144 research outputs found

    Maternal Postsecondary Education Associated With Improved Cerebellar Growth After Preterm Birth.

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    The preterm cerebellum is vulnerable to impaired development impacting long-term outcome. Preterm newborns (\u3c32 \u3eweeks) underwent serial magnetic resonance imaging (MRI) scans. The association between parental education and cerebellar volume at each time point was assessed, adjusting for age at scan. In 26 infants, cerebellar volumes at term (P = .001), but not birth (P = .4), were associated with 2-year volumes. For 1 cm(3) smaller cerebellar volume (4% total volume) at term, the cerebellum was 3.18 cm(3) smaller (3% total volume) by 2 years. Maternal postsecondary education was not associated with cerebellar volume at term (P = .16). Maternal postsecondary education was a significant confounder in the relationship between term and 2-year cerebellar volumes (P = .016), with higher education associated with improved volumes by 2 years. Although preterm birth has been found to be associated with smaller cerebellar volumes at term, maternal postsecondary education is associated with improved growth detectable by 2 years

    Potential for Post-Fire Recovery of Greater Sage-Grouse Habitat

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    In the western United States, fire has become a significant concern in the management of big sagebrush (Artemisia tridentata Nutt.) ecosystems. This is due to largeā€scale increases in cover of the fireā€prone invasive annual cheatgrass (Bromus tectorum L.) and, concurrently, concerns about declining quantity and quality of habitat for Greater Sageā€grouse (Centrocercus urophasianus). The prevailing paradigm is that fire results in a loss of sageā€grouse habitat on timescales relevant to conservation planning (i.e., 1ā€“20 yr), since sagebrush cover can take many more years to recover postā€fire. However, fire can have effects that improve sageā€grouse habitat, including stimulating perennial grass and forb production. The conditions under which fire results in the permanent loss or enhancement of sageā€grouse habitat are not well understood. We used longā€term data from the Utah Division of Wildlife Resources Range Trend Project to assess shortā€term (1ā€“4 yr postā€treatment) and longā€term (6ā€“10 yr postā€treatment) effects of fire on vegetation cover at 16 sites relative to sageā€grouse habitat vegetation guidelines. Sagebrush cover remained low postā€fire at sites considered historically unsuitable for sageā€grouse (10%) preā€fire sagebrush cover, sagebrush cover decreased to10% cover. Postā€fire sagebrush cover was positively related to elevation. Across all sites, perennial grasses and forbs increased in cover to approximately meet the habitat vegetation guidelines for sageā€grouse. Cheatgrass cover did not change in response to fire, and increased perennial grass cover appears to have played an important role in suppressing cheatgrass. Our results indicate that, while fire poses a potential risk for sageā€grouse habitat loss and degradation, burned sites do not necessarily need to be considered permanently altered, especially if they are located at higher elevation, have high sagebrush cover preā€fire, and are reseeded with perennial grasses and forbs postā€fire. However, our results confirm that fire at more degraded sites, for example, those wit

    Sageā€Grouse Breeding and Late Broodā€Rearing Habitat Guidelines in Utah

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    Delineation, protection, and restoration of habitats provide the basis for endangered and threatened species recovery plans. Species recovery plans typically contain guidelines that provide managers with a scientific basis to designate and manage critical habitats. As such, habitat guidelines are best developed using data that capture the full diversity of ecological and environmental conditions that provide habitat across the speciesā€™ range. However, when baseline information, which fails to capture habitat diversity, is used to develop guidelines, inconsistencies and problems arise when applying those guidelines to habitats within an ecologically diverse landscape. Greater sageā€grouse (Centrocercus urophasianus; sageā€ grouse) populations in Utah, USA, reflect this scenarioā€”published rangeā€wide habitat guidelines developed through a literature synthesis did not include data from the full range of the species. Although all sageā€ grouse are considered sagebrush obligates (Artemisia spp.), the species occupies a diversity of sagebrush communities from shrubā€dominated semideserts in the southwest to more perennial grassā€dominated sagebrushā€steppe in the northeast portions of their distribution. Concomitantly, local ecological site and environmental conditions may limit the ability of managers to achieve broader rangeā€wide habitat guidelines. We combined microsite habitat vegetation parameters from radiomarked sageā€grouse nest and brood locations with stateā€wide spatially continuous vegetation, climatic, and elevation data in a cluster analysis to develop empirically based sageā€grouse habitat guidelines that encompass the range of ecological and environmental variation across Utah. Using this novel approach, we identified 3 distinct clusters of sageā€grouse breeding (i.e., nesting and early broodā€rearing) and late broodā€rearing habitats in Utah. For each cluster, we identified specific vegetation recommendations that managers can use to assess sageā€grouse breeding and late broodā€rearing habitat. Our results provide relevant guidelines to Utahā€™s sageā€grouse populations and are feasible given the unique ecological variation found therein. This approach may have application to other species that occupy diverse habitats and physiographic regions

    Dimension reduction for systems with slow relaxation

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    We develop reduced, stochastic models for high dimensional, dissipative dynamical systems that relax very slowly to equilibrium and can encode long term memory. We present a variety of empirical and first principles approaches for model reduction, and build a mathematical framework for analyzing the reduced models. We introduce the notions of universal and asymptotic filters to characterize `optimal' model reductions for sloppy linear models. We illustrate our methods by applying them to the practically important problem of modeling evaporation in oil spills.Comment: 48 Pages, 13 figures. Paper dedicated to the memory of Leo Kadanof

    Importance of regional variation in conservation planning: a rangewide example of the Greater Sageā€Grouse

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    Abstract We developed rangewide population and habitat models for Greater Sage?Grouse (Centrocercus urophasianus) that account for regional variation in habitat selection and relative densities of birds for use in conservation planning and risk assessments. We developed a probabilistic model of occupied breeding habitat by statistically linking habitat characteristics within 4 miles of an occupied lek using a nonlinear machine learning technique (Random Forests). Habitat characteristics used were quantified in GIS and represent standard abiotic and biotic variables related to sage?grouse biology. Statistical model fit was high (mean correctly classified = 82.0%, range = 75.4?88.0%) as were cross?validation statistics (mean = 80.9%, range = 75.1?85.8%). We also developed a spatially explicit model to quantify the relative density of breeding birds across each Greater Sage?Grouse management zone. The models demonstrate distinct clustering of relative abundance of sage?grouse populations across all management zones. On average, approximately half of the breeding population is predicted to be within 10% of the occupied range. We also found that 80% of sage?grouse populations were contained in 25?34% of the occupied range within each management zone. Our rangewide population and habitat models account for regional variation in habitat selection and the relative densities of birds, and thus, they can serve as a consistent and common currency to assess how sage?grouse habitat and populations overlap with conservation actions or threats over the entire sage?grouse range. We also quantified differences in functional habitat responses and disturbance thresholds across the Western Association of Fish and Wildlife Agencies (WAFWA) management zones using statistical relationships identified during habitat modeling. Even for a species as specialized as Greater Sage?Grouse, our results show that ecological context matters in both the strength of habitat selection (i.e., functional response curves) and response to disturbance

    Classical and revisionary theism on the divine as personal: a rapprochement?

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    To claim that the divine is a person or personal is, according to Richard Swinburne, ā€˜the most elementary claim of theismā€™ (1993, 101). I argue that, whether the classical theistā€™s concept of the divine as a person or personal is construed as an analogy or a metaphor, or a combination of the two, analysis necessitates qualification of that concept such that any differences between the classical theistā€™s concept of the divine as a person or personal and revisionary interpretations of that concept are merely superficial. Thus, either the classical theist has more in common with revisionary theism than he/she might care to admit, or classical theism is a multi-faceted position which encompasses interpretations which some might regard as revisionist. This article also explores and employs the use of a gender-neutral pronoun in talk about God

    The female perspective of personality in a wild songbird: repeatable aggressiveness relates to exploration behaviour

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    ABSTRACT: Males often express traits that improve competitive ability, such as aggressiveness. Females also express such traits but our understanding about why is limited. Intraspecific aggression between females might be used to gain access to reproductive resources but simultaneously incurs costs in terms of energy and time available for reproductive activities, resulting in a trade-off. Although consistent individual differences in female behaviour (i.e. personality) like aggressiveness are likely to influence these reproductive trade-offs, little is known about the consistency of aggressiveness in females. To quantify aggression we presented a female decoy to free-living female great tits (Parus major) during the egg-laying period, and assessed whether they were consistent in their response towards this decoy. Moreover, we assessed whether female aggression related to consistent individual differences in exploration behaviour in a novel environment. We found that females consistently differed in aggressiveness, although first-year females were on average more aggressive than older females. Moreover, conform life history theory predictions, ā€˜fastā€™ exploring females were more aggressive towards the decoy than ā€˜slowā€™ exploring females. Given that personality traits are often heritable, and correlations between behaviours can constrain short term adaptive evolution, our findings highlight the importance of studying female aggression within a multivariate behavioural framework
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