391 research outputs found
Chirocentrodon Bleekerianus (teleostei: Clupeiformes: Pristigasteridae), A Small Predaceous Herring With Folded And Distinctively Oriented Prey In Stomach.
Predaceous fish-eating species of the order Clupeiformes have a large mouth with well-developed teeth, and reach the greatest sizes within their families (up to 90 cm). We found that the pristigasterid Chirocentrodon bleekerianus, a small clupeiform (about 10 cm) from the tropical SW Atlantic, is able to prey on proportionally large clupeoid fishes and caridean shrimps. Fish preys are folded in the stomach of this herring, their heads and tails pointing toward the predator's head. This distinctive orientation of fish prey is also recorded for some small to medium-sized, fish-eating species of the tropical freshwater order Characiformes with canine-like teeth similar to those found in C. bleekerianus.64116516
Minimizing ruin probability under dependencies for insurance pricing
In this work the ruin probability of the Lundberg risk process is used as a criterion for determining the optimal security loading of premia in the presence of price-sensitive demand for insurance. Both single and aggregated claim processes are considered and the independent and the dependent cases are analyzed. For the single-risk case, we show that the optimal loading does not depend on the initial reserve. In the multiple risk case we account for arbitrary dependency structures between different risks and for dependencies between the probabilities of a client acquiring policies for different risks. In this case, the optimal loadings depend on the initial reserve. In all cases the loadings minimizing the ruin probability do not coincide with the loadings maximizing the expected profitinfo:eu-repo/semantics/publishedVersio
Association of TNF-\u3b1, CTLA4, and PTPN22 polymorphisms with type 1 diabetes and other autoimmune diseases in Brazil
Type 1 diabetes mellitus (T1D) is a complex disorder characterized by an autoimmune response against human pancreatic beta-cells. Patients with T1D can also develop a response toward one or more other factors, such as in autoimmune thyroiditis (AITD) and celiac disease (CD). In the presence of T1D + AITD, the patient is diagnosed with autoimmune polyglandular syndrome type III (APSIII); patients with APSIII may also present with CD. These diseases have a strong genetic component and share many susceptibility genes, suggesting potentially overlapping pathogenic pathways. Polymorphisms in the TNF-\u3b1(rs1800629), CTLA-4 (rs231775), and PTPN22 (rs2476601) genes have been previous associated with T1D; however, there is no consensus regarding their role in T1D and scarce literature focusing on AIDT and/or CD. Thus, we analyzed these genetic variants in 205 Northeast Brazilian patients with T1D and with/without AITD and/or CD, and in 308 healthy controls. The PTPN22 gene variants were associated with T1D susceptibility and APSIII [odds ratio (OR) = 2.57 and 2.77, respectively]. CTLA4 rs231775 and TNF-\u3b1rs1800629 were not associated with T1D onset in the Brazilian population. However, when comparing APSIII individuals in the T1D only group, we observed an association of the TNF-\u3b1SNP in the allelic (P = 0.0442; OR = 0.44) and dominant models (P = 0.0387; OR = 0.40). This study reinforces the importance of CTLA-4 and other variants in unraveling the pathogenic mechanisms of T1D in different populations and in understanding their relationships with the development of other T1D-related autoimmune diseases
Diskitis in children: study of eight cases
The authors report the study of eight children with diskitis diagnosed through clinical, neurogical and orthopedic evaluation. The evidence of self limiting inflammation or infection of the intervertebral disk space and of soft tissue were avaliable by image studies. Findings with routine roentgenograms, computed tomography and magnetic resonance imaging are discussed.Os autores apresentam o estudo de oito crianças com diagnóstico de discite estabelecido através da avaliação clínica, neurológica e ortopédica. A comprovação de alterações inflamatórias em um espaço discal, vertebral e em tecidos moles foi possível em estudos por imagem, sendo discutidos aqueles obtidos por radiologia convencional, tomografia computadorizada e ressonância magnética.53553
Torque-angle-velocity relationships and muscle performance of professional and youth soccer players
Soccer matches consist of a variety of different activities, including repeated sprints. Time to attain velocity (TTAV), load range (LR) and the torque-angle-velocity relationship (TAV3D) represent an important measurement of muscle performance however there are few studies related. The aim of this study was to compare these outcomes between soccer players of different age category. Seventeen professional (PRO) and seventeen under-17 (U17) soccer players were assessed for concentric knee flexion/extension at 60, 120 and 300 °/s. For the extensor muscles, differences were found in favor of the U17 group for TTAV and LR outcomes at 120 °/s, however, the PRO group maintained higher torques in both movement directions in comparison to the U17 in TAV3D evaluation. These results suggest that muscle performance of the PRO group is more efficient than the U17 group
Meta-analysis of STAT4 and IFIH1 polymorphisms in type 1 diabetes mellitus patients with autoimmune polyglandular syndrome type III
Type 1 diabetes mellitus (T1D) is an organ-specific autoimmune disease characterized by T-cell mediated self-destruction of insulin-producing \u3b2 cells in the pancreas. T1D patients are prone to develop other glandular autoimmune disorders, such as autoimmune thyroid disease that occurs simultaneously with autoimmune polyglandular syndrome type III (APSIII). Signal transducer and activator of transcription 4 (STAT4) is a well-known regulator of proinflammatory cytokines, and interferon-induced with helicase C domain 1 (IFIH1) is activated in the interferon type I response. Both genes have been examined separately in autoimmune diseases and, in this study, we assessed their joint role in T1D and APSIII. We conducted a case-control study, enrolling 173 T1D patients and 191 healthy controls from northeastern Brazil, to assess the distribution of the rs7574865 and rs3024839 SNPs in STAT4 and the rs3747517 and rs1990760 SNPs in IFIH1 in T1D and APSIII patients. Additionally, we conducted a meta-analysis with the rs7574865 SNP in STAT4 (1392 T1D patients and 1629 controls) and the rs1990760 SNP in IFIH1 (25092 T1D patients and 28544 controls) to examine their association with T1D. Distribution of STAT4 and IFIH1 allelic frequencies did not show statistically significant differences between T1D patients and controls in our study population; however, the meta-analysis indicated that SNPs in STAT4 and IFIH1 are associated with T1D worldwide. Our findings indicate that although STAT4 and IFIH1 SNPs are not associated with T1D in a Brazilian population, they might play a role in susceptibility to T1D on a larger worldwide scale
Spatial and seasonal variations in the stable carbon isotopic composition of methane in stream sediments of eastern Amazonia
The stable carbon isotopic composition of methane (δ13 C-CH4) gas bubbles formed in the sediments of three Amazonian streams was determined over a 5-yr period. The study sites were two ' 'várzea' floodplain (Açu and Maicá) and one 'terra-firme' (Jamaraquá) streams. The δ 13C of sedimentary organic matter (SOM) from the surrounding vegetation and bottom sediments were also determined. The mean δ13C value of SOM was lower in the terra-firme (-29.6‰) than in the várzea stream (-23.8‰) as a result of less C4 plant deposition in the former. The δ 13C-CH4 values varied systematically both seasonally and spatially among the sites during all 5 yr of the study, in association with changes during hydrologic cycle. Overall, the variation in values of δ 13C-CH4 during the high water phase covered a narrower range of values, -63 to -56‰. Contrastively, during the low water phase the δ 13C-CH4 values for várzea and terra-firme streams are different and are in direct opposition. At this phase, the δ13C-CH4 at terra-firme stream is at least 20‰ depleted of 13C compared to várzea streams. Changes in organic matter sources, water levels and associated microbial degradation processes control the observed seasonal and spatial variations in net stable carbon isotopic composition of methane
Demonstration of the temporal matter-wave Talbot effect for trapped matter waves
We demonstrate the temporal Talbot effect for trapped matter waves using
ultracold atoms in an optical lattice. We investigate the phase evolution of an
array of essentially non-interacting matter waves and observe matter-wave
collapse and revival in the form of a Talbot interference pattern. By using
long expansion times, we image momentum space with sub-recoil resolution,
allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure
Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at \snn=130 GeV
Mid-rapidity transverse mass spectra and multiplicity densities of charged
and neutral kaons are reported for Au+Au collisions at \snn=130 GeV at RHIC.
The spectra are exponential in transverse mass, with an inverse slope of about
280 MeV in central collisions. The multiplicity densities for these particles
scale with the negative hadron pseudo-rapidity density. The charged kaon to
pion ratios are and
for the most central collisions. The ratio is lower than the same
ratio observed at the SPS while the is higher than the SPS result.
Both ratios are enhanced by about 50% relative to p+p and +p
collision data at similar energies.Comment: 6 pages, 3 figures, 1 tabl
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