The Struggle for a Uniform Monitoring System

Development of rangeland inventory and monitoring was initiated as early as in 1908. The early efforts were simple methods to establish rangeland stocking rates. With advancing scientific methodologies and the recognition for moitoring needs, the evaluation of range conditions and management planning increase well after WWII by a number of US federal agencies. By 1970s the environmental protection measures were first emphasized in the USA and were applied also to rangeland utilization. Since then the approaches and methodologies for evaluation of rangelands have changed periodically by accommodating the tenets of federal administrations. The methodologies applied have been geared either to support the environmental preservation or to support economic exploitation. There is still no system, however, for national or regional reporting on range conditions and trends. Local monitoring and management systems often lack scientific and objective basis. Local surveys, however, are important for evaluating existing conditions and should not be based on national reporting requirements. The ecological site concept has been adopted as the toxonomic unit for rangeland classification. It is important that monitoring methods are not biased, based on sufficient sample sizes, and not based on "estimations". The forage allocation based on one-time inventories are seriously flawed and the methods for evaluating stocking rates must be reevaluated. The same applies to the evaluating the rangeland "health." A unified national reporting system must be developed on scientific and objective basis.     

Flavonoids in Food and Their Health Benefits

There has been increasing interest in the research of flavonoids from dietary sources, due to growing evidence of the versatile health benefits of flavonoids through epidemiological studies. As occurrence of flavonoids is directly associated with human daily dietary intake of antioxidants, it is important to evaluate flavonoid sources in food. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. However, there is still difficulty in accurately measuring the daily intake of flavonoids because of the complexity of existence of flavonoids from various food sources, the diversity of dietary culture, and the occurrence of a large amount of flavonoids itself in nature. Nevertheless, research on the health aspects of flavonoids for humans is expanding rapidly. Many flavonoids are shown to have antioxidative activity, free-radical scavenging capacity, coronary heart disease prevention, and anticancer activity, while some flavonoids exhibit potential for anti–human immunodeficiency virus functions. As such research progresses, further achievements will undoubtedly lead to a new era of flavonoids in either foods or pharmaceutical supplements. Accordingly, an appropriate model for a precise assessment of intake of flavonoids needs to be developed.Most recent research has focused on the health aspects of flavonoids from food sources for humans. This paper reviews the current advances in flavonoids in food, with emphasis on health aspects on the basis of the published literature, which may provide some guidance for researchers in further investigations and for industries in developing practical health agents.     

不同土地利用类型下土壤-作物砷的积累特征及健康风险

以菜地、稻田、果园、旱地等4种典型土地利用为研究对象,通过413个土壤和对应作物样品的测试分析,探讨了研究区不同土地利用方式下土壤及其种植作物的As积累特征和对人体的健康风险。结果表明,稻田土壤As含量在5.69～148.5 mg kg-1,积累程度最高;果园土壤As含量在3.29～24.7 mg kg-1积累程度最低。研究区各土地利用类型下土壤As变异系数均在0.5以上,为中等变异性,各样点之间土壤As含量变化较大。研究区不同土地利用方式下,作物As含量差异较大,油料作物As平均含量最高达2.15 mg kg-1,旱地谷物和水果As含量均值最低,均为0.032 mg kg-1。根据研究区作物As的富集系数进行聚类分析,将研究区作物划分为4类,油料作物富集系数最高可划分为第1类,水稻划分为第2类,叶菜类蔬菜划分第3类,而富集系数较低的水果、瓜果类蔬菜、豆荚类蔬菜、根菜类蔬菜和谷物划分为第4类。依据JECFA推荐的ADI值和研究区居民膳食结构进行计算,结果表明研究区不同土地利用类型土壤As对人体健康的风险为稻田>菜地>旱地>果园,尤其是稻田土壤As对人体健康的风险较大,因水稻食用导致的居民As摄入量高达0.00...     

Body weight and range usage affect net energy utilisation in commercial free-range laying hens when evaluated in net energy chambers

Within a given free-range flock, some hens prefer to spend the majority of their time in the shed (stayers), while others frequently access the range (rangers). Laying performance has been associated not only with the development of these sub-populations but also with different body weights (BW). The purpose of this study was to determine if range usage, BW or a combination of both is associated with energy metabolism and as such contribute to improved hen performance. Forty-eight Lohmann Brown hens at 74 wk of age were selected from a commercial free-range farm based on their BW and range usage over a 56-week period. Using a 2 × 2 factorial arrangement, hens were either classified as heavy (mean ± SEM; 2.01 ± 0.02 kg, n = 24) or light (1.68 ± 0.01 kg, n = 24), and also classified as rangers (accessed the range for 84.1% of available days, 242 ± 3.75 d; n = 24) or stayers (accessed the range for 7.17% of available days; 23.4 ± 6.08 d, n = 24). Stayers had significantly higher metabolizable energy (ME) intake per metabolic BW per d (0.852 vs. 0.798 MJ/kg BW^0.75 per d; P = 0.025), higher heat production (0.637 vs. 0.607 MJ/kg BW^0.75 per d; P = 0.005), higher heat increment (0.267 vs. 0.237 MJ/kg BW^0.75 per d; P = 0.005) and retained more nitrogen (1.59 vs. 1.46 g/hen per d; P = 0.023) compared to the rangers. Light hens had significantly higher metabolic energy intake per metabolic BW (0.854 vs. 0.796 MJ/kg BW^0.75 per d; P = 0.018), net energy (NE) intake (0.595 vs. 0.551 MJ/kg BW^0.75 per d; P = 0.032), and retained energy (0.225 vs. 0.181 MJ/kg BW^0.75 per d; P = 0.032), as well as lower heat production (0.936 vs. 1.003 MJ/hen per d; P = 0.002) compared to heavier hens. An interaction was observed across levels of analysis i.e. between light stayers and light rangers. The light rangers had significantly higher NE intake compared to the light stayers (9.77 vs. 9.27 MJ/kg BW^0.75 per d; P = 0.024). In conclusion, light hens were more energy efficient compared to heavy hens. Moreover, light rangers had a more efficient feed utilisation compared to the light stayers.     

人性化的居住区景观设计

提出了居住区景观设计应对居民的综合需求进行深入理性思考,并从自然与和谐、文化与美感、健康与交流3个方面对人性化的居住区景观设计进行了探讨。     

茶叶主要活性成分的保健功能与作用机制研究进展

茶叶中的生物活性物质对人体具有多种保健功效,如调节糖脂代谢、抗氧化、防癌抗癌、增强免疫力等。本文综述了近五年来国内外有关茶叶中几种主要活性成分保健功效及其作用机制的研究进展。     

Strategies for increasing the selenium content of wheat

Selenium (Se) is essential for humans and animals but has no known function in plants. Excess accumulation is toxic to both plants and animals. Dietary intake of Se is low in a large number of people worldwide. This is due to low bioavailability of Se in some soils and consequently low concentrations of Se in plant tissues.Both selenate and selenite are taken up by plants and subsequently translocated around the plant. Selenate, an analogue of sulphate, is transported by the sulphate transporter family. Some plants are able to accumulate high internal concentrations of Se (hyperaccumulators); however, genetic variation in accumulation ability amongst non-accumulators such as cereals, is relatively small.Within plant tissues, Se enters the pathways for sulphate assimilation and metabolism and will replace cysteine and methionine in proteins, often with detrimental effect. Alternatively, Se may be accumulated as methylated derivatives or lost from the plant following volatilisation.Agronomic biofortification of crops with Se-containing fertilisers, which is practised in some countries, provides the best short-term solution for improving Se content of wheat. Longer-term genetic improvement, particularly by targeting substrate discrimination of transporters between selenate and sulphate, for example, may provide a means to enhance uptake and promote accumulation.     

艾草南瓜保健蛋糕工艺的研究

目的]研究优化艾草南瓜保健蛋糕的制作工艺.[方法]以艾草、南瓜、面粉、鸡蛋为原料,采用单因素试验和L9(34)正交试验,探讨面粉与艾草用量、南瓜泥添加量、鸡蛋添加量、白砂糖添加量对艾草南瓜保健蛋糕品质的影响.[结果]试验表明,制作艾草南瓜保健蛋糕的最佳工艺参数为:面粉+艾草用量为(30+ 10)g,南瓜泥添加量为50 g,鸡蛋添加量为300 g,白砂糖添加量为30 g.[结论]研究可为艾草南瓜保健蛋糕的生产提供一定的理论依据.     

海湾生态系统健康评价研究进展

海湾在生态系统中占有重要地位,其健康状况研究受到越来越多的关注。该研究回顾了生态系统健康的定义和进展,阐述了海湾生态系统健康评价的两种方法,其中指示物种法从单物种和多物种指示物种法2个方面进行对比分析,多指标综合指数法从综合指数法、活力组织恢复(Vigor-organization-resilience,VOR,结构功能)法和压力状态响应(Pressure-State-Response,PSR模型)法3个方面进行阐述。同时,讨论了海湾生态系统健康评价在近海水产增养殖中的应用,展望了海湾生态系统健康评价的研究方向。     

浙江海域虾姑中重金属镉的监测及健康风险评估

[目的]监测浙江海域中虾姑的重金属镉的含量,并对其健康风险进行评估。[方法]以浙江附近海域捕获的虾姑为材料,根据GB5009.12-2010中的石墨炉原子吸收光谱法测定其体内的重金属镉含量,并利用健康风险指数的方法对多个菜场或码头采来的虾姑中镉的健康风险进行评估。[结果]试验发现,所采集的海捕虾姑样品中镉含量都符合国家规定标准,各个虾姑样品的健康风险指数均小于1,按照平均摄入量来计算,每个虾姑都是处于安全水平的。[结论]浙江海域虾姑镉含量未超标,健康风险指数也在安全范围内,且营养丰富,但摄入也应有一定的限值。