1,240 research outputs found

    Cosmological expansion and contraction from Pauli exclusion principle in M0M0-branes

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    We show that the Pauli exclusion principle in a system of M0M0-branes can give rise to the expansion and contraction of the universe which is located on an M3M3-brane. We start with a system of M0M0-branes with high symmetry, which join mutually and form pairs of M1M1-anti-M1M1-branes. The resulting symmetry breaking creates gauge fields that live on the M1M1-branes and play the role of graviton tensor modes, which induce an attractive force between the M1M1 and anti-M1M1 branes. Consequently, the gauge fields that live on the M1M1-branes, and the scalar fields which are attached symmetrically to all parts of these branes, decay to fermions that attach anti-symmetrically to the upper and lower parts of the branes, and hence the Pauli exclusion principle emerges. By closing M1M1-branes mutually, the curvatures produced by parallel spins will be different from the curvatures produced by anti-parallel spins, and this leads to an inequality between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in the bulk region. This behavior is inherited in the M3M3-brane on which the universe is located, and hence this leads to the emergence of the universe expansion and contraction. In this sense, the Pauli exclusion principle rules the cosmic dynamics.Comment: 27 pages. arXiv admin note: text overlap with arXiv:1607.0149

    Multiplier effects on socioeconomic development from investment in renewable energy projects in Egypt: Desertec versus energy for local consumption scenarios

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    Egypt is considering initiatives to deploy renewable energies, such as solar and wind; these would be financed through national and international public funds and private investment. Direct and induced impacts of investments could be significant drivers of socioeconomic development in Egypt, which currently has high level of poverty and unemployment plus volatile economic growth due to recent political upheaval. The initiatives would have two goals: i) export of electricity from renewable sources to Europe; and ii) generation of electricity to satisfy Egypt's growing energy need. We thus posed two research questions: i) what are possible effects of investment in concentrating solar power (CSP), at a scale that would attract national and international policy incentives; and ii) what are effects of investment in CSP compared with the effects of a) the business-as-usual scenario, b) the DESERTEC investment plan, which foresees a large share of electricity being exported to Europe, and c) the national energy targets, under which CSP will be deployed to satisfy local energy demand. Our method is Social Accounting Matrix (SAM) of Egypt and the Leontief Input-Output model. Our results show that even though impacts from investments foreseen by the DESERTEC scenario will be highest in terms of GDP, output will be higher in the case of the scenario aiming to secure local demand of electricity from CSP. However, under this scenario, the income multiplier impacts will be the lowest, compared with the DESERTEC and business-as-usual scenarios

    VLSI low-power digital signal processing

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    Polyunsaturated fatty acids inhibit k<sub>v</sub>1.4 by interacting with positively charged extracellular pore residues

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    Polyunsaturated fatty acids (PUFAs) modulate voltage-gated K(+) channel inactivation by an unknown site and mechanism. The effects of ω-6 and ω-3 PUFAs were investigated on the heterologously expressed K(v)1.4 channel. PUFAs inhibited wild-type K(v)1.4 during repetitive pulsing as a result of slowing of recovery from inactivation. In a mutant K(v)1.4 channel lacking N-type inactivation, PUFAs reversibly enhanced C-type inactivation (K(d), 15–43 μM). C-type inactivation was affected by extracellular H(+) and K(+) as well as PUFAs and there was an interaction among the three: the effect of PUFAs was reversed during acidosis and abolished on raising K(+). Replacement of two positively charged residues in the extracellular pore (H508 and K532) abolished the effects of the PUFAs (and extracellular H(+) and K(+)) on C-type inactivation but had no effect on the lipoelectric modulation of voltage sensor activation, suggesting two separable interaction sites/mechanisms of action of PUFAs. Charge calculations suggest that the acidic head group of the PUFAs raises the pK(a) of H508 and this reduces the K(+) occupancy of the selectivity filter, stabilizing the C-type inactivated state

    Contemporary outcomes of continuous-flow biventricular assist devices.

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    BACKGROUND: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10–30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients. METHODS: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias. RESULTS: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82–97.8%) and 12-month survival was a median of 58.5% (IQR 47.5–62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14–36%), although pump exchange was only 9% (IQR 1.5–12.5%). CONCLUSIONS: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD

    Clinical, Hematologic, and Molecular Findings in Naturally Occurring Babesia canis vogeli

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    Background. Canine babesiosis is a clinically important hemoprotozoan parasite affecting dogs. The goal of this present study was to determine the clinical symptoms and to establish its hematological and microscopic detection and compare it with the PCR findings attained from dogs infected with Babesia canis vogeli. Methodology/Principal Findings. 13-PCR confirmed Babesia-infected dogs were examined; seminested PCR was used to discover the precise type of Babesia and Babesia canis vogeli was the only subspecies detected. The most consistent clinical signs were elevated rectal temperature and a pale mucous membrane. Thrombocytopenia, monocytosis, and lymphocytosis, along with a significant reduction in red cell parameters, were the most commonly recorded hematologic alterations. Microscopic examination revealed the presence of typical large merozoites and trophozoites of B. canis in the ratio 76.92%. Conclusions/Significance. The presumptive diagnosis of canine babesiosis should be based on a fever and anemia, while thrombocytopenia is considered the hallmark of the disease; microscopic examination may not be very revealing in the detection at low parasitemia, but it remains the most rapid confirmatory method. Seminested PCR turned out to be a sensitive and accurate method for diagnosis; during the process of differentiation between Babesia subspecies, only B. canis subsp. vogeli was detected

    Altered regulation of metabolic pathways in human lung cancer discerned by 13C stable isotope-resolved metabolomics (SIRM)

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    <p>Abstract</p> <p>Background</p> <p>Metabolic perturbations arising from malignant transformation have not been systematically characterized in human lung cancers <it>in situ</it>. Stable isotope resolved metabolomic analysis (SIRM) enables functional analysis of gene dysregulations in lung cancer. To this purpose, metabolic changes were investigated by infusing uniformly labeled <sup>13</sup>C-glucose into human lung cancer patients, followed by resection and processing of paired non-cancerous lung and non small cell carcinoma tissues. NMR and GC-MS were used for <sup>13</sup>C-isotopomer-based metabolomic analysis of the extracts of tissues and blood plasma.</p> <p>Results</p> <p>Many primary metabolites were consistently found at higher levels in lung cancer tissues than their surrounding non-cancerous tissues. <sup>13</sup>C-enrichment in lactate, Ala, succinate, Glu, Asp, and citrate was also higher in the tumors, suggesting more active glycolysis and Krebs cycle in the tumor tissues. Particularly notable were the enhanced production of the Asp isotopomer with three <sup>13</sup>C-labeled carbons and the buildup of <sup>13</sup>C-2,3-Glu isotopomer in lung tumor tissues. This is consistent with the transformations of glucose into Asp or Glu via glycolysis, anaplerotic pyruvate carboxylation (PC), and the Krebs cycle. PC activation in tumor tissues was also shown by an increased level of pyruvate carboxylase mRNA and protein.</p> <p>Conclusion</p> <p>PC activation – revealed here for the first time in human subjects – may be important for replenishing the Krebs cycle intermediates which can be diverted to lipid, protein, and nucleic acid biosynthesis to fulfill the high anabolic demands for growth in lung tumor tissues. We hypothesize that this is an important event in non-small cell lung cancer and possibly in other tumor development.</p

    Emergence and patterning dynamics of mouse-definitive endoderm

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    The segregation of definitive endoderm (DE) from bipotent mesendoderm progenitors leads to the formation of two distinct germ layers. Dissecting DE commitment and onset has been challenging as it occurs within a narrow spatiotemporal window in the embryo. Here, we employ a dual Bra/Sox17 reporter cell line to study DE onset dynamics. We find Sox17 expression initiates in vivo in isolated cells within a temporally restricted window. In 2D and 3D in vitro models, DE cells emerge from mesendoderm progenitors at a temporally regular, but spatially stochastic pattern, which is subsequently arranged by self-sorting of Sox17 + cells. A subpopulation of Bra-high cells commits to a Sox17+ fate independent of external Wnt signal. Self-sorting coincides with upregulation of E-cadherin but is not necessary for DE differentiation or proliferation. Our in vivo and in vitro results highlight basic rules governing DE onset and patterning through the commonalities and differences between these systems
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