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OBJECTIVE: To investigate the effect of television food advertising on children's food intake, specifically whether childhood obesity is related to a greater susceptibility to food promotion. DESIGN: The study was a within-subject, counterbalanced design. The children were tested on two occasions separated by two weeks. One condition involved the children viewing food advertisements followed by a cartoon, in the other condition the children viewed non-food adverts followed by the same cartoon. Following the cartoon, their food intake and choice was assessed in a standard paradigm. SETTING: The study was conducted in Liverpool, UK. SUBJECTS: Fifty-nine children (32 male, 27 female) aged 9-11 years were recruited from a UK school to participate in the study. Thirty-three children were normal-weight (NW), 15 overweight (OW) and 11 obese (OB). RESULTS: Exposure to food adverts produced substantial and significant increases in energy intake in all children (P < 0.001). The increase in intake was largest in the obese children (P = 0.04). All children increased their consumption of high-fat and/or sweet energy-dense snacks in response to the adverts (P < 0.001). In the food advert condition, total intake and the intake of these specific snack items correlated with the children's modified age- and gender-specific body mass index score. CONCLUSIONS: These data suggest that obese and overweight children are indeed more responsive to food promotion, which specifically stimulates the intake of energy-dense snacks.  相似文献   

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OBJECTIVES: To identify the main knowledge gaps and to propose research lines that will be developed within the European Union-funded 'Healthy Lifestyle in Europe by Nutrition in Adolescence' (HELENA) project, concerning the nutritional status, physical fitness and physical activity of adolescents in Europe. DESIGN: Review of the currently existing literature. RESULTS: The main gaps identified were: lack of harmonised and comparable data on food intake; lack of understanding regarding the role of eating attitudes, food choices and food preferences; lack of harmonised and comparable data on levels and patterns of physical activity and physical fitness; lack of comparable data about obesity prevalence and body composition; lack of comparable data about micronutrient and immunological status; and lack of effective intervention methodologies for healthier lifestyles. CONCLUSIONS: The HELENA Study Group should develop, test and describe harmonised and state-of-the-art methods to assess the nutritional status and lifestyle of adolescents across Europe; develop and evaluate an intervention on eating habits and physical activity; and develop and test new healthy food products attractive for European adolescents.  相似文献   

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In southern Africa the samango monkey Cercopithecus mitis is confined to small (< 500 ha) forest fragments and is considered a locally rare species. Monkey populations from 17 of Natal's forests were visited and 14 of these were censused using King's strip transect method. Enviromental correlates and disturbance factors affecting samango population density are examined. The results of this provincial census show that it may be possible to predict samango density according to the plant species richness and diversity of a forest. The potential effect of the latter on the vagaries of food abundance and availability and hence the primate carrying capacity of a forest are considered. The important conclusion is that forests in Natal with very high species richness and diversity values do not necessarily support high samango densities. In fact these forests appear to maintain population densities similar to those forests with low plant species richness and diversity (swamp and sand forests). This has important implications for the conservation and management of the species, since it high-lights the importance to its survival, of those, often young, forests that can maintain high population densities (coastal dune and coastal lowland forest). Furthermore, results of this study permit a more objective interpretation of the evaluation of the observed abundance of samango monkeys in different forest types, and in so doing may form the basis for sound management proposals in the future.  相似文献   

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OBJECTIVES: To report the nutritional status of children aged up to 15 years and their mothers living in a remote Amazonian area of Bolivia, and to study its main social, familial and maternal determinants.SETTING: Fifteen Beni River communities located at the foot of the Andes.DESIGN: Cross-sectional survey of riverside populations. All childbearing mothers and their children in the 15 communities were examined.METHODS: Information on household production, dietary habits and demography was collected. Individual clinical, anthropometric and parasitological examinations were carried out.SUBJECTS: A total of 631 persons were examined: 171 mothers and 460 children and adolescents aged 0 to 15 years.Results: There were no cases of severe wasting, but 41% of 0-5-year-olds and 36% of 5-10-year-olds were stunted. Among 346 stool specimens examined, 75% were positive for at least one helminth. Diversity of food and quality of diet were satisfactory in 54% of households, but 27% had low diversity scores. Mothers were lighter and shorter than those observed at the national level: 20% had height below 145 cm. Prevalence of anaemia (42%) was also higher. In pre-school children, multivariate analysis indicated a relationship between growth retardation and household factors such as dietary quality, ethnic group and clinical state, but not maternal anthropometry. In contrast, in school-age children and adolescents, growth retardation was related to maternal characteristics.CONCLUSIONS: Growth retardation appeared mainly during the weaning period and did not seem to improve thereafter. To ameliorate this situation, an effort should be made to prevent common parasitic and infectious diseases in young children. Follow-up of pregnant mothers during pregnancy and delivery also needs to be reinforced.  相似文献   

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硫对大豆生长发育及生理效应影响的研究   总被引:8,自引:0,他引:8  
采用砂培试验研究了硫素对大豆营养生长、营养元素吸收、氮硫比值和光合作用强度及酶活性等生理效应影响。结果显示,正常供硫能保证大豆生长发育和生理生化反应;不同生长关键时期低硫处理对大豆营养生长和生理效应均有一定不利影响。特别是苗期缺硫明显降低大豆生物量和营养元素的吸收,叶面积生长量不足,叶片中叶绿素含量下降,硝酸还原酶活性下降,硝态氮含量增加,氮代谢受阻,氮硫比值提高,严重影响大豆的正常生长发育。  相似文献   

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Geographic disbursement, unsecured environments, and the concentration and commingling of agricultural products make agriculture a vulnerable target for a terrorist attack. To counter an act of agroterrorism, efforts are needed at the organism level, the farm level, the agricultural sector level, and the national level. Producers and the measures they take are essential in countering an attack at the farm level. However, producers may question the need for security measures, especially if they feel that their farm or ranch is an unlikely target. The attitudes and perceptions of Utah agricultural producers towards agroterrorism were examined in a mixed methods study using a QUAN-QUAL model. Twenty-five producers were purposefully selected to provide a cross-section of Utah agriculture. All participants filled out a questionnaire followed by a face-to-face interview in which they were asked to rate their level of concern about an act of agroterrorism at the farm, state, and national level. They were also asked about any security measures that they had taken and why, the identification of highly transmissible diseases, and their willingness to implement security measures. Producers were most concerned about an act of agroterrorism at the national level and least concerned about an act of agroterrorism occurring on their farm or ranch. Although many of the producers had implemented some security measures within the last year, most actions were in response to vandalism. More efforts are needed to educate Utah producers regarding highly transmissible diseases and their symptoms.  相似文献   

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Research on biological invasions has traditionally focused on the ecological component of invasive alien species, either without considering or by considering in a restricted way, the knowledge of the social component. An understanding of the human dimension of invasions is critical to effectively tackle the problems associated with invasive alien species. We distributed questionnaires to evaluate the social perceptions and attitudes of different stakeholder groups affected by invasive alien species in the Doñana social-ecological system (SW Spain). Our analysis served to characterize respondents based on their knowledge and perceptions of the impacts of invasive alien species, and the attitudes toward their introduction and eradication. Hierarchical cluster and principal component analyses identified five categories of respondents, and potential support of eradication programs was assessed using a contingent valuation approach. The five stakeholder groups differed in their degree of knowledge, perceptions, attitudes, and willingness to pay for eradication. The fact that different stakeholders have remarkably different perceptions about the impacts and benefits caused by invasive alien species, and different attitudes toward their introduction or eradication should be considered in any decision-making process regarding their management, particularly when developing appropriate educational and informative programs. Consultation with different stakeholders should also be encouraged from the onset of any decision-making process. In this way, trade-offs involved in IAS management are directly addressed and successful implementation of management practices is facilitated.  相似文献   

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为提高我国北方温室生产蔬菜的经济效益,研制了适应我国国情、采用无土栽培和蔬菜—食用菌互补栽培的日光温室。本文论述了该温室及栽培设施的结构特征与设计参数。经使用测试表明:当京郊冬季夜间气温降至-13℃时,温室内不加温运行,气温为5.45℃;互补栽培使温室有效面积利用率达117.6%;菇—菜共生,解决了蔬菜生产的CO2施肥问题,使冬茬黄瓜增产25%左右。  相似文献   

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作物生长指标与土壤水分状况及地温关系研究   总被引:3,自引:0,他引:3  
作物生长指标与土壤水分、地温的关系是制定灌溉制度的重要依据,对于提高水分利用效率、改善作物生长状态具有重要的意义。根据试验资料重点分析土壤水分、土壤温度以及采用覆膜、保水剂等农艺措施对青贮玉米株高、茎粗和产量的影响,结果表明:对于喜热、喜水的青贮玉米使用覆膜技术最好,覆膜能同时提高地温和保持土壤水分,其次是使用保水剂浸种比使用沟施保水剂效果好;影响地温变化的主要因素是气温和土壤水分,充分灌溉在提供作物生长所需足够水分的同时,降低了地温,不利于作物生长,因此对于水资源相对紧缺的北方寒冷地区,可适当采用非充分灌溉。  相似文献   

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From historical times the traditionally nomadic people in desert environments of Turkmenistan have applied a range of innovative technologies to secure water supply for consumptive and productive purposes. These technologies make use of takyrs , flat or slightly sloping dense clay surfaces which act as natural catchment areas. In recent history, these technologies have been neglected, in part due to a booming water supply through irrigation development, and takyr surfaces have suffered various degradation processes. However, the limited scope for further extension of irrigation systems presents a challenge to reconsider these traditional technologies. In this paper, results of cost‐benefit analysis are presented by which an assessment is made of the potential of both traditional and experimental takyr use technologies. It is shown that they bear considerable potential for the future at relatively low investment cost, that they may help limit degradation processes and provide for a sustainable development pathway for the inhabitants of the desert. A main challenge in order to benefit from this potential is to find an appropriate management structure for maintenance and resource use of these water‐harvesting technologies. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

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In the context of current demands in the animal feed industry for controls and analyses, the use of instruments that may be applied on the process line has acquired a significant interest. A key aspect is that the calibrations developed for quality control with instruments sited in the laboratory (at-line) must be transferred to instruments that will be used in the plant itself (online). This study evaluates the standardization and the calibration transfer between a grating monochromator instrument (predispersive) designed for laboratory analysis and a diode array instrument (postdispersive) more adapted to process conditions. Two procedures that correct differences between spectra of two instruments were tested: the patented algorithm by Shenk and Westerhaus and piecewise direct standardization (PDS). Although results were slightly better with PDS, both methods achieved good spectral matching between the two instruments, with levels of repeatability similar to that of the grating instrument itself. The calibration transfer was evaluated in terms of the standard error of prediction (SEP), which was considerably reduced after standardization. However, final calibration models to be used in the diode array instrument must contain spectra from both types of instruments to give acceptable prediction accuracy.  相似文献   

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This study focuses on farmers' perceptions of roadway safety and reviews specific and pertinent North Carolina rural road crash data to evaluate their perceptions and concerns. A survey was mailed to 1,357 prospective participants throughout North Carolina. Of these, 656 (48.3%) North Carolina farmers completed and returned the survey. The study revealed that while the majority of respondents took a number of specific safety measures to ensure their safety while driving their tractor on rural roads, most believed that driving their tractor on rural roads was more dangerous than it was five years ago. Few respondents believed that laws governing tractors on rural roads are well known by urban residents. While a majority of the respondents would support a law to mandate the use of a slow-moving vehicle (SMV) emblem on the back of slow-moving farm equipment, a majority also believed that a more effective way to mitigate potential crashes would be to ensure that all farm vehicles had blinking or flashing lights, that diamond-shaped caution signs depicting a tractor were posted on roadways with frequent tractor traffic, and that roadway shoulders were created or widened on roads with heavy farm traffic so that tractors could move off the roadway. Only 22% of respondents felt safe driving their tractor on rural roadways in North Carolina. Most respondents felt that the biggest problem with roadway safety was the lack of respect and increased speed of other drivers. Recent data indicate that in crashes involving farm vehicles, citations were issued to 34% of the non-farm vehicle operators and 24% to farm vehicle operators. For those driving non-farm vehicle who were deemed at fault, 66% were cited for failure to reduce speed. For those driving farm vehicles, the most frequent citation involved the lack of safe movement.  相似文献   

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Growth of sugar maple trees and element concentrations of soil and foliage were investigated at 12 stands in north-central Pennsylvania and southern New York. The goal of this exploratory study was to evaluate growth trends since the 1950s and to determine whether element concentrations were within limits conducive for normal growth. Basal area growth of overstory maple trees increased at six sites, declined at five, and remained nearly constant at one. Overall, the growth of overstory sugar maple trees did not change appreciably since the late 1950s, but growth of subcanopy maples decreased markedly, probably because of intensified shading in these maturing stands. Concentrations of Al, Cu, Fe, K, Mg, N, P, and Zn in soil and maple foliage were within the range of values reported for other sugar maple stands in North America. Calcium concentrations appeared adequate for growth, although at some sites they were near the low end of the typical range. Basal area growth of the overstory maples was correlated to the concentrations of Ca, Al, and the Ca∶Al ratio of soil, whereas growth of the subcanopy maples was not. Growth of the overstory trees was also correlated to the Ca concentration of maple foliage, which in turn was correlated to pH, Ca, Al, and the Ca∶Al ratio of soil. Manganese concentrations in soil and foliage were comparatively high, but were not correlated to trends in growth. The results of this investigation do not indicate abnormal changes in growth of sugar maple since the late 1950s. They suggest, however, that Ca availability limits growth at some sites and indicate that Al concentrations in the soil may be inhibiting Ca uptake.  相似文献   

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