7,966 research outputs found
Some Grüss' Type Inequalities in 2-Inner Product Spaces and Applications for Determinantal Integral Inequalities
Some new Grüss type inequalities in 2-inner product spaces are given. Using this framework, some determinantal integral inequalities for synchronous functions are also derived
Role of sea ice on satellite-observed chlorophyll-a concentration variations during spring bloom in the East/Japan sea
The relationship between the spring bloom along the Primorye coast and the sea ice of the Tatarskiy Strait in the northern region of the East/Japan Sea, a semi-enclosed marginal sea in the North Pacific, was investigated using the ten-year SeaWiFS chlorophyll-a concentration data and DMSP/SSMI sea ice concentration data from 1998 to 2007. Year-to-year variations in the chlorophyll-a concentrations in the spring were positively correlated with those of the sea ice concentrations in the Tatarskiy Strait in the previous winter with a correlation coefficient of 0.77. Abrupt increases in nutrients, essential for the spring bloom in the upper ocean during spring, were supplied from sea ice-melted waters. Time series of vertical distributions of the nutrients indicated that phosphate concentrations were extremely elevated in the upper ocean (less than 100 m) without any connection to high concentrations in the deep waters below. The water mass from sea ice provided preferable conditions for the spring bloom through changes in the vertical stratification structure of the water columns. Along-coast ratios of stability parameters between two neighboring months clearly showed the rapid progression of the generation of a shallow pycnocline due to fresh water originating from sea ice. This study addressed the importance of the physical environment for biogeochemical processes in semi-enclosed marginal seas affected by local sea ice. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.1166Ysciescopu
Enhanced mitochondrial superoxide scavenging does not Improve muscle insulin action in the high fat-fed mouse
Improving mitochondrial oxidant scavenging may be a viable strategy for the treatment of insulin resistance and diabetes. Mice overexpressing the mitochondrial matrix isoform of superoxide dismutase (sod2(tg) mice) and/or transgenically expressing catalase within the mitochondrial matrix (mcat(tg) mice) have increased scavenging of O2(˙-) and H2O2, respectively. Furthermore, muscle insulin action is partially preserved in high fat (HF)-fed mcat(tg) mice. The goal of the current study was to test the hypothesis that increased O2(˙-) scavenging alone or in combination with increased H2O2 scavenging (mtAO mice) enhances in vivo muscle insulin action in the HF-fed mouse. Insulin action was examined in conscious, unrestrained and unstressed wild type (WT), sod2(tg), mcat(tg) and mtAO mice using hyperinsulinemic-euglycemic clamps (insulin clamps) combined with radioactive glucose tracers following sixteen weeks of normal chow or HF (60% calories from fat) feeding. Glucose infusion rates, whole body glucose disappearance, and muscle glucose uptake during the insulin clamp were similar in chow- and HF-fed WT and sod2(tg) mice. Consistent with our previous work, HF-fed mcat(tg) mice had improved muscle insulin action, however, an additive effect was not seen in mtAO mice. Insulin-stimulated Akt phosphorylation in muscle from clamped mice was consistent with glucose flux measurements. These results demonstrate that increased O2(˙-) scavenging does not improve muscle insulin action in the HF-fed mouse alone or when coupled to increased H2O2 scavenging
Transcriptional Regulator TonEBP Mediates Oxidative Damages in Ischemic Kidney Injury
TonEBP (tonicity-responsive enhancer binding protein) is a transcriptional regulator whose expression is elevated in response to various forms of stress including hyperglycemia, inflammation, and hypoxia. Here we investigated the role of TonEBP in acute kidney injury (AKI) using a line of TonEBP haplo-deficient mice subjected to bilateral renal ischemia followed by reperfusion (I/R). In the TonEBP haplo-deficient animals, induction of TonEBP, oxidative stress, inflammation, cell death, and functional injury in the kidney in response to I/R were all reduced. Analyses of renal transcriptome revealed that genes in several cellular pathways including peroxisome and mitochondrial inner membrane were suppressed in response to I/R, and the suppression was relieved in the TonEBP deficiency. Production of reactive oxygen species (ROS) and the cellular injury was reproduced in a renal epithelial cell line in response to hypoxia, ATP depletion, or hydrogen peroxide. The knockdown of TonEBP reduced ROS production and cellular injury in correlation with increased expression of the suppressed genes. The cellular injury was also blocked by inhibitors of necrosis. These results demonstrate that ischemic insult suppresses many genes involved in cellular metabolism leading to local oxidative stress by way of TonEBP induction. Thus, TonEBP is a promising target to prevent AKI
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The AIM2 inflammasome is critical for innate immunity to Francisella tularensis.
Francisella tularensis, the causative agent of tularemia, infects host macrophages, which triggers production of the proinflammatory cytokines interleukin 1beta (IL-1beta) and IL-18. We elucidate here how host macrophages recognize F. tularensis and elicit this proinflammatory response. Using mice deficient in the DNA-sensing inflammasome component AIM2, we demonstrate here that AIM2 is required for sensing F. tularensis. AIM2-deficient mice were extremely susceptible to F. tularensis infection, with greater mortality and bacterial burden than that of wild-type mice. Caspase-1 activation, IL-1beta secretion and cell death were absent in Aim2(-/-) macrophages in response to F. tularensis infection or the presence of cytoplasmic DNA. Our study identifies AIM2 as a crucial sensor of F. tularensis infection and provides genetic proof of its critical role in host innate immunity to intracellular pathogens
Orbital-selective confinement effect of Ru orbitals in SrRuO ultrathin film
The electronic structure of SrRuO thin film with thickness from 50 to 1
unit cell (u.c.) is investigated via the resonant inelastic x-ray scattering
(RIXS) technique at the O K-edge to unravel the intriguing interplay of orbital
and charge degrees of freedom. We found that orbital-selective quantum
confinement effect (QCE) induces the splitting of Ru orbitals. At the same
time, we observed a clear suppression of the electron-hole continuum across the
metal-to-insulator transition (MIT) occurring at the 4 u.c. sample. From these
two clear observations we conclude that QCE gives rise to a Mott insulating
phase in ultrathin SrRuO films. Our interpretation of the RIXS spectra is
supported by the configuration interaction calculations of RuO clusters.Comment: 7 pages, 7 figure
Is it possible to have CBE from CL-PKE?
Recently, Al-Riyami and Paterson proposed a generic conversion from
CL-PKE (Certificateless Public Key Encryption) to CBE (Certificate
Based Encryption) and claimed that the derived CBE scheme is secure
and even more efficient than the original scheme of Gentry. In this
paper, we show that their conversion is wrong due to the flaw of the
security proof. It leads the new concrete CBE scheme by Al-Riyami
and Paterson to be invalidated. In addition, our result supports the
impossibility to relate both notions in any directions
On the relationship between squared pairings and plain pairings
In this paper, we investigate the relationship between the squared Weil/Tate pairing and the plain Weil/Tate pairing. Along these lines, we first show that the squared pairing for arbitrary chosen point can be transformed into a plain pairing for the trace zero point which has a special form to compute them more efficiently. This transformation requires only a cost of some Frobenius actions. Additionally, we show that the squared Weil pairing can be computed more efficiently for trace zero point and derive an explicit formula for the 4th powered Weil pairing as an optimized version of the Weil pairing
Endogenous Retroelements in Cancer: Molecular Roles and Clinical Approach
Retroelements have been considered as “Junk” DNA although the encyclopedia of DNA elements (ENCODE) project has demonstrated that most of the genome is functional. Since the contribution of LINE1 (L1) and human endogenous retrovirus (HERV) has been suspected to cause human cancers, their regulations and putative molecular functions have been investigated in diverse types of cancer. Their diagnostic, prognostic, and therapeutic potentials have been incessantly proposed using cancer associated or specific properties, such as hypomethylation, increased transcripts, and reverse transcriptase, as well as cancer-associated antigens. This chapter presents the current knowledge on retroelements in various aspects during tumorigenesis and their clinical usage in many cancer studies
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