234 resultados para ghost crabs
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We show that the BRST cohomology of the massless sector of the Type IIB superstring on AdS(5) x S (5) can be described as the relative cohomology of an infinite-dimensional Lie superalgebra. We explain how the vertex operators of ghost number 1, which correspond to conserved currents, are described in this language. We also give some algebraic description of the ghost number 2 vertices, which appears to be new. We use this algebraic description to clarify the structure of the zero mode sector of the ghost number two states in flat space, and initiate the study of the vertices of the higher ghost number.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The use of gastropod shells by hermit crabs is determined by the availability of shells in the environment or through selection for size and volume. This study analyzed patterns in the use of shells by Dardanus insignis (Saussure, 1858). From January 1998 to December 1999, 386 individuals were collected from two islands at Ubatuba, Sao Paulo. The crabs were measured for cephalothoracic shield length (CSL) and wet weight (CWW). The gastropod shells occupied by hermit crabs were identified, and the shell aperture width (SAW), dry weight (SDW) and internal volume (STY) were measured. The relationships between the dimensions of the gastropod shell and the hermit crabs were evaluated by linear regression analysis. Among the 11 species of gastropod shells used by D. insignis, the most often used was Olivancillaria urceus (31%), followed by Strombus pugilis (22%) and Siratus tenuivaricosus (18%). The shell of O. urceus was used most probably due to its high availability on Couves and Mar Virado islands. The most significant biometric parameter was shell aperture width (F=18.231; p<0.0001), highlighting the importance of this variable for the shell choice by D. insignis at both sites.
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The best way to detect breast cancer is by screening mammography. The mammography equipments are dedicated and require a rigorous quality control in order to have a good quality image and to early detect this disease. The digital equipment is relatively new in the market and there isn’t a national rule for quality control for several types of digital detectors. This study has proposed to compare two different tests manuals for quality control provided by the manufacturers of digital mammography equipments, and also compare them to the “European guidelines for quality assurance in breast cancer screening and diagnosis “(2006). The studied equipments were: Senographe 2000D from General Electric (GE) and the Hologic Selenia Lorad. Both were digital mammography equipments, the GE unit presents an indirect digital system and the other presents a direct digital system. Physical parameters of the image have been studied, such as spatial resolution, contrast resolution, noise, signal-tonoise ratio, contrast-to-noise ratio and modulation transfer function. After that, a study of the importance of quality control and the requirement to implement a Quality Assurance Program has been done. One data collection was done to compare those manual, it was done by checking which tests are indicated and the minimum frequency which they should be conducted in accordance with each manufacturer. The tests were performed by different methodologies and the results were compared. The examined tests were: the breast entrance skin dose, mean glandular dose, contrast-to-noise ratio, signal-to-noise ratio, automatic exposure control and automatic control of density, modulation transfer function, equipment resolution, homogeneity and ghost
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The reproductive capacity of the swimming crab Callinectes danae Smith, 1869 was assessed based on the reproductive investment (RI) of ovigerous females and the gonadosomatic index (GI) of non-ovigerous adult females. Crabs were collected in June 2009 with a shrimp fishing boat at Ubatuba (23° 26′S 45° 02′W) São Paulo, Brazil. Overall, 191 adult females were analyzed, of which 108 were ovigerous and 83 non-ovigerous. The size of ovigerous females ranged from 54.5 to 79.8 mm carapace width (CW) and non-ovigerous females ranged from 56.0 to 80.9 mm CW. RI values did not differ among the size classes (ANOVA, p > 0.05), with an overall mean of 15.8%. The same occurred with the Gonadossomatic index for non-ovigerous females, for which the mean value was 11.7%. The regression between the dry weight of the egg mass and the dry weight of the crab (Student’s t, p = 0.25; ttab = 1.66; tcal = 0.66) indicated an isometric relationship for the variables analyzed. The simultaneous occurrence of gonadal maturation and embryonic development in ovigerous females suggests that these crabs may spawn at least twice in the same breeding season and reveals the need for evaluation of the allocation of energy in subsequent spawns.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)