22 resultados para strange situation
em CentAUR: Central Archive University of Reading - UK
Resumo:
Background: The importance of understanding which environmental and biological factors are involved in determining individual differences in physiological response to stress is widely recognized, given the impact that stress has on physical and mental health. Methods: The child-mother attachment relationship and some genetic polymorphisms (5-HTTLPR, COMT and GABRA6) were tested as predictors of salivary cortisol and alpha amylase concentrations, two biomarkers of hypothalamic-pituitary-adrenocortical (HPA) axis and sympathetic adrenomedullary (SAM) system activity, during the Strange Situation (SS) procedure in a sample of more than 100 healthy infants, aged 12 to 18 months. Results: Individual differences in alpha amylase response to separation were predicted by security of attachment in interaction with 5-HTTLPR and GABRA6 genetic polymorphisms, whereas alpha amylase basal levels were predicted by COMT x attachment interaction. No significant effect of attachment, genetics and their interaction on cortisol activity emerged. Conclusions: These results help to disentangle the role played by both genetic and environmental factors in determining individual differences in stress response in infancy. The results also shed light on the suggestion that HPA and SAM systems are likely to have different characteristic responses to stress.
Resumo:
This study addresses the extent to which insecure and disorganized attachments increase risk for externalizing problems using meta-analysis. From 69 samples (N = 5,947), the association between insecurity and externalizing problems was significant, d = 0.31 (95% CI: 0.23, 0.40). Larger effects were found for boys (d = 0.35), clinical samples (d = 0.49), and from observation-based outcome assessments (d = 0.58). Larger effects were found for attachment assessments other than the Strange Situation. Overall, disorganized children appeared at elevated risk (d = 0.34, 95% CI: 0.18, 0.50), with weaker effects for avoidance (d = 0.12, 95% CI: 0.03, 0.21) and resistance (d = 0.11, 95% CI: −0.04, 0.26). The results are discussed in terms of the potential significance of attachment for mental health.
Resumo:
1. Invasive ants commonly reach abnormally high abundances and have severe impacts on the ecosystems they invade. Current invasion theory recognises that not only negative interactions, such as natural enemy release, but positive interactions, such as facilitation, are important in causing this increased abundance. 2. For invasive ants, facilitation can occur through mutualism with exudate-producing plants and insects. To obtain such partnerships, however, invaders must first displace native ants, whose communities are highly structured around such resources. 3. By manipulating the abundance of an invasive ant relative to a native, we show that a minimum threshold abundance exists for invasive ants to monopolise exudate-producing resources. In addition, we show that behavioural dominance is context dependent and varies with spatial location and numerical abundance. 4. Thus, we suggest a 'facilitation-threshold' hypothesis of ant invasion, whereby a minimum abundance of invasive ants is required before facilitation and behavioural dominance can drive abundance rapidly upwards through positive feedback.
Resumo:
According to the Chinese State Council's "Building Energy Efficiency Management Ordinance", a large-scale investigation of energy efficiency (EE) in buildings in contemporary China has been carried out in 22 provincial capitals and major cities in China. The aim of this project is to provide reliable information for drawing up the "Decision on reinforcing building energy efficiency" by the Ministry of Construction of China. The surveyed organizations include government departments, research institutions, property developers, design institutions, construction companies, construction consultancy services companies, facility management departments, financial institutions and those which relate to the business of building energy efficiency. In addition, representatives of the media and residents were also involved. A detailed analysis of the results of the investigation concerning aspects of the cur-rent situation and trends in building energy consumption, energy efficiency strategy and the implementation of energy efficiency measures has been conducted. The investigation supplies essential information to formulate the market entrance policy for new buildings and the refurbishment policy for existing buildings to encourage the development of energy efficient technology.
Resumo:
Increased concerns over food safety have led to the adoption of international guidance on the key elements for national food control systems. This guidance had been used to conduct an initial assessment of the status of the food control systems in the countries belonging to the Gulf Cooperation Council. Our research has identified how the countries have been attempting to enhance their food control systems. Although the countries have different approaches to food control management, cooperation is leading to increased harmonization of legislation and food control practices. Progress is being made but there is evidence of some weakness where additional efforts may be needed. (c) 2009 Elsevier Ltd. All rights reserved.