cssi/SciSciGPT-SciSciNet huggingface dataset:
Viscous Effects on Performance of Linear Plug Micronozzles

A parametric, two-dimensional, computational study examining steady-state plug micronozzle performance has been conducted. As part of the study, a new method for plug contour construction is proposed. The performance of several different nozzle geometries is compared to that of a traditional plug nozzle geometry designed using the Method of Characteristics (MOC). New nozzle designs are derived from the MOC based design and geometric transformations are used to produce plug nozzles of reduced length. Spike lengths corresponding to 60, 50, 40, and 27% of the MOC nozzle’s length are examined. The throat Reynolds number is varied from 80–820. Thrust is used a metric to assess nozzle performance. The geometry which maximizes performance is found to vary with Reynolds number. It is observed that reducing the plug length improves thrust production for the range of Reynolds number examined.Copyright © 2014 by ASME
Changes in Micelle Compositions and Monomer Concentrations in Mixed Surfactant Solutions

Monomer concentration changes in mixtures of a cationic surfactant, tetradecyltrimethylammonium chloride (TTAC), and a nonionic surfactant, pentadecyl ethoxylated nonylphenol (NP-15), have been studied with the help of the ultrafiltration technique. While the pseudophase separation model is valid for describing the micellization behavior of single surfactants, it was found to fail for mixed systems. In the case of TTAC and NP-15 mixed systems, both the monomer concentrations and mixed micellar composition changed continuously above the critical micelle concentration (cmc) of the mixtures. The measured changes of monomer concentrations above the mixed cmc were different from those predicted by the regular solution theory. Two different mixed micelles, TTAC-rich and NP-15-rich micelles, are proposed to form above a concentration range which in turn depends on the ratio of the two surfactants in the mixed system.
Mean energy of excess electrons in liquid Ar as a function of E/N: Electron attachment to N2O in gaseous and liquid Ar☆

Abstract The mean energy of excess electrons in liquid Ar as a function of the density-reduced electric field has been determined and used to obtain the mean energy dependence of the rate constant for electron attachment to N2O in liquid Ar. The latter has been compared with that in gaseous Ar; from this comparison the polarization energy of O− in liquid Ar is found to be −1.8 eV.
Communication of climate projections in US media amid politicization of model science

The complexity and politicization of climate computer models can hinder communication of their science, uses and limitations. Evidence suggests that information on climate models in US newspapers is declining and that when it appears, it is often within sceptic discourses. Furthermore, model projections are frequently portrayed as probably being inaccurate, and political opinion outlets provide more explanation of model results than many news sources.
Reduce Afterpulsing of Single Photon Avalanche Diodes Using Passive Quenching With Active Reset

In this paper, we report a passive-quenching-with-active-reset circuit designed to reduce afterpulsing for single photon avalanche diodes. This circuit uses a large resistor to passively quench the avalanche current and a transistor to actively reset the device to the operating voltage after a specified hold-off time. Afterpulsing can be reduced by minimizing the stray capacitance of the package to reduce the total charge flow during avalanche. Proof of principle is demonstrated with discrete components. It is expected that by integrating the transistor with the avalanche photodiode the stray capacitance can be minimized to significantly reduce afterpulsing.
Influence of route of administration on the humoral response of channel catfish (Ictalurus punctatus) toYersinia ruckeri

Abstract Channel catfish were inoculated intraperitoneally, intramuscularly, or intraesophageally with Yersinia ruckeri . Three antigen doses were administered by each route of injection. Four fish from each treatment were sacrificed at 5-day intervals for 40 days. Serum from each individual was tested for antibody activity against Y. ruckeri by indirect enzyme-linked immunosorbent assay (ELISA). High titers of anti- Y. ruckeri antibody were elicited by all doses (10 5 to 10 9 cells/g of fish) regardless of the route of administration. Mean titers for saline injected fish ranged up to 1:64 for each route of inoculation while mean titers for bacteria injected fish ranged up to 1:4096. Mean titers of 1:128 or greater were observed by day 15 post injection; titers peaked about day 30 and diminished thereafter. Channel catfish were most responsive to the antigen (10 7 to 10 9 cells/g of fish) when administered intramuscularly although lower doses (10 5 to 10 6 cells/g of fish) administered intraperitoneally elicited a substantial response. There was little evidence of dose-dependent responses for any of the routes of immunization. The rapid onset of relatively high serum titers suggests that the fish were mounting a secondary response to Yersinia ruckeri .
Use of micellar electrokinetic chromatography to measure palmitoylation of a peptide.

Abstract Palmitoylation is the thioester linkage of the fatty acid, palmitate (C16:0), to cysteine residues on a protein or peptide. This dynamic and reversible post-translational modification increases the hydrophobicity of proteins/peptides, facilitating protein–membrane interactions, protein–protein interactions and intracellular trafficking of proteins. Manipulation of palmitoylation provides a new mechanism for control over protein location and function, which may lead to better understanding of cell signaling disorders, such as cancer. Unfortunately, few methods exist to quantitatively monitor protein or peptide palmitoylation. In this study, a capillary electrophoresis-based assay was developed, using MEKC, to measure palmitoylation of a fluorescently-labeled peptide in vitro . A fluorescently-labeled peptide derived from the growth-associated protein, GAP-43, was palmitoylated in vitro using palmitoyl coenzyme A. Formation of a doubly palmitoylated GAP-peptide product was confirmed by mass spectrometry. The GAP-peptide substrate was separated from the palmitoylated peptide product in less than 7 min by MEKC. The rate of in vitro palmitoylation with respect to reaction time, GAP-peptide concentration, pH, and inhibitor concentration were also examined. This capillary electrophoresis-based assay for monitoring palmitoylation has applications in biochemical studies of acyltransferases and thioesterases as well as in the screening of acyltransferase and thioesterase inhibitors for drug development.
Composition and molecular weights of butyrylcholinesterase from horse serum

Abstract The physical and chemical characterization of horse serum butyrylcholinesterase has been extended. The results show that the enzyme is a glycoprotein containing about 20% carbohydrate by weight. Mannose, glucosamine, galactose, and sialic acid are the sugar residues found. The extinction coefficient of butyrylcholinesterase, E1cm1% at 280 nm, was found to be 15.2 ± 0.3 by dry weight determination. The molecular weight of the protein in dilute phosphate buffer was determined to be (31.7 ± 1.2) × 104 by high speed equilibrium sedimentation with a redetermined partial specific volume of 0.723 ± 0.003 ml/g. Subunit molecular weights for the dissociated protein were found to be (7.9 ± 0.4) × 104 and (8.1 ± 0.1) × 104, respectively, in guanidine hydrochloride and in a solution at pH 11.8. The subunit molecular weight was also estimated to be (8.8 ± 0.2) × 104 by analytical sodium dodecyl sulfate-gel electrophoresis. This apparently higher subunit molecular weight from dodecyl sulfate gels is expected for glycoproteins containing significant amounts of carbohydrate. No free sulfhydryl group was detected, even though there are six half-cystines in each subunit. Therefore, it seems likely that there are three pairs of disulfide bonds per subunit. The available data indicate that native butyrylcholinesterase is a tetrameric glycoprotein consisting of subunits of equal molecular weight.
Improvement in Numerical Prediction of Cavitating Flows Over Various 2D Geometries Using Modification to the Turbulence Model

Cavitation often causes performance breakdown and damage. So, it is very essential to accurately predict and control this phenomenon. In the present study, the unsteady effects associated with cavitation are investigated for various geometries including a NACA 0015 hydrofoil, a convergent-divergent nozzle, and a wedge, using the flow solver FLUENT. The turbulent viscosity and/or the turbulence dissipation in the k-epsilon turbulence model are modified. The cavitation phenomenon is represented based on the full cavitation model developed by Singhal et al. (2002), and it considers the liquid-vapor mixture as a homogeneous fluid whose density varies with respect to the static pressure and whose mass fraction is known in advance. Also, this model takes into account the formation and collapse of the vapor bubbles. The k-epsilon model was originally developed for fully incompressible fluids, and does not account for highly compressible two-phase mixtures. Hence, it has been found to be unsatisfactory for predicting cavitating flow in presence of high compressibility in the vapor region. Coutier-Delgosha et al. (2001) attributed this to the over-prediction of eddy viscosity in regions of flow with high vapor concentration, and suggested a modification for the calculation of eddy viscosity. Though the modification works in capturing the dynamic behavior of the cavitation sheet, the accuracy of cavity length and frequency are not accurately predicted for high cavitation numbers. This is due to inability of Coutier-Delgosha’s turbulence modification to completely account for all the complex flow features present in the cavity closure region. Thus, a further modification based on geometry and cavitation type is introduced in the turbulence modification of Coutier-Delgosha. Better results were obtained for moderate cavitation numbers, but this modification failed to accurately predict the frequency of vapor-cloud shedding at high cavitation numbers. This discrepancy is attributed to the large (40000:1) variation of density in the liquid-vapor region. Hence, a new modification is suggested in the present work where the closure coefficients of dissipation production (C1epsilon) and dissipation (C2epsilon) in the turbulent dissipation equation are dynamically varied in the liquid-vapor region. A User-Defined Function (UDF) is implemented in FLUENT to achieve this dynamic variation of the above mentioned closure coefficients. This modification is being tested to predict the time-averaged cavity length and vapor-cloud shedding frequency of cavitating flow over a NACA 0015 airfoil. The poster will present comparisons of cavity length and vapor-cloud shedding frequency over a wide range of cavitation numbers as predicted by the present and previous turbulence modifications and those observed in experimental studies.Copyright © 2007 by ASME
Completion of the ATLAS control system upgrade.

In the fall of 1992 at the SNEAP (Symposium of North Eastern Accelerator Personnel) a project to upgrade the ATLAS (Argonne Tandem Linear Accelerator System) control system was first reported (1). Not unlike the accelerator it services the control system will continue to evolve. However, the first of this year has marked the completion of this most recent upgrade project. Since the control system upgrade took place during a period when ATLAS was operating at a record number of hours, special techniques were necessary to enable the development of the new control system “on line” while still serving the needs of normal operations. This paper reviews the techniques used for upgrading the ATLAS control system while the system was in use. In addition a summary of the upgrade project and final configuration, as well as some of the features of the new control system is provided.
Language Variables Related to Reading Ability of Children with Verbal Deficits.

This study examined verbal reception and verbal mediation skills of children with low verbal/high performance WISC profiles. Of specific interest was the identification of possible sources of language impairment and the relationship between language variables and reading achievement. Eighty-five children in second through fifth grades (ages 8–11) with low verbal/high performance WISC profiles were evaluated, using cognitive tasks requiring verbal reception or verbal mediation strategies without requiring vocal responses. The results support the use of a verbal mediation hypothesis in the diagnostic evaluation of children with verbal deficit. Verbal mediation skills appear to be closely associated with reading ability, while the verbal reception task provided little useful diagnostic information for verbally deficient children.
Site selectivity in carbonyl reduction of mixed Fe2Co2 clusters. Formyl intermediates in the formation of hydrido derivatives

Abstract The mixed metal cluster Co2Fe2(CO)11(μ4-PPh)2 (II) undergoes a site-selective reduction of one of the carbonyl ligands by triethylborohydride reagent to afford a single formyl derivative Co2Fe2(CO)10(PPh)2CHO− (III) in excellent yields at −78°C. The same terminal CO bound to cobalt also selectively undergoes addition of methyllithium to afford the corresponding acetyl derivative (V). Whereas V is thermally robust at room temperature, the formyl derivative III is a transient species which readily loses carbon monoxide at −30°C to afford the μ2-hydride Co2Fe2(CO)10(PPh)2H− in quantitative yields. All of these site-selective reactions are compared to the corresponding transformations which were previously observed in the homonuclear analogue Co4(CO)10(μ4-PPh)2 (I). The structural similarities of homo- and heteronuclear clusters I and II, respectively, are considered in the context of the fluxional behavior of their bound carbonyl ligands. The comparisons are extended to the IR, 1H and 13C NMR properties of their formyl, hydrido, and acetyl derivatives.
Stability and Instability: A Note in Comparative Political Analysis

C OMPARATIVE POLITICAL ANALYSTS are presented with a variety of manifestations of political instability among which, for example, are unstable democracies, unstable dictatorships, and fragmented societies. Within each category of unstable society, moreover, there is, both empirically and speculatively, an infinite gradation. The purpose of the present paper, while heuristic in nature, is, first to identify political stability and second, to delineate two broad but significant categories of political instability. There is an underlying hope that such an effort will elicit meaningful hypotheses concerning a theory of political development.1
A limited lupus anti-spliceosomal response targets a cross-reactive, proline-rich motif.

Abstract Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of large amounts of characteristic autoantibodies. Anti-Sm and anti-nRNP (also known as anti-spliceosome) autoantibodies are among these. Previous epitope mapping of anti-spliceosomal antibodies has identified multiple antigenic determinants within this complex immune response. In this report we describe an SLE patient with a relatively simple, long-lasting anti-spliceosomal response. In the earliest serum sample tested the autoimmune response appeared restricted to the similar peptides PPPGMR(P,G)P of Sm B/B′, PAPGMRPP of nRNP C, and PPPGMIPP of nRNP A. Unlike all the other tested lupus patients with anti-spliceosomal autoantibodies, in this patient these proline-rich epitopes remained the primary target for humoral autoimmunity in subsequent serum samples collected over many years. Absorption of anti-PAPGMRPP antibodies also removed binding to PPPGMR(P,G)P and PPPGMIPP. Isolated antibodies to PAPGMRPP were capable of binding Sm B/B′, nRNP C and nRNP A by Western blot. For this particular SLE patient the autoimmune response observed against these three proteins is a single cross-reactive response against a similar proline-rich motif. Also, this patient has failed to undergo the B cell epitope spreading, typically observed in the naturally arising autoimmune response against the spliceosome in human lupus patients.
Studies on the neural tissue-limb deplant of salamander

Abstract The growth of deplanted salamander limbs and parts of the central nervous system in the fin matrix of host (Axolotl) animals, using procedures introduced by Weiss, was confirmed. An outgrowth of nerve fibers was traced to the muscular deplant and observed to terminate on motor end plates. Acetylcholinesterase was observed in many of the innervated end plates. Reorganization of the cellular elements in the deplanted spinal cord appears to be dependent on the formation of new cells from the proliferating germinal cells lining the central cavity. Various stages of multiplication, proliferation, and maturation of these cells were studied.
Physiologic responses of cardiac patients to supine, recumbent, and upright cycle ergometry

Physiological responses were compared in nine stable male cardiac patients (mean +/- standard error (SE): age, 68.3 +/- 8.1 years; height, 172.7 +/- 3.9cm; weight, 72.8 +/- 14.5kg) during stationary cycling in the supine, recumbent, and upright positions. A discontinuous exercise protocol was performed in which each stage included 3 minutes of exercise and 1 minute of recovery. Each subject's workload started at 150kgm.min-1 and increased by 150kgm.min-1 per stage until volitional fatigue. Testing sessions were randomized and performed 1 week apart. Subjects continued their normal medication regimen. All subjects were participants in a community-based cardiac rehabilitation program. Dependent variables were assessed at two different intensities; submaximal (300kgm.min +/- 1) and maximal. A two-way repeated measures ANOVA found no significant differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), minute ventilation (VE), respiratory exchange ratio (R), rate pressure product (RPP), and rating of perceived exertion (RPE) at submaximal (300kgm.min +/- 1) and maximal exercise efforts. Heart rate (HR) was significantly lower (p < or = .05) in the supine position compared with either the upright or recumbent positions during the submaximal workload. In addition, oxygen uptake (VO2) was significantly lower in the supine position at the submaximal workload (p < or = .05) compared with both upright and recumbent. No difference in HR or VO2 was observed at maximal exercise. Regressions of HR on VO2 showed similar slopes and intercepts for supine, recumbent, and upright ergometry.(ABSTRACT TRUNCATED AT 250 WORDS)
Monomial conditions on rings

Drazin introduced the notion ofpivotal monomial, a condition on the evaluations of monomials in a ring, and characterized simple artinian rings as those primitive rings which have pivotal monomials. In this paper we consider monomial conditions related to pivotal monomials. The two major results are a characterization of prime Goldie rings in terms of pivotal monomials, and a characterization of the socle of a primitive ring in terms of generalized pivotal monomials.
Multimegawatt nuclear power systems for nuclear electric propulsion

Results from systems analysis studies of multimegawatt nuclear power systems are presented for application to nuclear electric propulsion. Specific mass estimates are presented for nearer term SP-100 reactor-based potassium Rankine and Brayton power systems for piloted and cargo missions. Growth SP-100/Rankine systems were found to range from roughly 7 to 10 kg/kWe specific mass depending on full power life requirements. The SP-100/Rankine systems were also found to result in a 4-kg/kWe savings in specific mass over SP-100/Brayton systems. The potential of advanced, higher temperature reactor and power conversion technologies for achieving reduced mass Rankine and Brayton systems was also investigated. A target goal of 5 kg/kWe specific mass was deemed reasonable given either 1400 K potassium Rankine with 1500 K lithium-cooled reactors or 2000 K gas cooled reactors with Brayton conversion.
SEROTONIN-1A ANTAGONISTS ATTENUATE THE EFFECTS OF NICOTINE WITHDRAWAL ON THE AUDITORY STARTLE RESPONSE

Withdrawal from the chronic administration of nicotine has previously been shown to lead to an enhanced auditory startle response in rats. In order to explore the neuropharmacology and neurophysiology underlying this phenomenon, we examined the effects of various 5-hydroxytryptamine (5-HT)-1A antagonists and agonists on the nicotine-withdrawal-enhanced auditory startle response in male rats. Animals were treated with nicotine (6 mg/kg/day nicotine base, via subcutaneously implanted osmotic minipumps) for 12 days. After 12 days the pumps were removed and the animals allowed to undergo spontaneous withdrawal for several days. In agreement with previous results, nicotine withdrawal led to a significant elevation of the auditory startle response. Pretreatment with the 5-HT-1A agonists (+)8-OH-DPAT (0.001–0.1 mg/kg) and LY274600 (0.3–3.0 mg/kg) either had no affect or exacerbated the nicotine-withdrawal-enhanced startle response. Pretreatment with the 5-HT-1A antagonists NAN-190 (1–3 mg/kg), LY206130 (1–10 mg/kg), or WAY-100635 (0.1–1.0 mg/kg) blocked the increase in the startle response caused by nicotine withdrawal at doses that had no effect on baseline startle responses. These data indicate that 5-HT-1A receptors play a role in the neurophysiology of nicotine withdrawal. In addition, 5-HT-1A antagonists may be able to relieve some nicotine withdrawal symptoms in man and may represent a novel pharmacotherapy for smoking cessation. Synapse 27:145–152, 1997. © 1997 Wiley-Liss, Inc.
Are there Psychological Species

A common reaction to functional diversity is to group entities into clusters that are functionally similar. I argue here that people are diverse with respect to reasoning-related processes, and that these processes satisfy the basic requirements for evolving entities: they are heritable, mutable, and subject to selective pressures. I propose a metric to quantify functional difference and show how this can be used to place psychological processes into a structure akin to a phylogenetic or evolutionary tree. Three species concepts are repurposed from biology and used to understand relationships in that tree.
Cooperation and Punishment

In an era in which the “tragedy of the commons” has acquired new meaning on a global scale, social scientists are beginning to find hope in human nature. True, we are self-interested creatures capable of destroying the habitats that support us as we each focus on getting our share of the global commons before others beat us to it. Yet Homo sapiens could never have populated the planet and mastered complex technologies and organizational forms had nature not also made us sensitive to one another's regard. Both field studies and laboratory experiments depict humans as willing to cooperate when convinced that others are doing the same and that at least some will incur costs to sanction cheating. On page [613][1] in this issue, Janssen et al. ( 1 ) show that communication among members of a group is key to establishing cooperation and using punishment effectively, and on page [617][2], Boyd et al. ( 2 ) provide a model of how signaling (a stylized kind of communication) could have allowed punishment and cooperation to evolve. [1]: /lookup/doi/10.1126/science.1183532 [2]: /lookup/doi/10.1126/science.1183665
Geographic associations of breeding bird distribution in an urban open space

Abstract The Puente-Chino Hills, extending west into the highly urbanized Los Angeles Basin, represent one of the largest expanses of lowland habitats in the region. During spring and early summer of 1997 and 1998, birds and vegetation surveys were conducted to clarify the influence of geographical position in the distribution of birds in the hills. Using logistic regression, the inclusion of longitudinal position as a variable is shown to make a statistically significant contribution to bird species presence beyond that of habitat alone for 12 of the 49 most commonly detected species. Species more common than would be expected based on habitat in the east were typical of grassland and open habitats, whereas those more common in the west were characteristic of tall scrub or urban habitats. Thus, species’ distributions in the hills are likely influenced by landscape-scale vegetation patterns and by the aggregate amount of urbanized areas in the west. This emphasizes the importance of using geographical position as a variable when analyzing patterns in bird distribution and siting conservation areas.
Dielectronic Recombination: A Crossed-Beams Observation and Measurement of Cross Section

Dielectronic recombination has been directly observed with use of crossed beams of electrons and ${\mathrm{Mg}}^{+}$ ions. Measurements were made of delayed coincidences between the stabilizing photon near 280 nm and the resultant neutral atom, and cross sections were determined. Theoretical cross sections are more than a factor of 5 smaller than those measured.
Pod breakdown resistance in peanuts.

Abstract During 19 69–73, 13 commonly grown Virginia-type peanut (Arachis hypogaea L.) cultivars, 15 plant introductions. and two breeding lines were evaluated under field conditions for resistance to the pod breakdown fungi Pythium myriotylum and Rhizoctonia solani. Four cultivars—Early Runner. Florunner, Florigiant, and NC 17—having related pedigrees were consistently more resistant to infection by these two fungi. P.I. 341880 and P.I. 341885 and Florida breeding line F439–16–6 showed similar resistance to infection. Cultivars most susceptible to pod breakdown were NC 5, Va. 56R, Ga. 119–20 and Va. 72R. P.I. 343410 and a selection from P.I. 319178 were extremely susceptible to pod breakdown. Resistance to pod breakdown seems to have been derived from a cross between a small, white-seeded Spanish-type peanut and Dixie Giant, a large-seeded Virginia-type peanut. All resistant cultivars are related to this cross, whereas the susceptible cultivars lack these parental types in the pedigrees.
Comparison of the Ferno Scoop Stretcher with the Long Backboard for Spinal Immobilization

Objectives. Spinal immobilization is essential in reducing risk of further spinal injuries in trauma patients. The authors compared the traditional long backboard (LBB) with the Ferno Scoop Stretcher (FSS) (Model 65-EXL). They hypothesized no difference in movement during application andimmobilization between the FSS andthe LBB. Methods. Thirty-one adult subjects had electromagnetic sensors secured over the nasion (forehead) andthe C3 andT12 spinous processes andwere placed in a rigid cervical collar, with movement recorded by a goniometer (a motion analysis system). Subjects were tested on both the FSS andthe LBB. The sagittal flexion, lateral flexion, andaxial rotation were recorded during each of four phases: 1) baseline, 2) application (logroll onto the LBB or placement of the FSS around the patient), 3) secured logroll, and4) lifting. Comfort andperceived security also were assessed on a visual analog scale. Results. There was approximately 6–8 degrees greater motion in the sagittal, lateral, andaxia...
Phenotyping milk proteins: a review.

Abstract A variety of methods for phenotyping whey proteins and the caseins is summarized. The writer suggests what he believes are the best methods for phenotyping genetic variants of the milk protein system depending upon the availability of apparatus. No single method has yet been devised to simultaneously type the variants of α s1 - and β -caseins
Ethics in preventive HIV vaccine research

It is widely acknowledged that the best hope of slowing the worldwide HIV epidemic lies in the development of a safe and effective preventive method. Yet, like any other research enterprise, the quest for an HIV vaccine requires adherence to ethical standards. Debates surrounding appropriate ethical standards for preventive vaccine research include, but are not limited to, the following questions. What should be provided to participants in vaccine trials who acquire HIV infection during the trial? Once an efficacious vaccine is approved by regulatory authorities and becomes available, is it acceptable to use a placebo for the control group in future vaccine trials? As other modes of prevention are found to be effective, should a prevention package be provided to all participants in HIV vaccine trials? What obligation exists to provide successful vaccine products to the community or country when trials have successful outcomes?
Problems in the detection of acute severe mitral insufficiency using flow‐directed catheters

A case of acute severe mitral insufficiency is described wherein bedside Swan-Ganz right heart catheterization failed to established the diagnosis. Emphasis is given to problems inherent in recording the diagnostic large dominant V-waves with this technique, and to the necessity of resolving conflicting measurements with conventional cardiac catheterization.
Breakdown characteristics and conditioning of carbon and refractory metal electrodes

High voltage carbon and refractory metal electrodes employed in devices used in space, such as ion thrusters and traveling wave tubes, can be easily damaged by electrical breakdown and arcing events. Modification of the electrode surfaces due to these events can impact the voltage hold off capability of the surfaces, which could lead to additional arcing, further damage, and the potential for device failure. On the cathode-potential surface, the arc energy is deposited by all of the processes at the surface ultimately responsible for net electron emission, such as melting, vapor and paniculate formation, sputtering, ion bombardment, etc. On the anode-potential surface, the energy is deposited from the plasma or electron stream that crosses the gap, which causes surface damage by local heating. In spite of this energy dependence on the damage, many systems that use arc discharges characterize the amount of material removed from the surfaces and the lifetime of the device for voltage hold-off by the amount of current that passes through the arc, or the "Coulomb-rating". The results of a series of tests that were performed on the voltage hold off capability and damage to carbon-carbon composite surfaces and molybdenum surfaces due to induced arcing will be presented and discussed. Damage to the surfaces was characterized by the field emission performance after the arc initiation and SEM photographs for the different energy and coulomb-transfer arc conditions. Both conditioning and damage to the surfaces were observed, and will be related to the characteristics of the electrical breakdown
Onset Drinking: How It Is Related Both to Mother's Drinking and Mother–Child Relationships

Employing the National Longitudinal Survey of Youth (NLSY) as a sample of adolescents and their mothers, the present study connected the onset of adolescents’ drinking to certain posited risk and protective factors characterizing their families. Via event history analysis and the discrete-time method, the data analysis involved more than 6,331 pair-interview-year units. The results show that both peer influences and mother's daily alcohol consumption enhance the risk that an adolescent aged between 10 and 14 years will begin drinking. At the same time, the quality of a mother's relationship with her child is an important posited protective factor delaying onset drinking.
Specificity of brain activation patterns in people at genetic risk for Alzheimer disease.

Previous studies with positron-emission tomography (PET) and functional magnetic resonance imaging (fMRI) have indicated differences in neural metabolism and activity between carriers of the APOE ɛ4 allele and those who are not at risk for Alzheimer disease (AD). Persons without dementia carrying the ɛ4 allele showed greater magnitude and extent of brain activation than noncarriers in regions required for memory, suggesting they performed additional cognitive work to accomplish the same task. To determine whether the fMRI differences were specific to a memory task or generalizable to any difficult cognitive task, the authors performed fMRI and compared images from 25 subjects with and without the APOE ɛ4 allele. In the most difficult conditions, all subjects showed increased MR signal in the prefrontal cortex, indicating increased cognitive effort. However, the two genetic groups showed no differences in activation patterns even at the most difficult task level, suggesting that additional cognitive effort in persons at genetic risk for AD is specific to episodic encoding and is not merely a reflection of task difficulty.
Behavioral Economics and the Law

Part I Classical Stochastic Geometry: 1 Poisson Point Process 2 Marked Point Processes and Shot-Noise Fields 3 Boolean Model 4 Voronoi Tessellation Bibliographical Notes on Part I.
Changes in incidence and risk factors of Mycobacterium avium complex infections in patients with AIDS in the era of new antiretroviral therapies.

The aim of the study presented here was to determine the incidence, risk factors and prognostic indicators of Mycobacterium avium complex (MAC) infection in HIV-infected subjects prior to and after the introduction of highly active antiretroviral therapy (HAART). In the HAART era, the incidence of MAC infection decreased significantly from 3.7 to 0.9 per 100 person-years. Using logistic regression analysis, a high acute physiology and chronic health evaluation (APACHE) III score, a low number of CD4+ cells/mm3 and a high level of HIV viremia were found to be independent predictors of the risk to develop MAC disease; however, a high APACHE III score was the only prognostic indicator associated with an unfavourable outcome of a disseminated MAC infection. These results indicate that MAC infections, although considerably less frequent in the HAART era, are still responsible for cases of severe disease.
The salience of ethno-psychology for medical education and practice

Abstract The author posits that ethno-psychology, as one expression of community-psychology, cannot a priori be assumed to be either a vital or an inconsequential variable in a given patient. The paper presents a model whereby the salience of ethnicity can be assessed in terms of levels and parameters of personal cultural meaning, as opposed to a formulistic ethnic “cookbook”. Ethnographic vignettes are provided from the writer's teaching experience with medical students, and with residents in family practice and psychiatry. While the teaching of psycho-cultural dimensions of illness and health has traditionally focused on the identified patient and the culture “out there”, the author suggests that the social sciences could be taught with greater clinical effectiveness if the issues of ethno-psychology (that is, the influence of conscious and out-of-awareness values, premises, roles, expectations, attitudes, beliefs, conflicts, etc.) were to be explored (a) in relation to the student and practitioner's own lives, and (b) dialectically, as the student and practitioner experience and attempt to understand their patients' experiences. With insight into how they use their own cultural “tool kit”, medical students and residents feel freer to inquire into their patients' normative base line and how their patients use their culture—which knowledge physicians can use in their treatment plans in the service of meta-cultural health. Psycho-cultural “context” becomes for the clinician inseparable from the pathological “content” first presented. By personalizing the medical students and residents' clinical learning of ethno-psychology, we can discern in their treatment of patients a subtlety that would not have been possible without this approach. That is to say, the “subject” of ethno-psychology in medical education and practice is simultaneously the student/practitioner, the patient, and comparative epistemology.
NSFD discretizations of interacting population models satisfying conservation laws

We consider the roles conservation laws can play in providing restrictions on the construction of finite difference discretizations of interacting population systems, modeled by coupled ordinary differential equations. Our analysis is formulated within the nonstandard finite difference (NSFD) methodology of Mickens. A major feature of this paper is the recognition that several distinct types of conservation laws exist. Using a number of well-known population models, we illustrate the details of our procedures by constructing appropriate NSFD discretizations. The relevance of these results to various issues associated with the numerical integration of the original population system differential equations is also presented, especially the role of positivity of the solutions.
Physical Layer Techniques for Enhanced Situational Awareness

Wireless devices are being developed that can scan spectrum to take advantage of spectrum opportunities for enhanced communication. For these devices to communicate better, it is desirable that they have an awareness of their setting. In this paper, we present a collection of techniques, which we call PLATEAU: Physical Layer Techniques for Enhanced Situational Awareness, which leverages physical layer properties from existing signals to gain an accurate picture of a device's environment as well as understanding of that device's mobility. We show through experiments using measurements from a software defined radio that, by utilizing radar and machine learning signal processing, a device can make more informed operational decisions.
Glaucoma screening. A cost-effectiveness analysis☆

We designed an intricate model of the process of glaucoma screening, diagnosis, and treatment in order to evaluate the medical care costs of such efforts in relation to the benefits in terms of quality-adjusted years of vision saved, utilizing the economic principles of cost-effectiveness analysis. Although a relatively limited data base and numerous assumptions concerning the accuracy of diagnostic tests, the natural history of ocular hypertension and glaucoma, and the effectiveness of available treatment modalities, limit our ability to draw definitive conclusions concerning the cost-effectiveness of various glaucoma screening options, our analysis indicates that glaucoma screening is probably cost-effective when targeted at certain subgroups of the population. Our analysis suggests that changes in several aspects of existing screening policies may be appropriate if cost-effectiveness is to be used as one of the criteria for the efficient allocation of resources to and within screening programs. Specifically, combinations of screening tests and screening targeted at high risk populations such as blacks, diabetics, and relatives of glaucoma patients are probably more cost-effective than screening of the general population with a single test. In younger populations, the importance of detecting ocular hypertension argues for the use of tonometry. Ophthalmoscopy may be more cost-effective in older age groups in whom the higher prevalence of glaucoma outweighs the need for identifying ocular hypertensives. In the very elderly, automated perimetry becomes cost-effective since the detection of established field loss will have greater yield. In addition, it is evident that diversion of resources away from actual screening efforts and towards efforts aimed at improving follow-up and compliance would be an additional cost-effective strategy.
Use of operant response duration to distinguish the effects of haloperidol from nonreward

Prior experimentation, making exclusive use of operant response rate, has offered conflicting evidence regarding the role of reinforcement and motor effects in neuroleptic-induced changes in operant responding. In the present work, response rate and response duration were recorded for 12 rats responding under a fixed-ratio 10 schedule of food reinforcement. On six consecutive days separate groups of animals were given haloperidol or saline-with-extinction. Although both drug treatment and extinction produced elevated durations compared to pre-treatment baseline, the haloperidol group exhibited response durations that were significantly higher than those of the no-drug-extinction group. In view of these results, and since prior work has shown that response duration provides information which is nonredundant with response rate, it is suggested that response duration may be a valuable tool in future work attempting to partial out the motivational and motor effects of neuroleptics on operant responding.
Men and Women Holding Hands: Whose Hand is Uppermost?:

This study explored the issue of whether status and power differences are expressed in the way men and women hold hands. It was hypothesized that men's hands would be upper in heterosexual handholding couples significantly more often than women's. Also, to explore the possibility that height differences of handholding partners might affect handholding position, all handholding couples observed in this study were classified as couples with men and women of equal height or couples where either the men or women were taller. A total of 1,006 handholing couples were observed, and men's hands were significantly more likely to be the upper one in couples when men were taller than women and in couples where men and women were of equal height, suggesting that, while height does matter, it is less important for this handholding pattern than sex differences.
Trace Amount of Satellite RNA Associated with Tobacco Ringspot Virus: Increase Stimulated by Nonaccumulating Satellite RNA Mutants

The small satellite RNA of tobacco ringspot virus (sTRSV RNA) is dependent on tobacco ringspot virus (TRSV) for replication and encapsidation. sTRSV RNA has appeared during serial passage of certain TRSV strains in some hosts. Co-inoculation of bean with TRSV and either of two related, nonaccumulating mutants of sTRSV RNA induced the appearance of sTRSV RNA in a single passage (van Tol et al., 1991, Virology 180, 23-30). The sTRSV RNA obtained after serial passage and after co-inoculation have the same nucleotide sequence, designated the endogenous sequence. The endogenous sTRSV RNA nucleotide sequence differs from that of each of the nonaccumulating sTRSV RNA at three positions. In order to detect possible trace amounts of endogenous satellite RNA in virion RNA preparations, RNA from two TRSV isolates was subjected to reverse transcription and polymerase chain reaction of the transcript (RT-PCR), using primers with sTRSV RNA terminal sequences. The yield of RT-PCR product suggests that the virion RNA preparations contained approximately 0.1 fg of sTRSV RNA per microgram of virion RNA. The nucleotide sequence of the RT-PCR product corresponded to that of the endogenous sTRSV RNA. The endogenous sTRSV RNA of TRSV inocula appears to be latent, being maintained in very small amounts during serial passage of TRSV in some hosts but capable of dramatic increase during serial passage in other hosts or when TRSV was co-inoculated with either of two specific sTRSV RNA mutants. Ten other nonaccumulating sTRSV RNA mutants did not induce a detected increase in sTRSV RNA.
Arginine vasotocin: structure-activity relationships and influence on gonadal growth and function.

When AVT (arginine vasotocin) was given neonatally during the period when the brain is undergoing sexual differentiation, increased growth of the reproductive organs was observed in adulthood. Injection of AVT after this neonatal period in immature animals led to diminished growth of the accessory organs and in some cases the gonads themselves. The hypertrophic response of the in situ ovary in adult mice following unilateral ovariectomy (UO) was inhibited in a dose-related manner by a single intraperitoneal injection of freshly prepared AVT. Much less AVT was required for this response when injected into the third ventricle. After intraperitoneal injection, arginine vasopressin (AVP), lysine vasopressin (LVP), and 4-leucine vasotocin (4-leu-AVT) also inhibited compensatory ovarian hypertrophy whereas oxytocin did not. The commonality in die structure of these antigonadotrophic peptides include a closed ring and a basic amino acid in position 8. After opening the disulfide bond of these nonapeptides with mercaptoethanol, a single injection of the reduced AVT, AVP, LVP, or 4-leu-AVT into UO mice causes exaggerated hypertrophy of the remaining ovary. When added with leuteinizing hormone-releasing hormone (LRH) to culture medium containing hemipituitaries from castrated estrogen-progesterone primed female rats, AVT significantly increased the release of radioimmunoassayable LH above that due to LRH alone. AVT might interact at all levels of the hypothalamo-hypophysealgonadal axis.
Changes in Pickling Cucumber Yield and Economic Value in Response to Planting Density

Studies on density-dependent variations in yield and economic value of crops could help identify optimum plant density. Field experiments were conducted in 2003 and 2004 using a wide range of densities (from 88000 to 330000 plants ha -1 ) of pickling cucumber (Cucumis sativus L.) grown for once-over machine harvest. Fruit set was identified as a major yield-limiting factor at low densities. When plant density decreased by 73%, fruit number only increased by 50% within the range of densities used. Total marketable yield increased with density. However, the highest yield observed at the highest density did not translate into the highest economic value. This was mainly due to the added cost of the seed under high densities. Optimum density required to maximize economic value, was between 220000 and 245000 plants ha -1 and depended on the selling price of the fruits. Our results support the hypothesis that the density of 330000 plants ha -1 currently used by many growers could be significantly reduced without losses in economic value of the crop. Finally we propose that seed cost be included in studies designed to identify optimum planting density of crops.
A Review of Mortality From Choroidal Melanoma: I. Quality of Published Reports, 1966 Through 1988

• The literature concerning mortality after a diagnosis of choroidal melanoma was reviewed to identify relevant articles published from 1966 through 1988 and to select those with mortality rates presented separately by tumor size for inclusion in a pooled analysis (meta-analysis) of 5-year mortality after enucleation for choroidal melanoma. The quality of the published literature for our purposes was assessed. Candidate articles were identified from a search of the MEDLINE files by an information specialist. Altogether, of 217 candidate articles, 76 (70 from the MEDLINE search and six more from our files) qualified for review. Allcause mortality rates were reported in 80% of the articles. Among six aspects of design and methods for which information was sought, eligibility criteria were reported in 52 (68%) of the 76 articles and statistical methods were cited in 38 (50%); other information was reported with intermediate frequency. Quality scores based on completeness of reporting with respect to 16 factors ranged from 13.3 to 92.3 of a possible 100.0. Findings suggest that researchers, clinicians, journal editors, and reviewers should be more attentive to the completeness of reports from clinical research studies with respect to basic information regarding design and methods.