930 resultados para CUMULATIVE ADVERSITY


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The Water and Global Change (WATCH) project evaluation of the terrestrial water cycle involves using land surface models and general hydrological models to assess hydrologically important variables including evaporation, soil moisture, and runoff. Such models require meteorological forcing data, and this paper describes the creation of the WATCH Forcing Data for 1958–2001 based on the 40-yr ECMWF Re-Analysis (ERA-40) and for 1901–57 based on reordered reanalysis data. It also discusses and analyses modelindependent estimates of reference crop evaporation. Global average annual cumulative reference crop evaporation was selected as a widely adopted measure of potential evapotranspiration. It exhibits no significant trend from 1979 to 2001 although there are significant long-term increases in global average vapor pressure deficit and concurrent significant decreases in global average net radiation and wind speed. The near-constant global average of annual reference crop evaporation in the late twentieth century masks significant decreases in some regions (e.g., the Murray–Darling basin) with significant increases in others.

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Aluminium (Al) has been measured in human breast tissue, nipple aspirate fluid and breast cyst fluid, and recent studies have shown that at tissue concentrations, aluminium can induce DNA damage and suspension growth in human breast epithelial cells. This paper demonstrates for the first time that exposure to aluminium can also increase migratory and invasive properties of MCF-7 human breast cancer cells. Long-term (32 weeks) but not short-term (1 week) exposure of MCF-7 cells to 10-4M aluminium chloride or 10-4M aluminium chlorohydrate increased motility of the cells as measured by live cell imaging (cumulative length moved by individual cells), by a wound healing assay and by migration in real time through 8m pores of a membrane using xCELLigence technology. Long-term exposure (37weeks) to 10-4M aluminium chloride or 10-4M aluminium chlorohydrate also increased the ability of MCF-7 cells to invade through a matrigel layer as measured in real time using the xCELLigence system. Although molecular mechanisms remain to be characterized, the ability of aluminium salts to increase migratory and invasive properties of MCF-7 cells suggests that the presence of aluminium in the human breast could influence metastatic processes. This is important because mortality from breast cancer arises mainly from tumour spread rather than from the presence of a primary tumour in the breast.

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Under particular large-scale atmospheric conditions, several windstorms may affect Europe within a short time period. The occurrence of such cyclone families leads to large socioeconomic impacts and cumulative losses. The serial clustering of windstorms is analyzed for the North Atlantic/western Europe. Clustering is quantified as the dispersion (ratio variance/mean) of cyclone passages over a certain area. Dispersion statistics are derived for three reanalysis data sets and a 20-run European Centre Hamburg Version 5 /Max Planck Institute Version–Ocean Model Version 1 global climate model (ECHAM5/MPI-OM1 GCM) ensemble. The dependence of the seriality on cyclone intensity is analyzed. Confirming previous studies, serial clustering is identified in reanalysis data sets primarily on both flanks and downstream regions of the North Atlantic storm track. This pattern is a robust feature in the reanalysis data sets. For the whole area, extreme cyclones cluster more than nonextreme cyclones. The ECHAM5/MPI-OM1 GCM is generally able to reproduce the spatial patterns of clustering under recent climate conditions, but some biases are identified. Under future climate conditions (A1B scenario), the GCM ensemble indicates that serial clustering may decrease over the North Atlantic storm track area and parts of western Europe. This decrease is associated with an extension of the polar jet toward Europe, which implies a tendency to a more regular occurrence of cyclones over parts of the North Atlantic Basin poleward of 50°N and western Europe. An increase of clustering of cyclones is projected south of Newfoundland. The detected shifts imply a change in the risk of occurrence of cumulative events over Europe under future climate conditions.

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Aggression in children is associated with an enhanced tendency to attribute hostile intentions to others. However, limited information is available regarding the factors that contribute to the development of such hostile attribution tendencies. We examined factors that contribute to individual differences in child hostile attributions and aggression, focusing on potential pathways from maternal hostile attributions via negative parenting behavior. We conducted a longitudinal study of 98 mothers and children (47 male, 51 female), recruited from groups experiencing high and low levels of psychosocial adversity. Maternal hostile attributions, observed parenting, and child behaviour were assessed at 18 months and 5 years child age, and child hostile attributions were also examined at 5 years. Independent assessments of maternal and child processes were utilized where possible. Analyses provided support for a direct influence of maternal hostile attributions on the development of child hostile attributions and aggressive behaviour. Maternal hostile attributions were also associated with negative parenting behaviour, which in turn influenced child adjustment. Even taking account of possible parenting influences and preexisting child difficulties, hostile attributions in the mother showed a direct link with child aggression at 5 years. Maternal hostile attributions were themselves related to psychosocial adversity. We conclude that maternal hostile attributions are prevalent in high-risk samples and are related to less optimal parenting behaviour, child hostile attributions, and child aggression. Targeting hostile maternal cognitions may be a useful adjunct to parenting programs

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Objectives To investigate whether sleep disturbances previously found to characterise high risk infants: (a) persist into childhood; (b) are influenced by early maternal settling strategies and (c) predict cognitive and emotional/behavioural functioning. Methods Mothers experiencing high and low levels of psychosocial adversity (risk) were recruited antenatally and longitudinally assessed with their children. Mothers completed measures of settling strategies and infant sleep postnatally, and at 12 and 18 months, infant age. At five years, child sleep characteristics were measured via an actigraphy and maternal report; IQ and child adjustment were also assessed. Results Sleep disturbances observed in high-risk infants persisted at five years. Maternal involvement in infant settling was greater in high risk mothers, and predicted less optimal sleep at five years. Poorer five year sleep was associated with concurrent child anxiety/depression and aggression, but there was limited evidence for an influence of early sleep problems. Associations between infant/child sleep characteristics and IQ were also limited. Conclusions Early maternal over-involvement in infant settling is associated with less optimal sleep in children, which in turn, is related to child adjustment. The findings highlight the importance of supporting parents in the early development of good settling practices, particularly in high-risk populations.

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Early mother–infant interactions are characterised by periods of synchronous interaction that are interrupted by periods of mismatch; the experience of such mismatches and their subsequent repair is held to facilitate the development of infant self-regulatory capacities (Tronick, Als, Adamson, Wise, & Brazelton, 1978). Infant responding to such interactive challenge is assumed to be a function of both maternal behaviour and pre-existing infant characteristics. However, the latter has received relatively little attention. In a prospective longitudinal study of a sample comprising high and low adversity dyads (n = 122), we examined the contributions of both maternal sensitivity and neonatal irritability to infant behavioural and physiological responding to the interactive challenge of the Still Face paradigm. Results indicated that higher levels of maternal sensitivity were associated with more regulated infant behaviour during the Still Face paradigm. Neonatal irritability also predicted poorer behavioural and heart rate recovery following the Still Face challenge. Furthermore, there was an interaction such that irritable infants with insensitive mothers showed the worst behavioural outcomes. The findings highlight the importance of the interplay between maternal and infant characteristics in determining dyadic responding.

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Background The objective was to examine the course and longitudinal associations of generalized anxiety disorder (GAD) and major depressive disorder (MDD) in mothers over the postpartum 2 years. Method Using a prospective naturalistic design, 296 mothers recruited from a large community pool were assessed for GAD and MDD at 3, 6, 10, 14, and 24 months postpartum. Structured clinical interviews were used for diagnoses, and symptoms were assessed using self-report questionnaires. Logistic regression analyses were used to examine diagnostic stability and longitudinal relations, and latent variable modeling was employed to examine change in symptoms. Results MDD without co-occurring GAD, GAD without co-occurring MDD, and co-occurring GAD and MDD, displayed significant stability during the postpartum period. Whereas MDD did not predict subsequent GAD, GAD predicted subsequent MDD (in the form of GAD + MDD). Those with GAD + MDD at 3 months postpartum were significantly less likely to be diagnosis free during the follow-up period than those in other diagnostic categories. At the symptom level, symptoms of GAD were more trait-like than those of depression. Conclusions Postpartum GAD and MDD are relatively stable conditions, and GAD is a risk factor for MDD but not vice versa. Given the tendency of MDD and GAD to be persistent, especially when comorbid, and the increased risk for MDD in mothers with GAD, as well as the potential negative effects of cumulative exposure to maternal depression and anxiety on child development, the present findings clearly highlight the need for screening and treatment of GAD in addition to MDD during the postpartum period.

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The low rates of child literacy in South Africa are cause for considerable concern. Research from the developed world shows that parental sharing of picture books with infants and young children is beneficial for child language and cognitive development, as well as literacy skills. We conducted a pilot study to examine whether such benefits might extend to an impoverished community in South Africa, by evaluating the impact of training mothers in book sharing with their 14–18 month old infants. Seventeen mothers received book sharing training; and 13 mothers did not, but instead received a comparison training in toy play. We assessed the mothers’ behavior during both book sharing and toy play before and after training, and we also assessed infant attention and language. Mothers receiving book sharing training engaged well with it, and they also benefited from it; thus, compared to the comparison group mothers, they became more sensitive, more facilitating, and more elaborative with their infants during book sharing, and they also became more sensitive to their infants during toy play. In addition, infants whose mothers received the book sharing training showed greater benefits than the comparison group infants in both their attention and language. Training in book sharing for families living in conditions of marked socio-economic adversity in South Africa has the potential to be of considerable benefit to child developmental progress. A large scale controlled trial is required to confirm this.

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Extinction following positively reinforced operant conditioning reduces response frequency, at least in part through the aversive or frustrative effects of non-reinforcement. According to J.A. Gray's theory, non-reinforcement activates the behavioural inhibition system which in turn causes anxiety. As predicted, anxiolytic drugs including benzodiazepines affect the operant extinction process. Recent studies have shown that reducing GABA-mediated neurotransmission retards extinction of aversive conditioning. We have shown in a series of studies that anxiolytic compounds that potentiate GABA facilitate extinction of positively reinforced fixed-ratio operant behaviour in C57B1/6 male mice. This effect does not occur in the early stages of extinction, nor is it dependent on cumulative effects of the compound administered. Potentiation of GABA at later stages has the effect of increasing sensitivity to the extinction contingency and facilitates the inhibition of the behaviour that is no longer required. The GABAergic hypnotic, zolpidem, has the same selective effects on operant extinction in this procedure. The effects of zolpidem are not due to sedative action. There is evidence across our series of experiments that different GABA-A subtype receptors are involved in extinction facilitation and anxiolysis. Consequently, this procedure may not be an appropriate model for anxiolytic drug action, but it may be a useful technique for analysing the neural bases of extinction and designing therapeutic interventions in humans where failure to extinguish inappropriate behaviours can lead to pathological conditions such as post-traumatic stress disorder.

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Purpose – Effective leadership action requires managers to harness power that is intrinsically political. This paper aims to study and characterise the political nature of a manager's behaviour when taking leadership action. Design/methodology/approach – The methodological approach is qualitative and examines three organisations over a three-year period when these entities experienced a major product failure. The paper analyses the actual managerial behaviour of managers and provides insight into the factors that most strongly influence the effectiveness of managers when taking leadership action. Findings – Political behaviour when taking leadership action can be conceptualised in terms of rationality and emotionality. In so doing, it can be clarified how behaviour must be modified to ensure that leadership action is consistently effective. Research limitations/implications – A case study of three multinational engineering companies engaged in the design, development and manufacturing of turbomachinery provides the platform for the research. The concepts presented in the paper will require validating in other organisations of different demographic profiles. Practical implications – The concepts presented and the implications discussed provide insight into the political nature of managerial behaviour when taking leadership action. The paper highlights the practical steps individual managers can embrace to ensure that their behaviour is appropriate to context, even under the most traumatic situations. Thus, the paper provides managers with a model that facilitates effective leadership action. Originality/value – This paper provides insight into how managers behaved in circumstances that mattered to them. Through immersion in events at the time they took place, the authors captured situations in which managers were under real pressure and, in so doing, avoided the bias inherent when interviewing a manager about past events. As such, the paper concludes that the political behaviour in which managers engage when taking leadership action is rooted in the reality of the adversity that the most capable managers have both experienced and overcome. This detailed study reports behaviour in a situation where managers' business and future prospects were in jeopardy. This paper identifies why some managers were able to use the experience positively, helping them to adopt politically intrinsic behaviour to facilitate effective leadership action.

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This study investigates the financial effects of additions to and deletions from the most well-known social stock index: the MSCI KLD 400. Our study makes use of the unique setting that index reconstitution provides and allows us to bypass possible issues of endogeneity that commonly plague empirical studies of the link between corporate social and financial performance. By examining not only short-term returns but also trading activity, earnings per share, and long-term performance of stocks that are involved in these events, we bring forward evidence of a ‘social index effect’ where unethical transgressions are penalized more heavily than responsibility is rewarded. We find that the addition of a stock to the index does not lead to material changes in its market price, whereas deletions are accompanied by negative cumulative abnormal returns. Trading volumes for deleted stocks are significantly increased on the event date, while the operational performances of the respective firms deteriorate after their deletion from the social index.

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The behaviour of building occupants can have a significant impact on in-use energy performance. In these pilot studies, based on the Elaboration Likelihood Model, interactivity was incorporated in the design of behavioural interventions to assess its effectiveness in promoting energy-saving behaviours. An interactive poster and an interactive prompt were designed to ‘nudge’ occupants’ behaviours towards energy-saving. The poster was installed in an office building and was intended to encourage occupants to save energy by taking the stairs, rather than the lifts, by providing them with cumulative metaphorical feedback. The prompt was installed in student halls of residence and intended to act as a reminder to the occupants to turn the lights off by providing them with an immediate playful reward. The results showed that interactivity can ‘nudge’ occupants’ behaviours when it is combined with a clear message/feedback. The results also suggest that simple immediate feedback can be effective in encouraging energy-efficient behaviours.

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A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria–mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small -molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of δ-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process.

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This study examines the long-run performance of initial public offerings on the Stock Exchange of Mauritius (SEM). The results show that the 3-year equally weighted cumulative adjusted returns average −16.5%. The magnitude of this underperformance is consistent with most reported studies in different developed and emerging markets. Based on multivariate regression models, firms with small issues and higher ex ante financial strength seem on average to experience greater long-run underperformance, supporting the divergence of opinion and overreaction hypotheses. On the other hand, Mauritian firms do not on average time their offerings to lower cost of capital and as such, there seems to be limited support for the windows of opportunity hypothesis.

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Tropical Applications of Meteorology Using Satellite Data and Ground-Based Observations (TAMSAT) rainfall monitoring products have been extended to provide spatially contiguous rainfall estimates across Africa. This has been achieved through a new, climatology-based calibration, which varies in both space and time. As a result, cumulative estimates of rainfall are now issued at the end of each 10-day period (dekad) at 4-km spatial resolution with pan-African coverage. The utility of the products for decision making is improved by the routine provision of validation reports, for which the 10-day (dekadal) TAMSAT rainfall estimates are compared with independent gauge observations. This paper describes the methodology by which the TAMSAT method has been applied to generate the pan-African rainfall monitoring products. It is demonstrated through comparison with gauge measurements that the method provides skillful estimates, although with a systematic dry bias. This study illustrates TAMSAT’s value as a complementary method of estimating rainfall through examples of successful operational application.