cssi/SciSciGPT-SciSciNet huggingface dataset:
Lead-free relaxor-ferroelectric thin films for energy harvesting from low-grade waste-heat.

One of the ways to mitigate the world energy crisis is to harvest clean and green energy from waste-heat, which is abundant, ubiquitous, and free. Energy harvesting of this waste-heat is one of the most encouraging methods to capture freely accessible electrical energy. Ferroelectric materials can be used to harvest energy for low power electronic devices, as they exhibit switchable polarization, excellent piezoelectric and pyroelectric properties. The most important characteristic of ferroelectric materials, in the context of energy harvesting, is their ability to generate electric power from a time-dependent temperature change. In this work, we grew highly c-axis oriented heterostructures of BaZr0.2Ti0.8O3 (barium zirconium titanate, BZT)/Ba0.7Ca0.3TiO3 (barium calcium titanate, BCT) on SrRuO3 (strontium ruthenate, SRO) and deposited on SrTiO3 (strontium titanate, STO) single crystalline substrate using pulsed laser deposition (PLD) technique. We investigated the structural, electrical, dielectric, and pyroelectric properties of the above-mentioned fabricated heterostructures. The wide range of θ-2θ X-ray diffraction (XRD) patterns only shows (00l) reflection peaks of heterostructures and the substrate which confirmed that the films are highly c-axis oriented. We are also capable to convert the low-grade waste-heat into electrical energy by measuring various temperature-dependent ferroelectric hysteresis loops of our nanostructure films via pyroelectric Ericsson cycles and the structures show an energy conversion density ~ 10,970 kJ/m3 per cycle. These devices exhibit a large pyroelectric current density of ~ 25 mA/m2 with 11.8 °C of temperature fluctuation and the corresponding pyroelectric coefficient of 3425 μC/m2K. Our research findings suggest that these lead-free relaxor-ferroelectric heterostructures might be the potential candidates to harvest electrical energy from waste low-grade thermal energy.
Anaerobic degradation and dehalogenation of chlorosalicylates and salicylate under four reducing conditions.

The anaerobic biodegradability and transformationof the mono-and dichlorinated salicylates(2-hydroxybenzoates) was examined under denitrifying,Fe (III) reducing, sulfate reducing andmethanogenic conditions. 3,6-Dichlorosalicylateand 6-chlorosalicylate are anaerobic microbialmetabolites of dicamba, a widely used herbicide.Anaerobic microcosms were established withdicamba treated soil from Wyoming, and golfcourse drainage stream sediments from NewJersey, which were each spiked with salicylate,3,6-dichlorosalicylate or one of the fourmonochlorosalicylate isomers. Salicylatewas degraded under denitrifying, sulfidogenic andmethanogenic conditions. In methanogenicenrichments 5-chlorosalicylate and 3-chlorosalicylatewere reductively dehalogenated to salicylatewhich was then utilized. Dehalogenation ofmonochlorinated salicylates to salicylate wasalso observed in denitrifying chlorosalicylatedegrading cultures. The study revealed thatthe position of the chlorine substituent as well as thepredominant electron accepting process affectthe rate and extent of chlorosalicylate degradationin anoxic environments.
Comparing ecmo characteristics and outcomes among COVID-19 and non-COVID-19 patients at a tertiary academic medical center

Rationale: Coronavirus disease 2019 (COVID-19) can cause severe respiratory failure that worsens despite maximal medical management. When to initiate extracorporeal membrane oxygenation (ECMO) and how to manage these patients on ECMO is not clear. Here, we present our experience with venovenous ECMO to support patients with COVID-19 and compare it to historic patients supported with VV-ECMO for other causes of respiratory failure. Methods: Patients admitted to our tertiary academic medical center in 2019 and 2020 who received VV ECMO support were included in this retrospective chart review. We examined patients with and without COVID-19 infection. We placed COVID-19 patients on ECMO who failed supportive care with mechanical ventilation using a high PEEP low tidal volume strategy, prone positioning, and neuromuscular blockade. Data analysis were done in Excel and Prism. Non-parametric data were compared with unpaired, two-tailed Mann-Whitney tests. Results: ECMO was provided to 26 COVID-19 patients and 38 patients without COVID-19. Median (interquartile range) age of COVID-19 patients was 49.5 (40.5-56.25), compared with non-COVID-19 patients: 53.5 (30.5-60.25), p=0.28. COVID-19 patients had a significantly higher BMI: 32 (30.1-35.9) vs. 26.4 (23.6-29.4), p<0.001. There were 27% female COVID-19 patients compared with 37% female non-COVID patients (p=0.43). COVID-19 patients had similar PaO2:FiO2 ratios as non-COVID patients on day of cannulation: 74 (69-112) vs 78 (60-205), p=0.65. COVID-19 patients had longer ventilator duration pre-cannulation (not including time spent intubated at outside hospitals prior to transfer to our center)-1.9 (1.4-7.0) days vs 0.7 (-.2-1.0) days, p<0.001. COVID patients spent more days on ECMO compared with non-COVID patients: 20.7 (7.3-36.5) vs. 11.5 (3.8-26.8), p=0.14. Twelve (46%) of the COVID-19 ECMO patients died, compared with 9 (25%) of the non-COVID ECMO patients, p=0.10. Conclusions: In patients with severe SARS-CoV-2 pneumonia induced ARDS who fail maximal supportive therapy with mechanical ventilation, outcomes are similar or worse than patients historically receiving VV ECMO support for respiratory failure. These findings highlight the need to determine the optimal timing of ECMO initiation and management in patients with severe SARS-CoV-2 pneumonia.
Parâmetros hematológicos de cachara, Pseudoplatystoma fasciatum Linnaeus, 1766 (Osteichthyes, Pimelodidae), criado em cativeiro

This study was carried out with Pseudoplatystoma fasciatum ("cachara") reared at PDSA - APTA, Pariquera-Acu, Sao Paulo, Brazil, stocked in eight 200 m² ponds, from January 1999 to February 2001, totalizing 190 fishes (71 males, 99 females and 20 undetermined). The total weight (138.5 to 2,430.0 g) and total length (29.5 to 79.0 cm) were recorded. The sex and the gonadal stages (Juvenile, Resting, Maturation, Final Maturation, Regression) were also identified. Blood was collected to determine the hematocrit (mean value: 28.0 ± 0.6%), hemoglobin level (mean value: 6.4 ± 0.2 g/100 mL) and red blood cell (mean value: 224.0 ± 6.0 x 104/mm³). Mean corpuscular volume (MCV) (mean value: 131.0 ± 2.3 µm³), mean corpuscular hemoglobin (MCH) (mean value: 26.6 ± 1.0 ppg) and mean corpuscular hemoglobin concentration (MCHC) (mean value: 19.8 ± 0.7%) were calculated. There was difference between males and females, and a slight increase in the mean values of the hematological variables with gonadal maturation was registered. Differences among fish according to the several classes of total length were also verified.
Perils and Benefits of Free Trials in Large Scale Service Systems: An Operations Perspective

Despite their pervasive use in practice, the operational implications of offering free trials are not well understood. Motivated by this, we consider a service provider that has the option of offering free trials to a new market while catering to an existing market of price and delay sensitive customers. Then, we pose the following question: Under what conditions is offering free trials beneficial and what is the extent of this benefit? This question is relevant because with free trials the firm essentially gives away part of its capacity to potentially generate more revenue in the future. Hence, it is not apriori clear if offering free trials is beneficial. To answer these questions, we pursue an asymptotic analysis that allows us to glean novel insights as to when and how a large-scale service firm should offer free trials: When the firm offers free trials with no control, we find, somewhat surprisingly, that offering free trials is beneficial only for small free trial market sizes with correspondingly small relative benefits. When capacity can be adjusted, we derive tractable expressions that can accurately determine when offering free trials is beneficial and the extent of this benefit. Consequently, we establish that offering free trials is always beneficial when capacity can be adjusted below a cost threshold. Thus, we conclude that service firms should opt to simultaneously increase capacity as free trials are offered to unlock the expected benefits, and otherwise not offer free trials at all.
Entrepreneurs’ Ethnic and Political Identity Alignment as Determinants of Access to Government Support in Africa: A Conceptual Framework:

This article contributes to research on the role of government in entrepreneurship by extending the current focus from government policies to policymakers. Specifically, we examine how entrepreneur...
Family Caregiving in Mental Illness

PART ONE: INTRODUCTION AND OVERVIEW Mental Illness and Caregiving Needs An Introduction Historical Overview of Family Caregiving PART TWO: THE UNIQUE BACKGROUND OF MENTAL ILLNESS Defining Mental Illness Historical and Cultural Influences Conceptual Models of Mental Illness Research on Family Theories PART THREE: EXPERIENCING MENTAL ILLNESS IN THE FAMILY Caregiver Stress and Dimensions of Family Burden Caregiving during the Family Life Cycle The Life Cycle of the Person with Mental Illness Caregiving during the Family Life Cycle The Life Cycle of the Caregivers Families' Coping Strategies Services for Families PART FOUR: THE SOCIAL CONTEXT: THE FUTURE OF FAMILY CAREGIVING Cross-Cultural Issues in Family Caregiving The Effects of Advocacy Movements on Caregivers Patients' Rights versus Treatment Needs The Family Dilemma Social Change, Mental Health Policy, and Future Directions
Product Orientation: the no Fear Strategy

Marketing writers seem to take one of three approaches to product orientation: denigrate it; ignore it; or claim it is part of the marketing concept. In this literature review, product orientation emerges as the province of the bold, proactive risk-taker. Caring not that the source, use, or acceptance of invention is unpredictable, the entrepreneur assumes customers will adapt to the new product. Product orientation calls for active market experimentation, educating customers, and a belief that, rather than adapting to the environment, one can change it.
Origins of Political Extremism: Mortality Salience: Intimations of the Corporeally Finite

This chapter establishes the connection between intimations of mortality, or mortality salience as it is known in the social psychological literature, and the rise of political extremism. Mortality salience is the companion variable to the ephemeral gain, whose pathways to extremism were explored in the preceding chapter. War is not only a clear processual incubator of violence, but ultimately can yield political extremism. World War I is the seminal event of the twentieth century, which, despite important antecedent events like the Russo-Japanese War of 1904–05 that will be explored elsewhere in this book, nevertheless exerted its unique and extraordinary impact. On the whole, the immediate origins of European fascism are not in dispute. Virtually all major analysts of the etiology of this phenomenon agree that World War I was crucial. Fundamental causes, or more precisely long-term processes, as well as ideational content tend to be disputed, but the immediate importance of World War I is seldom contested. Reasons for this emerging consensus are not hard to find. Virtually all of the important fascist leaders of the interwar period experienced battle at the front, or were close to those who did. According to the cognitive psychologist, Seymour Epstein, “Experientially derived knowledge is often more compelling and more likely to influence behavior than is abstract knowledge.” Simply the return of large numbers of battle-hardened veterans could destabilize societies already exposed to significant economic, social, and especially political strains associated with maintaining the home front intact.
The Halting Problem and Undecidability of Document Generation under Access Control for Tree Updates

We show by reduction from the halting problem for Turing machines that typical rule-based models of fine-grained access control of trees make impossible certain forms of analysis, limiting the ability to audit existing policies and evaluate new ones. Fine-grained access control is the problem of specifying the set of operations that may be performed on a complex structure. For tree-structured databases and documents, particularly XML, a rule-based approach is most common. In this model, access control policies consist of rules that select the allowed or disallowed targets of queries based on their hierarchical relationships to other nodes. We consider the problem of determining whether a given document (that is, a rooted vertex-labelled tree) could have been produced in accordance with a particular access control policy for updates. We show that, for rule-based policies based on a simple fragment of XPath, this problem is undecidable. This result shows that rule-based access control policies based on XPath languages are, in some sense, too powerful, demonstrating the need for a model of access control of tree updates that bridges the gap between expressive and analyzable policies.
A nonlinear full order observer for oscillator tracking

We present a class of nonlinear observers that track oscillator states from observations of the complex envelope. We first identify core state variables that are observable and provide a general observer structure for estimating these state variables, that results in globally uniformly asymptotically stable observers. We provide a specialization that induces the 2-norm of the state estimation error to monotonically decline to zero, and has an intuitively appealing structure that has parallels to full order observers of Linear Time Invariant systems.
Progestins in the treatment of patients with endometrial adenocarcinoma.

Abstract Forty-five women with disseminated adenocarcinoma of the endometrium were studied in an attempt to determine the type of patient who could expect a response to treatment with a progestin. Younger patients responded more often, possibly because of the estrogen dependence of these tumors or the effects of prior stimulation of the endometrial cells by estrogen. The response of endometrial adenocarcinoma to a progestin seems to be unrelated to its location or any previous treatment of the patient. In this series, 40 per cent of 42 patients who were treated with medroxyprogesterone or AY-62022 obtained and objective response for 3 to 42 months, and 2 others exhibited a significant clinical response of 10 and 12 months. Thus, the tumors of 19, or 45.2 per cent of the group, were favorably affected. Thirty, or 71 per cent of the 42 patients, obtained excellent subjective responses.
Applied Quantum Mechanics

Preface to the second edition Preface to the first edition Matlab programs 1. Introduction 2. Toward quantum mechanics 3. Using the Schrodinger wave equation 4. Electron propagation 5. Eigenstates and operators 6. The harmonic oscillator 7. Fermions and bosons 8. Time-dependent perturbation 9. The semiconductor laser 10. Time-independent perturbation 11. Angular momentum and the hydrogenic atom Appendix A. Physical values Appendix B. Coordinates Appendix C. Expansions, differentiation, integrals, and mathematical relations Appendix D. Matrices and determinants Appendix E. Vector calculus and Maxwell's equations Appendix F. The Greek alphabet Index.
Interactive comorbidity between opioid drug abuse and HIV-1 Tat: chronic exposure augments spine loss and sublethal dendritic pathology in striatal neurons.

HIV-1 infection predisposes the central nervous system to damage by opportunistic infections and environmental insults. Such maladaptive plasticity may underlie the exaggerated comorbidity seen with HIV-1 infection and opioid abuse. Although morphine and HIV-1 Tat synergize at high concentrations to increase neuronal death in vitro, we questioned whether chronic low Tat exposure in vivo might contribute to the spectrum of neuropathology through sublethal neuronal injury. We used a doxycycline-driven, inducible, HIV-1 Tat transgenic mouse, in which striatal neuron death was previously shown to be absent, to examine effects of differential Tat expression, alone and combined with morphine. Low constitutive Tat expression caused neurodegeneration; higher levels induced by 7 days of doxycycline significantly reduced dendritic spine numbers. Moreover, Tat expression widely disrupted the endogenous opioid system, altering μ and κ, but not δ, opioid receptor and proopiomelanocortin, proenkephalin, and prodynorphin transcript levels in cortex, hippocampus, and striatum. In addition to markedly reducing spine density by itself, morphine amplified the effect of higher levels of Tat on spines, and also potentiated Tat-mediated dendritic pathology, thus contributing to maladaptive neuroplasticity at multiple levels. The dendritic pathology and reductions in spine density suggest that sustained Tat ± morphine exposure underlie key aspects of chronic neurodegenerative changes in neuroAIDS, which may contribute to the exacerbated neurological impairment in HIV patients who abuse opioids.
Ex Vivo Expansion of Human Tregs by Rabbit ATG Is Dependent on Intact STAT3‐Signaling in CD4+ T Cells and Requires the Presence of Monocytes

The addition of low, nondepleting doses of rabbit antithymocyte globulin (ATG) to human peripheral blood mononuclear cells has been shown to expand functional CD4+CD25+FoxP3+ regulatory T cells (Tregs) in vitro. This report is the first to elucidate the exact cellular mechanisms of ATG-mediated Treg expansion. CD4+ T cells require monocytes, but not other antigen presenting cell subsets, to be present in coculture to expand Tregs. However, T cells do not require direct cell–cell contact with monocytes, suggesting the importance of soluble factors. Moreover, ATG initially “reprograms” CD4+ T cells, but not monocytes, and induces STAT3 and STAT5 signaling in CD4+ cells. These reprogrammed CD4+ T cells subsequently secrete GM-CSF and IL-10 only in case of intact STAT3 signaling, which in turn promote the generation of tolerogenic CD14+CD11c+ dendritic cells characterized by enhanced IL-10 and decreased IL-12 production. Treg expansion following ATG treatment is accompanied by enhanced gene expression of both GM-CSF and Bcl-2, but not TGF-β, in peripheral blood mononuclear cells. These results demonstrate that ex vivo expansion of human Tregs by ATG is due to its ability to reprogram CD4+ T cells in a STAT3-dependent but TGF-β-independent manner, leading to the generation of monocyte-derived dendritic cells with a tolerogenic cytokine profile.
Design of a Multi-Function Vector Bar

The University of Delaware Department of Mechanical Engineering curriculum includes a senior design project, where teams address real design challenges facing local firms. The SURVICE Engineering Company tasked a team to design an improved metrology vector bar for use with an indoor global positioning system (iGPS) computer system. This vector bar needed to be ergonomic, easy to use, and easy to manufacture. To fulfill these requirements, metrics for a smaller, lighter, and more ergonomically designed Multi-Function Vector Bar were established. To encompass these metrics, four different subsystems were identified and integrated into a final design. Of these systems, emphasis was placed on a new ergonomic handle designed through an iterative process. New features were added to the handle to facilitate a decrease in human error and an increase in functionality. Multiple handle models were designed and tested to accomplish this. The final handle design resulted in a balanced, lighter, and more comfortable prototype that had two control buttons and indicator lights.Copyright © 2009 by ASME
An interval scale for measuring visual pattern discrimination of a mammal (Rattus norvegicus).

Laboratory rats, trained to horizontal or vertical stripes, were scored on visual stripe tilt discrimination in a series of binary choice tests. The resulting choice-percent-scales can be shown to be linear measurements (interval scales) of the stripe tilt differences as perceived by the rats. A crude model system for describing and explaining the binary choice behavior of rats is propounded. Three main processes constitute this model system. The first determines the magnitude of similarity between any pattern offered and the previous training pattern. The second compares these similarity-magnitudes by subtraction and the third injects evenly distributed noise into the system, thus accounting for the scatter in the choice behavior. The similarity functions (“generalization gradients”) for the edge orientation in the visual field of the rat range over ± 90°, which appears to be typical for both vertebrates and arthropods.
Association and ancestry analysis of sequence variants in ADH and ALDH using alcohol-related phenotypes in a Native American community sample.

Higher rates of alcohol use and other drug-dependence have been observed in some Native American populations relative to other ethnic groups in the U.S. Previous studies have shown that alcohol dehydrogenase (ADH) genes and aldehyde dehydrogenase (ALDH) genes may affect the risk of development of alcohol dependence, and that polymorphisms within these genes may differentially affect risk for the disorder depending on the ethnic group evaluated. We evaluated variations in the ADH and ALDH genes in a large study investigating risk factors for substance use in a Native American population. We assessed ancestry admixture and tested for associations between alcohol-related phenotypes in the genomic regions around the ADH1-7 and ALDH2 and ALDH1A1 genes. Seventy-two (72) ADH variants showed significant evidence of association with a severity level of alcohol drinking-related dependence symptoms phenotype. These significant variants spanned across the entire 7 ADH gene cluster regions. Two significant associations, one in ADH and one in ALDH2, were observed with alcohol dependence diagnosis. Seventeen (17) variants showed significant association with the largest number of alcohol drinks ingested during any 24-hour period. Variants in or near ADH7 were significantly negatively associated with alcohol-related phenotypes, suggesting a potential protective effect of this gene. In addition, our results suggested that a higher degree of Native American ancestry is associated with higher frequencies of potential risk variants and lower frequencies of potential protective variants for alcohol dependence phenotypes.
A remark on the characterization of the gradient of a distribution

It is shown in this paper that a scalar test function in Rn is the divergence of a vector valued test function if and if its integral over the domain vanishes. Using this result, we are able to give an elementary proof of the characterization of the gradient of a distribution. Also an application on characterization of the curl of a distribution in R2 is presented.
Electromagnetic Scattering of Randomly Rough Soil Surfaces Based on Numerical Solutions of Maxwell Equations in Three-Dimensional Simulations Using a Hybrid UV/PBTG/SMCG Method

A hybrid UV/PBTG/SMCG method is developed to accelerate the solution of NMM3D for 3-D electromagnetic wave scattering by random rough soil surfaces. It takes only 1.5 min using 16 processors on a cluster of NSF TeraGrid to compute 3-D solution of Maxwell equations of 8 by 8 square wavelengths. With the improved computational efficiency, we computed results using areas up to 32 by 32 square wavelengths. With the larger surface area, we were able to compute cases with larger rms heights up to 8 cm at SMAP radar frequency of 1.26 GHz that corresponds to kh = 2.28. New results computed include the cross-polarization. The five tests on the accuracy of results were performed: convergence with realizations, convergence with discrete samplings, convergence with sample surface sizes, energy conservation for each realization, and reciprocity for each realization. The numerical results show that for a single realization VH = HV within 0.5 dB in the backscattering direction showing that reciprocity is obeyed. Results were compared with experimental data, and both co-polarization and cross-polarization were in good agreements with experimental data.
TEMPERATURE-DEPENDENT CONCENTRATION QUENCHING OF FLUORESCENCE BY CROSS RELAXATION OF Nd$sup 3+$ IN LaF$sub 3$

The fluorescence lifetimes of the $^{4}F_{\frac{3}{2}}$ level of ${\mathrm{Nd}}^{3+}$ in La${\mathrm{F}}_{3}$ and ${\mathrm{Nd}}^{3+}$ in La${\mathrm{Cl}}_{3}$ were measured for various concentrations of ${\mathrm{Nd}}^{3+}$ at 4.2, 77, and 300\ifmmode^\circ\else\textdegree\fi{}K and intermediate temperatures. It is found that the lifetime-concentration curves differ greatly for the two crystals. The optical energy levels of ${\mathrm{Nd}}^{3+}$ in La${\mathrm{F}}_{3}$ at various concentrations were examined and two sets of levels with precisely overlapping electric dipole transitions have been found; no such overlapping transitions were found for the La${\mathrm{Cl}}_{3}$ crystal, however. It is suggested that cross relaxation between these levels can account for the strong, temperature-dependent concentration quenching in the La${\mathrm{F}}_{3}$ crystal. Using rate equations with cross relaxation terms, a one-parameter expression for fluorescence lifetime versus temperature was found which fitted experimental points for the 4.7 and 8.3% concentration crystals reasonably well. Since the overlap of transitions greatly affects cross relaxation rates, the linewidths and lineshifts were examined. Large heterogeneous linewidths and wavelength shifts were observed for the intermediate concentration crystals. The transitions were observed to sharpen in the low-dilution crystals and in the 100%-concentration crystals (Nd${\mathrm{F}}_{3}$), but relative shifts in wavelengths are observed.
The Metaphysical Assumptions Required for Political Autonomy

In his article, Dubljevic (2013) promotes a political concept of autonomy that is supposedly devoid of metaphysical assumptions concerning free will, yet still allows us to ascribe moral responsibi...
Interplay between bulk medium evolution and (D)GLV energy loss

Abstract We study the consistency between high- p T nuclear suppression ( R A A ) and elliptic flow ( v 2 ) using Gyulassy–Levai–Vitev (GLV) energy loss or a simpler power-law d E / d L formula, for a variety of bulk evolution models. The results generally confirm our earlier work [1] that found suppressed elliptic flow for transversely expanding media. One exception is the set of hydrodynamic solutions used recently [2] by Betz and Gyulassy, which give significantly higher v 2 but unfortunately assume unrealistic bag-model equation of state. On the other hand, we show that covariant treatment of energy loss introduces an interplay between jet direction and hydrodynamic flow of the medium, which largely counteracts elliptic flow suppression caused by transverse expansion.
A finite element method for computing the bifurcation function for semilinear elliptic BVPs

Abstract The method of alternative problems can be used to show that a semilinear elliptic boundary value problem (Lu + g(x, u) = 0 with gu(x, u) bounded below) is equivalent to a finite-dimensional problem ( F(c) = 0 ∈ R d , c ∈ R d ), in the sense that their solution sets, which are not necessarily singletons, are in a one-to-one correspondence. This correspondence is based on a map σ from low-frequency to high-frequency Fourier components of solutions. A numerical method is presented for approximating σ and hence also solutions of the BVP. The method uses finite element approximations and avoids the use of eigenfunction expansions. Existence, uniqueness, and error estimates for the approximations of σ and solutions u are derived.
The Association of Women Surgeons. A historical perspective 1981 to 1992.

IN 1975, the American College of Surgeons (ACS) published a review of women in surgery as one in a series of socioeconomic reports.1The intent of this review was to "... present a descriptive profile of women in surgery as a baseline and stimulus for later studies on the continually evolving role of women in surgical practice." The director's memo accompanying this report urged "... all of us to look beyond our prejudices and unsupported convictions toward full use of the gifts women can bring to surgery." The Association of Women Surgeons (AWS) was founded in 1981, when Patricia Numann, MD, a general surgeon from Syracuse, NY, invited all the female surgeons she could identify for breakfast at the ACS' Clinical Congress in San Francisco, Calif. The 12 women who gathered at this first meeting found that they shared many common experiences, interests, and concerns, and they decided to meet annually
Efficient route to phase selective synthesis of type II silicon clathrates with low sodium occupancy

Phase selective synthesis of type II silicon clathrates from thermal decomposition of NaSi has previously been limited to small quantities due to the simultaneous formation of competing phases. In this work we show that the local sodium vapor pressure during the NaSi precursor decomposition is a critical parameter for controlling phase selection. We demonstrate synthesis techniques that allow us to tune the local Na vapor pressure, yielding type I or II clathrate products that are ≥90 wt.% phase pure. The “cold plate” reactor design discussed in this work maintains low Na vapor pressure during thermal decomposition of NaSi, thus yielding large scale, phase selective synthesis of type II silicon clathrates. The low Na vapor pressure maintained in this reactor is also shown to efficiently produce low Na (x ~ 1; NaxSi136) Si clathrate through Na sublimation. To further reduce sodium occupancy (x < 1), we demonstrate etching of NaxSi136 in HF/HNO3 solutions, which rapidly yields a clathrate product with reduced x. 29Si NMR and electron spin resonance (ESR) characterization validate the low Na occupancy of Si clathrate synthesized. The acid etch also selectively dissolves the type I silicon clathrate impurity phase, thereby enabling the synthesis of large quantities of phase pure type II silicon clathrate with low Na content.
Impact of threading dislocation density on metamorphic In x Ga 1-x As and In z Ga 1-z P p-i-n photodetectors on GaAs

Bandgap tunability achievable using metamorphic epitaxy enables maximization of photodetector performance at target wavelengths. However, an increase in threading dislocation density (TDD), which is inherent for the growth of relaxed, lattice-mismatched layers, could offset this advantage and severely limit detector performance. In this regard, we are investigating the performance of In x Ga 1-x As and In z Ga 1-z P p-i-n photodetectors as a function of TDD, by utilizing a number of different InxGa1-xAs buffer designs. In particular, internally lattice-matched metamorphic In 0.20 Ga 0.80 As and In 0.68 Ga 0.32 P individual p-i-n detectors are studied to optimize the buffer design and performance of optically-aligned In 0.68 Ga 0.32 P/In 0.20 Ga 0.80 As visible/near-infrared dual-photodetectors. Reverse-bias dark current density of In 0.68 Ga 0.32 P detectors were found to be extremely sensitive to TDD compared to that observed for In 0.20 Ga 0.80 As detectors. Nearidentical spectral response curves were obtained for both detectors as a function of TDD due to the relative insensitivity of the p-i-n detector structure to the minority carrier lifetime. A comprehensive comparison between the different graded buffer designs, TDD achieved and photodetector characteristics are presented.
A comparative study of respiratory pigment concentrations in six species of turtles.

Abstract 1. 1. Myoglobin and hemoglobin concentrations were determined in six species of turtles. 2. 2. Myoglobin content was similar to that found in mammals but hemoglobin was generally lower. 3. 3. Relatively high levels of respiratory pigments were found in Sternothaerus odoratus and this may be of adaptive significance for its highly aquatic life.
Polyoxymethylene in Comet Halley

It is shown that polyoxymethylene (POM) with n about four or five explains the mass spectrum obtained with the PICCA instrument during the Giotto encounter with Comet Halley. A sequence of processes is presented showing the likelihood that POM will form under interstellar conditions. A preliminary comet coma model that includes POM is presented which predicts a qualitatively correct spectral intensity behavior when compared with observations.
The influence of carbon tetrachloride metabolism on the carbon tetrachloride-induced activation of rat liver cell phospholipase C activity

Abstract Hepatocytes and hepatocellular fractions (plasma membranes and 1000g fraction) exposed to CCl4 in vitro exhibit a rapid rise in a phospholipase C-mediated degradation of membrane phospholipids. This CCl4-dependent destruction of liver cell phospholipids may represent an important event in CCl4-induced liver cell injury. Therefore, we assessed the influence of CCl4 metabolism on the CCl4-dependent activation of hepatocellular phospholipase C in vitro. CCl4 metabolism was measured in intact hepatocytes and 1000g liver cell fractions by determining the amount of [14C]CCl4 metabolites covalently bound to cellular proteins, neutral lipids, and phospholipids. The presence of carbon monoxide and NADPH markedly reduced (90 to 100%) and increased (4 to 50-fold) the production of covalently bound CCl4 metabolites, respectively. However, the presence or absence of NADPH and/or carbon monoxide did not alter the CCl4-induced rise in hepatocellular (1000g fraction) phospholipase C activity. Therefore, under exposure conditions where CCl4 metabolism is present (+NADPH), absent (−NADPH, +CO), or inhibited (+NADPH, +CO), the CCl4-induced increase in phospholipase C activity is not altered. These results suggest that the CCl4-dependent rise in cell surface phospholipase C activity is caused by CCl4 rather than CCl4 metabolites.
Adult Sexual Experiences as a Mediator Between Child Abuse and Current Secretory Immunoglobulin A Levels

The current study investigated whether a history of child abuse is a predictor of adult immune status, with unwanted adult sexual experiences as a proximal mediator. Participants included 89 young adult women (Mage = 19.24) who were classified as having experienced no child abuse, child physical abuse, or child sexual abuse, based upon self-reported victimization history before 14 years of age. Participants also reported on unwanted sexual experiences in young adulthood and provided four saliva samples, which were collected over two consecutive days to determine secretory immunoglobulin A (sIgA). Age and negative life events were considered as covariates. The results indicated that adult sexual victimization partially mediated the relationship between child abuse (physical and sexual) and sIgA. Specifically, child abuse experiences predicted more adult sexual victimization experiences, which in turn predicted lower sIgA levels. These findings support long-term health effects of victimization, and suggest ...
Effect of chorioamnionitis on early childhood asthma.

a 1.23-fold (95% CI, 1.02-1.49), 1.51-fold (95% CI, 1.26-1.80), and 1.20-fold (95% CI, 1.03-1.47), respectively, increased risk of asthma compared with children of similar gestational age born after pregnancies not complicated by chorioamnionitis. A preterm pregnancy complicated by chorioamnionitis was associated with increased risk of asthma among white (hazard ratio [HR],1.66; 95% CI, 1.32-2.07), African American (HR,1.98; 95% CI, 1.60-2.44), and Hispanic (HR,1.70; 95% CI, 1.45-2.00), but not Asian/Pacific Islander (HR,1.15; 95% CI, 0.83-1.58) women. Conclusion: Findings suggest that chorioamnionitis at preterm gestation is independently associated with increased risk of childhood asthma.
In vitro studies of the transmission barrier.

Protein misfolding cyclic amplification (PMCA) has proved to be an efficient method mimicking in vitro some of the fundamental steps involved in prion replication in vivo. Thus, it can be used to efficiently replicate a variety of prion strains/species. The in vitro generated prions possess key prion features, i.e., they are infectious in vivo and maintain their strain specificity. One of the big challenges is its use for studying prion transmission barriers. PMCA has been efficiently used for adapting different prion species through a range of species barriers; however its capacity for overcoming purportedly unbreakable species barriers compels us to adapt it in order to use it as a reliable technique. In addition, this in vitro method might be a crucial tool in evaluating the potential risks of different prion strains (natural or experimentally generated in vitro) to humans and animals.
The Evolution of Equality: Rethinking Variability and Egalitarianism Among Modern Forager Societies

AbstractUsing hunter-gatherer societies as a focus, we argue for a heuristic continuum of egalitarian social systems ranging between relatively strong and weak forms. Weak egalitarianism is characterized by an absence of real political hierarchy, and limited differences between individuals in terms of rank, status, wealth, or power, while strongly egalitarian societies are characterized by these with some combination of powerful sharing and leveling norms, extensive formal networks of reciprocity spanning geographical regions, assertive social mechanisms of norm enforcement, and ritual practices designed to alleviate resulting social tensions. While weak forms of egalitarianism may result from some long-recognized properties of mobile foraging societies, such as group membership flexibility and universal access to both means of economic production and the means of coercion, we argue that strong egalitarianism emerged as a social strategy for coping with foraging risk at larger temporal and spatial scales....
Calcium phosphate precipitation in aqueous suspensions of phosphatidylserine-containing anionic liposomes

Liposomes prepared from 6.3∶1.8∶0.9∶ 1.0 molar mixtures of phosphatidylcholine, dicetyl phosphate, cholesterol, and phosphatidylserine, respectively, (PS(+) liposomes) were compared with similarly prepared liposomes without the phosphatidylserine (PS(−) liposomes) for their effect on calcium phosphate precipitate formation in aqueous solutions at pH 7.4 and 22°C. The liposomes, encapsulated with 50 mM phosphate (PI), were suspended in buffered 2.2 mM CaCl2, 0 or 1.5 mM KH2PO4 solutions and made permeable to Ca2+ fluxes with the ionophore, X-537A. External solution Ca2+ losses were found to be small in both PS(+) and PS(−) liposome suspensions when no ionophore was added. Even with 1.5 mM PI in the external solution, these losses did not exceed 0.2 mM. However, inoculating both liposome preparations with X-537A resulted in rapid, appreciable losses in solution Ca2+. Previous studies showed that in PS(−) liposomes, these latter losses were due to calcium phosphate precipitation, with the precipitate confined to the interior of the liposomes when no external PI was present, but extending to outside the liposomes when the suspending medium was rendered metastable. In the present study, Ca2+ losses resulting from intraliposomally confined precipitation were found to be marginally greater in PS(+) liposomes due primarily to a larger volume of entrapped PI available for reaction in these liposomes. However, with the addition of PI to the external solution, the reverse was observed, i.e., considerably less Ca2+ was lost in PS(+) than in PS(−) suspensions, a result of markedly less X-537A-induced precipitate forming outside PS(+) liposomes. The most probable explanation for this latter decrease was a PS-induced adherence of the outer liposome membranes to the surfaces of developing crystals, restricting the avialability of these surfaces as sites for further growth.
Protein kinase C isoforms as specific targets for modulation of vascular smooth muscle function in hypertension

Vascular contraction is an important determinant of the peripheral vascular resistance and blood pressure. The mechanisms underlying vascular smooth muscle (VSM) contraction and the pathological changes that occur in hypertension have been the subject of numerous studies and interpretations. Activation of VSM by vasoconstrictor stimuli at the cell surface causes an increase in [Ca(2+)](i), Ca(2+)-dependent activation of myosin light chain (MLC) kinase, MLC phosphorylation, actin-myosin interaction and VSM contraction. Additional signaling pathways involving Rho-kinase and protein kinase C (PKC) may increase the myofilament force sensitivity to [Ca(2+)](i) and MLC phosphorylation, and thereby maintain vascular contraction. PKC is a particularly intriguing protein kinase as it comprises a family of Ca(2+)-dependent and Ca(2+)-independent isoforms, which have different tissue and subcellular distribution, and undergo differential translocation during cell activation. PKC translocation to the cell surface may trigger a cascade of protein kinases, such as mitogen-activated protein kinase (MAPK) and MAPK kinase (MEK) that ultimately interact with the contractile myofilaments and cause VSM contraction. Also, PKC translocation to the nucleus may promote VSM growth and proliferation. Increased PKC expression and activity have been identified in several forms of hypertension. The subcellular location of PKC may determine the state of VSM activity, and may be useful in the diagnosis/prognosis of hypertension. Vascular PKC isoforms may represent specific targets for modulation of VSM hyperactivity, and isoform-specific PKC inhibitors may be useful in treatment of Ca(2+) antagonist-resistant forms of hypertension.
The science of useful superconductors - and beyond

Improved methods of depositing thin film composites embodying transition metals have opened opportunities for finding out more about transition metal superconductors. Results from many research groups are reviewed. In order to reach higher transition temperatures with A-15 structures it will be necessary to synthesize them as ordered structures with more metastable compositions. An interesting dependence of the critical currents upon resistivity of A-15 superconductors has been found. Some indication of the temperature dependence of phase boundaries at low temperatures is discussed. The bottleneck in tunneling into transition metals due to the lack of well-behaved barriers has been broken. Superconducting tunneling spectroscopy has given new insights into the stability of high transition temperature superconductors with the A-15; an important role of impurity gases such as oxygen has been demonstrated. Composites consisting of very fine-scaled multilayered films can be synthesized and show crossover and other interesting behavior when the period is reduced below 50A.
The functional relationship of the posterior oblique ligament to the medial collateral ligament of the human knee

Strain in the human knee medial collateral ligament (MCL) was measured in cadavers with a Hall effect strain transducer during normal passive knee flexion, as well as knee flexion accompanied by applied external tibial rotation and valgus torques. In an attempt to determine the contribution of the posterior oblique ligament (POL) to the strain behavior of the MCL, the POL was systematically separated from the MCL and changes in strain in the MCL were observed. These changes in strain were mild and variable, except in the one knee which was later found to be lacking an anterior cruciate ligament. In that particular knee, strain in the MCL increased up to 9.97% under the influence of a valgus torque once the POL fibers had been separated from the MCL. Anatomical dissection and transillumination techniques of the MCL/POL complex demonstrated definite ligament fibers connecting the MCL to the POL. The results demonstrate an intimate anatomical relationship between the POL and MCL. However, the POL and MCL appear to work independently from each other according to our test method.
Emission Spectrometric Determination of Trace Elements in Biological Fluids

An emission spectrometric method of analysis is described, in which trace quantities of copper, iron, aluminum, barium, manganese, nickel, cesium, tin, strontium, chromium, zinc, lead, molybdenum, and cadmium were determined in blood serum. The sample preparation, starting with 2.0 ml of blood serum, is discussed in detail. The source of excitation was a 10 A dc arc. Quantitation was achieved with a direct reading emission spectrometer. The metal concentration, in micrograms per 100 ml of blood serum, was calculated from the experimental data by means of a computer.
Role of microtubule organization in centrosome migration and mitotic spindle formation in PtK1 cells

Quinacrine, an acridine derivative, has previously been shown to disrupt lateral associations between non-kinetochore microtubules (nkMTs) of opposite polarity in PtK1 metaphase spindles such that the balance of spindle forces is significantly altered. We extended the analysis of the spatial relationship of spindle microtubules (MTs) in this study by using quinacrine to compare ATP-dependent requirements for early prometaphase centrosome separation and spindle formation. The route used for centrosome migration can take a variety of pathways in PtK1 cells, depending on the location of the centrosomes at the time of nuclear envelope breakdown. Following quinacrine treatment centrosome separation decresased by 1.9 to 14.0 μm depending on the pathway utilized. However, birefringence of the centrosomal region increased approximately 50% after quinacrine treatment. Quinacrine-treated mid-prometaphase cells, where chromosome attachment to MTs had occurred, showed a decrease in spindle length of approximately 6.0 μm with only a slight increase in astral birefringence. Computer-generated reconstructions of quinacrine-treated prometaphase cells were used to confirm changes in MT reorganization. Early-prometaphase cells showed more astral MTs (aMTs) of varied length while mid-prometaphase cells showed only a few short aMTs. Late prometaphase cells again showed a large number of aMTs. Our results suggest that: (1) quinacrine treatment affects centrosome separation, (2) recruitment of nkMTs by kinetochores is quinacrine-sensitive, and (3) development of the prometaphase spindle is dependent on quinacrine-sensitive lateral interactions between nkMTs of opposite polarity. These data also suggest that lateral interactions between MTs formed during prometaphase are necessary for centrosome separation and normal spindle formation but not necessarily chromosome motion.
Ethanol elimination rates in mice: effects of gender, nutrition, and chronic ethanol treatment.

Abstract Twenty male and 20 female mice of a heterogeneous stock were assigned to each of three groups. One group was administered ethanol in a liquid diet for 9 days, a second group was fed an isocalorically controlled diet containing no ethanol for the same length of time, and the third group was fed standard lab chow. Each animal was injected with a dose of ethanol equal to 3.5 g/kg body weight at the time corresponding to 6 hr post-withdrawal for the ethanol-treated group. Blood ethanol elimination rates were determined at 1, 2, and 3 hr post-injection. Neither gender, nutritional state, nor chronic ethanol treatment was found to affect ethanol elimination rates.