cssi/SciSciGPT-SciSciNet huggingface dataset:
Feedback models of gamma rhythms

Jefferys et al.1 in the May issue of TINS reviewed the use of neuronal network analysis for modeling oscillations in the gamma range, particularly to distinguish between intrinsic oscillations from neurons that entrain others and interneuronal oscillations that arise from feedback between excitatory and inhibitory populations. They write (Ref. 1, p. 204) that in the olfactory system, ‘Freeman et al.2 predicted that inhibitory cells should lag behind the excitatory cells by a quarter cycle (6.5 ms at 40 Hz)….
Mean value analysis for blocking queueing networks

An approximation is introduced for the mean value analysis of queueing networks with transfer blocking. The blocking occurs when a job, after completing service at a station, wants to join a station which is full. The job resides in the server of the source station until a place becomes available in the destination station. The approximation is based on the modification of mean residence times, due to the blocking events that occur in the network. Several examples are executed that validate the approximate results. >
Neurotensin attenuates dopamine D2 agonist quinpirole-induced inhibition of midbrain dopamine neurons.

Abstract The effects of intracerebroventricular (i.c.v.) administration of NT on the activity of midbrain DA neurons were studied in rats using single unit recording techniques. NT (i.c.v., 50 μg) was found to have no significant effect on the spontaneous activity of DA cells. On the other hand, NT treatment significantly attenuated the inhibitory effect of quinpirole (i.v.), a specific D2 agonist, on a subpopulation of DA cells. This result is consistent with previous behavioral and biochemical studies suggesting that NT may produce some of its effects through modulation of central DA systems.
Proteins as paradigms of complex systems

The science of complexity has moved to center stage within the past few decades. Complex systems range from glasses to the immune system and the brain. Glasses are too simple to possess all aspects of complexity; brains are too complex to expose common concepts and laws of complexity. Proteins, however, are systems where many concepts and laws of complexity can be explored experimentally, theoretically, and computationally. Such studies have elucidated crucial aspects. The energy landscape has emerged as one central concept; it describes the free energy of a system as a function of temperature and the coordinates of all relevant atoms. A second concept is that of fluctuations. Without fluctuations, proteins would be dead and life impossible. A third concept is slaving. Proteins are not isolated systems; they are embedded in cells and membranes. Slaving arises when the fluctuations in the surroundings of a protein dominate many of the motions of the protein proper.
Potential for using rapid solidification for improved irradiation performance in the fusion environment

Abstract Rapid solidification has a potential for improving performance in the fusion environment (first-wall materials, limiters, superconductors, 3.) through structural refinements of crystalline materials and the preparation of amorphous materials with selected compositions. Compaction techniques which are used for rapidly solidified particulates allow as well for preparation of graded or layered materials. The following topics are being studied by using rapid solidification under a current M.I.T. alloy development program: swelling resistance and high temperature strength of austenitic stainless steels; DBTT and high-temperature strength of ferritic steels; high strength copper alloys; simulation techniques (boron, lithium doping); irradiation damage in metallic glasses at high fluences.
Estimating nearshore bedform amplitudes with altimeters

Abstract Estimates of the heights of large (0.1–0.4 m heights and 1–10 m horizontal lengths) migrating bedforms on a sandy beach made with fixed, single-point altimeters are similar to heights estimated from profiles across the bedforms made with altimeters mounted on an amphibious vehicle that traversed the surf zone. Unlike many profiling systems, the robust, fixed altimeters can measure bedforms in bubbly, sediment-laden surf zone waters nearly continuously, including during storms, thus allowing investigation of the relationships between bedform heights and near-bottom velocities to be extended to a wide range of wave conditions. The fixed-altimeter observations of migrating bedforms suggest a sandy surf zone seafloor is not always smooth during energetic conditions with strong mean currents and large wave-orbital velocities.
Perceived resource deficiency and internationalization of small- and medium-sized firms

It is documented in the literature that resource deficiency constitutes a barrier to firms’ internationalization. However, small- and medium-sized firms' (SMEs) perceptual barriers to internationalization have received little attention. By highlighting the importance of managerial perceptions in strategic decisions and integrating the resource-based view and the technology acceptance model, this study examines the role of perceived resource deficiency in SMEs’ internationalization. The major finding of this study suggests that perceived resource deficiency in knowledge-based resources constitutes a major perceptual barrier to SMEs’ internationalization. Particularly, perceived resource deficiency in knowledge-based resources has more negative impact on internationalization than does that in other firm-specific resources.
Measuring the motives of Soviet leadership and Soviet society: Congruence reflected or congruence created?

Abstract We explore the relationship between the motive profiles of Soviet leadership and Soviet society, using the first Communist Party Congress speeches of four Soviet leaders (Stalin, Khrushchev, Brezhnev, and Gorbachev). During the two years before the leaders' speeches, the societal motive profile tended to diverge from that reflected in the speeches. During the two years after the speeches, however, societal motives tended to converge with leadership motives. These results suggest that in Soviet society, the leadership shaped or influenced societal motives (i.e., the “popular will”), rather than reflecting them.
Conservation of structure detected in two trypanosome surface glycoproteins by amino acid sequence alignment

The predominant molecule exposed to antibody on the surface of Trypanosoma brucei is a glycoprotein of about 60 000 molecular weight which varies in amino acid sequence. The complete sequences of two such variable surface glycoproteins (VSGs) from randomly isolated, different antigenic types of trypanosomes were compared by amino acid sequence alignment. Homologous sequences were found distributed over various regions of the VSGs. Particularly good homology was observed between residues 16-34, 91-115, 177-194 and 254-345 from the N-terminus, in addition to the known conserved region close to the C-terminus. Homology was also demonstrated in the corresponding regions of the cDNA sequences by matrix analysis.
Risk-Taking, Justifiability, Recklessness, and Responsibility

The role of risk and justification in perceptions of recklessness and attributions of responsibility and blame were examined in a 2 x 2factorial design. Subjects read a scenario in which an ambulance driver struck a child while speeding or driving slowly to the hospital with a patient who had suffered either a broken leg or a heart attack. The driver who was speeding for insufficient justification was considered more reckless, blameworthy, and deserving of punishment than was the driver in the other three conditions. Recklessness, responsibility, blame, and support of punishment were positively correlated with one another, and all of these variables were correlated negatively with perceived justification.
Insight into the Alternating Access Mechanism of the Sodium Symporter Mhp1 using Path Sampling Simulations

Sodium coupled co-transporters of the LeuT superfamily use an alternating access mechanism to move small molecules across the cell membrane. A key step in the transport cycle involves the transporter undergoing a conformational transition from a state poised to bind extracellular substrates to one that is competent to deliver substrate to the cytoplasm. To investigate this step in semi-atomistic detail, we construct a coarse-grained model of the benzylhydantoin transporter Mhp1 that incorporates experimental structures of the outward- and inward-open states. We obtain a rigorous sampling of the unbiased outward- to inward-facing transition path ensemble (TPE) using the weighted ensemble path-sampling method. Analysis of the TPE reveals two distinct sets of pathways connecting the inward- and outward-facing conformations. The first is consistent with a strict alternating access mechanism, while in the other, decoupling of the inner and outer gates transiently forms a putative permeation pathway through the transporter. Our simulations additionally show that transitions between the outward- and inward-open states result from rigid body motions of the hash motif relative to the substrate bundle, supporting the rocking bundle hypothesis. This methodology provides the groundwork for more chemically detailed investigations of the transport mechanism of superfamily members using fully atomistic simulations.
CORDS: hardware-software co-synthesis of reconfigurable real-time distributed embedded systems

Field programmable gate arrays (FPGAs) are commonly used in embedded systems. Although it is possible to reconfigure some FPGAs while an embedded system is operational, this feature is seldom exploited. Recent improvements in the flexibility and reconfiguration speed of FPGAs have made it practical to reconfigure them dynamically, reducing the amount of hardware required in an embedded system. We have developed a system, called CORDS, which synthesizes multi-rate, real-time, periodic distributed embedded systems containing dynamically reconfigurable FPGAs. Executing different tasks on the same FPGA requires that potentially time-consuming reconfiguration be carried out between tasks. CORDS uses a novel preemptive, dynamic priority, multi-rate scheduling algorithm to deal with this problem. To the best of our knowledge, dynamically reconfigured FPGAs have not previously been used in hardware-software co-synthesis of embedded systems. Experimental results indicate that using dynamically reconfigured FPGAs in distributed real-time embedded systems has the potential to reduce their price and allow the synthesis of architectures which meet system specifications that would otherwise be infeasible.
Optical properties of granular magnesium films

Abstract We studied the optical properties of magnesium cermets formed by co- sputtering magnesium metal and MgF 2 . An absorption peak was observed at about 2500 A, in good agreement with the predictions of the Maxwell-Garnett theory. The weakness and large width of the absorption is indicative of very small metal grains.
False Equivalency: Think Tank References on Education in the News Media

Abstract This study explores the use and presentation of information and research on education by the news media. Using content analysis, this study compares four types of think tanks—contract research, academic, advocacy, and mixed academic and advocacy—and shows how the news media represented each one as a source of research, facts, and figures on education. The findings from this study show that the news media presented all the think tanks as credible sources of research, facts, and figures on education, regardless of the extent to which each think tank emphasized policy and political advocacy over the professional norms of academic research.
Effects of slider sensitivity optimization

Optimization of a 25 nm air bearing slider is performed. The objective of the optimization is to maintain the basic design goals of a flat fly height profile at a specified fly height and roll minimization while decreasing the sensitivity of the bearing to external loading. By decreasing the sensitivity of the slider fly height to an applied load variation, the slider's stiffness in the vertical direction can be, conversely, increased. By increasing the slider's vertical and pitch stiffness simultaneously, a decrease in dynamic fly height modulation is expected. It was found, however, that the modulation increased.
Liapunov functions: Geometry and stability

Several geometrical interpretations of Liapunov functions for non-linear ecological models are examined and their limitations pointed out. In particular the geometrical nonuniqueness of Liapunov functions is illustrated by displaying explicitly and comparing four different Liapunov functions for the symmetric competition model for two species. The main point is that considerable care must be taken in using the geometrical properties of an arbitrary Liapunov function as a guide to stability under perturbations.
Glutathione dependent metabolism and detoxification of 4-hydroxy-2-nonenal

Abstract The involvement of glutathione (GSH) dependent processes in the detoxification of 4-hydroxy-2-nonenal (4HNE) was investigated using Chinese hamster fibroblasts and clonogenic cell survival. GSH reacted, in a dose-dependent fashion, with 4HNE in phosphate buffer at pH 6.5, leading to the disappearance of 4HNE. The addition of glutathione transferase activity (GST) facilitated a more rapid disappearance of 4HNE but the reaction was still dependent on the concentration of GSH. When cell cultures were exposed to the reaction mixtures, 4HNE cytotoxicity was also reduced in a manner which was dependent on the concentration of GSH. When 2.16- or 1.08-mM GSH were incubated in phosphate buffer with 1.08-mM 4HNE in the presence or absence of GST, then mixed with media and placed on cells for 1 h, the cytotoxicity associated with exogenous exposure to free 4HNE was abolished. GSH depletion (>90%) using buthionine sulfoximine (BSO) was accomplished in control (HA1) and H2O2-resistant variants derived from HA1. GSH depletion resulted in enhanced cytotoxicity of 4HNE in all cell lines. This BSO-induced sensitization to 4HNE cytotoxicity was accompanied by a significant reduction in the ability of cells to metabolize 4HNE. The magnitude of the sensitization to 4HNE toxicity caused by GSH depletion was similar to the magnitude of the reduction in the ability of cells to metabolize 4HNE. These results support the hypothesis that GHS and GST provide a biologically significant pathway for protection against aldehydic by-products of lipid peroxidation.
The Case for Stem Cell Counselors

In this article, Scott describes how a new counseling profession could support clinical sites and patients enrolling in stem cell clinical trials. A possible model is proposed, along with a curriculum that would provide counselors with the tools to address challenges facing the clinical stem cell field. Finally, a candidate recruitment and clinical site interface scheme is offered.
Classification of 2- and 3-field rational conformal field theories

Using the fact that the fusion algebra of a rational conformal field theory is specified in terms of integers that are related to modular transformation properties, we completely classify 2-field chiral RCFT's. We show that the only possibilities for the non-trivial fusion rule are ϕ × ϕ = 1 or ϕ × ϕ = 1 + ϕ. We reduce the 3-field classification to a set of algebraic equations and solve them in a few cases.
Effect of hot-pressing time and post-heat treatment on the microstructure and mechanical properties of SiC-fibre-reinforced glass-ceramic composites

Nicalon-SiC-fibre-reinforced (35 vol %) lithium-aluminosilicate (LAS) glass-ceramic composites were fabricated by a slurry-infiltration process followed by hot pressing at 1400°C and 10 MPa for varying soaking times. The ultimate strength and elastic modulus of the as-fabricated composites, as determined by four-point flexural tests, increased rapidly with the densification time, saturating after 30 min at 550 MPa and 130 GPa, respectively. Longer hotpressing times caused a decrease in the elastic modulus via fibre degradation. A carbon-rich interfacial layer formed between the fibres and the matrix, the thickness of which reached a maximum of ∼ 400 nm after ∼ 30 min soaking time. The flexural strength of post-heat-treated composites in air decreased by a factor of approximately four, due to oxidation and removal of the carbon content of the interfacial layer. The silica-rich bridges left behind between the fibres and the matrix contributed to brittle fracture of the composite.
The relationship between obesity and the prevalence of fast food restaurants: state-level analysis.

Abstract Purpose. Obesity accounts for approximately 300,000 deaths a year in the United States, and prevalence rates have been increasing over the past decade. The nutrition environment may be contributing to this epidemic. This study examined the relationship between fast food restaurants and obesity on a state-wide basis. Design. A one-time cross-sectional analysis of secondary data was used for this study. Setting. The setting for this study was the United States. Subjects. State-level data were used as the unit of analysis. Alaska was excluded as an outlier, and the District of Columbia was added (N = 50). Measures. Measures included aggregate state-level means for square miles per fast food restaurant, population per fast food restaurant, population density, ethnicity, age, gender, physical inactivity, fruit and vegetable intake, and obesity rates. Data were obtained from the 2002 Behavioral Risk Factor and Surveillance Survey, the 2000 U.S. Census, and the 2002 U.S. Yellow Pages. Results. Multiple ...
Using the concept of the learning curve to increase the productivity of geophysical surveys

Geophysical techniques offer many advantages and should be part of the common practice of field archaeology. However, geophysical instruments are useful only when they are operated correctly and efficiently. New or potential users want to obtain effective results as rapidly as possible and experienced users are constantly seeking to improve the results of geophysical surveys. The concept of the learning curve can be used to develop techniques and approaches that increase both the effectiveness of geophysical surveys in archaeology and the speed with which geophysical techniques are learned and applied. © 1997 John Wiley & Sons, Ltd.
Novel thiazolidinedione mitoNEET ligand-1 acutely improves cardiac stem cell survival under oxidative stress

Ischemic heart disease (IHD) is a leading cause of death worldwide, and regenerative therapies through exogenous stem cell delivery hold promising potential. One limitation of such therapies is the vulnerability of stem cells to the oxidative environment associated with IHD. Accordingly, manipulation of stem cell mitochondrial metabolism may be an effective strategy to improve survival of stem cells under oxidative stress. MitoNEET is a redox-sensitive, mitochondrial target of thiazolidinediones (TZDs), and influences cellular oxidative capacity. Pharmacological targeting of mitoNEET with the novel TZD, mitoNEET Ligand-1 (NL-1), improved cardiac stem cell (CSC) survival compared to vehicle (0.1 % DMSO) during in vitro oxidative stress (H2O2). 10 μM NL-1 also reduced CSC maximal oxygen consumption rate (OCR) compared to vehicle. Following treatment with dexamethasone, CSC maximal OCR increased compared to baseline, but NL-1 prevented this effect. Smooth muscle α-actin expression increased significantly in CSC following differentiation compared to baseline, irrespective of NL-1 treatment. When CSCs were treated with glucose oxidase for 7 days, NL-1 significantly improved cell survival compared to vehicle (trypan blue exclusion). NL-1 treatment of cells isolated from mitoNEET knockout mice did not increase CSC survival with H2O2 treatment. Following intramyocardial injection of CSCs into Zucker obese fatty rats, NL-1 significantly improved CSC survival after 24 h, but not after 10 days. These data suggest that pharmacological targeting of mitoNEET with TZDs may acutely protect stem cells following transplantation into an oxidative environment. Continued treatment or manipulation of mitochondrial metabolism may be necessary to produce long-term benefits related to stem cell therapies.
A Quantitative Description of In Vitro Assembly of Human Papillomavirus 16 Virus-Like Particles

The full-length human papillomavirus 16 major capsid protein L1 is expressed in Saccharomyces cerevisiae as virus-like particles (VLPs). However, yeast-expressed human papillomavirus 16 particles are irregular in shape and are prone to aggregate. When disassembled and reassembled, the resulting particles have improved stability and solubility. We have examined VLP dissociation and reassembly to define the important features of the assembly mechanism. We found that the VLPs rapidly disassemble at pH 8.2 and low ionic strength in the presence of low concentrations of reducing agents. The pH dependence of assembly kinetics and extent of assembly under reducing conditions were differentially sensitive to ionic strength. Assembly at pH 5.2 was very fast and led to heavily aggregated particles. This sort of kinetic trap is expected for overinitiated assembly. We observed that reassembly at pH 6.2, 7.2, and 8.2 yielded regular particles over a broad range of ionic strength. At these three pH values, assembly was quantitative at 1 M NaCl. At pH 7.2, much more than at pH 6.2 or pH 8.2, assembly decreased monotonically with ionic strength. The free energy of association ranged from -8 to -10 kcal/mol per pentamer. The effect of pH on assembly was further investigated by examining dissociation of reassembled particles. Though indistinguishable by negative stain electron microscopy, particles assembled at pH 7.2 disassembled slower than pH 5.2, 6.2, or 8.2 VLPs. We hypothesize that pH 7.2 assembly reactions lead to formation of particles with conformationally different interactions.
Self-verification and bulimic symptoms: do bulimic women play a role in perpetuating their own dissatisfaction and symptoms?

Objective: It is suggested that self-verification theory may provide insight as to why bulimic symptoms often persist for years, sometimes even despite intervention. In an effort to meet basic needs for self-confirmation, bulimic women may invite the very responses they fear (e.g., negative feedback about appearance), and thus propagate their symptoms. It was thus predicted that interest in negative feedback would be correlated with body dissatisfaction and bulimic symptoms, and that interest in negative feedback would serve as a risk factor for development of later symptoms, via the mediating effects of increased body dissatisfaction. Method: Seventy-nine undergraduate women completed self-report assessments of interest in negative feedback, bulimic symptoms, and body dissatisfaction. Results and Discussion: Results supported the prediction that, despite serious concerns about body appearance, bulimic women were interested in the very feedback that would aggravate these concerns. Moreover, interest in negative feedback appeared to serve as a risk factor for development of later symptoms, via the mediating effects of increased body dissatisfaction. The clinical implications of these findings are discussed.
BeeSign: designing to support mediated group inquiry of complex science by early elementary students

All too often, designers assume that complex science and cycles of inquiry are beyond the capabilities of young children (5--8 years old). However, with carefully designed mediators, we argue that such concepts are well within their grasp. In this paper we describe two design iterations of the BeeSign simulation software that was designed to help young children learn about honeybees collect nectar from a complex systems perspective. We summarize findings from two studies that suggest that this design has been successful in teaching and motivating these young children and demonstrates how activity theory can guide design.
Alcohol consumption and carotid atherosclerosis in older adults: the Cardiovascular Health Study.

Objective—The association of alcohol use with atherosclerosis is inconsistent in previous studies. Methods and Results—For the Cardiovascular Health Study, 5888 adults aged 65 years and older underwent a standardized interview and examination. They reported beer, wine, and liquor use individually and underwent B-mode ultrasonography to determine internal and common carotid intima-media thickness (IMT). We compared composite carotid IMT values cross-sectionally using linear regression to adjust for demographic and clinical characteristics. Among 4247 participants free of cardiovascular disease, consumers of 1 to 6 drinks per week had 0.070.04-mm lower composite IMT and consumers of 14 or more drinks per week had 0.070.05-mm higher IMT than abstainers (P quadratic trend0.02). We found similar relationships using internal and common carotid thickness measures and among men and women. The higher IMT associated with heavier alcohol use was particularly strong among 1592 participants with confirmed cardiovascular disease (0.240.09 mm greater than abstainers). Controlling for HDL cholesterol levels reduced the effect on composite IMT among consumers of 1 to 6 drinks per week by 22%. Conclusions—Relative to older adults who abstain from alcohol, consumption of 1 to 6 drinks per week had an inverse association with carotid atherosclerosis whereas consumption of 14 or more drinks had a positive association. (Arterioscler Thromb Vasc Biol. 2003;23:2252-2259.)
Why And How Should Students In Technical Programs Be Exposed To Ethical And International Issues

This paper makes the case for infusing topics such as ethics and global perspectives into engineering and technology programs. a convincing argument for inclusion of these topics as part of course requirements in technical degree programs.
A new approach to historical reconstruction: Combining descriptive and experimental paleolimnology

Here we introduce a combined experimental and descriptive approach (termed resurrection ecology) to reconstructing historical perturbations, pointing out how direct tests with sediments and hatched resting eggs complement the traditional descriptive calculation of microfossil fluxes. In the Keweenaw Waterway, a freshwater estuary off Lake Superior, turn-of-the-century copper mining impacted the resident biota. Remain fluxes document that diatom, rhizopod, and Bosmina production all declined during stamp sand discharges but recovered rapidly after World War II, moving above background levels due to developing eutrophication. In addition to biogenic silica, we discovered that bromine flux holds promise as an indicator of diatom production and confirmed that this element is present in several genera. Fluxes of Daphnia resting eggs also increased dramatically since the 1940s, dominated by a hybrid apparently produced from crosses between offshore and interior Waterway species, after channeling promoted greater mixing of water masses. Toxicity studies with sediments and Daphnia clones directly tested recovery of environments after cessation of mining activities. The studies document that increased concentrations and fluxes of copper in the Waterway during mining discharges were toxic to invertebrates. Once stamp sand discharges ceased, the biota recovered rapidly due to a combination of decreased copper cycling and organic complexation. Although sedimentation has returned to near-background conditions and surficial sediments in much of Portage Lake are no longer toxic, eutrophication and faunal exchange with Lake Superior make it unlikely that the original zooplankton community composition will return to the Waterway system. Because they are strongly coupled to biotic production, fluxes of certain pelagic microfossils (diatom frustrules, cladoceran exuviae, and resting eggs) offer insights into the magnitude of historic environmental perturbations and the time scales of population responses to ecosystem recovery. A recent attempt to improve the ecological relevance of paleolimnological reconstructions includes comparing expect1
Features of a visualization tool for specification and analysis of security protocol

Visualization tools can be an effective and entertaining means to teach students concepts in the class room. Providing accessibility to the tools allows motivated students to interact “live” with visualizations. Security protocols are an important concept in teaching information and network security. Students need to understand both the sequence of passed information, computations and analysis. In this paper, we propose an animated interactive visualization tool for teaching undergraduate students security protocols (design and analysis of authentication protocols). The student can play the animation to see the protocol in action. They can also realize and define the protocol problems by using an interactive (animation) analyzer, included within the tool, to determine the exact invalid section of the running protocol.
Symbolic manipulation and analysis of morphological expressions

A LISP based system is described for performing the automatic manipulation and analysis of morphological expressions. The system is capable of four types of symbolic manipulations: expression simplification, equivalent-form generation, signal-property analysis, and dual-form generation. The different types of knowledge that need to be represented in such a system include morphological system knowledge, signal and structuring element knowledge, and knowledge about the interaction of signals and morphological systems. As integral components of the analysis system, signals and structuring elements are represented by abstract classes which are distinguished by their properties. In addition, actual structuring elements are also represented and may be used with both abstract signals and abstract structuring elements. The interaction of signals, structuring elements, and systems is determined by a collection of morphological rule bases. >
Activation of Raf-1 by Interferon γ and Oncostatin M Requires Expression of the Stat1 Transcription Factor

Abstract A primary signaling cascade responsible for the expression of cytokine-stimulated immediate early genes involves the activation of the Jak/Stat pathway. In addition to being tyrosine-phosphorylated, several signal transducers and activators of transcription (Stats), including Stat1α, Stat3, and Stat4, are phosphorylated on a conserved serine residue, which is a consensus phosphorylation site for mitogen-activated protein kinases (MAPKs). Serine phosphorylation of Stat1α is required for maximal transcriptional activation of early response genes by interferon γ (IFNγ) as well as the antiviral and antigrowth actions of this cytokine. Incubation of cells with either IFNγ or oncostatin M (OSM) activates Raf-1, a serine/threonine kinase responsible for the ultimate activation of p42 MAPK. To examine whether any of the signaling components that are required for activation of the Jak/Stat pathway are also necessary for activation of Raf-1 by IFNs and OSM, we examined activation of Raf-1 in cell lines that are deficient in either Stat1α or Stat2. Unexpectedly, incubation of Stat1-deficient, but not Stat2-deficient cells with IFNγ or OSM for 5 min displayed no increase in Raf-1 activity. In peripheral blood lymphocytes Raf-1 was associated with Stat1, and this interaction was disrupted after incubation of cells with IFNγ. Stat1-negative cells reconstituted with either Stat1α or Stat1α with a point mutation in the site where it is serine-phosphorylated displayed normal activation of Raf-1 by IFNγ and OSM. However, activation of Raf-1 was not observed in lines that expressed Stat1α containing a mutation in its tyrosine phosphorylation site or in its SH2 domain. These results provide the first example of a novel role of Stat1α not as a transcription factor, but as a protein which may function to scaffold signaling components required for activation of the distinct Raf/MEK/MAPK signaling cascade.
Tidal pacing, skipped slips and the slowdown of Whillans Ice Stream, Antarctica

We summarize new observations of the deceleration and stick–slip motion of Whillans Ice Stream (WIS), Antarctica. We refine the location of the large sticky spots that resist motion between slip events, the locations of which are controlled by the patterns of subglacial water flow. Our examination of the long-term velocity time series for the ice stream reveals that the decadal-scale deceleration is not occurring at a steady rate, but varies at the sub-decadal timescale. This unsteady deceleration modulates the temporal evolution of a broad (~50 km across) surface-elevation bulge forming at the junction between the relatively narrow upstream portion of the ice stream and broad ice plain that constitutes the downstream end of WIS. Comparison of observations from April 2003 and November 2010 reveals significant changes in the tidally modulated stick–slip cycle that regulates motion on the ice plain. We observe that the timing of slip events has become less regular in response to decreased flow speed in the upstream portions of the ice stream. The decreased regularity of slip events has reduced the release of stored elastic strain during slip events, increasing the rate of deceleration.
Reachability analysis of hybrid control systems using reduced-order models

Complexity of reachability computations for continuous and hybrid dynamic systems typically grows exponentially with respect to the dimension of the continuous state space. Consequently, reduced-order models usually need to be constructed to make reachability analysis tractable. However, use of reduced-order models makes reachability-based verification unsound. This work presents a method for incorporating bounds on errors due to model reduction into reachability analysis for a class of hybrid control systems so that the computed sets are guaranteed to be conservative (i.e., over-) approximations of the reachable sets for the original system. We also present an efficient method for computing error bounds due to model reduction for finite-time horizons that are less conservative than error bounds from the model-reduction literature. The effectiveness of the approach is illustrated with an example.
General measures of cognition for the preschool child

Preschool-age children who are experiencing delays in physical, cognitive, communication, social, emotional, or adaptive development are often referred for a comprehensive assessment to make diagnostic determinations and to help develop appropriate interventions. Typically cognitive assessment has a key role in a comprehensive evaluation of a young child. In this article, five individually administered tests of cognitive ability, normed for the preschool-age child, are reviewed. These specific tests include the Bayley Scales of Infant Development, 2nd edition, the Kaufman Assessment Battery for Children, 2nd edition, the Wechsler Preschool and Primary Scale of Intelligence, 3rd edition, the Stanford-Binet Intelligence Scale, 5th edition, and the Differential Abilities Scales. The following is provided for these cognitive instruments: a description of the test procedures, information on scoring systems, highlights of the technical qualities, and a summary of the general meaning of test results. The article concludes with strengths and limitations of the instruments.
« Le passé recomposé? Une réflexion sur les expositions d'art et d'artefacts amérindiens aux États-Unis »

A partir d’une reflexion sur l’evolution des collections et des expositions d’artefacts et d’objets d’art amerindiens aux Etats-Unis depuis le 19e siecle, l’auteur brosse un tableau des principales mutations des pratiques de categorisation et d’exposition des collections ethnographiques aux Etats-Unis. Si au 19e siecle la rage de l’ordre incite les conservateurs a organiser les collections a partir de criteres de forme et de fonctions des objets, au tournant du 20e siecle, sous l’influence de Franz Boas, ils s’appuient de plus en plus sur la geographie et les histoires culturelles pour categoriser les objets et construire de nouvelles typologies. En museologie, cette nouvelle orientation s’est traduite par les dioramas destines a reconstituer un aspect du mode de vie traditionnel d’un groupe donne. Plus recemment, les musees americains tendent a esthetiser fortement les artefacts amerindiens pour en faire des objets d’art alors que les Amerindiens « patrimoinisent » les objets rapatries des musees d’Etat.
Different Selective Pressures Shape the Molecular Evolution of Color Vision in Chimpanzee and Human Populations

A population genetic analysis of the long-wavelength opsin (OPN1LW, "red") color vision gene in a global sample of 236 human nucleotide sequences had previously discovered nine amino acid replacement single nucleotide polymorphisms, which were found at high frequencies in both African and non-African populations and associated with an unusual haplotype diversity. Although this pattern of nucleotide diversity is consistent with balancing selection, it has been argued that a recombination "hot spot" or gene conversion within and between X-linked color vision genes alone may explain these patterns. The current analysis investigates a closely related primate with trichromatism to determine whether color vision gene amino acid polymorphism and signatures of adaptive evolution are characteristic of humans alone. Our population sample of 56 chimpanzee (Pan troglodytes) OPN1LW sequences shows three singleton amino acid polymorphisms and no unusual recombination or linkage disequilibrium patterns across the approximately 5.5-kb region analyzed. Our comparative population genetic approach shows that the patterns of OPN1LW variation in humans and chimpanzees are consistent with positive and purifying selection within the two lineages, respectively. Although the complex role of color vision has been greatly documented in primate evolution in general, it is surprising that trichromatism has followed very different selective trajectories even between humans and our closest relatives.
A Study of the Relationship Between American Sign Language and English Literacy

This article presents the findings of a study of the relationship between American Sign Language (ASL) skills and English literacy among 160 deaf children. Using a specially designed test of ASL to determine three levels of ASL ability, we found that deaf children who attained the higher two levels significantly outperformed children in the lowest ASL ability level in English literacy, regardless of age and IQ. Furthermore, although deaf children with deaf mothers outperformed deaf children of hearing mothers in both ASL and English literacy, when ASL level was held constant, there was no difference between these two groups, except in the lowest level of ASL ability. The implication of this research is straightforward and powerful: Deaf children's learning of English appears to benefit from the acquisition of even a moderate fluency in ASL.
Newer Antithrombotic Strategies in the Initial Management of Non–ST-Segment Elevation Acute Coronary Syndromes

OBJECTIVE:To review the place in therapy of currently available antithrombotic agents in the non–ST-segment elevation acute coronary syndromes, that is, unstable angina and non–Q-wave myocardial infarction (MI). Recommendations are made based on currently available data.DATA SOURCE:English-language clinical studies, position statements, and review articles pertaining to the management of unstable angina and non–Q-wave MI with currently available products.STUDY SELECTION:Selection of prospective clinical studies was limited to those focusing on the management of the non–ST-segment elevation acute coronary syndromes, unstable angina, and non–Q-wave MI.DATA SYNTHESIS:It has yet to be determined which combination of agents (dalteparin, enoxaparin, lepirudin, clopidogrel, ticlopidine, abciximab, eptifibatide, tirofiban) and procedural strategies most significantly reduces mortality and serious events in these patients. The relevant pathophysiology, diagnostic criteria, and risk-stratifying procedures are revie...
Organizational Resource Bundles and Institutional Change in the U.S. Organic Food and Agricultural Certification Sector

This analysis explores the competitive implications of new institutional standards within the organic certification industry based on a theoretical perspective that integrates institutional and res...
ROC analysis of statistical methods used in functional MRI: individual subjects.

The complicated structure of fMRI signals and associated noise sources make it difficult to assess the validity of various steps involved in the statistical analysis of brain activation. Most methods used for fMRI analysis assume that observations are independent and that the noise can be treated as white gaussian noise. These assumptions are usually not true but it is difficult to assess how severely these assumptions are violated and what are their practical consequences. In this study a direct comparison is made between the power of various analytical methods used to detect activations, without reference to estimates of statistical significance. The statistics used in fMRI are treated as metrics designed to detect activations and are not interpreted probabilistically. The receiver operator characteristic (ROC) method is used to compare the efficacy of various steps in calculating an activation map in the study of a single subject based on optimizing the ratio of the number of detected activations to the number of false-positive findings. The main findings are as follows: Preprocessing. The removal of intensity drifts and high-pass filtering applied on the voxel time-course level is beneficial to the efficacy of analysis. Temporal normalization of the global image intensity, smoothing in the temporal domain, and low-pass filtering do not improve power of analysis. Choices of statistics. the cross-correlation coefficient and t-statistic, as well as nonparametric Mann-Whitney statistics, prove to be the most effective and are similar in performance, by our criterion. Task design. the proper design of task protocols is shown to be crucial. In an alternating block design the optimal block length is be approximately 18 s. Spatial clustering. an initial spatial smoothing of images is more efficient than cluster filtering of the statistical parametric activation maps.
Beta interferon-mediated activation of signal transducer and activator of transcription protein 1 interferes with Rickettsia conorii replication in human endothelial cells

Infection of the endothelial cell lining of blood vessels with Rickettsia conorii, the causative agent of Mediterranean spotted fever, results in endothelial activation. We investigated the effects of R. conorii infection on the status of the Janus kinase (JAK)-signal transducer and activator of transcription protein (STAT) signaling pathway in human microvascular endothelial cells (HMECs), the most relevant host cell type, in light of rickettsial tropism for microvascular endothelium in vivo. R. conorii infection induced phosphorylation of STAT1 on tyrosine 701 and serine 727 at 24, 48, and 72 h postinfection in HMECs. Employing transcription profile analysis and neutralizing antibodies, we further determined that beta interferon (IFN-β) production and secretion are critical for STAT1 activation. Secreted IFN-β further amplified its own expression via a positive-feedback mechanism, while expression of transcription factors interferon regulatory factor 7 (IRF7) and IRF9, implicated in the IFN-β-STAT1 feedback loop, was also induced. Metabolic activity of rickettsiae was essential for the IFN-β-mediated response(s) because tetracycline treatment inhibited R. conorii replication, IFN-β expression, and STAT1 phosphorylation. Inclusion of IFN-β-neutralizing antibody during infection resulted in significantly enhanced R. conorii replication, whereas addition of exogenous IFN-β had the opposite inhibitory effect. Finally, small interfering RNA-mediated knockdown further confirmed a protective role for STAT1 against intracellular R. conorii replication. In concert, these findings implicate an important role for IFN-β-mediated STAT1 activation in innate immune responses of vascular endothelium to R. conorii infection.
Is mindfulness Buddhist? (and why it matters):

Modern exponents of mindfulness meditation promote the therapeutic effects of "bare attention"--a sort of non-judgmental, non-discursive attending to the moment-to-moment flow of consciousness. This approach to Buddhist meditation can be traced to Burmese Buddhist reform movements of the first half of the 20th century, and is arguably at odds with more traditional Theravāda Buddhist doctrine and meditative practices. But the cultivation of present-centered awareness is not without precedent in Buddhist history; similar innovations arose in medieval Chinese Zen (Chan) and Tibetan Dzogchen. These movements have several things in common. In each case the reforms were, in part, attempts to render Buddhist practice and insight accessible to laypersons unfamiliar with Buddhist philosophy and/or unwilling to adopt a renunciatory lifestyle. In addition, these movements all promised astonishingly quick results. And finally, the innovations in practice were met with suspicion and criticism from traditional Buddhist quarters. Those interested in the therapeutic effects of mindfulness and bare attention are often not aware of the existence, much less the content, of the controversies surrounding these practices in Asian Buddhist history.
Localized Pigmented Villonodular Synovitis of the Knee

Five cases of localized pigmented villonodular synovitis of the knee are presented. From analysis of these cases, it is evident that the local form of the disease does not present the well known chronic inflammatory pattern of the diffuse form but most often presents itself as a mechanical derangement of the knee. The symptoms are typically acute and episodic and include complaints of pain, locking, and giving way; the findings are generally those of slight-to-moderate effusion and limitation of motion. The finding which may serve to distinguish the lesion from other causes of mechanical derangement is a firm, movable soft-tissue mass attached to the deep structures. It is suggested that localized pigmented villonodular synovitis should be kept in mind as an occasional cause of mechanical derangement of the knee.
Effective Communication Strategies for Store Remodeling

Hospitality operators spend millions of dollars on store remodeling; however, existing research offers little guidance on how to effectively communicate such investments to consumers. This study examines the joint effects of explanation type (customer-focused vs. brand-focused vs. control) and relationship type (communal vs. exchange) on consumers’ opinions of remodeling, feelings of trust, and brand attitudes. Overall, the results indicate that a customer-focused explanation is more effective in gaining customer support for store remodeling. The positive impact of a brand-focused explanation is limited to brand attitudes among exchange-type customers, while a customer-focused explanation is effective in both communal and exchange relationships. Furthermore, the results show that feelings of trust are the underlying mechanism explaining the relationship between explanation type and brand attitudes. Findings of this study suggest that hospitality managers should consider store remodeling as a great adverti...