Pronuclear Embryo Yield in Canindé and Saanen Goats for DNA Microinjection     

RR Moura  ES Lopes‐Junior  DIA Teixeira  IA Serova  LE Andreeva  LM Melo  VJF Freitas 《Reproduction in domestic animals》2010,45(5):e101-e106

The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.  相似文献   

Untersuchungen über pathogene Eigenschaften von Adenovirusstämmen des Schweines     

M. Brack  D. Bernhardt  B. Liess  H. Bhr  G. Rohde  G. Amtsberg 《Zoonoses and public health》1969,16(8):671-688

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Effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment     

A. M. PIRES  M. F. MAGALHÃES  L. MOREIRA DA COSTA  M. J. ALVES  & M. M. COELHO 《Fisheries Management and Ecology》2008,15(1):49-58

Abstract  The effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment in Southwest Portugal were investigated. The fish community structure and habitat were surveyed at 10 sites pre- and post-flood. Overall species richness and rank abundances changed little after the flood, despite there being a consistent decline in the abundance of small cyprinids. Pre- and post-flood habitat correlates of abundance changed for at least some species, and variability in assemblage structure was associated with flood, depth and pH. These results indicate that extreme floods occurring early in the wet season may have little disruptive effects on the overall structure of native fish assemblages in Mediterranean streams, although may at least partially influence population dynamics for some species. Habitat quality and complexity are likely to play a role in mediating species responses to flooding.  相似文献   

Mineralogy at Gusev Crater from the Mössbauer spectrometer on the Spirit Rover     

Morris RV  Klingelhöfer G  Bernhardt B  Schröder C  Rodionov DS  De Souza PA  Yen A  Gellert R  Evlanov EN  Foh J  Kankeleit E  Gütlich P  Ming DW  Renz F  Wdowiak T  Squyres SW  Arvidson RE 《Science (New York, N.Y.)》2004,305(5685):833-836

M?ssbauer spectra measured on Mars by the Spirit rover during the primary mission are characterized by two ferrous iron doublets (olivine and probably pyroxene) and a ferric iron doublet (tentatively associated to nanophase ferric iron oxide). Two sextets resulting from nonstoichiometric magnetite are also present, except for a coating on the rock Mazatzal, where a hematite-like sextet is present. Greater proportions of ferric-bearing phases are associated with undisturbed soils and rock surfaces as compared to fresh rock surfaces exposed by grinding. The ubiquitous presence of olivine in soil suggests that physical rather than chemical weathering processes currently dominate at Gusev crater.  相似文献   

Ecology. Ecology for a crowded planet     

Palmer M  Bernhardt E  Chornesky E  Collins S  Dobson A  Duke C  Gold B  Jacobson R  Kingsland S  Kranz R  Mappin M  Martinez ML  Micheli F  Morse J  Pace M  Pascual M  Palumbi S  Reichman OJ  Simons A  Townsend A  Turner M 《Science (New York, N.Y.)》2004,304(5675):1251-1252

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Artificial airglow excited by high-power radio waves   总被引：1，自引：0，他引：1  

Bernhardt PA  Duncan LM  Tepley CA 《Science (New York, N.Y.)》1988,242(4881):1022-1027

High-power electromagnetic waves beamed into the ionosphere from ground-based transmitters illuminate the night sky with enhanced airglow. The recent development of a new intensified, charge coupled-device imager made it possible to record optical emissions during ionospheric heating. Clouds of enhanced airglow are associated with large-scale plasma density cavities that are generated by the heater beam. Trapping and focusing of electromagnetic waves in these cavities produces accelerated electrons that collisionally excite oxygen atoms, which emit light at visible wavelengths. Convection of plasma across magnetic field lines is the primary source for horizontal motion of the cavities and the airglow enhancements. During ionospheric heating experiments, quasi-cyclic formation, convection, dissipation and reappearance of the cavites comprise a major source of long-term variability in plasma densities during ionospheric heating experiments.  相似文献   

Ecology. Synthesizing U.S. river restoration efforts     

Bernhardt ES  Palmer MA  Allan JD  Alexander G  Barnas K  Brooks S  Carr J  Clayton S  Dahm C  Follstad-Shah J  Galat D  Gloss S  Goodwin P  Hart D  Hassett B  Jenkinson R  Katz S  Kondolf GM  Lake PS  Lave R  Meyer JL  O'donnell TK  Pagano L  Powell B  Sudduth E 《Science (New York, N.Y.)》2005,308(5722):636-637

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Determination of the efficiency of foot-and-mouth disease vaccines by the 3-point test in mice]     

D Bernhardt  W Runge  H Kindt 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1977,24(4):293-296

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The relation between hemagglutination inhibition and neutralization tests for the detection of coronavirus antibodies in cow's milk     

H J Bengelsdorff  D Bernhardt 《Berliner und Münchener tier?rztliche Wochenschrift》1987,100(12):414-418

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Welchen Einfluss haben invasive Pflanzenarten auf die Phytodiversität von renaturierten Flusslandschaften?     

Katharina Lapin  Karl-Georg Bernhardt  Peter Lichtenwöhrer  Stefanie Roithmayr 《Gesunde Pflanzen》2015,67(2):75-82

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