Comparison of Efficacy of Two Dose Rates of Histrelin for Inducing Ovulation in Broodmares     

Allison M. Kiser  A. Kendrick Sudderth  Steven P. Brinsko  Patrick J. Burns  Robert H. Douglas  Terry L. Blanchard 《Journal of Equine Veterinary Science》2013

Between February 14 and April 26, 2012, 75 broodmares (7 maiden, 11 barren, and 57 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥30-mm diameter were alternately assigned to treatment with 0.5 mg of intramuscular (IM) histrelin (group 1) or 0.25 mg IM histrelin (group 2). Ovulation was confirmed by ultrasound examination. No differences in proportion of maiden plus barren (96%) compared to foaling (86%) mares ovulating within 2 days was found (P > .10); therefore, responses for all mares were combined for analysis. No differences in ovulation rates within 2 days were noted for 0.5 mg histrelin compared to those for 0.25 mg histrelin treatment (42 of 46, 91%; 44 of 52, 85%; P > .10). No differences were detected between response rates to 0.5 or to 0.25 mg histrelin for any month (P > .10). The use of 0.5 or 0.25 mg histrelin were found to be effective treatments for inducing ovulation within 2 days of administration throughout the early breeding season.  相似文献   

Technical and Economic Analysis of Aeroponics and other Systems for Potato Mini-Tuber Production in Latin America     

Julian R. Mateus-Rodriguez  Stef de Haan  Jorge L. Andrade-Piedra  Luis Maldonado  Guy Hareau  Ian Barker  Carlos Chuquillanqui  Victor Otazú  Rebeca Frisancho  Carolina Bastos  Arione S. Pereira  Carlos A. Medeiros  Fabian Montesdeoca  Jacqueline Benítez 《American Journal of Potato Research》2013,90(4):357-368

Producing large quantities of high quality mini-tubers at low cost is essential for an economically viable supply of seed potatoes. Here we systematize the technical and economic aspects of aeroponics and provide a benchmark comparison of this technology with other mini-tuber production systems as developed in Latin America: conventional, semi-hydroponics, and fiber-cement tiles technology. Research methodologies included: 3-year registration of cash flows and production registers of aeroponics, economic and technical surveys, in-depth inquiry with managers of technologies. Results show that aeroponics as promoted by the International Potato Center (CIP) has several advantages, including high multiplication rates (up to 1:45), high production efficiency per area (> 900 mini-tubers per m²), savings in water, chemicals and/or energy, and positive economic indicators. The fiber-cement tiles technology from Brazil is also shown to be highly efficient and slightly more robust compared to aeroponics. Preconditions for the successful adoption of the different technologies in developing countries are discussed.  相似文献   

Study of the impact of wheat flour type,flour particle size and protein content in a cake-like dough: Proton mobility and rheological properties assessment     

C. Blanchard  H. Labouré  A. Verel  D. Champion 《Journal of Cereal Science》2012

The study of food products is always a challenge due to the number of components involved and the interactions that may occur between them. Water is a particular ingredient which interacts with all hydrophilic compounds, although affinities may differ for limiting water amount. During this study, results obtained using ¹H NMR on cake dough were compared in terms of the effects of flour type (soft or medium hard), the addition of gluten (5%–20%) and the use of soft flour fractions (flour particle fractions smaller or larger than 50 μm). T₂ values and the signal intensities of different proton populations were studied as a function of the wheat protein contents of dough samples. Physicochemical characterization methods were used to better understand how the origin and particle size of flour might impact the hydration properties and mobility of a model system. Increasing the protein content in dough samples was related to an increase of the mobility of fat protons and of the least mobile proton population (relaxation times ranging from 175 to 180 ms and from 5 to 7 ms, respectively).  相似文献   

The influence of the extensional viscosity of very low concentrations of high molecular mass water-soluble polymers on atomisation and droplet impact     

Williams PA  English RJ  Blanchard RL  Rose SA  Lyons L  Whitehead M 《Pest management science》2008,64(5):497-504

BACKGROUND: Water-soluble polymers are increasingly added to herbicide and pesticide formulations at very low concentrations (100-1000 mg L(-1)) in order to control the spray characteristics, notably to reduce spray drift and influence droplet bounce. The incorporation of polymeric adjuvants improves the efficacy of the spray solutions, thus enabling crop growers to maximise the performance of agrochemical sprays at lower dose rates of active ingredient. It is important to establish a fundamental understanding of how polymers influence the processes involved in droplet deposition.RESULTS: The shear and extensional viscosities of a series of high molecular mass (M(w)) poly(acrylamides) (M(w) approximately 10(6)-10(7)) have been determined at very low concentrations (100-1000 mg L(-1)). The polymer solutions demonstrated typical shear thinning characteristics under shear, and strain hardening behaviour under extension above a critical strain rate. The presence of the polymers was shown to increase the size of droplets produced in atomisation using an agricultural spray nozzle, as measured by laser diffraction. This was attributed to the increase in the extensional viscosity at the strain rates generated under pressure in the spray nozzle and was a function of both polymer concentration and M(w). In addition, the presence of polymer was found to have a significant influence on droplet bounce.CONCLUSIONS: The presence of very low concentrations of high molecular mass poly(acrylamides) significantly influences the size of droplets formed on atomisation and subsequent bounce characteristics. Large extensional viscosities generated above a critical strain rate are responsible for both processes.  相似文献   

Life cycle and population growth rate of Caenorhabditis elegans studied by a new method     

Daniel Muschiol  Fabian Schroeder  Walter Traunspurger 《BMC ecology》2009,9(1):14-13

Background  

The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, age-specific fecundity/mortality, total reproduction, mean and maximum lifespan, and intrinsic population growth rates. However, we found that in life-cycle experiments care is needed regarding protocol design. Here, we test a recently developed method that overcomes some problems associated with traditional cultivation techniques. In this fast and yet precise approach, single individuals are maintained within hanging drops of semi-fluid culture medium, allowing the simultaneous investigation of various life-history traits at any desired degree of accuracy. Here, the life cycles of wild-type C. elegans strains N2 (Bristol, UK) and MY6 (Münster, Germany) were compared at 20°C with 5 × 10⁹ Escherichia coli ml^-1 as food source.  相似文献   

Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management     

Ane T Laugen  Georg H Engelhard  Rebecca Whitlock  Robert Arlinghaus  Dorothy J Dankel  Erin S Dunlop  Anne M Eikeset  Katja Enberg  Christian Jørgensen  Shuichi Matsumura  Sébastien Nusslé  Davnah Urbach  Loїc Baulier  David S Boukal  Bruno Ernande  Fiona D Johnston  Fabian Mollet  Heidi Pardoe  Nina O Therkildsen  Silva Uusi‐Heikkilä  Anssi Vainikka  Mikko Heino  Adriaan D Rijnsdorp  Ulf Dieckmann 《Fish and Fisheries》2014,15(1):65-96

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries‐induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life‐history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.  相似文献   

Pregnancy Rates in Tranquilized Maiden Thoroughbred Mares     

T.L. Blanchard  J.A. Thompson  S.P. Brinsko  D.D. Varner  C.C. Love  J. Ramsey  A. O'Meara 《Journal of Equine Veterinary Science》2010

In Thoroughbred breeding, it is sometimes necessary to tranquilize a maiden mare to accomplish safe breeding by natural service. To determine whether tranquilization adversely affected fertility of maiden mares, pregnancy rates achieved in 792 matings of 531 maiden Thoroughbred mares were evaluated. One hundred sixty-three matings were accomplished after administration of a tranquilizer cocktail (20 mg acepromazine, 100 mg xylazine, and 10 mg butorphanol tartrate, injected intravenously), whereas 598 matings were accomplished without tranquilization. Pregnancy rate/cycle did not differ between maiden mares tranquilized before (64%; 105/163) and mares not tranquilized before mating (69%; 434/629) (χ² = 1.048; P > .05). We concluded that tranquilization of maiden Thoroughbred mares immediately before mating did not adversely affect fertility.  相似文献   

PAH Fluctuations in Rivers in the Paris Region (France): Impact of Floods and Rainy Events     

Ollivon  D.  Blanchard  M.  Garban  B. 《Water, air, and soil pollution》1999,115(1-4):429-444

PAHs produced by motor vehicle combustion were determined in the dusts from the substructures of a parisian car park. The high levels of benzo(ghi)perylene (bgp) and pyrene (pyr) expressed as ratios to fluoranthene (flu), were 1.73 and 1.23, respectively, which was typical of these exhausts. From these findings, bgp and pyr may be used as tracers for estimating the contamination fluctuations and transfer processes in rain waters and river waters, in a highly industrialized and urbanized area. During flood events, the pollution related to atmospheric scavenging alone was negligible as compared to that due to urban surface leaching, contrary to steady period events. During that last period, when the river contamination was low, about 40 ng L^?1, and when mean bulk precipitation concentrations were about 350 ng L^?1, minor precipitations might contribute less than 2% to river contamination, whereas heavy showers might induce a quite important pollution flush: PAH concentrations were twice higher and 26% of the inputs came from rain and 74% from runoff in the river Seine.

  相似文献   

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor   总被引：1，自引：0，他引：1  

GM Keating  SW Bougher  RW Zurek  RH Tolson  GJ Cancro  SN Noll  JS Parker  TJ Schellenberg  RW Shane  BL Wilkerson  JR Murphy  JL Hollingsworth  RM Haberle  M Joshi  JC Pearl  BJ Conrath  MD Smith  RT Clancy  RC Blanchard  RG Wilmoth  DF Rault  TZ Martin  DT Lyons  PB Esposito  MD Johnston  al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.  相似文献   

Common trends in recruitment dynamics of north‐east Atlantic fish stocks and their links to environment,ecology and management     

Fabian Zimmermann  Marion Claireaux  Katja Enberg 《Fish and Fisheries》2019,20(3):518-536

Recruitment dynamics are challenging to assess or predict because of the many underlying drivers that vary in their relevance over time and space. Stock size, demographic and trait composition, condition and distribution of spawning fish and the spatio‐temporal dynamics of trophic and environmental interactions all influence recruitment processes. Exploring common patterns among stocks and linking them to potential drivers may therefore provide insights into key mechanisms of recruitment dynamics. Here, we analysed stock‐recruitment data of 64 stocks from the north‐east Atlantic Ocean for common trends in variation and synchrony among stocks using correlation, cluster and dynamic factor analyses. We tested common trends in recruitment success for relationships with large‐scale environmental processes as well as stock state indicators, and we explored links between recruitment success and demographic, environmental and ecological variables for a subset of individual stocks. The results revealed few statistically significant correlations between stocks but showed that underlying common trends in recruitment success are linked to environmental indices and management indicators. Statistical analyses confirmed previously suggested relationships of environmental–ecological factors such as the subpolar gyre and Norwegian coastal current with specific stocks, and indicated a large relevance of spawning stock biomass and demographics, as well as predation, whereas other suggested relationships were not supported by the data. Our study shows that despite persistent challenges in determining drivers of recruitment due to poor data quality and unclear mechanisms, combining different data analysis techniques can improve our understanding of recruitment dynamics in fish stocks.  相似文献