Lightning Proof Performance of 500 kV Transmission Line in Chongqing Area     

YANG Cui ping  SIMA Wen xi  GU Le guan 《保鲜与加工》2001,(5):98-102

Considering the importance of 500 kV line and taking 500 kV transmission line in Chongqing as an example, the authors calculate lightning strike outage rate (including return stroke and lightning shielding failure) using regulation method, outage rate of return stroke using travelling wave method, and outage rate of lightning shielding failure using EGM. By comparing and analysing the calculating fesults, weakness of insulation and the area of easy to striking are found out, and corresponding improving measure is brought forward. The results show bigger gradient of lightning higher return stroke tripping, and in regulations result of accounting return stroke tripping is more closed to practical experience, accounting shielding failure rate exists obviously defect, and in EGM accounting shielding failure rate have take much factor, result is more close to practical experience.  相似文献   

Optimization of dynamic headspace extraction of the edible red algae Palmaria palmata and identification of the volatile components     

Le Pape MA  Grua-Priol J  Prost C  Demaimay M 《Journal of agricultural and food chemistry》2004,52(3):550-556

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Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children     

Marques RC  Dórea JG  McManus C  Leão RS  Brandão KG  Marques RC  Vieira IH  Guimarães JR  Malm O 《Public health nutrition》2011,14(4):661-669

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A 50-year record of quinolone and sulphonamide antimicrobial agents in Seine River sediments     

Fatima Tamtam  Barbara Le Bot  Tuc Dinh  Sophie Mompelat  Joelle Eurin  Marc Chevreuil  Philippe Bonté  Jean-Marie Mouchel  Sophie Ayrault 《Journal of Soils and Sediments》2011,11(5):852-859

Purpose  

Even though sediments may represent a reservoir for antimicrobial agents, little is known about the persistence of these molecules over time or their accumulation. In this study, six antimicrobial agents, oxolinic acid, flumequine, nalidixic acid, norfloxacin, sulphamethoxazole and trimethoprim, were investigated in a sediment core from the Seine River. This work aimed to (1) measure antimicrobial agent contamination levels in the sediment and identify their origins, (2) obtain information on the persistence of these compounds in sediment over long periods (>4 years) and (3) show the existence of a historical record in sediment of river contamination by antimicrobial agents.  相似文献   

Endotoxin concentration in poultry houses for laying hens kept in cages or in alternative housing systems     

Huneau-Salaün A  Le Bouquin S  Bex-Capelle V  Huonnic D  Balaine L  Guillam MT  Squizani F  Segala C  Michel V 《British poultry science》2011,52(5):523-530

1. Endotoxins as components of organic dust may have adverse effects on the respiratory health of workers in poultry buildings. The move towards more welfare-friendly housing systems for layers may increase worker exposure to air contaminants due to the use of litter.

2. The endotoxin concentrations in the inhalable fraction of airborne dust (below 100?µm) from cage and alternative system houses (on-floor, free range and aviaries) were compared under both experimental and commercial conditions.

3. The endotoxin concentration was higher in experimental aviaries (median: 565?EU/m³, range: 362-1491?EU/m³) than in cage housing (98?EU/m³ (51-470)).

4. In field conditions, the endotoxin concentration in the air of 13 alternative houses was higher (35 to 3156?EU/m³) than in cage system buildings (n?=?8, 78-576?EU/m³). It was correlated to the respirable dust concentration (fraction below 5?µm) and to the temperature inside the hen house but no seasonal variation was observed.

5. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems.  相似文献   

Occurrence of associative effects between grasses and legumes in binary mixtures on in vitro rumen fermentation characteristics     

Niderkorn V  Baumont R  Le Morvan A  Macheboeuf D 《Journal of animal science》2011,89(4):1138-1145

When animals are fed a grass and legume mixture, digestive interactions can occur in the rumen between the substrates contained in the different plants, and the response of the animal to the combination of forages can differ from the balanced median values of their components considered individually. Our objective was to assess the associative effects between temperate forages in 8 grass-legume binary combinations on in vitro rumen fermentation characteristics to highlight synergies or antagonisms in terms of nutritional and environmental impacts. Two grasses (cocksfoot, CF; ryegrass, RG) and 4 legume species (alfalfa, A; white clover, WC; red clover, RC; sainfoin, SAN) were incubated alone and in grass-legume mixture (1:1, wt/wt) in batches containing buffered rumen fluid during 3.5 and 24 h. For each substrate and each incubation time, parameters describing the degradation of the energetic and nitrogenous compounds and their partition into fermentation end products were measured. Data were subjected to ANOVA using a mixed procedure to test quadratic contrasts. At 3.5 h of incubation, many quadratic effects were observed. The presence of A, WC, or RC in mixtures quadratically increased the NH(3)-N production (up to +28% when compared with the calculated value, P < 0.001), whereas the presence of condensed tannin (CT) activity in SAN considerably decreased it (up to -67%, quadratic effect, P < 0.001) and the N disappearance. To a lesser extent, the presence of SAN reduced the proportion of methane in the gas produced (up to 7%, quadratic effect, P = 0.018). Generally, the degradation of OM and NDF was not stimulated by mixing grass and legume, except for SAN. However, the presence of SAN severely impaired the NDF digestion at the early phase of fermentation. At 24 h of incubation, few associative effects were observed in comparison with those observed at 3.5 h of incubation, but the effect of CT of SAN on N metabolism was still clearly present. This study shows that, among the grass-legume mixtures tested in vitro, only the presence of SAN can interact with the grasses to reduce the degradation of proteins and the production of methane but with a transitory negative effect on fiber digestion.  相似文献   

Idiopathic chylothorax and lymphedema in 2 whippet littermates     

Schuller S  Le Garrérès A  Remy I  Peeters D 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(11):1243-1245

Idiopathic chylothorax and limb edema was diagnosed in two 2-year-old male whippet siblings. The fact that the 2 related animals developed similar clinical signs at a young age may suggest a congenital or hereditary etiology.  相似文献   

Effect of fluoxetine on blood concentrations of serotonin, cortisol and dehydroepiandrosterone in canine aggression     

Rosado B  García-Belenguer S  León M  Chacón G  Villegas A  Palacio J 《Journal of veterinary pharmacology and therapeutics》2011,34(5):430-436

Canine aggression directed towards people is the most frequent reason for referral to behaviour practices. The serotonergic system and the hypothalamic-pituitary-adrenal (HPA) axis are believed to play an important role in controlling aggression. The selective serotonin reuptake inhibitor fluoxetine is the most commonly used drug in canine aggression. The aim of the present study was to assess the effect of a 30-day-long fluoxetine treatment on the peripheral serotonergic system and the HPA axis in canine aggression. To this end, the concentrations of serum serotonin (5-HT) and plasma cortisol and dehydroepiandrosterone (DHEA) were analysed in a group of aggressive (n = 22) and nonaggressive dogs (n = 9) during pre- (day 0) and posttreatment (day 30) conditions. Treatment caused a significant decrease in 5-HT concentrations (46% in the aggressive group and 32% in the control group). There was a trend towards a rise of DHEA/cortisol ratio values after treatment both in the aggressive and the control group. The determination of blood 5-HT and the DHEA/cortisol ratio could have important clinical applications in the future for deciding which animals might benefit from a given treatment as well as for monitoring the response. Further large-scale studies with this aim should be carried out to obtain sound conclusions.  相似文献   

Risk factors for Listeria monocytogenes contamination in French laying hens and broiler flocks     

Aury K  Le Bouquin S  Toquin MT  Huneau-Salaün A  Le Nôtre Y  Allain V  Petetin I  Fravalo P  Chemaly M 《Preventive veterinary medicine》2011,98(4):271-278

The objective of this study was to identify potential risk factors for Listeria monocytogenes contamination in French poultry production. Eighty-four flocks of layer hens kept in cages and 142 broiler flocks were included in this study. For each production type, a questionnaire was submitted to farmers and fecal samples were taken to assess the L. monocytogenes status of the flocks during a single visit to the farm. Two logistic regression models (specific to each production) were used to assess the association between management practices and the risk of L. monocytogenes contamination of the flock. The prevalence of L. monocytogenes-positive flocks was 30.9% (95% CI: 21.0; 40.9) and 31.7% (95% CI: 24.0; 39.4) for cage-layers and broiler flocks, respectively. For layer flocks, the risk of L. monocytogenes contamination was increased when pets were present on the production site. When droppings were evacuated by conveyor belt with deep pit storage, the risk of L. monocytogenes contamination decreased significantly. Feed meal was found to be associated with a higher risk of L. monocytogenes contamination than feed crumb. For broiler flocks, the risk of L. monocytogenes contamination was increased when farmers did not respect the principle of two areas (clean and dirty) at the poultry house entrance. A first disinfection by thermal fogging and the absence of pest control of the poultry house before the arrival of the next flock was found to increase the risk of contamination. When litter was not protected during storage and when farm staff also took care of other broiler chicken houses, the risk of L. monocytogenes contamination increased significantly. In the case of the watering system, nipples with cups were found to decrease the risk of contamination.  相似文献   

Clinical and microbial efficacy of antimicrobial treatments of experimental avian colibacillosis     

Dheilly A  Bouder A  Le Devendec L  Hellard G  Kempf I 《Veterinary microbiology》2011,149(3-4):422-429

The clinical and microbial efficacy of antimicrobial treatments of avian colibacillosis was studied, using an experimental model on chickens previously inoculated with multiresistant commensal Escherichia coli strains. One E. coli with pMG252 plasmid containing bla(FOX5) and qnrA1 genes and another E. coli with pMG298 plasmid containing bla(CTX-M15) and qnrB1 genes were first orally inoculated to chickens Both isolates were also resistant to chloramphenicol, sulphamethoxazole, trimethoprim, streptomycin, gentamicin, kanamycin, and tetracycline. The birds were then experimentally infected with an avian pathogenic E. coli (APEC), via the air sac. Treatments (oxytetracycline (OTC), trimethoprim-sulfadimethoxin (SXT), amoxicillin (AMX) or enrofloxacin (ENR) were then offered at the therapeutic doses. Symptoms, lesions in dead or sacrificed birds, and isolation and characterization of APEC from internal organs were studied. Results showed that OTC, SXT or ENR treatments could control the pathology. AMX worsened the disease, possibly due to endotoxin shock. All APEC re-isolated from internal organs showed the same antimicrobial susceptibility as the APEC inoculated strain, except for one APEC isolate from an infected OTC-treated bird, which acquired tetracycline resistance only, and one APEC isolate recovered from the air sacs of a chicken in the infected SXT-treated group, which acquired the pMG252 plasmid and became multi-resistant. Thus three antimicrobials could control the disease but the experimental model enabled, to our knowledge, the first observation of plasmid transfer from a bacterium of the intestinal tract to a pathogenic isolate from the respiratory tract.  相似文献