cssi/SciSciGPT-SciSciNet huggingface dataset:
Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage(1-3). Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease(4). The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve(5). Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves(6-9). Pulsatile bioreactors have also been developed to study a range of tissues including cartilage(10), bone(11) and bladder(12). The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed air into the system at the appropriate rate. The system mimicked the dynamic transvalvular pressure levels associated with the aortic valve; a saw tooth wave produced a gradual increase in pressure, typical of the transvalvular pressure gradient that is present across the valve during diastole, followed by a sharp pressure drop depicting valve opening in systole. The LabVIEW program allowed users to control the magnitude and frequency of cyclic pressure. The system was able to subject tissue samples to physiological and pathological pressure conditions. This device can be used to increase our understanding of how heart valves respond to changes in the local mechanical environment.
Dual Focused Photoacoustic Microscopy

We developed a dual focused technique for depth extended photoacoustic microscopy (PAM). Employing an improved synthetic-aperture-focusing-technique for the dual focused PAM, the imaging depth can be double extended with 2× improved signal intensity.
The role of C2 intermediates in Fischer-Tropsch synthesis over ruthenium

The C2 products formed over Ru during Fischer-Tropsch synthesis often lie well below the Anderson-Schulz-Flory line describing the C4+ products. This has led to speculation that either the surface precursor to C2 hydrocarbons is exceptionally long lived, or that the ethylene formed by CO hydrogenation readsorbs and thereby reenters the chain growth process. In this study, the role of ethylene readsorption on the dynamics of chain initiation and growth is investigated using13CO/H2 and12C2H4 to differentiate between the carbon sources. Ethylene addition is found to suppress the rate of methanation and increase the rates of formation of C3+ hydrocarbons. Ethylene serves as an effective chain initiator, as well as a source of C1 monomer species which participate in chain propagation. No evidence is seen, though, for the participation of C2 species in chain propagation.
Iron Loading and Overloading due to Ineffective Erythropoiesis

Erythropoiesis describes the hematopoietic process of cell proliferation and differentiation that results in the production of mature circulating erythrocytes. Adult humans produce 200 billion erythrocytes daily, and approximately 1 billion iron molecules are incorporated into the hemoglobin contained within each erythrocyte. Thus, iron usage for the hemoglobin production is a primary regulator of plasma iron supply and demand. In many anemias, additional sources of iron from diet and tissue stores are needed to meet the erythroid demand. Among a subset of anemias that arise from ineffective erythropoiesis, iron absorption and accumulation in the tissues increases to levels that are in excess of erythropoiesis demand even in the absence of transfusion. The mechanisms responsible for iron overloading due to ineffective erythropoiesis are not fully understood. Based upon data that is currently available, it is proposed in this review that loading and overloading of iron can be regulated by distinct or combined mechanisms associated with erythropoiesis. The concept of erythroid regulation of iron is broadened to include both physiological and pathological hepcidin suppression in cases of ineffective erythropoiesis.
CHROMOSOME STUDIES ON GASTERIA III. CHROMOSOME STRUCTURE DURING MICROSPOROGENESIS AND THE POSTMEIOTIC MITOSIS

The writer began regular collections for a study of chromosome form in Gasteria in I922 at the University of Pennsylvania, following casual earlier observations indicating that this genus was suitable for careful cytological work. The study of chromosome form through the various developmental stages came to tolerably satisfactory completion and was published (I924, I925, 1929). As it progressed, evidences of internal structural differentiation became apparent, and a preliminary note was published calling attention to one aspect of this (I922). Accumulating material of Gasteria and of other plants studied in the writer's laboratory soon showed the inadequacy of this preliminary interpretation, so that a redescription of the conditions was undertaken. The structure of the chromosomes being inseparable from the changes occurring during the meiotic phases, it was necessary to secure material for a description of meiosis, which task has, from interference by other work, been but slowly accomplished. Only the comparative adequacy of the available material in character and quantity, and its preparation by distinctly improved methods, justify the publication of another description of meiosis. It is not worth while to analyze here the various views propounded regarding chromosome structure. The literature has been growing rapidly, and has been reviewed several times. It is impracticable to separate the literature upon chromomeres and chromonemata from that dealing with synapsis and the chromosome tetrad, with both of which this present paper is also concerned. The publications of Kaufmann (1926x, b) on Tradescantia and Podophyllum report the first studies in which the writer had a direct interest, and fairly review the earlier literature. A double spiral structure is described in somatic chromosomes, and a history contrasting with that offered by Martens (1922 et seq.). A spiral chromonema was also found in meiotic chromosomes. Spiral structures are next reported by Kuwada (1927) also in Tradescantia, who finds mechanical difficulties in separating
Immunochemical studies on a galactosyl-protein conjugate

Antibodies formed in rabbits immunized with galactosido- β - D -azophenyl bovine serum albumin, after absorption with bovine serum albumin, were studied by quantitative hapten-inhibition techniques. It was shown (a) that the surface profile of the antibody is specific for the β - D -galactopyranosyl structure, (b) that the dimension of the combining site is complementary to the galactopyranosyl-phenylazo moiety and is approximately half that of the previously well-defined human antidextran site, (c) that the antibody or spectrum of antibodies in sera from two rabbits present an apparent micro-identity.
Heterotaxia, Congenital Heart Disease, and Primary Ciliary Dyskinesia

The human heart is strikingly asymmetrical along the left-right body axis. If one begins with the position of the heart in the left chest, continues through asymmetrical venous drainage into the atria and asymmetrical orientation of the 2 anatomically and functionally distinct ventricles, and finally proceeds through the highly asymmetrical coil of semilunar valves and great vessels, the structure and function of the human heart are precisely aligned to the left-right axis. When cardiac asymmetries either fail to develop or align incorrectly relative to each other or relative to other organs, a plethora of congenital heart disease results. This group of heart diseases is called heterotaxy syndrome and represents both a difficult clinical challenge and a fascinating window into the biology underlying one of the most fundamental embryological processes, namely, the mechanism by which an organism establishes the 3 body axes. Positioning of organs along the left-right axis can be divided into 3 broad classes: situs solitus, in which all organs are positioned normally; situs inversus, in which there is mirror image reversal of all organs; and heterotaxy, in which there is any positioning of organs along the left-right axis differing from situs solitus and situs inversus (Figure). Pure situs inversus is found in 1 of 8500 in the general population and is usually not associated with intracardiac defects. In contrast, heterotaxy has a high degree of association with intracardiac defects. It has a reported incidence of 1 of 10 000 and is associated with at least 3% of cases of congenital heart disease.1 The anatomic spectrum of organ laterality. A, Situs solitus. B, Right atrial isomerism. The liver is midline, there are 2 eparterial bronchi, the position of the stomach and cardiac apex is indeterminate, and there is asplenia. C, Left atrial isomerism. The liver is midline, there …
Time-Resolved Infrared Dynamics of C−F Bond Activation by a Tungsten Metal−Carbonyl

Chemical reactions that break, or activate, C-H and C-F are of tremendous synthetic interest. The intramolecular C-F bond activation of a tungsten carbonyl system has been studied by time-resolved infrared spectroscopy. The formation of solvent complexes and the final product are monitored using time-resolved infrared spectroscopy of the CO stretches. The rate of the reaction is shown to be limited by the formation of an intermolecular complex between the tungsten metal center and a solvent molecule. Comparison with DFT calculations shows that in the absence of solvent molecules the intramolecular complex with the tethered perfluorobenzene ring is energetically favorable, but is not the primary kinetic product because of the initial geometry of the complex.
Rapid Deposition of Gold Nanoparticle Films with Controlled Thickness and Structure by Convective Assembly

We report how convective assembly at high volume fraction combined with thermal treatment allows robust fabrication of gold nanocoatings whose structure can be varied and correlated to their optica...
Solid-phase parallel synthesis of 2-aminoimidazolidin-4-ones

Abstract The solid phase synthesis of 2-aminoimidazolidin-4-ones from resin-bound amino acids is described. Resin-bound thioureas were treated with Mukaiyama's reagent (2-chloro-1-methypyridinium iodide) to form, via intramolecular cyclization, resin-bound 2-iminoimidazolidin-4-ones. Following alkylation and cleavage, the corresponding 1,5-disubstituted 2-aminoimidazolidin-4-ones were provided in good yield and purity.
Production of Muon Pairs by 225-GeV/c π +/- , K + , p +/- Beams on Nuclear Targets

Results are presented from a large-acceptance experiment in which muon-pair production was observed in the mass range 2 to 11 GeV/${\mathit{c}}^{2}$. Data were taken with ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{+}$, and ${p}^{\ifmmode\pm\else\textpm\fi{}}$ beams at 225 GeV/c on carbon, copper, and tungsten targets. Differential cross sections and the production dependence on pair mass, ${x}_{\mathrm{F}}$, ${p}_{T}$, incident-particle type, and target nucleus are discussed.
Analysis of the ultrastructure of vitrosin fibers on the basis of the polarization optical method.

1. 1. Fibers were prepared from a structural protein (vitrosin) of the vitreous body and their form and crystalline double refraction were determined. 2. 2. The form double refraction was calculated as 9·10−4, the crystalline double refraction as 14·10−4. 3. 3. On the basis of these data, and Wiener's theory, the conclusion was drawn that vitrosin fibers are composed of rodlet-shaped submicroscopic particles, which have a longitudinally oriented molecular structure.
Ethical Issues in New Drug Prescribing

We use the format of a hypothetical case study to review issues related to pharmaceutical product approval and physician prescribing practices. In this case, a new FDA-approved drug is recommended for a patient who subsequently experiences an adverse event that may or may not be related to the prescription. This case raises a number of ethical and legal considerations physicians routinely face when deciding whether to recommend such drugs for their patients. Despite the need for ongoing observation by the regulatory apparatus, physicians should be cognizant of the limitations of the drug approval system and the post-approval prescription drug surveillance system. We discuss physicians’ ethical obligations when faced with a newly approved drug, including seeking out independent sources of learning, reporting adverse effects, and notifying patients about limitations in available knowledge about therapeutic recommendations.
Differential scanning calorimetric studies of the reaction between lignocellulosic materials and hydrogen peroxide using model compounds

Abstract Reaction of hydrogen peroxide with twenty lignocellulosic polymers and model compounds was studied by differential scanning calorimetry at 6722 kPa (975 psi) in nitrogen and oxygen atmospheres. Two exotherms were identified. Exotherm A peaked between 109 and 186°C in N 2 and O 2 with the heat of reaction Δ H a ranging from 738 to 2638 cal g −1 . Exotherm B peaked between 180 and 254° C in either atmosphere with Δ H b = 109–346 cal g −1 in N 2 and with Δ H b = 1356–4325 cal g −1 in O 2 . With one exception, exotherm B appeared in N 2 only in the case of the materials which possessed acetal or hemiacetal linkages. It was concluded that exotherm A resulted from decomposition of H 2 O 2 under formation of O 2 and oxidation of organic compounds, while exotherm B resulted from oxidation of hydroxyl groups by O 2 . A mechanism was proposed for the formation of O 2 , which involved hydrolysis of acetal or hemiacetal linkages to aldehydes or ketones, formation of α-hydroxyperoxides by addition of H 2 O 2 , oxidation of a-hydroxyperoxides by hydroxyl radicals, decomposition of the resulting free radicals under formation of superoxyl radicals and oxidation of superoxyl radicals either by hydrogen peroxide or by hydroxyl radicals to oxygen.
Chlorine-Induced Mortality of Eggs and Larvae of Spotted Seatrout (Cynoscion nebulosus)

Abstract The acute lethal effects of sodium hypochlorite, chloramine, and 5-chlorouracil on eggs and larvae of spotted seatrout, Cynoscion nebulosus, are presented. Forty-eight-h median tolerance limits (TLm) for the various toxicants and age classes (2-h-old eggs, 10-h eggs, and 1-h posthatch larvae) were, respectively: sodium hypochlorite—0.21 ± 0.01, 0.21 ± 0.01, 0.17 ± 0.28 ppm; chloramine—14.14 ± 1.13, 0.57 ± 0.28, 5.75 ± 3.01 ppm; 5-chlorouracil-8.91 ± 1.03, > 100, 79.43 ± 44.97 ppm. The 48-h TLm varied depending on toxicant and age class.
On the mechanism of the intramolecular samarium Barbier reaction. Probes for formation of radical and organosamarium intermediates

Abstract A new type of mechanistic probe for the intramolecular samarium Barbier reaction has been designed, and two different probe substrates have been investigated in detail. Remarkably, no unambiguous evidence could be obtained in favor of any of the obvious intermediates (free alkyl or alkoxy radicals, ketyls, organosamarium species) that are postulated for this reaction. Several possibilities for modified mechanisms are suggested.
Inductively coupled plasma assisted deposition and mechanical properties of metal-free and Ti-containing hydrocarbon coatings

Metal-free amorphous hydrocarbon (a-C:H) and Ti-containing hydrocarbon (Ti–C:H) coatings have been synthesized in a hybrid chemical vapor deposition (CVD)/physical vapor deposition (PVD) system which combines inductively coupled plasma (ICP) and sputter deposition. a-C:H coatings have been fabricated by ICP assisted CVD in inert/hydrocarbon gas mixtures while Ti–C:H coatings have been fabricated by ICP assisted magnetron sputtering of Ti in inert/hydrocarbon gas mixtures. We present results of structural characterization and mechanical property measurements on these a-C:H and Ti–C:H coatings. In particular, the influence of hydrogen on the coating mechanical properties is probed experimentally. We show that hydrogen significantly influences the mechanical properties of a-C:H and Ti–C:H coatings and needs to be considered for a full understanding of the mechanical properties of Ti–C:H coatings. Our results demonstrate that combining ICP with sputter deposition makes a versatile CVD/PVD tool capable of depo...
Presencia de Ptychodus mortoni (Elasmobranchii: Ptychodontidae) en el Cretácico Superior de Venezuela

Ptychodus mortoni es un tiburon durofago caracteristico del Cretacico Superior, con un registro cronoestratigrafico entre el Turoniano- Maastrichtiano. En la presente contribucion se ilustra y describe un conjunto de dientes de un mismo ejemplar de Ptychodus mortoni, proveniente de la Formacion La Luna, del Cretacico Superior de La Sierra de Perija, Estado Zulia, Venezuela. Este material representa el unico registro conocido de esta especie para America del sur y extiende la distribucion paleobiogeografica del taxon, el cual era conocido solo para Africa, America del Norte y Europa.
Cathodoluminescence-Activated Imaging by Resonance Energy Transfer: A New Approach to Imaging Nanoscale Aqueous Biodynamics

The organization, complexing, and aggregation of biomolecules in solution and in lipid membranes lie at the foundation of many critical processes in metabolism, signaling, and disease. Yet, our understanding of these phenomena remains limited by our ability to probe small aqueous volumes under physiological conditions. Here we present progress toward a high-brightness, rapidly scannable, nanoscale light source aimed at interrogating biomolecular dynamics in highly concentrated aqueous environments below the diffraction limit. This light source consists of a thin film of cathodoluminescent (CL) material excited by a low energy, tightly focused electron beam from a scanning electron microscope (SEM). By integrating the CL film into a liquid sample cell, a biological sample can be isolated from the SEM's vacuum environment.Our CL optical source consists of a highly crystalline film of cerium-doped yttrium aluminum perovskite (YAlO3:Ce3+), an efficient CL material. With our custom CL detection apparatus, we have shown that the CL excitation volume in the film is at least as small as 20 nm in diameter. Because the CL film is only 10 nm thick, optical excitations from the Ce3+ dopants in the CL film can be non-radiatively transferred to adjacent fluorescently labeled molecules in an encapsulated sample volume via Forster resonance energy transfer (FRET). We characterize this non-invasive interaction by coupling the donor CL film to various acceptor materials. When imaging biological systems, we anticipate achieving a spectrally-specific scanning optical microscopy with at least 20 nm lateral resolution and 10 nm axial resolution, with video frame rates, and no moving parts.
On the importance of philosophy for history of science: Studies in the logic of erudition

The importance of history for the philosophy of science is hardly open to doubt any longer nowadays. Thus one direction in which the discussion can now be fruitfully moved is to inquire into the details of exactly how history is important and useful. This is already being done in many quarters, both at a level and in a manner that attempt to be systematic as well as exhaustive,1 and in simpler ways that avoid pedantries without losing substance.2 In this flurry of activity, philosophers are apt to forget about the importance of philosophy in the study of the history of science. The nature of this latter topic being what it is, one can hardly expect historians of science to take it seriously if philosophers neglect it. Thus I feel that another useful direction in which to move the problem of the history/philosophy connection is to analyze the uses of philosophy in the history of science. To be sure, this latter problem has not been totally neglected. For example, Joseph Agassi has argued that epistemological and methodological principles can serve as covering laws for historical explanations of scientific episodes,3 and Imre Lakatos has argued that theories of rationality are guides for the reconstruction of past episodes.4 However, Agassi has been criticized by the counter argument that philosophical principles of the type mentioned by him are not needed in history-of-science explanation, thus making the latter somewhat autonomous,5 and Lakatos has been criticized by many, the latest being perhaps Larry Laudan, who has argued that the rational reconstructions of the past mentioned by Lakatos themselves presuppose historical reconstructions of the usual kind.6 Moreover, and more importantly, the historical accounts produced by both Agassi and Lakatos have tended to receive a very unfavorable reaction among historians of science, thus indicating that historical
A creative approach to HIV/AIDS programs for adolescents.

SUMMARY An empowerment-oriented approach is presented to effectively teach/inform youth about prevention of HIV/AIDS and sexually transmitted diseases. The article describes: an assessment of the target population and its results; steps to comprehensive peer education with this population; an action plan for mobilizing and linking resources for this population through social networks and community; and the importance of empowerment-oriented program evaluation. The target population are youth aged 12-18, housed in alternative settings such as residential child care facilities, psychiatric hospitals, or youth detention centers. This population is reliant upon residential programs for training and services, because they are unlikely to take part in school or other community-based programs.
The neural basis of humour processing

In this Perspective article, Reiss and colleagues summarize the most recent neuroimaging studies attempting to determine the neural correlates of humour and discuss the influence of sex, personality traits and certain psychiatric disorders on humour appreciation.
Lattice strain framework for plastic deformation in complex concentrated alloys including high entropy alloys

AbstractAlloys involving multiple solutes where the concentrations are such that it becomes difficult to identify a “solvent”, such as the so called “high entropy alloys”, have the potential for interesting combinations of properties. A key question relates to the fundamental mechanisms of plastic deformation in these alloys. A simple lattice strain framework is proposed for complex concentrated alloys to address the energetics and kinetics of dislocations and twins. It is argued that the lattice strain in highly concentrated alloys raises the base energy of the crystal and thereby reduces the additional energy required to nucleate dislocations and twins. However, the kinetics of dislocation motion are dampened by the lattice strain and local energy variations. This is reflected in lower values of activation volume. This framework can be used to design non-equiatomic high entropy alloy matrixes that enhance the properties achieved thus far.
Fixed effects with interpersonal and intertemporal covariance

The paper considers the estimation of a fixed effects time series-cross section model where errors have both unspecified interpersonal and intertemporal covariance. Efficient estimators in the form of GLS are suggested, which can be implemented on the data in their actual form or in deviations from time-means. As an empirical example, the determinants of new residential construction activity in the New England states of the US during the 80's are investigated. Results show substantial sensitivity to changes in the interest rate and the unemployment rate, whilst responses to changes in income are more muted. Long term factors related to the region are also influential.
Scoyenia Escape Burrows in Fluvial Pebbly Sand: Upper Triassic Sugarloaf Arkose, Deerfield Rift Basin, Massachusetts, USA

Late Triassic larvae of an insect, probably a beetle, moved diagonally upwards though fluvial pebbly sand along a thin mud layer, constructing Scoyenia burrows in the Sugarloaf Arkose, Deerfield rift basin, Massachusetts. They may have been escaping a temporary rise of the water table in the monsoonal dry season.
Industrial–Organizational Psychology's Chicken Little Syndrome

Aguinis, Bradley, and Brodersen (2014) offer an assessment of the extent industrial–organizational (I–O) psychologists have moved to business schools and predictions for the future. We present additional quantitative data that speak to the extent such migration is occurring, examine other indices of influence, and report qualitative data concerning why individuals stay in psychology. We conclude with brief thoughts on the future of the field.
Dance for Special Populations

(1982). Dance for Special Populations. Journal of Physical Education, Recreation & Dance: Vol. 53, No. 7, pp. 70-72.
VELOCITY OF THE EARTH WITH RESPECT TO THE COSMIC BACKGROUND RADIATION.

THE discovery of the 3 K background radiation has provided a new tool for studying the universe. The radiation exhibits a black-body spectrum over a frequency range of 280 to 1 (ref. 1) and is highly isotropic2–4, which supports the hypothesis that the radiation was produced at an early stage in the expansion of the universe. If this is correct, the radiation defines an extremely distant reference frame—that of the matter which last scattered it5. If the Earth has a total velocity v with respect to this frame, there will be an apparent excess of radiation in the direction of motion6 of magnitude (v/c) cos θ. Preliminary experimental results at Stanford show a definite excess with this kind of angular variation. Assuming that intrinsic anisotropy of this type is negligible, a large value for the Earth's motion is indicated in addition to rotation around the galaxy.
Tensile Durability of Cement-Based FRP Composite Wrapped Specimens

Fiber-reinforced polymer composite (FRPC) wraps are increasingly being used for rehabilitation and strengthening of concrete structures. This paper presents the results of an experimental study on the tensile performance of cement-based specimens wrapped with FRPC sheets subjected to wet-dry and freeze-thaw cycles. The tensile strength values were evaluated using the ASCERA hydraulic tensile tester. This simple testing technique provides a uniform stress distribution throughout the specimen, thus minimizing eccentricity and gripping effects, which can be of a significant source of error. Cement-based specimens were wrapped with three different types of FRP tow sheets: two carbon and one glass. Test variables included the type of fiber (C1, C5, and GE) and the environmental exposure conditions. The specimens were conditioned in three different environments, as follows: (1) room temperature (23°C); (2) 300 wet-dry cycles using salt water; and (3) 300 freeze/thaw cycles. At the end of each exposure, ultimate...
The purinergic P2X7 receptor is not required for control of pulmonary Mycobacterium tuberculosis infection.

Signaling through the purinergic P2X7 receptor by mM concentrations of extracellular ATP has been shown to induce apoptosis and lead to killing of mycobacteria in infected human and murine macrophages (4, 6, 10). The mechanism of this Mycobacterium tuberculosis growth reduction is due to increased phagosome-lysosome fusion after signaling of the P2X7 receptor (3, 5, 15). Previously, we created an in vitro human system where lysed cells provided bystander ATP in the local microenvironment of mycobacterium-infected monocytes. No evidence of mycobacterial killing was observed in spite of achieving significant local concentrations of ATP (2). It is not clear whether sufficient extracellular ATP concentrations can be achieved in vivo or if there are modulating factors in vivo that cannot be recreated with in vitro models. As a result, we wanted to determine if ATP signaling of the P2X7 receptor plays a role in control of mycobacteria in vivo.
Dendritic spine morphology and dynamics in health and disease

Dendritic spines are actin-rich structures that form the postsynaptic terminals of excitatory synapses in the brain. The development and plasticity of spines are essential for cognitive processes, such as learning and memory, and defects in their density, morphology, and size underlie a number of neurological disorders. In this review, we discuss the contribution and regulation of the actin cytoskeleton in spine formation and plasticity as well as learning and memory. We also highlight the role of key receptors and intracellular signaling pathways in modulating the development and morphology of spines and cognitive function. Moreover, we provide insight into spine/synapse defects associated with several neurological disorders and the molecular mechanisms that underlie these spine defects.
Viral Interference: The Case of Influenza Viruses.

During the influenza season, numerous strains of influenza A and B viruses can cocirculate within populations. For example, in the United States, influenza A(H3N2) viruses cocirculated with influenza B viruses, while influenza A(H1N1) pdm09 viruses were reported only rarely during the 2014–2015 season [5]. Complicating the situation is the cocirculation with other respiratory viruses [6], several of which have been hypothesized to influence influenza virus infection in humans [7] or directly shown to cause viral interference in animal models [8–10].However, there is little information about viral interference among human influenza A and B viruses in relevant animal models, including the duration and extent of temporary immunity, if it occurs. The studies by Laurie et al in this issue of The Journal of Infectious Diseases fill this gap in knowledge and provide important new information on the importance of time and viral strain in viral interference during influenza virus infections. To understand the impact of cocirculating human influenza A and B viruses on viral interference, Laurie et al coinfected ferrets with combinations of influenza A and B viruses that circulated in 2009 and 2010, with intervals of 1–14 days between primary and secondary viral challenge. Two of the intervals (days 1 and 3) represented the start and peak of virus shedding in the upper respiratory tract; day 5 corresponded to decreased viral shedding, day 7 represented the end of viral shedding, while days 10 and 14 represented a time when the adaptive immune response was activated. Viral shedding,
Ability of the exercise electrocardiogram test to detect ischemia in stable coronary artery disease patients with ST-segment depression on the resting electrocardiogram

Abstract Background The appearance of ST-segment depression on the exercise electrocardiogram (ETT) generally indicates myocardial ischemia. Disorders that produce ST-segment depression on the resting electrocardiogram can confound the results of the ETT. The purpose of this study was to assess the reliability of exercise ST-segment depression as an indicator of ischemia in patients with a resting electrocardiographic ST depression, presumably caused by coronary disease. Methods We studied 882 patients 1 to 6 months after a hospitalization for myocardial infarction or unstable angina as part of the Multicenter Study of Myocardial Ischemia. An ETT and thallium-201 perfusion scan were performed in all patients. For the purpose of this study, the perfusion scan was considered the "gold standard" for ischemia. We correlated the ETT ST-segment responses with the perfusion scan in a group with a normal electrocardiogram baseline ST segment (NO ST DEP group) and in a group with resting electrocardiographic ST depression ≥0.5 mm (ST DEP group). Results Although the frequency of ischemia by perfusion scan was similar in the ST DEP group (48%) to that in the NO ST DEP group (40%), the ST DEP group had a significantly higher ( p = 0.03) sensitivity (54%) in detecting ischemia than the NO ST DEP group (35%). The ST DEP group, however, had a lower (58% vs 74%) specificity than the NO ST DEP group ( p = 0.056). Baseline characteristics of the two groups probably account for these differences. The overall diagnostic accuracy is similar (58% vs 56%) in the two groups. Conclusion We conclude that in a stable population with known coronary disease, the presence of ST depression on the resting electrocardiogram does not impair the detection of ischemia by the ETT, but may be associated with a higher false-positive rate.(Am Heart J 1998;135:901-6.)
Growth of BN thin films by pulsed laser deposition

A new UHV system for pulsed laser deposition of materials is described, together with results from preliminary experiments for depositions of BN on Si. The system is designed to allow for in-situ diagnostics of the ablation plasma, as well as UHV preparation and characterization of clean sample substrates. The room temperature depositions of BN result in amorphous, B-rich films, whose particle content is a strong function of laser wavelength.
New Madrid seismic zone fault geometry

The New Madrid seismic zone of the central Mississippi River valley has been interpreted to be a right-lateral strike-slip fault zone with a left stepover restraining bend (Reelfoot reverse fault). This model is overly simplistic because New Madrid seismicity continues 30 km southeast of the stepover. In this study we have analyzed 1704 earthquake hypocenters obtained between 1995 and 2006 in three-dimensional (3-D) space to more accurately map fault geometry in the New Madrid seismic zone. Most of the earthquakes appear to align along fault planes. The faults identifi ed include the New Madrid North (29°, 72° SE), Risco (92°, 82° N), Axial (46°, 90°), Reelfoot North (167°, 30° SW), and Reelfoot South (150°, 44° SW) faults. A diffuse zone of earthquakes exists where the Axial fault divides the Reelfoot fault into the Reelfoot North and Reelfoot South faults. Regional mapping of the top of the Precambrian crystalline basement indicates that the Reelfoot North fault has an average of 500 m and the Reelfoot South fault 1200 m of down-to-the-southwest normal displacement. Since previously published seismic refl ection profi les reveal reverse displacement on top of the Paleozoic and younger strata, the Reelfoot North and South faults are herein interpreted to be inverted basement normal faults. The Reelfoot North and Reelfoot South faults differ in strike, dip, depth, and displacement, and only the Reelfoot North fault has a surface scarp (monocline). Thus, the Reelfoot fault is actually composed of two left-stepping restraining bends and two faults that together extend across the entire width of the Reelfoot rift.
A survey of nuclear ribosomal internal transcribed spacer substitution rates across angiosperms: an approximate molecular clock with life history effects

A full understanding of the patterns and processes of biological diversification requires the dating of evolutionary events, yet the fossil record is inadequate for most lineages under study. Alternatively, a molecular clock approach, in which DNA or amino acid substitution rates are calibrated with fossils or geological/climatic events, can provide indirect estimates of clade ages and diversification rates. The utility of this approach depends on the rate constancy of molecular evolution at a genetic locus across time and across lineages. Although the nuclear ribosomal internal transcribed spacer region (nrITS) is increasingly being used to infer clade ages in plants, little is known about the sources or magnitude of variation in its substitution rate. Here, we systematically review the literature to assess substitution rate variation in nrITS among angiosperms, and we evaluate possible correlates of the variation. We summarize 28 independently calibrated nrITS substitution rates ranging from 0.38 × 10-9 to 8.34 × 10-9 substitutions/site/yr. We find that herbaceous lineages have substitution rates almost twice as high as woody plants, on average. We do not find any among-lineage phylogenetic constraint to the rates, or any effect of the type of calibration used. Within life history categories, both the magnitude of the rates and the variance among rates tend to decrease with calibration age. Angiosperm nrITS substitution rates vary by approximately an order of magnitude, and some of this variation can be attributed to life history categories. We make cautious recommendations for the use of nrITS as an approximate plant molecular clock, including an outline of more appropriate phylogenetic methodology and caveats against over interpretation of results. We also suggest that for lineages with independent calibrations, much of the variation in nrITS substitution rates may come from uncertainty in calibration date estimates, highlighting the importance of accurate and/or multiple calibration dates.
Global health in times of violence

Global health in times of violence, edited by Barbara Rylko-Bauer, Linda Whiteford and Paul Farmer, Santa Fe, School for Advanced Research Press, 2009, 304 pp., US$29.95 (paperback), ISBN 978-1-934...
Conserved interdomain linker promotes phase separation of the multivalent adaptor protein Nck

The organization of membranes, the cytosol, and the nucleus of eukaryotic cells can be controlled through phase separation of lipids, proteins, and nucleic acids. Collective interactions of multivalent molecules mediated by modular binding domains can induce gelation and phase separation in several cytosolic and membrane-associated systems. The adaptor protein Nck has three SRC-homology 3 (SH3) domains that bind multiple proline-rich segments in the actin regulatory protein neuronal Wiskott-Aldrich syndrome protein (N-WASP) and an SH2 domain that binds to multiple phosphotyrosine sites in the adhesion protein nephrin, leading to phase separation. Here, we show that the 50-residue linker between the first two SH3 domains of Nck enhances phase separation of Nck/N-WASP/nephrin assemblies. Two linear motifs within this element, as well as its overall positively charged character, are important for this effect. The linker increases the driving force for self-assembly of Nck, likely through weak interactions with the second SH3 domain, and this effect appears to promote phase separation. The linker sequence is highly conserved, suggesting that the sequence determinants of the driving forces for phase separation may be generally important to Nck functions. Our studies demonstrate that linker regions between modular domains can contribute to the driving forces for self-assembly and phase separation of multivalent proteins.
Contextualized Views of Practices and Competencies in CALL Teacher Education Research.

Nike Arnold, Portland State University Lara Ducate, University of South Carolina While teachers play a central role in capitalizing on the potentials of computer assisted language learning (CALL), CALL teacher education overall still appears not to be adequate and effective (Healey et al., 2011; Hubbard, 2008). Furthermore, foreign/second language teachers have expressed a desire for more and better professional development opportunities in that area (Beaven, Emke, Ernest, Germain-Rutherford, Hampel, Hopkins, Stanojevic & Stickler, 2010; Digedu, 2014; Kessler, 2006). Given the continuing and new challenges for CALL teacher education, this special issue of Language Learning & Technology on CALL teacher education further speaks to its importance for our field and ultimately our students. To advance our understanding of CALL teacher education, the main goal for this issue is to move beyond research on teacher beliefs and attitudes to investigate actual practices and competencies, especially from a longitudinal perspective, that traces teachers’ development. The current issue brings together a collection of articles that represents a wide variety of contexts, formats, foci, and research methods. This variety is particularly important given the highly contextualized nature of teaching and learning (Freeman & Johnson, 1998) and the different needs of pre-service and in-service teachers (Beaven et al., 2010).
Criteria for the Choice of Synchronous or Medium-Altitude System

The peculiar requirements of a military communications satellite system as distinguished from a commercial one are examined. The effects on the system of requiring the system to operate with transportable ground stations, to be jam resistant, and to degrade gracefully are discussed. The choice of orbit inclination and altitude along with the number of satellites is shown to be a function of booster payload capability, geometric coverage, and the communications power budget. The effect of altitude on Anti-Jamming is also considered. It is shown that the choice of a communications satellite system is critically dependent on the reliability of the booster mission, the possibility of multiple launching, and the mean time-to-failure of the satellite. A booster mission for a medium-altitude system is shown in detail, as is the injection and random dispersion of satellites into a common orbit. Typical communications link calculations are shown to demonstrate the effects of key parameters on performance. A short discussion of the dependence of performance to weather, especially for very low temperature receivers, is given. The growth of satellites from a spin to gravity gradient stabilization without serious changes in either dispenser or spacecraft is described. The implications of this growth to system performance are outlined. The paper is in general terms without reference to specific spacecraft or booster data or other information that is classified.
Customized delivery of e-government Web services

The Web is revolutionizing the way citizens interact with businesses and government agencies. Almost all key functions of modern society are being reshaped to exploit opportunities the Web opens. As part of an effort to improve government-citizen interactions, government agencies are providing a wide spectrum of online services. Virginia Tech is collaborating with the Virginia Department for the Aging (VDA) on a project called WebSenior. A middleware infrastructure, WebSenior automatically delivers e-government services customized for seniors. It uses ontologies to automatically generate Web services customized to senior citizens' needs and government program laws and regulations.
High-order treatment of corner singularities with the locally-corrected Nyström method

High-order techniques have been proposed for obtaining high accuracy and rapid convergence in numerical solutions of integral equations for electromagnetics [1–2]. Results obtained for structures with smooth surfaces exhibit relatively low errors, and the rate of decrease in the error improves with reduced cell sizes as either the basis function or the representation order increases. Recent publications report a method-of-moments procedure that permits similar improvement in accuracy for structures with corners where the current density or charge density exhibits a singularity [3–4]. In the following, a similar procedure is incorporated into the locally-corrected Nystrom (LCN) method. Extensions of the LCN for the special case of a knife-edge singularity were proposed by Gedney [5] and Tong and Chew [6]. The present work differs in that it is applicable to corners of any angle, and it incorporates multiple singular terms at each corner in order to achieve true high order behavior. Results indicate that as the order of the representation for the current density increases, the accuracy of the solution improves at rates identical to those observed for smooth geometries.
Tachycardia and abdominal pain in a 37-year-old woman.

A 37-year-old woman presented to the emergency department with severe right upper quadrant abdominal pain that had begun 12 hours earlier. The pain was persistent, non- radiating, and associated wi...
Effect of investment mass on distortion of MOD wax patterns

Flaring of proximal walls of years, but not examined. In this experiment, the mass of investment peripheral to the wax patterns was varied by use of casting rings of the same lengths but of different diameters. Thirty castings were made individually, ten from each ring of 28 mm, 48 mm, and 60 mm diameter. The castings were cemented to their parent dies, sectioned mesiodistally, and the cement spaces at specific sites measured. Flaring angles were calculated for the proximal walls and were found to be inversely proportional to the diameters of the casting rings, and, thus, to the peripheral mass of investment. Further studies to detail the fluid mechanics of investments and to predict wax pattern behavior are warranted.
Equal Citizenship, Civil Rights, and the Constitution: The Original Sense of the Privileges or Immunities Clause

1. Introduction 2. The Five-Fold Textual Background of the Privileges or Immunities Clause 3. A Short Biography of the Privileges or Immunities Clause from Conception to Age Ten 4. Possible Relationships between Rights and "Citizens of the United States" 5. The Original Sense of "Of" 6. Applications
Modeling Bubble Growth in Micro-Channel Cooling Systems

The solution of the heat conduction equation in the liquid layer beneath a moving bubble’s base and the resulting local heat transfer coefficient are presented. An analytical model was constructed using separation of variables to solve the heat conduction equation for the thermal profile in the liquid film beneath the base of a bubble moving through a microchannel at a given velocity. Differentiating the resulting liquid thermal profile and applying the standard definition for the local heat transfer coefficient resulted in a solution for local heat transfer coefficient as a function of bubble length. Analysis included varying pertinent parameters such as film thickness beneath the bubble base, wall heat flux, and superheated temperature in the microchannel. Water and FC-72 were analyzed as prospective coolant fluids. Analytical data revealed that as the superheated temperature in the microchannel increases, local heat transfer coefficients increase and arrive at a higher steady-state value. Increasing wall heat flux achieved the same result, while increasing film thickness resulted in lower heat transfer coefficients. The model indicated that water had superior performance as a coolant, provided the dielectric fluid (FC-72) is not mandated.