Evaporation of a black hole off of a tense brane

We calculate the gray-body factors for scalar, vector and graviton fields in the background of an exact black hole localized on a tensional 3-brane in a world with two large extra dimensions. Finite brane tension modifies the standard results for the case with of a black hole on a brane with negligible tension. For a black hole of a fixed mass, the power carried away into the bulk diminishes as the tension increases, because the effective Planck constant, and therefore entropy of a fixed mass black hole, increase. In this limit, the semiclassical description of black hole decay becomes more reliable.Comment: a few typos corrected, accepted for publication in PR

Murine brain endothelial cells differently modulate interferon-γ and interleukin-17 production in vitro

Brain endothelial cells (BEC) are the major constituents of the blood-brain barrier (BBB), the structure that controls entrance of immune cells into CNS parenchyma. Our aim was to investigate the influence of BEC on production of IL-17 and IFN-γ-cytokines that are important for CNS inflammation. To that end, co-cultivations of the bEnd.3 brain endothelial cell line and lymph node cells (LNC) were performed, and gene expression and production of IL-17 and IFN-γ were determined. It was found that bEnd.3 cells inhibited expression and production of IFN-γ, but not of IL-17. Additionally, bEnd.3 cells also reduced production of the major IFN-γ-promoting cytokine - IL-12 - in LNC. The observed variation in modulation of pro-inflammatory cytokines by BEC could be of importance for the understanding of CNS inflammation

Theory of the Optical Conductivity in the Cuprate Superconductors

We present a study of the normal state optical conductivity in the cuprate superconductors using the nearly antiferromagnetic Fermi liquid (NAFL) description of the magnetic interaction between their planar quasiparticles. We find that the highly anisotropic scattering rate in different regions of the Brillouin zone, both as a function of frequency and temperature, a benchmark of NAFL theory, leads to an average relaxation rate of the Marginal Fermi Liquid form for overdoped and optimally doped systems, as well as for underdoped systems at high temperatures. We carry out numerical calculations of the optical conductivity for several compounds for which the input spin fluctuation parameters are known. Our results, which are in agreement with experiment on both overdoped and optimally doped systems, show that NAFL theory explains the anomalous optical behavior found in these cuprate superconductors.Comment: REVTEX file, 8 PostScript figure

Assessment of the nucleotide modifications in the high-resolution cryo-electron microscopy structure of the Escherichia coli 50S subunit.

Post-transcriptional ribosomal RNA (rRNA) modifications are present in all organisms, but their exact functional roles and positions are yet to be fully characterized. Modified nucleotides have been implicated in the stabilization of RNA structure and regulation of ribosome biogenesis and protein synthesis. In some instances, rRNA modifications can confer antibiotic resistance. High-resolution ribosome structures are thus necessary for precise determination of modified nucleotides' positions, a task that has previously been accomplished by X-ray crystallography. Here, we present a cryo-electron microscopy (cryo-EM) structure of the Escherichia coli 50S subunit at an average resolution of 2.2 Å as an additional approach for mapping modification sites. Our structure confirms known modifications present in 23S rRNA and additionally allows for localization of Mg2+ ions and their coordinated water molecules. Using our cryo-EM structure as a testbed, we developed a program for assessment of cryo-EM map quality. This program can be easily used on any RNA-containing cryo-EM structure, and an associated Coot plugin allows for visualization of validated modifications, making it highly accessible

Drama hero in modern Serbian literature (1890-1918)

У намери да понудимо прецизну и убедљиву слику епохе, односно позицију драмске књижевности у њој, у фокус интересовања постављен је драмски јунак, преко кога смо посредно осветлили и друге аспекте дела условљене његовом егзистенцијом, ломовима, сукобима и хтењима. Сам јунак је постао оличење сукоба и чувар граничности између два сукобљена света, а неретко и знамен подвојености. Како је концепт јунака условљен правилима жанра, покушали смо да путем жанровске класификације осветлимо различите типове јунака као носиоце и реализаторе пишчевих идеја. Међутим, док се, са једне стране, у традиционалним врстама јунак прилагођава жанру, дотле је, на другој страни, сам јунак, као човек преузет из стварности онога времена, управо захваљујући таквој стварности транспонованој у књижевноуметнички свет, условио настанак појединих нових драмских врста. Узвишени и врлинама обдарени јунак трагедије и историјске драме је, силазећи са тих висина, све више постајао пишчев савременик, маргинализован и неспреман за борбу са животом. Такав јунак се све више испољавао као играчка случаја и носилац унутрашње трагике која се манифестовала као трајни раскол између унутрашњег и спољног света, између његовог јавног и приватног бића...In order to offer a precise and convincing image of the epoch, that is, the position of drama in it, the focus of our interests was positioned on the drama hero, by means of whom we indirectly shed light on other aspects of the work conditioned by the hero’s existence, ambiguities, conflicts and desires. The hero themselves became the embodiment of conflict and the guardian of the border between two competing worlds, and often a sign of ambivalence. Since the concept of a hero is conditioned by the rules of the genre, we tried to illuminate different types of heroes as the carriers and agents of the writer’s ideas by using genre classifications. However, on the one hand, in the traditional types, the hero adapts to the genre in question, the hero themselves, on the other hand, as a human being taken from the reality of that time, conditioned the emergence of some new types of drama, precisely owing to such reality which is transported into the literary and artistic world. An exalted and virtue-endowed hero of a tragedy and historical drama, by descending from these heights, was increasingly becoming the writer’s contemporary marginalized and unprepared for a fight with life. Such a hero demonstrated themselves more and more as a toy of the case and a carrier of internal tragedy which was manifested as a permanent dissidence between the inner and outer world, between its public and private being..

Weak Pseudogap Behavior in the Underdoped Cuprate Superconductors

We report on an exact solution of the nearly antiferromagnetic Fermi liquid spin fermion model in the limit \pi T << \omega_{sf}, which demonstrates that the broad high energy features found in ARPES measurements of the spectral density of the underdoped cuprate superconductors are determined by strong antiferromagnetic (AF) correlations and precursor effects of an SDW state. We show that the onset temperature, T^{cr}, of weak pseudo-gap (pseudoscaling) behavior is determined by the strength, \xi, of the AF correlations, and obtain the generic changes in low frequency magnetic behavior seen in NMR experiments with \xi(T^{cr}) \approx 2, confirming the Barzykin and Pines crossover criterion.Comment: REVTEX, 4 pages, 3 EPS figure

Pentoxifylline Prevents Autoimmune Mediated Inflammation in Low Dose Streptozotocin Induced Diabetes

Xanthine derivative, pentoxifylline (PTX), has been recently shown to exert a protective effects in certain animal models of autoimmunity, including diabetes in NOD mice. In the present study, the immunomodulatory potential of PTX was investigated in autoimmune diabetes induced by multiple low doses of streptozotocin (MLD-SZ) in genetically susceptible CBA/H mice (tested with 40 mg SZ/kg b.w. for 5 days) and DA rats (tested with 20 mg/kg b.w. for 5 days). In both species, 2 – 3 weeks following the MLD-SZ treatment, sustained hyperglycemia developed, as an outcome of inflammatory reaction with endothelial cell activation and accumulation of mononuclear cells. Although there was no evidence of typical insulitis in early disease development (day 10), in both rats and mice, macrophages, CD4+ and CD8+ cells were present in the islets of Langerhans as diffuse mononuclear infiltrates with the expression of IFN-γ and inducible NO synthase (iNOS). Administration of PTX (200 mg/kg/day for 10 days) in combination with MLD-SZ reduced insulitis and the production of mediators tested, and prevented the development of hyperglycemia. These results suggest that beneficial effects of PTX involve down-regulation of local proinflammatory cytokine-mediated NO synthase pathway. They also demonstrate that in addition to ameliorating spontaneous autoimmunity in NOD mice, PTX may be effective in downregulating an inflammatory autoimmune process triggered in susceptible host by an external agents, such as streptozotocin

STR loci D19S216, D20S502 and D20S842 analysis in the Serbian population using dentin DNA

Dentin provides a protective enclosure for genomic and mitochondrial DNA. In the present study, DNA was obtained from pulverized or ground teeth. The quality of the DNA extracted from the teeth of 70 unrelated individuals was tested in the context of assessing the allelic and genotypic frequencies of autosomal loci D19S216, D20S502 and D20S842, and calculating a number of parameters of population genetics and forensic interest. This study illustrates that teeth can be a convenient tissue to extract DNA from large numbers of individuals for population genetic studies as well as for forensic case work

Rat duodenal motility in vitro: Prokinetic effects of DL-homocysteine thiolactone and modulation of nitric oxide mediated inhibition

Homocysteine is a significant but modifiable risk factor for vascular diseases. As gastrointestinal smooth musculature is similar to blood vessel muscles, we investigated how elevated homocysteine levels affect nitric oxide-mediated neurotransmission in the gut. There is accumulated evidence that a dysfunction of NO neurons in the myenteric plexus may cause various diseases in the gastrointestinal tract such as achalasia, diabetic gastroparesis and infantile hypertrophic pyloric stenosis. In the present study, we aimed to assess the effects of homocysteine on NO-mediated responses in vitro, and to examine the effects of DL-homocysteine thiolactone on the spontaneous motility of rat duodenum and nitrergic neurotransmission. DL-homocysteine thiolactone concentration of 10 μmol/L leads to the immediate increase in tone, amplitude and frequency of spontaneous movements in isolated rat duodenum. L-NAME (30 μmol/L) leads to an increase in basal tone, amplitude and frequency of spontaneous contractions. The relaxations induced by EFS were significantly reduced in duodenal segments incubated in DL-homocysteine thiolactone compared with the control group. EFS-induced relaxations were inhibited by L-NAME in both experimental and control groups. These results suggest that a high level of homocysteine causes an important impairment of non-adrenergic non-cholinergic innervation of the rat duodenum. [Projekat Ministarstva nauke Republike Srbije, br. 175043

KOMPETENCIJE ODGAJATELJA ZA RJEŠAVANJE SUKOBA U UČENIČKOM DOMU

U ovom radu predstavljeni su rezultati empirijske studije koja je imala za cilj ispitati stavove domskih odgajatelja o njihovim kompetencijama za rješavanje sukoba među učenicima. Istraživanje je provedeno u studentskim domovima u Srbiji, na uzorku od 61 odgajatelj, 28 odgajatelja i 33 odgajateljice. Za ispitivanje stavova odgajatelja koristili smo instrument N. Suzić [1], koji smo prilagodili za potrebe ovog istraživanja. Rezultati koje smo dobili pokazuju da odgajatelji imaju sve potrebne kompetencije za posredovanje u sukobima među učenicima i da prepoznaju da je njihova uloga u rješavanju sukoba među učenicima relevantna. Osim što odgajatelji navode da posjeduju potrebne kompetencije za posredovanje u sukobima među učenicima, potrebno je posvetiti više pozornosti sukobima u domovima učenika i kompetencijama odgajatelja za njihovo rješavanje