualization challenges. First, a methodology for generating a parameterized representation of the line congruences is reviewed. This is followed by strategies for visually representing the line congruences which are appropriate for both workstation and immersive virtual reality computer graphics. Next, strategies and supporting algorithms for interacting with the line congruences to obtain solution mechanisms with fixed links or coupler links in desired regions of the workspace are presented. The result is an intuitive interactive visual design methodology for generating and interacting with the line congruences associated with four general finite spatial poses for spatial 4C mechanism design. It is our desire that this effort, albeit focused upon the challenge of creating computer-aided design environments for spatial 4C mechanisms, will facilitate as well as motivate other efforts to address the inherent visualization and interaction challenges in designing three dimensional mechanical systems. @DOI: 10.1115/1.1529211#
Molecular mechanisms of varicella zoster virus pathogenesis

Varicella zoster virus (VZV) is the causative agent of varicella (chickenpox) and zoster (shingles). Investigating VZV pathogenesis is challenging as VZV is a human-specific virus and infection does not occur, or is highly restricted, in other species. However, the use of human tissue xenografts in mice with severe combined immunodeficiency (SCID) enables the analysis of VZV infection in differentiated human cells in their typical tissue microenvironment. Xenografts of human skin, dorsal root ganglia or foetal thymus that contains T cells can be infected with mutant viruses or in the presence of inhibitors of viral or cellular functions to assess the molecular mechanisms of VZV-host interactions. In this Review, we discuss how these models have improved our understanding of VZV pathogenesis.
Determination of carbon monoxide with palladium chloride

Abstract The gas sample transfer apparatus, as shown in Fig. 1, was designed to facilitate the analysis of several carbon monoxide samples during a normal work day. With this apparatus, gas samples were accurately transferred from the Tedlar bags leak free through the system to the reaction flask. Changing from one gas concentration to another was greatly simplified by using the quick-connect fittings; gas volumes were readily calculated from direct readings taken from the differential pressure gauge. Tests were conducted to assess the performance of the PdCl 2 method and the sampling system with various gas mixtures. The proposed PdCl 2 method utilizing this particular sampling scheme is capable of successfully measuring carbon monoxide in nitrogen cylinder gas at levels of 0.1, 0.05, and 0.01% with expected average recoveries of 96, 96, and 93%, respectively.
Quantum and classical studies of the O(3P)+H2(v=0–3,j=0)→OH+H reaction using benchmark potential surfaces

We present results of time-dependent quantum mechanics (TDQM) and quasiclassical trajectory (QCT) studies of the excitation function for O(3P)+H2(v=0–3,j=0)→OH+H from threshold to 30 kcal/mol collision energy using benchmark potential energy surfaces [Rogers et al., J. Phys. Chem. A 104, 2308 (2000)]. For H2(v=0) there is excellent agreement between quantum and classical results. The TDQM results show that the reactive threshold drops from 10 kcal/mol for v=0 to 6 for v=1, 5 for v=2 and 4 for v=3, suggesting a much slower increase in rate constant with vibrational excitation above v=1 than below. For H2(v>0), the classical results are larger than the quantum results by a factor ∼2 near threshold, but the agreement monotonically improves until they are within ∼10% near 30 kcal/mol collision energy. We believe these differences arise from stronger vibrational adiabaticity in the quantum dynamics, an effect examined before for this system at lower energies. We have also computed QCT OH(v′,j′) state-resolved ...
878 RECATEGORIZING CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA WITH MONOCLONAL ANTIBODIES TO HUMAN T CELLS

The immunologic surface markers of lymphoblasts from three patients with childhood acute lymphoblastic leukemia (ALL) were analyzed. Blasts from two of these patients did not form rosettes with sheep erythrocytes and the third did so marginally, suggesting these patients had non-T cell leukemia. These blasts were also tested with commercially available monoclonal antibodies (OKT 3, 4, 6, 8,) that detect thymocyte differentiation markers, and all three patients were highly reactive with at least 2 of these reagents. We anticipate the availability of multiple standardized monoclonal reagents will necessitate a recategorization of ALL phenotypes. Furthermore, some of these leukemic phenotypes may not correspond to normal stages of lymphoid differentiation. Therefore, it may be inappropriate to attempt to identify and categorize leukemic cells by the pathways of normal differentiation. We suggest that leukemic cells be identified by the presence or absence of standardized immunologic and enzymatic markers without attempting to classify them by prior labels of “T, null, B, pre-B or pre T.”
Bactericidal activity of alkaline glutaraldehyde solution against a number of atypical mycobacterial species

The mycobactericidal activity of 2% alkaline glutaraldehyde solution was determined using standardized suspensions of 10 species of atypical mycobacteria and compared with that for virulent Mycobacterium tuberculosis. Suspensions of M. avium, M. intracellulare and M. gordonae were more resistant to disinfection by the glutaraldehyde than were virulent tubercle bacilli while M. kansasii, M. scrofulaceum and M. szulgae were somewhat more susceptible. Mycobacterium marinum, M. smegmatis and M. fortuitum were highly sensitive to the disinfectant action of the alkaline glutaraldehyde solution. This variation in sensitivity shown by apparently closely related strains of mycobacteria to this disinfectant has important practical implications.
Development of Microbodies in Sunflower Cotyledons and Castor Bean Endosperm during Germination.

In cotyledons of sunflower seedlings glyoxysomal and peroxisomal enzymes exhibit different rates of development during germination. The total activity of isocitrate lyase, a glyoxysomal marker enzyme, rapidly increased during the first 3 days, and then decreased 89% by day 9. Exposure to light accelerated this decrease only slightly. The specific activity of glyoxysomal enzymes (malate synthetase, isocitrate lyase, citrate synthetase, and aconitase) in the microbody fraction from sucrose density gradients increased between days 2 and 4 about 2- to 3-fold, and thereafter it remained about constant in light or darkness.Total activity of the peroxisomal enzymes increased slowly in the dark during the first 4 days of germination and thereafter remained at a constant level of activity in the dark or increased 2-fold in 24 hours of light. The specific activties of glycolate oxidase, hydroxypyruvate reductase, and serine-glyoxylate aminotransferase in the isolated microbody fraction increased about 10-fold between days 2 and 4 in the dark and then remained constant or increased again 10-fold after an additional 48 hours in the light.The total activity of the common microbody marker, catalase, developed similarly to isocitrate lyase, but decreased only 72% by day 9. The specific activities of enzymes (catalase, malate dehydrogenase, and aspartate aminotransferase) common to both microbody systems were 10- to 1000-fold greater than those of other enzymes. It is proposed that malate and aspartate may be involved in hydrogen transport between microbodies and other cellular sites.Glutamate-glyoxylate aminotransferase was very active in microbodies from castor bean endosperm and sunflower cotyledons. The specific activity of this aminotransferase developed similarly to glyoxysomal enzymes in the dark but further increased in the light, as did peroxisomal enzymes.The microbody fraction of castor bean endosperm germinated in the dark for 5 days contained both glyoxysomal and peroxisomal enzymes of similar specific activity.Adjacent to the microbody fraction on sucrose gradients from sunflower cotyledons were etioplasts at slightly lower densities and protein bodies at similar and higher densities. Their presence in the microbody fractions resulted in artificially low specific activities.
The prediction of averages

Criterion measures are frequently obtained by averaging ratings, but the number and kind of ratings available may differ from individual to individual. This raises issues as to the appropriateness of any single regression equation, about the relation of variance about regression to number and kind of criterion observations, and about the preferred estimate of regression parameters. It is shown that if criterion ratings all have the same true score the regression equation for predicting the average is independent of the number and kind of criterion scores averaged.
Serological responses of dogs to cell wall and internal antigens of Brucella canis (B. canis).

Abstract The serological responses of dogs to cell wall and internal antigens of B. canis were studied in experimentally infected specific-pathogen-free (SPF) Beagles. Sera from infected and false positive field dogs also were examined. Cell wall antigens were extracted from B. canis by two procedures that employed either hot phosphate buffered saline (PBS) or sodium desoxycholate (SDC). Agar gel immunodiffusion (AGID) tests employing sera from experimentally infected SPF dogs were used to evaluate antigenic extracts. Extraction with PBS yielded two antigens; SDC extracted an antigen complex and sonication of PBS extracted cells liberated four internal antigens. Sera from field dogs that were negative for B. canis infection in repeated tests often had heterospecific antibodies. Such cross-reactive sere commonly gave “spur” (partial fusion) reactions with a positive reference serum when tested against the SDC cell wall antigen. In addition, false positive dogs did not have antibody to one of the cell wall antigens or to the internal antigens. In contrast, sera from infected field dogs commonly gave “identity” (fusion) reactions in the AGID test with two antigens in the SDC extract, and produced precipitin lines to one to four internal antigens. Examination of a library of sera obtained from experimentally infected SPF dogs over a period spanning 4 1 2 years revealed that none of the serodiagnostic tests employed (tube agglutination, slide agglutination, AGID) was accurate during the inital 12 weeks of infection; hemocultures were the most sensitive during this period. Tube and slide agglutination tests were initially sensitive, but they showed a lack of sensitivity and specificity after the bacteremic period ceased, as well as in their failure to exclude false positive reactions in field animals. Immunodiffusion tests that employed SDC or PBS extracts of B. canis cell walls were sensitive and accurate in identifying most infected dogs. After the bacteremia had ceased, however, AGID tests that employed cell wall antigens gave equivocal results. Immunodiffusion tests that employed sonicated (internal) antigens were sensitive shortly after the onset of bacteremia, and they had the advantage of detecting infected animals for at least 6 months following the cessation of bacteremia, a time when other serological tests gave equivocal results.
Elimination of disturbing naptime behaviors of preschool children through withdrawal and re-presentation of TV audio reception.

Summary.-Withdrawal of the audio portion of midday television programs was used to suppress the "disturbing" naptime behaviors of three preschool children. Conversely, the contingent reinstatement of the audio portion following the occurrence of nondisturbing behaviors served to establish and maintain appropriate naptime behaviors. Free access to the audio and visual components, however, did not diminish disruptive behaviors. Naptime periods should constitute about 25% of the child's time at day care facilities (The Office of Child Development's, "Model for Day Care Licensing," in press). Spot checks of many day care schedules confirm this rather substantial time commitment to midday naps. However, rarely do all children fall asleep or rest quietly; about one-third of a group of head start children were found by Herman and Tramoncana ( 1971 ) to engage in high rates of disruptive behaviors during rest periods. The repeated subjugation of restless children to a prolonged monotonous environment which demands minimal activity from them does not seem a realistic and defensible endeavor. Instead, the aim of the naptime or quiet period could be one where not only are disruptive behaviors minimized but a number of constructive behaviors are strengthened. Several studies (Baer, 1961, 1962; Greene & Hoats, 1969) have demonstrated the strengthening of a variety of behaviors in children by contingently delivered perceptual stimuli (e.g., cartoons, TV material), whose same presentation might also develop sustained interest during rest time. Moreover, children will respond to postpone the programmed removal of these stimuli; and, if such avoidance behavior is impossible, they will learn to escape from not having the material available and also attempt to reintroduce it. These features suggest the elimination of naptime disturbances by withdrawing ongoing sensory material and establishing and maintaining nondisturbing attentive behaviors by returning the previously withdrawn material.
Theoretical and Scale Model EMP Response Analysis of Interconnected System Cables

A technique for calculating the EMP response of complex networks of coaxially shielded cables has been demonstrated for a generic system. A circuit code was employed at the systems level, but parameters used in the circuit code were determined and verified both by a more elaborate theoretical cable response code and by scaled experimental measurements. Details of the system level circuit code development are presented along with comparisons between the calculated and experimental responses.
Population Screening for Von Willebrand Disease in Adolescents with Heavy Menstrual Bleeding

We used Ohio Medicaid data to determine frequency and predictors of laboratory screening for von Willebrand disease and other bleeding disorders in adolescents with heavy menses. Despite expert guidelines, screening was performed in only a minority of subjects (<15% of those with heavy menses and <25% of those with menstrual bleeding defined as severe), with younger adolescents and those from more urban counties more likely to undergo screening.
Molecular pathogenesis in non-Hodgkin lymphoma: Implications for therapy

Although Diffuse Large B-Cell lymphoma (DLBCL) represents 30% of all non-Hodgkin lymphomas, there are many different subtypes of DLBCL with various prognostic implications. We are now recognizing that the molecular subtype of the DLBCL may be associated with specific clinical characteristics as well as outcome of the treatment. With this additional information, we may be able to better select a treatment for the patient which will improve the expected response. Only large scale clinical testing will help us with understanding these molecular subtypes and designing therapies for patients with DLBCL.
Subspace identification of stable nonnegative and compartmental dynamical systems via constrained optimization

Nonnegative and compartmental dynamical system models are widespread in biological, physiological, and ecological sciences and play a key role in understanding these processes. In the specific field of pharmacokinetics involving the study of drug concentrations (in various tissue groups) as a function of time and dose, nonnegative and compartmental models are vital in understanding system wide effects of pharmacological agents. These systems are stable with nonnegative system matrices. In this paper, we present a constrained optimization framework for nonnegative and compartmental system identification that guarantees asymptotic stability of the plant system dynamics as well as the nonnegativity of the system matrices. Our approach is based on a subspace identification method wherein the resulting constrained optimization problem is cast as a convex linear programming problem with mixed equality, inequality, quadratic, and nonnegative-definite constraints. Finally, several examples are presented to illustrate the utility of the proposed approach.
Preliminary Structural Design of OCAES Vessel

A vessel for Offshore Compressed Air Energy Storage (OCAES) is being considered as a part of the emerging technology to store intermittently generated energy from offshore renewable sources. The basic idea is to submerge the storage vessel into the ocean at a large water depth, convert the energy into compressed air, store it with using the hydrostatic water pressure to balance the compressed air pressure without requiring the storage vessels to resist high internal air pressure. An additional advantage is that the interface of air and water acts as a piston to maintain the air pressure level.In this study, a rectangular configuration and a cylindrical configuration are proposed for the OCEAS vessel. Stress controlled analyses are performed for the preliminary design of the OCAES vessel with emphasis on characterization of applied cyclic load induced by the air/water exchange in the inflation/deflation process. The stress distribution and deformation pattern in the OCAES vessel at different loading stages are studied by using the multi-physics FEM program COMSOL. Key parameters including storage volume, geometry of OCAES vessel, and material selection are discussed.Copyright © 2014 by ASME
Matrix tests for period 1 and 2 limit cycles in discrete threshold networks

The dynamics of discrete threshold neural networks is studied using a matrix inequality which is shown to be equivalent to the nonlinear state transition equation of the network. Some matrix tests for the existence of period 1 and 2 limit cycles are presented. Some types of vector sequences are shown not to be limit cycles. >
Depth judgment tasks and environments in near-field augmented reality

In this poster abstract we describe an experiment that measured depth judgments in optical see-through augmented reality at near-field distances of 34 to 50 centimeters. The experiment compared two depth judgment tasks: perceptual matching, a closed-loop task, and blind reaching, a visually open-loop task. The experiment tested each of these tasks in both a real-world environment and an augmented reality environment, and used a between-subjects design that included 40 participants. The experiment found that matching judgments were very accurate in the real world, with errors on the order of millimeters and very little variance. In contrast, matching judgments in augmented reality showed a linear trend of increasing overestimation with increasing distance, with a mean overestimation of ∼ 1 cm. With reaching judgments participants underestimated ∼ 4.5 cm in both augmented reality and the real world. We also discovered and solved a calibration problem that arises at near-field distances.
Sparse Approximation Property and Stable Recovery of Sparse Signals From Noisy Measurements

In this correspondence, we introduce a sparse approximation property of order s for a measurement matrix A:||xs||2 ≤ D||Ax||2+β(σs(x))/√s for all x,where xs is the best s -sparse approximation of the vector x in l2, σs(x)is the s-sparse approximation error of the vector x in l1 , and D and β are positive constants. The sparse approximation property for a measurement matrix can be thought of as a weaker version of its restricted isometry property and a stronger version of its null space property. In this correspondence, we show that the sparse approximation property is an appropriate condition on a measurement matrix to consider stable recovery of any compressible signal from its noisy measurements. In particular, we show that any compressible signal can be stably recovered from its noisy measurements via solving an l1-minimization problem if the measurement matrix has the sparse approximation property with β ∈ (0,1), and conversely the measurement matrix has the sparse approximation property with β ∈ (0,∞) if any compressible signal can be stably recovered from its noisy measurements via solving an l1 -minimization problem.
Simulation analysis of multithreaded programs under deadlock-avoidance control

We employ discrete event simulation to evaluate the performance of deadlock-prone multithreaded programs, either general-purpose software or parallel simulators, under a novel technique for deadlock-avoidance control recently proposed in the literature. The programs are modeled by a special class of Petri nets, called Gadara nets. We propose a formal simulation methodology for Gadara nets. We then use simulation to analyze two deadlock-prone multithreaded programs, where we study system performance in terms of safety, efficiency, and activity level, both before and after deadlock-avoidance control is applied. We further conduct a sensitivity analysis to investigate the effect of key parameters on the program's performance. We discuss the implications of the above results on the practical implementation of control strategies that prevent deadlocks in multithreaded programs.
Inter‐individual differences in rates of routine energy loss and growth in young‐of‐the‐year juvenile Atlantic cod

Inter-individual differences in rates of routine (non-feeding) metabolism and growth were evaluated in young-of-the-year (YOY) juvenile Atlantic cod Gadus morhua. Rates of O 2 consumption, CO 2 production and ammonia (TAN) excretion were measured in 64, 25-43 mm standard length (Ls) YOY growing at different rates (0.27-0.47 mm day -1 ) in a common rearing tank. Parameter rates (y) increased allometrically (y =a.M b ) with increasing body mass (M) with b-values for O 2 production, CO 2 consumption and TAN excretion equal to 0.81, 0.89 and 0.56, respectively. In some cases, residuals from these regressions were significantly negatively correlated to fish growth rate. In no cases did residuals of parameter rates increase with increasing growth rate. These data suggest that, during unfed periods, relatively fast-growing fish were more metabolically efficient than slower-growing fish from the same cohort. The fish condition factor, derived from M . L -2.89 S, also significantly decreased with increasing growth rate. Results indicated differences in both the rates of routine energy loss and the patterns of growth allocation among YOY Atlantic cod. Since these physiological attributes were positively correlated with growth rate, they may be indicative of 'survivors' in field populations.
Has Antifungal Susceptibility Testing Come of Age

The in vitro susceptibility of an infecting organism to the antimicrobial agent selected for therapy is one of several factors that influence the likelihood that therapy for an infection will be successful. To appreciate the value of antifungal susceptibility testing, it is helpful to review the overall predictive utility of antibacterial susceptibility testing. After >30 years of study, in vitro susceptibility can be said to predict the response of bacterial infections with an accuracy that is well summarized as the "90-60 rule": infections due to susceptible isolates respond to therapy approximately 90% of the time, whereas infections due to resistant isolates respond approximately 60% of the time. On the basis of a growing body of knowledge, standardized susceptibility testing for selected organism-drug combinations (most notably, Candida species and the azole antifungal agents) has been shown to have similar predictive utility. Antifungal susceptibility testing is now increasingly and appropriately used as a routine adjunct to the treatment of fungal infections.
Empirical inflation models in developing countries: Sensitivity to the definition of inflation

Previous developing country inflation studies have demonstrated that the Harberger (monetarist) model's explanatory power may be quite sensitive to the time period or explanatory variables used. In this study, the model's sensitivity to the definition of the inflation rate variable itself ‐ the dependent variable ‐ is investigated. Using a cross‐section, time‐series data set of 19 developing nations, it is shown that the Harberger model is sensitive to the manner in which inflation is defined. Then, a similar investigation is conducted for another, more recently developed, model of the inflationary process (the Hanson model). This model exhibits less sensitivity to the choice of inflation variable.
The scoop on the fly brain: glial engulfment functions in Drosophila

Glial cells provide support and protection for neurons in the embryonic and adult brain, mediated in part through the phagocytic activity of glia. Glial cells engulf apoptotic cells and pruned neurites from the developing nervous system, and also clear degenerating neuronal debris from the adult brain after neural trauma. Studies indicate that Drosophila melanogaster is an ideal model system to elucidate the mechanisms of engulfment by glia. The recent studies reviewed here show that many features of glial engulfment are conserved across species and argue that work in Drosophila will provide valuable cellular and molecular insight into glial engulfment activity in mammals.
Two mitogenic regions of myelin basic protein interact with different receptors to induce Schwann cell proliferation in a cAMP dependent process

Previous studies have shown that myelin basic protein (MBP) is mitogenic for Schwann cells (SCs) in the presence of elevated intracellular cAMP. Two mitogenic regions of MBP have been identified: one mitogenic region within the first 44 residues of the aminoterminus (1–44) and the other mitogenic region within the terminal 15 residues of the carboxyl end of the molecule (152–167). Unlike the mitogenic effect of a myelin enriched fraction (MEF), the mitogenic effect of MBP was not reduced by the addition of the lysosomal inhibitor, ammonium chloride. These data indicate that MBP causes SC proliferation by direct interaction of MBP with a surface receptor. Using Scatchard analysis of the binding of MBP to SCs, we report that treatment with forskolin does not cause the upregulation of receptors for MBP. Moreover, MBP blocks the cross-linking of 125I-bFGF with two fibroblast growth factor (FGF) receptors having apparent molecular weights of 140 kDa and 120 kDa, respectively. Since neither TGF-β nor PDGFBB displaced cell surface bound 125I-MBP, we conclude that MBP binds to the FGF receptor rather than other growth factor receptors. Furthermore, only MBP1–44 interacted with ganglioside GM1, whereas MBP152–167 did not interact with this ganglioside. These results are consistent with the view that ganglioside GM1 mediates the mitogenic effects of MBP1–44, while the FGF receptor mediates the mitogenic effect of MBP152–67. Intracellular cAMP of SCs was transiently increased after the addition of macrophage conditioned medium, suggesting that macrophages may produce factors in vivo which can transiently elevate intracellular cAMP levels, allowing a wave of SC proliferation in response to MBP-related mitogens. ©1995 Wiley-Liss, Inc.
HIV disease in primary care

During the past decade, a large number of new drugs for treating HIV and its complications have been developed. The increasingly sophisticated use of these drugs in combination has led to a marked reduction in HIV-related morbidity and mortality in countries where they are available. HIV/AIDS patients receiving treatment are now expected to live into old age. The beneficial effect of HIV treatment has resulted in an expanding population of persons living with HIV/AIDS who will need the care of an HIV specialist because of the complexity of the treatment regimens and the rapidly changing HIV/AIDS knowledge base. However, this growing and aging population will also benefit from the care of a primary care physician. The primary care generalist is in the best position to recognize and diagnose HIV infection, evaluate HIV risk in his or her patient population, and help prevent HIV infection in persons at risk. In patients known to be infected, the primary care generalist will be best able to manage hyperlipidemia, diabetes, cardiovascular disease, and other disorders of an aging population with an increased risk of these and other conditions. Patients with HIV infection frequently accumulate a large number of specialist physicians, and the unique ability of the primary care physician to monitor their care and act as a knowledgeable patient advocate is a great benefit to the patient.
Glider surveillance of physics and biology in the southern California Current System

Since 2005, Spray underwater gliders have been used to sample sections across the southern California Current System (CCS). Properties measured are depth-averaged velocity and profiles of temperature, salinity, Acoustic Doppler Profiler shear, chlorophyll a fluorescence, and 750-kHz acoustic backscatter. Although slow and carrying a relatively small sensor suite, gliders observed multiple 350-700-km sections that reveal details of known elements of the CCS circulation like the California Current and Undercurrent as well as a previously undescribed undercurrent 100-200 km offshore. The long time series with high spatial resolution disclose the close link between fronts in physical and biological variables, both the main pycnocline front and secondary weaker but sharp fronts farther offshore. These fronts appear to organize chlorophyll and acoustic backscatter fields, particularly during spring. Much of the patchiness of chlorophyll is associated with vertical displacements of fields that are much smoother within potential density surfaces. The horizontal structure of both chlorophyll and spice (the dynamically passive variable formed from temperature and salinity) appear to be formed by mesoscale stirring.
Atomic-Level Characterization of the Activation Mechanism of SERCA by Calcium

We have performed molecular dynamics (MD) simulations to elucidate, in atomic detail, the mechanism by which the sarcoplasmic reticulum Ca 2+ -ATPase (SERCA) is activated by Ca 2+ . Crystal structures suggest that activation of SERCA occurs when the cytoplasmic head-piece, in an open (E1) conformation stabilized by Ca 2+ , undergoes a large-scale open-to-closed (E1 to E2) transition that is induced by ATP binding. However, spectroscopic measurements in solution suggest that these structural states (E1 and E2) are not tightly coupled to biochemical states (defined by bound ligands); the closed E2 state predominates even in the absence of ATP, in both the presence and absence of Ca 2+ . How is this loose coupling consistent with the high efficiency of energy transduction in the Ca 2+ -ATPase? To provide insight into this question, we performed long (500 ns) all-atom MD simulations starting from the open crystal structure, including a lipid bilayer and water. In both the presence and absence of Ca 2+ , we observed a large-scale open-to-closed conformational transition within 400 ns, supporting the weak coupling between structural and biochemical states. However, upon closer inspection, it is clear that Ca 2+ is necessary and sufficient for SERCA to reach the precise geometrical arrangement necessary for activation of ATP hydrolysis. Contrary to suggestions from crystal structures, but in agreement with solution spectroscopy, the presence of ATP is not required for this activating transition. Principal component analysis showed that Ca 2+ reshapes the free energy landscape of SERCA to create a path between the open conformation and the activated closed conformation. Thus the malleability of the free energy landscape is essential for SERCA efficiency, ensuring that ATP hydrolysis is tightly coupled to Ca 2+ transport. These results demonstrate the importance of real-time dynamics in the formation of catalytically competent conformations of SERCA, with broad implications for understanding enzymatic catalysis in atomic detail.
Welcome to the Journal of Astronomical Telescopes, Instruments, and Systems

This PDF file contains the editorial “Welcome to the Journal of Astronomical Telescopes, Instruments, and Systems” for JATIS Vol. 1 Issue 01
Modeling the snow surface temperature with a one-layer energy balance snowmelt model

Abstract. Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach when they are integrated as part of a complete energy and mass balance snowmelt model. The force-restore and modified force-restore approaches have not been incorporated into the UEB in early versions, even though Luce and Tartoton have done work in calculating the energy components using these approaches. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and subnivean snow laboratory at Niwot Ridge, CO. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and internal energy content while still retaining a parsimonious one layer format.
K‐means clustering: A half‐century synthesis

This paper synthesizes the results, methodology, and research conducted concerning the K-means clustering method over the last fifty years. The K-means method is first introduced, various formulations of the minimum variance loss function and alternative loss functions within the same class are outlined, and different methods of choosing the number of clusters and initialization, variable preprocessing, and data reduction schemes are discussed. Theoretic statistical results are provided and various extensions of K-means using different metrics or modifications of the original algorithm are given, leading to a unifying treatment of K-means and some of its extensions. Finally, several future studies are outlined that could enhance the understanding of numerous subtleties affecting the performance of the K-means method.
Dark production of hydrogen peroxide in the Gulf of Alaska

Dark H2O2 production rates were measured in samples collected in the Gulf of Alaska. We used a simple, novel method for determining absolute rates of dark production and decay of H2O2, both of which are occurring simultaneously (presumably as a result of biological activity) in unfiltered samples. [H2O2] vs. time was measured in 24-h dark incubations of both unaltered samples and the same samples spiked with 100–250 nmol L21 H2O2. Data were modeled with zero-order H2O2 production rates and first-order H2O2 decay coefficients as fitting parameters, with the assumption that addition of [H2O2] to a sample does not change either parameter. H2O2 production rates ranged from , 0.5 nmol L21 h21 to 8 nmol L21 h21, and generally decreased with depth and decreasing chlorophyll. Comparison of dark production with estimates of average photochemical H2O2 production rates in the top 50 m of the water column indicated that dark production is likely to be a significant source of H2O2. Indeed, many of the unaltered incubations indicated that in situ [H2O2] was close to a steady state between dark production and decay, especially in samples from depths of $ 10 m. The reactive oxygen species hydrogen peroxide (H2O2) and superoxide (O { ) are intermediates formed during the sequential one-electron reduction of O2 to H2O. Thanks to recently developed techniques allowing direct detection of O { in marine water samples (Rose et al. 2008a,b), interest is growing in its role as a reductant or oxidant of redoxactive trace metals in the ocean. Reactions with H2O2 have also been suggested to be important to the marine redox cycling of Cu (Moffett and Zika 1987), Fe (Moffett and Zika 1987; Millero and Sotolongo 1989), Mn (Sunda and Huntsman 1994), and Cr (Pettine et al. 2008).
Donor-derived, tolerogenic dendritic cells suppress immune rejection in the indirect allosensitization-dominant setting of corneal transplantation

Significant interest has been focused on the use of ex vivo-manipulated DCs to optimally induce transplant tolerance and promote allograft survival. Although it is understood that donor-derived, tolerogenic DCs suppress the direct pathway of allosensitization, whether such DCs can similarly suppress the indirect pathway remains unclear. We therefore used the murine model of corneal transplantation to address this, as these allografts are rejected in an indirect pathway-dominant manner. Interestingly, recipients administered with donor bone marrow-derived DCregs, generated via culturing with GM-CSF, IL-10, and TGF-β1, significantly prolonged survival of corneal allografts. Correspondingly, these recipients demonstrated a potent reduction in the frequency of indirectly allosensitized T cells, as determined by ELISPOT. Examination of DCregs relative to mDCs or iDCs showed a resistance to up-regulation of MHC-II and costimulatory molecules, as well as an impaired capacity to stimulate MLRs. In vivo, DCreg administration in corneal-allografted recipients led to inhibition of CD4(+)IFN-γ(+) T cell frequencies and an associated increase in Foxp3 expression in the Treg compartment. We conclude that donor-derived, tolerogenic DCs significantly suppress the indirect pathway, thereby identifying a novel regulatory mechanism for these cells in transplantation.
Digital Storytelling: Conveying the Essence of a Face-to-Face Lecture in an Online Learning Environment.

As the percentage of university-level courses delivered online continues to increase, instructors who rely on storytelling approaches to convey key concepts in lecture-based coursework will likely face the need to translate their oral storytelling modules into one or more formats that are suitable for use in an online learning environment. While in simple cases it may be sufficient to supply text-based transcriptions of stories and narratives or straightforward “talking head” style videos to online learners, more elaborate storylines may require the application of advanced multimedia presentation technologies, often referred to as digital storytelling. In this paper, the selection and preparation of video-based digital storytelling learning modules is discussed in the context of meeting the self-directed learning preferences of students enrolled in a senior-level undergraduate leadership course. An example video produced on the topic of mentorship illustrates how the gap between personalized face-to-face storytelling in a lecture-based course and the less personal asynchronous learning in an online section of the same course may be bridged to maintain student comprehension of the key concepts involved.
Assessment of Steel and Fiber Reinforced Plastic Jackets for Seismic Retrofit of Reinforced Concrete Columns with Structural Flares

An analytical and experimental study of reinforced concrete flared bridge columns was conducted to determine an appropriate retrofit method for columns with inadequate shear capacity under earthquake loads. Four 0.3-scale models were tested on a shake table to failure, one representing as-built columns and the other three retrofitted with jackets, one with steel, one with a glass fiber reinforced plastic ~FRP!, and the third with a carbon FRP jacket. The jackets were designed to keep the plastic hinge away from the column end. A new lay up method was developed for FRP fabrics used on nonprismatic members. The results showed that all jackets improved the seismic performance. The effectiveness of the jackets was nearly the same for all materials. The method to estimate shear capacity based on the guidelines of the California Department of Transportation and a modified version of that method were found to closely estimate the shear capacity. However, the method in the Federal Highway Administration seismic retrofit manual overestimated the shear capacity and was unconservative.