cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficient temporal reasoning (extended abstract)

There has been much interest in decision procedures for testing satisfiability (or validity) of formulae in various systems of Temporal Logic. This is due to the potential applications of such decision procedures to mechanical reasoning about correctness of concurrent programs. We show that there exist Temporal Logics that are (i) decidable in polynomial time, and (ii) still useful in applications. One surprising corollary of our results is that the fragment of CTL (Computation Tree Logic) actually used by Emerson & Clarke [EC82] to synthesize concurrent programs from temporal specifications is decidable in polynomial time. Another is that the verification of many correctness properties of concurrent programs (such as in Owicki & Lamport [OL82]) can be efficiently automated. This demonstrates that many useful correctness properties can be expressed with a rather restricted syntax. Finally, our results provide insight into the relation between the structural (i.e., syntactic) complexity of temporal logics and the complexity of their decision problems.
Carrier-carrier interactions in GaAs investigated by femtosecond spectroscopy

We present systematic femtosecond pump-probe studies of the initial scattering and cooling processes of hot electrons in intrinsic, n-type, and p-type GaAs for carrier densities from 8 X 1015 to 1019 cm-3 excited at 2 eV. The role of electron- electron scattering in intra-(Gamma) -valley equilibrium, its dependence on the injected carrier density, and its influence on the amplitude and recovery rate of the initial absorption bleaching are established. For a low density (approximately 3 X 1016 cm-3), the electron-electron scattering is observed to be most efficient when all the electrons are in Bloch states with the same (large) kinetic energy. The importance and time scales of electron-hole and electron-plasmon interactions are also revealed.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
RADIATION-INDUCED GANCLIONEUROBLASTOMA AND NEURAL TUMORS

Radiation therapy induces thyroid neoplasia, but the frequency and nature of other tumors are incompletely defined in man. A7-year-old who presented with supraclavicular ganglioneuroblastoma had received gamma radiation for a cutaneous hemangioma in the same area during infancy. A review of institutional records of patients receiving moderate dose radiation therapy between 1938 and 1951 revealed an additional 4 cases of neural tumors (2 neurofibroma, 2 neurilemmoma) diagnosed 6–31 years (median: 25 years) following localized radiation therapy for enlarged tonsils (3) and keloid (1). The age at the time of radiation therapy ranged from 1–13 years (median: 4 years) and at the time of diagnosis 7–34 years (median: 30 years). The three with enlarged tonsils had received 750 rads, while the others had received unknown doses of “contact” gamma radiation. All tumors occurred within the radiation field, and no patient had a family history of congenital malformations or neurofibromatosis. We estimate that less than one such tumor should have occurred among the 5000 patients similarly irradiated. Our observations suggest a previously unreported etiologic relationship between moderate dose radiation therapy and neurogenic tumors with an extremely long latency period.
Orientation dynamics of main-chain liquid crystal polymers. 2. Structure and kinetics in a magnetic field

Influence d'un champ magnetique de 4,7 T sur les spectres RMN du proton avec transformation de Fourier
Settlement of inhomogeneous consolidating soils; I, The single-drained layer under confined compression

The settlement and excess pore pressure are calculated for a column of water-saturated clay in which the permeability and/or shear modulus vary with depth. Several fairly general laws of variation are investigated. In each case, the soil is assumed to have a permeable top surface and to rest on an impervious substrate. For all the variations examined, in which the shear modulus increases with depth below the surface but the permeability of the soil remains constant, the deflection at a given instant after imposition of the load decreases and the degree of settlement increases with increasing rate at which the change with depth takes place. It is found that, when the variation over the height of the column is one order of magnitude or less, the curve of degree-of-consolidation versus time is reasonably wellapproximated by the curve for a homogeneous soil whose modulus equals the depth-averaged value. When, in addition, the permeability decreases with depth, the approximation becomes less accurate. The same approximation, for moderate increase in shear modulus with depth, predicts satisfactorily the process of dissipation of excess pore pressure at a given depth, but breaks down when the variation in modulus is large. Finally, it is shown that the effect of variable modulus on the settlement is greater than of a comparable variation in permeability.
Inactivation and injury of Listeria monocytogenes as affected by heating and freezing

Abstract The effects of heating and freezing Listeria monocytogenes in tryptose phosphate broth an inactivation and injury were investigate. Four strains (Scott A, Brie-1, LCDC 81–861, and DA-3) were examined. Only slight decreases in the viable populations pf all four strains were detected after 75 min at 50°C. Populations of strains Scott A, LCDC 81–861, and DA-3 were reduced to non-detectable levels after 10 min at 60°C while viable cells of strain Brie-1 were recovered after heating at 60°C for 30 min. Viable populations of all four strains declined steadily at 52,54, and 56°C; similar inactivation rates were observed for strains Scott A, LcDC 81–861, and DA-3. Strain Brie-1 was consistently the most heat resistant. Substantial populations of viable cells of all strains heated at 52, 54, and 56°C were injured as evidenced by increased sensitivity to NaCl when plated on tryptose phosphate recover agar. Strain DA-3 was the most susceptible strain to sublethal heat injury. Viable populations of all four test strains were not appreciably reduced after 14 days at −18°C, although strain LCDC 81–861 lost viability at a more rapid rate at this temperature than did the other test strains. About 72, 82, 73, and 80% of Scott A, Brie-1, LCDC 81–861, and DA-3 cells, respectively, held at −18°C for 14 days were not receovered on tryptose phosphate agar (TPA) supplemented with 8% NaCl compared to populations recovered on TPA not supplemented with NaCl.
FAILURE OF AUSTRALIA ANTIBODY TO PREVENT POST-TRANSFUSION HEPATITIS

Abstract In a prospective study of 64 patients who received multiple transfusions at the time of open-heart surgery, the presence in the serum of Australia antibody was studied in relation to the development of post-transfusion hepatitis. Australia antibody developed in 2 of 32 patients with hepatitis and in 4 or 32 patients without hepatitis. Australia antigen was found in 4 of the patients with hepatitis but was not detected in those without hepatitis. The coexistence of both Australia antigen and Australia antibody was not demonstrated in any patient. In 2 patients Australia antibody, which was shown to be present before the onset of post-transfusion hepatitis, did not prevent the disease. The occurrence of hepatitis in patients with antibody to the Australia antigen suggests that such antibody does not completely protect against hepatitis, or, alternatively, that the hepatitis was caused by an agent serologically distinct from Australia antigen.
Correlating Ultrafast Function with Structure in Single Crystals of the Photosynthetic Reaction Center

Femtosecond transient absorbance spectroscopy was applied to the study of primary electron transfer in single reaction center crystals from Rhodobacter sphaeroides. Polarized transient absorption spectra of individual crystals are shown to correlate with polarized ground-state absorption spectra and to track cofactor transition moment directions calculated from the crystallographic structure. Electron transfer from the bacteriochlorophyll dimer to the bacteriopheophytin acceptor was found to be multiphasic in crystals and ∼2-fold slower than in solution. This work demonstrates the ability to resolve ultrafast photosynthetic function in single crystals and allows ultrafast function to be directly correlated with structure.
Quantum dot lasers and integrated guided wave devices on Si

We have studied the growth and characteristics of self-organized InGaAs/GaAs quantum dot lasers and their monolithic integration with waveguides and quantum well electroabsorption modulators on Si. Utilizing multiple layers of InAs quantum dots as effective dislocation filters near the GaAs-Si interface, we have demonstrated high performance quantum dot lasers grown directly on Si that exhibit, for the first time, relatively low threshold current (J th = 900 A/cm 2 ), large characteristic temperature (T 0 = 278 K), and output slope efficiency ( g0.3 W/A). Focused-ion-beam milling has been used to form high-quality facets for the cavity mirror and coupling groove of an integrated laser/waveguide system on Si. We have also achieved a groove-coupled laser/modulator system on Si that exhibits a coupling coefficient greater than 20% and a modulation depth of ~ 100% at 5 V reverse bias.
Influence of GNSS Integrity Monitoring on Undetected Fault Probabilities for Single and Multiple Fault Events

Cases of multiple simultaneous faults are generally considered low probability in integrity analysis of GNSS augmentation systems. This assumption is not necessarily valid given the sensitivity limitations of practical integrity monitors. This paper introduces a method to account for monitor sensitivity in quantifying the probability that undetected faults occur. Analysis of the two-fault case suggests that the conventional method of designating a small integrity risk allocation to cover all multiple-fault events does not necessarily ensure integrity for difficult-to-detect, small, and moderate-sized faults.
Practical Applications of Thermophysical Property Measurements in Oil Shale Technology

Abstract The dependence of thermophysical properties such as thermal conductivity, thermal diffusivity, specific heat, and dielectric constant on organic content is discussed for oil shales of the Green River Formation. The applicability of thermophysical measurements for assaying and retort diagnostic purposes is also discussed in the light of methods that are currently in use in oil shale science and technology.
How (not) to study terrorism

This article disputes the premise dominant in moral philosophy and the social sciences that a strict definition of terrorism is needed in order to evaluate and confront contemporary political violence. It argues that a definition of terrorism is not only unhelpful, but also impossible if the historicity and flexibility of the concept are to be taken seriously. Failure to account for terrorism as a historical phenomenon produces serious analytical and epistemological problems that result in an anachronistic, ahistorical, and reductive understanding. Because there are no historically or contextually stable answers to the question what terrorism is, this article argues for a novel account of terrorism that replaces the attempt to define terrorism with an analysis of its meaning and function within a specific context.
Multi-channel input-queueing for high throughput switches

If input queued switches can be designed to maintain two or more separate queues per input line, with each queue associated with a subset of the output addresses, throughputs exceeding the well known limit of 58.6% due to head-of-line (HOL) blocking effects can be obtained. The switch complexity is only O(N), not O(N/sup 2/) as in some recent proposals. The author proposes three switching rules and presents simulation results which indicate that all three do better than the performance of a familiar theoretical baseline model.
Effects of GABA on acutely isolated neurons from the gustatory zone of the rat nucleus of the solitary tract.

Responses of acutely isolated neurons from the rostral nucleus of the solitary tract (rNST) to GABA receptor agonists and antagonists were investigated using whole-cell recording in current clamp mode. The isolated neurons retain their morphology and can be divided into multipolar, elongate and ovoid cell types. Most rNST neurons (97%), including all three cell types, respond to GABA with membrane hyperpolarization and a reduction in input resistance. The GABA A receptor agonist muscimol reduces neuronal input resistance in a concentration-dependent manner, whereas the GABA B receptor agonist baclofen had no effect on any of the neurons tested. The GABA and muscimol reversal potentials were both found to be -75 mV. Both the GABA competitive antagonist picrotoxin and the GABA A receptor antagonist bicuculline block the effect of GABA in a concentration-dependent manner. These results suggest that GABA activates all neurons in the rNST and that inhibitory synaptic activity is important in brainstem processing of gustatory and somatosensory information.
Analysis of Asymmetrical Gaits

Asymmetrical gaits (that is, gallops and bounds) have the footfalls of a pair of feet unevenly spaced in time. Such gaits were studied from slow motion film for 79 genera. All information about the timing of events at the ground can be expressed by five variables. Foot contact intervals range from 16 to 70 percent of the cycle. Fore and hind contacts are nearly equal for most ungulates and carnivores; fore contacts are the shorter for most rodents and rabbits. Fore contacts are proportionately shorter at higher speeds. The size of the fore lead is less than the hind for some apes; fore and hind leads are about equal for many carnivores and ungulates; fore leads are the longer for most mammals-particularly for smaller, more agile genera when moving fast. Actions of the forefeet as a pair are related to those of the hind feet by “midtime lag.” When this variable is plotted against the percentage duration of ground contact by one or both hind feet, a basic gait graph is derived on which are distinguished gaits with no suspensions, with a gathered suspension, an extended suspension, and both suspensions. The distribution of plots on the graph also correlates roughly with body size, maneuverability, and lead sequence (that is, transverse, rotary, half bound, or bound). A terminology of asymmetrical gaits is presented. The distribution on the graph of 104 identified footfall formulas is shown, and formulas characteristic of 55 genera are depicted. Asymmetrical gaits probably evolved, in amphibians and several times in reptiles, to benefit escape. Gaits with short leads or none, and an extended suspension are considered primitive. All lead sequences evolved early.
An Analytical Approach for Comparing Linearization Methods in EKF and UKF

The transformation of the mean and variance of a normally distributed random variable was considered through three different nonlinear functions: sin(x), cos(x), and xk, where k is a positive integer. The true mean and variance of the random variable after these transformations is theoretically derived within, and verified with respect to Monte Carlo experiments. These statistics are used as a reference in order to compare the accuracy of two different linearization techniques: analytical linearization used in the Extended Kalman Filter (EKF) and statistical linearization used in the Unscented Kalman Filter (UKF). This comparison demonstrated the advantage of using the unscented transformation in estimating the mean after transforming through each of the considered nonlinear functions. However, the variance estimation led to mixed results in terms of which linearization technique provided the best performance. As an additional analysis, the unscented transformation was evaluated with respect to its primary scaling parameter. A nonlinear filtering example is presented to demonstrate the usefulness of the theoretically derived results.
Deformable mesh algorithm for strain imaging with complex tissue deformation

This article introduces a framework for strain estimation using interpolated landmark displacement methods. Two implementations of this paradigm, namely, the block matching algorithm and the landmark displacement perturbation algorithm, are described. Results for experiments with phantoms and biological tissues are presented.
Differential public physically unclonable functions: architecture and applications

We have developed an ultra low power (well below 1 nano-joule per transaction), ultra high speed (less than 1 nanosecond), and low cost (a few hundred gates) public physically unclonable function (PPUF). We have also developed the first PPUF-based smart card (SC). We analyze and demonstrate the security of this new SC against several families of potential security attacks.
Rare temperature histories and cirrus ice number density in a parcel and a one-dimensional model

Abstract. A parcel and a one-dimensional model are used to investigate the temperature dependence of ice crystal number density. The number of ice crystals initially formed in a cold cirrus cloud is very sensitive to the nucleation mechanism and the detailed history of cooling rates during nucleation. A possible small spread in the homogeneous freezing threshold due to varying particle composition is identified as a sensitive nucleation parameter. In a parcel model, the slow growth rate of ice crystals at low temperatures inherently leads to a strong increase in ice number density at low temperatures. This temperature dependence is not observed. The model temperature dependence occurs for a wide range of assumptions and for either homogeneous or, less strongly, heterogeneous freezing. However, the parcel model also shows that random temperature fluctuations result in an extremely wide range of ice number densities. A one-dimensional model is used to show that the rare temperature trajectories resulting in the lowest number densities are disproportionately important. Low number density ice crystals sediment and influence a large volume of air. When such fall streaks are included, the ice number becomes less sensitive to the details of nucleation than it is in a parcel model. The one-dimensional simulations have a more realistic temperature dependence than the parcel mode. The one-dimensional model also produces layers with vertical dimensions of meters even if the temperature forcing has a much broader vertical wavelength. Unlike warm clouds, cirrus clouds are frequently surrounded by supersaturated air. Sedimentation through supersaturated air increases the importance of any process that produces small numbers of ice crystals. This paper emphasizes the relatively rare temperature trajectories that produce the fewest crystals. Other processes are heterogeneous nucleation, sedimentation from the very bottom of clouds, annealing of disordered to hexagonal ice, and entrainment.
Green's tensor and radiation patterns of point sources in general anisotropic inhomogeneous elastic media

SUMMARY i (Marshall McLuhan, 1958) The elastodynamic ‘ray-theoretical’ Green's tensor for general anisotropic and inhomogeneous media (GANIMED) is derived in the far-field high-frequency approximation. This allows the quantification of the amplitude and phase charac-teristics of arbitrary point sources. The displacement field is controlled by the phase velocity and the Gaussian curvature of the wave surface. Exploiting the already existing computer codes for dynamic ray tracing in GANIMED, we demonstrate how one may couple it to source theory in order to calculate displacement-radiation patterns for unipolar and dipolar sources in various earth crustal materials, such as shales, sandstones, and olivine. The existence of a velocity gradient at the source causes asymmetry in the radiation patterns. In contradistinction, anisotropy at the source tends to distort the lobes and in some cases can beam excessive energy in specific directions. Our calculated radiation patterns for shear waves are similar to those observed from some explosions in soil.
Neuroanatomic Overlap of Working Memory and Spatial Attention Networks: A Functional MRI Comparison within Subjects

Frontal and posterior parietal activations have been reported in numerous studies of working memory and visuospatial attention. To directly compare the brain regions engaged by these two cognitive functions, the same set of subjects consecutively participated in tasks of working memory and spatial attention while undergoing functional MRI (fMRI). The working memory task required the subject to maintain an on-line representation of foveally displayed letters against a background of distracters. The spatial attention task required the subject to shift visual attention covertly in response to a centrally presented directional cue. The spatial attention task had no working memory requirement, and the working memory task had no covert spatial attention requirement. Subjects' ability to maintain central fixation was confirmed outside the MRI scanner using infrared oculography. According to cognitive conjunction analysis, the set of activations common to both tasks included the intraparietal sulcus, ventral precentral sulcus, supplementary motor area, frontal eye fields, thalamus, cerebellum, left temporal neocortex, and right insula. Double-subtraction analyses yielded additional activations attributable to verbal working memory in premotor cortex, left inferior prefrontal cortex, right inferior parietal lobule, precuneus, and right cerebellum. Additional activations attributable to covert spatial attention included the occipitotemporal junction and extrastriate cortex. The use of two different tasks in the same set of subjects allowed us to provide an unequivocal demonstration that the neural networks subserving spatial attention and working memory intersect at several frontoparietal sites. These findings support the view that major cognitive domains are represented by partially overlapping large-scale neural networks. The presence of this overlap also suggests that spatial attention and working memory share common cognitive features related to the dynamic shifting of attentional resources.
Effective interprocedural resource leak detection

Garbage collection relieves programmers from the burden of explicit memory management. However, explicit management is still required for finite system resources, such as I/O streams, fonts, and database connections. Failure to release unneeded system resources results in resource leaks, which can lead to performance degradation and system crashes. In this paper, we present a new tool, Tracker, that performs static analysis to find resource leaks in Java programs. Tracker is an industrial-strength tool that is usable in an interactive setting: it works on millions of lines of code in a matter of minutes and it has a low false positive rate. We describe the design, implementation and evaluation of Tracker, focusing on the features that make the tool scalable and its output actionable by the user.
Toward a Perceptual Theory of Flow Visualization

Currently, most researchers in visualization pay very little attention to vision science. The exception is when the effective use of color is the subject. Little research in flow visualization includes a discussion of the related perceptual theory. Nor does it include an evaluation of effectiveness of the display techniques that are generated. This is so, despite Laidlaw's paper showing that such an evaluation is relatively straightforward. Of course, it's not always necessary to relate visualization research to perceptual theory. If the purpose of the research is to increase the efficiency of an algorithm, then the proper test is one of efficiency, not of perceptual validity. But when a new representation of data is the subject of research, addressing how perceptually effective it is - either by means of a straightforward empirical comparison with existing methods or analytically, relating the new mapping to perceptual theory - should be a matter of course. A strong interdisciplinary approach, including the disciplines of perception, design, and computer science will produce better science and better design in that empirically and theoretically validated visual display techniques will result.
Perceptions of discriminatory practices and attitudes : A survey of African American librarians

The perceptions of African American librarians regarding discriminatory practices and attitudes in the workplace and how they influence job satisfaction were the focus of this study. A descriptive survey, including a questionnaire, was used to observe both personal and observed experience of racial discrimination within the profession. Practicing librarians were surveyed for their observations of the situation as it stands today, as well as for their ideas and opinions on issues facing the African American librarian in the future. This study focused on relationships with supervisors, patrons, coworkers, and management.
Overweight and Perceived Health in Mexican American Children: A Pilot Study in a Central Texas Community

This study assessed actual and perceived health status of overweight Mexican American clients at a central Texas school-based health center in a predominately Hispanic school district. It also expl...
Functional Genomics of the Paraoxonase (PON1) Polymorphisms: Effects on Pesticide Sensitivity, Cardiovascular Disease, and Drug Metabolism

This review focuses on the functional genomics of the human paraoxonase (PON1) polymorphisms. Levels and genetic variability of the PON1 position 192 isoforms (Gln/Arg) influence sensitivity to specific insecticides or nerve agents and risk for cardiovascular disease. A more recent area of investigation, the role of PON1 in drug metabolism, is also discussed. We emphasize the importance of considering both PON1 isoforms and PON1 levels in disease/sensitivity association studies.
Close mimicry of lung surfactant protein B by “clicked” dimers of helical, cationic peptoids

A family of peptoid dimers developed to mimic SP-B is presented, where two amphipathic, cationic helices are linked by an achiral octameric chain. SP-B is a vital therapeutic protein in lung surfactant replacement therapy, but its large-scale isolation or chemical synthesis is impractical. Enhanced biomimicry of SP-B’s disulfide-bonded structure has been previously attempted via disulfide-mediated dimerization of SP-B1-25 and other peptide mimics, which improved surface activity relative to the monomers. Herein, the effects of disulfide- or ‘click’-mediated (1,3-dipolar cycloaddition) dimerization, as well as linker chemistry, on the lipid-associated surfactant activity of a peptoid monomer are described. Results revealed that the ‘clicked’ peptoid dimer enhanced in vitro surface activity in a DPPC:POPG:PA lipid film relative to its disulfide-bonded and monomeric counterparts in both surface balance and pulsating bubble surfactometry studies. On the pulsating bubble surfactometer, the film containing the ‘clicked’ peptoid dimer outperformed all presented peptoid monomers and dimers, and two SP-B derived peptides, attaining an adsorbed surface tension of 22 mN m −1 , and maximum and minimum cycling values of 42 mN m −1 and near-zero, respectively.
Unusually negative nitrogen isotopic compositions (δ 15 N) of mangroves and lichens in an oligotrophic, microbially-influenced ecosystem

Abstract. Extremes in δ15N values in mangrove tissues and lichens (range =+4 to −22‰) were measured from a mangrove forest ecosystem located on Twin Cays, offshore islands in Belize, Central America. The N isotopic compositions and concentrations of NH4+/NH3 in porewater, rainwater, and atmospheric ammonia, and the δ15N of lichens, mangrove leaves, roots, stems, and wood were examined to study the biogeochemical processes important for establishing these unusual N isotopic ratios. Dwarfed Rhizophora mangle trees had the most negative δ15N, whereas fringing Rhizophora trees, the most positive δ15N values. Porewater ammonium concentrations had little relationship to N isotopic fractionation in mangrove tissues. In dwarfed mangroves, the δ15N of fine and coarse roots were 6–9‰ more positive than leaf tissue from the same tree, indicating different sources of N for root and leaf tissues. When P was added to dwarfed mangrove trees without added N, δ15N increased within one year from −12‰ to −2‰, approaching the δ15N of porewater ammonium (δ15N=+4‰). Isotopically depleted ammonia in the atmosphere (δ15N=−19‰) and in rainwater (δ15N=−10‰) were found on Twin Cays. We propose that foliar uptake of these atmospheric sources by P-stressed, dwarfed mangrove trees and lichens can explain their very negative δ15N values. In environments where P is limiting for growth, uptake of atmospheric N by Rhizophora mangle may be an important adaptive strategy.
The Status Model of Racial Identity Development in African American Adolescents: Evidence of Structure, Trajectories, and Well‐Being

Although the identity formation model is widely used to assess adolescent ethnic identity development, the model propositions have rarely been tested. The existence of the identity statuses (diffuse, foreclosed, moratorium, achieved), the proposed developmental trajectories, and whether youth in the achieved status report higher levels of psychological well-being were examined among a longitudinal sample of 224 African American adolescents, aged 11-17. Cluster analyses were used to create 4 identity statuses consistent with the theoretical model at both time points. The findings indicate that some adolescents progressed, while others regressed or remained constant across time periods. Lastly, the results generally support the assumption that individuals in the achieved status had the highest levels of psychological well-being at both time periods.
On Anisotropic Mobility of Non-magnetic Microspheres in Ferrofluid

This article reports results demonstrating that inhomogeneities in the ferrofluid caused by the presence of tiny non-magnetic inclusions can change this behavior not only quantitatively, but qualitatively as well. The effect is studied here by observing Brownian motion of non-magnetic polystyrene microspheres confined to thin layers of ferrofluid (EMG 707, Ferrotech, 1% and 0.5% iron-oxide by volume) between two glass slides. Results show that microspheres' mobility decreased with the applied field significantly. However, the observed mobility of the non-magnetic microspheres is up to 20% lower in the field direction compared with the direction perpendicular to the field. which contradicts the macroscopic Poiseuille flow.
Infection after urogynecologic surgery with the use of dexamethasone for nausea prophylaxis

Abstract Study Objective To determine if a single perioperative dose of dexamethasone increases the risk of infection after urogynecologic surgery. Design Retrospective chart review (2004 - 2006) of patient records from the preoperative period to follow-up of 6 weeks from procedure. Setting University-affiliated tertiary-care hospital. Measurements The records of 574 ASA physical status 1, 2, and 3 women who had undergone urogynecologic surgery and who consented to have their information utilized for research were studied. The perioperative course of those who did and did not receive single-dose dexamethasone (4-8 mg) for postoperative nausea and vomiting prophylaxis was compared. Data collected included dexamethasone use, patient age, body mass index, ASA physical status, preexisting cardiovascular or respiratory disease, diabetes mellitus, type of surgery (vaginal vs abdominal), type of anesthesia (general vs regional, or combination), and duration of surgery. Postoperative infectious complications, including urinary tract infection (UTI), wound infection, other infections, and other complications, were noted. Main Results Univariate and multivariable analysis found no significant association between single-dose dexamethasone use and perioperative complications, including wound infection and UTI. There was an increased incidence of UTI with vaginal versus abdominal procedures, and longer duration of surgery. Conclusions There was no significant association between single-dose dexamethasone and perioperative infectious complications.
Conditions for mutation-order speciation.

Two models for speciation via selection have been proposed. In the well-known model of ‘ecological speciation’, divergent natural selection between environments drives the evolution of reproductive isolation. In a second ‘mutation-order’ model, different, incompatible mutations (alleles) fix in different populations adapting to the same selective pressure. How to demonstrate mutation-order speciation has been unclear, although it has been argued that it can be ruled out when gene flow occurs because the same, most advantageous allele will fix in all populations. However, quantitative examination of the interaction of factors influencing the likelihood of mutation-order speciation is lacking. We used simulation models to study how gene flow, hybrid incompatibility, selective advantage, timing of origination of new mutations and an initial period of allopatric differentiation affect population divergence via the mutation-order process. We find that at least some population divergence can occur under a reasonably wide range of conditions, even with moderate gene flow. However, strong divergence (e.g. fixation of different alleles in different populations) requires very low gene flow, and is promoted when (i) incompatible mutations have similar fitness advantages, (ii) less fit mutations arise slightly earlier in evolutionary time than more fit alternatives, and (iii) allopatric divergence occurs prior to secondary contact.
Load characteristics and control of a hybrid fuel cell / battery vehicle

The Polymer Electrolyte Membrane Fuel Cell (PEMFC) has been projected to be the fuel cell of choice for future automotive applications. Among the most challenging aspect of this application is the occurrence of severe and frequent changes in power demand. This paper will present a model aimed at mimicking the load expected in a fuel cell vehicle, including a DC motor, DC-DC converters and a rechargeable battery for peak-shaving and regenerative braking. The model also includes the kinematics of the vehicle (rotational and translational inertia as well as a simple wind resistance model), and thus can be connected to standardized drive cycle scenarios. In contrast to simple lab focused loads (resistive, constant current, constant voltage or constant power) where load impendence is directly manipulated, the manipulated variable within this load is the gain signal to the DC-DC converter. Based on this model we develop a control system architecture consisting of a number of low level regulatory loops, a power distributor for peak-shaving and finally a high level loop for tracking vehicle speed.
ANP and CNP activate CFTR expressed in Xenopus laevis oocytes by direct activation of PKA.

AbstractContext: Acting through different receptors, natriuretic peptides (atrial natriuretic peptide [ANP], brain type natriuretic peptide [BNP] and C-type natriuretic peptide [CNP]) increase intracellular cGMP, which then stimulates different pathways that activate fluid secretion. Objective: We used two-electrode voltage clamping to define the dominant pathway that is employed when natriuretic peptides activate cystic fibrosis transmembrane conductance regulator (CFTR) in the Xenopus oocyte expression system. Natriuretic peptides could activate CFTR by 1) cGMP cross-activation of protein kinase A (PKA), 2) cGMP activation of cGMP-dependent protein kinase II, 3) cGMP inhibition of phosphodiesterase type III (PDE3), or 4) direct activation of CFTR. Materials and Methods: cRNA-microinjected Xenopus laevis oocytes were perfused with diverse compounds that examined these pathways of natriuretic peptide signaling. Results and Discussion: ANP stimulated the shark CFTR (sCFTR)-mediated chloride conductance and...
Evidence for early fibrosis and increased airway resistance in bone marrow transplant recipient mice deficient in MMP12.

Idiopathic pneumonia syndrome (IPS) is a significant cause of morbidity and mortality post-bone marrow transplantation (BMT) in humans. In our established murine IPS model in which lethally conditi...
Spatial Competition and Ethanol Plant Location Decisions

Ethanol is one of the fastest growing industries in the United States. This study estimates factors that impact location decisions for new ethanol plants using logistic regression analysis and spatial correlation techniques. The results indicate that location decisions are impacted by county agricultural characteristics, competing ethanol plants, and state-level subsidies. Spatial competition is particularly important. Existence of competing ethanol plants reduces the likelihood of making a positive location decision, and this impact decreases with distance. Finally, state-level subsidies are significant and a very important variable impacting ethanol location decisions. [JEL Classification: C13, C21, C25, C35, Q42]
Cardiovascular Imaging for the Primary Prevention of Atherosclerotic Cardiovascular Disease Events

Traditional cardiovascular risk factors have well-known limitations for the accurate assessment of individual cardiovascular risk. Unlike risk factor-based scores which rely on probabilistic calculations derived from population-based studies, coronary artery calcium (CAC) scoring, and carotid ultrasound allow for the direct visualization and quantification of subclinical atherosclerosis with the potential for a more accurate, personalized risk assessment and treatment approach. Among strategies used to guide preventive management, CAC scoring has consistently and convincingly outperformed traditional risk factors for the prediction of adverse cardiovascular events. Moreover, several studies have demonstrated the potential of CAC testing to improve precision for the use of more intensive pharmacologic therapies, such as aspirin and statins, in patients most likely to derive benefit, as compared to atherosclerotic cardiovascular disease risk calculators. By comparison to CAC, the role of carotid ultrasound for the measurement of carotid intima-media thickness (CIMT) remains less well-elucidated but may be significantly improved with the inclusion of plaque screening and novel three-dimensional measurements of plaque volume and morphology. Despite significant evidence supporting the ability of non-invasive atherosclerosis imaging (particularly CAC) to guide preventive management, imaging remains an under-utilized strategy among current guidelines and clinical practice. Herein, we review evidence regarding CAC and carotid ultrasound for patient risk classification, with a comparison of these techniques to currently advocated traditional risk factor-based scores.
ENSO Simulated by Intermediate Coupled Models and Evaluated with Observations over 1970-98. Part II: Role of the Off-Equatorial Ocean and Meridional Winds

Introducing new parameterizations of subsurface temperature and atmospheric convection in the Cane and Zebiak model allows the reproducing of oscillations with a period close to 4 yr ; equatorial wind anomalies that are located close to the date line; and realistic amplitudes of SST, wind, and thermocline anomalies in the equatorial Pacific both in warm and cold phases. When the weight given to the atmospheric convection term is increased, the simulated wind maximum along the equator is displaced farther west, and the amplitude and duration of the warm events decrease. Compared to the simulations with the standard parameterization, the ENSO-like oscillations are not lost when the friction is increased with a decay time ranging from 30 to 12 months. Off-equatorial baroclinic ocean and wind anomalies are much less strong, but still necessary for the system to oscillate. Unrealistic easterlies are still present in the eastern Pacific. Replacing the atmospheric model by a statistical relationship between SST and wind stress anomalies allows further reducing of these deficiencies. The simulated ENSO-like events are in good agreement with observed oceanic and atmospheric fields in terms of amplitude and spatial patterns within 158 of the equator. Sensitivity tests to the statistics prescribed in the atmospheric component show that the model simulates warm events with duration and amplitude that increase with the eastern penetration of the westerlies in the central Pacific, whereas cold events do not last longer and easterlies remain located at the date line whatever their strength. After warm events, the model simulates a gain of heat content on average in the north, and similar features are found in
The Current State of Urological Residency Education

AbstractIntroduction: We reviewed literature pertaining to the current state of urological education for residents in the United States.Methods: A literature review was performed to identify relevant manuscripts using a key word search of the PubMed® and MEDLINE® databases. Central themes of the literature were identified and summarized for the purpose of this review.Results: A literature search identified 23 articles related to urological residency education. Key themes identified in the available literature included surgical simulation, decreasing open experience, and improving the efficiency and quality of resident education and evaluation. With increasing limitations in available resident training hours as well as increasing utilization of minimally invasive approaches in the field of urology it is important to critically assess how urological residents are trained.Conclusions: As the scope and complexity of medical knowledge and surgical approaches evolve in the field of urology it is imperative to c...
Massive panniculectomy in the super obese and super-super obese: retrospective comparison of primary closure versus partial open wound management.

Background The incidence of obesity is on the rise in the United States and worldwide. Complications following panniculectomy are higher for super obese patients, often requiring readmission and additional interventions. In this study, the authors compare the outcomes of patients who underwent primary closure of their resection wounds to the outcomes of patients who underwent initial open wound management with a negative-pressure dressing. Methods The records of all patients who underwent panniculectomy between 2007 and 2012 were reviewed. Of 14 patients with a body mass index greater than 50, nine underwent primary closure and five were treated with open wound management. A retrospective chart review was performed. Results There were no statistically significant differences in age or preoperative comorbidities, but body mass index was higher for the open wound management group (66.4 versus 58.9, p = 0.039). There were no statistically significant differences in mean operative time, resection weight, estimated blood loss, or hospital length of stay. The primary closure group had a 44 percent readmission rate and a 33 percent reoperation rate for wound complications. The open wound management group had no wound-related readmissions or secondary procedures for debridement. Conclusions Open wound management in the massive panniculectomy patient reduces hospital readmission and secondary operations. This case series provides reasons to support the consideration of open wound management following massive panniculectomy in the super morbidly obese patient population.
Two remarkable new African Russula species with reddening context

Two new Russula species having the rare combination of spores with isolated warts together with the typical habit and oxydation reactions of the Russula nigricans group are here described: Russula gossypina sp. nov. from Madagascar is described in Gossypinae sect. nov.; R. pseudolateriticola sp. nov., widespread in Zambian miombo woodlands, is described as a new member of sect. Compactae.
Courtship Feeding and Osprey Reproduction

A female Osprey (Pandion haliaetus) usually is fed exclusively by its mate be- tween pair formation and egg-laying. Laying dates and courtship periods--but not clutch size, egg size, breeding success, or female weight reserves--were correlated (negatively) with the prelaying feeding rates of 12 females breeding in a coastal Massachusetts colony. However, the age of a pair and of its bond influenced laying dates and courtship periods more than food intake. Older and more experienced pairs arrived earlier and laid eggs more quickly than younger pairs. As an independent test of food limitation in Ospreys producing eggs, supplemental food was provided to 4 nests during courtship. Supplemental food did not influence a female's reproductive output or timing, but males at nests receiving extra food showed reduced rates of foraging. Egg production boosted the daily energy expenditure of female Ospreys by only about 20% and females gained little weight during courtship, suggesting that egg-laying is not a demanding process in this species. Because age and mate retention had a greater effect on the reproductive output and timing of female Ospreys than rates of food consumption during courtship, and because there was evidence that poorly fed females were less willing to copulate and less faithful to their mates than well-fed females, it is argued that Osprey courtship feeding may function primarily to ensure mate fidelity. Received 9 January 1984, accepted 20 November 1984.
Myxedema Coma: Diagnosis and Treatment

Myxedema coma, the extreme manifestation of hypothyroidism, is an uncommon but potentially lethal condition. Patients with hypothyroidism may exhibit a number of physiologic alterations to compensate for the lack of thyroid hormone. If these homeostatic mechanisms are overwhelmed by factors such as infection, the patient may decompensate into myxedema coma. Patients with hypothyroidism typically have a history of fatigue, weight gain, constipation and cold intolerance. Physicians should include hypothyroidism in the differential diagnosis of every patient with hyponatremia. Patients with suspected myxedema coma should be admitted to an intensive care unit for vigorous pulmonary and cardiovascular support. Most authorities recommend treatment with intravenous levothyroxine (T4) as opposed to intravenous liothyronine (T3). Hydrocortisone should be administered until coexisting adrenal insufficiency is ruled out. Family physicians are in an important position to prevent myxedema coma by maintaining a high level of suspicion for hypothyroidism.
Radiation-induced pyrolysis of solid fuels for ramjet application

Abstract A wide variety of hydroxyl-terminated polybutadiene (HTPB) based fuels are experimentally assessed in anaerobic reaction. In this study HTPB pyrolysis is investigated using a CO 2 laser as the energy source. The formulation of the solid fuel samples is systematically changed to isolate the effects of carbon black, metal fuel additives, and small amounts of oxidizer. In addition, chemical changes to the fuels including curative type and base polymer are varied. Rates of pyrolysis reaction are reported for a wide range of solid fuels applicable to ramjet application. Processes involving the sintering together of metal particles, accumulation of carbon black, and formation of a melt layer are found to affect the reaction rate. It is determined that the surface composition is the most influential factor influencing the regression rate of HTPB based fuels.