Leaching of Mycobacterium avium Subsp paratuberculosis in Soil under In Vitro Conditions

Mycobacterium avium subsp paratuberculosis (Map), the causative agent of Johne's disease, has a robust ability to survive in the environment. However, the ability of Map to migrate through soil to drainage tiles or ground water, leave the farm, and leak into local watersheds is inadequately documented. In order to assess the ability of Map to leach through soil, two laboratory experiments were conducted. In the first study, 8 columns (30 cm long each) of a sandy loam soil were treated with pure cultures of Map. Two soil moisture levels and two Map concentrations were used. The columns were leached with 500 mL of water once a week for three weeks, the leachate was collected, and detection analysis was conducted. In the second experiment, manure from Map negative cows (control) and Map high shedder cows (treatment) were deposited on 8 similar columns and the columns were leached with 500 mL of water once a week for four weeks. Map detection and numeration in leachate samples were done with RT-PCR and culture techniques, respectively. Using RT-PCR, Map could be detected in the leachates in both experiments for several weeks but could only be recovered using culture techniques in experiment one. Combined, these experiments indicate the potential for Map to move through soil as a result of rainfall or irrigation following application

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Mycobacterium avium subsp paratuberculosis (Map), the causative agent of Johne's disease, has a robust ability to survive in the environment. However, the ability of Map to migrate through soil to drainage tiles or ground water, leave the farm, and leak into local watersheds is inadequately documented. In order to assess the ability of Map to leach through soil, two laboratory experiments were conducted. In the first study, 8 columns (30 cm long each) of a sandy loam soil were treated with pure cultures of Map. Two soil moisture levels and two Map concentrations were used. The columns were leached with 500 mL of water once a week for three weeks, the leachate was collected, and detection analysis was conducted. In the second experiment, manure from Map negative cows (control) and Map high shedder cows (treatment) were deposited on 8 similar columns and the columns were leached with 500 mL of water once a week for four weeks. Map detection and numeration in leachate samples were done with RT-PCR and culture techniques, respectively. Using RT-PCR, Map could be detected in the leachates in both experiments for several weeks but could only be recovered using culture techniques in experiment one. Combined, these experiments indicate the potential for Map to move through soil as a result of rainfall or irrigation following application

Conformational ensemble-dependent lipid recognition and segregation by prenylated intrinsically disordered regions in small GTPases

Abstract We studied diverse prenylated intrinsically disordered regions (PIDRs) of Ras and Rho family small GTPases using long timescale atomistic molecular dynamics simulations in an asymmetric model membrane of phosphatidylcholine (PC) and phosphatidylserine (PS) lipids. Here we show that conformational plasticity is a key determinant of lipid sorting by polybasic PIDRs and provide evidence for lipid sorting based on both headgroup and acyl chain structures. We further show that conformational ensemble-based lipid recognition is generalizable to all polybasic PIDRs, and that the sequence outside the polybasic domain (PBD) modulates the conformational plasticity, bilayer adsorption, and interactions of PIDRs with membrane lipids. Specifically, we find that palmitoylation, the ratio of basic to acidic residues, and the hydrophobic content of the sequence outside the PBD significantly impact the diversity of conformational substates and hence the extent of conformation-dependent lipid interactions. We thus propose that the PBD is required but not sufficient for the full realization of lipid sorting by prenylated PBD-containing membrane anchors, and that the membrane anchor is not only responsible for high affinity membrane binding but also directs the protein to the right target membrane where it participates in lipid sorting

Comparison of different interpolation techniques to map temperature in the southern region of Eritrea

Tewolde, M. G., Beza, T. A., Costa, A. C., & Painho, M. (2010). Comparison of different interpolation techniques to map temperature in the southern region of Eritrea. In P. M., S. M. Y., & P. H. (Eds.), Geospatial Thinking: Proceedings of the 13th AGILE International Conference on Geographic Information Science (pp. 1-5). Association of Geographic Information Laboratories for Europe (AGILE). https://agile-online.org/conference_paper/cds/agile_2010/posterabstracts_pdf/84_doc.pdfTemperature and rainfall vary markedly throughout Eritrea, from hot desert in the east to a mild, subhumid climate in the highlands (Wolfe et al., 2008). Prediction and understanding of the spatial variation of climate data, particularly temperature, is important to many agricultural and economic sectors for planning and management activities (Moral, 2009). This is especially important in Eritrea where agriculture provides 12.4% of the gross domestic product, and 80% of the population are involved in farming and herding (Wolfe et al., 2008). Several studies have demonstrated that various spatial interpolation techniques perform differently depending on the type of attribute, geometrical configuration of the samples, spatial resolution, world region, etc. (Martínez-Cob, 1996; Goovaerts, 2000; Haberlandt, 2007). Hence, selecting the best interpolation technique for each particular situation is a key factor. The major objective of this study is to assess the spatial variability of annual average temperature in the southern region of Eritrea by comparing different interpolation procedures. The temperature data were interpolated using a deterministic method (Inverse square distance) and three geostatistical methods (Ordinary, Universal and Simple kriging). The performance of the different techniques was compared through error statistics computed using Jackknife cross-validationpublishersversionpublishe

The potential for scaling up a fog collection system on the eastern escarpment of Eritrea

Fog is an untapped natural resource. A number of studies have been undertaken to understand its potential as an alternative or complementary water source. In 2007, a pilot fog-collection project was implemented in 2 villages on the Eastern Escarpment of Eritrea. The government of Eritrea, buoyed by the project’s positive results, has encouraged research into and application of fog-collection technologies to alleviate water-supply problems in this region. In 2014, this study was undertaken to assess the coverage, prevalence, intensity, and seasonality of fog on the Eastern Escarpment of Eritrea and consequently to identify potential beneficiary villages. Three independent methods used in the study—satellite image analyses, personal interviews, and a standard fog collector—produced reasonably similar characterizations of fog coverage and timing. The period with high fog incidence is mainly between November and March, with the highest number of fog days per year (96) on the central Eastern Escarpment and decreasing frequency to the south (78 days) and north (73 days). The fog intensity on the central Eastern Escarpment is very high and in most cases reduces visibility to less than 500 m. In this period, a light to moderate breeze blows predominantly from the north and northeast. More than half of the villages in the region currently have a reliable water-supply system. The rest depend on seasonal roof-water harvesting, rock-water harvesting, and truck delivery and, therefore, could potentially benefit from fog collection as a supplementary water source. In particular, fog water could be useful for a small number of beneficiaries, including public services like schools and health facilities, where conventional water-delivery systems are not viable

Fog-water collection for community use

Fog is a potential source of water that could be exploited using the innovative technology of fog collection. Naturally, the potential of fog has proven its significance in cloud forests that are thriving from fog interception. Historically, the remains of artificial structures in different countries prove that fog has been collected as an alternative and/or supplementary water source. In the beginning of the 19th century, fog collection was investigated as a potential natural resource. After the mid-1980s, following success in Chile, fog-water collection commenced in a number of developing countries. Most of these countries are located in arid and semi-arid regions with topographic and climatic conditions that favour fog-water collection. This paper reviews the technology of fog collection with initial background information on natural fog collection and its historical development. It reviews the climatic and topographic features that dictate fog formation (mainly advection and orographic) and the innovative technology to collect it, focusing on the amount collected, the quality of fog water, and the impact of the technology on the livelihoods of beneficiary communities. By and large, the technology described is simple, cost-effective, and energy-free. However, fog-water collection has disadvantages in that it is seasonal, localised, and the technology needs continual maintenance. Based on the experience in several countries, the sustainability of the technology could be guaranteed if technical, economic, social, and management factors are addressed during its planning and implementation

Assessment of fog-water collection on the eastern escarpment of Eritrea

Fog can be considered a potential water resource for certain semi-arid and arid countries. In Eritrea, a fog-water collection project was implemented in 2007 in the villages of Arborobue and Nefasit. This study presents an assessment of the project after five years of implementation and identifies the main strengths to be technical viability, since it is simple and manageable by communities, and reasonable in areas where conventional water delivery systems are not feasible. The main limitations are that it is not economically viable unless its initial cost is subsidized; moreover, fog capture is seasonal, and net damage occurs during strong winds