947 resultados para POTENTIAL CONTROL
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Growing evidence indicates that cells of the mononuclear phagocyte lineage, which includes peripheral blood monocytes (PBM) and tissue macrophages, participate in a variety of neurodestructive events and may play a pivotal role in neurodegenerative conditions such as Alzheimer disease. The present study sought to determine whether exposure of PBM to beta-amyloid peptide (A beta), the major protein of the amyloid fibrils that accumulate in the brain in Alzheimer disease, could induce cytopathic activity in these cells upon their subsequent incubation with neural tissue. PBM were incubated with A beta for 3 days, centrifuged and washed to remove traces of cell-free A beta, and then applied to organotypic cultures of rat brain for varying periods of time. By using a cell-viability assay to quantitate neurocytopathic effect, an increase in the ratio of dead to live cells was detected in cultures containing A beta-stimulated PBM versus control PBM (stimulated with either bovine serum albumin or reverse A beta peptide) as early as 3 days after coculture. The ratio of dead to live cells increased further by 10 days of coculture. By 30 days of coculture, the dead to live cell ratio remained elevated, and the intensity of neurocytopathic effect was such that large areas of brain mass dissociated from the cultures. These results indicate that stimulation of PBM with A beta significantly heightens their neurocytopathic activity and highlight the possibility that inflammatory reactions in the brain play a role in the neurodegeneration that accompanies Alzheimer disease.
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Coastal erosion is an important and constant issue facing coastal areas all over the world today. The rate of coastal development over the years has increased, in turn requiring that action be taken to protect structures from the threat of erosion. A review of the causes of coastal erosion and the methods implemented to control it was conducted in order to determine the best course of action in response to coastal erosion issues. The potential positive and negative economic and environmental impacts are key concerns in determining whether or not to restore an eroding beach and which erosion control method(s) to implement. Results focus on providing a comparison of these concerns as well as recommendations for addressing coastal erosion issues.
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Nonnative aquatic species are invasive worldwide. These species adversely affect natural aquatic ecosystems in a variety of ways and can negatively affect agriculture, recreation and industry. This study addresses identification and control of aquatic plant species of concern in Colorado State Parks. Seventeen species identified as potential threats to the parks and safe, effective chemical control methodologies were determined for each species. A matrix was developed to include the plants, appropriate chemical controls and the type of aquatic habitat where chemical use would be safe and effective. The matrix and recommendations for its use will be provided to the Colorado Division of Parks and Outdoor Recreation to develop a management plan under Section 1204 of the National Invasive Species Act.
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Introducción: En España, cerca del 14% de la población es diabética y el 95% corresponde a DM2. Un pobre control glucémico provoca un aumento de la morbilidad y mortalidad. Tres son los pilares en el tratamiento de la DM2: la dieta, la medicación y el ejercicio físico, sin embargo, el potencial de la prescripción de entrenamiento físico no ha sido totalmente explotado. Objetivo: Analizar el efecto de las distintas modalidades de ejercicio físico (AE, RT, Combo, INT) en el control glucémico en pacientes con diabetes mellitus tipo 2. Métodos: La búsqueda bibliográfica se realizó en 3 bases de datos electrónicas (Pubmed, Scopus y Proquest), incluyendo publicaciones desde enero de 2011 hasta mayo de 2014, que realizaran la intervención con AE, RT, Combo o INT, y que midieran la glucemia a través de la glucosa capilar, CGMS o HbA1c. Resultados: Del total de 386 artículos encontrados, 14 cumplieron los criterios de inclusión. Estos artículos fueron clasificados atendiendo a la modalidad de ejercicio físico de la intervención (AE, RT, Combo, INT), y en función de si analizaban el control glucémico como consecuencia del entrenamiento a largo plazo o tras una sesión de entrenamiento. Conclusiones: El AE, RT, Combo e INT muestran eficacia en el control glucémico tanto en el entrenamiento prolongado como en las 24-48h post-entrenamiento. Es necesaria la prescripción de un entrenamiento estructurado con una frecuencia, volumen e intensidad determinados para lograr beneficios en el control glucémico. El combo es la modalidad que obtiene mejores resultados a través del entrenamiento a largo plazo.
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The production of virulence factors by many pathogenic microorganisms depends on the intercellular communication system called quorum sensing, which involves the production and release of signal molecules known as autoinducers. Based on this, new-therapeutic strategies have emerged for the treatment of a variety of infections, such as the enzymatic degradation of signaling molecules, known as quorum quenching (QQ). In this study, we present the screening of QQ activity amongst 450 strains isolated from a bivalve hatchery in Granada (Spain), and the selection of the strain PQQ-42, which degrades a wide range of N-acylhomoserine lactones (AHLs). The selected strain, identified as Alteromonas stellipolaris, degraded the accumulation of AHLs and reduced the production of protease and chitinase and swimming motility of a Vibrio species in co-cultivation experiments in vitro. In the bio-control experiment, strain PQQ-42 significantly reduced the pathogenicity of Vibrio mediterranei VibC-Oc-097 upon the coral Oculina patagonica showing a lower degree of tissue damage (29.25 ± 14.63%) in its presence, compared to when the coral was infected with V. mediterranei VibC-Oc-097 alone (77.53 ± 13.22%). Our results suggest that this AHL-degrading bacterium may have biotechnological applications in aquaculture.
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Standards reduce production costs and increase products’ value to consumers. Standards however entail risks of anti-competitive abuse. After the adoption of a standard, the chosen technology normally lacks credible substitutes. The owner of the patented technology might thus have additional market power relative to locked-in licensees, and might exploit this power to charge higher access rates. In the economic literature this phenomenon is referred to as ‘hold-up’. To reduce the risk of hold-up, standard-setting organisations often require patent holders to disclose their standard-essential patents before the adoption of the standard and to commit to license on fair, reasonable and non-discriminatory (FRAND) terms. The European Commission normally investigates unfair pricing abuse in a standard-setting context if a patent holder who committed to FRAND ex-ante is suspected not to abide to it ex-post. However, this approach risks ignoring a number of potential abuses which are likely harmful for welfare. That can happen if, for example, ex-post a licensee is able to impose excessively low access rates (‘reverse hold-up’) or if a patent holder acquires additional market power thanks to the standard but its essential patents are not encumbered by FRAND commitments, for instance because the patent holder did not directly participate to the standard setting process and was therefore not required by the standard-setting organisations to commit to FRAND ex-ante. A consistent policy by the Commission capable of tackling all sources of harm should be enforced regardless of whether FRAND commitments are given. Antitrust enforcement should hinge on the identification of a distortion in the bargaining process around technology access prices, which is determined by the adoption of the standard and is not attributable to pro-competitive merits of any of the involved players.
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Tese de doutoramento, Farmácia (Biologia Celular e Molecular), Universidade de Lisboa, Faculdade de Farmácia, 2016
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Russia has been Moldova’s main trade partner and Russian capital has accounted for a large part of its foreign investments, dominating in the energy and the banking sectors. Moreover, Russia has been a key job market for Moldovan expatriate workers. In the economic sphere, this is making Moldova unilaterally dependent on Russia. Moscow has been attempting to exploit this situation to put pressure on the authorities in Chișinău for quite some time. In recent months Russia has increasingly used instruments for exerting economic pressure on Moldova, as a means of responding to the current authorities’ pro-Western policy. A key element of this policy was Moldova’s signing on 27 June 2014 of the Association Agreement with the EU (which came into force on 1 September 2014). Over the last year, Russia has implemented a number of import restrictions on Moldovan goods. The aim of the Russian actions is to fuel social disappointment, and ultimately – to prevent the pro-European coalition currently in power from winning the parliamentary elections scheduled for 30 November 2014. Another aim might be to convince the Moldovan authorities to suspend the implementation of the Association Agreement – a plan openly put forward by Vladimir Putin during the CIS summit in Minsk on 10 October 2014. So far, however, the Russian economic sanctions have failed to produce the expected results. Support for the pro-European parties has been high, and there is little chance that the pro-Russian groups might achieve a parliamentary majority. It is not inconceivable, then, that in the upcoming months Moscow might decide to resort to other, more potent instruments of economic pressure such as speculation on the financial market, carried out as part of its de facto control over the banking sector. Another possibility is further tightening of trade restrictions, issuing expatriate workers from Russia or using Moldova’s dependence on Russian energy.
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Small hive beetles (SHBs) are generalists native to sub-Saharan Africa and reproduce in association with honeybees, bumblebees, stingless bees, fruits and meat. The SHB has recently become an invasive species, and introductions have been recorded from America, Australia, Europe and Asia since 1996. hile SHBs are usually considered a minor pest in Africa, they can cause significant damage to social bee colonies in their new ranges. Potential reasons for differential impact include differences in bee behaviour, climate and release from natural enemies. Here, we provide an overview on biology, distribution, pest status, diagnosis, control and prevention to foster adequate mitigation and stimulate future research. SHBs have become a global threat to both apiculture and wild bee populations, but our knowledge of this pest is still limited, reating demand for more research in all areas of its biology.
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Long distance transport of amino acids is mediated by several families of differentially expressed amino acid transporters. The two genes AAP1 and AAP2 encode broad specificity H+-amino acid co-transporters and are expressed to high levels in siliques of Arabidopsis, indicating a potential role in supplying the seeds with organic nitrogen. The expression of both genes is developmentally controlled and is strongly induced in siliques at heart stage of embryogenesis, shortly before induction of storage protein genes. Histochemical analysis of transgenic plants expressing promoter-GUS fusions shows that the genes have non-overlapping expression patterns in siliques. AAP1 is expressed in the endosperm and the cotyledons whereas AAP2 is expressed in the vascular strands of siliques and in funiculi. The endosperm expression of AAP1 during early stages of seed development indicates that the endosperm serves as a transient storage tissue for organic nitrogen. Amino acids are transported in both xylem and phloem but during seed filling are imported only via the phloem. AAP2, which is expressed in the phloem of stems and in the veins supplying seeds, may function in uptake of amino acids assimilated in the green silique tissue, in the retrieval of amino acids leaking passively out of the phloem and in xylem-to-phloem transfer along the path. The promoters provide excellent tools to study developmental, hormonal and metabolic control of nitrogen nutrition during development and may help to manipulate the timing and composition of amino acid import into seeds.
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The synthetic control (SC) method has been recently proposed as an alternative to estimate treatment effects in comparative case studies. The SC relies on the assumption that there is a weighted average of the control units that reconstruct the potential outcome of the treated unit in the absence of treatment. If these weights were known, then one could estimate the counterfactual for the treated unit using this weighted average. With these weights, the SC would provide an unbiased estimator for the treatment effect even if selection into treatment is correlated with the unobserved heterogeneity. In this paper, we revisit the SC method in a linear factor model where the SC weights are considered nuisance parameters that are estimated to construct the SC estimator. We show that, when the number of control units is fixed, the estimated SC weights will generally not converge to the weights that reconstruct the factor loadings of the treated unit, even when the number of pre-intervention periods goes to infinity. As a consequence, the SC estimator will be asymptotically biased if treatment assignment is correlated with the unobserved heterogeneity. The asymptotic bias only vanishes when the variance of the idiosyncratic error goes to zero. We suggest a slight modification in the SC method that guarantees that the SC estimator is asymptotically unbiased and has a lower asymptotic variance than the difference-in-differences (DID) estimator when the DID identification assumption is satisfied. If the DID assumption is not satisfied, then both estimators would be asymptotically biased, and it would not be possible to rank them in terms of their asymptotic bias.
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Issued July 1978.
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Turner-Fairbank Highway Research Center, McLean, Va.
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National Highway Traffic Safety Administration, Washington, D.C.