cssi/SciSciGPT-SciSciNet huggingface dataset:
Model for Cyclic Inelastic Buckling of Steel Braces

The paper presents a model for the inelastic buckling behavior of steel braces. The model consists of a force-based frame element with distributed inelasticity and fiber discretization of the cross section. With this approach, the response of the element can be derived by integration of the uniaxial stress-strain relation of the fibers and can account for kinematic and isotropic hardening as well as the Bauschinger effect of the material. The interaction between axial force and bending moment is thus accounted for. Even though the element only accounts for small deformations in the basic system, large displacement geometry is included in the nonlinear transformation of the force-deformation relation of the basic element following the concept of the corotational formulation. With this approach, two elements for each brace suffice to yield results that match an extensive set of experimental data of braces with different cross sections and slenderness ratios. Even though the model does not account for the effect of local buckling, this phenomenon does not seem to appreciably affect the global response of braces with compact sections.
The importance of the pollutant dispersion along the nominal wind direction

Abstract The dispersion model, obtained starting from the pollutant conservation equation and the stochastic nature of the wind speed fluctuations, takes into account the pollutant dispersion along the wind 9direction. From the statistical point of view, we conclude that for the case of a continuous point source there is no significant difference between the predictions of the Gaussian plume and dispersion model. Excepting the theoretical background, the dispersion model has the advantage of using just three dispersion coefficients, instead of the four parameters required by the Gaussian plume model. Moreover, while the Gaussian plume is useful just for a continuous source, the dispersion model can be used to estimate the pollutant concentration for multiple sources, both continuous and instantaneous.
Stress-induced reduction in the rat mixed lymphocyte reaction is due to macrophages and not to changes in T cell phenotypes

Exposure to aversive events or stressors modulates various aspects of immune function. We have previously reported that exposure to an acute stressor, inescapable tail shock (IS), resulted in a shift in T cell subpopulations in rat mesenteric lymph nodes but not in cervical lymph nodes (Fleshner et al. (1992) J. Neuroimmunol. 41, 131-142). The mesenteric CD4+/CD8+ ratio was increased immediately after exposure to IS and was due primarily to an increase in the percent of CD4+ cells. The present experiments were designed to determine the relationship between the IS-associated phenotypic shift and its significance in the function of CD4+ T cells. The function assessed was the in vitro proliferative response to alloantigens coded for by the Major Histocompatibility Complex (MHC). Using the mixed lymphocyte reaction (MLR), we report that exposure to IS resulted in a decrease in the MLR response of cells from both cervical and mesenteric lymph nodes. Depletion of macrophages (nylon wool adherent cells) eliminated the IS-induced reduction and co-culture of macrophages (irradiation-insensitive cells) from shocked rats produced the suppression. One interpretation of these data is that exposure to IS resulted in the activation of macrophages and the release of a suppressive factor which reduced the MLR response of peripheral lymph node lymphocytes.
Anchorage: Dependent Persistent Alignment of Perfused Microvasculature in Implanted Tissue Constructs

One of the challenges in engineering complex artificial tissue constructs, with defined matrix and cellular architecture, is the formation of a viable microcirculation within them, that inosculates with the host vasculature and matures into a functional microvascular bed. Current methods based on complex cell patterning in 2-D or 3-D matrix systems rely on ‘printing’ cells or patterns of cells on/ in a substrate, direct culture on patterned substrates, or endothelialization of decellularized vessels. We are now beginning to understand the effects of the microenvironment on microvascular constructs. Flow induced remodeling and maturation of angiogenic microvasculature and changes in functional characteristics when co-implanted with astrocyte precursors strongly suggests a role for the local environment in determining characteristics of the microvascular bed [1, 2]. Chang et al. have shown that neovascular networks from microvessels pre-aligned by direct-bioprinting in a collagen matrix, retain alignment when cultured in vitro, but lose alignment on implantation in vivo [3]. Though unloading of mechanically loaded tissue influences cell behavior [4], it does not explain this loss of orientation after implantation, of previously unloaded constructs. Implanted constructs have an additional level of complexity in the form of network revision and maturation with blood flow. We hypothesize that the local mechanical microenvironment, in addition to flow, dictates network morphology in vivo. This study compares the changes in pre-aligned microvascular networks implanted with and without anchorage.Copyright © 2011 by ASME
Activation of the Insulin-like Growth Factor Type 1 Receptor by Deletion of Amino Acids 870–905

We have created a deletion mutant of the insulin-like growth factor type 1 receptor (IGF-1 R) which lacks the 36 amino acids (aa) immediately N-terminal to the transmembrane domain (Delta870-905 IGF-1 R). This region has been reported to have a negative effect on the transforming potential of an avian sarcoma virus gag-IGF-1 R fusion protein. We have sought to determine whether this region plays a similar role in the intact IGF-1 R. Analysis of the tyrosine kinase activity of the Delta870-905 IGF-1 R shows that the mutant receptor is autophosphorylated without IGF-1 stimulation, indicating that the tyrosine kinase domain is constitutively active. In addition, processing of the receptor is decreased, resulting in accumulation of a high molecular weight proreceptor containing both alpha and beta-subunits. A well-characterized substrate of the IGF-1 R, IRS-1, is constitutively phosphorylated by the Delta870-905 IGF-1 R and phosphoinositide (PI) 3-kinase activity, which is normally activated by the phosphorylation of IRS-1 following IGF-1 stimulation, is increased even in the absence of IGF-1. A second intracellular signal pathway normally activated by IGF-1, the MAP kinase pathway, showed no increase in activity in the absence of IGF-1. The Delta870-905 IGF-1 R promoted cell proliferation only in the presence of IGF-1. We conclude that this deletion increases the basal activity of the IGF-1 receptor tyrosine kinase and activates PI 3-kinase, but is unable to stimulate MAP kinase in the absence of ligand. These results confirm those seen in the gag-IGF-1 R fusion protein and indicate that aa 870-905 exert a negative effect on the tyrosine kinase domain of the beta-subunit of the IGF-1 R.
Signatures of hippocampal oxidative stress in aged spatial learning-impaired rodents

Neurons and glia within the hippocampus of aged, spatial learning-impaired Long-Evans rats exhibit uniquely altered gene expression profiles, and we have postulated oxidative stress as the basis for this. To test this hypothesis we quantitated the extent of protein and nucleic acid oxidative damage, evaluated the status of mitochondrial DNA integrity, and examined several signaling entities and molecular indicators frequently associated with oxidative stress and gliosis. Immunoblotting demonstrated elevated heme oxygenase-1 in the aged-impaired hippocampus and immunocytochemistry suggested that heme oxygenase-1 is largely cytosolic and at least partly neuronal in nature. In the aged-impaired group, immunoreactivity to 8-hydroxy-2'-deoxyguanosine, an oxidative nucleic acid adduct, was found to be elevated in the dentate gyrus and in area CA1 of the hippocampal formation. Isolated mitochondrial DNA was found to be significantly damaged in the aged-impaired group. In the aged learning-impaired rats only, proteins in a 65-kDa band were found to contain excessive levels of carbonyl residues. Glial activation was examined by in situ hybridization histochemistry to tumor necrosis factor alpha and by immunocytochemistry with OX-6, which detects activated microglia. White matter in aged brains exhibited a modest up-regulation of tumor necrosis factor alpha mRNA and OX-6 immunoreactivity, but the hippocampal formation expressed tumor necrosis factor alpha mRNA equivalent to young animals and few OX-6-positive microglia. The mRNA for manganese-dependent superoxide dismutase, which is elevated in the aged hippocampus, was found preferentially expressed in neurons. We conclude that aged hippocampal neurons appear to be under oxidative stress and this is more severe in the learning-impaired subjects, suggesting a possible basis for age-induced cognitive decline.
Distribution of developmental myosin isoforms in isolated A-segments

Immunogold labelling was used to determine the distribution of myosin isoforms within the A-bands of developing chicken pectoralis muscles. Previous localization studies led to the suggestion that neonatal myosin is preferentially located in the centre of heterogeneous thick filaments that contain either embryonic or adult myosin in addition to neonatal myosin. To further explore the possibility that neonatal myosin may serve to nucleate thick filament assembly, a method was developed to isolate A-segments (arrays of myosin filaments) from myofibrils in the presence of MgATP. A-bands usually dissociate into thick and thin filaments in a relaxing buffer, but the inclusion of an antibody against M-line protein prevented separation of the thick filament array. Well-ordered A-segments, approximately 1.5 μm in length, were prepared from muscles 12, 29, 40 days, and approximately 1 year after hatching. After reaction with monoclonal antibodies specific for neonatal and adult myosins, the A-segments were labelled with gold-conjugated secondary antibodies prior to negative staining. An antibody which cross-reacts with embryonic myosin was used to localize that epitope in A-bands of myofibrils from day 1 and day 3 posthatch muscles. At ages where expression of neonatal myosin was high, extensive gold labelling of A-segments was observed in the electron microscope. However, no preferential distribution of antibodies was observed at any age, independent of whether embryonic or adult myosin was coexpressed with the neonatal myosin, suggesting that neonatal myosin is not segregated to any particular region in the A-bands of developing muscles.
The rotation-torsion contour of the 2668 Å origin band of toluene. High-resolution 295 K absorption spectrum

Abstract The 2668 A vibrational origin band of toluene was measured and analyzed using an asymmetric-top/free-internal-rotor model. The change in the methyl group geometry between the ground (eA′1) and the excited eA″1 ( ππ ∗ ) state was found to be slight. Rough values found for the changes in the phenyl frame rotational constants are similar to those for other monosubstituted benzenes with substituents lacking lone-pair electrons. The torsional structure in the toluene origin band is blue-degraded whereas the rotational structure in each Δm = 0 torsional manifold of transitions is red-degraded. Deconvolution of the torsional structure in the calculated contour shows that strong R-branch heads for transitions emanating from each torsional level of the ground state persist in the experimental contour for 0 ≤ |m| ≤ 12.
Changes in prescribed doses for the Seattle neutron therapy system

From the beginning of the neutron therapy program at the University of Washington Medical Center, the neutron dose distribution in tissue has been calculated using an in-house treatment planning system called PRISM. In order to increase the accuracy of the absorbed dose calculations, two main improvements were made to the PRISM treatment planning system: (a) the algorithm was changed by the addition of an analytical expression of the central axis wedge factor dependence with field size and depth developed at UWMC. Older versions of the treatment-planning algorithm used a constant central axis wedge factor; (b) a complete newly commissioned set of measured data was introduced in the latest version of PRISM. The new version of the PRISM algorithm allowed for the use of the wedge profiles measured at different depths instead of one wedge profile measured at one depth. The comparison of the absorbed dose calculations using the old and the improved algorithm showed discrepancies mainly due to the missing central axis wedge factor dependence with field size and depth and due to the absence of the wedge profiles at depths different from 10 cm. This study concludes that the previously reported prescribed doses for neutron therapy should be changed.
The effect of various filters on covariance consistency in the presence of a nonlinear tracking problem

The new generation of high resolution radars now being developed present a nonlinear tracking problem due to a combination of long target ranges, small range errors, and relatively imprecise angle measurements. A variety of filtering techniques have been proposed for ameliorating the effects of this non-linearity, including the (debiased) converted measurements Kalman filter and the unscented filter. The benefits of these techniques are often described in terms of tracking error; however, for handover of a dense target complex to downrange sensors, it is as important that the errors be consistent with their ascribed covariance. The purpose of this paper is to identify when the nonlinear conversion bias effects covariance consistency by examining the relative performance of various filtering techniques.
Low-temperature transport properties of the filled skutterudites CeFe 4 − x Co x Sb 12 s

Thermal conductivity, thermoelectric power, electrical resistivity, Hall coefficient, and magnetic susceptibility of the filled skutterudites ${\mathrm{CeFe}}_{4\mathrm{\ensuremath{-}}\mathrm{x}}$ ${\mathrm{Co}}_{\mathrm{x}}$ ${\mathrm{Sb}}_{12}$ , with x=0, 0.5, 1.0, 1.5, and 2.0, have been studied from 2 to 300 K. We find that the substitution of Co at Fe sites has a dramatic effect on all transport properties. While the resistivity of ${\mathrm{CeFe}}_{4}$ ${\mathrm{Sb}}_{12}$ has a metallic character, substitution of Co leads to a progressively stronger activated behavior and a decrease in hole concentration. The thermopower increases with increasing Co, while the thermal conductivity is depressed, notably at low temperatures. Susceptibility data suggest the presence of large effective moments. At high temperatures Ce is nearly trivalent, but valence fluctuations prevail at low temperatures. Strong hybridization of the Ce 4f states with the Fe 3d and pnicogen p states appears to be important in understanding the physical properties of these compounds.
The link between smoking and impotence: two decades of evidence.

Abstract Background. Anti-tobacco advertisements now feature the risk of impotence as a reason to avoid or cease tobacco use. The scientific evidence, however, is mixed. To shed light on the controversy, we compiled 2 decades of published data on the link between smoking and impotence. Methods. We searched MEDLINE from 1980 to the present for studies that reported smoking prevalence among impotent male subjects. For each study we recorded the age of subjects, their state of residence, the percentage that were current smokers, and the time period over which study data were collected. For comparison purposes, we estimated age-, state-, and year-specific smoking rates in the general male population using the Behavioral Risk Factors Surveillance System. We performed a meta-analysis using a random effects model. Results. Among the 1008 journal articles examined, we identified 19 studies that reported the smoking habits of 3819 impotent men. Of these 19 studies, 16 indicated a smoking prevalence exceeding that of the general population. The 6 largest studies all revealed a higher prevalence of smoking among impotent men. Meta-analysis reveals that 40% of impotent men were current smokers compared with 28% of men in the general population. Conclusions. Based on almost 2 decades of evidence, tobacco use is an important risk factor for impotence. Anti-tobacco advertisements featuring impotence as a reason to avoid or cease tobacco use are well grounded in scientific fact.
Shape and impedance recovery of obstacles from electromagnetic scattering data

The problem of shape and impedance recovery of an arbitrary cylindrical obstacle from scattering data for electromagnetic waves generated by a line source parallel to the cylindrical obstacle is considered. Using the method of lines (MoL), an inversion procedure is developed that recovers both shape and impedance from scattering data for all angles and two different frequencies of the incident waves. Several numerical examples with synthetic scattering data and added noise are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 596–600, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21418
CULTURE‐LED DEVELOPMENT AND CONFLICT OVER URBAN SPACE: REIMAG(IN)ING ST PETERSBURG, RUSSIA

Culture‐led projects have long been part of strategies to regenerate cities in advanced capitalist economies. In recent decades those projects also have become a focal point of urban development in...
Nucleus hears axon's pain.

Upon injury, axons can send a message to the cell body to implement repair programs. This message is now shown to require a complex of the microtubule motor dynein and proteins that mediates nuclear-cytoplasmic transport.
Strategies and difficulties of applying models to aquatic populations and food webs

Abstract The models of mathematical ecology have often been constructed with a view towards their analytic tractability and, as a consequence, have been criticized frequently on the grounds of their lack of realism. It is argued here that recent trends in ecological modeling have been away from abstraction towards the incorporation of more mechanistic detail. This detail may include such features of natural systems as spatial heterogeneity, the demographic structure of populations, the dependence of population parameters on varying environmental conditions, and the physiology and behavior of individual organisms. Frequently, such apparent details are crucial in determining population and community dynamics. This is illustrated by models of the ‘match-mismatch’ hypothesis of recruitment success in fish populations, plant competition and succession, and stability of food webs. Great progress is likely to be made in understanding and predicting the dynamics of aquatic populations and food webs as models come to be based more on an appropriate level of mechanistic detail.
A time domain photoacoustic study of the collisional relaxation of vibrationally excited H2

Abstract We report the first direct measurement of the vibration-to-vibration (V-V) and vibration-to-translation (V-T) rates for vibrational relaxation out of the ν=2 vibrational level in hydrogen gas. Time domain photoacoustic spectroscopy was used to monitor the collision dynamics after excitation into ν=2 through overtone stimulated Raman pumping. The V-V relaxation rate is found to be (1–4) × 10−14 cm3 s−1 molecule−1 and the V-T rate constant is (0.6–2) × 10−15 cm3 s−1 molecule−1 for normal hydrogen at 298 K.
A Numerical simulation of transition in plane channel flow

This paper involves a numerical simulation of the final stages of transition to turbulence in plane channel flow at a Reynolds number of 7500. Three-dimensional, incompressible Navier-Stokes equations are numerically integrated to obtain the time-evolution of two- and three-dimensional finite-amplitude disturbances. Computations are performed on the CYBER-203 vector processor for a 32 x 33 x 32 grid. Solutions indicate the existence of structures similar to those observed in the laboratory and which are characteristic of various stages of transition that lead to final breakdown. Details of the resulting flow field after breakdown indicate the evolution of streak-like formations found in turbulent flows. Although the flow field does approach a steady-state (turbulent channel flow), implementation of subgrid-scale terms are necesary to obtain proper turbulent statistics.
Blowout!: Firestone’s image restoration campaign

Abstract In this application of image restoration theory, Blaney, Benoit, and Brazeal discover that Firestone botched its recovery efforts. Its attempt to shift blame to Ford was poorly conceived. Its corrective action was not perceived as addressing the problem at hand. Moreover, its use of Michael and Mario Andretti to bolster its product and reputation was limited by the obvious financial relationship with these professional drivers. Finally, the authors support past scholarship that scrutinizes the appropriateness of certain strategy combinations. Specifically, mortification and bolstering can be undermined by denial and corrective action.
Political Agency and Citizen Journalism: Twitter as a Tool of Evaluation

Technology and the globalization of communication have significantly altered the spatial–temporal scale at which information is disseminated, and tools like Twitter have made control over information more decentralized and democratic. Many have debated the precise relationship and networks of power and influence between the media and policy, but few have analyzed the role of citizen journalism and its implications for the social landscape. An analysis of tweets about United Nations Peacekeeping Operations in Haiti and Cote d’Ivoire revealed the usefulness of Twitter, as a medium for citizen journalism, in evaluating phenomena like peacekeeping missions.
The secondary impact of nonpoint-pollution controls: A linear-programming-input/output analysis

Abstract A joint linear-programming-interindustry model is used to estimate the impact on small regional economies of nonpoint-pollution controls on agriculture. Results from the linear-programming submodel of the farm-production sector of a region are entered as final-demand changes in the “rows-only” interindustry model of the regional economy. Emphasis is placed on describing the models, the linkages between them, and on evaluating the usefulness and limitations of the modeling approach. A brief review of empirical results is also given.
Psychiatric disorder and juvenile delinquency in adopted children and adolescents

ABSTRACT A survey of the proportion of adopted children and adolescents in the general population, in a psychiatric inpatient program, and in the juvenile court of the same region revealed a significantly lower rate of intrafamilial adoption in both psychiatric inpatient and juvenile court subjects than in the general population. When compared with the extrafamilial adoption rate of the general population in the region, a significant overrepresentation of adopted children and adolescents among the inpatient psychiatric subjects, and a significant underrepresentation of adopted children and adolescents referred to the juvenile court, were found.
Plasmacytoma of the nasal cavity with lambda III amyloid deposition

A patient presented with a large nasal plasmacytoma that involved the palate, ethmoid and maxillary sinuses and contained deposits of amyloid. Immunoglobulin (AL) amyloid was found in the tumor. Amyloid fibrils extracted from the resected tumor were found to contain lambda light chain protein. Complete sequence analysis identified the protein as lambda III immunoglobulin light chain. Evaluation of the patient failed to reveal any sign of systemic amyloidosis and three years of follow-up has shown no evidence of recurrence.
A Conserved Seven Amino Acid Stretch Important for Murine Mitochondrial Glycerol-3-phosphate Acyltransferase Activity SIGNIFICANCE OF ARGININE 318 IN CATALYSIS

Glycerol-3-phosphate acyltransferase (GPAT) catalyzes the initial and committed step in glycerolipid biosynthesis. We previously cloned the cDNA sequence to murine mitochondrial GPAT (Yet, S-F., Lee, S., Hahm, Y. T., and Sul, H.S. (1993) Biochemistry 32, 9486-9491). We expressed the protein in insect cells which was targeted to mitochondria, purified, and reconstituted mitochondrial GPAT activity using phospholipids (Yet, S.-F., Moon, Y., and Sul, H. S. (1995) Biochemistry 34, 7303-7310). Deletion of the seven amino acids from mitochondrial GPAT, (312)IFLEGTR(318), which is highly conserved among acyltransferases in glycerolipid biosynthesis, drastically reduced mitochondrial GPAT activity. Treatment of mitochondrial GPAT with arginine-modifying agents, phenylglyoxal and cyclohexanedione, inactivated the enzyme. Two highly conserved arginine residues, Arg-318, in the seven amino stretch, and Arg-278, were identified. Substitution of Arg-318 with either alanine, histidine, or lysine reduced the mitochondrial GPAT activity by over 90%. On the other hand, although substitution of Arg-278 with alanine and histidine decreased mitochondrial GPAT activity by 90%, replacement with lysine reduced activity by only 25%. A substitution of the nonconserved Arg-279 with either alanine, histidine, or lysine did not alter mitochondrial GPAT activity. Moreover, R278K mitochondrial GPAT still showed sensitivity to arginine-modifying agents, as in the case of wild-type mitochondrial GPAT. These results suggest that Arg-318 may be critical for mitochondrial GPAT activity, whereas Arg-278 can be replaced by a basic amino acid. Examination of the other conserved residues in the seven amino acid stretch revealed that Phe-313 and Glu-315 are also important, but conservative substitutions can partially maintain activity; substitution with alanine reduced activity by 83 and 72%, respectively, whereas substituting Phe-313 with tyrosine and Glu-315 with glutamine had even lesser effect. In addition, there was no change in fatty acyl-CoA selectivity. Kinetic analysis of the R318K and R318A mitochondrial GPAT showed an 89 and 95%, respectively, decrease in catalytic efficiency but no major change in substrate binding as indicated by the K(m) values for palmitoyl-CoA and glycerol 3-phosphate. These studies indicate importance of the conserved seven amino acid stretch for mitochondrial GPAT activity and the significance of Arg-318 for catalysis.
Prefetch injection based on hardware monitoring and object metadata

Cache miss stalls hurt performance because of the large gap between memory and processor speeds - for example, the popular server benchmark SPEC JBB2000 spends 45% of its cycles stalled waiting for memory requests on the Itanium® 2 processor. Traversing linked data structures causes a large portion of these stalls. Prefetching for linked data structures remains a major challenge because serial data dependencies between elements in a linked data structure preclude the timely materialization of prefetch addresses. This paper presents Mississippi Delta (MS Delta), a novel technique for prefetching linked data structures that closely integrates the hardware performance monitor (HPM), the garbage collector's global view of heap and object layout, the type-level metadata inherent in type-safe programs, and JIT compiler analysis. The garbage collector uses the HPM's data cache miss information to identify cache miss intensive traversal paths through linked data structures, and then discovers regular distances (deltas) between these linked objects. JIT compiler analysis injects prefetch instructions using deltas to materialize prefetch addresses.We have implemented MS Delta in a fully dynamic profile-guided optimization system: the StarJIT dynamic compiler [1] and the ORP Java virtual machine [9]. We demonstrate a 28-29% reduction in stall cycles attributable to the high-latency cache misses targeted by MS Delta and a speedup of 11-14% on the cache miss intensive SPEC JBB2000 benchmark.
Interorganizational and Collective Strategies in Small Firms: Environmental Effects and Performance

This study provides evidence that collective strategy is prevalent in small firms in fragmented industries. COMPUSTAT data were combined with afield survey of small manufacturingfirms to test hypotheses concerning the relative frequencies of various collective strategies, the effects of environmental variables on collective activity, and the contribution of collective behavior to firm performance. Results indicate that agglomerate and organic collective strategies are the most frequently employed, and that munificent environments were positively associated with collective behavior and performance. Complex environments were negatively associated with collective strategy and no effect was found for volatile environments. The study also discusses methodological issues concerning the use of the COMPUSTAT database, and the usual practice of omitting cases with missing financial information.
High fetal plasma adenosine concentration: a role for the fetus in preeclampsia?

Objective Clinical observations suggest a role for the fetus in the maternal manifestations of preeclampsia, but the possible signaling mechanisms remain unclear. This study compares the fetal plasma concentrations of adenosine from normal pregnancies with those from preeclampsia. Study Design This secondary data analysis included normal pregnancies (n = 27) and patients with preeclampsia (n = 39). Patients with preeclampsia were subclassified into patients with (n = 25) and without (n = 14) abnormal uterine artery Doppler velocimetry (UADV). Results Fetal plasma concentrations of adenosine were significantly higher in patients with preeclampsia (1.35 ± 0.09 μmol/L) than in normal pregnancies (0.52 ± 0.06 μmol/L; P P Conclusion Patients with preeclampsia with sonographic evidence of chronic uteroplacental ischemia have high fetal plasma concentrations of adenosine.
Risk Factors for Self-Reported Exercise-Related Leg Pain in High School Cross-Country Athletes

Abstract Context: Prevention of exercise-related leg pain (ERLP) has not been successful because ERLP risk factors are not well known. Objective: To determine the percentage of high school cross-co...
Nondynamical Formalism and Tests of Time-Reversal Invariance

In this paper we consider those consequences of time-reversal invariance (or, briefly, $T$ invariance) which are independent of dynamics. A general prescription is developed to find all those tests of $T$ invariance which are valid for arbitrary values of the form factors. Our considerations are independent of whether or not any of the other usual conservation laws (such as parity conservation) hold. The spins of the particles may be arbitrary. The results and methods of earlier papers dealing with the nondynamical properties of particle reactions are used. For elastic processes it is shown that $T$ invariance eliminates some of the product sets and curtails others, but that no entire subclasses are eliminated. The restrictions on observables imposed by $T$ invariance are of two types: There are so-called "mirror relations" between pairs of observable components, and there are relations which are not of the mirror type and involve a number of observable components. It is shown that the number of relations of the latter type is always nonzero whenever $T$ invariance is not implied by other assumed conservation laws. Therefore, the mirror relations do not form a complete set of tests of $T$ invariance. They do not even form a sufficient set of such tests, as they can be satisfied by a symmetric as well as an antisymmetric $M$ matrix. A proof is given that in any non-mirror-type relation no particle is unpolarized in all the observable components which appear in the relation. It is also shown that the only reaction in which all mirror relations follow from parity conservation alone is the reaction involving two spin-\textonehalf{} and two spin-0 particles. A number of examples of elastic reactions are worked out in detail. For inelastic reactions the results are less interesting, since the restrictions imposed by $T$ invariance can all be written as mirror-type relations between observable components of the direct and time-reversed reactions.
Classroom Age Composition and Academic Achievement in College

The continuing influx of adult students in colleges and universities raises many questions for research, including how their presence affects classroom learning. We postulated that, controlling for student age, the greater the proportion of adults in a classroom the higher the aggregate average performance of the class as measured by class grades. The hypothesis was tested in two very different settings: a suburban community college and a nearby large, public research university. Data for 2,794 subjects were obtained from official records. The findings from the community college sample strongly supported the predicted relationship. At the university, a modified hypothesis that excluded performance in math classes was also supported.
Importance of Cost and Quality of Life in Decisions About Routine Angiography After Acute Myocardial Infarction The Role of Cost-effectiveness Models

In 1992, health care was the fastest-growing sector of the US economy, accounting for 14% of the gross national product. Amid concern about whether such rapid growth could realistically be sustained, the editor of the Journal of the American Medical Association predicted that the US healthcare system would experience an apocalyptic “meltdown” by 1996 if the situation persisted.1 Four years later, the US healthcare system has not experienced “meltdown.” However, the manner in which healthcare services are provided, financed, and evaluated has changed dramatically. Healthcare insurers and policy makers have justified these changes by asserting that Americans receive much unnecessary health care and that even the necessary care is overpriced. In contrast to the US situation, Canada and the Western European countries spend less per capita on health care but have apparently similar levels of overall health as measured by key indicators. Beginning with the use of diagnosis-related groups in the early 1980s, hospitals and physicians witnessed an accelerating shift of financial responsibility from insurers and other health services purchasers to healthcare providers. By 1992, many providers had found that reimbursements from Medicare and Medicaid were not adequate to cover their expenses for these services.2 3 Four years later, capitation and other forms of managed care have so limited reimbursements from private insurers that many providers are unable to cover their expenses for these patients as well. In this increasingly competitive healthcare environment, providers, purchasers, and policy makers are finding that they can no longer finance healthcare services at their pre-1992 levels, and they are faced with making hard decisions regarding the appropriateness and cost-effectiveness of competing medical therapies. Often, these decisions are made without access to relevant economic information and without the benefit of good long-term outcome information. Because of the high costs and the frequency with …
Financial Statistics and Financial Policy

T HE LAST FEW YEARS have seen a large and interesting development of financial statistics. Starting out from certain wellestablished bases-the statistics of banks, of government finance, and of the balance of payments-financial statistics have stretched their tentacles upward and sideways, and intertwined them, until they now cover, in principle, an area as broad as that of the national income and social accounting statistics-in principle, for the new area is only thinly held. In fact, not much more than the bare lattice work of the concepts is visible at this stage, with empty squares for the statistics to occupy in the future.' Many countries leading in the field of national income statistics are now in the process of matching the "upper halves" of their accounts, containing data on income, investment, and saving by sectors, with similarly articulated "bottom halves," showing borrowings and lendings. In Germany, France, the Netherlands, and Sweden (to mention only a few countries), these financing statistics have been tied on to the existing national income accounts; in the United States, a wholly new set of accounts, integrating income and financing accounts, has been developed by the Board of Governors of the Federal Reserve System in the form of the "Flow of Funds." These developments have breathed a welcome new life into social accounting statistics. This new field with its new vistas has rekindled interest in social accounting work, which, having slid down a steep slope of diminishing returns, seemed to be keeping barely alive on minuscule definitional crumbs. The development of financial statistics has occurred broadly at the same time as the revival of interest in financial, and in particular
Femur fracture with limb shortening causing occlusion of a polytetrafluoroethylene femoral popliteal graft

Traumatic occlusion of lower extremity polytetrafluoroethylene arterial grafts is exceedingly rare. We report a patient who suffered a supracondylar femur fracture resulting in shortening of her right lower extremity with kinking and thrombosis of her above-knee polytetrafluoroethylene arterial graft. This is the first report in the English language of prosthetic graft occlusion as a result of traumatic limb shortening. The graft thrombus was successfully lysed by use of intraarterial urokinase, and the kink was repaired by graft resection and reanastomosis. The mechanism of injury and treatment are discussed.
The impact of contact time on pyrene sorptive behavior by a sandy-loam soil.

Abstract Batch experiments with pyrene (PYR) were conducted to quantify the effect of contact time on its sorption and desorption behavior by a sandy-loam soil. Twenty-four and 48 h contact times were chosen for the nonequilibrium conditions and 240 h for the pseudoequilibrium study. All times was selected based on the kinetic results. The nonlinear, pseudoequilibrium sorption isotherm was fit to a two-stage Freundlich model: 3–7 mg/l for the first stage and 7–15 mg/l for the second stage. A substantial fraction of the sorbed PYR was not desorbed within the given desorption time. The reason of hysteresis was found to be a sorption enhancement due to soil hydration which provided more sorption sites. A desorption enhancement at 240-h desorption steps was attributed to the increased dissolved organic matter evolution. This study also found that both soil organic matter and clay materials had an equal role in PYR sorption enhancement and desorption resistance.
Performance analysis of a class of clustered wireless networks

We derive performance expressions for the throughput and blocking probability for a class of wireless networks with a clustering protocol. The nodes are assumed stationary and establish connections with the master node according to a priority scheme that relates to their distances from the master node. The latter is selected randomly in a cell and data are transmitted within predefined sectors.
Cellular expression of renal, cardiac and pulmonary inducible nitric oxide synthase in double-transgenic mice expressing human renin and angiotensinogen genes.

SUMMARY 1 Hypertensive mice expressing the human renin (REN) and angiotensinogen (AGT) genes are used as a model for human hypertension. 2 The aim of the present study was to investigate the cellular expression and distribution of inducible nitric oxide synthase (iNOS) using immunohistochemistry in lung, heart and kidney tissues from a model of human hypertension using male and female double-transgenic (h-Ang 204/1h-Ren6) mice and wild-type C57/BI6J mice as controls. 3 In the kidney, the pattern of iNOS expression in various renal microanatomical regions during hypertension was similar to that of age-matched controls, except in the medullary ascending limb (MAL). In hypertension, iNOS expression was downregulated in the MAL. No significant differences in iNOS expression were seen between control or hypertensive mice in various cardiac microanatomical locations. In the lungs of hypertensive mice, iNOS expression was upregulated in bronchial airway epithelium and bronchial and vascular smooth muscle cells, but downregulated in alveolar macrophages, alveolar septa and pulmonary vascular endothelial cells. Expression of iNOS was similar between male and female mice in the kidney, heart and lungs. 4 In conclusion, iNOS regulation in hypertension is complex and depends on the cell type in which it is expressed and the localization of the cell type in the cardiorenal and pulmonary systems.
Death Orientation and Communication with the Terminally Ill

This study examines the relationship between attitude toward death and the terminal patient and communication with the terminally ill. Participants were medical students and family physicians at a Midwestern university. Instruments included a Terminal Illness Questionnaire and a Threat Index modified to include measures of identification with the patient, as well as of death orientation. Relationships were found between the indices and factors used in determining whether to reveal a terminal diagnosis.
Exposure to Indoor Tanning Without Burning and Melanoma Risk by Sunburn History

Indoor tanning is carcinogenic to humans. Individuals report that they tan indoors before planning to be in the sun to prevent sunburns, but whether skin cancer is subsequently reduced is unknown. Using a population-based case-control study, we calculated the association between melanoma and indoor tanning after excluding exposed participants reporting indoor tanning-related burns, stratified by their number of lifetime sunburns (0, 1-2, 3-5, >5). Confounding was addressed using propensity score analysis methods. All statistical tests were two-sided. We observed increased risk of melanoma across all sunburn categories for participants who had tanned indoors without burning compared with those who never tanned indoors, including those who reported zero lifetime sunburns (odds ratio = 3.87; 95% confidence interval = 1.68 to 8.91; P = .002). These data provide evidence that indoor tanning is a risk factor for melanoma even among persons who reported never experiencing burns from indoor tanning or outdoor sun exposure.
Hemodynamic and Anesthetic Effects of Sufentanil as the Sole Anesthetic for Pediatric Cardiovascular Surgery

The efficacy, safety, and hemodynamic response to 5 micrograms/kg, 10 micrograms/kg, or 20 micrograms/kg of sufentanil and 0.1 mg/kg pancuronium was evaluated in children between 4 and 12 years of age scheduled for open heart surgery. Systolic time intervals, 2-D echocardiograms, systolic blood pressures (SBP), diastolic blood pressures (DBP), and heart rates (HR) were recorded before and after induction of anesthesia. Significant changes 10 min following induction of anesthesia but before intubation included increases in SBP in the 5 micrograms/kg group (P less than 0.01) and in the ratio of preejection period to left ventricular ejection time in the 20 micrograms/kg group (P less than 0.05). Instances of myoclonic jerking and coughing episodes were observed in all three study groups. Following intubation there were significant (P less than 0.05) increases in SBP in all groups, in DBP in the 5 micrograms/kg group, and in HR in the 5 micrograms/kg and 10 micrograms/kg groups. Smaller increases in SBP, DBP, and HR were seen in all groups after skin incision and sternotomy. Mean plasma catecholamine levels showed nonsignificant increases following periods of intraoperative stimulation with wide patient variations. Recovery of responsiveness to command occurred in all groups within one hour from the end of surgery but extubation was impeded by shallow periodic breathing and hypercapnea. The authors conclude that for children undergoing open heart surgery use of sufentanil as a sole anesthetic in bolus form did not provide a reliable depth of anesthesia with any of the induction doses studied.
Exploring the roles of emotional numbing, depression, and dissociation in PTSD

Some researchers consider emotional numbing a cardinal feature of posttraumatic stress disorder (PTSD). Others view numbing symptoms as representing an overlap between PTSD, depression, and dissociation. In this study, we examined the ability of early emotional numbing, depression, and dissociation symptoms to predict PTSD. One-hundred sixty-one women who were recent victims of sexual or nonsexual assault were assessed prospectively for 12 weeks. Emotional numbing, depression, and dissociation were each associated with initial PTSD severity. Notably, regression analyses revealed that after depression and dissociation were accounted for, early numbing contributed to the prediction of later PTSD.
Furosemide for symptomatic patent ductus arteriosus in indomethacin-treated infants.

Background Inhibition of prostaglandin synthesis mediates closure of the ductus arteriosus and renal side effects after indomethacin administration. Because furosemide increases prostaglandin production, it could potentially help prevent indomethacin-related toxicity but also decrease ductal response to indomethacin. Objectives The primary objectives of this review were to assess (1) whether furosemide affects the incidence of failure of ductal closure after indomethacin and that of indomethacin-related toxicity and (2) the effect of furosemide on mid-term and long-term outcome. The secondary objective was to determine whether the effect of furosemide on renal function and water balance depends on prior extracellular volume (assessed by blood urea nitrogen [BUN]/creatinine ratio). Search strategy We searched electronic databases (Medline, Embase and Cochrane) and selected abstract books, without language restriction. Selection criteria We selected studies with (1) random allocation to either indomethacin alone or indomethacin and furosemide and (2) analysis of either short-term risk-benefit ratio of furosemide, mid- or long-term outcome, or the relationship between extracellular volume at study entry and changes in renal function. Data collection and analysis We assessed studies for possible bias and for quality of assessment of ductal patency. We assessed categorical variables using relative risk and absolute risk reduction. We assessed the effects of furosemide on renal function and fluid balance by comparing changes from baseline in the treatment group with those in controls. Subsets were determined a priori based on BUN/creatinine ratio at study entry. Main results All 3 studies fulfilling the entry criteria had limitations, including possible or definite bias. There was substantial heterogeneity among studies. Furosemide administration did not significantly increase the risk of failure of ductal closure; however, sample size was insufficient to rule out even a 31% increase. In the subset with initial BUN/creatinine ratio > 20 mg/mg, 2 of 18 patients receiving furosemide could not complete a 3-dose course of indomethacin because of toxicity. Minimal or no information was available about any of the other main outcome variables. Furosemide increased urine output regardless of the initial BUN/creatinine ratio, leading to a 5% weight loss during a 3-dose course, an undesired effect in patients with initial BUN/creatinine ratio > 20 mg/mg. Furosemide increased creatinine clearance only in patients with initial BUN/creatinine ratio Reviewer's conclusions There is not enough evidence to support the administration of furosemide to premature infants treated with indomethacin for symptomatic patent ductus arteriosus. Furosemide appears to be contraindicated in the presence of dehydration in those infants.