570 research outputs found

    Effect of type of explosives and physical-mechanical properties of explosive rock on formation of toxic gases in atmosphere of shafts

    Get PDF
    The quality of toxic gases formed during explosive work in underground shafts depends upon the type of explosives and the conditions of explosion. Several types of explosives and rocks were examined. All remaining conditions were maintained the same (sandy-argillaceous stemming, electrical method of explosions, diameter of blast holes, and the direct triggering of charges)

    Nonequilibrium electron spin polarization in a double quantum dot. Lande mechanism

    Full text link
    In moderately strong magnetic fields, the difference in Lande g-factors in each of the dots of a coupled double quantum dot device may induce oscillations between singlet and triplet states of the entangled electron pair and lead to a nonequilibrium electron spin polarization. We will show that this polarization may partially survive the rapid inhomogeneous decoherence due to random nuclear magnetic fields.Comment: New version contains figures. New title better reflects the content of the pape

    Blubber Transciptome Response to Acute Stress Axis Activation Involves Transient Charges in Adipogenesis and Lipolysis in Fast-Adapted Marine Mammal

    Get PDF
    Stress can compromise an animal\u27s ability to conserve metabolic stores and participate in energy-demanding activities that are critical for fitness. Understanding how wild animals, especially those already experiencing physiological extremes (e.g. fasting), regulate stress responses is critical for evaluating the impacts of anthropogenic disturbance on physiology and fitness, key challenges for conservation. However, studies of stress in wildlife are often limited to baseline endocrine measurements and few have investigated stress effects in fasting-adapted species. We examined downstream molecular consequences of hypothalamic-pituitary-adrenal (HPA) axis activation by exogenous adrenocorticotropic hormone (ACTH) in blubber of northern elephant seals due to the ease of blubber sampling and its key role in metabolic regulation in marine mammals. We report the first phocid blubber transcriptome produced by RNAseq, containing over 140,000 annotated transcripts, including metabolic and adipocytokine genes of interest. The acute response of blubber to stress axis activation, measured 2 hours after ACTH administration, involved highly specific, transient (lasting \u3c24 \u3ehours) induction of gene networks that promote lipolysis and adipogenesis in mammalian adipocytes. Differentially expressed genes included key adipogenesis factors which can be used as blubber-specific markers of acute stress in marine mammals of concern for which sampling of other tissues is not possible

    Transcriptome analysis of northern elephant seal (Mirounga angustirostris) muscle tissue provides a novel molecular resource and physiological insights

    Get PDF
    BackgroundThe northern elephant seal, Mirounga angustirostris, is a valuable animal model of fasting adaptation and hypoxic stress tolerance. However, no reference sequence is currently available for this and many other marine mammal study systems, hindering molecular understanding of marine adaptations and unique physiology.ResultsWe sequenced a transcriptome of M. angustirostris derived from muscle sampled during an acute stress challenge experiment to identify species-specific markers of stress axis activation and recovery. De novo assembly generated 164,966 contigs and a total of 522,699 transcripts, of which 68.70% were annotated using mouse, human, and domestic dog reference protein sequences. To reduce transcript redundancy, we removed highly similar isoforms in large gene families and produced a filtered assembly containing 336,657 transcripts. We found that a large number of annotated genes are associated with metabolic signaling, immune and stress responses, and muscle function. Preliminary differential expression analysis suggests a limited transcriptional response to acute stress involving alterations in metabolic and immune pathways and muscle tissue maintenance, potentially driven by early response transcription factors such as Cebpd.ConclusionsWe present the first reference sequence for Mirounga angustirostris produced by RNA sequencing of muscle tissue and cloud-based de novo transcriptome assembly. We annotated 395,102 transcripts, some of which may be novel isoforms, and have identified thousands of genes involved in key physiological processes. This resource provides elephant seal-specific gene sequences, complementing existing metabolite and protein expression studies and enabling future work on molecular pathways regulating adaptations such as fasting, hypoxia, and environmental stress responses in marine mammals

    Correction of Y-Branches on Proton-exchanged Waveguides in Lithium Niobate By Femtosecond Writing Technology

    Get PDF
    Correction Y-branches power dividers of the multi-function integrated optics chips on proton-exchanged waveguides in lithium niobate by the technology of direct femtosecond laser writing were investigated. Optimal correction parameters and their influence on temperature stability of Y-splitter are determined. Keywords: lithium niobate, Y-splitters, proton exchange, femtosecond writing, refractive index, integrated optics

    Application of phenotypic microarrays to environmental microbiology

    Get PDF
    Environmental organisms are extremely diverse and only a small fraction has been successfully cultured in the laboratory. Culture in micro wells provides a method for rapid screening of a wide variety of growth conditions and commercially available plates contain a large number of substrates, nutrient sources, and inhibitors, which can provide an assessment of the phenotype of an organism. This review describes applications of phenotype arrays to anaerobic and thermophilic microorganisms, use of the plates in stress response studies, in development of culture media for newly discovered strains, and for assessment of phenotype of environmental communities. Also discussed are considerations and challenges in data interpretation and visualization, including data normalization, statistics, and curve fitting

    Development and evaluation of the organization`s logistics strategy based on the application of bifurcation theory

    Get PDF
    The article considers the main approaches to the development and evaluation of the organization’s logistics strategy based on the application of bifurcation theory. The paper notes that the greatest competitive advantages in the process of carrying out activities can be obtained by the company when designing a unique logistics strategy based on the individual features of the organization’s logistics system. The authors reveal that the bifurcation theory allows you to determine the conditionality of a qualitative dynamic change in the behavior of a logistics system by an infinitesimal change in certain parameters of the system. As part of the assessment of the organization’s logistics management strategy, bifurcation theory forms the basis for determining shift in the qualitative parameter of the system and makes it possible to assess the effect of this parameter on the behavior of the entire system as a whole and each functional subsystem separately. The study reflects that it is possible to determine the critical values of individual variables, when overcoming which the logistics system itself goes into unstable state. The main concept defining the process of critical transition of the state of the logistic system is the bifurcation point

    Free Energy of an SU(2) Model of (2+1)-dimensional QCD in the Constant Condensate Background

    Get PDF
    Gluon and quark contributions to the thermodynamic potential (free energy) of a (2+1)-dimensional QCD model at finite temperature in the background of a constant homogeneous chromomagnetic field H combined with A_0 condensate are calculated. The role of the tachyonic mode in the gluon energy spectrum is discussed. A possibility of the free energy global minimum generation at nonzero values of H and A_0 condensates is investigated.Comment: LaTeX 2e, 14 pages, 6 eps figures, some miscalculations were correcte

    The Design Optimization and Experimental Investigation of the 4.4 ÎĽm Raman Laser Basedon Hydrogen-filled Revolver Silica Fiber

    Get PDF
    Optical properties of hollow-core revolver fibers are numerically investigated depending on various parameters: the hollow-core diameter, the capillary wall thickness, the values of the minimum gap between the capillaries, the number of capillaries in the cladding and the type of glass (silica and chalcogenide). Preliminary, similar calculations are made for simple models of hollow-core fibers. Based on the obtained results, the optimal design of the revolver fiber for Raman laser frequency conversion (1.56 μm → 4.4 μm in 1H2) was determined. As a result, efficient ns-pulsed 4.42 μm Raman laser based on 1H2-filled revolver silica fiber is realized. Quantum efficiency as high as 36 % is achieved and output average power as high as 250 mW is demonstrated
    • …
    corecore