cssi/SciSciGPT-SciSciNet huggingface dataset:
Role of intraoperative transesophageal echocardiography in patients having coronary artery bypass graft surgery.

Abstract Background Previous studies have shown that intraoperative transesophageal echocardiography provides important preoperative and postoperative information in various cardiac and noncardiac surgeries that may alter patient management and outcome. The role of intraoperative transesophageal echocardiography in patients in whom isolated coronary artery bypass graft surgery is anticipated has been reported only in small selected groups. This study was designed to prospectively evaluate the role of intraoperative transesophageal echocardiography in a large, nonselected group of patients undergoing primarily coronary artery bypass graft surgery. Methods From January 2001 to December 2003, 474 consecutive patients (76% men, 24% women) aged 30 to 89 years (mean age of 70 ± 10 years) who were undergoing coronary artery bypass graft surgery had prebypass and postbypass intraoperative transesophageal echocardiography. New findings and alterations in the surgical plan were documented prospectively. Results New prebypass findings were found in 10% of patients, and the surgical plan was altered in 3.4% of patients. New postbypass findings were found in 3.2% of patients, altering the surgical plan in 2% of patients. Conclusions This large consecutive, nonselected, prospective study reveals the significant impact of intraoperative transesophageal echocardiography in patients having coronary artery bypass graft surgery as a primary procedure. New findings (prebypass and postbypass) were found in 13% of patients overall, and the surgical plan was altered in 5.5% of patients. This study supports the use of intraoperative transesophageal echocardiography in patients undergoing primarily coronary artery bypass graft surgery.
Spectroscopic and conductimetric studies of halogen fluoride compounds in anhydrous hydrogen fluoride

Abstract Raman, infrared and electrical conductance studies have been undertaken on liquid mixtures of chlorine trifluoride and hydrogen fluoride and of bromine pentafluoride and hydrogen fluoride. The experimental data reveal the existence of a fluoride-ion transfer equilibrium, ClF 3 + HF ⇄ ClF 2 + + HF 2 -, in the former case. No fluoride-ion transfer is observed in the HF/BrF 5 system. In addition, Raman studies have been undertaken on separate solutions of CsBrF 4 , CsClF 4 , CsBrF 6 , ClF 2 SbF 6 , BrF 2 SbF 6 and BrF 4 Sb 2 F 11 in hydrogen fluoride. For the cesium salt solutions, experimental data reveal that the halogen fluoride anions act as Lewis bases in the reaction ClF − 4 + HF ⇌ HF − 2 + ClF 3 . Fluoride-ion transfer, BrF 4 + + 2HF ⇄; BrF 5 + H 2 F + , is also observed for BrF 4 Sb 2 F 11 in HF. The spectra of BrF 2 + and ClF 2 + in HF are similar to the spectra of these cations in their respective solid compounds. However, addition of excess halogen fluoride to these solutions lowers the frequencies attributed to the stretching vibrations of the cations. Approximate acidity function values have been determined for BrF 3 , ClF 3 and BrF 5 relative to hydrogen fluoride. Numerical values are based on the H o values previously reported for hydrogen fluoride solutions.
Bolus intravenous nitroglycerin predominantly reduces afterload in patients with excessive arterial elastance

Abstract Objectives. We hypothesized that bolus intravenous nitroglycerin would be an afterload-reducing agent in patients with excessive initial afterload for their level of left ventricular systolic function. Conversely, bolus intravenous nitroglycerin should be a preload-reducing in patients without excessive initial afterload. Background. Although nitroglycerin has both preload- and afterload-reducing actions, methods to predict its predominant site of action in an individual patient have not been previously described. Methods. Left ventricular pressure-volume relations were recorded with micromanometer and conductance catheters during bolus injection of intravenous nitroglycerin in 27 patients with both normal left ventricular systolic function and varying degrees of congestive heart failure. Preload was determined by end-diastolic volume, afterload by effective arterial elastance, left ventricular systolic function by end-systolic elastance and coupling of afterload and ventricular function by the ratio of effective arterial elastance to end-systolic elastance (EaEesratio). An EaEesratio >1 was defined as excessive afterload for the level of ventricular function. Results. Patients with an initial EaEesratio 1 and normal or mildly depressed ventricular function (Group 2a) constitude a group of patients, most of whom were hypertensive, who exhibited a predominant afterload reduction. Finally, those with an initial EaEesratio >1 and abnormal ventricular function (Group 2b) constituted a group of patients with clinical congestive failure who exhibited both preload and afterload reduction but a predominant afterload reduction because stroke volume increased. Conclusions. Patients with normal arterial elastance and ventricular function respond to nitroglycerin with a predominant preload reduction, whereas patients with either excessive arterial elastance or abnormal ventricular function respond with a predominant afterload reduction.
Sun protection behaviors and stages of change for the primary prevention of skin cancers among beachgoers in Southeastern New England

Sun exposure is the most important avoidable cause of skin cancers. We report characteristics of a representative sample (N = 2,324) of beachgoers in Southeastern New England during the summer of 1995. This sample was not employing adequate sun protection behaviors (83% did not often avoid the sun during midday and only 45% often used sunscreen). Important demographic and skin cancer risk factor differences in sun protective behaviors and stages of change for sun protection were found, especially differences based on age, gender, and degree of sun sensitivity. Consistent with previous research, increased age, female gender, and greater sun sensitivity were each independently associated with more sun protective behaviors. These findings underscore the need for interventions targeting high-risk populations, such as those receiving high-intensity sun exposures at the beach.
In vitro and in vivo models for assessing drug efflux transporter activity

Determining the activity of drug efflux transport proteins has important implications in the identification of substrates and/or inhibitors of the various transport systems, as well as mechanistic determination of localization, and functional role of the transporters in absorption, distribution and elimination of compounds in the body. This review examines both in vitro and in vivo approaches used to determine drug efflux transporter activity, their applications, and advantages and potential limitations.
Geometric theory of columnar phases on curved substrates

We study thin self-assembled columns constrained to lie on a curved, rigid substrate. The curvature presents no local obstruction to equally spaced columns in contrast with curved crystals for which the crystalline bonds are frustrated. Instead, the vanishing compressional strain of the columns implies that their normals lie on geodesics which converge (diverge) in regions of positive (negative) Gaussian curvature, in analogy to the focusing of light rays by a lens. We show that the out of plane bending of the cylinders acts as an effective ordering field.
Age-related changes to speech breathing with increased vocal loudness.

Purpose The present study examines the effect of normal aging on respiratory support for speech when utterance length is controlled. Method Fifteen women (M = 71 years of age) and 10 men (M = 73 ye...
The transport and fate of Fe, Mn, Cu, Zn, Cd, Pb and SO4 in a groundwater plume and in downstream surface waters in the Coeur d'Alene Mining District, Idaho, U.S.A.

Abstract The controls on metal concentrations in a plume of acidic (pH 3.29–5.55) groundwater in the Moon Creek watershed in Idaho, U.S.A., were investigated with the use of property-property plots. A plot of Ca vs S demonstrated that a plume of contaminated groundwater was being diluted by infiltration of rain and creek water at shallow depths and by ambient groundwater near bedrock. The small amount of dissolved Fe (2.1 mg/l) was removed while dissolved Pb was added, reaching a maximum concentration of 0.37 mg/l. The other metals (Zn ≤ 16, Al ≤ 6.2, Cu ≤ 2.1 and Cd ≤ 0.077 mg/l) in the shallow groundwater were essentially conserved until they emerged as a seep along the creek bank. Upon mixing with the creek water, groundwater was diluted by factors between 11 and 50, and the pH of the mixture became neutral. Metals originating from the contaminated groundwater were removed in the creek in the following order: Fe > Al > Pb ≫ Cu > Mn > Zn = Cd. Pb and Cu continued to be removed from solution even as the creek passed adjacent to a tailings pile. In contrast, Zn concentrations in the creek increased adjacent to the tailings area, presumably as a result of the reemergence of the upgradient plume as the creek lost elevation. Below the tailings dam, contaminated creek water (400–800 μg Zn/l) was diluted by both smaller side streams and a creek of equal flow. The presence of 3 distinctive water masses required the use of two tracers (dissolved Si and S) to distinguish between mixing and geochemical reactions. The removal of metals was greater during low flow conditions. Pb was removed to the greatest extent, falling below detection limits (0.5 μ/l) at the first sampling location. Copper and Mn were removed to a lesser extent during low flow conditions and approached conservative behavior during high flow conditions. During a 5-km journey through two hydrological regimes, less than 10% of the dissolved Zn and Cd was lost.
Modeling simultaneous worker learning and forgetting in dual resource constrained systems

Abstract This paper addresses issues related to modeling worker learning and forgetting effects in Dual Resource Constrained (DRC) systems. The learn-forget-learn (LFL) model of Carlson and Rowe (Carlson, J.C., Rowe, A.J., 1976. Industrial Engineering 8, 40–47) is used to critically evaluate several worker training related issues that are associated with the learning and forgetting phenomenon. A numerical analysis is performed on the LFL model within a DRC system to gain insights into the nature of relationships between the extent of worker flexibility, forgetting rates, attrition rates, and flexibility acquisition policies. Results suggest that in the presence of higher attrition and forgetting rates, a worker may not be able to achieve full efficiency in as little as two different departments. Thus acquiring even incremental worker flexibility under such conditions may be infeasible. We also show that managers can use different flexibility acquisition policies designed in this study to reduce relearning losses and consequently improve the system performance.
A Primer on Marginal Effects—Part II: Health Services Research Applications

Marginal analysis evaluates changes in a regression function associated with a unit change in a relevant variable. The primary statistic of marginal analysis is the marginal effect (ME). The ME facilitates the examination of outcomes for defined patient profiles or individuals while measuring the change in original units (e.g., costs, probabilities). The ME has a long history in economics; however, it is not widely used in health services research despite its flexibility and ability to provide unique insights. This article, the second in a two-part series, discusses practical issues that arise in the estimation and interpretation of the ME for a variety of regression models often used in health services research. Part one provided an overview of prior studies discussing ME followed by derivation of ME formulas for various regression models relevant for health services research studies examining costs and utilization. The current article illustrates the calculation and interpretation of ME in practice and discusses practical issues that arise during the implementation, including: understanding differences between software packages in terms of functionality available for calculating the ME and its confidence interval, interpretation of average marginal effect versus marginal effect at the mean, and the difference between ME and relative effects (e.g., odds ratio). Programming code to calculate ME using SAS, STATA, LIMDEP, and MATLAB are also provided. The illustration, discussion, and application of ME in this two-part series support the conduct of future studies applying the concept of marginal analysis.
More evidence for association of a rare TREM2 mutation (R47H) with Alzheimer's disease risk.

Abstract Over 20 risk loci have been identified for late-onset Alzheimer's disease (LOAD), most of which display relatively small effect sizes. Recently, a rare missense (R47H) variant, rs75932628 in TREM2, has been shown to mediate LOAD risk substantially in Icelandic and Caucasian populations. Here, we present more evidence for the association of the R47H with LOAD risk in a Caucasian population comprising 4567 LOAD cases and controls. Our results show that carriers of the R47H variant have a significantly increased risk for LOAD (odds ratio = 7.40, p = 3.66E-06). In addition to Alzheimer's disease risk, we also examined the association of R47H with Alzheimer's disease–related phenotypes, including age-at-onset, psychosis, and amyloid deposition but found no significant association. Our results corroborate those of other studies implicating TREM2 as an LOAD risk locus and indicate the need to determine its biological role in the context of neurodegeneration.
Anesthesia and the Developing Brain: Relevance to the Pediatric Cardiac Surgery

Anesthetic neurotoxicity has been a hot topic in anesthesia for the past decade. It is of special interest to pediatric anesthesiologists. A subgroup of children potentially at greater risk for anesthetic neurotoxicity, based on a prolonged anesthetic exposure early in development, are those children receiving anesthesia for surgical repair of congenital heart disease. These children have a known risk of neurologic deficit after cardiopulmonary bypass for surgical repair of congenital heart disease. Yet, the type of anesthesia used has not been considered as a potential etiology for their neurologic deficits. These children not only receive prolonged anesthetic exposure during surgical repair, but also receive repeated anesthetic exposures during a critical period of brain development. Their propensity to abnormal brain development, as a result of congenital heart disease, may modify their risk of anesthetic neurotoxicity. This review article provides an overview of anesthetic neurotoxicity from the perspective of a pediatric cardiac anesthesiologist and provides insight into basic science and clinical investigations as it relates to this unique group of children who have been studied over several decades for their risk of neurologic injury.
Employing behavioral methods to improve the context of care in a public psychiatric hospital: Reducing hospital reliance on seclusion/restraint and psychotropic PRN medication

Many behaviorally trained scientist-practitioners have noted the poor utilization of behavioral interventions in psychiatric treatment settings. However, few have applied their behavior change skills to improve the organizational systems that are failing. This study first reviews the additive impact of a three-phase organizational change program, grounded in behavioral science, to reduce seclusion/restraint reliance in a public psychiatric hospital. It then describes a variation of the procedure that was subsequently applied to the problem of psychotropic prn medication reliance, both within the hospital and to a specific ward that evinces relatively high reliance. Significant reductions were realized in reliance on these procedures for the management of difficult cases. The results supplement previous evidence of the value of behavioral methods for individualized and ward-level program interventions by demonstrating that they also hold value for identifying relevant organizational problems and for instigating, strengthening, and maintaining organizational system changes to improve the quality of care. The advantages of a grounding in behavioral science and intervention methods for the provision of health care in management of public systems, as well as guidelines for behavioral clinicians who wish to enhance their impact on such systems, are discussed.
Migration and remyelination by oligodendrocyte progenitor cells transplanted adjacent to focal areas of spinal cord inflammation

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Exogenous cell replacement in MS lesions has been proposed as a means of achieving remyelination when endogenous remyelination has failed. However, the ability of exogenous cells to remyelinate axons in the presence of inflammation remains uncertain. We have explored the remyelinating capacity of an oligodendrocyte progenitor cell line CG-4 transduced with the GFP gene and transplanted adjacent to a zymosan-induced focal demyelination model in the rat spinal cord. The resulting zymosan-induced lesions were characterized by persistent macrophage/microglia activation, focal demyelination, degeneration of axons, and reactive astrogliosis. GFP(+) CG-4 cells were found to migrate preferentially toward the inflammatory lesion and survive inside the lesion. A proportion of GFP(+) CG-4 cells differentiated into mature oligodendrocytes and remyelinated axons within the lesion. These findings suggest that grafted oligodendrocyte progenitors may migrate toward areas of inflammation in the adult rat spinal cord, where they can survive and differentiate into myelinating oligodendrocytes.
Multi-objective optimization models for patient allocation during a pandemic influenza outbreak

Pandemic influenza has been an important public health concern with several historical outbreaks in 1918, 1957, and 1968. During an influenza pandemic outbreak, hospitals are often overwhelmed by the surge demand of influenza patients. It is important to prepare response plans to react to a pandemic influenza outbreak. Because of the widespread effect of the disease and the increased demand on limited medical resources, collaboration among hospitals both in planning and in response is necessary. This paper focuses on patient and resource allocation among hospitals in a healthcare network. Mathematical models are built to optimize the patient allocation considering two objectives related to patients' cost of access to healthcare services: (1) minimization of the total travel distance by patients to hospitals; and (2) minimizing the maximum distance a patient travels to a hospital. Moreover, the models help to predict a resource shortage during an outbreak; this prediction will alert decision makers to consider increasing the medical capacity or requesting additional capacity from state or national agencies. In addition, the model aids in the determination of the optimal allocation of the additional resources, when available, among hospitals by considering the above two objectives related to patients' cost of access to services. A case study from Metro Louisville, Kentucky, is presented to demonstrate how the models would aid in patient allocation during a pandemic influenza outbreak.
Diffusion waves in the soil

Abstract Periodically altering boundary conditions can be used to define seasonal and diurnal gas diffusion waves in soils. The amplitude and phase properties of the propagated diffusion waves provide an indirect means for measuring the gas diffusion coefficient in the soil. Modeled gas distributions obtained using these coefficients compare well with the known experimental data.
THE EFFECT OF MOISTURE STRESS ON NURSERY–GROWN GUAYULE WITH REFERENCE TO CHANGES IN RESERVE CARBOHYDRATES

IN A PREVIOUS paper, Kelley, Hunter, and Hobbs (1945) reported on the effects of soil moisture stresses on nursery-grown guayule, Parthenium argentatum A. Gray, with respect to the amount and type of growth and subsequent growth responses on transplanting. The results included in the present paper are based on samples from a portion of the same experimental plots but are concerned with the effect of soil moisture stresses on changes in reserve carbohydrates, and 89 per cent ethanol solution levulins and 89 per cent ethanol insoluble levulins, in guayule tissues. This additional study was made possible by recent work which elucidated the nature of the reserve carbohydrates in the guayule plant (McRary and Traub, 1944; Hassid et al., 1944; Traub and Slattery, 1946a, 1946b; Traub, Slattery, and Walter, 1946). According to Traub (1946b), and contrary to the results reported by Spence and McCallum (1935), the rubber hydrocarbon in guayule apparently does not function as a reserve food. Although MeRary and Traub (1944) and Hassid et al. (1944) reported the presence of inulin in guayule, Traub and Slattery (1946a, 1946b) showed that the main reserve carbohydrates in this plant are levulins, with inulin second in importance from the standpoint of total amounts present. Traub and Slattery (1946a, 1946b) have also shown that the measurement of the relative proportion of the 89 per cent ethanol soluble levulins, and 89 per cent ethanol insoluble levulins is a more sensitive tool in plant physiological research than the estimation of the total levulins and inulin. Since the free sugars are present in guayule stems and roots in relatively small amounts, Traub and Slattery (1946a, 1946b) conclude that the monosaccharides are not reserve materials but function as the carbohydrates of translocation. McRary and Slattery (1945) have reported on a method for the estimation of pentosans in guayule. The detailed plan of the experimental plots and the methods for maintaining and measuring soil moisture stresses are included in the paper by Kelley, Hunter, and Hobbs (1945) and need not be repeated here in full. The following brief excerpts,
Insulin-receptor interaction in isolated fat cells.

Abstract We have presented data which attempt to summarize recent observations relating to the interaction between insulin and its receptor on the surface of isolated fat cells. The data suggest that the receptors contain, as an essential component, some rapidly renewable polypeptide element. Furthermore, they suggest that sulfhydryl residues, present on the cell surface, are important participants in the insulin-like action of certain small molecules, and perhaps in the action of insulin itself. It seems probable that the binding of insulin to the receptor induces a conformational change within the receptor, which then generates a signal to the cell. The nature of this signal and the specific enzyme systems which it regulates are unknown. But, among other effects, it activates the glucose transport system and reduces the level of cyclic AMP within the cell. Whether these effects are sufficient to fully explain the antilipolytic action of insulin and the stimulation of protein synthesis remains unknown.
A note on the problem of flexure of prismatical beams

Abstract In the classical St Venant flexure solution all differential equations and certain boundary conditions are satisfied exactly, while other boundary conditions are satisfied approximately only. In this note an alternate solution to the flexure problem is considered, in which the components of stress which do not act over the end sections of the beam are again set identically equal to zero, the same as in the St Venant solution. However, in place of St Venant's exact satisfaction of the stress-strain differential equations we now associate the approximate satisfaction of boundary conditions with an approximate satisfaction of the stress-strain relations, via use of the principle of minimum complementary energy. The possible applications of the foregoing results are illustrated by the solution of two problems concerning the effect of transverse shear deformability and of end section warping constraint on deflection and shear center location for a circular and a semi-circular cross-section cantilever, respectively.
Topological strings in d < 1

We calculate correlation functions in minimal topological field theories. These twisted versions of N = 2 minimal models have recently been proposed to describe d < 1 matrix models, once coupled to topological gravity. In our calculation we make use of the Landau-Ginzburg formulation of the N = 2 models, and we find a direct relation between the Landau-Ginzburg superpotential and the KdV differential operator. Using this correspondence we show that the minimal topological models are in perfect agreement with the matrix models as solved in terms of the KdV hierarchy. This proves the equivalence at tree-level of topological and ordinary string thoery in d < 1.
Prevention: A Report of Progress and Momentum into the Future

Prevention is a critical component in the spectrum of interventions that also include traditional clinical treatments and rehabilitation. As reported in several meta-analyses, significant progress has been made in developing efficacious preventive interventions for a variety of problems. While there is the need for continued development of preventive interventions and for deepening our understanding of how they achieve their effects, increased attention is turning to the dissemination of effective prevention programs. We discuss that and related topics that have momentum to carry themselves into prevention's future.
Neurotensin: peptide for the next millennium

Neurotensin is an endogenous tridecapeptide neurotransmitter (pGlu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Try-Ile-Leu-OH) that was discovered by Carraway and Leeman in bovine hypothalami in the early 1970s. Since then this peptide has been the subject of a multitude of articles detailing discoveries related to its activity, receptors, localization, synthesis, and interactions with other systems. This review article does not intend to summarize again all the history of this fascinating peptide and its receptors, since this has been done quite well by others. The reader will be directed to these other reviews, where appropriate. Instead, this review attempts to provide a summary of current knowledge about neurotensin, why it is an important peptide to study, and where the field is heading. Special emphasis is placed on the behavioral studies, particularly with reference to agonists, antagonists, and antisense studies, as well as, the interaction of neurotensin with other neurotransmitters.
Are interpretations of video defecographies reliable and reproducible

Video defecography is a dynamic investigation which can influence surgical decision making in constipated patients. A study was therefore undertaken to assess the inter and intraobserver variability in video defecography. Specifically, we sought to assess the interpretation of video defecographies by a group of observers with the same training, guidelines and standards. To determine interobserver variation, four independent observers, two blinded to the patient's history, reviewed 100 randomly sequenced video defecographies performed in constipated patients. The presence or absence of sigmoidocele, rectocele, intussusception or prolapse was noted. Adequate or improper function of the puborectalis, anal canal opening, anorectal angle (ARA) and grade of emptying of the rectum were also assessed. Two weeks after the initial assessment, intraobserver variation was determined by a repeat blinded review of unlabelled randomly sequenced studies. The results of interobserver accuracy for sigmoidoceles, rectoceles, intussusception, rectal prolapse, rectal emptying, opening of the anal canal, puborectalis contraction and straightening of the ARA and rectal emptying were 89.5%, 46.0%, 87.5%, 97.5%, 86.5%, 88.5%, 83.0%, and 80.0%, respectively. The intraobserver variations were 88.5%, 83.8%, 80.5%, 94.5%, 77.0%, 84.8%, 80.5% and 85.5%, respectively. Prior knowledge of the patient's history did not significantly influence the outcome. In summery, video defecography has an overall accuracy of 83.3% and as such is a valid tool in assessing constipated patients.
Simplified Methods for Determination of Calcium and Magnesium in the Saliva

Calcium, magnesium, and other metals are firmly bound in un-ionized complexes by certain organic compounds which have been called complexones. Certain dyes have a similar although weaker, metal-binding capacity. If the color of such a dye is distinctly different from that of its complex with a metal, it can be used as an indicator for titration of the metal ion in question with a complexone. Techniques based upon this principle have been rapidly developed during the last few years. For determination of the alkaline earth metals, disodium ethylene diamine tetraacetate (EDTA) has been applied most often; a basic paper on this subject is that of Biedermann and Schwarzenbach.' In the biologic field, methods have been evolved to determine calcium in plasma3 and in serum, urine, and spinal fluid15 by titration with EDTA, using murexide (ammonium purpurate) as indicator. Another technique uses Eriochrome Black T as indicator for Mg ions. This dye shifts from red to blue when all Mg ions have been bound by the EDTA titration solution. It can hardly be used for titrations of Ca alone, because its color shift is then too gradual and indistinct. If Ca and Mg are present simultaneously, however, Ca is bound first by the EDTA, and a sharp end point is obtained in the Mg range. The total amount of Ca and Mg can thus be determined; if Mg is determined in a separate sample after the Ca has been precipitated as the oxalate, Ca is obtained as the difference. Such methods have been applied mainly in water analysis,5" 11 but also for determinations in biologic fluids.9 A third method, used for ultra-micro estimations on serum," involves the same determination of Ca and Mg, followed by the separate determination of Mg by a special colorimetric method"; Ca is obtained as the difference.
Valley susceptibility of interacting electrons and composite fermions

Abstract We report magnetotransport measurements of integer and fractional quantum Hall states in an AlAs quantum well where two conduction band valleys are occupied. By monitoring the valley level crossings for these states as a function of applied symmetry-breaking strain, we determine the “valley susceptibility” (the change of valley population with strain) for both electrons and composite Fermions. The data reveal that these valley susceptibilities are significantly enhanced over the band values, reflecting the role of strong interaction. Moreover, the measured valley susceptibilities are quite similar to the values of spin susceptibility, establishing the analogy between the spin and valley degrees of freedom.
SYNTHETIC OFF-AXIS LIGHT CURVES FOR LOW-ENERGY GAMMA-RAY BURSTS

We present results for a large number of gamma-ray burst (GRB) afterglow light curve calculations, done by combining high-resolution two-dimensional relativistic hydrodynamics simulations using RAM with a synchrotron radiation code. Results were obtained for jet energies, circumburst medium densities, and jet angles typical for short and underluminous GRBs, different observer angles, and observer frequencies from low radio (75 MHz) to X-ray (1.5 keV). We summarize the light curves through smooth power-law fits with up to three breaks, covering jet breaks for small observer angles, the rising phase for large observer angles, and the rise and decay of the counterjet. All light curve data are publicly available on the Web. The data can be used for model fits to observational data and as an aid for predicting observations by future telescopes such as LOFAR or the Square Kilometer Array and will benefit the study of neutron star mergers using different channels, such as gravitational-wave observations with LIGO or Virgo. For small observer angles, we find jet break times that vary significantly between frequencies, with the break time in the radio substantially postponed. Increasing the observer angle also postpones the measured jet break time. The rising phase of the light curve for large observer angle has a complex shape that cannot always be summarized by a simple power law. Except for very large observer angles, the counterjet is a distinct feature in the light curve, although in practice the signal will be exceedingly difficult to observe by then.
The relationship between cortical electrical activity and regional cerebral glucose metabolic rate in rats exposed to 3 atmospheres absolute oxygen

The regional cerebral metabolic rate for glucose (rCMRgl) was autoradiographically measured in conscious rats during 180–210 min of exposure to 3 atmospheres absolute oxygen (ATA O2), 3 ATA N2-O2 normoxia and air at 1 ATA. The exposure time and oxygen pressure in the present study were purposely matched to a parallel project in human subjects. The electrocorticogram (ECoG) was continuously recorded throughout the exposure. According to the ECoG responses, the oxygen-exposed rats fell into two categories: (1) ‘resistant’ ones, those without changes in ECoG throughout the exposure; and (2) ‘sensitive’ rats, those with changes in EcoG before or during the rCMRgl measurements. The observed ECoG changes were increased slow wave activity in the δ range, which was in some cases followed by paroxysmal electrical discharges. No changes in rCMRgl were observed in oxygen-exposed ‘resistant’ rats as compared to air breathing or N2-O2 normoxic rats at 3 ATA. However, in the ‘sensitive’ rats there were increases in rCMRgl in 8 of the 28 neuroanatomical structures examined as compared to the air breathing and 3 ATA normoxic controls. It is concluded that the increase in rCMRgl are related to the onset of the oxygen-induced preconvulsive changes in ECoG.
Dimensional stability and micromechanical properties of materials for use in an Orbiting Astronomical Observatory.

This paper considers the problem of irreversible dimensional changes of the order of one thousandth of an inch per inch in several candidate materials for orbiting observatories. Although there are a number of potential sources for such dimensional changes, those given major consideration here are applied stresses and residual stresses. Results of room-temperature microyield strength (MYS) and microcreep tests to detect permanent strains associated with both short- and long-duration loading are reported for several engineering materials, including four aluminum alloys (2024, 5456, 6061, and 2014), I400 beryllium, TZM molybdenum, AZ31 magnesium, two titanium alloys (Ti-6Al-4V and Ti-5Al-2.5Sn), 321 stainless steel, a graphite/epoxy composite, and low-expansion glass ceramics. The data indicate that: metallic materials have no true elastic limit; the MYS cannot be predicted reliably from, and is appreciably less than, the conventional yield strength: significant microcreep and stress relaxation can occur at stresses somewhat below the MYS.
Current therapy of chronic liver disease.

The study of chronic liver disease has been hampered by insufficient information relative to the pathogenesis of the many forms of hepatitis. Consequently, well-designed treatment strategies are frequently lacking. Wilson’s disease is characterised by excessive copper accumulation in the liver and other organs. While d-penicillamine is clearly effective, many patients may not tolerate its many adverse effects. Trientine, oral zinc and unithiol have all shown promise as therapeutic alternatives.
Review of fluorosis risk of self‐applied topical fluorides: dentifrices, mouthrinses and gels

– The literature on the risks of dental fluorosis and the benefits from the use of fluoride dentifrices, mouthrinses and self-applied gels has been briefly reviewed. While there are several studies that have investigated the impact of dentifrices on the development of dental fluorosis, results are mixed. Although there is far less research investigating the relationship between the use of mouthrinses and dental fluorosis, the available evidence generally fails to identify this technology as one of the major causes of dental fluorosis. Although there is little direct evidence to suggest that the use of self-applied fluoride gels contributes to the development of denial fluorosis, ingestion of fluoride from these systems is of genuine concern and their use by preschool age children is not recommended.
High-performance liquid chromatography of seized drugs at elevated pressure with 1.7 μm hybrid C18 stationary phase columns

Abstract High-performance liquid chromatography (HPLC) separation of drugs at elevated pressure with 1.7 μm hybrid C18 stationary phase columns was investigated. This technique, which uses instrumentation engineered to handle the narrow peaks and high back pressures generated by 1.7 μm particle columns, provided significantly better resolution and/or faster analysis than conventional HPLC and capillary electrophoresis (CE). The use of 2 mm internal diameter (i.d.) columns of 3–10 cm length has been evaluated for the separation of basic and neutral drugs, drug profiling, and general screening (including acidic drugs). For these applications, compared to conventional HPLC and CE, it provided up to 12× and 3× faster analyses, respectively. Precision was excellent for both isocratic and gradient analyses. For retention time and peak area, RSDs of ≤0.1% were obtainable. Fifteen anabolic steroids and esters were well separated in a 2.5 min gradient. For drug profiling, compared to HPLC and CE, approximately twice as many peaks were resolved. HPLC at elevated pressure is also well suited as a general screening technique. Twenty-four solutes of varying drug classes including narcotic analgesics, stimulants, depressants, hallucinogens, and anabolic steroids were fully separated in a 13.5 min gradient.
Malaria in pregnancy

This review summarizes the epidemiology, clinical course, and diagnosis of malaria. The influence of infection during pregnancy upon maternal and neonatal anemia, stillbirth, preterm labor, low birth weight, and congenital malaria is discussed. Options for treatment and prophylaxis during pregnancy are presented.
Renal dysfunction after thoracic aortic surgery requiring deep hypothermic circulatory arrest: definition, incidence, and clinical predictors.

Objective: The purpose of this study was to evaluate renal dysfunction (RD) after thoracic aortic surgery (TAS) requiring deep hypothermic circulatory arrest (DHCA), to determine the influence of definition on RD after TAS-DHCA, to determine univariate predictors of RD after TAS-DHCA, and to determine multivariate predictors for RD TAS-DHCA. RD was defined in 3 ways: (1) >25% reduction in creatinine clearance, (2) >50% increase in serum creatinine, and (3) >50% increase in serum creatinine with an abnormal peak serum creatinine (>1.3 mg/dL for men and >1.0 mg/dL for women). Study Design: Retrospective and observational. Study Setting: Single large university hospital. Participants: All adults requiring TAS-DHCA in 2000 and 2001. Main Results: The cohort size was 144. Antifibrinolytic exposure was 100%: aprotinin 66% and aminocaproic acid 34%. The incidence of RD TAS-DHCA was 22.9% to 38.2%, depending on the definition. The incidence of renal replacement therapy was 2.8%. Multivariate predictors for RD after TAS-DHCA were sepsis, aprotinin exposure, preoperative hypertension, age, and donor exposures. Conclusions: Although RD after TAS-DHCA varies substantially because of definition, it is still very common. Its multivariate predictors merit further focused research to enhance perioperative protection of the kidney.
Octyl Butyrate, an Effective Attractant for the Yellowjacket

Davis et al. (1969) determined that heptyl butyrate (HB) is a highly specific attractant for yellowjackets, especially for the common western species, Vespula pensylvanica (Saussure). This lure appears to be superior to 2,4-hexadienyl butyrate, the compound used as the standard of comparison in the several studies by Davis et al. (1967, 1968) and by McGovern et al. (1970). Therefore, for the past 3 years, we have conducted tests designed to compare heptyl butyrate with another promising lure, octyl butyrate (OB).
Long-term effects of the family bereavement program on multiple indicators of grief in parentally bereaved children and adolescents.

Nearly 4% of American children experience the death of a parent before the age of 18 (Social Security Administration, 2000). The death of a parent is a major stressful event that has been found to increase risk for a wide range of mental health problems in childhood and adulthood (Cerel, Fristad, Verducci, Weller, & Weller, 2006; Lutzke, Ayers, Sandler, & Barr, 1997; Melhem, Walker, Moritz & Brent, 2008). Recent studies have extended the research on the effects of parental bereavement by focusing on grief as a set of cognitive and affective responses that are distinct from mental health symptoms and that have significant implications for healthy functioning. Although several studies have investigated the effects of intervention programs to reduce mental health problems of parentally-bereaved children (Currier, Holland, & Neimeyer, 2007), no randomized experimental trials have examined the effects of interventions on children’s or adolescents’ grief responses. The current study uses data from a six-year follow-up of a randomized experimental trial of the FBP, to assess the program’s impact on grief responses of children and adolescents. Because researchers have only recently focused on the assessment of child and adolescent grief, we first discuss issues related to assessment. We then discuss the results of research on the effects of interventions with parentally-bereaved children and issues in evaluating such programs. Finally, we describe the goals of the current study.
Cerebral perfusion imaging in acute stroke.

Herein, the author discusses four perfusion technologies, including the diffusible tracer methods—xenon-enhanced computed tomography (CT) and single photon emission CT with various radioisotopes—and the nondiffusible tracer techniques—CT perfusion and magnetic resonance (MR) perfusion and diffusion. The methods for and important issues in the performance of each technique are presented, along with the accuracy of the data acquired with each technique, as demonstrated with experimental studies. In addition, the use of each technique in the evaluation of patients with acute stroke and their relative advantages and disadvantages are presented.
Keeping internet marketing up and running: potential disasters and how to plan for them

E-commerce is critical to a company's overall marketing efforts. This article presents examples of some of the potential disasters that can threaten a company's e-commerce website. In addition the article provides steps in disaster recovery planning (DRP). Whether a disaster is natural or manmade, an effective DRP will help prevent or minimise the effects of disasters on company e-commerce operations. A well-designed DRP can help companies avoid costly interruptions to business.
Synthesis and Biological Activity of Sugar-Fluorinated 2′,3′-dideoxy-4′-thioribofuranosyl Nucleosides

Abstract The efficient DAST fluorination of deoxy-4′-thiopyrimidine nucleosides is reported. The cytidine analogue 3b was marginally effective against HIV.
STATs and Gene Regulation

STATs (signal transducers and activators of transcription) are a family of latent cytoplasmic proteins that are activated to participate in gene control when cells encounter various extracellular polypeptides. Biochemical and molecular genetic explorations have defined a single tyrosine phosphorylation site and, in a dimeric partner molecule, an Src homology 2 (SH2) phosphotyrosine-binding domain, a DNA interaction domain, and a number of protein-protein interaction domains (with receptors, other transcription factors, the transcription machinery, and perhaps a tyrosine phosphatase). Mouse genetics experiments have defined crucial roles for each known mammalian STAT. The discovery of a STAT in Drosophila , and most recently in Dictyostelium discoideum , implies an ancient evolutionary origin for this dual-function set of proteins.
The energy balance of divertor discharges in the PDX tokamak

Abstract The energy balance of divertor discharges in the PDX tokamak has been studied as a function of the divertor geometry, heating method, and discharge parameters. In the original open divertor geometry, energy flow to the neutralizers accounted for 50–60% of the input energy, while radiation from the main plasma accounted for 20–40%, depending on the density and the heating source. For single-null discharges in the modified closed divertor geometry, the main plasma radiation remains at a similar level, but the neutralizer deposition decreases to
On the dimensionality of psychological processes

In general, most of the techniques now in common use for the determination of the dimensionality of MDS spaces tend to under-estimate the number of dimensions needed to represent the underlying configuration accurately. This tendency is exaggerated when time-sequenced MDS observations are under study. Fortunately, econometric time-series (autocorrelation) procedures may prove helpful in resolving this problem [6].
Isols and burnside's lemma

Abstract A nonnegative integer is called a number, a collection of numbers a set and a collection of sets a class. Suppose P is a partition of a finite set σ into nonempty finite sets; the members of P are called blocks. If the finite group G acts on the finite set σ, it induces a partition PG of σ whose blocks are the orbits of G. Writing card Δ for the cardinality of a collection Δ we have 1. (A) if P = (δ1,…, δk), then Σi=1k card δi = card σ, 2. (B) if G = (g1,…, gt), βi = {xϵσ | gi(x) = x}, k = card PG, then Σi=1t = kt (Frobenius-Burnside). This paper deals with generalizations of (A) and (B), in particular with the case where all blocks of P and orbits of G remain finite, while the roles of the numbers card βi, k and t are played by isols. The main results are presented in Section 5. An application to enumeration theory is discussed in Section 6.
Molecular Architecture of the KvAP Voltage-Dependent K+ Channel in a Lipid Bilayer

We have analyzed the local structure and dynamics of the prokaryotic voltage-dependent K+ channel (KvAP) at 0 millivolts, using site-directed spin labeling and electron paramagnetic resonance spectroscopy. We show that the S4 segment is located at the protein/lipid interface, with most of its charges protected from the lipid environment. Structurally, S4 is highly dynamic and is separated into two short helices by a flexible linker. Accessibility and dynamics data indicate that the S1 segment is surrounded by other parts of the protein. We propose that S1 is at the contact interface between the voltage-sensing and pore domains. These results establish the general principles of voltage-dependent channel structure in a biological membrane.
Ab initio QM/MM study of class a β-lactamase acylation : Dual participation of Glu166 and Lys73 in a concerted base promotion of Ser70

β-Lactamase acquisition is the most prevalent basis for Gram-negative bacteria resistance to the β-lactam antibiotics. The mechanism used by the most common class A Gram-negative β-lactamases is serine acylation followed by hydrolytic deacylation, destroying the β-lactam. The ab initio quantum mechanical/molecular mechanical (QM/MM) calculations, augmented by extensive molecular dynamics simulations reported herein, describe the serine acylation mechanism for the class A TEM-1 β-lactamase with penicillanic acid as substrate. Potential energy surfaces (based on approximately 350 MP2/6-31+G* calculations) reveal the proton movements that govern Ser70 tetrahedral formation and then collapse to the acyl-enzyme. A remarkable duality of mechanism for tetrahedral formation is implicated. Following substrate binding, the pathway initiates by a low energy barrier (5 kcal mol-1) and an energetically favorable transfer of a proton from Lys73 to Glu166, through the catalytic water molecule and Ser70. This gives unpro...