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Uterus didelphys is a rare congenital abnormality of the reproductive tract. Although it occurs in various species, there are no published reports describing pregnancy outcome in association with this abnormality. Herein we describe a case of successful unilateral singleton pregnancy in a ewe incidentally found to have uterus didelphys during the course of a biomedical research study. The pregnancy was established using assisted reproductive techniques and interrupted in late gestation, at which point the abnormality was identified. Serial ultrasound assessment of foetal biometry revealed a normal foetal growth trajectory. Despite a 45% reduction in placentome number, total placentome weight was near normal secondary to compensatory placentome growth and development. To our knowledge, this is the first detailed report of normal foetal growth in an animal with uterus didelphys and illustrates the ability of the ovine placenta to adapt to a reduced number of placentomes and maintain foetal nutrient supply.  相似文献   
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The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw‐IVF system with 10 min of coincubation, a straw‐IVF system with 6‐h coincubation and the microdrop‐IVF system with 6‐h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration ( Experiment 1 ). When the straw‐IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 ± 6.4% vs 31.9 ± 6.5% and 41.5 ± 2.5% vs 17.6 ± 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 ± 5.1% and 67.7 ± 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6‐h microdrop‐IVF system was higher (93.8 ± 3.6%; p < 0.001) compared with the 10‐min straw‐IVF system (67.7 ± 6.4%), however, monospermy was severely reduced (25.0 ± 4.3% vs 67.7 ± 3.4%, for the 6‐h microdrop‐IVF system and 10‐min straw‐IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6‐h straw‐IVF systems, but efficiency was significantly improved (p < 0.05) when the 10‐min straw‐IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6‐h microdrop‐IVF system (1000 sperm per oocyte) and 10‐min straw‐IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10‐min straw‐IVF system was used compared with the 6‐h microdrop‐IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10‐min straw‐IVF system. These results showed that the 10‐min straw‐IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.  相似文献   
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As one of the few felids that is predominantly diurnal, cheetahs (Acinonyx jubatus) can be exposed to high heat loads in their natural habitat. Little is known about long‐term patterns of body temperature and activity (including hunting) in cheetahs because long‐term concurrent measurements of body temperature and activity have never been reported for cheetahs, or, indeed, for any free‐living felid. We report here body temperature and locomotor activity measured with implanted data loggers over 7 months in 5 free‐living cheetahs in Namibia. Air temperature ranged from a maximum of 39 °C in summer to ?2 °C in winter. Cheetahs had higher (~0.4 °C) maximum 24‐h body temperatures, later acrophase (~1 h), with larger fluctuations in the range of the 24‐h body temperature rhythm (approximately 0.4 °C) during a hot‐dry period than during a cool‐dry period, but maintained homeothermy irrespective of the climatic conditions. As ambient temperatures increased, the cheetahs shifted from a diurnal to a crepuscular activity pattern, with reduced activity between 900 and 1500 hours and increased nocturnal activity. The timing of hunts followed the general pattern of activity; the cheetahs hunted when they were on the move. Cheetahs hunted if an opportunity presented itself; on occasion they hunted in the midday heat or in total darkness (new moon). Biologging revealed insights into cheetah biology that are not accessible by traditional observer‐based techniques.  相似文献   
50.
The anatomy of the shoot system of red maple and white ash was examined at various times after treatment with picloram. Xylem blockage, enlargement of cortical and pith cells and eventual necrosis of the shoot apex, parenchymatous and phloem tissues of red maple plants were features shown by picloram treatment. Red maple shoots were desiccated and dead by 22 days after treatment commenced. White ash shoots showed some increased mitotic activity but at the end of 22 days of picloram treatment, the leaves were still turgid and the internal anatomy of the shoot system scarcely altered. It is suggested that the susceptibility of red maple plants can be explained in part by the effects picloram has on xylem blockage and necrosis of parenchymatous tissues in the shoot system of this species. Effects du piclorame sur l'analomie de la partie aérienne de l'erable rouge et du frêne blanc L'anatomie de la partie aérienne de l'érable rouge et du frêne blanc a été examinee i diverses dpoques aprés un traitement au piclorame. Le blocage du xyléme, le grossissement des cellules corticales et médullaires, ainsi qu'une Éventuelle nécrose des apex des tiges, des tissus parenchymateux et du phloéme des Arables rouges furent les effects consécutifs au traitement par le piclorame. La partie aérienne des Arables rouges se déssécha et mourut 22 jours aprés le dé A but du traitement. La partie aérienne du Fréne blanc manifesta un accrolssement d'activité mitotique. mais, 22 jours aprés le traitement au piclorame, les feuilles étaient encore turgesccntes et l'anatomie interne des organes aériens k peine altérte. II est suggéré que la sensibility de rérable rouge peut être expliquée en partie par les effets du piclorame sur le blocage du xyléme et les necroses des tissus parenchymateux dans les organes adriens de cette espèce. Die Wirkung von Picloram auf die Anatomic des Sprosses von Acer rubrum L. und Fraxinus americana L. Es wurde die Anatomie des Sprosssystems von Acer rubrum L. und von Fraxinus americana L. zu verschiedencn Zeiten nach einer PJilorambehandlung untersucht. Bei Acer rubrum traten als Sympiome auf: Verstopfen des Xylems, VergröBerung der Rinden-und Markzellen und schliesslich Absterben der Sprossspitze, des parenchymatischen und des Phloemgewebcs. 22 Tage nach der Behandlung waren dis Sprosse ausgelrocknet und tot. Bei Fraxinus americana zeigten die Sprosse erhohte mitotische AktivitSt, aber 22 Tage nach der Piclorambehandlung waren die Blotter noch turgeszent und der innere Auf bau des Sprols systems war kaum verSndert. Die Befunde deuten darauf hin, daβ die Empfindlichkeit von Acer rubrum gegenuber Pictoram zum Teil mit seiner Wirkung auf das Xylem und das parenchymatische Gewebe im Sproβsystem erklärt werden kann.  相似文献   
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