Raptor Gastroenterology

Birds of prey have developed talons, a hooked beak, and a tongue and oral cavity replete with pronounced hooks and papillae for prehending large boluses of food. The size of the proventriculus in relation to the ventriculus and weak musculature of the ventriculus, combined with an extremely acidic luminal pH, are consistent with a gastric digestive physiology maximized for protein digestion. The pyloric sphincter retains indigestible matter in the stomach, which is later compressed into a pellet and egested. The ventriculus, pylorus, pancreas, and an elongated duodenum coordinate to maximize neutralization of acidic peptic juices and increase the efficiency of digestion and absorption. Raptors are susceptible to a variety of infectious and noninfectious diseases that affect the digestive tract. Diagnostic testing and treatment recommendations for raptor intestinal disease conditions are discussed in this article.     

Farmlink: promoting conservation buffers farmer-to-farmer

Farmer-to-farmer outreach was used within a targeted watershed to promote the installation of conservation buffers. In this program called “FarmLink”, four farmers/landowners were employed part-time as “advisors” and trained by University of Nebraska-Lincoln Extension, Natural Resources Conservation Service, and Natural Resources District personnel. Topics included basic buffer design and benefits, availability of incentive programs, and sales techniques. These individuals then contacted their neighbors to explain the need for and benefits of buffers and other conservation practices. In early 2003, 42 landowners were contacted, leading to contracts for the establishment of 16 separate conservation practices on 24.8 ha (61.3 acres) of farmland. These included just over 8 ha (20 acres) of grassed waterways or similar plantings and 14 ha (35 acres) of streamside buffers. In addition, because of information received in the training sessions, one of the advisors installed 1.7 ha (4.3 acres) of streamside buffers, 0.45 ha (1.1 acres) of grassed waterways, and 2.0 ha (5.0 acres) of grasses and forbs on his own land. During these contacts, it became apparent that: (1) many farmers and landowners were not familiar with the multitude of programs available to assist with the installation and maintenance of conservation practices; and (2) landowners generally appreciated the personal touch of someone coming out to talk directly to them, pointing out specific areas on their land where conservation practices could best be implemented, discussing available compensation programs, and describing management needed to help ensure practice success. Although one-to-one contacts cannot be used in all cases, it was demonstrated to be effective in this watershed.     

The response of understory herbaceous plants to nitrogen fertilization in forests of different land-use history

Forests growing on former agricultural land often have reduced frequencies of many native forest herbs compared with forests that were never cleared for agriculture. A leading explanation for this pattern is that many forest herbs are dispersal limited, but environmental conditions may also hinder colonization. We examined the response of six forest herb taxa (Arisaema triphyllum, Cimicifuga racemosa, Disporum lanuginosum, Osmorhiza spp., Polygonatum spp., and Prenanthes altissima) to nitrogen (N) fertilization in forests with and without an agricultural history to investigate how N availability affects plant performance. The study was conducted in the southern Appalachian Mountains in western North Carolina, USA. There was a significant interaction between land-use history and N treatment for several species. In A. triphyllum and Osmorhiza spp., N fertilization increased aboveground biomass or leaf area more in the post-agriculture site than in the reference site. However, in the reference site, N fertilization depressed aboveground biomass or leaf area in the same taxa, as well as in C. racemosa. The foliar N concentration of these three taxa was elevated in fertilized plots regardless of land-use history, and there was no indication that the light environment differed among plots. These results suggest that some plants growing in post-agricultural stands may be N limited, whereas undisturbed stands in this region appear to be approaching N saturation. Thus, environmental conditions, and particularly N availability, may be an obstacle to the restoration of forest herb communities.     

Managing productivity and drought risk in Eucalyptus globulus plantations in south-western Australia

More than 2.5 million ha of Eucalyptus globulus are now planted across the globe including approximately 500 000 ha in southern Australia. In this region average annual rainfall has declined since 1960 and this trend is predicted to continue in the coming decades. E. globulus is a premium species for paper manufacture and grows well under moderate seasonal water stress. The traits that underpin this rapid early growth also make the species vulnerable to prolonged water stress. We established nitrogen rate and nitrogen-by-stocking experiments in five 2-year-old E. globulus plantations along a climatic gradient in south-western Australia. We measured volume growth, predawn leaf water potential and leaf area index over 7 years or until the plantations were 9 years old. These data were used to explore the relationship between growth and water stress, to understand the mechanistic basis for the relationship and to identify best-bet management strategies for E. globulus plantations in southern Australia.     

Grain number and grain weight in wheat lines contrasting for stem water soluble carbohydrate concentration

In wheat, the ability to store and remobilise large amounts of stem water soluble carbohydrates (WSC) to grain constitutes a desirable trait to incorporate into germplasm targeted to regions with frequent terminal drought. The main aim of this paper was to examine the relationships between WSC storage, grain number and grain weight across several environments. A small set of recombinant inbred lines (2–4) contrasting in stem WSC were grown in six field trials where water availability, sowing date and/or N level were manipulated, with line yields ranging from 400 to 850 g m⁻² across experiments. Biomass, N and WSC concentration (WSCc, mg g⁻¹ dry weight) and amount (WSCa, g m⁻²) were monitored. A resource-oriented area-based model [Fischer, R.A., 1984. Growth and yield of wheat. In: Smith, W.H., Bante, S.J. (Eds.), Potential Productivity of Field Crops Under Different Environments. International Rice Research Institute, Los Baños, pp. 129–154] and intrinsic rates of organ growth were used to investigate the consequences on grain number of potential competition between spike and stem around flowering.     

Association analysis reveals effects of wheat glutenin alleles and rye translocations on dough-mixing properties

The glutenin loci of wheat (Triticum aestivum L.) are important determinants of bread-making quality, although the effects of alleles at those loci are incompletely understood. We applied an association analysis method to assess the effects of glutenin alleles and 1RS wheat–rye (Secale cereale L.) translocations on dough-mixing properties in 96 wheat cultivars and advanced lines grown at three Colorado locations while accounting for population structure and relatedness of individuals in the population. The results indicated that (1) in the majority of cases, controlling relatedness of individuals reduced the significance of associations between glutenin loci and Mixograph traits; (2) the Glu-D1 and Glu-B3 loci and 1RS translocations had greater impacts on dough-mixing properties compared to other glutenin loci; (3) Glu-B1w, Glu-D1d, and Glu-B3b were consistently associated with greater (more favorable) Mixograph peak time (MPT) than other alleles at the respective loci, whereas Glu-B1e, Glu-D1a, and Glu-B3c were associated with reduced MPT; (4) the 1BL.1RS translocation was associated with a decrease in Mixograph properties. Our results indicate that taking multiple-level relatedness of individuals into account can improve the results of association analysis for wheat-quality traits.     

太阳能再热式有机朗肯循环发电系统性能研究

建立了带抛物槽式集热器的太阳能再热式有机朗肯循环发电系统模型,研究了再热式有机朗肯循环系统热效率增加量与输出功增加量随蒸发温度的变化规律。结果表明:当再热压力比为0.25时,太阳能再热式有机朗肯循环系统能有效地提高系统总效率,输出功随蒸发温度增加近似呈线性增加。对分别以R11、R114、R134a和R245fa为工质的再热式有机朗肯循环系统热效率提高量进行比较,以R245fa为工质的再热式有机朗肯循环热效率提高最大,达4.3%。     

Multifunctionality and agrarian transition in alternative agro‐food production in the global South: The case of organic shrimp certification in the Mekong Delta,Vietnam

Processes of globalisation in the conventional food provision system have had widespread negative impacts on small‐scale farmers. Yet, alternative food networks, which are characterised by more sustainable production/consumption practices and fairer trade relations, have increasingly been ‘going global’ and, in the process, have been integrating small‐scale farms in the South. One such high‐value export‐led commodity is certified organic shrimp. International third‐party certification schemes are becoming popular as a tool to verify the intangible attributes of such commodities. Using concepts of multifunctionality and agrarian change, this paper examines the implications of introducing an international environmental certification programme to a site where the ‘peasantry’ has been preserved and has limited integration in the global agro‐food system. Drawing on a case study that examines the first certified organic shrimp production project in Vietnam, this paper concludes that the current movement towards post‐productivism in the global North has potential to keep local farming practices in the global South by justifying the value of peasant‐like production methods through international certification. As a result, the development path of agrarian transition might be reshaped into a form not necessarily pursuing industrialisation. This leads to the new interpretation of pre‐ and post‐productivism beyond the North and South divide.