Environmental Exchange Box

In this activity, teachers in one state create and share an “exchange box” of environmental and cultural items with students of another state. The Environmental Exchange Box activity enables teachers to improve students' skills in scientific inquiry and develop attitudes and values conducive to science learning such as wonder, curiosity, and respect for different social perceptions. Teachers will be able to work beyond the limits of the classroom and introduce outside resources to help increase students' global awareness and promote respect for the culture and environment of diverse populations. Specifically, this activity can help teachers fulfill national Teaching Standards B, D, and E.     

Evaluation of the sustainability of contrasted pig farming systems: breeding programmes

The sustainability of breeding activities in 15 pig farming systems in five European countries was evaluated. One conventional and two differentiated systems per country were studied. The Conventional systems were the standard systems in their countries. The differentiated systems were of three categories: Adapted Conventional with focus on animal welfare, meat quality or environment (five systems); Traditional with local breeds in small-scale production (three systems) and Organic (two systems). Data were collected with a questionnaire from nine breeding organisations providing animals and semen to the studied farming systems and from, on average, five farmers per farming system. The sustainability assessment of breeding activities was performed in four dimensions. The first dimension described whether the market for the product was well defined, and whether the breeding goal reflected the farming system and the farmers’ demands. The second dimension described recording and selection procedures, together with genetic change in traits that were important in the system. The third dimension described genetic variation, both within and between pig breeds. The fourth dimension described the management of the breeding organisation, including communication, transparency, and technical and human resources. The results show substantial differences in the sustainability of breeding activities, both between farming systems within the same category and between different categories of farming systems. The breeding activities are assessed to be more sustainable for conventional systems than for differentiated systems in three of the four dimensions. In most differentiated farming systems, breeding goals are not related to the system, as these systems use the same genetic material as conventional systems. The breeds used in Traditional farming systems are important for genetic biodiversity, but the small scale of these systems renders them vulnerable. It is hoped that, by reflecting on different aspects of sustainability, this study will encourage sustainable developments in pig production.     

Structural dynamics bridge the gap between the genetic and functional levels of GPCRs

G protein–coupled receptors (GPCRs) are implicated in nearly all physiological processes in the human body and represent an important drug targeting class. The genes encoding the different GPCR (sub)types determine their specific functionality, which can be altered by natural genetic variants and isoforms. Deciphering the molecular link between sequence diversity and its functional consequences is a current challenge and critical for the comprehension of the physiological response of GPCRs. It requires a global understanding of how protein sequence translates into protein structure, how this impacts the structural motions of the protein, and, finally, how all these factors determine the receptor functionality. Here, we discuss available resources and state-of-the-art computational approaches to address this question.     

Distribution of chloroplast DNA diversity within and among populations in gynodioecious Beta vulgaris ssp. maritima (Chenopodiaceae)

With the recent technical advances in molecular biology, chloroplast DNA (cpDNA) has become a marker used for the study of cytoplasmic differentiation of natural populations of plants. As chloroplasts are maternally inherited in most plant species, the seed component of gene flow is thus made accessible. We present here a study of cpDNA polymorphism within the maritima subspecies of the gynodioecious Beta vulgaris in which we try to assess the impact of such a reproductive system on seed flow. One hundred and eighty-eight wild beets were sampled from 20 hermaphroditic and 20 gynodioecious (i.e. containing both hermaphroditic and female plants) populations from the Atlantic coast of Europe. cpDNA variability in these populations was characterized with a rapid restriction fragment length polymorphism (RFLP) method. Eight cpDNA haplotypes were found. Strong differentiation among populations was observed ( F _ST = 0.43) and was consistent with isolation by distance, although most of the cpDNA haplotypes were ubiquitous. Gynodioecy seems to affect the distribution of cpDNA diversity: gynodioecious populations of Beta vulgaris ssp. maritima contained a greater number of cpDNA types but were less differentiated among themselves than hermaphroditic ones.     

Trophic resource partitioning among five flatfish species (Actinopterygii, Pleuronectiformes) in a tropical bay in south-eastern Brazil

Five species of flatfishes in a tropical bay in south-eastern Brazil were studied to test the hypothesis that resource partitioning along the spatial and size dimensions has been used as a mechanism to enable coexistence. Three zones in the study area were defined according to environmental characteristics (inner, middle and outer). Sampling was conducted by otter trawl tows during daylight hours, between October 1998 and September 1999. Achiridae species ( Achirus lineatus and Trinectes paulistanus ) showed narrow niche width, indicating a specialized feeding strategy, preying on Polychaeta, and occurring mainly in the inner bay zone. Paralichthyidae ( Citharichthys spilopterus and Etropus crossotus ) and the Cynoglossidae ( Symphurus tessellatus ) showed broad niche width and a generalized feeding strategy preying on a large number of Crustacea. Symphurus tessellatus did not change diet with size-dimension feeding on Amphipoda and Polychaeta, whereas C. spilopterus and E. crossotus shifted diet with growth. Citharichthys spilopterus fed mainly on Mysida and secondarily on shrimps, with juvenile preying on large amounts of Calanoida, whereas adults consumed large amounts of fishes. Isaeidae amphipods were a significant prey for both small and large E. crossotus , whereas Polychaeta Errantia were used mainly by large fishes. Etropus crossotus and S. tessellatus share similar feeding resources in outer bay zone preying on Isaeidae and Polychaeta Errantia. Differences in the Pleuronectiformes diet composition along with spatial and size changes in the use of the available resources contributed to allow the organisms' coexistence in Sepetiba Bay. The high item diversity used by flatfishes indicates that the system plays an important role as a feeding ground, and that interspecific competition for food was unlikely.     

Analysis of over-consumption of natural resources and the ecological trade deficit in China based on ecological footprints

China has experienced unprecedented economic development in recent years and is now facing severe challenges caused by the over-consumption of resources and by ecological and environmental degradation. To assess the influence of resource exploitation and ecological trade, we have developed an index of excessive resource consumption based on the concepts of ecological deficit and ecological over-shoot, and we have used the ecological trade deficit to assess the pressure created by the export and import of resources and products. Our analysis indicated that China's consumption footprint surpassed its biocapacity in 1983, leading to an ecological deficit, and the production footprint surpassed its biocapacity in 1986, leading to an ecological over-shoot, as the over-consumption of natural resources grew. By 2010, 3.6 times the current area of bioproductive land was needed to provide sufficient resources to meet the consumption. China has been encouraging the development of exporting enterprises by implementing a series of financial and tax incentives, which have stimulated the economy in the short-term but have gradually increased the ecological trade deficit since 2000.     

森林生态系统健康与野生动植物资源的可持续利用

研究了森林生态系统健康与野生动植物资源之间的关系,以及人类活动对森林生态系统健康的影响,提出了以下三个论点：(1)野生动植物资源是构成森林生态系统的基本物质内容。野生动植物资源对森林生态系统具有不可估量的影响和作用。(2)野生动植物资源的减少是森林生态系统健康状况下降的“显示器”。森林生态系统健康状况的下降或衰退,会导致野生动植物资源数量或种类的减少甚至种群灭绝。(3)森林生态系统是野生动植物资源与人类活动关系的集合体和反映体。人类与野生动植物资源是对立又统一的矛盾综合体,而森林生态系统健康与否就取决于这二者的关系。如果人类对野生动植物资源在保护的基础上进行合理的利用,就能保证森林生态系统的结构的完整和功能的良好,因此森林生态系统处于健康的状态;但若人类对野生动植物资源过度利用而不加保护,那么随着野生动植物资源的逐渐衰竭,森林生态系统将逐渐失去某些功能且变得支离破碎,也就无法保持健康的状态。提出了维持森林生态系统健康并实现野生动植物资源可持续利用的解决途径：(1)实行森林的可持续经营。森林可持续经营是指长期保持森林的生产力和可再生性,以及森林生态系统的物种和生物多样性。(2)发展“接近自然的林业”。近自然林业是在服从自然规律的前提下为人类的木材及林产品利用目的而设计的容许有一点偏离自然的森林模式,以森林生态健康为目标的建设方法。     

药用前胡研究进展

介绍了中药前胡近10年来的植物资源、化学成分和药理作用的研究成果,详细阐述了其主要药用部位药理作用研究的最新进展.