Sensors for detecting and logging spatial distribution of urine patches of grazing female sheep and cattle

Urine excreted in patches by grazing livestock accounts for much of the nitrogen (N) loss to the environment in grazing systems. These losses arise mainly through N leaching to ground water and gaseous losses to the atmosphere. Models of grazing systems ideally require data on urination frequency, N load in each urination event and spatial distribution patterns of urine. To date there has been a lack of suitable equipment for obtaining information on urination characteristics of grazing animals. This paper describes a urine sensor that detects and logs each urination event of female sheep and cattle. A thermistor suspended below the vulva continuously measures ambient temperature except when urine passes over it, causing the temperature to rise to near body temperature. Field validation showed 85% and 78% of sensor-detected urination events by sheep and cattle sensors, respectively, were seen by the observer. Some of the urination events identified by the sensor but not seen by the observer were confirmed by video footage. For cattle, only one observed urination event was not detected by the urine sensor, giving a 4% error rate of detection. Daily urination frequencies (ewes: 13-23 events day⁻¹; cows: 11-26 events day⁻¹) were similar to published data for these species. A custom-made GPS unit worn on the rump of the ewe and on the collar of the cow logged animal position continuously so that urine patch position could be determined. Examples of urine distribution patterns by ewes and beef cows in large, hilly paddocks clearly show campsite locations where a disproportionate number of urination events occurred. For sheep, the correlation between time spent in an area and the number of urination events in the same area was r = 0.82, but this correlation was weaker for cattle (r = 0.54).     

Correction to: A meta-analysis of factors driving the adoption of precision agriculture

Precision Agriculture -     

pestMapper—A internet-based software tool for reporting and mapping biological invasions and other geographical and temporal events

An internet-based Google^® Maps application, pestMapper, is developed for sharing biological events such as invasive species and pest distribution over large geographical areas. This data gathering and mapping tool facilitates reporting, viewing, and providing alerts about important pest occurrences and research activities both regionally and globally.This Google^® application provides reported events dynamically to a Google^® Maps interface with detailed information displayed for each event. Users can make use of various built-in options such as region, event, pest, country, or time to display the map selectively. Alerts can be automatically sent to interested parties when system-specified types of events, such as pest outbreaks, occur. The system also generates web-based alerts for certain pre-defined events. A time slider is available for users to view temporal distributions of a biological event.Data are entered using an online data report component. The software can be modified for many other applications, such as species regional or global distribution mapping.     

Genetic determinants of self identity and social recognition in bacteria

The bacterium Proteus mirabilis is capable of movement on solid surfaces by a type of motility called swarming. Boundaries form between swarming colonies of different P. mirabilis strains but not between colonies of a single strain. A fundamental requirement for boundary formation is the ability to discriminate between self and nonself. We have isolated mutants that form boundaries with their parent. The mutations map within a six-gene locus that we term ids for identification of self. Five of the genes in the ids locus are required for recognition of the parent strain as self. Three of the ids genes are interchangeable between strains, and two encode specific molecular identifiers.     

Simulation of the soil-water dynamics and corn yields under deficit irrigation

Summary A simulation model capable of predicting the yield response of corn to a limited water supply was developed by combining two existing mathematical models. The resulting computer model was evaluated using experimental data taken under a wide range of soil moisture conditions. The soil profile water balances was simulated using SWATRE and SUCROS was used to model the crop growth in response to environmental conditions. In addition to the integration of the two existing models, some minor changes were made to each in an effort to improve the accuracy of the combined models. The model input parameters were derived entirely from published literature. The experimental data necessary for model validation were available from irrigation studies at the Sandhills Agricultural Laboratory of the University of Nebraska. These experiments not only provided the required input soil and climatic data, but also the observed irrigation levels, soil moisture distributions and crop yield required for model validation. Initial evaluation of the computer model indicates that the combined model adequately describes crop evapotranspiration, soil moisture extraction and crop yield under a fairly wide range of soil moisture stress. Additional modifications for the prediction of leaf area expansion and senescence, especially under moisture stress, are needed to improve the accuracy of the model.     

作物模型输入变量的敏感性分析

 运行作物模型需要大量的输入变量。为了方便模型用户建立模型变量数据库 ,研究估计了作物模型 ALMANAC主要模型输入变量的重要程度。根据在美国德克萨斯州 8个县主要玉米品种的田间试验资料 ,首先建立了模拟 10年 (1989～ 1998年 )玉米和高粱产量的标准数据库 ,模拟结果与实产吻合程度很好。以此为基础 ,分别分析了产量对太阳辐射、降雨、土壤层厚度、土壤有效水分以及径流曲线数变化的敏感性。结果表明 ,径流曲线数变化对于模拟结果的影响最大 ,其次分别是降雨和太阳辐射。玉米对所有变量变化的敏感性都大于高粱。获得合适的降雨资料 ,准确估计径流曲线数 ,对于作物生长模拟十分重要。     

Microbial dehalorespiration with 1,1,1-trichloroethane

1,1,1-Trichloroethane (TCA) is a ubiquitous environmental pollutant because of its widespread use as an industrial solvent, its improper disposal, and its substantial emission to the atmosphere. We report the isolation of an anaerobic bacterium, strain TCA1, that reductively dechlorinates TCA to 1,1-dichloroethane and chloroethane. Strain TCA1 required H2 as an electron donor and TCA as an electron acceptor for growth, indicating that dechlorination is a respiratory process. Phylogenetic analysis indicated that strain TCA1 is related to gram-positive bacteria with low DNA G+C content and that its closest relative is Dehalobacter restrictus, an obligate H2-oxidizing, chloroethene-respiring bacterium.     

Activation of integrin alphaIIbbeta3 by modulation of transmembrane helix associations

Transmembrane helices of integrin alpha and beta subunits have been implicated in the regulation of integrin activity. Two mutations, glycine-708 to asparagine-708 (G708N)and methionine-701 to asparagine-701, in the transmembrane helix of the beta3 subunit enabled integrin alphaIIbbeta3 to constitutively bind soluble fibrinogen. Further characterization of the G708N mutant revealed that it induced alphaIIbbeta3 clustering and constitutive phosphorylation of focal adhesion kinase. This mutation also enhanced the tendency of the transmembrane helix to form homotrimers. These results suggest that homomeric associations involving transmembrane domains provide a driving force for integrin activation. They also suggest a structural basis for the coincidence of integrin activation and clustering.