Application of spatial analysis techniques to adjust for fertility trends and identify interplot competition in early stage sugarcane selection trials

Most sugarcane breeding programs in Australia use large unreplicated trials to evaluate clones in the early stages of selection. Commercial varieties that are replicated provide a method of local control of soil fertility. Although such methods may be useful in detecting broad trends in the field, variation often occurs on a much smaller scale. Methods such as spatial analysis adjust a plot for variability by using information from immediate neighbours. These techniques are routinely used to analyse cereal data in Australia and have resulted in increased accuracy and precision in the estimates of variety effects. In this paper, spatial analyses in which the variability is decomposed into local, natural, and extraneous components are applied to early selection trials in sugarcane. Interplot competition in cane yield and trend in sugar content were substantial in many of the trials and there were often large differences in the selections between the spatial and current method used by the Bureau of Sugar Experiment Stations. A joint modelling approach for tonnes sugar per hectare in response to fertility trends and interplot competition is recommended.

Development of a measure of coping with multiple sclerosis caregiving

Development of a self-report measure of coping specific to multiple sclerosis (MS) caregiving is needed to advance our understanding of the role of coping in adaptation to caring for a person with MS and to contribute to a lack of empirical data on MS caregiving. A total of 213 MS caregivers and their care recipients completed a Coping with MS Caregiving Inventory (CMSCI) and measures of adjustment (psychological distress), appraisal and illness. A subsample (n = 64) also completed the Ways of Coping Checklist (WCC) and additional adjustment measures (depression, caregiving impact. dyadic adjustment, and relationship conflict and reciprocity). Factor analyses revealed 5 factors: Supportive Engagement, Criticism and Coercion, Practical Assistance, Avoidance, and Positive Reframing. Subscales had internal reliabilities comparable to similar scales and were empirically distinct. Preliminary construct validation data are consistent with recent MS caregiving research that links passive avoidant emotion-focused coping with poorer adjustment, and relationship-focused coping caregiving research that links greater reliance on positive relationship-focused coping and less reliance on criticism with better adjustment. Results extend this research by revealing new relations between coping and adaptation to MS caregiving. Convergent validation data suggest that although the inventory differs from the WCC, it does share certain conceptual similarities with this scale.

Development of the HIV/AIDS stress scale

Development of a self-report measure of stress specific to HIV/AIDS is needed to advance our understanding of the role of stress in adaptation to HIV/AIDS: hence, the aim of this study was the development of the HIV/AIDS Stress Scale. A total of 132 homosexual/bisexual men with HIV/AIDS v ere interviewed and completed the HIV/AIDS Stress Scale and measures of coping strategies, appraisal, social support and adjustment (global distress, depression, social adjustment, number of HIV symptoms, and subjective health status) at three time points. Thirty-nine primary caregivers were interviewed and completed measures of stress and adjustment. Exploratory factor analyses of the HIV/AIDS Stress Scale items revealed three factors: Social, Instrumental and Emotional/Existential Stress. Factors had adequate internal reliabilities and were stable over 12 months. Construct validation data are consistent with recent stress/coping research that links higher levels of stress with more HIV symptoms. reliance on emotion-focused coping, lower social support, poorer levels of adjustment and higher levels of caregiver stress. Results extend this research by revealing new differential relations between various stress dimensions and stress/coping variables. Convergent validation data suggest that the HIV/AIDS Stress Scale shares conceptual similarity with threat appraisal. and differs from control liability and challenge appraisals. The HIV/AIDS Stress Scale shows potential for the elucidation of the role of stress in coping and adaptation to HIV/AIDS and disease progression in both research and clinical applications.

Adjustment of homeless adolescents to a crisis shelter: Application of a stress and coping model

The present study examined the utility of a stress and coping model of adaptation to a homeless shelter among homeless adolescents. Seventy-eight homeless adolescents were interviewed and completed self-administered scales at Time 1 (day of shelter entry) and Time 2 (day of discharge). The mean duration of stay at the shelter was 7.23 days (SD = 7.01). Predictors included appraisal (threat and self-efficacy), coping resources, and coping strategies (productive, nonproductive, and reference to others coping). Adjustment outcomes were Time I measures of global distress, physical health, clinician-and youthworker- rated social adjustment, and externalizing behavior and Time 2 youthworker-rated social adjustment and goal achievement. Results of hierarchical regression analyses indicated that after controlling for the effects of relevant background variables (number of other shelters visited, sexual, emotional, and physical abuse), measures of coping resources, appraisal, and coping strategies evidenced distinct relations with measures of adjustment in ways consistent with the model's predictions with few exceptions. In cross-sectional analyses better Time I adjustment was related to reports of higher levels of coping resources, self-efficacy beliefs, and productive coping strategies, and reports of lower levels of threat appraisal and nonproductive coping strategies. Prospective analyses showed a link between reports of higher levels of reference to others coping strategies and greater goal achievement and, unexpectedly, an association between lower self-efficacy beliefs and better Time 2 youthworker-rated social adjustment. Hence, whereas prospective analyses provide only limited support for the use of a stress and coping model in explaining the adjustment of homeless adolescents to a crisis shelter, cross-sectional findings provide stronger support.

The efficacy of a psychosocial intervention for HIV/AIDS caregiving dyads and individual caregivers: a controlled treatment outcome study

The present study examined the comparative efficacy of intervening at the caregiver/care-recipient dyadic level, versus the individual caregiver level, for caregivers and their care-recipients with HIV/AIDS. Participants were randomly assigned to a Dyad Intervention (DI), a Caregiver Intervention (CI) or Wait List Control group (WLC), and assessed by interview and self-administered scales immediately before treatment and eight weeks later. Participants in the intervention groups also completed a four-month follow-up assessment. Dependent variables included global distress, social adjustment, dyadic adjustment, subjective health status, HIV/AIDS knowledge and target problem ratings. Results showed that caregivers in the DI group showed greater improvement from pre- to post-treatment on global distress, dyadic adjustment and target problems than the CI and WLC caregivers. The CI and DI caregivers showed greater improvement than the WLC group on all dependent variables except social adjustment. Care-recipients in the DI group improved significantly from pre- to post-treatment on dyadic adjustment, social adjustment, knowledge, subjective health status and Target Problem 1, whereas the CI and WLC care-recipients failed to improve on any of these measures. The treatment gains made by the DI caregivers and care-recipients on most dependent variables were maintained at a four-month follow-up. Findings support a reciprocal determinism approach to the process of dyadic adjustment and suggest that intervening at the caregiver/care-recipient level may produce better outcomes for both the caregiver and care-recipient than intervening at the individual caregiver level.

Adjustment to chronic obstructive pulmonary disease: the importance of psychological factors

Research has indicated a weak relationship between the degree of physical problems and quality of life in patients with chronic obstructive pulmonary disease (COPD). The importance of adaptive psychological functioning to maintain optimum quality of life has long been recognized, but there is a lack of empirical evidence concerning the nature of psychological factors involved in adjustment to COPD. Ninety-two males completed questionnaires to determine their coping strategies, levels of self-efficacy of symptom management and social support. Adjustment was measured in terms of depression, anxiety and quality of life. Symptom severity, socioeconomic status, duration of disease and age, which have been demonstrated to be of consequence in COPD, were used as control variables in hierarchical multiple regression analyses. Higher levels of catastrophic withdrawal coping strategies and lower levels of self-efficacy of symptom management were associated with higher levels of depression, anxiety and a reduced quality of life. Higher levels of positive social support were linked to lower levels of depression and anxiety, while higher levels of negative social support were linked to higher levels of depression and anxiety. To maximize quality of life in patients with chronic obstructive pulmonary disease, psychological factors need to be carefully assessed and addressed.

Leaf water potential and osmotic adjustment as physiological traits to improve drought tolerance in rice

A sample of recombinant inbred lines (RILs) was derived from a bi-parental cross between Lemont and BK88-BR6, which contrasted in maintenance of leaf water potential (LWP) and expression of osmotic adjustment (OA). Genotypic variation for LWP and OA, and their associations with yield determination under water deficit, was studied in a series of five field experiments. Genotypic variation in the maintenance of high LWP was consistent across water deficit experiments. In the determination of genotypic variation in the maintenance of LWP, rate of water deficit was not an important factor influencing ranking, but degree of water deficit, and phenological development stage were important, particularly around heading. Genotypic variation in expression of OA was also observed under water deficits during both vegetative and flowering stages but ranking was inconsistent across experiments. This was in part because of large experimental errors associated with its measurement, but also because the expression of OA was associated with extent of decline of LWP. The relationship between OA and LWP was demonstrated when data were combined across experiments for vegetative and flowering stages. Under water-limited conditions around flowering, grain yield reduction was mainly due to a increased spikelet sterility. Variation in OA was not related to grain yield nor yield components. There were however, negative phenotypic and genetic correlations between LWP and percentage spikelet sterility measured at flowering stage on panicles at the same development stage during a water deficit treatment. This suggests that traits contributing to the maintenance of high LWP minimized the effects of water deficit on spikelet sterility and consequently grain yield. (C) 2002 Elsevier Science B.V. All rights reserved.

Adolescents' perceptions of differential parenting: Links with attachment style and adolescent adjustment

The study examines whether adolescent twins' attachment style mediates the association between their perceptions of differential parental treatment and their reported adjustment. Data from a survey of 174 adolescent twins are used to assess the links between twins' reports of differential parental affection and differential parental control, their attachment style, and their reported personal self-esteem, social self-esteem, and anxiety. Twins' reports of having been disfavored in comparison with their co-twin were associated with attachment insecurity, anxiety, and lower personal self-esteem. Attachment was found to mediate the association between the twins' reports of differential parental affection and their reported anxiety and personal self-esteem. The strongest evidence for mediation was found for twins' reports of differential maternal affection in predicting adolescent twins' anxiety.

Couple communication and female problem drinking: A behavioral observation study

Couples with alcohol and relationship problems often report poor communication, yet little is known about the communication of maritally distressed couples in which the woman abuses alcohol (MDWA couples). Compared with maritally distressed couples without alcohol problems (MDNA) and couples with neither problem (NDNA), MDWA couples showed a distinctive pattern of negative communication. Similar to MDNA men, MDWA men spoke negatively to their partners but listened positively to their partners much like NDNA men. MDWA women listened negatively, much as MDNA women did, but spoke positively, like NDNA women did. The interactions of MDWA couples can be characterized as a male-demand-female-withdraw pattern, which is a gender reversal of the female-demand-male-withdraw pattern often observed in MDNA couples.