cssi/SciSciGPT-SciSciNet huggingface dataset:
Do Older Adults Who Meet 2008 Physical Activity Guidelines Have Better Physical Performance Than Those Who Do Not Meet

An observed consequence of aging is a decline in muscle performance that includes a loss in both muscle strength and muscle power. This decline can lead to loss of function and independence and is a predictor of disability in older adults. Although the 2008 Physical Activity (PA) Guidelines for Americans provides a guideline for muscle strengthening, there is no evidence that performing muscle strengthening 2 times a week for all major muscle groups is related to better performance on measures known to be important factors in development or progression of frailty in older adults. The purposes of this study were to assess muscle-strengthening and aerobic PA behaviors in older adults and to determine the relationship between the PA behaviors and physical performance measures. This was a cross-sectional study of 85 community-dwelling, ambulatory adults (50 women, 35 men) with a mean (standard deviation) age of 67.5 (5.6) years. All used an internet-based survey, TREST (Tracking Resistance Exercise and Strength Training), to report muscle-strengthening and aerobic PA behavior. Physical performance measures of grip strength, 10-m walk test (10-MWT), five-time sit-to-stand test (FTSST), and stair climb test (SCT) were obtained following completion of the survey. Participants were grouped by whether they met 2008 PA Guidelines for (1) muscle strengthening 2 or more days per week, (2) muscle strengthening 2 or more days per week using all major muscle groups, or (3) 150 minutes or more per week of aerobic moderate to vigorous physical activity. Comparisons of physical performance measures were conducted between participants who met and did not meet guidelines using multivariate analyses. Significant multivariate results were followed with one-tailed t tests. The participants meeting muscle strengthening 2 or more days per week performed significantly better on measures of grip strength and SCT. Only 27% of participants met the more stringent-strengthening guideline of 2 or more days per week using all major muscle groups, and these individuals performed significantly better on the SCT and FTSST. The participants meeting the aerobic activity guideline performed significantly better on the SCT, the FTSST, and the 10-MWT. However, participants who met both the strengthening and aerobic activity guidelines performed significantly better on all 4 physical performance measures than participants who met neither of the guidelines. Meeting guidelines for both aerobic and muscle-strengthening activities may be the most effective way of preserving muscle strength, muscle power, and gait velocity in older adults, but this conclusion must be tested with an intervention study.
Native American Landscapes in the Plains and Northwest Coast

This chapter compares the well-documented historic landscapes of the Plains Indians and Northwest Coast Indians with the contemporary landscape in which only highly selective elements of their former material cultures are visible. The chapter summarizes the contemporary pattern of Native American population within most of the western United States. It explains that large areas of land were incorporated into Indian Reservations in Oklahoma (Indian Territory) and the other Plains states and it looks at the landscapes of poverty that have evolved on many of these reservations. The historical cultural landscape in the Plains is seen both through ruins of earth lodges, tepee rings, and sacred sites, some of which feature prominently in contemporary disputes. The contemporary Native American landscape in parts of the Pacific Northwest has incorporated certain historical features, but the generic American landscape dominates. This chapter briefly contrasts the status of Alaskan Natives (Indians, Inuits, and Aleuts) with Native Americans elsewhere in the nation, noting that in much of the 49th State Native Americans dominate the landscape.
Training Students To Use 3-D Model Sets via Peer-Generated Videos Facilitates Learning of Difficult Concepts in an Introductory Organic Chemistry Course

It is generally accepted that the use of 3-D model sets (ball-and-stick models) can be beneficial for students learning organic chemistry. However, with the amount of content that needs to be covered, there is not much time to learn how to use the model sets during class time. This report describes the use of student-generated videos designed to show how to use the model sets as an adjuvant to the learning process in a one-semester introductory organic chemistry course. The videos were made available to the students taking the course on an on-demand basis, and the learning outcomes of the class were compared to data from a previous semester in which the videos were not available, but where the instructor had used class time to train the students in the use of the model sets. Results show that the videos were widely used by students taking the class, and that learning outcomes were comparable between the classes with video training and with in-class training; in fact, no significant difference was found be...
Isolated intraventricular hemorrhage secondary to dural arteriovenous fistula

Isolated intraventricular hemorrhage due to dural arteriovenous fistula (dAVF) is extremely rare and has been reported only a few times in the literature. The pathophysiological cause of isolated intraventricular hemorrhage in these cases was hypothetically attributed to retrograde venous flow into subependymal vessels, although none of these cases demonstrated radiographic evidence of such reflux. We present the first case of a dAVF with radiographic evidence of severe cortical venous reflux into the subependymal venous network causing isolated intraventricular hemorrhage, thus lending proof for the underlying pathophysiology. Furthermore, ours is the first case of dAVF with isolated intraventricular hemorrhage that was successfully treated using multimodality transvenous and transarterial embolization techniques. In cases of high-grade dAVF, multimodality treatment may offer the greatest chance for success, and should be strongly considered for management.
Legal Authority and State Public Health Response to Climate Change

The article discusses legal aspects of U.S. state public health responses to climate change impacts. Topics include the draft legislation Comprehensive Climate Change Health Protection Act, the role of U.S. federal public health agencies in addressing health impacts of climate change, and U.S. state policies addressing greenhouse gas mitigation and climate change adaptation.
Collaborative Coding and Composing of JazzHands: Integrating the Learning of Advanced Computational Concepts with Electronic Textiles to Make Music Wearables

The links between music and computation date back at least three decades. This trend has led to the development of learning environments for novices to make music and learn computational concepts. However, research connecting music and computation is mostly situated within the context of on-screen programming, with little research involving hybrid, tangible environments. Electronic textiles (e-textiles) is one such hybrid context where learners craft interactive physical artifacts by sewing microcontrollers, sensors, and actuators onto toys, clothes, or other fabric accessories. Prior studies show that Arduino-based e-textiles afford opportunities for students to learn basic concepts such as variables and control flow but not more advanced concepts such as arrays and for loops. In our study, we expand learning with e-textiles as learners compose and code music to address the following research question: What are the affordances of designing musical wearables to deepen computational conceptual learning? We present a case study of a group of four 15-17-year-old youth and an adult co-making a musical wearable-JazzHands-a glove augmented with actuators such as LEDs and speaker, and motion, touch, and light sensors. We analyzed videos of the group's collaborative design sessions, student daily journals, multiple versions of the code, and post-workshop, artifact-based interviews with the youth. Our analysis revealed that making musical wearables not only allowed the youth to express themselves and relate to computing as a creative endeavor but also afforded unique opportunities to work with constructs such as arrays indices, sensor data integration, and logical expressions to control for loops.
User Adaptation to Constant Change in Algorithmically-Driven Social Platforms

Social platforms present a challenge for self-presentation and identity management by obscuring audiences behind algorithmic mechanisms. Users are increasingly aware of this and actively adapting through folk theorization, but we do not know how users are coping with the constant change endemic to these platforms, or how we can assist users in this coping process. My dissertation will examine how users perceive and adapt to the constantly-changing platform space using self-presentation and audience management as an illustrative case.
An open, transparent, industry-driven approach to AV safety (keynote)

At Intel and Mobileye, saving lives drives us. But in the world of automated driving, we believe safety is not merely an impact of AD, but the bedrock on which we will build this industry. And so we have proposed Responsibility-Sensitive Safety (RSS), a formal model to define what it means to drive safely - a formulation of the implicit traffic rules that enable human-like negotiation on roads that will contain a bix of machine and human driven vehicles. We intend this open, industry driven model to drive industry, academic and government discussion; let’s come together as an industry and use RSS as a starting point to clarify safety today, to enable the autonomous tomorrow.
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing

AbstractThe Antarctic Circumpolar Current plays a central role in the ventilation of heat and carbon in the global ocean. In particular, the isopycnal slopes determine where each water mass outcrop...
Hypoxia-Inducible Factor-2α Reprograms Liver Macrophages to Protect Against Acute Liver Injury Through the Production of Interleukin-6

Background and aims Acetaminophen (APAP) overdose represents the most frequent cause of acute liver failure, resulting in death or liver transplantation in more than one third of patients in the United States. The effectiveness of the only antidote, N-acetylcysteine, declines rapidly after APAP ingestion, long before patients are admitted to the clinic with symptoms of severe liver injury. The direct hepatotoxicity of APAP triggers a cascade of innate immune responses that may exacerbate or limit the progression of tissue damage. A better understanding of this complex mechanism will help uncover targets for therapeutic interventions. Approach and results We observed that APAP challenge caused stabilization of hypoxia-inducible factors (HIFs) in the liver and hepatic macrophages (MΦs), particularly HIF-2α. Genetic deletion of the HIF-2α gene in myeloid cells (HIF-2αmye/- ) markedly exacerbated APAP-induced liver injury (AILI) without affecting APAP bioactivation and detoxification. In contrast, hepatic and serum levels of the hepatoprotective cytokine interleukin 6 (IL-6), its downstream signal transducer and transcription factor 3 activation in hepatocytes, as well as hepatic MΦ IL-6 expression were markedly reduced in HIF-2αmye/- mice compared to wild-type mice post-APAP challenge. In vitro experiments revealed that hypoxia induced IL-6 production in hepatic MΦs and that such induction was abolished in HIF-2α-deleted hepatic MΦs. Restoration of IL-6 by administration of exogenous IL-6 ameliorated AILI in HIF-2αmye/- mice. Finally, IL-6-mediated hepatoprotection against AILI was abolished in hepatocyte-specific IL-6 receptor knockout mice. Conclusions The data demonstrate that APAP treatment leads to HIF-2α stabilization in hepatic MΦs and that HIF-2α subsequently reprograms hepatic MΦs to produce the hepatoprotective cytokine IL-6, thereby ameliorating AILI.
Brief Behavioral Intervention for Distressed Patients Undergoing Cancer Surgery: A Case Series

Abstract Preoperative distress is associated with poor postoperative outcomes, such as increased risk of surgical site infection and readmission, and brief psychosocial interventions delivered during the perioperative period may improve postoperative mental and physical health. However, there are few protocols for screening and treating distress in the surgical oncology setting. The current article describes the development and feasibility pilot testing of a four-session intervention (Behavioral Intervention for Wellness and Engaged Living [Be-WEL]) that combines behavioral and self-management strategies to manage preoperative distress and improve postoperative recovery. Data from three patients who participated in an ongoing open clinical trial are reviewed to illustrate the feasibility, acceptability, and potential strengths and limitations of this intervention.
Recessions and the vulnerable

Abstract This study evaluates the impact of recessions on households vulnerable to poverty. The results indicate that recessions impact vulnerable households asymmetrically in comparison to the impact of growth on poor households. We also demonstrate that this outcome is significantly influenced by a country’s extent of development. We argue that a direct consequence of the foregoing is that the efficacy of growth in poverty reduction tends to be under-stated by conventional measures of poor households’ responses to economic growth; and that safety nets need to be constructed to incorporate vulnerability to recessions.
Are clinicians' self-reported empathic concern and perspective-taking traits associated with their response to patient emotions?: Communication Studies.

ABSTRACT Objective To understand whether clinicians’ empathic concern and perspective-taking traits are associated with their response to patient emotions. Methods We audio-recorded 41 HIV clinician interactions with 342 patients at two academic medical centers. We assessed clinicians’ self-reported empathic concern and perspective-taking traits using the Interpersonal Reactivity Index and coded emotional communication using the Verona Coding Definitions of Emotional Sequences. We used random effects models to assess associations between clinician traits and clinician responses to patients’ negative emotions, accounting for clustering of emotions within encounters and patients within clinicians. Results Clinicians with more self-reported empathic concern received fewer emotional expressions from their patients (β -0.06; 95% CI -0.10, -0.01) and had greater odds of responding to emotions by giving information/advice (OR 1.10; 95% CI 1.01, 1.20). There were no associations between empathic concern or perspective-taking and any other clinician responses. Conclusion Clinicians with higher levels of empathic concern respond to patient emotions by giving information and advice, a response traditionally thought of as a missed empathic opportunity, not by exploring emotions or providing empathy. Whether this is helpful to patients is unknown. Practice Implications Clinicians should be aware of their tendency to give information to patients with emotional distress, and consider whether this response is helpful to patients.
Reliability of DNA methylation measures using Illumina methylation BeadChip.

Illumina BeadChips are widely utilized in epigenome-wide association studies (EWAS). Several studies have reported that many probes on these arrays have poor reliability. Here, we compare different...
Variance Regularization for Accelerating Stochastic Optimization.

While nowadays most gradient-based optimization methods focus on exploring the high-dimensional geometric features, the random error accumulated in a stochastic version of any algorithm implementation has not been stressed yet. In this work, we propose a universal principle which reduces the random error accumulation by exploiting statistic information hidden in mini-batch gradients. This is achieved by regularizing the learning-rate according to mini-batch variances. Due to the complementarity of our perspective, this regularization could provide a further improvement for stochastic implementation of generic 1st order approaches. With empirical results, we demonstrated the variance regularization could speed up the convergence as well as stabilize the stochastic optimization.
Risk Factors for Opioid Use After Patellofemoral Stabilization Surgery: A Population-Based Study of 1,316 Cases.

Background Orthopaedic surgeons remain the third-highest group of opioid prescribers among physicians in the United States, accounting for 8% of all opioid prescriptions. The purpose of this study was to identify risk factors for opioid consumption and opioid prescription refills after patellofemoral stabilization surgery. We hypothesized that preoperative opioid use and younger age would be independent risk factors for postoperative opioid use. Methods Patients undergoing primary patellar stabilization surgery between 2007-2017 in the Humana Inc. administrative claims database were identified using Current Procedural Terminology (CPT) codes for patellofemoral stabilization procedures (CPT-27420, 27422, 27427,27418). Patients were categorized into opioid naive (N-OU) and those who filled opioid prescriptions within 3 months prior to surgery (OU). Patients in the OU cohort were further categorized into those who filled prescriptions at 1-3 months before surgery (C-OU) and those who filled opioid prescriptions only in the month preceding surgery (A-OU). Descriptive statistics and multivariate analyses were performed to identify risk factors for postoperative opioid use at 3 and 12 months using the open-source R software (www.r-project.org) housed within PearlDiver. Results A total of 1,316 eligible patients were included. One year postoperatively, there was a greater risk of opioid consumption in the OU cohort (OU vs N-OU: 22.2% vs 4.1%; Relative Risk [RR]: 1.233; 95% CI: 1.172- 1.298; P< 0.0001). C-OU (OR: 5.74; 95% CI: 3.75- 8.9; P< 0.0001), obesity (OR: 1.76; 95% CI: 1.14- 2.69; P = 0.0099), and preoperative diagnosis of depression or anxiety (OR: 1.83; 95% CI: 1.01- 3.25; P = 0.0435) were independent risk factors for opioid use at 12 months postoperatively. Younger age (age <30) was associated witha lower risk of opioid use at 3 months (OR: 0.3, 95% CI: 0.21- 0.44; P< 0.0001) and 12 months (OR: 0.29; 95% CI: 0.17- 0.46; P< 0.0001) postoperatively. Conclusions Preoperative opioid utilization significantly increased opioid prescription filling following patellofemoral stabilization surgery. Patient-specific variables including obesity and preoperatively diagnosed depression or anxiety also increased the risk of postoperative opioid utilization. Given the relatively young age and high activity level of patients undergoing patellofemoral stabilization surgery, heightened awareness of patient-specific factors must be considered when selecting appropriate pain management regimens postoperatively.Level of Evidence: III.
Feasibility of P wave Centric Ambulatory Electrocardiogram Monitoring in Infants and Young Children

P wave centric ambulatory electrocardiographic (ECG) monitoring has emerged as an important tool aiding the diagnosis of arrhythmias. However, their efficacy and user experience in infants and young children are not well established. A retrospective study was performed to detail clinical and user experience of ECG monitoring using the Carnation Ambulatory Monitor (CAM) patch (Bardy Diagnostics Inc., Seattle, WA) in patients less than 10 kg. Additionally, 2 different monitor locations (over the sternum and horizontal over the left axilla) were assessed to address the optimal placement in these patients. A total of 33 CAM reports from 25 patients, aged 0 to15 months were included in the study. Mean patient age was 4.2 months ± 5.0 and mean weight was 5.3 kg ± 2.4. Thirty-six percent of patients (9/25) had known congenital heart disease. Indications for monitoring included: tachyarrhythmia (15/33, 45%), bradyarrhythmia (6/33, 18%), ectopic rhythm (9/33, 27%), cardiac tumor (1/33, 1%), and prolonged QT interval (1/33, 1%). All CAM reports showed clear, identifiable P waves which were diagnostic and lead to changes in medical management for 30% of patients (e.g., medication adjustments or discharge from cardiology care). We found the upright placement over the sternum performed better than the horizontal placement over the left axilla for small infants and children less than 10 kg. A P wave centric single-lead ECG monitor is helpful in providing accurate diagnostics tracings in infants and small children aiding in their clinical management.
Investigating the Relationship between Adhesion Forces and Surface Functionalization Using Atomic Force Microscopy

Surface chemistry impacts technology, advancing the development of new heterogeneous catalysts, semiconductor devices, and materials synthesis. Carbon surfaces are ubiquitous in various fields, and the surface reactivity can be altered by surface functionalization on the molecular scale, introducing functional groups, thus shifting their macroscale properties. In this physical chemistry lab experiment, students use atomic force microscopy to investigate the surface of graphite (organic) and gold (inorganic) samples (solid phase) to compare topographical features, surface roughness, and adhesion forces of the samples. Students relate the force–displacement measurements with the Lennard-Jones potential to obtain measurable adhesion forces. Emphasis is placed on quantification of the adhesion forces between a hydrophobic highly oriented pyrolytic graphite (HOPG) surface, a hydrophilic (hydroxy) functionalized HOPG surface, and a metallic gold-coated glass slide. The surface of each sample is explored, allowing students to compare the difference between the hydrophobic and hydrophilic surfaces from surface functionalization.
Strengthening Surgical Systems Through Cleft Care

The provision of cleft care in low-resource settings has seen massive improvements and innovation in the last half century as providers attempt to access all children while providing high-quality care. In attempts to understand the challenges to patients and practitioners, it is evident that the parts of the world with the greatest barriers to receiving and providing cleft care are also the areas with the weakest surgical health systems (Fig. 42.1) [1]. In order to provide sustainable solutions that secure safe, timely, and affordable care for all cleft patients, the surgical systems of low- and middle-income countries (LMICs) must be concomitantly strengthened. Just as cleft surgery has taken dramatic steps forward, so too has “global surgery” which seeks to improve health outcomes and equity for all people in need of surgical care [2]. By aligning the goals of cleft providers with the global surgery efforts, surgical systems can be strengthened to provide a foundation on which comprehensive cleft care can thrive.
Learning from past respiratory failure patients to triage COVID-19 patient ventilator needs: A multi-institutional study.

Abstract Background Unlike well-established diseases that base clinical care on randomized trials, past experiences, and training, prognosis in COVID19 relies on a weaker foundation. Knowledge from other respiratory failure diseases may inform clinical decisions in this novel disease. The objective was to predict 48-hour invasive mechanical ventilation (IMV) within 48 h in patients hospitalized with COVID-19 using COVID-like diseases (CLD). Methods This retrospective multicenter study trained machine learning (ML) models on patients hospitalized with CLD to predict IMV within 48 h in COVID-19 patients. CLD patients were identified using diagnosis codes for bacterial pneumonia, viral pneumonia, influenza, unspecified pneumonia and acute respiratory distress syndrome (ARDS), 2008–2019. A total of 16 cohorts were constructed, including any combinations of the four diseases plus an exploratory ARDS cohort, to determine the most appropriate cohort to use. Candidate predictors included demographic and clinical parameters that were previously associated with poor COVID-19 outcomes. Model development included the implementation of logistic regression and three ensemble tree-based algorithms: decision tree, AdaBoost, and XGBoost. Models were validated in hospitalized COVID-19 patients at two healthcare systems, March 2020–July 2020. ML models were trained on CLD patients at Stanford Hospital Alliance (SHA). Models were validated on hospitalized COVID-19 patients at both SHA and Intermountain Healthcare. Results CLD training data were obtained from SHA (n = 14,030), and validation data included 444 adult COVID-19 hospitalized patients from SHA (n = 185) and Intermountain (n = 259). XGBoost was the top-performing ML model, and among the 16 CLD training cohorts, the best model achieved an area under curve (AUC) of 0.883 in the validation set. In COVID-19 patients, the prediction models exhibited moderate discrimination performance, with the best models achieving an AUC of 0.77 at SHA and 0.65 at Intermountain. The model trained on all pneumonia and influenza cohorts had the best overall performance (SHA: positive predictive value (PPV) 0.29, negative predictive value (NPV) 0.97, positive likelihood ratio (PLR) 10.7; Intermountain: PPV, 0.23, NPV 0.97, PLR 10.3). We identified important factors associated with IMV that are not traditionally considered for respiratory diseases. Conclusions The performance of prediction models derived from CLD for 48-hour IMV in patients hospitalized with COVID-19 demonstrate high specificity and can be used as a triage tool at point of care. Novel predictors of IMV identified in COVID-19 are often overlooked in clinical practice. Lessons learned from our approach may assist other research institutes seeking to build artificial intelligence technologies for novel or rare diseases with limited data for training and validation.
Quantifying the effect of freeze-thaw cycles on track surface deformation and degradation of railway track geometry; Case study

Abstract Freeze-thaw cycles (FTC) are known to have an effect on railway track stability, safety, and performance. FTC are expected to become more frequent in the future due to climate change. This paper presents the results of a field investigation in which the mechanism of FTC development within the track embankment and its effect on the performance of railway tracks including track surface deformation and track geometry degradation are studied. Field observations suggested that the frost depth within the track embankment is influenced by the freezing index and winter snow cover. They also showed that a warmer and drier winter leads to more intermittent FTC and even though the average frost heave is lower than for a colder winter, the frost heaves occurring at culvert locations creates a larger differential deformation and thus may lead to a worse operating condition. The comparison of geometry measurements before freezing and after thawing indicated that the track geometry is in poorer and rougher condition during springs that were preceded by increased FTC. It was also concluded that track in proximity to culverts suffered the highest geometry degradation. Overall, the limited field observations of this study suggest that future winters, mild with less precipitation and higher occurrence of FTC, may increase the rate of track deterioration and more maintenance will be required to keep track within safe limits.
The Case for Interprofessional Teaching in Graduate Medical Education

Interprofessional education has been promoted as a strategy to dismantle professional silos and promote collaborative patient care. Citing this, medical educators have emphasized the widespread int...
Euler and Navier-Stokes Equations for Incompressible Fluids

This chapter deals with equations describing motion of an incompressible fluid moving in a fixed compact space M, which it fills completely. We consider two types of fluid motion, with or without viscosity, and two types of compact space, a compact smooth Riemannian manifold with or without boundary. The two types of fluid motion are modeled by the Euler equation $$\frac{\partial u} {\partial t} + {\nabla }_{u}u = -\text{ grad }p,\qquad \text{ div}u = 0,$$ (0.1) for the velocity field u, in the absence of viscosity, and the Navier–Stokes equation $$\frac{\partial u} {\partial t} + {\nabla }_{u}u = \nu \mathcal{L}u -\text{ grad }p,\qquad \text{ div }u = 0,$$ (0.2) in the presence of viscosity. In (0.2), ν is a positive constant and \(\mathcal{L}\) is the second-order differential operator $$\mathcal{L}u = \text{ div Def }u,$$ (0.3) which on flat Euclidean space is equal to Δu, when div u = 0. If there is a boundary, the Euler equation has boundary condition n ⋅u = 0, that is, u is tangent to the boundary, while for the Navier–Stokes equation one poses the no-slip boundary condition u = 0 on ∂M.
30 years later - landscape ecology: directions and approaches

To continue the reflections on the 30 year anniversary of the Allerton Park Workshop as initiated by Wu (2013), we present some reflections of the situation just before and developments after the workshop from two participantsone who was a chief organizer and synthesizer of the workshop as well as lead author of the subsequent document (and this piece), and one who was a brand new entrant into the newly formulated and wonderfully fascinating field of landscape ecology at the time of the workshop.
Chapter 8 Capillary electrophoresis in the study of amino acids

Publisher Summary Peptide or protein products contain primarily only the 20 common amino acids or their derivatives and thus represent a narrower range of amino acid structures than are encountered in endogenous samples. The methodologies developed for peptide and protein product analyses are well established with respect to efficient separations and reproducible and accurate quantitation. Because of the success of liquid chromatography (LC) in the routine analysis of amino acid products of peptide or protein origin, there is little advantage in using capillary electrophoresis (CE) for these applications. Because the basis of LC separation rests primarily on differences in polarity rather than size and charge, resolution of such amino acid mixtures is inherently difficult. The simplest form of CE—capillary zone electrophoresis (CZE)—separates analytes on the basis of their effective size and charge and is thus ideally suited to such a task. Compared to LC, CE exhibits higher efficiencies and provides much easier means to explore different separation conditions for optimization.
The XRS low temperature cryogenic system: Ground performance tests results

The X-Ray Spectrometer (XRS) instrument is part of the Astro-E mission scheduled to launch early in 2000. Its cryogenic system is required to cool a 32-element square array of x-ray microcalorimeters to 60-65 mK over a mission lifetime of at least 2 years. This is accomplished using an adiabatic demagnetization refrigerator (ADR) contained within a two-stage superfluid helium/solid neon cooler. Goddard Space Flight Center is providing the ADR and helium dewar. The flight system was assembled in Sept. 1997 and subjected to extensive thermal performance tests. This paper presents test results at both the system and component levels. In addition, results of the low temperature topoff performed in Japan with the engineering unit neon and helium dewars are discussed.
Studies on the biochemical basis of spontaneous mutation: V. Effect of temperature on mutation frequency

Abstract Temperature, in the range of 15 °C to 40 °C, has a pronounced effect on the incorporation of 2-aminopurine deoxynucleotides into DNA by purified bacteriophage T4-induced DNA polymerase. Whereas the total rate of utilization of the 2-aminopurine deoxynucleoside triphosphate increases with increasing temperature, a greater proportion is converted to the monophosphate by the editing nuclease of the enzyme. Therefore, the amount of analogue incorporated goes through a maximum and then decreases with increasing temperature. These results, obtained in vitro , have been correlated with effects of temperature on 2-aminopurine induced and spontaneous mutation rates of several r II markers, and they have been generalized to an hypothesis which holds that the stability of the helix immediately preceding the incoming nucleotide is an important factor in determining the accuracy of DNA replication. We suggest that there is a higher probability of making errors via base substitutions in a more stable (G + C-rich) rather than a less stable (A + T-rich) microenvironment.
The contents of resource decisions in the diffusion of Internet strategies in less-developed countries: lessons from Bolsa de Valores de Guayaquil

This research examined how Bolsa de Valores de Guayaquil, a Latin American stock exchange, pioneered a strategy to reach global investors in Ecuador and educate its local market using the Internet. The paper focuses not only on the attributes of the innovation, but also on firm-specific capabilities to explain how combinations of competencies and resources were developed, deployed, and protected over the diffusion process. The research complements the diffusion of innovations theory by incorporating the “resource-based” view approach in the context of less-developed countries.
Cloning and characterization of a gene (fadR) involved in regulation of fatty acid metabolism in Escherichia coli

The regulatory gene fadR has been previously characterized by classical genetic means as a diffusible protein which exerts negative control over fatty acid degradation and acetate metabolism. fadR has also been implicated in the regulation of unsaturated fatty acid biosynthesis. To facilitate the identification of the product of the fadR gene and to study the mechanism by which this multifunctional regulatory gene exerts its control, we cloned a segment of DNA containing the fadR gene in the phage vector lambda L47. Subsequent subcloning of a segment of the chromosomal DNA from the lambda fadR+ phage into various plasmid vectors resulted in the isolation of the fadR gene on a 1.3-kilobase-pair HindIII-EcoRV fragment. fadR strains harboring the cloned fadR+ gene showed inducible levels of fatty acid oxidation and crotonase (enoyl-coenzyme A-hydratase, fadB) activity. The cloned gene exerted transcriptional control over beta-galactosidase synthesis in an fadR strain that had a lambda phi (fad-lacZ+) operon fusion. An fadR mutation in fabA(Ts) strains prevents growth at permissive temperatures without unsaturated fatty acid supplementation (Nunn et al., J. Bacteriol. 154:554-560, 1983). Plasmids carrying the fadR+ gene suppress this unsaturated fatty acid auxotrophy in fadR fabA(Ts) strains at the permissive condition. Maxicell analysis identified a 29,000-dalton protein encoded by the 1.3-kilobase fragment which appeared to be associated with functional fadR gene activity.
Oral and genetic study of Chileans 1960. III. Periodontal disease and nutritional factors.

Abstract A survey of the prevalence of periodontal disease and related nutritional status was made in 1906 Chileans. Both prevalence and severity were found to increase with age. Destructive periodontal disease, as assessed by pocket formation, was found to be a disease of middle and later life. Highly significant differences in mean Periodontal Index scores were found between persons with calculus, debris or both, and persons without them. No significant differences from expected distributions were found between persons with low PI score and persons with high PI scores, when classified by ABO blood groups. No significant differences in mean PI score were found between persons with deficient and low vitamin levels and persons with acceptable and high levels. Periodontal lesions associated with tuberous sclerosis are described.
The developmental consequences of child emotional abuse: A neurodevelopmental perspective.

Abstract This article provides an empirical and theoretical foundation to support increased attention to neurodevelopmental processes in understanding the developmental sequelae of child emotional abuse (CEA). After reviewing the socioemotional consequences of CEA, an overview of the mammalian stress response system is provided, the deleterious impact of early psychosocial adversity on the organization and integration of this system is discussed, and the applicability of these findings for considering CEA and its developmental consequences within a multi-level, integrative, developmental psychopathology framework is explained. Building on evidence that CEA is likely to result in significant and enduring alterations in the neurobiology of stress response systems and, by extension, in neurodevelopment more broadly, specific suggestions for future research and practice are offered. This article encourages greater attention to CEA as a salient developmental experience and to neurophysiological processes as a ...
Using island-style bi-directional intra-CLB routing in low-power FPGAs

Increased clustering in Field Programmable Gate Arrays (FPGAs) has shifted a larger fraction of the overall routing load into the configurable logic blocks (CLBs), reducing usage of the costly global interconnect. However, increases in CLB size introduce additional overheads inside CLBs, which can limit the savings gained by minimizing the global interconnect use, motivating more efficient intra-CLB routing. This paper explores different topologies for the intra-CLB connectivity and identifies how the optimal local-CLB interconnect changes for different FPGA architecture and circuit parameters. This work compares area, delay, and energy for two intra-CLB topologies: multiplexer-based routing and island-style bi-directional routing, similar to the global FPGA interconnect, but used inside the CLB (which we call a mini-FPGA). The mini-FPGA style of local CLB interconnect prove to be favorable for minimum-energy operation, as they can reduce transistor count by as much as 62%, and consume as much as 77.9% less energy. Multipexer-based CLBs have performance benefits by reducing delays by almost 3×. Multiplexer-based CLBs can consume less energy at nominal voltages, but only if additional measures are taken to limit power consumption in the multiplexers. A 130-nm CMOS test chip confirms that simulation results track measured data for mini-FPGA CLBs.
Disparate effects of preconditioning and MLA on 5'-NT and adenosine levels during coronary occlusion.

Ischemic preconditioning has been proposed to protect the heart against infarction by increasing 5'-nucleotidase (5'-NT) activities and augmenting adenosine levels during sustained coronary artery occlusion. To test this theory, anesthetized dogs received four 5-min episodes of preconditioning ischemia, pretreatment with the pharmacological "preconditioning mimetic" monophosphoryl lipid A (MLA, 35 micrograms/kg i.v.) or no intervention before coronary artery ligation. At 20 min into occlusion (the crucial time at which myocyte death begins in this model), myocardial samples were obtained for measurement (by high-performance liquid chromatography) of ectosolic and cytosolic 5'-NT activity and adenosine levels. Preconditioning and MLA pretreatment limit infarct size in the canine model by 75 and 50%, respectively. However, only MLA augmented 5'-NT activity [i.e., cytosolic 5'-NT in the ischemic subendocardium was 26 +/- 1, 39 +/- 7, and 26 +/- 6 nmol. mg protein-1. min-1 in preconditioned, MLA, and control groups (P < 0.05), respectively]. Moreover, adenosine levels (in nmol/mg protein) were increased with MLA treatment (2.30 +/- 0.44) but attenuated in preconditioned dogs (1.11 +/- 0.23; P < 0.05) versus controls (1.87 +/- 0.29). Thus 5'-NT and adenosine levels need not be increased beyond control values during sustained occlusion to elicit cardioprotection.
Inadequate nutrient intakes among homebound elderly and their correlation with individual characteristics and health-related factors

Background: The prevalence of inadequate nutrient intakes among the homebound elderly and their correlation with individual characteristics and health-related factors remain poorly understood. Objective: We assessed the extent of inadequate dietary intakes of key nutrients among the homebound elderly by using the newly released dietary reference intakes and examined the associations of individual characteristics and health-related factors with low nutrient intakes. Design: This was a cross-sectional examination of data collected during the baseline assessment of a prospective study of nutrition and function among a randomly recruited sample of cognitively eligible recipients of home-delivered meals who completed a home visit and three 24-h dietary recalls (n = 345). Nutrient analysis was performed with the NUTRITION DATA SYSTEM software, and associations were identified through multiple regression models. Results: In multiple regression models, lower intakes of specific nutrients were associated with subjects who were women, who were black, who reported a low income and limited education, and who did not usually eat breakfast. On the basis of the estimated average requirement standard for nutrient inadequacy, the intake of ≥6 nutrients was inadequate in 27% of subjects, of 3-5 nutrients in 40% of subjects, and of 1-2 nutrients in 29% of subjects. On the basis of the adequate intake standard, a less than adequate intake of calcium was reported by 96% of subjects and of vitamin D by 99% of subjects. Conclusions: The findings suggest that home-delivered meals programs should target specific subgroups of participants with interventions, such as a breakfast meal or more-nutrient-dense meals, tailored to increase nutrient intakes and reduce the prevalence of nutrient inadequacy.
Determining RF angle of arrival using COTS antenna arrays: A field evaluation

We are interested in estimating the angle of arrival of an RF signal by using commercial-off-the-shelf (COTS) software-defined radios (SDRs). The proposed COTS-based approach has the advantages of flexibility, low cost and ease of deployment, but-unlike traditional phased antenna arrays in which elements are already phase-aligned — we face the challenge of aligning individual SDRs during field deployment in order to ensure coherent phase detection. We propose a strategy to relax the requirement of tight phase synchronization between distributed oscillators by using a novel phase difference of arrival mechanism based on a field-deployable reference transmitter. This approach enables flexible and inexpensive COTS phased-array designs. We evaluate our method in an outdoor, 20m×20m open field and observe localization errors below 3m. We conclude that a COTS-based approach to RF source localization is amenable to rapid and low-cost deployment of sensing infrastructure and could potentially be of interest to the Intelligence, Surveillance and Reconnaissance (ISR) community at the tactical edge.
Amphiphilic Templating of Mesostructured Zirconium Oxide

The synthesis of zirconium oxide with a mesostructured framework (Zr-TMS) has been achieved through the use of amphiphilic compounds with a variety of headgroups (anionic and nonionic) and tail group chain lengths (1−18 carbons). Anionic surfactants with phosphate, carboxylate, sulfate, and sulfonate headgroups led to disordered hexagonal and/or layered phases. Mesoporous zirconia with high surface areas could be obtained through calcination of materials templated with phosphate amphiphiles; the phosphate headgroups remained on the pore walls and appeared necessary for thermal stability. Nonionic amine amphiphiles have been found to lead to less ordered zirconia mesostructures, due to the weak interaction with the zirconium n-propoxide precursor. The chain-length-independent templating ability of the amphiphiles and ex situ 31P MAS NMR of dodecyl phosphate (before and after incorporation into Zr-TMS) supported a method of formation involving covalent-bond interactions between the headgroup and the inorgan...
The chemical formation of excited states during hydroxylation of the carcinogenic hydrocarbon benzo[α]pyrene by liver microsomes

Abstract We have verified that the enzymatic hydroxylation of carcinogenic aromatic hydrocarbons produces product molecules in electronically excited states. Introduction of the carcinogen benzo[α]pyrene into liver microsomes from 3-methylcholanthrene-induced rats results in a significant chemiluminescence which is shown for the first time to be correlated with the enzymatic hydroxylation of the parent carcinogen. The kinetics of the chemiluminescence implicate the intermediate epoxide as the precursor to the excited state product molecules.
Architectural Sketches and the Power of Caricature

Architects use caricatures, or quick sketches, in many ways. They can be means of working out a problem as well as springboards for new ideas, or they can record existing work or engage in critique. This article explores the ways architects manipulate images and offers possibilities for interpretations of architectural caricatures.
Inhibitory Effects of Gastrointestinal Electrical Stimulation on Rectal Tone are both Organ-Specific and Distance-Related in Dogs

Purpose A phenomenon of cross-talk has been noted that electrical stimulation of one part of the gut affects another part of the gut. This study was designed to investigate whether the effect of electrical stimulation of one part of the gut on another part of the gut was related to the organ or the distance between the stimulation site and the affected organ, and the mechanism of ileum electrical stimulation on rectal tone.
Two‐dimensional electrophoretic analysis of myosin light chain phosphorylation in heart

The phosphorylatable light chain of myosin (P-light chain) from hearts of the turtle, rat, frog, dog, cat, adult chicken and 1 week old chick was compared by two dimensional gel electrophoresis. The technique separates the phospho and dephospho forms of P-light chain and allows quantitation of its percentage distribution. The P-light chain was found to exist in multiple forms. The turtle heart possessed the highest percentage, 75%, of the phospho form of P-light chain, whereas 25% of P-light chain was in the dephospho form. In rat heart, 35% of the P-light chain was phosphorylated and 65% dephosphorylated. In frog heart, the P-light chain exhibited three forms: two phosphorylated and one dephosphorylated. The P-light chain of dog, cat and adult chicken hearts displayed four spots on two-dimensional gel electrophoresis: two phospho and two dephospho forms. In these species the percentage of total P-light chain being in the phospho forms was in the range of 10–25%. Comparison of adult chicken and 1 week old chick preparations suggests that during maturation from the chick to the chicken the percentage phospho form of the total P-light chain decreases. The myosin light chain kinase and phosphatase activities in whole homogenates of the above heart preparations were assayed. The data, with the exception of those from frog heart, suggest that the extent of light chain phosphorylation is correlated with the ratio of light chain kinase to phosphatase activity.
Exogenous Bacterial Endophthalmitis Treated Without Systemic Antibiotics

We treated 16 patients (16 eyes) with culture-proven exogenous bacterial endophthalmitis with intravitreal and subconjunctival antibiotics but without systemic antibiotics. After one to two sets of intravitreal injections, intraocular inflammation abated in all patients. After further surgery in four patients, all 16 eyes had clear media and attached retinas. Fifteen eyes attained a visual acuity of 20/400 or better; 12 eyes achieved 20/80 or better.