共查询到20条相似文献,搜索用时 15 毫秒
1.
K. C. Copeland D. M. Johnson L. E. Underwood J. J. Van Wyk 《American journal of primatology》1983,5(2):161-169
This study was undertaken to assess the nature of somatomedin-C (SM-C) in baboon (Papio cynocephalus) blood and to compare various methods for estimating SM-C concentrations. Parallel dose-response curves were obtained with normal baboon serum, normal human serum, and purified SM-C. Recovery of purified SM-C added to baboon serum over a wide dosage range (n = 17) was 111 ± 12%, with slightly better recovery at higher potencies. Chromatography of normal baboon serum on Sephadex G-200 at neutral pH produced a profile similar to that observed in the human, as did samples chromatographed on Sephadex G-50 in acid. Although the SM-C content in acid chromatographed plasma was approximately 2.5 times higher than in native unprocessed plasma, there was excellent correlation between the values (r = 0.9143, p < 0.0001). The SM-C in baboon plasma which had been preincubated with glycine HCl was approximately twice that of unprocessed plasma, but the correlation between the two methods was excellent (r = 0.9593, p < 0.0001). The correlation between values obtained after simple acid-ethanol extraction and those observed in unextracted plasma were also significant (r = 0.7689, p < 0.0001). Following a series of four injections of human growth hormone (hGH) to a normal baboon, plasma SM-C rose approximately sevenfold above the initial concentration and returned to basal levels five days after the final injection. These studies show that although the radioimmunoassay (RIA) for SM-C in unprocessed baboon plasma does not measure all of the SM-C present, it provides a reliable index of the total SM-C concentration and reflects GH status in the baboon. 相似文献
2.
Yves W. Brans Thomas J. Kuehl Robert H. Hayashi Donna L. Shannon Patty Reyes 《American journal of primatology》1983,5(1):69-75
Water contents of various body water compartments were estimated within nine hours of birth in 11 preterm and eight term baboon (Papio cynocephalus neonates. Estimated water contents of all body compartments (in ml) increased linearly with birthweight (r = 0.52 to 0.90, P ≦ 0.007) and with gestational age (r = 0.46–0.94, P ≤ 0.05). When body water estimates were expressed in proportion to bodyweight (in ml/kg), preterm neonates had significantly larger mean antipyrine space and intracellular water than their term peers. Mean corrected bromide space, interstitial water, plasma volume, blood volume, and red cell volume were similar in preterm and term neonates. Although there are minor differences in body water contents and distribution between baboon and human neonates, baboon data are sufficiently similar to human data to justify using the baboon fetus and neonate as a model for investigations of human development. 相似文献
3.
The pattern of excretion of urinary steroid metabolites in the olive baboon (Papio anubis) was examined during the menstrual cycle and in conception cycles in which embryos were surgically removed at intervals between day 11 and day 21 (day 0 = day of preovulatory estrogen peak). Conjugated estrone and pregnanediol-3α-glucuronide were measured in overnight urine samples by direct, nonextraction assays, and the levels were indexed by creatinine. Results showed that measurement of urinary conjugated estrone reflected preovulatory estrogen output and that pregnanediol-3α-glucuronide was an abundant urinary metabolite of progesterone. There was a defined postovulatory increase in the excretion of conjugated estrone during conception cycles in eight of ten animals. The timing of the increase ranged between day 13 and day 19 and was related to the appearance of elevated levels of urinary gonadotrophin. In four animals, increased estrogen excretion was first detected after the day of embryo removal, but this was most likely a response to chorionic gonadotrophin secreted before surgery. The findings demonstrate that measurement of conjugated estrone offers a rapid and practical approach for monitoring ovulation and implantation in the baboon by a single assay technique. 相似文献
4.
Robert M. Sapolsky 《American journal of primatology》1983,5(4):365-379
The relationships among social status and the cortisol and testosterone stress-response were studied in the non-natal male members of a troop of olive baboons (Papio anubis) before and during a period of social instability. The unstable period was characterized by dominance interactions that were more frequent, more inconsistent, and produced less linear hierarchies than during the stable period. These changes occurred predominantly among the high-ranking males. Such males engaged in coalitions and consortship harassments at a higher rate during the unstable period than during the stable period. Finally, high-ranking males had the highest rates of involvement in and initiation of escalated fighting during the unstable period, in contrast with the stable period. A number of endocrine correlates of instability emerged. During the stable period, high-ranking males (by reproductive criteria) showed an endocrine profile different from that of subordinates. They had the lowest basal cortisol titers, the largest and fastest increases in cortisol titer during stress, and had elevated testosterone titers during stress. None of these attributes was found in high-ranking males during the unstable period. Males during the unstable period had elevated basal cortisol titers, suppressed cortisol responsiveness to stress, and no longer showed elevated testosterone titers during stress. When psychological advantages associated with social status in a stable social environment were lost, endocrine efficiency previously associated with social status was apparently also lost. Further, high-ranking males, who were most aggressive exclusively during the unstable period, had the highest absolute titers of testosterone exclusively during the unstable period. Thus, elevated testosterone and high levels of aggression were unrelated to social status during the period of social stability, but were traits associated with dominant individuals during the unstable period. 相似文献
5.
L. R. Boots J. R. Dollar P. E. Cornwell E. L. Bradley 《American journal of primatology》1981,1(4):427-437
The baboon has been used increasingly for reproductive studies. While hormonal regulation of the menstrual cycle and ovulation as well as the endocrinology of gestation have been reported, little information is available describing endometrial parameters. It is the purpose of this paper to describe the ease with which repeated transcervical biopsies can be performed, to describe baseline endometrial protein and dry weight data and to demonstrate that the biopsy procedure itself does not significantly affect the baboons' ability to continue normal menstrual cycle function. Endometrial biopsy samples were taken throughout the menstrual cycle under light ketamine anesthesia. Protein and dry weight contents were determined. Endometrial biopsies Protein and dry weight contents were determined. Endometrial biopsies averaged 25 mg (wet weight) and contained 7.54% protein and 16.3% dry matter. The formulas (Y = a + bx) which expressed the linear relationships between wet weight (mg), protein (μg) and dry matter (μg) content and the correlation coefficients (r) were as follows: between wet weight and protein content – wet weight = 5.58 + 10.0 (protein), Sxy = 4.83, r = 0.883; between wet weight and dry weight – wet weight = 1.99 + 7.94 (dry weight), Sxy = 4.52, r = 0.904; between protein and dry weight – protein = 0.446 + 0.446 (dry weight), Sxy = 4.82, r = 0.870. All three linear regression coefficients were statistically significant (P < 0.001). No significant cyclical patterns in either protein or dry matter content were demonstrable throughout the menstrual cycles. The average length of all nonbiopsy cycles was 32.4 ± 2.7 days and 32.8 ± 3.6 days for those in which biopsies were taken. Similarly, follicular and luteal phase lengths for nonbiopsy and biopsy cycles were 15.4 ± 2.3 and 15.5 ± 2.8 days and 16.9 ± 2.2 and 17.2 ± 3.2 days, respectively. The time required for sex-skin swelling to decrease from maximum to minimum during the luteal phase was shorter, but the quiescent stage was equally lengthened. It was concluded that the endometrium of the baboon was easily accessible for study without causing serious alterations in menstrual cycle function. These studies further demonstrate the potential of the baboon as a model o reproductive studies. In fact, the baboon may well the only practical primate model available for endometrial studies. 相似文献
6.
Female perineal swelling and its effects on male sexual arousal: An apparent sexual releaser in the chacma baboon (Papio ursinus) 总被引:1,自引:0,他引:1
The function of the periodic perineal swelling that females of some primate species show in relation to their menstrual cycle
has long puzzled many scientists. A role in female attractiveness was suspected, but fluctuations in female behaviors concomitant
to these changes in female appearance have always prevented its assessment. By attaching a plastic reproduction of a fully
swollen perineum to ovariectomized female chacma baboons, it has finally been demonstrated that the sexual swelling hasan important function in the sexual communication of this species. It induces sexual arousal in male conspecifics. The way
the perineal swelling acts and other characteristic aspects of this feature appear to qualify it as a releaser for sexual
behavior. 相似文献
7.
Impact of global warming on the distribution and survival of the gelada baboon: a modelling approach 总被引:2,自引:0,他引:2
R. I. M. Dunbar 《Global Change Biology》1998,4(3):293-304
The gelada baboon is a graminivorous primate whose ecology is unusually sensitive to ambient temperature. A systems model of the socio-ecology of the gelada is used to predict the impact of global warming on the species’ altitudinal distribution. The species’ lower altitudinal limit will rise by ≈ 500 m for every 2 °C increase in global mean temperature. A 7 °C rise in temperature would be sufficient to result in the species being confined to a small number of isolated mountain peaks, where its chances of survival will be greatly reduced. Changes in local climate are also likely to have significant effects on agricultural practice on the Ethiopian highlands, and this in turn is likely to have repercussions for the distribution patterns of the gelada by further constraining the habitat available to them. 相似文献
8.
This paper analyzes data from a study conducted by the United States Office of Naval Research on the effects of pulsed magnetic fields on chick embryos. The experiment involved incubation of eggs under carefully controlled conditions in six different laboratories. The original analysis included inappropriate statistical methodology for analyzing the experimental results. Since the conclusions from this study rest so heavily on the results of statistical analyses, choosing the proper methodology is imperative. The major aim of this paper then is to introduce more appropriate analytic tools and illustrate their use in the present context. Qualitatively our results agree with those of the original analysis; our findings about interactions between effects, however, makes interpretation of these effects more subtle. We apply linear logistic modeling to counts of damaged embryos, using as covariates factors corresponding to exposure, laboratory, incubator, run, and measurements of background radiation. This facilitates estimation of the size of the effects. The effects of laboratory, incubator, and run are explored both as fixed and random effects. We find statistically significant exposure and laboratory effects, in accordance with the original study. However, we also find that the inter-laboratory variation in exposure effect is at least as large as the exposure effect itself. The presence of such effects fundamentally alters the interpretation of the fitted model, as is graphically presented. 相似文献
9.
The embryos from many outbred and inbred strains of mice are arrested at the late 2-cell stage when cultured in vitro in simple culture media. This phenomenon is referred to as the "2-cell block in vitro". The ultrastructural morphology of the nuclei of the blocked embryos is not yet well described. In the present paper we documented the results of a comparative study on the nuclei of mouse embryos, both normally developing and arrested at the 2-cell stage. The blocked embryos maintain the morphological integrity of their nuclei. Main nuclear domains (nucleolus precursor bodies, interchromatin granule clusters, perichromatin granules, and perichromatin fibrils), typical for the control embryos, are observed in the blocked ones. A number and morphological characteristics of these nuclear substructures are not changed significantly in the blocked embryos. At the same time, RNA polymerase II and pre-mRNA splicing factors are redistributed in the nucleus of the blocked embryos. Although something goes to show that nuclear organization of the blocked embryos differ from that of the control, we could not reveal in the blocked embryos distinct signs of degeneration which might characterize aged or dying cells. Our data confirm a peculiar functional state of the 2-cell blocked embryos. 相似文献
10.
Helen Carol Hechler 《Journal of nematology》1972,4(4):243-245
Both Neodiplogaster pinicola and Panagrellus redivivoides reproduce amphimictically, with XO type of sex determination. In N. pinicola, primary spermatocytes have six bivalent chromosomes and one univalent; after two meiotic divisions, sperm are produced with either six or seven chromosomes. In primary oocytes, with seven bivalents, meiosis is initiated by entrance of a sperm. After two meiotic divisions, three polar nuclei are produced, and egg and sperm pronuclei fuse. Cleavage begins after the egg is laid. Males have a 2n number of 13 chromosomes; females, 14. In P. redivivoides, primary spermatocytes have four bivalents and one univalent. After two meiotic divisions, spermatids are produced with either four or five well separated chromosomes. In primary oocytes, the first maturation division is initiated after penetration of a sperm; after two meiotic divisions, each egg has five chromosomes. Cleavage begins immediately after fusion of egg and sperm pronuclei, and embryonic development and hatching occur within the uterus. Males have a 2n chromosome number of 9; females, 10. 相似文献
11.
Bibliographical study of articles published in scientific journals over the last 10 years, and of books published over the last 20 years, reveals a clear increase in the number of publications dealing with ecological engineering, particularly on aquatic ecosystems, which today are becoming a major topic. The concept of ecological restoration must be clearly defined scientifically and include adequate pre- and post-restoration monitoring of various performance indicators, to allow for restoration, evaluation and increase its success. A restoration experiment was carried out in a former channel of the Rhône River according to a scientifically based decision framework. Long-term monitoring of aquatic vegetation (17 years of data) on two former channels (reference and restored ecosystem) clearly demonstrated human impacts on aquatic ecosystems. A channel exhibiting rapid terrestrialization and eutrophication processes after completion of a hydroelectric scheme construction was restored. In keeping with the hypothesis, the increase in groundwater supply led the restored ecosystem to return to a less advanced and self-sustainable successional stage, whereas vegetation monitoring in the reference channel did not show significant changes over this 17-year of period, supporting long-term studies to determine the effects of restoration on the biota. 相似文献
12.
In June 2015, the fourth European Workshop on Plant Chromatin took place in Uppsala, Sweden, bringing together 80 researchers studying various aspects of plant chromatin and epigenetics. The intricate relationships between plant chromatin dynamics and gene expression change, chromatin organization within the plant cell nucleus, and the impact of chromatin structure on plant development were discussed. Among the main highlights of the meeting were an ever-growing list of newly identified players in chromatin structure establishment and the development of novel tools and approaches to foster our understanding of chromatin-mediated gene regulation, taking into account the context of the plant cell nucleus and its architecture. In this report, we summarize some of the main advances and prospects of plant chromatin research presented at this meeting. 相似文献
13.
Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5?µg g?1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92?µg g?1) from these sites and were reduced down-estuary (maximum of 2.67?µg g?1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2?µg g?1). When tissue concentrations of Ag decreased (≤1?µg g?1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis. 相似文献
14.
The results from many experiments conducted over 5 years to determine the tolerance of 34 plant species (87 cultivars) to aluminium (Al) are summarised. All experiments were conducted in a temperature-controlled glasshouse using a low-ionic-strength solution culture technique. The activity of Al3+ (M) at which top yields were reduced by 50% (AlRY50) was determined for each cultivar.The species Bromus wildenowii, Cynosurus cristatus, Hordeum vulgare, Triticum aestivum (cvs Warigal, Scout, Sonora-63), Avena byzantina, Arabidopsis thaliana, Lycopersicon esculentum and Nicotiana plumbaginifolia were all very sensitive to Al (AlRY50<1). The species Poa pratense, Lolium perenne (NZ-derived cultivars), Lotus corniculatus, Avena sativa (cvs West, Carbeen, Camellia and Coolabah), Triticum aestivum (cvs Cardinal and Waalt), Allium cepa and Asparagus officinalis were sensitive to Al (AlRY50 1–2).The pasture grass species Lolium perenne (Australian and European and derived cultivars), Lolium hybridum and Lolium multiflorum, Dactylis glomerata (Apanui and Kara), Phalaris aquatica, Festuca arundinacea and the pasture legumes species Trifolium pratense, Trifolium repens and Trifolium subterraneum were all moderately sensitive to Al (AlRY50 2–5). Other species that were also moderately sensitive included Triticum aestivum (cvs Atlas-66, BH146, and Carazinho), Avena sativa (cvs Swan and Blackbutt), Avena Strigosa, Petunia x and Phaseolus vulgaris (cvs Red Kidney, Black Turtle and Haricot).The most tolerant species (AlRY50>5) were (in order of increasing tolerance) Phaseolus vulgaris (cvs Tendergreen, The Prince and Yatescrop), Cucurbita maxima, Dactylis glomerata (cv Wana), Paspalum dilatatum, Lotus pedunculatus, Ehrharta calycina, Medicago sativa, Holcus lanatus, Festuca rubra, Phaseolus lunatus and Agrostis tenuis. Agrostis tenuis was at least twice as tolerant as the next most tolerant species (AlRY50>30 compared to 15.6). 相似文献
15.
Darren J. Gray Yue-Sheng Li Gail M. Williams Zheng-Yuan Zhao Donald A. Harn Sheng-Ming Li Mao-Yuan Ren Zeng Feng Feng-Ying Guo Jia-Gang Guo Jie Zhou Yu-Lan Dong Yuan Li Allen G. Ross Donald P. McManus 《International journal for parasitology》2014
Despite major successes in its control over the past 50 years, schistosomiasis japonica continues to be a public health problem in the People’s Republic of China (P.R. China). Historically, the major endemic foci occur in the lakes and marshlands along the Yangtze River, areas where transmission interruption has proven difficult. The current endemic situation may alter due to the closure of the Three Gorges Dam. Considerable environmental and ecological changes are anticipated that may result in new habitats for the oncomelanid intermediate snail host of Schistosoma japonicum (Sj), thereby increasing the risk of transmission. The current national control program for P.R. China involves a multi-component integrated strategy but, despite targeting multiple transmission pathways, certain challenges remain. As the Chinese government pushes towards elimination, there is a requirement for additional tools, such as vaccination, for long-term prevention. Whereas the zoonotic nature of schistosomiasis japonica adds to the complexity of control, it provides a unique opportunity to develop a transmission blocking vaccine targeting bovines to assist in the prevention of human infection and disease. Mathematical modelling has shown that control options targeting the various transmission pathways of schistosomiasis japonica and incorporating bovine vaccination, mass human chemotherapy and mollusciciding could lead to its elimination from P.R. China. Here we present the study design and baseline results of a four-year cluster randomised intervention trial we are undertaking around the schistosomiasis-endemic Dongting Lake in Hunan Province aimed at determining the impact on schistosome transmission of the multi-component integrated control strategy, including bovine vaccination using a heterologous “prime-boost” delivery platform based on the previously tested SjCTPI vaccine. 相似文献
16.
Gary W. Ferguson J. R. Jones W. H. Gehrmann S. H. Hammack L. G. Talent R. D. Hudson E. S. Dierenfeld M. P. Fitzpatrick F. L. Frye M. F. Holick T. C. Chen Z. Lu T. S. Gross J. J. Vogel 《Zoo biology》1996,15(3):279-299
To assess the importance of diet and light for indoor maintenance, hatchling panther chameleons were reared for 1 year on crickets fed diets that differed in vitamin concentrations and in different light environments. Dietary transfer of vitamins from the cricket diet to the lizards via the crickets was quantified, as was UV irradiance. There was a statistically significant dietary enhancement of growth by both vitamins on males. UV-A irradiation significantly suppressed growth of females. Low vitamin A shortened life span and resulted in a number of gross and histological pathologies. Hepatocellular lipidosis, indicating a possible toxicosis, occurred with all diets and light treatments. Higher vitamin A resulted in mild soft-tissue mineralization, and high vitamin D shortened the life span of females. Low vitamin A drastically reduced reproduction in both sexes. The intermediate levels of dietary vitamins resulted in the best production of viable eggs by females. However, without high UV-B irradiation, all viable eggs died at term and contained different vitamin levels than hatching eggs from wild-caught females. Baseline levels of egg calcium are given for hatching eggs from wild-caught females. Modifications in current husbandry procedures are recommended. © 1996 Wiley-Liss, Inc. 相似文献
17.
Development periods were determined for eggs and juvenile stages of the predatory phytoseiid mite Typhlodromus pyri at four constant temperatures and three feeding levels. For the non-feeding stages (eggs and larvae) power curve functions were fitted to development rate in terms of temperature. The results are compared to the general arthropod response to temperature. A non-linear model was fitted to nymphal development rate in terns of temperature and food, in which the weight gain over an instar is assumed to be a linear function of daily food consumption. Examples of the same shape development rate—food relationship are given for two more phytoseiid mites and for other arthropods. The results are discussed with respect to T. pyri as an integrated control agent. 相似文献
18.
Takashi Torigoe 《Primates; journal of primatology》1987,28(4):533-538
Thirteen captive species of the genusMacaca were presented with certain non-edible objects and the subsequent manipulation was observed. The following results were obtained: (1) Thefascicularis group species displayed a great variety in rolling the manipulandum, which has been reported to be one of the actions characterizing cercopithecine species; (2) manipulating the object with one finger was typical of thesilenus-sylvanus andsinica groups, whereas use of the fingers moving opposably was common to all species ofMacaca; (3) secondary manipulations in relation to the wire-mesh were observed only inM. silenus, M. sinica, andM. nemestrina, whereas those in relation to water were common to allMacaca species; and (4) within-subgroup differences were great in thesilenus-sylvanus andsinica groups as compared to thefascicularis group. 相似文献
19.