932 resultados para Alan Hill


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There is evidence across several species for genetic control of phenotypic variation of complex traits1, 2, 3, 4, such that the variance among phenotypes is genotype dependent. Understanding genetic control of variability is important in evolutionary biology, agricultural selection programmes and human medicine, yet for complex traits, no individual genetic variants associated with variance, as opposed to the mean, have been identified. Here we perform a meta-analysis of genome-wide association studies of phenotypic variation using ~170,000 samples on height and body mass index (BMI) in human populations. We report evidence that the single nucleotide polymorphism (SNP) rs7202116 at the FTO gene locus, which is known to be associated with obesity (as measured by mean BMI for each rs7202116 genotype)5, 6, 7, is also associated with phenotypic variability. We show that the results are not due to scale effects or other artefacts, and find no other experiment-wise significant evidence for effects on variability, either at loci other than FTO for BMI or at any locus for height. The difference in variance for BMI among individuals with opposite homozygous genotypes at the FTO locus is approximately 7%, corresponding to a difference of ~0.5 kilograms in the standard deviation of weight. Our results indicate that genetic variants can be discovered that are associated with variability, and that between-person variability in obesity can partly be explained by the genotype at the FTO locus. The results are consistent with reported FTO by environment interactions for BMI8, possibly mediated by DNA methylation9, 10. Our BMI results for other SNPs and our height results for all SNPs suggest that most genetic variants, including those that influence mean height or mean BMI, are not associated with phenotypic variance, or that their effects on variability are too small to detect even with samples sizes greater than 100,000.

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The wetland resources of the Queensland coastline have been mapped by the Resource Condition and Trend Unit, Fisheries Group, Department of Primary Industries Queensland. This process is being undertaken in order to provide a baseline dataset for Fish Habitat Area (FHA) declaration, Ramsar site nomination and continued monitoring of these important fish habitats. This report summarises the results of the mapping undertaken from Round Hill Head to Tin Can Inlet. The study was undertaken in order to: 1. document and map the coastal wetland communities from Round Hill Head (24°S) to Tin Can Inlet (26°S); 2. document levels of existing disturbance to and protection of the wetlands; 3. examine existing recreational and commercial fisheries in the region; and 4. evaluate the conservation values of the areas investigated from the viewpoint of fisheries productivity and as habitat for important and/or threatened species.

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The eradication of an invasive plant species can provide substantial ecological and economic benefits by eliminating completely the negative effects of the weed and reducing the high cost of continuing control. A 5-yr program toward the eradication of hill raspberry (Rubus niveus Thunb.) in Santiago Island is evaluated using delimitation and extirpation criteria, as well as assessment of the ecological community response to management techniques. Currently, hill raspberry is located in the humid zone of Santiago island. It is distributed over three main infestations, small patches, and many scattered individuals within an area of approximately 1,000 ha. New infestations are constantly being found; every year, new detections add an area of approximately 175 ha. Adult and juvenile individuals are still found, both beyond and within known infestations. Both plant and seed bank density of hill raspberry decreased over time where infestations were controlled. Species composition in the seed bank and existing vegetation were significantly different between areas under intensive control and adjacent uninvaded forest. After 5 yr of intensive management, delimitation of hill raspberry has not been achieved; new populations are found every year, increasing the infested area that requires management. Off-target effects on native species resulting from control efforts seem to be substantial. Although a vast increase in economic investment would allow intensive searching that might enable all individuals to be found and controlled, the resultant disturbance and off-targets effects could outweigh the conservation benefits of eradication.

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Mechanical hill direct seeding of hybrid rice could be the way to solve the problems of high seeding rates and uneven plant establishment now faced in direct seeded rice; however, it is not clear what the optimum hill seeding density should be for high-yielding hybrid rice in the single-season rice production system. Experiments were conducted in 2010 and 2011 to determine the effects of hill seeding density (25 cm 615 cm, 25 cm 617 cm, 25 cm 619 cm, 25 cm 621 cm, and 25 cm 623 cm; three to five seeds per hill) on plant growth and grain yield of a hybrid variety, Nei2you6, in two fields with different fertility (soil fertility 1 and 2). In addition, in 2012 and 2013, comparisons among mechanical hill seeding, broadcasting, and transplanting were conducted with three hybrid varieties to evaluate the optimum seeding density. With increases in seeding spacing from 25 cm615 cm to 25 cm623 cm, productive tillers per hill increased by 34.2% and 50.0% in soil fertility 1 and 2. Panicles per m2 declined with increases in seeding spacing in soil fertility 1. In soil fertility 2, no difference in panicles per m2 was found at spacing ranging from 25 cm617 cm to 25 cm623 cm, while decreases in the area of the top three leaves and aboveground dry weight per shoot at flowering were observed. Grain yield was the maximum at 25 cm 617 cm spacing in both soil fertility fields. Our results suggest that a seeding density of 25 cm617 cm was suitable for high-yielding hybrid rice. These results were verified through on-farm demonstration experiments, in which mechanical hill-seeded rice at this density had equal or higher grain yield than transplanted rice

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Tutkimukseni kohteena ovat mies- ja naispuoliset tutkijat ja tohtoriopiskelijat, jotka ovat osallistuneet katalyysitutkimukseen keskittyvän tutkimusverkosto IDECAT:in toimintaan. Tutkielmassani pyrin selvittämään, onko naisten ja miesten tutkijanuran välillä eroa ja jos on, niin minkälainen tämä ero on. Pyrin myös saamaan selville, onko naisten tutkijanuralla esteitä ja esiintyykö tiedeyhteisössä sukupuolesta johtuvaa syrjintää. IDECAT (Integrated Design of Catalytic Nanomaterials for a Sustainable Production) on EU-rahoitteinen, kemian tekniikkaan liittyvään katalyysitutkimukseen keskittyvä tutkimusverkosto, johon kuuluu alan tutkimusyksiköitä ja yliopistoja 12 Euroopan maasta. IDECAT:iin kuuluu noin 500-600 henkilöä. Tutkimukseni pohjautuu kahteen kyselytutkimukseen, jotka toteutettiin Internetissä 2009-2010. Ensimmäinen kyselytutkimus oli vastaajien saatavilla loka-marraskuussa 2009 ja siinä selvitettiin IDECAT:in tutkijoiden ja tohtoriopiskelijoiden tasa-arvotilannetta yleisesti. Kyselyyn vastasi 83 henkilöä, joista 51% oli naisia ja 49 % miehiä. Kyselyssä käytettiin strukturoitua kyselylomaketta ja tulokset analysoitiin kvantitatiivisesti SPSS tilasto-ohjelmalla. Tilastollisena menetelmänä käytän ristiintaulukointia. Toinen kyselytutkimus (jatkokysely) keskittyy tiedeyhteisössä tapahtuvaan sukupuolesta johtuvaan syrjintään ja se oli vastaajien saatavilla huhti-toukokuussa 2010. Jatkokyselyn kysymykset ovat avokysymyksiä ja ne analysoitiin laadullisesti. Jatkokyselyyn vastasi 24 henkilöä, joista 6 kuvasi yksityiskohtaisesti syrjintäkokemuksiaan tiedeyhteisössä. Teoreettisena viitekehyksenä käytän tutkimuksessani Joan Ackerin sukupuolittuneen organisaation teoriaa ja siihen liittyviä, organisaation toiminnassa ilmeneviä sukupuolittuneita prosesseja. Sukupuolittuneet prosessit ovat ajattelutapoja , käytäntöjä ja asenteita, joilla sukupuolet erotetaan toisistaan ja joilla tuotetaan sukupuolten välisiä valtasuhteita. Naisten ja miesten tutkijanuran välillä on aineistossani joitakin merkittäviä eroja. Sukupuolesta johtuva syrjintä on yleistä vastaajien keskuudessa ja naiset ovat kokeneet sitä useammin kuin miehet. 67% naisvastaajista ja 37% miesvastaajista on kokenut sukupuolesta johtuvaa syrjintää. Naisvastaajat myös kokevat miehiä useammin, että he eivät saa riittävästi tukea ja kannustusta esimiehiltään. Lisäksi naisia on pyydetty mukaan tieteelliseen yhteistyöhön miehiä harvemmin. Useimmat muuttujat eivät kuitenkaan tuo eroa sukupuolten välille. Tutkijanaiset kokevat ylenemismahdollisuutensa lähes yhtä hyviksi kuin miehet, naiset ja miehet työskentelevät yhtä usein määräaikaisissa tehtävissä ja naiset työskentelevät kokopäiväisesti lähes yhtä usein kuin miehet. Naiset pitävät perheen ja työn yhdistämistä helppona. Sukupuolittuneita prosesseja ilmenee erityisesti sukupuolten väliseen työnjakoon ja sosiaalisen tuen ja vallan jakoon tiedeyhteisössä liittyvissä tilanteissa. Sukupuolittuneisuus ei kuitenkaan ole totaalista, monien kyselyn muuttujien kohdalla sukupuolittumista tai eroa sukupuolten välille ei tullut. Monet kyselyn muuttujat osoittavatkin, että naiset ja miehet kokevat, että heitä kohdellaan melko tasa-arvoisesti. Tietyillä osa-alueilla epätasa-arvoisen kohtelun kokemukset ovat kuitenkin yleisiä, mikä tuottaa ristiriitaisen kuvan tiedeyhteisön tasa-arvotilanteesta. Tämä voi viitata siihen, että tutkijanaisten ja miesten asemat ja roolit tiedeyhteisössä eivät ole pysyviä ja staattisia, vaan aktiivisessa muutoksen tilassa. Tutkijanaisten asemaa tiedeyhteisössä voidaan lisäksi parantaa reagoimalla ja puuttumalla sukupuolesta johtuvaan syrjintään, pitämällä tasa-arvoasioita esillä sekä kiinnittämällä huomiota johtamiskäytäntöihin, esimerkiksi palkkaamalla lisää naisjohtajia. Avainsanat Keywords: Sukupuolittunut organisaatio, sukupuolittuneet prosessit, kyselytutkimus, kvantitatiivinen tutkimus, tiedeyhteisö, sukupuolisyrjintä, tutkijanaiset, naistutkijat, sukupuolten tasa-arvo, gendered organization, academia, female scientists, gender equality

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Spatial information at the landscape scale is extremely important for conservation planning, especially in the case of long-ranging vertebrates. The biodiversity-rich Anamalai hill ranges in the Western Ghats of southern India hold a viable population for the long-term conservation of the Asian elephant. Through rapid but extensive field surveys we mapped elephant habitat, corridors, vegetation and land-use patterns, estimated the elephant population density and structure, and assessed elephant-human conflict across this landscape. GIS and remote sensing analyses indicate that elephants are distributed among three blocks over a total area of about 4600 km(2). Approximately 92% remains contiguous because of four corridors; however, under 4000 km2 of this area may be effectively used by elephants. Nine landscape elements were identified, including five natural vegetation types, of which tropical moist deciduous forest is dominant. Population density assessed through the dung count method using line transects covering 275 km of walk across the effective elephant habitat of the landscape yielded a mean density of 1.1 (95% Cl = 0.99-1.2) elephant/km(2). Population structure from direct sighting of elephants showed that adult male elephants constitute just 2.9% and adult females 42.3% of the population with the rest being subadults (27.4%), juveniles (16%) and calves (11.4%). Sex ratios show an increasing skew toward females from juvenile (1:1.8) to sub-adult (1:2.4) and adult (1:14.7) indicating higher mortality of sub-adult and adult males that is most likely due to historical poaching for ivory. A rapid questionnaire survey and secondary data on elephant-human conflict from forest department records reveals that villages in and around the forest divisions on the eastern side of landscape experience higher levels of elephant-human conflict than those on the western side; this seems to relate to a greater degree of habitat fragmentation and percentage farmers cultivating annual crops in the east. We provide several recommendations that could help maintain population viability and reduce elephant-human conflict of the Anamalai elephant landscape. (C) 2013 Deutsche Gesellschaft far Saugetierkunde. Published by Elsevier GmbH. All rights reserved.

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研究了空间飞行器编队中最具基础性的问题之一,即相对运动的解析表达及Hill方程的适用条件。通过建立相对运动的通解公式,针对不同性质的初值深入地分析了其相对运动轨迹的本质特征,并给出了Hill方程的适用条件。此外,文中还给出了一个新的编队设计简化公式。

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This paper presents the Hill instability analysis of Tension Leg Platform (TLP) tether it, deep sea. The 2-D nonlinear beam model which is Undergoing Coupled axial and transverse vibrations, is applied. The governing equations are reduced to nonlinear Hill equation by use of the Galerkin's method and the modes superposition principle. The Hill instability charted Lip to large parameters is obtained. An important parameter M is defined and can he expressed as the functions of tether length, the platform surge and heave motion amplitudes. Some example studies are performed for various environmental conditions. The results demonstrate that the nonlinear coupling between the axial and transverse vibrations has a significant effect on the response of structure.. It needs to be considered for the accurate dynamic analysis of long TLP tether subjected to the combined platform surge and heave motions.

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methods of lifetime measurement are discussed.

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研究了空间飞行器编队中最具基础性的问题之一,即相对运动的解析表达及Hill方程的适用条件。通过建立相对运动的通解公式,针对不同性质的初值深入地分析了其相对运动轨迹的本质特征,并给出了Hill方程的适用条件。此外,文中还给出了一个新的编队设计简化公式。