cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of the Irreversible Inhibition of High‐Affinity Choline Transport Produced by Hemicholinium Mustard

The inhibition of high-affinity choline transport by hemicholinium mustard (HCM), an alkylating analogue of hemicholinium-3, was examined in rat brain synaptosomes and guinea pig myenteric plexus. In synaptosomes, 50% high-affinity choline transport inhibition occurs with an HCM concentration of 104 nM (4-min incubation). A 10-min preincubation with 10 microM HCM results in essentially complete (greater than 95%) inactivation that persists after washing. Low-affinity choline transport in synaptosomes is unaffected by HCM inhibition at all concentrations examined (1-50 microM). Time course experiments indicate that the maximum irreversible inhibition (58%) seen after a 1-min preincubation with 500 nM HCM decreases to 46% inhibition after a 15-min preincubation; however, analysis of variance reveals that this difference is not significant. HCM inhibition of acetylcholine release from myenteric plexus-longitudinal muscle preparations persists for at least 2 h after removal of drug from the incubation bath; this inactivation can be prevented by coincubation with a high choline concentration during treatment with the mustard. In contrast, inhibition produced by the parent compound hemicholinium-3 is largely reversed by washing in both preparations examined. The observed potency and selectivity of HCM suggest its usefulness as a covalent probe for high-affinity choline transport.
An experimental and comparative study of jet penetration in supersonic flow.

A series of experiments was conducted in which H^ or N2 was injected at Mach numbers of 1.00, 1.31, 1.50, and 1.67 from a nozzle in a flat plate transversely into a Mach 2.72 free airstream. The structure of the emergent jet was recorded in schlieren photographs, and injectant concentration profiles at several locations in the near downstream (x/dj* < 10) region from gas samples. Normalized penetration was found to be governed by both the ratio of the jet pressure to an effective back pressure (behind a shock in the airstream) and the ratio of jet to freestream momentum. Absolute penetration was not substantially increased by increasing the stagnation pressure of the sonic jets, but was increased by going to supersonic injection. Both underexpanded sonic jets and supersonic jets produced normal shocks (Mach disks) in the emergent flow. The location of the Mach disk in the sonic injection tests was correlated with similar results of sonic injection into a quiescent medium. An analytical relationship based on a solid-body-drag model (equivalent inclined cylinder) best described the maximum concentration trajectory in the near downstream region where the effect of coaxial mixing has not yet become appreciable.
CO desorption from supported Ru particles

Abstract The low-pressure interaction of CO with small Ru particles supported on ultrahigh-vacuum-cleaved mica has been studied using flash thermal desorption, Auger electron spectroscopy, transmission electron microscopy, and transmission electron diffraction. Average particle size for these experiments varied between 1.2 and 6 nm. A careful search for CO decomposition on the Ru particles revealed no evidence for dissociation over pressure and temperature ranges of 10 −11 to 10 −6 Torr and 300 to 550 °C, respectively. Gas and heat treatments caused significant changes in the morphology and dispersion of the Ru particles which in turn affected CO desorption. These effects were particle-size dependent.
Optical Recording of Impulses in Individual Neurones of an Invertebrate Central Nervous System

FOR many purposes it would be a great advantage if one could measure the activity of individual neurones without the use of an electrode. Since the discovery of changes in the optical properties of axons that occur during the action potential1,2, it has been possible, in principle, to accomplish this using optical techniques. Recently, this was achieved in a giant axon using a merocyanine dye; in a stained axon a single action potential gave rise to a fluorescence increase which was detectable with a signal-to-noise ratio greater than 10 : 1 (ref. 3). Because the membrane area observed in the giant axon experiments was about 103 times larger than that of a 50 µm cell body, it was by no means evident that this fluorescent probe would be sensitive enough to monitor electrical activity in smaller cells. Happily, it is; with the merocyanine dye, we are able to detect action potentials in individual sensory neurones of leech segmental ganglia. We hope that this technique can be developed into a powerful tool for studying the functional organisation of populations of neurones.
A simplified water temperature model for the Colorado River below Glen Canyon Dam.

Glen Canyon Dam, located on the Colorado River in northern Arizona, has affected the physical, biological and cultural resources of the river downstream in Grand Canyon. One of the impacts to the downstream physical environment that has important implications for the aquatic ecosystem is the transformation of the thermal regime from highly variable seasonally to relatively constant year-round, owing to hypolimnetic releases from the upstream reservoir, Lake Powell. Because of the perceived impacts on the downstream aquatic ecosystem and native fish communities, the Glen Canyon Dam Adaptive Management Program has considered modifications to flow releases and release temperatures designed to increase downstream temperatures. Here, we present a new model of monthly average water temperatures below Glen Canyon Dam designed for first-order, relatively simple evaluation of various alternative dam operations. The model is based on a simplified heat-exchange equation, and model parameters are estimated empirically. The model predicts monthly average temperatures at locations up to 421 km downstream from the dam with average absolute errors less than 0.5°C for the dataset considered. The modelling approach used here may also prove useful for other systems, particularly below large dams where release temperatures are substantially out of equilibrium with meteorological conditions. We also present some examples of how the model can be used to evaluate scenarios for the operation of Glen Canyon Dam. Published in 2008 by John Wiley & Sons, Ltd.
Collective Focusing of an Intense Ion Beam

The space-charge coupling between the electrons and ions composing an intense, charge-neutralized ion beam is shown theoretically and experimentally to result in both species being brought to a common focus by a solenoidal magnetic lens. The collective focal length is the geometric mean of the focal lengths of the two species calculated independently. Upper and lower limits on the electron density allowed with the lens are derived.
Coherent and incoherent frontal patterns of multicomponent adsorption dynamics for variable linear fluid velocity in the fixed bed. I: Frontal patterns for linear adsorption isotherms

The coherent constant and proportional patterns for the equilibrium and nonequilibrium models of adsorption dynamics have been analyzed for linear adsorption isotherms at variable linear fluid velocity in the fixed bed. The Riemann, Rk, and Li invariants are found in the simple analytical form. The conditions of existence of the coherent patterns are obtained for the equilibrium and nonequilibrium models. The influence of the dispersive factors (kinetics and longitudinal dispersion) on the nature of the concentrations distributions is considered. For different nonequilibrium theoretical models, the simple formula is derived to calculate the mass transfer zone for the coherent constant patterns. It is shown that the dispersive factors can convert coherent patterns into incoherent ones.
Influences of retrieval processes on the spacing effect in free recall

A two-process theory of the spacing effect in free recall is presented and tested. The first process, differential organization, produces a positive correlation between the spacing of the presentations of repeated words and the number of different retrieval routes that can provide access to the words. The retrieval process interacts with the differential organization to control performance. If the cues used to retrieve the words provide approximately equal access to all retrieval routes, then the function relating spacing to recall will increase monotonically. If only selected retrieval routes are used, then the spacing function will be nonmonotonic. Evidence supporting this theory is that (a) the monotonic spacing function is most robust when subjects study the list using an organizational strategy, (b) cuing and directing retrieval with input words can result in a nonmonotonic effect of spacing when subjects have used an organizational strategy, and (c) directing retrieval by instructions about the order of recall can result in a nonmonotonic effect of spacing.
Reliability analysis of nondeterministic steel beam-columns

Abstract The main effort in both FORM (first-order-reliability methods) and SORM (second-order reliability methods) is to find the design point and the distance from this point to the origin of the space of uncorrelated and standardized normal variables in which the limit state surface is defined. Mathematically, this is a constrained minimization programming problem. In this paper, the solution to this problem is investigated by using a general purpose numerical optimization program containing a wide variety of algorithms. Furthermore, a new method for reliability analysis of nondeterministic steel beam-columns is proposed. This method is based on the total probability theorem. Numerical results are presented primarily to illustrate the application of the proposed method, and to compare different strategies for finding the solution.
Evidence for the cell surface expression of intracisternal A particle-associated antigens during early mouse development.

Abstract The cell surface expression of antigens detected by an antiserum to intracisternal A particles (IAP) was investigated using cytotoxicity, immunohistochemical, and immunoradiolabeling assays. IAP antigen(s) appear first on zygotes, show peak expression on two- to eight-cell embryos, and are not detectable on morulae, blastocysts, or inner cell mass. This is the first report of viral antigen expression on the cell surface during early mammalian development.
Preparation of Cross-Sectional Samples of Proton Exchange Membrane Fuel Cells by Ultramicrotomy for TEM

Transmission electron microscopy (TEM) microstructural characterization and microchemical analysis are two tools which can help relate proton exchange membrane (PEM) processing and resulting structure to fuel cell performance as well as structural changes to performance loss. A necessary first step is the preparation of specimens suitable for TEM characterization that maintain the spatial relationships among the various macro- and microcomponents of an entire PEM fuel cell. By carefully keeping the structure intact during the sample preparation, valuable information regarding the relationships among the many components of the fuel cell can he preserved. Previous TEM studies of PEM fuel cells have only been conducted on parts of the cell. No single preparation technique has resulted in keeping the entire fuel cell intact to image the entire cross section. In the present work, diamond knife ultramicrotomy has successfully been used to create thin sections suitable for TEM of entire PEM membrane electrode assemblies both before and after use in a fuel cell test stand.
A constraint-based method for solving sequential manipulation planning problems

In this paper, we describe a strategy for integrated task and motion planning based on performing a symbolic search for a sequence of high-level operations, such as pick, move and place, while postponing geometric decisions. Partial plans (skeletons) in this search thus pose a geometric constraintsatisfaction problem (CSP), involving sequences of placements and paths for the robot, and grasps and locations of objects. We propose a formulation for these problems in a discretized configuration space for the robot. The resulting problems can be solved using existing methods for discrete CSP.
Bounds on noise response of structures

Using continuum models, explicit closed-form formulas are developed for the RMS (attitude) error response of structures to sensor and actuator noise for collocated actuators/sensors as a function of both control gain parameters and structure parameters, for dissipative (PD) controllers, and performance bounds deduced therefrom. One conclusion is that the maximum attainable improvement in the RMS attitude response varying either structure parameters or control gains is 3 dB at most for the axial and torsion modes, the bending being essentially insensitive, whether the Bernoulli model or the anisotropic Timoshenko model is used. The results should be useful in CSI optimization in the preliminary design phase.
ALCOHOL HYPOGLYCEMIA. II. A POSTULATED MECHANISM OF ACTION BASED ON EXPERIMENTS WITH RAT LIVER SLICES.

Liver slices from fed and fasted rats were incubated in Krebs-Ringer phosphate (KRP) and Krebs-Ringer bicarbonate (KRB) with “tracer” and “substrate” quantities of uniformly abeled alanine-14C. The alanine was employed to provide a modulated generation of labeled pyruvate that might simulate the delivery of gluconeogenic precursor during starvation in vivo. The experimental manipulationswere designed to assess how the metabolic response to constant amounts of ethanol (10.0 mM) could be influenced by prevailing levels of pyruvate turnover (i.e., KRP vs. KRB); intrinsic intrahepatic pathways and preformed substrates (i.e., fed vs. fasted rats); and the availability of exogenous 3-carbon fragments (i.e., “tracer” vs. “substrate” alanine). Under conditions of limited pyruvate turnover and availability, ethanol inhibited the formation of glucose-14C and increased lactic acid-14C, although the consumption of oxygen was reduced only minimally. With “substrate” quantities of alanine in KRB, the net formation of g...
Quantification of SPECT myocardial perfusion images: Methodology and validation of the Yale-CQ method

Quantification of single photon emission computed tomography (SPECT) images is important for reproducible and accurate image interpretation. In addition, SPECT quantification provides important prognostic information. The purpose of this study was to validate the Yale circumferential quantification (Yale-CQ) method in phantom studies. Myocardial perfusion defects of varying extent and severities were simulated in a cardiac phantom with fillable defect inserts. Forty-five different phantom configurations simulated 45 different myocardial perfusion defect sizes, ranging from 1.6% to 32% of the cardiac phantom volume. Automatic processing was compared with manual processing in the phantom SPECT studies. The automatic Yale-CQ algorithm performed well in all phantom studies. Compared with manual processing, the mean absolute error for automatically determined center of short axis slices was 0.27 pixel in the x direction, 0.45 pixel in the y direction, and 0.15 pixel in radius. Quantification of phantom defects with the Yale-CQ method correlated well with actual defect sizes (R=0.99), but there was a systematic underestimation (mean error=−7.9%). With derived correction factors the overall correlation between 45 phantom defects and actual defect sizes was excellent, and the estimation error was significantly improved (R=0.98, mean error=−0.82% for manual method and −0.95% for automatic method). The automatic processing algorithm performs well for the phantom studies. Myocardial perfusion abnormalities can be quantified accurately by use of the Yale-CQ method. Quantified SPECT defect size can be expressed as a percentage of the left ventricle.
Oestradiol up-regulates oestrogen receptor, cyclophilin, and glyceraldehyde phosphate dehydrogenase mRNA concentrations in endometrium, but down-regulates them in liver

Oestradiol regulates reproductive physiology and cardiovascular health in women. In the endometrium of ovariectomized ewes, previous work demonstrated that a single dose of oestradiol (50 microg) up-regulates oestrogen receptor-alpha (ER) and progesterone receptor (PR) gene expression within 24 h. Here we compared responses to different doses of oestradiol and different dosing regimens in two diverse tissues: endometrium and liver. ER, c-fos, cyclophilin and glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA concentrations were analyzed on replicate RNA slot blots in both tissues, while PR and apolipoprotein AI (apo AI) mRNA concentrations were only analyzed in endometrium or liver, respectively. Along with ER mRNA, oestradiol strongly up-regulated GAPDH and cyclophilin mRNA concentrations in endometrium. In liver, however, oestradiol down-regulated them, along with apo AI mRNA. Responses to different doses and dose regimens, including repeated 50 microg doses, were similar to those evoked by a single 50 microg dose of oestradiol. Thus, oestradiol appears to have all-or-none effects which include up-regulation of ER, cyclophilin and GAPDH gene expression in endometrium and down-regulation of ER, apo AI, cyclophilin and GAPDH gene expression in liver. These results illustrate the sharp contrast between two mammalian tissues in their responses to physiological levels of oestradiol.
A comparison of phenytoin dosing methods in private practice seizure patients.

Summary: In an attempt to evaluate the accuracy of phenytoin (PHT) pharmacokinetic dosage adjustments in a private practice setting, three single dose-concentration pair methods and three multiple point PHT pharmacokinetic dosing methods were studied. Dose and concentration data from 28 patients seen in a private neurology practice were utilized for the study. From a comparison of these methods in private practice seizure patients, it appears that the Bayesian feedback method may be the most accurate in making routine PHT dosage adjustments, perhaps by minimizing the contribution of unknown variables within the Bayesian approach. RESUME Dans le but d'evaluer l'exactitude de l'adaptation de posologie pharmacocinetique de la PHT dans des conditions de pratique privee, 3 methodes d'evaluation par paire de concentration en dose unique et 3 methodes de dosages pharmacocinetiques de la PHT a determination multiple ont eteetudiees. Les resultats des concentrations et des doses chez 28 patients vus en pratique privee neurologique ont ete utilises pour cette etude. La comparaison de ces methodes chez des epileptiques suivis en pratique privee montre que celle du feed-back Bayesien pourrait ětre la plus exacte pour l'adaptation de la posologie de la PHT en routine, peut-ětre en minimisant la contribution de variables inconnues dans l'approche bayesienne. RESUMEN Intentando evaluar la exactitud, de los ajustes farmacocineticos de dosis de fenitoina (PHT) en un consultorio privado de neurologia, se estudiaron 6 metodos farmacocineticos de dosificacion, 3 de los cuales requerian que se proveyera una sola dosis (par dosis sencilla-concentracion) y los 3 restantes requerian multiples dosis (par dosis multiple-concentracion). Se utilizaron para el estudio datos de dosis y concentracion de 28 pacientes epilepticos. Si se comparan los metodos de dosificacion en dichos pacientes, parece ser que el metodo Bayesiano seria el mas exacto para hacer ajustes de rutina en la dosis de PHT quizas porque dicho metodo minimiza variables desconocidas y su posible contribucion en el calculo de la dosis final. ZUSAMMENFASSUNG In einem Versuch, die Genauigkeit der Phenytoin (PHT) Pharmakokinetik entsprechend der Dosierung in einer privaten Praxis zu prufen, wurden verschiedene Methoden (3 Einzeldosis- Konzentrationspaare und 3 PHT-Profile) untersucht. Dosierungs- und Konzentrationsdaten lieferten 28 Patienten einer privaten neurologischen Praxis. Ein Vergleich dieser Methoden bei Patienten einer Privatpraxis lat vermuten, das die feedback-Methode nach Bayes die besten Ergebnisse fur die routinemaige PHT-Dosisoptimierung liefert. Das mag daran liegen, das der Einflu unbekannter Variablen bei Anwendung dieser Methode minimiert wird.
Calpains, mitochondria, and apoptosis

Mitochondrial activity is critical for efficient function of the cardiovascular system. In response to cardiovascular injury, mitochondrial dysfunction occurs and can lead to apoptosis and necrosis. Calpains are a 15-member family of Ca2+-activated cysteine proteases localized to the cytosol and mitochondria, and several have been shown to regulate apoptosis and necrosis. For example, in endothelial cells, Ca2+ overload causes mitochondrial calpain 1 cleavage of the Na+/Ca2+ exchanger leading to mitochondrial Ca2+ accumulation. Also, activated calpain 1 cleaves Bid, inducing cytochrome c release and apoptosis. In renal cells, calpains 1 and 2 promote apoptosis and necrosis by cleaving cytoskeletal proteins, which increases plasma membrane permeability and cleavage of caspases. Calpain 10 cleaves electron transport chain proteins, causing decreased mitochondrial respiration and excessive activation, or inhibition of calpain 10 activity induces mitochondrial dysfunction and apoptosis. In cardiomyocytes, calpain 1 activates caspase 3 and poly-ADP ribose polymerase during tumour necrosis factor-α-induced apoptosis, and calpain 1 cleaves apoptosis-inducing factor after Ca2+ overload. Many of these observations have been elucidated with calpain inhibitors, but most calpain inhibitors are not specific for calpains or a specific calpain family member, creating more questions. The following review will discuss how calpains affect mitochondrial function and apoptosis within the cardiovascular system.
A Pharmacokinetic/Pharmacodynamic Approach to Predict Total Prednisolone Concentrations in Human Plasma

Prednisolone and prednisone are two widely used corticosteroids for various inflammatory and immune diseases. Prednisolone is the active form of prednisone in vivo. Total prednisolone in plasma exhibits nonlinear pharmacokinetics mainly due to its nonlinear protein binding. Other factors such as reversible metabolism (or interconversion between prednisolone and prednisone), competitive protein binding from endogenous cortisol, cortisol circadian rhythm, and prednisolone mediated cortisol suppression complicate prednisolone pharmacokinetics. This study was aimed to develop a new approach to describe the nonlinear pharmacokinetics of total prednisolone and predict total prednisolone concentrations in plasma. Based on literature datasets, a linear two-compartment pharmacokinetic model was developed to adequately describe the reversible metabolism between free prednisone and prednisolone. Cortisol and prednisolone protein binding were described via the sum of a Langmuir and linear type binding. The endogenous cortisol circadian rhythm and cortisol suppression during prednisone or prednisolone exposure were described with a previously reported linear release rate pharmacokinetic/pharmacodynamic (PK/PD) model. By combining the pharmacokinetic models for free prednisone and prednisolone, the linear release rate model for cortisol suppression, and competitive protein binding between cortisol and prednisolone, we were able to predict total prednisolone concentrations in plasma. The predicted total prednisolone concentrations in plasma were in good agreement with the literature reported data. Thus, this PK/PD approach shows that the combination of nonlinear protein binding, cortisol circadian rhythm, and cortisol suppression could account for the nonlinearity of total prednisolone. In addition, it also allows a valid prediction of total prednisolone in plasma after either prednisone or prednisolone administration.
Evaluation of Role of Factor V Leiden Mutation in Fatal Pulmonary Thromboembolism

Abstract Association of a mutation in the coagulation factor V gene (FV Leiden) with deep vein thrombosis and pulmonary thromboembolism has been well documented in the literature, but no study has specifically screened cases of fatal pulmonary thromboembolism for the mutation. This study sought to determine whether FV Leiden plays a role in the pathogenesis of fatal pulmonary thromboembolism. We isolated DNA from archived paraffin-embedded tissues derived from 46 necropsy cases in which pulmonary thromboembolism was listed as the cause of death n =27 or was secondarily associated with death n =19 . FV Leiden genotypes were determined by using polymerase chain reaction and Mnl I digestion of amplified products. The Leiden mutation occurred in the heterozygous state in one (2.1%) of the necropsy specimens. The prevalence of the mutation was higher (8.7%) in gender- and ethnic-matched blood donor controls. The FV Leiden mutation is not independently associated with fatal pulmonary thromboembolism in the group of patients analyzed. The results suggest different etiologies for nonfatal, chronic deep vein thrombosis/pulmonary thromboembolism and fatal, acute pulmonary thromboembolism.
The 1990s and Beyond: Determining the Need for Community Health and Primary Care Nurses for Rural Populations*

Increased numbers of primary care and advanced practice nurses with unique generalist skills will be required to meet the accelerating physiologic and sociocultural health care needs of rural populations. Several factors have been identified that will influence the demands and position of community-based nurses in rural practice settings during the next decade. A back-to-basics type of health care offered out of a growing elderly population; technological breakthroughs that make it possible for more chronically ill patients to live at home; serious substance abuse and other adolescent problems; AIDS; and high infant morbidity and mortality statistics are only some of the concerns that will demand nursing intervention. These changes speak to the need for improved nursing coordination, stronger collegial relationships, and better communication between physicians and nurses. Health care is moving in new directions to offer more efficient and technologically sophisticated care. These changes enhance the need for clinically expert educators who teach and jointly practice in programs with a rural focus. Telecommunications, and heightened computer literacy, will play a major role both in nursing education and clinical practice. The goals of kindergarten through 12th grade health promotion and disease prevention strategies in school health will be the norm and will require better prepared, and positions for, school nurses. More midwives and public health nurses will be needed to care for the growing population of sexually active adolescents who are in need of family planning and prenatal care. Underinsured and indigent populations will continue to fall within the purview of midlevel practitioners, as will providing anesthesia services in small rural hospitals. The transition of some rural hospitals into expanded primary care units (e.g., EACHs and RPCHs), and new models of case management will greatly influence nursing demands. This paper will further identify critical areas of advanced practice nursing within community settings, including new relationships with other health care providers, and will introduce strategies upon which rural health policy recommendations for the 1990s can be addressed.
Oxidation of sulfoxides by hydrogen peroxide, catalyzed by methyltrioxorhenium(VII)

Dialkyl and diaryl sulfoxides are oxidized to sulfones by hydrogen peroxide using methyltrioxorhenium as the catalyst. The reaction rate is negligible without a catalyst. The kinetics study was performed in CH3CN−H2O (4:1 v/v) at 298 K with [H+] at 0.1 M, conditions which make the equilibration between MTO and its peroxo complexes more rapid than the oxygen-transfer step. The values for the rate constant for the oxygen-transfer step lie in the range 0.1−3 L mol-1 s-1. The rate constants were significantly smaller than for the oxidation of sulfides to sulfoxides. A study of ring-substituted diaryl sulfoxides yielded kinetics results that are consistent with nucleophilic attack of the sulfur atom on the peroxide oxygen group since ρ = −0.65. The results cited refer to the reactions of the diperoxo from the catalyst, MeRe(O)(η2-O2)2H2O. The monoperoxo complex showed no measurable reactivity toward sulfoxides, in contrast with the situation for nearly every other substrate. That unusual finding suggests a hyd...
Fate of Gelatin–Resorcinol–Formaldehyde/Glutaraldehyde Adhesive on Femoral Vessel Morphology

Abstract Several clinical reports have demonstrated that gelatin–resorcinol–formaldehyde/glutaraldehyde (GRFG) glue can be useful in the repair of acute aortic dissection; however, the cellular and extracellular events that follow GRFG application, as well as the mechanisms responsible for the long-term strength and adhesive properties of GRFG, remain unclear. Accordingly, the present study examined the long-term effects of GRFG adhesive application on femoral vessel extracellular structure and composition. The left and right femoral artery and vein were sterilely exposed in adult rats, and GRFG (2 mL) was applied between and around one pair of vessels. An equivalent amount of sterile saline was applied to the contralateral vessels to serve as an intrinsic control. At either 1 ( n = 6) or 2 ( n = 6) months postoperatively, the lower extremities were perfusion fixed and harvested to preserve the native anatomy and cytoarchitecture of the femoral region. Gross examination of the specimens revealed no evidence of necrosis or wound breakdown. Tissue blocks (4 μm) were then sectioned perpendicular to the treated vessel region and subjected to histomorphometric analysis using computer-assisted microscopy. The perivascular capsule area, relative content of fibrillar collagen, and number of nucleated cells within the interstitial space were computed. At 1 and 2 months following the application of GRFG adhesive, perivascular capsular size increased by 42 and 221%, respectively. Perivascular interstitial collagen content increased by 21% at 1 month and by 50% at 2 months. The nucleated cell number increased by 107% at 1 month and by 166% at 2 months. This cellular infiltrate appeared to be of fibroblastic morphology. Thus, a potential contributory mechanism to the long-term strength and adhesive capacities of GRFG adhesive may be extracellular remodeling and not the intrinsic properties of GRFG glue itself.
Interactions of thyrotropin releasing hormone and morphine sulfate in rodents.

Abstract Thyrotopin releasing hormone (TRH) produces “wet dog shakes” in rats similar to those observed during morphine withdrawal. The shaking behavior precipitated by morphine abstinence can be exacerbated by TRH administration while the other components of the morphine withdrawal syndrome remain unchanged. Morphine, chlorpromazine, apomorphine, and Δ 9 -tetrahydrocannabinol effectively block shakes induced by either TRH administration or morphine withdrawal. These results suggest the possibility that endogenous TRH may be associated with the “wet dog shakes” observed as a portion of morphine's abstinence syndrome in rats. However, TRH is unable to alter the stereospecific binding of morphine in vivo or in vitro , and naloxone fails to potentiate the number of TRH-induced shakes. TRH has no antinociceptive properties, and it cannot alter those of morphine. These data suggest that more than one neuromechanism may be responsible for shaking behavior in rats.
Effect of branching on rod-coil block polyimides as membrane materials for lithium polymer batteries

This paper describes a series of rod-coil block co-polymers that produce easy to fabricate, dimensionally stable films with good ionic conductivity down to room temperature for use as electrolytes for lithium polymer batteries. The polymers consist of short, rigid rod polyimide segments, alternating with flexible, polyalkylene oxide coil segments. The highly incompatible rods and coils should phase separate, especially in the presence of lithium ions. The coil phase would allow for conduction of lithium ions, while the rigid rod phase would provide a high degree of dimensional stability. An optimization study was carried out to study the effect of four variables (degree of branching, formulated molecular weight, polymerization solvent and lithium salt concentration) on ionic conductivity, glass transition temperature and dimensional stability in this system.
Ionic diffusion through Calcite (CaCO3) layer during the reaction of CaO and CO2

This work explores the dominating ionic diffusion mechanism during the formation of calcite (CaCO3) by CaO and CO2 using inert marker experiment. It was found that the solid-phase ionic diffusion is dominated by the counter-current diffusion of inward CO32− anion groups and outward O2− anions. That is, after the initial CaCO3 layer is formed on the solid surface, the gaseous CO2 reacts with the O2− anions on the solid surface and forms CO32− anion groups, which then diffuse inward through the CaCO3 layer to the CaCO3/CaO interface to form new CaCO3. Meanwhile, the O2− anions diffuse outward from the CaCO3/CaO interface through the CaCO3 layer to the solid surface to react with the gaseous CO2. In order to satisfy local and global charge balance, the molar ratio of inward CO32− anion groups to outward O2− anions is 1:1. Even though the Ca2+ cation and O2− anion have theoretically lower diffusion energy barriers than the CO32− anion group, the possibility of co-occurrence of a cation vacancy and a neighboring anion vacancy for the co-current diffusion of a Ca2+cation and an O2− anion is extremely low. This extremely low possibility makes this co-diffusion process a less favorable pattern, thereby making the counter-current diffusion the dominating ionic diffusion process during the formation of calcite (CaCO3).
Systematic reflection as a learning opportunity

As Shelby Hunt’s article in this issue illustrates, reflective manuscripts offer significant opportunities to illuminate the processes and drivers that lead to successful theory adoption and success. Reflective articles can serve as educational resources to pass down institutional knowledge within the field and illustrate routes to generating influential theory contributions. Building from literature on “post-mortem” project management analysis, this article proposes a system of five questions that can be used to guide reflective manuscripts.
Nitric oxide downregulates lung macrophage inflammatory cytokine production

Abstract Background . Inflammatory cytokine production contributes to lung injury after lung ischemia reperfusion and during lung transplant rejection. Although nitric oxide has been demonstrated to reduce lung injury associated with the adult respiratory distress syndrome, it remains unknown whether the mechanism of nitric oxide's beneficial effects involves reducing lung macrophage inflammatory cytokine production. The purpose of this study was to determine whether nitric oxide downregulates lung macrophage inflammatory cytokine production. Methods . Lung macrophages were harvested by bronchoalveolar lavage (10 6 macrophage per milliliter from normal Sprague-Dawley rats, 6 animals per group) and treated under ex vivo tissue culture conditions with the nitric oxide releasing compound S -nitoso- N -acetyl-d, l-penicillamine (0, 10 −5 , 10 −4 , 10 −3 , 10 −2 mol/L) before induction of inflammatory cytokines with endotoxin, (50 ng/mL for 24 hours). Supernatants were assayed for inflammatory cytokine production (tumor necrosis factor α, interleukin-1β) by enzyme-linked immunosorbent assay. Results . Continuous nitric oxide release by S -nitoso- N -acetyl-d, l-penicillamine decreased lung macrophage tumor necrosis factor-α and interleukin-1β production in a dose-dependent fashion (6 rats per group; data were analyzed for significance [ p Conclusions . Nitric oxide decreases inflammatory cytokine production by lung macrophage. The mechanism of nitric oxide's beneficial effects may be partially attributable to decreased production of inflammatory cytokines. Nitric oxide may serve an expanded role for reducing inflammatory cytokine production during acute lung injury, ischemia-reperfusion–induced inflammation, or lung transplant rejection.
Linking Personality to Helping Behaviors at Work: An Interactional Perspective

Previous efforts to elucidate dispositional antecedents of organizational citizenship behaviors have yielded equivocal results. The current study presents and tests a theoretical argument for expecting conscientiousness to interact with interpersonal dimensions of personality in predicting helping behaviors. As hypothesized, the responses of 374 women and their supervisors reveal significant interactions between conscientiousness, on the one hand, and agreeableness, extraversion, and emotional stability, on the other, in predicting helping behaviors. Clarifying the relationship between personality and helping, these results suggest that the impact of conscientiousness in a social context depends on a positive interpersonal orientation. The implications of these findings for research and practice are discussed.
The ERK/MAP kinase pathway couples light to immediate‐early gene expression in the suprachiasmatic nucleus

Signalling via the p42/44 mitogen-activated protein kinase (MAPK) pathway has been identified as an intermediate event coupling light to entrainment of the mammalian circadian clock located in the suprachiasmatic nucleus (SCN). Given this observation, it was of interest to determine where within the entrainment process the MAPK pathway was functioning. In this study, we examined the role of the MAPK pathway as a regulator of light-induced gene expression in the SCN. Towards this end, we characterized the effect pharmacological disruption of the MAPK cascade has on the expression of the immediate-early genes c-Fos, JunB and EGR-1. We report that uncoupling light from MAPK pathway activation attenuated the expression of all three gene products. In the absence of photic stimulation, inhibition of the MAPK pathway did not alter basal gene product expression levels. Light-induced activation of cAMP response element (CRE)-dependent transcription, as assessed using a CRE-LacZ transgenic mouse strain, was also disrupted by blocking MAPK pathway activation. These results reveal that the MAPK cascade functions as one of the first transduction steps leading from light to rapid transcriptional activation, an essential event in the entrainment process. MAPK pathway-dependent gene expression in the SCN may result, in part, from stimulation of CRE-dependent transcription.
The Distribution and Implications of Heat Flow from the Gregory Rift in Kenya

Abstract Data from geothermal mapping along the Kenyan Gregory Rift zone using ground and aerial infrared techniques indicate that an average of 11–30 MW/km are advectively emitted along the rift. The bulk of the advected heat is lost through the central part of the Kenyan dome. Two other secondary geothermal sites are at the northern and southern limits of the rift adjacent to rift bifuration zones. These three geothermal sites are separated by ≈ 300 km. Active thermal fields occur only 1 7 as frequently as rift volcanoes. Geothermal spacing could be controlled by the length of the heat source at the lithosphere-upper mantle boundary, the thickness of the crust and the length of the rift segment between major structural breaks. At faster spreading centers the heat source is probably more continuous and following Elder's models should produce upwelling domes much more frequently than along the East African Rift. Advective cooling on one section of the East Pacific Rise at 21°N indicates that domes should appear every 40–80 km. If this is the case then approximately four times more heat is given off along a kilometer of East Pacific Rise crest as it is emitted along the Gregory Rift.
Organic chemistry: Catalysis in tight spaces

An acid has been found to catalyse the formation of a common chemical group, the spiroacetals, and to control which mirror-image isomer of the group is made. The key to success is the acid's bulky molecular structure. See Letter p.315 The sex pheromone olean, found in the olive fruitfly, has the interesting property that one mirror-image variant attracts males and the other females. Olean contains as its only source of chirality a spiroacetal, a natural product consisting of an acetal (a molecule that contains two oxygen–carbon single bonds at the same carbon atom) joining two rings. Until now chemists have not been able to mimic the enzymatic feat of synthesizing this type of chiral acetal centre, but this paper reports the design and synthesis of new chiral acids that can catalyse selective spiroacetalizations, including one to furnish olean with remarkably high selectivity. A distinctive characteristic of these artificial catalysts is an extremely tight chiral pocket, reminiscent of those found in natural enzymes.
Trends in epidemiology of knee arthroplasty in the United States, 1990-2000.

Objective There is little information on longitudinal trends in the epidemiology of total knee arthroplasty (TKA). This study was undertaken to determine whether, during the past decade, TKA rates increased in younger adults and older adults, whether utilization of TKA increased among minorities, and whether more patients underwent surgery at high-volume hospitals. Methods TKA cases (n = 443,008) were extracted from the 1990–2000 Nationwide Inpatient Sample database. TKA trends for 3 time periods were obtained (1990–1993 [period I], 1994–1997 [period II], and 1998–2000 [period III]). Results Between period I and period III, the proportion of TKAs performed increased by 95.2% in the 40–49-year age group and by 53.7% in the 50–59-year age group. Black patients and Hispanic patients were more likely to undergo TKA in period III than in period I (odds ratio [OR] = 1.6, 95% confidence interval [95% CI] 1.5–1.6 and OR 2.7, 95% CI 2.5–2.9, respectively). However, white patients accounted for 93.0%, 89.9%, and 87.5% of TKAs in the 3 time periods, respectively. In period III, the proportion of patients undergoing surgery in high-volume hospitals increased compared with periods I and II. Both mortality and length of hospital stay diminished significantly in period III, but the rate of discharge to an inpatient facility increased by 89.7% (period I to period III). Conclusion Over the past decade, TKA was increasingly performed in younger patients, which suggests a broadening of indications for this procedure. Although utilization of TKA increased among minorities, the vast majority of TKAs were performed in white patients. Further efforts to narrow this disparity are required. The shift toward TKAs being increasingly performed at high-volume centers may improve surgical outcomes. Finally, the effect of increased discharge to inpatient facilities on TKA outcomes needs to be ascertained.
Geonium "K" experiment using spin dependency of cyclotron frequency supports g data of earlier geonium "S" work.

Abstract By substituting the relativistic spin state dependence of the cyclotron frequency for the continuous Stern-Gerlach effect and running the geonium atom as a microsynchrocyclotron accelerator we have detected spin flips of the individual trapped electron. In our initial efforts we have been able to obtain a simple symmetric spin resonance about 4-fold narrower instead of a complex asymmetric one and also to support but not as yet seriously test the result of the earlier geonium "S" work, g/2 = 1. 001 159 652 185 5(40).
The Credibility Crisis of Community Regulation

The credibility crisis of Community regulation is symbolized by the recurrent food scares, and even more by official reactions such as the refusal of the German and French governments to abide by the decision of the Commission to lift the ban on exports of British beef. However, the crisis is not new, nor is it limited to food safety. Problems of regulatory credibility in the EC/EU arise at different levels. Some are rooted in the deep structure of the founding treaties, while other problems result from path-dependent aspects of the integration process, from institutional inertia, or from the pursuit of short-term advantages. This article is primarily concerned with the second group of problems, but a short discussion of the more fundamental issues seems useful as a reminder of the limits of what can be achieved by piecemeal institutional engineering. The article addresses two specific threats to credibility: the mismatch between the Community’s highly complex and differentiated regulatory tasks and the available administrative instruments; and the problem of credible commitment caused by the increasing level of politicization and parliamentarization of the Commission. The solution to both sets of problems, it is argued, may be found in a more far-reaching delegation of powers to independent European agencies embedded in transnational networks of national regulators and international organizations. Recent theoretical advances in the area of institutional design and procedural controls suggest that such networks could be made to satisfy all reasonable requirements of subsidiarity, accountability and efficiency.
Approximate Analysis of Queues in Series with Phase-Type Service Times and Blocking

Queues in series with phase-type service times and finite queue capacities are considered. Servers may get blocked due to the limited space in queues. An approximation method is developed to compute the steady state probability distributions of the number of units in each queue. Three cases are considered: the first queue has an infinite capacity; the first queue has a finite capacity; and the first server is always busy. The method decomposes the system of tandem queues into individual queues with revised arrival and service processes and with queue capacities. Then, each queue is analyzed in isolation within an iterative scheme which relates these queues to each other. The approximation method is computationally efficient and it appears to have an acceptable error level.
Beyond Content, Deeper than Delivery: What Critique Feedback Reveals about Communication Expectations in Design Education

In design education, the critique is a communication event in which students present their design and critics provide feedback. Presumably, the feedback gives the students information about their progress on the design. Yet critic feedback also serves a socializing function—providing students information about what it means to communicate well in the design education context. Using a qualitative research methodology, this study explores what critic feedback reflects about expected communication competencies in design studios. Results suggest that communication competence in this setting involves interaction management, demonstration of design evolution, transparent advocacy of intent, explanation of visuals, and the staging of the performance—all of which imply a communicative identity for students that is tethered to the content and delivery of the presentation, but has implications beyond the content and delivery to the broader disciplinary culture. Implications of this study provide insight for faculty and students involved in pedagogical spaces in which feedback plays an important role in the instructional process—suggesting its potential for shaping disciplinary identities, relationships, and social contexts.
Study of the higher order Lamb resonances on elastic shells: their prediction and interpretation

We study all the resonances generated on elastic shells for a ka from 0 to 500 for steel and aluminum for a thickness of 5%. We observe the lowest order symmetric and antisymmetric model or Lamb resonances, waterborne and pseudo-Stoneley resonances and the higher order Lamb modes Ai and Si where i equals 1, 2, 3 . . .. We plot some of the phase velocities of some of the relevant resonances out to a ka of 500 and indicate simple expressions that predict the onset of each of the resonances. We demonstrate by use of partial wave analysis that the new expressions that predict the onset (critical frequencies) of the highest order Lamb modes are reliable. Further, interesting phenomena occur at the inception of some of the resonances and we discuss some of those cases.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.