Tunnelling through black rings

Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton gravity theory is analyzed by use of the Parikh-Wilczek tunnelling method. To get the correct tunnelling amplitude and emission rate, we adopted and developed the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronic discharge all at once, and the effect of back reaction is also taken into account. This constitute a unified approach to the tunnelling problem. Provided the first law of thermodynamics for black rings holds, the emission rate is proportional to the exponential of the change of Bekenstein-Hawking entropy. Explicit calculation for black ring temperatures agree exactly with the results obtained via the classical surface gravity method and the quasilocal formalism.Comment: 10 pages, V2: various modifications throughout the text, plus a lot of newly added reference

Performances of linseed oil-free bakelite RPC prototypes with cosmic ray muons

A comparative study has been performed on Resistive Plate Chambers (RPC) made of two different grades of bakelite paper laminates, produced and commercially available in India. The chambers, operated in the streamer mode using argon, tetrafluroethane and isobutane in 34:59:7 mixing ratio, are tested for the efficiency and the stability with cosmic rays. A particular grade of bakelite (P-120, NEMA LI-1989 Grade XXX), used for high voltage insulation in humid conditions, was found to give satisfactory performance with stable efficiency of > 96% continuously for more than 130 days. A thin coating of silicone fluid on the inner surfaces of the bakelite RPC is found to be necessary for operation of the detector.Comment: 6 figures, Presented in IX International Workshop on Resistive Plate Chamber and related Detectors-2007, TIFR, Mumbai, India, February 13-16, 200

Evidencia experimental de la abundancia de bacterias del suelo como el principal iniciador del efecto de preparación de la rizosfera

Se piensa que las comunidades microbianas del suelo son responsables del efecto de preparación de la rizósfera (RPE). Sin embargo, desde que las comunidades microbiales están compuestas de diversos componentes, se conoce muy poco acerca de cuál es el componente que tiene el rol principal en dicho efecto. En este estudio, se hicieron crecer soja y algodón en dos lugares a diferentes latitudes con diferentes condiciones de luz y temperatura in situ. Se cuantificó RPE usando un método natural de δC13 y se midió la abundancia, riqueza y composición de las comunidades de hongos y bacterias con métodos moleculares basados en el ADN. Entre todas las variables potenciales, incluyendo los tres índices de comunidades de hongos y bacterias anteriormente mencionados, e índices vegetales y físico-químicos del suelo, se mostró que la abundancia de bacterias explicó una gran proporción de la variación en RPE. Nuestro estudio identificó el mecanismo biológico que subyace este importante proceso ecológico.Soil microbial communities are thougth to be responsible for the rhizosphere priming effect (RPE). However, because soil microbial communities are comprised of diverse components, very little is known about which component plays the critical role. Here, soybean and cottonwood were grown at two latitudinal locations with different temperature and light conditions in-situ. We quantified RPE using a natural 13C method, and measured the abundance, richness and composition of bacteria and fungi communities with DNA-based molecular methods. Among all potential variables, including the three aforementioned indexes of bacteria and fungi communities and soil physiochemical and plant indexes, bacterial abundance was found to explain a large proportion of variation in RPE. Our study identified the biological mechanism underlying this important ecological process.Fil: Ma, Y.P.. Chinese Academy of Sciences. Institute of Applied Ecology; China. Chinese Academy of Agricultural Sciences. Institute of Environment and Sustainable Development in Agriculture. Key Laboratory of Dryland Agriculture;; China. University of Chinese Academy of Science; ChinaFil: Zhang, Z.J.. Chinese Academy of Sciences. Institute of Applied Ecology; China. Chinese Academy of Agricultural Sciences. Institute of Environment and Sustainable Development in Agriculture. Key Laboratory of Dryland Agriculture;; ChinaFil: Su, T.Q.. Chinese Academy of Sciences. Institute of Applied Ecology; ChinaFil: Busso, Carlos Alberto. Universidad Nacional del Sur. Departamento de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Johnston, E.R.. Georgia Institute of Technology. School of Civil and Environmental Engineering; Estados UnidosFil: Han, X.G.. Chinese Academy of Sciences. Institute of Applied Ecology; China. Chinese Academy of Sciences. Institute of Botany. State Key Laboratory of Vegetation and Environmental Change; ChinaFil: Zhang, X.M.. Chinese Academy of Agricultural Sciences. Institute of Environment and Sustainable Development in Agriculture. Key Laboratory of Dryland Agriculture;; Chin

Production Optimization,Molecular Characterization and Biological Activities of Exopolysaccharides from Xylaria nigripes

The optimal culture conditions of exopolysaccharides (EPS) production in submerged culture medium by Xylaria nigripes were determined using orthogonal matrix method. The optimal medium (per liter) EPS was 60.0 g L–1 maltose, 1.0 g L–1 peptone, 5 mmol L–1 KH2PO4, and initial pH 7.0 at 28 oC. In the optimal culture medium, the maximum EPS production was 11.967 g L–1 in shake flask. Two groups of EPSs (designated as Fr-I and Fr-II) were obtained from the culture filtrates by size exclusion chromatography (SEC), and their molecular characteristics were examined by a multiangle laser-light scattering (MALLS) and refractive index (RI) detector system. The weight-average molar masses of Fr-I and Fr-II of EPS were determined to be 6.327104 and 1.478104 g mol–1, respectively. The SEC/MALLS analysis revealed that the molecular formation of Fr-I is of nearly globular shape. Furthermore, the experiments in vitro indicated that X. nigripes EPS exhibited high antioxidative effects though its antitumour activity was limited

Preparation, characterization and anti-ageing activity of Gastrodia elata blume polysaccharide

Gastrodia elata Blume polysaccharide (GEP) was extracted and then chemically characterised. Its antioxidant activity was evaluated in vitro and in vivo. The results of the in vitro investigation show that GEP consists of glucose with molecular weight of 875 185 Da and exhibits high hydroxyl radical scavenging, as well as 2,2-diphenyl-1- picrylhydrazyl activity and reducing capacity. For antioxidant activity in vivo, D-galactose-induced-aged mice were orally administered with three different doses of GEP over a period of 6 weeks. The administration of GEP dosedependently increased the body weight gain rates, liver and brain indices, superoxide dismutase and glutathione peroxidase activities, and malondialdehyde levels in the sera and brains of ageing mice. These results suggest that GEP exhibits high antioxidant activity and can retard human ageing associated with free radicals

Tortoise coordinate and Hawking effect in a dynamical Kerr black hole

Hawking effect from a dynamical Kerr black hole is investigated using the improved Damour-Ruffini method with a new tortoise coordinate transformation. Hawking temperature of the black hole can be obtained point by point at the event horizon. It is found that Hawking temperatures of different points on the surface are different. Moreover, the temperature does not turn to zero while the dynamical black hole turns to an extreme one.Comment: 7 page

Hepatitis B virus subgenotype C2 is the most prevalent subgenotype in northeast China

AbstractThe geographical distribution of hepatitis B virus (HBV) subgenotypes and their clinical implications in patients with acute and chronic hepatitis B in the Heilung-kiang province of northeast China were investigated. Nested PCR and multiplex PCR were performed with genotype-specific primers and with subgenotype-specific primers to identify genotypes and subgenotypes from serum samples of 412 HBV infections including 69 with acute self-limited hepatitis (ASH) and 343 with chronic hepatitis (CH). A total of 361 samples were genotyped and 304 were further subgenotyped. The most common HBV genotype was C (93.63%, 338/361), with subgenotype group C2 (83.73%, 283/338) predominating. Genotype B was also found and subgenotype B2 predominated within this genotype. Out of 69 infected patients with ASH, 48 were identified as genotype C and all belonged to subgenotype C2. Of 343 infected patients with CH, 313 were genotyped and 256 were subgenotyped; amongst these, C2 (91.80%, 235/256), B2 (7.42%, 19/256) and mixed subgenotypes B2 and C2 (0.78%, 2/256) were found. In HBV subgenotype C2 infections, ASH had a higher ratio of women than CH patients. These results show that HBV subgenotypes C2 and B2 were found in Heilung-kiang province of northeast China. In ASH and CH groups, the distributions of subgenotypes were coincident with C2, the predominant subgenotype. Analysis of the association between subgenotype and the outcomes of HBV infection was inconclusive in our study

Molecular cytogenetic aberrations in patients with multiple myeloma studied by interphase fluorescence in situ hybridization

Background: Multiple myeloma (MM) is an incurable hematological disorder characterized by the accumulation of malignant plasma cells within the bone marrow (BM). The clinical heterogeneity of MM is dictated by the cytogenetic aberrations present in the clonal plasma cells (PCs). Cytogenetic studies in MM are hampered by the hypoproliferative nature of plasma cells in MM. Therefore, fluorescence in situ hybridization (FISH) analysis combined with magnetic-activated cell sorting (MACS) is an attractive alternative for evaluation of numerical and structural chromosomal changes in MM. Methods: Interphase FISH studies with three different specific probes for the regions containing 13q14.3 (D13S319), 14q32 (IGHC/IGHV) and 1q12(CEP1 ) were performed in 48 MM patients. Interphase FISH studies with LSI IGH/CCND1, LSI IGH/FGFR3, and LSI IGH/MAF probes were used to detect t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23) in patients with 14q32 rearrangement. Results: Molecular cytogenetic aberrations were found in 40 (83.3%) of the 48 MM patients. 13 patients (27.1%) simultaneously had 13q deletion/monosomy 13 [del(13q14)], illegitimate IGH rearrangement and chromosome 1 abnormality. Del(13q14) was detected in 21 cases (43.7%), and illegitimate IGH rearrangements in 29 (60.4%) including 6 with t(11;14) and 5 with t(4;14). None of 9 patients with illegitimate IGH rearrangements and without t(11;14) or t(4;14) we detected had t(14;16) (q32;q23). 24 of the 48 MM patients (50%) had chromosome 1 abnormalities. Among 21 patients with del(13q14), 15 patients had Amp1q12;16 had IgH rearrangements. Whereas, among 27 cases without del(13q14), 8 had Amp1q12; 13 had IgH rearrangements. There was a strong association between del(13q14) and Amp1q12(c2 = 8.26, р < 0.01), and between del(13q14) and IgH rearrangement(c2 = 3.88, p < 0.05). Conclusion: 13q deletion/monosomy 13, IGH rearrangement and chromosome 1 abnormality are frequent in MM. They are not randomly distributed, but strongly interconnected. Interphase FISH technique combined with MACS using CD138-specific antibody is a highly sensitive technique at detecting molecular cytogenetic aberrations in MM.Обоснование: множественная миелома (MM) — неизлечимое гематологическое заболевание, характеризирующееся накоплением злокачественных плазматических клеток в костном мозге (КM). Клиническая гетерогенность MM определяется цитогенетическими аберрациями, присутствующими в клоне плазматических клеток (ПК). Цитогенетические исследования MM осложнены гипопролиферативными особенностями ПК. В связи с этим флуоресцентная гибридизация in situ (FISH) в комбинации с сортировкой клеток, активированных магнитными полями (MACS) представляется достойной альтернативой методам оценки точечных и структурных изменений хромосом при MM. Методы: интерфазные исследования методом FISH с использованием трех различных специфических зондов для участков, содержащих 13q14.3 (D13S319), 14q32 (IGHC/IGHV) и 1q12(CEP1), проводили у 48 больных с MM. Интерфазные исследования методом FISH с использованием зондов LSI IGH/CCND1, LSI IGH/FGFR3 и LSI IGH/MAF применяли для детекции t(11;14)(q13;q32), t(4;14)(p16;q32), и t(14;16)(q32;q23) у пациентов с перестройкой 14q32. Результаты: молекулярные цитогенетические аберрации выявляли у 40 (83,3%) из 48 больных с MM. У 13 пациентов (27,1%) одновременно определены 13q делеция/моносомия 13 [del(13q14)], аномальная перестройка IGH и аномалия хромосомы 1. Del(13q14) детектировали в 21 случае (43,7%), а аномальные перестройки IGH — в 29 (60,4%), в том числе у 6 пациентов с t(11;14) и 5 с t(4;14). Ни у одного из 9 больных с аномальными перестройками IGH и без t(11;14) или t(4;14) не выявляли транслокацию t(14;16) (q32;q23). У 24 из 48 пациентов с MM (50%) определяли аномалии хромосомы 1. В группе из 21 больных с del(13q14) в 15 случаях имелись перестройки IgH Amp1q12;16. В то же время из 27 случаев без del(13q14) у 8 содержались Amp1q12; в 13 случаях отмечали перестройки IgH. Выявлена взаимосвязь между del(13q14) и Amp1q12(χ2 = 8,26, p < 0,01) и между del(13q14) и перестройками IgH (χ2 = 3,88, p < 0,05). Выводы: 13q делецию/моносомию 13, перестройку IGH и аномалию хромосомы 1 часто отмечают при MM, причем их распределение не случайно и тесно взаимосвязано. Интерфазный анализ FISH в комбинации с MACS с использованием CD138-специфичных антител является высокочувствительным методом детекции молекулярных цитогенетических аберраций при MM

The anti-caries efficacy of a dentifrice containing 1.5% arginine and 1450ppm fluoride as sodium monofluorophosphate assessed using Quantitative Light-induced Fluorescence (QLF)

AbstractObjectiveTo compare the efficacy of a new dentifrice containing 1.5% arginine, an insoluble calcium compound and 1450ppm fluoride to arrest and reverse naturally occurring buccal caries lesions in children relative to a positive control dentifrice containing 1450ppm fluoride alone.Study designParticipants from Chengdu, Sichuan Province, China tested three dentifrices: a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride, as sodium monofluorophosphate, a positive control dentifrice containing 1450ppm fluoride, as sodium fluoride, in a silica base, and a matched negative control dentifrice without arginine and fluoride. Quantitative Light-induced Fluorescence (QLF) was used to assess buccal caries lesions at baseline and after 3 and 6 months of product use.Results438 participants (initial age 9–13 years (mean 11.1±0.78) and 48.6% female) completed the study. No adverse events attributable to the products were reported during the course of the study. The subject mean ΔQ (mm2%), representing lesion volume, was 27.26 at baseline. After 6 months of product use, the ΔQ values for the arginine-containing, positive and negative control dentifrices were 13.46, 17.99 and 23.70 representing improvements from baseline of 50.6%, 34.0% and 13.1%. After 6 months product use, the differences between the pair wise comparisons for all three groups were statistically significant (p<0.01). The arginine-containing dentifrice demonstrated an improvement after only 3 months that was almost identical to that achieved by the conventional 1450ppm fluoride dentifrice after 6 months.ConclusionThe new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride provides statistically significantly superior efficacy in arresting and reversing buccal caries lesions to a conventional dentifrice containing 1450ppm fluoride alone