cssi/SciSciGPT-SciSciNet huggingface dataset:
Beyond accessibility: Design ethics, edge users, and the role of active proxies in unwinding the spiral of exclusion

The ethics and responsibilities of technology companies are under increased scrutiny over the power to design the User Experiences (UXs) embedded in their products. Researchers advocating a Rawlsian “just and fair” design process have suggested a “veil of ignorance” thought experiment in which designers adopt the standpoint of unspecified hypothetical users to ensure designers are not biasing their own perspectives at the expense of others. This article examines including and excluding such standpoints through the lens of edge users—a term based on extreme “edge cases” in which systems are more likely to break down. Edge users are particularly marginalized and subject to a spiral of exclusion when interacting via Internet and Web resources whose design disregards them because their ability to research and voice their experiences is further limited. Active proxies, those already helping or standing in for marginalized users, can be enlisted as design allies to develop a deeper understanding of such edge groups and contexts. Design ethics, in short, needs to move beyond making technologies accessible to all people, to making all types of people accessible to designers.
Widespread distribution of collagens and collagen-associated domains in eukaryotes

The origin of collagen, the dominant structural component of metazoan extracellular matrix, has long been cited as a critical step in the evolution of metazoan multicellularity. While collagens were once thought to be found only in metazoans, scattered reports of collagen domains in Fungi, and more recently in close relatives of metazoans, have called into question whether collagens are truly unique to metazoans. Here, we take advantage of recently sequenced genomes and transcriptomes of diverse holozoans (the clade encompassing metazoans and their close relatives), as well as publicly available proteomes from diverse non-holozoan eukaryotes, to conduct a systematic search for collagen domains across eukaryotic diversity. We find that collagen domains are ubiquitous in choanoflagellates, the sister group of metazoans, and widespread across many other major eukaryotic taxa. Many predicted collagens in non-metazoans are comparable to metazoan collagens in length and proline content. Moreover, most are present in species that also encode putative prolyl 4-hydroxylase domains, suggesting that, like metazoan collagens, they may be stabilized through the hydroxylation of prolines. Fibrillar collagen and collagen IV appear to be unique to metazoans, and we posit that their ability to assemble into superstructures may have contributed to the origin of metazoan multicellularity.
ECHO virus, type 25, in respiratory illness. Case report.

An acute upper respiratory illness in a 2 1/2-year-old child associated with ECHO virus 25 is presented. The virus diagnosis was established by isolation and identification of virus recovered from the respiratory secretions, by the demonstration of a diagnostic increase in neutralizing antibody against ECHO virus 25 and against the isologous agent, and by negative serodiagnostic tests with influenza A 1 , A 2 , B and C, parainfluenza 1, 2 and 3, reovirus (group), adenovirus (group), and respiratory syncytial virus antigens. The illness was characterized by mild febril upper respiratory symptoms with coryza, pharyngitis, mild tonsillar exudate, and abnormal stools. There were no signs of involvement of the lower respiratory tract or the central nervous system. Recovery was uneventful. This represents the first detailed clinical description of a case of acute respiratory illness associated with ECHO virus 25.
Path Loss Prediction Models in Cellular Communication Channels

The characteristics of the radio channel provide a challenge to the communications engineer in designing systems that are spectrally efficient so as to provide high speed services to a large numbers of subscribers. Path loss is the most basic of the channel characteristics since it influences coverage and interference predictions for any system. Because the radio links in modern wireless systems are between low base station antennas and the subscribers over relatively short paths within cities, or even inside buildings, the buildings have a major influence on the received signal. Modern systems operate at frequencies f in the UHF (300 MHz - 3 GHz) and microwave bands, so that the radio waves have wavelength λ less than a meter. Since the buildings are large compared to wavelength, it is appropriate to think of the radio waves as traveling along rays between the base station and the subscriber. Ray concepts are used in this chapter to make quantitative predictions of the path loss. These predictions are to compare well with measurements, and measurement based prediction models. Keywords: Path loss; path gain; small area average; two ray model; reflection coefficient; break point; diffraction; Hata model; ray paths; VPL method
Multilayer cladding with hyperbolic dispersion for plasmonic waveguides

We study the properties of plasmonic waveguides with a dielectric core and multilayer metal-dielectric claddings that possess hyperbolic dispersion. The waveguides hyperbolic multilayer claddings show better performance in comparison to conventional plasmonic waveguides.
Rough Terrain Autonomous Mobility—Part 1: A Theoretical Analysisof Requirements

A basic requirement of autonomous vehicles is that of guaranteeing the safety of the vehicle by avoiding hazardous situations. This paper analyses this requirement in general terms of real-time response, throughput, and the resolution and accuracy of sensors and computations. Several nondimensional expressions emerge which characterize requirements in canonical form. The automatic generation of dense geometric models for autonomously navigating vehicles is a computationally expensive process. Using first principles, it is possible to quantify the relationship between the raw throughput required of the perception system and the maximum safely achievable speed of the vehicle. We derive several useful expressions for the complexity of terrain mapping perception under various assumptions. All of them can be reduced to polynomials in the response distance. The significant time consumed by geometric perception degrades real-time response characteristics. Using our results, several strategies of active geometric perception arise which are practical for autonomous vehicles and increasingly important at higher speeds.
Perfusion and Delayed Enhancement Imaging

A 54 year old male with diabetes and family history of CAD comes to a cardiologist for the first time for atypical chest pain. The patient reports “having to grasp for air” while in chest pain. A rest ECG is done at the office, in which nonspecific T wave changes were the only abnormality. Besides blood tests, the cardiologist orders an echocardiogram that shows reduced LV function and akinesis of the mid and apical anterior-septal walls, and a stress SPECT study that shows a perfusion defect in the same regions, with little reversibility on the rest images. Thinking this is most likely ischemic coronary disease, the cardiologist orders a cardiac MRI for viability evaluation prior to the invasive coronary angiography, which showed an occluded mid LAD artery with distal filling via collaterals. Given the presence of viability on the MRI scan, the patient successfully underwent PTCA of the mid-LAD lesion, and, two months later, LV function shows improvement and the patient is asymptomatic. Cardiologists are familiar with relying on a number of different imaging modalities for a thorough assessment of cardiovascular disorders. Coronary anatomy evaluation is usually performed using invasive catheterization or more recently by noninvasive MDCT scans. Global and regional myocardial function as well as structural abnormalities can be assessed with echo, MRI, and MDCT. Subclinical atherosclerosis is usually assessed via detection of coronary calcium using MDCT or EBCT scanners or via measuring carotid intima-media thickness with ultrasound; while stress tests for ischemia detection and quantification are usually performed with nuclear SPECT or PET, echo stress, or stress MRI imaging. Finally, myocardial fibrosis for viability and prognosis assessment is usually detected and quantified by MRI and nuclear techniques.
A novel cholinergic "slow effect" of efferent stimulation on cochlear potentials in the guinea pig.

This report documents slow changes in cochlear responses produced by electrical stimulation of the olivocochlear bundle (OCB), which provides efferent innervation to the hair cells of the cochlea. These slow changes have time constants of 25–50 sec, three orders of magnitude slower than those reported previously. Such “slow effects” are similar to classically described “fast effects” in that (1) they comprise a suppression of the compound action potential (CAP) of the auditory nerve mirrored by an enhancement of the cochlear microphonic potential (CM) generated largely by the outer hair cells; (2) the magnitude of suppression decreases as the intensity of the acoustic stimulus increases; (3) they share the same dependence on OCB stimulation rate; (4) both are extinguished upon cutting the OCB; and (5) both are blocked with similar concentrations of a variety of cholinergic antagonists as well as with strychnine and bicuculline. These observations suggest that both fast and slow effects are mediated by the same receptor and are produced by conductance changes in outer hair cells. Slow effects differ from fast effects in that (1) fast effects are greatest for acoustic stimulus frequencies between 6 and 10 kHz, whereas slow effects peak for frequencies from 12 to 16 kHz, and (2) fast effects persist over long periods of OCB stimulation, whereas slow effects diminish after 60 sec of stimulation. The time course of the slow effects can be described mathematically by assuming that each shock-burst produces, in addition to a fast effect, a small decrease in CAP amplitude that decays exponentially with a time constant that is long relative to the intershock interval. The long time constant of the slow effect compared to the fast effect suggests that it may arise from a distinct intracellular mechanism, possibly mediated by second- messenger systems.
Vertical sleeve gastrectomy reduces hepatic steatosis while increasing serum bile acids in a weight-loss-independent manner.

Objective Our objective was to investigate the role of bile acids in hepatic steatosis reduction after vertical sleeve gastrectomy (VSG). Design and Methods High fat diet (HFD)-induced obese C57Bl/6 mice were randomized to VSG, Sham operation (Sham), Sham operation with pair feeding to VSG (Sham-PF), or nonsurgical controls (Naive). All mice were on HFD until sacrifice. Mice were observed postsurgery and data for body weight, body composition, metabolic parameters, serum bile acid level and composition were collected. Further hepatic gene expression by mRNA-seq and RT-PCR analysis was assessed. Results VSG and Sham-PF mice lost equal weight postsurgery while VSG mice had the lowest hepatic triglyceride content at sacrifice. The VSG mice had elevated serum bile acid levels that positively correlated with maximal weight loss. Serum bile composition in the VSG group had increased cholic and tauroursodeoxycholic acid. These bile acid composition changes in VSG mice explained observed downregulation of hepatic lipogenic and bile acid synthetic genes. Conclusion VSG in obese mice results in greater hepatic steatosis reduction than seen with caloric restriction alone. VSG surgery increases serum bile acids that correlate with weight lost postsurgery and changes serum bile composition that could explain suppression of hepatic genes responsible for lipogenesis.
Structure/function studies on the allosteric mechanism of Rad51 recombinase (549.8)

Eukaryotic Rad51 recombinase plays a central role in maintaining genome stability by promoting homology-directed repair of DNA double-strand breaks and stalled replication forks. Rad51 forms presyn...
Excitonic Solar Cells

Existing types of solar cells may be divided into two distinct classes: conventional solar cells, such as silicon p−n junctions, and excitonic solar cells, XSCs. Most organic-based solar cells, including dye-sensitized solar cells, DSSCs, fall into the category of XSCs. In these cells, excitons are generated upon light absorption, and if not created directly at the heterointerface as in DSSCs, they must diffuse to it in order to photogenerate charge carriers. The distinguishing characteristic of XSCs is that charge carriers are generated and simultaneously separated across a heterointerface. In contrast, photogeneration of free electron−hole pairs occurs throughout the bulk semiconductor in conventional cells, and carrier separation upon their arrival at the junction is a subsequent process. This apparently minor mechanistic distinction results in fundamental differences in photovoltaic behavior. For example, the open circuit photovoltage Voc in conventional cells is limited to less than the magnitude of...
Some recent results using spin echo resolved grazing incidence scattering (SERGIS)

The advantages of neutrons for probing bulk structures are well known: they provide statistically averaged correlation functions over a large range of length scales and they are sensitive to light atoms such as hydrogen. These same qualities are, in principle, useful in the study of surfaces and buried morphologies in thin films, especially when the films are polymeric or biological. However, because of the limited sample volume for such systems, the scattering is weak, especially if the neutron beam has to be severely collimated in order to resolve distances of interest (typically 10 to several 100 nm parallel to the surface of the sample). SERGIS is a technique that can potentially overcome these limitations by allowing high resolution measurements of lateral surface structure without requiring tight beam collimation. In this paper we discuss recent progress towards implementing SERGIS both at the Low Energy Neutron Source at Indiana University and on the Asterix reflectometer at the Los Alamos Neutron Science Center (LANSCE). The architecture we use exploits a robust symmetry-related cancellation of Larmor phase aberrations. The spatial resolution it achieves closely mimics that of the ideal magnetic Wollaston prisms. To make progress in understanding SERGIS, we have applied it to the measurement of simple diffraction gratings and developed a dynamical theory that accounts quantitatively and without adjustable parameters for all of the data sets we have measured to date. We argue here that, if SERGIS is to be applied to the study of weakly scattering thin films, it will be necessary to develop the technique of dark-field spin echo scattering angle measurement.
Linkage analysis of a candidate locus (HLA) in autosomal dominant sacral defect with anterior meningocele.

Sacral defect with anterior meningocele (SDAM) is a type of caudal dysgenesis. It is present at birth and becomes symptomatic later in life, usually because of obstructive labor in females, chronic constipation, rectal fistula and abscess, or meningitis. The inheritance is autosomal dominant. HLA has been implicated in caudal dysgenesis because of analogy with disorders of the T-locus complex, a tail length determining gene in mice which is linked to the major histocompatibility complex, H-2. Members of a 5-generation family with sacral defect and anterior meningocele (SDAM) were typed with polymorphic markers (dinucleotide repeats D6S89, D6S105, D6S109, and TCTE1) linked to HLA. Two-point and multipoint analysis exclude the HLA region as the location for the SDAM gene in this family. © 1994 Wiley-Liss, Inc.
Comparison of Shock-Induced Two- and Three- Dimensional Incipient Turbulent Seperation

2 Garnet, H. and Armen, H., Evaluation of Numerical Time Integration Methods as Applied to Elastic-Plastic Dynamic Problems Involving Wave Propagation, Rept. RE-475, March 1974, Research Dept., Grumman Aircraft Corp., Bethpage, N.Y. 3 Stoodley, G. R. and Ball, D. J., Mathematical Background of Two Numerical Integration Techniques for Ordinary Differential Equations, Memo. RM-192, Oct. 1961, Research Dept, Grumman Aircraft Corp., Bethpage, N.Y. 4 Mantus, M., Lerner, E., and Elkins, W., "Landing Dynamics of the Lunar Excursion Module (Method of Analysis)," Rept. LED-5206A, Revised April 10, 1967, Grumman Aircraft Corp., Bethpage, N.Y. 5 Lerner, E. and Mantus, M., "Dynamics of Unsymmetric Landing," Rept. ADR 02-10-10-62-1, Jan. 1963, Grumman Aircraft Corp, Bethpage, N.Y. 6 Donnell, L. H., "Longitudinal Wave Transmission and Impact," Transactions of the ASME, Vol, 52, 1930, pp. 153-167. 7 DeJuhasz, K. J., "Graphical Analysis of Impact of Bars Stressed Above the Elastic Range," Journal of the Franklin Institute, Vol. 248, No. 2, Aug. 1949, pp. 113-142. 8 Davids, N. and Kumar, S., "A Contour Method for One Dimensional Pulse Propagation in Elastic-Plastic Materials," Proceedings of the Third U.S. National Congress of Applied Mechanics, Brown University, Providence, R.I., 1958, pp. 502-512. 9 Garnet, H. and Armen, H., One Dimensional Elastic-Plastic Wave Propagation and Boundary Reflections, Memo, Grumman Research Department, Bethpage, N.Y. (in preparation).
What helps or undermines adolescents' anticipated capacity to cope with mental illness stigma following psychiatric hospitalization.

Background:Better understanding of the individual and environmental factors that promote adolescents’ use of more or less adaptive coping strategies with mental illness stigma would inform interventions designed to bolster youth resilience.Aims:This cross-sectional study draws on data from research on adolescents’ well-being after discharge from a first psychiatric hospitalization to explore the relationships between anticipated coping in reaction to a hypothetical social stigma scenario, and various factors conceptualized as ‘coping resource’ and ‘coping vulnerability’ factors. Focusing on coping strategies also identified in the companion article, we hypothesize that primary and secondary control engagement coping would relate to more coping resource and less coping vulnerability factors, and the opposite would be true for disengagement, aggression/confrontation and efforts to disconfirm stereotypes.Methods:Data were elicited from interviews with 102 adolescents within 7 days of discharge. Hypothesized ...
Dose-dependent absorption and excretion of vitamin C in humans

Abstract Four subjects ingested 500, 1000 and 2000 mg of ascorbic acid daily for one week according to a three-way crossover design. Following the last dose, serial urine and plasma samples were obtained over a 12-h period. The ascorbic acid content of these samples were determined by an HPLC method employing electrochemical detection. The plasma concentration-time profiles are similar at all 3 doses, with the area under the curve values (mean ± S.D.) being 206.0 ± 50.5, 212.1 ± 40.7, and 231.8 ± 52.6 mg · h/1 for the 500, 1000 and 2000 mg doses. The corresponding percents (mean ± S.D.) of dose recovered in urine are 73.2 ± 25.7, 46.9 ± 21.7 and35.8 ± 12.4. This decrease in recovery is significantly different ( P
Inhibition of insulin amyloid formation by small stress molecules.

Amyloidogenic proteins undergo an alternative folding pathway under stressful conditions leading to formation of fibrils having cross β-sheet structure, which is the hallmark of many neurodegenerative diseases. As a means of surviving against external stress, on the other hand, many microorganisms accumulate small stress molecules to prevent abnormal protein folding and to contribute to protein stability, which hints at the efficacy of the solutes against amyloid formation. The current work demonstrates the effectiveness of small stress molecules such as ectoine, betaine, trehalose, and citrulline on inhibition of insulin amyloid formation in vitro. The inhibitory effects were analyzed by thioflavin T-induced fluorescence, circular dichroism, and atomic force microscopy. This report suggests that naturally occurring small molecules may serve a function that is typically fulfilled by protein chaperones, and it provides a hint for designing inhibitors against amyloid formation associated with neurodegenerative disorders.
Densification behavior of dynamically shock compacted AI 2 O 3 /ZrO 2 powders synthesized through rapid solidification

The rapidly solidified alumina-zirconia eutectic contains high volume fractions of nanocrystallinet- ZrO2, which makes the material a promising precursor for the manufacturer of fracture-resistant ceramic specimens. Unfortunately, conventional powder processing and sintering techniques are inadequate for the fabrication of dense specimens using this material. We have used dynamic shock compaction to facilitate the achievement of high density specimens which retain the unique microstructure of the precursor material. In an attempt to quantify the dynamics of the microstructural evolution which occurs during the compaction process, we have investigated the effect of various particle size distributions on the densification behavior of the material during the shock compaction and postcompaction sintering cycles. The shock compaction process produced high densities (∼73 to 78 pct of single-crystal theoretical) by inducing a highly efficient packing of the particles. A bimodal powder distribution was also compacted and this specimen exhibited a relative density of 86.2 pct, approximately 10 pct higher that those of the unimodal compositions. In this compact, the small particles efficiently filled the interstices between the larger particles. The high density of the bimodal compact did not translate to a high sintered density, however.
Interorganizational Co-operation and the Implementation of Labour Market Training Policies: Sweden and the Federal Republic of Germany

In this article a theory of interorganizational co-operation is utilized to render some cases of local implementation understandable. The policy studied is labour market training and placement. Data from four locales in Sweden and the Federal Republic of Germany are analysed. In each nation one more- and one less-successful community are examined. First, the author compares the administrative requirements of the labour market task with the two national policies to assess their suitability. Then reasons for the degree of policy success and degree of interorganizational co-operation observed are sought. Perceived common interest in the locale and the presence of an interorganiza tional facilitative agent seem to be among the factors which affect co-operation. Some conclusions and implications for policy makers, implementers, and students of administration are sketched.
Medical History as Justification Rather Than Explanation: A Critique of Starr's The Social Transformation of American Medicine

This paper discusses the major positions presented in Paul Starr's The Social Transformation of American Medicine and critically analyzes the major ideological and political assumptions that sustain Starr's explanation of the evolution of the institutions of medicine in the United States. These assumptions include, among others, that the evolution of medicine is an outcome of conflicts among the different interest groups that exist within medicine, interacting within the parameters defined by the majority of Americans whose beliefs and wants eventually determine what occurs in medicine, and the hegemonic positions in the ideology, practice, and institutions of medicine are dominant because of their powers of persuasion. This paper questions these positions on theoretical and empirical grounds and it presents an alternative explanation of the evolution of medicine. In this alternate explanation, the evolution of medicine (including its recent corporatization) is viewed as the outcome of power relations defined not by the majority of Americans but by a series of conflicts between classes, races, genders and other power groupings, within a matrix of dominant-dominated relations, in which dominance is reproduced by coercion and repression, and not merely by persuasion. Specific historical events are analyzed and alternative explanations are given to Starr's interpretations.
A biogenic hydrocarbon emission inventory for the U.S.A. using a simple forest canopy model

Abstract A biogenic hydrocarbon emission inventory system, developed for acid deposition and regional oxidant modeling, is described, and results for a U.S. emission inventory are presented. For deciduous and coniferous forests, scaling relationships are used to account for canopy effects upon solar radiation temperature, humidity and wind speed as a function of height through the canopy. Leaf temperature is calculated iteratively from a leaf energy balance as a function of height through the canopy. The predicted light and temperature levels are used with mean emprical emission rate factors and laboratory emission algorithms to predict hydrocarbon emission rates. For application to a U.S. inventory, diurnal emission fluxes of isoprene, α-pinene, other monoterpenes adn otehr hydrocarbons are predicted for eight land cover classes by state climatic division by month. The total U.S. emissions range from 22 to 50 Tg yr −1 depending upon the formulation of different emission rate factors. In the case where the forest canopy model is not used, the isoprene emissions increase by 50% and terpene emissions increase by 6%. In case study analyses, the predicted leaf temperatures were within 1–2°C of observed for a deciduous forest, and predicted emissions were within a factor of two of observations. Further evaluation of the inventory using field measurements is required to determine the overall accuracy of the emission estimates.
Pain, suffering, and meaning.

EVERY DOCTOR WHO TREATS PATIENTS WILL CONFRONT THEIR PAIN AND suffering. Yet for each individual patient the experience of pain will be private and largely unique. This creates difficulty not only for the clinician but for anyone who tries to grasp the meaning of someone else’s pain. The sensory component of pain, the neuronal capacity to localize and identify noxious stimuli, is largely consistent both within an individual and between populations. But the meaning of pain becomes much more than the ability simply to localize or discern it. For the affective component of pain—the subjective sense of suffering that accompanies its perception—is multifactorial. Myriad factors underlie our ability to conceptualize our own pain, or tocomprehendthatofanother: themeaningofthepainwithinone’s larger life context, the intensity and location of the pain, the particular illness associated with the pain, the rituals of medicine around pain, and the social understanding of suffering. The pain that results from this multiplicityof factors isuniquelydefined for each individual; painbecomes framedintheclinicalencounterbythe interplaybetweenthephysician’s gaze into the patient and the patient’s gaze into himself or herself. This exercise of framing is at the center of every patient-physician encounter, but most particularly so for pain. For pain is not an objective and visible clinical finding in the manner of a fractured femur or purulent sputum. Rather, pain is a perception communicated through both language and nonverbal behaviors such as tears or agitation. As such, pain is intrinsically subjective and inaccessible, “that which cannot be denied, and that which cannot be confirmed.” This intangibility contributes to misunderstanding and undertreatment of pain in the clinical setting. As discussed by Kathleen Foley in this issue, pain remains a serious public health problem. Many patients are inadequately palliated, especially at the end of life. This need not be so. Janet Abrahm describes how we can make palliative care itself a goal of medicine. Even when cure of the underlying disease is not possible, there is still much we can do to relieve physical and psychosocial suffering. Jane Loitman recounts that many patients seek pain relief from complementary therapies. Often they feel that these methods offeraholisticapproach that is lacking in the traditional allopathicmodel. As we grapple for solutions to these problems within our current clinical context, we might do well to realize that none of these experiences are entirely new. Schuyler Henderson describes the expressions and definitions of pain as a function of not only personal but social, cultural, and historical influences as well. To treat pain adequately therefore requires not just that we understand its pathophysiology, solicit patient reporting, and follow practice guidelines, but that we also reflect on its meanings and thoughtfully incorporate them into our clinical interactions. We hope that this issue of MSJAMA will encourage further thought about current issues in pain management and its significance within the clinical encounter.
Immunochemical studies on α-lactalbumin

The antigenic structural features of alpha-lactalbumin have been investigated using a radioimmunoassay, peptide inhibition of the quantitative precipitin reaction, and by immunodiffusion analysis after chemical modification of the molecule. Antigenic activity (in rabbits) was localized to several peptic fragments and the single arginine residue of bovine alpha-lactalbumin. Antigenic activity was also found to be associated with the single methionine residue. A peptic fragment containing a disulfide loop was found to possess antigenic activity in both bovine and goat alpha-lactalbumin. Radioimmunoassay cross-reactivity between the alpha-lactalbumins is correlated with amino acid sequence similarities; bovine alpha-lactalbumin antiserum cross-reacts with goat alpha-lactalbumin more extensively than with human alpha-lactalbumin, while the more distantly homologous protein, chicken lysozyme, does not cross-react at all. Nevertheless our data indicate that the alpha-lactalbumins and lysozyme share a similar distribution of antigenic determinants on their surfaces.
Considering interlocutors in university discourse communities: Impacting U.S. undergraduates’ perceptions of ITAs through a structured contact program

Abstract In discussions of non-native speakers in ESP settings, the importance of discourse communities has been emphasized (e.g., Hyland & Hamp-Lyons, 2002 ). Native speakers are often the primary members of these discourse communities, especially in inner circle countries such as the U.S. ITA (international teaching assistant) researchers and practitioners have long emphasized the importance of U.S. undergraduates in ITA program design (e.g., Bailey, 1982 ). ITA research shows that the attitudes of U.S. undergraduates impact their perception of ITAS’ comprehensibility, accentedness, and teaching ability (e.g., Kang & Rubin, 2009 ). These negative perceptions can be mitigated by ITA programs which introduce opportunities for structured contact between undergraduates and international students. Structured contact programs can offer benefits to undergraduates, promote collaboration, and enjoy institutional support, among other features. The current study investigates the impact of this contact on U.S. undergraduate students’ perceptions of ITAs’ speech and teaching ability. In addition, specific details about the contact program are provided in order to offer suggestions to ITA coordinators. Findings have important implications for other ESP settings beyond the context of ITAs.
Promoting physical activity in patients with colon adenomas: a randomized pilot intervention trial.

Background Physical activity decreases risk of colon polyps and colon cancer and might reduce risk of colon cancer recurrence. Focusing on recent calls for translation of epidemiologic evidence into clinical care, our pilot study delivered an evidence-based physical activity intervention in adults with polyps, who are thus at elevated risk of developing colon cancer. The objective was to evaluate change in physical activity, measured by steps per day and minutes of moderate/vigorous physical activity. Methods Sixteen adults with adenomas detected and removed at screening colonoscopy were recruited to a 12-week physical activity intervention. Participants were randomized to receive a standard (30 minutes/day) or high (60 minutes/day) walking program. Physical activity was measured via blinded pedometer and accelerometer at baseline and follow-up. Intervention messages focused on self-monitoring using pedometers and overcoming barriers to engaging in physical activity. Results Participants in both arms significantly increased objectively measured minutes of moderate/vigorous physical activity over the course of the intervention. Both arms exceeded the intervention goal, but there was not a significant difference between arms at follow-up. Results were similar for pedometer measured physical activity, with a significant overall increase in steps/day from baseline to follow-up, but no between arm difference in change. Conclusion Simple interventions of minimal contact time focusing on walking can significantly increase physical activity in individuals at increased risk of developing colon cancer. Trial Registration ClinicalTrials.gov NCT01476631
Guanine nucleotide regulation of the interconversion of the two-state hepatic glucagon receptor system of rat.

Abstract To investigate whether guanine nucleotides regulate interconversion of the two-state hepatic glucagon receptor we have utilized kinetic assays of glucagon binding to partially purified rat liver plasma membranes. Dissociation of glucagon at 30 °C exhibited biexponential character in either the absence or presence of GTP, indicating that the system previously seen in intact hepatocytes is independent of intracellular modulators. In each case the receptors underwent a time-dependent conversion from a low affinity to a high affinity state. However, GTP decreased the fraction of receptors in the high affinity state. The rank order for stabilizing the low affinity state was Gpp(NH)p > GTP > GDP ≫ GMP = no nucleotides. Data from competition binding assays with increasing concentrations of GTP allow calculation of equilibrium constants which are 3.32 n m for glucagon and receptor in the absence of GTP, 18.6 n m for glucagon and receptor in the presence of GTP, 1.55 μ m for the association of receptor and GTP presumably linked to an N protein, and 8.86 μ m for the association of the glucagon-receptor complex and GTP again presumably linked to an N protein. Glucagon binding to receptor is noncooperative in both the absence and presence of GTP, distinguishing this system from the β-adrenergic system. With GTP, binding to the low affinity state is favored because of the relative affinities reported. Therefore, GTP regulates the activation by slowing the conversion of the receptor from a low affinity to high affinity form.
Moving visual stimuli rapidly induce direction sensitivity of developing tectal neurons

During development of the visual system, the pattern of visual inputs may have an instructive role in refining developing neural circuits1,2,3,4. How visual inputs of specific spatiotemporal patterns shape the circuit development remains largely unknown. We report here that, in the developing Xenopus retinotectal system, the receptive field of tectal neurons can be ‘trained’ to become direction-sensitive within minutes after repetitive exposure of the retina to moving bars in a particular direction. The induction of direction-sensitivity depends on the speed of the moving bar, can not be induced by random visual stimuli, and is accompanied by an asymmetric modification of the tectal neuron's receptive field. Furthermore, such training-induced changes require spiking of the tectal neuron and activation of a NMDA (N-methyl-d-aspartate) subtype of glutamate receptors during training, and are attributable to an activity-induced enhancement of glutamate-mediated inputs. Thus, developing neural circuits can be modified rapidly and specifically by visual inputs of defined spatiotemporal patterns, in a manner consistent with predictions based on spike-time-dependent synaptic modification.
Increased septal 5-HIAA efflux in rats that do not develop learned helplessness after inescapable stress

Learned helplessness is a behavioral deficit that can be induced by exposure to inescapable stress. Previous studies have implicated the lateral septum in mediating this phenomenon, and in this brain region, serotonin plays an important role in the development, maintenance, prevention, and reversal of learned helplessness behavior. Using the technique of in vivo microdialysis, we measured the efflux of serotonin (5-HT), dopamine (DA), and their respective metabolites, 5-hydroxyindoleacetic acid (5-HIAA) and 3, 4-dihydroxyphenylacetic acid (DOPAC), from the lateral septum of rats that either developed or did not develop learned helplessness. During the microdialysis session all rats were subjected to restraint stress. Control groups included naive, home cage rats as well as tested control rats that were subjected to the identical handling, restraint, and shuttlebox testing as the rats that received inescapable shock. Overall, levels of 5-HIAA were significantly higher in non-helpless rats. There were no significant effects of restraint or differences in levels of 5-HT, DA, or DOPAC. We propose that this increase in 5-HIAA is indicative of an overall increase in serotonin metabolism in the lateral septum of rats that do not become helpless after inescapable stress. This increased serotonin metabolism in the lateral septum may protect the animal from adverse behavioral consequences of inescapable stress. J. Neurosci. Res. 61:101-106, 2000. Published 2000 Wiley-Liss, Inc.
Ventricular Fibrillation During and After Coronary Artery Occlusion Incidence and Protection Afforded by Various Drugs

Abstract The incidence of ventricular fibrillation during and after temporary experimental occlusion of the left anterior descending coronary artery or its branches was studied in 351 dogs. A standardized procedure of thirty-minute temporary occlusion of this artery was employed in 330. There is usually a critical period after twelve and up to fifteen minutes of ischemia which is characterized by a tendency to arrhythmia: extrasystoles, singly or in runs, ventricular tachycardia, or both extrasystoles and tachycardia if not a fatal ventricular fibrillation. Several instances of transient ventricular fibrillation were observed. Of 239 animals surviving thirty minutes of occlusion, 71 per cent developed ventricular fibrillation immediately after release of the artery, while only 28 per cent of 330 animals developed fibrillation during the occlusion. The re-establishment of blood flow to an area of the myocardium made ischemic for thirty minutes by occlusion of the anterior descending coronary artery is more likely to precipitate ventricular fibrillation than is the period of ischemia itself. Various drugs were evaluated in 324 dogs. Quinidine was the most effective drug in affording protection from ventricular arrhythmia during (7 per cent) and following (47 per cent) occlusion. Procaine, procaine amide and Apresoline offered good protection during the ischemic period. Apresoline and Regitine also reduced the incidence (44 and 37 per cent) of ventricular fibrillation upon reopening the ligature. Of the other drugs tested, only one, pendiomide, showed significant protection (52 per cent incidence). Systemic arterial pressures did not predict the onset of ventricular arrhythmia. Electrical countershock accomplished cardiac resuscitation in 75 per cent of the fibrillating dogs. From these experiments, quinidine appears to be the drug of choice in the prophylaxis of fatal ventricular arrhythmias.
Sociolinguistic Dimensions of Foreign and Second Language Teaching

While foreign and second language teachers have devoted their efforts to the development of the linguistic competence of their students, not enough attention has been paid to their communicative competence, which is the ability to adjust their language according to social context. This paper briefly describes those findings in sociolinguistic research that can be used by language teachers to elicit from their students meaningful and authentic communication.
Immunoselection and characterization of moloney murine leukemia virus-infected cell lines deficient in surface gag antigen expression

Abstract NIH/3T3 cells infected with Moloney murine leukemia virus (M-MuLV) which were deficient in gag surface antigen were selected by incubation with anti-serum to the major gag virion protein, p30, in the presence of complement. Survivors of the selection were cloned and characterized with respect to intracellular production of gag and env gene products, gag surface antigen expression as revealed by indirect immunofluorescence, and virus production. Nineteen clones tested were all positive for env gene products in cytoplasmic extracts. Seventeen of the nineteen were positive for gag gene products, and two were negative. The gag -positive clones all produced Pr65 gag (the precursor to the internal structural proteins) and they also produced gPr80 gag (the precursor to the cell-surface gag antigen). The selected clones were all deficient in the presence of surface gag antigen as measured by immunofluorescent microscopy or flow microfluorimetry, and they all processed Pr65 gag to mature p30 more slowly than the parental cells. In addition, all of the surface gag -deficient clones produced virus at a reduced rate. The nature of the defect in one gag -deficient clone was studied by infection of progeny virus onto uninfected NIH/3T3 cells. The resultant cells showed normal gag surface fluorescence and virus production. This suggests that the defect was cellular rather than viral.
Swelling of hen erythrocyte nuclei in cytoplasm from Xenopus eggs.

Abstract When a sperm enters a mature egg of Xenopus laevis both the sperm nucleus and egg pronucleus swell during the first 20 min. Erythrocyte and other nuclei also undergo a similar swelling when injected into Xenopus eggs. We have obtained a similar swelling of hen erythrocyte nuclei in cytoplasm isolated from Xenopus eggs. The swelling occurs in two stages. The first is an immediate small increase in volume similar to that which occurs in media with low concentrations of unbound cations and this can be prevented by adding magnesium ions to the cytoplasm. The second is a slower, irreversible increase to about 40 times the original volume. Neither of these types of swelling occurs in cytoplasm isolated from Xenopus oocytes (as opposed to eggs) but the large irreversible increase in volume can be induced by the addition of heparin. In the light of these experiments we consider the physiological mechanism by which the sperm and egg pronucleus are induced to swell after penetration of the sperm.
On the shift-table in Boyer-Moore’s String Matching Algorithm

The Boyer-Moore’s string matching algorithm uses two pre-computed tables skip, which utilizes the occurrence heuristic of symbols in a pattern, and shift, which utilizes the match heuristic of the pattern, for searching a string. Some experts have pointed out that the difficulty of understanding the computation of the shift table has hindered utilization of the algorithm in a wider range of applications. This paper describes an alternative way to compute the shift table. We believe that the new method is more intuitive and straightforward both conceptually and logically than the original method, and thus, easier to understand and to implement. Also, the new method has a O(m) complexity in both required space and time for a pattern of length m. Therefore, it preserves the high performance of the Boyer-Moore algorithm.
Visualization of dynamic systems with performance maps: A rough computing approach

A visualization technique titled the “performance map” is considered, which is derived from the Julia set common in the visualization of iterative chaos. Such maps are generated automatically and require a minimum of a priori knowledge of the system under evaluation. By the use of intuitively derived evaluation rules combined with color coding, they convey a wealth of information to the informed user about dynamic behaviors of a system that may be hidden from all but the expert analyst. The concept of rough sets is then presented and used to derive a new set of rules to affect map generation. This derivation serves to formalize rule generation and further serves to minimize the number of variables to test during the system evaluation. © 2002 John Wiley & Sons, Inc.
Pain Sensitivity following Taste Aversion Conditioning: Analgesia Depends on the Method Used to Assess Taste Aversion Learning☆

Abstract Previous reports indicate that a conditioned analgesic response may be elicited by reexposure to a gustatory CS that has been previously paired with an analgesia-producing agent such as morphine. The current experiments examine the extent to which this observed analgesic response can be attributed to the particulars of the procedures used to assess conditioned taste aversion, rather than to a conditioning of an analgesic CR per se. Experiment 1 indicated that animals given pairings of a taste with lithium chloride (LiCl) will upon reexposure to the taste CS alone (one-bottle test) not only express a conditioned taste aversion, but will also express a decrease in pain sensitivity. This analgesic response was evident immediately following CS reexposure and 15 min following the assessment of taste aversion learning. The results further indicated that the analgesic response was unaffected by pretest administration of naloxone, indicating that the response was not mediated by opioid pain inhibition systems. Experiment 2 indicated that the analgesic response observed in the first experiment was not evident when taste aversion conditioning was assessed using a choice procedure (two-bottle test). Implications of these data for explanations of conditioned analgesia are discussed.
Matrix creep accommodation in diffusion controlled phase transformations

Abstract Although matrix creep accommodation occurs for a variety of diffusion controlled phase transformations, the focus is usually on the diffusion kinetics. However, interface control of kinetics, associated with the development of elastic stresses at a growing interface, is also possible. The displacement reaction Fe + Cu2O → FeO + Cu is used as a model system to determine the role of such stresses. The reaction is shown to occur in a regime where the metal matrix phase undergoes either Nabarro-Herring or power law creep. The models developed herein to describe the interface and matrix stresses are tested on several diffusional phase transformations. The general results are that matrix stresses very near growing precipitates are often appreciable. The results have implications for the control of microstructure in in situ composites produced by such reactions.