950 resultados para variablefrequency drive


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Investigating the mechanisms underlying female mate choice is important for sexual-selection theory, but also for population-genetic studies, because distinctive breeding strategies affect differently the dynamics of gene diversity within populations. Using field-monitoring, genetic-assignment, and laboratory-rearing methods, we investigated chorus attendance, mating success and offspring fitness in a population of lek-breeding tree-frogs (Hyla arborea) to test whether female choice is driven by good genes or complementary genes. Chorus attendance explained approximately 50% of the variance in male mating success, but did not correlate with offspring fitness. By contrast, offspring body mass and growth rate correlated with male attractiveness, measured as the number of matings obtained per night of calling. Genetic similarity between mating partners did not depart from random, and did not affect offspring fitness. We conclude that females are able to choose good partners under natural settings and obtain benefits from the good genes, rather than compatible genes, their offspring inherit. This heritability of fitness is likely to reduce effective population sizes below values previously estimated.

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Tout médecin de premier recours devrait pouvoir se prononcer sur l'aptitude à la conduite automobile de son patient. La problématique du conducteur âgé, dépendant soit de l'alcool ou de drogues, sous traitement de médicaments psychotropes, ou encore diabétique, est abordée à la lumière des dispositions légales et des récentes recommandations. Cet article aborde également les aspects relatifs aux problèmes neurologiques, cardiologiques et orthopédiques. Any primary care doctor should be able to decide on the fitness to drive of a given patient. The issue of an older driver, patients addicted to alcohol or drugs, under current psychotropic drug treatment, or diabetic, is discussed in the light of legal provisions and current recommendations. This article also discusses aspects associated with neurological, cardiac and orthopedic issues.

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Cape Verde is a tropical oceanic ecosystem, highly fragmented and dispersed, with islands physically isolated by distance and depth. To understand how isolation affects the ecological variability in this archipelago, we conducted a research project on the community structure of the 18 commercially most important demersal fishes. An index of ecological distance based on species relative dominance (Di) is developed from Catch Per Unit Effort, derived from an extensive database of artisanal fisheries. Two ecological measures of distance between islands are calculated: at the species level, DDi, and at the community level, DD (sum of DDi). A physical isolation factor (Idb) combining distance (d) and bathymetry (b) is proposed. Covariance analysis shows that isolation factor is positively correlated with both DDi and DD, suggesting that Idb can be considered as an ecological isolation factor. The effect of Idb varies with season and species. This effect is stronger in summer (May to November), than in winter (December to April), which appears to be more unstable. Species react differently to Idb, independently of season. A principal component analysis on the monthly (DDi) for the 12 islands and the 18 species, complemented by an agglomerative hierarchical clustering, shows a geographic pattern of island organization, according to Idb. Results indicate that the ecological structure of demersal fish communities of Cape Verde archipelago, both in time and space, can be explained by a geographic isolation factor. The analytical approach used here is promising and could be tested in other archipelago systems.

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There is a substancial literature on the accounting procedures needed to trackdown the costs of quality control and quality failure. In a drive for improved quality the changes in the process of production or service delivery will also give rise to new accounting needs. In this article we take one example of an industry, wine production, where in most countries there has been a movement towards expanding higher quality production. We report on interviews with wine producers in the US, Australia, Canada, New Zealand and Spain, and identify avariety of ways in which a more sophisticated approach to accounting has become necessary as a result of the drive for quality.

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In the Arabidopsis root meristem, polar auxin transport creates a transcriptional auxin response gradient that peaks at the stem cell niche and gradually decreases as stem cell daughters divide and differentiate [1-3]. The amplitude and extent of this gradient are essential for both stem cell maintenance and root meristem growth [4, 5]. To investigate why expression of some auxin-responsive genes, such as the essential root meristem growth regulator BREVIS RADIX (BRX) [6], deviates from this gradient, we combined experimental and computational approaches. We created cellular-level root meristem models that accurately reproduce distribution of nuclear auxin activity and allow dynamic modeling of regulatory processes to guide experimentation. Expression profiles deviating from the auxin gradient could only be modeled after intersection of auxin activity with the observed differential endocytosis pattern and positive autoregulatory feedback through plasma-membrane-to-nucleus transfer of BRX. Because BRX is required for expression of certain auxin response factor targets, our data suggest a cell-type-specific endocytosis-dependent input into transcriptional auxin perception. This input sustains expression of a subset of auxin-responsive genes across the root meristem's division and transition zones and is essential for meristem growth. Thus, the endocytosis pattern provides specific positional information to modulate auxin response.

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Freud defined the drive as "a concept on the frontier between the mental and the somatic". Today this view that was based on clinical observations interpreted within the psychoanalytical framework, can be revisited in light of the current neuroscientific notions of neuronal plasticity and somatic states. Indeed, through the mechanisms of plasticity experience leaves a trace that forms the neural basis of a representation of the experience. Such a representation R is associated with a somatic state S in the sense taken from the "somatic marker" model of Damasio. Thus, the internal reality of the subject, particularly the unconscious one, is constituted by such connected R's and S's. In the model that we discuss, the posterior insula represents the primary interoceptive cortex where information about somatic states S converges, while in the anterior insula the connection between R and S can take place and establish a neurobiological correlate for the notion of drive. We posit that the re-representations of S associated with R in the anterior insula may correspond to the Vorstellungsrepräsentanz postulated by Freud. We further propose that the tension between R and S established in the anterior insula is discharged according to the notion of drive through the motor arm of the limbic system, namely the anterior cingulate cortex which is heavily connected with the anterior insula.

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Collective behaviour enhances environmental sensing and decision-making in groups of animals. Experimental and theoretical investigations of schooling fish, flocking birds and human crowds have demonstrated that simple interactions between individuals can explain emergent group dynamics. These findings indicate the existence of neural circuits that support distributed behaviours, but the molecular and cellular identities of relevant sensory pathways are unknown. Here we show that Drosophila melanogaster exhibits collective responses to an aversive odour: individual flies weakly avoid the stimulus, but groups show enhanced escape reactions. Using high-resolution behavioural tracking, computational simulations, genetic perturbations, neural silencing and optogenetic activation we demonstrate that this collective odour avoidance arises from cascades of appendage touch interactions between pairs of flies. Inter-fly touch sensing and collective behaviour require the activity of distal leg mechanosensory sensilla neurons and the mechanosensory channel NOMPC. Remarkably, through these inter-fly encounters, wild-type flies can elicit avoidance behaviour in mutant animals that cannot sense the odour--a basic form of communication. Our data highlight the unexpected importance of social context in the sensory responses of a solitary species and open the door to a neural-circuit-level understanding of collective behaviour in animal groups.

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The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: The Drive to Destroy: Removing data from computer hard drives, storage devices & wireless phones

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The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: The Drive to Destroy: Heath Fraud: Protecting Your Wellness and Your Wallet

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The proposed action consists of upgrading Mississippi Drive (Iowa Highway 92) through downtown Muscatine, Iowa. The Mississippi Drive Corridor Project begins south of the Main Street/Grandview Avenue intersection, continuing to the East 2nd Street/Norbert F. Beckey Bridge intersection, which marks the end of the project. It passes through a mix of commercial, residential, Central Business District and industrial land uses. The total length of the project is approximately 1.6 miles, including 19 intersections (6 with traffic signals). Refer to the vicinity map on Figure 1. The current roadway is a 3- to 4-lane, urban facility with both divided and undivided medians. The roadway, ranging from 40 to 64 feet wide, is considered difficult to cross for pedestrians, especially for small children or elderly. The width of this roadway is being considered to be narrowed to improve the accessibility to the downtown from the Mississippi River riverfront area by pedestrians. This project also includes accommodations for bicycles and pedestrians and measures to reduce flooding on the roadway.

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From Proposed Action: "Iowa Northland Regional Council of Governments (INRCOG) and the City of Cedar Falls, in coordination with the Iowa Department of Transportation (Iowa DOT) and the Federal Highway Administration (FHWA), are proposing to upgrade and modernize an approximate 4,900-foot segment of Iowa Highway 57 (IA 57), locally known as West 1st Street, in Cedar Falls, Black Hawk County, Iowa."

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Meiotic drive has attracted much interest because it concerns the robustness of Mendelian segregation and its genetic and evolutionary stability. We studied chromosomal meiotic drive in the common shrew (Sorex araneus, Insectivora, Mammalia), which exhibits one of the most remarkable chromosomal polymorphisms within mammalian species. The open question of the evolutionary success of metacentric chromosomes (Robertsonian fusions) versus acrocentrics in the common shrew prompted us to test whether a segregation distortion in favor of metacentrics is present in female and/or male meiosis. Performing crosses under controlled laboratory conditions with animals from natural populations, we found a clear trend toward a segregation distortion in favor of metacentrics during male meiosis, two chromosome combinations (gm and jl) being significantly preferred over their acrocentric homologs. Apart for one Robertsonian fusion (hi), this trend was absent in female meiosis. We propose a model based on recombination events between twin acrocentrics to explain the difference in transmission ratios of the same metacentric in different sexes and unequal drive of particular metacentrics in the same sex. Pooled data for female and male meiosis revealed a trend toward stronger segregation distortion for larger metacentrics. This is partially in agreement with the frequency of metacentrics occurring in natural populations of a chromosome race showing a high degree of chromosomal polymorphism.

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The Iowa Department of Natural Resources (IDNR) requested the Iowa Department of Public Health (IDPH) Hazardous Waste Site Health Assessment Program to evaluate the health impacts of exposure to soil contaminated with heavy metals at a commercial property located in Cedar Rapids, Iowa. The specific request was to evaluate the health impacts from exposure to contaminants that were above IDNR statewide standards. This health consultation addresses potential health risks to people from exposure to the soil within the property. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.