268 research outputs found

    A Comment on Bonnor-Steadman Closed Timelike Curves

    Full text link
    The existence and stability closed timelike curves in a Bonnor-Ward spacetime without torsion line singularities is shown by exhibiting particular examples.Comment: 2 pages, RevTex, minor correction

    Influences of cosmic radiation, artificial radioactivity and aerosol concentration upon the fair-weather atmospheric electric field in Lisbon (1955–1991)

    Get PDF
    The atmospheric electric field is influenced by cosmic radiation, radioactivity and aerosols. In this work we investigate the existence of: (i) correlations between relative anomalies of annual values of atmospheric electric field and cosmic radiation intensity, artificial radioactivity and aerosol concentration; (ii) seasonal correlations between relative anomalies of the atmospheric electric field and cosmic radiation intensity. We used data of the electric field strength recorded at the Portela meteorological station (Lisbon) in the period 1955–1991. We found statistically significant inverse correlations between atmospheric electric field and cosmic radiation in the period 1967–1991. We also found that the influence of cosmic radiation on the atmospheric electric field is strong in wintertime and very weak in summertime. The GCR–CN–CCN–Cloud Hypothesis and the wintertime reduced boundary layer convection are analyzed as possible explanations for this difference

    Spinning Strings, Black Holes and Stable Closed Timelike Geodesics

    Full text link
    The existence and stability under linear perturbation of closed timelike curves in the spacetime associated to Schwarzschild black hole pierced by a spinning string are studied. Due to the superposition of the black hole, we find that the spinning string spacetime is deformed in such a way to allow the existence of closed timelike geodesics.Comment: 5 pages, RevTex4, some corrections and new material adde

    Extrajudicial Killing Terhadap Terduga Pelaku Tindak Pidana Terorisme Dalam Perspektif Asas Presumption of Innoncent dan HAM

    Get PDF
    This article aims to analyse regulations related to extrajudicial killing against suspected terrorists from the perspective of the principle of presumption of innocence and human rights. The fact that counter-terrorism often leaves legal problems and human rights violations is clear in the KM 50 case when 6 members of the FPI were shot to death under suspicion of terrorism, allegedly committed by the anti-terrorism of Densus 88. This article attempts to see the problem from a legal perspective which leaves a normative vagueness with regard to the use of power by the Police and the implementation of the Human Rights Principles and Standards in the administration of the Indonesian National Police. As a normative legal research, the legal issue of this research concerns the guiding principles that give authority to the police to use force against suspects of terrorism vis-Ă -vis the principle of presumption of innocence and the enforcement of human rights. It is found that the extrajudicial killing of suspected terrorists is a violation of human rights. However, from a normative perspective, the act is controversial due to the vagueness of the law that guides the police in carrying out their duties. It is suggested that this regulation be made clearer to avoid abuse of power by the Police in combating criminal acts of terrorism. Abstrak Artikel ini bertujuan untuk mengetahui dan menganalisis pengaturan terkait extrajudicial killing terhadap pelaku terduga tindak pidana terorisme dilihat dari perspektif asas preassumption of innosence dan HAM. Artikel penelitian ini berangkat dari fakta bahwa upaya penanggulangan tindak pidana terorisme seringkali menyisakan isu-isu pelanggaran hukum dan HAM, terutama dilakukan oleh Densus 88 anti terorisme. Permasalahan seputar extrajudicial killing mencuat pasca kasus KM 50 dengan terbunuhnya 6 anggota laskar FPI dengan dugaan tindak pidana terorisme. Artikel ini melihat adanya permasalahan dari perspektif hukum yang secara normatif menyisakan kekaburan norma pada aturan mengenai peingguinaan keikuiatan dalam tindakan keipolisian dan impleimeintasi Prinsip dan Standar Hak Asasi Manuisia dalam peinyeileinggaraan Tuigas Keipolisian Neigara Indoneisia. Sebagai penelitian yuridis normatif, isu hukum penelitian ini mempermasalhakan guiding principles yang memberikan kewenangan kepolisian dalam penggunaan kekerasan dalam terhadap terduga tindak pidana terorisme vis-Ă -vis asas preassumtion of innocent and penegakan HAM. Ditemukan bahwa tindakan extrajudicial killing terhadap terduga teroris merupakan pelanggaran HAM. Namun secara yuridis, perbuatan tersebut bersifat kontroversial mengingat kekaburan yang terdapat pada aturan hukum yang menjadi panduan dalam menjalan tugas oleh Kepolisian. Disarankan agar pengaturan ini lebih jelas lagi agar tidak terjadi abuse of power oleh Kepolisian dalam memberantas tindak pidana terorisme

    Combining Xylose Reductase from Spathaspora arborariae with Xylitol Dehydrogenase from Spathaspora passalidarum to Promote Xylose Consumption and Fermentation into Xylitol by Saccharomyces cerevisiae

    Get PDF
    In recent years, many novel xylose-fermenting yeasts belonging to the new genus Spathaspora have been isolated from the gut of wood-feeding insects and/or wood-decaying substrates. We have cloned and expressed, in Saccharomyces cerevisiae, a Spathaspora arborariae xylose reductase gene (SaXYL1) that accepts both NADH and NADPH as co-substrates, as well as a Spathaspora passalidarum NADPH-dependent xylose reductase (SpXYL1.1 gene) and the SpXYL2.2 gene encoding for a NAD+-dependent xylitol dehydrogenase. These enzymes were co-expressed in a S. cerevisiae strain over-expressing the native XKS1 gene encoding xylulokinase, as well as being deleted in the alkaline phosphatase encoded by the PHO13 gene. The S. cerevisiae strains expressing the Spathaspora enzymes consumed xylose, and xylitol was the major fermentation product. Higher specific growth rates, xylose consumption and xylitol volumetric productivities were obtained by the co-expression of the SaXYL1 and SpXYL2.2 genes, when compared with the co-expression of the NADPH-dependent SpXYL1.1 xylose reductase. During glucose-xylose co-fermentation by the strain with co-expression of the SaXYL1 and SpXYL2.2 genes, both ethanol and xylitol were produced efficiently. Our results open up the possibility of using the advantageous Saccharomyces yeasts for xylitol production, a commodity with wide commercial applications in pharmaceuticals, nutraceuticals, food and beverage industries

    Acute Hormonal Responses to Multi-Joint Resistance Exercises with Blood Flow Restriction

    Get PDF
    The purpose of this study was to investigate the acute effects of multi-joint resistance exercises (MJRE) with blood flow restriction on hormonal responses. Ten men participated in the study and underwent two experimental protocols in random order: four sets (30, 15, 15, and 15 reps, respectively) of MJRE (half squat and horizontal chest press) were performed with 20% of 1RM and a rest time between sets of 30 s, combined with intermittent blood flow restriction (LI + BFR protocol); and four sets (8, 8, 8, 20 reps, respectively) of the same MJRE performed with 75% of 1RM load (HI protocol), with a 90 s rest between the first three sets and 30 s between the third to the fourth set. Blood samples were collected before (PRE), immediately after (POST), and 15 min after the performance of MJRE (POST15). A time effect was observed for growth hormone (GH) and insulin-like-growth-factor-1-binding-protein-3 (IGFPB-3), but no protocol effects or interactions between protocol and times were observed (p > 0.05). There was no effect of either protocol or time (p > 0.05) on total testosterone, free testosterone, or cortisol concentrations. However, significant (p < 0.05) increases were observed in the GH serum concentrations of 2072.73% and 2278.5%, HI, and LI + BFR protocols, respectively, from the PRE to POST15 test. In addition, there was an increase of 15.30% and 13.29% in the IGFPB-3 concentrations (p < 0.05) from PRE to POST0 times for HI and LI + BFR protocols, respectively. Furthermore, there was a decrease of 6.17% and 11.54%, p = 0.00, between the times POST0 to POST15 in the IGFPB-3 for the HI and LI + BFR protocols, respectively. It is concluded that multi-joint resistance exercises combined with intermittent blood flow restriction seemed to promote acute hormonal responses in a manner similar to traditional exercise with high loads. Future studies may investigate whether chronic use of LI + BFR with MJRE may promote muscle hypertrophy

    EvaluaciĂłn de la calidad del aceite de palma crudo comercializado en BahĂ­a, Brasil

    Get PDF
    The characteristics of the quality of crude palm oil (CPO) and crude palm olein (CPOL) produced in the states of Bahia and ParĂĄ were investigated. Twelve oil samples were analyzed; 2 (CPO) were from ParĂĄ (produced industrially), while the other 10 were from Bahia (3 CPOs and 3 CPOLs produced industrially, while 1 CPOL and 3 CPOs were traditionally processed). The chemical analyses included the determination of fatty acid methyl esters (FAME), free fatty acids (FFA%), peroxide value (PV), induction time (IT), total carotenoids (TC) and total polar compounds (TPC). The major saturated fatty acids in these samples were palmitic (34.79-42.89 g 100 g–1) and stearic (4.49-5.84 g 100 g–1) acid, and the main unsaturated fatty acids were oleic (37.31-43.69 g 100 g–1) and linoleic (9.04- 12.74 g100 g–1) acid. All samples produced in Bahia exhibited higher FFA (6.77-13.49%) and TPC (13.71-19.50%) levels than permitted in the international quality standards, unlike the samples produced in ParĂĄ. TC, PV and IT ranged from 422.1 to 584.2 mg g–1, 1.32 to 3.7 meq O2 kg–1 oil and 1.72 to 4.66 h, respectively. PV, FFA and TPC were inversely correlated with TC and IT. The use of inappropriate oil extraction processes in Bahia is clearly becoming a food safety problem.Las caracterĂ­sticas de calidad del aceite de palma crudo (CPO) y oleĂ­na de palma cruda (CPOL) producidos en los estados de BahĂ­a y ParĂĄ fueron investigados. Se analizaron doce muestras de aceites; 2 (CPO) eran de ParĂĄ (producido industrialmente), mientras que las otras 10 procedĂ­an de BahĂ­a (3 CPOs y 3 CPOLs producidos industrialmente, mientras que 1 CPOL y 3 CPOs fueron procesadas tradicionalmente). El anĂĄlisis quĂ­mico incluyĂł la determinaciĂłn de Ă©steres metĂ­licos de ĂĄcidos grasos (FAME), ĂĄcidos grasos libres (FFA%), Ă­ndice de perĂłxido (PV), el tiempo de inducciĂłn (TI), los carotenoides totales (TC) y el total de compuestos polares (TPC). Los principales ĂĄcidos grasos saturados en estas muestras fueron palmĂ­tico (34,79 a 42,89 g 100 g–1) y esteĂĄrico (4.49 a 5.84 g 100 g–1), y los principales ĂĄcidos grasos insaturados fueron oleico (37.31-43.69 g 100 g–1) y linoleico (9,04-12,74 g 100 g–1). Todas las muestras producidas en BahĂ­a muestran valores de FFA (6,77-13,49%) y TPC (13,71 a 19,50%), por encima de los niveles de los estĂĄndares internacionales de calidad, a diferencia de las muestras producidas en ParĂĄ. TC, PV y TPC oscilaron entre 422,1 a 584,2 mg g–1, 1,32 a 3,7 meq O2 kg–1 y 1,72 a 4,66 h, respectivamente. PV, FFA y TPC se correlacionan inversamente con TC y IT. El uso de procesos inadecuados de extracciĂłn de aceites en BahĂ­a se estĂĄ convirtiendo claramente en un problema de seguridad alimentaria

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

    Get PDF
    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
    • 

    corecore