cssi/SciSciGPT-SciSciNet huggingface dataset:
Forest Productivity and Efficiency of Resource Use Across a Chronosequence of Tropical Montane Soils

We tested the hypothesis that plants adjust to nutrient availability by altering carbon allocation patterns and nutrient-use efficiency (NUE = net primary production [NPP] per unit nutrient uptake), but are constrained by a trade-off between NUE and light-use efficiency (e= NPP per unit intercepted light). NPP, NUE and e were measured in montane Metrosiderospolymorpha forest across a 4.1 x 106 yr space for time substitution chronosequence in which available soil N and P pools change with site age. Although the range of N and P availability across sites was broad, there was little difference in NPP between sites, and in contrast to theories of carbon allocation relative to limiting resources, we found no consistent relationships in production allocation to leaves, fine roots or wood. However, canopy nutrient pools and fluxes were correlated with the mass of fine roots per unit soil volume and there was a weak but positive correlation of NPP with LAI. Patterns of e and NUE across the soil developmental sequence were opposite to each other. e increased as nutrient availability and nutrient turnover increased, while NUE decreased in response to the same influences but reached its highest values where either N or P availability and turnover of both N and P were low. A negative correlation between e and NUE supports the hypothesis that a trade-off exists between e and leaf characteristics affecting NUE.
A method for the 32P labeling of peptides or peptide nucleic acid oligomers

A novel approach to the radioactive labeling of peptides and PNA oligomers is described. It is based on the conjugation of a deoxynucleoside 3'-phosphate with the terminal amine of the substrate, followed by phosphorylation of the 5'-hydroxyl group of the nucleotide using T4 polynucleotide kinase and [gamma-32P]ATP.
Non-linguistic strategies and the acquisition of word meanings

Abstract The present study proposes that children's apparent comprehension of certain words is at first dependent on a combination of their linguistic hypotheses about a word's meaning and certain non-linguistic strategies. Children aged 1;6-5;0 were given instructions requiring comprehension of the locative terms in, on and under. The results showed that children go through three stages: At first, they consistently use certain non-linguistic strategies that can be characterized by two ordered rules; next, they apply these rules to only one or two of the locative instructions; and finally, they exhibit full semantic knowledge of the three word meanings. Because of these non-linguistic strategies, the younger children always appear to understand in correctly, sometimes appear to understand on and never understand under. It is argued, nevertheless, that these non-linguistic strategies determine the order of acquisition of the three locative terms.
Correlation of stress state and nanohardness via heat treatment of nickel-aluminide multilayer thin films

Heat treatment of γ-Ni(Al)/γ′-Ni3Al multilayer thin films demonstrates that multilayer hardness correlates with the magnitude of biaxial stress in alternating layers. Films with a columnar grain morphology and (001) texture were fabricated over a range of volume fraction and bilayer thickness via direct current magnetron sputtering onto NaCl (001) substrates at 623 K. The films were removed from substrates, heat-treated at either 673 K or 1073 K in argon, and then mounted for nanoindentation and x-ray diffraction. The biaxial stress state in each phase was furnished from x-ray diffraction measurement of (002) interplanar spacings. The 673 K treatment increases the magnitude of alternating biaxial stress state by 70 to 100% and increases hardness by 25 to 100%, depending on bilayer thickness. In contrast, the 1073 K heat treatment decreases the stress magnitude by 70% and decreases hardness by 50%. The results suggest that the yield strength of these thin films is controlled, in part, by the magnitude of internal stress. Further, thermal treatments are demonstrated to be an effective means to manipulate internal stress.
FETAL LUNG GROWTH IN EXTRA-UTERINE PREGNANCY

Several hundred cases of advanced abdominal pregnancy have been reported. Although 20-40% resulted in livebirths, only 50-70% of those survived the early neonatal period. The major cause of death is unknown and most infants have multiple deformities involving mainly the joints and skin. Using an animal model, we freed rat fetuses from the uterus without disturbing the placental implantation site. The fetuses were allowed to reside in the peritoneal cavity, either within intact membranes (with amniotic fluid), or outside of the fetal membranes. Untouched littermate fetuses served as controls. The surgery was performed on either days 17, 18 or 19 of gestation and the outcome was analyzed at term (i.e. 2,3, or 4 days later). The fetuses were then killed, photographed and body, lung, liver, brain and placenta weights recorded. Total lung DNA was determined. Results: Extra-uterine fetuses with intact membranes were in all respects indistinguishable from littermate controls. Extra-uterine and extramembranous fetuses weighed slightly less than controls, all had thin, shiny skin with webs and contractures of multiple joints. After correction for body weight, only their lungs weighed significantly less (p<.01) and contained less DNA (p<.02). Lung DNA per gram of fetal weight was less (p<.05). The difference was even more significant following surgery on days 17 and 18. This animal model highlights the protective role of the amniotic environment and suggests that lung hypoplasia is a major cause of neonatal death in human abdominal pregnancy.
Conclusion: Nowhere nation or better life? Ukraine's past and future

Abstract All the authors in this collection of essays on Ukrainian politics stress the lack of improvement in the political situation in recent years. The authors identify a range of reasons including pre-Soviet history, the Soviet legacy, national identity, and political gridlock. While the authors disagree slightly on the extent to which change is impossible or merely difficulty, none is hopeful. The challenge for scholars is to avoid moving from objective analysis to assigning political blame. Some authors identify specific political actors on whom they fix blame, while others focus on less personal structural factors. The relative weight of structure-based and agent-based explanations is important in assessing the prospects for change in the future, and the possible paths to it.
Periodic orbits around a rotating ellipsoid

This paper studies families of symmetric periodic satellite orbits around a rotating triaxial ellipsoid. Existence of the families of orbits is established, and Morse's lemma is used to analyze their bifurcations. Several consequences of the many symmetries of the ellipsoid are discussed.
Coverage of causes of death among women cited in 1991 magazines.

Seven 1991 magazines were reviewed for their content on causes of mortality in women of four age groups: 15-24, 25-44, 45-64, and 65 & older. Two hundred and fifty-one articles were coded and analyzed using frequency distributions and a Spearman rank order correlation to determine the relationship between the frequency of coverage and the rankings of mortality causes from the 1990 National Center for Health Statistics (NCHS). Analysis of the data showed no relationship in coverage of mortality causes in the magazines read by the 25-44 age category and NCHS data, and a significant relationship in coverage of mortality causes in magazines read by the 15-24, 45-64 and 65 & older ages and NCHS data. The articles did not always include information on prevention, nor did they always identify behaviors causing mortality. Physicians, their professional journals and organizations were used most frequently as the expert reference sources. Cancer and cardiac disease were written about most frequently, followed by accidents, diabetes and homicide. There was a lack of information on pneumonia, congenital anomalies, pregnancy, congestive obstructive pulmonary disease, and atherosclerosis. Minority issues were not specifically identified when mortality issues were discussed.
Addictive potential of cannabinoids: the underlying neurobiology

Drugs that are addictive in humans have a number of commonalities in animal model systems-(1). they enhance electrical brain-stimulation reward in the core meso-accumbens reward circuitry of the brain, a circuit encompassing that portion of the medial forebrain bundle (MFB) which links the ventral tegmental area (VTA) of the mesencephalic midbrain with the nucleus accumbens (Acb) of the ventral limbic forebrain; (2). they enhance neural firing of a core dopamine (DA) component of this meso-accumbens reward circuit; (3). they enhance DA tone in this reward-relevant meso-accumbens DA circuit, with resultant enhancement of extracellular Acb DA; (4). they produce conditioned place preference (CPP), a behavioral model of incentive motivation; (5). they are self-administered; and (6). they trigger reinstatement of drug-seeking behavior in animals behaviorally extinguished from intravenous drug self-administration behavior and, perforce, pharmacologically detoxified from their self-administered drug. Cannabinoids were long considered 'anomalous', in that they were believed to not interact with these brain reward processes or support drug-seeking and drug-taking behavior in these animal model systems. However, it is now clear-from the published data of several research groups over the last 15 years-that this view of cannabinoid action on brain reward processes and reward-related behaviors is untenable. This paper reviews those data, and concludes that cannabinoids act on brain reward processes and reward-related behaviors in strikingly similar fashion to other addictive drugs.
Tolerance and metabolism of furanocoumarins by the phytopathogenic fungus Gibberella pulicaris (Fusarium sambucinum)

Abstract Sixty-two strains of Gibberella pulicaris (anamorph: Fusarium sambucinum) from diseased plants and from soil were tested for tolerance of the furanocoumarin xanthotoxin in vitro. Twenty-one (88%) of the plant-derived strains and two (5%) of the soil-derived strains were highly tolerant of xanthotoxin. Sixteen selected strains were tested further against 16 furanocoumarins or furanocoumarin precursors. All plant-derived strains tested were highly tolerant of and, in most cases, able to completely metabolize all 16 compounds. Most soil-derived strains tested were tolerant of furanocoumarin precursors but sensitive to certain furanocoumarins. Linear compounds methoxylated at C-8 appeared more toxic than both those unsubstituted and those with longer-chain ethers. Tolerance of angelicin, xanthotoxin, pimpinellin and isopimpinellin correlated in large part with their metabolism. All strains that were highly virulent on Pastinaca sativa root were tolerant of xanthotoxin, which is corroboration that xanthotoxin is a phytoalexin in P. sativa.
Thermomigration in alloys for which substitutional-vacancy and interstitial-vacancy mechanisms are operative

Abstract The theoretical treatments of alloy diffusion in a temperature gradient by the substitutional-vaoanoy mechanism and by the interstitial-vacancy mechanism have been combined, and two types of thermomigration experiments which differ in initial condition have been analysed. It is shown that these experiments, as for measurements of the impurity heat of transport, are apparently incapable of distinguishing between the two mechanisms of diffusion. However, an expression for the lattice velocity in such a combined state alloy is developed and will distinguish between the two mechanisms in a rather specific fashion.
Dendritic Ca2+ signalling due to activation of α7-containing nicotinic acetylcholine receptors in rat hippocampal neurons

Neuronal nicotinic acetylcholine receptors (nAChRs) are in the superfamily of Cys-loop ligand-gated ion channels, which are widely expressed in the brain. Among the many different subtypes of nAChRs known to be expressed in the rat brain, the α7-containing nAChRs are considered to be the most permeable to Ca2+. Utilizing highly localized and rapid iontophoretic agonist delivery, combined with patch-clamp electrophysiology and fura-2 fluorescence imaging techniques, we examined the α7 nAChR-mediated currents and [Ca2+]i transients in the dendrites of rat hippocampal CA1 interneurons in the slice. We found that in the dendrites, whereas the amplitudes of the current responses were smaller and the decay kinetics faster than the responses in the soma, the amplitudes of the [Ca2+]i signals were significantly larger. Cultured hippocampal neurons were studied since the dendritic field lies in the same focal plane, which allowed for a broader investigation of the spatiotemporal dynamics of [Ca2+]i signalling. In cultured neurons, the [Ca2+]i signals in the dendrites were similar to those in slices. Interestingly in cultures, even though the amplitude of the α7 nAChR-mediated currents dramatically decreased with distance from the soma (from ∼20–250 μm), the amplitude of the [Ca2+]i signals did not correlate with distance. This indicates that the relative efficacy of α7 nAChR activation to increase [Ca2+]i levels in dendrites increased severalfold with distance from the soma. These results may have implications for the role that α7 nAChRs have in regulating various signal transduction cascades, synaptic plasticity, and memory processes, via significant changes in [Ca2+]i levels.
Comments on the variational principle and superfluid mechanics

Abstract When a classical lagrangian written in eulerian coordinates is supplemented with the quantum theoretical insight that individual particle trajectories do not exist when the ground state is macroscopically occupied, one arrives at the London equation as an extremum of the first variation. Thus Edwards' derivation of the London equations from classical mechanics in unfounded.
Section Review: Cardiovascular & Renal: Developments in antiarrhythmic drugs: An overview

In the more industrialised part of the world, sudden cardiac (arrhythmic) death has remained, throughout recent years, the leading cause of mortality. Preventing lethal arrhythmias has been a top priority in medical research and the literature abounds with reports describing the mechanisms of action of anti- or pro-arrhythmic agents and their cardiac electrophysiological effects. Studies such as the Cardiac Arrhythmia Suppression Trials (CAST-I and -II) [1], CASCADE (Cardiac Arrest in Seattle, Conventional versus Amiodarone Drug Evaluation) [2], CASH (Cardiac Arrest Study Hamburg), CAMIAT (Canadian Amiodarone Myocardial Infarction Arrhythmia Trial) [3], ESVEM (Electrophysiologic Study versus Electrocardiographic Monitoring Trial) [4], CAPS (Cardiac Arrhythmia Pilot Study) and DAVIT (Danish Verapamil Infarction Trial) [5] for example, and new approaches to the classification of antiarrhythmic drugs, based on their actions on arrhythmogenic mechanisms and studies of ‘cardioprotective’ agents and potassium c...
Radiocarbon Assessment of Aerobic Petroleum Bioremediation in the Vadose Zone and Groundwater at an AS/SVE Site

Radiocarbon (14C) measurement from vadose zone air and groundwater is an alternative technique to quantitatively estimate aerobic microbial CO2 production from petroleum mineralization. The objectives of this study were (1) to demonstrate the effectiveness of radiocarbon in providing direct quantified evidence of in situ aerobic petroleum hydrocarbon biodegradation from vadose zone CO2 and groundwater DIC at a gasoline-contaminated site being remediated by an air sparging/soil vapor extraction (AS/SVE) system and (2) to quantify the microbial contribution to vadose zone CO2 and DIC production. Vadose zone CO2 and groundwater DIC were collected from soil vapor probes, SVE wells, AS/SVE stack exhaust, and groundwater monitoring wells. Analogous gas and groundwater samples were collected from a geologically similar uncontaminated site. Vadose zone CO2 and DIC extracted from groundwater were concentrated using NaOH traps and sent to analytical laboratories for conventional 14C analysis using β counters. 14C v...
Foundations of content preparation for the web

The objective of this paper is to develop a model for content preparation of websites. Content preparation describes a process of web design that equally weighs the identification of information requirements with the presentation modes of that information. This paper focuses on what information should be available on the web instead of how the information should be presented. It reviews studies concerning: (a) credibility evaluation of printed media; (b) quality dimensions of information systems; (c) Internet domain-specific information needs. Based on the review, two key figures synthesise the aspects related to content preparation. First, the convergence hierarchy integrates domain-specific components into a general information structure. Second, the conceptual model proposed eight factors for effective content preparation. These factors are site, transaction, company, security, product, customer service, shipping and membership. It highlights specific content elements and yields major implications for ...
A Laboratory Decanting Procedure to Simulate Whole Stillage Separation in Dry-Grind Corn Ethanol Process

In the dry-grind corn ethanol industry, horizontal decanter centrifuges are used to separate the whole stillage into wet grains and thin stillage. The wet grains mixed with condensed thin stillage are dried to form dried distiller’s grains with solubles (DDGS). In order to investigate the effect of different corn breaking treatments on increasing oil partitioning in thin stillage, a laboratory method is needed to simulate industrial decanting where a typical thin stillage is produced. The thin stillage obtained using a conventional laboratory centrifuge had much lower solids content and less than one-half of the dry-matter yield compared to the industry counterpart because the conventional laboratory centrifuge and industry decanter centrifuge have different separation mechanisms. By evaluating the properties of industrial thin stillage and the mechanism of industrial decanter centrifugation, a laboratory decanting device was designed and a decanting procedure, the multiple-wash centrifugal filtration (MWCF) method, was developed. This method involves multiple steps of filtration under centrifugal force after washing the solids with the liquid generated from the same mash. Four cycles of MWCF produced a thin stillage with similar solids content (7.3 vs. 7.2%), dry-matter yield (54.2 vs. 54.7%), and wet yield (83.3 vs. 80.6%) compared to industrial thin stillage. The presence of ethanol did not influence the laboratory decanting results, which indicates the application robustness of this laboratory thin stillage preparation method.
Effects of strength training and balance practice on final performances of three balance tasks.

Summary.-56 female Ss completed an identical battery of three familiarizing, initial, and final tests of balance. Divided into a Control Group, a Strength Group, and a Balance Group, Ss experienced either strength training of the ankle dorsi and plantar flexors, practice on the balance tests, or no activity between the initial and final tests. Balance performance was best improved by balance practice, not strength training; however, strength of the musculacure involved was significantly increased by a balance practice schedule. Individuals who are interested in physical activities such as ice skating, water skiing, and gymnastics, must develop refined abilities to balance on one foot in order to become skilled performers. It is empirical knowledge, however, that the neophyte's initial practice periods in these particular balance skills may be limited by early fatigue in the supportive musculature of the lower extremities. This may be particularly true for women, who do not generally possess levels of strength commensurate with those of men. It has often been posmlated that low suength levels in women greatly retard their performances in early phases of any learning period in which the task to be learned requires substantial strength levels. It would be beneficial to the physical educator to know whether a strength training schedule or a balance practice schedule would best improve balance performances. Other factors which may affect balance ability in activities of this namre are the concerns of the beginner with her personal safety and her ability to persevere throughout a fatiguing practice session. It is possible that the ability of some beginners to cope with these factors negates any advantage that high strength levels in supportive musculature provide. Knowledge concerning the effect strength training or balance practice has upon a woman's abilicy to balance in a non-physically demanding balance task, as well as her ability to balance in tasks to be completed under conditions of potential physical injury and mental stress, would be edifying. The purpose of this study was to compare a strength training program for ankle flexors to a balance practice program, in terms of their effects on women's ability to balance on one foot (a) placed transversely across a wooden stick, (b) during a task that was muscularly demanding, and (c) during a task that also offered the possibility of physical injury if the balance were lost. Previous studies which have investigated the relationship of ankle strength to balance performance have been general in approach. In almost all cases, suength exercises, attempts to fatigue Ss, and balance exercises have utilized
Time changes in spatial structure of surface variability in the Southern Great Plains

This study focuses on time changes in the spatial structure of vegetation density and land surface temperature derived from satellite remote sensing in the Southern Great Plains. In this region the spatial distribution of vegetation density for a diverse land surface was anisotropic and statistically heterogeneous. As a drying period progressed, heterogeneity decreased slightly and the variability became more dependent on smaller length scales. Within similar land cover classifications, vegetation density was approximately homogeneous with a correlation scale up to 40 km. In the same region, land surface temperature exhibited anisotropy and heterogeneity with dramatic changes in structure from day-to-day. Land cover did not exert a significant control on the land surface temperature structure.
Vapor-Liquid equilibrium for systems comprised of a non-volatile strong electrolyte in a mixed solvent

Abstract Various procedures are examined for the reduction of isothermal vapor-liquid equilibrium data for systems comprised of a non-volatile electrolyte in a mixed solvent. The procedures are tested both on real experimental data and on simulated data. Based on the results for the systems examined here, a recommended procedure is given. The utility of the total pressure method for obtaining VLE data for systems of this type is discussed.
Strategic processing of test questions: The test marking responses of college students

Abstract Students' strategies for answering multiple-choice questions were investigated by analyzing the marks students spontaneously made on the test booklets. Among 227 undergraduate students, 60 students' test booklets were randomly selected. Inspection of test booklets led to the identification of six marking categories: answer indication marks, option elimination marks, key term marks, selective item marks, elaboration annotation marks, and answer change marks. Results indicated that 95% of students made one or more marks. Students' test scores were related to option elimination marks, and use of marking strategies increased as items became more difficult. The results suggest that the marks students make while taking a test may provide a valuable window on their underlying strategies.
Resonance structure of S-32+n from measurements of neutron total and capture cross sections

Neutron total and capture cross sections of /sup 32/S have been measured up to 1100 keV neutron energy (E/sub exc/(/sup 33/S) =9700 keV). Spin and parity assignments have been made for 28 of the 64 resonances found in this region. Values of total radiation widths, reduced neutron widths, level spacings, and neutron strength functions have been evaluated for s/sub 1/2/, p/sub 1/2/, p/sub 3/2/, and d/sub 5/2/ levels. Single particle contributions using the valency model account for a significant portion of the total radiation width only for the p/sub 1/2/-wave resonances. A significant number of resonances can be identified with reported levels excited in /sup 32/S(d,p) and /sup 29/Si(..cap alpha..,n) reactions. A calculation of the Maxwellian average cross section appropriate to stellar interiors indicates an average capture cross section at 30 keV, sigma-bar approx. = 4.2(2) mb, a result that is relatively insensitive to the assumed stellar temperature. Direct (potential) capture and the s-wave resonance capture contributions to the thermal capture cross section do not fully account for the reported thermal cross section (530 +- 40 mb) and a bound state is invoked to account for the discrepancy.
On the asymptotic directions of thes-dimensional optimum gradient method

The optimum s-gradient method for minimizing a positive definite quadratic function f(x) on $E_n$ has long been known to converge for s $\geq$ 1. For these $\underline{s}$ the author studies the directions from which the iterates $x_k$ approach their limit, and extends to s < 1 a theory proved by Akaike for s = 1. It is shown that f($x_k$) can never converge to its minimum value faster than linearly, except in degenerate cases where it attains the minimum in one step.
Schedule‐induced aggression in humans and animals: A comparative parametric review

Studies of animal and human aggression induced by schedules of reinforcement are reviewed. Parameters reviewed include: schedules, characteristics of induced aggression, subject variables, target variables, and the control or modification of schedule-induced aggression. With the exception of temporal locus of schedule-induced attack, the parameters identified with animal subjects are remarkably similar to those identified with human subjects.
Photoinduced insertion of molecular oxygen into metal–hydrogen bonds

Abstract Rhodium(III) hydrides L(H 2 O)RhH 2+ (L=(NH 3 ) 4 and [14] aneN 4 ) are efficient quenchers for the excited uranyl ions, ∗ UO 2 2+ . In the presence of molecular oxygen, the reaction ultimately yields the hydroperoxorhodium complexes, L(H 2 O)RhOOH 2+ . The replacement of the coordinated hydride by deuteride and the solvent H 2 O by D 2 O results in a combined kinetic isotope effect of 1.5 for the macrocyclic complex. The proposed mechanism features L(H 2 O)Rh 2+ , L(H 2 O)RhOO 2+ , and UO 2 + as intermediates.
Influence of the Criterion Variable on the Identification of Differentially Functioning Test Items Using the Mantel-Haenszel Statistic.

This study investigated the effectiveness of the Mantel-Haenszel (MH) statistic in detecting dif ferentially functioning (DIF) test items when the internal criterion was varied. Using a dataset from a statewide administration of a life skills examina tion, a sample of 1,000 Anglo-American and 1,000 Native American examinee item response sets were analyzed. The MH procedure was first applied to all the items involved. The items were then cate gorized as belonging to one or more of four subtests based on the skills or knowledge needed to select the correct response. Each subtest was then analyzed as a separate test, using the MH pro cedure. Three control subtests were also established using random assignment of test items and were analyzed using the MH procedure. The results revealed that the choice of criterion, total test score versus subtest score, had a substantial influence on the classification of items as to whether or not they were differentially functioning in the American and Native American group...
Long-Term Outcomes With Intraoperative Radiotherapy as a Component of Treatment for Locally Advanced or Recurrent Uterine Sarcoma

Purpose To report our institutional experience with intraoperative radiotherapy (IORT) as a component of treatment for women with locally advanced or recurrent uterine sarcoma. Methods and Materials From 1990 to 2010, 16 women with primary ( n = 3) or locoregionally recurrent ( n = 13) uterine sarcoma received IORT as a component of combined modality treatment. Tumor histology studies found leiomyosarcoma ( n = 9), endometrial stromal sarcoma ( n = 4), and carcinosarcoma ( n = 3). Surgery consisted of gross total resection in 2 patients, subtotal resection in 6 patients, and resection with close surgical margins in 8 patients. The median IORT dose was 12.5 Gy (range, 10–20 Gy). All patients received perioperative external beam radiotherapy (EBRT; median dose, 50.4 Gy; range, 20–62.5 Gy), and 6 patients also received perioperative systemic therapy. Results Seven of the 16 patients are alive at a median follow-up of 44 months (range, 11–203 months). The 3-year Kaplan-Meier estimate of local relapse (within the EBRT field) was 7%, and central control (within the IORT field) was 100%. No local failures occurred in any of the 6 patients who underwent subtotal resection. The 3-year freedom from distant relapse was 48%, with failures occurring most frequently in the lungs or mediastinum. Median survival was 18 months, and 3-year Kaplan-Meier estimates of cause-specific and overall survival were 58% and 53%, respectively. Three patients (19%) experienced late Grade 3 toxicity. Conclusions A combined modality approach with perioperative EBRT, surgery, and IORT for locally advanced or recurrent uterine sarcoma resulted in excellent local disease control with acceptable toxicity, even in patients with positive resection margins. With this approach, some patients were able to experience long-term freedom from recurrence.
Reciprocal Regulation of Endothelial Nitric-oxide Synthase by Ca2+-Calmodulin and Caveolin

The endothelial nitric-oxide synthase (eNOS) is a key determinant of vascular homeostasis. Like all known nitric-oxide synthases, eNOS enzyme activity is dependent on Ca2+-calmodulin. eNOS is dynamically targeted to specialized cell surface signal-transducing domains termed plasmalemmal caveolae and interacts with caveolin, an integral membrane protein that comprises a key structural component of caveolae. We have previously reported that the association between eNOS and caveolin is quantitative and tissue-specific (Feron, O., Belhassen, L., Kobzick, L., Smith, T. W., Kelly, R. A., and Michel, T. (1996) J. Biol. Chem. 271, 22810-22814). We now report that in endothelial cells the interaction between eNOS and caveolin is importantly regulated by Ca2+-calmodulin. Addition of calmodulin disrupts the heteromeric complex formed between eNOS and caveolin in a Ca2+-dependent fashion. In addition, overexpression of caveolin markedly attenuates eNOS enzyme activity, but this inhibition is reversed by purified calmodulin. Caveolin overexpression does not affect the activity of the other NOS isoforms, suggesting eNOS-specific inhibition of NO synthase by caveolin. We propose a model of reciprocal regulation of eNOS in endothelial cells wherein the inhibitory eNOS-caveolin complex is disrupted by binding of Ca2+-calmodulin to eNOS, leading to enzyme activation. These findings may have broad implications for the regulation of Ca2+-dependent signal transduction in plasmalemmal caveolae.
Stability and Yield of Cool-Season Pasture Grass Species Grown at Five Irrigation Levels

The yield stability of cool-season pasture grasses at different irrigation levels has not been well documented. Objectives were to evaluate selection of pasture grass species in environments where irrigation may be limited or unreliable. Dry matter yield was determined for eight grass species during 1996 through 1998 at five irrigation levels. Shukla's stability statistics were calculated and species selection based on mean-yield versus Kang's yield-stability indices were compared. Tall fescue (Festuca arundinacea Schreb.), meadow brome (Bromus riparius Rehm.), and orchardgrass (Dactylis glomerata L.) had higher than average dry matter yield and were selected on a mean-yield basis. On the basis of Shukla's statistics, meadow brome and orchardgrass did not contribute to the genotype x irrigation level interaction or the genotype × irrigation level × year interaction, respectively. Perennial ryegrass (Lolium perenne L.) also did not contribute to these genotype × environment interactions; however, Shukla's statistics suggested that the linear effect of irrigation was the underlying determinant of perennial ryegrass's apparent stability. Species selection based on yield-stability indices were generally in close agreement to selection of species on a mean-yield basis. One exception, Kang's Modified Rank Sum method, placed too much emphasis on stability resulting in selection of species with low forage yields. Tall fescue had superior forage yield at all irrigation levels and was always selected by yield-stability indices. Orchardgrass and meadow brome were also selected by all yield-stability indices. These results indicate that tall fescue, orchardgrass, and meadow brome are the species of choice where irrigation may be limited.
Estimation of haploid cell content of parthenogenetic turkey embryos: A cytofluorometric study†

A quantitative cytofluorometric study was undertaken to test the proposition that parthenogenetic development in turkeys begins in a haploid cell and proceeds toward the development of a completely diploid embryo. Embryo cell suspensions were obtained from eggs laid by virgin Beltsville Small White (BSW) turkey hens, and the cells from individual embryos were fluorescently stained with acriflavine, which is specific for DNA. The fluorescent emissions from individual cell nuclei were analyzed on a modified Bio/Physics Cytofluorograf, Model 6300A, and DNA distributions were obtained by analyzing nearly all of the cells in embryos ranging in age from five to nine days. These distributions were compared by computer analysis to the DNA distribution of a normally produced embryo. The DNA distributions revealed that many embryos contained large proportions of haploid cells and other abnormal cells. This study of haploid cells lends further support to the proposition that parthenogenesis in turkeys originates in a haploid egg cell, and diploidization observed in embryos occurs after meiosis. It was also shown that proportions of haploid and other non-diploid cells declined with increasing embryo age.
The martensitic phase transition in NiTi

The technique of perturbed angular correlation of gamma rays (PAC) was applied to study the martensitic phase transition of a shape-memory-effect alloy Ni49.9Ti50.1 doped with111In/Cd probe atoms. Spectra measured above and below the martensite starting temperature,Ms ≈ 340 K, exhibit quadrupole interactions of probes at cubic and noncubic lattice sites, consistent with the respective crystal structures. Unlike spectra measured belowMs those measured above exhibit a large frequency distribution attributed to lattice displacement waves observed in diffraction studies. Analysis tentatively suggests that the waves are dynamic and not static. BelowMs, at 290 K, a static quadrupole interaction was observed with coupling frequency ω1=34 Mrad/s and asymmetry parameter η=0.18, increasing to ω1=40.5 Mrad/s and η=0.34 at 77 K.
Growth of nonlinear crystals for frequency conversion

Etude de la croissance de materiaux optiques non lineaires utilisables dans les zones visible et ultraviolet. Analyse de methodes de croissance employees et de leur influence sur les cristaux obtenus, au point de vue mode de croissance, morphologie, defauts, composition. Discussion des avantages de la methode de croissance utilisee par un compose par rapport a d'autres methodes
A Quasi-Experimental Design for the Assessment of Posttest Sensitization:

Researchers have long been aware that "pretest sensitization" is a potential threat to the external validity of experimental studies. Only recently, however, has it been suggested that "posttest sensitization" might also limit the generalizability of results. This latter phenomenon would exist if the administration of a posttest caused the treatment's impact to become more (or less) pronounced. Under this condition, the treatment would work differently for Ss in the researcher's sample than for other individuals who might later receive only the treatment without the accompanying posttest. To be scientifically useful, it is imperative that the hypothesis of posttest sensitization be capable of empirical verification. A quasi-experimental design is proposed for this purpose.
Evidence for Sorption as a Mechanism of the Olfactory Analysis of Vapours

THE physiological basis for olfactory discrimination may involve at least two basic mechanisms which need not be mutually exclusive : (a) the receptors themselves may be more or less selectively sensitive to different groups of chemicals ; (b) the receptor sheet as a whole might separate chemical vapours by adsorption or absorption in a manner analogous to gas chromatography columns. There has been some supporting evidence for the first mechanism1,2, and suggestive evidence for the second has recently been reported3. The evidence suggesting the second mechanism depends, in part, on sampling the activity from different regions of the frog olfactory mucosa by recording the discharges from two olfactory nerve branches (a lateral one and a medial one), which under a dissecting microscope appear to subserve different mucosal regions. That these branches do indeed subserve different mucosal regions is supported by recent electrical stimulation experiments. The antidromically conducted discharges in response to individual stimulation of the lateral and medial nerve branches were recorded by an electrode placed at several points on the epithelium. The discharge tracts for the two branches were quite separate and localized (Fig. 1).
Case report: computed tomography in the diagnosis of yersinia infection in a patient with thalassemia major

Yersinia enterocolitica is becoming increasingly recognized as a source of abscess formation in patients with numerous underlying disease entities, most notably hepatic and hematologic disorders. Patients ranging in age from infancy to adulthood can become infected with this worldwide pathogen, which seems to be relatively rare in the United States. We present the appearance of a Yersinia abscess on computed tomography in the hope that an increased awareness of this infection will result in earlier diagnosis and improved therapeutic management.
Isolated attosecond pulses generated by relativistic effects in a wavelength-cubed focal volume

Lasers that provide an energy encompassed in a focal volume of a few cubic wavelengths (λ3) can create relativistic intensity with maximal gradients using minimal energy. With particle-in-cell simulations we found that single 200-as pulses could be produced efficiently in a λ3 laser pulse reflection by means of deflection and phase compression caused by the coherent motion of the plasma electrons that emit these pulses. This novel technique is efficient (∼10%) and can produce single attosecond pulses from the millijoule to the joule level.
Field assays for hygienic behavior in honey bees (Hymenoptera: Apidae)

Honey bee, Apis mellifera L., hygienic behavior is a mechanism of disease resistance and a mode of defense against the parasitic mite Varroa jacobsoni Oudemans. Hygienic bees uncap and remove diseased and parasitized brood from the nest. The propagation of colonies that demonstrate resistance to chalkbrood and American foulbrood and that remove pupae infested by Varroa mites is becoming increasingly important in apiculture. This study evaluates 2 commonly used field assays used to screen colonies for hygienic behavior: the freeze-killed brood and the pierced brood assays. Both involve determining the time required for worker bees to remove dead capped brood from a section of comb. Colonies in the experiment displayed a wide range of removal rates and were grouped as hygienic, nonhygienic, or intermediate. The results of experiments 1 and 2 indicated that neither the age nor the source of the frozen brood had a significant effect on the removal rate by hygienic colonies (i.e., those colonies that consistently uncapped and removed freeze-killed brood within 48 h). In experiment 3, only a weak correlation was found between the removal of young freeze-killed and pierced pupae, but a significant correlation existed between the removal of pre-eclosion freeze-killed and pierced pupae. Experiment 4 examined cues that elicit removal behavior by hygienic and non hygienic colonies. When pupae were pierced with an insect pin through the base of the cell (without piercing the wax cell capping), there was no difference in the number of pupae removed by the hygienic and nonhygienic colonies. On average, 30% of all pierced pupae survived the treatment, which considerably diminished the accuracy and reproducibility of the test. When pupae were treated with hemolymph extracted from either a live or freeze-killed pupa, there was also no difference in the rate of removal by hygienic and nonhygienic colonies. These results indicate that bees from nonhygienic lines can be induced to express hygienic behavior only if a sufficiently strong stimulus is present. Both hygienic and nonhygienic colonies removed significantly more pupae treated with hemolymph from a dead pupa than hemolymph from a live pupa, indicating that the cue that stimulates removal behavior is stronger in dead pupae. It is concluded that the freeze-killed brood assay is the most conservative and reliable screening procedure for hygienic behavior. The following procedures are recommended: Randomly selected comb sections (5 by 6 cm each) of capped brood should be cut from 1 healthy colony, frozen, and introduced into the test colonies. The assay should be repeated at least twice. Only colonies that remove >95% of freeze-killed brood within 48 h in both tests should be considered hygienic. When developing hygienic breeder stock, the hygienic colonies should be challenged with the American foulbrood or chalkbrood pathogen to ensure resistance.
Multiscale Modeling of Flow Induced Thrombogenicity Using Dissipative Particle Dynamics and Molecular Dynamics

The coagulation cascade of blood may be initiated by flow induced platelet activation, which prompts clot formation in prosthetic cardiovascular devices and arterial disease processes. While platelet activation may be induced by biochemical agonists, shear stresses arising from pathological flow patterns enhance the propensity of platelets to activate and initiate the intrinsic pathway of coagulation, leading to thrombosis. Upon activation platelets undergo complex biochemical and morphological changes: organelles are centralized, membrane glycoproteins undergo conformational changes, and adhesive pseudopods are extended. Activated platelets polymerize fibrinogen into a fibrin network that enmeshes red blood cells. Activated platelets also cross-talk and aggregate to form thrombi. Current numerical simulations to model this complex process mostly treat blood as a continuum and solve the Navier-Stokes equations governing blood flow, coupled with diffusion-convection-reaction equations. It requires various complex constitutive relations or simplifying assumptions, and is limited to μm level scales. However, molecular mechanisms governing platelet shape change upon activation and their effect on rheological properties can be in the nm level scales. To address this challenge, a multiscale approach which departs from continuum approaches, may offer an effective means to bridge the gap between macroscopic flow and cellular scales. Molecular dynamics (MD) and dissipative particle dynamics (DPD) methods have been employed in recent years to simulate complex processes at the molecular scales, and various viscous fluids at low-to-high Reynolds numbers at mesoscopic scales. Such particle methods possess important properties at the mesoscopic scale: complex fluids with heterogeneous particles can be modeled, allowing the simulation of processes which are otherwise very difficult to solve by continuum approaches. It is becoming a powerful tool for simulating complex blood flow, red blood cells interactions, and platelet-mediated thrombosis involving platelet activation, aggregation, and adhesion.Copyright © 2013 by ASME
Counseling parents and children on sun protection: a national survey of pediatricians.

Objective. To describe pediatricians’ attitudes toward skin cancer (SC), sun protection (SP) counseling, and the quantity and content of such counseling and to identify barriers to counseling. Methods. An American Academy of Pediatrics Periodic Survey was mailed to 1616 randomly selected US members between October 2001 and February 2002. The response rate was 54.6%. Results. More than 90% of pediatricians agreed that SC is a significant public health problem and that preventing episodic high exposures to the sun during childhood will reduce the risk of adult melanoma. However, only 22.3% of respondents reported counseling most patients in all age groups. Female pediatricians were more likely to counsel most patients; pediatricians located in the South and West and those who practice in hospital/clinic settings were least likely to counsel compared with those in other regions. Approximately half (53%) of pediatricians reported selectively counseling on the basis of patient characteristics The most important SP recommendation named was using a sunscreen with a sun protection factor ≥15. Only 38% of pediatricians rated SP as very important to their patients’ health compared with other topics such as use of car seats (86%), nutrition (79%), immunization issues (76%), and smoking/avoidance of environmental tobacco smoke (74%). The most frequently named barrier to SP counseling was lack of time (58% reporting). Conclusions. Although the majority of pediatricians believe that SC prevention is a worthy issue, only a minority reported providing routine SP counseling to most patients in every age group, and most ranked SP lower in importance than other issues. Interventions might include programs and materials to educate patients and pediatricians alike. To have an effect on increasing rates of SC and SC mortality, a broader public health approach is needed as a complement to pediatricians’ counseling efforts.
The "hidden curriculum" and residents' attitudes about medical error disclosure: comparison of surgical and nonsurgical residents.

Background The "hidden curriculum" and role models for responding to medical errors might play a central role in influencing residents' attitudes about disclosure. We sought to compare surgical and nonsurgical residents' exposure to role modeling for responding to medical errors and their attitudes about error disclosure. Study Design We conducted a cross-sectional, electronic survey of surgical and nonsurgical residents at 2 large academic medical centers. The questionnaire asked respondents about personal experience with medical errors; training for responding to errors; frequency of exposure to role modeling related to disclosure; and attitudes about disclosure. Descriptive statistics were used to describe frequencies. Chi-square and Fisher's exact test were used to compare proportions between surgical and nonsurgical trainees. Results The response rate was 58% (253 of 435). Surgical residents reported more frequently observing a colleague be treated harshly (eg, humiliated or verbally abused) for an error than nonsurgical residents (sometimes or often, 39% [26 of 66] vs 20% [37 of 187]; p = 0.002). Surgical residents were more likely than nonsurgical residents to believe they would be treated harshly by others if they acknowledged making a medical error (35% [23 of 66] vs 12% [23 of 187]; p Conclusions The punitive response to error by senior members of the health care team might be an impediment to the transparent disclosure of errors among residents that might disproportionally affect surgical training programs.