The economic viability and potential of a novel poultry agroforestry system

Investigating agroforestry systems that incorporate poultry is warranted in Northern Europe as they may offer benefits including: improved welfare and use of range; reduced feed costs; price premia on products; reduced payback periods for forests; and, greater returns on investment. Free-range egg production accounts for 27% of the United Kingdom egg market and demand for outdoor broilers is increasing. No research has been conducted recently on the economic viability of agroforestry systems with poultry. An economic model was constructed to: assess economic viability of a broiler agroforestry system; and, investigate the sensitivity of economic performance to key factors and interactions, and identify those which warrant attention in research and management. The system modelled is a commercial trial established in Southern England in 2002 where deciduous trees were planted and broilers reared in six- or nine-week periods. The model uses Monte Carlo simulation and financial performance analyses run for a 120-year period. An Internal Rate of Return (IRR) of 15.5% is predicted for the six-week system which remains viable under a ‘worst case’ scenario (IRR of 12.6%). Factors which affect financial performance most (decreasing in magnitude) are prices achieved for broilers, costs of brooding houses, chicks, arks, feed and timber prices. The main anticipated effects of biological interactions on financial performance (increased ranging on feed conversion and excess nutrient supply on tree health) were not supported by analysis. Further research is particularly warranted on the welfare benefits offered by the tree component and its relation to price premia.     

The role of sensitivity to abscisic acid and gibberellin in pre-maturity α-amylase formation in wheat grains

To study the role of abscisic acid (ABA) and gibberellin (GA) sensitivity in regulating pre-maturity α-amylase (PMA) in wheat grains, plants were grown in a glasshouse under cold-shock and ambient conditions. α-amylase activity in response to applied ABA and GA was measured in detached-grains with the embryo removed (in vitro) and in intact-grains attached to the plant (in situ). The in vitro experiment was conducted using Spark (low PMA-susceptible genotype) and Rialto (highly PMA-susceptible genotype), with the aim of defining the time point for GA-sensitivity. The results showed an increase in GA-sensitivity at about 640 degree days after anthesis (DAA) in Rialto. There was no evidence for a change in ABA-sensitivity in either variety. The in situ experiments were conducted using genotypes from a Spark × Rialto doubled haploid population segregating for the Rht-D1a (tall) or Rht-D1b allele and for the presence or absence of 1BS/1RS. For Rht-D1a (tall) or Rht-D1b genotypes with or without 1BS/1RS, the cold-shock significantly increased GA-sensitivity, whereas there was no significant change in ABA-sensitivity. These results show PMA is related to an increase in GA-sensitivity that occurs in the aleurone at around 640 degree DAA, and can be enhanced by environmental factors (e.g. cold-shock).     

Camel tuberculosis–a case report

An adult male dromedary bull was diagnosed with pulmonary tuberculosis (Tb). The dromedary was severely emaciated and died 2 months after the onset of the disease. It exhibited typical Tb lesions in both lungs and lung lymph nodes. A guinea pig inoculated with lung tissue from the Tb camel died after 3 weeks from typical Tb. Mycobacteria were isolated from the dromedary's lung and lung lymph nodes and also from different organs of the guinea pig. The microorganism was identified as member of the antelope clade of the Mycobacterium tuberculosis complex.     

国内外绿豆农药最大残留限量标准对比研究

为了研究农药最大残留限量标准对中国绿豆对外贸易的影响,以中国、国际食品法典委员会(CAC)、欧盟、日本、美国、韩国和加拿大等国家绿豆农药最大残留限量标准为基础,从限量标准数量、限量大小和占比、限量宽松度等方面对比分析中国与贸易国之间的差异.结果发现,中国绿豆农药最大残留限量标准少,共83项,与日本的388项、欧盟的56...     

《吴越春秋》中的诗歌辨源

《吴越春秋》中保留了大量的诗歌,这些诗歌产生于汉代或汉代以前,对研究唐诗鼎盛以前的诗歌发展情况有一定的参考价值。根据对其来源的考证,这些诗歌大致可以分为三类：引用前人的诗歌、改用前人的诗歌、自己创作的诗歌。总览这些诗歌,可以从中了解诗歌从先秦到汉代发展的一些特点。     

以美国纽约市高线公园为例论公共空间种植设计

简述了纽约市高线公园的设计背景及设计策略,着重分析其植物景观营造手法,以期为公共空间种植设计提供参考。     

美国与欧盟的转基因食品安全性政策演变比对(英文)

随着转基因食品的研究与发展,人们对待转基因食品的态度表现为主要以美国和欧盟为主的两种代表性政策美国采取遵循可靠科学原则,坚决反对预防原则,即对转基因食品采取积极支持,自愿标识的宽松政策;欧盟采取谨慎预防原则,必须标识和可追溯从管理原则出发,结合相应采取的监管措施和相关条例,对两国从开始颁布转基因食品政策到当下态势的发展,并结合最新出台的政策进行跟踪分析,比对美国及欧盟对这些指令和条例的执行情况。     

美国马铃薯产业发展及启示

为推进中国马铃薯产业的健康发展,研究和分析美国马铃薯产业的成功经验十分必要。美国是世界上第5大马铃薯生产国,种植面积和总产量均不及居于世界首位的中国,但是却在马铃薯的世界贸易中处于领先地位,成为世界上利用马铃薯挣钱最多的国家。通过研究发现:严格的行业标准是美国马铃薯产业发展的先决条件;科技创新是美国马铃薯产业飞速发展的机制要素;马铃薯产业化及产业链的整体延伸是美国马铃薯升值的重要基石;强有力的协会是美国马铃薯产业持续发展的有效支撑。经分析可知,马铃薯加工产业化是美国马铃薯加工企业的有效模式和成功经验。     

The impact of resistance on the use of second-generation anticoagulants against rats on farms in Southern England

Resistance amongst rats to second-generation anticoagulants, notably difenacoum, has been recognised since the 1970s. Although initially considered to be of practical significance, doubts were subsequently expressed that the degree of resistance was sufficient to explain ineffective rodenticide treatments. Research published elsewhere demonstrated the overriding importance of poor poisoned bait consumption, caused by the influence of certain ecological factors on rat behaviour, in reducing the effectiveness of second-generation anticoagulant treatments on farms in southern England. In this paper we consider, however, the subtle effects of resistance to anticoagulants on treatment outcome. The prevalence of resistance was increased amongst survivors of treatments and bait consumption by resistant survivors was higher than amongst susceptible survivors. The overall prevalence and degree of resistance to second-generation anticoagulants does not, however, currently represent a practical problem. Nevertheless, selection favouring increased resistance remains a long-term threat to the effectiveness of both difenacoum and bromadiolone.     

Inoculation of earthworms into reclaimed soils: the UK experience

Earthworms have positive effects on soil structure, therefore their incorporation during the process of soil reclamation is a sensible route towards the final restoration of a site. Over the past 20 years, 16 documented field trials have been conducted in the United Kingdom. These trials took place at locations with a number of previous uses, for example, landfill sites, steelworks and opencast mines. The species of earthworm used varied, as did the techniques used for introducing them into the soil. This paper assessed the suitability of the earthworms chosen for each trial and, more importantly, trial outcomes. The most appropriate species were not always selected (possibly due to availability) and the introduction technique was not always the most appropriate for the site. Monitoring of trials generally occurred over relatively short periods of time (possibly due to limited funding). It is evident that more recent trials were not always informed by previous events. It is suggested that work of this nature may only be viable if brought about through site-related legal obligations. Copyright © 1999 John Wiley & Sons, Ltd.