970 resultados para Müller
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Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D1), Simpson's dominance (D2), Simpson's evenness (E), and Berger–Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P. lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.
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Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated 1/42,000, 1/43,700 and 1/49,500 SNPs explained 1/421%, 1/424% and 1/429% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/I 2-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants.
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Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
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Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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Measurements of explosive nucleosynthesis yields in core-collapse supernovae provide tests for explosion models. We investigate constraints on explosive conditions derivable from measured amounts of nickel and iron after radioactive decays using nucleosynthesis networks with parameterized thermodynamic trajectories. The Ni/Fe ratio is for most regimes dominated by the production ratio of Ni-58/(Fe-54 + Ni-56), which tends to grow with higher neutron excess and with higher entropy. For SN 2012ec, a supernova (SN) that produced a Ni/Fe ratio of 3.4 +/- 1.2 times solar, we find that burning of a fuel with neutron excess eta approximate to 6 x 10(-3) is required. Unless the progenitor metallicity is over five times solar, the only layer in the progenitor with such a neutron excess is the silicon shell. SNe producing large amounts of stable nickel thus suggest that this deep-lying layer can be, at least partially, ejected in the explosion. We find that common spherically symmetric models of M-ZAMS less than or similar to 13 M-circle dot stars exploding with a delay time of less than one second (M-cut < 1.5 M-circle dot) are able to achieve such silicon-shell ejection. SNe that produce solar or subsolar Ni/Fe ratios, such as SN 1987A, must instead have burnt and ejected only oxygen-shell material, which allows a lower limit to the mass cut to be set. Finally, we find that the extreme Ni/Fe value of 60-75 times solar derived for the Crab cannot be reproduced by any realistic entropy burning outside the iron core, and neutrino-neutronization obtained in electron capture models remains the only viable explanation.
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BACKGROUND: Reactive microglia are commonly seen in retinal degenerative diseases, and neurotoxic microglia responses can contribute to photoreceptor cell death. We and others have previously shown that translocator protein (18 kDa) (TSPO) is highly induced in retinal degenerations and that the selective TSPO ligand XBD173 (AC-5216, emapunil) exerts strong anti-inflammatory effects on microglia in vitro and ex vivo. Here, we investigated whether targeting TSPO with XBD173 has immuno-modulatory and neuroprotective functions in two mouse models of acute retinal degeneration using bright white light exposure.
METHODS: BALB/cJ and Cx3cr1 (GFP/+) mice received intraperitoneal injections of 10 mg/kg XBD173 or vehicle for five consecutive days, starting 1 day prior to exposure to either 15,000 lux white light for 1 h or 50,000 lux focal light for 10 min, respectively. The effects of XBD173 treatment on microglia and Müller cell reactivity were analyzed by immuno-stainings of retinal sections and flat mounts, fluorescence-activated cell sorting (FACS) analysis, and mRNA expression of microglia markers using quantitative real-time PCR (qRT-PCR). Optical coherence tomography (OCT), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stainings, and morphometric analyses were used to quantify the extent of retinal degeneration and photoreceptor apoptosis.
RESULTS: Four days after the mice were challenged with bright white light, a large number of amoeboid-shaped alerted microglia appeared in the degenerating outer retina, which was nearly completely prevented by treatment with XBD173. This treatment also down-regulated the expression of TSPO protein in microglia but did not change the TSPO levels in the retinal pigment epithelium (RPE). RT-PCR analysis showed that the microglia/macrophage markers Cd68 and activated microglia/macrophage whey acidic protein (Amwap) as well as the pro-inflammatory genes Ccl2 and Il6 were reduced after XBD173 treatment. Light-induced degeneration of the outer retina was nearly fully blocked by XBD173 treatment. We further confirmed these findings in an independent mouse model of focal light damage. Retinas of animals receiving XBD173 therapy displayed significantly more ramified non-reactive microglia and more viable arrestin-positive cone photoreceptors than vehicle controls.
CONCLUSIONS: Targeting TSPO with XBD173 effectively counter-regulates microgliosis and ameliorates light-induced retinal damage, highlighting a new pharmacological concept for the treatment of retinal degenerations.
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Background: Poor follow-up after cataract surgery in developing countries makes assessment of operative quality uncertain. We aimed to assess two strategies to measure visual outcome: recording the visual acuity of all patients 3 or fewer days postoperatively (early postoperative assessment), and recording that of only those patients who returned for the final follow-up examination after 40 or more days without additional prompting. Methods: Each of 40 centres in ten countries in Asia, Africa, and Latin America recruited 40-120 consecutive surgical cataract patients. Operative-eye best-corrected visual acuity and uncorrected visual acuity were recorded before surgery, 3 or fewer days postoperatively, and 40 or more days postoperatively. Clinics logged whether each patient had returned for the final follow-up examination without additional prompting, had to be actively encouraged to return, or had to be examined at home. Visual outcome for each centre was defined as the proportion of patients with uncorrected visual acuity of 6/18 or better minus the proportion with uncorrected visual acuity of 6/60 or worse, and was calculated for each participating hospital with results from the early assessment of all patients and the late assessment of only those returning unprompted, with results from the final follow-up assessment for all patients used as the standard. Findings: Of 3708 participants, 3441 (93%) had final follow-up vision data recorded 40 or more days after surgery, 1831 of whom (51% of the 3581 total participants for whom mode of follow-up was recorded) had returned to the clinic without additional prompting. Visual outcome by hospital from early postoperative and final follow-up assessment for all patients were highly correlated (Spearman's rs=0·74, p<0·0001). Visual outcome from final follow-up assessment for all patients and for only those who returned without additional prompting were also highly correlated (rs=0·86, p<0·0001), even for the 17 hospitals with unprompted return rates of less than 50% (rs=0·71, p=0·002). When we divided hospitals into top 25%, middle 50%, and bottom 25% by visual outcome, classification based on final follow-up assessment for all patients was the same as that based on early postoperative assessment for 27 (68%) of 40 centres, and the same as that based on data from patients who returned without additional prompting in 31 (84%) of 37 centres. Use of glasses to optimise vision at the time of the early and late examinations did not further improve the correlations. Interpretation: Early vision assessment for all patients and follow-up assessment only for patients who return to the clinic without prompting are valid measures of operative quality in settings where follow-up is poor. Funding: ORBIS International, Fred Hollows Foundation, Helen Keller International, International Association for the Prevention of Blindness Latin American Office, Aravind Eye Care System. © 2013 Congdon et al. Open Access article distributed under the terms of CC BY.
Magnitude, form and bioavailability of fluvial carbon exports from Irish organic soils under pasture
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Organic soils are widespread in Ireland and vulnerable to degradation via drainage for agriculture. The soil-landuse combination of pasture on organic soils may play a disproportionate role in regional C dynamics but is yet to receive study. Fluvial C fluxes and labile organic fractions were determined for two such sites at nested field (c.4 ha) and subcatchment scales (>40 ha); one relatively dry and nutrient rich, the other wetter and nutrient poor. Field scale flux from the nutrient poor site over 2 years was 38.9 ± 6.6 g C m−2 yr−1 with DIC > DOC > POC at 57, 32 and 11 % respectively, and 72 % DIC was comprised of above equilibrium CO2. At the nutrient rich site, which overlies limestone geology, field scale export over an individual year was 90.4 g C m−2 with DIC > DOC > POC at 49, 42 and 9 %, but with 90 % DIC as bicarbonate. By comparison with the nutrient poor site, the magnitude and composition of inorganic C exports from the nutrient rich site implied considerable export of soil-respiratory C as bicarbonate, and lower evasion losses due to carbonate system buffering. Labile DOC determined using dark incubations indicated small fractions (5–10 %) available for remineralisation over typical downstream transit times of days to weeks. These fractions are probably conservative as photolysis in the environment can increase the proportion of labile compounds via photocleavage and directly remineralise organic matter. This study demonstrates that monitoring at soil–water interfaces can aid capture of total landscape fluvial fluxes by precluding the need to incorporate prior C evasion, although rapid runoff responses at field scales can necessitate high resolution flow proportional, and hydrograph sampling to constrain uncertainty of flux estimates.
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Petaflop architectures are currently being utilized efficiently to perform large scale computations in Atomic, Molecular and Optical Collisions. We solve the Schr\"odinger or Dirac equation for the appropriate collision problem using the R-matrix or R-matrix with pseudo-states approach. We briefly outline the parallel methodology used and implemented for the current suite of Breit-Pauli and DARC codes. In this report, various examples are shown from our theoretical results compared with experimental results obtained from Synchrotron Radiation facilities where the Cray architecture at HLRS is playing an integral part in our computational projects.
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Experimental and theoretical results are reported for photoionization of Ta-like (W+) tungsten ions. Absolute cross sections were measured in the energy range 16–245 eV employing the photon–ion merged-beam setup at the advanced light source in Berkeley. Detailed photon-energy scans at 100 meV bandwidth were performed in the 16–108 eV range. In addition, the cross section was scanned at 50 meV resolution in regions where fine resonance structures could be observed. Theoretical results were obtained from a Dirac–Coulomb R-matrix approach. Photoionization cross section calculations were performed for singly ionized atomic tungsten ions in their 5s25p65d4(5D)6s 6Dj. J = 1/2, ground level and the associated excited metastable levels with J = 3/2, 5/2, 7/2 and 9/2. Since the ion beams used in the experiments must be expected to contain long-lived excited states also from excited configurations, additional cross-section calculations were performed for the second-lowest term, 5d56Sj, J = 5/2, and for the 4F term, 5d36s2 4Fj, with J = 3/2, 5/2, 7/2 and 9/2. Given the complexity of the electronic structure of W+ the calculations reproduce the main features of the experimental cross section quite well.
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A família Nephtyidae é uma das mais frequentes em habitats costeiros e marinhos de todo o mundo. São organismos errantes típicos de sedimentos arenosos e lodosos, ocorrendo frequentemente no domínio costeiro até 100 m de profundidade, e mais raramente em profundidades batiais e abissais. As primeiras espécies descritas foram o Nephtys caeca (Fabricius, 1780) e o N. ciliata (O. F. Müller, 1789), ambas atribuídas inicialmente ao género Nereis e posteriormente transferidas para o género Nephtys por Savigny, em 1818. A família Nephtyidae foi criada em 1851 por Grube para o género Nephtys Cuvier, 1817. No âmbito desta tese é feito um estudo taxonómico e filogenético da família Nephtyidae. O estudo filogenético inclui dados morfológicos e moleculares de 24 taxa representantes dos cinco géneros da família, Nephtys Cuvier, 1817, Aglaophamus Kinberg, 1866, Micronephthys (Friedrich, 1939), Inermonephtys Fauchald, 1967 e Dentinephtys Imajima e Takeda, 1987. A análise evidenciou dois grandes grupos correspondentes aos dois principais géneros, Aglaophamus e Nephtys. Duas espécies do género Nephtys (N. pulchra e N. australiensis) são transferidas para o género Aglaophamus, e consequentemente são propostas novas diagnoses para os géneros. O género Dentinephtys é sinonimizado com Nephtys e um novo género, Bipalponephtys, é descrito para acomodar as espécies Nephtys cornuta, N. danida e Micronephthys neotena. As relações filogenéticas entre os géneros são discutidas. Do estudo taxonómico resultou a revisão da família Nephtyidae para o Sul da Europa (entre o Canal da Mancha e o Mediterrâneo), com a descrição de uma nova espécie, Inermonephtys foretmontardoi. A espécie Micronephthys maryae é sinonimizada com M. stammeri. Para cada espécie são incluídas notas sobre a sua ecologia bem como a distribuição geográfica e batimétrica. São propostas novas diagnoses para os géneros do Sul da Europa bem como uma chave de identificação taxonómica para as espécies desta região. Após uma exaustiva revisão bibliográfica da família, e da observação de material museológico relativo a 44 espécies, foi compilada uma lista completa para a família de 128 espécies, distribuídas por cinco géneros (57 Nephtys, 53 Aglaophamus, sete Micronephthys, oito Inermonephtys e três Bipalponephtys), na qual são incluídas sinonímias e considerações taxonómicas para cada espécie. A espécie Nephtys serrata é sinonimizada com N. serratifolia. São apresentados as distribuições geográficas e batimétricas das diferentes espécies e notas sobre o seu habitat. São também incluídas tabelas de identificação com as principais características taxonómicas das espécies. O valor diagnóstico dos caracteres morfológicos é discutido. Vários problemas taxonómicos são realçados, indicando a necessidade de revisões adicionais para 23 espécies. Este trabalho realça a existência de vários problemas taxonómicos e filogenéticos dentro da família Nephtyidae, podendo ser considerado como a base para estudos futuros. Análises filogenéticas adicionais incluindo dados morfológicos e moleculares de um maior número de espécies vão certamente conduzir a uma melhor avaliação do estatuto e relações entre os géneros dentro da família.
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Enquadrado numa perspectiva sócio-construtivista em Didáctica de Línguas (DL), o presente trabalho propõe-se identificar e descrever as imagens face às línguas estrangeiras, em particular à língua Alemã, e sua aprendizagem, que se manifestam numa determinada comunidade escolar. Com base nas imagens identificadas, pretende-se compreender de que forma elas se relacionam com a dimensão afectiva presente no processo de ensinoaprendizagem, nomeadamente no que diz respeito à relação afectiva que o aprendente vai construindo com o alemão, objecto de estudo. Neste quadro, foram traçadas as seguintes questões de investigação para este trabalho: (1) Que imagens face às línguas escolares (inglês, francês, espanhol, português e, em particular, alemão), se manifestam numa determinada comunidade escolar (considerando os alunos, encarregados de educação, professores, administração da escola e funcionários)?; Como se (inter-) relacionam estas imagens nos diferentes públicos considerados?; (2) De que forma se manifestam as imagens face à língua alemã e sua aprendizagem na interacção em sala de aula de Alemão (LE)? Quais as marcas discursivas que as identificam e tecem?; De que forma estão estas imagens associadas às emoções e (3) Quais as emoções associadas às imagens do Alemão e sua aprendizagem em contexto de sala de aula? A investigação recente em DL sugere que as imagens que um determinado sujeito constrói face a uma dada língua permitem compreender as suas atitudes e comportamentos face à mesma, nomeadamente no que diz respeito à relação afectiva que vai construindo com a língua em causa e sua aprendizagem (cf. ARAÚJO E SÁ & SCHMIDT 2008, DE PIETRO & MÜLLER 1997, MÜLLER 1998, PERREFORT 2001). Estas imagens, enquanto constructos sociais, elaboram-se, revitalizam-se e cristalizam-se na e pela interacção verbal em sala de aula. Nesta perspectiva, o presente trabalho discute os conceitos de imagem/representação face às línguas, relacionandoos com a dimensão afectiva (inegavelmente) presente nos processos de ensino-aprendizagem das LE e à luz de uma abordagem interaccional em DL. A investigação desenrolou-se em duas fases. Numa primeira, aplicou-se um inquérito por questionário a toda uma comunidade escolar (incluindo todos os públicos anteriormente referidos), numa escola secundária com terceiro ciclo em Albergaria-a-Velha, no distrito de Aveiro. Os dados recolhidos foram analisados segundo uma abordagem mista (quantitativa e qualitativa). Os resultados apontam para imagens fortemente escolarizadas, na medida em que os inquiridos parecem considerar as línguas estrangeiras sobretudo enquanto objectos de apropriação em contextos escolares. Identificaram-se imagens homogéneas e consistentes das línguas estrangeiras, evidenciando-se, no que à língua alemã diz respeito, a sua dificuldade. Os resultados relacionam-se com os obtidos noutras investigações realizadas em terreno nacional em DL, corroborando alguns e complementando outros (ARAÚJO E SÁ 2008, SIMÕES 2006, PINTO 2005, MELO 2006 e Projecto Imagens das Línguas na comunicação intercultural: contributos para o desenvolvimento da competência plurilingue). Numa segunda fase, acompanhou-se uma turma de alemão (LE) ao longo de um ano lectivo completo, tendo-se procedido à vídeo-gravação das aulas e, posteriormente, à identificação do que designámos por ‘episódios significativos’, para constituição do corpus de análise. A análise interaccional destes episódios permitiu a identificação de diferentes marcas discursivas (verbais, para-verbais e não-verbais) que indiciam, por um lado, a circulação e (re)construção de imagens face ao alemão e sua aprendizagem e, por outro, a presença de um conjunto de emoções associadas a estas imagens, nos discursos dos aprendentes e da professora. No que diz respeito à imagem da dificuldade do alemão e da sua aprendizagem, cristalizaram-se seis indicadores: (1) a compreensão oral e a pronúncia, (2) o léxico e as palavras compostas (3) os números, (4) a leitura, (5) o sistema de regras gramaticais e, finalmente, (6) a auto-imagem dos alunos enquanto aprendentes de alemão. Os resultados sugerem ainda a associação destas imagens a emoções tendencialmente ‘negativas’ (por exemplo a arrelia e o embaraço), isto é, que se traduzem numa atitude de distanciamento e de evitamento linguístico. Face às conclusões obtidas, propõe-se um conjunto de princípios enquadradores para uma educação em línguas ‘afectivamente consciente’ e capaz de promover imagens mais positivas das línguas e das suas aprendizagens, designadamante do alemão. Considerando-se a diminuição acentuada dos aprendentes de alemão (LE) em contexto escolar nacional nos últimos dez anos, aponta-se para a necessidade de melhor compreender a relação entre a falta de popularidade escolar desta língua e a imagem da sua dificuldade (de aprendizagem).
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Der Versuch, nachrichtendienstliche Fragestellungen unter psychologischen Aspekten zu betrachten, ist auf ein positives Interesse gestoßen. In den beiden Bänden Nachrichtendienstpsychologie 1 (Litzcke, 2003) und 2 (Schwan, 2004) der FH Bund erschienen eine Reihe von Aufsätzen, die ein breites Themenspektrum behandeln. Mit Band 1 wurde eine Struktur eingeführt, die sich bewährt hat, und die daher auch für Band 3 beibehalten wird. Die Beiträge des Bandes 3 lassen sich wie folgt zuordnen: 1) Anwendungen vorhandener Konzepte der Psychologie und aus Nachbardisziplinen in den Nachrichtendiensten. Siehe hierzu die Beiträge von Scherer zur Moderation von Qualitätszirkeln im Bundesnachrichtendienst, von Damm und Litzcke zur Akzeptanz des Sicherheitsakteurs „Europa“, von Schwan zur Bedeutung aggressiven Verhaltens für die Arbeit der Nachrichtendienste, von Löhr zum kognitiven Interview und von Wiesen zu den Möglichkeiten einer Gesprächssteuerung. 2) Übertragung psychologischer Methoden auf das Forschungsgebiet Nachrichtendienste zur Gewinnung neuer Ergebnisse / Konzepte. Siehe hierzu die Beiträge von Müller-Enbergs zu den Motiven für eine geheimdienstliche oder nachrichtendienstliche Kooperation bei den inoffiziellen Mitarbeitern der DDR-Staatssicherheit, von Horn zu den Einsatzmöglichkeiten der Operativen Fallanalyse und von Schmalzl zum Konstrukt Einsatzkompetenz. 3) Generierung eigenständiger psychologischer Erkenntnisse und Methoden im Bereich Nachrichtendienste. Dieser Rubrik ist kein Beitrag des Bandes 3 zuzuordnen. Der Abschlussbeitrag von Freitag zur Anwendbarkeit von Täuschungsprinzipien der Zauberkunst in der nachrichtendienstlichen Arbeit entzieht sich dieser Struktur. Der Beitrag ist mit Augenzwinkern geschrieben und soll auch so gelesen werden. Die Themen der Aufsätze sind nicht auf rein nachrichtendienstliche Aufgabenstellungen beschränkt. So werden beispielsweise auch Querschnittsproblematiken behandelt, die nicht nur einem Arbeitsbereich innerhalb der Nachrichtendienste zuzuordnen wären. Damit werden auch Themen behandelt, die ebenso in anderen Behörden und Institutionen von praktischer Relevanz sein können. So ist beispielsweise die Einrichtung von Qualitätszirkeln kein spezifisches Thema der Nachrichtendienste. Da sich aber auch Nachrichtendienste mit der Qualitätssteigerung ihrer Arbeit befassen, ist es angezeigt, entsprechende Ausarbeitungen in die Reihe Nachrichtendienstpsychologie zu integrieren. Auch in Band 3 werden interdisziplinäre Ansätze und Verknüpfungen mit der Polizeipsychologie vorgestellt, auch wenn die dort entwickelten Erkenntnisse und Methoden nicht ungeprüft auf nachrichtendienstliche Aufgabenstellungen übertragen werden können. Gleichwohl können sich aus dem Kontakt zur Polizeipsychologie Anregungen für die Nachrichtendienstpsychologie ergeben.