Scintillation counter with MRS APD light readout

START, a high-efficiency and low-noise scintillation detector for ionizing particles, was developed for the purpose of creating a high-granular system for triggering cosmic muons. Scintillation light in START is detected by MRS APDs (Avalanche Photo-Diodes with Metal-Resistance-Semiconductor structure), operated in the Geiger mode, which have 1 mm^2 sensitive areas. START is assembled from a 15 x 15 x 1 cm^3 scintillating plastic plate, two MRS APDs and two pieces of wavelength-shifting optical fiber stacked in circular coils inside the plastic. The front-end electronic card is mounted directly on the detector. Tests with START have confirmed its operational consistency, over 99% efficiency of MIP registration and good homogeneity. START demonstrates a low intrinsic noise of about 10^{-2} Hz. If these detectors are to be mass-produced, the cost of a mosaic array of STARTs is estimated at a moderate level of 2-3 kUSD/m^2.Comment: 6 pages, 5 figure

The O(2) model in polar coordinates at nonzero temperature

We study the restoration of spontaneously broken symmetry at nonzero temperature in the framework of the O(2) model using polar coordinates. We apply the CJT formalism to calculate the masses and the condensate in the double-bubble approximation, both with and without a term that explicitly breaks the O(2) symmetry. We find that, in the case with explicitly broken symmetry, the mass of the angular degree of freedom becomes tachyonic above a temperature of about 300 MeV. Taking the term that explicitly breaks the symmetry to be infinitesimally small, we find that the Goldstone theorem is respected below the critical temperature. However, this limit cannot be performed for temperatures above the phase transition. We find that, no matter whether we break the symmetry explicitly or not, there is no region of temperature in which the radial and the angular degree of freedom become degenerate in mass. These results hold also when the mass of the radial mode is sent to infinity.Comment: 23 pages, 10 figure

Uma contribuição para a etnografia da fala : pregões nas feiras livres da cidade de São Paulo

Orientador: Maurizzio GnerreDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da LinguagemResumo: Este trabalho situa-se no campo da etnografia da fala e pretende estudar uma manifestação verbal própria de uma situação social determinada: os pregões de feiras livres em São Paulo. Preocupei -me em responder às indagações básicas da etnografia da fala: ¿Quem fala o que para quem, onde, quando, de que maneira e com que finalidade construindo assim um quadro de definição deste gênero verbal. Procurei na lingüística o método de coleta e análise de dados - gravação, transcrição - e a base teórica para o desenvolvimento do trabalho, e na sociologia e antropologia o quadro social onde encaixar este material. Os dados para análise, 144 pregões, foram classificados como criativos quanto ao enunciado ou quanto à enunciação situei as funções da linguagem, segundo Jakobson e Hymes, existentes nos pregões e defini as interelações entre os tipos de criatividade e funções da linguagem. Conclui que a função conativa, característica inerente dos pregões, não visa só o contato com os compradores, o que denotaria um aspecto puramente funcional. Ela visa também um contato com os outros feirantes, evidenciando o aspecto lúdico dos pregões, encaixando este gênero lingüístico como uma manifestação menor de arte verbalAbstract: Not informed.MestradoMestre em Linguístic

Mitochondrial Activity and Cyr1 are Key Regulators of Ras1 Activation of C. albicans Virulence Pathways

Candida albicans is both a major fungal pathogen and a member of the commensal human microflora. The morphological switch from yeast to hyphal growth is associated with disease and many environmental factors are known to influence the yeast-to-hyphae switch. The Ras1-Cyr1-PKA pathway is a major regulator of C. albicans morphogenesis as well as biofilm formation and white-opaque switching. Previous studies have shown that hyphal growth is strongly repressed by mitochondrial inhibitors. Here, we show that mitochondrial inhibitors strongly decreased Ras1 GTP-binding and activity in C. albicans and similar effects were observed in other Candida species. Consistent with there being a connection between respiratory activity and GTP-Ras1 binding, mutants lacking complex I or complex IV grew as yeast in hypha-inducing conditions, had lower levels of GTP-Ras1, and Ras1 GTP-binding was unaffected by respiratory inhibitors. Mitochondria-perturbing agents decreased intracellular ATP concentrations and metabolomics analyses of cells grown with different respiratory inhibitors found consistent perturbation of pyruvate metabolism and the TCA cycle, changes in redox state, increased catabolism of lipids, and decreased sterol content which suggested increased AMP kinase activity. Biochemical and genetic experiments provide strong evidence for a model in which the activation of Ras1 is controlled by ATP levels in an AMP kinase independent manner. The Ras1 GTPase activating protein, Ira2, but not the Ras1 guanine nucleotide exchange factor, Cdc25, was required for the reduction of Ras1-GTP in response to inhibitor-mediated reduction of ATP levels. Furthermore, Cyr1, a well-characterized Ras1 effector, participated in the control of Ras1-GTP binding in response to decreased mitochondrial activity suggesting a revised model for Ras1 and Cyr1 signaling in which Cyr1 and Ras1 influence each other and, together with Ira2, seem to form a master-regulatory complex necessary to integrate different environmental and intracellular signals, including metabolic status, to decide the fate of cellular morphology

Control of Candida albicans Metabolism and Biofilm Formation by Pseudomonas aeruginosa Phenazines

Candidaalbicanshasdevelopmentalprogramsthatgoverntransitionsbetweenyeastandfilamentousmorphologies and between unattached and biofilm lifestyles. Here, we report that filamentation, intercellular adherence, and biofilm develop- ment were inhibited during interactions between Candida albicans and Pseudomonas aeruginosa through the action of P. aeruginosa-produced phenazines. While phenazines are toxic to C. albicans at millimolar concentrations, we found that lower concentrations of any of three different phenazines (pyocyanin, phenazine methosulfate, and phenazine-1-carboxylate) allowed growth but affected the development of C. albicans wrinkled colony biofilms and inhibited the fungal yeast-to-filament transition. Phenazines impaired C. albicans growth on nonfermentable carbon sources and led to increased production of fer- mentation products (ethanol, glycerol, and acetate) in glucose-containing medium, leading us to propose that phenazines specif- ically inhibited respiration. Methylene blue, another inhibitor of respiration, also prevented the formation of structured colony biofilms. The inhibition of filamentation and colony wrinkling was not solely due to lowered extracellular pH induced by fer- mentation. Compared to smooth, unstructured colonies, wrinkled colony biofilms had higher oxygen concentrations within the colony, and wrinkled regions of these colonies had higher levels of respiration. Together, our data suggest that the structure of the fungal biofilm promotes access to oxygen and enhances respiratory metabolism and that the perturbation of respiration by bacterial molecules such as phenazines or compounds with similar activities disrupts these pathways. These findings may sug- gest new ways to limit fungal biofilms in the context of disease

The paediatric Confusion Assessment Method for the Intensive Care Unit (pCAM-ICU): Translation and cognitive debriefing for the German-speaking area

Purpose: To date there are only a few studies published, dealing with delirium in critically ill patients. The problem with these studies is that prevalence rates of delirium could only be estimated because of the lack of validated delirium assessment tools for the paediatric intensive care unit (PICU). The paediatric Confusion Assessment Method for the Intensive Care Unit (pCAM-ICU) was specifically developed and validated for the detection of delirium in PICU patients. The purpose of this study was the translation of the English pCAM-ICU into German according to international validated guidelines

Folksonomies and clustering in the collaborative system CiteULike

We analyze CiteULike, an online collaborative tagging system where users bookmark and annotate scientific papers. Such a system can be naturally represented as a tripartite graph whose nodes represent papers, users and tags connected by individual tag assignments. The semantics of tags is studied here, in order to uncover the hidden relationships between tags. We find that the clustering coefficient reflects the semantical patterns among tags, providing useful ideas for the designing of more efficient methods of data classification and spam detection.Comment: 9 pages, 5 figures, iop style; corrected typo

Bloch-Wall Phase Transition in the Spherical Model

The temperature-induced second-order phase transition from Bloch to linear (Ising-like) domain walls in uniaxial ferromagnets is investigated for the model of D-component classical spin vectors in the limit D \to \infty. This exactly soluble model is equivalent to the standard spherical model in the homogeneous case, but deviates from it and is free from unphysical behavior in a general inhomogeneous situation. It is shown that the thermal fluctuations of the transverse magnetization in the wall (the Bloch-wall order parameter) result in the diminishing of the wall transition temperature T_B in comparison to its mean-field value, thus favouring the existence of linear walls. For finite values of T_B an additional anisotropy in the basis plane x,y is required; in purely uniaxial ferromagnets a domain wall behaves like a 2-dimensional system with a continuous spin symmetry and does not order into the Bloch one.Comment: 16 pages, 2 figure

Трансформация жирнокислотного состава липидов подкожной жировой ткани морских и пресноводных тюленей

Correlation between blubber fatty acid composition of two different kind of seals with their prey and environmental conditions as ecology factors is shown. Regularities of fatty acid layering and its composition in the blubber of Baikal seals and ringed seals of North sea are revealedПоказана взаимосвязь жирнокислотного состава липидов подкожной жировой ткани разных видов тюленей с характеристиками условий обитания, объектов питания как экологическими факторами. Выявлены закономерности послойного изменения состава жирных кислот жировой ткани байкальской нерпы и кольчатого тюленя Северного моря