4,564 research outputs found

    Broadbalk: Historical Introduction

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    S-, P- and D-wave resonances in positronium-sodium and positronium-potassium scattering

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    Scattering of positronium (Ps) by sodium and potassium atoms has been investigated employing a three-Ps-state coupled-channel model with Ps(1s,2s,2p) states using a time-reversal-symmetric regularized electron-exchange model potential fitted to reproduce accurate theoretical results for PsNa and PsK binding energies. We find a narrow S-wave singlet resonance at 4.58 eV of width 0.002 eV in the Ps-Na system and at 4.77 eV of width 0.003 eV in the Ps-K system. Singlet P-wave resonances in both systems are found at 5.07 eV of width 0.3 eV. Singlet D-wave structures are found at 5.3 eV in both systems. We also report results for elastic and Ps-excitation cross sections for Ps scattering by Na and K.Comment: 9 pages, 5 figures, Accepted in Journal of Physics

    The fertilizers requirements of sugar beet

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    The paper describes the results of over 300 factorial experiments carried out in each factory area in the years 1934–49 for the Sugar Beet Research and Education Committee of the Ministry of Agriculture as a result of co-operation between Rothamsted workers and the agriculturists and fieldmen attached to the beet factories. All the experiments tested the effects of levels of nitrogen, phosphate and potash, and rather more than half tested the effect of salt also. Except on fen soils, nitrogen gave substantial responses in all factory areas, especially in the presence of high levels of potash or salt. Large variations in response from season to season were closely associated with the rainfall of the preceding winter months, responses being greater after wet winters than dry ones. In spite of some selection of sites in favour of greater responses, the average net returns from phosphate were relatively small. The effect of potash was closely linked with the amount of nitrogen applied; in the presence of nitrogen, dressings well above the level of 1·2 cwt. K2O per acre tested in the experiments are likely to give a useful net return. Soils derived from the Chalky Boulder Clay seem to be exceptional in showing no response. Apart from this, there were only small variations in responses to nitrogen and potash between factory areas. The application of 5 cwt. salt gave substantial responses in almost all parts of the country, whether or not potash was also applied; on the other hand, responses to potash were usually small when salt was also applied. Whilst there was a general relationship between soil analysis for phosphate and potash (citric acid method) and crop response, adjustments to the optimal dressings according to soil analysis were not of sufficient reliability to be of much practical value. RESP-375

    Indirect and direct energy gaps in the Kondo semiconductor YbB12

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    Optical conductivity [σ(ω)\sigma(\omega)] of the Kondo semiconductor YbB12_{12} has been measured over wide ranges of temperature (TT=8-690 K) and photon energy (ω\hbar \omega \geq 1.3 meV). The σ(ω)\sigma(\omega) data reveal the entire crossover of YbB12_{12} from a metallic electronic structure at high TT into a semiconducting one at low TT. Associated with the gap development in σ(ω)\sigma(\omega), a clear onset is newly found at ω\hbar\omega=15 meV for TT \leq 20 K. The onset energy is identified as the gap width of YbB12_{12} appearing in σ(ω)\sigma(\omega). This gap in \sigma(\omega)isinterpretedastheindirectgap,whichhasbeenpredictedinthebandmodelofKondosemiconductor.Ontheotherhand,thestrongmidinfrared(mIR)peakobservedin is interpreted as the indirect gap, which has been predicted in the band model of Kondo semiconductor. On the other hand, the strong mid-infrared (mIR) peak observed in \sigma(\omega)$ is interpreted as arising from the direct gap. The absorption coefficient around the onset and the mIR peak indeed show characteristic energy dependences expected for indirect and direct optical transitions in conventional semiconductors.Comment: 4 pages, 3 figures, submitted to J. Phys. Soc. Jp

    Structures of CD6 and Its Ligand CD166 Give Insight into Their Interaction

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    SummaryCD6 is a transmembrane protein with an extracellular region containing three scavenger receptor cysteine rich (SRCR) domains. The membrane proximal domain of CD6 binds the N-terminal immunoglobulin superfamily (IgSF) domain of another cell surface receptor, CD166, which also engages in homophilic interactions. CD6 expression is mainly restricted to T cells, and the interaction between CD6 and CD166 regulates T-cell activation. We have solved the X-ray crystal structures of the three SRCR domains of CD6 and two N-terminal domains of CD166. This first structure of consecutive SRCR domains reveals a nonlinear organization. We characterized the binding sites on CD6 and CD166 and showed that a SNP in CD6 causes glycosylation that hinders the CD6/CD166 interaction. Native mass spectrometry analysis showed that there is competition between the heterophilic and homophilic interactions. These data give insight into how interactions of consecutive SRCR domains are perturbed by SNPs and potential therapeutic reagents

    THE SPIRITUAL QUEST OF PETAR HEKTOROVIĆ

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    Na temelju motiva iz gralskih romana (izgubljeni pehar, nepostavljeno pitanje, obnova istrošenih snaga), te analizom simbola i tema (vitezovi, pustinjaci, dvorci, plovidba i sl.), u članku se dokazuje da je »Ribanje i ribarsko prigovaranje« Petra Hektorovića stanovit viteški roman o potrazi za gralom. Semiotičko istraživanje, nadalje, pokazat će da je među njima ključna poveznica – vrlina: Petru Hektoroviću, kao i protagonistima srednjovjekovnih gralskih romana, zadatak potrage bio je postizanje jedinstva uma i tijela, pojedinca i Boga, individue i univerzuma, učitelja i učenika. Junaci tragaju za vrlinom problematizirajući čovjeku naizgled prirođeno manjkavo stanje nasavršenstva. Nezadovoljstvo, neznanje, nepažnja/nepomnja, neravnoteža i sl., uzroci su svih nesporazuma i problema, kako u »Ribanju« Petra Hektorovića, tako i u »Parzivalu« Wolframa von Eschenbacha. Stoga se likovi posvećuju ustrajnoj potrazi, bez jamstva da će dobiti uvid u završnicu. Odlučili su napraviti golem skok iz racionalnoga u nepoznato, iracionalno, usavršavati vrline i vladati svojim žudnjama da bi, sukladno primjeru srednjovjekovnih mistika sv. Augustina, Pseudodionizija Areopagita, sv. Bernardina Sienskog i drugih, ostvarili svoju božansku prirodu.The article demonstrates how Fishing and the Fishermen`s Discourse by Petar Hektorović is a novel about a knight’s quest for the holy grail. We are basing this theory on the motifs found in the novels about the holy grail (lost grail, questions which haven’t been asked, the renewal of the exhausted forces), in addition to the analysis of various symbols and themes (knights, hermits, castles, etc.). A semiotic study will show that there lies a key connection between the motifs and symbols, which is thus a virtue. Petar Hektorovic’s search was to realize the union between the mind and the body, between the individual and God, between the individual and the Universe, and between the teacher and the student. The heroes are searching for the virtue while illustrating the problems associated with the apparently innate and imperfect nature of human beings. Dissatisfaction, ignorance, disequilibrium and so on are the causes of misunderstandings and problems in the Petar Hektorovic’s Fishing and theFishermen`s Discourse as well as in the Parzival by Wolfram von Eschenbach. The characters are dedicated to the search, without the guarantee of an insight about the ending. They decide to take a leap from the rational to the unfamiliar and the irrational. They decided to perfect the virtues and rule over their desires so that they would, in line with the medieval mystics such as St. Augustine, Pseudo-Dionysius the Areopagit, St. Bernardino of Siena, realize their divine nature

    Consumer price indexes: an analysis of heterogeneity across sub-populations

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    La rilevanza dell'Indece dei Prezzi al Consumo quale misura dell'inflazione è stata a lungo dibattuta in particolare esminando le differenti cause di distorsione dovute all'utilizzo di un paniere fisso di beni e servizi. Di conseguenza la letteratura ha proposto indici dei prezzi sperimentali per particolari sottogruppi di popolazioni. tali indici hanno rilevanza ai fini della politica economica e sociale, poiché è probabile che differenti gruppi di popolazione abbiano comportamenti nei consumi differenti dalla media, ad esempio i consumatori poveri (Garner, Johnson & Kokoski, 1996) e quelli anziani (Stewart, 2008). Lo scopo di questo lavoro è quello di esaminare le possibilità offerte da metodi di costruzione alternativi degli Indici dei Prezzi al Consumo ai fini di cogliere la variabilità dei tassi di inflazione relativi a differenti categorie di consumatori.The soundeness of Consumer Price Indexes (CPI) as a measure of inflation has long been debeate, focusing on the different sources of bias inherent to use of a constant basket of goods and services. Thus experimental consumer price indexes have been proposed for targeted sub-populations specifically relevant for social and economic policy, that are likely to have consumption patterns different from yhe average, i.e poor (Garner, Johnson & Kokoski, 1996) and elderly (Stewart, 2008)houseolds. Aim of this work is to investigate the possibilities offered by alternative methods of construction of consumer price indices in order to capture the variability of inflation rates facing different houseolds' types

    The effects of immigration and media influence on body image among Pakistani men

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    This study examined the role of media influence and immigration on body image among Pakistani men. Attitudes toward the body were compared between those living in Pakistan (n = 56) and those who had immigrated to the United Arab Emirates (n = 58). Results of a factorial analysis of variance demonstrated a significant main effect of immigrant status. Pakistani men living in the United Arab Emirates displayed poorer body image than those in the Pakistan sample. Results also indicated a second main effect of media influence.Those highly influenced by the media displayed poorer body image. No interaction effect was observed between immigrant status and media influence on body image. These findings suggest that media influence and immigration are among important risk factors for the development of negative body image among non-Western men. Interventions designed to address the negative effects of the media and immigration may be effective at reducing body image disorders and other related health problems in this population

    Religion and HIV in Tanzania: Influence of Religious Beliefs on HIV stigma, Disclosure, and Treatment Attitudes.

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    Religion shapes everyday beliefs and activities, but few studies have examined its associations with attitudes about HIV. This exploratory study in Tanzania probed associations between religious beliefs and HIV stigma, disclosure, and attitudes toward antiretroviral (ARV) treatment. A self-administered survey was distributed to a convenience sample of parishioners (n = 438) attending Catholic, Lutheran, and Pentecostal churches in both urban and rural areas. The survey included questions about religious beliefs, opinions about HIV, and knowledge and attitudes about ARVs. Multivariate logistic regression analysis was performed to assess how religion was associated with perceptions about HIV, HIV treatment, and people living with HIV/AIDS. Results indicate that shame-related HIV stigma is strongly associated with religious beliefs such as the belief that HIV is a punishment from God (p < 0.01) or that people living with HIV/AIDS (PLWHA) have not followed the Word of God (p < 0.001). Most participants (84.2%) said that they would disclose their HIV status to their pastor or congregation if they became infected. Although the majority of respondents (80.8%) believed that prayer could cure HIV, almost all (93.7%) said that they would begin ARV treatment if they became HIV-infected. The multivariate analysis found that respondents' hypothetical willingness to begin ARV treatme was not significantly associated with the belief that prayer could cure HIV or with other religious factors. Refusal of ARV treatment was instead correlated with lack of secondary schooling and lack of knowledge about ARVs. The decision to start ARVs hinged primarily on education-level and knowledge about ARVs rather than on religious factors. Research results highlight the influence of religious beliefs on HIV-related stigma and willingness to disclose, and should help to inform HIV-education outreach for religious groups
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