高寒阴湿地区半开放型暖棚牛舍冬季内环境监测评价

在高寒阴湿的寒冷地区修建半开放型暖棚牛舍,充分利用塑料膜的温室效应,能够达到保暖增膘的饲养目的,本课题研究采用定期定点观测的方法,在冬春季扣膜后,对暖棚牛舍和普通圈舍的采光系数、入射角、透光角、舍内外的温度、湿度及CO2、NH3、H2S等主要技术指标进行了监测和对比.结果表明暖棚牛舍(试验组)舍内11月份～3月份平均温度为8.78℃;平均湿度为55.53%;舍内的CO2含量平均为0.141%;NH3平均为19.02 mg/m3;H2S平均为9.91 mg/m3;采光系数为0.86;入射角为64°;透光角为45°.普通牛舍(对照组)的平均温度为0.25℃;平均湿度为66.75%;舍内的CO2平均为0.137%;NH3平均为18.49 mg/m3;H2S平均为9.64 mg/m3;采光系数为0.082;入射角为35°;透光角为10°.试验组牛的授配率、产仔成活率、繁活率分别比对照组提高了24%、17%、50%,而患病率降低了2.6%.     

景观生态学在植被监测中的应用——以塔里木河中游英巴扎地区为例

以塔里木河中游英巴扎地区为例,探讨了景观生态学的多样性指数,优势度指数及均匀度指数在植被监测中的应用。结果显示,景观生态学中的一些指数研究方法在植被监测方面有良好的应用前景。     

Monitoring the Immune Status of Broilers Against Reoviruses Using Challenge and Serologic Data

Reoviruses are an important cause of suboptimum performance in commercial broilers worldwide. Integrators use the enzyme-linked immunosorbent assay against the S1133 antigen for monitoring serum of breeders for indicating pullet vaccine success. However, without correlating serology to reovirus challenge, it is difficult to determine whether titers reflect protective immunity. We developed a broiler challenge test against 2 common reovirus isolates (2408 and S1133) to evaluate the efficacy of reovirus pullet vaccine programs. Two reovirus serologic and challenge studies were undertaken using chicks from broiler integrators from the southeastern United States. Breeder flocks, from which the chicks were obtained, received at least 1 live and 2 inactivated reovirus vaccines during their pullet phase. One-day-old progeny were collected from 6 breeder flocks. At 1 d of age, 20 chicks from each broiler flock were bled, and serum was analyzed for antibodies. At 3 to 4 d of age, 20 progeny per flock were challenged with the 2408 reovirus by intratracheal route. At 10 to 14 d of age, another 20 birds per flock were challenged with the S1133 reovirus by footpad. Twenty birds per flock were used as nonchallenged controls. At 3 wk of age, all birds were killed and weighed. Percentage of protection was calculated for each flock based on the absence of gross lesions. Flocks with at least 50% protection were considered well protected. Most flocks were well protected against both viruses. The percentage of protection correlated with day-old enzyme-linked immunosorbent assay titers. Chicks from younger hens had higher titers and the best protection against challenge. Producers, whose hen flocks were monitored herein, were doing a good job of immunizing pullets against reovirus. They are now using reovirus progeny challenge studies along with breeder antibody titers to determine vaccination success of their pullets.     

Landscape improvement, or ongoing degradation – reconciling apparent contradictions from the arid rangelands of Western Australia

Recent quantitative site-based monitoring and qualitative aerial and ground traverses provide contrasting assessments of the health of much of the arid shrublands of Western Australia extensively grazed by livestock (‘rangelands’). Although these results seem incompatible, we explain the apparent contradictions based on landscape succession processes operating at multiple levels of ecological organisation. Specifically, we suggest that the intact areas in which site-based monitoring is conducted are contracting as catchment canalisation and desiccation increase. However, the impacts of these processes have not yet become manifest at the site scale. The site-based system addresses important regional questions. These relate to the large, relatively intact areas away from most active surface flows, which should be a focus for resource conservation, given practical limits to repairing widespread degradation with low management inputs. We provide a complementary set of questions to provide a more comprehensive audit of rangeland dynamics in the context of underlying hierarchical landscape patterns and processes that might threaten intact areas. We recognise the need to match questions and levels of ecological organisation and the implications these have for sampling. We also recognise the difficulty in producing concise statements of change for clients when reporting on complex ecological issues and processes. Without a clearly articulated, and well understood, hierarchical model of pattern and process within which apparently contradictory findings can be reported meaningfully, policy makers may be confused by the results, with the consequent risk of policy inaction.     

Can the occurrence of Senecio jacobaea be influenced by management practice?

Senecio jacobaea is a poisonous weed in grasslands of various countries (e.g. Great Britain, New Zealand, Central European states) and the further spread of the species into farmland must be prevented. To assess the influence of management practice and site conditions on the occurrence of S. jacobaea, we conducted a survey in the northern and central part of Switzerland. Botanical assessments were carried out on grassland plots with S. jacobaea occurrence and on neighbour plots without S. jacobaea. For these plots, we analysed the soil nutrients and the details of management practice, such as type and intensity of management and fertiliser application. The most important factors influencing the occurrence of S. jacobaea were related to management: There was a high risk for the occurrence of the species on parcels with low nitrogen fertilisation, continuous‐extensive grazing (set stocking) and a very open sward. Senecio jacobaea was not present in intensively managed meadows cut more than twice per year. As an exception, with a high propagule pressure from the vicinity, S. jacobaea was also found in intensively grazed pastures and in meadows of moderate management intensity (two cuts). We conclude that long‐term control of S. jacobaea can best be achieved by avoiding sward damage and by preventing the species’ seed formation in the pasture and local vicinity.     

A Simple Apparatus for Frequent Measurement of Gastrointestinal Intraluminal PCO2

The accuracy and precision of an end-tidal infrared CO₂ monitor and customized capnography tubing system designed to measure gastrointestinal intraluminal CO₂ partial pressure (P_iCO₂) were tested in vitro. Samples were taken from the customized capnography tubing placed in either 5% or 10% CO₂ gas at discrete intervals ranging from one minute to twelve minutes. For a given time interval, the tubing PCO₂ measurement was a constant fraction of the actual PCO₂ (all standard errors < 0.02). For increasing time intervals, the ratio of the tubing PCO₂ to actual PCO₂ increased logarithmically. In the 5% and 10% CO₂, the regression coefficients were 0.89 and 0.85 for 8 French tubing and 0.99 and 0.91 for 6 French tubing. Beacuase of its accuracy and precision, this system may provide automated gastrointestinal CO₂ partial pressure monitoring at short intervals (e.g. 5 minutes), facilitating testing of the role of gastrointestinal P_iCO₂ information in treatment algorithms. (Vet Emerg & Crit Care, 1998; 8: 109–116)     

排种器振动种盘内种群质量实时监测方法

采用悬臂梁称重传感器测量排种器振动种盘内种群的冲击力,在分析不同参数下输出信号变化特征的基础上,设计了由加法器、精密半波整流、二阶巴特沃斯低通滤波和差动放大串联组成的信号处理电路,实现了振动状态下种群质量的实时监测。在振动种盘试验台上进行了性能试验,设定振幅为3、4、5mm,相应振动频率分别在11~13Hz、10~12Hz、9~11Hz范围,结果表明:当单位面积籽粒质量κ1.8 g/cm2时,信号处理电路输出电压Vout与κ的非线性误差小于5.5%;当κ2.0g/cm2时,由于种群振动运动的不稳定导致输出电压Vout的波动性增强,测量的非线性误差增大。信号处理电路零点输出电压随种盘振动强度的提高而增大,测量灵敏度随种盘振动频率的提高而降低,籽粒形状和力学特性差异对测量结果的影响可以被忽略,监测方法具有很好的适应性。     

滴灌施肥对加工番茄产量和品质的影响

为了寻求滴灌施肥条件下连作加工番茄持续优质高产平衡施肥方案,以番茄为材料,采用"3414"优化试验方法,分析了滴灌平衡施肥对加工番茄生长发育、产量和品质的影响。结果表明,滴灌施肥条件下,增施氮、磷、钾肥和配施微肥明显促进番茄生长发育;增磷和配施微肥显著提高产投比,实现增收;增氮、增钾的增产效果不显著,但减氮、减钾显著降低了产量;增钾、配施微肥显著提高加工番茄品质,尤其在提高番茄糖酸比,降低硝酸盐量积累,促进可溶性固形物的形成及改良色差等方面成效显著。滴灌施肥条件下,增施磷、钾肥,配施微肥对连作加工番茄具有显著的增产提质作用。     

生物大分子标记物检测在环境监测中的应用

生物大分子标记物是指生物体内的一些对外界环境变化敏感并能产生一些可检测变化的大分子物质,这些大分子物质能够反映环境变化对生物体的影响。随着社会对环境保护的日益重视和分子生物学技术的发展,将生物大分子标记物的检测应用到环境监测中已经成为一种趋势。生物大分子标记物检测由于其测定指标全面、准确、系统且具有特异性等优点,近十几年来作为污染物暴露和毒性效应的早期预警工具已被广泛应用于环境评价中。本文对一些主要的生物大分子标记物及其检测技术在环境监测中的应用状况及应用前景进行综述,旨在为生物大分子标记技术在环境检测实际操作中的应用提供参考依据。     

基于ZigBee无线网络的大棚种植温度监测系统

针对大棚种植温度监测系统,讨论了无线温度监测系统的技术要求,阐述了基于ZigBee无线检测网络的系统结构与硬件、软件设计。随着规模农业的快速发展,无线网络农业自动化系统将有非常广阔的推广应用前景。