Density and Water Exchange-Dependent Growth and Survival of Litopenaeus setiferus Postlarvae     

Gabriela  Palomino  Fabian  Contreras  Adolfo  Sanchez Carlos  Rosas 《Journal of the World Aquaculture Society》2001,32(2):167-176

This present study was designed to investigate the effects of stocking density and water exchange on the growth rate, survival and performance index of L. setiferus postlarvae under controlled laboratory conditions. The experiment was done with postlarvae (PL10 to PL40) at densities of 50, 150, 250 and 350 shrimp/m² and various different water exchanges rate per day (0, 6, 12 and 18%). The maximum growth rate was obtained for shrimp with 12% water exchange per day at all densities. A reduction of the maximum growth rate was observed in relation to density with the highest values in shrimp stocked in a density of 50 and 150 shrimp/m² (mean value of 0.53 mg/d) and the lowest in shrimp stocked in a density of 350 shrimp/m² (0.24 mg/d). The multiple regression equation obtained to relate performance index (growth rate* survival : PI), shrimp density (X₁) and water exchange (X₂) was: PI = 0.31 + (0.001) X₁+ 0.039 X₂+ 2.28 × 10⁻⁶ X₁²+ (−0.0017) X₂²+ (0.000026)X₁X₂, R ²= 0.78; P > 0.03. According to this equation the optimum shrimp density-water exchange comhination was between 5 to 12% of water exchange at stocking density of between 50 and 150 shrimp/m². Salinity, ammonia-N and nitrite-N increased according to the time spent in tanks without water exchange. With no (0%) water exchange, water quality parameters measured were outside the optimum for L. setiferus postlarvae. The use of optimum density and water exchange in a nursery system for L. setiferus with optimum variables established is proposed.  相似文献   

Economic impact of the use of prostaglandin to induce estrus in dairy cows   总被引：1，自引：0，他引：1  

J Fetrow  T Blanchard 《Journal of the American Veterinary Medical Association》1987,190(2):163-169

An economic model concerning the value of using prostaglandin (PG) in dairy cows with nondetected estrus was developed. Considering numerous and varied assumptions, it was more profitable to treat cows with PG and to breed the cows at a detected estrus than it was not to treat the cows and to wait to breed the cows at a detected estrus. Generally, using timed artificial insemination, it was also more profitable to breed PG-treated cows than it was not to use PG. However, timed insemination was less profitable than was breeding PG-treated cows by artificial insemination at a detected estrus.  相似文献   

USE OF THE RHOMBOID FLAP GRAFT IN RECONSTRUCTIVE LID SURGERY     

G. L. Blanchard D.V.M.  † W.F. Keller D.V.M.  M.S.  † 《Veterinary surgery : VS》1976,5(1):26-28

Extensive destructive and erosive lesions of the eye lids may be the result of neoplasia, severe trauma, or inflammation. Surgical repair requires blepharoplastic procedures to restore the lid integrity and maintain a functionally sighted globe. The use of the rhomboid advancement flap is illustrated for the repair of lid defects involving destruction of 50% or more of the lid tissue.  相似文献   

Identification of the etiologic agent of epizootic bovine abortion in field-collected Ornithodoros coriaceus Koch ticks     

Chen CI  King DP  Blanchard MT  Hall MR  Aldridge BM  Bowen L  Stott JL 《Veterinary microbiology》2007,120(3-4):320-327

Epizootic bovine abortion (EBA), or foothill abortion as it has often been termed, is a tick-borne disease of pregnant cattle recognized in California, Nevada and Oregon. The primary objective of this study was to better define the relationship of a novel deltaproteobacterium, the putative etiological agent of EBA (aoEBA), with the Pajaroello tick (Ornithodoros coriaceus Koch), the recognized vector of EBA. Three developmental stages of O. coriaceus (larva, nymph, and adult) were collected from five locations in California, Nevada and Oregon. A polymerase chain reaction (PCR), developed for detection of aoEBA, was applied to DNA extracted from ticks. Southern blotting of the PCR products increased the number of ticks determined to be carrying the bacteria by seven-fold, suggesting the majority of infected ticks carry relatively low numbers of the pathogen. An effort was made to determine if an artificial blood meal would stimulate replication of the bacterial pathogen, thereby increasing the frequency in which aoEBA could be identified; no statistically significant effect was evident. The number of ticks determined to be carrying aoEBA varied with geographic location and ranged from 5 to 20%. aoEBA was found in both adults (12% of the males and 12% of the females) and nymphs (13%) but not larvae. Comparative analysis of dissected ticks provided strong evidence that the salivary gland was the most common location of aoEBA in field-collected ticks. No significant correlations were identified between the frequency of infection and tick weight, suggesting that increasing tick age and increased number of blood meals did not increase infectivity.  相似文献   

Astronomy. A blast from the past     

Fabian AC 《Science (New York, N.Y.)》2008,320(5880):1167-1168

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Strong influence of local habitat structure on mammals reveals mismatch with edge effects models     

Nélida R. Villaseñor  Wade Blanchard  Don A. Driscoll  Philip Gibbons  David B. Lindenmayer 《Landscape Ecology》2015,30(2):229-245

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Vertical Distribution and Fate of Trace Metals and Persistent Organic Pollutants in Sediments of the Seine and Marne Rivers (France)     

D. Ollivon  B. Garban  M. Blanchard  M. J. Teil  A. M. Carru  C. Chesterikoff  M. Chevreuil 《Water, air, and soil pollution》2002,134(1-4):57-79

Trace metals: Cd, Cu, Cr, Ni, Pb and Zn and persistent organicpollutants: polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) were investigated in a fraction ofsediments characterized by a granulometry < 200 μm. Coresfrom 17 to 54 cm depth, were collected at two sites of theSeine river upstream (Port à l'Anglais) and downstream (Saint-Cloud) from Paris and at one site of the Marne river (Saint-Maurice). Marne river sediments displayed higher Cu andPb levels than those of the Seine river. Except for Cd and Cr,contents did not vary notably in the Seine river sediments.Metal contents, except Pb, were significantly correlated withthe sediment fraction which granulometry is < 50 μm,particularly at Port à l'Anglais (p < 0.001). Correlationcoefficients between Cr, Cu, Ni and Zn contents and clayfractions of the cores ranged from 0.85 to 0.99 at both sitesof the Seine river. PCB levels varied widely, ranging from 27to 689 μg kg^-1 and were highly correlated with bothsediment fraction < 50μm and particulate organic carbon(POC) ratio. PAH levels ranged from 2.30 to 41.3 μg g^-1 and displayed the highest values close to dams; theyshowed no correlations with sediment fraction < 50 μm and POC.  相似文献   

Phthalate Fate in the Hydrographic Network of the River Seine Basin (France) Under Contrasted Hydrological Conditions     

Teil  Marie-Jeanne  Blanchard  Martine  Moreau-Guigon  Elodie  Dargnat  Cendrine  Alliot  Fabrice  Bourges  Catherine  Desportes  Annie  Chevreuil  Marc 《Water, air, and soil pollution》2013,224(6):1-14

Water, Air, &; Soil Pollution - This study investigated how forest soil acidification is affected by edge proximity. We measured pH(KCl) and exchangeable K, Ca, Mg and Al concentrations of the...  相似文献   

Bremia lactucae populations on cultivated lettuce originate from prickly lettuce and are interconnected with the wild pathosystem     

Runge  Fabian  Gärber  Ute  Lebeda  Aleš  Thines  Marco 《European journal of plant pathology / European Foundation for Plant Pathology》2021,160(2):411-425

European Journal of Plant Pathology - Maize rough dwarf disease (MRDD) is one of the most important viral diseases around the world. Rice black-streaked dwarf virus (RBSDV) and maize rough dwarf...  相似文献   

The conserved surface M-protein SiMA of Streptococcus iniae is not effective as a cross-protective vaccine against differing capsular serotypes in farmed fish     

Fabian Aviles  Meiman May ZhangJanlin Chan  Jerome Delamare-DebouttevilleTimothy J. Green  Cecile DangAndrew C. Barnes 《Veterinary microbiology》2013

Streptococcus iniae causes invasive infections in fresh and saltwater fish and occasional zoonoses. Vaccination against S. iniae is complicated by serotypic variation determined by capsular polysaccharide. A potential target for serologically cross-protective vaccines is the M-like protein SiMA, an essential virulence factor in S. iniae that is highly conserved amongst virulent strains. The present study determined how SiMA is regulated and investigated potential as a cross-protective vaccine for fish. Electrophoretic mobility shift suggested that SiMA is regulated by the multigene regulator Mgx via a binding site in the −35 region of the simA promoter. Moreover, expression of simA and mgx was highly correlated, with the highest level of simA and mgx expression during exponential growth under iron limitation (20-fold increase in relative expression compared to growth in Todd-Hewitt broth). Based on these results, a vaccination and challenge experiment was conducted in barramundi (Lates calcarifer) to determine whether SiMA is protective against S. iniae infection and cross-protective against a different capsular serotype. The challenge resulted in 60% mortality in control fish. Formalin-killed bacterins prepared from the challenge strain resulted in 100% protection, whereas bacterins prepared from a serotypically heterologous strain resulted in significantly reduced protection, even when culture conditions were manipulated to optimise SiMA expression. Moreover, recombinant SiMA protein was not protective against the challenge strain in spite of eliciting specific antibody response in vaccinated fish. Specific antibody did not increase oxidative activity or phagocytosis by barramundi macrophages. Indeed incubating S. iniae with antisera significantly reduced phagocytosis. Lack of specific-antibody mediated opsonisation in spite of 100% protection against challenge with the homologous vaccine suggests that other immune parameters result in protection of challenged fish.  相似文献