175 research outputs found

    Social entrainment of the circadian rhythm in the flight activity of the microchiropteran bat Hipposideros speoris

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    1. We investigated the problem of how members of the microchiropteran bat species Hipposideros speoris that live in a true cave clock their flight activity rhythms in the absence of time cues. 2. The bats become restless well in advance of sunset and then fly towards the cavemouth to sample light. 3. We investigated whether each bat roosting 40 m from the cave entrance must sample outside light levels for itself in order to emerge at the appropriate time. Three captive bats were tested and each began activity when the conspecifics left the cave in the evenings. 4. In another series of experiments a solitary bat was held captive in a solitary cave for 50 days and its circadian rhythm was recorded. In the absence of other conspecifics the circadian rhythm 'free ran' with a period shorter than 24 h. 5. We concluded from the results of our studies that there exists a clear-cut case for social synchronization of the circadian rhythms of this cave-dwelling bat

    Semi Quantitative Expression Analysis of Potential Cancer Biomarkers

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    A cancer biomarker refers to a substance or process that is indicative of the presence of cancer it may be a molecule secreted by a tumor or a specific response of the body to the presence of cancer. Background: The aim of the present study is to investigate the feasibility and potential of the molecules Cytokeratin 20, Cytokeratin 17, Cytokeratin 10 and Anillin as tumor specific markers to rapidly detect cancer. Materials and Methods: The expression of biomarkers was analyzed by preparing RNA and synthesized cDNA. Specific primers were synthesized for the biomarkers Cytokeratin 10, Cytokeratin 20 Cytokeratin 17 and Anillin and semi quantitative gene expression was carried out using mMLuv reverse transcriptase. Results: All the three biomarkers showed an enhanced expression compared with normal fibroblasts while the expression of cytokeratin 10 did not show much expression in HCT116 while Cytokeratin 20 and Anillin showed better expression in both cell lines. Conclusion: All the biomarkers showed comparatively good expression indicating the use of these genes as potential makers for detection of cancer

    Direct correlation between the circadian sleep-wakefulness rhythm and time estimation in humans under social and temporal isolation

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    Several bodily functions in humans vary on a 24 h pattern and most of these variations persist with a circadian period of ca 25 h when subjects are studied under conditions of social and temporal isolation. We report in this paper that the estimates of short time intervals (TE) of 2 h are strongly coupled to the circadian rhythm in sleepwakefulness. There is a linear correlation between the number of hours humans stay awake (α) and their estimation of 2 h intervals. The coupling of TE to α appears to obtain only under conditions of physical well-being

    Investigating Bayesian optimization for rail network optimization

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    Optimizing the operation of rail networks using simulations is an on-going task where heuristic methods such as Genetic Algorithms have been applied. However, these simulations are often expensive to compute and consequently, because the optimization methods require many (typically >104) repeat simulations, the computational cost of optimization is dominated by them. This paper examines Bayesian Optimization and benchmarks it against the Genetic Algorithm method. By applying both methods to test-tasks seeking to maximize passenger satisfaction by optimum resource allocation, it is experimentally determined that a Bayesian Optimization implementation finds ‘good’ solutions in an order of magnitude fewer simulations than a Genetic Algorithm. Similar improvement for real-world problems will allow the predictive power of detailed simulation models to be used for a wider range of network optimization tasks. To the best of the authors’ knowledge, this paper documents the first application of Bayesian Optimization within the field of rail network optimization

    Mempelajari Sifat Fisika Sol Karet Cetak Dengan Filler Cangkang Telur Ayam

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    Tujuan penelitian adalah untuk menpelajari sifat fisika sol karet cetak dengan filler cangkang telur ayam. Sifat fisika yang dipelajari meliputi kekerasan, tegangan putus, ketahanan sobek dan ketahanan kikis. Penelitian dilakukan dengan 4 tahap yaitu pembuatan filler cangkang telur ayam, pembuatan sol karet cetak, pengujian sifat fisika dan penilaian secara visual. Perlakuan terdiri dari penggunaan cangkang telur ayam menggantikan filer karbon hitam meliputi perlakuan tanpa penggunaan cangkang telur ayam (A1), penggunaan filler cangkang telur ayam 15 Phr (B1), penggunaan filer cangkang telur ayam 30 Phr (C1) dan penggunaan filler cangkang telur ayam 45 Phr (D1). Hasil penelitian menunjukkan bahwa cangkang telur ayam dapat digunakan sebagai filler pada pembuatan sol karet cetak. Penggunaan filler cangkang telur ayam yang semakin meningkat menghasilkan sol karet cetak dengan kekerasan yang cenderung semakin menurun, tegangan putus yang semakin menurun, ketahanan sobek yang semakin menurun dan ketahanan kikis yang semakin meningkat. Secara fisual sol karet cetak yang dihasilkan dari filler cangkang telur ayam menghasilkan sol karet cetak yang baik (tidak cacat berupa sobek, lubang, lepuh, retak dan goresan)

    The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

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    Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

    A natural product compound inhibits coronaviral replication in vitro by binding to the conserved Nsp9 SARS-CoV-2 protein

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    The Nsp9 replicase is a conserved coronaviral protein that acts as an essential accessory component of the multi-subunit viral replication/transcription complex. Nsp9 is the predominant substrate for the essential nucleotidylation activity of Nsp12. Compounds specifically interfering with this viral activity would facilitate its study. Using a native mass-spectrometry-based approach to screen a natural product library for Nsp9 binders, we identified an ent-kaurane natural product, oridonin, capable of binding to purified SARS-CoV-2 Nsp9 with micromolar affinities. By determining the crystal structure of the Nsp9-oridonin complex, we showed that oridonin binds through a conserved site near Nsp9’s C-terminal GxxxG-helix. In enzymatic assays, oridonin’s binding to Nsp9 reduces its potential to act as substrate for Nsp12’s Nidovirus RdRp-Associated Nucleotidyl transferase (NiRAN) domain. We also showed using in vitro cellular assays oridonin, while cytotoxic at higher doses has broad antiviral activity, reducing viral titer following infection with either SARS-CoV-2 or, to a lesser extent, MERS-CoV. Accordingly, these preliminary findings suggest that the oridonin molecular scaffold may have the potential to be developed into an antiviral compound to inhibit the function of Nsp9 during coronaviral replication

    Altered Gut Microbiome in a Mouse Model of Gulf War Illness Causes Neuroinflammation and Intestinal Injury via Leaky Gut and TLR4 Activation

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    Many of the symptoms of Gulf War Illness (GWI) that include neurological abnormalities, neuroinflammation, chronic fatigue and gastrointestinal disturbances have been traced to Gulf War chemical exposure. Though the association and subsequent evidences are strong, the mechanisms that connect exposure to intestinal and neurological abnormalities remain unclear. Using an established rodent model of Gulf War Illness, we show that chemical exposure caused significant dysbiosis in the gut that included increased abundance of phylum Firmicutes and Tenericutes, and decreased abundance of Bacteroidetes. Several gram negative bacterial genera were enriched in the GWI-model that included Allobaculum sp. Altered microbiome caused significant decrease in tight junction protein Occludin with a concomitant increase in Claudin-2, a signature of a leaky gut. Resultant leaching of gut caused portal endotoxemia that led to upregulation of toll like receptor 4 (TLR4) activation in the small intestine and the brain. TLR4 knock out mice and mice that had gut decontamination showed significant decrease in tyrosine nitration and inflammatory mediators IL1β and MCP-1 in both the small intestine and frontal cortex. These events signified that gut dysbiosis with simultaneous leaky gut and systemic endotoxemia-induced TLR4 activation contributes to GW chemical-induced neuroinflammation and gastrointestinal disturbances
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