155 research outputs found

    Variability in Saturn's bow shock and magnetopause from pioneer and voyager: Probabilistic predictions and initial observations by Cassini

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    Probability distributions for the location of the Saturnian bow shock and magnetopause have been derived by extrapolating observations of dynamic solar wind pressures to the position of Saturn's orbit. These observations are those made by the Pioneer 11, Voyager 1 and 2 spacecraft near Saturn's orbit and by the Ulysses spacecraft near its aphelion. The magnetopause subsolar distance (measured from Saturn's center) is obtained using pressure equilibrium. The bow shock standoff distance is determined using empirical relations between bow shock size and solar wind dynamic pressure. Simple 2-D geometric models of the magnetopause and bow shock surfaces have been used to determine their morphologies over a large range in local time. Three cases have been studied: (1) An Earth-type magnetosphere with low internal plasma pressure; (2) An intermediate case calibrated with Voyager 1 observations; and (3) A Jupiter-like inflated magnetosphere. The comparison of these models with initial observations from the initial sunward orbits of the Cassini spacecraft indicates a more inflated magnetosphere than postulated by the previous modelling of the Pioneer-Voyager encounters

    Evaluation of a nutrition supplementation programme in the Northern Cape Province of South Africa

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    AIM: This study aimed at assessing the effectiveness regarding implementation and impact of a take-home nutrition supplementation programme, the Protein Energy Malnutrition (PEM) Scheme, that targets malnourished pre-school children and pregnant and lactating women in the Northern Cape Province of South Africa. METHODOLOGY: In assessing implementation of the PEM Scheme, a cross-sectional descriptive study was undertaken over a 6-month period in the six regions of the Northern Cape Province. Interviews were conducted with programme managers and health personnel at clinics who were responsible for implementing the PEM Scheme. In assessing the impact of the PEM Scheme on growth, a retrospective review was done of the clinic records (including anthropometric data) of children enrolled in the PEM Scheme over a 1-year period. RESULTS: About 76% of the budget allocated to the PEM Scheme had been utilised over the 1-year period. The budget for the following financial year was based solely on food supplements purchased in the previous year. Coverage of malnourished pre-school children and eligible pregnant and lactating women for enrolment was estimated to be 50% and 60%, respectively. Eighty-five per cent of health facilities in the province participated in the PEM Scheme. Some of the main problems identified included: lack of training, inappropriate targeting of certain groups, incorrect application especially of discharge criteria for pregnant and lactating women, inadequate assessment for nutrition-related disease, inadequate nutrition counselling and no standardised monitoring. Of the 319 children enrolled over a year, the mean age was 16.2 (standard deviation 16.2) months, 41% had been low-birth-weight and 18% had been diagnosed with tuberculosis. Ten per cent of the children with a weight-for-age Z-score of <-2 moved into the normal Z-score range after being on the PEM Scheme for a mean duration of 8 months. There was an overall improvement in the weight-for-age Z-scores of 25% of the sample, with a significant difference between the mean weight-for-age Z-scores at enrolment and follow-up This was mainly related to significant improvement in the mean weight-for-age Z-scores of children <2 years. CONCLUSIONS: Numerous problems with the PEM Scheme have been identified which could have limited its impact. Recommendations are proposed for improving the effectiveness and impact of the PEM Scheme in the province

    The targeting of nutritionally at-risk children attending a primary health care facility in the Western Cape Province of South Africa

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    AIM: The aim of this study was to determine the practices of primary health care (PHC) nurses in targeting nutritionally at-risk infants and children for intervention at a PHC facility in a peri-urban area of the Western Cape Province of South Africa. METHODOLOGY: Nutritional risk status of infants and children <6 years of age was based on criteria specified in standardised nutrition case management guidelines developed for PHC facilities in the province. Children were identified as being nutritionally at-risk if their weight was below the 3rd centile, their birth weight was less than 2500 g, and their growth curve showed flattening or dropping off for at least two consecutive monthly visits. The study assessed the practices of nurses in identifying children who were nutritionally at-risk and the entry of these children into the food supplementation programme (formerly the Protein-Energy Malnutrition Scheme) of the health facility. Structured interviews were conducted with nurses to determine their knowledge of the case management guidelines; interviews were also conducted with caregivers to determine their sociodemographic status. RESULTS: One hundred and thirty-four children were enrolled in the study. The mean age of their caregivers was 29.5 (standard deviation 7.5) years and only 47 (38%) were married. Of the caregivers, 77% were unemployed, 46% had poor household food security and 40% were financially dependent on non-family members. Significantly more children were nutritionally at-risk if the caregiver was unemployed (54%) compared with employed (32%) (P=0.04) and when there was household food insecurity (63%) compared with household food security (37%) (P<0.004). Significantly more children were found not to be nutritionally at-risk if the caregiver was financially self-supporting or supported by their partners (61%) compared with those who were financially dependent on non-family members (35%) (P=0.003). The weight results of the nurses and the researcher differed significantly (P<0.001), which was largely due to the different scales used and weighing methods. The researcher's weight measurements were consistently higher than the nurses' (P<0.00). The researcher identified 67 (50%) infants and children as being nutritionally at-risk compared with 14 (10%) by the nurses. The nurses' poor detection and targeting of nutritionally at-risk children were largely a result of failure to plot weights on the weight-for-age chart (55%) and poor utilisation of the Road to Health Chart. CONCLUSIONS: Problems identified in the practices of PHC nurses must be addressed in targeting children at nutritional risk so that appropriate intervention and support can be provided. More attention must be given to socio-economic criteria in identifying children who are nutritionally at-risk to ensure their access to adequate social security networks

    Nutritional, immune, micronutrient and health status of HIV-infected children in care centres in Mangaung

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    Aim: To assess the nutritional, immune, micronutrient and health status of antiretroviral-naïve HIV-infected children.Method: A cross-sectional descriptive study was undertaken between September 2004 and March 2006 amongst HIV-infected children of which none received antiretroviral therapy, in care centres in Mangaung, Free State.Results: The study included 37 clinically stable and food-secure HIV-infected children. Their median age was 5.4 years (range 1.2–10.2 years). Fifteen children (41%) were underweight, 30 (81%) were stunted and one (3%) was wasted. The most commonly observed clinical features were lymphadenopathy (84%), skin rashes (51%), hepatomegaly (32%) and pallor (41%). Eight per cent of children had features of TB, while 19% had a lower respiratory tract infection. The median viral load of the group (n = 35) was 117 000 copies/ml, the median CD4+ cell count was 477 cells/mm3 and the median CD4 percentage was 22.5%. A significant negative correlation could be demonstrated between viral load and nutritional indicators. Children had deficient serum levels relative to normal reference values for glutathione (91% of children), albumin (78%), vitamin A (63%), vitamin D (44%), zinc (38%) and vitamin E (13%). Sixty per cent of the children were anaemic and 30% were iron deficient.Conclusion: A high prevalence of acute and chronic malnutrition and micronutrient deficiencies occurred among HIV-infected children residing in care centres. The study highlights the need to investigate early initiation of antiretroviral therapy and nutrition interventions, including aggressive supplementation, in order to improve the prognosis of these children

    Introduction of Solid Food to Young Infants

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    Timing of the first introduction of solid food during infancy may have potential effects on life-long health. To understand the characteristics that are associated with the timing of infants’ initial exposure to solid foods. The 2000 National Survey of Early Childhood Health (NSECH) was a nationally representative telephone survey of 2,068 parents of children aged 4–35 months, which profiled content and quality of health care for young children. African-American and Latino families were over-sampled. Analyses in this report include bivariate tests and logistic regressions. 62% of parents reported introducing solids to their child between 4–6 months of age. African-American mothers (OR = 0.5 [0.3, 0.9]), English-speaking Latino mothers (OR = 0.4 [0.2, 0.7]), White mothers with more than high school education (OR = 0.5 [0.2, 1.0]), and mothers who breastfed for 4 months or longer (OR = 0.4 [0.3, 0.7]) were less likely to introduce solids early. Most parents (92%) of children 4–9 months of age reported that their pediatric provider had discussed introduction of solids with them since the child’s birth, and provider discussion of feeding was not associated with the timing of introduction of solids. Although most parents recall discussing the introduction of solid foods with their child’s physician, several subgroups of mothers introduce solid foods earlier than the AAP recommendation of 4–6 months. More effective discussion of solid food introduction linked to counseling and support of breastfeeding by the primary health care provider may reduce early introduction of solids

    Tracking of dietary intakes in early childhood : the Melbourne InFANT program

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    Background/Objectives: The objectives of the present study were to describe food and nutrient intakes in children aged 9 and 18 months, and to assess tracking of intakes between these two ages.Subjects/Methods: Participants were 177 children of first-time mothers from the control arm of the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program. Dietary intake was collected at 9 and 18 months using three 24&thinsp;h diet recalls. Tracking was assessed for food and nutrient intakes using logistic regression analysis and estimating partial correlation coefficients, respectively.Results: Although overall nutrient intakes estimated in this study did not indicate a particular risk of nutrient deficiency, our findings suggest that consumption of energy-dense, nutrient-poor foods occurred as early as 9 months of age, with some of these foods tracking highly over the weaning period. Intakes of healthier foods such as fruits, vegetables, dairy products, eggs, fish and water were also relatively stable over this transition from infancy to toddlerhood, along with moderate tracking for riboflavin, iodine, fibre, calcium and iron. Tracking was low but close to &rho;=0.3 for zinc, magnesium and potassium intakes.Conclusions: The tracking of energy-dense, nutrient-poor foods has important implications for public health, given the development of early eating behaviours is likely to be modifiable. At this stage of life, dietary intakes are largely influenced by the foods parents provide, parental feeding practices and modelling. This study supports the importance of promoting healthy dietary trajectories from infancy.<br /

    Predicted risks of radiogenic cardiac toxicity in two pediatric patients undergoing photon or proton radiotherapy

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    BACKGROUND: Hodgkin disease (HD) and medulloblastoma (MB) are common malignancies found in children and young adults, and radiotherapy is part of the standard treatment. It was reported that these patients who received radiation therapy have an increased risk of cardiovascular late effects. We compared the predicted risk of developing radiogenic cardiac toxicity after photon versus proton radiotherapies for a pediatric patient with HD and a pediatric patient with MB. METHODS: In the treatment plans, each patient’s heart was contoured in fine detail, including substructures of the pericardium and myocardium. Risk calculations took into account both therapeutic and stray radiation doses. We calculated the relative risk (RR) of cardiac toxicity using a linear risk model and the normal tissue complication probability (NTCP) values using relative seriality and Lyman models. Uncertainty analyses were also performed. RESULTS: The RR values of cardiac toxicity for the HD patient were 7.27 (proton) and 8.37 (photon), respectively; the RR values for the MB patient were 1.28 (proton) and 8.39 (photon), respectively. The predicted NTCP values for the HD patient were 2.17% (proton) and 2.67% (photon) for the myocardium, and were 2.11% (proton) and 1.92% (photon) for the whole heart. The predicted ratios of NTCP values (proton/photon) for the MB patient were much less than unity. Uncertainty analyses revealed that the predicted ratio of risk between proton and photon therapies was sensitive to uncertainties in the NTCP model parameters and the mean radiation weighting factor for neutrons, but was not sensitive to heart structure contours. The qualitative findings of the study were not sensitive to uncertainties in these factors. CONCLUSIONS: We conclude that proton and photon radiotherapies confer similar predicted risks of cardiac toxicity for the HD patient in this study, and that proton therapy reduced the predicted risk for the MB patient in this study

    Living with myotonic dystrophy; what can be learned from couples? a qualitative study

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    Contains fulltext : 96062.pdf (publisher's version ) (Open Access)BACKGROUND: Myotonic dystrophy type 1 (MD1) is one of the most prevalent neuromuscular diseases, yet very little is known about how MD1 affects the lives of couples and how they themselves manage individually and together. To better match health care to their problems, concerns and needs, it is important to understand their perspective of living with this hereditary, systemic disease. METHODS: A qualitative study was carried out with a purposive sample of five middle-aged couples, including three men and two women with MD1 and their partners. Fifteen in-depth interviews with persons with MD1, with their partners and with both of them as a couple took place in the homes of the couples in two cities and three villages in the Netherlands in 2009. Results : People with MD1 associate this progressive, neuromuscular condition with decreasing abilities, describing physical, cognitive and psychosocial barriers to everyday activities and social participation. Partners highlighted the increasing care giving burden, giving directions and using reminders to compensate for the lack of initiative and avoidant behaviour due to MD1. Couples portrayed the dilemmas and frustrations of renegotiating roles and responsibilities; stressing the importance of achieving a balance between individual and shared activities. All participants experienced a lack of understanding from relatives, friends, and society, including health care, leading to withdrawal and isolation. Health care was perceived as fragmentary, with specialists focusing on specific aspects of the disease rather than seeking to understand the implications of the systemic disorder on daily life. CONCLUSIONS: Learning from these couples has resulted in recommendations that challenge the tendency to treat MD1 as a condition with primarily physical impairments. It is vital to listen to couples, to elicit the impact of MD1, as a multisystem disorder that influences every aspect of their life together. Couple management, supporting the self-management skills of both partners is proposed as a way of reducing the mismatch between health services and health needs

    Exploring CRM effectiveness: an institutional theory perspective

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    This study identifies the potential contribution that institutional theory can make to understanding the success of marketing practices. Based on institutional theory, we argue that the effectiveness of marketing practices decreases when firms are motivated to adopt such practices under the influence of institutional pressures originating in firms' environments. However, alignment between a practice and a firm's marketing strategy may buffer against these negative effects. We apply these insights to the case of customer relationship management (CRM). CRM is considered an important way to enhance customer loyalty and firm performance, but it has also been criticized for being expensive and for not living up to expectations. Empirical data from 107 organizations confirm that, in general, adopting CRM for mimetic motives is likely to result in fewer customer insights as a result of using this practice. Our study suggests that institutional theory has much to offer to the investigation of the effectiveness of marketing practices

    Increased Expression of PcG Protein YY1 Negatively Regulates B Cell Development while Allowing Accumulation of Myeloid Cells and LT-HSC Cells

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    Ying Yang 1 (YY1) is a multifunctional Polycomb Group (PcG) transcription factor that binds to multiple enhancer binding sites in the immunoglobulin (Ig) loci and plays vital roles in early B cell development. PcG proteins have important functions in hematopoietic stem cell renewal and YY1 is the only mammalian PcG protein with DNA binding specificity. Conditional knock-out of YY1 in the mouse B cell lineage results in arrest at the pro-B cell stage, and dosage effects have been observed at various YY1 expression levels. To investigate the impact of elevated YY1 expression on hematopoetic development, we utilized a mouse in vivo bone marrow reconstitution system. We found that mouse bone marrow cells expressing elevated levels of YY1 exhibited a selective disadvantage as they progressed from hematopoietic stem/progenitor cells to pro-B, pre-B, immature B and re-circulating B cell stages, but no disadvantage of YY1 over-expression was observed in myeloid lineage cells. Furthermore, mouse bone marrow cells expressing elevated levels of YY1 displayed enrichment for cells with surface markers characteristic of long-term hematopoietic stem cells (HSC). YY1 expression induced apoptosis in mouse B cell lines in vitro, and resulted in down-regulated expression of anti-apoptotic genes Bcl-xl and NFκB2, while no impact was observed in a mouse myeloid line. B cell apoptosis and LT-HSC enrichment induced by YY1 suggest that novel strategies to induce YY1 expression could have beneficial effects in the treatment of B lineage malignancies while preserving normal HSCs
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