458 research outputs found

    Inflation with improved D3-brane potential and the fine tunings associated with the model

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    We investigate brane-antibrane inflation in a warped deformed conifold background that includes contributions to the potential arising from imaginary anti-self-dual (IASD) fluxes including the term with irrational scaling dimension discovered recently. We find that the model can give rise to required number of e-foldings; observational constraint on COBE normalization is easily satisfied and low value of the tensor to scalar ratio of perturbations is achieved. We observe that these corrections to the effective potential help in relaxing the severe fine tunings associated with the earlier analysis.Comment: 8 pages, 4 figures; typos corrected, minor clarifications and new refs added, to appear in epj

    Metabolomic ā€œDark Matterā€ Dependent on Peroxisomal Ī²-Oxidation in Caenorhabditis elegans

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    Peroxisomal Ī²-oxidation (pĪ²o) is a highly conserved fat metabolism pathway involved in the biosynthesis of diverse signaling molecules in animals and plants. In Caenorhabditis elegans, pĪ²o is required for the biosynthesis of the ascarosides, signaling molecules that control development, lifespan, and behavior in this model organism. Via comparative mass spectrometric analysis of pĪ²o mutants and wildtype, we show that pĪ²o in C. elegans and the satellite model P. pacificus contributes to life stage-specific biosynthesis of several hundred previously unknown metabolites. The pĪ²o-dependent portion of the metabolome is unexpectedly diverse, e.g., intersecting with nucleoside and neurotransmitter metabolism. Cell type-specific restoration of pĪ²o in pĪ²o-defective mutants further revealed that pĪ²o-dependent submetabolomes differ between tissues. These results suggest that interactions of fat, nucleoside, and other primary metabolism pathways can generate structural diversity reminiscent of that arising from combinatorial strategies in microbial natural product biosynthesis

    Biosynthesis of Modular Ascarosides in C. elegans

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    The nematode Caenorhabditis elegans uses simple building blocks from primary metabolism and a strategy of modular assembly to build a great diversity of signaling molecules, the ascarosides, which function as a chemical language in this model organism. In the ascarosides, the dideoxysugar ascarylose serves as a scaffold to which diverse moieties from lipid, amino acid, neurotransmitter, and nucleoside metabolism are attached. However, the mechanisms that underlie the highly specific assembly of ascarosides are not understood. We show that the acyl-CoA synthetase ACS-7, which localizes to lysosome-related organelles, is specifically required for the attachment of different building blocks to the 4ā€²-position of ascr#9. We further show that mutants lacking lysosome-related organelles are defective in the production of all 4ā€²-modified ascarosides, thus identifying the waste disposal system of the cell as a hotspot for ascaroside biosynthesis

    Experimental avian paramyxovirus serotype-3 infection in chickens and turkeys

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    Avian paramyxoviruses (APMV) are divided into nine serotypes. Newcastle disease virus (APMV-1) is the most extensively characterized, while relatively little information is available for the other APMV serotypes. In the present study, we examined the pathogenicity of two divergent strains of APMV-3, Netherlands and Wisconsin, in (i) 9-day-old embryonated chicken eggs, (ii) 1-day-old specific pathogen free (SPF) chicks and turkeys, and (iii) 2-week-old SPF chickens and turkeys. The mean death time in 9-day-old embryonated chicken eggs was 112Ā h for APMV-3 strain Netherlands and >Ā 168Ā h for strain Wisconsin. The intracerebral pathogenicity index in 1-day-old chicks for strain Netherlands was 0.39 and for strain Wisconsin was zero. Thus, both strains are lentogenic. Both the strains replicated well in brain tissue when inoculated intracerebrally in 1-day-old SPF chicks, but without causing death. Mild respiratory disease signs were observed in 1-day-old chickens and turkeys when inoculated through oculonasal route with either strain. There were no overt signs of illness in 2-weeks-old chickens and turkeys by either strain, although all the birds seroconverted after infection. The viruses were isolated predominantly from brain, lungs, spleens, trachea, pancreas and kidney. Immunohistochemistry studies also showed the presence of large amount of viral antigens in both epithelial and sub-epithelial lining of respiratory and alimentary tracts. Our result suggests systemic spread of APMV-3 even though the viral fusion glycoprotein does not contain the canonical furin proteases cleavage site. Furthermore, there was little or no disease despite systemic viral spread and abundant viral replication in all the tissues tested

    Tissue- and development-stage-specific mRNA and heterogeneous CNV signatures of human ribosomal proteins in normal and cancer samples.

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    Panda A, Yadav A, Yeerna H, et al. Tissue- and development-stage-specific mRNA and heterogeneous CNV signatures of human ribosomal proteins in normal and cancer samples. Nucleic acids research. 2020.We give results from a detailed analysis of human Ribosomal Protein (RP) levels in normal and cancer samples and cell lines from large mRNA, copy number variation and ribosome profiling datasets. After normalizing total RP mRNA levels per sample, we find highly consistent tissue specific RP mRNA signatures in normal and tumor samples. Multiple RP mRNA-subtypes exist in several cancers, with significant survival and genomic differences. Some RP mRNA variations among subtypes correlate with copy number loss of RP genes. In kidney cancer, RP subtypes map to molecular subtypes related to cell-of-origin. Pan-cancer analysis of TCGA data showed widespread single/double copy loss of RP genes, without significantly affecting survival. In several cancer cell lines, CRISPR-Cas9 knockout of RP genes did not affect cell viability. Matched RP ribosome profiling and mRNA data in humans and rodents stratified by tissue and development stage and were strongly correlated, showing that RP translation rates were proportional to mRNA levels. In a small dataset of human adult and fetal tissues, RP protein levels showed development stage and tissue specific heterogeneity of RP levels. Our results suggest that heterogeneous RP levels play a significant functional role in cellular physiology, in both normal and disease states. Ā© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research

    Engineering Temperatureā€Dependent Carrier Concentration in Bulk Composite Materials via Temperatureā€Dependent Fermi Level Offset

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    Precise control of carrier concentration in both bulk and thinā€film materials is crucial for many solidā€state devices, including photovoltaic cells, superconductors, and high mobility transistors. For applications that span a wide temperature range (thermoelectric power generation being a prime example) the optimal carrier concentration varies as a function of temperature. This work presents a modified modulation doping method to engineer the temperature dependence of the carrier concentration by incorporating a nanosize secondary phase that controls the temperatureā€dependent doping in the bulk matrix. This study demonstrates this technique by deā€doping the heavily defectā€doped degenerate semiconductor GeTe, thereby enhancing its average power factor by 100% at low temperatures, with no deterioration at high temperatures. This can be a general method to improve the average thermoelectric performance of many other materials.Temperatureā€dependent modulation doping is demonstrated in a GeTeā€“CuInTe2 composite material. Temperatureā€dependent carrier concentration is achieved by controlling the temperatureā€dependent Fermi level offset between the GeTe matrix and CuInTe2 inclusions. An enhanced average power factor over a wide temperature range is demonstrated.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/1/aenm201701623.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/2/aenm201701623-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/3/aenm201701623_am.pd

    Metabolomic ā€œDark Matterā€ Dependent on Peroxisomal Ī²-Oxidation in Caenorhabditis elegans

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    Peroxisomal Ī²-oxidation (pĪ²o) is a highly conserved fat metabolism pathway involved in the biosynthesis of diverse signaling molecules in animals and plants. In Caenorhabditis elegans, pĪ²o is required for the biosynthesis of the ascarosides, signaling molecules that control development, lifespan, and behavior in this model organism. Via comparative mass spectrometric analysis of pĪ²o mutants and wildtype, we show that pĪ²o in C. elegans and the satellite model P. pacificus contributes to life stage-specific biosynthesis of several hundred previously unknown metabolites. The pĪ²o-dependent portion of the metabolome is unexpectedly diverse, e.g., intersecting with nucleoside and neurotransmitter metabolism. Cell type-specific restoration of pĪ²o in pĪ²o-defective mutants further revealed that pĪ²o-dependent submetabolomes differ between tissues. These results suggest that interactions of fat, nucleoside, and other primary metabolism pathways can generate structural diversity reminiscent of that arising from combinatorial strategies in microbial natural product biosynthesis

    Echocardiographic diagnosis, management and monitoring of pulmonary embolism with right heart thrombus in a patient with myotonic dystrophy: a case report

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    Acute pulmonary embolism (PE) is a common disease which frequently results in life-threatening right ventricular (RV) failure. High-risk PE, presenting with hypotension, shock, RV dysfunction or right heart thrombus is associated with a high mortality, particularly during the first few hours. Accordingly, it is important to commence effective therapy as soon as possible. In the case described in this report, a 49-year-old woman with myotonic dystrophy type 1 presented with acute respiratory failure and hypotension. Transthoracic echocardiography showed signs of right heart failure and a mobile right heart mass highly suspicious of a thrombus. Based on echocardiographic findings, acute thrombolysis was performed resulting in hemodynamic stabilization of the patient and complete resolution of the right heart thrombus. This case underscores the important role of transthoracic echocardiography for the diagnosis, management and monitoring of PE and underlines the efficacy and safety of thrombolysis in the treatment of PE associated with right heart thrombus

    Northern Hemisphere permafrost map based on TTOP modelling for 2000-2016 at 1 km<sup>2 </sup>scale

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    Permafrost is a key element of the cryosphere and an essential climate variable in the Global Climate Observing System. There is no remote-sensing method available to reliably monitor the permafrost thermal state. To estimate permafrost distribution at a hemispheric scale, we employ an equilibrium state model for the temperature at the top of the permafrost (TTOP model) for the 2000ā€“2016 period, driven by remotely-sensed land surface temperatures, down-scaled ERA-Interim climate reanalysis data, tundra wetness classes and landcover map from the ESA Landcover Climate Change Initiative (CCI) project. Subgrid variability of ground temperatures due to snow and landcover variability is represented in the model using subpixel statistics. The results are validated against borehole measurements and reviewed regionally. The accuracy of the modelled mean annual ground temperature (MAGT) at the top of the permafrost is Ā±2ā€ÆĀ°C when compared to permafrost borehole data. The modelled permafrost area (MAGT 0) is around 21ā€ÆƗā€Æ106ā€Ækm2 (22% of exposed land area), which is approximately 2ā€ÆƗā€Æ106ā€Ækm2 less than estimated previously. Detailed comparisons at a regional scale show that the model performs well in sparsely vegetated tundra regions and mountains, but is less accurate in densely vegetated boreal spruce and larch forests

    Noninvasive monitoring of myocardial function after surgical and cytostatic therapy in a peritoneal metastasis rat model: assessment with tissue Doppler and non-Doppler 2D strain echocardiography

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    <p>Abstract</p> <p>Objective</p> <p>We sought to evaluate the impact of different antineoplastic treatment methods on systolic and diastolic myocardial function, and the feasibility estimation of regional deformation parameters with non-Doppler 2D echocardiography in rats.</p> <p>Background</p> <p>The optimal method for quantitative assessment of global and regional ventricular function in rats and the impact of complex oncological multimodal therapy on left- and right-ventricular function in rats remains unclear.</p> <p>Methods</p> <p>90 rats after subperitoneal implantation of syngenetic colonic carcinoma cells underwent different onclogical treatment methods and were diveded into one control group and five treatment groups (with 15 rats in each group): group 1 = control group (without operation and without medication), group 2 = operation group without additional therapy, group 3 = combination of operation and photodynamic therapy, group 4 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with mitomycine, and group 5 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with gemcitabine, group 6 = operation in combination with taurolidin i.p. instillation. Echocardiographic examination with estimation of wall thickness, diameters, left ventricular fractional shortening, ejection fraction, early and late diastolic transmitral and myocardial velocities, radial and circumferential strain were performed 3ā€“4 days after therapy.</p> <p>Results</p> <p>There was an increase of LVEDD and LVESD in all groups after the follow-up period (P = 0.0037). Other LV dimensions, FS and EF as well as diastolic mitral filling parameters measured by echocardiography were not significantly affected by the different treatments. Values for right ventricular dimensions and function remained unchanged, whereas circumferential 2D strain of the inferior wall was slightly, but significantly reduced under the treatment (-18.1 Ā± 2.5 before and -16.2 Ā± 2.9 % after treatment; P = 0.001) without differences between the single treatment groups.</p> <p>Conclusion</p> <p>It is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats under different oncological therapy. The deformation was decreased under overall treatment without influence by one specific therapy. Therefore, deformation assessment with non-Doppler 2D strain echocardiography is more sensitive than conventional echocardiography for assessing myocardial dysfunction in rats under oncological treatment.</p
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