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991.
Barbara Schimmer Saskia Luttikholt Jeannine LA Hautvast Elisabeth AM Graat Piet Vellema Yvonne THP van Duynhoven 《BMC veterinary research》2011,7(1):1-14
Background
Highly pathogenic avian influenza (HPAI) viruses have had devastating effects on poultry industries worldwide, and there is concern about the potential for HPAI outbreaks in the poultry industry in Great Britain (GB). Critical to the potential for HPAI to spread between poultry premises are the connections made between farms by movements related to human activity. Movement records of catching teams and slaughterhouse vehicles were obtained from a large catching company, and these data were used in a simulation model of HPAI spread between farms serviced by the catching company, and surrounding (geographic) areas. The spread of HPAI through real-time movements was modelled, with the addition of spread via company personnel and local transmission.Results
The model predicted that although large outbreaks are rare, they may occur, with long distances between infected premises. Final outbreak size was most sensitive to the probability of spread via slaughterhouse-linked movements whereas the probability of onward spread beyond an index premises was most sensitive to the frequency of company personnel movements.Conclusions
Results obtained from this study show that, whilst there is the possibility that HPAI virus will jump from one cluster of farms to another, movements made by catching teams connected fewer poultry premises in an outbreak situation than slaughterhouses and company personnel. The potential connection of a large number of infected farms, however, highlights the importance of retaining up-to-date data on poultry premises so that control measures can be effectively prioritised in an outbreak situation. 相似文献992.
Process water and effluents from mining operations treating sulfide rich ores often contain considerable concentrations of metastable inorganic sulfur compounds such as thiosulfate and tetrathionate. These species may cause environmental problems if released to downstream recipients due to oxidation to sulfuric acid catalyzed by acidophilic microorganisms. Molecular phylogenic analysis of the tailings pond and recipient streams identified psychrotolerant and mesophilic inorganic sulfur compound oxidizing microorganisms. This suggested year round thiosalt oxidation occurs. Mining process waters may also contain inhibiting substances such as thiocyanate from cyanidation plants. However, toxicity experiments suggested their expected concentrations would not inhibit thiosalt oxidation by Acidithiobacillus ferrivorans SS3. A mixed culture from a permanently cold (4-6 °C) low pH environment was tested for thiosalt removal in a reactor design including a biogenerator and a main reactor containing a biofilm carrier. The biogenerator and main reactors were successively reduced in temperature to 5-6 °C when 43.8% of the chemical oxidation demand was removed. However, it was found that the oxidation of thiosulfate was not fully completed to sulfate since low residual concentrations of tetrathionate and trithionate were found in the discharge. This study has demonstrated the potential of using biotechnological solutions to remove inorganic sulfur compounds at 6°C and thus, reduce the impact of mining on the environment. 相似文献
993.
This work aimed to determine the inter- and intra-specific variations in populations of Bulinus truncatus and Bulinus beccari, the intermediate hosts of Schistosoma haematobium in Saudi Arabia, and to develop species-specific primers to identify these snails as a first step in the development of multiplex PCR for simultaneously identifying the snails and diagnosing its infections in a single step. Two populations of B. truncatus were collected from Asser and Bisha (A and B), and two B. beccari populations were collected from Mahial Asser and Merba (C and D). The snails' genomic DNA was extracted and amplified using 5 different primers. The primers displayed variable intra- and inter-specific differences across the populations. The largest RAPD-PCR fragments were cloned into a vector as a preparatory step for sequencing. Similarity searches for the sequenced cloned inserts revealed no similar sequences in the GenBank database or its associated databases. Specific primers used to target the B. truncatus and B. beccari genomes were designed using the Gene Runner program and based on the DNA sequences obtained from RAPD fragment sequence analyses. Using these primers for specific PCRs resulted in expected single-band PCR products of 536 bp for B. beccari and 478 bp for B. truncatus. These results will be helpful for simultaneously identifying B. truncatus and B. beccari snails and diagnosing S. haematobium infections within the snails using single step multiplex PCR. 相似文献
994.
John WM Bastiaansen Albart Coster Mario PL Calus Johan AM van Arendonk Henk Bovenhuis 《遗传、选种与进化》2012,44(1):3
Background
Genomic selection has become an important tool in the genetic improvement of animals and plants. The objective of this study was to investigate the impacts of breeding value estimation method, reference population structure, and trait genetic architecture, on long-term response to genomic selection without updating marker effects.Methods
Three methods were used to estimate genomic breeding values: a BLUP method with relationships estimated from genome-wide markers (GBLUP), a Bayesian method, and a partial least squares regression method (PLSR). A shallow (individuals from one generation) or deep reference population (individuals from five generations) was used with each method. The effects of the different selection approaches were compared under four different genetic architectures for the trait under selection. Selection was based on one of the three genomic breeding values, on pedigree BLUP breeding values, or performed at random. Selection continued for ten generations.Results
Differences in long-term selection response were small. For a genetic architecture with a very small number of three to four quantitative trait loci (QTL), the Bayesian method achieved a response that was 0.05 to 0.1 genetic standard deviation higher than other methods in generation 10. For genetic architectures with approximately 30 to 300 QTL, PLSR (shallow reference) or GBLUP (deep reference) had an average advantage of 0.2 genetic standard deviation over the Bayesian method in generation 10. GBLUP resulted in 0.6% and 0.9% less inbreeding than PLSR and BM and on average a one third smaller reduction of genetic variance. Responses in early generations were greater with the shallow reference population while long-term response was not affected by reference population structure.Conclusions
The ranking of estimation methods was different with than without selection. Under selection, applying GBLUP led to lower inbreeding and a smaller reduction of genetic variance while a similar response to selection was achieved. The reference population structure had a limited effect on long-term accuracy and response. Use of a shallow reference population, most closely related to the selection candidates, gave early benefits while in later generations, when marker effects were not updated, the estimation of marker effects based on a deeper reference population did not pay off. 相似文献995.
996.
Nikkhah D Rodrigues J Saleh DB Jeffers R 《Plastic and reconstructive surgery》2012,129(3):557e-558e; author reply 558e-559e
997.
Chen X Hu X Gong J Al-Rasheid KA Al-Farraj SA Song W 《European journal of protistology》2012,48(1):63-72
The morphology and infraciliature of two new marine cyrtophorid ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec., isolated from tropical waters in southern China, were investigated using live observation and protargol impregnation methods. Paracyrtophoron nov. gen. differs from the closely related Cyrtophoron by lack of fragment kinety at anterior ends of right somatic kineties and thigmotactic cilia in posterior portion of ventral surface, while from the well-defined Chlamydodon by lack of the cross-striped band around the periphery of the somatic field. Paracyrtophoron tropicum nov. spec., the type of the new genus, can be recognized by the combination of the following characters: cell size about 150-175×70-90μm in vivo; elliptical to kidney-shaped in outline, dorsoventrally flattened about 2.5:1; conspicuous cortical granules; one canal-like depression extending from postoral area to subcaudal region of cell; ca. 90 somatic kineties; 12-16 nematodesmal rods; one or two terminal fragments on dorsal side. Aegyria rostellum is characterized by the following features: size about 90-150×40-70μm in vivo, triangular or ear-shaped body with broad anterior end, having a rostriform structure and pigment spots, 56-63 somatic kineties, one preoral kinety, three or four circumoral kineties, and 32-42 nematodesmal rods. Based on previous and current studies, the definition for the genus Aegyria is updated: body dorsoventrally flattened; oral ciliature consisting of one preoral and several circumoral kineties; podite located in posterior ventral region and surrounded by somatic kineties; no obvious gap between right and left somatic kineties; postoral and left somatic kineties progressively shortened posteriorly from right to left. Additionally, two new combinations were proposed. 相似文献
998.
999.
Abu El-Asrar AM Struyf S Kangave D Al-Obeidan SA Opdenakker G Geboes K Van Damme J 《Cytokine》2012,59(2):377-381
Aqueous humor (AH) samples from 14 patients with presumed tuberculous uveitis (PTU), and 30 control patients were assayed for the proinflammatory cytokines interleukin IL-4, IL-12, IL-15, IL-17, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α, the immunosuppressive cytokine IL-10, and the chemokines GRO-α/CXCL1, IL-8/CXCL8, MIG/CXCL9, IP-10/CXCL10 and SDF-1/CXCL12 with the use of a multiplex assay. Among cytokines, IL-4 and IL-12 were not detected. IL-15, IL-17, IFN-γ, TNF-α and IL-10 levels in AH were significantly higher in patients than in controls (p<0.001; p=0.004; p<0.001; p<0.001; p<0.001, respectively). Among chemokines, SDF-1 levels did not differ significantly between patients and controls, whereas GRO-α, IL-8, MIG and IP-10 levels were significantly higher in patients than in controls (p=0.001; p<0.001; p<0.001; p<0.001, respectively). Mean GRO-α levels in AH of PTU patients were 6-fold higher than IL-8 levels and mean IP-10 levels were 15-fold higher than MIG levels. Clinical disease activity correlated significantly with the levels of IL-15, IFN-γ, TNF-α and IP-10. Logistic regression analysis demonstrated a significant positive association between PTU and high levels of IFN-γ, IL-8, MIG and IP-10. These data suggest that both T helper (Th) Th(1) and Th(17) cells are involved in PTU and that the cytokine profile is polarized toward a Th(1) response. GRO-α and IP-10 might be involved in neutrophil and activated T lymphocyte chemoattraction in PTU, respectively. 相似文献
1000.
This paper describes the morphological characteristics of a new species of Haemogregarina Danilewsky, 1885, from naturally infected Acanthodactylus
boskianus (Daudin) in Egypt, based on both blood and tissue stages. The prevalence of infection was found to be 66% (33/50). The blood
stages were found to be confined to the erythrocytes and could be differentiated into small and large forms. The small form
(trophozoites) measures 8 × 3.5 μm, whereas the large form (mature gamonts) measures 12 × 5 μm. The tissue stages were observed
only in the liver. Meronts occurred within parasitophorous vacuoles in hepatocytes and ranged from mononucleate forms to mature
forms that contained c.10–15 merozoites. 相似文献