A comparison of the programme coverage of two therapeutic feeding interventions implemented in neighbouring districts of Malawi

OBJECTIVE: To compare therapeutic feeding programme coverage for severely malnourished children achieved by a community-based therapeutic care (CTC) programme and a therapeutic feeding centre (TFC) programme operating in neighbouring districts in Malawi. DESIGN: Two surveys were implemented simultaneously one in each of the two programme areas. Each survey used a stratified design with strata defined using the centric systematic area sample method. Thirty 100 km2 quadrats were sampled. The community or communities located closest to the centre of each quadrat were sampled using a case-finding approach. Cases were defined as children aged under 5 years with 相似文献   

Evaluation of health, nutrition and food security programmes in a complex emergency: the case of Congo as an example of a chronic post-conflict situation

OBJECTIVE: To describe the case of Congo as an example of the assessment and appropriateness of donor operational and sectoral strategies in a complex emergency. DESIGN AND SETTING: The paper reports the findings of an external evaluation of operations financed by the European Commission Humanitarian Office in the Democratic Republic of Congo (DRC). RESULTS: The Congolese health system is suffering from severe deterioration. What is functioning in the public health context is donor-dependent with high costs and limited coverage. Despite a relatively favourable agro-climatic situation, food shortage and famine severely affect the nutritional status of large population groups. In this context, humanitarian programmes have generally improved access to health care and the nutritional status of beneficiaries. The reduction of malnutrition in project areas is often demonstrated even though the context did not permit consolidation of these results. Malnutrition continues to claim a massive cost of lives owing to the effect of widespread food insecurity that follows a circular cause-and-effect pattern of very low food production and extreme poverty. CONCLUSIONS: The current context in DRC does not correspond yet to 'post-crisis': neither at population level with regard to indicators of poverty, malnutrition, disease and death, nor at institutional level, with regard to state support to institutions. In these situations, the international community is often called upon to replace the state as service provider. Integrated humanitarian actions should be the future of relief projects in DRC. Health, nutrition and food security components should be considered a standard public health intervention strategy representing the most sensible approach to address the needs of the affected population.     

Do childhood growth indicators in developing countries cluster? Implications for intervention strategies

OBJECTIVE: The effectiveness of geographic targeting in nutrition programmes depends largely on the degree to which malnutrition clusters within particular areas. This study investigates the extent to which the childhood nutrition indicators, stunting (height-for-age Z-score <-2) and wasting (weight-for-height Z-score <-2), are spatially clustered; this information is used to determine the implications of spatial clustering for the effectiveness of geographic targeting. DESIGN: Analysis of data from Demographic and Health Survey (DHS) results. Clustering is assessed by calculating intra-cluster correlation coefficients (ICCs). Estimating the proportion of malnourished children covered by a programme successfully targeting 10% of clusters with the highest malnutrition prevalences allows an assessment of the effectiveness of geographic targeting. SETTING: Fifty-eight DHS III (1992-1997) and DHS IV (1998-2001) reports from 46 developing countries. SUBJECTS: Pre-school children of mothers interviewed by DHS. MAIN RESULTS: The extent of clustering of nutritional status was surprisingly low (median ICC for national samples: stunting=0.054, wasting=0.032) and most countries were characterised by having an ICC <0.1--i.e. low clustering--for childhood undernutrition (91% of countries for wasting and 78% for stunting). Our assessment of the effectiveness of geographic targeting showed that coverage was better for wasting than for stunting; for wasting, 23% of countries would achieve less than 20% coverage, compared with 76% of countries achieving less than 20% coverage for stunting. Coverage is dependent on the overall prevalence of malnutrition and the ICC. CONCLUSIONS: Childhood nutritional status is determined at the household, or even individual, level; nutrition programmes that are geographically targeted may result in high levels of under-coverage and leakage, thereby compromising their cost-effectiveness; the lack of clustering questions the appropriateness of current nutrition interventions.     

Food insecurity, malnutrition and mortality in Maewo and Ambae Islands, Vanuatu

CONTEXT: This paper reports on findings from the ex-post evaluation of the Maewo Capacity Building project in Maewo Island, Vanuatu, which was funded by World Vision Australia. OBJECTIVES: To examine the extent to which the infrastructure and systems left behind by the project contributed to the improvement of household food security and health and nutritional outcomes in Maewo Island, using Ambae Island as a comparator. SETTING: Two-stage cluster survey conducted from 6 to 20 July 2004, which included anthropometric measures and 4.5-year retrospective mortality data collection. PARTICIPANTS: A total of 406 households in Maewo comprising 1623 people and 411 households in Ambae comprising 1799 people. MAIN OUTCOME MEASURES: Household food insecurity, crude mortality rate (CMR), under-five mortality rate (U5MR) and malnutrition prevalence among children. RESULTS: The prevalence of food insecurity without hunger was estimated at 15.3% (95% confidence interval (CI): 12.1, 19.2%) in Maewo versus 38.2% (95% CI: 33.6, 43.0%) in Ambae, while food insecurity with hunger in children did not vary by location. After controlling for the child's age and gender, children in Maewo had higher weight-for-age and height-for-age Z-scores than children of the same age in Ambae. The CMR was lower in Maewo (CMR = 0.47/10 000 per day, 95% CI: 0.39, 0.55) than in Ambae (CMR=0.59/10 000 per day, 95% CI: 0.51, 0.67) but no difference existed in U5MR. The major causes of death were similar in both locations, with frequently reported causes being malaria, acute respiratory infection and diarrhoeal disease. CONCLUSIONS: Project initiatives in Maewo Island have reduced the risks of mortality and malnutrition. Using a cross-sectional 'external control group' design, this paper demonstrates that it is possible to draw conclusions about project effectiveness where baseline data are incomplete or absent. Shifting from donor-driven evaluations to impact evaluations has greater learning value for the organisation, and greater value when reporting back to the beneficiaries about project impact and transformational development in their community. Public health nutritionists working in the field are well versed in the collection and interpretation of anthropometric data for evaluation of nutritional interventions such as emergency feeding programmes. These same skills can be used to conduct impact evaluations, even some time after project completion, and elucidate lessons to be learned and shared. These skills can also be applied more widely to projects which impact on the longer-term nutritional status of communities and their food security.     

Effectiveness of a community-based intervention to improve nutrition in young children in Senegal: a difference in difference analysis

There are few studies of community growth promotion as a means of addressing malnutrition that are based on longitudinal analysis of large-scale programmes with adequate controls to construct a counterfactual. The current study uses a difference in difference comparison of cohorts to assess the impact on the proportion of underweight children who lived in villages receiving services provided by the Senegal Nutrition Enhancement Project between 2004 and 2006. The project, designed to extend nutrition and growth promotion intervention into rural areas through non-governmental organisation service providers, significantly lowered the risk of a child having a weight more than 2 sd below international norms. The odds ratio of being underweight for children in programme villages after introduction of the intervention was 0.83 (95% CI 0.686, 1.000), after controlling for regional trends and village and household characteristics. Most measured aspects of health care and health seeking behaviour improved in the treatment relative to the control.     

Vitamin A deficiency and child mortality in Mozambique

BACKGROUND: In areas where vitamin A deficiency (VAD) is prevalent, vitamin A repletion reduces child mortality by 23% on average. OBJECTIVES: To estimate the potential child survival benefits of policies and programmes aimed at controlling VAD in Mozambique, and to make policy and programme recommendations. METHODS: The potential contribution of VAD to child mortality in Mozambique was estimated by combining the observed VAD prevalence in the under-5s (71.2%), the measured child mortality effects of VAD (risk of death in children with VAD=1.75 times higher than in children without VAD) and the observed under-5 mortality rate in the country (210 per 1000 live births). RESULTS: In Mozambique, an estimated 2.3 million children below the age of 5 years are vitamin-A-deficient. In the absence of appropriate policy and programme action, VAD will be the attributable cause of over 30,000 deaths annually in the under-5s. This represents 34.8% of all-cause mortality in this age group. DISCUSSION: Vitamin A supplementation (VAS) has been adopted as a short- to medium-term strategy to control VAD in children, and is integrated into routine child health services. However, the last VAS coverage survey showed that only 46% of children received a vitamin A supplement in the 6 months preceding the survey. If VAS coverage is to increase significantly in the foreseeable future, four areas appear to be of paramount importance: (1) reduce missed opportunities for VAS such as visits of sick children to child health services and community outreach activities; (2) take advantage of all potential opportunities for accelerating VAS coverage, such as additional vaccination campaigns and emergency response activities; (3) strengthen health workers' training, supervision and monitoring skills; and (4) increase community demand for VAS of children. Biannual VAS, as the primary component of an integrated strategy for VAD control in children, has the promise to be among the most cost-effective/high-impact child survival interventions in Mozambique.     

Comparison of the World Health Organization (WHO) Child Growth Standards and the National Center for Health Statistics/WHO international growth reference: implications for child health programmes

OBJECTIVES: To compare growth patterns and estimates of malnutrition based on the World Health Organization (WHO) Child Growth Standards ('the WHO standards') and the National Center for Health Statistics (NCHS)/WHO international growth reference ('the NCHS reference'), and discuss implications for child health programmes. DESIGN: Secondary analysis of longitudinal data to compare growth patterns (birth to 12 months) and data from two cross-sectional surveys to compare estimates of malnutrition among under-fives. SETTINGS: Bangladesh, Dominican Republic and a pooled sample of infants from North America and Northern Europe. SUBJECTS: Respectively 4787, 10 381 and 226 infants and children. RESULTS: Healthy breast-fed infants tracked along the WHO standard's weight-for-age mean Z-score while appearing to falter on the NCHS reference from 2 months onwards. Underweight rates increased during the first six months and thereafter decreased when based on the WHO standards. For all age groups stunting rates were higher according to the WHO standards. Wasting and severe wasting were substantially higher during the first half of infancy. Thereafter, the prevalence of severe wasting continued to be 1.5 to 2.5 times that of the NCHS reference. The increase in overweight rates based on the WHO standards varied by age group, with an overall relative increase of 34%. CONCLUSIONS: The WHO standards provide a better tool to monitor the rapid and changing rate of growth in early infancy. Their adoption will have important implications for child health with respect to the assessment of lactation performance and the adequacy of infant feeding. Population estimates of malnutrition will vary by age, growth indicator and the nutritional status of index populations.     

Studies on the nutritional status of children aged 0-5 years in a drought-affected desert area of western Rajasthan, India

OBJECTIVE: The present study was undertaken to assess the impact of drought on the nutritional status of pre-school children aged 0-5 years from a rural population in a desert area facing drought conditions very frequently. DESIGN: The sampling design for assessment was the three-stage sampling technique. SETTING: The study was carried out in 24 villages belonging to six tehsils (sub-units of district) of Jodhpur District, a drought-affected desert district of western Rajasthan, during a drought in 2003. SUBJECTS: A total of 914 children were examined at household level, with nutritional status assessed by anthropometry, dietary intake and clinical signs of nutritional deficiency. RESULTS: The results revealed growth retardation. Stunting (malnutrition of long duration) was observed in 53% of children and underweight in 60%. Wasting, an indicator of short-duration malnutrition, was present in 28% of children. The extent of malnutrition was significantly higher in girls than boys (P<0.05). Vitamin A and B complex deficiencies were found in 0.7 and 3.0% of children, respectively. Prevalence of marasmus (protein-energy malnutrition, PEM) was 1.7% (2.3% in boys and 1.1% in girls). Overall deficits in mean energy and protein intakes were very high (76 and 54%, respectively). Comparison of the present drought results with earlier studies in desert normal and desert drought conditions showed higher prevalence of PEM and higher dietary energy and protein deficiencies. CONCLUSIONS: The prevalence of wasting was high, greater than the cut-off point of 15% stated by the World Health Organization to indicate that the severity of malnutrition is critical. PEM, vitamin A and B complex deficiencies and anaemia, along with dietary deficits of energy and protein, were observed to be higher than in non-desert areas. This may be due to the harsh environmental conditions in desert areas where drought occurs quite frequently and adversely affects the economy, largely by eroding the coping capacity and economic potential of the people as a result of heavy livestock losses and reduced harvests, leading to increased poverty and poor food intake of the inhabitants. Due to inadequate consumption of daily food the children were suffering from wasting and PEM. Efforts should be made to incorporate measures, such as ensuring the supply of adequate energy and protein to all age groups and especially pre-school children, into ongoing nutrition programmes in order to improve the food security of local inhabitants in this area.     

Mini Nutritional Assessment of rural elderly people in Bangladesh: the impact of demographic, socio-economic and health factors

OBJECTIVE: In stating the Millennium Development Goals, the United Nations aims to halve malnutrition around the world by 2015. Nutritional status of the elderly population in low-income countries is seldom focused upon. The present study aimed to evaluate the magnitude of malnutrition among an elderly population in rural Bangladesh. DESIGN AND SETTING: Data collection for a multidimensional cross-sectional study of community-based elderly people aged 60 years and over was conducted in a rural area in Bangladesh. SUBJECTS: Of 850 randomly selected elderly individuals, 625 participated in home interviews. Complete nutritional information was available for 457 individuals (mean age 69+/-8 years, 55% female). Nutritional status was assessed using an adapted form of the Mini Nutritional Assessment (MNA) including body mass index (BMI). Age, sex, education, household expenditure on food and self-reported health problems were investigated as potential predictors of nutritional status. RESULTS: BMI<18.5 kg m(-2), indicating chronic energy deficiency, was found in 50% of the population. MNA revealed a prevalence of 26% for protein-energy malnutrition and 62% for risk of malnutrition. Health problems rather than age had a negative impact on nutritional status. Level of education and food expenditure were directly associated with nutritional status. CONCLUSION: In order to reduce world hunger by half in the coming decade, it is important to recognise that a substantial proportion of the elderly population, particularly in low-income countries, is undernourished.     

Malnutrition and high childhood mortality among the Onge tribe of the Andaman and Nicobar Islands

OBJECTIVES: A study was conducted among the Onge tribe of the Andaman and Nicobar Islands with the objectives of identifying demographic factors responsible for the decline in their population and assessing their nutritional status, which is an important determinant of child survival. STUDY DESIGN AND SUBJECTS: The study included estimation of indices of fertility and child mortality, and assessment of nutritional status. All individuals of the Onge community settled on Little Andaman Island were included. RESULTS: The mean total marital fertility rate was estimated to be 5.15 live births per woman and the general fertility rate was 200 live births per 1000 married-woman-years. Although the gross reproduction rate was estimated to be 2.2 female children per married woman, the net reproduction rate was only 0.9 surviving female child per married woman. The mean infant mortality rate during the past 30 years was 192.7 per 1000 live births, and the child survival rate was found to be only 53.2%. A mild to moderate degree of malnutrition was found in 85% of children of pre-school age and severe malnutrition in 10%. The Onges had low intakes of iron, vitamin A and vitamin C. All the screened Onges were found to be infested with one or more intestinal parasites. CONCLUSIONS: High childhood mortality appears to be the predominant demographic factor responsible for the decline in the Onge population. The high prevalence of undernutrition and micronutrient deficiency disorders could be important factors contributing to the high childhood mortality.     

Increasing children's fruit and vegetable consumption: distribution or a multicomponent programme?

OBJECTIVE: To measure the effects of two school-based interventions on children's intake of fruit and vegetables (F&V). DESIGN AND METHODS: A total of six primary schools were randomly assigned to (1) a free F&V distribution programme, or (2) a multicomponent programme, consisting of a classroom curriculum and parental involvement. The two interventions were evaluated on their effects and compared with six control schools in a pre-test-post-test design. Two methods were used for dietary assessment: a pre-structured food recall and a food-frequency questionnaire including only F&V. SUBJECTS: A total of 939 parents of children aged 4-12 years filled out the questionnaire at both pre-test and post-test. The response rate was 54%. RESULTS: Multilevel analyses showed that both programmes were equally effective in increasing children's fruit consumption by 0.2 portions per day. The free F&V distribution increased vegetable intake among non-native children and the oldest age group, and the multicomponent programme among the oldest children and girls. The distribution also caused an increased 24 h fruit, juice and vegetable intake among the youngest and the oldest age groups, and the multicomponent programme among all children. CONCLUSION: The results of this study indicate that both interventions were shown to be effective for different subgroups regarding age, gender and ethnicity. When comparing both interventions, the distribution programme was shown to be more effective, especially in increasing vegetable consumption. An important next step will be to investigate which intervention has the greatest potential to be implemented in primary schools.     

Delivery of nutrition services in health systems in sub-Saharan Africa: opportunities in Burkina Faso, Mozambique and Niger

BACKGROUND: In sub-Saharan Africa, underweight and micronutrient deficiencies account for an estimated 25% of the burden of disease. As the coverage of national health systems expands, increased opportunities exist to address the needs of children and women, the most vulnerable to these deficiencies, through high-quality nutrition services. OBJECTIVES: To assess health providers' knowledge and practice with regard to essential nutrition services for women and children in Burkina Faso, Mozambique and Niger, in order to assist the development of a standard guide and tools to assess and monitor the quality of the nutrition services delivered through national health systems. FINDINGS: The three surveys reveal the extent of missed opportunities to deliver nutrition services during routine prenatal, postnatal and child-care consultations for the prevention and treatment of highly prevalent nutritional deficiencies. CONCLUSION: A commitment to improving the quality of facility-based nutrition services is necessary to impact on the health outcomes of women and children 'covered' by national health systems. Rigorous assessment and monitoring of the quality of nutrition services should inform health programme and policy development. Building on the lessons learned in these three assessments, Helen Keller International has developed a standard Guide and Tools to assess the quality of the nutrition services delivered through national health systems. These tools can be adapted to assess ongoing nutrition services in health facilities, provide a framework for nutrition programming, inform the development of pre-service as well as in-service nutrition training curricula for providers, and evaluate the impact of nutrition training on providers' practices.     

2000-2013年西安市植被覆盖度时空演变

随着黄土高原地区退耕还林政策的实施,近十几年西安市植被覆盖情况变化发生了显著变化。为了对西安市植被覆盖变化进行深入的研究,利用Mann-Kendall趋势检验法及Hurst指数、Pettitt检验法分析了2000-2013年来西安市植被覆盖度变化特征,并利用重心转移模型和相对发展率分析了西安市植被覆盖度变化的空间变化差异。结果表明:（1）西安市植被覆盖度中等程度变异面积占总面积10.02%;（2）西安市植被覆盖度呈增加趋势的面积占区域总面积86.54%,具有正向持续性的面积占区域总面积72.62%,35.30%面积植被覆盖度呈持续改善;（3）西安市植被覆盖度突变年份均显著发生在2004年、2005年、2006年、2007年、2008年,发生显著突变年份的面积占总面积的17.58%;（4）西安市植被覆盖度相对发展率空间变化范围为-9.07~7.49,相对发展率的负值占区域总面积的20.77%,西安市植被覆盖度空间重心呈现由西南逐渐向东北方向转移的趋势;（5）西安市降雨量与植被覆盖度均值均呈现增加趋势,相关系数为0.47（p<0.09）,空间分布重心呈现从东北向西南转移的趋势,与植被变化呈现相反的趋势。研究成果有助于进一步深化对西安市植被恢复状况及其影响因素的认识,为西安市植被恢复等生态建设工程提供一定的科学依据。     

National diet and nutrition surveys: the British experience

OBJECTIVE: The National Diet and Nutrition Surveys (NDNS) are a series of government-funded surveys of food intake, nutrient intake and nutritional status of individuals, undertaken to support nutritional policy and risk assessment. This paper summarises a review that considered the extent to which NDNS met the needs of users and suggested options for the future. The Food Standards Agency has since progressed favoured options. This paper aims to help others wishing to obtain this type of information within their own populations. DESIGN: A detailed questionnaire was used to probe use of data and gather opinions from users, producers and managers of the NDNS. It asked about general information needs from NDNS and changes that might be made. This was followed by a two-day workshop which included discussion of the main issues and the generation of 19 possible future options for consideration by the Agency. RESULTS: Options to improve effectiveness included methods to prioritise breadth and depth of coverage and possible ways of improving response and compliance. Strategies to make surveys more efficient and timely, such as adopting a rolling programme, disaggregating survey components, integrating with other studies and improving data access, were also suggested. A rolling programme, in which data are collected continuously, was the favoured option to address some of the concerns and a strategy is now in place to achieve this. CONCLUSIONS: There is widespread support for the NDNS from its users. There is no alternative source for such high-quality data on food and nutrient consumption and nutritional status and physical measurements in the same individuals. Useful information, such as the potential value of using a rolling programme from the outset, can be gained from this British experience by others wishing to measure food and nutrient intakes and status in their own populations.     

The CATCH Kids Club: a pilot after-school study for improving elementary students' nutrition and physical activity

BACKGROUND: Although many school-based diet and physical activity interventions have been designed and evaluated, relatively few have been tested for the after-school setting. After-school day-care programmes at either elementary schools or private locations provide a ready-made opportunity for health programmes that may be difficult to incorporate into an already-full school day. The purpose of this paper is to report on a pilot study of an after-school adaptation of the CATCH (Coordinated Approach To Child Health) elementary school programme called the CATCH Kids Club (CKC). METHODS: The CKC was pilot-tested and formatively evaluated in 16 Texas after-school programmes: eight in El Paso and eight in Austin (four intervention and four reference sites each). Evaluation consisted of direct observation of moderate to vigorous physical activity during play time, self-reported food intake and physical activity, and focus group interviews with after-school programme staff. RESULTS: Students responded well to the physical activity and snack components and were less interested in the five-module education component. Routine staff training was a key variable in achieving proper implementation; the ideal would be a full day with repeated follow-up model teaching visits. Staff turnover was a logistic issue, as was programme leader readiness and interest in conducting the programme. Strong and significant effects were observed for the physical activity but not for the education component. The results of the physical education component suggest it is feasible, effective and ready for larger-scale evaluation or dissemination.     

蒸汽爆破对红豆和绿豆多酚含量及抗氧化活性的影响

为提高红豆和绿豆中酚类化合物的得率及抗氧化能力,本试验采取蒸汽爆破加工对红豆和绿豆进行预处理,研究不同爆破处理组红豆和绿豆中总酚、总黄酮的含量及其抗氧化活性,并分析了两者之间的关系。结果表明,蒸汽爆破处理后的原料结构破裂严重,形成大量的碎片物质,促进原料中活性成分与溶剂的接触可及性。与对照组(CK)相比,经爆破处理后,红豆、绿豆中总酚、总黄酮含量明显上升,0.5 MPa、60 s爆破条件下绿豆中总酚、总黄酮含量最高,分别为4.57和3.00 mg·g^-1;而红豆中的总酚、总黄酮含量在0.75 MPa、60 s爆破条件下最高,分别为4.66和3.07 mg·g^-1。红豆中的总酚、总黄酮的含量均高于绿豆(除0.5 MPa、60 s爆破处理组)。不同处理组中提取物的抗氧化活性与总酚及总黄酮的含量变化基本一致,红豆中总酚含量与DPPH自由基清除率之间的相关性最高(r=0.966),绿豆中总酚含量与FRAP还原能力的相关性最高(r=0.895)。本研究结果为蒸汽爆破适用于不同生物质及有效成分的提取提供了一定的理论指导,进一步拓展了爆破技术在食品加工业的应用范围。     

Hypolipidemic effect of soluble fiber isolated from seeds of Cassia tora Linn. in rats fed a high-cholesterol diet

Soluble fibers isolated from the seeds of Cassia tora Linn. (SFC) have attracted considerable attention in recent years due to their phenomenal rheological behavior. In this study were investigated the effects of SFC on lipid metabolism. Male Sprague-Dawley rats were fed one of three experimental diets, a normal diet, a high-cholesterol diet, or a high-cholesterol diet with 5% SFC, for 5 weeks. The serum concentration of total cholesterol in rats fed SFC was 27% lower (p < 0.05) compared to that of the control group, but the serum high-density lipoprotein cholesterol level was increased in the SFC group. Liver total cholesterol and triglyceride levels were reduced significantly (p < 0.05) in rats fed the SFC diet. In addition, fecal bile acid and lipid excretion was significantly increased by SFC consumption. These results indicate that SFC enhances fecal lipid excretion and may cause a reduction in serum and hepatic lipid concentrations in rats.     

Excluding infants under 6 months of age from surveys: impact on prevalence of pre-school undernutrition

OBJECTIVE: Infants aged 0-5 months are not systematically included in assessments of child nutritional status and are generally excluded from surveys conducted in emergencies. We estimated the impact of excluding 0-5-month-old infants on the prevalence of stunting, wasting and underweight among children under 5 years (U5) and under 3 years (U3) of age. DESIGN: Comparison of the prevalence of stunting, wasting and underweight in U5 and U3 with or without inclusion of the age group 0-5 months. SETTING: Demographic and Health Surveys and Multiple Indicator Cluster Surveys from 76 developing countries and countries in transition. SUBJECTS: Children under 3 or under 5 years of age included in the surveys.Results Excluding 0-5-month-old infants resulted in an overestimation of the prevalence of stunting, wasting and underweight in U5 of 3.0, 0.3 and 2.6 percentage points, respectively, and of 4.8, 1.0 and 5.2 percentage points, respectively, in U3. The overestimation for wasting was negligible. The regions showing the highest overestimations for stunting and underweight were Asia and sub-Saharan Africa. Overall, countries with high prevalences of stunting and underweight showed especially large overestimations. The prevalence of underweight in infants aged 0-5 months was correlated with the prevalence of low maternal body mass index. CONCLUSION: All surveys, even in situations of nutrition emergency, should include 0-5-month-old infants. Strictly comparable age ranges are essential in nutrition surveys for monitoring trends and evaluating programme impact. Greater awareness of prenatal and early child undernutrition is needed among policy-makers.     

河蟹养殖全覆盖自动均匀投饲的轨迹规划与试验

河蟹养殖投饵喂料需要全塘均匀覆盖,目前主要靠人工驾驶或遥控船载投饲机在池塘中进行投喂,准确度和效率较低,难以保证投饲效果。针对以上情况,基于GPS（global positioning system）船载移动式自动投饲系统,研究了一种全覆盖轨迹规划方法,满足河蟹养殖池塘自动均匀投饲要求。该文利用轨迹规划系统建立池塘区域平面坐标系;以实际饵料累积密度与期望分布密度间的均方差最小作为衡量投饲均匀度的目标函数,求解出系统最优运行参数,生成往复遍历式自动投饲轨迹。仿真结果表明,在面积为2298.08 m2的不规则四边形池塘区域中,取饵料分布密度期望值为9 g/m2时,最优计算投饲系统运行参数对应的轨迹规划效果要优于传统经验估算参数。试验结果表明,当分别用两组参数进行自动投饲作业时,投饲船的实际航行轨迹与理论投饲轨迹都只有很小的偏移,与仿真结果具有一致性;同时,最优计算运行参数对应实际路径总长度、投饲路径长度、作业总时间、投饲时长、饵料分布密度均值、覆盖率等各项指标与仿真结果相比,相对误差分别为6.85%、2.71%、10.07%、10.41%、3.06%和1.87%,验证了全覆盖轨迹规划方法的可行性。该文可为河蟹养殖自动均匀投饲和其他水产养殖中需要沿池或全池自动均匀投饲轨迹规划研究提供重要参考。