cssi/SciSciGPT-SciSciNet huggingface dataset:
Diet therapy of peptic ulcer disease

Information from 326 dietitians representing 50 states and Puerto Rico on the diet therapy of peptic ulcer disease (PUD) in their hospitals was analyzed. There were 74 teaching, 65 teaching/private, 46 private, 120 Veterans Administration, and 21 miscellaneous hospitals. A bland diet was the most commonly used diet for PUD in 250 (77%) of the hospitals. Of the 161 providing information on the type of bland diet, 72% used a bland I or II. Milk was given routinely or usually in 55% of the 326 hospitals. On discharge, dietitians in one-half of the hospitals instructed patients on a bland diet, usually a bland IV, whereas the remaining dietitians instructed their patients on a regular or modified regular diet. Outpatient PUD instruction was similar. Review of bland diets in 105 manuals revealed marked variation in nomenclature and composition of even supposedly similar diets. Uniformity would benefit patients, dietitians, and physicians.
An application of the Gyárfás path argument

Abstract We adapt the Gyarfas path argument to prove that t − 2 cops can capture a robber, in at most t − 1 moves, in the game of Cops and Robbers played in a graph that does not contain the t -vertex path as an induced subgraph.
Regularity analyses and approximation of nonlocal variational equality and inequality problems

Abstract We consider linear and obstacle problems driven by a nonlocal integral operator, for which nonlocal interactions are restricted to a ball of finite radius. These types of operators are used to model anomalous diffusion and, for a special choice of the integral kernels, reduce to the fractional Laplace operator on a bounded domain. By means of a nonlocal vector calculus we recast the problems in a weak form, leading to corresponding nonlocal variational equality and inequality problems. We prove optimal regularity results for both problems, including a higher regularity of the solution and the Lagrange multiplier. Based on the regularity results, we analyze the convergence of finite element approximations for a linear problem and illustrate the theoretical findings by numerical results.
Cyclization of 1,1-Disubstituted Alkenes to Cyclopentenes

A general method for the cyclization of an unactivated 1,1-disubstituted alkene such as 1 to the corresponding cyclopentene 5 is described. Bromination followed by the addition of strong base in the same pot gave the vinyl bromide 3, which reacted further in situ to give the alkylidene carbene 4. This then inserted 1,5 into a C−H bond to give the cyclopentene 5.
Explicación de las variables que inciden en la evaluación financiera de proyectos en empresas de los distintos sectores industriales

A la hora de evaluar un proyecto las variables que se utilizan juegan un rol importante, depende de cada persona como interpretara aquello y como afectaran las decisiones. La presente investigacion busca explicar las variables que inciden en la evaluacion financiera de proyectos en empresas de los distintos sectores industriales, la cual se llevara a cabo mediante cuestionarios a empresas que tengan incorporada la evaluacion de proyectos en sus procesos. Con los resultados obtenidos se destaca que no todas las variables senaladas en la investigacion son siempre utilizadas para evaluar un proyecto, donde las principales en considerar son: la Demanda, la Oferta, la Tasa de Interes de Mercado, la Tasa de interes para proyecto, el Tipo de cambio y la Competencia.
Integrative Feature Ranking by Applying Deep Learning on Multi Source Genomic Data

Extracting cancer-related information from genomic data specially multi-source datasets has been an ever-growing challenge during the past years. The identification of subtype-specific genomic markers can lead to a sounder diagnosis and treatment. While several algorithms are proposed for feature extraction, to best of our knowledge, none of them consider between modality relations to discover modular disease associated biomarkers. In this paper, we represent an integrative deep learning approach to identify modular subtype-associated critical genes from three sets of input modalities for a better diagnosis of cancer subtypes. First, we train deep classifiers with different integration stages and distinct number of input modalities to predict cancer subtypes. Next, we use the optimized weight matrices of the classifier with the best performance to extract interactive top-ranked features among all input modalities. Lastly, we evaluate those ranks with other feature scoring methods according to their classification performance after feature extraction. Our results and analysis illustrate that the modular candidate biomarkers can be useful for cancer subtype detection.
Convex Optimization-based Controller Design for Stochastic Nonlinear Systems using Contraction Analysis

This paper presents an optimal feedback tracking controller for a class of Ito stochastic nonlinear systems, the design of which involves recasting a nonlinear system equation into a convex combination of multiple non-unique State-Dependent Coefficient (SDC) models. Its feedback gain and controller parameters are found by solving a convex optimization problem to minimize an upper bound of the steady-state tracking error. Multiple SDC parametrizations are utilized to provide a design flexibility to mitigate the effects of stochastic noise and to ensure that the system is controllable. Incremental stability of this controller is studied using stochastic contraction analysis and it is proven that the controlled trajectory exponentially converges to the desired trajectory with a non-vanishing error due to the linear matrix inequality state-dependent algebraic Riccati equation constraint. A discrete-time version of stochastic contraction analysis with respect to a state- and time-dependent metric is also presented in this paper. A simulation is performed to show the superiority of the proposed optimal feedback controller compared to a known exponentially-stabilizing nonlinear controller and a PID controller.
Micromotors for Active Delivery of Minerals toward the Treatment of Iron Deficiency Anemia

As the most common nutritional disorder, iron deficiency represents a major public health problem with broad impacts on physical and mental development. However, treatment is often compromised by low iron bioavailability and undesired side effects. Here, we report on the development of active mineral delivery vehicles using Mg-based micromotors, which can autonomously propel in gastrointestinal fluids, aiding in the dynamic delivery of minerals. Iron and selenium are combined as a model mineral payload in the micromotor platform. We demonstrate the ability of our mineral-loaded micromotors to replenish iron and selenium stores in an anemic mouse model after 30 days of treatment, normalizing hematological parameters such as red blood count, hemoglobin, and hematocrit. Additionally, the micromotor platform exhibits no toxicity after the treatment regimen. This proof-of-concept study indicates that micromotor-based active delivery of mineral supplements represents an attractive approach toward alleviating nutritional deficiencies.
Measuring economic freedom: an alternative functional specification and subsequent ranking

ABSTRACTThe widely cited Economic Freedom of the World index is an aggregate measure of economic freedom calculated by using a simple arithmetic mean of scores over five sub-dimensions: (1) size of...
Cumulative Violence and PTSD Symptom Severity Among Urban Street-Based Female Sex Workers:

Female sex workers (FSW) are a marginalized and vulnerable population at high risk of gender-based violence within and outside of their occupation. However, FSW remain underrepresented in the trauma and mental health literature. The aims of this study were to (a) characterize exposure to violence among street-based FSW, including violence type, patterns over the life course, and key perpetrator groups, and (b) examine the multivariate associations between posttraumatic stress disorder (PTSD) symptom severity and two constructs (revictimization across life stages and cumulative violence). Data were drawn from the Sex Workers and Police Promoting Health in Risky Environments (SAPPHIRE) study, an observational community-based cohort of street-based FSW recruited through targeted sampling across Baltimore, Maryland (USA) in 2016 to 2017. PTSD symptom severity was measured using the PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (PCL-5). At baseline, 61% of FSW screened positive for PTSD symptoms. The mean PCL-5 score was 38.6. We documented extensive histories of sexual and physical violence (lifetime: 81.8%; childhood and adult revictimization: 15.0% for sexual and 37.7% for physical). The vast majority of perpetrators were male and included paying clients, police officers, family members, and intimate partners. Exposure to childhood and adult sexual violence were independently associated with higher PTSD severity (p < .05), with marginal associations observed for physical violence. Data supported a cumulative violence model of PTSD severity (p < .05). Binge drinking also appeared to be a contributing factor (p < .05). The levels of PTSD observed among our sample were comparable with that reported among treatment-seeking war veterans. Our findings underscore the urgent need for tailored trauma-informed interventions and policies to address violence among urban street-based FSW, a population experiencing extremely high levels of violence, PTSD, and substance use.
Defeat the Peak: Behavioral insights for electricity demand response program design

Abstract Electric utilities and regulators primarily rely on rate design strategies and economic incentives to achieve customer load malleability at the residential level. However, demand-side management strategies are broadening to incorporate new motivational cues based on pro-social impulses to reduce negative environmental impact and contribute meaningfully to local communities. This evolving relationship between residential customers and utilities is explored to better understand the potential for load malleability achieved through non-economic incentive structures and rate design. Following a review of interdisciplinary perspectives on pro-social behavior and utility demand-side management strategies, we analyze the impact of a pro-social demand response program on the energy use of over 16,000 households served by a municipally owned electric utility in Burlington, Vermont, USA. Results indicate that the program achieved a 13.5% decrease in energy use during the peak annual event in August 2018 with a return on investment of 11 to 1 for the distribution utility. This study builds on the work of other researchers studying individual energy behavior change and supports the argument that pro-social incentives can improve the effectiveness of demand response programs.
Comparing Patient-reported Outcomes to Patient Satisfaction After a Microdiscectomy for Patient's With a Lumbar Disk Herniation.

STUDY DESIGN A retrospective cohort study. OBJECTIVE The objective of this study was to determine if patient satisfaction is predicted by improvement in health-related quality of life (HRQOL) metrics. SUMMARY OF BACKGROUND DATA Patient satisfaction is becoming an increasingly common proxy for treatment quality; however, the correlation between patient satisfaction and HRQOL outcome metrics following a lumbar disk herniation is unclear. METHODS Patients enrolled in the Spine Patient Outcomes Research Trial (SPORT) study were prospectively enrolled at 13 institutions. A retrospective subgroup analysis of prospectively collected data from the SPORT trial was performed. Receiver operating characteristic curves were used to determine if improvement in HRQOL metrics could accurately identify patient satisfaction. HRQOL metrics included: Short Form-36 (SF-36), Oswestry Disability Index (ODI), Sciatica Bothersomeness Index, Back Pain Bothersomeness Scale, and Leg Pain Bothersomeness Scale. RESULTS A total of 709 patients who underwent surgery and 319 patients treated without surgery were included. In the surgical cohort, receiver operating characteristic curve analysis demonstrated that SF-36 Physical Component Summary improvement had moderate accuracy [area under the curve (AUC)=0.77 (95% confidence interval, CI: 0.73-0.82)] at predicting satisfaction at 3 months, and it had excellent accuracy at predicting satisfaction at 2 years [AUC=0.81 (95% CI: 0.77-0.85)] and 4 years [AUC=0.81 (95% CI: 0.76-0.85)]. Absolute Physical Component Summary score had excellent accuracy at 3 months [AUC=0.83 (95% CI: 0.79-0.87)], 2 years [AUC=0.87 (95% CI: 0.84-0.9)] and 4 years [AUC=0.84 (95% CI: 0.8-0.89)]. Similarly improvement in the ODI had moderate accuracy of predicting satisfaction at 3 months [AUC=0.77 (95% CI: 0.72-0.81)], 2 years [AUC=0.78 (95% CI: 0.74-0.82)] and 4 years [AUC=0.78 (95% CI: 0.73-0.83)], and the absolute ODI score had excellent accuracy at 3 months [AUC=0.85 (95% CI: 0.82-0.89)], 2 years [AUC=0.89 (95% CI: 0.86-0.92)], and 4 years [AUC=0.88 (95% CI: 0.85-0.92)]. CONCLUSIONS HRQOL metrics can accurately predict patient satisfaction with symptoms at 3 months, 2 years, and 4 years after surgical intervention for a lumbar disk herniation. Absolute outcome scores were somewhat more predictive than change scores.
Causes of Cancer Re-Admissions: A Patient-Centered Approach

PURPOSE:Patients with a cancer diagnosis have a high risk of re-admission during the 30 days after discharge. Clinicians, payers, and patients consider this to be an indicator of care quality. The ...
Parent TRAP: Discriminating Infant Cries Requires a Higher-Order Auditory Association Area in Mice.

A circuit understanding of how perception links to response requires integrating neural connectivity, activity, and behavior. In this issue of Neuron, Tasaka et al. (2020) target neurons activated by ultrasonic pup vocalizations and discover a functional synaptic network embedded through acoustically selective TeA neurons that help link the calls to a discriminative maternal behavioral response.
Explaining neural network predictions of acoustic fields in ideal single- and multi-path environments

Neural networks are an increasingly popular tool for solving a wide variety of problems. Given some up-front computational effort, the complex patterns which exist in large datasets can be embedded in an explicit, though difficult to interpret, neural-network ‘formula’ for future predictions. As reliance on neural networks increases, so does the demand for their explainability, since practitioners must create safe and unbiased methods. In this presentation, an effort is made to better explain and understand neural networks which are trained to provide solutions to the point-source Helmholtz-equation in axisymmetric single-path, two-path, and multi-path (ideal waveguide) environments having constant sound speed. This analysis emphasizes source frequencies in the 100s of Hz, depths up to 500 m, and ranges up to 1 km for sound speeds near 1500 m/s. In all cases, the neural networks' intermediate computational values are compared to those of the corresponding analytical Helmholtz-equation solution used to generate the neural networks' training dataset. The effects of the choice of neural network inputs, noise-like inputs, and correlated input features are also considered. The insights developed from this investigation provide insights for the extension of neural network predictions of acoustic fields to more complex environments. [Work supported by the NDSEG fellowship program.]
The Two Appointments Clauses: Statutory Qualifications for Federal Officers

Congress often exercises control over appointments to federal office by writing job qualifications and putting them directly into the statute creating the office. This practice is best examined by viewing the Appointments Clause not as a single entity, but as two related clauses that set up two very different methods of appointment: presidential nomination and Senate confirmation as the default method, and vesting in one of three authorized positions as an optional alternative method for certain types of officers. When creating an office, Congress must choose one of these methods for appointing the officer, but cannot create a hybrid method combining the two procedures. In this article, I examine the text, history, and structure of the Constitution to determine what is required by each of the two appointments processes. I conclude that statutory qualifications are consistent with the Constitution's process for vested appointments, but inconsistent with the nomination and confirmation process.
Technology transfer analysis in the Italian National Research Council

Abstract This paper analyses the technology transfer (t.t.) in the nine Cnr research Institutes located in Piedmont, a highly industrialised region of the north-west of Italy. Some taxonomic criterions are used for classifying the t.t. In particularly we have two main types of actions from research structures: (A) Market-oriented technology transfer split into: strict sense and wide sense of the term. (B) Education-oriented technology transfer (training and teaching activities i.e. not generated ‘financial revenues’). It is measured using physical quantities (for example, number of subjects, number of contacts, etc.). The correlation of outcomes shows that, if we consider as value of t.t. activity the ‘financial revenues’ (market-oriented technological transfer), the best Institutes are those operating in the technological area; instead, if we use, as indicator of t.t. activity, the number of external courses and the number of personnel trained (education-oriented technological transfer), the ranking changes to favour non-technological research institutes. Moreover, spatial dynamics of technology transfer are investigated; in particular, we verified whether the propagation of technology follows the Hagerstrand proximity-effect and finally the causes when these effects do not function.
A Potential Package for Organic Chemistry Remote Teaching

The pandemic has brought both challenges and opportunities to all universities across the globe. Every challenge will open the door for new opportunities. As the world was fighting against the global pandemic, all universities were transitioned online over a short period without any prior preparation. Over time as an instructor, I shape myself for combating the situation. Utilizing Zoom, whiteboard, molecular model, videos, ChemDraw, Respondus, LockDown Browser, blackboard, mandated attendance, interactive class, and office hour, this instructor was able to facilitate the learning process compatible with the face-to-face model. Laboratory was the blend of lab manuals, lab videos, and simulation experiments. Prelab, quiz, and report were prepared based on the lab manual and lab video. Similarly, simulation experiments were conducted for each lab via Beyond Labz which helped to connect the lecture with the techniques of the laboratory. In fall 2020, a survey was conducted on sixty students representing different organic chemistry lectures (CHEM 2311) and laboratories (CHEM 2111) at the University of the Incarnate Word, San Antonio, Texas. The outcome of the survey revealed that live synchronous with mandated attendance and office hour fulfills the expectations of the students as well as the standards of the course. This instructor’s perspective also aligned with the outcome of the students’ thoughts. The preferred response for live synchronous is almost half of the total so it is equally beneficial, provides full expectation, and almost as effective as face to face.
Analysis and Control of Critical Conduction Mode High-Frequency Single-Phase Transformerless PV Inverter

This article presents a critical conduction mode (CRM) single-phase transformerless full-bridge inverter in a residential photovoltaic system. The CRM full-bridge inverter in bipolar mode features zero-voltage switching capability for the whole line cycle. This enables the inverter to push switching frequency up to hundreds of kHz and achieve high power density with high efficiency. However, CRM operation incurs nonconstant common mode (CM) voltage during the resonant period, causing high frequency leakage current. To minimize the leakage current, a new switching modulation strategy is proposed introducing triangular current mode (TCM) near the ac voltage zero crossing. The switching modulation scheme alleviates the CM voltage by shortening the resonant period and consequently reduces the leakage current. Then, discontinuous conduction mode is inserted between the CRM and TCM operation regions to improve light load efficiency. In this article, the basic operation principle of the CRM full-bridge inverter, impacts of CRM operation on the leakage current, and details of the proposed switching modulation method are discussed. Experimental results with a 2.4-kW prototype built with GaN devices validate its performance.
Climate Rationality: From Bias to Balance

Most environmental statutes passed since 1970 have endorsed a pragmatic or 'precautionary' principle under which the existence of a significant risk is enough to trigger regulation. At the same time, targets of such regulation have often argued on grounds of inefficiency that the associated costs outweigh any potential benefits. In this work, Jason Johnston unpacks and critiques the legal, economic, and scientific basis for precautionary climate policies pursued in the United States and in doing so sheds light on why the global warming policy debate has become increasingly bitter and disconnected from both climate science and economics. Johnston analyzes the most influential international climate science assessment organizations, the US electric power industry, and land management and renewable energy policies. Bridging sound economics and climate science, this pathbreaking book shows how the United States can efficiently adapt to a changing climate while radically reducing greenhouse gas emissions.
Effects of the Mindfulness-Based Blood Pressure Reduction (MB-BP) Program on Depression and Neural Structural Connectivity

Abstract Hypertension-related illnesses are a leading cause of disability and death in the United States, where 46% of adults have hypertension and only half have it controlled. It is critical to reduce hypertension, and either new classes of interventions are required, or we need to develop enhanced approaches to improve medical regimen adherence. The Mindfulness-Based Blood Pressure Reduction program (MB-BP) is showing novel mechanisms and early evidence of efficacy, but the neural correlates are unknown. The objectives of this study were to identify structural neural correlates of MB-BP using diffusion tensor magnetic resonance imaging (DTI) and assess potential correlations with key clinical outcomes. In a subset of participants from a larger randomized controlled trial, MB-BP participants exhibited increased interoception and decreased depressive symptoms compared to controls. Analyses of DTI data revealed significant group differences in several white matter neural tracts associated with the limbic system and/or hypertension. Specific changes in neural structural connectivity were significantly associated with measures of blood pressure, depression anxiety and symptoms, mindfulness, and emotional regulation. It is concluded that MB-BP has extensive and substantial effects on brain structural connectivity which could mediate beneficial changes in depression, interoceptive awareness, blood pressure, and related measures in individuals with hypertension.
Structure and RNA template requirements of Arabidopsis RNA-DEPENDENT RNA POLYMERASE 2

Abstract RNA-dependent RNA polymerases play essential roles in RNA-mediated gene silencing in eukaryotes. In Arabidopsis, RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) physically interacts with DNA-dependent NUCLEAR RNA POLYMERASE IV (Pol IV) and their activities are tightly coupled, with Pol IV transcriptional arrest or termination, involving the nontemplate DNA strand, somehow enabling RDR2 to engage Pol IV transcripts and generate double-stranded RNAs. The dsRNAs are then released from the Pol IV-RDR2 complex and diced into siRNAs that guide RNA-directed DNA methylation and silencing. Here we report the structure of full-length RDR2, at an overall resolution of 3.1 A, determined by cryo-electron microscopy. The N-terminal region contains an RNA-recognition motif (RRM) adjacent to a positively charged channel that leads to a catalytic center with striking structural homology to the catalytic centers of multisubunit DNA-dependent RNA polymerases. We show that RDR2 initiates 1-2 nucleotides (nt) internal to the 3’ ends of its templates and can transcribe the RNA of an RNA-DNA hybrid provided that 9 or more nucleotides at the RNA’s 3’ end is unpaired. Using a nucleic acid configuration that mimics the arrangement of RNA and DNA strands upon Pol IV transcriptional arrest, we show that displacement of the RNA 3’ end occurs as the DNA template and non-template strands reanneal, enabling RDR2 transcription. These results suggest a model in which Pol IV arrest and backtracking displaces the RNA 3’ end as the DNA strands reanneal, allowing RDR2 to engage the RNA and transcribe the second strand. Significance RDR2 is critical for siRNA-directed DNA methylation in Arabidopsis, functioning in physical association with DNA-dependent Pol IV to synthesize the second strands of double-stranded siRNA precursors. Basepairing between the DNA template strand transcribed by Pol IV and the nontemplate DNA strand is known to induce Pol IV arrest and Pol IV-RDR2 transcriptional coupling, but how this occurs is unknown. We report the structure of RDR2 and experimental evidence for how RDR2 engages its RNA templates and initiates transcription. RDR2 engages the ends of RNAs displaced from RNA-DNA hybrids, suggesting a model in which Pol IV arrest and backtracking, accompanied by DNA strand reannealing, extrudes the 3’ end of the Pol IV transcript, allowing RNA engagement and second-strand synthesis.
Citizen Scientists: Student Experiences in the GTP Georgia/Russian Exchange Project

During the past two years, the Global Thinking Project, through grants from the United States Information Agency, facilitated student and educator exchanges among 10 schools in Georgia (USA) and Russia. This paper describes the results of the experience during the 1995–1996 school year. One hundred students lived in each others' homes for two three-week periods, participated in environmental research activities in American and Russian communities, and lived in the context of each others culture. Students were helped by their teachers to construct ideas about environmental topics outlined in the curriculum of the Global Thinking Project (http://www.gsu.edu/~wwwgtp/gtp.html). Students and teachers were involved in two episodes of problem identification, data collection and analysis at five sites in each country, and two “Global Environmental Summits” in Moscow and Atlanta. The students activity is described as that of a “citizen scientist”—one who combines the process of science with public policy decision making.
Interactions of acridine orange with nucleic acids: Properties of complexes of acridine orange with single stranded ribonucleic acid

Interactions between acridine orange (AO) and nucleic acids (calf thymus DNA, and homoribo- and homodeoxyribo-polynucleotides) were studied in solutions containing ethanol as a cosolvent. Light absorption, scattering and luminescence were measured as a function of AO concentration at different dye/phosphate (D/P) ratios, and the data were analyzed using the McGhee-von Hippel probabilistic model of the polymer-ligand interactions. The absorption spectra of AO complexes with four homoribopolymers are presented. The intrinsic association constants and cooperativity coefficients of the formation of the complexes were calculated. The effects of ethanol (up to 35%, v/v) on these interactions were concentration dependent and may be extrapolated to zero concentration of this cosolvent. The possibility of destabilization of the double helix of nucleic acids by AO at high D/P ratios is discussed in light of the available thermodynamic data.
Signals in eukaryotic DNA promote and influence formation of nucleosome arrays.

Publisher Summary This chapter reviews the current information available on nucleosome-array formation, discusses the implications of different models, and presents some speculative new ideas concerning the genomic organization of chromatin. One of the hallmarks of chromatin structure is the periodic arrays of nucleosomes revealed in the electron micrographs of chromatin spread at low ionic strength, or by the ladders of bands in gels following micrococcal nuclease digestion and electrophoresis of the purified fragmented DNA. The periodic nucleosome arrays must in some way reflect or influence the higher order chromatin structures in which they reside, even though they persist when the higher order structure of chromatin is unfolded, because of the very tight association of core histone octamers with DNA. In turn, the higher order structures of chromatin are thought to be responsible both for organizing the folding of DNA in chromosomes and, in cooperation with transcription factors, for regulating access to the genetic material in a cell-type specific way. There are technical difficulties in examining the chromatin structures of single-copy DNA sequences in higher cells by Southern hybridization. Signals are weak, necessitating the application of large amounts of genomic DNA to gel lanes, which can affect band resolution and DNA fragment mobility and long exposure times are required that can lead to high background signals.
Regional Cerebral Blood Flow After Cortical Impact Injury Complicated by a Secondary Insult in Rats

Background and Purpose —Traumatic injury makes the brain susceptible to secondary insults. An uncomplicated mild lateral cortical impact injury (3 m/s, 2.5-mm deformation) that causes little or no permanent sequelae results in a large contusion at the impact site when the traumatic injury is complicated by a secondary insult, such as 40 minutes of bilateral carotid occlusion. Methods —To determine whether the increased sensitivity to secondary insults in this model is caused by a vascular mechanism, cerebral blood flow (CBF) was measured with 14C-isopropyliodoamphetamine quantitative autoradiography, and brain tissue Po2 (Pbto2) was measured at the impact site and in the contralateral parietal cortex. Results —In animals that underwent bilateral carotid occlusion 1 hour after the impact injury, CBF and Pbto2 were lower at the impact site than they were in animals that had either the impact injury or the carotid occlusion alone. In the immediate area of the impact, CBF was 14±6 mL · 100 g−1 · min−1 in the animals with the impact injury followed by carotid occlusion compared with 53±24 mL · 100 g−1 · min−1 in the animals with the impact injury alone and 74±14 mL · 100 g−1 · min−1 in the animals with the carotid occlusion alone ( P <0.001). At the time of this very low CBF value in the animals with the carotid occlusion after the impact injury, Pbto2 at the impact site averaged 1.3±1.6 mm Hg and was <3 mm Hg in 5 of the 6 animals. In contrast, Pbto2 in the animals with the impact injury alone averaged 9.3±2.9 mm Hg, and none of the animals had a Pbto2 of <3 mm Hg ( P =0.008). Conclusions —The CBF and Pbto2 findings in this model suggest that the reduced CBF after traumatic injury predisposes the brain to secondary insults and results in ischemia when confronted with a reduction in cerebral perfusion pressure.
Wind-tunnel investigation of the low-speed aerodynamics of slender accelerator-type configurations

The NASA-Langley 14x22-ft subsonic wind tunnel has been used to ascertain the low speed aerodynamics of a conical-forebody/annular conformal propulsion system/truncated conical afterbody hypersonic-accelerator configuration with delta-planform wing. Six-component force-and-moment data were obtained over the -4 to +30 deg alpha range and + or - 20 deg sideslip. Flow visualization diagnostics were used to characterize configuration aerodynamics. Vortex flows from the conical forebody created large values of local inflow angles at the engine inlet locations on the lee side of the model, at the moderate-alpha values associated with takeoff and landing.
A Note on the Use of Marketing Research by Small Businesses

There is no question that timely and accurate information is as valuable to small business decision makers as it is to decision makers in large organizations. Interestingly though, evidence exists that small businesses make little use of (Oumlil, 1989; Hall, Anglin, and Elliott, 1997; McDaniel and Parasuraman, 1986), and place limited value on (Brush, 1992; Callahan and Cassar, 1995), marketing research -- the very discipline capable of providing this valuable information.
Photon echoes from the absorption continuum of a semiconductor

The theory of photon echoes has been intensively investigated for interaction-free particles since 1979.1 Numerical calculations for semiconductors, excited at or below the band edge, have been reported.2 However, a very important configuration for ultrashort-pulse experiments corresponds to excitation in the continuum or simultaneous excitation of bound and continuum states, as shown in Fig. 1. To the best of our knowledge, this configuration has never been studied theoretically, despite the fact that one can expect marked differences between the responses of bound and continuum states.
Optical design of the large sub-millimeter Atacama telescope, LSAT

The study of the evolution of the early universe, when the first galaxies began to form, is one of the driving factors in the development of large infrared and sub-millimeter telescopes. The large sub-millimeter Atacama telescope (LSAT) is the result of a collaborative effort between Cornell University and the California Institute of Technology (Caltech) to develop a conceptual design of a 25-meter class sub-mm telescope that will operate primarily in the far-infrared/sub-millimeter (FIR/sub-mm) spectral regime, from 350 GHz up to 1.5 THz (/spl lambda/>200 /spl mu/m), at a high, dry site in the Atacama region of northern Chile, at an altitude of more than 5,000 meters. LSAT, with larger field of view and large format focal plane arrays, will have mapping speeds up to 2,500 times those of ALMA (Atacama large millimeter array), 2 arc-sec resolution at shortest wavelengths, point-source sensitivities at least 20 times better than any planned sub-mm facility and confusion 10 times lower than any existing single-aperture telescope. The paper discusses the telescope's reflector optics.
Contending with the “Double Handicap”: Political Activism Among Women with Disabilities

Abstract To what extent do women with disabilities experience a “double handicap,” and how do the economic and social disparities they face affect political activism? This paper analyzes these disparities and political activism among women and men with and without disabilities using data from national household surveys conducted in 1998 and 2000. Women with disabilities have particularly low employment and income levels, and lower self-evaluations of civic skills and internal political efficacy, but are similar to men with disabilities in educational attainment and psychological well-being. Their overall political participation is lower than that of men and women without disabilities, which is primarily explained by lower employment and income levels and greater social isolation. They are less likely than men with disabilities to participate in several political activities, but equally likely to take action on disability issues and more likely to participate in protests and take action against perceived d...
Genetic Algorithms for Minimal Fuel Consumption of Electric Propulsion Space Vehicles

This paper demonstrates the utility of genetic algorithms (GAs) to determine a near optimal control strategy for electric propulsion systems. The various strategies implemented are simple GA, simple GA with elitism and micro GA. The accuracy and performance of the control strategy obtained using these methods are discussed along with their detailed description. This work inherently validates the use of ionic thrust for deep space missions
Transcription, one allele at a time

A recent study presents a technique allowing one to image transcription from a single gene copy in live cells, and highlights the dynamic nature of transcriptional regulation.
Acoustic frequency discrimination in the goldfish.

Abstract The capacity of the goldfish (Carassius auratus) to discriminate between two acoustic frequencies was tested by means of avoidance conditioning techniques. The pulsed-tone method was used in which the subject had to discriminate between a pulsed single frequency and pulses of two frequencies in alternation. Sound pressure levels were kept at 0 dB re 1 μb. This is equivalent to a sensation level of 40 to 45 dB at the frequencies used. Discrimination limens (JND) were determined by the staircase audiometric method. At 200 Hz, the mean JND was 9-4 Hz (4·7 per cent difference); at 500 Hz, the mean JND was 17·4 Hz (3·5 per cent difference); and at 1000 Hz, the mean JND was 50·1 Hz (5·0 per cent difference). The JND at 500 Hz was significantly lower than at the other two frequencies tested. The standard frequencies covered the most sensitive hearing range of this species. Comparison with human frequency discrimination showed that the goldfish JND was an order of magnitude greater. The problem of the mechanism of frequency analysis in fish was discussed.
What does mathematical modeling tell us about harm reduction

This paper argues, primarily by example, that mathematical modeling can contribute to harm reduction-orientated drug policy making in three ways: by contributing to quantitative evaluations of effectiveness, by improving data and understanding of the underlying drug-related phenomena, and by encouraging precise thinking about the goals and objectives of harm reduction.
Magnetic resonance studies of the mitochondrial divalent cation carrier

Measurements of water proton spin relaxation enhancements (epsilon) can be used to discriminate high-affinity binding of Mn-2+ or Gd-3+ to biological membranes, from low-affinity binding. In rat liver mitochondria, epsilon b values of approx. 11 are observed upon binding of Mn-2+ to the inner membrane, while internal or low-affinity binding remains invisible to this technique. Energy-driven Mn-2+ uptake by liver mitochondria results in the subsequent decay of epsilon. Comparison of epsilon with the initial velocity of Mn-2+ uptake in rat liver mitochondria reveals a linear correlation, which holds at all temperatures between 0 degrees C and 40 degrees C, regardless of the mitochondrial protein concentration. Consequently, enhancement appears to reflect the binding of Mn-2+ to the divalent cation pump. Binding of Mn-2+ to blowfly flight muscle also results in substantial epsilon, which is associated with the glycerol-1-phosphate dehydrogenase instead of divalent cation transport. Consequently, no decay in epsilon due to uptake occurs after Mn-2+ is bound. Lanthanide ions are also bound and transported by mitochondria. Addition of Gd-3+ to pigeon heart or rat liver mitochondria results in epsilon b approximately equal to 5-6, which decays with similar kinetics in both systems. The uptake velocity of Gd-3+ in rat liver mitochondria is about 1/6 the rate with which Mn-2+ is transported. Lanthanides also diminish epsilon due to the addition of Mn-2+, and greatly retard the Mn-2+ uptake kinetics. The presence of carbonylcyanide-p-trifluoromethoxyphenylhydrazone depresses epsilon upon addition of Mn-2+ or Gd-3+ and also uncouples energy-driven uptake. On the other hand, prolonged anaerobic incubation in the presence of antimycin and rotenone exhausts the mitochondria of their energy stores, blocks the uptake of Mn-2+, but does not affect epsilon significantly. Evidently, the uncoupler-induced disappearance of divalent cation binding sites is not the result of "de-energization". Measurements of epsilon at several NMR frequencies indicate a correlation time (tau b) for carrier-bound Mn-2+ in rat liver mitochondria between 20 ns and 4 ns as one varies the temperature between 10 degrees C and 30 degrees C. The 13 Kcal/mole activation energy for tau b suggests that the 11 ns time constant at room temperature represents the movement of the Mn-11-carrier comples. On the other hand, tau b is probably approx. 100 times too short to represent the rotational motion of a carrier protein. Apparently, Mn-2+ binds to a small arm of the carrier which moves independent
The phylogeny of Xantusiid lizards: The concern for analysis in the search for a best estimate of phylogeny

In the onrush of molecular-based phylogenetic hypotheses, previous morphological-based phylogenies are being ignored, discarded, or even treated with disdain. Coupled with this implicit superiority of molecular data is the sometimes tendency to construct a phylogeny from the molecular data with less than analytical rigor. This paper examines the phylogenetic relationships within the lizard family Xantusiidae employing both molecular and morphological data. The analysis focuses on four analytical points of the molecular data and on the phylogenetics synthesis of the two data sets. We conclude that the phylogeny of xantusiid lizards is not yet a robust hypothesis.
Simulator evaluation of green and flashing amber signal phasing

A research study conducted to evaluate the efficacy of flashing amber signal phasing is reported. Flashing amber, which is set to overlap with the green indication a few seconds before the onset of solid amber, is a form of time reference aid used to warn drivers of an impending onset of amber. The time reference aid is a concept predicated on the principle that driver decisions will be easier and more predictable if drivers have advance information that allows them to predict the onset of amber. The evaluation of the flashing amber method showed that its implementation has the potential to reduce red-light violations, severity of maximum decelerations, and kinematically defined inappropriate stop or cross decisions. However, the data also showed that compared with the regular signal phasing, the flashing amber phasing increased the size of the indecision zone, a mechanism usually responsible for increased rear-end collisions. A measure not previously used in literature was introduced to compare the regular and the experimental signal phasing. This measure, which analyzes first-response time variability in relation to the indecision zone, predicted that increased rear-end collisions might be expected as a result of implementation of the flashing amber signal phasing. Generally, the results suggest that the implementation of a flashing amber signal phasing would not significantly increase intersection safety despite the notion that it would improve driver anticipation of the onset of solid amber.
Glutathione peroxidase activity in selenium-deficient rat liver☆

Abstract Glutathione peroxidase activity in the liver supernatant from rats fed a Se-deficient diet for 2 weeks was 8% of control when measured with H 2 O 2 but 42% of control when assayed with cumene hydroperoxide. Two peaks of glutathione peroxidase activity were present in the Sephadex G-150 gel filtration chromatogram of rat liver supernatant when 1.5 mM cumene hydroperoxide was used as substrate. Only the first peak was detected when 0.25 mM H 2 O 2 was used as substrate. The first peak was absent from chromatograms of Se-deficient rat liver supernatants; but the second peak, which eluted at a position corresponding to M.W. = 39,000, appeared unchanged. The second peak thus represents a second glutathione peroxidase activity which catalyzes the destruction of organic hydroperoxides but has little activity toward H 2 O 2 and which persists in severe selenium deficiency.
Estrus-associated decrements in a water maze task are limited to acquisition.

Abstract To ascertain whether gonadal hormones have activational influences on spatial ability, the relationship between estrous cycle, sex differences and water maze performance was examined in two studies. In the first study, the performance of females at different cycle phases was compared within females and to that of males. All animals were naive to the task. Similar to other studies, females had longer latencies and distances to reach the water maze platform than males. This sex difference was statistically significant only in comparisons of estrous females and males, not in comparisons of diestrous females and males. To determine whether estrus-associated decrements in acquisition of the water maze task extended to postacquisition performance, a second study assessed performance of ovariectomized rats—trained to criterion in the task—whose cycle phases were mimicked by exogenous hormones. In the initial trial, “estrous” animals had longer latencies to reach the platform than “diestrous” and ovariectomized animals. In subsequent trials, no hormone-dependent differences in performance were observed. Taken together, the results indicate a modest association between phase of estrous cycle, acquisition, and postacquisition performance when the task is novel. These findings suggest estrus-associated decrements in acquisition may account for previous discrepancies among studies of sex differences in spatial ability.
Gene Therapy in Patient-specific Stem Cell Lines and a Preclinical Model of Retinitis Pigmentosa With Membrane Frizzled-related Protein Defects

Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naive human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrprd6/Mfrprd6 mice—an established preclinical model of RP—and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrprd6/Mfrprd6 preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials.
The Relationship between Civic Behavior and Civic Values: A Conceptual Model

This study examined the relationships among college students’ civic values and behaviors, college culture, and college involvement, accounting for their pre-college inclinations toward civic responsibility. Using a longitudinal, national dataset comprised of 3,680 college students, the study employed structural equation modeling to identify a model that suggests social activism goals mediate the relationship between co-curricular engagement and charitable involvement behaviors.
Two case reports of Clostridium difficile bacteremia, one with the epidemic NAP-1 strain

Clostridium difficile bacteremia is rare. Here, we report two cases of C. difficile bacteremia in patients with significant underlying gastrointestinal pathology. In one case, the bacteremia was caused by the North American pulsed-field gel electrophoresis (PFGE) type 1 (NAP-1) strain, which is responsible for recent outbreaks of C. difficile infections of increased severity.