Women's iodine status and its determinants in an iodine-deficient area in the Kayes region, Mali

OBJECTIVE: To assess iodine status and its determinants in women of childbearing age in a rural area in the Kayes region, Mali, West Africa. DESIGN: Cross-sectional study where women's iodine status was indicated by urinary iodine concentration (UIC) and level of goitre based on palpation. Salt iodine was assessed semi-quantitatively at household level. Individual characteristics were collected using questionnaires. SETTING: Fifteen villages in a rural area in the Kayes region of Mali. SUBJECTS: Women aged 15-45 years (n=423). RESULTS: Median UIC was 2.7 microg dl(-1), and only 6% of the women had adequate iodine status of UIC >10 microg dl(-1). Most women (60%) had visible goitre, and only 9% were classified as without goitre. Only 39% of the households were using salt with any iodine, and level of knowledge about salt iodisation was low. Main determinants of UIC were breast-feeding and level of salt iodisation; currently breast-feeding women had lower UIC, and UIC increased with increasing level of iodine in household salt. Prevalence of goitre was lower in older women with higher body mass index. CONCLUSION: The study indicates severe iodine deficiency in the study area. Urgent action is needed to improve the situation through enforcing salt iodisation legislation and increasing the level of knowledge about the importance of iodised salt in the population.     

An evaluation of the impact of a school nutrition programme in Vietnam

OBJECTIVE: To evaluate the effectiveness of a school nutrition programme on the weight gain and growth of Vietnamese schoolchildren. DESIGN: A proximate cluster evaluation of children in seven schools, in which fortified milk and biscuits supplying 300 kcal of energy were being given on school days, compared with children in 14 nearby schools with no feeding. All children were dewormed. SETTING: Twenty-one primary schools in Dong Thap Province, Vietnam. SUBJECTS: A cohort of 1080 children in grade 1 of 21 primary schools, and a cross-sectional interview of 400 children in grade 3. RESULTS: The programme gave children the equivalent of 90 kcal day- 1 over 17 months. t-Tests showed a small but statistically significant difference between groups in their average gain in weight and height: 3.19 versus 2.95 kg (P < 0.001) and 8.15 versus 7.88 cm (P = 0.008). A multiple-level model showed that the programme was statistically significant after controlling for clustering of children in schools, sex, age and initial underweight (P = 0.024). A significant impact on height was also seen in a regression model, but not when controlling for school. The most undernourished children tended to gain the least weight. There was no evidence of substitution. CONCLUSION: The programme had a small but significant effect on weight gain, but the most undernourished children benefited the least. Methods need to be developed to target them. This design may offer a means of estimating the impact of school feeding on growth in other programme settings.     

The impact of food supplementation on infant weight gain in rural Bangladesh; an assessment of the Bangladesh Integrated Nutritional Program (BINP)

OBJECTIVES: To examine the efficiency of the Bangladesh Integrated Nutritional Program (BINP) in identifying which infants should be supplemented, whether full supplementation was given for the stipulated period of time, and whether the correct exit criteria from the supplementation programme were used. To test whether targeted food supplementation of infants between 6-12 months of age resulted in enhanced weight gain. SETTING: Mallickbari Union, Bhaluka, a rural area located about 100 km north of Dhaka, Bangladesh. PARTICIPANTS: Five hundred and twenty-six infants followed for 6 to 12 months. RESULTS: Of the 526 infants studied, 368 should have received supplementation based on BINP criteria but only 111 infants (30%) did so, while a further 13% were incorrectly given supplementation. So in total over half (52.8%) of the sample was incorrectly identified for supplementation. In addition, less than a quarter of the infants received the full 90 days of supplementation and close to half of the infants exited the programme without the requisite weight gain. Infants were assigned to one of four groups: correctly supplemented, correctly non-supplemented, incorrectly supplemented or incorrectly non-supplemented. This classification provided natural controls; the correctly supplemented infants versus the incorrectly non-supplemented infants, and the correctly non-supplemented infants versus the incorrectly supplemented infants. There were no significant differences in weight gain between the correctly supplemented group and the incorrectly non-supplemented group or between the correctly non-supplemented and the incorrectly supplemented groups, nor was there any evidence of growth faltering in the incorrectly non-supplemented group. CONCLUSIONS: This study found serious programmatic deficiencies - inability to identify growth faltering in infants, failure to supplement for the full time period and incorrect exit procedures. There was no evidence that food supplementation had any impact on improving infant weight gain.     

Evaluation of the soil fauna impact on decomposition in a simulated coniferous forest soil

Summary Long-term experiments (ca. 2 years) were carried out in laboratory systems that simulated the complexity of a coniferous forest floor. The test materials were partially sterilized by freezing and thawing, and reinoculated with (1) microbes alone or (2) microbes with fauna. Removable microcosms containing birch litter, spruce litter, or humus were inserted into a humus substrate. Two experiments used organic matter only, and another included a layer of mineral soil below the humus. Both were incubated in climate chambers that simulated both summer and winter conditions. The evolution of CO₂ was measured at regular intervals. In order to determine the C content of the leachates, the macrocosms and the microcosms were watered periodically.Soil fauna significantly increased respiration in the litter, but not in the microcosms containing humus. In the later phases of decomposition the presence of fauna had a negative effect. In the total systems the fauna consistently increased the respiration rate. The loss of mass was greater in the presence of fauna, especially during the middle phases (5–11 months), but it was higher in the controls later.Throughout the whole incubation period the decomposition rate was strongly influenced by the composition of the animal community. The interpretation of the results is affected by the fact that the controls, to which no fauna had been added, contained dense populations of microbial feeders (nematodes, rotifers, and protozoans).     

湖北省集约化生猪生产系统的环境影响评估

为了解湖北省集约化生猪养殖系统的资源消耗及环境影响程度和识别重点生产环节造成的环境问题,基于生命周期评价(life cycle assessment,LCA)理论和Sima Pro(Version7.1.8)软件,利用Eco-indicator99生态指数法环境影响评价指标体系对湖北省集约化生猪养殖系统的环境影响进行了评估。结果表明:1)集约化养殖系统的环境单一评分为45.13分;2)主要的影响类型是土地占用(59.84%)、吸入无机物对呼吸系统损害(14.29%)、化石资源消耗(9.97%)、致癌物损害(7.80%)、酸化/富营养化(5.18%)、气候变化(1.90%);3)环境单一评分构成中仔猪生产阶段比例占17.91%,断奶后育肥阶段比例占82.09%,而且仔猪生产和育肥阶段的饲料消耗对土地占用、致癌物损害影响类型贡献较大,日常生产管理和粪污处理对吸入无机物对呼吸系统损害、酸化/富营养化、气候变化影响类型贡献较大;4)损害结果表明对人体健康影响最大环节是日常生产管理,对生态质量、资源消耗影响最大环节是饲料消耗。由此表明研究结果对生猪生产过程中减少资源消耗,采取降低环境影响的方法和措施,推动生猪养殖可持续发展有指导意义。     

城镇化人为扰动下垫面类型影响水源涵养功能的评价

城镇化引起的各种人为扰动地貌单元的水源涵养功能较原地貌明显降低是造成城市水土流失的主要原因,在降雨和排水管网设计能力一定条件下,也是加剧城市内涝的主要原因。该文采用野外调查、室内物理分析及AHP(analytic hierarchy process)层次分析综合评价法,系统地分析了各种人为地貌单元的物质组成和持水性能变化并综合评价了其对原地貌水源涵养功能的影响特征。结果表明:1)各种扰动地貌单元2 mm土体颗粒质量分数在45%以上,原地貌2 mm土壤颗粒质量分数在92%以上;扰动地貌不均匀系数和曲率系数分别在11.05~41.30和0.32~3.15之间变化,其中不均匀系数较原地貌减小了4.51%~80.27%;各种扰动地貌单元土壤容重为施工便道(1.74 g/cm3)边坡绿化带(1.54 g/cm3)1 a弃渣堆积体(1.48 g/cm3)2 a弃渣堆积体(1.34 g/cm3)3 a弃渣堆积体(1.31 g/cm3),比坡耕地依次增加33.85%、18.46%、13.85%、3.08%和0.77%;扰动地貌的土壤总孔隙度、土壤田间持水量和饱和含水量则表现出相反趋势。2)人为扰动地貌单元土壤入渗性能总体小于原地貌单元,而原地貌土壤稳定入渗率则在2.83~6.22 mm/min之间变化;当项目区林地转化为新弃渣堆积体时对降雨和城市洪水动态调节功能影响最大,转化为施工便道时影响最小;人为扰动地貌单元土壤水库总库容、兴利库容和滞洪库容总体低于原地貌,当项目区草地转化为施工便道时对土壤持水能力及调蓄地表径流能力危害最大。3)各种扰动地貌单元水源涵养能力明显小于原地貌单元,以施工便道(0.421)最差,林地最好(0.651);在城镇化过程中应重视城镇水面、林草地的空间分布及占地面积,对短期松散堆积体也最好进行临时绿化措施。4)加强对扰动地貌物质组成、大孔隙结构和降雨-径流-入渗连续性定位研究,同时关注各扰动地貌在不同压实条件下土壤水库蓄水性能对项目区雨洪过程线和排水系统的影响。研究结果可为城市水土保持生态服务功能恢复、城市绿化带建设和洪水内涝缓解提供科学依据。     

菹草颗粒饲料对蛋鸭生产红心蛋性能的影响

用该课题组中试生产的菹草颗粒饲料(红色素含量20.59mg/kg)做了蛋鸭喂养试验,以考察它对生产红心蛋性能(着色效果、产蛋率、平均蛋重)的影响.试验设置4个组、15d,菹草颗粒添加量为0(对照组)、15%、20%和25%,分别与100%、85%、80%和75%的普通蛋鸭配合饲料混合组成试验饲料.结果表明在一定范围内,菹草颗粒的添加量与红心蛋的平均色度(罗氏色度,下同)及15度以上红心蛋所占的比例呈现一定的量效关系;其中将20%的菹草颗粒与80%的普通蛋鸭配合饲料混合组成的饲料综合效果最好,喂养第4d即使蛋黄平均色度由对照的7度上升到15度,其差异达到极显著水平(p＜0.01),并随喂养天数增加其蛋黄色度平均值保持在15度以上,喂养13、14d时15度以上红心蛋占所产蛋总数的80%,并全部达到14度以上;该试验组饲料的平均产蛋率为96.2%,与对照组比较没有显著差别;该试验组饲料可显著增加平均蛋重(p＜0.05).对菹草粉、菹草颗粒及试验优选的红心蛋颗粒饲料进行了理化和营养成分检测,结果表明菹草粉的粗蛋白含量为13.36%、总类胡萝卜素的含量为463.1mg/kg,两者都大大高于玉米,而粗蛋白与小麦麸相近;菹草颗粒的主要成分含量分别为干物质90.05%、粗蛋白12.96%、粗脂肪4.36%、粗纤维4.75%、无氮浸出物54.16%、粗灰分13.82%、钙1.72%、总磷0.24%,与菹草粉比较,其粗蛋白含量相近,粗纤维下降一半多,粗灰分下降近40%,粗脂肪和无氮浸出物都明显提高,其营养成分更趋向合理;红心蛋颗粒饲料的主要指标基本符合部颁标准(SB/T 10262-1996生长鸭、产蛋鸭、肉用仔鸭配合饲料)的要求.由于菹草粉和菹草颗粒含有多种营养成分,具有较全面的营养价值,特别是它含较高的蛋白质、类胡萝卜素及其它维生素,这可能是菹草饲料在快速有效地提高蛋黄色度的同时、又能促进蛋鸭生长、增加蛋重、维持较高产蛋率的重要原因.试验证明菹草颗粒饲料的研制开发是成功的,它配置使用灵活方便,具有良好的应用前景.     

Behavior of iodine in a forest plot,an upland field and a paddy field in the upland area of Tsukuba,Japan: Seasonal variations in iodine concentration in precipitation and soil water and estimation of the annual iodine accumulative amount in soil horizons

Abstract

In the course of a series of studies conducted to investigate the long-term behavior of ¹²⁹I (which has a half-life of 16 million years) in the environment, seasonal variation in the concentration of stable iodine (¹²⁷I) in precipitation and soil water to a depth of 2.5 m in a forest plot, an upland field and a paddy field in the upland area of Tsukuba, Japan, were determined. Iodine concentration in precipitation tended to increase during the summer (high air temperature) season and low-rainfall period, and a positive high correlation was observed between annual rainfall and the annual amount of iodine supplied by precipitation. No seasonal variations in iodine concentration in soil water were observed at any depth in the forest plot and upland field unlike at shallow depths (0.2 and 0.5 m) in the paddy field. In the paddy field, from the beginning of summer irrigation, under flooding conditions, iodine concentration in soil water at shallow depths (0.2 and 0.5 m) continuously increased, and immediately before mid-summer (intermittent) drainage and drainage, the maximum iodine concentration (approximately 50 µg L^?1) and lowest E_h values (approximately ?150 to ?200 mV) were recorded. These high iodine concentration levels and low E_h values were ascribed to high air temperature (approximately > 25°C on average every 10 days) and the continuation of the groundwater level above the ground surface. As for the temporary winter irrigation period (mean daily air temperature 2?4°C), the iodine concentration was low (1.7–3.7 µg L^?1) at all depths, as was the case in the non-irrigation period. After mid-summer drainage, and drainage, the iodine concentration in soil water at depths of 0.2 and 0.5 m decreased drastically as the groundwater level decreased. The mean annual amount of iodine accumulated in the surface soil horizons (0–0.67 m) in the forest plot was estimated to be approximately 2.9 mg m^?2 (7.5 µg kg^?1 dry soil), which coincided with the mean annual amount of iodine supplied to the earth surface by precipitation. A mildly oxidative subsurface 2Bw horizon (0.60–0.89 m) in the paddy field was estimated to illuviate approximately 3.1 mg m^?2 (20 µg kg^?1 dry soil) of iodine annually by retaining iodine in the soil water percolated to this horizon.     

Evaluation of the potential impact of Cu competition on the performance of o,o‐FeEDDHA in soil applications

Ferric ethylene diamine‐N,N′‐bis(hydroxy phenyl acetic acid) (FeEDDHA)‐based iron (Fe) fertilizers are commonly applied to plants grown on calcareous soils and comprise a mixture of FeEDDHA components. Upon application to the soil, the pore water concentrations of the active ingredients racemic and meso o,o‐FeEDDHA show a gradual decline unrelated to plant uptake or biodegradation. In the present study, the potential of soil copper (Cu) to reduce the effectiveness of FeEDDHA‐based fertilizers in calcareous soils by displacing Fe from o,o‐FeEDDHA has been evaluated through modelling and experiments. Predictions with mechanistic multi‐surface models show that there is a thermodynamic basis for assuming that under equilibrium conditions a certain fraction of o,o‐EDDHA ligands in soil solution can be chelated to Cu, in particular for meso o,o‐EDDHA. The large affinity of o,o‐CuEDDHA for binding to the soil solid phase, demonstrated in a batch interaction experiment, greatly increases the potential impact of Cu competition on the o,o‐FeEDDHA solution concentration; for a given quantity of o,o‐CuEDDHA in soil solution, a much larger quantity of o,o‐CuEDDHA is adsorbed to the solid phase. Finally, evidence for the actual displacement of Fe from o,o‐FeEDDHA by Cu was found in a soil incubation study. With these results, the boundary conditions are met for explaining the observed gradual decline in o,o‐FeEDDHA concentration with Cu competition.     

The impact of sludge amendment on methanogen community structure in an upland soil

In the EU, municipal sewage sludge application to agricultural land has increased dramatically since the ban on dumping at sea came into effect in 1998. There are many concerns related to potential contamination and reduction in plant productivity. In this study, the aim was to assess the impact of repeated long-term soil amendment with anaerobically digested sewage sludge on methanogen diversity in an upland soil ecosystem. Sludge-treated and untreated upland soil samples as well as samples of the sludge used, were analysed for the diversity of methanogens using TGGE, PCR-RFLP and DNA sequence analysis of approximately 490 bp of the mcrA operon. PCR analysis using mcrA specific oligonucleotide primers confirmed the presence of methanogen DNA in treated and untreated soil samples and in sewage sludge. TGGE was used to describe the diversity of methanogen mcrA sequences and the differences in community structure between samples. Ninety-six mcrA gene PCR products were screened using RFLP analysis representing methanogen DNA amplified from anaerobically digested sewage sludge, control soils and sludge treated soils. Fourteen RFP's were detected in all treatments, five of which were common to all three treatments. Thirty-eight cloned amplimers were selected for sequencing and phylogenetic analysis. These included representatives of each RFP. From control soils, sludge and sludged soil samples 15, 16 and 7 clones were sequenced, respectively. Phylogenetic analysis suggested that they represented hitherto uncharacterised mcr genes; 35 of the clones fell into 7 clusters supported by moderate to high bootstrap values. The diversity of methanogens in an upland soil (treated and untreated) and sludge was evaluated and marked differences in the diversity of the methanogen communities was observed between the treatments. Our results indicate that sludge application may reduce soil methanogen community diversity.     

The impact of sport-hunting on the population dynamics of an African lion population in a protected area

Between 1999 and 2004 we undertook an ecological study of African lions (Panthera leo) in Hwange National Park, western Zimbabwe to measure the impact of sport-hunting beyond the park on the lion population within the park, using radio-telemetry and direct observation. 34 of 62 tagged lions died during the study (of which 24 were shot by sport hunters: 13 adult males, 5 adult females, 6 sub-adult males). Sport hunters in the safari areas surrounding the park killed 72% of tagged adult males from the study area. Over 30% of all males shot were sub-adult (<4 years). Hunting off-take of male lions doubled during 2001-2003 compared to levels in the three preceding years, which caused a decline in numbers of adult males in the population (from an adult sex ratio of 1:3 to 1:6 in favour of adult females). Home ranges made vacant by removal of adult males were filled by immigration of males from the park core. Infanticide was observed when new males entered prides. The proportion of male cubs increased between 1999 and 2004, which may have occurred to compensate for high adult male mortality.     

Temperature has a strong impact on the abundance and community structure of comammox Nitrospira in an Ultisol

Journal of Soils and Sediments - Temperature is a key factor influencing the growth and activities of microorganisms and their associated biogeochemical processes including nitrification. However,...     

Assessment of the impact of water erosion on productivity of maize in Kenya: an integrated modelling approach

The impact of degradation on functional properties of land and its productive capacity may vary between land units and soils. The present study explores the methodology for assessment of the impact of 20 years of simulated water erosion on production of maize in Kenya. It uses databases on soils, climate and crops and several models are combined to arrive at a productivity impact calculation. Outcome of the modelling exercise may serve as a basis for prioritizing land-use policies, conservation measures and research at a national level. The methodology comprises four steps: (1) creating basic evaluation units, by climatic zonation of soil and terrain units, (2) suitability assessment for low input and rainfed maize cultivation, (3) definition of a water erosion scenario, by translating computed water erosion risk into four classes of depth of topsoil lost over 20 years' time, (4) calculation of crop yield potentials for the current situation and with inclusion of the erosion scenario, accounting for lost nutrients through topsoil erosion and for altered soil physical conditions. The study shows that a major part of Kenya is too dry for growing maize. Potentially suitable areas for growing maize in Kenya generally have a high yield potential, but considerable yield gaps exist. Furthermore, these areas are highly vulnerable to water erosion. In the very steep patches of land in the central and central-western part of Kenya, water-limit yield decline projected over 20 years is over 50 per cent. Nutrient-limited yield potentials are even more affected by the loss of topsoil. Copyright © 1999 John Wiley & Sons, Ltd.     

Moderating the impact of agriculture on climate

Many options are available for reducing the impact of agriculture on climate; however, it is difficult to provide a comprehensive set of solutions because several aspects are still poorly understood. An overall assessment of the various impacts of agriculture on climate is presented. It focuses on the trade-offs among the relevant greenhouse gases (GHG), CO_2, N₂O and CH₄, and the geochemical and biophysical interactions between agriculture and climate.Three spatial scales are examined: field, farm, and regional scale. At the field level, both GHG and energy fluxes are related to technical decisions by the farmer. At the farm level, strategic decisions on the choice of production systems are governed by economical constraints. Land use and landscape govern the biophysical factors that act on the regional climate when spatially integrated. At the regional level, national and regional policies on GHG emissions and surface forcing influence global climate. The biochemical and geophysical contribution of agriculture to climate need to be considered using new approaches in terms of global warming. The use of GCMs appears to be an adequate tool at this scale for assessing the global effect on climate, upon which smaller-scale effects will be superimposed.