cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantum conductance of monatomic Ni nanobridges

Abstract The quantum conductance phenomena in narrow metal nanobridges were investigated. The nanobridge devices with small atomic-wide gap were formed by a novel controlled electroplating method on a nanolithographed quartz wafer. The metallic contact nanowires were grown across the gap by field evaporation. The field-induced formation and field-stabilization of monatomic Ni nanobridges are described. Thus formed Ni nanowires appeared to be unstable in the absence of electric field and disassembled quickly under no field conditions. The minimum quantum conductance associated with monatomic constriction in the nanobridge was observed. Exceptionally stable monatomic quantum nanobridges (QNB) were obtained by chemical treatment. They were investigated in the dry state and in the electrolyte solutions. The quantum conductance with zero temperature coefficient was observed at low electric field strength E (bias voltage | V b | E (| V b | > 0.8 V) leading to the conductance increase with temperature, opposite to the behavior of a bulk Ni metal. The mechanism of the observed phenomenon is presented. To gain further insights into the thermionic barrier formation in QNB, we have performed quantum mechanical calculations, using semi-empirical method, for model Ni nanobridge atom clusters (base:nanowire:base = 6: n :6 atoms, with n = 1–5). They have shown that in longer joining nanowires ( n > 1) the lowest unoccupied molecular orbitals (LUMO) are predominantly concentrated over base electrodes (reservoirs) rather than over the nanowire constriction, while the short (monatomic) nanowires are densely populated with low lying LUMO's. The results of calculations suggest also that the location of the quantum confinement (the constriction) may not necessarily be at the nanowire center (as generally assumed) but rather at the joints of nanowire with base electrodes where the wire width is the lowest.
On the theory of normal grain growth

Abstract Grain growth is analysed on the basis that the necessary boundary motion is random in its essentials. This analysis leads to a growth rate proportional to the reciprocal of the square root of time. It also leads to a common distribution function for grain diameters and grain edges. This distribution accords well with experiment.
Using word reading time in text processing research

A study that employed a moving-window task was designed to test the paradigm’s sensitivity to different levels of interclause integration. The program that controlled the task, implemented on a Terak 8510/a microcomputer in UCSD Pascal, is described. The results of the study indicate that word reading time is indicative of lower and “midlevel” types of integration, but not higher order domain knowledge considerations.
Modelling multivariate failure time associations in the presence of a competing risk

There has been much research on analysing multivariate failure times, but little that has accommodated failures that arise in the presence of a competing failure process. This paper studies the problem of describing associations among times to such failures. It proposes a modified conditional hazard ratio measure of association that is tailored to competing risks data, develops frailty models and a nonparametric method for describing the proposed measure, and contrasts estimation by proposed methods with the 'standard' of treating competing risks as independently censoring failure times due to targeted causes. The methods are investigated on simulated and real data.
De novo chronic graft-versus-host disease presenting as hemolytic anemia following partially mismatched related donor bone marrow transplant

Chronic graft-versus-host disease (cGVHD) is a disease of immune dysregulation that resembles an autoimmune disease. It usually involves the skin, mucosal and serosal surfaces and, less commonly, the hematopoietic system. We report hemolytic anemia (HA) as the primary manifestation of de novo cGVHD in recipients of partially mismatched related donor transplants. Five of 40 eligible patients developed HA at a median of 168 days post-transplant. Recipients were mismatched for one to three major HLA antigens. Conditioning therapy consisted of total body irradiation, etoposide, Ara-C, cycle-phosphamide and steroids. GVHD prophylaxis included partial T cell depletion, using anti alpha/beta CD3 antibody (T10B9) and complement, in addition to post-transplant immunosuppression. At presentation, all patients were receiving cyclosporine with or without low-dose steroids. Along with a mean Hb of 7.1 g%, patients had an increased reticulocyte count, a mild raised lactic dehydrogenase and a positive Coombs' test (in 2/5 patients). Four patients had also demonstrated a decrease in platelet count. Treatment was initiated with high-dose steroids and intravenous gamma globulin and response was observed within 1 week. Awareness of this presentation of cGVHD and early therapeutic intervention can result in successful reversal of presumed immune-mediated red cell and platelet destruction.
Hospital Management of Hyponatremia in Patients With Heart Failure: Interim Data from a Multi-Center Registry

Background: While the pathophysiology of hyponatremia (HN) in systolic heart failure (HF) is well described, little is known regarding its management in contemporary clinical practice. The goal of the ongoing “HN Registry” is to observe actual treatment and length of stay (LOS) in patients with both HF and HN in the hospital setting. Methods: Medical records were collected for patients meeting “HN Registry” criteria. Informed consent or waiver was obtained for all patients. HN was defined as a serum sodium #130 mmol/L. The study population includes other conditions (e.g. cirrhosis); the current interim analysis only includes patients with HF (N5537) collected over 30 months (9/2010-3/2012) at 149 US sites. Observational chart data are collected throughout the duration of the hospitalization; there is no prospective treatment algorithm or protocol. For patients on therapy for HN, LOS is calculated from the day HN is first treated. Results: Baseline patient demographic data are shown in the figure. Baseline BNP and creatinine values are elevated. HN was first documented on day 2.4d (range 134). Serum sodium increased regardless of baseline GFR (GFR !30: median 2.75 mmol/L; GFR O30 !60: 2.00, GFRO60: 2.00). Many patients did not have documentation of therapy, including fluid restriction, targeting HN (N5194, 36%). Lengths of stay appeared to be longer for patients who received fluid restriction or saline infusions alone. Conclusion: Patients with HF and HN have elevated biomarkers and renal insufficiency but are often not treated with approaches known to lead to correction of serum sodium. Median LOS appears to vary in part by treatment. Additional data collection should permit a more accurate description of the impact of therapies on in-hospital processes and outcomes. 306
Oncogenic Kras Initiates Leukemia in Hematopoietic Stem Cells

How oncogenes modulate the self-renewal properties of cancer-initiating cells is incompletely understood. Activating KRAS and NRAS mutations are among the most common oncogenic lesions detected in human cancer, and occur in myeloproliferative disorders (MPDs) and leukemias. We investigated the effects of expressing oncogenic KrasG12D from its endogenous locus on the proliferation and tumor-initiating properties of murine hematopoietic stem and progenitor cells. MPD could be initiated by KrasG12D expression in a highly restricted population enriched for hematopoietic stem cells (HSCs), but not in common myeloid progenitors. KrasG12D HSCs demonstrated a marked in vivo competitive advantage over wild-type cells. KrasG12D expression also increased the fraction of proliferating HSCs and reduced the overall size of this compartment. Transplanted KrasG12D HSCs efficiently initiated acute T-lineage leukemia/lymphoma, which was associated with secondary Notch1 mutations in thymocytes. We conclude that MPD-initiating activity is restricted to the HSC compartment in KrasG12D mice, and that distinct self-renewing populations with cooperating mutations emerge during cancer progression.
An experimental study of the autoignition characteristics of conventional jet fuel/oxidizer mixtures: Jet-A and JP-8

Abstract Ignition delay times of Jet-A/oxidizer and JP-8/oxidizer mixtures are measured using a heated rapid compression machine at compressed charge pressures corresponding to 7, 15, and 30 bar, compressed temperatures ranging from 650 to 1100 K, and equivalence ratios varying from 0.42 to 2.26. When using air as the oxidant, two oxidizer-to-fuel mass ratios of 13 and 19 are investigated. To achieve higher compressed temperatures for fuel lean mixtures (equivalence ratio of ∼0.42), argon dilution is also used and the corresponding oxidizer-to-fuel mass ratio is 84.9. For the conditions studied, experimental results show two-stage ignition characteristics for both Jet-A and JP-8. Variations of both the first-stage and overall ignition delays with compressed temperature, compressed pressure, and equivalence ratio are reported and correlated. It is noted that the negative temperature coefficient phenomenon becomes more prominent at relatively lower pressures. Furthermore, the first-stage-ignition delay is found to be less sensitive to changes in equivalence ratio and primarily dependent on temperature.
Selected Bibliography of Comparative Teacher Education.

The following list includes a sampling, in several languages, of the wide literature on the history, theory, practice, and problems of teacher education in various parts of the world. Acknowledgment is made to Mrs. Ann B. Weissmann, graduate assistant in comparative education, for valuable aid in checking bibliographical data and in suggesting additional titles.
An intersection theorem for four sets

Abstract Fix integers n , r ⩾ 4 and let F denote a family of r-sets of an n-element set. Suppose that for every four distinct A , B , C , D ∈ F with | A ∪ B ∪ C ∪ D | ⩽ 2 r , we have A ∩ B ∩ C ∩ D ≠ ∅ . We prove that for n sufficiently large, | F | ⩽ ( n − 1 r − 1 ) , with equality only if ⋂ F ∈ F F ≠ ∅ . This is closely related to a problem of Katona and a result of Frankl and Furedi [P. Frankl, Z. Furedi, A new generalization of the Erdős–Ko–Rado theorem, Combinatorica 3 (3–4) (1983) 341–349], who proved a similar statement for three sets. It has been conjectured by the author [D. Mubayi, Erdős–Ko–Rado for three sets, J. Combin. Theory Ser. A, 113 (3) (2006) 547–550] that the same result holds for d sets (instead of just four), where d ⩽ r , and for all n ⩾ d r / ( d − 1 ) . This exact result is obtained by first proving a stability result, namely that if | F | is close to ( n − 1 r − 1 ) then F is close to satisfying ⋂ F ∈ F F ≠ ∅ . The stability theorem is analogous to, and motivated by the fundamental result of Erdős and Simonovits for graphs.
The Relationship between Medicare Supplemental Insurance and Health-care Spending: Selection Across Multiple Dimensions

This paper investigates Medicare supplemental insurance and health-care spending. The empirical models attempt to determine whether seniors who possess certain traits, particularly health- and risk-related factors, choose supplemental coverage based on expectations of health-care needs. Employer-provided supplemental coverage is considered separately from official “Medigap” policies. Results indicate favorable selection into supplemental insurance based on health status, but no selection based on risk attitudes. The models indicate that Medigap and employer-provided enrollees spend approximately $1,000 and $1,500 more annually, respectively, than those without supplemental coverage. Finally, moral hazard induced by Medicare supplemental coverage appears to add $5.5 billion annually to the federal budget, although this estimate lacks statistical significance.
Protection from Acoustic Trauma Is Not a Primary Function of the Medial Olivocochlear Efferent System

The medial olivocochlear (MOC) efferent system is an important component of an active mechanical outer hair cell system in mammals. An extensive neurophysiological literature demonstrates that the MOC system attenuates the response of the cochlea to sound by reducing the gain of the outer hair cell mechanical response to stimulation. Despite a growing understanding of MOC physiology, the biological role of the MOC system in mammalian audition remains uncertain. Some evidence suggests that the MOC system functions in a protective role by acting to reduce receptor damage during intense acoustic exposure. For the MOC system to have evolved as a protective mechanism, however, the inner ears of mammals must be exposed to potentially damaging sources of noise that can elicit MOC-mediated protective effects under natural conditions. In this review, we evaluate the possibility that the MOC system evolved to protect the inner ear from naturally occurring environmental noise. Our survey of nonanthropogenic noise levels shows that while sustained sources of broadband noise are found in nearly all natural acoustic environments, frequency-averaged ambient noise levels in these environments rarely exceed 70 dB SPL. Similarly, sources reporting ambient noise spectra in natural acoustic environments suggest that noise levels within narrow frequency bands are typically low in intensity (<40 dB SPL). Only in rare instances (e.g., during frog choruses) are ambient noise levels sustained at moderately high intensities (~70–90 dB SPL). By contrast, all experiments in which an MOC-mediated protective effect was demonstrated used much higher sound intensities to traumatize the cochlea (100–150 dB SPL). This substantial difference between natural ambient noise levels and the experimental conditions necessary to evoke MOC-mediated protection suggests that even the noisiest natural acoustic environments are not sufficiently intense to have selected for the evolution of the MOC system as a protective mechanism. Furthermore, although relatively intense noise environments do exist in nature, they are insufficiently distributed to account for the widespread distribution of the MOC system in mammals. The paucity of high-intensity noise and the near ubiquity of low-level noise in natural environments supports the hypothesis that the MOC system evolved as a mechanism for “unmasking” biologically significant acoustic stimuli by reducing the response of the cochlea to simultaneous low-level noise. This suggested role enjoys widespread experimental support.
The health assessment questionnaire 1992. Status and review

Over 100 papers describing and utilizing the Stanford Health Assessment Questionnaire (HAQ) have been published since 1980. A brief overview of the HAQ is presented along with a guide to the accumulated literature. The topics covered include: studies using the disability, pain, economic, and drug side effect dimensions of the HAQ; reliability and validity studies; applications to various rheumatic diseases; language adaptations; modifications and derivative scales; studies correlating the HAQ with sociodemographic, health status, laboratory, and physical measures; and randomized controlled trials and observational studies using the HAQ. A few comments regarding future directions for research are also presented.
Testing of gastric contents for peanut proteins in a 13-year old anaphylaxis victim.

Abstract Background We report the case of a 13-y female who went into anaphylactic shock following the ingestion of a meal suspected to be contaminated by peanuts. The teenager had a known sensitivity to peanuts, however, the restaurant claimed that no peanut products were used in the preparation of her meal. The gastric contents of the decedent were retained and tested for peanut proteins due to the possible legal liability of the proprietor. Method Using antibodies against peanut proteins (roasted and unroasted), we optimized a method to detect total soluble peanut proteins by Western-blot analysis in gastric contents. In addition, we validated two commercially available tests which were originally intended for detection of peanut proteins in food matrices to examine the same gastric sample. One was an enzyme-linked immunosorbent assay (ELISA) that utilized polyclonal antibodies against Ara h 1 (Tepnel Life Sciences). The other was a laminar-flow assay directed against Ara h 1, Ara h 2 and Ara h 3 (R-Biopharm). A positive food-based control was created by reducing bread and peanuts (1:1, w/w) with water (1:1, w/v) using a mortar and pestle. A food-based negative food control was created similar to the positive control, except the peanuts were omitted and the amount of bread was doubled. Results The Western-blot assay was sensitive down to 2.5 ng/ml of total peanut protein. The laminar flow was the most rapid and least complex. The ELISA was the most analytically sensitive with a cut-off of 1 ng/ml of Ara h 1 protein compared to the laminar flow which had a cut-off of 4 ng/ml Ara h 1 equivalent. Both ELISA and laminar flow assays were able to detect peanut proteins in the food matrices and positive controls, and not in negative controls. No peanut related proteins were detected in the decedent's gastric sample. The gastric sample spiked with peanuts was reliably detectable. Conclusion The anaphylaxis patient had no peanut allergens detected in her gastric contents by any of the three methods employed. Both commercially available assays are easily adaptable for testing peanut allergens in the gastric contents as judged by the results of the immunoassays as well as the Western blot analysis. Due to the rising need for detecting peanut proteins in various heterogeneous and complex matrices, the use of appropriate controls should be also considered in these unique investigations.
Collagen Types I and III Localization by In Situ Hybridization and Immunohistochemistry in the Partially Obstructed Young Rabbit Bladder

AbstractPurpose: The objective of the study was to investigate the alteration of collagen expression patterns at the transcription and translation levels during partial outlet obstruction and to compare changes in collagen types I and III gene expression, and protein deposition during early and subacute phases of obstruction.Materials and Methods: Following 1, 2, 7, 14 and 21 days of partial bladder obstruction in 2-week-old rabbits bladder tissues were evaluated for collagen types I and III messenger ribonucleic acid localization by in situ hybridization and for protein localization by immunohistochemical study.Results: There is up regulation of collagen types I and III gene expression after obstruction. Up regulation of collagen gene expression immediately after obstruction is within the lamina propria and the message moves into the muscular layer as obstruction progresses. Protein deposition for both collagen types is analogous to that of gene expression.Conclusions: Up regulation of collagen types I a...
Improved derivative of a phage λ EK2 vector for cloning recombinant DNA

THOMAS et al.1 have constructed a derivative of phage λ (λgt·λC) that is useful for cloning DNA fragments 1,000 to 15,000 base pairs long from other organisms. Their cloning procedure involves cutting the phage DNA into three fragments with EcoRI nuclease, removing the central (or “C”) fragment, and annealing the outside fragments with an RI digest of foreign DNA. We have recently introduced three amber mutations—Wam403, Eam1100, and Sam100—into λgt·λC with the object of making the phage less likely to encounter a susceptible host in nature2. The NIH Advisory Committee on Recombinant DNA Research, on the basis of appropriate tests, has certified λgtWES·λC as an EK2 vector3,4.
Characterization of Pyroclastic Deposits and Pre-eruptive Soils following the 2008 Eruption of Kasatochi Island Volcano, Alaska

Abstract The 7–8 August 2008 eruption of Kasatochi Island volcano blanketed the island in newly generated pyroclastic deposits and deposited ash into the ocean and onto nearby islands. Concentrations of water soluble Fe, Cu, and Zn determined from a 1:20 deionized water leachate of the ash were sufficient to provide short-term fertilization of the surface ocean. The 2008 pyroclastic deposits were thicker in concavities at bases of steeper slopes and thinner on steep slopes and ridge crests. By summer 2009, secondary erosion had exposed the pre-eruption soils along gulley walls and in gully bottoms on the southern and eastern slopes, respectively. Topographic and microtopographic position altered the depositional patterns of the pyroclastic flows and resulted in pre-eruption soils being buried by as little as 1 m of ash. The different erosion patterns gave rise to three surfaces on which future ecosystems will likely develop: largely pre-eruptive soils; fresh pyroclastic deposits influenced by shallowly bu...
Human growth hormone immunoassay: two-antibody method using I-125 tracer.

SummaryImmunoassay of human growth hormone with a 2-antibody method utilizing commercially prepared I-125 tracer provides a simple procedure for determining the concentration of human growth hormone in plasma. The method is sensitive to as little as 1 mμg.
Photoactive Antimicrobial Agents/Polyurethane Finished Leather

Received 14 May 2009; accepted 27 July 2009DOI 10.1002/app.31221Published online 15 September 2009 in Wiley InterScience (www.interscience.wiley.com).ABSTRACT: To prepare antimicrobial coating on leathersurfaces with high potency against microbes, photoactiveagents such as benzophenone (BP) and rose bengal (RB)were incorporated into polyurethane-based coatingsolutions, respectively, and then the BP or RB containingsolutions were applied onto surfaces of leather by a paintingmethod. The photoactive antimicrobial agents treatedleather samples were characterized by FTIR, SEM, andantimicrobial tests. The treated-leather samples demon-strated excellent antibacterial activity under fluorescentlight as well as UVA light and also the antimicrobial abilityshowed the effective durability to abrasion and daylight.
A HIMALAYAN LEGEND DESCRIBES AN EARLY EXAMPLE OF SCIENCE APPLIED TO THE PACKING AND TRANSPORT OF A WORK OF ART

The chance discovery of the field notebooks of the Himalayan explorer Wilhelm Froschfeld (died 1887) led the author to a Nangali legend about a wooden idol with silver eyes that weeped at dramatic moments. The author suggests a scientific explanation based on the way in which wood interacts with water vapour in the air. Transport of the statue in a box created a microclimate that led to condensation when the statue was unpacked. Drawings, graph, diagram.
Cryogenic Temperature Dependence of the Yield Strength of High-Strength Alloys

The effect of cryogenic temperatures (from 78 F to −423 F) on the yield strength of twenty alloys was studied. Experimental results prove that they do not conform to any of the following theories: Hollomon and Zener’s, Cottrell and Bilby’s, or Fisher’s. However, all the plottings in loge -loge scale of yield strength versus absolute cryogenic temperatures of these alloys fall on straight lines which are governed by one single general equation, σy = bT−m . From the Cottrell’s dislocation theory on yielding and Fisher’s equation of activation energy in forming a dislocation loop, the same type of equation of yield strength versus temperature as expressed by the empirical ones can be derived theoretically. The empirical equations are very useful in predicting yield strengths at any cryogenic temperature within or slightly out of the test range for which data were available. Some limited yield strength data at elevated temperatures for a few alloys were studied for comparison. It was observed the general equation for yield strength versus cryogenic temperatures holds valid for stainless steels but not so well for titanium, nickel, and aluminum alloys at elevated temperatures. However, no conclusion can be drawn until further detailed studies at elevated temperatures are made.
A chiral porous 3D metal-organic framework with an unprecedented 4-connected network topology.

A novel homochiral 3D metal–organic framework [CdL2(H2O)2][ClO4]2·2DMF·3EtOH·5/3H2O, 1, (L = (R)-6,6′-dichloro-2,2′-diethoxy-1,1′-binaphthyl-4,4′-bipyridine) exhibits an unprecedented 4-connected network topology owing to the cis- configuration of the Cd coordination and possesses permanent porosity as demonstrated by TGA, XRPD, and CO2 adsorption isotherm studies.
Systematic modeling of discrete-continuous optimization models through generalized disjunctive programming

Discrete-continuous optimization problems are commonly modeled in algebraic form as mixed-integer linear or nonlinear programming models. Since these models can be formulated in different ways, leading either to solvable or nonsolvable problems, there is a need for a systematic modeling framework that provides a fundamental understanding on the nature of these models. This work presents a modeling framework, generalized disjunctive programming (GDP), which represents problems in terms of Boolean and continuous variables, allowing the representation of constraints as algebraic equations, disjunctions and logic propositions. An overview is provided of major research results that have emerged in this area. Basic concepts are emphasized as well as the major classes of formulations that can be derived. These are illustrated with a number of examples in the area of process systems engineering. As will be shown, GDP provides a structured way for systematically deriving mixed-integer optimization models that exhibit strong continuous relaxations, which often translates into shorter computational times. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3276–3295, 2013
Risk of hospitalization for heart failure associated with thiazolidinedione therapy: a medicaid claims-based case-control study.

Study Objectives. To determine, in patients with type 2 diabetes mellitus, whether an association exists between thiazolidinedione therapy or other diabetes therapies and hospital admission for heart failure. Design. Retrospective case-control study. Data Source. Oregon Medicaid claims database. Patients. A total of 288 case patients and 1652 control patients. Measurements and Main Results. Case patients were defined as any patients hospitalized for heart failure, controls as any patients with a hospital claim for a condition other than heart failure. Controls were matched by age and sex in a 6:1 ratio. Exposure to a thiazolidinedione or other antihyperglycemic drug was assessed 60 days before the first hospitalization. This was used to construct an odds ratio of exposure in case patients compared with controls using a multivariate logistic regression model and controlling for potential confounders. Charlson comorbidity index scores and frequency of diabetes-related office visits were significantly higher for case patients than for controls. The unadjusted and adjusted odds ratios for exposure to a thiazolidinedione were 1.71 (95% confidence interval [CI] 1.24–2.36) and 1.37 (95% CI 0.98–1.92), respectively. The unadjusted and adjusted odds ratios for exposure to insulin in patients hospitalized for heart failure were 1.68 (95% CI 1.27–2.22) and 1.25 (95% CI 0.92–1.69), respectively. The unadjusted and adjusted odds ratios for exposure to a combination of insulin and a thiazolidinedione in case patients were 1.81 (95% CI 1.14–2.86) and 1.35 (95% CI 0.84–2.18), respectively. No association with hospitalization for heart failure was found for patients exposed to a sulfonylurea, metformin, or α-glucosidase inhibitor. Conclusion. This study showed a likely association between thiazolidinedione therapy and hospitalization for heart failure within 60 days of the prescription date. A similar trend occurred with insulin therapy alone and with the combination of thiazolidinedione and insulin, but not with other oral antihyperglycemics. When thiazolidinediones are prescribed, careful consideration should be given to patients with known heart failure. In addition, all patients should be educated regarding heart failure and monitored for signs and symptoms.
Sodium sensitivity of baroreceptors mediates reflex changes of blood pressure and urine flow

CARDIOVASCULAR baroreceptors are sensitive to vascular pressures and their input to the central nervous system is essential for the regulation of arterial blood pressure. They also contribute to the regulation of extracellular fluid volume, because their reflex effects upon arterial pressure and renal blood flow have marked consequences for urine flow1,2. Since they are mechanoreceptors their properties may be affected by sodium and potassium ions3–5. Lowering extracellular Na+ (Nao+) increases the threshold pressure at which arterial baroreceptors begin to discharge and reduces their sensitivity to suprathreshold pressures6,7. We therefore investigated the reflex effects upon arterial blood pressure and urine flow elicited by lowering the Nao+ of carotid sinus baroreceptors. We report that reductions in Nao+ of as little as 5% increase arterial blood pressure and urine flow. We propose that the sodium sensitivity of baroreceptors is important for their function as regulators of arterial blood pressure and body fluid volume.
Do Engineers Make Better Naval Officers

The hypothesis that engineering graduates are best suited for junior officer positions aboard increasingly sophisticated surface and submarine warships is tested empirically for a subset of 1,560 U.S. Naval Academy graduates from the classes 1976-80. Following the guidelines set by Admiral Rickover, policymakers presume the best preparation for leadership positions is provided by college majors that emphasize mathematics, sciences, and (especially) engineering. The results of the study, based on advanced multivariate regression techniques, fail to support this common notion. For the subset of USNA graduates, neither academic major selection nor achievement within defined academic class groupings is found to be statistically related to performance and retention of junior officers at the completion of their initial tour of duty. The results are applicable to both the conventional surface and nuclear navies for the subset of academy graduates. The study suggests the approach be applied to the Officer Candida...
Recession and Recovery in the United Kingdom in the 1990s: A Vector Autoregression Approach

This paper uses a vector autoregression (VAR) approach to identify the causes of the 1990-92 recession in the UK. The VAR approach is shown to be particularly pertinent for quantifying the relative magnitude of the different demand shocks, and in decomposing them into monetary and expectational factors. The main finding is that the recent recession was precipitated primarily by shocks to consumption, and that monetary factors explain just part of this contraction. The VAR model also offers interesting insights about the long duration of the recession and the nature of the recovery that is currently underway.
Functional Analysis of the Plant Disease Resistance Gene Pto Using DNA Shuffling

Pto is a serine/threonine kinase that mediates resistance in tomato to strains of Pseudomonas syringae pv. tomato expressing the (a)virulence proteins AvrPto or AvrPtoB. DNA shuffling was used as a combinatorial in vitro genetic approach to dissect the functional regions of Pto. The Pto gene was shuffled with four of its paralogs from a resistant haplotype to create a library of recombinant products that was screened for interaction with AvrPto in yeast. All interacting clones and a representative sample of noninteracting clones were sequenced, and their ability to signal downstream was tested by the elicitation of a hypersensitive response in an AvrPto-dependent or -independent manner in planta. Eight candidate regions important for binding to AvrPto or for downstream signaling were identified by statistical correlations between individual amino acid positions and phenotype. A subset of the regions had previously been identified as important for recognition, confirming the validity of the shuffling approach. Three novel regions important for Pto function were validated by site-directed mutagenesis. Several chimeras and point mutants exhibited a differential interaction with (a)virulence proteins in the AvrPto and VirPphA family, demonstrating distinct binding requirements for different ligands. Additionally, the identification of chimeras that are both constitutively active as well as capable of binding AvrPto indicates that elicitation of downstream signaling does not involve a conformational change that precludes binding of AvrPto, as previously hypothesized. The correlations between phenotypes and variation generated by DNA shuffling paralleled natural variation observed between orthologs of Pto from Lycopersicon spp.
Overview of endocrine disruptor research activity in the United States.

The issue of whether environmental contaminants are inducing adverse health effects in humans and wildlife via interaction with endocrine systems has gained increasing interest during the 1990s. Endocrine disruption is one of the highest priority research topics for the US EPA, and a detailed research strategy has been developed to guide the placement of resources over the next several years. To address the deficiency of testing guidelines in detecting and characterizing damage mediated by interaction with the endocrine system, EPA has issued new multi-generation testing guidelines. The new endpoints for monitoring pubertal development, semen quality, and estrous cyclicity will better enable determination of the affected sex, target organ, and life stage following exposure throughout the life cycle. Another major area of effort within EPA is the development of an endocrine disruptor screening program in response to passage of the Food Quality Protection Act of 1996. The current status of these efforts is described. On the federal level, endocrine disruption is one of the five priority research areas for the Committee on the Environment and Natural Resources (CENR) within the Executive Office of President. The CENR has developed a framework to assess research needs for endocrine disruptors, inventoried existing efforts of the federal government (nearly 400 projects were identified as active in FY96), and prioritized additional research needs based upon the needs and gaps in current efforts. It is clear that a great deal of research is underway to clarify the validity of the endocrine disruptor hypothesis and to determine the breadth of chemicals that pose a risk to the endocrine system. The degree of forward research planning and coordination across many organizations should ensure that sufficient data will be available within the next few years to allow a rigorous weight of evidence evaluation that is needed to bring together diverse types of information to make informed decisions regarding risks to humans and wildlife.
Standing body sway in women with and without morning sickness in pregnancy.

A B S T R A C T Morning sickness typically is attributed to hormonal changes in pregnancy. We asked whether morning sickness is associated with changes in standing postural equilibrium, as occurs in research on visually induced motion sickness. Twenty-one pregnant women (mean age = 30 years, mean height = 163 cm; mean weight = 63 kg) were tested during the first trimester. Laboratory-based balance measures were collected, along with perceived postural stability, the presence of morning sickness, and the severity of subjective symptoms. We varied the distance between the feet and the visual task performed during stance. Participants were classified as either experiencing (Sick, n = 12) or not experiencing (Well, n = 9) morning sickness. Perceived balance stability was lower for Sick than for Well women. The positional variability of sway was reduced for the Sick group, relative to the Well group. Positional variability decreased with wider stance width, and was reduced during performance of a more demanding visual task. Stance width and visual task also influenced the temporal dynamics of sway. Effects of stance width and visual task on postural sway were similar to effects in non-pregnant adults, suggesting that sensitive tuning of posture is maintained during the first trimester. The findings suggest that women with morning sickness may attempt to stabilize their bodies by reducing overall body sway. It may be useful to recommend that women adopt wider stance early in pregnancy.
Effects of gas leak around endotracheal tubes on indirect calorimetry measurement.

The use of uncuffed endotracheal tubes (ETT) in pediatric patients raises concern over the accuracy of indirect calorimetry measurement in the presence of a gas leak around an ETT. We examined the effects of ETT gas leak on respiratory gas measurements in a dog model.Mongrel dogs (n=12) were sedated, paralyzed, intubated, and placed on mechanical ventilation. Leak was achieved by adjusting cuff volume. Oxygen consumption (VO2), CO2 production (VCO2), respiratory exchange ratio (RER), and resting energy expenditure (REE) were measured at each leak pressure (Pleak). Peak inspiratory pressure (PIP), Pleak, inspiratory and expiratory tidal volume (VTinsp, VTexp), VE, end tidal CO2 (ETCO2), and blood gases were recorded at each leak pressure.VO2, VCO 2, and REE decreased significantly with increasing gas leak. There was a linear relationship between VO2, VCO2, and REE with both TVratio (VTexp/VTinsp) and Pdiff (PIP-Pleak). Multiple regression equations based on TVratio and Pdiff were obtained which allowed cor...
Studies on gluconeogenesis, protein synthesis and cyclic AMP levels in isolated hepatocytes from alloxan diabetic rats

Alloxan diabetic rats maintained on protamine zinc insulin for two weeks were used for these studies. Hepatocytes were isolated from these rats at various time intervals after withdrawal of insulin (0, 48, 72 and 96 hr). Gluconeogenesis with various concentrations of lactate and fructose was studied. Both lactate and fructose stimulated gluconeogenesis and showed progressive increases in glucose production up to 72 hr after the insulin withdrawal. Glucose production decreased at 96 hr. Protein synthesis in isolated hepatocytes from diabetic liver cells, as measured by the incorporation of radioactive isoleucine, valine and phenylalanine into protein, showed adecrease (5-to 6-fold) with time after insulin withdrawal. Glucagon (10−6M) alone increased cyclic AMP levels 10-fold in liver cells, in isolated cells from rats maintained on insulin (0 hr) or from rats withdrawn from insulin for 48 hr. The ability of glucagon to elevate cyclic AMP levels in isolated diabetic liver cells decreases 72 hr following insulin withdrawal.
Resonance Raman Intensity Analysis of Merocyanine Dimers in Solution

Resonance Raman excitation profiles and absolute cross sections are presented for three closely related merocyanine dyes as monomers in dichloromethane solution and as H-dimers in dioxane solution. For both monomers and dimers the absorption spectra and the resonance Raman intensities of the 24 to 30 strongest vibrations are quantitatively simulated using time-dependent wave packet propagation methods to determine the geometry changes along each Franck−Condon active mode upon electronic excitation, as well as the homogeneous and inhomogeneous electronic line widths. In addition, an approach previously formulated to describe the vibronic structure of an excitonically coupled homodimer with multiple vibrational modes [Kelley, A. M. J. Chem. Phys. 2003, 119, 3320−3331] is applied to model the dimer spectra. Comparison of these two calculations demonstrates that when the intermonomer coupling is strong the theoretical absorption and resonance Raman spectra of the dimer can be very well approximated by treatin...
The universal semigroup of relations

Abstract Semigroup theory is shown to be a very flexible and appropriate language for the study of social relations. Some of the difficulties with the application of the Lorrain and White (1971) approach to social relations are discussed. It is pointed out that the ‘universal’ semigroup of relations is often more suitable for studying relations than the more commonly used ‘semigroup of relations’. Several standard examples and techniques are presented for the study of semigroups. The concept of structural equivalence is generalized to structural similarity modulo a congruence relation. A Galois connection, between the set of relations on the social relations themselves and the lattice of congruences on the universal semigroup, is applied to the evolution of kinship systems.
Agent vision in multi-agent based simulation systems

In this paper, we propose virtual agent vision perception techniques to approximate realistic vision while maintaining low execution time. We discuss virtual agent vision in large scale multi-agent based simulations where agents are situated in open environments (i.e., inaccessible, non-deterministic, dynamic, continuous). When dealing with open environments, the efficiency of agent vision algorithms is of great importance since every agent's perception must be calculated in simulated real-time. We discuss optimizations for vision algorithms in DIVAs, a large scale multi-agent based simulation framework.
The missing bridge: How immigrant networks keep Americans out of dirty jobs

Immigrants are over half of the new entrants in occupations in southwestern labor markets that range from farmworker to janitor to engineering professor. This paper explains how the availability of immigrant workers changes employment practices in ways that push and pull Americans out of jobs which remain "dirty" or unattractive to U.S. workers. An immigrant network that eventually takes over an enterprise's jobs can begin by accident or design. Accidental immigrant takeovers begin with pioneer workers who persist in high turnover jobs such as seasonal farmworker. These workers offer to bring their friends and relatives to fill vacancies as they occur. Takeovers by design sometimes follow a strike in which immigrants are recruited to be strikebreakers. After immigrants dominate the workforce, the language and culture of the workplace change in ways that make American workers feel out-of-place. Employers feel under no compulsion to upgrade dirty jobs as long as immigrant workers are available, so the technology and productivity of immigrant-enclave jobs tend to be frozen, guaranteeing that dirty jobs get less and less attractive to Americans. Indeed, industries dependent on immigrant workers often turn protectionist when they realize that even low immigrant wages are not sufficient to ensure their survival in the global marketplace. In this way, Americans lose out in several ways: They must compete directly with immigrant workers in the labor market, and then pay higher prices for the goods produced by immigrant workers because the industries preserved by them demand protection from imports. This paper will explore the manner in which immigrant networks displace Americans from dirty jobs and how the availability of immigrant workers can preserve sunset industries which turn protectionist. Examples from fruit and vegetable agriculture, garments, and shoes will be discussed.
114. Revisiting rAAV Vector Integration in scid Mice: DNA-PKcs Deficiency Does Not Substantially Increase Integration Frequency in Hepatic and Non-Hepatic Tissues In Vivo

Top of pageAbstract DNA-dependent protein kinase catalytic subunit (DNA-PKcs) plays an important role in rAAV vector transduction. Recently, it has been reported that rAAV vector genome integration into chromosomes is substantially increased in scid mouse muscles and livers (PNAS 98: 4084, 2001; PNAS 101:2112, 2004). In scid livers, they observed that >40% of transgene expression and >50% of vector genomes remained after partial hepatectomy (PHx). However, we have not been able to confirm their observations. Rather we have found that liver regeneration is impaired and slowed in scid mice, particularly in older animals, resulting in insufficient dilution of episomal genomes after PHx. In order to revisit this subject, we have established a method that can directly quantify integrated vector genomes by Southern blot, and performed an experiment with a careful monitoring of liver regeneration after PHx. Since we found that animal age is a critical factor for liver regeneration in scid mice, we prepared relatively young age-matched 8-week-old C57BL/6 and C57BL/6 scid male mice. We injected these mice with AAV2 or 8-ISceI.AO3 vector as indicated in Table 1 (n=5|[ndash]|6 per group). The AAV-ISceI.AO3 vectors had an ISceI site in their vector genomes. With these vectors and ISceI digestion, we could clearly separate episomal and integrated vector genomes in transduced tissues, therefore quantify the amount of integrated vector genomes by Southern blot. 7 weeks after injection, 3 mice from each group underwent PHx, and all the mice were sacrificed 8 weeks after PHx. Careful liver weight measurement revealed that liver regeneration in scid mice was impaired by a factor of 0.88. Vector genome copy numbers at and 8 weeks after PHx are summarized in Table 1. The results demonstrate that vector genome copy numbers substantially dropped by 71|[ndash]|90% in scid mouse livers, and there was no significant difference in the reduction of vector genome copy numbers between B6 and scid mice. This sharply contrasts with the previous observations by Song et al. In addition, Southern blot analysis that can quantify integrated vector genomes revealed no detectable integrated vector genomes in any of the liver, skeletal muscle and kidney. Thus we conclude that scid phenotype does not substantially increase rAAV vector genome integration frequency at a detectable level in vivo.
Sex Differences, Repression-Sensitization, and Self-Disclosure: A Behavioral Look

Sex differences in the relationship between three classes of verbal self-references and repression-sensitization were examined in behavioral samples from male and female disclosures to a same-sexed...