956 resultados para lay percentage


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Aim Acute respiratory infections (ARI) are common in children, and symptoms range from days to weeks. The aim of this study was to determine if children with asthma have more severe ARI episodes compared with children with protracted bronchitis and controls. Methods Parents prospectively scored their child's next ARI using the Canadian acute respiratory illness and flu scale (CARIFS) and a validated cough diary (on days 1–7, 10 and 14 of illness). Children were age- and season-matched. Results On days 10 and 14 of illness, children with protracted bronchitis had significantly higher median CARIFS when compared with children with asthma and healthy controls. On day 14, the median CARIFS were: asthma = 4.1 (interquartile range (IQR) 4.0), protracted bronchitis = 19.6 (IQR 25.8) and controls = 4.1 (IQR 5.25). The median cough score was significantly different between groups on days 1, 7, 10 and 14 (P < 0.001). A significantly higher proportion of children with protracted bronchitis (63%) were still coughing at day 14 in comparison with children with asthma (24%) and healthy controls (26%). Conclusion Children with protracted bronchitis had the most severe ARI symptoms and higher percentage of respiratory morbidity at day 14 in comparison with children with asthma and healthy controls.

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Background Parents play a significant role in shaping youth physical activity (PA). However, interventions targeting PA parenting have been ineffective. Methodological inconsistencies related to the measurement of parental influences may be a contributing factor. The purpose of this article is to review the extant peer-reviewed literature related to the measurement of general and specific parental influences on youth PA. Methods A systematic review of studies measuring constructs of PA parenting was conducted. Computerized searches were completed using PubMed, MEDLINE, Academic Search Premier, SPORTDiscus, and PsycINFO. Reference lists of the identified articles were manually reviewed as well as the authors' personal collections. Articles were selected on the basis of strict inclusion criteria and details regarding the measurement protocols were extracted. A total of 117 articles met the inclusionary criteria. Methodological articles that evaluated the validity and reliability of PA parenting measures (n=10) were reviewed separately from parental influence articles (n=107). Results A significant percentage of studies used measures with indeterminate validity and reliability. A significant percentage of articles did not provide sample items, describe the response format, or report the possible range of scores. No studies were located that evaluated sensitivity to change. Conclusion The reporting of measurement properties and the use of valid and reliable measurement scales need to be improved considerably.

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Purpose This study aimed to objectively measure the physical activity (PA) characteristics of a racially and ethnically diverse sample of inner-city elementary schoolchildren and to examine the influence of sex, race/ethnicity, grade level, and weight status on PA. Methods A total of 470 students in grades 4-6 from six inner-city schools in Philadelphia wore an ActiGraph GT3X+ accelerometer (Actigraph, Pensacola, FL) for up to 7 d. The resultant data were uploaded to a customized Visual Basic EXCEL macro to determine the time spent in sedentary (SED), light-intensity PA (LPA), and moderate- to vigorous-intensity PA (MVPA). Results On average, students accumulated 48 min of MVPA daily. Expressed as a percentage of monitoring time, students were sedentary for 63% of the time, in LPA 31% of the time, and in MVPA 6% of the time. Across all race/ethnicity and grade level groups, boys exhibited significantly higher levels of MVPA than girls did; fifth-grade boys exhibited significantly lower MVPA levels than fourth-and sixth-grade boys did, and sixth-grade girls exhibited significantly lower MVPA levels than fourth-and fifth-grade girls did. Hispanic children exhibited lower levels of MVPA than children from other racial/ethnic groups did, and overweight and obese children exhibited significantly lower MVPA levels than children in the healthy weight range did. Across the entire sample, only 24.3% met the current public health guidelines for PA. Physical inactivity was significantly greater among females, Hispanics, and overweight and obese students. Conclusions Fewer than one in four inner-city schoolchildren accumulated the recommended 60 min of MVPA daily. These findings highlight the need for effective and sustainable programs to promote PA in inner-city youth.

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Background Accelerometers have become one of the most common methods of measuring physical activity (PA). Thus, validity of accelerometer data reduction approaches remains an important research area. Yet, few studies directly compare data reduction approaches and other PA measures in free-living samples. Objective To compare PA estimates provided by 3 accelerometer data reduction approaches, steps, and 2 self-reported estimates: Crouter's 2-regression model, Crouter's refined 2-regression model, the weighted cut-point method adopted in the National Health and Nutrition Examination Survey (NHANES; 2003-2004 and 2005-2006 cycles), steps, IPAQ, and 7-day PA recall. Methods A worksite sample (N = 87) completed online-surveys and wore ActiGraph GT1M accelerometers and pedometers (SW-200) during waking hours for 7 consecutive days. Daily time spent in sedentary, light, moderate, and vigorous intensity activity and percentage of participants meeting PA recommendations were calculated and compared. Results Crouter's 2-regression (161.8 +/- 52.3 minutes/day) and refined 2-regression (137.6 +/- 40.3 minutes/day) models provided significantly higher estimates of moderate and vigorous PA and proportions of those meeting PA recommendations (91% and 92%, respectively) as compared with the NHANES weighted cut-point method (39.5 +/- 20.2 minutes/day, 18%). Differences between other measures were also significant. Conclusions When comparing 3 accelerometer cut-point methods, steps, and self-report measures, estimates of PA participation vary substantially.

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Importance Active video games may offer an effective strategy to increase physical activity in overweight and obese children. However, the specific effects of active gaming when delivered within the context of a pediatric weight management program are unknown. Objective To evaluate the effects of active video gaming on physical activity and weight loss in children participating in an evidence-based weight management program delivered in the community. Design, Setting, and Participants Group-randomized clinical trial conducted during a 16-week period in YMCAs and schools located in Massachusetts, Rhode Island, and Texas. Seventy-five overweight or obese children (41 girls [55%], 34 whites [45%], 20 Hispanics [27%], and 17 blacks [23%]) enrolled in a community-based pediatric weight management program. Mean (SD) age of the participants was 10.0 (1.7) years; body mass index (BMI) z score, 2.15 (0.40); and percentage overweight from the median BMI for age and sex, 64.3% (19.9%). Interventions All participants received a comprehensive family-based pediatric weight management program (JOIN for ME). Participants in the program and active gaming group received hardware consisting of a game console and motion capture device and 1 active game at their second treatment session and a second game in week 9 of the program. Participants in the program-only group were given the hardware and 2 games at the completion of the 16-week program. Main Outcomes and Measures Objectively measured daily moderate-to-vigorous and vigorous physical activity, percentage overweight, and BMI z score. Results Participants in the program and active gaming group exhibited significant increases in moderate-to-vigorous (mean [SD], 7.4 [2.7] min/d) and vigorous (2.8 [0.9] min/d) physical activity at week 16 (P < .05). In the program-only group, a decline or no change was observed in the moderate-to-vigorous (mean [SD] net difference, 8.0 [3.8] min/d; P = .04) and vigorous (3.1 [1.3] min/d; P = .02) physical activity. Participants in both groups exhibited significant reductions in percentage overweight and BMI z scores at week 16. However, the program and active gaming group exhibited significantly greater reductions in percentage overweight (mean [SD], −10.9% [1.6%] vs −5.5% [1.5%]; P = .02) and BMI z score (−0.25 [0.03] vs −0.11 [0.03]; P < .001). Conclusions and Relevance Incorporating active video gaming into an evidence-based pediatric weight management program has positive effects on physical activity and relative weight.

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Background Family child care homes (FCCHs) are the second-largest provider of nonrelative care in the U.S. However, despite providing care for nearly 1.9 million children aged <5 years, little is known about the nutrition and physical activity practices of FCCHs. Purpose To address this gap, this study aims to describe policies and practices related to nutrition and physical activity in a representative sample of FCCHs. Methods A stratified random sample of registered FCCHs operating in Kansas (N=297) completed the Nutrition and Physical Activity Self Assessment for Child Care (NAPSACC) instrument. Prevalence estimates and 95% CIs for meeting or exceeding accepted child care standards were calculated using SAS PROC SURVEYFREQ. Results Most providers either met or exceeded child care standards related to serving fruit and vegetables and provision of daily physical activity. Very few providers reported serving fried meats or vegetables or unhealthy snack foods on a regular basis. Areas of concern included infrequent servings of low-fat milk, frequent use of unhealthy foods for celebrations, widespread use of TV and video games throughout the day, restricting physical activity for children who misbehave, and lack of appropriate indoor spaces for physical activity. Only a small percentage of providers reported receiving regular training in nutrition or physical activity. Relatively few providers had written guidelines on nutrition or physical activity. Conclusions Some strengths were exhibited by FCCHs, but substantial weaknesses were shown with respect to meeting established child care standards for nutrition and physical activity. Interventions to promote healthy eating and regular physical activity in FCCHs are thus warranted.

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The development of resistance to the antiestrogen tamoxifen occurs in a high percentage of initially responsive patients. We have developed a new model in which to investigate acquired resistance to triphenylethylenes. A stepwise in vitro selection of the hormone-independent human breast cancer variant MCF-7/LCC1 against 4-hydroxytamoxifen produced a stable resistant population designated MCF7/LCC2. MCF7/LCC2 cells retain levels of estrogen receptor expression comparable to the parental MCF7/LCC1 and MCF-7 cells. Progesterone receptor expression remains estrogen inducible in MCF7/LCC2 cells, although to levels significantly lower than observed in MCF-7 and MCF7/LCC1 cells. MCF7/ LCC2 cells form tumors in ovariectomized nude mice without estrogen supplementation, and these tumors are tamoxifen resistant but can be tstrogen stimulated. Significantly, MCF7/LCC2 cells have retained sensitivity to the steroidal antiestrogen ICI 182,780. These data suggest that some breast cancer patients who acquire resistance to tamoxifen may not develop cross-resistance to treatment with steroidal antiestrogens.

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The aim of this thesis is to show how character analysis can be used to approach conceptions of saga authorship in medieval Iceland. The idea of possession is a metaphor that is adopted early in the thesis, and is used to describe Icelandic sagas as works in which traditional material is subtly interpreted by medieval authors. For example, we can say that if authors claim greater possession of the sagas, they interpret, and not merely record, the sagas' historical information. On the other hand, tradition holds onto its possession of the narrative whenever it is not possible for an author to develop his own creative and historical interests. The metaphor of possession also underpins the character analysis in the thesis, which is based on the idea that saga authors used characters as a vehicle by which to possess saga narratives and so develop their own historical interests. The idea of possession signals the kinds of problems of authorship study which are addressed here, in particular, the question of the authors' sense of saga writing as an act either of preservation or of creation. While, in that sense, the thesis represents an additional voice in a long-standing debate about the saga writers' relation to their source materials, I argue against a clear-cut distinction between creative and non-creative authors, and focus instead on the wide variation in authorial control over saga materials. This variation suggests that saga authorship is a multi-functional activity, or one which co-exists with tradition. Further, by emphasising characterisation as a method, I am adding to the weight of scholarship that seeks to understand the sagas in terms of their literary effects. The Introduction and chapter one lay out the theoretical scope of this thesis. My aim in these first two sections is to inform the reader of the type of critical questions that arise when authorship is approached in relation to characterisation, and to suggest an interpretive framework with which to approach these questions. In the Introduction this aim manifests as a brief discussion of the application of the term "authorship" to the medieval Icelandic corpus, a definition of the scope of this study, and an introduction to the connections, made throughout this thesis, between saga authors, the sagas' narrative style, and the style of characterisation in the sagas. Chapter one is a far more detailed discussion of our ability to make these connections. In particular, the chapter develops the definition of the analytical term "secondary authorship" that I introduce in order to delineate the type of characterisation that is of most interest in this thesis. "Secondary authorship" is a literary term that aims to sharpen our approach to saga authors' relationship to their characters by focusing on characters who make representations about the events of the saga. The term refers to any instance in which characters behave in a manner that resembles the creativity, interpretation, and understanding associated with authorship more generally. Character analysis cannot, however, be divorced from socio-historical approaches to the saga corpus. Most importantly, the sagas themselves are socio-historical representations that claim some degree of truth value. This claim that the sagas make by implication about their historicity is the starting point of a discussion of authorship in medieval Iceland. Therefore, at the beginning of chapter one I discuss some of the approaches to the social context of saga writing. This discussion serves as an introduction to both the culture of saga writing in medieval Iceland and to the nature of the sagas' historical perspective, and reflects my sense that literary interpretations of the sagas cannot be isolated from the historical discourses that frame them. The chapter also discusses possession, which, as I note above, is used alongside the concept of secondary authorship to describe the saga authors' relationship with the stories and characters of the past. At the close of chapter one, I offer a preliminary list the various functions of saga authorship, and give some examples of secondary authorship. From this point I am able to tie my argument about secondary authorship to specific examples from the sagas. Chapter two examines the effect of family obligations and domestic points of view in the depiction of characters' choices and conception of themselves. The examples that are given in that chapter - from Gisla saga Súrssonar and Íslendinga saga - are the first of a number of textual analyses that demonstrate the application of the concepts of secondary authorship and possession of saga narratives. The relationship between narratives about national and domestic matters shows how authorial creativity in the area of kinship obligation provides the basis for the saga's development of historical themes. Thus, the two major case studies given in chapter two tie authorial engagement with characters to the most influential social institution in early and medieval Iceland, the family. The remaining chapters represent similar attempts to relate authorial possession of saga characters to central socio-historical themes in the sagas, such as the settlement process in early Iceland and its influence on the development of regional political life (chapter three). Likewise, the strong authorial interest in an Icelander's journey to Norway in Heimskringla is presented as evidence of the author's use of a saga character to express an Icelandic interpretation of Norwegian history and to promote a sense that Iceland shared the ownership of regal history with Norway (chapter four). In that authorial engagement with the Icelander abroad, we witness saga characterisation being used as a basis for historical interpretation and the means by which foreign traditions and influence, not least the narratives of royal lives and of the Christianisation, are claimed as part of medieval Icelanders' self-conception. While saga authors observe the conventions of saga narration, characters are often subtly positioned as the authors' interpretive mirrors, especially clear than when they act as secondary authors. Nowhere is this more apparent than in Brennu- Njáls saga, which contains many characters who voice the author's claim to interpret the past. Even Hrútr Herjólfsson, through his remarkable perception of events and his conspicuous comments about them, acts as a secondary author by enabling the author to emphasise the importance of the disposition of characters. In Laxdœla saga and Þorgils saga ok Hafliða, authorial interest in characters' perception is matched by the thematising of learning, from the inception of knowledge as prophecy or advice to complete understanding by saga characters (chapter six). In Þorgils saga skarða, a character's inner development from an excessively ambitious and politically ruthless youth to a Christian leader killed by his kinsman allows the author to shape a political life into a lesson about leadership and the community's ability to moderate and contain the behaviour of extraordinary individuals. The portrayal draws on methods of characterisation that we can identify in Grettis saga Ásmundarson, Fóstbrœðra saga, and Orkneyinga saga. A comparison of the characterisation of figures with intense political or military ambitions suggests that saga authors were interested in the community's ability to balance their strength and ability with a degree of social moderation. The discussion of these sagas shows that character study can be used to analyse how the saga authors added their own voice to the voices passed down to medieval Icelanders in traditional narratives. Authorial engagement with characters allowed inherited traditions about early Norway and Iceland and records of thirteenth century events to be transformed into sophisticated historical works with highly creative elements. Through secondary authorship, saga authors took joint-possession of narratives and contested the power of tradition in setting the interpretive framework of a saga.

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The purpose of this study was to determine whether physical activity behavior tracks during early childhood. Forty-seven children (22 males, 25 females) aged 3-4 yr at the beginning of the study were followed over a 3-yr period. Heart rates were measured at least 2 and up to 4 d . yr(-1) with a Quantum XL Telemetry heart rate monitor. Physical activity was quantified as the percentage of observed minutes between 3:00 and 6:00 p.m. during which heart rate was 50% or more above individual resting heart rate (PAHR-50 Index). Tracking of physical activity was analyzed using Pearson and Spearman correlations. Yearly PAHR-50 index tertiles were created and examined for percent agreement and Cohen's kappa. Repeated measures ANOVA was used to calculate the intraclass correlation coefficient across the 3 yr of the study. Spearman rank order correlations ranged from 0.57 to 0.66 (P < 0.0001). Percent agreement ranged from 49% to 62%. The intraclass R for the 3 yr was 0.81. It was concluded that physical activity behavior tends to track during early childhood.

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Previous studies have demonstrated that pattern recognition approaches to accelerometer data reduction are feasible and moderately accurate in classifying activity type in children. Whether pattern recognition techniques can be used to provide valid estimates of physical activity (PA) energy expenditure in youth remains unexplored in the research literature. Purpose: The objective of this study is to develop and test artificial neural networks (ANNs) to predict PA type and energy expenditure (PAEE) from processed accelerometer data collected in children and adolescents. Methods: One hundred participants between the ages of 5 and 15 yr completed 12 activity trials that were categorized into five PA types: sedentary, walking, running, light-intensity household activities or games, and moderate-to-vigorous intensity games or sports. During each trial, participants wore an ActiGraph GTIM on the right hip, and (V) Over dotO(2) was measured using the Oxycon Mobile (Viasys Healthcare, Yorba Linda, CA) portable metabolic system. ANNs to predict PA type and PAEE (METs) were developed using the following features: 10th, 25th, 50th, 75th, and 90th percentiles and the lag one autocorrelation. To determine the highest time resolution achievable, we extracted features from 10-, 15-, 20-, 30-, and 60-s windows. Accuracy was assessed by calculating the percentage of windows correctly classified and root mean square en-or (RMSE). Results: As window size increased from 10 to 60 s, accuracy for the PA-type ANN increased from 81.3% to 88.4%. RMSE for the MET prediction ANN decreased from 1.1 METs to 0.9 METs. At any given window size, RMSE values for the MET prediction ANN were 30-40% lower than the conventional regression-based approaches. Conclusions: ANNs can be used to predict both PA type and PAEE in children and adolescents using count data from a single waist mounted accelerometer.

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BACKGROUND Tissue engineering of patient-specific adipose tissue has the potential to revolutionize reconstructive surgery. Numerous models have been described for the production of adipose tissue with success in the short term, but little has been reported on the stability of this tissue-engineered fat beyond 4 months. METHODS A murine model of de novo adipogenesis producing a potentially transplantable adipose tissue flap within 4 to 6 weeks was developed in the authors' laboratory. In this study, the authors assess the ability of three-chamber (44-μl volume) configurations shown to be adipogenic in previous short-term studies (autograft, n = 8; open, n = 6; fat flap, n = 11) to maintain their tissue volume for up to 12 months in vivo, to determine the most adipogenic configuration in the long term. RESULTS Those chambers having the most contact with existing vascularized adipose tissue (open and fat flap groups) showed increased mean adipose tissue percentage (77 ± 5.6 percent and 81 ± 6.9 percent, respectively; p < 0.0007) and volume (12 ± 6.8 μl and 30 ± 14 μl, respectively; p < 0.025) when compared with short-term controls and greater adipose tissue volume than the autograft (sealed) chamber group (4.9 ± 5.8 μl; p = 0.0001) at 1 year. Inclusion of a vascularized fat flap within the chamber produced the best results, with new fat completely filling the chamber by 1 year. CONCLUSIONS These findings demonstrate that fat produced by tissue engineering is capable of maintaining its volume when the appropriate microenvironment is provided. This has important implications for the application of tissue-engineering techniques in humans.

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Objective To evaluate the theory of reasoned action (TRA) and planned behavior (TPB) in predicting moderate-to-vigorous physical activity (MVPA) in sixth-grade youth. Methods One hundred ninety-eight students completed a questionnaire measuring attitudes, subjective norms, perceived behavioral control, and intentions to be active. MVPA was measured using the CSA 7,164 accelerometer. Results Although demonstrating an acceptable fit, the TRA and TPB accounted for only a small percentage of the variance in MVPA. In support of the TPB: the addition: of control perceptions to the reasoned! action model! added to the prediction of intentions and MVPA. Conclusion Within our sample of sixth graders, the utility of the, TRA or TPB;as a framework for activity interventions appears to be limited.

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Childhood obesity and physical inactivity are major health concerns for the Singaporean government (Ministry of Health, Singapore [MOH], 2001). Data from the 1998 Singaporean National Health Survey indicate that 10.8–14.7% of Singaporean children ages 6–16 years are either overweight or obese (MOH, 2001). Although true population estimates of youth physical activity are not available, descriptive epidemiological studies conducted in the 1990s suggest that a large percentage of school-aged children in Singapore fail to meet established guidelines for participation in physical activity...

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Regular physical activity is an important component of a healthy lifestyle in children and adolescents. However, despite the noted short- and long-term health benefits associated with physical activity, monitoring and surveillance studies show that a significant percentage of children and adolescents fail to meet the recommended guideline of 60 minutes or more of moderate-to-vigorous physical activity daily. This review examines key evidence from the public health and health promotion literature on promotion of health-enhancing physical activity in children and adolescents. We describe best practice in three key behavior settings—schools, homes, and health care settings. In school-based settings, it has been shown that physical education programs can be modified to increase the percentage of class time engaged in moderate-to-vigorous physical activity. In the home setting, there is evidence that teaching parents to establish and monitor physical activity goals and provide appropriate rewards for meeting these goals results in gains in physical activity and/or physical fitness. In health care settings, evidence from two studies suggests that physician-based counseling coupled with stage appropriate written materials can be effective among adolescent youth.

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Baseline findings from the Healthy Home Child Care Project include data from Family Child Care Providers (FCCPs) in Oregon (n=53) who completed assessments of nutrition and physical activity policies and practices and BMI data for children in the care of FCCPs (n=205). Results show that a significant percentage of FCCPs failed to meet child care standards in several areas and that 26.8% of children under the care of FCCPs were overweight or obese. These data supported the development of an Extension-delivered intervention specific to FCCPs in Oregon and highlight areas of concern that should be addressed through targeted trainings of FCCPs.