cssi/SciSciGPT-SciSciNet huggingface dataset:
Multiple-goal reinforcement learning with modular Sarsa(O)

We present a new algorithm, GM-Sarsa(O), for finding approximate solutions to multiple-goal reinforcement learning problems that are modeled as composite Markov decision processes. According to our formulation different sub-goals are modeled as MDPs that are coupled by the requirement that they share actions. Existing reinforcement learning algorithms address similar problem formulations by first finding optimal policies for the component MDPs, and then merging these into a policy for the composite task. The problem with such methods is that policies that are optimized separately may or may not perform well when they are merged into a composite solution. Instead of searching for optimal policies for the component MDPs in isolation, our approach finds good policies in the context of the composite task.
Flowering, Fruit Set and Development under Warm Conditions

Flowering, fruit set, and development under tropical and subtropical conditions parallel these processes as they occur in temperate zones (for reviews see Buttrose, 1974; Monselise, 1986; Mullins. et al., 1992; Sedgley, 1990; Srinavasan and Mullins, 1981); however, higher temperatures during the vegetative period and the lack of sufficient chilling pose problems not observed under most conditions in the temperate regions. Retardation or stoppage of growth favors flower induction, particularly in pome fruits that form terminal flower buds, but growth rate may be excessive under high temperatures. Marginal chilling results in erratic bloom, with flowers opening over an extended period of time. This leads to problems in pollination, in timing of pesticide and thinning treatments, and variable size and maturity of the fruits on the same tree. Thus cultural practices and choice of site often differ from those in colder regions. In this chapter I will discuss some of the environmental factors and cultural practices that affect flowering, fruit set, and fruit development in warm climates. Sherman and Rodriguez-A. (1996) recently reviewed temperature effects on growth and fruiting of peach under such conditions.
High Pressure Crystal Chemistry: “Stuffed” Framework Structures at High-Pressure

This chapter explores the role of alkali and alkaline earth atoms in complex framework structures synthesized at high pressure, as well as their role in these compounds at high pressure using the procrystal model. This model approximates the electron density distribution of a crystal by superimposing spherically-averaged electron density distributions of static, ground state neutral atoms at the observed atomic sites in the crystal. We assume that a bonded interaction occurs between a pair of atoms if a topological feature, a (3,-1) critical point, exists in the electron density between the atoms. The bonded interactions of non-framework cations in tetrahedral frameworks (low albite and microcline), novel high-pressure frameworks with corner-linked SiO4 and SiO6 polyhedra (high-pressure Na-silicates, titanites, KTiOPO4) and octahedral frameworks (perovskites) are described. The role of the non-framework cations in these compounds at high pressure is also investigated, including phase transitions.
LOURENÇO FILHO E JUAZEIRO DO PADRE CÍCERO: UMA HIERARQUIA DISCURSIVA CIVILIZACIONAL

A presente pesquisa analisa a escrita e os olhares apresentados sobre o sertao do Juazeiro do Norte (CE), pelo educador brasileiro Lourenco Filho, em sua primeira publicacao, Juazeiro do Padre Cicero: cenas e quadros do fanatismo no nordeste . A publicacao e fruto do seu exercicio na funcao de diretor de instrucao publica do Ceara (1922-1923). E um diario etnografico de sua viagem, que ocorre em virtude da proibicao do padre Cicero Romao Batista, na condicao de prefeito, da realizacao do servico de recenseamento das criancas. Lourenco Filho apresentou uma imagem miseravel e insana da cidade e do padre, devido ao seu envolvimento na producao e na divulgacao das teorias cientificas dominantes do pensamento intelectual do inicio da Republica brasileira, em contraposicao ao mundo mitico. Para isso, recorremos ao conceito de Processo Civilizador de Norbert Elias (1993;1994) para compreender essa producao e os seus desdobramentos na imagem negativa dos sertanistas e do Padre Cicero em contraposicao a valorizacao do discurso do intelectual preocupado com a modernizacao do Brasil. Concluimos que a polarizacao Fortaleza (Cidade) – Juazeiro (Sertao) reforcou o discurso de que o habitante da capital, era sujeito integrado ao ideal de nacao, enquanto o devoto sertanejo pertencia a comunidade primitiva de “fanaticos”, considerada um “grande hospicio”, que precisava ser incorporada a civilizacao.
Statistical considerations of parasiticide screening tests and confirmation trials

Abstract This chapter gives an overview of statistical design and analysis methods that may be applied to the screening tests and confirmatory trials such as those presented in this book. Particular attention is given to defining and understanding the fundamental elements of experimental design, such as the experimental unit, true replication versus pseudoreplication, and the importance of randomization, so that the statistical methods described can be appropriately applied and results be correctly interpreted. The topics covered span simple univariate summaries to statistical modeling techniques of varying degrees of complexity.
Information literacy at an academic library : Development of a library course in an online environment

Abstract An increase in its distance-learning student population prompted Regent University Library to consolidate the library's information literacy program into one course. The course eventually went online to meet the needs of distance learners. During course development and implementation, librarians learned what worked well and what did not. Unexpected obstacles, such as database name and interface changes, created problems that were handled and overcome. As student surveys were analyzed and librarian experience increased, the course evolved and changed.
Inhibitory effects of phenylbutyrate on the proliferation, morphology, migration and invasiveness of malignant glioma cells

The purpose of this study was to characterize the effects of sodium 4-phenylbutyrate (phenylbutyrate) on the proliferation, morphology, migration and invasiveness of malignant glioma cells in vitro. Phenylbutyrate is a novel differentiating and cytotoxic compound used clinically with low toxicity in the treatment of beta-thalassemia, sickle cell anemia and urea cycle disorders. Preliminary clinical trials testing phenylbutyrate as an anti-cancer agent have included patients with malignant glioma. However, little information is available regarding the effects of phenylbutyrate on glioma cells, particularly with respect to the expression of genes important in the pathogenesis of glial malignancy. In experiments reported here, glioma cell lines and explant cells from a tumor patient were exposed to 2, 4 and 8 mM phenylbutyrate and compared to untreated control cells. The effect on cellular proliferation was assessed using cell counts and DNA flow cytometry. Changes in morphology were evaluated using vimentin staining. Scratch and Matrigel assays were performed to assess changes in cellular migration and invasiveness. Finally, Northern blot analysis was used to study c-myc and urokinase expression. Phenylbutyrate was found to have dose-dependent inhibitory effects on glioma cell proliferation, morphology, migration, invasiveness and c-myc and urokinase expression. Mean growth-inhibitory (IC50) phenylbutyrate concentrations ranged from 0.5 mM for T98G cells to 5.0 mM for explant cells. Phenylbutyrate treatment reduced % S phase cells, increased % G0/G1 cells, and produced morphologic changes consistent with induction of differentiation. 24 hours of treatment with 4 mM phenylbutyrate resulted in a 50% reduction in migration and invasiveness. Northern blots showed a decrease in urokinase and c-myc expression at non-cytotoxic doses. We conclude that phenylbutyrate is a promising candidate compound for treating patients with malignant glioma.
Toward closed loop recycling of polyester fabric: Step 1. decolorization using sodium formaldehyde sulfoxylate

Abstract Although polyethylene terephthalate (PET) fibers comprise the largest single fiber type used in the global textile community, recycling of dyed PET-based fabric is limited, resulting in the disposal of considerable amounts of PET fabric in landfills every year. Because PET does not readily biodegrade, interest in recycling some or all of the dyed textiles derived from this substrate is of interest. A step toward achieving this vision was investigated in this study, namely the development of an effective decolorization process. In this study, sodium formaldehyde sulfoxylate (SFS) was employed to decolorize disperse dyes developed for PET and it was found effective for decolorizing C.I. Disperse Yellow 42, C.I. Disperse Orange 30, and C.I. Disperse Blue 56 in water/acetone media and the process was extended to the decolorization of dyed PET fabric. An optimized combination of treatment time (30 min), water to acetone ratio (1:2), SFS concentration (10 g/L), temperature (100 °C), and liquor ratio (50/1) was found to give good color removal for a range of well-known and widely used disperse dye types. Fabric strength assessments were also investigated and it was found that SFS decolorization had no influence on PET strength, as judged by intrinsic viscosity and bursting strength measurements. It was also found that the acetone component of the decolorization medium could be recovered and reused.
Avoidant/restrictive food intake disorder symptoms are frequent in patients presenting for symptoms of gastroparesis

INTRODUCTION Patients with symptoms of gastroparesis/dyspepsia often avoid foods or restrict eating for symptom management. There is growing interest in understanding risk for feeding/eating disorders (FEDs) like avoidant/restrictive food intake disorder (ARFID). Among patients presenting with gastroparesis/dyspepsia symptoms, we aimed to determine: (a) FED symptom frequency, and (b) relation of FED symptoms to gastrointestinal symptom severity and gastric retention abnormalities. METHODS Adult patients (N = 288; 78% female) referred for gastroparesis/dyspepsia symptoms at two academic medical centers from January 2018-February 2019 completed self-report surveys for gastrointestinal symptom severity and FED symptoms. Gastric retention data were available for 210 patients, using 4-hour EggBeater gastric emptying scintigraphy (GES). RESULTS Clinically significant FED symptoms were present in 158 patients (54.9%). Interestingly, 115 patients (39.9%) met conservative self-report cutoff for ARFID symptoms, with 67 (23.3%) patients having documented psychosocial/medical impairment. Of those with survey data for other FEDs (n = 239), only 28 patients (11.7%) had restrictive eating disorders (anorexia nervosa; unspecified FED). Likelihood of having FED symptoms was significantly associated with greater gastroparesis symptom severity (OR = 2.23, P < .001), but not GES. In addition, gastroparesis symptom severity was moderately and significantly associated with greater ARFID symptom severity (b = 0.45, P < .001), but neither GES nor other FED symptoms. DISCUSSION In patients presenting with gastroparesis/dyspepsia symptoms, FED symptoms were frequent (55%), particularly ARFID, and were associated with greater gastrointestinal symptom severity, but not gastric retention. Gastroparesis/dyspepsia symptoms may mimic FEDs, particularly ARFID. Clinicians should be cautious about diagnosing ARFID in gastroparesis/dyspepsia patients, and screening for ARFID could assist behavioral treatment referral.
Predictors of increased risk for early treatment non-adherence to oral anti-estrogen therapies in early-stage breast cancer patients

Non-adherence to the oral anti-estrogen therapies (AET) tamoxifen and aromatase inhibitors in early-stage hormone receptor-positive breast cancer is associated with numerous negative clinical outcomes. Prior studies have identified that non-adherence is associated with psychological and menopause-related factors which are present during AET, but the presence of these characteristics prior to AET initiation has not been investigated. Psychological and menopause symptoms (depression, generalized anxiety, insomnia, somatosensory amplification, hot flash frequency, and hot flash-related interference) were assessed pre-AET initiation as predictors of subsequent non-adherence in 73 participants (Mage = 55.0, SD = 10.1 years). Participants self-reported treatment adherence after three and 6 weeks on AET. Participants who did not initiate treatment were excluded from the analysis. Discriminant function analyses revealed that the hypothesized set of psychological and menopause symptoms at baseline (pre-AET) together statistically distinguished between those who were non-adherent (n = 19; 26.0%) from adherent (n = 54; 74.0%) at 6 weeks. Model classification accuracy was statistically significant (Wilks’ ƛ = 0.782, χ2(6) = 15.50, p = 0.017) at the 6-week timepoint. Results were consistent at 3 weeks. Pre-AET psychological and menopause symptoms correctly classified 6-week treatment adherence 77.9% of the time. Depression contributed most to distinguishing between adherers and non-adherers. The presence of a composite profile of psychological and menopause symptoms prior to AET initiation may help to identify early treatment non-adherence. Results can be used to identify patients at risk for non-adherence and to guide psychological and symptom management interventions.
GUI-focused overviews of mobile development videos

The need for mobile applications and mobile programming is increasing due to the continuous rise in the pervasiveness of mobile devices. Developers often refer to video programming tutorials to learn more about mobile programming topics. To find the right video to watch, developers typically skim over several videos, looking at their title, description, and video content in order to determine if they are relevant to their information needs. Unfortunately, the title and description do not always provide an accurate overview, and skimming over videos is time-consuming and can lead to missing important information. We propose a novel approach that locates and extracts the GUI screens showcased in a video tutorial, then selects and displays the most representative ones to provide a GUI-focused overview of the video. We believe this overview can be used by developers as an additional source of information for determining if a video contains the information they need. To evaluate our approach, we performed an empirical study on iOS and Android programming screencasts which investigates the accuracy of our automated GUI extraction. The results reveal that our approach can detect and extract GUI screens with an accuracy of 94%.
Everyday life and the management of risky bodies in the COVID-19 era

This essay explores how public reception of, and individual resistance to, public health mandates have reinforced agentic notions of bodily management in the COVID-19 era. Our collective approach t...
The Willingness to Pay for Improving Drinking water supply in Tamil Nadu: A Case study of tannery water pollution in Vellore District

Tannery pollution and the resulting health impacts are a worldwide problem. Due to the cheap labour availability and tax pollution regulation leather tanning has become a popular export earning industry in countries like India, Pakistan and Bangladesh. Given its huge potential for export earnings and local economic livelihood especially for poor households, its adverse health impacts seem to have been ignored. Also thus far there has been no systematic economic valuation study in India. This also attempts to estimate the health cost of this industry to people including those very households that have made leather tanning their livelihood. Therefore the present research study aims to examine economic valuation of human health impact of the pollution from the tannery industry in Vellore district, using the Willingness to Pay method. Vellore district in Tamil Nadu state of India is purposively selected because of its larger number of tanneries.
Association between acculturation and metabolic syndrome in Hispanic adults mediated by fruits intake.

Objectives Hispanic adults in the USA tend to have a disproportionate prevalence of metabolic syndrome (MetS) as compared to other races. Design We examined whether the association between acculturation and MetS and its components are mediated by the intake of fruit in Hispanics. Setting Data from the National Health and Nutrition Examination Surveys 2009-2016 were used in this study. Participants A total of 2078 Hispanics aged ≥ 20 years were included in this analysis. Results The mediating role of total fruit intake was assessed using multivariable-adjusted logistic structural equation models with the bootstrapping method by estimating indirect (IE) and direct (DE) effects from acculturation to MetS. High acculturation was associated with increased odds of MetS (adjusted OR = 1·20, 95 % CI 1·04, 1·39), central obesity (OR = 1·24, 95 % CI 1·07, 1·44) and high blood pressure (OR = 1·16, 95 % CI 1·02, 1·32) among Hispanic adults. Total fruits intake partially mediated the associations of acculturation with MetS (ORIE = 1·02, 95 % CI 1·00, 1·03) and central obesity (ORIE = 1·02, 95 % CI 1·00, 1·03), whereas fully mediated the association between acculturation and high blood pressure (ORIE = 1·03, 95 % CI 1·01, 1·06). Moreover, intake of total fruits fully mediated the acculturation-MetS association among Mexican Americans (ORIE = 1·02, 95 % CI 1·00, 1·05). Conclusions Our findings suggested that increasing fruit consumption may reduce the impact of high acculturation on MetS development in Hispanic adults. Further studies are needed to confirm these findings.
Scaling Generalized N-Body Problems, A Case Study from Genomics

This work examines a data-intensive irregular application from genomics that represents a type of Generalized N-Body problems, one of the “seven giants” of the NRC Big Data motifs. In this problem, computations (genome alignments) are performed on sparse data-dependent pairs of inputs, with variable cost computation and variable datum sizes. Unlike simulation-based N-Body problems, there is no inherent locality in the pairwise interactions, and the interaction sparsity depends on particular parameters of the input, which can also affect the quality of the output. We build-on a pre-existing bulk-synchronous implementation, using collective communication in MPI, and implement a new asynchronous one, using cross-node RPCs in UPC++. We establish the intranode comparability and efficiency of both, scaling from one to all core(s) on node. Then we evaluate the multinode scalability from 1 node to 512 nodes (32,768 cores) of NERSC’s Cray XC40 with Intel Xeon Phi “Knight’s Landing” nodes. With real workloads, we examine the load balance of the irregular computation and communication, and the costs of many small asynchronous messages versus few large-aggregated messages, in both latency and overall application memory footprint. While both implementations demonstrate good scaling, the study reveals some of the programming and architectural challenges for scaling this type of data-intensive irregular application, and contributes code that can be used in genomics pipelines or in benchmarking for data analytics more broadly.
The utility of repeated cytologic evaluation of cerebrospinal fluid in individuals with metastatic breast cancer

Introduction Metastasis of breast cancer to the central nervous system, either in the brain parenchyma or leptomeninges (LMC), is a late feature of the disease . Detection of malignant cells in the cerebrospinal fluid (CSF) is the diagnostic standard for LMC. Repeated CSF examinations are often performed following an initial diagnosis positive for malignancy. This study evaluates the significance of repeated CSF evaluation in women with metastatic breast cancer to the central nervous system. Materials and Methods Cases of adenocarcinoma of breast diagnosed by CSF cytology from 1990 through 2012 documenting: age, radiologic findings, treatment modality, and the number of repeated CSF cytology specimens and their respective interpretations. Results Fifty-one patients were identified; 28 patients (54.9%) had a single initial positive CSF performed and 23 (45.1%) had multiple CSF cytology samples (range = 2-25, mean = 5.5). Despite interval “negative” and “atypical cells” results on CSF cytology specimens, all 23 patients with multiple samples had at least one follow-up positive CSF cytology sample. Conclusion The prognosis of the patients with an initial CSF diagnosis of adenocarcinoma was poor, regardless of the respective interpretations on the repeated CSF specimens, even in the presence of interval negative CSF.
Plancherel-Pôlya type inequality on spaces of homogeneous type and its applications

In this paper, using the discrete Calderon reproducing formula on spaces of homogeneous type obtained by the author, we obtain the PlancherelP6lya type inequalities on spaces of homogeneous type. These inequalities give new characterizations of the Besov spaces ip'I and the 'riebel-Lizorkin spaces F'qon spaces of homogeneous type introduced earlier by the author and E. T. Sawyer and also allow us to generalize these spaces to the case where p, q < 1. Moreover, using these inequalities, we can easily show that the Littlewood-Paley G-function and S-function are equivalent on spaces of homogeneous type, which gives a new characterization of the Hardy spaces on spaces of homogeneous type introduced by Macias and Segovia.
Beyond the Limits: Flight Enters the Computer Age

Computers and flying machines are two dominant technologies of our time. Beyond the Limits shows the ways in which they interact, clearly illustrating the complex issues and devices involved in their mutual evolution. It describes and illustrates how computer technology has affected the theory and practice of the engineering and operations of aircraft and spacecraft from 1945 to the present. Paul Ceruzzi points out that the "revolution" in aerospace technology has been going on for at least forty years. For the first time, he tells how modern flight depends on computers, how this came about, and what its consequences are. He brings to light new facets of the individual stories of aerospace and computing, while also revealing more general themes about the dynamics and evolution of these modern technologies. Spacecraft and fighters make use of leading-edge computer technologies in their design, testing manufacture, navigation and operation; moreover pilots and astronauts rely on computer simulations throughout their training. Ceruzzi describes these technologies and their history. In separate chapters he focuses on Northrop ("midwife of the computer industry"), missile tracking, Whirlwind, Apollo, Minuteman, and the software involved. An appendix discusses the role that on-board and ground computers played in the explosion of the space shuttle Challenger.
Topological Crystalline Insulator Phase in Graphene Multilayers.

Interlayer coupling in graphene multilayers with certain commensurate twists is predicted to form a 2D topological insulator.
Drug–Nutrient Interactions in Transplantation

Although nutrient effects and nutritional status are specific to each type of organ transplant, there are some basic premises that apply to transplantation in general. Those guidelines can be explained in terms of the time period surrounding transplantation.
Neural networks with cellular atrophy for geometric database classifications

In this paper we examine the use of geometric modeling in grouping and classification. A neural network approach is suggested to combine the completeness of information provided by a geometric modeler with the uncertainty required in the grouping process. The utilization of highly connectionist systems in such an environment is investigated. The advantages and shortcomings of these systems are discussed. The impact of cellular atrophy, as observed in biological systems, on highly connectionist systems is proposed. The effect of atrophy criterion on systems' size and efficiency is examined.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Parametric representation of a superconducting high-current generator

An equivalent circuit model of a superconducting high-current brushless generator, the rotating-spot flux pump, is derived. The idealized version of the flux pump consists of a superconducting strip and a reciprocating magnet. This configuration has been used to make the mathematics manageable. Various design parameters describing the performance of the flux pump are derived. These derivations are used to determine the equivalent circuit model of the flux pump. The internal inductance of the pump associated with the switching loss is estimated from the surface current distribution on the superconducting sheet. The inductive transfer effects taking place in the pump are discussed, and a numerical example is given to provide an idea of the order of magnitude of the design parameters. The results of the calculations point to the advantages of the low internal inductance of the flux pump and of the current switching occurring as late as possible in the pumping cycle. >
Sex differences in the dendritic branching of dentate granule cells following differential experience

Abstract Male and female hooded rats were raised from weaning in either a complex or an isolated environment in two separate replications. After one month, the brains were Golgi-Cox stained and dendritic fields of dendate gyrus granule cells were quantified. There was a sex differences in response to the environment. Female raised in the complex environment had more dendrite per neuron than females from the isolated environment in both replications. This difference was evident chiefly in the length of dendritic branches. Males showed few difference in response to the environments in either replication and, to the extent that there were differences, there was a slight tendency for isolated males to have more dendrite per neuron than males from the complex environment. In comparisons between the sexes within an environment, males had more dendritic material per neuron than females in the isolated environment while females had a larger dendritic tree than males in the complex environment. The above pattern of differences was not altered when hemisphere or location of the cell body within the granule cell layer were taken into account, although the shape of the dendritic tree varied with the cell's position in the layer in all groups. Thus, females show greater structural change in the dentate granule cells in response to these environments than do males.
Line strengths for erbium in yttrium orthoaluminate

Absorption measurements are used to calculate the oscillator strengths for transitions from the $^{4}I_{\frac{15}{2}}$ ground state of ${\mathrm{Er}}^{3+}$ in YAl${\mathrm{O}}_{3}$ to the 14 lowest multiplets lying between 12 540 and 36 360 ${\mathrm{cm}}^{\ensuremath{-}1}$. The results of these measurements and computations employing the Judd-Ofelt theory are compared to recently published results.
Interplay between Jahn-Teller instability, uniaxial magnetism, and ferroelectricity in Ca 3 CoMnO 6

${\text{Ca}}_{3}{\text{CoMnO}}_{6}$ is composed of ${\text{CoMnO}}_{6}$ chains made up of face-sharing ${\text{CoO}}_{6}$ trigonal prisms and ${\text{MnO}}_{6}$ octahedra. The structural, magnetic, and ferroelectric properties of this compound were investigated on the basis of density-functional theory calculations. ${\text{Ca}}_{3}{\text{CoMnO}}_{6}$ is found to undergo a Jahn-Teller distortion associated with the ${\text{CoO}}_{6}$ trigonal prisms containing high-spin ${\text{Co}}^{2+}$ $({d}^{7})$ ions, which removes the ${\text{C}}_{3}$ rotational symmetry and hence uniaxial magnetism. However, the Jahn-Teller distortion is not strong enough to fully quench the orbital moment of the high-spin ${\text{Co}}^{2+}$ ions thereby leading to an electronic state with substantial magnetic anisotropy. The Jahn-Teller distorted ${\text{Ca}}_{3}{\text{CoMnO}}_{6}$ in the magnetic ground state with up-up-down-down spin arrangement is predicted to have electric polarizations much greater than experimentally observed. Implications of the discrepancy between theory and experiment were discussed.
Optimization of Electrospinning an SU-8 Negative Photoresist to Create Patterned Carbon Nanofibers and Nanobeads

The optimization of electrospinning SU-8 2100 negative photoresist was performed to create carbon micro/nanofibers and beads that can be patterned after electrospinning by using UV radiation. The fiber diameters had a range of 300 nm to 1 μm, based upon the selected electrospinning parameters. Low concentrations of the SU-8 2100 resulted in beads while specific higher concentrations produced well-defined fibers. Fibers and beads were converted to carbon through pyrolysis and retained their three dimensional structure. By utilizing the photosensitive properties of the SU-8 negative photoresist, the electrospun fibers were patterned by UV photolithography. The fibers and beads were characterized by SEM and Raman microscopy, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A novel AC-AC converter with minimum snubber requirement

Matrix converters inherently have problems with commutation which are generally mitigated by using snubbers. Problem of commutation also places a limitation on their voltage transfer ratio. In this paper, a new high frequency linked AC-AC converter topology is proposed which ensures reliable commutation, taking care of parasitic inductances, with minimum snubber on the input side. A simple switching algorithm to achieve this is also suggested. The topology has the flexibility to improve the voltage transfer ratio of a conventional matrix converter while maintaining unity power factor on the input AC side. Simulation results support the feasibility of the scheme.
Genetic toxicology of metal compounds: An examination of appropriate cellular models †

Bacterial systems have not had success predicting metal carcinogenicity. Hypotheses explaining this failure are examined. Using a broad genetic endpoint, λ prophage induction, under sub‐toxic growing conditions, genotoxicity is seen for compounds of chromium, manganese, lead, molybdenum and tungsten. Copper, manganese, arsenic and molybdenum compounds enhanced UV mutagenesis in E. coli WP2. The toxicity of metal compounds to cultured mammalian cells correlates well with rat oral LD50 values. Whereas insolubility can present problems in bacterial studies, concentrations of metal compounds toxic to mammalian cells can be determined even in the presence of precipitate, and sometimes [Pb(NO3)2, BaCl2 and BeCl2] occurs only in its presence. PbS and MnS, which are insoluble, are much more toxic than the more soluble compounds Pb(NO3)2 and MnCl2. These results demonstrate the importance of cellular phagocytosis of insoluble metal compounds as a factor in studying the toxicity and genotoxicity of metal compounds.
Social identity as a useful perspective for self-concept–based consumer research

Psychology's study of the self-concept has generated numerous paradigms with different underlying assumptions. In this article it is argued that these assumptions must be considered before a self-concept paradigm can be meaningfully applied to consumer research. The major premise in this article is that the recent work on social identity is a particularly meaningful paradigm to adopt for consumer research that implicates the self. This argument is developed with a conceptual discussion of major self-concept issues, an overview of basic self-concept paradigms in psychology, and a synthesis of possible factors that may be considered in future theories of social-identity–based consumption decision making. © 2002 Wiley Periodicals, Inc.
Reconsidering the Regional Economic Development Impacts of Higher Education Institutions in the United States.

Drucker J. Reconsidering the regional economic development impacts of higher education institutions in the United States, Regional Studies. This study models relationships between US higher education activities and regional economic performance, 2001–11. Advances include incorporating all degree-granting institutions; estimating spatial spillovers; and comparing multiple economic outcomes, including production and entrepreneurship. Higher education impacts vary by outcome measure but are less influential than in previous studies. Spillovers are substantial up to 60 miles (97 kilometres), reflecting considerable influence across space. More advanced degrees, science and engineering education, and population educational attainment are positively associated with entrepreneurial activity. These findings encourage the traditional university missions of research and teaching, and general policies promoting entrepreneurship, to support economic performance.
Subnanosecond risetime high power pulse generation using photoconductive bulk GaAs devices

The interest in fast risetime, high power photoconductive devices stems from several potential applications including pulse, impulse, and high power microwave generation [1, 2]. As the voltage becomes large and the switching speed becomes extremely fast, the generation of high power electrical pulses using photoconductive devices becomes very complicated because of effects such as surface flash-over, stray inductance, stray capacitance, and abrupt impedance transitions. Two ap- proaches were taken to produce maximum output voltage amplitude without degradation in switch risetime. A coaxial transmission line with a switch holder filled with a high dielectric strength liquid was fabricated for long pulsewidths ( 2 ns) . For the narrow pulsewidths ( 2 ns) a quasi-radial transmission line was fabricated. By incorporating a photoconductive bulk GaAs device with opposite gridded elec- trodes into these specially designed energy storage elements, and illuminating the switch with a mode-locked Nd:YAG laser, electrical pulses with risetimes of several picoseconds have been realized.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Three-dimensional magnetic terahertz metamaterials using a multilayer electroplating technique

In the last decade, the development of metamaterials has led to exotic phenomena not shown in nature, including negative refractive index, invisibility cloaking and perfect absorption. To achieve these effects requires creating magnetically resonant subwavelength structures, since naturally occurring magnetism typically occurs at relatively low frequencies. In the far-infrared, or terahertz (THz), region of the electromagnetic spectrum, it is difficult to obtain a strong magnetic response from planar metamaterials at normal incidence. In this paper, multilayer electroplating is used to fabricate three-dimensional (3D) split-ring resonators that stand up out of plane. This enables the maximum coupling to the magnetic response at normal incidence. Characterization using THz time-domain spectroscopy indicates a strong magnetic resonance, and parameter extraction reveals a negative permeability from 1 to 1.3 THz with the minimal value of −2. The successful design, fabrication and characterization of 3D metamaterials provide opportunities to achieve different electromagnetic properties and novel devices in the THz range.
Role of Russell - Taylor delta reconstruction nail in the management of complex proximal femoral fractures

Background: Complex proximal femoral fractures are challenging problem. Methods: Forty-one patients had Russell- Taylor Delta reconstruction nailing done during the period from March 1992 to December 1996. 38 patients could be followed both clinically and radiologically either up to the fracture union or death. Clinical outcome was assessed by Kyle's criteria. Out of 13 patients with high-energy comminuted fractures, 12 were rated excellent or good. There was one death due to poly trauma. Results: Out of six elderly subtrochanteric fractures, 4 had excellent or good results. There was one poor result and one death. Out of 11 elderly interochanteric fractures with subtrochanteric extension, 8 had excellent or good results. There was 1 fair, 1 poor result and 1 death. In the elderly groups, the poor results were due to poor pre- existing medical conditions of the patients. In all the seven cases of pathological lesions, excellent or good results were achieved either till fracture union or death because of their malignant pathology. Conclusion: Russell- Taylor Delta reconstruction nail is a very useful device in high-energy comminuted proximal femoral fractures, in elderly low energy proximal femoral fractures and also in pathological lesions. The implant provides bio-mechanically stable fixation. The relatively high complication rate in elderly patients is because of their poor medical condition. In cases of pathological lesions, it is always preferable to fix the bone at the stage of impending fracture.
The effect of noise-cancelling headphones or music on pain perception and anxiety in men undergoing transrectal prostate biopsy.

Objective To assess the effect of noise-cancelling headphones with or without music on patient pain and anxiety associated with routine, office-based transrectal ultrasound (TRUS)-guided prostate biopsy in a prospective randomized study. Methods Patients scheduled for prostate biopsy as a result of elevated prostate-specific antigen and/or abnormal digital rectal examination were prospectively enrolled and randomized into a control, noise-cancelling headphones, or music-headphones group. Patients completed pain and anxiety questionnaires and had their physiological parameters assessed before and after the procedure and compared across groups. Results Eighty-eight patients were enrolled. Pain scores increased from baseline across all study groups, with the lowest mean score in the music group. No appreciable change was noted in anxiety scores after the procedure between groups (P >.05). Although postbiopsy systolic blood pressure values remained comparable with baseline levels in all groups, postbiopsy diastolic blood pressure increased in the control and headphones groups (P = .062 and .088, respectively) but remained stable in the music group (P = .552) after biopsy, indicating lesser physiological response to anxiety and pain in this group. Conclusion Music-induced attention shift during prostate biopsy may have a beneficial impact on procedural anxiety and pain perception, but no apparent effect was noted for use of headphones alone. Further studies are necessary to explore strategies to reduce perceived anxiety and pain in men undergoing prostate biopsy.
SELECTIVE CYCLOOXYGENASE-2 INHIBITORS REDUCE URETERAL CONTRACTION IN VITRO: A BETTER ALTERNATIVE FOR RENAL COLIC?

Purpose: To quantitate the effects of a selective cyclooxygenase (COX)-2 inhibitor, NS-398, on porcine and human ureteral contractility in vitro.Materials and Methods: This study was performed in 3 distinct groups. In group 1, segments of ureter were obtained from freshly sacrificed domestic swine. Sections were isolated and suspended longitudinally. Twenty-four ureteral segments were treated with either indomethacin (a nonselective COX inhibitor), NS-398 (selective COX-2 inhibitor), or DMSO (control). Spontaneous contractions were then recorded in each group. In group 2, fifteen segments of human ureter were obtained from patients undergoing donor nephrectomy or ureteral reimplantation. Segments were isolated and suspended as above, and treated with either indomethacin, NS-398, or DMSO. In group 3, eighteen sections of human ureter obtained from donor nephrectomy patients were passively sensitized for 20 hours in ragweed allergic donor serum. Ureteral segments were then treated with either indomethacin, ...
Demographics and the fate of the young scientist

Many have suggested that young scientists are having a more difficult time getting research grants, citing the fact that the average age of recipients of prestigious grants is getting higher. We present a population model that suggests that the reason the average age of grant recipients is now higher is because the growth rate of science has slowed down in the last four decades.
Helping as a Function of Number of Bystanders and Ambiguity of Emergency

Previous research has shown that bystanders in groups are less likely to intervene in emergencies than bystanders who are alone (a "numbers effect"). In the present research, in one field and three lab studies, this numbers effect was stronger and there was less help when an emergency could be heard only rather than both seen and heard.
Weighted polynomial approximation on the integers

We prove here some polynomial approximation theorems, somewhat related to the Szasz-Mfintz theorem, but where the domain of approximation is the integers, by dualizing a gap theorem of C. l ~ Y I for periodic entire functions. In another Paper [7], we shall prove, by similar means, a completeness theorem ibr some special sets of entire functions. I t is well known (see, for example [l]) tha t i f E is the space of all entire functions in the topology of uniform convergence on compact sets, then the dual space of continuous complex-valued linear functionals on E may be represented as E0, the space of entire functions of exponential type. Now let E (1) b e the space of entire functions of period 1. Then it may be shown that the dual of E (1) can be represented as E0 (l), where E0(1) is the following quotient space of E0: define / ~ g for functions 1, g e E0 i f / _ g is a multiple of sin z~z, and let E0 (l) be the space of equivalence classes of E0 modulo this relation of equivalence. Now E0(1) is apparent ly the same space as the space of restrictions of functions in E0 to the integers Z. Each such restriction is just a two-sided sequence of complex numbers, of at most exponential growth. ConVersely, it is easy to interpolate any such sequence by an entire function of exponential type. Thus, the dual of E(1) is just the space of all such sequences. Actually, we establish this identification by another procedure. To any theorem about periodic entire functions will correspond a theorem about the space of sequences described above. In [6], C. RI~NYI proved an interesting gap theorem, reproduced below. We show by means of duality tha t certain theorems of polynomial approximation are equivalent to this theorem. The domain of approximation is the integers in one case, and the positive integers in another ease. To our knowledge, the problem of polynomial approximation on the integers has not been Considered except in the note [3]. We know of no direct proof of our results. Ultimately, the R ~ Y I result depends on a simple application of Rolle's theorem. I t Would be of interest to have more precise gap theorems than the R~NYr theorem and also to have direct proofs of the results we prove by means of it.
Modeling the variable amplitude fatigue of composite materials: A review and evaluation of the state of the art for spectrum loading

Abstract In this article, we review the experimental research and modeling of fiber reinforced polymer composite materials subjected to variable amplitude fatigue. In general, these models are empirical or phenomenological and contain parameters that must be determined using constant, and in some cases variable, amplitude fatigue data for the material system in question. In many cases, the authors who proposed these models simply fit them to their experimental variable amplitude results and thus their predictive ability has remained uncertain. The predictive accuracy of the fatigue models examined in this article was compared by applying them to four material systems for which extensive fatigue data was available. Several approaches are rejected because the data required to fit them are not available or their formulation prevents straightforward application to a spectrum loading with blocks of one cycle in length. Four damage accumulation rules and eight residual strength approaches are fit to the static, constant amplitude fatigue, residual strength, and two block repeated fatigue loading for each data set. Then the models are used to predict the fatigue life under variations of WISPER, WISPERX, and Rayleigh distributed spectrum fatigue loads that were applied experimentally. Results show that the Palmgren–Miner rule is non-conservative in every case and gains in accuracy are possible by using a simple residual strength law such as the one proposed by Broutman and Sahu. More complex residual strength approaches gave more accurate results in some cases, but overall did not provide a significant improvement relative to Broutman and Sahu’s model.
Autobiography of a first-time discretionary microcomputer user

Research in the area of human-computer interaction has typically concentrated on hardware and software design characteristics which increase the usability of the system, or the effectiveness of the relationship between the user and the system in the accomplishment of a task (Bennett, 1979).Few of these studies have concentrated on documentation. This is striking since the documentation of a computer system is a major portion of the user's learning experience with the system and also the primary interface when difficulties with the system occur. There is a growing market of users who are expected to learn how to use a computer system solely by reading the documentation, namely, the personal computer users. The number of privately authored books on “how to survive the personal computer experience” bespeak both the growing number of such users and the inadequacy of the documentation provided by the vendors.
Trayvon Martin and the curriculum of tragedy: critical race lessons for education

In what ways do the tragedies centered on the lives of black youth, particularly black male youth, inform teachers, education policymakers, and teacher educators about what knowledge is most worth knowing? In this counter/story, we will examine the details of the life and death of Trayvon Martin. From these details, we will extract and interpret a curriculum of tragedy that draws from Derrick Bell’s particular contributions to critical race theory (CRT) applies its central tenets. This article will conclude with lesson for black education for teachers, education policymakers and teacher educators.
Convection and diffusion effects during dendritic solidification

A report is presented of the first quantitative measurements of dendritic growth at supercooling levels where convection instead of diffusion is the controlling heat transfer mechanism. Precautions similar to that used in an investigation conducted by Glicksman et al. (1976) were taken to insure 'free' dendritic growth conditions. Dendritic growth velocity was measured as a function of growth orientation at seventeen supercoolings which ranged from 0.043 C to 2 C. Selected but representative measurements of velocity versus orientation angle are shown in a graph. The relative growth velocity of a downward growing dendrite is found to be greater than that of a diffusion-limited dendrite. This result is consistent with that expected from the enhanced heat transfer arising from natural convection.