263 research outputs found
Intergenerational mobility of housework time in the United Kingdom
This paper analyzes the relationship between parents’ time devoted to housework and the time devoted to housework by their children. Using data from the Multinational Time Use Study for the UK, we find positive intergenerational correlations in housework for both parents, indicating that the more time parents devote to housework, the more time their children will devote to housework. Using data from the British Household Panel Survey, we find that a higher father–mother housework ratio is positively related to a higher child–mother housework ratio, even after allowing for individual fixed-effects. In order to address the potential exacerbation of errors-in-variables arising from the fixed-effects specification, we instrument the father–mother ratio of housework using father’s and mother’s lagged weekly working hours. The Instrumental-Variable estimates fully support the fixed-effects estimates, and suggest that the latter should be regarded as a lower bound. We also present evidence of the link between housework during adolescence and duringadulthood, which may indicate that housework time during adulthood depends on the housework time during childhood, which may also be affected by parents’ housework time. Our results contribute to the field of the intergenerational mobility of behaviors
Identification of Bone Marrow Cell Subpopulations Associated With Improved Functional Outcomes in Patients With Chronic Left Ventricular Dysfunction: An Embedded Cohort Evaluation of the FOCUS-CCTRN Trial
In the current study, we sought to identify bone marrow-derived mononuclear cell (BM-MNC) subpopulations associated with a combined improvement in left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), and maximal oxygen consumption (VO2 max) in patients with chronic ischemic cardiomyopathy 6 months after receiving transendocardial injections of autologous BM-MNCs or placebo. For this prospectively planned analysis, we conducted an embedded cohort study comprising 78 patients from the FOCUS-Cardiovascular Cell Therapy Research Network (CCTRN) trial. Baseline BM-MNC immunophenotypes and progenitor cell activity were determined by flow cytometry and colony-forming assays, respectively. Previously stable patients who demonstrated improvement in LVEF, LVESV, and VO2 max during the 6-month course of the FOCUS-CCTRN study (group 1, n = 17) were compared to those who showed no change or worsened in one to three of these endpoints (group 2, n = 61) and to a subset of patients from group 2 who declined in all three functional endpoints (group 2A, n = 11). Group 1 had higher frequencies of B-cell and CXCR4(+) BM-MNC subpopulations at study baseline than group 2 or 2A. Furthermore, patients in group 1 had fewer endothelial colony-forming cells and monocytes/macrophages in their bone marrow than those in group 2A. To our knowledge, this is the first study to show that in patients with ischemic cardiomyopathy, certain bone marrow-derived cell subsets are associated with improvement in LVEF, LVESV, and VO2 max at 6 months. These results suggest that the presence of both progenitor and immune cell populations in the bone marrow may influence the natural history of chronic ischemic cardiomyopathy-even in stable patients. Thus, it may be important to consider the bone marrow composition and associated regenerative capacity of patients when assigning them to treatment groups and evaluating the results of cell therapy trials
Development and validation of PozQoL: A scale to assess quality of life of PLHIV
Background: Advances in medical treatment for HIV are driving major changes in HIV policy and practice, including the encouragement of intake and adherence to HIV antiretroviral treatment (ART) by people living with HIV (PLHIV) for both personal and public health benefits. However, there is increasing recognition that achieving these goals will require a concurrent focus on the broader psychological and social wellbeing of PLHIV. Increasingly calls are being been made to incorporate a stronger focus on quality of life (QoL) of PLHIV into HIV prevention policy. In order to achieve this goal, HIV community, support and healthcare services need a valid, short and practical way to evaluate QoL of PLHIV accessing their programs. Current QoL measures are either long, complex, restricted in their use, or expensive. To address these shortcomings, the PozQoL study aimed to develop, test and validate a short and freely available scale assessing QoL among PLHIV. Methods: Drawing on a literature review, the prioritisation of domains and development of the initial pool of items was conducted in consultation with PLHIV community organisations in Australia. The items covered health concerns, psychological, social, and functional wellbeing. Testing involved a baseline and a follow-up survey of 465 adult Australians living with HIV. Participants were recruited through social media and various community organizations nationwide. The survey included the pilot PozQoL scale and other validated measures of health and wellbeing. Results: Guided by an Exploratory Factor Analysis and conceptual considerations, a 13-item scale was developed. The PozQoL scale demonstrated high levels of fit in a Confirmatory Factor Analysis, very good internal consistency, test-retest reliability, and concurrent validity with other measures that approximated different aspects of QoL. Conclusion: The PozQoL scale has been tested in a diverse sample of adult PLHIV living in Australia, demonstrating very good reliability and validity. The insights from PLHIV and other stakeholders supported the balancing of statistical rigour and conceptual accuracy. The scale is now ready to be implemented and field-tested across a range of community, support and healthcare programs for PLHIV. This will make a significant contribution to the evaluation and enhancement of programs for PLHIV
Soil management and production of alfisols in the semi-arid tropics. IV. Simulation of decline in productivity caused by soil erosion
Maintenance of a productive soil base by minimizing soil erosion is vital to long-term crop production. In this study, a modelling approach is used to estimate the effects of soil erosion on productivity for a sorghum cropping system on an Alfisol in the semi-arid tropics of India. Predictions of erosion, runoff and yield decline due to erosion, for variations in initial soil depth, slope, tillage strategy and amendment treatment, are presented.
On average, soil depth decreased by 0.91 cm/year at Hyderabad for a 10% slope, 80 cm initial soil depth, shallow tillage at planting and no surface amendment. Rates of soil removal and subsequent yield decline were higher for shallower soils, steeper slopes and if management practices provided less surface cover during the crop. The productive life of the soil was less than 91 years for some soil depths, slope and management combinations. For other combinations, significant yield decline was predicted after 91 years of cropping.
The quantification of erosion-productivity relationships allows us to identify regions with a higher risk of degradation from soil erosion and to estimate the impact of various management options on long-term sustainability. Models provide a basis to focus research and a means of assessing alternative management strategies to preserve long-term production
Effects of soil management on population abundance and biomass of earthworms in a semi-arid tropical alfisol
Soil Management and Seasonal Community Structure of Soil Microarthropods in Semi-Arid Tropical Alfisols
Response of the soil microarthropod community was monitored across different soil
management treatments with annual and perennial crops in semi-arid tropical Alfisols.
Annual crop management treatments included zero, shallow and deep tillage either bare,
or with application of 15 t ha" farm-yard manure or 5 t ha" rice-straw. Perennial crop
treatments were Stylosanthes hamala, Cenchrus ciliaris and pigeonpea either alone or
in combination. Microarthropods, across all the treatments, included Collembola, Acarina,
Araneae, Pseudoscorpiones, Pauropods, Symphyla, Diplura, Dermaptera. Psocoptera,
Isoptera, Thysanoptera, Homoptera, Hymenoptera and Coleoptera adults and larvae. The
number of Collembola and Acarina together constituted > 62% of the total
microarthropods. The population densities of all microarthropods showed a more or less
similar pattern of temporal variations under all treatments. They were higher during the
rainy season of 1990 and 1991 in bare plots under zero-tillage treatment followed by plots
under rice-straw treatment. However, densities during rainy months of 1989 were low
compared to those of 1990 because of the high dose of carbofuran treatment. Population
densities showed significant treatment differences during some months indicating
significant impact of soil management practices on microarthropod community structure
Soil management and production of alfisols in the semi-arid tropics. III. Long-term effects on water conservation and production
A calibrated cropping systems model was used to provide long-term biophysical responses of various land managements at two differing semi-arid tropic environments in India. Organic based practices such as farmyard manure or straw amendments and perennial pastures reduced runoff by between 50 and 87%, and are optimum for in situ, water and soil conservation. A consequence of the reduced runoff was an increase in drainage below the root zone. Furthermore, the detrimental effects of cropping on high slopes and long slope lengths showed that it is not feasible to crop on slopes greater than 5%. Our study did not incorporate farmer preferences for land management, but the results can still be used as an integral part of decision making for optimum land management
On-Farm Evaluation oF Land Treatments to increase Infiltration and Crop Yield on a Shallow vertic soil
An on-farm experiment was conducted on a Vertic Inceptisol site with a 2% slope at Chevella watershed, Medak disrrict (Andhra Pradesh), lo compare the effect of three land treatments: (i) graded contour cultivation ort 0.2% gradient.........
Soil management and rroduction of alfisols in the semi-arid tropics. I. Modelling the effects of soil management on runoff and erosion
Techniques to simulate effects of surface cover and tillage on runoff and erosion are described. Data for 15 soil management treatments on an Alfisol in the semi-arid tropics, India, were used to modify existing procedures of runoff prediction using USDA runoff curve numbers. A relationship between surface cover and curve number was developed to account for the effects of surface cover on runoff. Impact of shallow or deep tillage was predicted using functions that relate curve number to cumulative rainfall since tillage. The derived relationships were applied to adjust curve number due to the effects of cover and tillage on a daily basis and were incorporated into the cropping systems model called PERFECT-IND.
Results of model validation showed that PERFECT-IND explained between 71 and 91% of the variation in daily runoff volumes. The model also provided accurate predictions of average annual runoff ranging from 33 to 217 mm for the 15 soil management treatments. Runoff was reduced to a much greater extent by surface cover compared with surface roughness. Surface cover reduced runoff curve number by a maximum of 35 units. The maximum reduction in curve number due to surface roughness was 5 units for shallow tillage and 10 units for deep tillage. Erosion predictions were acceptable but the lack of erosion data for all years in the experimental data limits the confidence in model output.
Model calibration and validation have provided a set of parameters that can be coupled with historical climate records to provide a long-term perspective of the effects of soil management on runoff and erosion. Keywords: simulation, model, runoff, water balance, curve number
Soil management of alfisols for water conservation and utilization
Alfisols are abundarrt soils used for rainfed agrkulfure but have a wide rarrse of problrrtrs due lo lora irrfilfratiorr rates.
We studied a ranse of soil and crop managemenl options (fillngc and muklring for anrtunl crops, a~rrl ~wrerrninl crolrs) t:, incrcase
infiltration during 1989 and 1990. With annual crops sfraw ~rrul~.ahn d FYM trrulch reducrd runof by 52% ar~d1 7% reslwcfitrly compared
to barc freatmenfs but tillage h d small and inconsislent effecfs. Perennial crops produced high rutaolf duritrg the esfahlisl~~rrepnetr iod
in 1988 and sukquetrfly a wide range of response depending or1 flu foliage slructure of fire r.roj>. Tall groroirtg pererrnial
pigeon pea did not reduce runoff compared lo crops with no surface amendment but llrc derrse, shorf, s~rrtrulitrg stylosarrthes harr~ata
reduced runofl more than straw mulch. Reduction in runof will decrease soil erosion and nrny increme draitra~e by up to 200 nrm
pcr year. This drainage is a mmsive potential resource for dcrp rooted crups or irrigation fro111 grou~ritiuafer. Sustairrnble agrkultural
production a1 a wntershed scale will involve soil manageme71t lo increase irtftltrafion in rairrfed areas and exploitafion of cortscqurnt
increases in groundwater resources by irrigation or deep roofed crops
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