950 research outputs found

    Automatic Configuration of Opaque Network Functions in CMS

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    Cloud Management Systems (CMS) such as OpenStack are commonly used to manage IT resources such as computing and storage in large datacenters. Recently, CMS are starting to offer customers also the possibility to customize their network infrastructure, allowing each tenant to build his virtual network made of elementary blocks such as traffic monitors, switches, routers, firewalls, and more. However, tenants have to choose those network services among the list of services made available by the CMS and have no possibilities to customize the applications they want. This paper examines some of the modifications required in CMS to support a tenant-centric network service model, in which each tenant can install and configure their preferred network functions, without being limited to use only the list provided by the CMS. A prototype implementation validates the proposed approach and demonstrates the extent of the modifications in terms of languages and software components

    The role of weighing-bathing sequence and postmenstrual age in eliciting adaptive/maladaptive responses in very low birth weight preterm infants

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    Purpose: In the neonatal intensive care unit, preterm infants are exposed to several stressful stimuli. Inappropriate stimulation led to high risk for short- and long-term neurocognitive disabilities. This study aimed to evaluate whether the sequence of execution of weighing/bathing nursing procedures and postmenstrual age (PMA) have any effect on preterm infants' stress responses. Design and Methods: Prospective cross-sectional study on a sample of 21 preterm infants. Responses to the procedures were assessed using an observational sheet based on Als's Synactive Theory of Development. Autonomic and motor responses were scored according to five-point Likert scales. The order of execution of weighing/bathing nursing procedures and PMA were documented. Effects of weighing/bathing execution sequence and PMA on autonomic and motor response scores were analyzed by linear multiple regression analysis. Results: The sequence of execution had a significant effect on the autonomic score during weighing (p =.035), evidencing more stress when weighing was executed first. A higher level of stress response on the autonomic score during both weighing (p =.015) and bathing (p =.018) procedure was independently associated with a lower infant PMA. Conclusions and Practice Implications: The real-time recognition of adaptive/maladaptive responses allows nurses to personalize their approach to preterm infants, taking into account PMA and adjusting the appropriate sequence of execution of weighing/bathing nursing procedures

    A competitive approach for the reduction of unsaturated compounds based on fungal ene-reductases

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    The aim of this work was to select potential biocatalysts for the reduction of unsaturated compounds. The ability of Gliomastix masseei, Mucor circinelloides, Mucor plumbeus, Penicillium citrinum and Syncephalastrum racemosum to convert structurally diverse substrates was tested, also considering the role of substituents linked to the C=C bond on the process efficiency. All the tested fungi expressed ene-reductase activity when tested with several types of compounds; the ketone derivative was the best substrate, followed by the nitroalkene and the unsaturated aldehyde, whereas the ester was the most recalcitrant to bioreduction. The results highlighted the potential of Mucor circinelloides MUT 44 and Mucor plumbeus MUT 2769 as versatile whole-cell systems; fast and efficient reduction was obtained using these biocatalysts for most of the compounds. Comparative analysis of the substrate spectrum was performed for three Mucor circinelloides strains, and reaction rates and timings were shown to vary, indicating a strong physiological diversity of ene-reductase activity at the intraspecific level

    Thermal convection in fluidized granular systems

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    Thermal convection is observed in molecular dynamic simulation of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a rectangular box. Boundaries introduce no shearing or time dependence, but the energy injection comes from a slip (shear-free) thermalizing base. The top wall is perfectly elastic and lateral boundaries are either elastic or periodic. The observed convection comes from the effect of gravity and the spontaneous granular temperature gradient that the system dynamically develops.Comment: 4 pages, 5 figure

    Meiotic Arrest Compromises Pollen Fertility in an Interspecific Hybrid Between \u3cem\u3eBrachiaria Ruziziensis\u3c/em\u3e X \u3cem\u3eBrachiaria Decumbens\u3c/em\u3e (Gramineae)

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    Disruptions in meiosis, development of the free microspores, microspore mitosis, pollen differentiation or anthesis can result in male-sterile plants (Glover et al., 1998). An understanding of the meiotic process is pivotal to work on reproduction, fertility, genetics and breeding in plants, with serious implications in crop production (Armstrong & Jones, 2003). Some African species of Brachiaria are the most important for pastures in the American tropics due to good adaptation and production. Artificial hybridization is underway in Embrapa to improve production, quality and insect resistance (Valle & Miles, 2001). For a cultivar to be successfully adopted good seed production and pollen viability are required. This paper reports on meiotic abnormalities impairing pollen fertility in a hybrid between B. ruziziensis x B. decumbens

    Hydrodynamic theory for granular gases

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    A granular gas subjected to a permanent injection of energy is described by means of hydrodynamic equations derived from a moment expansion method. The method uses as reference function not a Maxwellian distribution fMf_{\sf M} but a distribution f0=ΦfMf_0 = \Phi f_{\sf M}, such that Φ\Phi adds a fourth cumulant κ\kappa to the velocity distribution. The formalism is applied to a stationary conductive case showing that the theory fits extraordinarily well the results coming from our molecular dynamic simulations once we determine κ\kappa as a function of the inelasticity of the particle-particle collisions. The shape of κ\kappa is independent of the size NN of the system.Comment: 10 pages, 9 figures, more about our research in http://www.cec.uchile.cl/cinetica

    Analysis of Genomic Affinity Between \u3cem\u3eBrachiaria Ruziziensis\u3c/em\u3e and \u3cem\u3eB. Brizantha\u3c/em\u3e Through Meiotic Behaviour

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    Genetic divergence between polyploid hybrids is displayed in chromosome pairing and in the rate of chromosome elimination due to differences in cell cycle between the two combined genomes (Sundberg et al. 1991). In Brachiaria, a genus of African grasses reaching continental proportions as a tropical pasture in Latin America, genome analysis has never been performed. The majority of accessions in this genus is polyploid and apomictic, which restricts breeding. The relative ease of obtaining fertile interspecific hybrids once ploidy barriers are overcome (Pereira et al. 2001) confirms the phylogenetic proximity among B. ruziziensis, B. decumbens and B. brizantha. Hybrids were synthesised using sexual artificial 4x as the female genitor and natural apomictic 4x as the pollen donors. Genome affinity is a pre-requisite for chosen genitors to produce fertile hybrids and plenty of viable seed to assure adoption of the new cultivar. Microsporogenesis of a hybrid between B. ruziziensis and B. brizantha is described in this paper, focusing on the behaviour of both genomes

    Free Thermal Convection Driven by Nonlocal Effects

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    We report and explain a convective phenomenon observed in molecular dynamics simulations that cannot be classified either as a hydrodynamics instability nor as a macroscopically forced convection. Two complementary arguments show that the velocity field by a thermalizing wall is proportional to the ratio between the heat flux and the pressure. This prediction is quantitatively corroborated by our simulations.Comment: RevTex, figures is eps, submited for publicatio
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