提高繁殖猪群效率纵横谈

繁殖猪群的目标是不断地以低成本生产计划数量的优质断奶仔猪。图 1显示了影响断奶仔猪产量的因素。断奶仔猪产量是繁殖群母猪存栏数 (能力 )与每头母猪年产断奶仔猪数 (效率 )的乘积。确定繁殖猪群的适当大小而使其适合于养猪设施的容量 ,同时确定后备母猪群的适当大小而使其适合于每周的配种计划 ,是为实现断奶仔猪产量计划和充分利用产仔栏所必需的。一般来说 ,是否适合于配种计划和分娩率 ,是影响每头存栏母猪年产断奶仔猪数量的最重要的因素(表 1 )。图 1　影响断奶仔猪产量的各种因素之间的相互关系　表 1　每周断奶仔猪产量影响因素…     

The challenges of effective model scoping: A FLORES case study from the mafungautsi forest margins,Zimbabwe

This paper explores the challenge of defining the scope of a systems model, emphasising three aspects: boundary, granularity and conceptual scope. The significance of these is illustrated by reference to a model of land-use decisions made in villages bordering on the Mafungautsi forest in Zimbabwe. The purpose of this model was to help policy players (Forestry Commission staff, non-governmental organisations, researchers and local people) to understand the impact of policy interventions on local people’s livelihoods. Scoping decisions that were made in building the Mafungautsi model were deliberately liberal, to encompass the interests of all participants in the modelling process. These decisions now present a range of serious challenges: the difficulty of model calibration, the computational expense of running simulations, and the difficulty for new users to understand the model. Facilitators of modelling teams need to consider the serious implications of giving everyone what they want and including all participants’ ideas in a model. In the long run, it may be better to be tough and reject many suggestions at the outset. The former approach is unlikely to lead to a tractable model, while the latter may ultimately offer greater satisfaction for all. We are grateful to the UK’s Department for International Development (DFID) and the European Community for financial support of this project. Thanks also to all of the ACM team who have contributed ideas on the process and content of the modelling work and who make it fun to undertake collaborative research. Thanks also to the participants in the Zimbabwe FLAC workshops for their input into the specification of the Mafungautsi model. Finally thanks to Robert Muetzelfeldt, Jasper Taylor, Jonathan Massheder, Fergus Sinclair and Jerry Vanclay for helping us to ride on the FLORES bandwagon.     

丹参抗氧化成分及其分布特征

借助超声波萃取法，以反相高效液相色谱（RP－HPLC－DAD）为分析检测手段，研究了丹参6种抗氧化成分的提取方法和分离定量条件，并对这些成分在全株丹参不同部位中的含量分布特征进行了探讨，结果表明：常温下的超声波萃取可避免热解作用给丹参酮类化合物带来的损失，布辅助的加热处理可使原儿茶醛获得较高的提取率，两种操作方法简单可行，6种化学成分在丹参不同部位及不同等级中的分布有较大差异，丹参酮类化合物主要分布在根部皮层，而叶子中丹参素的含量却较为丰富，可为丹参品质鉴定和质量标准研究及该资源的综合利用奠定理想基础。     

Salmon prices in France and the UK: Does origin or market place matter?

Abstract

There have been several attempts to distinguish farmed Atlantic salmon by origin using trademarks. Whether there exist different regional markets for salmon, and in particular whether the UK market is separate from the market in continental Europe, is also an issue that has received attention. To address these questions, we investigate the relationship between Norwegian and Scottish salmon both in France and the UK, and between Scottish salmon in France and the UK. The analysis is carried out by investigating how the development of prices is related using co‐integration tests.     

Cardiorespiratory effects of a 7° reverse Trendelenburg position in anaesthetized horses: a randomized clinical trial

Objective

To evaluate the cardiorespiratory effects of a 7° reverse Trendelenburg position (RTP) in anaesthetized horses.

Zur hydrologischen Bedeutung der organischen Auflage im Wald: Untersuchungsmethoden und erste Ergebnisse

About the hydrological role of organic layers in forest: methods and first results The forest floor (total organic matter above the surface of the mineral soil) is an important interception storage for throughfall. Therefore, it must be considered in detailed water balances of forest. The objective in this paper is to present a method for measuring the forest floor percolation. It was developed within the framework of the interdisciplinary project Ecosystem research in the Bornhöved lake region. A technique for permanent registration of mineral soil input and a vacuum control system for mini lysimeters and suction plates are described. The registration system has a resolution about 0,1 mm. Some figures illustrate the instrumentation, respectively measured row data and some results. Finally, the used materials, their properties and sources of supply are presented.     

Antioxidant effectiveness of phenolic apple juice extracts and their gut fermentation products in the human colon carcinoma cell line caco-2

Apples represent a major dietary source of antioxidative polyphenols. Their metabolic conversion by the gut microflora might generate products that protect the intestine against oxidative damage. We studied the antioxidant effectiveness of supernatants of fermented apple juice extracts (F-AEs, 6 and 24 h fermentation) and of selected phenolic degradation products, identified by HPLC-DAD-ESI-MS. Cell free antioxidant capacity of unfermented apple juice extracts (AEs) was decreased after fermentation by 30-50%. In the human colon carcinoma cell line Caco-2, F-AEs (containing <0.5% of original AE-phenolics) decreased the reactive oxygen species (ROS) level more efficiently than the F-blank (fermented without AE) but were less effective than the respective AEs. Similarly, antioxidant effectiveness of individual degradation products was lower compared to respective AE constituents. Glutathione level was slightly increased and oxidative DNA damage slightly decreased by fermented AE03, rich in quercetin glycosides. In conclusion, F-AEs/degradation products exhibit antioxidant activity in colon cells but to a lesser extent than the respective unfermented AEs/constituents.     

Introduction to the special issue “scaling up of agroforestry innovations: enhancing food,nutrition and income security”

Agroforestry Systems - It is more and more acknowledged that agroecological innovations, such as agroforestry practices, should be co-created through a combination of research and traditional...     

Microtubule stabilization reduces scarring and causes axon regeneration after spinal cord injury

Hypertrophic scarring and poor intrinsic axon growth capacity constitute major obstacles for spinal cord repair. These processes are tightly regulated by microtubule dynamics. Here, moderate microtubule stabilization decreased scar formation after spinal cord injury in rodents through various cellular mechanisms, including dampening of transforming growth factor-β signaling. It prevented accumulation of chondroitin sulfate proteoglycans and rendered the lesion site permissive for axon regeneration of growth-competent sensory neurons. Microtubule stabilization also promoted growth of central nervous system axons of the Raphe-spinal tract and led to functional improvement. Thus, microtubule stabilization reduces fibrotic scarring and enhances the capacity of axons to grow.