2,508 research outputs found
Analysis of the BATSE Continuous MER data
The CGRO/BATSE database includes many types of data such as the 16-channel
continuous background or medium energy resolution burst data (CONT and MER data
types). We have calculated some four hundred burst's medium energy resolution
spectra and Principal Component Analysis has been applied. We found five
components can describe GRBs' spectra.Comment: 4 pages, 2 figures, accepted in Nuovo Ciment
Cosmology with Gamma-Ray Bursts Using k-correction
In the case of Gamma-Ray Bursts with measured redshift, we can calculate the
k-correction to get the fluence and energy that were actually produced in the
comoving system of the GRB. To achieve this we have to use well-fitted
parameters of a GRB spectrum, available in the GCN database. The output of the
calculations is the comoving isotropic energy E_iso, but this is not the
endpoint: this data can be useful for estimating the {\Omega}M parameter of the
Universe and for making a GRB Hubble diagram using Amati's relation.Comment: 4 pages, 6 figures. Presented as a talk on the conference '7th
INTEGRAL/BART Workshop 14 -18 April 2010, Karlovy Vary, Czech Republic'.
Published in Acta Polytechnic
PRODUCT ATTRIBUTE PREFERENCES – A MULTIDISCIPLINARY APPROACH
The basis of buyers’ preferences are the differences of goods. Revealed preferences can be deducted from the market behaviour of the consumers, that is from their choices. In marketing consumer preferences are defined as the subjective tastes, as measured by utility, of various bundles of goods. They permit the consumer to rank these bundles of goods according to the levels of utility they give the consumer. In an expert brainstorming process we have identified eight factors that can determine the perception of product attributes: attribute strengths, preference interval, stability, product complexity, consumer task, lifelikeness, environment and experience. Our series of research plans to analyse the perception of product attributes and the system of the parameters of preferences related to them in a complex way. We aim to investigate preference systems that relate to the system of attributes with a multidisciplinary, multifocus, hierarchic series of surveys. As a first stage in our experimental study we are investigating intransitivity occurring in participants’ preferences during selection between simple, medium complex, and complex products. The participants’ task is to make pair-wise comparisons of preference between specific realizations of each product group. There are two possible versions to show up the pairs of virtual products to the subjects. We show up to the subject those attributes, which are not different, then only those that are different from each other. Using a computer based experimental design every participant has the personalized attribute set
Anisotropy in the sky distributions of the short and intermediate gamma-ray bursts: Breakdown of the cosmological principle?
After the discovery of the anisotropy in the sky-distribution of intermediate
gamma-ray bursts recently also the distribution of the short gamma-ray bursts
is proven to be anisotropic. The impact of these behaviors on the validity of
the cosmological principle is shortly discussed.Comment: 3 pages, 1 figure, to appear in the proceedings of the Sixth
Huntsville Gamma-Ray Burst Symposium, edited by C.A. Meegan, N. Gehrels, and
C. Kouvelioto
Lack of cyclophilin D protects against the development of acute lung injury in endotoxemia.
Sepsis caused by LPS is characterized by an intense systemic inflammatory response affecting the lungs, causing acute lung injury (ALI). Dysfunction of mitochondria and the role of reactive oxygen (ROS) and nitrogen species produced by mitochondria have already been proposed in the pathogenesis of sepsis; however, the exact molecular mechanism is poorly understood. Oxidative stress induces cyclophilin D (CypD)-dependent mitochondrial permeability transition (mPT), leading to organ failure in sepsis. In previous studies mPT was inhibited by cyclosporine A which, beside CypD, inhibits cyclophilin A, B, C and calcineurin, regulating cell death and inflammatory pathways. The immunomodulatory side effects of cyclosporine A make it unfavorable in inflammatory model systems. To avoid these uncertainties in the molecular mechanism, we studied endotoxemia-induced ALI in CypD-/- mice providing unambiguous data for the pathological role of CypD-dependent mPT in ALI. Our key finding is that the loss of this essential protein improves survival rate and it can intensely ameliorate endotoxin-induced lung injury through attenuated proinflammatory cytokine release, down-regulation of redox sensitive cellular pathways such as MAPKs, Akt, and NF-kappaB and reducing the production of ROS. Functional inhibition of NF-kappaB was confirmed by decreased expression of NF-kappaB-mediated proinflammatory genes. We demonstrated that impaired mPT due to the lack of CypD reduces the severity of endotoxemia-induced lung injury suggesting that CypD specific inhibitors might have a great therapeutic potential in sepsis-induced organ failure. Our data highlight a previously unknown regulatory function of mitochondria during inflammatory response
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