2,778,609 research outputs found

    Microbial Isolation

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    The importance of isolating a microbe from the environment, such as food (solid substrate), drinks (liquid substrate), and yourself because of the many microbes that are difficult to observe or distinguish directly using the five senses. A sample can contain bacteria or fungi. By isolating, the shape of the colonies and the contents in a sample can be observed. Bacteria from the air and normal flora form colonies with lobate-shaped edges, whereas bacteria found in well water samples form colonies with irregular edges and there are also fungi found in the well water samples

    Isolation and folk physics

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    There is a huge chasm between the notion of lawful determination that figures in fundamental physics, and the notion of causal determination that figures in the "folk physics" of everyday objects. In everyday life, we think of the behavior of an ordinary object as being determined by a small set of simple conditions. But in fundamental physics, no such conditions suffice to determine an ordinary object's behavior. What bridges the chasm is that fundamental physical laws make the folk picture of the world approximately true in certain domains. How? In part, by entailing that many objects are approximately isolated from most of their environments. Dynamical laws yield this result only in conjunction with appropriate statistical assumptions about initial conditions

    Isolation and social instigation in animal models of aggression: effects of an mGLU1 receptor antagonist administration

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    Isolate-induced aggression in male mice is a model widely used in psychoparmacology of aggression. Animals are usually isolated for 30 days and subsequently treated and confronted with an anosmic opponent in a neutral area. For 10 min, the complete agonistic repertoire exhibited by the experimental animals is examined, allowing a detailed analysis of aggressive behaviors and other exploratory and motor behaviors. We have recently investigated the role of glutamate metabotropic receptors (mGluR) in this experimental model. Glutamate is the major excitatory neurotransmitter in the brain and it acts both at ionotropic (NMDA, AMPA and kainate receptors) and mGluRs, which are members of the G-protein-coupled receptor family. Eight mGluRs have been characterized and grouped into three classes: group I (mGlu1 and 5), group II (mGlu2 and 3) and group III (mGlu4, 6, 7 and 8). We have tested selective ligands available for the subtypes of mGluRs. Group I antagonists were the most effective ones reducing aggression, being especially remarkable the antiaggressive action observed after the administration of JNJ16259685 (an mGlu1 selective antagonist; 0.125-8 mg/kg i.p.), that produced a strong reduction of offensive behaviors (threat and attack), without affecting immobility with all doses. In this context, we wonder whether this drug could also reduce forms of intensified-heightened aggression. In recent years there is an increasing interest in studying excessive-abnormal forms of aggression in rodents, with the aim of providing a higher translational value to the observed violence in humans, in which aggression becomes intense, disproportionate and dysfunctional. We select a social instigation model, where mice are exposed to a brief territory intrusion of an adult male mice physically inaccessible. After this social provocation mice are exposed to a second opponent which now is unprotected. Social instigation dramatically increases aggressive behaviors, which renders this model appropriate for investigating the neurobiological mechanisms of excessive aggressive behavior. Therefore, we implemented a social instigation procedure in the isolation-induced aggression model with a double objective: first, to examine whether “instigation” could increase the aggression obtained by social isolation; and second, to evaluate the antiaggressive effect of an mGlu1 antagonist in heightened aggression. For this purpose, an acute dose of JNJ16259685 (0.5 mg/kg) was administrated to socially instigated animals after isolation, as well as to animals only isolated. Our results revealed that social instigation reduced latency of attack and increased the frequency and duration of attacks against not instigated animals, without affecting motor behaviors. Likewise, JNJ16259685 (0.5 mg/kg) administration significantly reduced aggressive behaviors in both cases. Taken together, this study shows that social instigation is an useful experimental procedure that increases significantly the levels of aggression observed in an isolated-induced aggression model, also demonstrating the involvement of mGlu1 receptors in the modulation of normal and heightened aggression in male mice.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Vibration isolation

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    Viewgraphs on vibration isolation are presented. Techniques to control and isolate centrifuge disturbances were identified. Topics covered include: disturbance sources in the microgravity environment; microgravity assessment criteria; life sciences centrifuge; flight support equipment for launch; active vibration isolation system; active balancing system; and fuzzy logic control

    Serializable Snapshot Isolation in PostgreSQL

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    This paper describes our experience implementing PostgreSQL's new serializable isolation level. It is based on the recently-developed Serializable Snapshot Isolation (SSI) technique. This is the first implementation of SSI in a production database release as well as the first in a database that did not previously have a lock-based serializable isolation level. We reflect on our experience and describe how we overcame some of the resulting challenges, including the implementation of a new lock manager, a technique for ensuring memory usage is bounded, and integration with other PostgreSQL features. We also introduce an extension to SSI that improves performance for read-only transactions. We evaluate PostgreSQL's serializable isolation level using several benchmarks and show that it achieves performance only slightly below that of snapshot isolation, and significantly outperforms the traditional two-phase locking approach on read-intensive workloads.Comment: VLDB201

    Epidemic model with isolation in multilayer networks

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    The Susceptible-Infected-Recovered (SIR) model has successfully mimicked the propagation of such airborne diseases as influenza A (H1N1). Although the SIR model has recently been studied in a multilayer networks configuration, in almost all the research the isolation of infected individuals is disregarded. Hence we focus our study in an epidemic model in a two-layer network and we use an isolation parameter w to measure the effect of quarantining infected individuals from both layers during an isolation period tw. We call this process the Susceptible-Infected-Isolated-Recovered (SIIR) model. Using the framework of link percolation we find that isolation increases the critical epidemic threshold of the disease because the time in which infection can spread is reduced. In this scenario we find that this threshold increases with w and tw. When the isolation period is maximum there is a critical threshold for w above which the disease never becomes an epidemic. We simulate the process and find an excellent agreement with the theoretical results.We thank the NSF (grants CMMI 1125290 and CHE-1213217) and the Keck Foundation for financial support. LGAZ and LAB wish to thank to UNMdP and FONCyT (Pict 0429/2013) for financial support. (CMMI 1125290 - NSF; CHE-1213217 - NSF; Keck Foundation; UNMdP; Pict 0429/2013 - FONCyT)Published versio
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