Effect of Sperm Cryopreservation on the European Eel Sperm Viability and Spermatozoa Morphology     

JF Asturiano  F Marco-Jiménez  DS Peñaranda  DL Garzón  L Pérez  JS Vicente  M Jover 《Reproduction in domestic animals》2007,42(2):162-166

The main objective of the present work was to study the effect of cryopreservation of European eel sperm both on the sperm viability and the spermatozoa head morphology. Spermatozoa morphology was evaluated with computer-assisted morphology analysis after collection in fresh samples, after adding the freezing medium containing dimethyl sulfoxide as cryoprotectant and, finally, after the cryopreservation process and thawing. Cell viability was assessed, in both fresh and thawed samples, by Hoechst 33258 staining. Computer-assisted sperm analysis (CASA) was used to determine the percentage of motile cells and to measure motility parameters in sperm samples. A significant decrease of head perimeter (12.56%) and area (17.90%) was detected from spermatozoa in fresh to thawed samples, indicating that cells do not recover the original size after the cryopreservation process. CASA was used to measure the percentage of motile cells (51.9%) and spermatozoa motility parameters such as curvilinear, straight line and angular path velocities, as well as beating cross frequency. This technique was employed in the fresh sperm samples but proteins present at the freezing medium (L-alpha-phosphatidylcholine) made impossible to use this last technique in thawed samples. When sperm viability was assessed by Hoechst staining, a significant decrease of approximately 15% (73.10 vs 58.26%) of alive spermatozoa was registered from fresh to thawed samples. The percentage of motile cells measured by CASA in fresh samples (51.9%) was lower than the percentage of alive cells determined by Hoechst stainning, suggesting the existence of different batches of spermatozoa in different stages of development, even during the eight to tenth weeks of treatment, when the highest sperm quality was found.  相似文献   

Dietary management of renal senescence and failure in dogs     

DS KRONFELD 《Australian veterinary journal》1994,71(10):328-331

SUMMARY The need for dietary management of renal senescence and the beginning of chronic renal failure should be evaluated in all middle-aged dogs. One survey found that 35% were overweight and 10% underweight; another that 25% were mildly azotaemic, with 5% showing slight clinical signs of chronic renal failure. Dogs in prime condition or overweight are candidates for a diet low in energy (for example 3.0–3.3 kcal/g dry matter, DM), but thin dogs need a higher caloric density (such as 4.0–4.5 kcal/g DM). Healthy older dogs need higher dietary protein than the minimum for maintenance (about 20% on a metabolisable energy basis, ME) of young mature dogs. Thin older dogs showing signs of renal insufficiency may benefit from moderate protein and near-minimal phosphorus in the diet. In dogs with chronic renal failure, clinical, haematological and biochemical responses to the combination of low protein (13–16% ME) and low phosphorus (0.4% DM) were positive in one clinical trial but not in three others. Only beneficial responses, such as less proteinuria, less renal impairment and lower mortality, have been reported for diets containing low phosphorus and moderate protein (20–31% ME). Individual dietary goals for energy, protein and phosphorus should be chosen for each middle-aged or older dog; these goals may be met by a single product or mixtures of products.  相似文献   

Comparative Development of Embryonic Age by Organogenesis in Domestic Dogs and Cats          下载免费PDF全文

NCG Pieri  AF Souza  JB Casals  KCS Roballo  CE Ambrósio  DS Martins 《Reproduction in domestic animals》2015,50(4):625-631

The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown‐rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.  相似文献   

Borehole Temperatures and a Baseline for 20th-Century Global Warming Estimates     

RN Harris  DS Chapman 《Science (New York, N.Y.)》1997,275(5306):1618-1621

Lack of a 19th-century baseline temperature against which 20th-century warming can be referenced constitutes a deficiency in understanding recent climate change. Combination of borehole temperature profiles, which contain a memory of surface temperature changes in previous centuries, with the meteorological archive of surface air temperatures can provide a 19th-century baseline temperature tied to the current observational record. A test case in Utah, where boreholes are interspersed with meteorological stations belonging to the Historical Climatological Network, yields a noise reduction in estimates of 20th-century warming and a baseline temperature that is 0.6° ± 0.1°C below the 1951 to 1970 mean temperature for the region.  相似文献   

Drenching adult ewes: Implications of anthelmintic treatments pre- and post-lambing on the development of anthelmintic resistance     

DM Leathwick  CM Miller  DS Atkinson  NA Haack  RA Alexander  A-M Oliver 《New Zealand veterinary journal》2013,61(6):297-304

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Up‐Regulation of Insulin‐Like Growth Factor I and Uteroglobin in In Vivo‐Developed Parthenogenetic Embryos     

C Naturil‐Alfonso  JS Vicente  DS Peñaranda  F Marco‐Jiménez 《Reproduction in domestic animals》2013,48(1):126-130

Parthenote embryos are being considered as an alternative source of embryonic stem cells. However, as there is still a dearth of knowledge of this kind of embryos, a better understanding of their biology is needed for their application. In this work, we studied the differences and similarities between parthenotes and normal embryos at the blastocyst stage in vivo developed. We analysed the expression of factor OCT‐4, vascular endothelial growth factor (VEGF), insulin‐like growth factor I (IGF‐I) and uteroglobin (UG) by real‐time PCR. To do so, oocytes were recovered and after activation procedure were transferred by ventral middle laparoscopy to receptive does to undergo completely in vivo development. Does were slaughtered 6 days post‐ovulation induction, and parthenote and normal embryos were recovered for mRNA expression analysis. Our results reported that parthenotes and normal embryos showed similar mRNA expression for OCT‐4 and VEGF. However, IGF‐I and UG showed to be over‐expressed in parthenote embryos. Thus, our study highlights that despite the in vivo development of parthenotes, they still seem to have an altered expression and, therefore, to be different to normal embryos. The altered expression pattern of parthenote embryos suggests that these embryos should be studied carefully before future application.  相似文献   

Feed restriction regime in a rabbit line selected for growth rate alters oocyte maturation manifested by alteration in MSY2 gene expression          下载免费PDF全文

C Naturil‐Alfonso  DS Peñaranda  JS Vicente  F Marco‐Jiménez 《Reproduction in domestic animals》2017,52(6):976-984

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The Quantum Event of Oceanic Crustal Accretion: Impacts of Diking at Mid-Ocean Ridges     

JR Delaney  DS Kelley  MD Lilley  DA Butterfield  JA Baross  WSD Wilcock  RW Embley  M Summit 《Science (New York, N.Y.)》1998,281(5374):222-230

Seafloor diking-eruptive events represent the irreducible, quantum events of upper oceanic crustal accretion. They record events by which a large portion of the oceanic crust has formed through geological history. Since 1993, the U.S. Navy's real-time Sound Surveillance System has allowed location of ongoing acoustic signatures of dike emplacement and basalt eruptions at ridge crests in the northeast Pacific. These diking-eruptive events trigger a sequence of related, rapidly evolving physical, chemical, and biological processes. Magmatic volatiles released during these events may provide nutrients for communities of subseafloor microorganisms, some of which thrive in high-temperature anaerobic environments. Many of the organisms identified from these systems are Archaea. If microorganisms can thrive in the water-saturated pores and cracks within deep, volcanically active portions of our planet, other hydrothermally active planets may harbor similar life forms.  相似文献   

Shipboard geophysical indications of asymmetry and melt production beneath the east pacific rise near the MELT experiment     

DS Scheirer  DW Forsyth  MH Cormier  KC Macdonald 《Science (New York, N.Y.)》1998,280(5367):1221-1224

Near the Mantle Electromagnetic and Tomography (MELT) Experiment, seamounts form and off-axis lava flows occur in a zone that extends farther to the west of the East Pacific Rise than to the east, indicating a broad, asymmetric region of melt production. More seamounts, slower subsidence, and less dense mantle on the western flank suggest transport of hotter mantle toward the axis from the west. Variations in axial ridge shape, axial magma chamber continuity, off-axis volcanism, and apparent mantle density indicate that upwelling is probably faster and more melt is produced beneath 17 degrees15'S than beneath 15 degrees55'S. Recent volcanism occurs above mantle with the lowest seismic velocities.  相似文献   

Bosonic stimulation in the formation of a bose-einstein condensate     

H Miesner  DM Stamper-Kurn  MR Andrews  DS Durfee  S Inouye  W Ketterle 《Science (New York, N.Y.)》1998,279(5353):1005-1007

The formation of a Bose-Einstein condensate of a dilute atomic gas has been studied in situ with a nondestructive, time-resolved imaging technique. Sodium atoms were evaporatively cooled close to the onset of Bose-Einstein condensation and then suddenly quenched to below the transition temperature. The subsequent equilibration and condensate formation showed a slow onset distinctly different from simple relaxation. This behavior provided evidence for the process of bosonic stimulation, or coherent matter-wave amplification, crucial to the concept of an atom laser.  相似文献