587 research outputs found

    The G-O Rule and Waldmeier Effect in the Variations of the Numbers of Large and Small Sunspot Groups

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    We have analysed the combined Greenwich and Solar Optical Observing Network (SOON) sunspot group data during the period of 1874-2011 and determined variations in the annual numbers (counts) of the small, large and big sunspot groups (these classifications are made on the basis of the maximum areas of the sunspot groups). We found that the amplitude of an even-numbered cycle of the number of large groups is smaller than that of its immediately following odd-numbered cycle. This is consistent with the well known Gnevyshev and Ohl rule or G-O rule of solar cycles, generally described by using the Zurich sunspot number (Rz). During cycles 12-21 the G-O rule holds good for the variation in the number of small groups also, but it is violated by cycle pair (22, 23) as in the case of Rz. This behaviour of the variations in the small groups is largely responsible for the anomalous behaviour of Rz in cycle pair (22, 23). It is also found that the amplitude of an odd-numbered cycle of the number of small groups is larger than that of its immediately following even-numbered cycle. This can be called as `reverse G-O rule'. In the case of the number of the big groups, both cycle pairs (12, 13) and (22, 23) violated the G-O rule. In many cycles the positions of the peaks of the small, large, and big groups are different and considerably differ with respect to the corresponding positions of the Rz peaks. In the case of cycle 23, the corresponding cycles of the small and large groups are largely symmetric/less asymmetric (Waldmeier effect is weak/absent) with their maxima taking place two years later than that of Rz. The corresponding cycle of the big groups is more asymmetric (strong Waldmeier effect) with its maximum epoch taking place at the same time as that of Rz.Comment: 13 pages, 5 figures, 1 table, accepted by Solar Physic

    Leveraging family dynamics to increase the effectiveness of incentives for physical activity: The FIT-FAM randomized controlled trial

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    Background: Insufficient physical activity is a global public health concern. Research indicates incentives can increase physical activity levels of children but has not tested whether incentives targeted at children can be leveraged to increase physical activity levels of their parents. This study evaluates whether a novel incentive design linking children's incentives to both their and their parent's physical activity levels can increase parent's physical activity. Methods: We conducted a two-arm, parallel, open-labelled randomized controlled trial in Singapore where parent-child dyads were randomly assigned to either (1) rewards to child contingent on child's physical activity (child-based) or (2) rewards to child contingent on both child's and parent's physical activity (family-based). Parents had to be English-speaking, computer-literate, non-pregnant, full-time employees, aged 25-65 years, and with a participating child aged 7-11 years. Parent-child dyads were randomized within strata (self-reported low vs high weekly physical activity) into study arms in a 1:1 ratio. Participants were given activity trackers to assess daily steps. The outcome of interest was the between-arm difference in the change from baseline in parent's mean steps/day measured by accelerometry at months 6 and 12 (primary endpoint). Results: Overall, 159 and 157 parent-child dyads were randomized to the child-based or family-based arms, respectively. Outcomes were evaluated on an intent-to-treat basis. At month 6, there was a 613 steps/day (95% CI: 54-1171) differential in favour of family-based parents. At month 12, our primary endpoint, the differential was reduced to 369 steps/day (95% CI: - 88-1114) and was no longer statistically significant. Conclusions: Our findings suggest that novel incentive designs that take advantage of group dynamics may be effective. However, in this design, the effectiveness of the family-based incentive to increase parent's physical activity was not sustained through one year. Trial registration: NCT02516345 (ClinicalTrials.gov) registered on August 5, 2015

    New Approach to GUTs

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    We introduce a new string-inspired approach to the subject of grand unification which allows the GUT scale to be small, \lesssim 200 TeV, so that it is within the reach of {\em conceivable} laboratory accelerated colliding beam devices. The key ingredient is a novel use of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date. This part of the approach involves new unknown parameters to be tested experimentally. A possible hint at the existence of these new parameters may already exist in the EW precision data comparisons with the SM expectations.Comment: 8 pages; improved text and references, note added; extended text, 1 figure added; extended text for publication in Eur. Phys. Journal

    Racial Differences in weight loss Mediated by engagement and behavior change

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    Objective: We set out to determine if a primarily Internet-delivered behavioral weight loss intervention produced differential weight loss in African American and non-Hispanic White women, and to identify possible mediators. Design: Data for this analysis were from a randomized controlled trial, collected at baseline and 4-months. Setting: The intervention included monthly face-to-face group sessions and an Internet component that participants were recommended to use at least once weekly. Participants: We included overweight or obese African American and non-Hispanic White women (n=170), with at least weekly Internet access, who were able to attend group sessions. Intervention: Monthly face-to-face group sessions were delivered in large or small groups. The Internet component included automated tailored feedback, self-monitoring tools, written lessons, video resources, problem solving, exercise action planning tools, and social support through message boards. Main outcome measure: Multiple linear regression was used to evaluate race group differences in weight change. Results: Non-Hispanic White women lost more weight than African American women (-5.03% vs.-2.39%, P=.0002). Greater website log-ins and higher change in Eating Behavior Inventory score in non-Hispanic White women partially mediated the race-weight loss relationship. Conclusions: The weight loss disparity may be addressed through improved website engagement and adoption of weight control behaviors

    Physical activity opportunities within the schedule of early care and education centers

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    Background: Physical activity has many benefits for young children's health and overall development, but few studies have investigated how early care and education centers allot time for physical activity, along with measured individual physical activity levels for indoor/outdoor activities during a typical day. Methods: Fifty early care and education centers in central North Carolina participated in 4 full-day observations, and 559 children aged 3-5 years within centers wore accelerometers assessing physical activity during observation days. Observation and physical activity data were linked and analyzed for associations between child activity and type of classroom activity. Results: Children averaged 51 (13) minutes per day of moderate to vigorous physical activity and 99 (18) minutes per day of light physical activity while in child care. Children averaged 6 (10) and 10 (13) minutes per day of observed outdoor and indoor daily teacher-led physical activity, respectively. Outdoor time averaged 67 (49) minutes per day, and physical activity levels were higher during outdoor time than during common indoor activities (center time, circle time, and TV time). Conclusions: Physical activity levels varied between indoor and outdoor class activities. Policy and program-related efforts to increase physical activity in preschoolers should consider these patterns to leverage opportunities to optimize physical activity within early care and education centers

    Comparative effectiveness of a standard behavioral and physical activity enhanced behavioral weight loss intervention in Black women

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    Black women typically lose small amounts of weight in behavioral weight loss interventions, partially due to low engagement in physical activity. Culturally relevant enhancement of the physical activity component may improve weight loss. This study compared the effectiveness of a culturally-relevant, physical activity-enhanced behavioral weight loss intervention to a standard behavioral weight loss intervention in Black women (n = 85) over 6 months. The study was conducted in two cohorts from March 2016 to February 2017 at the University of North Carolina at Chapel Hill. Participants had an average age of 48.30 ± 11.02 years with an average body mass index of 36.46 ± 4.50 kg/m2. Standard and enhanced groups’ weight change (−2.83 kg and −2.08 kg, respectively) and change in physical activity (43.93 min/ week and 15.29 min/week, respectively) did not differ between groups. Significantly more standard group participants lost 5% of baseline weight compared to enhanced group participants. This study produced typical weight loss results in Black women. Behavioral weight loss treatment remains moderately effective for Black women. Strategies to increase attendance and self-monitoring, and the inclusion of cultural contexts to weight-related behaviors are needed to improve outcomes

    How important is perception of safety to park use? A four-city survey

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    Our purpose was to determine the relative importance of individual- and park-related characteristics in influencing both local park use and specific engagement in active sports, walking and sedentary pursuits. We surveyed 3815 adults living within 0.80 km of one of 24 study parks in four US metropolitan areas. Chi-square statistics and baseline-category logit models examined how perceived safety and park characteristics were related to park visitation and types of park activities, controlling for city, individual and park characteristics. Survey participants who perceived the parks as safe (88%) had 4.6 times the odds (95% CI 3.5–6.0) of reporting having visited the study park. Men and African Americans were more likely, and older individuals and those who self-reported being in fair or poor health less likely to perceive parks as safe. Parks having low incivilities scores and those with four or more different facilities, such as tennis courts, swimming pools, basketball courts, etc., were more likely than parks with fewer facilities to be perceived as safe. While park facilities had a much smaller odds ratio for predicting park visits (1.8), it affected 70% of the population. The implication is, if these associations are causal, modifying park facilities may have a greater population impact than improving perceptions of park safety. Our findings are consistent with studies suggesting that increasing the variety of park facilities and offering more organised activities may encourage physical activity among specific target groups

    Use of neighbourhood parks: does socio-economic status matter? A four-city study

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    To determine if neighborhood socio-economic status (SES) influences park use and park-based physical activity

    A Comparison of Solar Cycle Variations in the Equatorial Rotation Rates of the Sun's Subsurface, Surface, Corona, and Sunspot Groups

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    Using the Solar Optical Observing Network (SOON) sunspot-group data for the period 1985-2010, the variations in the annual mean equatorial-rotation rates of the sunspot groups are determined and compared with the known variations in the solar equatorial-rotation rates determined from the following data: i) the plasma rotation rates at 0.94Rsun, 0.95Rsun,...,1.0Rsun measured by Global Oscillation Network Group (GONG) during the period 1995-2010, ii) the data on the soft X-ray corona determined from Yohkoh/SXT full disk images for the years 1992-2001, iii) the data on small bright coronal structures (SBCS) which were traced in Solar and Heliospheric Observatory (SOHO)/EIT images during the period 1998-2006, and iv) the Mount Wilson Doppler-velocity measurements during the period 1986-2007. A large portion (up to approximate 30 deg latitude) of the mean differential-rotation profile of the sunspot groups lies between those of the internal differential-rotation rates at 0.94Rsun and 0.98Rsun.The variation in the yearly mean equatorial-rotation rate of the sunspot groups seems to be lagging that of the equatorial-rotation rate determined from the GONG measurements by one to two years.The amplitude of the latter is very small.The solar-cycle variation in the equatorial-rotation rate of the solar corona closely matches that determined from the sunspot-group data.The variation in the equatorial-rotation rate determined from the Mount Wilson Doppler-velocity data closely resembles the corresponding variation in the equatorial-rotation rate determined from the sunspot-group data that included the values of the abnormal angular motions (> 3 deg per day) of the sunspot groups. Implications of these results are pointed out.Comment: 22 pages, 10 figures, accepted by Solar Physic
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