cssi/SciSciGPT-SciSciNet huggingface dataset:
A LEED, TPD and HREELS investigation of NO adsorption on Sn/Pt(111) surface alloys

The adsorption of NO on Pt(111), and the (2 × 2)Sn/Pt(111) and (√3 × √3)R30°Sn/Pt(111) surface alloys has been studied using LEED, TPD and HREELS. NO adsorption produces a (2 × 2) LEED pattern on Pt(111) and a (2√3 × 2√3)R30° LEED pattern on the (2 × 2)Sn/Pt(111) surface. The initial sticking coefficient of NO on the (2 × 2)Sn/Pt(111) surface alloy at 100 K is the same as that on Pt(111), S0 = 0.9, while the initial sticking coefficient of NO on the (√3 × √3)R30°Sn/Pt(111) surface decreases to 0.6. The presence of Sn in the surface layer of Pt(111) strongly reduces the binding energy of NO in contrast to the minor effect it has on CO. The binding energy of β-state NO is reduced by 8–10 kcal/mol on the Sn/Pt(111) surface alloys compared to Pt(111). HREELS data for saturation NO coverage on both surface alloys show two vibrational frequencies at 285 and 478 cm−1 in the low frequency range and only one N-O stretching frequency at 1698 cm−1. We assign this NO species as atop, bent-bonded NO. At small NO coverage, a species with a loss at 1455 cm−1 was also observed on the (2 × 2)Sn/ Pt(111) surface alloy, similar to that observed on the Pt(111) surface. However, the atop, bent-bonded NO is the only species observed on the (√3 × √3)R30°Sn/Pt(111) surface alloy at any NO coverage studied.
Choosing and using screening criteria for palliative care consultation in the ICU: a report from the Improving Palliative Care in the ICU (IPAL-ICU) Advisory Board.

Objective:To review the use of screening criteria (also known as “triggers”) as a mechanism for engaging palliative care consultants to assist with care of critically ill patients and their families in the ICU.Data Sources:We searched the MEDLINE database from inception to December 2012 for all Engl
Optimal Path Finding in Direction, Location and Time Dependent Environments.

This article examines optimal path finding problems where cost function and constraints are direction, location, and time dependent. Recent advancements in sensor and data-processing technology facilitate the collection of detailed real-time information about the environment surrounding a ground vehicle, an airplane, or a naval vessel. We present a navigation model that makes use of such information. We relax a number of assumptions from existing literature on path-finding problems and create an accurate, yet tractable, model suitable for implementation for a large class of problems. We present a dynamic programming model which integrates our earlier results for direction-dependent, time and space homogeneous environment, and consequently, improves its accuracy, efficiency, and run-time. The proposed path finding model also addresses limited information about the surrounding environment, control-feasibility of the considered paths, such as sharpest feasible turns a vehicle can make, and computational demands of a time-dependent environment. To demonstrate the applicability and performance of our path-finding algorithm, computational experiments for a short-range ship routing in dynamic wave-field problem are presented. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Attribution of Atmospheric Variations in the 1997–2003 Period to SST Anomalies in the Pacific and Indian Ocean Basins

Abstract The individual impacts of sea surface temperature (SST) anomalies in the deep tropical eastern–central Pacific (DTEP) and Indo-western–central Pacific (IWP) on the evolution of the observed global atmospheric circulation during the 1997–2003 period have been investigated using a new general circulation model. Ensemble integrations were conducted with monthly varying SST conditions being prescribed separately in the DTEP sector, the IWP sector, and throughout the World Ocean. During the 1998–2002 subperiod, when prolonged La Nina conditions occurred in DTEP and the SST in IWP was above normal, the simulated midlatitude atmospheric responses to SST forcing in the DTEP and IWP sectors reinforced each other. The anomalous geopotential height ridges at 200 mb in the extratropics of both hemispheres exhibited a distinct zonal symmetry. This circulation change was accompanied by extensive dry and warm anomalies in many regions, including North America. During the 1997–98 and 2002–03 El Nino events, the ...
Teaching Writing in Graduate School

Graduate students are typically expected to know how to write. Those who write poorly are occasionally penalized, but little in-class attention is given to help students continue to develop and refine their writing skills. More often than not, writing courses at the graduate level are remedial programs designed for international students and others with significant challenges to writing. In this article, we describe the ways in which we introduced writing into the curriculum of a master's-level qualitative methods course. We structured the course around a semester-long research project that called for students to work in a team with others to improve both their research and writing. We share the strategies we used to demystify the writing process and encourage improvement, both in the course and beyond.
The units of calcium conduction in Helix neurones.

VOLTAGE-DEPENDENT membrane calcium currents, ICa, occur in muscle1,2, axons3,4 and nerve cell bodies5–9 but are not well characterised because of difficulties in separating them from other ionic currents, and inadequate spatial and temporal control of the clamp voltages used to examine them. As a result, information on the conduction process underlying ICa is limited. Recently two new techniques have been reported6,9,10 which overcome most of the problems associated with experimental investigations of ICa. We have used the suction pipette technique9,10, which combines methods of internal perfusion and voltage clamp, to study ICa in isolated nerve cell bodies of the snail, Helix aspersa. The time course of ICa in response to step changes in membrane potential was readily examined and, in addition, very small fluctuations (noise) in current were also observed. Assuming that the fluctuations represent current contributions from a population of independent two-state (conducting/nonconducting) unit conductances, 〈ICa〉, the average value of the fluctuations in the steady state, and σ2, the variance of the fluctuations can be used to estimate a single unit conductance, γca. Analysis of spontaneous current noise has been used previously to obtain γ values for the Na and K systems in several axon membranes11–14, and γ values for acetylcholine-sensitive conductances at the neuromuscular junction15,16 and in molluscan neurones17, but γCa is unknown. Unit ion conductances of a few picosiemens or greater have been reported and where comparisons can be made, these values are similar to those estimated using quite different techniques such as tetrodotoxin binding18–21. We found γCa to be less than 1 pS however, and we suggest that the low value results from the effect of a Ca2+ binding site in the conductance.
Basic criteria for formation of growth twins in high stacking fault energy metals

Nanotwinned metals received significant interest lately as twin boundaries may enable simultaneous enhancement of strength, ductility, thermal stability, and radiation tolerance. However, nanotwins have been the privilege of metals with low-to-intermediate stacking fault energy (SFE). Recent scattered studies show that nanotwins could be introduced into high SFE metals, such as Al. In this paper, we examine several sputter-deposited, {111} textured Ag/Al, Cu/Ni, and Cu/Fe multilayers, wherein growth twins were observed in Al, Ni, and face-centered cubic (fcc) Fe. The comparisons lead to two important design criteria that dictate the introduction of growth twins in high SFE metals. The validity of these criteria was then examined in Ag/Ni multilayers. Furthermore, another twin formation mechanism in high SFE metals was discovered in Ag/Ni system.
State‐of‐the‐art update on combined sewer overflow control

Control and treatment of stormwater discharges and combined sewage overflows from urban areas are problems of increasing importance in the field of water quality management. Over the past decade much research effort has been expended and a large amount of data has been generated. The purposes of past research were to quantify urban overflow pollution problems and develop countermeasure controls. This review presents an updated state‐of‐the‐art overview of those efforts emphasizing the combined sewer overflow aspects.
Selection for enhanced adhesion to microvessel endothelial cells or resistance to interferon-γ modulates the metastatic potential of murine RAW117 large-cell lymphoma cells

Poorly liver metastatic large-cell lymphoma RAW117-P cells were sequentially selected in vitro for increased adhesion to murine hepatic sinusoidal endothelial cells. After three or four sequential selections, the selected sublines showed increased rates of adhesion to target hepatic microvessel endothelial cells and increased formation of experimental metastases in the liver. However, the endothelial cell adhesion-selected RAW117 sublines were generally unstable and gradually lost their enhanced adhesive and metastatic properties during passage in culture. Highly metastatic, liver-selected RAW117-H10 large-cell lymphoma cells were more resistant to the cytostatic effects of interferon-7 (IFN-γ) than poorly metastatic unselected parental RAW117-P cells. When tested for their sensitivity to IFN-γ, the endothelial cell adhesion variants were significantly more resistant than the unselected RAW117-P cells, but after a 72-h treatment with IFN-γ, the in vitro-selected cells lost their enhanced endothelial cell adhesion characteristics, their potential to colonize the liver, and their ability to grow when injected at subcutaneous or intramuscular sites. In contrast, the metastatic potential of similarly treated RAW117-P cells was unaffected by IFN-γ during a 72-h treatment. Sequential selection of RAW117-P cells for increased resistance to IFN-γ in vitro resulted in variant lines that were refractory to the growth-inhibiting effects of IFN-γ, and these IFN-γ-selected variants were also less adhesive to liver microvessel endothelial cells. The IFN-γ-selected variants also lost their experimental metastatic potentials completely and their tumorigenicities at sites of subcutaneous or intramuscular injection. Cytofluorographic analysis indicated reduced cell surface expression of H-2Kd antigen and fibronectin receptor on the selected variant cells but no change in cell surface µ heavy chain immunoglobulin. The unselected and selected RAW117 lines had similar sensitivities to natural killer (NK) cell-mediated cytolysis, indicating that the in vivo differences were probably not due to differences in NK cell-mediated cytolysis. The results suggest that selection for adhesion to organ microvessel endothelial cells or sequential exposure to certain cytokines can affect the adhesive, growth and metastatic properties of RAW117 cells without modifying their responses to NK cells.
A comparison of different methods for calculating tangent-stiffness matrices in a massively parallel computational peridynamics code

Abstract In order to maintain the quadratic convergence properties of Newton’s method in quasi-static nonlinear analysis of solid structures it is crucial to obtain accurate, algorithmically consistent tangent-stiffness matrices. A goal of the study described in this paper was to establish the suitability of an underexplored method for numerical computation of tangent-stiffness operators, referred to as “complex-step”, and compare the method with other techniques for numerical derivative calculation: automatic differentiation, forward finite difference, and central finite difference. The complex-step method was implemented in a massively parallel computational peridynamics code for the purpose of this comparison. The methods were compared through profiling of the code for accuracy, speed, efficiency, and parallel scalability. This research provides data that can serve as practical guide for code developers and analysts faced with choosing which method best suits the needs of their application code. Additionally, motivated by the reproducible research movement, all of the code, examples, and workflow to regenerate the data and figures in this paper are provided as open source.
Structure-function analysis reveals discrete β3 integrin inside-out and outside-in signaling pathways in platelets

A unique aspect of integrin receptor function is the transmission of bidirectional signals. In platelets alphaIIbbeta3 integrins require "inside-out" signals to bind fibrinogen and form thrombi. Following ligand binding, alphaIIbbeta3 integrins generate "outside-in" signals that contribute to thrombus stability. Because integrin cytoplasmic tails are short and lack enzymatic activity, bidirectional signals are believed to be mediated by interactions with intracellular proteins, but the molecular basis for integrin signal transduction remains poorly understood. In the present study we have used retroviral vectors to express alphaIIbbeta3 integrins with mutant beta3 tails in mouse platelets and test mechanisms of bidirectional signaling. Using this approach we identify mutations (eg, beta3Y747A) that confer loss of signaling in both directions and others (eg, beta3T762A) that confer a selective loss of outside-in signals. These results reveal the presence of discrete bidirectional signaling pathways controlled by integrin beta subunits in platelets and describe a high-throughput means of further investigating these pathways in vivo.
Ontogeny of angiotensinogen mRNA and angiotensin II receptors in rat brain and liver.

The renin-angiotensin-system (RAS) is active in fetal and neonatal life. This study was undertaken to examine the ontogenic regulation of angiotensinogen (AT) gene expression and angiotensin II (A II) receptors in liver and brain. AT gene expression was studied in fetal, neonatal, adult and aged rats, using slot blot hybridization to quantify AT mRNA levels. During fetal life (gestational days 15–20), AT mRNA was more abundant in brain than in liver. Soon after birth, brain AT mRNA levels increased to a concentration 3 fold above fetal levels. In contrast, liver AT mRNA abundance increased 30-fold within 12 h of birth. Aging (3–20 months) resulted in a gradual decrease in AT mRNA in both the brain and liver. Liver A II receptors in the neonate were 2-fold higher than in the fetus, but returned to fetal levels by 8 weeks of age. In the brain, A II receptor abundance increased to a level 75% above fetal levels in 7 day old animals, but returned to fetal levels by 14 days of age. These studies suggest than in the fetus, the liver is not the primary source of AT but that unknown factors at parturition result in a dramatic increase in liver AT mRNA. In contrast, the more modest increases in brain AT mRNA parallel the gradual maturation of the CNS. In both tissues, further aging resulted in a gradual decrease in AT mRNA, reflecting either increased sensitivity to feedback down regulation by A II or age related increases in other extrahepatic sites of AT synthesis. Age related changes were also found in the A II receptor in both the liver and brain.
The effect of tobacco exposure on birth outcomes in diabetic pregnancies

DIABETIC PREGNANCIES SAMEER GOPALANI, MICHELLE WILLIAMS, University of Washington, Maternal-Fetal Medicine, Seattle, WA University of Washington, Epidemiology, Seattle, WA OBJECTIVE: Smoking increases insulin resistance (IR) and contributes independently to microvascular disease. Microvascular injury in the placenta is implicated in the pathophysiology of preeclampsia (PE) and other adverse outcomes. We sought to determine if joint exposure to tobacco and diabetes (DM) increases the risk of these outcomes beyond that expected from each exposure alone. STUDY DESIGN: We conducted a population-based cohort study using computerized records in WA State. Singleton births from 1992-2001 to diabetic women (gestational [GDM] and preexisting [PDM]) were selected, with nonDM subjects as controls. The cohort was stratified in order of hypothesized increasing risk of adverse outcome into six groups, with the first as the reference group: non-smoking non-diabetics (n = 78,071); non-DM smokers (n = 13,862); GDM non-smokers (n = 17,587); GDM smokers (n = 2896); PDM non-smokers (n = 2176); and PDM smokers (n = 391). Adjusted incidence rate ratios (IRR) were calculated using a multivariable generalized linear model. All reported IRR were statistically significant (P < .05). RESULTS: Smoking increased the risk of preterm delivery (PTD) (IRR 1.4) and fetal/infant death (IRR 1.7) but was associated with reduced risk of PE (IRR 0.7). The IRR for PE in nonsmokers and smokers with GDM were 1.8 and 1.5, respectively. The corresponding IRR for nonsmokers and smokers with PDM were 2.6 and 2.3. This pattern of PDM subjects experiencing the highest risks was also evident for PTD and fetal/infant death. CONCLUSION: Tobacco and DM act independently on adverse outcomes in subjects with joint exposure. The reduced risk of PE in diabetic smokers compared to non-smokers suggests that the increased incidence of PE in DM may not be solely attributable to insulin resistance (IR).
Level scheme of I129

Abstract The decay of 33 d Te 129m has been studied by means of beta-gamma and gamma-gamma coincidence and sum peak techniques. The gamma rays were found to depopulate at the levels 27, 280, 492, 570, 710, 840, 1045, 1127, 1255 and 1400 keV. The analysis of the coincidence spectra suggests that the 210, 280 and 820 keV gamma rays are each composed of two transitions of nearly the same energies. From the gamma-ray intensities and the beta-gamma coincidence spectra, the beta-ray feedings and the log ft values are calculated.
Solute Travel Times to Wellsa,b

Theoretical travel times are given for a solute to reach a well from an injection point, for wells that fully penetrate confined aquifers of constant thickness and mainly constant conductivity and porosity. Solute is assumed to move along streamlines with the water in piston flow under steady flow conditions. Three cases are considered. 1 For a “standard” well of external radius of influence re and well radius rw, the travel time varies approximately directly as the square of the distance r of the injection point from the well, as the ratio f/K of porosity to conductivity, and as ln re/rw. 2 For a well in which the flow region is divided by radius re into two regions, with the region next to the well clogged and of very low conductivity KI the travel time varies approximately directly as r squared, as KI, and as ln rc/rw. 3 For a well being fed from a line drive (river) at a distance d from the well, the travel time from a point on the line drive to the well varies as the distance d squared, as f/K, as ln 2d/rw, and as a function of the position of the point along the line drive. In each case, the travel time is inversely proportional to he - hw, where he is the head at the radius of influence re (or at the line drive) and hw is the head at the well. In the three cases, doubling the pumping rate halves the travel time. Travel times can affect the extent of chemical changes of the solute (contaminant) during its flow to the well.
How to Design a Contingent Convertible Debt Requirement That Helps Solve Our Too-Big-to-Fail Problem

As bank regulatory reform tries to come to grips with the lessons of the financial crisis, several experts have proposed that some form of contingent convertible debt (CoCo) requirement be added to the prudential regulatory toolkit. In this article, the authors show how properly designed CoCos can be used not just to absorb losses, but more importantly to encourage banks to recognize losses and replace lost equity in a timely way, as well as to manage risk more effectively. Their proposed CoCos requirement strengthens management's incentives to promptly replace lost capital and enhance risk management by imposing major costs on the managers and existing shareholders of banks that fail to do so. Key elements of the proposal are that conversion of the CoCos into equity would be (1) triggered at a high trigger ratio of equity to assets (long before the bank is near an insolvency point), (2) determined by a market trigger (using a 90-day moving average market equity ratio) rather than by supervisory discretion, and (3) significantly dilutive to shareholders. The only clear way for bank managements to avoid such dilution would be to issue equity into the market. Under most circumstances�barring an extremely rapid plunge of a bank's financial condition�management should be able and eager to replace lost capital in a timely way; as a result, dilutive conversions should almost never occur. Banks would face strong incentives to maintain high ratios of true economic capital relative to risky assets, and to manage their risks effectively. This implies that �too-big-to-fail� financial institutions would not be permitted to approach the point of insolvency; they would face strong incentives to recapitalize long before that point. And if they should fail to issue new equity in a timely manner, the CoCos conversion would provide an alternative means of recapitalizing banks well before they reach the brink of insolvency. Thus, a CoCos requirement would go a long way to resolving the �too-big-to-fail� problem. Such a CoCos requirement would not only increase the effectiveness of regulation, but also reduce its cost. It would be less costly for banks to raise CoCos than equity, reflecting both the lower adverseselection costs of CoCos issuance and the potential tax advantages of debt. And precisely because of the low probability of CoCo conversion, the Cocos would be issued at relatively modest (if any) discounts to otherwise comparable but straight subordinated debt. Thus requiring a mix of equity and appropriately designed CoCos would be less costly to banks, and would entail less of a reduction in the supply of loans than would a much higher book equity requirement alone.
Television Broadcast Demand in Markets Without Local Teams

This article uses television ratings from the 2006 and 2007 National Football League (NFL) seasons to estimate viewer demand in large markets without local teams. The factors that are found to be s...
Development of Coupled Thermo-Electrical-Mechanical Models for Studying Degradation of AlGaN/GaN HFETs

We present a coupled thermo-electrical-mechanical finite element based model to investigate material behaviors of wide bandgap (WBG) devices in operating conditions. The mechanisms of degradation and ultimately failure in wide bandgap devices are very complex. Under operating conditions, the devices are usually subject to high electric fields, high stress/strain fields, high current densities, high temperatures and high thermal gradients. The application of electronic devices is limited by lack of a detailed understanding of involved mechanisms. There is a long overdue of development of a comprehensive model which fully couples thermal, electrical and mechanical effects. The proposed model is capable of computing stress, temperature, and electric fields based on an innovative finite element approach for the solution of non-linear coupled thermo-electrical-mechanical problems. The developed model will address major issues of performance and lifetime of wide bandgap electronic devices.
Experimental mononeuropathy reduces the antinociceptive effects of morphine: implications for common intracellular mechanisms involved in morphine tolerance and neuropathic pain

Recent evidence suggests that hyperalgesia and morphine tolerance, two seemingly unrelated phenomena, have in common certain neural substrates such as activation of the N-methyl-D-aspartate (NMDA) receptor and the subsequent intracellular activation of protein kinase C and nitric oxide. Should common cellular elements be involved in hyperalgesia and morphine tolerance, these cellular and intracellular commonalities might be expected to result in interactions between these two phenomena. Indeed, our previous studies have shown that thermal hyperalgesia develops when animals are made tolerant to the antinociceptive effects of morphine. In this study, we examined the hypothesis that reduction of morphine antinociception occurs following unilateral ligation of the rats's sciatic nerve, a procedure which produces symptoms of a neuropathic pain syndrome including thermal hyperalgesia. When tested using the paw-withdrawal test on day 8 (D8) after either nerve ligation or sham operation, a single intrathecal treatment with 10 micrograms morphine sulfate (30 min after administration) produced significant antinociception in sham-operated rats but not in nerve-injured ones. These results also were obtained when thermal hyperalgesia was reversed in nerve-injured rats by the non-competitive NMDA receptor antagonist MK-801. Consistently, 8 days after sciatic nerve ligation but not after a sham operation, an approximately 6-fold rightward shift occurred in the morphine antinociceptive dose-response curve. This rightward shift of the morphine antinociceptive dose-response curve did not occur at 24 h after either nerve ligation or sham operation. In addition, once daily treatment with 10 nmol MK-801 from D2 to D7 after nerve ligation prevented both the development of thermal hyperalgesia and the rightward shift of the morphine antinociceptive dose-response curve on D8. The results indicate that the antinociceptive effects of morphine are reduced in nerve-injured rats in the absence of daily exposure to morphine and that the NMDA receptor activation may have a critical role in mechanisms of this phenomenon. These data provide further evidence indicating that interactions do occur between neural mechanisms underlying thermal hyperalgesia and morphine tolerance.
Assessing the Roles of Endogenous Retrovirus EAV-HP in Avian Leukosis Virus Subgroup J Emergence and Tolerance

Avian leukosis virus (ALV) subgroup J is thought to have emerged through a recombination event between an unknown exogenous ALV and the endogenous retrovirus elements designated EAV-HP. All EAV-HP elements identified to date in the chicken genome show large deletions, including that of the entire pol gene. Here we report the identification of four segregating chicken EAV-HP proviruses with complete pol genes, one of which shows exceptionally high sequence identity and a close phylogenetic relationship with ALV-J with respect to the env gene. Embryonic expression of EAV-HP env has been suggested as a factor associated with immunological tolerance induction in a proportion of ALV-J-infected meat-type chickens. In support of this, env gene transcripts expressed from two of the four newly identified EAV-HP proviruses were demonstrated in chicken embryos. However, when ALV-J-infected outbred meat-type chickens were assessed, the presence of intact EAV-HP proviruses failed to directly correlate with ALV-J tolerance. This association was further examined using F(2) progeny of two inbred lines of layer chicken that differed in EAV-HP status and immunological responses to ALV-J. Immunological tolerance developed in a small proportion of F(2) progeny birds, reflecting the expected phenotypic ratio for inheritance of a double-recessive genotype; however, the status of tolerance did not show any direct correlation with the presence of the intact EAV-HP sequence. Nevertheless, identification of an intact chicken EAV-HP locus showing a uniquely close relationship to the ALV-J prototype clone HPRS-103 in the env region provides the strongest evidence of its contribution to the emergence of ALV-J by recombination.
Reproductive cycle of Baird's pocket gopher (Geomys breviceps) in northern Louisiana

Abstract We examined the reproductive status of Baird's pocket gophers (Geomys breviceps) in Union Parish, Louisiana, for 18 months in 2010 and 2011. We found that pocket gophers were potentially reproductively active throughout the year, although the number of reproductively active gophers peaked during late spring through autumn. Our results are similar to those of studies of Baird's pocket gopher in other states and of other pocket gophers in the genus Geomys.
Synergetic localization for groups of mobile robots

We present a new approach to the problem of simultaneously localizing a group of mobile robots capable of sensing each other. Each of the robots collects sensor data regarding its own motion and shares this information with the rest of the team during the update cycles. A single estimator, in the form of a Kalman filter, processes the available positioning information from all the members of the team and produces a pose estimate for each of them. The equations for this centralized estimator can be written in a decentralized form thus allowing this single Kalman filter to be decomposed into a number of smaller communicating filters, each of them processing local data for most of the time. The resulting decentralized estimation scheme constitutes a unique mean for fusing measurements collected from a variety of sensors with minimal communication and processing requirements. The distributed localization algorithm is applied to a group of 3 robots and the improvement in localization accuracy is presented. Finally, a comparison to the equivalent distributed information filter is provided.
Nanoscale flagellar-motor based MEMS biosensor for explosive detection

Detection of explosive compounds has taken on a new degree of importance since 9/11 due to heightened terrorist threats. The primary goal of the current study was to design, fabricate, and test a flagellar-motor based biosensor that will provide sensitive, fast, and portable trace level detection of nitroaromatic and organic nitrate explosives, including trinitrotoluene (TNT), one of the most used explosive materials. The flagellar-motor based sensing system (FMS) integrates Escherichia coli flagellar motors with a microfluidic system to detect the presence of explosives by monitoring the rotational behavior of the flagellar filaments. The operational principle of the FMS is based on sensing the chemo-tactic responses of the nanoscale flagellar filament in the presence of nitrate or nitrite, which are the key components of explosive compounds. Our results indicated that the FMS is as sensitive as existing sensors for explosives, including the conventional electrochemical and the more portable biological based. The threshold concentrations for detection were around 50 pg of nitrate and 250 pg of nitrite on the basis of the dimension of the MEMS-based reaction system used for this study (200 mum times 50 mum times 50 mum). Using a smaller channel size can lower these low detection limits even further. Additionally, the response time of the flagellar motor biosensor is almost instantaneous due to the fast chemo-tactic response of flagellar motors to external stimuli.
A new technique for avoiding barotrauma-induced complications in apnea testing for brain death

Prompted by our experience with complications occurring with apnea testing (AT), we discuss complications reported in the literature. AT is an integral part of brain death assessment. Many complications of AT have been described, including hypoxemia, arterial hypotension, tension pneumothorax and cardiac arrest. We conclude that a commonly used technique in conducting AT can create auto-positive end expiratory pressure (PEEP) and contributes to many complications. The mechanism of occult auto-PEEP in AT is discussed. Intensive care unit patients may have a compensated and asymptomatic relative hypovolemia that can be decompensated by a small amount of auto-PEEP produced by air trapping during insufflating oxygen (O2) through a 7.0 endotracheal tube (ETT). It could then lead to decreased preload, decreased stroke volume, decreased cardiac output and thus, to hypotension and a compensatory tachycardia. The placement of the standard O2 tubing (6 mm outside diameter [OD]) inside the 7.0 ETT (7 mm inside diameter [ID]) greatly decreased the ETT lumen (73%). We changed our practice to instead use readily available small pressure tubing to insufflate O2 for AT to avoid excessive reduction in the ETT lumen. The change from standard O2 tubing (6 mm OD) to pressure tubing (3 mm OD) will greatly decrease the reduction in cross-sectional area of 7.0 ETT lumen from 73 to 18% and avoid potential complications of air trapping, auto-PEEP and barotrauma. We have successfully used this new simple technique with readily available equipment to eliminate auto-PEEP in AT while preserving oxygenation.
Lesions in Phycoerythrin Chromophore Biosynthesis in Fremyella diplosiphon Reveal Coordinated Light Regulation of Apoprotein and Pigment Biosynthetic Enzyme Gene Expression

We have characterized the regulation of the expression of the pebAB operon, which encodes the enzymes required for phycoerythrobilin synthesis in the filamentous cyanobacterium Fremyella diplosiphon. The expression of the pebAB operon was found to be regulated during complementary chromatic adaptation, the system that controls the light responsiveness of genes that encode several light-harvesting proteins in F. diplosiphon. Our analyses of pebA mutants demonstrated that although the levels of phycoerythrin and its associated linker proteins decreased in the absence of phycoerythrobilin, there was no significant modulation of the expression of pebAB and the genes that encode phycoerythrin. Instead, regulation of the expression of these genes is coordinated at the level of RNA accumulation by the recently discovered activator CpeR.
Cultivating trees - an essay in APL2

General arrays and the each operator allow tree-structures to be modelled in ways which have not hitherto been possible in any programming language. There are many algorithms in mathematics associated with tree-structures, which suggests that a whole new collection of relevant idioms and techniques will evolve. This paper is intended to illustrate ways in which the concepts of APL2 match those which arise in studying trees. After an introductory overview addressed to those who are unfamiliar with the basic notions of general arrays the discussion is developed through a set of 6 problems, which appear between them to raise many of the more important considerations involved.
Oxygen radicals stimulate guinea pig gallbladder glycoprotein secretion in vitro

In several animal models of cholelithiasis, and in humans with gallstones, hypersecretion of gallbladder mucin is observed. This study was undertaken to determine the effect of oxygen radicals on guinea pig gallbladder glycoprotein secretion in organ culture. Mucosal explants were incubated with [3H]glucosamine hydrochloride to label glycoproteins, then exposed to oxygen radicals generated by chelated ferric iron and ascorbic acid. Marked stimulation of glycoprotein release was observed after a 30-min exposure to the oxygen radical-generating system, and the effect was inhibited by mannitol. The stimulatory effect of hydroxyl radical was not accompanied by leakage of intracellular lactate dehydrogenase. Parallel experiments with human granulocytes activated with f-Met-Leu-Phe and coincubated with gallbladder explants revealed similar results. These results indicate that oxygen radicals, especially the hydroxyl radical (OH.), are capable of stimulating rapid release of mucous-type glycoproteins from gallbladder epithelium.
Empirical model for μ scattering caused by field line curvature in a realistic magnetosphere

[1] The combination of magnetic field line curvature (FLC) and weak magnetic field strength affects charged particle motion in a magnetic field by causing changes of the particle's first adiabatic invariant, μ. In this paper we refer to these changes as FLC induced μ scattering or simply μ scattering. Both large single scatterings and the cumulative effects of many small scatterings (Δμ/μ ≪ 1) influence particle populations in the Earth's magnetosphere. Because FLC-induced μ scattering is strongly dependent on the magnetic field geometry and strength, realistic magnetospheric models must be employed in order to gain a quantitative understanding of how μ scattering affects the evolution of these populations. This requires a μ-scattering model that is accurate for many different magnetic field geometries. Though several μ-scattering models have been developed previously, we demonstrate that their accuracy is limited to the simple field geometries for which they were derived. In realistic magnetic fields, there are regions where these μ-scattering models depart from Lorentz integration results by a factor of 2 or greater. The source of these discrepancies is attributed to the fact that the only magnetic field information used is the field line curvature RC and magnetic field strength B both evaluated at a single point, the magnetic equator. To generalize the analytical representation of μ scattering to a range of magnetic field geometries, we have developed a new μ-scattering model that uses two additional parameters. These are proportional to the second derivatives of the field line curvature, ∂2RC/∂S2, and the field intensity, ∂2B /∂S2, where S is the distance along the field line and the derivatives are evaluated at the magnetic equator. We have defined an error parameter that measures the fit between the model and Lorentz integration results. Using this parameter, we show that the difference between our model Δμ values and those based on Lorentz integration is, on average, only 4%; this is at least a factor of 5 less than the difference using previous analytical models. Our new model will greatly facilitate quantitative analysis of μ scattering for realistic magnetospheric magnetic field geometries including active as well as quiet conditions.
Survival Benefit From Transplantation in Patients Listed for Heart Transplantation in the United States

Objectives The aim of this study was to assess the survival benefit from heart transplantation (HT), defined as reduction in the risks for 90-day and 1-year mortality on undergoing HT close to listing, in candidates stratified by their risk for waiting list mortality. Background Among patients listed for HT, those at higher risk for death without transplantation are also at higher risk for early post-transplantation mortality. Methods All patients age ≥18 years listed for HT in the United States from 2007 to 2010 were analyzed. A model was developed to predict the risk for waiting list mortality within 90 days, and listed patients were stratified into 10 risk groups (deciles). All groups were followed for 1 year to assess cumulative 1-year mortality while on the waiting list. Models of 90-day and 1-year post-transplantation mortality were developed using recipient data, and these risks were estimated at listing in all listed candidates. Results Of 10,159 patients listed for HT, 596 (5.9%) died within 90 days and 1,054 (10.4%) within 1 year without undergoing transplantation. Of 5,720 recipients of transplants with 1-year follow-up, 576 (10.1%) died within 1 year. The risk for death while on the waiting list within 90 days increased from 1.6% to 19% across the 10 risk groups. The survival benefit from HT increased progressively with higher risk for death without transplantation (p Conclusions The risk for waiting list mortality varies considerably among HT candidates. Although the survival benefit of HT generally increases with increasing risk for waiting list mortality, there is no measurable benefit in many candidates at the lower end of the risk spectrum.
Mechanics of contact and adhesion between viscoelastic spheres: An analysis of hysteresis during loading and unloading

Detailed finite element simulations are carried out to study the adhesive contact of viscoelastic spheres. The spheres are brought into contact by a compressive force that increases at a constant rate. Upon reaching a maximum load, the spheres are unloaded until they separate. We studied in detail the effect of loading and unloading rates on hysteresis and on the pull-off force for a standard viscoelastic solid. The surface interaction is modeled by the Dugdale–Barenblatt model. Numerical results are compared with analytical models for bonding and debonding, including a recent theory proposed by Johnson. There is excellent agreement between analytical and finite element results for the bonding phase. However, for the debonding phase, current analytical models break down unless the loading and unloading rates are slow in comparison with the material relaxation time. Based on the finite element results, a simple approximate analytical model is proposed to quantify adhesive contact in the debonding phase. We also examine the dependence of hysteresis on interfacial parameters such as the cohesive strength and the intrinsic work of adhesion. Our results show that viscoelastic adhesive contact depends on the details of the surface interaction and cannot be determined solely by the work of adhesion. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 772–793, 2002
Do quality improvement organizations improve the quality of hospital care for Medicare beneficiaries

ContextQuality improvement organizations (QIOs) are charged with improving the quality of medical care for Medicare beneficiaries.ObjectiveTo explore whether the quality of hospital care for Medicare beneficiaries improves more in hospitals that voluntarily participate with Medicare’s QIOs compared with nonparticipating hospitals.Design, Setting, and DataData from 4 QIOs charged with improving the quality of care in 5 states (Maryland, Nevada, New York, Utah, and Washington) and the District of Columbia were used. Hospitals participate with the QIOs on quality improvement on a voluntary basis. A retrospective study was conducted comparing improvement in the quality of care of patients in hospitals that actively participated with the QIOs vs hospitals that did not. The medical records of approximately 750 Medicare beneficiaries per state in each of 5 clinical areas (atrial fibrillation, acute myocardial infarction, heart failure, pneumonia, and stroke) were abstracted at baseline (1998) and follow-up (2000-2001).Main Outcome MeasureFifteen quality indicators associated with improved outcomes in the prevention or treatment of the 5 clinical areas were used as quality of care measures. These 15 indicators were specifically targeted by the QIOs for quality improvement during the study period.ResultsHospitals that voluntarily participate with the QIOs are more likely to be larger than nonparticipating hospitals (P<.05). At baseline, there were statistically significant (P<.05) differences between participating and nonparticipating hospitals on 5 of 15 quality indicators, with participating hospitals performing better on 3 of 5. There was no statistically significant difference in change from baseline to follow-up between participating and nonparticipating hospitals on 14 of 15 quality indicators. The one exception was that participating hospitals improved more on the pneumonia immunization indicator than nonparticipating hospitals (P = .005).ConclusionHospitals that participate with the QIO program are not more likely to show improvement on quality indicators than hospitals that do not participate.
Comorbidity: Implications for the Importance of Primary Care in ‘Case’ Management

BACKGROUND Although comorbidity is very common in the population, little is known about the types of health service that are used by people with comorbid conditions. METHODS Data from claims on the nonelderly were classified by diagnosis and extent of comorbidity, using a case-mix measure known as the Johns Hopkins Adjusted Clinical Groups, to study variation in extent of comorbidity and resource utilization. Visits of patients (adults and children) with 11 conditions were classified as to whether they were to primary care physicians or to other specialists, and whether they involved the chosen condition or other conditions. RESULTS Comorbidity varied within each diagnosis; resource use depended on the degree of comorbidity rather than the diagnosis. When stratified by degree of comorbidity, the number of visits for comorbid conditions exceeded the number of visits for the index condition in almost all comorbidity groups and for visits to both primary care physicians and to specialists. The number of visits to primary care physicians for both the index condition and for comorbid conditions almost invariably exceeded the number of visits to specialists. These patterns differed only for uncommon conditions in which specialists played a greater role in the care of the condition, but not for comorbid conditions. CONCLUSIONS In view of the high degree of comorbidity, even in a nonelderly population, single-disease management does not appear promising as a strategy to care for patients. In contrast, the burden is on primary care physicians to provide the majority of care, not only for the target condition but for other conditions. Thus, management in the context of ongoing primary care and oriented more toward patients’ overall health care needs appears to be a more promising strategy than care oriented to individual diseases. New paradigms of care that acknowledge actual patterns of comorbidities as well as the need for close coordination between generalists and specialists require support.
Collaborative Learning and Interinstitutional Partnerships: An Opportunity for Integrative Fieldwork in Geography

Abstract This article explores the contemporary function and value of field-oriented geography experiences for university-level students. The article details the design and delivery of an interinstitutional field course that partnered faculty and students—both graduate and undergraduate—from two geography programs with different curricular and research emphases. The article examines key aspects of the field course including strategies for obtaining and analyzing field data from both physical and human aspects of the discipline, the application and limitation of distance technologies within the context of field research, and the challenges and opportunities associated with field course experiences.
Shale gas-to-syngas chemical looping process for stable shale gas conversion to high purity syngas with a H2 : CO ratio of 2 : 1

The shale gas-to-syngas (STS) chemical looping process was conceived by Fan and associates in 2013 for the production of high-purity syngas from shale gas. The STS process producing syngas does not require the use of molecular oxygen from air separation and steam. This paper describes the rationale for the process concept with experimental data that substantiates the process validity. Specifically, the STS process consists of a co-current gas (shale gas)–solid (metal oxides) moving bed contact mode reducer operation with metal oxides for shale gas conversion to syngas. The reduced metal oxides from the reducer operation are regenerated via an oxidation operation with air. Various active metal oxides or metal oxide composites can be utilized. However, it is through the combination of desired metal oxides and co-current moving bed reducer that high syngas purity and a desirable H2 : CO molar ratio of ∼2 : 1 can be achieved. In this study, active iron–titanium composite metal oxide (ITCMO) materials are used as the oxygen carrier for the demonstration of the STS process. The desirable thermodynamic property of ITCMO is a key factor for the generation of high quality syngas. The co-current moving bed provides a desirable gas–solid contacting pattern that minimizes carbon deposition and maximizes the syngas yield. The syngas produced by the STS process can achieve a H2 : CO molar ratio of ∼2 : 1 with little CO2, CH4 and steam, which is required for downstream processes to produce liquid fuels and chemicals. The experimental results for reaction kinetics including oxygen carrier recyclability and pressure effects are obtained by thermogravimetric analysis (TGA), and syngas generation using a fixed bed, a bench-scale moving bed, and a sub-pilot scale moving bed reactor demonstrations are achieved in this study. The bench and sub-pilot demonstrations confirm that the syngas produced by the STS process is close to thermodynamic equilibrium with the reduced ITCMO. Furthermore, simulation studies are conducted to compare the efficiency of the STS process with a conventional autothermal natural gas reforming process.