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41.
Impacts of atmospheric anthropogenic nitrogen on the open ocean 总被引：3，自引：0，他引：3
Duce RA LaRoche J Altieri K Arrigo KR Baker AR Capone DG Cornell S Dentener F Galloway J Ganeshram RS Geider RJ Jickells T Kuypers MM Langlois R Liss PS Liu SM Middelburg JJ Moore CM Nickovic S Oschlies A Pedersen T Prospero J Schlitzer R Seitzinger S Sorensen LL Uematsu M Ulloa O Voss M Ward B Zamora L 《Science (New York, N.Y.)》2008,320(5878):893-897
Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to approximately 3% of the annual new marine biological production, approximately 0.3 petagram of carbon per year. This input could account for the production of up to approximately 1.6 teragrams of nitrous oxide (N2O) per year. Although approximately 10% of the ocean's drawdown of atmospheric anthropogenic carbon dioxide may result from this atmospheric nitrogen fertilization, leading to a decrease in radiative forcing, up to about two-thirds of this amount may be offset by the increase in N2O emissions. The effects of increasing atmospheric nitrogen deposition are expected to continue to grow in the future. 相似文献
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A Tvarijonaviciute JD Carrillo‐Sanchez JJ Ceron 《Reproduction in domestic animals》2013,48(3):520-524
The aim of this study was to evaluate the possible association between hormonal changes that occur during oestrus and biomarkers related with glucose metabolism (glucose and insulin), lipid metabolism (lipidic profile and BChE) and adipokines (adiponectin and ghrelin) in healthy bitches. For this purpose, we measured these analytes in serum of bitches, at two times: before (T1) and after (T2) the LH peak that were established according to progesterone concentrations. Increased levels of total cholesterol (p < 0.01), high density lipoprotein cholesterol (HDL‐C) (p < 0.01), low density lipoprotein cholesterol (LDL‐C) (p < 0.01), adiponectin (p < 0.01) and ghrelin (p < 0.05) were observed at T2 in comparison with T1. No statistically significant changes were observed in serum glucose, insulin, homoeostasis model assessment for insulin sensitivity (HOMA), triglycerides and BChE. When all data of T1 and T2 were pooled, serum adiponectin showed positive correlation with progesterone (r = 0.353; p = 0.022) and HDL‐C (r = 0.307; p = 0.048), and negative with insulin (r = ?0.429; p = 0.005), HOMA (r = ?0.446; p = 0.003) and BChE (r = ?0.522; p < 0.001). Ghrelin showed negative correlation with estradiol (r = ?0.701; p = 0.004). BChE was negatively correlated with estradiol (r = ?0.441; p = 0.018) and glucose (r = ?0.343; p = 0.028), and positively with insulin (r = 0.460; p = 0.003) and HOMA (r = 0.505; p < 0.001). In conclusion, changes in metabolic biomarkers occur in bitches after LH peak, characterized by increased lipids (total cholesterol, HDL cholesterol and LDL cholesterol) without changes in BChE activity, and increased adiponectin and ghrelin concentrations, without significant changes in glucose and insulin. 相似文献
43.
The inbred SLA miniature pig is a unique animal model developed for organ transplantation studies and pre‐clinical experimental purposes. Reported oestrous synchronization and superovulation treatments were examined in two SLA haplotypes (AA and DD) to allow collection of embryos for both practical embryo transfer and experimental technologies from a closed breeding colony. Pre‐puberal miniature pigs were poor responders to oestrous synchronization treatments, while post‐puberal sows were equivalent to commercial sows. Following superovulation, the ovulation number (corpora .hemorrhagica) was higher (p < 0.05) in the cycling sows when compared with non‐cycling sows. Ovulations were equivalent to commercial pre‐puberal gilts and non‐cycling sows (p > 0.05). No difference in ovulation number between haplotypes was observed, which differs from the previous report (DD>AA). Collection of zygotes for pronuclear injection was the highest in the non‐cycling post‐puberal miniature pig group (p < 0.05), although significantly lower when compared with the commercial pig treatment groups (p < 0.05). The incidence of cystic endometrial hyperplasia in our colony was equivalent to rates observed in commercial pigs. Pronuclear visualization following centrifugation was the highest in the non‐cycling miniature sow group and approximates to about 25% of ovulations and about half the rate observed in the commercial pigs (50%). Miniature pig embryos transferred between SLA haplotypes and transfer of DD embryos to commercial pigs resulted in live births at a higher efficiency than previously reported. This study demonstrates the feasibility of undertaking assisted reproductive technologies in a closed breeding colony of inbred SLA miniature pigs without compromise to the breeding programmes. 相似文献
44.
Inbreeding and Reproduction in Endangered Ungulates: Preservation of Genetic Variation through the Organization of Genetic Resource Banks 总被引：1，自引：0，他引：1
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MC Esteso MR Fernández-Santos AJ Soler V Montoro A Quintero-Moreno JJ Garde 《Reproduction in domestic animals》2006,41(3):241-246
Computer-automated sperm-head morphometry was used in this study to determine the effects of cryopreservation on red deer sperm-head morphometry. Epididymal sperm samples were collected from 40 mature stags and were divided. One portion was diluted at room temperature in a Tris-citrate egg yolk medium, containing 6% glycerol. A microscope slide was prepared from single extended sperm samples prior to freezing. The remainder of each sample was frozen in nitrogen vapours. After thawing, sperm smears were prepared as described above. All slides were air dried and stained with Hemacolor. The sperm-head dimensions for length, width, area, perimeter and shape factor (length/width), for a minimum of 135 spermatozoa were determined for each slide by means of the Sperm-Class Analyser (SCA). Firstly, our results show that cryopreservation substantially reduced (p < 0.001) sperm motility and plasma membrane and acrosome integrities. In addition, sperm heads were significantly smaller in cryopreserved spermatozoa than in the companion extended samples for area (32.05 microm2 vs 32.56 microm2; p < 0.05), length (8.46 microm vs 8.53 microm; p < 0.0001) and shape factor (1.833 vs 1.849; p < 0.0001) for all stags. These differences were found within 29 of 40 stags (75%) for at least three of the morphometric parameters. The individual variability (CV) of sperm head measurements from extended samples was negatively correlated (p < 0.005) with the per cent of change in sperm head measurements after cryopreservation for area (r = -0.465), width (r = -0.483) and perimeter (r = -0.375). Thus, the lower the sperm head variability in the extended samples, the greater the sperm change as a consequence of the cryopreservation. These results suggest that the variability (heterogeneity) in sperm head dimensions of individual stags may be a good indicator of sperm freezability. 相似文献
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48.
AI Peña M Barrio JJ Becerra LA Quintela PG Herradón 《Reproduction in domestic animals》2007,42(5):471-478
A 4-year-old Basque Shepherd male dog was presented for breeding soundness evaluation after the dog failed to impregnate the three bitches he had mated. Clinical examination showed no anomaly of the reproductive system. Semen evaluation showed normal sperm count (640 x 10(6)), 80% had progressively motile spermatozoa, and 96% had morphologically abnormal sperm of which 84% had proximal cytoplasmic droplet and 12% had proximal droplet plus other anomaly. A zona pellucida-binding assay, using canine oocytes derived from frozen-thawed ovaries, was performed in order to investigate the zona-binding ability of dog spermatozoa with proximal cytoplasmic droplets. For the zona pellucida-binding assay, ovaries were thawed and minced in phosphate-buffered saline + 0.4% bovine serum albumin, the oocytes recovered were divided into two groups of 35-40 oocytes to be, respectively, used with the infertile dog and with a control fertile dog. Spermatozoa were capacitated in Canine Capacitating Medium (CCM) at 38.5 degrees C and 5% CO(2) in air for 2 h before oocyte insemination. Groups of five to six oocytes placed in 45 microl droplets of CCM were incubated for 1 h. Afterwards, 5 microl of CCM containing 25,000 spermatozoa were added to each droplet and co-incubated for 2 h before fixation and evaluation of the complexes. After oocyte insemination, sperm motility and viability were evaluated: the sample from the infertile dog had 85% sperm motility with fast and linear progressive movement, and sperm viability of 92%. The sample from the control dog showed 40% sperm motility with fast and highly curvilinear and erratic movement, high degree of sperm agglutination and sperm viability of 32%. For the infertile dog the mean number of bound spermatozoa/oocyte was 0.33 whereas for the control dog it was 1.80. It was concluded that dog sperm with proximal cytoplasmic droplets seem to lack normal capacitating ability in vitro, and consequently, they may have reduced capacity to bind to the zona pellucida of canine oocytes. 相似文献
49.
The objectives of this study were to determine the non‐specific aerobic and anaerobic bacterial causes of endometritis causing repeat breeding of cycling Iraqi buffalo cows at Nineveh province, validate diagnostic criteria for endometritis and to evaluate the treatment efficiency of using systemic or intra‐uterine infusion of antibiotics for the treatment of endometritis. Data were collected from 60 buffalo cows with history of repeat breeding in different herds. All buffaloes were subjected to detailed clinical examination including external inspection, vaginoscopy and transrectal palpation of the cervix, uterus and ovaries. Swabs for bacteriology and biopsies for histopathology were collected from the uterine lumen from each cow. Character, odour and estimation of polymorphonuclear cells (PMN) of the vaginal mucus were scored. Blood samples were collected from cows for creatine kinase (CK) and aspartate aminotransferase (AST) measurement. Treatment conducted using oxytetracycline with tylosin in local intrauterine infusion or systemically with hormonal treatment. The most pre‐disposing factor for uterine infection was retained placenta (13.3%). The most prevalent bacteria in uterine lumen were E. coli (23%), Archanobacterium pyogenes (13%) and Staphylococcus aureus (10%) were mostly isolated from buffaloes with repeat breeding. Vaginal mucus character score was associated with the bacterial growth density score. The difference in PMN was highly significant (p < 0.01) in animals with repeat breeding than control groups. In addition, PMNs was significantly (p < 0.01) correlated r = 0.894 with the character of vaginal discharge. High level of PMNs observed in buffaloes infected with A. pyogenes. Buffalo cows with endometritis had higher CK (321.47 ± 39.06 vs 162.01 ± 16.41 U/l) and AST (133.93 ± 12.43 vs 97.01 ± 6.86 U/l) activities (p < 0.05) than control‐heifers, but no significant difference was observed between buffalo cows with endometritis in CK (321.47 ± 39.06 vs 208.33 ± 5.84) and AST (133.93 ± 12.43 vs 156.17 ± 9.65) activities than control‐pluriparious. It could be concluded that A. pyogenes was the only non‐specific uterine pathogen directly associated with severe endometrial lesions. Vaginoscopy examination combined with palpation of uterus increase the accuracy of diagnosing endometritis and cytogenic examination of uterine discharge is more reliable method of establishing the presence or absence of uterine inflammation in buffalo cows. Animals with repeat breeding (endometritis) showed clinical cure and improved pregnancy in all treatment groups with no significant difference. The use of oestradiol in repeat breeder cases has no effect in improving neither clinical cure rate nor pregnancy rate. 相似文献
50.
AJ Soler N Poulin MR Fernández-Santos Y Cognie MC Esteso JJ Garde P Mermillod 《Reproduction in domestic animals》2008,43(3):293-298
A heterologous in vitro system, using zona‐intact sheep oocytes, was used to evaluate the relationship between sperm factors of Iberian red deer thawed epididymal sperm and the percentage of cleaved oocytes. Epididymal spermatozoa were recovered from six males, diluted with freezing extender and cryopreserved. After thawing sperm motility (SM) and acrosome and membrane integrities were evaluated. Again, these parameters were assessed after incubation in freezing extender at 37°C for 2 h. After cryopreservation the values for SM and acrosome and membrane integrities were high (～80, 80 and 70% respectively). However, these values significantly decreased after incubation (～59, 62 and 47% respectively). Red deer thawed epididymal sperm fertilized zona‐intact sheep oocytes, although the percentage of cleaved oocytes was low (～22%). No relationship was found between sperm parameters assessed after thawing and the percentage of cleaved oocytes. Likewise, any sperm parameter evaluated after incubation was assessed in relation to the percentage of cleaved oocytes. However, acrosome and membrane integrities were near to significance (p = 0.06 and p = 0.09 respectively). Then, we conducted a reduced model with these two variables and both were related to the percentage of cleaved oocytes (p = 0.02 and p = 0.04 respectively). Thus, acrosome and membrane integrities were related to the percentage of cleaved oocytes negatively and positively respectively. It was concluded that the classical parameters assessed in deer thawed sperm samples can be good predictors of the ability to fertilize zona‐intact sheep oocytes. 相似文献