918 resultados para maximum contrast analysis
Resumo:
Approximately 350 base pairs (bp) of the mitochondrial 16S rRNA gene were used to study the phylogenetic relationships among 5 genera of the clawed lobster family Nephropidae (infraorder Astacidea), including Homarus, Homarinus, Metanephrops, Nephrops, and Nephropsis. Maximum-parsimony analysis, using a hermit crab, Pagurus pollicaris (infraorder Anomura), as an outgroup. produced a tree topology in which Homarus and Nephrops formed a well-supported clade that excluded Homarinus. The same tree topology was obtained from both neighbor-joining and maximum-likelihood analyses, Some morphological characters that appear synapomorphic for Nephrops and Metanephrops may be due to convergence rather than symplesiomorphy. The current taxonomy, therefore, does not reflect the phylogeny of this group as suggested by the molecular data. More molecular data and studies using homologous morphological characters me needed to reach a better understanding of the phylogenetic history of clawed lobsters.
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El objetivo de este trabajo fue evaluar a campo la efectividad de diferentes tipos de labranzas junto con distintos grados de cobertura vegetal (CV) del suelo sobre el escurrimiento (E) y la pérdida de suelo (Ps). Se seleccionaron 34 sitios experimentales bajo labranza tradicional (LT) y siembra directa (SD), con diferentes niveles de CV (C1- < 49, C2- 50-79% y C3- > 80%). Se utilizó un diseño experimental completamente aleatorizado con 4 tratamientos y desigual número de repeticiones: 1) SD-C3, 2) LT-C3, 3) LT-C2, y 4) LT-C1, resultante de combinar el tipo de labranza con CV. Se realizó un ANOVA (p ≤ 0,05) y un análisis de contrastes ortogonales: 1) SD-C3 vs LT-C3, 2) LT-C1 vs LT-C2, y 3) C3 vs LT-C2+C1. Al cabo de cada simulación de lluvia se obtuvo el E y Ps. Se determinó: contenido de materia orgánica (CMO), contenido hídrico (CH) y densidad aparente del suelo (DA) en los 10 cm superficiales, y la pendiente (P) del terreno. La LT presentó mayor E y Ps en todos tratamientos evaluados respecto de SD. El mayor E (26,8 mm) se registró en LT-C2, y el menor (0,5 mm) en SD-C3. La Ps mostró igual tendencia que el E con 11,6 y 0,1 g respectivamente. Los contrastes mostraron E estadísticamente diferentes para los tres contrastes, mientras la Ps fue estadísticamente diferente en los contrastes Nº 2 y 3. Escurrimiento y Ps se correlacionaron entre sí (R2 = 0,98) y con P (R2 = 0,83 y 0,72 respectivamente). Los resultados obtenidos demuestran la importancia del efecto protector de la CV del suelo. Sin embargo, el CMO y CH, y la P y DA deben ser considerados también en el proceso de E - erosión del suelo.
Resumo:
Electrospray ionization time-of-flight (ESI-TOF) mass spectrometry was used to study the quaternary structure of 4-oxalocrotonate tautomerase (EC 5.3.2; 4OT), and four analogues prepared by total chemical synthesis. Wild-type 4OT is a hexamer of 62 amino acid subunits and contains no cysteine residues. The analogues were: (desPro1)4OT, a truncated construct in which Pro1 was deleted; (Cpc1)4OT in which Pro1 was replaced with cyclopentane carboxylate; a derivative [Met(O)45]4OT in which Met45 was oxidized to the sulfoxide; and an analogue (Nle45)4OT in which Met45 was replaced with norleucine. ESI of (Nle45)4OT, (Cpc1)4OT, and 4OT from solution conditions under which the native enzyme was fully active (5 mM ammonium bicarbonate buffer, pH 7.5) gave the intact hexamer as the major species detected by TOF mass spectrometry. In contrast, analysis of [Met(O)45]4OT and (desPro1)4OT under similar conditions yielded predominantly monomer ions. The ESI-TOF measurements were consistent with structural data obtained from circular dichroism spectroscopy. In the context of kinetic data collected for 4OT and these analogues, ESI-TOF mass spectrometry also provided important evidence for the structural and mechanistic significance of the catalytically important Pro1 residue in 4OT.
Resumo:
Some of the rules for how members of the calmodulin (CaM) superfamily bind to target peptides are revealed by the crystal structure of the regulatory domain of scallop myosin. The structure shows that the IQ motif of the heavy chain in this invertebrate myosin imposes constraints on both the positioning and conformation of the individual lobes of the light chains. In contrast, analysis of the contact residues in the targets bound by Ca(2+)-CaM reveals how the structure of CaM accommodates a broader range of sequences consonant with this protein's functional diversity.
Resumo:
We have studied the effects of food restriction (FR) and substitution of fish oil (FO; omega 3) for corn oil (CO; omega 6) on breast tumor incidence and survival in mouse mammary tumor virus/v-Ha-ras transgenic (Onco) mice. The diets were as follows: group 1, 5% (wt/wt) CO fed ad libitum (AL); group 2, 5% CO, restricted calories (40% fewer calories than AL; FR); group 3, 20% CO fed AL; and group 4, 20% FO fed AL. After 3 years, 40% of FR Onco (group 2) mice were alive, whereas there were no survivors in the other three groups. Similarly, tumor incidence was reduced to 27% (5 out of 18) in FR animals (group 2), whereas it was 83% (11 out of 13) in group 1 mice, 89% (16 out of 18) in group 3 mice, and 71% (10 out of 14) in group 4 mice. These protective effects of FR on survival and tumor incidence were paralleled by higher expression of the tumor suppressor gene p53 (wild type) and free-radical scavenging enzymes (catalase and superoxide dismutase) in breast tumors. Immunoblotting showed less ras gene product, p21, and increased p53 levels in the tumors of FR mice. In addition, FR decreased RNA levels of c-erbB-2, interleukin 6, and the transgene v-Ha-ras in tumors. In contrast, analysis of hepatic mRNA from tumor-bearing FR mice revealed higher expression of catalase, glutathione peroxidase, and superoxide dismutase. Survival and tumor incidence were not influenced significantly by dietary supplementation with FO in place of CO. Taken together, our studies suggest that moderate restriction of energy intake significantly inhibited the development of mammary tumors and altered expression of cytokines, oncogenes, and free-radical scavenging enzymes.
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The combined effects of drought stress and grazing pressure on shaping plant–plant interactions are still poorly understood, while this combination is common in arid ecosystems. In this study we assessed the relative effect of grazing pressure and slope aspect (drought stress) on vegetation cover and soil functioning in semi-arid Mediterranean grassland–shrublands in southeastern Spain. Moreover, we linked these two stress factors to plant co-occurrence patterns at species-pair and community levels, by performing C-score analyses. Vegetation cover and soil functioning decreased with higher grazing pressure and more south-facing (drier) slopes. At the community level, plants at south-facing slopes were negatively associated at no grazing but positively associated at low grazing pressure and randomly associated at high grazing pressure. At north-facing slopes, grazing did not result in a shift in the direction of the association. In contrast, analysis of pairwise species co-occurrence patterns showed that the dominant species Stipa tenacissima and Anthyllis cytisoides shifted from excluding each other to co-occurring with increasing grazing pressure at north-facing slopes. Our findings highlight that for improved understanding of plant interactions along stress gradients, interactions between species pairs and interactions at the community level should be assessed, as these may reveal contrasting results.
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Thesis (Master's)--University of Washington, 2016-06
Resumo:
A restricted maximum likelihood analysis applied to an animal model showed no significant differences (P > 0.05) in pH value of the longissimus dorsi measured at 24 h post-mortem (pH24) between high and low lines of Large White pigs selected over 4 years for post-weaning growth rate on restricted feeding. Genetic and phenotypic correlations between pH24 and production and carcass traits were estimated using all performance testing records combined with the pH24 measurements (5.05–7.02) on slaughtered animals. The estimate of heritability for pH24 was moderate (0.29 ± 0.18). Genetic correlations between pH24 and production or carcass composition traits, except for ultrasonic backfat (UBF), were not significantly different from zero. UBF had a moderate, positive genetic correlation with pH24 (0.24 ± 0.33). These estimates of genetic correlations affirmed that selection for increased growth rate on restricted feeding is likely to result in limited changes in pH24 and pork quality since the selection does not put a high emphasis on reduced fatness.
Resumo:
Our object was to describe the process of coping in King-Kopetzky syndrome and hypothesise how the process is mediated. We used a qualitative study using open-ended interviews. The data were gathered purposefully from 19 cases in the first phase of the study. Accounts were then compared deductively with six accounts from a previous interview-based study. Maximum contrast was sought in cases and in experience of clinical interventions. Participants were recruited from Hearing Therapy services in Bath and North East Somerset Primary Care Trust and The Welsh Hearing Institute. Interviews were conducted in participants’ homes or clinic setting. Coping was determined by the concept that the individual developed about their hearing difficulties. The process of conceptualizing involves reconciling the symptoms experienced with the information obtained from clinicians. The process is mediated by the context in which hearing difficulties occur and the interventions that are received. Forming a coherent concept of hearing difficulties facilitates coping. Clinicians can assist this process by giving patients with King-Kopetzky Syndrome an explanation of the condition.
Resumo:
Since the end of the Cold War, Japan's defense policy and politics has gone through significant changes. Throughout the post cold war period, US-Japan alliance managers, politicians with differing visions and preferences, scholars, think tanks, and the actions of foreign governments have all played significant roles in influencing these changes. Along with these actors, the Japanese prime minister has played an important, if sometimes subtle, role in the realm of defense policy and politics. Japanese prime ministers, though significantly weaker than many heads of state, nevertheless play an important role in policy by empowering different actors (bureaucratic actors, independent commissions, or civil actors), through personal diplomacy, through agenda-setting, and through symbolic acts of state. The power of the prime minister to influence policy processes, however, has frequently varied by prime minister. My dissertation investigates how different political strategies and entrepreneurial insights by the prime minister have influenced defense policy and politics since the end of the Cold War. In addition, it seeks to explain how the quality of political strategy and entrepreneurial insight employed by different prime ministers was important in the success of different approaches to defense. My dissertation employs a comparative case study approach to examine how different prime ministerial strategies have mattered in the realm of Japanese defense policy and politics. Three prime ministers have been chosen: Prime Minister Hashimoto Ryutaro (1996-1998); Prime Minister Koizumi Junichiro (2001-2006); and Prime Minister Hatoyama Yukio (2009-2010). These prime ministers have been chosen to provide maximum contrast on issues of policy preference, cabinet management, choice of partners, and overall strategy. As my dissertation finds, the quality of political strategy has been an important aspect of Japan's defense transformation. Successful strategies have frequently used the knowledge and accumulated personal networks of bureaucrats, supplemented bureaucratic initiatives with top-down personal diplomacy, and used a revitalized US-Japan strategic relationship as a political resource for a stronger prime ministership. Though alternative approaches, such as those that have looked to displace the influence of bureaucrats and the US in defense policy, have been less successful, this dissertation also finds theoretical evidence that alternatives may exist.
Resumo:
Since the end of the Cold War, Japan’s defense policy and politics has gone through significant changes. Throughout the post cold war period, US-Japan alliance managers, politicians with differing visions and preferences, scholars, think tanks, and the actions of foreign governments have all played significant roles in influencing these changes. Along with these actors, the Japanese prime minister has played an important, if sometimes subtle, role in the realm of defense policy and politics. Japanese prime ministers, though significantly weaker than many heads of state, nevertheless play an important role in policy by empowering different actors (bureaucratic actors, independent commissions, or civil actors), through personal diplomacy, through agenda-setting, and through symbolic acts of state. The power of the prime minister to influence policy processes, however, has frequently varied by prime minister. My dissertation investigates how different political strategies and entrepreneurial insights by the prime minister have influenced defense policy and politics since the end of the Cold War. In addition, it seeks to explain how the quality of political strategy and entrepreneurial insight employed by different prime ministers was important in the success of different approaches to defense. My dissertation employs a comparative case study approach to examine how different prime ministerial strategies have mattered in the realm of Japanese defense policy and politics. Three prime ministers have been chosen: Prime Minister Hashimoto Ryutaro (1996-1998); Prime Minister Koizumi Junichiro (2001-2006); and Prime Minister Hatoyama Yukio (2009-2010). These prime ministers have been chosen to provide maximum contrast on issues of policy preference, cabinet management, choice of partners, and overall strategy. As my dissertation finds, the quality of political strategy has been an important aspect of Japan’s defense transformation. Successful strategies have frequently used the knowledge and accumulated personal networks of bureaucrats, supplemented bureaucratic initiatives with top-down personal diplomacy, and used a revitalized US-Japan strategic relationship as a political resource for a stronger prime ministership. Though alternative approaches, such as those that have looked to displace the influence of bureaucrats and the US in defense policy, have been less successful, this dissertation also finds theoretical evidence that alternatives may exist.
Resumo:
Fire activity has varied globally and continuously since the last glacial maximum (LGM) in response to long-term changes in global climate and shorter-term regional changes in climate, vegetation, and human land use. We have synthesized sedimentary charcoal records of biomass burning since the LGM and present global maps showing changes in fire activity for time slices during the past 21,000 years (as differences in charcoal accumulation values compared to pre-industrial). There is strong broad-scale coherence in fire activity after the LGM, but spatial heterogeneity in the signals increases thereafter. In North America, Europe and southern South America, charcoal records indicate less-than-present fire activity during the deglacial period, from 21,000 to ∼11,000 cal yr BP. In contrast, the tropical latitudes of South America and Africa show greater-than-present fire activity from ∼19,000 to ∼17,000 cal yr BP and most sites from Indochina and Australia show greater-than-present fire activity from 16,000 to ∼13,000 cal yr BP. Many sites indicate greater-than-present or near-present activity during the Holocene with the exception of eastern North America and eastern Asia from 8,000 to ∼3,000 cal yr BP, Indonesia and Australia from 11,000 to 4,000 cal yr BP, and southern South America from 6,000 to 3,000 cal yr BP where fire activity was less than present. Regional coherence in the patterns of change in fire activity was evident throughout the post-glacial period. These complex patterns can largely be explained in terms of large-scale climate controls modulated by local changes in vegetation and fuel load
Resumo:
Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness. CO2 concentration constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence on CO2 concentration, the quantitative relationship between atmospheric CO2 concentration and biomass burning is not well understood. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial–interglacial changes in biomass burning to an increase in CO2, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided last glacial maximum (LGM) climate anomalies – that is, differences from the pre-industrial (PI) control climate – from the Palaeoclimate Modelling Intercomparison Project Phase~2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes from biomass burning were corrected for the model's observed prediction biases in contemporary regional average values for biomes. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux at the LGM was in the range of 1.0–1.4 Pg C year-1, about a third less than that modelled for PI time. LGM climate with pre-industrial CO2 (280 ppm) yielded unrealistic results, with global biomass burning fluxes similar to or even greater than in the pre-industrial climate. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on primary production and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.
Resumo:
The aim of this systematic review was to examine the effect of Contrast Water Therapy (CWT) on recovery following exercise induced muscle damage. Controlled trials were identified from computerized literature searching and citation tracking performed up to February 2013. Eighteen trials met the inclusion criteria; all had a high risk of bias. Pooled data from 13 studies showed that CWT resulted in significantly greater improvements in muscle soreness at the five follow-up time points(<6, 24, 48, 72 and 96 hours) in comparison to passive recovery. Pooled data also showed that CWT significantly reduced muscle strength loss at each follow-up time (<6, 24, 48, 72 and 96 hours) in comparison to passive recovery. Despite comparing CWT to a large number of other recovery interventions, including cold water immersion, warm water immersion, compression, active recovery and stretching, there was little evidence for a superior treatment intervention. The current evidence base shows that CWT is superior to using passive recovery or rest after exercise; the magnitudes of these effects may be most relevant to an elite sporting population. There seems to be little difference in recovery outcome between CWT and other popular recovery interventions.
Resumo:
We introduce a framework for population analysis of white matter tracts based on diffusion-weighted images of the brain. The framework enables extraction of fibers from high angular resolution diffusion images (HARDI); clustering of the fibers based partly on prior knowledge from an atlas; representation of the fiber bundles compactly using a path following points of highest density (maximum density path; MDP); and registration of these paths together using geodesic curve matching to find local correspondences across a population. We demonstrate our method on 4-Tesla HARDI scans from 565 young adults to compute localized statistics across 50 white matter tracts based on fractional anisotropy (FA). Experimental results show increased sensitivity in the determination of genetic influences on principal fiber tracts compared to the tract-based spatial statistics (TBSS) method. Our results show that the MDP representation reveals important parts of the white matter structure and considerably reduces the dimensionality over comparable fiber matching approaches.