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151.
?ystein Wiig Mads Peter Heide-J?rgensen Kristin L. Laidre Eva Garde Randall R. Reeves 《Polar Biology》2012,35(1):63-71
We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one
in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and Uummannaq
samples with the samples from Inglefield Bredning and Scoresby Sound using three different multivariate techniques for each
sex. None of the results were significant. Seven of the non-metric variables were independent of age and sex and were used
in comparing samples from the six localities. No differences were found among the four localities in West Greenland, but differences
were found in two of the non-metric variables between the combined West Greenland sample and the one from Scoresby Sound.
A major shortcoming of the analysis based on metric data was the small sample size from several of the areas, which resulted
in low statistical power. Genetic as well as environmental factors could explain the differences detected here between narwhals
living along the west and the east coasts of Greenland. 相似文献
152.
M Mata-Campuzano M Alvarez-Rodríguez E Del Olmo MR Fernández-Santos JJ Garde F Martínez-Pastor 《Theriogenology》2012,78(5):1005-1019
Antioxidants may be useful for supplementing sperm extenders. We have tested dehydroascorbic acid (DHA), TEMPOL, N-acetyl-cysteine (NAC) and rutin on epididymal spermatozoa from red deer, during incubation at 37 °C. Cryopreserved spermatozoa were thawed, washed and incubated with 1 mm or 0.1 mm of each antioxidant, including oxidative stress (Fe2+/ascorbate). Motility (CASA and clustering of subpopulations), viability, mitochondrial membrane potential, and acrosomal status were assessed at 2 and 4 h. Lipoperoxidation, intracellular reactive oxygen species (ROS) and DNA damage (DNA) status (TUNEL) were checked at 4 h. Oxidative stress increased ROS, lipoperoxidation and DNA damage. Overall, antioxidants negatively affected motility and physiological parameters. Only DHA 1 mm protected motility, increasing the fast and progressive subpopulation. However, it had a detrimental effect on acrosomal and DNA status, in absence of oxidative stress. Tempol and rutin efficiently reduced lipoperoxidation, ROS, and DNA damage in presence of oxidative stress. NAC was not as efficient as TEMPOL or rutin reducing lipoperoxidation or protecting DNA, and did not reduce ROS, but its negative effects were lower than the other antioxidants when used at 1 mm, increasing the subpopulation of hyperactivated-like spermatozoa at 2 h. Our results show that these antioxidants have mixed effects when spermatozoa are incubated at physiological temperatures. DHA may not be suitable because of prooxidant effects, but TEMPOL, NAC and rutin may be considered for cryopreservation trials. In general, exposure of red deer spermatozoa to these antioxidants should be limited to low temperatures, when only protective effects may develop. 相似文献
153.
Diurnal urinary 6-sulfatoxymelatonin levels among healthy Danish nurses during work and leisure time
The present study aims to examine the influence of evening and night shift work, compared to day shift work, on melatonin secretion in nurses in a field setting. Effects were examined during a workday and during a day off. Both fixed schedules and mixed or rotating schedules were studied. In total, 170 nurses were studied: 89 nurses worked fixed schedules, 27 nurses worked the day shift, 12 nurses worked the evening shift, 50 nurses worked the night shift, and 82 nurses worked mixed schedules, with data collected during a day (n=17), evening (n=14), or night shift (n=50). All spot urine samples were collected during 24 h from the participants on a work day and on a day off and were analyzed for 6-sulphatoxymelatonin. On the day of urine sampling, participants filled in the Karolinska Sleep Diary. Additional information was collected through a telephone interview. Data were analyzed using a mixed procedure with autoregressive covariance structure. The present study showed that shift work affected the concentrations of 6-sulphatoxymelatonin in the short term by lower excretion in urine from nurses working the night compared to day shift on a workday and on a day off as well. No significant differences were observed between a workday and a day off when doing day and evening shifts, irrespective of mixed and fixed schedules. Sleep length was reduced workdays (from 6.1-6.8 h) among all nurses, compared to days off (from 7.8-8.7 h). 相似文献
154.
155.
Effects of UVB radiation on marine phytoplankton communities 总被引:1,自引:0,他引:1
The impact of enhanced and reduced UVB radiation (UVBR) on pelagic
ecosystems was studied during two mesocosm experiments in May and June/July
1994. The ambient UVBR exposure was either reduced with mylar foil or
artificially enhanced with UVB fluorescent tubes. Developments in the
phytoplankton communities were followed during 11 and 8 day periods using
several structural and functional parameters. In the May experiment,
enhanced UVBR significantly stimulated carbon dioxide fixation, activity of
alkaline phosphatase and content of fatty acids. In the June-July
experiment, the effects induced by changed UVBR were smaller with some
indications of decreased algal biomass with enhanced UVBR. Several of the
measured parameters indicated that the two experiments represented
different stages in the plankton community development. In the May
experiment, the community was in a development stage, moving from
nutrient-replete to nutrient-depleted conditions, while the community in
June/July was depleted of nutrients from the start. The stimulating effects
of UVBR in May are suggested to be the secondary effects of a
photochemically induced breakdown of dissolved organic matter, resulting in
an increase in available nutrients.
相似文献
156.
.E. Domínguez-Rebolledo M.R. Fernndez-Santos O. García-lvarez A. Maroto-Morales J.J. Garde F. Martínez-Pastor 《Theriogenology》2009,72(8):1073-1084
The effects of routine sperm work are often overlooked. We assessed the effect of washing cryopreserved epididymal spermatozoa from red deer (Cervus elaphus hispanicus, Helzheimer 1909). After thawing, epididymal samples (four stags) were diluted in TALP-HEPES. A split was left untouched, another was centrifuged (300 × g, 5 min) and resuspended, and a third was centrifuged and the supernatant substituted by fresh TALP-HEPES (washing). Each split was supplemented either with nothing, 1 mM of the antioxidant Trolox, 100 μM of the oxidant Fe (with ascorbate), or both. The 3 × 4 treatments were incubated at 37°C and assessed each hour up to 3 h for motility (computer-aided sperm assessment) and viability/apoptosis plus mitochondrial status (YO-PRO-1, propidium iodide, Mitotracker Deep Red; flow cytometry). DNA damage at 4 h was assessed using the terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling assay. Centrifugation alone affected neither sperm quality nor DNA, and the oxidant had no effect in control or centrifuged samples. Washed samples were not different than control, but oxidant decreased motility, mitochondrial status and viability, and altered the motility subpopulation pattern, being partially suppressed by Trolox. Spermatozoa with damaged DNA dramatically increased in the washed-oxidized sample (from 22.30 ± 3.52% to 67.94 ± 5.07%), but not when antioxidant was present. Although samples from different males behaved similarly, male-to-male variability was detected regarding susceptibility to oxidative damage after washing. We concluded that, although red deer thawed spermatozoa seemed resilient to centrifugation, the vulnerability to oxidative stress after washing makes it advisable to supplement manipulation media with antioxidants, especially taking into account male-to-male variability. 相似文献
157.
Hans Thijs Julie Garde Theo Goosen Brian Tomsett Klaas Swart Christa Heyting Henk W. J. van den Broek 《Molecular genetics and genomics : MGG》1995,247(3):343-350
We have examined polarity of meiotic gene conversion in the niiA-niaD gene cluster of Aspergillus nidulans in two-point crosses. The type and position of the mutations represented by the niaD alleles and the correlation between the relative frequency of gene conversion and the physical position of these mutations were determined. We show that polarity of meiotic gene conversion is 5′ to 3′ (transcribed strand) within the niaD gene. Additional crosses involving a niiA allele and a niaD allele show little polarity of gene conversion, which suggests that the recombination events leading to restoration of the niaD gene are initiated upstream of the coding region of the niaD gene but within the niiA-niaD gene cluster, possibly within the intergenic promoter region. 相似文献
158.
159.
G Garde?a 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1991,46(30-31):544-546
The antidepressants have been reported to be effective in the treatment of many pain syndromes, for example headache and neuralgia. The pain of the study was to evaluate the effectiveness on small (75 mg per die) dose of imipramine administered additionally to the routine. Conservative treatment of patients with acute low back pain. The analysis of six different indices of improvement revealed, that the outcome of therapy in the group of 50 patients treated with imipramine was significantly better, than in comparable group treated routinely. The effect of imipramine have not been related to the occurrence of depression or to the other factors from anamnesis and physical examination influencing pain. 相似文献
160.
Sonia S. Prez‐Garnelo Julin Garde Beln Pintado Concepcin Borque Covadonga Talavera María Delclaux Manuel Lpez Julio De La Fuente Martínez 《Zoo biology》2004,23(3):279-285
When Chu‐Lin, a male giant panda (studbook #249), died at Madrid Zoo, his reproductive tract was removed 4 hr postmortem and the epididymal spermatozoa were collected. Extended sperm were kept at 5°C for 4 hr, loaded into straws, and frozen for 7 min in liquid nitrogen vapor before the straws were plunged into liquid nitrogen. Two straws were thawed and evaluated. Sperm motility was assessed in fresh, refrigerated, and thawed spermatozoa (75%, 60%, 35%, respectively). Sperm viability and acrosome status were estimated using a triple‐stain technique (TST). The results showed 33% live sperm with intact acrosomes after thawing. A hypoosmotic swelling (HOS) test demonstrated the retention of membrane integrity in 72% of thawed sperm. To evaluate the in vitro fertilizing ability of thawed sperm, a sperm penetration assay (SPA) was performed. The values obtained for the percentage of penetration and the penetration index were 62% and 1.78 sperm/oocyte, respectively. The results obtained demonstrate that epididymal sperm recovered from a giant panda postmortem can be successfully cryopreserved. The sperm fertilizing ability demonstrated in vitro after thawing may provide a final opportunity for this male to contribute to the currently small germplasm reserves of this endangered species, and to reproduce in the future through assisted reproductive technology. Zoo Biol 23:279–285, 2004. © 2004 Wiley‐Liss, Inc. 相似文献