Interannual variability of the stratospheric wave driving during northern winter

The strength of the stratospheric wave driving during northern winter is often quantified by the January–February mean poleward eddy heat flux at 100 hPa, averaged over 40°–80° N (or a similar area and period). Despite the dynamical and chemical relevance of the wave driving, the causes for its variability are still not well understood. In this study, ERA-40 reanalysis data for the period 1979–2002 are used to examine several factors that significantly affect the interannual variability of the wave driving. The total poleward heat flux at 100 hPa is poorly correlated with that in the troposphere, suggesting a decoupling between 100 hPa and the troposphere. However, the individual zonal wave-1 and wave-2 contributions to the wave driving at 100 hPa do exhibit a significant coupling with the troposphere, predominantly their stationary components. The stationary wave-1 contribution to the total wave driving significantly depends on the latitude of the stationary wave-1 source in the troposphere. The results suggest that this dependence is associated with the varying ability of stationary wave-1 activity to enter the tropospheric waveguide at mid-latitudes. The wave driving anomalies are separated into three parts: one part due to anomalies in the zonal correlation coefficient between the eddy temperature and eddy meridional wind, another part due to anomalies in the zonal eddy temperature amplitude, and a third part due to anomalies in the zonal eddy meridional wind amplitude. It is found that year-to-year variability in the zonal correlation coefficient between the eddy temperature and the eddy meridional wind is the most dominant factor in explaining the year-to-year variability of the poleward eddy heat flux

Social support, physical activity and sedentary behavior among 6(th)-grade girls: a cross-sectional study

BACKGROUND: Despite the importance of social support in promoting physical activity, little is known about the relative influence of the type or source of social support on adolescent girls' physical activity and sedentary behaviors. This study examined the associations of two types of social support (social participation in and social encouragement for physical activity) and two social support sources (family and friends) with self-reported daily minutes of physical activity and sedentary behavior among sixth-grade girls in Texas. METHODS: A secondary analysis of 718 sixth-grade girls between the ages of 10 to 14 was performed using cross-sectional baseline data from an osteoporosis prevention intervention study. Physical activity and sedentary behaviors (television-video viewing and computer-video game playing) were assessed using 3 administrations of the Self-Administered Physical Activity Checklist; social support indicators were assessed with Likert-type items from a psychosocial questionnaire. RESULTS: In multiple linear regression analyses, friend physical activity participation (partial correlation coefficient (r) = 0.10, p = .009) and friend (r = 0.12) and family encouragement (r = 0.11) (p < .01, respectively) were positively related to moderate-to-vigorous physical activity in the full model with other support variables, BMI and ethnicity; friend encouragement was the only variable positively related to vigorous physical activity (r = 0.11, p = .005). Family participation in physical activity had the strongest negative correlation with total minutes of television-video viewing and computer-video playing (r = -0.08, p < .05). CONCLUSION: Findings lend support to the importance of social support for physical activity among adolescent girls but suggest that the source and type of social support may differ for physical activity and sedentary behaviors. Further research is needed to assess the causal or reciprocal relation between the roles of friends and family in promoting physical activity and of family physical activity in decreasing sedentary behaviors among early adolescent girls

Global ozone forecasting based on ERS-2 GOME observations

International audienceThe availability of near-real time ozone observations from satellite instruments has recently initiated the development of ozone data assimilation systems. In this paper we present the results of an ozone assimilation and forecasting system, in use since Autumn 2000. The forecasts are produced by an ozone transport and chemistry model, driven by the operational medium range forecasts of ECMWF. The forecasts are initialised with realistic ozone distributions, obtained by the assimilation of near-real time total column observations of the GOME spectrometer on ERS-2. The forecast error diagnostics demonstrate that the system produces meaningful total ozone forecasts for up to 6 days in the extratropics. In the tropics meaningful forecasts of the small anomalies are restricted to shorter periods of about two days with the present model setup. It is demonstrated that important events, such as the breakup of the South Pole ozone hole and mini-hole events above Europe can be successfully predicted 4--5 days in advance

Analysis of the frequency-dependent response to wave forcing in the extratropics

A quasigeostrophic model for the frequency-dependent response of the zonal-mean flow to planetary-wave forcing at Northern Hemisphere (NH) midlatitudes is applied to 4-D-Var ECMWF analysis data for six extended winter seasons. The theoretical response is a non-linear function of the frequency of the forcing, the thermal damping time &alpha;&minus;1, and a scaling parameter &micro; which includes the aspect ratio of the meridional to the vertical length scale of the response. Regression of the calculated response from the analyses onto the theoretical response yields height-dependent estimates for both &alpha;&minus;1 and &micro;. The thermal damping time estimated from this dynamical model is about 2 days in the troposphere, 7&ndash;10 days in the stratosphere, and 2&ndash;4 days in the lower mesosphere. For the stratosphere and lower mesosphere, the estimates lie within the range of existing radiative damping time estimates, but for the troposphere they are significantly smaller

Increasing physical activity and decreasing sedentary activity in adolescent girls – The Incorporating More Physical Activity and Calcium in Teens (IMPACT) study

<p>Abstract</p> <p>Background</p> <p>Lack of regular physical activity and consequent sub-optimal bone mass acquisition in youth has been implicated as a primary cause of adult-onset osteoporosis. IMPACT was a behavioral theory-based 1 1/2 year randomized controlled field study aimed at increasing bone accretion in middle school girls. The objective of this study was to determine the intervention effects of the IMPACT program upon key physical and sedentary activity endpoints among schools that participated in the IMPACT study. Endpoints examined included weight bearing physical activity (WBPA); moderate to vigorous physical activity (MVPA); vigorous physical activity (VPA); MET (metabolic equivalent) – weighted WBPA and MVPA; sedentary activity; before/after-school physical activity; and weekend physical activity.</p> <p>Methods</p> <p>Primary data analysis using a pretest-posttest control group design was conducted utilizing mixed model analysis of covariance. Data gathered from the IMPACT cohort from 2000–2002 were analyzed to determine baseline versus follow-up differences in activity endpoints. Confounders investigated included ethnicity, body mass index, menarcheal status, participation in 7^thgrade PE/athletics, friend/familial support and neighborhood safety.</p> <p>Results</p> <p>Follow-up means were higher for participating intervention schools relative to control schools for all physical activity variables but were statistically significant only for the following variables: daily minutes of vigorous physical activity (mean difference between Intervention (I) and Control (C) = 6.00↑ minutes, 95% CI = 5.82–6.18, p = 0.05), daily after school activity minutes (mean difference between I and C = 8.95↑ minutes, 95% CI = 8.69–9.21, p = 0.04), and daily weekend activity minutes (mean difference between I and C = 19.00↑ minutes, 95% CI = 18.40–19.60, p = 0.05). The intervention significantly reduced duration of student daily TV/Video watching (mean difference between I and C = 12.11↓ minutes, 95% CI = 11.74–12.48, p = 0.05) and total daily sedentary activity minutes (mean difference between I and C = 16.99↓ minutes, 95% CI = 16.49–17.50, p = 0.04).</p> <p>Conclusion</p> <p>A well designed and implemented school based health and physical activity intervention can result in a positive influence upon increasing physical activity levels and decreasing sedentary activity. Future interventions should consider a more structured intervention component to obtain significant changes in WBPA.</p

Formative Evaluation of the Time Twisters : A Comic Book Based Obesity Prevention Curriculum for Elementary School Students

Introduction: Obesity is a public health problem, particularly in Hispanic children. Alternative media channels may offer the potential to motivate children to engage in health promoting behaviors. A comic book, “Time Twisters”, was developed to impact screen time use, physical activity, and dietary behavior for elementary school children and evaluated for acceptability and feasibility prior to implementation in a multi-component physical activity intervention. [See PDF for complete abstract

Patient-Derived Papillary Thyroid Cancer Organoids for Radioactive Iodine Refractory Screening

Simple Summary Over the past three decades, the incidence of thyroid cancer has been rising, with 90% being the well-differentiated thyroid cancer subtype. After diagnosis and surgical removal of the thyroid gland, radioactive iodine is administered to induce a localized post-operative radiation treatment. However, in 15-33% of papillary thyroid cancer cases, the cells are unable to take up radioactive iodine, resulting in an ineffective treatment which sometimes has severe side effects. Pre-treatment diagnosis of non-responding patients would prevent ineffective and toxic iodine treatment. Therefore, in this study, we developed a patient-derived papillary thyroid cancer organoid model. Patient-derived organoids responding or not responding to radioactive iodine clearly resembled the tumor of origin, but showed clear differences in sodium/iodide symporter expression. Our results indicate that thyroid cancer organoids might be a suitable tool for the early diagnosis of non-responding patients, in order to eventually reduce radioactive iodine overtreatment and its many side effects for thyroid cancer patients. Patients with well-differentiated thyroid cancer, especially papillary thyroid cancer (PTC), are treated with surgical resection of the thyroid gland. This is followed by post-operative radioactive iodine (I-131), resulting in total thyroid ablation. Unfortunately, about 15-33% of PTC patients are unable to take up I-131, limiting further treatment options. The aim of our study was to develop a cancer organoid model with the potential for pre-treatment diagnosis of these I-131-resistant patients. PTC tissue from thirteen patients was used to establish a long-term organoid model. These organoids showed a self-renewal potential for at least five passages, suggesting the presence of cancer stem cells. We demonstrated that thyroid specific markers, a PTC marker, and transporters/receptors necessary for iodine uptake and thyroid hormone production were expressed on a gene and protein level. Additionally, we cultured organoids from I-131-resistant PTC material from three patients. When comparing PTC organoids to radioactive iodine (RAI)-refractory disease (RAIRD) organoids, a substantial discordance on both a protein and gene expression level was observed, indicating a treatment prediction potential. We showed that patient-derived PTC organoids recapitulate PTC tissue and a RAIRD phenotype. Patient-specific PTC organoids may enable the early identification of I-131-resistant patients, in order to reduce RAI overtreatment and its many side effects for thyroid cancer patients