953 resultados para determinants of plant community diversity and structure


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The current study aimed to investigate whether lack of evidence for the potential reality of the intrusion and ego-dystonicity are contextual determinants of unwanted intrusive thoughts and clinical obsessions. To this end, a total 248 non-clinical participants were asked to report an intrusion they had experienced as well as the context in which the intrusion arose. Utilizing this information, three independent clinicians rated these intrusions on ego-dystonicity and whether the intrusion had occurred with or without any evidence for its potential reality. Results showed that ego-dystonicity and lack of evidence for the intrusions were related, but distinct constructs. In particular, intrusions that occurred without evidence were significantly associated with higher levels of self-reported OC symptoms and related cognitive domains, whereas ego-dystonicity was not related to OC symptoms. Overall, the results are consistent with the notion that abnormal intrusions occur without evidence in the here-and-now, whereas normal intrusions do not. Intrusions that have no evidence to back them up, yet occur without any apparent cause, may be particularly likely to invite further negative cognitive processing, over-interpretation and control attempts. Implications for further research and treatment are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We examine stock return predictability for India and find strong evidence of sectoral return predictability over market return predictability. We show that mean-variance investors make statistically significant and economically meaningful profits by tracking financial ratios. For the first time in this literature, we examine the determinants of time-varying predictability and mean-variance profits. We show that both expected and unexpected shocks emanating from most financial ratios explain sectoral return predictability and profits. These are fresh contributions to the understanding of asset pricing.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Double-stranded RNA species ranging in molecular weight from 0.95 to 6.3 × 106 were detected in grapevines in New York. We recently showed that two of the species (Mr = 5.3 and 4.4 × 106) are associated with rupestris stem pitting disease. In this report, we show that the other eight detectable dsRNA species are associated with the powdery mildew fungus, Uncinula necator. These dsRNAs associated with the powdery mildew fungus were previously detected in leaves and epidermal stem tissue of grapevines infected with powdery mildew. The same dsRNA species were also detected from extracts of isolated cleistothecia and conidia of U. necator devoid of plant tissue. Isometric and rigid rodlike particles were observed in single cleistothecia preparations when examined under transmission electron microscopy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ross River virus (RRV) is a mosquito-borne member of the genus Alphavirus that causes epidemic polyarthritis in humans, costing the Australian health system at least US$10 million annually. Recent progress in RRV vaccine development requires accurate assessment of RRV genetic diversity and evolution, particularly as they may affect the utility of future vaccination. In this study, we provide novel RRV genome sequences and investigate the evolutionary dynamics of RRV from time-structured E2 gene datasets. Our analysis indicates that, although RRV evolves at a similar rate to other alphaviruses (mean evolutionary rate of approx. 8x10(-4) nucleotide substitutions per site year(-1)), the relative genetic diversity of RRV has been continuously low through time, possibly as a result of purifying selection imposed by replication in a wide range of natural host and vector species. Together, these findings suggest that vaccination against RRV is unlikely to result in the rapid antigenic evolution that could compromise the future efficacy of current RRV vaccines.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Previously, expected satiety (ES) has been measured using software and two-dimensional pictures presented on a computer screen. In this context, ES is an excellent predictor of self-selected portions, when quantified using similar images and similar software. In the present study we sought to establish the veracity of ES as a predictor of behaviours associated with real foods. Participants (N = 30) used computer software to assess their ES and ideal portion of three familiar foods. A real bowl of one food (pasta and sauce) was then presented and participants self-selected an ideal portion size. They then consumed the portion ad libitum. Additional measures of appetite, expected and actual liking, novelty, and reward, were also taken. Importantly, our screen-based measures of expected satiety and ideal portion size were both significantly related to intake (p < .05). By contrast, measures of liking were relatively poor predictors (p > .05). In addition, consistent with previous studies, the majority (90%) of participants engaged in plate cleaning. Of these, 29.6% consumed more when prompted by the experimenter. Together, these findings further validate the use of screen-based measures to explore determinants of portion-size selection and energy intake in humans.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background Kiwifruit (Actinidia spp.) are a relatively new, but economically important crop grown in many different parts of the world. Commercial success is driven by the development of new cultivars with novel consumer traits including flavor, appearance, healthful components and convenience. To increase our understanding of the genetic diversity and gene-based control of these key traits in Actinidia, we have produced a collection of 132,577 expressed sequence tags (ESTs). Results The ESTs were derived mainly from four Actinidia species (A. chinensis, A. deliciosa, A. arguta and A. eriantha) and fell into 41,858 non redundant clusters (18,070 tentative consensus sequences and 23,788 EST singletons). Analysis of flavor and fragrance-related gene families (acyltransferases and carboxylesterases) and pathways (terpenoid biosynthesis) is presented in comparison with a chemical analysis of the compounds present in Actinidia including esters, acids, alcohols and terpenes. ESTs are identified for most genes in color pathways controlling chlorophyll degradation and carotenoid biosynthesis. In the health area, data are presented on the ESTs involved in ascorbic acid and quinic acid biosynthesis showing not only that genes for many of the steps in these pathways are represented in the database, but that genes encoding some critical steps are absent. In the convenience area, genes related to different stages of fruit softening are identified. Conclusion This large EST resource will allow researchers to undertake the tremendous challenge of understanding the molecular basis of genetic diversity in the Actinidia genus as well as provide an EST resource for comparative fruit genomics. The various bioinformatics analyses we have undertaken demonstrates the extent of coverage of ESTs for genes encoding different biochemical pathways in Actinidia.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Campylobacter occur in fresh retail poultry products as a result of their colonization of the gastro-intestinal tract of chickens during growth. Feed additives could be used for suppression of Campylobacter levels in the chickens prior to slaughter. To address this opportunity, feed manufacturers are targeting natural antimicrobials from plant material as new forms of consumer-accepted feed additives. However, to be practical, these natural antimicrobials must be effective at low concentrations. The current study has validated an improved laboratory method to study minimal inhibitory concentrations of plant compounds and their combinations against Campylobacter. The assay was shown to be valid for testing lipid-soluble and water-soluble plant extracts and byproducts from the food industry. The study screened 29 extracts or plant-derived compounds and their mixtures for anti-Campylobacter activity using a laboratory assay. Combinations of oregano, lactic acid, and sorghum byproduct showed effective synergy in anti-Campylobacter activity. The synergies allowed a large reduction in the concentration of the individual compounds needed to kill the bacteria with an 80% reduction in concentration being achieved for oregano essential oil. The assay gives rise to further opportunities for the testing of a greater range of combinations of plant-derived compounds and other natural antimicrobials. The method is robust, simple, and easily automated, and it could be used to adjust the cost of feed formulations by reducing costs associated with antimicrobial feed additives.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Prospective studies and intervention evaluations that examine change over time assume that measurement tools measure the same construct at each occasion. In the area of parent-child feeding practices, longitudinal measurement properties of the questionnaires used are rarely verified. To ascertain that measured change in feeding practices reflects true change rather than change in the assessment, structure, or conceptualisation of the constructs over time, this study examined longitudinal measurement invariance of the Feeding Practices and Structure Questionnaire (FPSQ) subscales (9 constructs; 40 items) across 3 time points. Mothers participating in the NOURISH trial reported their feeding practices when children were aged 2, 3.7, and 5 years (N = 404). Confirmatory Factor Analysis (CFA) within a structural equation modelling framework was used. Comparisons of initial cross-sectional models followed by longitudinal modelling of subscales, resulted in the removal of 12 items, including two redundant or poorly performing subscales. The resulting 28-item FPSQ-28 comprised 7 multi-item subscales: Reward for Behaviour, Reward for Eating, Persuasive Feeding, Overt Restriction, Covert Restriction, Structured Meal Setting and Structured Meal Timing. All subscales showed good fit over 3 time points and each displayed at least partial scalar (thresholds equal) longitudinal measurement invariance. We recommend the use of a separate single item indicator to assess the family meal setting. This is the first study to examine longitudinal measurement invariance in a feeding practices questionnaire. Invariance was established, indicating that the subscales of the shortened FPSQ-28 can be used with mothers to validly assess change in 7 feeding constructs in samples of children aged 2-5 years of age.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

时间、空间格局的保持和发展及其对种群、群落和生态系统动态的影响是生态学中两个相互关联的基本课题。围绕这个中心议题作者在植物个体、种群、群落各个层次上开展了研究。 1)研究了克隆植物构型及其对资源异质性的响应,给出了描述该连续体的一个指数v:In1/ln刀.(士

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objectives: The objectives of this study were to compare behaviour problems and competencies, at home and school, in 7-year-old children with congenital heart disease with a sibling control group, to examine the prospective determinants of outcome from infancy, and to explore whether any gains were maintained in our sub-group of children who had participated in a previous trial of psychological interventions in infancy.
Methods: A total of 40 children who had undergone surgery to correct or palliate a significant congenital heart defect in infancy were compared (Child Behavior Checklist) with a nearest-age sibling control group (18 participants). Comparisons were made between sub-groups of children and families who had and had not participated in an early intervention trial.
Results: Problems with attention, thought and social problems, and limitations in activity and school competencies, were found in comparison with siblings. Teacher reports were consistent with parents, although problems were of a lower magnitude. Disease, surgical, and neurodevelopmental functioning in infancy were related to competence outcomes but not behaviour problems. The latter were mediated by family and maternal mental health profiles from infancy. Limited, but encouraging, gains were maintained in the sub-group that had participated in the early intervention programme.
Conclusions: The present study is strengthened by its longitudinal design, use of teacher informants, and sibling control group. The patterns of problems and limitations discerned, and differential determinants thereof, have clear implications for interventions. We consider these in the light of our previously reported intervention trial with this sample and current outcomes at the 7-year follow-up.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The impact of community stigmatisation upon service usage has been largely overlooked from a social identity perspective. Specifically, the social identity-mediated mechanisms by which stigmatisation hinders service use remain unspecified. The present study examines how service providers, community workers and residents recount their experience of the stigmatisation of local community identity and how this shapes residents’ uptake of welfare, education and community support services. Twenty individual and group interviews with 10 residents, 16 community workers and six statutory service providers in economically disadvantaged communities in Limerick, Ireland, were thematically analysed.Analysis indicates that statutory service providers endorsed negative stereotypes of disadvantaged areas as separate and anti-social. The awareness of this perceived division and the experience of ‘stigma consciousness’ was reported by residents and community workers to undermine trust, leading to under-utilisation of community and government services. We argue that stigmatisation acts as a ‘social curse’ by undermining shared identity between service users and providers and so turning a potentially cooperative intragroup relationship into a fraught intergroup one. We suggest that tackling stigma in order to foster a sense of shared identity is important in creating positive and cooperative service interactions for both service users and providers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study presents an empirical investigation of the determinants of net interest margins and spreads in the Russian and Japanese banking sectors with a particular focus on commercial banks. Net interest mar-gins and spreads serve as indicators of financial intermediation efficiency. This paper employed a bank-level unbalanced panel dataset prolonging from 2005 to 2014. My main empirical results show that bank characteristics explain the most of the variation in not only net interest margins but also in spreads. Capi-talization, liquidity risk, inflation, economic growth, private and government debt are important determi-nants of margin in Russia. In Japan to the contrary loan and deposit market concentration along with bank size do predominate. Common significant variables in both countries are the substitution effect, cost effi-ciency and profitability. Turning to net interest spreads, micro- and macro-specific variables are the main significant drivers in Russia. I reach the conclusion that there are no significant determinants of net interest spreads in Japan within the original selection of variables, but operating efficiency and deposits to total funding seem to prevail. In both countries, there are solid differences in the net interest margins as well as spreads once the pre- and the post-crisis periods are considered.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Thesis consist of the study of the electrical properties of antimony trisulphide films and the electrical behaviour of different metal contacts to antimony trisulphide films. Since the thermal evapouration of the compound antimony trisulphide as such mayresult in nonstoichiometric compound films , sb2s3 films in the present work were mostly prepared by the three temperature method ,keeping the substrate at different temperature ranging from 3031 to 4231 and evapourating antimony and sulphur simultaneously from separate sources.