The spatial and temporal disappearance of different oral rabies vaccine baits     

Vos A  Sutor A  Selhorst T  Schwarz S  Pötzsch C  Staubach C  Müller T 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(9-10):360-366

Bait disappearance can give valuable information for the assessment of oral vaccination campaigns of foxes against rabies. In this study, the spatial and temporal disappearance of three different vaccine baits under almost identical conditions was investigated. In the study area, 350 baits were placed at previously marked positions during two different periods; late autumn and early spring. The distribution of baits was in accordance with the method as recommended by the European Union; a density of 20 baits per km2 along flight lines 500m apart. Bait disappearance was checked 1, 3, 5 and 7 days after distribution. At least 80% of the baits had disappeared within one week after distribution. No difference in bait disappearance was observed between the two selected periods. However, a significant higher bait disappearance was observed in forested areas when compared to open agricultural areas. Furthermore, the differences in bait disappearance between the three type of baits tested were relatively small and not significant.  相似文献   

Sorption, mineralization and mobility of N-(phosphonomethyl)glycine (glyphosate) in five different types of gravel     

Strange-Hansen R  Holm PE  Jacobsen OS  Jacobsen CS 《Pest management science》2004,60(6):570-578

Sorption, mineralization and mobility of glyphosate were studied in six substrates: the five types of gravel most frequently used as surfacing in Denmark and a sandy agricultural soil from Simmelkaer that served as a reference soil. Cumulative mineralization of [methyl-14C]glyphosate in batch studies was highest in coarse gravel, amounting to 14% after 4 days at 30 degrees C and 32% after 31 days. Mineralization was slowest in the sandy reference soil, amounting to only 2% after 31 days. The adsorption coefficient (Kd) of glyphosate in gravel ranged from 62 to 164 litre kg(-1), while that in the sandy reference soil was 410 litre kg(-1). The results indicate that the relatively low Kd in gravel allows a relatively high rate of glyphosate mineralization by the biomass. When Kd is high, in contrast, mineralization is slow. Lowering the temperature to 10 degrees C decreased mineralization by 50% in one of two gravels. The leaching of glyphosate was screened in simple columns of gravel or soil in which precipitation events (20 mm over a 2-h period) were simulated on three occasions, starting either immediately after or 2 days after application of glyphosate. [14C]Glyphosate was applied as a tracer mixed with the commercial product Roundup Garden at the recommended rate of 2.4 kg glyphosate ha(-1), equivalent to 1 microg g(-1) soil. The highest concentration of [14C] compounds (expressed in terms of glyphosate concentration) in leachate from the columns exceeded 1300 microg litre(-1), and was detected in rounded gravel after the first rain event. No glyphosate was detected in leachate from the sandy reference soil.  相似文献   

Simulation of local anaesthetic nerve block of the infraorbital nerve within the pterygopalatine fossa: anatomical landmarks defined by computed tomography     

Staszyk C  Bienert A  Bäumer W  Feige K  Gasse H 《Research in veterinary science》2008,85(3):399-406

To provide anaesthesia of the maxillary cheek teeth, a local block of the infraorbital nerve in the pterygopalatine fossa has been suggested. The aim of this study was to re-examine the anatomy of the pterygopalatine fossa, giving special attention to relevant arteries, veins and nerves; simulate the infiltration of an anaesthetic by injecting a contrast medium; improve the injection technique to avoid puncturing of relevant anatomical structures. Five heads and two living horses were investigated using contrast medium injections and computed tomography (CT). Needles were inserted using two insertion techniques: "Palatine Bone Insertion" (PBI) and "Extraperiorbital Fat Body Insertion" (EFBI). Both techniques are suitable for achieving a consistent distribution of contrast medium around the infraorbital nerve. The periorbita prevents the contrast medium from penetrating into the intraperiorbital compartment. The EFBI-technique is most appropriate for providing a sufficient infraorbital nerve block with a minimised risk of complications.  相似文献   

Metagenomics to paleogenomics: large-scale sequencing of mammoth DNA   总被引：1，自引：0，他引：1  

Poinar HN  Schwarz C  Qi J  Shapiro B  Macphee RD  Buigues B  Tikhonov A  Huson DH  Tomsho LP  Auch A  Rampp M  Miller W  Schuster SC 《Science (New York, N.Y.)》2006,311(5759):392-394

We sequenced 28 million base pairs of DNA in a metagenomics approach, using a woolly mammoth (Mammuthus primigenius) sample from Siberia. As a result of exceptional sample preservation and the use of a recently developed emulsion polymerase chain reaction and pyrosequencing technique, 13 million base pairs (45.4%) of the sequencing reads were identified as mammoth DNA. Sequence identity between our data and African elephant (Loxodonta africana) was 98.55%, consistent with a paleontologically based divergence date of 5 to 6 million years. The sample includes a surprisingly small diversity of environmental DNAs. The high percentage of endogenous DNA recoverable from this single mammoth would allow for completion of its genome, unleashing the field of paleogenomics.  相似文献   

Ecology. How does climate change affect biodiversity?     

Araújo MB  Rahbek C 《Science (New York, N.Y.)》2006,313(5792):1396-1397

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Prevalence and severity of foot lesions in Danish Holstein heifers through first lactation     

Capion N  Thamsborg SM  Enevoldsen C 《Veterinary journal (London, England : 1997)》2009,182(1):50-58

Several studies have shown that foot lesions and clinical lameness occur before first calving and develop further during the lactation period. Lameness may cause production losses, but the relationship between foot lesions, particularly in the claw horn, and lameness in heifers is unclear. The objectives of this study were to describe the development of and evaluate the relationship between lameness and foot lesions in Danish Holsteins before and after first calving. In a longitudinal study, 147 heifers were examined for lameness and foot lesions 2–5 times over an 18-month period. Lameness was assessed by means of a visual locomotion score and foot lesion severity was recorded.The prevalence of a locomotion score 3 was 25% before calving, and 90% at approximately 250 days in milk (DIM). Prevalence of moderate to severe sole haemorrhage (SH) was 27% before calving and 56% at 250 DIM, and that of moderate to severe white line lesion (WLL) 44% before calving with a peak of 70% at 200 DIM. There was one case of white line abscess but SH was seen throughout the entire study period. Digital dermatitis (DD) was prevalent prior to first calving (15%) and peaked at 39% at 0–100 DIM. Heel horn erosion (HHE) occurred in almost all cows (93–100%) and was strongly correlated with DD (r = 0.51). The correlation coefficient between SH and WLL was also high (0.42). The relatively high correlations between WLL and both DD and HHE were more surprising (0.38 and 0.35, respectively), those between SH and both DD and HHE were moderate (around 0.18). Interdigital dermatitis was significantly correlated with both HHE and DD, but completely unrelated to SH and WLL.The overall average locomotion score increased by about one-half of a score unit from 1 month prior to calving until 250 DIM, with a large difference between herds, although this was unsurprising as cows may alter their locomotion pattern with management factors (e.g. floor properties). DD and WLL were both associated with a locomotion score 3 but of the cows with severe WLL there was no clear association between a locomotion score 3 and DD. The highest locomotion scores occurred among cows with DD but without WLL.  相似文献   

Adenylate cyclases of Trypanosoma brucei inhibit the innate immune response of the host     

Salmon D  Vanwalleghem G  Morias Y  Denoeud J  Krumbholz C  Lhommé F  Bachmaier S  Kador M  Gossmann J  Dias FB  De Muylder G  Uzureau P  Magez S  Moser M  De Baetselier P  Van Den Abbeele J  Beschin A  Boshart M  Pays E 《Science (New York, N.Y.)》2012,337(6093):463-466

The parasite Trypanosoma brucei possesses a large family of transmembrane receptor-like adenylate cyclases. Activation of these enzymes requires the dimerization of the catalytic domain and typically occurs under stress. Using a dominant-negative strategy, we found that reducing adenylate cyclase activity by about 50% allowed trypanosome growth but reduced the parasite's ability to control the early innate immune defense of the host. Specifically, activation of trypanosome adenylate cyclase resulting from parasite phagocytosis by liver myeloid cells inhibited the synthesis of the trypanosome-controlling cytokine tumor necrosis factor-α through activation of protein kinase A in these cells. Thus, adenylate cyclase activity of lyzed trypanosomes favors early host colonization by live parasites. The role of adenylate cyclases at the host-parasite interface could explain the expansion and polymorphism of this gene family.  相似文献   

Biodegradation of the herbicide mecoprop-p with soil depth and its relationship with class III tfdA genes     

Ma Sonia Rodríguez-Cruz  Jacob Bælum  Sebastian R. Sørensen  Thomas Aspray  Carsten S. Jacobsen  Gary D. Bending 《Soil biology & biochemistry》2010,42(1):32-39

Mecoprop-p [(R)-2-(4-chloro-2-methylphenoxy) propanoic acid) is widely used in agriculture and poses an environmental concern because of its susceptibility to leach from soil to water. We investigated the effect of soil depth on mecoprop-p biodegradation and its relationship with the number and diversity of tfdA related genes, which are the most widely known genes involved in degradation of the phenoxyalkanoic acid group of herbicides by bacteria. Mecoprop-p half-life (DT₅₀) was approximately 12 days in soil sampled from <30 cm depth, and increased progressively with soil depth, reaching over 84 days at 70-80 cm. In sub-soil there was a lag period of between 23 and 34 days prior to a phase of rapid degradation. No lag phase occurred in top-soil samples prior to the onset of degradation. The maximum degradation rate was the same in top-soil and sub-soil samples. Although diverse tfdAα and tfdA genes were present prior to mecoprop-p degradation, real time PCR revealed that degradation was associated with proliferation of tfdA genes. The number of tfdA genes and the most probable number of mecoprop-p degrading organisms in soil prior to mecoprop-p addition were below the limit of quantification and detection respectively. Melting curves from the real time PCR analysis showed that prior to mecoprop-p degradation both class I and class III tfdA genes were present in top- and sub-soil samples. However at all soil depths only tfdA class III genes proliferated during degradation. Denaturing gradient gel electrophoresis confirmed that class III tfdA genes were associated with mecoprop-p degradation. Degradation was not associated with the induction of novel tfdA genes in top- or sub-soil samples, and there were no apparent differences in tfdA gene diversity with soil depth prior to or following degradation.  相似文献   

Prey-predator dynamics in communities of culturable soil bacteria and protozoa: differential effects of mercury     

Maria S Holtze  Flemming EkelundLasse D Rasmussen  Carsten S JacobsenKaare Johnsen 《Soil biology & biochemistry》2003,35(9):1175-1181

We investigated whether the prey-predator dynamics of bacteria and protozoa were affected by inorganic mercury at concentrations of 0, 3.5 and 15 mg Hg(II) kg soil⁻¹. The amount of bioavailable Hg was estimated using a biosensor-assay based on the mer-lux gene fusion. The numbers of bacterial CFUs on the general medium 1/100 tryptic soy agar (TSA) were significantly decreased when the soil had been amended with Hg. In contrast, no effect was seen on the number of CFUs on the Pseudomonas-specific medium Gould's S1 agar. Protozoan numbers estimated by the most probable number (MPN) method with 1/100 TSB as growth medium were also negatively affected by Hg. The different fractions of protozoa were affected to different degrees suggesting that amoebae were less sensitive than slow-growing flagellates, which again were less sensitive than the fast-growing flagellates. In contrast, Hg did not induce any detectable changes in the diversity of flagellate morphotypes. In the treatment with 15 mg Hg kg⁻¹ a transiently increased number of bacteria was seen at day 6 probably concomitant with a decrease in the numbers of protozoa. This might indicate that Hg affected the prey-predator dynamics in communities of culturable bacteria and protozoa in soil. Furthermore, we showed that the number of Pseudomonas spp. was not affected by Hg whereas the number of bacteria growing on a general medium was.  相似文献   

Using farmland prices to evaluate cost-efficiency of national versus regional reserve selection in Denmark     

Niels Strange  Carsten Rahbek  Jacob K. Jepsen  Mette P. Lund 《Biological conservation》2006,128(4):455-466

The current study focuses on the influence of geopolitical coordination of conservation strategies on cost and efficiency in terms of species representation when selecting network of protected areas. Conservation policies in the EU are implemented at many different administrative levels: from the European Union and national levels, to regional or/county levels within member countries. This arise the question what size of efficiency gains could be achieved if planning of conservation priorities could be coordinated between geopolitical units. Using data for the nationwide distribution of 763 species, representing all Danish species within eight taxa, we compared illustrative costs for the addition of new areas to the existing conservation network in order to ensure full coverage of all species. We found that the cost of independent regional planning is 20-fold higher than an inter-regional and nationally co-ordinated strategy. We also found that substituting land prices for a simple land-area measure in our analyses increased the expected conservation costs differential significantly, without increasing coverage of species representations. We suggest that in economic and biodiversity terms it can largely be a win-win situation to set a common goal, to develop priority-strategies, and to coordinate actions at higher rather than lower levels of administration.  相似文献