2,028 research outputs found

    The Educator\u27s Conscience

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    Resisting both tradition and technicist mystifications, the educator sees his task as a restless critical process

    Human complement factor H

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    We isolated cDNA clones coding for the functionally important tryptic N-terminal38- kDa fragment of human complement control protein factor H using polyclonal and monoclonal antibodies to screen a human liver cDNA library cloned in a bacterial expression vector, PEX-1. By testing the reactivity of antibodies specific for the recombinant proteins produced by individual clones with proteolytic fragments of serum H the exact position of these cDNA clones within H was mapped. One clone, H-19, coding for the 38-kDa fragment of H was sequenced and found to code for 289 amino acids derived from the 38-kDa N-terminal fragment as well as for the first 108 amino acids belonging to the complementary 142-kDa tryptic fragment. The derived protein sequence could be arranged in 6 highly homologous repeats of about 60 amino acids each, the homology between the repeats being determined by the characteristic position of cysteine, proline, glycine, tyrosine and tryptophane residues. The region coding for the epitope recognized by one of our monoclonal antibodies was localized by subcloning restriction fragments of H-19 into the expression plasmid and testing for the expression of this epitope

    Interstitial Solute Trapping In Irradiated And Quenched Iron

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    The interaction of interstitial carbon and nitrogen solutes with defects produced by low temperature neutron irradiation and by quenching was studied in high purity and Ferrovac E iron. Magnetic Dis accommodation techniques were applied to determine the interstitial solute content after irradiation and upon annealing. Doses of about 1017 neutrons/cm2 caused the trapping of about 20 ppm (atomic) interstitial solutes at 65 (carbon) and 40°C (nitrogen). Trapping of carbon in a Ferrovac E iron alloy occurred during a fast quench from 880°C. After trapping, the interstitial solutes reappeared in solid solution at 300 (carbon, neutron irradiation), 200 (nitrogen, neutron irradiation), and 620°C (carbon, quenching). Various possibilities for the defect traps were considered and it was concluded that trapping of the interstitial solutes occurred at iron interstitial clusters after neutron irradiation and at vacancy type defects after quenching. Copyright © 1968 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinhei

    Stimulus Coding Rules for Perceptual Learning

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    Perceptual learning of visual features occurs when multiple stimuli are presented in a fixed sequence (temporal patterning), but not when they are presented in random order (roving). This points to the need for proper stimulus coding in order for learning of multiple stimuli to occur. We examined the stimulus coding rules for learning with multiple stimuli. Our results demonstrate that: (1) stimulus rhythm is necessary for temporal patterning to take effect during practice; (2) learning consolidation is subject to disruption by roving up to 4 h after each practice session; (3) importantly, after completion of temporal-patterned learning, performance is undisrupted by extended roving training; (4) roving is ineffective if each stimulus is presented for five or more consecutive trials; and (5) roving is also ineffective if each stimulus has a distinct identity. We propose that for multi-stimulus learning to occur, the brain needs to conceptually “tag” each stimulus, in order to switch attention to the appropriate perceptual template. Stimulus temporal patterning assists in tagging stimuli and switching attention through its rhythmic stimulus sequence

    From pole to pole : 33 years of physical oceanography onboard R/V Polarstern

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    Measuring temperature and salinity profiles in the world's oceans is crucial to understanding ocean dynamics and its influence on the heat budget, the water cycle, the marine environment and on our climate. Since 1983 the German research vessel and icebreaker Polarstern has been the platform of numerous CTD (conductivity, temperature, depth instrument) deployments in the Arctic and the Antarctic. We report on a unique data collection spanning 33 years of polar CTD data. In total 131 data sets (1 data set per cruise leg) containing data from 10 063 CTD casts are now freely available at doi: 10.1594/PANGAEA.860066. During this long period five CTD types with different characteristics and accuracies have been used. Therefore the instruments and processing procedures (sensor calibration, data validation, etc.) are described in detail. This compilation is special not only with regard to the quantity but also the quality of the data -the latter indicated for each data set using defined quality codes. The complete data collection includes a number of repeated sections for which the quality code can be used to investigate and evaluate long-term changes. Beginning with 2010, the salinity measurements presented here are of the highest quality possible in this field owing to the introduction of the OPTIMARE Precision Salinometer.Peer reviewe

    Estimating trace deposition time with circadian biomarkers: a prospective and versatile tool for crime scene reconstruction

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    Linking biological samples found at a crime scene with the actual crime event represents the most important aspect of forensic investigation, together with the identification of the sample donor. While DNA profiling is well established for donor identification, no reliable methods exist for timing forensic samples. Here, we provide for the first time a biochemical approach for determining deposition time of human traces. Using commercial enzyme-linked immunosorbent assays we showed that the characteristic 24-h profiles of two circadian hormones, melatonin (concentration peak at late night) and cortisol (peak in the morning) can be reproduced from small samples of whole blood and saliva. We further demonstrated by analyzing small stains dried and stored up to 4 weeks the in vitro stability of melatonin, whereas for cortisol a statistically significant decay with storage time was observed, although the hormone was still reliably detectable in 4-week-old samples. Finally, we showed that the total protein concentration, also assessed using a commercial assay, can be used for normalization of hormone signals in blood, but less so in saliva. Our data thus demonstrate that estimating normalized concentrations of melatonin and cortisol represents a prospective approach for determining deposition time of biological trace samples, at least from blood, with promising expectations for forensic applications. In the broader context, our study opens up a new field of circadian biomarkers for deposition timing of forensic traces; future studies using other circadian biomarkers may reveal if the time range offered by the two hormones studied here can be specified more exactly

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
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