cssi/SciSciGPT-SciSciNet huggingface dataset:
Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Venous thromboembolism (VTE) is a potential sequela of injury, surgery, and critical illness. Patients in the Trauma Intensive Care Unit are at risk for this condition, prompting daily discussions during patient care rounds and routine use of mechanical and/or pharmacologic prophylaxis measures. While VTE rightfully garners much attention in clinical patient care and in the medical literature, optimal strategies for VTE prevention are still evolving. Furthermore, trauma and surgical patients often have real or perceived contraindications to prophylaxis that affect the timing of preventive measures and the consistency with which they can be applied. In this Clinical Consensus Document, the American Association for the Surgery of Trauma Critical Care Committee addresses several practical clinical questions pertaining to specific or unique aspects of VTE prophylaxis in critically ill and injured patients.
Sweating the big stuff: Arousal and stress as functions of self-uncertainty and identification.

Groups serve a variety of crucial functions, one of which is the provision of an identity and belief system that impart self-referent information, thereby reducing self-uncertainty. Entitative groups are more attractive for highly uncertain participants seeking groups for identification and self-uncertainty reduction than less entitative groups. The purpose of the current study was to explore how self-uncertainty impacts physiological arousal and stress responses. Using a mixed-methods design (N = 123), we found that self-uncertainty increased physiological arousal (measured via skin-conductance level) and stress responses (measured via heart rate). Furthermore, we found that uncertainty-activated physiological arousal and stress responses were decreased through identification with a high entitativity group. Our findings expand upon uncertainty identity theory by identifying physiological mechanisms that motivate uncertainty reduction.
Gene Expression Profiling in Liver of Mice Fed a High-Fat Diet Supplemented With Watermelon Flesh, Arginine, or Citrulline Shows Similar Pattern Changes

Objectives Watermelon is a nutrient-dense fruit known to contain high levels or arginine and citrulline; these two compounds may influence the nitric oxide pathway, vasodilation, and thus be hypotensive. We tested the hypothesis that when C57BL/6J male mice fed a high-fat diet (HF) had additions to the HF diet of either watermelon flesh (WF), arginine (ARG) or citrulline (CIT), changes in gene expression patterns would occur vs. those seen in HF. Further, we hypothesize that patterns of expression seen in WF, ARG, and CIT groups would be somewhat similar based on increased dietary levels of ARG and CIT in all three groups.
“De son sol et de son climat:” National Sport and Landscape in Roland Barthes

This essay considers Barthes’ notion of a national sport as an activity that emerges naturally from a country’s soil and climate, as explored in his essay from Mythologies, “Le Tour de France comme...
Observation of zero-degree pulse propagation in a resonant medium.

Experiments have recently been described[1] in which zero-degree optical pulses[2–5] have been generated and propagated through a resonantly absorbing medium with reduced absorption loss. We briefly review this experiment here and discuss the conditions for low loss propagation. We also describe some initial studies of the evolution of the pulse envelope and discuss the physics underlying this process.
Reciprocity in Chiral Recognition : Comparison of several chiral stationary phases

Abstract Several homologous series of N-acyl 1-(2-fluorenyl)-1-aminoalkanes are used to compare the perforances of chiral stationary phases (CSPs) derived from the N-3,5-dinitrobenzoyl derivaties of phenylglycine, leucine, valine, alanine and phenylalanine. The dependence of selectivity and elution order upon the structures of both analytes and CSPs supports the inference that, just as in the reciprocal situation, competing opposite-sense chiral recognition processes occur. Insight into the relationship between structure and chromatographic behavior in this analyte—CSP manifold is of practical utility, for it aids in the selection of a CSP appropriate for a given separation.
ORGANIZED MARKETS IN PRE-INDUSTRIAL EUROPE*

Pre-industrial Europe was served by a network of market centers— market towns, fairs, and commercial cities. Within these centers, there were organized markets that lowered the cost of trading. An organized market provided traders with information, facilities for trading, a system of settlement, and a process of dispute resolution (the law merchant). This paper examines how these markets worked, how they were regulated, and how they evolved to meet the changing needs of the economy.
Radiation inactivation analysis of oligomeric structure of the H,K-ATPase.

The oligomeric size of the H,K-ATPase was determined in frozen gastric microsomal vesicles irradiated with high energy electrons. Target sizes of various catalytic activities associated with H,K-ATPase function fell into two distinct groups. The lower group of target sizes described the radiation-induced loss of steady-state phosphoenzyme and structural monomer: the MgATP-dependent formation of a beta-aspartyl phosphate exhibited a size range of 133-147 kDa; the size range for the structural measurement (i.e. loss of H,K-ATPase monomer on sodium dodecyl sulfate-polyacrylamide gels) was 92-143 kDa. In contrast, a larger group of target sizes described the loss of full cycle catalytic activities (i.e. K+-dependent stimulation of p-nitrophenyl phosphate and ATP hydrolysis). The K+-phosphatase and K+-stimulated ATPase exhibited target sizes fo 200 +/- 13 and 232 +/- 23 kDa, respectively. The lower target size group represents the first evidence that a monomer of the catalytic subunit maintains partial enzyme function. The larger group of target sizes describing K+-phosphatase and ATPase activities suggest that subunit interactions contribute to full cycle catalytic activity. Subunit interactions appear to be involved in all ion transport activities. Passive Rb+ exchange and active H+ transport in reconstituted proteoliposomes exhibited target sizes of 233n = 2 and 388 +/- 48 kDa, respectively. H+ transport appears to require a subunit arrangement more complex than that associated with catalytic activity or passive ion transport.
Insights into volcanic conduit flow from an open‐source numerical model

[1] Numerical models that calculate the fluid dynamics of explosive volcanic eruptions have been used with increasing frequency to understand volcanic processes and evaluate volcanic hazards. Yet those who develop such models rarely make them publicly available so that they can be verified, used, and possibly improved by other scientists. In this paper I present a visual, interactive, open-source numerical model that calculates steady state flow of magma and gas in vertical eruptive conduits and contains user-friendly utilities for quickly determining physical, thermodynamic, and transport properties of silicate melts, H2O gases, and melt-gas-crystal mixtures. The model represents an advance over previously published conduit models by incorporating a non-Arrhenian viscosity relation for hydrous silicate melts, a relation between viscosity and volume fraction of gas that depends on Capillary number, and adiabatic temperature changes in the mixture using established thermodynamic relations for melts and H2O gas, respectively. Volcanologists who have not had access to conduit models have frequently approximated conduit flow using an analytical equation for incompressible, laminar, Newtonian pipe flow, which predicts that the mass flux is proportional to the fourth power of conduit radius and inversely proportional to mixture viscosity. The model presented here, which is not much more difficult to use than a back-of-the-envelope calculation, shows that the pipe-flow approximation significantly overestimates the sensitivity of mass flux to both conduit radius and mixture viscosity. Results from the model also show that viscous heating in the lower conduit, which is not considered in most other models, may increase the mass flux of large silicic eruptions by several percent and decrease the viscosity of the mixture at the fragmentation depth by a few tens of percent.
Observational evidence for global oscillations of the sun: A review

The results of many observations have been interpreted as evidence for global oscillations of the sun. The periods found in these analyses range from minutes to hundreds of years. The shorter period oscillations are usually interpreted as the normal modes proper whereas the longer period features may be manifestations of superpositions and/or nonlinear coupling of these normal modes. The work done to date in this broad area is reviewed.
Annual Research Review: Mental health and resilience in HIV/AIDS-affected children – a review of the literature and recommendations for future research

Background: To date research on mental health in HIV- affected children (children who have an HIV-positive caregiver or live with the virus themselves) has focused on risk factors associated with the disease. However simultaneous identification of factors that contribute to resilience in the face of risks is also needed. A greater understanding of modifiable protective processes that contribute to resilience in the mental health of children affected by HIV can inform the design of interventions that bolster naturally occurring supports and contribute to early prevention or better management of risks. Methods: We reviewed the recent literature on mental health and resilience in children and adolescents affected by HIV/AIDS. Literature searches of PsycInfo and PubMed were conducted during July-December 2011 consistent with Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) standards. Qualitative and quantitative studies were included for review if primary research questions pertained to mental health and coping or protective processes in children and families affected by HIV/AIDS. All studies subject to full review were evaluated for quality using a modified Systematic Assessment of Quality in Observational Research (SAQOR) rating system. Results: One hundred and seventy one unique studies were returned from online searches of the literature and bibliography mining. Of these 29 were evaluated as pertaining directly to mental health and resilience in families and children living with HIV/AIDS. Eight studies presented qualitative analyses. Ten quantitative studies examined individual resources contributing to child resilience and four quantitative studies looked at family-level resources. Ten studies also investigated community level interactions. Four presented findings from resilience-focused interventions. Conclusions: There is a clear need for rigorous research on mental health and resilience in HIV-affected children and adolescents. The evidence base would greatly benefit from more standardized and robust approaches to thinking about resilience from an ecological perspective inclusive of resources at multiple levels and their interactions.
A Short-Latency Labyrinthine Input to the Vestibular Nuclei in the Pigeon

Electrical stimulation of the pigeon labyrinth evokes responses in many second-order vestibular neurons with a latency shorter than the monosynaptic delay. These early responses are probably due to electrically mediated synaptic transmission, or perhaps to antidromic invasion of cells supplying efferent fibers to the labyrinth. In either case the results demonstrate a difference between cat and pigeon with respect to connections between labyrinth and vestibular nuclei.
An analysis of semantic stimulus factors in paired-associate learning

Summary Previous research has found the major stimulus characteristics related to difficulty of paired-associate learning to be meaningfulness, familiarity, and intralist similarity. In general, meaningfulness and familiarity have been shown to be inversely related to difficulty, while similarity is directly related. The present study employed a correlational design in order to examine the relationships between meaningfulness, familiarity, similarity, and several other semantic characteristics of stimuli, as well as their relation to difficulty. Thirty-two lists, consisting of six words each, were constructed from a basic pool of 32 common nouns. Measures of the difficulty, meaningfulness, and similarity of the lists were obtained experimentally, and published semantic-differential ratings were used to scale the lists on the remaining variables. The correlational analysis showed difficulty to be related to intralist stimulus similarity, but not to stimulus meaningfuness or familiarity. A factor analysis of the correlation matrix showed that both connotative and associative similarity are major factors in simple judged similarity, but that only associative similarity affects difficulty. Meaningfulness, to the extent that it is defined as intensity of meaning, had a negative relationship with difficulty. Familiarity, however, was not correlated with either difficulty or meaningfulness. Meaningfulness and similarity were found to be positively related.
Droplet size measurements in horizontal annular gas–liquid flow

Abstract Measurements of drop size distributions in air–water annular flow have been made in a horizontal 0.0953 m pipe, at atmospheric pressure. A laser diffraction technique has been employed, using a Malvern Spraytec R5008 instrument. Stratification of the droplets has been observed by obtaining measurements at the pipe centre line, and 0.019 m above and below it. The stratification, which is caused by the effects of gravitational settling and the asymmetry of the liquid film, decreases with increasing gas velocity. Measured Sauter mean diameters at the pipe centre are similar to what has been observed in vertical pipes. However, they show a stronger effect of liquid flow rate than predicted by the correlation of Azzopardi, that was developed from measurements made with an earlier diffraction technique that did not account for multiple scattering. A log-normal or an upper limit log-normal distribution underpredicts the measured contributions of small diameter drops.
Polymerisation and block copolymerisation of cyclic sulphides

The organolithium-initiated ring-opening polymerisation of cyclic sulphides in polar, aprotic solvents was investigated. It was found that at −78°C thiiranes are attacked at the sulphur atom by the carbanion of the organolithium. This reaction is followed by elimination of an olefin and formation of a lithium alkylthiolate. The polymerisation reaction then involves bimolecular nucleophilic displacement at a carbon atom of the monomer by the propagating thiolate. Similarly, the initiation of the thietanes takes place through reaction of the carbanion at the sulphur atom. This is followed by ring-opening and the formation of a new carbanion rather than the thiolate-lithium species. The homopolymerisation of thiiranes and thietanes is essentially free of termination and chain-transfer reactions. Thus, it is possible to prepare polythioethers of well-defined molecular characteristics. In addition, block polymers of poly-α-methylstyrene-poly(propylene sulphide)-poly-α-methylstyrene were synthesised using phosgene to couple the active lithium thiolate chain ends. Molecular weight measurements and gel permeation chromatograms indicate that block polymers were prepared possessing predictable molecular weights and narrow molecular weight distributions. Several other block polymers involving cyclic sulphides were also synthesised.
The ISPD2005 placement contest and benchmark suite

Without the MCNC and ISPD98 benchmarks, it would arguably not have been possible for the academic community to make consistent advances in physical design over the last decade. While still being used extensively in placement and floorplanning research, those benchmarks can no longer be considered representative of today's (and tomorrow's) physical design challenges. In order to drive physical design research over the next few years, a new benchmark suit is being released in conjunction with the ISPD2005 placement contest. These benchmarks are directly derived from industrial ASIC designs, with circuit sizes ranging from 210 thousand to 2.1 million placeable objects. Unlike the ISPD98 benchmarks, the physical structure of these designs is completely preserved, giving realistic challenging designs for today's placement tools. Hopefully, these benchmarks will help accelerate new physical design research in the placement, floor-planning, and routing.
Processing orientation — Fracture resistance relationships of V–5Cr–5Ti alloy

Abstract Vanadium alloys have been explored primarily for nuclear reactor applications. In the present study V–5Cr–5Ti was used as a candidate material to study the effect of rolling orientation on the fracture resistance of these alloys. Compact tension (1/2 T) specimens were prepared using Electrical Discharge Machining (EDM) from a vanadium block along the rolling A-direction and the perpendicular B-direction . The specimens were subjected to fatigue pre-cracking in order to introduce a sharp notch for the fracture resistance evaluation, according to ASTM standard E399. Three specimens were tested using an electromechanical materials testing system from each orientation. A value for the stress intensity factor K I was calculated based on the maximum load sustained by the specimens and found to be extremely consistent among the three tested specimens in each orientation. An average value of 65 MPa √m was obtained for the V–5Cr–5Ti along the rolling orientation. This value was only 56 MPa √m for the same material perpendicular to the rolling orientation. The rolling direction fracture displays ductile tearing features, plastic deformation, tearing ridges and pulled-up strips. On the other hand, the B-direction , displays cleavage facets, inter-granular secondary cracks and river patterns. These fracture surface morphologies correlate with the fracture resistance data.
Pressure inequalities in quantum statistics

Abstract It is shown that the respective pressures of an aggregate of noninteracting identical bosons or fermions at arbitrary finite temperature obey the inequality P B ⩽ P C ⩽ P F , where the subscript C denotes “classical”. The inequality is further shown to maintain at zero temperature through construction of the ground-state wavefunctions and energies of the respective gases confined to a spherical well of finite volume. It is further demonstrated that in the near classical-thermodynamic domain, v ( P F − P B )/ kT varies predominantly as λ 3 / v , where λ is thermal de Broglie wavelength and v is specific volume.
Heterogeneous diazo-transfer reaction: a facile unmasking of azide groups on amine-functionalized insoluble supports for solid-phase synthesis.

Solid-supported azides are commonly generated through direct nucleophilic displacement of appropriately activated supports by the azide ion. This reaction usually proceeds rather sluggishly under harsh conditions. Here, we report that triflyl azide rapidly reacts with a series of amine-functionalized solid supports to generate azide-coated supports under mild conditions. Further, we demonstrate that the “azide coat” allows facile loading of alkyne-functionalized leader nucleoside monomers by click chemistry. Finally, we show that the nucleoside-functionalized supports are suitable for solid-phase oligonucleotide synthetic applications. The approach herein described extends the scope of the amine−azide conversion reaction and may be adaptable for the introduction of azide to diverse amine-terminated solid supports that are not easily accessible by the conventional nucleophilic displacement method.
Effects of flight behaviour on body temperature and kinematics during inter‐male mate competition in the solitary desert bee Centris pallida

Body temperatures and kinematics are measured for male Centris pallida bees engaged in a variety of flight behaviours (hovering, patrolling, pursuit) at a nest aggregation site in the Sonoran Desert. The aim of the study is to test for evidence of thermoregulatory variation in convective heat loss and metabolic heat production and to assess the mechanisms of acceleration and forward flight in field conditions. Patrolling males have slightly (1-3 °C) cooler body temperatures than hoverers, despite similar wingbeat frequencies and larger body masses, suggesting that convective heat loss is likely to be greater during patrolling flight than during hovering. Comparisons of thorax and head temperature as a function of air temperature (T(a)) indicate that C. pallida males are thermoregulating the head by increasing heat transfer from the thorax to the head at cool T(a). During patrolling flight and hovering, wingbeat frequency significantly decreases as T(a) increases, indicating that variation in metabolic heat production contributes to thermal stability during these behaviours, as has been previously demonstrated for this species during flight in a metabolic chamber. However, wingbeat frequency during brief (1-2 s) pursuits is significantly higher than during other flight behaviours and independent of T(a). Unlike most other hovering insects, C. pallida males hover with extremely inclined stroke plane angles and nearly horizontal body angles, suggesting that its ability to vary flight speed depends on changes in wingbeat frequency and other kinematic mechanisms that are not yet described.
Purification and characterization of N-glycosylation mutant mouse and human P-glycoproteins expressed in Pichia pastoris cells.

Abstract P-glycoprotein confers multidrug resistance in mammalian cells and basic structure–function studies of it are germane to anti-cancer and anti-AIDS therapy. Pure, detergent-soluble mouse MDR3 and human MDR1 P-glycoproteins have recently been obtained in sufficient quantity for high-resolution structure analysis after expression in Pichia pastoris (N. Lerner-Marmarosh et al. (1999) J. Biol. Chem. 274, 34711–34718). The degree of glycosylation of these preparations was unknown, and was of relevance for crystallization studies. Therefore mutant proteins in which the N -glycosylation sites were eliminated (Asn → Gln in mouse MDR3 Pgp, Asn → Gln or Ala in human MDR1 Pgp) were expressed in P. pastoris and purified to homogeneity. Yields of mutant Pgp were the same as for parent wild-type proteins. Nucleotide-binding and catalytic (ATPase) characteristics were completely normal in the mutant proteins. Mass spectrometry indicated that mutant and wild-type proteins did not differ significantly in mass, demonstrating that the wild-type proteins contain no N -glycosylation.
Refined second-order reliability analysis☆

Abstract A refined second-order method is presented for structural reliability analysis. Exact and approximate reliability solutions are obtained for a circular shaft subject to random bending moments and a random torque. The comparison of the approximate results with exact ones shows that the first-order approximation is only applicable to the case where the failure surface is “far” from the origin, while the suggested second-order approximation yields quite accurate results even if the failure surface is “close” to the origin.
A New Humanized HLA Transgenic Mouse Model of Multiple Sclerosis Expressing Class II on Mouse CD4 T Cells

Among all the genetic factors associated with susceptibility to multiple sclerosis (MS), the strongest association has been seen with expression of certain major histocompatibility complex (MHC) class II molecules, although analysis of their exact function remains complicated. In general, the expression of class II is restricted to professional antigen-presenting cells; however, human but not mouse CD4+ T cells express class II on their surface. Functional studies of class II+ CD4+ T cells have been hampered due to lack of a proper animal model. Here, we describe development and characterization of a new humanized class II transgenic (tg) mouse expressing HLA-DR3 on mouse endogenous class II-negative background.
A gas chromatographic method for the determination of haloperidol in human plasma.

Abstract A gas chromatographic method for the qualitative and quantitative determination of haloperidol in plasma at therapeutic levels has been developed. The procedure involves extraction of the drug from alkalinized plasma into n-heptane, successive concentration into aqueous and organic solvents, and separation on a gas-liquid chromatograph equipped with an electron capture detector. The method has been applied to plasma samples from patients receiving 9 to 15 mg of haloperidol pro die. Plasma levels encountered after oral doses of 3 to 5 mg varied from zero to 10 ng of haloperidol per ml of plasma.
Pseudo-balanced signaling using power transmission lines for parallel links

Power integrity has become an indispensable part to ensure signal integrity in high-speed systems. Simultaneous switching noise (SSN) in the power delivery network (PDN) is now one of major factors to place the limit on the noise margin for off-chip communication so that a great emphasis is being placed on controlling SSN. A power transmission line (PTL) has been suggested as a new PDN design to achieve near-zero SSN. In this paper, a new signaling scheme is proposed to address the issues associated with the PTL, and yield a significant improvement in signal integrity.
Quantifying the cost in power of ignoring continuous covariate imbalances in clinical trial randomization

Motivated by potentially serious imbalances of continuous baseline covariates in clinical trials, we investigated the cost in statistical power of ignoring the balance of these covariates in treatment allocation design for a logistic regression model. Based on data from a clinical trial of acute ischemic stroke treatment, computer simulations were used to create scenarios varying from the best possible baseline covariate balance to the worst possible imbalance, with multiple balance levels between the two extremes. The likelihood of each scenario occurring under simple randomization was evaluated. The power of the main effect test for treatment was examined. Our simulation results show that the worst possible imbalance is highly unlikely, but it can still occur under simple random allocation. Also, power loss could be nontrivial if balancing distributions of important continuous covariates were ignored even if adjustment is made in the analysis for important covariates. This situation, although unlikely, is more serious for trials with a small sample size and for covariates with large influence on primary outcome. These results suggest that attempts should be made to balance known prognostic continuous covariates at the design phase of a clinical trial even when adjustment is planned for these covariates at the analysis.
Interview with Anne Kandler, Winner of the 2009 Gabriel W. Lasker Prize

An international jury composed of Mark Beaumont (United Kingdom), Lounes Chikhi (France, Portugal), Pierre Darlu (France), Mark Jobling (United Kingdom), and William Leonard (United States) has selected the article “Demography and Language Competition” (Human Biology 81:181–210 [2009]) by Anne Kandler as the best contribution to volume 81 (2009) of the journal. This review paper appeared in the special double issue “Demography and Cultural Macroevolution,” edited by guest editors James Steele (United Kingdom) and Stephen Shennan (United Kingdom). Anne Kandler is a Leverhulme Trust Early Career postdoctoral researcher based at the Centre for the Evolution of Cultural Diversity (University College, London). She received her Ph.D. in mathematics (stochastics) in 2006 from the University of Chemnitz (Germany) and currently works on models to explain cultural change. Kandler’s research interests are processes of cultural competition and selection of cultural traits, and the influences of demographic factors (such as population growth and dispersal) and social transmission biases on the outcomes of such processes. In particular, she studies models of language shift (Kandler 2009; Kandler and Steele 2008; Kandler et al. 2010); models of diffusion of innovations, such as the adoption of hybrid corn in the United States in the 20th century (Kandler and Steele 2009); and the relationship between cultural diversity, innovation rate, and transmission biases (Kandler and Laland 2009).
COMPLICATIONS OF HYSTERECTOMY

Hysterectomy is a popular operation that has a number of complications associated with it. The most common are hemorrhage, infection, and injuries to adjacent organs. Unintended major surgical procedures and second operations occur in approximately 4% of patients undergoing hysterectomy. Laparoscopic hysterectomy is a controversial new procedure that has both advocates and detractors. In skilled hands, the complication rate of laparoscopic hysterectomy does not exceed that of traditional hysterectomy methods. At the present time, there is a growing consensus that removal of the uterus only does not lead to an increase in psychosexual morbidity. It also appears that hysterectomy procedures have little, if any, effect on lower urinary tract function.
Phosphorylation of 3'-azido-2',3'-dideoxyuridine and preferential inhibition of human and simian immunodeficiency virus reverse transcriptases by its 5'-triphosphate.

Abstract 3'-Azido-2',3'-dideoxyuridine-5'-triphosphate was found to be a potent and highly selective inhibitor of human immunodeficiency virus type 1 and simian immunodeficiency virus reverse transcriptases. The affinity of 3'-azido-2',3'-dideoxyuridine-5'-triphosphate for the reverse transcriptases was similar to that observed for 3'-azido-3'-deoxythymidine-5'-triphosphate. Both compounds were competitive inhibitors with respect to the normal substrate dTTP and served at least 100 times better as substrates than did dTTP. In contrast, cellular DNA polymerase alpha showed an about 60-times-higher preference for dTTP as substrate than for either inhibitor. The phosphorylation of thymidine in human peripheral blood mononuclear cell extracts was inhibited in a competitive manner by both 3'-azido-2',3'-dideoxyuridine and 3'-azido-3'-deoxythymidine, with apparent inhibition constants of 290 and 3.4 microM, respectively. The Michaelis-Menten constant, Km, for thymidine was 7.0 microM. 3'-Azido-2',3'-dideoxyuridine and 3'-azido-3'-deoxythymidine both served as substrates, with apparent Km values of 67 and 1.4 microM, respectively. The maximal rates of phosphorylation with 3'-azido-2',3'-dideoxyuridine and 3'-azido-3'-deoxythymidine were 40 and 30%, respectively, of the rate with thymidine. The different affinities of 3'-azido-2',3'-dideoxyuridine and 3'-azido-3'-deoxythymidine for the thymidine kinase and the Km values observed with these compounds as substrates may explain the difference in effects on human immunodeficiency virus type 1 replication in infected peripheral blood mononuclear cells observed when equimolar concentrations of the two compounds are compared.
Coherent Regeneration and the Role of Water Vapor and Shear in a Long-Lived Convective Episode

Abstract In a recent radar-based climatological study of warm-season precipitation over the continental United States, Carbone et al. found a high frequency of long-lived coherent rainfall episodes. Many of the events were of longer duration than normally associated with mesoscale convective complexes and exhibited phase speeds ∼10 m s−1 in excess of the phase speed associated with synoptic systems. The observations led to the speculation that cold pool dynamics and wavelike propagation mechanisms were responsible for the longevity of the systems. One of the long-lived episodes included in the statistics of the Carbone et al. study is described here. Occurring on 14–15 July 1998, the system lasted ∼50 h and traveled over 2800 km. At its peak intensity the system was a bow echo producing damaging wind, large hail, and local flash flooding. An interesting aspect of the event was an abrupt 90° turn in the storm's orientation and propagation vector midway through its life. The environmental factors that led t...
The effect of isokinetic exercise on the relationship between blood lactate and muscle fatigue.

Exercise velocity may be an important variable in determining the amount of blood lactate accumulation during isokinetic exercise. The purpose of this study was to measure the effects of velocity-specific isokinetic exercise on blood lactate, muscle fatigue index, and rating of perceived exertion and to examine the relationship between blood lactate and muscle fatigue index. Ten experienced recreational weight trainers, aged 20-40 years, took part in a repeated measures design consisting of three separate treatments (constant angular velocity at 30, 120, and 300 degrees/sec performed at maximal effort for 1 minute by the right knee flexors and extensors). Rating of perceived exertion, blood lactate, and muscle fatigue index were measured in response to each treatment. Rating of perceived exertion was equal across all three speeds. Muscle fatigue and blood lactate increased significantly as the velocity of exercise increased. There was also a positive correlation coefficient (r = .82, < or = 0.01) between muscle fatigue index and blood lactate. The data suggested that the magnitude of muscle fatigue index and blood lactate responses are strongly dependent on the velocity of movement utilized during maximal isokinetic exercise, and there is a relationship between muscle fatigue index and blood lactate.
Improvement of Pump Tubes for Gas Guns and Shock Tube Drivers

In a pump tube, a gas is mechanically compressed, producing very high pressures and sound speeds. The intensely heated gas produced in such a tube can be used to drive light gas guns and shock tubes. Three concepts are presented that have the potential to allow substantial reductions in the size and mass of the pump tube to be achieved. The first concept involves the use of one or more diaphragms in the pump tube, thus replacing a single compression process by multiple, successive compressions. The second concept involves a radical reduction in the length-to-diameter ratio of the pump tube and the pump tube piston. The third concept involves shock heating of the working gas by high explosives in a cyclindrical geometry reusable device. Preliminary design analyses are performed on all three concepts and they appear to be quite feasible. Reductions in the length and mass of the pump tube by factors up to about 11 and about 7, respectively, are predicted, relative to a benchmark conventional pump tube.
N-(4-hydroxyphenyl)retinamide (4-HPR) modulates GADD45 expression in radiosensitive bladder cancer cell lines.

Abstract We previously demonstrated that N-(4-hydroxyphenyl)retinamide (4-HPR) and gamma-irradiation, when used in combination, had a synergistic effect in inducing apoptosis in bladder cancer cells, suggesting that 4-HPR may increase radiosensitivity in bladder cancer cells. To unravel molecular correlates in this radiosensitizing effect of 4-HPR, we examined the baseline and 4-HPR-induced expression of GADD45 to elucidate possible mechanisms by which 4-HPR enhanced the effect of gamma-irradiation in three bladder cancer cell lines. To investigate the role of p53 in mediating the radiosensitizing effect of 4-HPR, we also examined mutations in exons 5–9 by using direct sequencing and the levels of p53 expression by using RT-PCR and Western blot, before and after treatment with 4-HPR in these bladder cancer cell lines. Two cell lines had low expression of GADD45, and a dose-dependent increase in GADD45 expression induced by 4-HPR was found in bladder cancer cell lines without p53 mutations in exons 5–9. A combination of gamma-irradiation and 4-HPR showed a significantly greater effect in enhancing GADD45 expression than either agent used alone. The results indicate that the combined treatment with 4-HPR and gamma-irradiation has a stronger effect on GADD45 expression than the treatment with either agent alone, which suggests that the two agents may have an additive/synergistic effect. However, a normal p53 function appears to be necessary for the dose-dependent induction of GADD45 by 4-HPR. Once our results are verified and replicated by other investigators, 4-HPR may have a potential clinical implication in effectively treating bladder cancer in combination with low-gamma-irradiation therapy.
Emerging research on the treatment and etiology of secondary or comorbid insomnia

Secondary insomnia is defined as difficulty initiating or maintaining sleep that occurs as a consequence of another primary medical or psychiatric disorder. This distinction from primary insomnia has been thought to be important from a diagnostic standpoint so that treatment for secondary insomnia can appropriately target the primary disorder. By convention, treating insomnia directly has only been recommended with primary insomnia. However, a number of recent studies of cognitive-behavioral treatment for a wide range of secondary insomnias have demonstrated that this approach is an effective treatment in this population. These results are not predicted by the traditional conceptualization of secondary insomnia. Results of epidemiological research also argue against viewing insomnia that is comorbid with another disorder as being caused by that disorder. A revised model is needed to understand insomnia that is comorbid with medical and/or psychiatric illness, in addition to re-evaluating standard treatment protocols for comorbid insomnia.
Late recurrence of gestational trophoblastic disease

Persistent normal human chorionic gonadotrophin (hCG) levels for a period of 1 year after treatment is considered to be a reliable criterion of complete and sustained remission in patients with gestational trophoblastic disease. This is because such patients rarely require further therapy. Two patients are presented who developed recurrent disease after being in remission for 18 and 21 months. One of the patients initially had metastatic disease in the lungs; the other had tumor in the lungs and brain. Both of the patients have remained clinically free of disease after retreatment; one patient for 31 months and the other patient for more than 4 years. The management of the patients is presented with an emphasis on the requirement for long-term surveillance. Possible mechanisms to account for the reactivation of disease after a prolonged latency period are considered.
Impact of agroecosystems on groundwater resources in the Central High Plains, USA

Abstract Agroecosystems impact water resources by consuming most fresh water through irrigation and by changing water partitioning at the land surface. The study assesses impacts of agroecosystems on groundwater resources in the Texas Central High Plains (37,000 km 2 area) by evaluating temporal variations in groundwater storage and quality. Percolation/recharge rates were estimated using groundwater Cl data and using unsaturated zone matric potential and water-extractable chloride and nitrate from 33 boreholes beneath different agroecosystems. Total groundwater storage decreased by 57 km 3 since the 1950s when irrigation began and individual well hydrographs had declines ≤1.3 m/yr. The renewable portion of groundwater is controlled by percolation/recharge, which is related to soil texture and land use. In fine–medium (f–m) grained soils, there is no recharge beneath natural ecosystems or rain-fed agroecosystems; however, recharge is focused beneath playas and drainages. In medium–coarse (m–c) grained soils, percolation/recharge is low (median 4.8 mm/yr) beneath natural ecosystems and is moderate (median 27 mm/yr) beneath rain-fed agroecosystems. Although irrigation increased percolation under all soil types (median 37 mm/yr), irrigation return flow has not recharged the aquifer in most areas because of deep water tables. Groundwater depletion (21 km 3 over 52 yr) is 10 times greater than recharge (11 mm/yr; 2.1 km 3 ) where water table declines are greatest (≥30 m). Therefore, current irrigation practices are not sustainable and constitute mining of the aquifer, which is being managed as a nonrenewable resource.
Weather Index Insurance and Climate Change: Opportunities and Challenges in Lower Income Countries

Weather index insurance underwrites a weather risk, typically highly correlated with agricultural production losses, as a proxy for economic loss and is gaining popularity in lower income countries. This instrument, although subject to basis risk and high start-up costs, should reduce costs over traditional agricultural insurance. Multilateral institutions have suggested that weather index insurance could enhance the ability of stakeholders in lower income countries to adapt to climate change. While weather index insurance could have several benefits in this context (e.g. providing a safety net to vulnerable households and price signals regarding the weather risk), climate change impacts increase the price of insurance due to increasing weather risk. Uncertainty about the extent of regional impacts compounds pricing difficulties. Policy recommendations for insurance market development include funding risk assessments, start-up costs and the extreme layer of risk. General premium subsidies are cautioned against as they may actually slow household adaptation.
Detection of coronary artery calcium by ultrafast computed tomography and its relation to clinical evidence of coronary artery disease

Ultrafast computed tomography (CT) was used to evaluate the relation of coronary artery calcium, a marker of atherosclerosis, with a reported history of coronary artery disease (CAD) in 928 men and 290 women (mean age 53 +/- 10 years; 11% with previous CAD). Total calcium score was calculated as the sum of each lesion-specific score, calculated as the product of pixel area and density > 130 Hounsfeld units. Total score was 3 to 6 times greater (p < 0.01) and the probability of coronary artery calcium 30 to 40% greater (p < 0.01) in patients with a reported history of myocardial infarction, positive angiography, bypass surgery or angioplasty. From score cutoffs ranging from 1 to 500 for defining calcium, a negative test was accurate 93 to 98% of the time in ruling out CAD, whereas specificity increased from 43 to 93%; however, sensitivity decreased from 92 to 42%. A score cutoff of 50 showed modest sensitivity (78%) and specificity (71%); however, the predictive value for CAD from a positive test remained low (< or = 40%), regardless of score cutoff. From multiple logistic regression, total score was also an independent indicator of CAD after considering any effects due to age, sex and other CAD risk factors. Further study is needed to document the long-term prognostic use of coronary calcium screening, including criteria that best project future risk of CAD.
Spatial Frequencies from Human Periosteum at Different Depths using Two-Photon Microscopic Images

The outer layer of human bone, the periosteum, was studied using two-photon (2P) fluorescence microscopy. This layer of the periosteum is composed mostly of fibrous collagen. The inner cambium layer has less collagen and contains osteoblasts necessary for bone remodeling. The spatial frequencies from the layers of the periosteum of human bone at different depths were investigated using images acquired with two-photon excitation microscopy. This 2P spectroscopic method offers deeper depth penetration into samples, high fluorescence collection efficiency, and a reduction in photobleaching and photodamage. Using 130 femtosecond pulses with an 800 nm wavelength excitation, a 40× microscope objective, and a photomultiplier tube (PMT) detector, high contrast images of the collagen present in the periosteum at various micrometers depths from the surface were obtained. Fourier transform analysis of the 2P images was used to assess the structure of the periosteum at different depths in terms of spatial frequencies. The spatial frequency spectra from the outer and inner periosteal regions show significant spectral peak differences which can provide information on the structure of the layers of the periosteum. One may be able to use spatial frequency spectra for optical detection of abnormalities of the periosteum which can occur in disease.
No Job Too Small: Justice Without Bargaining in the lower Criminal Courts

Plea bargaining and other informal disposition devices dominate case processing in the lower criminal courts. Consistently, studies have found such courts characterized by assembly-line procedures, deemphasis or disregard of formal due process rights, and guilty plea rates approaching 100% of all convictions. Caseload pressures, tendencies toward cooperation among courtroom participants and, above all, process costs of litigation that greatly outweigh the stakes in minor cases are widely thought to render informality and high guilty plea rates inevitable. The study reported here challenges these assumptions. The author finds that in Philadelphia roughly one-fifth of all misdemeanor dispositions and one-half of all determinations of guilt are the result of genuine adversarial trials. He shows that an adversarial trial system need not impose prohibitive resource costs, even when extended to misdemeanor cases involving little likelihood of imprisonment, and that process costs will not deter defendants from invoking formal procedures when the court culture is committed to providing trials. Finally, the author argues that even routine misdemeanor cases benefit from guarantees of fairness and accuracy afforded by trial but unattainable when cases are processed by plea bargaining.
Sickle cell vaso-occlusive crisis is associated with abnormalities in the ratio of vasoconstrictor to vasodilator prostanoids.

Plasma levels of 6-keto-prostaglandin F 1α (6kPGF 1α ) and thromboxane (Tx) B 2 have been assessed in sickle cell disease (SCD) with discrepant results. Inasmuch as direct measurement of plasma prostanoids is fraught with the problem of interfering substances, we assessed plasma 6kPGF 1α and TxB 2 levels in patients with SCD by RIA after extraction of eicosanoids and separation by HPLC. We demonstrate that the 6kPGF 1α and TxB 2 levels in children with SCD in steady state as well as in vaso-occlusive crisis (VOC) are significantly lower when compared with those from age-matched controls. The VOC plasma 6kPGF 1 and TxB 2 levels were, however, significantly elevated when compared with those from children in steady state. Changes similar to those noted with unpaired plasma samples were also observed when paired steady state and VOC plasmas from the same patients were assessed. The ratio of TxB 2 to 6kPGF 1α was, however, significantly elevated in patients with SCD in crisis when compared with eicosanoid ratios obtained during steady state. In an attempt to understand whether the abnormality in 6kPGF 1α was due to an impairment in endothelial cell prostacyclin-regenerating ability, we compared the ability of plasma from controls and children with SCD to activate arachidonic acid (AA) release and prostacyclin production by [ 14 C]AAprelabeled bovine aortic endothelial cells. Our results suggest that the decreased 6kPGF 1α levels in plasma from children with SCD was not due to an effect on substrate AA release but rather a modulatory effect of sickle plasma components on endothelial cell cyclooxygenase activity. Although a decreased production of prostacyclin has previously been suggested to play a role in the initiation and/or propagation of vaso-occlusion in SCD, our study demonstrates a relative increase during VOC of 6kPGF 1α levels over those observed in steady state. However, the rise in 6kPGF 1α is accompanied by an increase in levels of TxB 2 such that the ratio of TxB 2 to 6kPGF 1α is significantly increased during VOC. The imbalance in the production of vasoactive eicosanoids, TxA 2 and prostacyclin, could potentially play a role in the potentiation of VOC in patients with SCD.