cssi/SciSciGPT-SciSciNet huggingface dataset:
Acute renal failure: from renal physiology to the renal transcriptome.

Acute renal failure: From renal physiology to the renal transcriptome. Acute renal failure (ARF) is defined as an abrupt fall in glomerular filtration rate. Fully 5% of all patients admitted to the hospital undergo ARF with an attendant increase in morbidity and mortality. We have studied murine models of ischemia/reperfusion and cisplatin-induced renal failure in detail to determine the physiologic and molecular events that are responsible for the syndrome. Both forms of treatment induce necrosis of the proximal tubules, as well as more subtle changes in distal nephron viability, including apoptosis. Both forms are characterized by reduced renal blood, reduced glomerular filtration rate, and a urine-concentrating defect. Simultaneous with the onset of these morphologic and functional features is the commitment of cells to DNA synthesis and cell division, which is preceded by activation of signal transduction pathways and gene transcription that presumably underlie the morphologic and functional changes responsible for the syndrome. We describe a functional genomic approach using microarray data and available database searches to attempt to predict new targets for investigation of the pathogenesis and treatment of this disease.
SDAT: analysis of 131mXe with 133Xe interference

The Spectral Deconvolution Analysis Tool (SDAT) software was developed at The University of Texas at Austin. SDAT utilizes a standard spectrum technique for the analysis of β–γ coincidence spectra. Testing was performed on the software to compare the standard spectrum analysis technique with a region of interest (ROI) analysis technique. Experimentally produced standard spectra and sample data were produced at the Nuclear Engineering Teaching Laboratory (NETL) TRIGA reactor. The results of the testing showed that the standard spectrum technique had lower errors than the ROI analysis technique for samples with low counting statistics. In contrast, the ROI analysis technique outperformed the standard spectrum technique in high counting statistics samples. It was also shown that the standard spectrum technique benefitted from a compression of the number of channels within the spectra.
Nuclear dependence in direct photon production.

We calculate the nuclear dependence of direct photon production in hadron-nucleus collisions. In terms of a multiple scattering picture, we factorize the cross section for direct photon production into calculable short-distance partonic parts times multiparton correlation functions in nuclei. We present the hadron-nucleus cross section as {ital A}{sup {alpha}} times the hadron-nucleon cross section. Using information on the multiparton correlation functions extracted from photon-nucleus experiments, we compute the value of {alpha} as a function of transverse momentum of the direct photon. We also compare our results with recent data from Fermilab experiment E706. {copyright} {ital 1996 The American Physical Society.}
Vinyl vicinal tricarbonyl esters as trielectrophiles. Reactions with diamines and related trinucleophiles

The scope of the reactions of vinyl vicinal tricarbonyl esters with trinucleophiles has been extended in forming dipyrroles and novel polycyclic heterocyclic systems. In particular, diamines and analogs have been studied as polynucleophiles.
Integrating a priori information in edge-linking algorithms

This research presents an approach to integrate a priori information to the path metric of the LINK algorithm. The zero-crossing contours of the $DEL2G are taken as a gross estimate of the boundaries in the image. This estimate of the boundaries is used to define the swath of important information, and to provide a distance measure for edge localization. During the linking process, a priori information plays important roles in (1) dramatically reducing the search space because the actual path lies within +/- 2 (sigma) f from the prototype contours ((sigma) f is the standard deviation of the Gaussian kernel used in the edge enhancement step); (2) breaking the ties when the search metrics give uncertain information; and (3) selecting the set of goal nodes for the search algorithm. We show that the integration of a priori information in the LINK algorithms provides faster and more accurate edge linking.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Comparison of Maximum Likelihood and Median-Rank Regression for Weibull Estimation

Many different methods have been proposed for inferring parameters and important functions for Weibull distributions, which are a common component of reliability determinations. This study compares the common methods and examines the reasons for ambigui..
The role of large rhizome dispersal and low salinity windows in the establishment of common reed, Phragmites australis , in salt marshes: New links to human activities

In spite of its long history,Phragmites australis’ (Cav.) Trin ex Stuedel invasion in tidal marshes defies explanation. Initial establishment in these systems is particularly perplexing, because seedlings and rhizome fragments do not perform well in poorly drained saline environments. We tested the possibility that dispersal and burial of large rhizomes, periods of low salinity, and localized, well-drained areas facilitate initial establishment in brackish marshes. In a greenhouse we exposed large and small rhizomes to two drainage treatments: mimics of poorly-drained, high marsh interiors and mimics of well-drained, mosquito ditch banks. In well-drained treatments we exposed rhizomes to one of three salinity treatments: fresh, natural salinity regime of an invaded brackish water marsh, and a 2-wk freshwater window followed by a natural salinity regime. Small rhizone fragments did not emerge in saline treatments or treatments with high water tables, while emergence was spotty in well-drained freshwater treatments. Large rhizomes emerged only in well-drained, treatments. For large rhizomes, growth, survival, and clonal spread decreased when exposed to the natural salinity regime, but improved with exposure to the 2-wk freshwater window. These results suggest that dispersal and burial of larger rhizomes, well-drained features, and low salinity windows following dispersal improve the chances of successful establishment. These results help explain case-specific historical links between establishment and such human activities as hydrological alterations, construction activities, and lowered salinity.
Interaction of buspirone and dopaminergic agents on punished behavior of pigeons.

Abstract The non-benzodiazepine anxiolytic buspirone was studied alone and in combination with either haloperidol or apomorphine. Drug effects were evaluated under a baseline of punished and unpunished keypeck responses of pigeons; every 30th response produced food (no punishment) in the presence of a white keylight and, when the keylight was red in alternate 3 min periods, every 30th response produced both food and a brief electric shock (punishment). Buspirone (0.03–3 mg/kg, IM) increased the low rates of punished responding to a maximum of 1000% of control at doses of 0.1–1 mg/kg. Unpunished responding was only marginally affected at lower doses and dose-dependent decreases were obtained from 1 to 10 mg/kg. Although less potent, chlordiazepoxide (1–100 mg/kg IM) produced effects which were similar to those of buspirone, a finding which contrasts with the greater efficacy of benzodiazepines for increasing punished behavior in mammals. Dose-effect functions for buspirone were unchanged by haloperidol administration (0.01 and 0.03 mg/kg, IM, 5 min prior) or by concurrent treatment with a behaviorally-ineffective dose of apomorphine (0.003 mg/kg, IM). Rate-decreasing doses of apomorphine (0.01–0.1 mg/kg) reversed the increases in punished responding produced by lower doses of buspirone (0.03 and 0.1 mg/kg) and the apomorphine-induced decreases in unpunished responding were antagonized by buspirone at doses which had little affect when given alone. The ability of buspirone to reverse the rate-decreasing effects of apomorphine on unpunished responding suggests that buspirone does exhibit dopaminergic antagonist properties in vivo . However, effects of buspirone on punished responding of pigeons do not appear to be due to dopaminergic mechanisms. Punished behavior of pigeons provides a unique model for further investigations of the mechanism of action of the potent anxiolytic buspirone.
Induction of T-cell anergy by altered T-cell-receptor ligand on live antigen-presenting cells

ACTIVATION of CD4+ T helper cells results from the occupancy of the T-cell receptor (TCR) by immunogenic peptide bound to a class II major histocompatibility complex (MHC) molecule1, together with a co-stimulatory signal from the antigen-presenting cell (APC)2. This activation leads to proliferation, cytokine production (Th1 or Th2 profile) and cytolysis3. Engagement of the TCR in the absence of co-stimulation causes Th1 cells to become unresponsive to subsequent antigenic stimulation4–6. We have previously demonstrated that analogues of an immunogenic peptide could stimulate Th1 and Th2 cells to carry out some effector functions without inducing proliferation7,25, a phenomenon we term partial activation. Here we study the consequences of such partial activation through the TCR of two Th1 clones using peptide analogues presented by a live APC. A peptide analogue that is unable to stimulate clonal proliferation or production of cytokine or inositol phosphate can induce the T cells to become profoundly unresponsive to subsequent stimulation with the immunogenic peptide. Thus, altering the ligand of the TCR by using a peptide analogue on a functional APC sends a signal to Th1 clones that results in anergy.
Response of grazing snails to phosphorus enrichment of modern stromatolitic microbial communities

SUMMARY 1. The effects of added phosphorus (P) on the growth, P and RNA : DNA contents, and survivorship of snails grazing on laminated microbial mats (living 'stromatolites') were examined in the Rio Mesquites at Cuatro Cienegas, Mexico (total P, c. 0.60 lmol L )1 ) to test the hypothesis that strong P-limitation of microautotroph growth produces a stoichio- metric constraint on herbivores because of mineral P-limitation. 2. In a 3-week experiment performed in summer 2001, addition of phosphorus (+15 lmol L )1 ) resulted in a strong decline in stromatolite biomass C : P ratio from very high levels (c. 2300 : 1 by atoms) to moderate levels (c. 550 : 1). The endemic hydrobiid snail Mexithauma quadripaludium responded to P-enrichment with elevated body P content and higher RNA : DNA ratios, especially for small animals likely to be actively growing. This positive response is consistent with the existence of a stoichiometric constraint on snail growth. 3. In a longer experiment (8 weeks) involving a more moderate P enrichment (+5 lmol L )1 ) in summer 2002, P enrichment reduced stromatolite C : P ratio from moderate values in control treatments (c. 750) to very low values (<100 : 1). Snails responded to stromatolite P-enrichment with increased body P content but, in contrast to the first experiment, with lower RNA : DNA ratio, lower growth rates, and higher mortality. 4. These contrasting results suggest that both very high and very low biomass C : P ratios in stromatolites are detrimental to M. quadripaludium performance, leading us to hypothesise that these herbivores live on a 'stoichiometric knife edge'.
Vibrational spectroscopy of group-II-acceptor-hydrogen complexes in GaP

Using infrared absorption spectroscopy, we have observed the local vibrational modes (LVM`s) of group-II-acceptor--hydrogen complexes in GaP. In addition to the previously observed zinc-hydrogen complexes, we report modes corresponding to beryllium-hydrogen and cadmium-hydrogen complexes. In GaP:Be, we attribute the modes at 2292.2 and 1669.8 cm{sup {minus}1} to phosphorus-hydrogen and phosphorus-deuterium bond-stretching modes of complexes adjacent to the beryllium acceptors. In GaP:Cd, we attribute the modes at 2434.0 and 1768.3 cm{sup {minus}1} to similar complexes adjacent to the cadmium acceptors. The temperature-dependent shifts of the hydrogen LVM`s in GaP:Be and GaP:Zn are shown to be proportional to the lattice thermal energy {ital U}({ital T}), a consequence of the anharmonic coupling between the LVM`s and the lattice phonons.
Channel modeling for millimeter wave MIMO

The large amounts of bandwidth available in the millimeter (mm) wave band enable multiGigabit wireless networks with applications ranging from indoor multimedia networking to outdoor backhaul for picocellular networks. Carrier wavelengths in this band are an order of magnitude smaller than those for existing cellular and WiFi systems, resulting in a drastically different propagation geometry. Omnidirectional transmission is essentially infeasible because of the increased propagation loss at smaller wavelengths; on the other hand, highly directive transmission and reception with electronically steerable beams can be achieved using compact antenna arrays. Thus, in contrast to the rich scattering environment at lower carrier frequencies, a small number of paths are dominant for directional mm wave links. The small wavelength also implies that spatial multiplexing gains can be obtained even in Line of Sight (LoS), or more generally, sparse scattering, environments with antennas with moderate separation. In this paper, we examine the consequences of these observations for two scenarios. The first is a lamppost-based outdoor deployment, where we model fading due to ground and wall reflections, and examine MIMO techniques for combating fading. The second is for spatial multiplexing for an indoor link, where we model the number of eigenmodes as a function of form factor, and examine the effect of blockage.
NHC-Cu-catalyzed protoboration of monosubstituted allenes. Ligand-controlled site selectivity, application to synthesis and mechanism.

Two types of NHC–Cu complexes catalyze protoborations of terminal allenes to afford valuable 1,1- or trisubstituted vinylboron species with high site selectivity and stereoselectivity. The scope of the method, application to natural product synthesis, and mechanistic basis for the observed selectivity trends are presented.
Feeding in water snakes: An electromyographic study

Synchronized cinematography and electromyography were used to study feeding behavior in water snakes, Nerodia rhombifera and Nerodia fasciata. While these species swallow their prey by alternate movements of the right and left toothed bones of the skull, the muscles show bilateral asymmetric activity during each movement. Opening of one side of the mouth is initiated by protraction of the palatomaxillary arch and slight depression of the mandible. These movements serve to disengage the teeth from the surface of the prey and correlate with activity of the protractors of the palatomaxillary arch and quadrate. Continued opening results primarily from rotation of the braincase around its longitudinal axis. During the latter half of the opening phase, the rates of protraction of both palatomaxillary arch and mandible increase; this correlates with increased activity of the depressor mandibulae, several of the mandibular adductors and three of the four cervical muscles analyzed. The cervical muscles appear to restrain the prey during the fast segment of mouth opening when the toothed bones reach their maximum displacements from the surface of the prey. Closing of the mouth is initiated by rapid depression of the palatopterygoid joint which correlates with a cessation of activity of the levator pterygoidei. Immediately thereafter, the posterior end of the maxilla is depressed and slightly retracted and the mandible tends to be protracted and slightly adducted. These movements correlate with synchronized activity of the palato-maxillary protractors, the pterygoideus and the depressor mandibulae. The rest of the closing phase consists primarily of adduction and retraction of the palatomaxillary and mandibular elements relative to the braincase; the toothed bones remain fixed to the surface of the prey while the braincase is moved forward. EMGs indicate that the complex bone movements of the latter stage of mouth opening and the initial stage of mouth closing are dependent upon the simultaneous firing of a number of morphologically antagonistic muscles.
Superconducting properties of Fe/V/Fe sandwiches

A study has been made of the superconducting properties of Fe/V/Fe sandwiches with V thickness ranging from 153 AP (atomic planes) to 5048 AP. All 20 samples studied were prepared in a single run. At zero magnetic field, the suppression of the transition temperature follows an inverse square dependence on the thickness, implying a strong pair-breaking effect in the Fe layers. The upper critical field data cross over smoothly from the 2D regime to the 3D regime with increasing V thickness. A comparison with some thin-film theories is given.
Comparison of T and B cell analyses on fresh and aged blood

We have compared T and B cell analyses using whole blood, separated lymphocytes, and separated, frozen, then thawed lymphocytes to see how long blood can be kept before separation and analysis. We also examined the effect of various anticoagulants and the effect of diluting blood in culture media on T and B cell analysis over time. We found that the whole blood method is a very reliable method for T and B cell analysis, even 4 days after the blood is drawn, provided that heparin or ACD is the anticoagulant used. Separated lymphocytes and cryopreserved lymphocytes from blood that was separated within 24 h of collection was satisfactory; however, results were less consistent if separation was delayed more than 24 h. For lymphocyte separation, blood collected in heparin or ACD held up better over time than did blood collected in EDTA, and dilution with either RPMI 1640 or McCoy's medium gave better lymphocyte separation in older blood.
Rotationally state-selected HBR+: Preparation and characterization

Abstract Rotationally state-selected HBr + ions have been prepared by 2 + 1 resonance-enhanced multiphoton ionization (REMPI) via Rydberg states of HBr, and characterized by laser-induced fluorescence (LIF) using the HBr + A 2 Σ + -X 2 Π system. The experiment has been conducted under bulb conditions of 10–50 m Torr. The rotationally unrelaxed distribution of HBr + internal states shows that the ionization step can be highly selective, depending on the intermediate Rydberg state chosen.
Low field anomalies in the magnetization behaviour of superconducting Zr-Nb alloys

The magnetization behaviour of superconducting Zr-Nb alloys has been examined to determine the effects of constitution and microstructure on anomalies in the form of a “peak effect” and flux instabilities. It is concluded that both of these phenomena depend on the particle size, volume fraction, and distribution of the omega phase. The occurrence of both anomalies is explained in terms of the transition of the omega phase from the superconducting to normal state as the applied field is increased. The absence of anomalies in reverted and re-aged alloys reflects the predominant role of the solute lean zones in determining the bulk superconducting properties.
A new technique for postsample model selection and validation

Abstract The model selection and Granger-causality literatures have focused on insample rather than postsample hypothesis testing. This is because postsample model validation periods are usually short, whereas the correlations in typical postsample forecast errors require large-sample methods. A resampling-based postsample inference procedure is described which explicitly estimates the uncertainty which its large-sample approximation induces in the inference significance levels it produces. The procedure is applied to postsample forecasting errors from the Ashley et al. (1980) study examining Granger-causation between US consumption and advertising expenditures. Postsample model validation is apparently feasible, but requires longer postsample periods than past studies have allocated.
Swallowing syncope: Observations in the absence of conduction system or esophageal disease

Abstract A patient is described with the clinical syndrome of "swallowing syncope" who reproducibly demonstrated sinus bradycardia, A-H prolongation, and intranodal atrioventricular block in response to swallowing during electrophysiologic study. Baseline electrophysiologic and esophageal manometric results were normal, as was his response to other vagal maneuvers. Demand ventricular pacing alleviated his symptoms. These findings suggest that "swallowing syncope" is mediated via an esophageocardiac reflex and can occur in the absence of cardiac conduction system or esophageal disease.
Improved solution of steady, viscous, incompressible flow between two rotating spheres

Abstract A refined solution is presented for the analysis of viscous, incompressible, steady flow between two rotating spheres. A new method, used previously for simpler problems only, is adapted to this problem. The method allows the use of small grid spacing and thus yields improved accuracy.
Wideband Channelization for Software-Defined Radio via Mobile Graphics Processors

Wideband channelization is a computationally intensive task within software-defined radio (SDR). To support this task, the underlying hardware should provide high performance and allow flexible implementations. Traditional solutions use field-programmable gate arrays (FPGAs) to satisfy these requirements. While FPGAs allow for flexible implementations, realizing a FPGA implementation is a difficult and time-consuming process. On the other hand, multicore processors while more programmable, fail to satisfy performance requirements. Graphics processing units (GPUs) overcome the above limitations. However, traditional GPUs are power-hungry and can consume as much as 350 watts, making them ill-suited for many SDR environments, particularly those that are battery-powered. Here we explore the viability of low-power mobile graphics processors to simultaneously overcome the limitations of performance, flexibility, and power. Via execution profiling and performance analysis, we identify major bottlenecks in mapping the wideband channelization algorithm onto these devices and adopt several optimization techniques to achieve multiplicative speed-up over a multithreaded implementation. Overall, our approach delivers a speedup of up to 43-fold on the discrete AMD Radeon HD 6470M GPU and 27-fold on the integrated AMD Radeon HD 6480G GPU, when compared to a vectorized and multithreaded version running on the AMD A4-3300M CPU.
Generations in organizations

Abstract Despite a rich tradition of scholarship across many disciplines, organizational research on the topic of generations has been relatively scarce. In this article we develop a framework for studying generations in organizations that draws on multiple conceptualizations across multiple disciplines. Our framework distills two distinct critical elements that give ‘generations’ agency in organizational settings – chronology (the idea that a unique location in time creates a ‘generation’) and genealogy (the idea that generations are linked through the transmission/descent of ideas/values/skills/knowledge). After an historic overview of the evolution of the topic of generations, we review generational research across the fields of political sociology, family sociology, psychology, social anthropology, cultural sociology, demography, and gerontology. Our framework elucidates how linkages between generations, based on chronology and genealogy, can be characterized in organizations and how the nature of intergenerational contact and transfer predicts a wide range of organizational outcomes such as change/innovation, conflict, turnover, and socialization. We outline the implications of this framework for future research on generations in organizations.
Ignorant or knowledgeable: Farmers speak out on consumers and biotechnology

The issue of genetically engineered food problematizes the spheres of expert and lay knowledge. The outcome of debates over biotechnology affects the very food people eat. Somewhere between the “lay public” and certified experts/researchers are farmers. It stands to question what their role should be over the direction of biotechnology. Further, farmers have a relationship with consumers themselves. Do they see consumers as having legitimate knowledge and concerns that they need to be aware of, or do they write off consumers as a lay, ignorant public? Conventional growers employ many techniques and arguments that work to explain away consumer complaints regarding biotechnology. They assert a sphere of influence to themselves, that of uncertified experts. In contrast, consumers are viewed as ignorant of farm issues. However, growers struggle some over the consumers’ role, because they may also believe in a consumers’ right to knowledge and influence in the market (demand and supply). Therefore, growers have mixed responses to the idea of labeling genetically modified products for consumers. On the other hand, organic/sustainable growers as a group have more direct connections with consumers, and benefit from consumers having knowledge about production practices. There is some evidence that organic growers define for themselves a sphere of expertise like the conventional growers, and they do question consumers’ knowledge over agricultural issues. However, compared to conventional growers, as a group they treat consumers as more knowledgeable, and grant consumers more of a role in technological decision-making.
A method for shipboard measurement of CO2 partial pressure in seawater

A dynamic method suitable for shipboard measurement of the partial pressure of CO2 exerted by a seawater sample has been developed. The system consists of a paddle-wheel-type gas-water equilibrator and an infrared gas analyzer. Since the system is open to the atmosphere at the in-take and the exhaust ends, it can be operated stably on shipboard conditions. A precision of ±2% has been obtained for shipboard measurement of pCO2.
Overview about Solution Representations for Elasticity Problems and Some Selected Particular Solutions

Solution representations for elasticity problems are presented in this overview article. The types of problems covered are (i) plane strain/stress for isotropic and anisotropic materials, (ii) plate bending for isotropic and anisotropic thin plates, (iii) three-dimensional plate analysis, and (iv) three-dimensional elasticity problems. The solution contributions are decomposed into homogeneous and particular solutions. All homogeneous solution representations involve arbitrary complex valued functions. Choosing different types of complex functions, it becomes possible to construct easily infinite sets of functions satisfying the governing differential equations. The solution representations are very useful for (i) solving problems analytically, (ii) analyzing a local solution behavior (as, for example, near comers, cracks, or holes), and (iii) for application in numerical methods.
Temperature profiles for turbulent flow of air in a pipe—II The thermal entrance region

Abstract By using a specially designed probe mechanism which entered the system through the pipe outlet and which could be located quite accurately at any radial or lingitudinal position in the pipe an extensive set of measurements was made of the temperature profiles in the heat-transfer entry section of an electrically heated pipe through which turbulent air was flowing. The results are compared with the theoretical approaches of D eissler and S parrow et al. and with calculations for a homogeneous turbulent field with uniform velocity. The approach of S parrow et al. should give an accurate description of the temperature field at distances into the heat-transfer section greater than about three pipe diameters if a Reynolds-number-dependent fully developed temperature relation is used. The accuracy of the measurements close to the wall is unsufficient to allow any definite statement to be made regarding the prediction of temperature profiles for smaller longitudinal distances.
Integrators of epidermal growth and differentiation: Distinct functions for β1 and β4 integrins

Mammalian epithelia are critically dependent on interactions with components in the underlying basal lamina for proper morphogenesis and function. Substratum attachment is essential for survival, proliferation, movement, and differentiation; detachment compromises the cell's ability to perform these functions, often resulting in human disease. Interactions with the extracellular matrix are mediated through transmembrane integrin receptors that transmit signals to the cytoskeleton and to signaling molecules within the proliferating cells of the epithelium. In the past year, novel insights have emerged regarding the specific role of integrins in their attachment to extracellular matrix and in their signal transduction pathways within the epidermis.
Role of glucose in fungal decolorization of wood pulp bleaching effluents

The white-rot fungus Phanerochaete chrysosporium, when immobilized on discs in a rotating biological contactor (RBC), can effectively decolorize the first alkaline extraction stage (E1) effluent from the bleach plant of a wood pulp production facility. We have shown that to degrade lignin and lignin-derived chromophoric structures, a co-substrate such as glucose must be added.
Nonlinearities in the static energetics and in the kinematics of dislocations

Abstract Methods for the atomistic simulation of dislocation core regions are discussed. Simulation of this type are shown to lead to a variety of core configurations and energies that are of nonlinear origin. The motion of dislocations by double kink formation is considered as an example of nonlinear dynamical effects.
Surprisingly simple mechanical behavior of a complex embryonic tissue.

Background: Previous studies suggest that mechanical feedback could coordinate morphogenetic events in embryos. Furthermore, embryonic tissues have complex structure and composition and undergo large deformations during morphogenesis. Hence we expect highly non-linear and loading-rate dependent tissue mechanical properties in embryos. Methodology/Principal Findings: We used micro-aspiration to test whether a simple linear viscoelastic model was sufficient to describe the mechanical behavior of gastrula stage Xenopus laevis embryonic tissue in vivo. We tested whether these embryonic tissues change their mechanical properties in response to mechanical stimuli but found no evidence of changes in the viscoelastic properties of the tissue in response to stress or stress application rate. We used this model to test hypotheses about the pattern of force generation during electrically induced tissue contractions. The dependence of contractions on suction pressure was most consistent with apical tension, and was inconsistent with isotropic contraction. Finally, stiffer clutches generated stronger contractions, suggesting that force generation and stiffness may be coupled in the embryo. Conclusions/Significance: The mechanical behavior of a complex, active embryonic tissue can be surprisingly well described by a simple linear viscoelastic model with power law creep compliance, even at high deformations. We found no evidence of mechanical feedback in this system. Together these results show that very simple mechanical models can be useful in describing embryo mechanics. © 2010 von Dassow et al.
STRATEGIES FOR SOLVING ECONOMIC PROBLEMS INVOLVING PERMUTATIONS

A number of common economic problems can be reduced to a search for a permutation which minimizes some function. Analytic solutions are available for unconstrained problems of this nature when certain conditions are satisfied. This article outlines a simple tree-search strategy for solving ordering problems in which some permutations are excluded due to explicit constraints.
Glycosidases of the guinea pig brush border membrane

Abstract The separation by polyacrylamide gel electrophoresis and subsequent enzymatic analysis of the components of the guinea pig intestinal brush border membrane revealed the presence of three enzyme complexes: maltase-gluco-amylase, maltase-sucrase-glucoamylase and maltase-sucrase. Additional bands possessing lactase, trehalase and alkaline phosphatase activity were identified but no phlorizin hydrolase or palatinase was detectable. After exposure to strong dissociating conditions the bands possessing enzymatic activity were either absent or greatly reduced in intensity.
Alterations in the distribution of glycoproteins in epithelial cells of murine colon after injection of tunicamycin.

Glycoproteins are associated with several structures of colonic absorptive cells of the mouse. These include the cell coat, Golgi apparatus and vesicles that transport the glycoproteins from the apparatus to the cell surface (Michaels and Leblond 1976). In many in vitro systems, the antibiotic tunicamycin inhibits the glycosylation of asparagine residues yielding carbohydrate-poor glycoproteins. In the present in vivo study, tunicamycin was injected into mice. The murine colonic epithelial cells were prepared routinely for electron microscopy and cytochemistry. Cells from the experimental and control animals were similar morphologically. However, staining by the periodic acid-chromic acid-silver methenamine technique, revealed differences in the distribution of glycoproteins. In animals that received the higher dosages of tunicamycin there was a substantial reduction in silver staining in both the Golgi apparatus and the vesicles of colonic epithelial cells compared to these structures in cells of identically treated control tissues, whereas the staining over the cell coat was not significantly altered. Possible explanations for the staining of the cell coat in the treated animals were provided in the text. This report demonstrates the feasibility of using tunicamycin in vivo and detection of the changes obtained by the silver methenamine method.
Synthesis, resolution and charge-donor properties of six tryptophan analogues.

In order to investigate the special function of tryptophan in peptide hormones, six tryptophan analogues have been synthesized, in which structural resemblance has been grossly retained and potentially essential properties have only partially been varied. The l-enantiomers have been isolated after enzymatic digestion of racemic dipeptide derivatives, and charge-transfer properties of the compounds have been studied.
Prognostic significance of creatine kinase-MB elevation after percutaneous coronary intervention in patients with chronic renal dysfunction

Abstract Background Multiple studies have demonstrated a relationship between creatine kinase-MB (CK-MB) elevation after percutaneous coronary intervention (PCI) and increased late mortality within the general population. Because CK-MB is frequently elevated in renal disease even in the absence of myocardial injury, the clinical significance of CK-MB elevation after PCI in patients with renal insufficiency has been questioned. Methods We sought to examine the association between elevated CK-MB after PCI and late mortality in 190 consecutive patients with chronic renal insufficiency (serum creatinine ≥2.0 mg/dL) undergoing PCI at the Cleveland Clinic between January 1997 and March 2000. Of the total group, 20 patients undergoing PCI for acute myocardial infarction, cardiogenic shock, or both were excluded. Follow-up was 99.4% complete at a mean duration of 24.8 ± 11.2 months (range 5-43 months). Results CK-MB elevation above the upper limit of normal after intervention was detected in 33 patients (19.4%). Baseline characteristics were not significantly different between the CK-MB elevation group and the normal CK-MB group. Late mortality, however, was significantly higher among patients with postprocedural CK-MB elevation (36.4% vs 17.5%, P =.017). Cox proportional hazard model revealed CK-MB elevation as an independent predictor of late mortality (hazard ratio 2.44, 95% CI 1.14-5.24, P =.02), in addition to New York Heart Association class (hazard ratio 1.35, 95% CI 1.05-1.73, P =.02). Conclusions This analysis of patients with chronic renal insufficiency undergoing PCI suggests that postprocedural CK-MB elevation is an independent predictor of late mortality even in the presence of renal dysfunction. (Am Heart J 2002;143:1040-5.)
Adaptive spatial spectrum estimation via conjugate gradients and dominant mode rejection beamforming

Under the condition of low sample support, there is deviation between the estimated and true correlation matrices. In this case, the full-rank sample matrix inversion (SMI) beamformer is no longer optimal. Instead, a low-rank adaptive beamformer could yield better performance. When extending from a couple of signal directions to the entire spatial spectrum, the output power is a more applicable touchstone than SINR, which is only defined for signal directions. Adaptive algorithms (CG/DMR), if operating at the best rank for each direction, could effectively reveal the spatial spectrum. The best rank is obtained by investigating an ideal evaluation from the true correlation matrix and adaptive beamformer.
The effect of composite vs. first person perspective view in real world tele-robotic operations

Tele-robotics is an area of robotics concerned with the control of robots from a distance, chiefly using wireless connections like Wi-Fi, Bluetooth, the Deep Space Network, ‘tethered’ connections, or the Internet. Most tele-robotic systems are teleoperated which means that it relies on the human operator’s capabilities. Many aspects like limited perception, cognitive workload, mental capacity, and stress of human operator can restrict human’s level 3 SA in operating tele-robotic systems. This study investigated the impact of tele-robotics system operation on operator SA and driving performance. Also it identified specific cognitive factors that affect operator performance and SA in operating a tele-robotic system. Finally, this study was to understand the impact of human workload on performance.
ROCI: a distributed framework for multi-robot perception and control

This paper presents ROCI, a framework for developing applications for multi-robot teams. In ROCI, each robot is considered a node, which contains several modules and may export different types of services and capabilities to other nodes. Each node runs a kernel that mediates the interactions of the robots in a team. This kernel keeps an updated database of all nodes and the functionalities that they export. Multi-robot applications can be built dynamically by connecting modules that may be running on different nodes over the network. As an example, we present an obstacle avoidance task implemented using our framework and also discuss the use of ROCI in a multi-robot scenario.
Relativistic approach for e+/- scattering from argon.

Differential and integrated elastic, integrated total cross sections as well as various polarization parameters-the spin polarization P and the parameters T and U describing the change in the polar­ ization vector during scattering-for the scattering of electrons and positrons from argon in the en­ ergy range of 3-300 eV are calculated using the relativistic Dirac equation. The real part of the projectile-target interaction is represented by a sum of model potentials. The phase shifts for large angular momenta "1 are calculated using the Born approximation. The relativistic calculations for the differential and integrated elastic cross sections obtained using the pure real potential show al­ most no improvement over those obtained nonrelativistically for positron scattering from argon while similar calculations show some effects, except at low energies ( ~ 5 eV) where relativistic terms are sensitive to the form of potentials used, on the values of the differential cross sections for elec­ tron scattering from argon. The polarization parameter P for electron scattering is found to be in good agreement with various calculated and measured values. A few different models of the absorp­ tion potential for the inelastic processes are used to calculate the integrated inelastic and the in­ tegrated total cross sections for positron and electron scattering from argon. It is noticed that even though the integrated elastic and the integrated total cross sections for the scattering of positrons and electrons calculated using some complex model potential agree well with the corresponding measured values, the differential cross section curves using the same model potentials can differ con­ siderably from each other as well as from the experimental values. I. INTRODUcrION Scattering of positrons and electrons (especially the electrons) by argon atoms has been an intensively studied problem for a long time (for references before 1987 see Ref. 1). In the present work, we investigate the same scattering problem using the relativistic approach, via the Dirac equation, which provides, in its standard formula­ tion, the interaction effects of the projectile's spin. Dur­ ing the scattering of electrons and positrons (spin-t particles) their magnetic moments interact with the magnetic field generated by the orbital motion of these particles with respect to the target atom, leading to the well­ known spin-orbit interaction term. Hence, even though the incident beam of projectiles may be unpolarized, the spin-orbit interaction can orient the spins of the scattered particles in a preferred direction causing a net spin polar­ ization. The study of spin polarization of the incident projectiles due to scattering provides more detailed infor­ mation about the projectile-target interaction. The spin polarization of electrons during scattering by a central field was first investigated by Mott 2 using a relativistic treatment based on the theory of Dirac 3 The measure­
On Circadian Variation of Myocardial Reperfusion Injury

See related article, pages 105–110 In 1729, Jean Jacques d'Ortous de Marian, a French scientist, made the fascinating observation that plants that unfolded their leaves when exposed to sunlight (presumably to increase photosynthesis, a process that had not yet been discovered) continued to rhythmically unfold their leaves in the morning and fold them in the evening even when they were maintained in constant darkness.1 d'Ortous had discovered an innate regulatory mechanism that allowed the plants to anticipate when daylight would be expected to begin and to wane. It is now widely appreciated that since fluctuations of the environment occur in the 24 hours required by the earth to rotate once on its axis, it would be useful if organisms could be prepared suitably for these fluctuations. Indeed, circadian “clocks” have been identified in all eukaryocytic cells and even in some prokaryocytes.2 It has been suggested that circadian clocks were present in the earth's earliest life forms. The uniform presence of circadian rhythmicity suggests that the ability to anticipate changes in the environment and to prepare for them provides an evolutionary advantage, otherwise it would probably not have persisted. All mammals studied to date have developed 2 major classes of circadian clocks. The first to be recognized, the central “master” clock, is controlled by light, converted in the retina into neural impulses that are transmitted via the retinohypothalamic tract to the suprachiasmatic nucleus within the hypothalamus. This clock is responsible for circadian variations in the activity of the autonomic nervous system, resulting in changes in physiological parameters, including vascular resistance, arterial pressure, cardiac output, and heart rate as well as in the secretion …
Dealing with drugs: heroin abuse as a social problem

Reported here are attitudes and perceptions regarding heroin control, prevention, and treatment obtained in a survey of community leaders in four high drug traffic and drug use neighborhoods in New York City. Studies in the past have focused on the causes and consequences of heroin use primarily from the standpoint of the drug user. Operationalizing the tenet that heroin abuse is a social problem, this study develops an ecological paradigm for analyzing the effects on neighborhoods of illicit drugs and of prevention, intervention, and treatment policies. The research was undertaken in 1981 for the New York State Heroin and Alcohol Study Commission. It demonstrates the importance of including community perspectives in policy decisions and the usefulness of a study group of community leaders as a reliable source of this information.
Multiscale sensing with stochastic modeling

Many sensing applications require monitoring phenomena with complex spatio-temporal dynamics spread over large spatial domains. Efficient monitoring of such phenomena would require an impractically large number of static sensors; therefore, actuated sensing - mobile robots carrying sensors - is required. Path planning for these robots, i.e., deciding on a subset of locations to observe, is critical for high fidelity monitoring of expansive areas with complex dynamics. We propose MUST - a MUltiscale approach with STochastic modeling. MUST is a hierarchical approach that models the phenomena as a stochastic Gaussian Process that is exploited to select a near-optimal subset of observation locations. We discuss in detail our proposed algorithm for the application of monitoring light intensity in a forest understory. We performed extensive empirical evaluations both in simulation using field data and on an actual cabled robotic system to validate the effectiveness of our proposed algorithm.
Light trapping designs for thin silicon solar cells based on photonic crystal and metallic diffractive grating structures

We present novel light trapping designs applied to thin (5 micron) silicon solar cells. The design structures incorporate diffractive gratings to increase the optical path length of light within the solar cells. We incorporate a combination of dielectric and metallic materials to create the gratings. We form a one dimensional photonic crystal stack with the dielectric materials to which we then add the metallic layers. The combination of the two materials enhances the reflective properties of the gratings and thus increasing their effectiveness in light trapping. We use the particle swarm optimization and scattering matrix methods to realize the design structures.
Manufacturing systems engineering and management

This paper presents a discussion of manufacturing systems engineering and manufacturing systems management as one of the major efforts that concern systems engineers. There are many ways in which we can describe systems engineering and within this manufacturing systems engineering and management. This paper takes a multifaceted view of systems engineering. It attempts to describe systems engineering in terms of a relatively large number of trilogies. The process view of systems engineering is expanded on in some detail. We identify three major life cycle processes for systems engineering: research, development, test and evaluation; acquisition and manufacturing; and planning and marketing. We present a brief discussion of systems engineering from the perspective of each of these life cycles and then illustrate how acquisition and manufacturing forms a vital part of systems engineering efforts. We conclude with a discussion of the necessary role of manufacturing and acquisition as it applies to the systems engineering and management of contemporary systems including some 21/sup st/ century projections.