cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular Subtyping Methods for Listeria monocytogenes

Conventional, phenotypic, and DNA-based subtyping methods allow differentiation of Listeria monocytogenes beyond the species and subspecies level. Bacterial subtyping methods not only improve our ability to detect and track human listeriosis outbreaks, but also provide tools to track sources of L. monocytogenes contamination throughout the food system. The use of subtyping methods also provides an opportunity to better understand the population genetics, epidemiology, and ecology of L. monocytogenes. The last 5 years have seen tremendous advancements in the development of sensitive, rapid, automated, and increasingly easy-to-use molecular subtyping methods for L. monocytogenes. This review highlights key aspects of different L. monocytogenes subtyping methods and provides examples of their application in public health, food safety, population genetics, and epidemiology. A significant focus is on the application of subtyping methods to define L. monocytogenes subtypes and clonal groups, which may differ in phenotypic characteristics and pathogenic potential.
Progressive increase in the angle of deviation in congenital esotropia.

Abstract The majority of patients with congenital esotropia in this consecutive series of 41 patients showed an increase in the angle of deviation when followed over an average of 3 months. The ages at the initial measurement and surgery, the cycloplegic refraction, and the clinical response to patching could not be used to identify those patients with a progressive increase in the quantity of the deviation. It was found, however, that if the preliminary surgical plan was adjusted (as it was in the majority of the patients in this series) to reflect the latest measurements obtained the day before surgery, a relatively high percentage of patients (90%) could be found to have achieved satisfactory alignment by the 6-week postoperative visit.
Labor Market Categorization: Theory and Evidence on Initial Wages from the NLSY

A pre-employment assessment of potential workers is often used by firms to mitigate the costs of poor employee selection and job placement. This paper presents an adverse selection model of the labor market wherein firms first use observable characteristics of employees as a sorting device and then offer a menu of wage contracts to induce worker self-selection by type within categories. The model yields a prediction on initial wages distinct from models of human capital, learning, and search. A test of the prediction is conducted using the 1986-1993 panels of the National Longitudinal Survey of Youth, and the main result provides evidence supporting the categorization model.
The arterial supply of the dura mater of the Rhesus monkey.

A study of the dural blood supply in 20 specimens by dissection, corrosion preparations and cleared specimens indicates that the dural arteries are similar to those of man yet significant differences were noted. The anterior cranial fossa is supplied by small twigs which spread through the dura of the anterior cranial fossa floor. The larger branch, the anterior meningeal artery, perforates the lateral orbital wall and supplies the lateral wall of anterior and middle cranial fossae. The middle meningeal artery, of the maxillary artery, divides into two branches in the floor of the middle fossa. The anterior or frontal branch always anastomoses with the anterior meningeal artery. Sometimes it also continues upward to the lateral wall of the middle fossa to supply it. The posterior middle meningeal branch passes backward to supply the parietal area. The posterior meningeal artery, of the occipital artery, enters the skull near the beginning of the sigmoid sinus and follows the general course of the lambdoidal suture.
Human disease from radon exposures: The impact of energy conservation in residential buildings

Abstract The level of radon and its daughters inside conventional buildings is often higher than the ambient background level. Interest in conserving energy is motivating home-owners and builders to reduce ventilation and hence to increase the concentration of indoor generated air contaminants, including radon. It is possible that the current radiation levels in conventional homes and buildings from radon daughters could account for a significant portion of the lung cancer rate in non-smokers. Moreover, it is likely that some increased lung cancer risk would result from increased radon exposures; hence, it is prudent not to allow radon concentrations to rise significantly. There are several ways to implement energy conservation measures without increasing risks.
Three-dimensional reconstruction of the valyl-tRNA synthetase/elongation factor-1H complex and localization of the δ subunit

Eukaryotic valyl-tRNA synthetase (ValRS) and the heavy form of elongation factor 1 (EF-1H) are isolated as a stable high molecular mass complex that catalyzes consecutive steps in protein biosynthesis--aminoacylation of tRNA and its transfer to elongation factor. Herein is the first three-dimensional structure of the particle as calculated from electron microscopic images of negatively stained samples of the human ValRS/EF-1H complex. The ca. 12 x 8 nm particle has two distinct domains and each appears to have twofold symmetry. Bound antibodies place two delta subunits near the particle's center. These data support a dimeric head-to-head arrangement of particle components.
Causes and consequences of life-history variation in North American stocks of Pacific cod

Ormseth, O. A., and Norcross, B. L. 2009. Causes and consequences of life-history variation in North American stocks of Pacific cod. - ICES Journal of Marine Science, 66: 349-357.Life-history strategies of four Pacific cod (Gadus macrocephalus) stocks in the eastern North Pacific Ocean are outlined. Southern stocks grew and matured quicker, but reached smaller maximum size and had shorter lifespans than northern stocks. The trade-offs resulted in similar lifetime reproductive success among all stocks. Growth was highly dependent on latitude, but not on temperature, possibly because of differences in the duration of the growing season. Comparisons with Atlantic cod (Gadus morhua) revealed similar latitude/growth relationships among Atlantic cod stocks grouped by geographic region. In Pacific cod, greater size and longevity in the north appeared to be adaptations to overcome environmental constraints on growth and to maintain fitness. An egg production-per-recruit model suggested that the life-history strategy of northern Pacific cod stocks made them less resilient to fishing activity and age truncation than southern stocks.
Sleep disordered breathing and depression among U.S. adults: National Health and Nutrition Examination Survey, 2005-2008.

Study objective To determine if symptoms of sleep disordered breathing (SDB) are associated with depression symptomology in a national sample. Design National Health and Nutrition Examination Survey. Setting U.S., 2005-2008. Participants 9,714 adults (≥ 18 years). Measurements Respondents were asked about frequency of snoring and snorting, gasping, or stopping breathing while asleep and completed the PHQ-9 (a 9-item depression screener). Odds ratios (OR) and 95% confidence intervals (CI) for SDB symptom-associated probable major depression (defined as a PHQ-9 score ≥ 10) were obtained from sex-specific logistic regression analyses adjusted for body mass index, age, race/ethnicity, and education. Results Among men, 6.0% reported physician-diagnosed sleep apnea, 37.2% snored ≥ 5 nights/week, 7.1% snorted/stopped breathing ≥ 5 nights/week, and 5.0% had PHQ-9 scores ≥ 10. Among women, 3.1% reported sleep apnea, 22.4% snored ≥ 5 nights/week, 4.3% snorted/stopped breathing ≥ 5 nights/week, and 8.4% had PHQ-9 scores ≥ 10. Sleep apnea was associated with probable major depression (OR = 2.4; 95% CI: 1.5, 3.6 among men; OR = 5.2; 95% CI: 2.7, 9.9 among women). Snoring was not associated with depression symptoms in men or women. Snorting/stopping breathing ≥ 5 nights/week compared to never was strongly associated with probable major depression in men (OR = 3.1; 95% CI: 1.8, 5.2) and women (OR = 3.0; 95% CI: 1.6, 5.4). Conclusion Frequent snorting/stopping breathing was associated with probable major depression by the PHQ-9 in a national sample of adults. Additional research may be needed to determine whether regular screening for these conditions by mental health professionals and sleep specialists should be recommended.
"Single-Electron Parametron": Reversible Computation in a Discrete-State System

The energy dissipation in a proposed digital device in which discrete degrees of freedom are used to represent digital information (a "single-electron parametron") was analyzed. If the switching speed is not too high, the device may operate reversibly (adiabatically), and the energy dissipation E per bit may be much less than the thermal energy scale kBT (where kB is Boltzmann's constant and T is temperature). The energy-time product Etau is, however, much greater than Planck's constant Planck's over 2pi, at least in the standard "orthodox" model of single-electron tunneling that was used in these calculations.
Optimal flow control of a class of queueing networks in equilibrium

The problem of optimum flow control of a class of queueing systems which appears as a model of datagram and virtual circuit computer communication networks is investigated. This class "intuitively" has the property that by increasing the load on the network, both the average throughput and the average time delay also increase. It is shown that the control that achieves the maximum throughput under a bounded average time delay criterion can be specified by a "window" flow control mechanism (bang-bang control). The window size L , the maximum number of unacknowledged packets in the system, can be easily derived from the preassigned upper bound on the time delay T , the Norton equivalent of the queueing system μ, and the maximum admissible total load on the network c .
Centrifugal instabilities in finite containers: a periodic model

A simplified model problem has recently been suggested by Schaeffer (1980) in order to explain the results obtained by Benjamin (1978) in his investigation of Taylor vortices in short cylinders. In particular Schaeffer reproduces the results obtained by Benjamin for cylinders so short that only two-cell or four-cell flows are possible. The model given by Schaeffer has artificial conditions imposed on the fluid velocity field at the end walls. These conditions depend on a parameter α and reduce to the no-slip condition when α = 1. If α = 0 the conditions require that the normal component of the velocity and the normal derivative of the tangential velocity vanish at the ends. In this case the onset of Taylor vortex-like motion occurs as a bifurcation from purely circumferential flow. If α is now taken to be small and positive, there is no bifurcation and the circulatory flow develops smoothly. We shall use perturbations method for the case of small α. The imperfect bifurcation problem which we obtain predicts some results consistent with those of Benjamin.
Thermal desorption spectroscopy investigation of CO adsorption on Cu/Pd(111) surfaces

Abstract Thermal desorption spectroscopy (TDS) experiments of CO adsorbates on vacuum deposited, epitaxial Pd(111) and Cu(111)/ Pd(111) bilayer films were carried out under UHV conditions. It was shown in this work that CO adsorption on these films takes place in two steps: the high energy sites (β 2 ) are filled first during early exposure and then one or more low energy sites are filled to saturation. CO adsorption on Cu(111)/Pd(111) bilayers occurs in decreasing amounts as the Cu overlayer thickens. Beyond approximately two monolayers (ML) Cu, no CO adsorbs. The saturation CO coverages decrease linearly by approximately 25% for every 1 2 ML Cu deposited. The peak temperature of the TDS curves decreases linearly with increasing CO coverage and does so more rapidly with increasing Cu coverage. This result shows that the binding energy of CO depends not only on the overlayer coverage but also on the density of CO molecules on the surface.
Organizational Commitment: A Reconceptualization And Empirical Test Of Public-Private Differences

This article examines the public-private dimension as an antecedent of organizational com mitment and assesses the effect of publicness on individual attachment to the organization. The findings suggest that (1) the strength of an individual's attachment to the organization is a function of several dimensions of organizational experience which can be inconsistent in their effects; and (2) that, public employees, in particular, may be simultaneously attracted to and repelled by the organization, with their desire to serve important values undercut by low or negative feelings of affiliation.
Control-augmented structural synthesis

A methodology for control augmented structural synthesis is proposed for a class of structures which can be modeled as an assemblage of frame and/or truss elements. It is assumed that both the plant (structure) and the active control system dynamics can be adequately represented with a linear model. The structural sizing variables, active control system feedback gains and nonstructural lumped masses are treated simultaneously as independent design variables. Design constraints are imposed on static and dynamic displacements, static stresses, actuator forces and natural frequencies to ensure acceptable system behavior. Multiple static and dynamic loading conditions are considered. Side constraints imposed on the design variables protect against the generation of unrealizable designs. While the proposed approach is fundamentally more general, here the methodology is developed and demonstrated for the case where: (1) the dynamic loading is harmonic and thus the steady state response is of primary interest; (2) direct output feedback is used for the control system model; and (3) the actuators and sensors are collocated.
Methionine degradation: ‘anabolic and catabolic’

Abstract The oxidation of methionine is commonly assumed to proceed via the formation of S -adenosylmethionine. There is now evidence for an alternative metabolic pathway which oxidizes the methionine in excess of dietary requirements and which appears to be present in a variety of animal species, including primates and man.
Tc(VII) reduction kinetics by titanomagnetite (Fe3−xTixO4) nanoparticles

Abstract Technetium contamination remains a major environmental problem at nuclear reprocessing sites, such as at the Hanford nuclear reservation, Washington, USA. Here we investigate the heterogeneous reduction of the highly soluble pertechnetate anion [Tc(VII)O 4 − ] to sparingly soluble Tc(IV)-bearing solids by a novel and well-characterized set of mixed-valent titanium-doped magnetite nanoparticles, structurally and chemically analogous to titanomagnetites naturally present in Hanford sediments. Titanomagnetite (Fe 3− x Ti x O 4 ) nanoparticles (10–12 nm) with varying Ti content (0 ⩽ x ⩽ 0.53) were synthesized in aqueous suspension. Reaction with 10 and 30 μM Tc(VII) solution yielded fast exponentially decaying reduction kinetics with rates that increased with increasing solid-state Fe(II)/Fe(III) ratio in the nanoparticles, a characteristic systematically controlled by the Ti-content. Nanoparticles before and after reduction experiments and surface-associated products of Tc(VII) reduction were characterized using transmission electron microscopy (TEM), X-ray absorption near-edge spectroscopy (XANES), extended X-ray absorption fine structure spectroscopy (EXAFS), micro X-ray diffraction (μ-XRD), X-ray absorption (XA) and X-ray magnetic circular dichroism (XMCD). A mechanistic reaction model was developed involving reduction of Tc(VII) to form Tc(IV)/Fe(III) solids by structural Fe(II) enriched at the nanoparticle surface, a reactive Fe(II) pool that during reaction is resupplied and sustained by outward migration of Fe(II) from the particle interior with concurrent inward migration of charge-balancing cationic vacancies in a ratio of 3:1. The reaction process was quantitatively linked to mass and electron balanced changes in the Fe 3− x Ti x O 4 nanoparticles, and the accessibility of structural Fe(II) from these phases was determined.
Human cell mutagens in respirable airborne particles from the northeastern United States. 2. Quantification of mutagens and other organic compounds.

Few reports have characterized mutagenic compounds in respirable airborne particles (<2.5 micrometers in diameter; PM_(2.5)) collected at different sites on a regional scale (hundreds of km). Previously, we reported differences in the human (h1A1v2) cell mutagenicity of whole and fractionated organic extracts of PM_(2.5) samples collected in Boston, MA, Rochester, NY, and Quabbin Reservoir, a rural site in western MA. Herein we describe the analysis of mutagens and other organic compounds in these samples. Gas chromatography−mass spectrometry (GC−MS) was used to quantify ∼150 organic compounds, including 31 known human cell mutagens. Molecular weight (MW) 226−302 amu PAHs were the most important mutagens identified: cyclopenta[cd]pyrene accounted for 1−2% of the measured mutagenicity of the samples, MW 252 PAHs accounted for 4−6%, MW 276−278 PAHs accounted for 2−5%, and MW 302 PAHs accounted for 2−3%. 6H-benzo[cd]pyren-6-one, a PAH ketone, accounted for 3−5% of the mutagenicity. The same compounds accounted for similar portions of the total attributed mutagenicity in each sample. Mutagen levels were similar in the Boston and Rochester samples, and both were significantly higher than the Quabbin sample. This may explain why the mutagenicities of the Boston and Rochester samples were higher than the Quabbin sample. The levels of mutagens found in semipolar fractions, however, could not explain why the mutagenicity of semipolar fractions was 2-fold higher in the Rochester sample than in the Boston sample. Known mutagens accounted for only 16−26% of the total mutagenicity of the unfractionated extracts, and only ∼20% of the mutagenicity of the nonpolar and semipolar fractions. The remaining mutagenicity is likely attributable to other, as-yet unknown, semipolar and polar mutagens, or to interactions among chemical constituents of the samples. These findings are consistent with similar studies performed on airborne particles from Los Angeles and Washington, DC, thus indicating that PAHs, PAH-ketones, and as-yet unidentified polar organic compounds are widely distributed airborne human cell mutagens.
High incidence of gastric bezoars in cystic fibrosis patients after lung transplantation.

Background. Bezoars are concretions of ingested matter which accumulate in the gastrointestinal tract and manifest as symptomatic foreign bodies. The aim of this study is to evaluate the incidence of gastric bezoars after lung transplantation and identify associated risk factors. Methods. We performed a retrospective analysis ofpatients who underwent lung transplantation from December, 1992 through July, 2005 at our tertiary care medical center. Patients who had endoscopically confirmed gastrointestinal bezoars in the posttransplant setting were identified and compared with patients without bezoars. Results. Of the 215 patients who received lung transplantation, 17 (7.9%) developed gastric bezoars confirmed by upper endoscopy. Cystic fibrosis was the leading indication for lung transplantation (n=145), and 11% ofcystic fibrosis patients (16 of 145) formed gastric bezoars after transplant. Additionally, 94% of patients with bezoars (16 of 17) had cystic fibrosis (P=0.02), with the exception being a subject with primary ciliary dyskinesia. No patient who underwent lung transplant for another indication was found to have a bezoar. The mean time to diagnosis was 34 days, with two-thirds of bezoars diagnosed within one month after transplant. The annual incidence was unchanged during the study period. Conclusions. Gastric bezoars are common in cystic fibrosis patients after lung transplantation. The etiology is likely multifactorial, related to gastric motility, respiratory secretions, and medications. Further investigation is needed to understand the pathogenesis of bezoar formation in this selected population, and strategies for primary prevention may be beneficial.
Protecting Youth Online: Family Use of Filtering and Blocking Software

Abstract Objective: This paper explores the characteristics associated with decisions to adopt or discontinue the use of filtering software, including a critical analysis of some explanations about why it is used or not used in households with children and adolescents. Method: This study consisted of a national telephone survey of households in the United States with youth (10 and 17 years) who use the Internet regularly. Interviews were completed with one youth in the appropriate age group and a parent or caretaker. Results: Thirty-three percent of parents reported using filtering or blocking software, with an additional 5% having discontinued its use within the past year. Parents were more likely to adopt filtering software if they had younger children (10–15 years), a high level of concern about exposure to sexual material on the Internet, more extensive knowledge of what their child did online, low trust in the child's ability to use the Internet responsibly, and if the child used America Online (AOL). Using the Internet for school assignments was associated with not having filtering software. Conclusion: Findings suggest the need for (1) evaluation research of filter programs used in a real family context and (2) the development of a variety of strategies to prevent exposure to inappropriate material for youth of different ages.
Activation of H2AX and ATM in varicella-zoster virus (VZV)-infected cells is associated with expression of specific VZV genes

Mammalian cells activate DNA damage response pathways in response to virus infections. Activation of these pathways can enhance replication of many viruses, including herpesviruses. Activation of cellular ATM results in phosphorylation of H2AX and recruits proteins to sites of DNA damage. We found that varicella-zoster (VZV) infected cells had elevated levels of phosphorylated H2AX and phosphorylated ATM and that these levels increased in cells infected with VZV deleted for ORF61 or ORF63, but not deleted for ORF67. Expression of VZV ORF61, ORF62, or ORF63 alone did not result in phosphorylation of H2AX. While BGLF4, the Epstein-Barr virus homolog of VZV ORF47 protein kinase, phosphorylates H2AX and ATM, neither VZV ORF47 nor ORF66 protein kinase phosphorylated H2AX or ATM. Cells lacking ATM had no reduction in VZV replication. Thus, VZV induces phosphorylation of H2AX and ATM and this effect is associated with the presence of specific VZV genes in virus-infected cells.
Faculty rewards for the generalist clinician-teacher.

Historically, medicine has regarded itself as a profession of great breadth, encompassing the total range of human activity: biological, behavioral, social and organizational. In the last several decades, however, it has become increasingly reductionist, fragmented, and specialized. Recent developments, as exemplified by the return of the generalist clinician-educator to the academic community, portend a reversal of this trend. Manifestations of a change in the orientation of medicine and medical education toward holism and humanism include a movement toward improved compensation for “cognitive” services, development of new promotion tracks for clinician-teachers, and increased support and recognition of applied clinical research. Generalist faculty are in a position to benefit from these trends, but obstacles remain; vigilism and activism are required to maintain momentum.
Laboratory measurements of the dynamic properties of intact and remolded offshore clays from Campeche Bay

Comparisons of the dynamic properties of intact and remolded offshore clay specimens has been carried out. The clay specimens were obtained from Campeche Bay, offshore Mexico. Combined resonant column and torsional shear (RCTS) equipment at the University of Texas at Austin was used to determine the dynamic soil properties. Each soil specimen was tested twice, first in the intact condition and second as remolded material. Remolding was done by kneading the intact material and then reforming the specimen by compacting in a mold. The effects on the dynamic properties, expressed by shear modulus and material damping ratio, between intact and remolded conditions are discussed. As expected, shear modulus and material damping at small and large strains are affected by remolding. Interestingly, the normalized modulus degradation curves were changed very little by remolding up to strains between 0.06 and 0.1%. The results offer insight into the effects of sampling disturbance on linear and nonlinear dynamic soil properties.Copyright © 2003 by ASME
WE-E-18A-03: How Accurately Can the Peak Skin Dose in Fluoroscopy Be Determined Using Indirect Dose Metrics?

Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that Result in skin reactions can be reached during these procedures. The purpose of this study was to assess the accuracy of different indirect dose estimates and to determine if PSD can be calculated within ±50% for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures. Indirect dose metrics from procedures were collected, including reference air kerma (RAK). Four different estimates of PSD were calculated and compared along with RAK to the measured PSD. The indirect estimates included a standard method, use of detailed information from the RDSR, and two simplified calculation methods. Indirect dosimetry was compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the indirect estimates were examined. Results: PSD calculated with the standard calculation method were within ±50% for all 41 procedures. This was also true for a simplified method using a single source-to-patient distance (SPD) for all calculations. RAK was within ±50% for all but one procedure. Cases for which RAK or calculated PSD exhibited large differences from the measured PSD were analyzed, and two causative factors were identified: ‘extreme’ SPD and large contributions to RAK from rotational angiography or runs acquired at large gantry angles. When calculated uncertainty limits [−12.8%, 10%] were applied to directly measured PSD, most indirect PSD estimates remained within ±50% of the measured PSD. Conclusions: Using indirect dose metrics, PSD can be determined within ±50% for embolization procedures, and usually to within ±35%. RAK can be used without modification to set notification limits and substantial radiation dose levels. These results can be extended to similar procedures, including vascular and interventional oncology. Film dosimetry is likely an unnecessary effort for these types of procedures.
Network DEA: efficiency analysis of organizations with complex internal structure

DEA models treat the DMU as a "black box." Inputs enter and outputs exit, with no consideration of the intervening steps. Consequently, it is difficult, if not impossible, to provide individual DMU managers with specific information regarding the sources of inefficiency within their DMUs. We show how to use DEA to look inside the DMU, allowing greater insight as to the sources of organizational inefficiency. Our model applies to DMUs that consist of a network of Sub-DMUs, some of which consume resources produced by other Sub-DMUs and some of which produce resources consumed by other Sub-DMUs. Our Network DEA Model allows for either an input orientation or an output orientation, any of the four standard assumptions regarding returns to scale in any Sub-DMU, and adjustments for site characteristics in each Sub-DMU. We demonstrate how to incorporate reverse quantities as inputs, intermediate products, or outputs. Thus, we can apply the Network DEA Model presented here in many managerial contexts. We also prove some theoretical properties of the Network DEA Model.By applying the Network DEA Model to Major League Baseball, we demonstrate the advantages of the Network DEA Model over the standard DEA Model. Specifically, the Network DEA Model can detect inefficiencies that the standard DEA Model misses. Perhaps of greatest significance, the Network DEA Model allows individual DMU managers to focus efficiency-enhancing strategies on the individual stages of the production process.
One hundred years of experimental psychology: An American perspective

At the 1979 annual meeting of the American Psychological Association a special series of twenty-two symposia and lectures was devoted to the theme of ‘A Century of Psychology as Science: Retrospections and Assessments.’ The speakers in this series, including many major psychologists, were charged with giving historical overviews and critical evaluations of various aspects of the first century of experimental psychology. This article, written by one of the organizers of this centennial program, presents an analysis of and commentary on the views expressed by these speakers.
A nearest neighbor architecture to overcome dephasing

We design a nearest-neighbor architectural layout that uses fixed positive and negative couplings between qubits, to overcome the effects of relative phases due to qubit precessions, both during idle times and gate operations. The scheme uses decoherence-free subspaces, and we show how to realize gate operations on these encoded qubits. The main advantage of our scheme is that most gate operations are realized by only varying a single control parameter, which greatly reduces the circuit complexity. Moreover, the scheme is robust against phase errors occurring as a result of finite rise and fall times due to non-ideal pulses.
A re-examination of the heat of formation of HO2 using ab initio molecular orbital theory

The heat of formation of HO2 radical has been estimated in a spin-conserved reaction scheme with energies calculated at QCISD(T)/6-311 + G(2df,p)//QCISD(T)/6-311G(d,p) level of theory. The result, ΔH o f(HO2, 298 K) = 21.4 ± 4.2 kJ mol-1, supports the most recent experimental value of 15.9 ± 5.0 kJ mol-1, and thus resolves the discrepancy in the heat of formation of this radical.
The crystal and molecular structure of [η5-C5H3(SiMe3)2]2Yb(THF

Abstract [ η 5 -C 5 H 3 (SiMe 3 ) 2 ] 2 Yb(THF has been structurally characterized. The compound crystallizes in the orthorhombic space group Pbcn with a = 11.345(4), b = 13.552(4), c = 21.185(6) A , and D calc = 1.354 mg m −1 for Z = 4 . The Yb and O atoms reside on a crystallographic two-fold axis. The formally seven-coordinate Yb(II) ion is symmetrically coordinated to the Cp″ ligands with an average Yb-C bond length of 2.67(2) A. The YbO bond length and centroid-Yb-centroid angle are 2.34(1) A and 136°, respectively. The calculated effective ionic radius of the Cp″ ligand, 1.59 A, is at the low end of those calculated for 18 Cp″ lanthanide, lanthanum, or scandium compounds.
On the dependence of electron planar channeling radiation upon lattice vibration amplitude

Abstract The energies of photons arising from transitions between low-lying bound states of channeled electrons are sensitive to the lattice vibration amplitude. It is shown that calculations incorporating accepted values of Debye temperatures for C (diamond), Si, Ge, and GaAs lead to excellent agreement with experiment for all cases, save Si. Channeling radiation data from Si are then used to derive a Debye temperature which is shown to be consistent with temperature dependent measurements in both planar and axial channeling.
23S rRNA similarity from selection for peptidyl transferase mimicry

RNAs from a randomized pool were selected by affinity elution for binding to the molecule CCdApPuro, a high-affinity ligand of ribosomal peptidyl transferase designed as a transition-state analogue of peptide formation. The selected RNAs show affinity for CCdApPuro comparable to that of the peptidyl transferase center itself (Kd approximately 10 nM). Chemical modification/protection experiments implicate bases completely conserved among the selected RNAs in CCdApPuro interaction, which appears to involve both CCdA and puromycin moieties, that is, both A- and P-site homologues. The apparent selected binding site shows up to 17 nucleotides with similarity to conserved nucleotides of the peptidyl transferase loop domain of 23S rRNA and is conserved when reselected under mutagenesis. Thus, these nucleotides of 23S rRNA likely provide elements of the peptidyl transferase active center that bind the reactants near the site of peptide bond formation. Binding of CCdApPuro by a peptidyl transferase-like motif in the absence of protein strengthens the hypothesis that peptidyl transfer originated in an RNA world.
INTESTINAL OBSTRUCTION : III. THE DEFENSIVE MECHANISM OF THE IMMUNIZED ANIMAL AGAINST DUODENAL LOOP POISON.

Dogs may be immunized against lethal doses of the duodenal loop poison by means of small doses of the loop fluid from dog or cat and by material obtained from human cases of intestinal obstruction. The immunity is transient and may disappear within a few weeks. Dogs immunized by repeated doses of loop fluid show a definite resistance against the intoxication of a closed duodenal loop and may survive twice the usual period. A dog that recovers from simple intestinal obstruction may possess a strong resistance to the intoxication of a closed duodenal loop, thus indicating a similar type of intoxication in the two conditions. The sera of immune dogs are inactive when incubated with duodenal loop fluid. The organ extracts and emulsions (liver, spleen, lung) of immune dogs rapidly destroy the loop poison during incubation in vitro. This destructive property is possessed by a clear filtrate of the digested immune organs, excluding adsorption, and is lost after long periods of incubation (twelve weeks). We are investigating the action of this immune organ extract to determine whether it can destroy the closed-loop poison in vivo and perhaps be of value in treatment.
Ion microprobe analysis of (231Pa)/(235U) and an appraisal of protactinium partitioning in igneous zircon

Ion microprobe U-Pa measurements in zircon crystals from a Holocene rhyolite (Salton Buttes, California) are utilized to assess the partitioning of Pa and U between zircon and melt. The relative sensitivity factor (RSF) for ion microprobe U-Pa zircon analysis was calibrated on a natural high-U secular equilibrium zircon from Buff Peak (Nevada). Zircon crystals from Salton Buttes rhyolite show evidence for excess 231 Pa with a weighted average ( 231 Pa)/( 235 U) activity ratio of 1.9. From this ratio, model zircon-melt partition coefficient ratios D Pa /D U = 0.9–2.2 are obtained, assuming plausible limits for ( 231 Pa)/( 235 U) melt and correcting for the age of zircon crystallization (~15 ka). These values roughly fit lattice strain models for tetravalent cations, but are more than one order of magnitude lower than predictions for pentavalent Pa. Based on this appraisal of Pa partitioning, initial 231 Pa disequilibrium caused by zircon-melt fractionation alone can produce minor discordance or excess 207 Pb in Late Cenozoic zircon, but is insignificant for older U-Pb zircon ages.
Operant rate of planarians as a function of time out from photic stimulation

Four groups of 10 D. dorotocephala were tested over a 1 h period in a free operant situation. A response of breaking a photobeam provided a time out (TO) from.4 log ft-c for periods of 0, 15, 30, and 60 sec. The 15- and 30-sec TO groups produced the same mean response rates, which were significantly different from the other two groups. The response rates declined for each of the four groups during successive 15-min periods but was least noticeable for the 15-sec TO.
Patriotism as an Environmental Virtue

Define “patriotism” as love for one’s country and devotion to its well-being. This essay contends that patriotism thus defined is a virtue and that environmentalism is one of its most important manifestations. Patriotism, as devotion to particular places and people, can occur at various levels, from the local to the national. Knowing and caring about particular places and people and working to protect them is good for us and good for them and hence a good thing overall. Knowing and caring and working less on behalf of more remote places and people is also good, since it allows us to focus our efforts, act effectively, and do more good in the world. Philosophical analyses of patriotism by Alasdair MacIntyre and Martha Nussbaum are complemented by the more “down to earth” understanding of the virtue presented here. While patriotism’s dangers are undeniable, so are the dangers stemming from lack of patriotism. The proper answer to bad patriotism is not cosmopolitanism, but good patriotism: the kind illustrated by environmental activists.
Morphological and Biomechanical Properties of Equine Laminar Junction

Abstract The interlocking of dermis and epidermis is called the laminar junction or interface. Laminae provide a sturdy junction in between the distal phalanx and the keratinized hoof wall transferring the forces between those structures. Although the horse's weight is imposed on the distal phalanx and the hoof capsule, the laminar junction plays a crucial role in absorbing and dissipating the applied forces both from the weight of the animal and the ground reaction forces. Understanding the morphologic and mechanical properties of the laminar junction is a key to recognizing influencing factors and is paramount to understanding performance and health in horses. This article will present a review of the significance of the morphological and biomechanical properties of the equine laminar junction.
Temporal Organization in Children's Strategy Formation

It is well established that children use study behaviors such as card sorting, category naming, and item-by-item rehearsal to assist subsequent word recall. In this article, we provide evidence that these behaviors are organized into coherent temporal patterns. Fourier analyses of individual behaviors over a sequence of five consecutive study/recall trials indicated that sorting was synchronized with the start of each trial, whereas rehearsal tended to occur later in each trial. Fourier analyses of pairs of behaviors indicated that sorting and category naming, both concerned with categorization of the to-be-remembered words, co-occurred early in each trial at a greater rate than expected based on their individual frequencies of occurrence (i.e., they were used cooperatively). In contrast, verbal rehearsal of individual words co-occurred with both sorting and category naming at a lesser rate than would be expected based on their individual frequencies of occurrence. The results thus point to a global strategy in which children learn the items' categories before they learn them individually. There was little apparent qualitative difference in temporal organization for second- and fourth-grade children. However, sorting early in each trial was more pronounced for children with better word recall (regardless of grade), and the suppressed co-occurrence of rehearsal with sorting and category naming (i.e., keeping category learning temporally separate from item learning) was more pronounced for the fourth-grade children.
vGreen: A System for Energy-Efficient Management of Virtual Machines

In this article, we present vGreen, a multitiered software system for energy-efficient virtual machine management in a clustered virtualized environment. The system leverages the use of novel hierarchical metrics that work across the different abstractions in a virtualized environment to capture power and performance characteristics of both the virtual and physical machines. These characteristics are then used to implement policies for scheduling and power management of virtual machines across the cluster. We show through real implementation of the system on a state-of-the-art testbed of server machines that vGreen improves both average performance and system-level energy savings by close to 40p across benchmarks with varying characteristics.
Collapsin-1/Semaphorin D Is a Repellent for Chick Ganglion of Remak Axons

Chick collapsin-1/human semaphorin III/mouse semaphorin D is believed to guide the extension of specific axons by a repellent mechanism. Here we examine its role in the guidance of axons of the ganglion of Remak (Remak) in the developing chick intestine. Early in embryogenesis Remak axons extend parallel to, but do not enter, the intestine when collapsin-1 is expressed in the adjacent rectal wall. Remak axons later penetrate the peripheral portions of the rectal wall when collapsin-1 expression retreats from the outer muscle layer to the more internal submucosal and mucosal layers of the rectum. Extension of Remak neurites is repelled in vitro by rectum explants and also by 293T cells expressing collapsin-1. The rectal chemorepellent activity is blocked by anti-collapsin-1 antibodies. Our results suggest that collapsin-1 may help prevent Remak axons from projecting into the intestinal wall at early developmental times and later restricts Remak axon trajectories to the outer part of the intestinal muscle layer.
Which antihypertensive agents in chronic kidney disease

In this issue, Rahman and colleagues report cardiovascular disease in chronic kidney disease from the randomized study known as ALLHAT. They had previously reported outcomes of kidney disease in th...
The vulnerable plaque and acute coronary syndromes

The interaction between the vulnerable atherosclerotic plaque and thrombus formation, a process referred to as atherothrombosis, is the cornerstone of acute coronary syndromes. Advances in noninvasive imaging have helped to identify novel approaches to plaque stabilization, with the potential to prevent plaque rupture, including lifestyle modification and dietary adjustments, as well as pharmacologic interventions such as statins. Following an acute coronary event, strategies combining mechanical and pharmacologic therapies provide considerable advances in prevention of subsequent cardiac events. Pharmacologic strategies to prevent and treat thrombotic complications related to acute coronary syndromes have been developed to dissolve preformed thrombi and to inhibit thrombogenesis. These regimens focus on inhibiting thrombin, preventing thrombi generation, blocking the initiation of coagulation, inhibiting platelet activation, and increasing fibrinolysis.
Effects of ion irradiation on the residual stresses in Cr thin films

Cr films sputtered onto {100} Si substrates at room temperature were found to be under residual tension, as revealed by wafer curvature measurements. A 150 nm thick Cr film was bombarded with 300 keV Ar ions after deposition. The intrinsic residual tensile stress increased slightly and then decreased with further increase in the ion dose. For ion doses >1×1015 ions/cm2, the stress in the film became compressive and increased with increasing dose. Transmission electron microscopy revealed that the grain boundaries in as-deposited Cr have columnar porosity. A Cr film, ion irradiated to a dose of 5×1015 ions/cm2, showed no grain boundary porosity. The changes in the residual stress during ion irradiation are explained by considering Ar incorporation in the film and the manner in which irradiation may change the interatomic distances and forces.
Effect of Protein Synthesis Inhibitors on Tobacco Seed Germination and Seedling Emergence

Summary This study is based on two earlier reports, one demonstrating that dark preincubation improves tobacco (Nicotiana tabacum L.) seed germination rate and the other demonstrating genetic variability in tobacco seed response to germination temperature. Each of these situations involves special classes of proteins: the phytochrome molecule and heat shock proteins, respectively. A better understanding of either process at the molecular level would involve investigations on the regulatory role of the protein synthesis mechanism. This study was undertaken to characterize the temporal relationship of the three major steps in protein synthesis - replication, transcription and translation - with the three major events associated with seedling morphogenesis: radicle protrusion, radicle elongation, and plumule protrusion. This was accomplished through the use of selected inhibitors of replication, transcription, and translation. Results suggest that a) radicle emergence is regulated by translation but is independent of replication and transcription; b) the translational regulation of the above event is mediated through preformed (i.e., longlived) m-RNAs; c) radicle elongation following its emergence and plumule emergence are regulated by all three components of protein synthesis; d) radicle length data obtained in laboratory investigations are a better predictor than radicle number (i.e., germination percentage) of seedling emergence potential under field conditions.
CDK Inhibitor p18INK4c Is a Downstream Target of GATA3 and Restrains Mammary Luminal Progenitor Cell Proliferation and Tumorigenesis

Mammary epithelia are composed of luminal and myoepithelial/basal cells whose neoplastic transformations lead to distinct types of breast cancers with diverse clinical features. We report that mice deficient for the CDK4/6 inhibitor p18(Ink4c) spontaneously develop ER-positive luminal tumors at a high penetrance. Ink4c deletion stimulates luminal progenitor cell proliferation at pubertal age and maintains an expanded luminal progenitor cell population throughout life. We demonstrate that GATA3 binds to and represses INK4C transcription. In human breast cancers, low INK4C and high GATA3 expressions are simultaneously observed in luminal A type tumors and predict a favorable patient outcome. Hence, p18(INK4C) is a downstream target of GATA3, constrains luminal progenitor cell expansion, and suppresses luminal tumorigenesis in the mammary gland.
Power combiner for high power Cherenkov devices

The output power of two Cherenkov devices is combined using a circular waveguide T-junction. The microwave sources are driven by the same high voltage pulser to prevent phase difference in the outputs. This passive power combiner not only combines the power, but also outputs a Gaussian beam when a TM 01 -mode is used as the input. An efficient serpentine mode converter has been used as the basis of the power combiner design. A conversion efficiency of 85% with a Gaussian pattern is achieved in simulations and is described in this paper.
"Looking the Other in the Eye" as a Guide for Policymaking

"Looking the other in the eye" is a figure of speech that has a moral significance beyond its literary service. To be extended to public policy (i.e., beyond the face-to-face interactions of tightly knit communities), it must be applied to interactions mediated by institutions and cultural patterns. This can be done through a careful reformulation of what the figure of speech means. The possible use of this figure of speech in guiding policymaking is illustrated by applying it to two issues—homelessness and setting highway speed limits—to show how it can guide and clarify consideration of complex issues.