834 resultados para Age factors in disease.
Resumo:
This paper presents a simple method to measure the effect of sector and regional factors in real estate returns, and thus provides a quantitative framework for analysing the relative impact of these two diversification categories to real estate portfolio selection. Using data on Retail, Office and Industrial properties spread across 326 real estate locations in the UK, over the period 1981 to 1995, the results show that the performance of real estate is largely sector-driven. A result in line with previous work. Which implies that the sector composition of the real estate fund should be the first level of analysis in constructing and managing the real estate portfolio. As a consequence real estate fund managers need to pay more attention to the sector allocation of their portfolios than the regional spread.
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Grasslands restoration is a key management tool contributing to the long-term maintenance of insect populations, providing functional connectivity and mitigating against extinction debt across landscapes. As knowledge of grassland insect communities is limited, the lag between the initiation of restoration and the ability of these new habitats to contribute to such processes is unclear. Using ten data sets, ranging from 3 to 14 years, we investigate the lag between restoration and the establishment of phytophagous beetle assemblages typical of species rich grasslands. We used traits and ecological characteristics to determine factors limiting beetle colonisation, and also considered how food-web structure changed during restoration. For sites where seed addition of host-plants occurred the success in replicating beetle assemblages increased over time following a negative exponential function. Extrapolation beyond the existing data set tentatively suggested that success would plateau after 20 years, representing a c. 60% increase in assemblage similarity to target grasslands. In the absence of seed addition, similarity to the target grasslands showed no increase over time. Where seed addition was used the connectance of plant-herbivore food webs decreased over time, approaching values typical of species rich grasslands after c. 7 years. This trend was, however, dependent on the inclusion of a single site containing data in excess of 6 years of restoration management. Beetles not capable of flight, those showing high degrees of host-plant specialisation and species feeding on nationally rare host plants take between 1 and 3 years longer to colonise. Successful grassland restoration is underpinned by the establishment of host-plants, although individual species traits compound the effects of poor host-plant establishment to slow colonisation. The use of pro-active grassland restoration to mitigate against future environmental change should account for lag periods in excess of 10 years if the value of these habitats is to be fully realised.
Resumo:
Grasslands restoration is a key management tool contributing to the long-term maintenance of insect populations, providing functional connectivity and mitigating against extinction debt across landscapes. As knowledge of grassland insect communities is limited, the lag between the initiation of restoration and the ability of these new habitats to contribute to the successful enhancement of native biodiversity is unclear. Using two long term data sets, we investigate differences in successional trajectories during the establishment of butterfly (11 years) and phytophagous beetle (13 years) communities during the recreation of calcareous grassland. Overall restoration success was higher for the butterflies than the beetles. However, both shared a general pattern of rapidly increasing restoration success over the first five years, awhich approached an asymptote after c. 10 years. The use of pro-active grassland restoration to mitigate against future environmental change therefore needs to account for such time lag if the value of these habitats is to be fully realised.
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Hardcore, or long-term derelict and vacant brownfield sites which are often contaminated, form a significant proportion of brownfield land in many cities, not only in the UK but also in other countries. The recent economic recession has placed the economic viability of such sites in jeopardy. This paper compares the approaches for bringing back hardcore brownfield sites into use in England and Japan by focusing on ten case studies in Manchester and Osaka, using an `agency'-based frame- work. The findings are set in the context of (i) national brownfield and related policy agendas; (ii) recent trends in land and property markets in both England and Japan; and (iii) city-level comparisons of brownfields in Manchester and Osaka. The research, which was conducted during 2009 ^ 10, suggests that hardcore brownfield sites have been badly affected by the recent recession in both Manchester and Osaka. Despite this, not only is there evidence that hardcore sites have been successfully regenerated in both cities, but also that the critical success factors (CSFs) operating in bringing sites back into use share a large degree of commonality. These CSFs include the presence of strong potential markets, seeing the recession as an opportunity, long-term vision, strong branding, strong partnerships, integrated development, and getting infrastructure into place. Finally, the paper outlines the policy implications of the research.
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A method is presented to calculate economic optimum fungicide doses accounting for the risk-aversion of growers responding to variability in disease severity between crops. Simple dose-response and disease-yield loss functions are used to estimate net disease-related costs (fungicide cost, plus disease-induced yield loss) as a function of dose and untreated severity. With fairly general assumptions about the shapes of the probability distribution of disease severity and the other functions involved, we show that a choice of fungicide dose which minimises net costs on average across seasons results in occasional large net costs caused by inadequate control in high disease seasons. This may be unacceptable to a grower with limited capital. A risk-averse grower can choose to reduce the size and frequency of such losses by applying a higher dose as insurance. For example, a grower may decide to accept ‘high loss’ years one year in ten or one year in twenty (i.e. specifying a proportion of years in which disease severity and net costs will be above a specified level). Our analysis shows that taking into account disease severity variation and risk-aversion will usually increase the dose applied by an economically rational grower. The analysis is illustrated with data on septoria tritici leaf blotch of wheat caused by Mycosphaerella graminicola. Observations from untreated field plots at sites across England over three years were used to estimate the probability distribution of disease severities at mid-grain filling. In the absence of a fully reliable disease forecasting scheme, reducing the frequency of ‘high loss’ years requires substantially higher doses to be applied to all crops. Disease resistant cultivars reduce both the optimal dose at all levels of risk and the disease-related costs at all doses.
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This ethnographic inquiry examines how family languages policies are planned and developed in ten Chinese immigrant families in Quebec, Canada, with regard to their children’s language and literacy education in three languages, Chinese, English, and French. The focus is on how multilingualism is perceived and valued, and how these three languages are linked to particular linguistic markets. The parental ideology that underpins the family language policy, the invisible language planning, is the central focus of analysis. The results suggest that family language policies are strongly influenced by socio-political and economical factors. In addition, the study confirms that the parents’ educational background, their immigration experiences and their cultural disposition, in this case pervaded by Confucian thinking, contribute significantly to parental expectations and aspirations and thus to the family language policies.
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Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults’ positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults’ positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496–502; Mather and Knight: Psychol Aging 2005;20:554–570] argues that the positivity effect is a result of older adults’ greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults’ positivity effect than the aging-brain model.
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This paper explores the nature and chronology of La Tène and early Roman unenclosed agglomerations in central-eastern France. It has been prompted by the discovery of a c. 115 ha La Tène D2b/Augustan (c. 50 bc to ad 15) site close to Bibracte in the Morvan, located around the source of the River Yonne. This complex provides a new perspective on the chronology and role of Late La Tène and early Roman unenclosed settlements, adding further complexity to the story of the development of Late La Tène oppida. It indicates that these ‘agglomerations’ followed remarkably varied chronological trajectories, raising important issues concerning the nature of landscape and social change at the end of the Iron Age. Dieser Aufsatz untersucht den Charakter und die Datierung von latènezeitlichen und frührömischen offenen Siedlungen im östlichen Zentralfrankreich. Die Anregung dazu erfolgte durch die Entdeckung einer Latène D2b-zeitlichen bis augusteischen (ca. 50 v. Chr. – 15 n. Chr.) Anlage im Morvan bei Bibracte, die ca. 115 ha Fläche bedeckt und sich um die Quellen des Flusses Yonne erstreckt. Es wird vorgeschlagen, dass dieser Siedlungskomplex eine Ergänzung, aber auch einen Kontrast zu den üblichen Interpretationsmodellen von spätlatènezeitlichen und frührömischen, offenen Großsiedlungen und ihrer zeitlichen Entwicklung darstellt, und weiter zur Komplexität der Entwicklung spätlatènezeitlicher Oppida beiträgt. Es deutet sich an, dass einige der ‘Agglomerationen’ anderen Entwicklungslinien folgen, die wichtige Fragen zur Landschaftsgenese und zum sozialen Wandel am Ende der Eisenzeit aufwerfen. Cet article a pour but d'explorer la nature ainsi que la chronologie des agglomérations ouvertes apparaissant à La Tène Final et au début de la période gallo-romaine du Centre-Est de la France. Il fut inspiré et écrit suite à la découverte dans le Morvan d'un site de 115 ha datant de La Tène D2b et de la période Augustéenne (50 av. J.C. à 15 ap. J.C.) s'étirant autour des Sources de l'Yonne. Cette agglomération apporte de nouvelles perspectives sur la chronologie et sur le rôle des habitats ouverts à la fin de l'Âge du Fer ainsi qu'au début de l'époque gallo-romaine apportant des éléments amenés à renforcer le caractère complexe de l'histoire du développement des oppida à La Tène Final. Cette synthèse tend à démontrer que ces agglomérations suivaient des trajectoires chronologiques variées, élevant un certain nombre de questions, et donc des nouvelles problématiques, concernant la nature du paysage et du changement social à la fin de l'Âge du Fer.
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A group of young (n=52, M=23.27 years) and old (n=52, M=68.62 years) adults studied two lists of semantically unrelated nouns. For one list a time of 2 s was allowed for encoding, and for the other, 5 s. A recognition test followed where participants classified their responses according to Gardiner’s (1988) remember–know procedure. Age differences for remembering and knowing were minimal in the faster 2-s encoding condition. However, in the longer 5-s encoding condition, younger persons produced significantly more remember responses, and older adults a greater number of know responses. This dissociation suggests that in the longer encoding condition, younger adults utilized a greater level of elaborative rehearsal governed by executive processes, whereas older persons employed maintenance rehearsal involving short-term memory. Statistical control procedures, however, found that independent measures of processing speed accounted for age differences in remembering and knowing and that independent measures of executive control had little influence. The findings are discussed in the light of contrasting theoretical accounts of recollective experience in old age.
Resumo:
The economic development of urban cities in China has attracted a large number of labour from the rural countryside. The married migrant workers will usually leave their wives’ homes to look after the other family members and the farmland. A special term liushou women, has been created for this group of women. Among the 87 million rural residents, 47 million of them are liushou women according to the recent survey conducted by China Agricultural University. They play a crucial role in the development of rural economy and an essential role to the social stability of rural China. In this research, the factors that influence the happiness of liushou women were investigated in the Western part of China. Based on the population investigated, it was found that the financial situation, personality, government efficiency, conjugal relationship and relationship with in-laws are the significant factors influencing the happiness of liushou women. This finding demonstrates that the Chinese women are willing to sacrifice their personal interest for the interests of their families.