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1.
Though obesity is common, some people remain resistant to weight gain even in an obesogenic environment. The propensity to remain lean may be partly associated with high endurance capacity along with high spontaneous physical activity and the energy expenditure of activity, called non-exercise activity thermogenesis (NEAT). Previous studies have shown that high-capacity running rats (HCR) are lean compared to low-capacity runners (LCR), which are susceptible to cardiovascular disease and metabolic syndrome. Here, we examine the effect of diet on spontaneous activity and NEAT, as well as potential mechanisms underlying these traits, in rats selectively bred for high or low intrinsic aerobic endurance capacity. Compared to LCR, HCR were resistant to the sizeable increases in body mass and fat mass induced by a high-fat diet; HCR also had lower levels of circulating leptin. HCR were consistently more active than LCR, and had lower fuel economy of activity, regardless of diet. Nonetheless, both HCR and LCR showed a similar decrease in daily activity levels after high-fat feeding, as well as decreases in hypothalamic orexin-A content. The HCR were more sensitive to the NEAT-activating effects of intra-paraventricular orexin-A compared to LCR, especially after high-fat feeding. Lastly, levels of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in the skeletal muscle of HCR were consistently higher than LCR, and the high-fat diet decreased skeletal muscle PEPCK-C in both groups of rats. Differences in muscle PEPCK were not secondary to the differing amount of activity. This suggests the possibility that intrinsic differences in physical activity levels may originate at the level of the skeletal muscle, which could alter brain responsiveness to neuropeptides and other factors that regulate spontaneous daily activity and NEAT.  相似文献   
2.
Various sites in the valley of the Sant Cugat stream in Cerdanyola del Vallès (Catalonia) were subject to systematic archaeobotanical sampling to obtain an overview of the crops and agriculture of the area during the Iron Age and late antiquity. In all cases, the most numerous taxa were crop plants. Among these, cereals were clearly predominant at all sites investigated, especially Hordeum vulgare var. vulgare (hulled barley) and Triticum aestivum/durum (bread or macaroni wheat), both in numbers and frequency. Other cereals, such as Triticum dicoccum (emmer) or Setaria italica (foxtail bristle-grass), were regularly present in considerably lower numbers but in fairly high frequencies. Pulses were much less numerous, although their presence increases in terms of frequency. Among them, clearly the best represented was Lens culinaris (lentil). The results show that the agriculture in the period considered was principally based on winter cereals, with a gradual substitution of hulled barley by bread/hard wheat, accompanied by other cereals of minor importance, led by Triticum dicoccum (emmer), and pulses. The appearance of Vitis (grapevine) in the Iberian period is one of the important characteristics of agriculture in the Iberian world. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
3.
Statistical optimization of culture conditions for production of a widely suited detergent protease from Bacillus sp. RGR-14 was carried out using a two-step approach. A quick identification of the important factors with simple screening experiment was followed by application of complex response surface design for further optimization. The production of extracellular alkaline protease by Bacillus sp. was favored in the presence of complex carbon and nitrogen sources, viz. starch, casamino acid and soybean meal. A reduced quadratic model was found to fit the alkaline protease production. Response surface analysis revealed the significant role of phosphate ions in determining alkaline protease production. A steep, stretched out response surface showed direct relation between the level of protease production and casamino acid and starch concentration in the medium. A 12.85 fold increase in protease production could be obtained within the design space. Protease production was found to be repressed in the presence of high concentrations of casamino acid. The model could be validated in up to 2 l shake flasks (3914 U ml−1). The same statistical design could explain economic protease production in cost-effective medium as well.  相似文献   
4.
符合经济生态效益的农田化肥施用量   总被引:7,自引:0,他引:7  
在洞庭湖区研究了农田化肥的外部成本和经济生态施用量.采用环境影响经济评价方法,估算了化肥的外部成本;运用外部不经济性原理和生产函数模型研究了兼顾农户经济效益、生态效益的农田适宜施肥量.结果表明,2002年洞庭湖区粮食生产中因化肥施用不当而带来的外部成本约为1.35×108元,每千克纯氮的外部成本约为0.3元.在洞庭湖区目前生产条件下,兼顾生产、经济、生态三效益的适宜施肥量是208.26~210.65 kg·hm-2,相应的粮食产量为5528~5539 kg·hm-2.2002年洞庭湖区粮食生产实际施肥量已超过农户经济最优施肥量和生态适宜施肥量,建议政府在一些化肥高投入、高污染的地区征收环境污染税.  相似文献   
5.
江苏省区域农业生态经济的时空变异分析   总被引:1,自引:0,他引:1  
唐婷  李超  张雷  吕坤  周治国 《生态学报》2014,34(14):4025-4036
以江苏省徐连、沿海、宁镇扬、沿江和太湖5个经济区及其9个代表县市区域为研究对象,基于"社会-生态-经济"的系统分析,建立了包括目标层、准则层和指标层3个层次多指标的农业生态经济综合评价指标体系,采用主成分分析方法对评价指标体系进行检验、筛选,并以江苏省为案例,综合分析了农业生态经济系统的时空变异特征。结果表明:江苏省农业生态经济发展水平的时空变异明显,空间上,徐连、沿海、宁镇扬、沿江和太湖5个经济区表现出由北向南逐渐上升的趋势,且随时间的推移逐渐上升;时间上,徐连和太湖经济区农业生态经济发展水平在1999—2008年间呈持续上升,处于良好或优质协调状态。虽然两经济区的农业生态环境-经济发展协调发展水平均较高,但差距较大,徐连和太湖经济区的农业生态环境-经济发展协调度从1999年到2008年呈逐渐下降趋势,但总体上仍处于良好或优质协调状态。  相似文献   
6.
Summary In 1985, 1986 and 1987, 600 clones were visually assessed at harvest on plant appearance. The clones were harvested 80 days after planting in the first year, in the following years after approximately 80 days as well as after 145 days. The correlation coefficients between years and between harvest times were low to medium. Simulating different selection intensities using the performance of these 600 clones in two successive years, the relation between selection pressure in the first year and the retained proportion of well performing clones in the second year was described. Including the costs of testing, the most economic selection procedure was calculated. This procedure consisted in testing 1,579 first-year clones and 499 second-year clones for every 100 third-year clones required. The optimal period of the main evaluation in the second clonal year is at ware potato harvest time. This selection procedure also provides good selection possibilities for underwater weight and foliage maturity.  相似文献   
7.
Karl J. Niklas 《Oecologia》1992,90(4):518-526
Summary Computer simulations were used to assess the influence of palmate leaf morphology, decussate phyllotaxy, and the elastic moduli of petioles on the capacity of turgid and wilted twigs ofAesculus hippocastanum to intercept direct solar radiation. Leaf size, morphology, orientation, and the Young's and shear moduli (E and G) of petioles were measured and related to leaf position on 8 twigs whose cut ends were placed in water (turgid twigs) and 8 twigs dried for 8 h at room temperature (wilted twigs). Petioles mechanically behaved as elastic cantilevered beams; the loads required to shear petioles at their base from twigs were correlated with the cross-sectional areas of phyllopodia but not with petiole length or tissue volume. Empirically determined morphometric and biomechanical data were used to construct average turgid and wilted twigs. The diurnal capacity to intercept direct sunlight for each was simulated for vertically oriented twigs for 15 h of daylight, 40° N latitude. The daily integrated irradiance (DII) of the wilted twig was roughly 3% less than that of the otherwise comparable twig bearing turgid leaves. Simulations indicated that the orientation of turgid leaves did not maximize DII. More decumbent (wilted) petioles increased DII by as much as 4%. Reduction in the girth, E, or G of petioles, or an increase in petiole length or the surface area of laminae (with attending increase in laminae weight), increased petiolar deflections and DII. Thus, the mechanical design of petioles ofA. hippocastanum was found not to be economical in terms of investing biomass for maximum light interception.  相似文献   
8.
Ongoing success throughout regional development is contingent on maintaining the function, quality and harmony progress in society, economy and environment domains, so exploring the interaction and relation among them should be considerable significant. The model by coupling principal component analysis and vector autoregressive, which relate the aggregated values and dynamic analysis among factors, is proposed to achieve the qualitative and quantitative analysis of interaction and relation among society, economy and environment subsystem, providing a framework to conceptualize the influences among their changes and simulate the future scenarios in the Bohai Rim region. The impulse response analysis and variance decomposition of vector autoregressive method, in particular, permit dynamic interaction between every two systems and display clear decomposition of contribution for each change, respectively. This study results show that: there is a virtuous circle of promotion between economic growth and social progress no matter which is regarded as the endogenous variable during the study period, and yet the negative effect to environmental changes had been produced; what the improvement of social and environmental situation need most might be advancing its own progress; it is also reflected that the entire complicated system walk on the path of unsustainable development due to the evident disequilibrium of three subsystems; and the scenario analysis results obviously tell that in order to attain coordinated development, the annual growth rate of 12% to 16% of overall environmental level should be anticipated along with 8% of social and economic level improve. The study guide future possibilities for relatively more harmonious interconnections among social, economic and the environmental development.  相似文献   
9.
《L'Anthropologie》2015,119(4):355-363
Epigravettian dwellings from Eastern Europe give the Mammoth a privileged place: in the spectacular and elaborated architecture of their huts, like in the leading site Mezhyrich. However, the range of hunted and/or eaten game shows a variety of species including small ones such as the hare, testifying economical choices or even cultural practices where the Mammoth is not dominant. Magdalenian cave art, in Western Europe, gives the Mammoth a significant, sometimes exceptional place, like in Rouffignac or Combarelles, next to the even more important place of the Bison or the Horse. However, the dietary habits of the artists prove the prominent value of the Reindeer compared with the Horse. In Western Europe, wide and different landscapes and environments produced an economical-cultural mosaic. In the eastern part of Europe, the strong uniformity of climates and environments promoted an economical and environmental block leading to a sedentary lifestyle of the people, demonstrated by the concentration of huts. In the dreams of the hunters, as well as in their daily life, the incredible complexity of the relationship between men with animals revealed its creative and nourishing power.  相似文献   
10.
《Anthropological Forum》2012,22(3):209-223
What does it mean to call something ‘knowledge’ today? What does this recognition or translation require? And what does it entrain? This introduction makes a novel synthesis of contributions to the Special Issue and advances observations regarding the ‘mythic’ qualities of intellectual property law, the precipitation of ‘nature’, and the importance of attending to what is lost when things and practices are also called ‘knowledge’. The papers cohere around a timely set of observations and critiques: critiques of the way the knowledge economy makes demands and defines expectations about value; of how intellectual property law lies behind and shapes exclusions, inclusions, and inequalities; of the ‘mythic’ status of assumptions informing laws about ownership; and the implicit hierarchy contained within types of knowledge as understood through the categories of western epistemology. By taking up effect rather than veracity and certainty, contributors leave the definition of knowledge to ethnographic subjects. That is, they attend to where and how things come to be called knowledge, and for what reasons, noticing how equivalences across practices, made for the purpose of creating the possibility of exchange value (and thus of encouraging circulation) does its work at the expense of multiple aspects, values, and relations that are also discernable in social processes that produce ‘knowledge’.  相似文献   
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