水质富营养化程度的人工神经网络决策模型

为了对水质富营养化程度进行综合评价,提出水质富营养化决策的人工神经网络模型,用此模型研究我国17个湖泊的富营养化状况,通过期望输出值的选取和对未知水体的评价原则充分体现了水质富营养化各等级之间的模糊性,正确地反映了水质富营养化作用的内部机理。     

海南岛儿童发钙量与土壤交换性钙关系的探讨

通过对海南岛上万名学龄前儿童头发钙含量以及所处地域农耕旱地土壤交换性钙的调查与分析发现：土壤钙与儿童头发钙含量呈极显著正相关;海南岛儿童头发钙均值低于国内其它地方的报道值;土壤环境钙含量的高低,能间接反映人体钙的营养状况。     

Using design effects from previous cluster surveys to guide sample size calculation in emergency settings

A good estimate of the design effect is critical for calculating the most efficient sample size for cluster surveys. We reviewed the design effects for seven nutrition and health outcomes from nine population-based cluster surveys conducted in emergency settings. Most of the design effects for outcomes in children, and one-half of the design effects for crude mortality, were below two. A reassessment of mortality data from Kosovo and Badghis, Afghanistan revealed that, given the same number of clusters, changing sample size had a relatively small impact on the precision of the estimate of mortality. We concluded that, in most surveys, assuming a design effect of 1.5 for acute malnutrition in children and two or less for crude mortality would produce a more efficient sample size. In addition, enhancing the sample size in cluster surveys without increasing the number of clusters may not result in substantial improvements in precision.     

锌、镉复合污染对重金属蓄集植物黑麦草养分吸收及锌、镉积累的影响

采用根袋盆栽试验研究了锌、镉单一及复合污染对重金属蓄集植物黑麦草(Lolium perenne L．)生长、养分吸收及锌、镉积累的影响．结果表明,锌、镉单一及复合污染对黑麦草生物量存在不同程度的抑制作用．锌、镉单一及复合污染均明显降低了黑麦草植株N、P、K含量,以锌、镉复合污染对植株养分吸收的抑制作用最大．锌、镉污染共存下,黑麦草对锌、镉的吸收为协同效应．黑麦草吸收的锌、镉主要集中在地上部,以锌、镉复合污染植株对锌、镉的蓄集量最大,其地上部锌、镉含量分别达到3108．72、73．97 mg·kg-1．     

沉水植物衰亡过程中营养盐的释放过程及规律

在实验室模拟条件下研究了常见沉水植物苦草、金鱼藻在自然衰亡过程中主要营养盐氮、磷的释放过程,探索沉水植物衰亡过程中营养盐的释放规律. 结果表明:秋、冬季低温条件下,苦草、金鱼藻逐渐衰亡腐败,该过程向水体中释放的氮、磷很少,大部分氮、磷保留在植物残体中. 至次年天气回暖后,植物体的腐败分解有所加快,向水体释放氮、磷并有部分氮、磷沉积进入底泥. 苦草、金鱼藻具有较低的分解速度,有利于降低系统中氮、磷的循环速度. 残留植物体的生物量可影响植物体的分解速度和程度,较大的生物残留量会引起水体缺氧,植物残体分解加剧,导致水质严重恶化.      

Emotional,physical, and social needs among 0–5‐year‐old children displaced by the 2010 Chilean earthquake: associated characteristics and exposures

An 8.8‐magnitude earthquake occurred off the coast of Chile on 27 February 2010, displacing nearly 2,000 children aged less than five years to emergency housing camps. Nine months later, this study assessed the needs of 140 displaced 0–5‐year‐old children in six domains: caregiver stability and protection; health; housing; nutrition; psychosocial situation; and stimulation. Multivariate regression was applied to examine the degree to which emotional, physical, and social needs were associated with baseline characteristics and exposure to the earthquake, to stressful events, and to ongoing risks in the proximal post‐earthquake context. In each domain, 20 per cent or fewer children had unmet needs. Of all children in the sample, 20 per cent had unmet needs in multiple domains. Children's emotional, physical, and social needs were associated with ongoing exposures amenable to intervention, more than with baseline characteristics or epicentre proximity. Relief efforts should address multiple interrelated domains of child well‐being and ongoing risks in post‐disaster settings.     

不同来源重金属污染的土壤对水稻的影响

采用人工污染土壤、尾矿砂、污泥等不同载体的污染源来模拟土壤污染 ,研究其对水稻生长、吸收养分和吸收重金属的影响。结果表明 ,不同污染载体对水稻生长的影响不同 ,其影响的大小顺序为人工污染土壤 >尾矿砂 >污泥 >尾矿砂 +污泥。不同污染载体对水稻吸收重金属的影响亦不同 ,以纯化学试剂的形式添加到土壤中的重金属最易被提取出来 ,植物从中吸收的Cu、Zn、Pb、Cd最多 ,而从以污泥为污染载体的土壤中吸收的Zn、Pb、Cd最少。研究表明 ,用添加纯化学试剂的方法来模拟污染土壤对生态与环境的影响是可行的 ,确定土壤负载容量是安全的 ,因为在实验条件下它对供试植物的影响最明显     

Fish consumption reduces transfer of BDE47 from dam to murine offspring

Fish and seafood are important contributions to a healthy diet, but also contain persistent organic pollutants (POPs) like polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs). Discrepancies have been found between intake and accumulated levels of POPs, where fish consumers have had similar levels of POPs to the general population. Similarly fish oil consumption has been found to reduce accumulation of POPs. This study examined the accumulation of BDE47 or PCB153 in mice fed diets with different nutritional composition, using female mice with pre-weanling pups exposed through gestation and lactation. A fish-based diet was compared to a standard casein-based rodent diet. All diets had low background levels of environmental contaminants and were spiked with BDE47 or PCB153 to levels representing a realistic (∼0.004 μmol kgbw⁻¹ d) or a high dietary exposure (∼1.3 μmol kgbw⁻¹ d). Accumulation of BDE47 or PCB153 in offspring tissues after 18 d lactation reflected the maternal exposure levels. However, the pups of dams fed a fish-based diet had consistently lower BDE47 accumulation in liver, fat and stomach than pups from casein-fed dams. Similarly the pups of dams fed a high dose of PCB153 in a fish diet also accumulated less PCB153 than pups of the dams fed a casein diet, although not significant. In conclusion, the fish based diets seemed to reduce transfer of BDE47 and PCB153 from dams to pups. The study highlights that in-depth knowledge about nutritional impact on toxicokinetics is of great interest to vulnerable consumers.     

A photovoice assessment for illuminating the role of inland fisheries to livelihoods and the local challenges experienced through the lens of fishers in a climate-driven lake of Malawi

Small-scale inland capture fisheries provide an important source of nutritious food, employment and income to millions of people in developing countries, particularly in rural environments where limited alternatives exist. However, the sector is one of most under-valued fisheries sectors and is increasingly experiencing environmental change. This study adopts a Sustainable Livelihoods Approach and investigates how important a fluctuating inland fishery is to livelihoods, and how local perceptions on challenges corresponds to global evidence. Through an innovative participatory method; photovoice, the lived experiences and perceptions of fishers are depicted. The findings illuminate the valuable role of the sector to food and nutrition security and the complex nexus with vulnerability to climate change. The study responds to the call for more local level assessments of the impacts of climate change on inland fisheries in data-limited environments, and the value of the sector in underpinning the Sustainable Development Goals. Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01583-1.     

Sustainable Exploitation of Borassus aethiopum, Elaeis guineensis and Raphia hookeri for the Extraction of Palm Wine in Côte d'Ivoire

In the rural areas of developing countries palms are major sources of many products. One of these is palm wine, which has an important role for nutrition, income and social life. In the Côte d'Ivoire (West Africa), palm wine is extracted from three different species: Borassus aethiopum Mart., Raphia hookeri Mann & Wendland and Elaeis guineensis Jacq. As the extraction methods are destructive, palm stands are locally threatened by extinction. This could have serious consequences not only for the nutritional situation of the population but also for their income. Field visits were conducted in order to assess the degree of sustainability of palm wine extraction in eight villages of Côte d'Ivoire's three major agro-ecozones. Based on the annual palm wine need for consumption and commercialisation and on the availability of palms, a sustainability index was calculated for each palm species in each village. The occurrence of palm trees depends on the vegetation type. B. aethiopum is a typical savanna tree (> 20 palms per hectare) and is almost absent in other vegetation types. In 75% of the villages the exploitation of B. aethiopum is not sustainable. The preferred vegetation type for R. hookeri is the forest along the rivers (> 33 palms per hectare) compared to the other vegetation types of the forest zone (< 5 palms per hectare). Due to the high preference for the palm wine of this species its exploitation is not sustainable in any of the selected villages. The distribution of E. guineensis depends mostly on human activities, the main vegetation types being plantations (34 palms per hectare), fallow land and cultivated fields (15 palms per hectare) and the forest along the rivers (31 palms per hectare). The exploitation of this species is in general sustainable throughout all ecozones with some rare exceptions.