cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrated Generator-Rectifier for Electric Ship DC Power System

Future ships are envisioned to be electric with a medium-voltage dc grid feeding all the subsystems, including propulsion, weapons, and auxiliary loads. Gas-turbine driven ac generators are prominent candidates for shipboard electricity generation due to a high energy density. Consequently, megawatt-class ac-to-dc conversion systems are essential to make electric ships feasible. At medium-voltage and megawatt power, conventional ac-to-dc conversion systems are challenged by limited power electronics switch-voltage ratings, high conversion loss, convoluted circuitry, and complex control schemes. An integrated generator-rectifier system has been proposed as an alternative that employs low-voltage switches to form a medium-voltage dc bus. Low conversion losses and high system reliability are achieved by shifting power to the efficient passive rectifiers. This paper presents an integrated design in context of shipboard power system. Theoretical analyses show the size of the active rectifier is reduced by 37% and the total conversion loss is cut by 50A laboratory setup is established to corroborate the proposed system.
Electrophysiological markers of cochlear function correlate with hearing-in-noise performance among audiometrically normal subjects

Hearing loss caused by noise exposure, ototoxic drugs, or aging results from the loss of sensory cells, as reflected in audiometric threshold elevation. Animal studies show that loss of hair cells can be preceded by loss of auditory-nerve peripheral synapses, which likely degrades auditory processing. While this condition, known as cochlear synaptopathy, can be diagnosed in mice by a reduction of suprathreshold cochlear neural responses, its diagnosis in humans remains challenging. To look for evidence of cochlear nerve damage in normal hearing subjects, we measured their word recognition performance in difficult listening environments and compared it to cochlear function as assessed by otoacoustic emissions and click-evoked electrocochleography. Several electrocochleographic markers were correlated with word scores, whereas distortion product otoacoustic emissions were not. Specifically, the summating potential (SP) was larger and the cochlear nerve action potential (AP) was smaller in those with the worst word scores. Adding a forward masker or increasing stimulus rate reduced SP in the worst performers, suggesting that this potential includes postsynaptic components as well as hair cell receptor potentials. Results suggests that some of the variance in word scores among listeners with normal audiometric threshold arises from cochlear neural damage.NEW & NOTEWORTHY Recent animal studies suggest that millions of people may be at risk of permanent impairment from cochlear synaptopathy, the age-related and noise-induced degeneration of neural connections in the inner ear that "hides" behind a normal audiogram. This study examines electrophysiological responses to clicks in a large cohort of subjects with normal hearing sensitivity. The resultant correlations with word recognition performance are consistent with an important contribution cochlear neural damage to deficits in hearing in noise abilities.
Cow-calf vaccination programs:

The term “herd health” means different things to different people, both producers and veterinarians. Many times producers equate a herd health program with a vaccination program. However, much more goes into preventive herd health programs than just a good vaccination program. To truly immunize cattle, they must have a working immune system at the time of vaccination. That means that we need to minimize all of the stressors that negatively impact the immune system. Herd health programs can be divided into 6 parts: nutrition; parasite control; biosecurity; vaccinations; genetics; and stress management. A good analogy is a 6-strand barbed wire fence. You need all the strands intact to keep cattle in. The more strands that are broken, the higher the risk of cattle escaping. All 6 parts of a herd health program are important. We can’t pick only the ones that are easy or cheap. It is most cost-effective to personalize each herd health/vaccination program. Many ranches don’t need every vaccine available, and in some cases recommendations don’t fit the business model of the ranch. “Cookbook” programs are a good place to start, but should be tailored to each ranch.
Debugging hiring: what went right and what went wrong in the technical interview process

The typical hiring pipeline for software engineering occurs over several stages---from phone screening and technical on-site interviews, to offer and negotiation. When these hiring pipelines are "leaky," otherwise qualified candidates are lost at some stage of the pipeline. These leaky pipelines impact companies in several ways, including hindering a company's ability to recruit competitive candidates and build diverse software teams.To understand where candidates become disengaged in the hiring pipeline---and what companies can do to prevent it---we conducted a qualitative study on over 10,000 reviews on 19 companies from Glassdoor, a website where candidates can leave reviews about their hiring process experiences. We identified several poor practices which prematurely sabotage the hiring process---for example, not adequately communicating hiring criteria, conducting interviews with inexperienced interviewers, and ghosting candidates. Our findings provide a set of guidelines to help companies improve their hiring pipeline practices---such as being deliberate about phrasing and language during initial contact with the candidate, providing candidates with constructive feedback after their interviews, and bringing salary transparency and long-term career discussions into offers and negotiations. Operationalizing these guidelines helps make the hiring pipeline more transparent, fair, and inclusive.
Sex hormones regulate NHE1 functional expression and brain endothelial proteome to control paracellular integrity of the blood endothelial barrier.

Abstract Background Sex hormones have been implicated in pH regulation of numerous physiological systems. One consistent factor of these studies is the sodium-hydrogen exchanger 1 (NHE1). NHE1 has been associated with pH homeostasis at epithelial barriers. Hormone fluctuations have been implicated in protection and risk for breaches in blood brain barrier (BBB)/blood endothelial barrier (BEB) integrity. Few studies, however, have investigated BBB/BEB integrity in neurological disorders in the context of sex-hormone regulation of pH homeostasis. Methods//Results Physiologically relevant concentrations of 17-β-estradiol (E2, 294 pM), progesterone (P, 100 nM), and testosterone (T,3.12 nM) were independently applied to cultured immortalized bEnd.3 brain endothelial cells to study the BEB. Individual gonadal hormones showed preferential effects on extracellular pH (E2), 14C-sucrose uptake (T), stimulated paracellular breaches (P) with dependence on functional NHE1 expression without impacting transendothelial resistance (TEER) or total protein expression. While total NHE1 expression was not changed as determined via whole cell lysate and subcellular fractionation experiment, biotinylation of NHE1 for surface membrane expression showed E2 reduced functional expression. Quantitative proteomic analysis revealed divergent effects of 17-β-estradiol and testosterone on changes in protein abundance in bEnd.3 endothelial cells as compared to untreated controls. Conclusions These data suggest that circulating levels of sex hormones may independently control BEB integrity by 1) regulating pH homeostasis through NHE1 functional expression and 2) modifying the endothelial proteome.
Clinical Skills in Military Behavioral Health Education: Efficacy of Role Play vs Standardized Actor Patient Training

The use of Role Play (RP) and Standardized Actor Patients (SAP) have significantly impacted the behavioral health field’s ability to train clinicians in clinical practice and the development of cli...
Monitoring of von Willebrand factor inhibitors in patients with type 3 von Willebrand disease using a quantitative assay

Background Antibodies inhibiting von Willebrand factor (VWF) develop in a subset of patients with type 3 von Willebrand disease (VWD3) and may be detected by their inhibition of ristocetin cofactor activity (VWF:RCo). Some also inhibit factor VIII activity (VIII:C). Aim To describe monitoring of ten VWD3 patients for VWF inhibitors using a quantitative assay. Methods VWF inhibitor was measured by comparing VWF:RCo activity of a mix of patient and pooled normal plasma (PNP) with a mix of buffer and PNP, using agglutination of fixed normal platelets in microtiter plates or lyophilized platelets in an aggregometer. VIII:C inhibitor was measured by Bethesda assay. Preanalytical heat treatment of patient plasma was used during treatment episodes. Results Four of 10 patients monitored developed VWF inhibitors, two detected during bleeding episodes refractory to treatment and two on routine screening. Data from the first five patients were used to establish an arbitrary unit, VWU, defined as the amount of inhibitor per millilitre of patient plasma inactivating 25% of the activity of 1 mL of PNP. In three of four patients, both VWF:RCo and VIIII:C were inhibited at some time points, although VIII:C inhibition sometimes disappeared. In one patient, no VIII:C inhibition was seen. Two patients remained inhibitor positive more than 15 years after inhibitor detection, one became negative following immune tolerance induction, and one was deceased. Conclusions VWF inhibitors can be quantitatively monitored in VWD3 patients. Preanalytical heat treatment may be required for their detection post infusion.
Racial disparities in the treatment of aortic stenosis: Has transcatheter aortic valve replacement bridged the gap?

BACKGROUND: Racial disparities in outcomes and utilization of surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis (AS) is well known. While transcatheter aortic valve replacement (TAVR) has become more widespread, its impact on racial disparities remains unclear. OBJECTIVES: Our goal was to assess the utilization of SAVR and TAVR and their clinical outcomes among various racial groups. METHODS: The National Inpatient database (2009-2015) was used to study the racial distribution of admissions for SAVR and TAVR, and their impact on inpatient outcomes. Survey estimation commands were used to determine weighted national estimates. RESULTS: There were 3,445,267; 294,108; and 52,913 inpatient visits for AS, SAVR, and TAVR, respectively. SAVR visits were 86% White, 3.8% Black, 5.5% Hispanic, 1.2% Asian/Pacific Islander (A/PI), 0.4% Native American (NA), and 2.9%; TAVR were 87.7% White, 3.7% Black, 3.8% Hispanic, 1.0% A/PI, 0.2% NA, and 3.5% Other while AS visits were 83.7% White, 6.7% Black, 5.3% Hispanic, 1.7% A/PI, 0.4% NA, and 2.2% Other. Racial minorities generally had more co-morbidities compared with Whites. After SAVR, Black patients had a higher unadjusted inpatient mortality than Whites, however, there was no difference after adjustment for other variables. A/PI were more likely to require a permanent pacemaker after SAVR. Need for blood transfusion was significantly higher among the minorities compared with Whites, except for NA, but there were no racial differences in stroke rates. There was no difference in inpatient mortality, pacemaker implantation, stroke, and bleeding after TAVR, but acute kidney injury occurred more often in Hispanics, A/PI, and "others" compared with Whites. CONCLUSIONS: Racial disparities in the treatment of AS continues in the contemporary era; however it was found that TAVR resulted in comparable inpatient outcomes, despite higher comorbidities, and adverse socioeconomic factors in minorities.
Mechanically induced nuclear shuttling of β-catenin requires co-transfer of actin

Mesenchymal stem cells (MSC) respond to environmental forces with both cytoskeletal re-structuring and activation of protein chaperones of mechanical information, {beta}-catenin and Yes-Associated Protein 1 (YAP1). To function, MSCs must differentiate between dynamic forces such as cyclic strains of extracellular matrix due to physical activity and static strains due to ECM stiffening. To delineate how MSCs recognize and respond differently to both force types, we compared effects of dynamic (200 cycles x 2%) and static (1 x 2% hold) strain on nuclear translocation of {beta}-catenin and YAP1 at 3h after force application. Dynamic strain induced nuclear accumulation of {beta}-catenin, and increased cytoskeletal actin structure and cell stiffness, but had no effect on nuclear YAP1 levels. Critically, both nuclear actin and nuclear stiffness increased along with dynamic strain-induced {beta}-catenin transport. Augmentation of cytoskeletal structure using either static strain or lysophosphatidic acid (LPA) did not increase nuclear content of {beta}-catenin or actin, but induced robust nuclear increase in YAP1. As actin binds {beta}-catenin, we considered whether {beta}-catenin, which lacks a nuclear localization signal, was dependent on actin to gain entry to the nucleus. Knockdown of cofilin-1 (Cfl1) or importin-9 (Ipo9), which co-mediate nuclear transfer of G-actin, prevented dynamic strain-mediated nuclear transfer of both {beta}-catenin and actin. In sum, dynamic strain induction of actin re-structuring promotes nuclear transport of G-actin, concurrently supporting nuclear access of {beta}-catenin via mechanisms utilized for actin transport. Thus, dynamic and static strain activate alternative mechanoresponses reflected by differences in the cellular distributions of actin, {beta}-catenin and YAP1. Significance statementCells integrate both static and dynamic mechanical signals through the actin cytoskeleton which is attached to the nuclear envelope, affecting nuclear transport of {beta}-catenin and YAP1. Dynamic strain induces nuclear translocation of {beta}-catenin, but not YAP1, while static strain causes nuclear translocation of YAP1, but not {beta}-catenin. Importantly, nuclear transport of actin is induced by dynamic but not static force. Furthermore, nuclear import of {beta}-catenin depends on cofilin/importin-9 dependent actin transport mechanisms. Thus the presence of {beta}-catenin and YAP1 in the nucleus represent specific responses to regulatory mechanical signals.
Electroweak phase transition nucleation with the MSSM and electromagnetic field creation

Using EW-MSSM field theory, so the electroweak phase transition (EWPT) is first order, we derive the equations of motion (e.o.m.) for the gauge fields. With an isospin ansatz we derive e.o.m. for the electrically charged W fields uncoupled from all other fields. These and the lepton currents serve as the current for the Maxwell-like e.o.m. for the electromagnetic field. The electromagnetic field arising during EWPT bubble nucleation without leptons is found. We then calculate the electron current contribution, which is seen to be quite large. This provides the basis for determining the magnetic field created by EWPT bubble collisions, which could seed galactic and extragalactic magnetic fields.
SEROLOGY, DENSITY, AND MORPHOLOGY OF STAPHYLOCOCCAL PHAGES.

Abstract Rosenblum, E. D. (The University of Texas, Dallas), and Sue Tyrone. Serology, density, and morphology of staphylococcal phages. J. Bacteriol. 88:1737–1742. 1964.—A correlation between serology, buoyant density, and morphology has been demonstrated for six serological groups of staphylococcal phages. Four morphological types have been observed and represent the following serological groups: (i) group A, (ii) groups B, F, and L, (iii) group D, and (iv) group G. The correlations were useful in the detection of serological variation among several staphylococcal typing phages.
Comparative Studies of Selenium-75 (Selenite and Selenomethionine) Absorption from Various Milk Diets in Suckling Rats

Selenium (Se) absorption was studied in human milk, bovine milk and infant formula (Similac) using suckling rats as a model. The effect of age on Se absorption from the three milk diets extrinsically labeled with 75Se, either as selenite or selenomethionine, was also investigated. Milk diets were fed by gastric intubation and the radioactivity in the carcass, gastrointestinal tract and the liver were measured 3 h after feeding. There was no difference in [75Se]selenite absorption from the three milk diets between 8-20 d of age. However, significantly higher quantity of 75Se was absorbed from all three milk diets by 20-d-old rats than by the younger rats (46 vs. 32%). This increase in [75Se]selenite absorption with advancing age is opposite to what has been found for most other trace elements. When rats were fed milk diets labeled with [75Se]selenomethionine, the absorption of 75Se was approximately twofold higher in all age groups compared with 75Se absorption from selenite. No difference in [75Se]selenomethionine absorption existed among the three milk diets in 8- or 10-d-old suckling rats. However, at 15 d of age [75Se]selenomethionine absorption from human milk was higher (82%) than from either bovine milk (72%) or infant formula (72%). Between 8 and 20 d of age, absorption of [75Se]selenomethionine from the three milk diets decreased with advancing age. Adding sodium selenate to increase the total nonradioactive Se of human milk, bovine milk (endogenous plus the added selenium) did not affect the absorption of either [75Se]selenomethionine or [75Se]selenite.
Defining, developing, and measuring “Proclivities for Teaching Mathematics”

This article presents a form of teacher reasoning that we call proclivities for teaching mathematics. We define proclivities for teaching mathematics as the beliefs, knowledge, and dispositions that are actionable in the flow of instruction, and we argue that growth in this area contributes to positive change in mathematics instruction. Proclivities for teaching mathematics encompass four domains: productive disposition, openness to new ideas, thought processes, and organization of mathematical thought; in this article, we focus on productive disposition. The article provides a rationale for the construct of proclivities for teaching mathematics, and describes an initial attempt to develop measures for these proclivities. Analyses of data from a sample of 63 teachers indicate that measures of proclivities for teaching mathematics are associated with increases in teacher knowledge, self-efficacy, and instructional improvement over time, and although the dataset is small, these positive indicators suggest that further exploration of this construct is warranted.
IFATS Collection: Adipose Stromal Cell Differentiation Is Reduced by Endothelial Cell Contact and Paracrine Communication: Role of Canonical Wnt Signaling

Adipose stromal cells (ASC) are multipotential mesenchymal progenitor cells that are readily induced to undergo adipogenic differentiation, and we have recently demonstrated them to have functional and phenotypic overlap with pericytes lining microvessels in adipose tissues. In this study we addressed the hypothesis that modulation of ASC fate within this perivascular niche can occur via interaction with endothelial cells (EC), which serve to modulate the adipogenic potential of ASC. To this end, we investigated contact as well as paracrine effects of EC on ASC adipogenesis, in two-dimensional coculture and via conditioned medium and analyzed mutual gene expression changes by real-time reverse transcription polymerase chain reaction (PCR). A significant decrease in adipogenic differentiation was observed in ASC when they were cocultured with EC but not control fibroblasts. This endothelial cell-specific effect was accompanied by increased expression of factors involved in Wnt signaling, most prominently Wnt1, Wnt4, and Wnt10a, which are well-known inhibitors of adipogenesis. Suppression of Wnt1 but not Wnt 10a or scrambled control short interfering RNA in cocultures partially reversed the endothelial cell effect, thus increasing adipogenic differentiation, suggesting a plausible role of Wnt1 ligand in modulation of adipogenesis by the vasculature. Furthermore, addition of recombinant Wnt ligand or the Wnt signaling agonist inhibited adipogenic differentiation of ASC in the absence of EC. In conclusion, these data define the relationship in adipose tissue between ASC and EC in the perivascular niche, in which the latter act to repress adipogenesis, thereby stabilizing vasculature. It is tempting to speculate that abnormal endothelial function may be associated with pathologic derepression of adipogenesis. Disclosure of potential conflicts of interest is found at the end of this article.
A modified procedure for evaluation of the lecithin-sphingomyelin ratio in amniotic fluid.

We describe several modifications of the procedure originated by Gluck et al. [ Amer. J. Obstet. Gynecol. 109, 440 (1971)] for evaluation of amniotic fluid lecithin/sphingomyelin (L/S) ratios. The acetone-precipitation step is eliminated, resulting in a faster extraction procedure and higher concentrations of phospholipids. For faster thin-layer chromatography, we use silica gel-impregnated sheets of glass-fiber and a modified solvent system. For spot detection we use a noncorrosive bismuth subnitrate reagent that is specific for lecithin and sphingomyelin, and an iodine vapor method to confirm the L/S ratio. The bismuth spray also detects significant specimen contamination by phospholipids from plasma or erythrocytes. The L/S ratio is evaluated by visually comparing the relative size and color intensity of the lecithin and sphingomyelin TLC spots. An L/S ratio of 5 or more is consistent with mature pulmonary function and an L/S ratio of less than 2 suggests fetal pulmonary immaturity.
Oxygen depth-profile channeling of radiation-damaged high-Tc thin-film superconductors

Abstract Low-energy channeling gives limited information on oxygen disorder in oxides. More detailed information has been obtained for oxygen disorder in thin-film superconductors by using a combination of channeling and depth profiling with the 3.05 MeV oxygen (α, α) resonance. Films of YBa 2 Cu 3 O 7 , ≈ 1 × 10 18 atoms/cm 2 thick, were irradiated with various doses of 400 keV O ++ ions and analyzed with this technique. There are large differences between disorder in the oxygen and other film constituents.
An Experimental Investigation of the Hahn-Noll Revenue Neutral Auction for Emissions Licenses

Abstract This paper reports on three series of laboratory experiments designed to test the performance of the Hahn-Noll revenue neutral auction (RNA). An alternative institution, a no-rebate uniform price auction (UPA), is also examined as a benchmark. In these experiments, the RNA markets were little different from UPA markets in terms of either prices or market efficiencies. The two institutions did differ in terms of the distribution of the gains from exchange and of the propensity of bidders to engage in a certain type of overbidding.
Diffusion forces and diffusion potentials

Diffusion as classically known is based on Fick's law, which describes the rate of flow of the diffusing particles in terms of their density gradient. Recently, a new formulation has been suggested by M.A. Melehy ["A fundamental extension of Einstein?s diffusion-mobility relationship," Nature (to be published)] which is based on forces rather than flow rates. The purpose of this communication is to discuss some simple aspects of the new formulation.
Effect of reserpine on tachycardia induced by thyroid in the isolated atriurn of the rat

Abstract Isolated rat atria have been used to study the mode of action of thyroid hormone on heart rate. Comparison of atria from normal control, hyperthyroid and reserpinized hyperthyroid rats demonstrates the probable role of catecholamines in mediation of thyroid-induced tachycardia.
An eigen-based high-order expansion basis for structured spectral elements

We present an eigen-based high-order expansion basis for the spectral element approach with structured elements. The new basis exhibits a numerical efficiency significantly superior, in terms of the conditioning of coefficient matrices and the number of iterations to convergence for the conjugate gradient solver, to the commonly-used Jacobi polynomial-based expansion basis. This basis results in extremely sparse mass matrices, and it is very amenable to the diagonal preconditioning. Ample numerical experiments demonstrate that with the new basis and a simple diagonal preconditioner the number of conjugate gradient iterations to convergence has essentially no dependence or only a very weak dependence on the element order. The expansion bases are constructed by a tensor product of a set of special one-dimensional (1D) basis functions. The 1D interior modes are constructed such that the interior mass and stiffness matrices are simultaneously diagonal and have identical condition numbers. The 1D vertex modes are constructed to be orthogonal to all the interior modes. The performance of the new basis has been investigated and compared with other expansion bases.
A general protocol for the preparation of phospholipids via phosphite coupling

Abstract A method for the facile preparation of a variety of phospholipids and their derivatives has been developed that utilizes a highly efficient phosphite coupling procedure for the synthesis of a phosphite triester, which may then be readily transformed into the corresponding phosphate diester by sequential oxidation and O-deprotection.
Effect of simulated rainfall on removal and In situ formation of particles on Taxus needles

Abstract The short-term retention of recently-deposited ambient aerosol particles on yew Taxus needles was characterised (on an individual particle basis) following simulated rainfall events. Taxus seedlings, which had twigs grown from bud break in a ‘particle-free’ environment, were exposed to the ambient aerosol at an industrial field site to acquire a deposit of particles. These seedlings were then subjected to simulated rainfall events of 15, 30 or 60 min at rainfall rates of 12 or 24 mm h −1 with pH 5·6 or pH4 rainwater. Particles on pre- and post-rain needles were characterised individually by Scanning electron microscopy interfaced with Automated image analysis and X-ray energy spectrometry (SAX). Rainfall at a rate of 12 mm h −1 removed 70–90% of the particle mass during the first 30 min. The distribution of particles in 29 chemical classes, defined on the basis of the relative intensity of X-rays collected from individual particles for up to 27 elements (Z > 10), changed dramatically during the first 15 min of rainfall due to efficient removal of the ‘more-soluble’ particles. The pH of the rainwater resulted in only minor differences in the retention of particles and their distribution in individual chemical classes. Deposits of crystalline particles, derived from the rainwater and/or the ions leached from the needle tissue, were observed on control needles following rainfall events. On an elemental weight composition basis, the per cent of mass contributed to the particle sample by sodium, sulphur, chlorine, and calcium was significantly less on post-rain needles. The differential removal of particles, changes in the chemical nature of the particulate sample, and the occurrence of crystalline particles on the needles are discussed with reference to precipitation throughfall studies and characterisation of dry deposition on field vegetation.
The Death Rates of Three Standard Breeds of Fowl

Abstract Among the characteristics of breeds of domestic animals which may be of economic importance as well as of biological interest are their relative death rates. Earlier studies have dealt with the problem of the differentiation of birds which died at some time during their first laying years from those which survived throughout that period. In these papers it has been shown that in the White Leghorn * and in the White Wyandotte and Rhode Island Red breeds of fowl ** the means, standard deviations, and coefficients of variations of the monthly egg production of these two classes, those which survived and those which died, are significantly different in many months of the year. The results have been confirmed by the application of other biometric criteria. *** While these studies deal adequately with the problem of the differentiation with respect to egg production of birds which survive for various periods of time, they leave . . .
3D free-boundary conditions for coordinate-transform finite-difference seismic modelling

New alternative formulations of exact boundary conditions for arbitrary three-dimensional (3D) free-surface topographies on seismic media have been derived. They are shown to be equivalent to previously published formulations, thereby verifying the validity of each set of formulations. The top of a curved grid represents the free-surface topography while the interior of the grid represents the physical medium. We assume the velocity-stress version of the viscoelastic wave equations to be valid in this grid before transforming the equations to a rectangular grid. In order to perform the numerical discretization we apply the latter version of the equations for seismic wave propagation simulation in the medium. The numerical discretization of the free-surface topography boundary conditions by second-order finite differences (FDs) is shown, as well as the spatially unconditional stability of the resulting system of equations. The FD order is increased by two for each point away from the free surface up to eight, which is the order used in the interior. We use staggered grids in both space and time and the second-order leap-frog and Crank-Nicholson methods for wavefield time propagation. An application using parameters typical of teleseismic earthquakes and explosions is presented using a 200 x 100 km 2 area of real topography from southwestern Norway over a homogeneous medium. A dipping plane wave simulates a teleseismic P-wave incident on the surface topography. Results show conversion from P- to Rg- (short period fundamental mode Rayleigh) waves in the steepest and/or roughest topography, as well as attenuated waves in valleys and fjords. The codes are parallelized for simulation on fast supercomputers and PC-clusters to model high frequencies and/or large areas.
The Nature of the Strong 24 μm Spitzer Source J222557+601148: Not a Young Galactic Supernova Remnant

The nebula J222557+601148, tentatively identified by Morris et al. as a young Galactic supernova remnant (SNR) from Spitzer Galactic First Look Survey images and a follow-up mid-infrared spectrum, is unlikely to be an SNR remnant based on Hα ,[ Oiii], [Sii] images, and low-dispersion optical spectra. The object is seen in Hα and [Oiii] λ5007 images as a faint, roughly circular ring nebula with dimensions matching that seen in 24 μm Spitzer images. Low-dispersion optical spectra show it to have narrow Hα and [Nii] λλ6548,6583 line emissions with no evidence of broad or high-velocity (v 300 km s −1 ) line emissions. The absence of any high-velocity optical features, the presence of relatively strong [Nii] emissions, the lack of detected [Sii] emission which would indicate the presence of shock-heated gas, plus no coincident X-ray or nonthermal radio emissions indicate that the nebula is unlikely to be an SNR, young or old. Instead, it is likely a faint, high-excitation planetary nebula (PN) as its elliptical morphology would suggest, lying at a distance ∼2–3 kpc with unusual but not extraordinary mid-IR colors and spectra. We have identified an mr � = 22.4 ± 0.2 star as a PN central star candidate.
Dynamics of disordered quantum Hall crystals

Abstract Charge density waves are thought to be common in two-dimensional electron systems in quantizing magnetic fields. Such phases are formed by the quasiparticles of the topmost occupied Landau level when it is partially filled. One class of charge density wave phases can be described as electron solids. In weak magnetic fields (at high Landau levels) solids with many particles per unit cell—bubble phases—predominate. In strong magnetic fields (at the lowest Landau level) only crystals with one particle per unit cell—Wigner crystals—can form. Experimental identification of these phases is facilitated by the fact that even a weak disorder influences their DC and AC magnetotransport in a very specific way. In the AC domain, a range of frequencies appears where the electromagnetic response is dominated by magnetophonon collective modes. The effect of disorder is to localize the collective modes and to create an inhomogeneously broadened absorption line, the pinning mode. In recent microwave experiments pinning modes have been discovered both at the lowest and at high Landau levels. We present the theory of the pinning mode for a classical two-dimensional electron crystal collectively pinned by weak impurities. We show that long-range Coulomb interaction causes a dramatic line narrowing, in qualitative agreement with the experiments.
Quantitative phase imaging of nanoscale electrostatic and magnetic fields using off-axis electron holography

Abstract Off-axis electron holography in the transmission electron microscope is a powerful interferometric technique that enables electrostatic and magnetic fields to be imaged and quantified with spatial resolution often approaching the nanometer scale. Here, we demonstrate the capabilities of the technique for phase quantification at the nanoscale by briefly reviewing some of our recent studies of nanostructured materials. Examples that are described include determination of the electrostatic potential profiles associated with doped Si- and GaAs-based semiconductor devices, measurement of hole accumulation in Ge quantum dots, mapping of polarization fields in III-nitride heterostructures, and observation of the remanent states and reversal mechanisms of lithographically patterned magnetic nanorings. Some issues associated with sample preparation for doped semiconductor heterostructures are also briefly discussed.
Cobalt Complexes as Antiviral and Antibacterial Agents

Metal ion complexes are playing an increasing role in the development of antimicrobials. We review here the antimicrobial properties of cobalt coordination complexes in oxidation state 3+. In addition to reviewing the cobalt complexes containing polydentate donor ligands, we also focus on the antimicrobial activity of the homoleptic [Co(NH3)6]3+ ion.
Give me liberty and give me surveillance: a case study of the US Government's discourse of surveillance

This article reports the critical discourse analysis of www.lifeandliberty.gov, a website constructed by the US Department of Justice, with the expressed intention to explain provisions of the USA ...
Reconstruction of the Archaeal Isoprenoid Ether Lipid Biosynthesis Pathway in Escherichia coli Through Digeranylgeranylglyceryl Phosphate

The membrane lipids of archaea are characterized by unique isoprenoid biochemistry, which typically is based on two core lipid structures, sn-2,3-diphytanylglycerol diether (archaeol) and sn-2,3-dibiphytanyldiglycerol tetraether (caldarchaeol). The biosynthetic pathway for the tetraether lipid entails unprecedented head-to-head coupling of isoprenoid intermediates by an unknown mechanism involving unidentified enzymes. To investigate the isoprenoid ether lipid biosynthesis pathway of the hyperthermophilic archaeon, Archaeoglobus fulgidus, its lipid synthesis machinery was reconstructed in an engineered Escherichia coli strain in an effort to demonstrate, for the first time, efficient isoprenoid ether lipid biosynthesis for the production of the intermediate, digeranylgeranylglyceryl phosphate (DGGGP). The biosynthesis of DGGGP was verified using an LC/MS/MS technique and was accomplished by cloning and expressing the native E. coli gene for isopentenyl diphosphate (IPP) isomerase (idi), along with the A. fulgidus genes for G1P dehydrogenase (egsA) and GGPP synthase (gps), under the control of the lac promoter. The A. fulgidus genes for GGGP synthase (GGGPS) and DGGGP synthase (DGGGPS), under the control of the araBAD promoter, were then introduced and expressed to enable DGGGP biosynthesis in vivo. This investigation established roles for four A. fulgidus genes in the isoprenoid ether lipid pathway for DGGGP biosynthesis and provides a platform useful for identification of subsequent, currently unknown, steps in tetraether lipid biosynthesis proceeding from DGGGP, which is the presumed substrate for the head-to-head coupling reaction yielding unsaturated caldarchaeol.
Bryophytes for Beginners: The usability of a printed dichotomous key versus a multi-access computer-based key for bryophyte identification

Bryophytes are a rewarding study group in field biology and the UK bryophyte flora has international importance to biodiversity conservation. We designed an identification key to common woodland moss species and compared the usability of two formats, web-based multi-access and printed dichotomous key, with undergraduate students. The rate of correct species identification and identification speed both showed an advantage for the printed dichotomous key. Our findings suggest that, even in the digital age, printed keys remain valuable in biological education and that quality of key design is more important than presentation medium. We discuss the relative advantages of multi-access and dichotomous keys and how to approach bryophyte identification with beginners.
Effects of nitrogen and foliar biomass on population parameters of cabbage insects

The effects of different nitrogen (N) fertilization rates (0, 45, 90, and 168 kg N/ha), plant nitrogen concentration, and plant biomass on abundance and population growth of diamondback moth, Plutella xylostella (L.), cabbage looper, Trichoplusia ni (Hubner), cabbage budworm, Hellula phidilealis (Walker), imported cabbageworm, Artogeia rapae (L.), and cross-striped cabbageworm, Evergestis rimosalis (Guenee), were investigated in Homestead and Sanford, Florida in 1987. The effects of these factors on the parasitization of P. xylostella were also examined. In Homestead, abundance of most insect pests and parasitized P. xylostella increased with an increase in the level of N applied and with an increase in plant biomass. Similar results were found in Sanford, although results were not consistently significant. Abundance of most insect pests was significantly positively correlated with plant N concentration. Multiple regression analyses indicated that foliar biomass was significantly more important than N fertilization rate and subsequent plant N concentration at predicting abundance of insect pests and parasitized P. xylostella on cabbage.
Sanitizer applicability in a laboratory model strawberry hydrocooling system

Abstract After harvest, strawberries are cooled to 2–5 °C, typically by forced-air cooling. Hydrocooling is an alternative method that ensures faster cooling and with the addition of various sanitizers can reduce the risk of microbial cross contamination. In this study, the effect of forced-air cooling and hydrocooling on the survival of Lactobacillus plantarum, a non-pathogenic, potential surrogate bacterium, was evaluated. Further, the efficacy of three antimicrobial compounds, sodium hypochlorite (HOCl, 100 μL/L), aqueous chlorine dioxide (ClO2, 5 μL/L) and peroxyacetic acid (PAA, 80 μL/L) in reducing Lactobacillus levels during strawberry hydrocooling was also investigated. The results indicated that the Lactobacillus population on forced-air cooled strawberries was not significantly different from untreated strawberries. Compared to forced-air cooling, hydrocooling significantly reduced Lactobacillus survival on inoculated intact strawberries, even in the absence of a sanitizer. The addition of ClO2 resulted in the least reduction in initial Lactobacillus levels (∼1 log CFU/mL), similar to those on strawberries hydrocooled without antimicrobials. The addition of HOCl or PAA to the hydrocooling water resulted in respective reductions of 2.5 log CFU/mL and 4.0 CFU/mL in the initial Lactobacillus levels, which continued to decrease throughout the sampling period. The results from this study indicate that antimicrobials HOCl and PAA are both effective in reducing surface contamination on strawberries during hydrocooling.
Joint Estimation of Migration Rate and Effective Population Size Using the Island Model

Using the island model of population demography, I report that the demographic parameters migration rate and effective population size can be jointly estimated with equilibrium probabilities of identity in state calculated using a sample of genotypes collected at a single point in time from a single generation. The method, which uses moment-type estimators, applies to dioecious populations in which females and males have identical demography and monoecious populations with no selfing and requires that offspring genotypes are sampled following reproduction and prior to migration. I illustrate the estimation procedure using the infinite-island model with no mutation and the finite-island model with three kinds of mutation models. In the infinite-island model with no mutation, the estimators can be expressed as simple functions of estimates of the F-statistic parameters FIT and FST. In the finite-island model with mutation among k alleles, mutation rate, migration rate, and effective population size can be simultaneously estimated. The estimates of migration rate and effective population size are somewhat robust to violations in assumptions that may arise in empirical applications such as different kinds of mutation models and deviations from temporal equilibrium.
Population Ecology of Desert Rodent Communities: Body Size and Seed-Husking as Bases for Heteromyid Coexistence

Seven species of heteromyid rodents varying in size from 8 to 114 g were studied in the laboratory. Starved rodents husked four kinds of large seeds (spinach, sunflower, squash and pumpkin) and were timed at the task. Geometric mean husking times varied from 3.1 to 70.1 seconds, depending on the seed and the rodent. Husking time was inversely proportional to an animal's body size. However, despite their slowness, smaller animals appear to be more efficient at dealing with these large seeds because they have a smaller metabolic drain. This conclusion is based on the assumption that gross caloric need increases linearly with (body weight).75. The authors defend the assumption and thus believe that smaller animals have a competitive advantage while husking seeds. These rodents might engage in a limited amount of habitat and resource selection based on their relative seed—husking abilities. However, the order in which the various species should prefer these seeds is quite similar, so resource allocation based on husking speed differences would seem of little potential importance in maintaining competing heteromyids in a state of coexistence. Previous investigators have shown that seed selection occurs in some cases, but many cases are also known in which little or no selection is practiced.
Adolescents' sense of community on myspace and facebook: a mixed-methods approach.

Communities are foundational to the field of Community Psychology yet they are difficult to define and measure. Once viewed as social groups with ties to geographical locations, online communities interact free of physical or face-to-face contact. This cyberexistence makes the study of communities more challenging. Social networking sites (SNS), such as Facebook and MySpace, are referred to as online communities; however, research has yet to explore whether these sites engender a psychological sense of community (PSC) for users. This study reanalyzes focus group and survey data from high school and college students to investigate whether uses of SNS demonstrate key components of PSC (i.e., membership, influence, immersion, shared emotional connection, and an integration and fulfillment of needs). This mixed-method analysis synthesizes data through a top-down (confirming PSC categories) and bottom-up (identifying emergent patterns/themes) analytic procedure. Results suggest that typical adolescent uses of SNS represent networked individualism, rather than online communities. C 2010 Wiley Period
Fluctuations and correlations in nuclear one-body dynamics

Abstract Effective theories of nuclear dynamics must be able to treat trajectory branching at the macroscopic level, a salient feature of nuclear collisions at intermediate energies. Such generalization is possible for Boltzmann-type one-body models. Idealized applications can provide economic model characterizations and thus facilitate model comparisons.
Enhanced field ionization/desorption on branched silicon nanowires: applications in gas ionization detection

We demonstrate anomalous gaseous field ionization and field desorption on branching intrinsic silicon nanowires grown by a two-step VLS technique. Field ionization and desorption I-V curves of argon, nitrogen, helium, and ammonia, were recorded individually within a wide pressure range (10 -7 to 10 Torr). Field ionization initiated at sub volt was followed by field desorption at about 7 - 38 V (applied field of ~ 7×10 2 to 3.8×10 3 V/cm). Such voltages are three orders of magnitude smaller than the applied voltages required to generate field ionization on sharp metallic tips having the same tip curvature. The measured I-V curves were pressure dependent. Low voltage filed ionization and desorption phenomena were attributed to the combination effects of geometrical field enhancement on the apex of nanoscale silicon branches, field penetration, increased tunneling critical distance, band gap widening due to quantum confinement, and the surface states formed by the catalyst. The results presented herein suggest that gold terminated branching silicon nanowires could be strong candidates in building low power gas ionization sensors useful in highly selective detection of gases with low adsorption energies.
The role of the young in the control of the hormonal events during lactation and behavioral weaning in the golden hamster

Abstract This study was designed to determine the relationship between the behavioral and physiological changes occurring in the hamster over the course of lactation. Experimental (E) females were given litters of six 3-day-old pups on Day 13 of lactation and allowed to raise them. Control (C) females raised their own litters of six pups. Groups of E and C females were decapitated at 1000 and 1700 hr when their pups were either 8, 18, or 28 days old. Nursing was observed for 1 hr on the 3 days prior to autopsy. Nursing behavior disappeared by Day 28 in C females. E females exhibited nursing behavior at levels equal to those observed in C females until E pups were 28 days old and 38 days had elapsed since parturition. Despite the fact that E mothers continued to nurse pups on day 18 postpartum when pups were 8 days old, E pups showed lower growth rates than did C pups. Prolactin (PRL) levels remained elevated when E pups were 8 days old even though E pups did not grow normally. PRL levels decreased over time in both C and E females and reached baseline by Day 28 although nursing behavior was still elevated in E females. Thus, nursing behavior did not stimulate PRL release during late lactation. Estradiol (E2) levels in C females remained at baseline until Day 28 when levels increased. LH, FSH, and Progesterone (P) levels in C females showed a dramatic diurnal pattern which disappeared by Day 28, when levels dropped. Levels of E2, P, LH, and FSH in E females closely paralleled those of C females only when groups were compared with respect to pup age. Thus, behavioral weaning and the return to estrous cyclicity appear to be dependent upon the age of the pups rather than the time elapsed since parturition. However, milk production and PRL release appear to be more closely tied to the number of days postpartum and can be dissociated from the amount of nursing behavior observed.
Quality Management: Practice Risks and Value-Added Roles for Organization Development Practitioners

As an increasing number of organizations move to adopt some form of quality management, organization development (OD) practitioners are being called on to assist with these efforts. A growing numbe...