cssi/SciSciGPT-SciSciNet huggingface dataset:
Orexigenic Hormone Ghrelin Attenuates Local and Remote Organ Injury after Intestinal Ischemia-Reperfusion

Background Gut ischemia/reperfusion (I/R) injury is a serious condition in intensive care patients. Activation of immune cells adjacent to the huge endothelial cell surface area of the intestinal microvasculature produces initially local and then systemic inflammatory responses. Stimulation of the vagus nerve can rapidly attenuate systemic inflammatory responses through inhibiting the activation of macrophages and endothelial cells. Ghrelin, a novel orexigenic hormone, is produced predominately in the gastrointestinal system. Ghrelin receptors are expressed at a high density in the dorsal vagal complex of the brain stem. In this study, we investigated the regulation of the cholinergic anti-inflammatory pathway by the novel gastrointestinal hormone, ghrelin, after gut I/R. Methods and Findings Gut ischemia was induced by placing a microvascular clip across the superior mesenteric artery for 90 min in male adult rats. Our results showed that ghrelin levels were significantly reduced after gut I/R and that ghrelin administration inhibited pro-inflammatory cytokine release, reduced neutrophil infiltration, ameliorated intestinal barrier dysfunction, attenuated organ injury, and improved survival after gut I/R. Administration of a specific ghrelin receptor antagonist worsened gut I/R-induced organ injury and mortality. To determine whether ghrelin's beneficial effects after gut I/R require the intact vagus nerve, vagotomy was performed in sham and gut I/R animals immediately prior to the induction of gut ischemia. Our result showed that vagotomy completely eliminated ghrelin's beneficial effect after gut I/R. To further confirm that ghrelin's beneficial effects after gut I/R are mediated through the central nervous system, intracerebroventricular administration of ghrelin was performed at the beginning of reperfusion after 90-min gut ischemia. Our result showed that intracerebroventricular injection of ghrelin also protected the rats from gut I/R injury. Conclusions These findings suggest that ghrelin attenuates excessive inflammation and reduces organ injury after gut I/R through activation of the cholinergic anti-inflammatory pathway.
Coupling efficiency of waveguide laser resonators formed by flat mirrors: Analysis and experiment

We present a new and more efficient method of calculating the losses of a waveguide laser resonator consisting of a hollow circular dielectric waveguide and flat mirrors, taking into account the effects of waveguide modes up to order HE 13 . Both symmetric and asymmetric cavities are considered. We show that low cavity losses, only slightly exceeding the HE 11 waveguiding losses, are predicted to be possible for much larger mirror distances than had previously been suspected, provided that an optimum total cavity length is chosen. The low losses arise when the HE 11 and HE 12 modes emerge from the guide with relative amplitudes and phases such that the returning diffraction patterns interfere to produce a narrow beam with low aperture losses. The theoretical predictions were checked experimentally for CO 2 lasers having various waveguide dimensions. Good qualitative agreement was found, but the optimum total cavity lengths were typically 3-5 percent longer than predicted. Possible explanations of this discrepancy are discussed. We also predicted and experimentally verified that variations of the cavity length over a few centimeters can exert a coarse wavelength selectivity sufficient to determine the band and branch on which a CO 2 laser oscillates; conversely, that for a grating tuned laser, the cavity length must be varied by a similar amount as the wavelength is tuned in order to maintain low cavity losses over the entire wavelength range.
Prospective Memory in HIV Infection: Is “Remembering to Remember” a Unique Predictor of Self-reported Medication Management?

Optimal adherence to antiretroviral medications is critical to the effective long-term management of HIV infection. Although prospective memory (ProM; i.e., “remembering to remember”) has long been theorized to play an important role in medication adherence, no prior studies have evaluated whether HIV-associated ProM impairment possesses unique predictive value in this regard. Results from this study demonstrate a robust association between ProM impairment and self-reported medication management in 87 HIV-infected persons currently prescribed antiretroviral medications. Specifically, more frequent ProM complaints and performance deficits on both laboratory and semi-naturalistic ProM tasks were all independently related to poorer self-reported medication management. A series of hierarchical regression analyses revealed that HIV-associated ProM impairment accounted for a significant amount of variance in self-reported medication management beyond that which was explained by other factors known to predict nonadherence, including mood disorders, psychosocial variables, environmental structure, and deficits on a traditional battery of neuropsychological tests. Overall, these findings support the hypothesis that ProM captures a unique and largely untapped aspect of cognition that is germane to optimal medication adherence. The potential benefits of individualized remediation strategies that are informed by conceptual models of ProM and specifically target medication adherence warrant further exploration.
Defining and identifying three-dimensional magnetic reconnection in resistive magnetohydrodynamic simulations of Earth’s magnetospherea)

Magnetic reconnection is thought to be the primary mode by which the solar wind couples to the terrestrial magnetosphere, driving phenomena such as magnetic storms and aurorae. While the theory of two-dimensional reconnection is well developed and has been applied with great success to axisymmetric and toroidal systems such as laboratory plasma experiments and fusion devices, it is difficult to justify the application of two-dimensional theory to nontoroidal plasma systems such as Earth’s magnetosphere. Unfortunately, the theory of three-dimensional magnetic reconnection is much less well developed, and even defining magnetic reconnection has turned out to be controversial. In this paper, recent progress in the use of magnetohydrodynamics (MHD) to address the physics of three-dimensional reconnection in Earth’s magnetosphere is reviewed. The paper consists of two parts. In the first part, various definitions of three-dimensional reconnection are reviewed, with the goal of mapping these definitions to sets...
Macroinvertebrate responses along a complex regulated stream environmental gradient

Samples were collected year-round over a one-year period at sites located downstream from a hypolimnetic-release reservoir on the Blue River, Colorado, to examine macroinvertebrate responses along a complex environmental gradient induced by river regulation. Six sampling sites were established in riffles downstream of the dam using approximately a geometric progression starting at 0.25 km. Ordination techniques were used to elucidate macroinvertebrate distributional patterns along the complex environmental gradient. The detrended correspondence analysis (DCA) showed a sequential faunal gradient with the most rapid change occurring within the first 2.0 km below the impoundment. Detrended canonical correspondence analysis (DCCA) was used to relate faunal distributions to downstream changes in environmental variables. Downstream decreases in periphyton standing crop and minimum temperatures, and downstream increases in food resources and maximum temperatures, were identified as the major variables structuring faunal assemblages. The combined use of different gradient analysis techniques proved useful for identifying distinct macroinvertebrate distributional patterns and the environmental variables that may be responsible for these patterns.
Circulatory and Metabolic Effects of Hypoxia in the Hyperinsulinemic Ovine Fetus

Fetuses of women whose diabetes is poorly controlled often exhibit hypoxemia and elevated catecholamine concentrations at birth. In the ovine fetus, experimental hyperinsulinemia results in hypoxemia, elevated catecholamine concentrations, and hemodynamic changes. Limited oxygen availability occurring during pregnancy-related complications and/or delivery may present an additional risk to the hyperinsulinemic fetus. In this study, we tested the hypothesis that hypoxia induced via acutely limiting oxygen availability compromises the hemodynamically and metabolically stressed but compensated hyperinsulinemic ovine fetus. Fetuses receiving insulin (n = 8) or placebo (n = 5) for 48 h were exposed to maternally induced hypoxia. Hypoxic hypoxia was associated with a surge in catecholamines in the hyperinsulinemic fetuses. During hypoxia, this group exhibited insulin-related sustained increases in the combined ventricular output and fetal body blood flow, accentuation of the prior insulin-related increase in blood flow to the heart, decreased systemic oxygen delivery, accentuation of the insulin-related increased oxygen extraction, reductions in the insulin-related increased systemic oxygen uptake, sustained increases in regional oxygen delivery to the heart and adrenal glands, reductions in the insulin-related increased delivery to the carcass, and decreased oxygen delivery to the kidneys and gastrointestinal tract. We conclude that, in the hyperinsulinemic ovine fetus, hypoxic hypoxia attenuates the hyperinsulinemia-mediated increased systemic oxygen uptake. Regional oxygen transport is preserved to vital regions (brain, heart, and adrenal glands) by increased perfusion and compromised to certain other regions (kidneys and gastrointestinal tract), because the increases in perfusion are insufficient to offset the limited oxygen availability.
Control of a chaotic system

The Lorenz equations are well known for their ability to produce chaotic motion. We investigate here the Lorenz system subject to a control input. Two different controllers are designed for this system, one based on linear methods and one based on a nonlinear analysis. The objective of the controller is to drive the system to one of the unstable equilibrium points associated with uncontrolled chaotic motion. Each controller is able to produce stable motion. However, the character of this motion may differ considerably, depending on adjustment of “Gains” used in the controller. In particular, the motion may contain chaotic transients. It is possible to create a system with intermediate-term-sensitive dependence on initial conditions, but with no such long-term dependence.
Exclusive decays of upsilons

Abstract The leading order contributions to decay rates of two-meson decays of an upsilon, in particular Y → K + K − , D + D − , are calculated using perturbative quantum chromodynamics. An interesting enhancement of Y → D + D − is found. The branching ratio of Y → D + D − to the upsilon's total hadronic width is larger than that of Y → K + K − by two orders of magnitude.
A conceptual model for demand management in the assemble-to-order environment

Abstract The term demand management encompasses the activities required to accept customer orders and promise them productive capacity. This activity is central to effective manufacturing planning and control. The popularity of just-in-time systems suggests that manufacturers are steadily losing authority for establishing order delivery dates, further confounding the demand management process. No reported research has suggested how this process can be performed. This paper presents a rigorous description of the demand management process in the assemble-to-order environment, as a mathematical model. The description provided in this model should be viewed as an initial attempt to define the complex challenges that arise in dealing with demand management on an operational level. The focus of this model is short-term decision making involved in controlling demand management—accepting orders and dispatching capacity to fill the orders. The problem is presented in the context of the assemble-to-order environment which requires the monitoring of both a final assembly schedule and a master production schedule. The factors involved in effective decision making for demand management including capacity availability, relative costs, and the relative timing of prospective customer orders are discussed. A simple example is presented to illustrate the performance of the mathematical model.
Genlocking to a video signal

Before overlaying color digital computer text or graphics data onto a television signal, a system must encode the graphics data into standard television format. This entails added horizontal and vertical synchronization signals and modulating the color information onto a subcarrier (usually 3.58 or 4.43 MHz). To avoid jagged distortions, the time base of the graphics signals must be locked to the horizontal and vertical sync pulses of the television signal. Similarly, for consistent reproduction of colors, the synthesized color subcarrier for the graphics must be in phase with that of the incoming video signal. Two new Raytheon integrated circuits, the TMC22070 genlocking digitizer and the TMC22190 video encoder, solve these problems cost-effectively. >
A new method for determining the heat of activation for relaxation processes

Abstract A straight line relationship is shown between t he heat of activation of a relaxation process and the temperature at which the maximum relaxation occurs. The utility of this relationship is pointed out as being the following: (1) a quick way of finding the heat of activation from a single measurement, (2) a means of helping to locate the position o a relaxation peak if its activation energy is known roughly from some other measurement, (3) an aid in analyzing mathematically the factors which describe a given phenomena.
Self-consistent chaotic transport in fluids and plasmas

Self-consistent chaotic transport is the transport of a field F by a velocity field v according to an advection-diffusion equation in which there is a dynamical constrain between the two fields, i.e., O(F,v)=0 where O is an integral or differential operator, and the Lagrangian trajectories of fluid particles exhibit sensitive dependence on initial conditions. In this paper we study self-consistent chaotic transport in two-dimensional incompressible shear flows. In this problem F is the vorticity ζ, the corresponding advection-diffusion equation is the vorticity equation, and the self-consistent constrain is the vorticity–velocity coupling z⋅∇×v=ζ. To study this problem we consider three self-consistent models of intermediate complexity between the simple but limited kinematic chaotic advection models and the approach based on the direct numerical simulation of the Navier–Stokes equation. The first two models, the vorticity defect model and the single wave model, are constructed by successive simplificati...
The solution structure of human thioredoxin complexed with its target from Ref-1 reveals peptide chain reversal

Abstract Background: Human thioredoxin (hTRX) is a 12 kDa cellular redox protein that has been shown to play an important role in the activation of a number of transcriptional and translational regulators via a thiol-redox mechanism. This activity may be direct or indirect via another redox protein known as Ref-1. The structure of a complex of hTRX with a peptide comprising its target from the transcription factor NF κ B has previously been solved. To further extend our knowledge of the recognition by and interaction of hTRX with its various targets, we have studied a complex between hTRX and a Ref-1 peptide. This complex represents a kinetically stable mixed disulfide intermediate along the reaction pathway. Results Using multidimensional heteronuclear edited and filtered NMR spectroscopy, we have solved the solution structure of a complex between hTRX and a 13-residue peptide comprising residues 59–71 of Ref-1. The Ref-1 peptide is located in a crescent-shaped groove on the surface of hTRX, the groove being formed by residues in the active-site loop (residues 32–36), helix 3, β strands 3 and 5, and the loop between β strands 3 and 4. The complex is stabilized by numerous hydrogen-bonding and hydrophobic interactions that involve residues 61–69 of the peptide and confer substrate specificity. Conclusion The orientation of the Ref-1 peptide in the hTRX–Ref-1 complex is opposite to that found in the previously solved complex of hTRX with the target peptide from the transcription factor NF κ B. Orientation is determined by three discriminating interactions involving the nature of the residues at the P −2 , P −4 and P −5 binding positions. (P 0 defines the active cysteine of the peptide, Cys65 for Ref-1 and Cys62 for NF κ B. Positive and negative numbers indicate residues N-terminal and C-terminal to this residue, respectively, and vice versa for NF κ B as it binds in the opposite orientation.) The environment surrounding the reactive Cys32 of hTRX, as well as the packing of the P +3 to P −4 residues are essentially the same in the two complexes, despite the opposing orientation of the peptide chains. This versatility in substrate recognition permits hTRX to act as a wide-ranging redox regulator for the cell.
Signaling to the epithelium is not sufficient to mediate all of the effects of transforming growth factor β and bone morphogenetic protein 4 on murine embryonic lung development

Many studies have suggested that transforming growth factor beta (TGF-beta) and bone morphogenetic protein 4 (Bmp4) regulate early development of the lung. In this study, administration of growth factors directly into the lumen of lungs grown in organ culture was used to limit their activity to the epithelium and test the hypothesis that signaling to the epithelium is sufficient to mediate the known effects of TGF-beta and BMP-4 on early lung development. Addition of TGF-beta1, beta2, or beta3 to the medium surrounding lungs grown in organ culture resulted in decreased branching, reduced cell proliferation, accumulation of alpha-smooth muscle actin protein (alpha-SMA) in the mesenchyme, and decreased expression of a marker for respiratory epithelium, surfactant protein-C (Sp-C). When TGF-beta1 was restricted to the epithelium, accumulation of alpha-SMA and inhibition of Sp-C expression were not observed but branching and proliferation were inhibited. In contrast, branching was not inhibited in lungs where TGF-beta2 or TGF-beta3 were restricted to the epithelium suggesting differences in the mechanism of signaling by TGF-beta1, TGF-beta2 or TGF -beta3 in lung. Addition of Bmp4 to the medium surrounding lungs grown in organ culture stimulated cell proliferation and branching morphogenesis; however, direct injection of Bmp4 into the lung lumen had no effect on proliferation or branching. Based on these data and data from mesenchyme-free cultures, we propose that the mesenchyme influences growth factor signaling in the lung.
A Zero-Footprint 3D Visualization System Utilizing Mobile Display Technology for Timely Evaluation of Stroke Patients

When a patient is accepted in the emergency room suspected of stroke, time is of the utmost importance. The infarct brain area suffers irreparable damage as soon as three hours after the onset of stroke symptoms. A CT scan is one of standard first line of investigations with imaging and is crucial to identify and properly triage stroke cases. The availability of an expert Radiologist in the emergency environment to diagnose the stroke patient in a timely manner only increases the challenges within the clinical workflow. Therefore, a truly zero-footprint web-based system with powerful advanced visualization tools for volumetric imaging including 2D. MIP/MPR, 3D display can greatly facilitate this dynamic clinical workflow for stroke patients. Together with mobile technology, the proper visualization tools can be delivered at the point of decision anywhere and anytime. We will present a small pilot project to evaluate the use of mobile technologies using devices such as iPhones in evaluating stroke patients. The results of the evaluation as well as any challenges in setting up the system will also be discussed.
High-field proton magnetic resonance spectroscopy reveals metabolic effects of normal brain aging

Abstract Altered brain metabolism is likely to be an important contributor to normal cognitive decline and brain pathology in elderly individuals. To characterize the metabolic changes associated with normal brain aging, we used high-field proton magnetic resonance spectroscopy in vivo to quantify 20 neurochemicals in the hippocampus and sensorimotor cortex of young adult and aged rats. We found significant differences in the neurochemical profile of the aged brain when compared with younger adults, including lower aspartate, ascorbate, glutamate, and macromolecules, and higher glucose, myo-inositol, N-acetylaspartylglutamate, total choline, and glutamine. These neurochemical biomarkers point to specific cellular mechanisms that are altered in brain aging, such as bioenergetics, oxidative stress, inflammation, cell membrane turnover, and endogenous neuroprotection. Proton magnetic resonance spectroscopy may be a valuable translational approach for studying mechanisms of brain aging and pathology, and for investigating treatments to preserve or enhance cognitive function in aging.
Measuring Social Status with Occupational Information: A Simple Method1

A measure of social status was devised: a multiple-choice question that obtains occupational information and is scalable with both the Duncan Socioeconomic Index and the Siegel Prestige Scale. The correlations of this device with other measures of social status and with tests of general ability were assessed in a study of white and black Navy recruits. The correlations were similar to those obtained with a conventional measure that relies on judges scaling occupational information elicited by an openended question. The present device may be a good prototype for a standardized, multiple-choice measure of social status.
Neuronal cell death in neonatal hypoxia-ischemia

Perinatal hypoxic-ischemic encephalopathy (HIE) is a significant cause of mortality and morbidity in infants and young children. Therapeutic opportunities are very limited for neonatal and pediatric HIE. Specific neural systems and populations of cells are selectively vulnerable in HIE; however, the mechanisms of degeneration are unresolved. These mechanisms involve oxidative stress, excitotoxicity, inflammation, and the activation of several different cell death pathways. Decades ago the structural and mechanistic basis of the cellular degeneration in HIE was thought to be necrosis. Subsequently, largely due to advances in cell biology and to experimental animal studies, emphasis has been switched to apoptosis or autophagy mediated by programmed cell death (PCD) mechanisms as important forms of degeneration in HIE. We have conceptualized based on morphological and biochemical data that this degeneration is better classified according to an apoptosis-necrosis cell death continuum and that programmed cell necrosis has prominent contribution in the neurodegeneration of HIE in animal models. It is likely that neonatal HIE evolves through many cell death chreodes influenced by the dynamic injury landscape. The relevant injury mechanisms remain to be determined in human neonatal HIE, though preliminary work suggests a complexity in the cell death mechanisms greater than that anticipated from experimental animal models. The accurate identification of the various cell death chreodes and their mechanisms unfolding within the immature brain matrix could provide fresh insight for developing meaningful therapies for neonatal and pediatric HIE.
Excess electrical noise during current flow through porous membranes separating ionic solutions.

Spectral analysis of electrical noise from various artificial membrane systems suggests that excess noise of anf −n spectral form, wheren is approximately unity, is not primarily a bulk phenomenon simply dependent on the number of charge carriers. Measurements from aqueous and nonaqueous electrolytic resistors, comprised of several different ionic species, show only flat power density spectra under applied currents, even at extreme dilutions. Excess noise off −n form is observed under applied d-c current in single pore membranes, as previously reported, but is also seen in multipore and polymer mesh membranes. Calculations based on single pore membrane noise data are in significant variance with the bulk charge carrier model proposed by Hooge. These observations suggest that such excess noise occurs in conjunction with anisotropic constraints to ion flow.
Central region design studies for a proposed 250 MeV proton cyclotron

Abstract The results of design studies of the central region for a proposed superconducting cyclotron for advanced cancer therapy are presented here. The studies considered a four sector cyclotron operating in the second harmonic (h = 2) acceleration mode capable of producing 250 MeV protons. The studies were based on detailed beam orbit calculations and the results presented here cover design considerations on the basis of beam centering, vertical focusing, and with an emphasis on phase selection.
Calorimetric determination of log Ki, ΔHiO, and ΔSiO values for the interaction of thiourea with Hg(CN)2 in water—formamide solvents at 25°C☆

Abstract Log K i , Δ H i O , and Δ S i O ( i = 1, 2) values have been determined calorimetrically at 25°C for the consecutive reaction of thiourea (Tu) with Hg(CN) 2 to form Hg(CN) 2 Tu 2 in formamide—water solvents. The log K i , Δ H ii O , and Δ S i O values determined in 20, 40, 60, 80, and 100% (w/w) formamide show little deviation from those which were determined previously in aqueous solution. The leveling nature of the formamide—water solvents is discussed and the results are compared with those obtained earlier in water and ethanol—water solvents.
Differential induction of numerical chromosome changes by sodium butyrate in two transformed cell lines.

Abstract Transformed cell lines generally exhibit similar response to a given chemical. However, when two transformed cell lines, the Chinese hamster (CHO 9) and mouse (L929) were treated with sodium butyrate (SB) to investigate its effect on chromosome distribution, the two lines behaved differently from each other. At concentrations as low as 10 −7 M, the CHO 9 cells exhibited polyploidy as well as errors of numerical distributions resulting in aneuploidy. The majority of aneuploid cells were in quasitetraploid range indicating an association between the induction of polyploidy and aneuploidy. Upon staining with spindle antibody, the CHO cells exhibited a disarray of spindle microtubules as well as an abnormal cytoskeleton. In many instances the metaphase chromosomes were found to have a distorted spindle or lack an associated spindle altogether. The L929 cells, however, turned out to be far less sensitive to SB: a 100-fold increase in concentration of sodium butyrate (10 −5 M) did not result in production of polyploid cells. However, when the extent of aneuploidy induction was measured by using a marker chromosome, both loss and gain of the chromosome was noticed. The effect of SB on the spindle was much more modest than it was the case with CHO cells as only minor disarray in cytoskeleton or spindle morphology was observed. The L929 cells, however, showed some effect on microtubule orientation as well as an effect on the segmentation of midbody. The application of SB resulted in less intense and more diffuse phosphorylation; the chromosomes had a punctate appearance of the label compared with the solid appearance on untreated cells. This was ture for both species. In mouse, the centromeric heterochromatin, which generally is intensely labeled, appeared to be labeled only as intensely as euchromatin. The data show that different transformed cell lines do not respond similarly to SB.
On the evaluation of biological hazards and competing risks

Abstract After some general remarks, and a brief explanation of Clifford's non-identifiability results for illness-death models, an attempt is made to view the competing-risk problem more biologically. The cause and time of death vary from individual to individual because they have different genetically determined susceptibilities and different life histories. Although one could define potential lifetimes associated with causes of death, averaging over different genetic susceptibilities means that from population data one cannot estimate the distribution of cause specific life spans in individuals with the same genetic susceptibility. In particular, the hazard curves for different genetic states cannot be resolved from population data.
THE QUANTIZATION OF THE RELATIVISTIC STRING

The classical field-dependent parametrization covariant Hamiltonian formulation of the open and the closed string is discussed. The formalism is not applicable to the open string. A conformally covariant formalism is developed for the open string. The Rohrlich gauge conditions are justified and applied. The parametrization of classical solutions is not uniquely fixed; the generators of rigid time translation in the parameter space remain first class. The constraints and gauge conditions are taken into account in the quantum theory as conditions on physical states. The required invariance of physical states under rigid displacement of parameter time leads to a mass superselection rule. The set of physical string quantum states is analogous to the set of states constructed by Di Vecchia, Del Guidice, and Fubini. A recursive construction is presented which permits the counting of physical states of any given mass, spin, and parity. Physical states lie on linearly rising Regge trajectories with one universal slope. The intercept of the leading trajectory is constrained only by the requirement that there be no tachyonic physical states. The quantization is carried out in four space-time dimensions.
Revisiting the form of dead time corrections for neutron coincidence counting

Abstract A standard nondestructive assay technique for determining the mass of plutonium in an item is passive neutron coincidence counting. In passive neutron coincidence counting, the dead time or rate loss corrections for the singles and doubles neutron counting rates are routinely made using empirical relationships that are based on the design and performance of the individual counter used to make the measurements. The empirical methods were developed ahead of any supporting theory for dead time losses and have worked well to date for the majority of safeguards measurement scenarios. Modern applications using highly efficient systems with short neutron lifetimes together with the challenges posed by highly multiplying items mean dead time corrections of higher fidelity are needed. While many attempts have been made to develop dead time corrections that are based on the physical principles of the measurements being performed, these corrections have often been found to be difficult to implement in a real system. For instance, Matthes and Haas developed an approach in 1985 which did not gain favor largely because the form of the doubles correction apparently required numerical integration which was difficult to implement with the computer technology of that time. A recent review into the approach that was developed by Matthes and Haas has determined that a straightforward analytical expression can be derived for the doubles correction that is similar to the singles rate correction that was developed in their original work. An analysis of the expressions is presented here to show how they relate to the traditional empirical methods. Further, we illustrate their implications and limitations. For instance the empirical methods do not address within burst losses i.e. rate related losses due to the correlated neutron bursts from fission, whereas the Matthes and Hass expression for singles counting does exhibit such an effect.
Electrodeposition of silver–copper bimetallic particles having two archetypes by facilitated nucleation

We describe two electrochemical methods by which the short-range ordering of two metals (M1 and M2) with respect to one another can be specified during the formation of bimetallic micro- and nanoparticles. These methods are based on the facilitated nucleation of metal M2 by electrodeposited particles of metal M1, as previously described by Deutscher and Fletcher in 1990 (J. Electroanal. Chem. 277 (1990) 1). We demonstrate these strategies using silver for metal M1 and copper for metal M2. Bimetallic core-shell particles having a silver core and a copper shell were obtained by electrodepositing silver particles first, and then electrodepositing copper using a small overpotential. Silver–copper ‘oligomers’, consisting of a central silver particle surrounded by one or more copper ‘satellite’ particles were obtained by first electrodepositing silver particles, assembling an n-alkane thiolate molecular layer on the surfaces of these particles from ethanolic solution, and then electrodepositing copper using a low overpotential. The structures of both types of bimetallic particles was determined using scanning electron microscopy in conjunction with spatially resolved X-ray fluorescence elemental analysis.
A Previously Undescribed Method of Song Matching in a Species with a Single Song “Type”, the Kentucky Warbler (Oporornis formosus)

The song of male Kentucky warblers consists of several repetitions of syllables containing 2 to 7 elements within a frequency range from 1.8 to 6.0 kHz. Each male has a single, individually distinctive song type that spans part or all of this frequency range. Song responses to playbacks of songs artificially elevated or lowered in frequency by 200 Hz show that a bird is able to alter its song in two ways. It may lower or raise the frequency range of the song or put more energy into the lower or higher frequencies within the song's elements to more closely match the energy distribution of the playback song. The syllable or element structure of the song is kept constant with only the song's energy distribution among frequencies changing. Thus, Kentucky warblers are able to alter their single song type to “match countersing” in a way similar to that of species with song repertoires who switch song types to match those of rivals. The Kentucky warbler may have a single songtype because of its ability to change its song's energy distribution. This ability may perform the same functions as song matching does in species with larger repertoires. This finding is discussed in relation to ideas on the evolution of song repertoires in intrasexual competition.
A message-passing model for highly concurrent computation

Abstract : Based on essentially the same computational model as the Torus, the cube uses a binary n-cube network instead of toroidal mesh, with the requested hardware upgrading of the nodes: a more powerful processor with a floating-point co-processor, a larger storage, full-duplex asynchronous channels. A version of C, extended with communication primitives is available as programming language, together with the required support software for loading the programs into the nodes. An important difference with the Torus, however, is the availability in the Cosmic Cube of a deadlock-free protocol for routing messages between any two nodes. The Torus was built on the premiss that locality of communication should be maintained by the programs; such a system is called a processing surface. The Cosmic Cube drops the locality requirement by providing a routing protocol between arbitrary nodes. The Cosmic Cube prototype proved so successful that the design was licensed and rapidly commercialized (1985). Several manufacturers are already offering "cube machines" which are routinely used by researchers at Caltech and elsewhere to solve computationally demanding scientific problems.
Compositionally-graded InGaAs–InGaP alloys and GaAsSb alloys for metamorphic InP on GaAs

Abstract Two approaches for metalorganic chemical vapor deposition (MOCVD)-grown compositionally graded metamorphic buffers on 6° offcut bulk GaAs were investigated. The first approach consisted of tandem graded layers of InGaAs and InGaP with compositional grading of the In concentration. This tandem approach was found to be necessary because phase separation in the InGaAs alloys leads to surface roughening and high threading dislocation density when grading to lattice constants greater than that of In 0.30 Ga 0.70 As. An In x Ga 1− x As graded buffer was grown at 700 °C for low In concentration ( X In =0–0.10) and then the growth temperature was decreased to 450 °C for high In concentration ( X In =0.10–0.30) to suppress the phase separation. The growth temperature was then increased to 650 °C and the graded In y Ga 1− y P system was implemented to continue grading the lattice constant from In 0.30 Ga 0.70 As to InP, which allowed us to achieve InP on 6° offcut GaAs with a threading dislocation density of 7.9×10 6 cm −2 and an RMS surface roughness of 33.0 nm on a 40 μm×40 μm AFM scale. The second approach used GaAsSb alloys with compositional grading of the Sb concentration. Graded mixed-anion GaAsSb alloys grown at 575 °C did not exhibit phase separation, resulting in high quality InP lattice constant films on GaAs without the need to transition to another material system for compositional grading. We demonstrated a GaAsSb alloy on GaAs (with a grading rate of 1.06% strain/μm) lattice-matched to InP with a threading dislocation density of 4.7×10 6 cm −2 and a roughness of 7.4 nm on a 40 μm×40 μm AFM scale. It was further demonstrated that the threading dislocation density of the GaAsSb graded buffer can be lowered to 2.7×10 6 cm -2 with a slower grading rate (0.64% strain/μm).
Promoting information literacy: A strategic approach

Abstract Faculty development workshops can be particularly effective if they address an issue or challenge faced by the faculty and present information literacy as part of an overall strategy for meeting that need. This article will discuss how Librarians at the University of Nevada, Las Vegas (UNLV), used this approach of capitalizing on faculty interests in an orientation workshop developed for the instructors of the entry-level Communications classes.
Total energies and energy gradients in electron propagator theory

From the second-order self-energy of electron propagator theory, one can obtain total energies for the initial, N-electron state and the final, N ± l-electron states. Recent derivations and computational studies have demonstrated the feasibility of calculating effective first-order density matrices corresponding to the electron-binding energies. One-electron properties and energy gradients of the final states are thereby made accessible. Applications to. the ground and excited states of CaCN and to C illustrate the capabilities of this method. © 1992 John Wiley & Sons, Inc.
Program/Abstract # 6The divergent development of marsupial limbs

The adult germ line of Caenorhabditis elegans hermaphrodites provides a well-established model for stem cell regulation and germline sex determination among other aspects of germline development and function. Here we turn to adult C. elegans males and investigate key features of the “mitotic region,” including its stem cell niche. We also compare features of adult hermaphrodites and males, which are oogenic and spermatogenic respectively. We find that the male mitotic region is responsible for germline self-renewal, as expected, and that some cellular features are similar in the two sexes. For example, all mitotic region cells actively cycle in both sexes. However, we also find that germ cells in the mitotic region, including stem cells, are sexually dimorphic. For example, the morphology of the mitotic region is sexually dimorphic and mitotic region cell cycles are faster in males than in hermaphrodites. In an attempt to ask whether intrinsic factors also control sex-specific features, we use germline sex determination mutants and discover feedback that lowers the mitotic index in the distal germline when gametes accumulate. Our findings extend the use of C. elegans germlines as a model for stem cell regulation and indicate that even the most immature adult germ cells have a sexual identity.
The Ambiguous Meanings of the Racial/Ethnic Categories Routinely used in Human Genetics Research

Many researchers are currently studying the distribution of genetic variations among diverse groups, with particular interest in explaining racial/ethnic health disparities. However, the use of racial/ethnic categories as variables in biological research is controversial. Just how racial/ethnic categories are conceptualized, operationalized, and interpreted is a key consideration in determining the legitimacy of their use, but has received little attention. We conducted semi-structured, open-ended interviews with 30 human genetics scientists from the US and Canada who use racial/ethnic variables in their research. They discussed the types of classifications they use, the criteria upon which they are based, and their methods for classifying individual samples and subjects. We found definitions of racial/ethnic variables were often lacking or unclear, the specific categories they used were inconsistent and context specific, and classification practices were often implicit and unexamined. We conclude that such conceptual and practical problems are inherent to routinely used racial/ethnic categories themselves, and that they lack sufficient rigor to be used as key variables in biological research. It is our position that it is unacceptable to persist in the constructing of scientific arguments based on these highly ambiguous variables.
Communality as a Dimension of Service Relationships

This article proposes a construct, communality, that can be used to differentiate service relations. Theoretical development of this construct suggests that (a) communality will affect the way consumers interpret behaviors of service providers and fellow consumers; (b) marketing variables can influence the degree to which consumers anticipate and experience communality; and (c) conflicting relationship norms will have consequences for service outcomes. A model and propositions are presented, along with suggestions for operationalizing the construct and developing future research.
The Effect of Heat Exposure and Bacterial Endotoxin on Plasma Zinc Concentration and the Body Temperature in the Broiler

The effect of heat exposure and bacterial endotoxins on plasma zinc levels and mean rectal temperature of 8 week old broilers and investigated. Broilers exposed for 2 hours to 35-35 degrees C. had higher (P less than 0.01) mean rectal temperatures (42.8 vs 41.7 degrees C.) than sham treated broilers maintained at 22-24 degrees C. Likewise, endotoxin (E. coli, 500 mug./kg) treated broilers also had mean rectal temperatures significantly higher (P less than 0.01, 42.4 vs 41.7 degrees C.) than sham treated broilers. Plasma zinc levels in the bacterial endotoxin treated broilers were lower (P less than 0.05) than in the sham treated (173 vs 220, and 219 mug/kg./100 ml. plasma, respectively). In contrast, the plasma zinc concentration was not significantly depressed in the broilers exposed to heat for 2 hours. In summary, either endotoxin or heat exposure resulted in increased body temperature, however only the response to endotoxin resulted in a significant depression of plasma zinc concentration.
Magnetically Driven Implosions for Inertial Confinement Fusion at Sandia National Laboratories

High current pulsed-power generators efficiently store and deliver magnetic energy to z-pinch targets. We review applications of magnetically driven implosions (MDIs) to inertial confinement fusion. Previous research on MDIs of wire-array z-pinches for radiation-driven indirect-drive target designs is summarized. Indirect-drive designs are compared with new targets that are imploded by direct application of magnetic pressure produced by the pulsed-power current pulse. We describe target design elements such as larger absorbed energy, magnetized and pre-heated fuel, and cryogenic fuel layers that may relax fusion requirements. These elements are embodied in the magnetized liner inertial fusion (MagLIF) concept [Slutz “Pulsed-power-driven cylindrical liner implosions of laser pre-heated fuel magnetized with an axial field,” Phys. Plasmas, 17, 056303 (2010), and Stephen A. Slutz and Roger A. Vesey, “High-Gain Magnetized Inertial Fusion,” Phys. Rev. Lett., 108, 025003 (2012)]. MagLIF is in the class of magneto-inertial fusion targets. In MagLIF, the large drive currents produce an azimuthal magnetic field that compresses cylindrical liners containing pre-heated and axially pre-magnetized fusion fuel. Scientific breakeven may be achievable on the Z facility with this concept. Simulations of MagLIF with deuterium-tritium fuel indicate that the fusion energy yield can exceed the energy invested in heating the fuel at a peak drive current of about 27 MA. Scientific breakeven does not require alpha particle self-heating and is therefore not equivalent to ignition. Capabilities to perform these experiments will be developed on Z starting in 2013. These simulations and predictions must be validated against a series of experiments over the next five years. Near-term experiments are planned at drive currents of 16 MA with D2 fuel. MagLIF increases the efficiency of coupling energy (=target absorbed energy/driver stored energy) to targets by 10-150X relative to indirect-drive targets. MagLIF also increases the absolute energy absorbed by the target by 10-50X relative to indirect-drive targets. These increases could lead to higher fusion gains and yields. Single-shot high yields are of great utility to national security missions. Higher efficiency and higher gains may also translate into more compelling (lower cost and complexity) fusion reactor designs. We will discuss the broad goals of the emerging research on the MagLIF concept and identify some of the challenges. We will also summarize advances in pulsed-power technology and pulsed-power driver architectures that double the efficiency of the driver.
Iliacus pyomyositis mimicking septic arthritis of the hip joint

The iliacus muscle is closely associated with the psoas muscle, femoral nerve, hip joint, pelvic and intraabdominal structures; thus, its disorders may present as lower abdominal pain, hip pain, or femoral neuropathy. Iliacus pyomyositis, a primary bacterial infection of the skeletal muscle not secondary to a contiguous skin, bone, or soft-tissue infection, presenting as hip pain, femoral neuropathy, and sympathetic effusion of the hip joint in an 8-year-old boy mimicked septic arthritis of the hip joint. Computed tomography was helpful in delineating the accurate location of the lesion. Surgical drainage and appropriate antibiotic therapy led to complete resolution and full functional recovery.