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21.
Tuyosi Sugimoto 《Population Ecology》1978,19(2):197-208
The present paper studies how the female parasite of Kratochviliana sp. visits and attacks its host larvae of Ranunculus leaf mining fly, P. ranunculi at a single leaf visit. The parasite visited its hosts at random on the leaf. The frequency of host visits was independent of the host density and the proportion of hosts survived from the parasite attack, in a leaf and its distribution was expressed as a single straight line. It almost always attacked living hosts at the first host visit after isolated from them for one day but with the rate of about 0.5 at the subsequent visits. In consequence, the relationships of the number of host attacks and killed hosts to the host density drew satulated curves in each. A model of host attack by this parasite at its single leaf visit was formulated by modifyingBakker et al.'s model (1972) basing upon these observations and the attack avoidance by the parasite to already attacked hosts previously reported. 相似文献
22.
Michael Chapman 《American journal of physical anthropology》1980,53(2):317-327
Until recently, certain Eskimo groups were reported to practice female infanticide in the belief that the time spent suckling a girl would delay the mother's next opportunity to bear a son, males being preferred to females because of their future role as providers in a hunting economy. From sex ratios in census data, rates of female infanticide of up to 66% for some groups have been inferred, leading some ethnographers to conclude that these groups were headed for extinction. Eskimo beliefs regarding the effects of infanticide on fertility, however, are in accord with the results of research on the relation of fertility and lactation: The cessation of lactation following infanticide would significantly shortern the expected interval until the next birth. Given this fact and available field data regarding the parameters of Eskimo population growth, the present computer simulation indicates that Eskimo populations could sustain a rate of 30% female infanticide and still survive. Higher reported rates are explained as the combined result of female infanticide plus the tendency of ethnographers to overestimate to overestimate the ages of juvenile females relative to juvenile males. 相似文献
23.
Summary Isolated egg cell protoplasts ofZea mays L., inbred line A 188, have been studied at the transmission electron microscope level. Their preparation for electron microscopy has been performed by embedding in ultra-low gelling agarose as a preliminary step. Five isolated egg cell protoplasts were serially ultrathin sectioned and studied in detail. One of these protoplasts was reconstructed in three dimensions to provide additional information on its structure. After enzymatic digestion and microdissection, isolated egg cells are true, highly vacuolized protoplasts. The structure of their organelles agrees with in situ observations, indicating an ultrastructural intactness after isolation: the mitochondria are polymorphic, form reticulate networks, and have well developed cristae; the plastids contain starch grains; and the spherical nucleus is euchromatic. As in situ, the organelles of the isolated egg cell protoplasts are aggregated near the nucleus. The complete picture provided by this work should serve as a comparative base for studies on in vitro fertilization products. 相似文献
24.
Population Ecology - Female deermice housed from weaning with groups of five females, five males or five males plus five females had significantly smaller uteri at 35–38 days of age compared... 相似文献
25.
河南省鹤壁市的淇县宋庄东周墓地的多座墓葬不仅出土大量青铜礼乐器和陶器,而且存在人殉现象,宋庄墓地的发现为探讨东周时期豫北地区考古学文化与政治格局提供了重要线索。为了分析宋庄墓地东周墓葬人殉的种系来源,本文对其中保存较好的7例女性人殉颅骨进行了形态学分析。淇县宋庄组与仰韶文化的宝鸡组和大汶口、龙山文化的呈子组均具有较大相似性,与青铜时代的毛饮合并B组、西村周组和双楼组也较为接近。初步认为,淇县宋庄女性人殉与东周时期的豫北和晋地传统居民在体质特征存在一定的区别,而与周人畿内和郑韩故城及其以西以北地区的中原文化居民有更多的亲缘关系。 相似文献
26.
摘要 目的:了解女性生殖道感染类型分布情况,分析生殖道感染对女性血清炎症因子、性功能和心理状态的影响。方法:选择2016年5月~2018年8月到我院就诊的生殖道感染女性患者60例(研究组),另选取同期到我院进行健康体检的健康女性60例(对照组)。统计研究组患者生殖道感染的感染类型,并比较两组血清炎症因子、性功能和心理状态情况。结果:60例生殖道感染患者感染类型以宫颈炎(33.33%)、非特异性阴道炎(26.67%)居多。研究组血清肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)以及白细胞介素-8(IL-8)水平分别为(144.38±31.85)ng/mL、(73.85±15.73)ng/mL、(218.64±43.28)ng/mL,均高于对照组的(99.01±22.25)ng/mL、(40.27±10.52)ng/mL、(113.82±26.08)ng/mL,差异有统计学意义(均P<0.05)。研究组性欲、高潮频数、性满意度、性焦虑、配偶高潮频数、配偶性满意度评分分别为(3.08±0.92)分、(4.38±1.01)分、(2.71±1.07)分、(3.66±1.30)分、(2.68±1.01)分、(2.95±1.04)分,均低于对照组的(3.84±0.51)分、(4.92±0.32)分、(3.87±0.47)分、(4.18±0.54)分、(3.82±0.38)分、(3.97±0.41)分,差异有统计学意义(均P<0.05)。研究组健康问卷抑郁量表(PHQ-9)与广泛性焦虑评定量表(GAD-7)评分分别为(16.35±5.88)分、(13.87±3.73)分,均高于对照组的(5.15±1.76)分、(5.89±1.39)分,差异有统计学意义(均P<0.05)。结论:女性生殖道感染以宫颈炎和非特异性阴道炎为主,生殖道感染会导致女性患者血清炎症因子水平显著升高,性功能降低,同时对患者心理状态也存在一定影响,因此,在临床工作中应予以患者及时有效的干预,从而改善患者性功能以及心理状态。 相似文献
27.
Hormones are critical for the development, maturation, and maintenance of physiological systems; therefore, understanding their involvement during maturation of the brain is important for the elucidation of mechanisms by which adults become behaviorally competent. Changes in exogenous and endogenous factors encountered during sexual maturation can have long lasting effects in mature adults. In this study, we investigated the role of the gonadotropic hormone, juvenile hormone (JH), in the modulation of adult behaviors in Drosophila. Here we utilized methoprene (a synthetic JH analog) and precocene (a JH synthesis inhibitor) to manipulate levels of JH in sexually immature male and female Drosophila with or without decreased synthesis of neuronal dopamine (DA). Locomotion and courtship behavior were assayed once the animals had grown to sexual maturity. The results demonstrate a sexually dimorphic role for JH in the modulation of these centrally controlled behaviors in mature animals that is dependent on the age of the animals assayed, and present DA as a candidate neuronal factor that differentially interacts with JH depending on the sex of the animal. The data also suggest that JH modulates these behaviors through an indirect mechanism. Since gonadotropic hormones and DA interact in mammals to affect brain development and later function, our results suggest that this mechanism for the development of adult behavioral competence may be evolutionarily conserved. 相似文献
28.
Furha Iram Cossor Lucile L. Adams-Campbell Rowan T. Chlebowski Marc J. Gunter Karen Johnson Robert E. Martell Anne McTiernan Michael S. Simon Thomas Rohan Robert B. Wallace Jessica K. Paulus 《Cancer epidemiology》2013,37(5):742-749
Background: Observational studies have associated metformin use with lower colorectal cancer (CRC) incidence but few studies have examined metformin's influence on CRC survival. We examined the relationships among metformin use, diabetes, and survival in postmenopausal women with CRC in the Women's Health Initiative (WHI) clinical trials and observational study. Methods: 2066 postmenopausal women with CRC were followed for a median of 4.1 years, with 589 deaths after CRC diagnosis from all causes and 414 deaths directly attributed to CRC. CRC-specific survival was compared among women with diabetes with metformin use (n = 84); women with diabetes with no metformin use (n = 128); and women without diabetes (n = 1854). Cox proportional hazard models were used to estimate associations among metformin use, diabetes and survival after CRC. Strategies to adjust for potential confounders included: multivariate adjustment with known predictors of colorectal cancer survival and construction of a propensity score for the likelihood of receiving metformin, with model stratification by propensity score quintile. Results: After adjusting for age and stage, CRC specific survival in women with diabetes with metformin use was not significantly different compared to that in women with diabetes with no metformin use (HR 0.75; 95% CI 0.40–1.38, p = 0.67) and to women without diabetes (HR 1.00; 95% CI 0.61–1.66, p = 0.99). Following propensity score adjustment, the HR for CRC-specific survival in women with diabetes with metformin use compared to non-users was 0.78 (95% CI 0.38–1.55, p = 0.47) and for overall survival was 0.86 (95% CI 0.49–1.52; p = 0.60). Conclusions: In postmenopausal women with CRC and DM, no statistically significant difference was seen in CRC specific survival in those who used metformin compared to non-users. Analyses in larger populations of colorectal cancer patients are warranted. 相似文献
29.
《Cryobiology》2016,72(3):367-373
Cryopreservation of ovarian tissue has been studied for female germline preservation of farm animals and endangered mammalian species. However, there are relatively few reports on cryopreservation of fish ovarian tissue and especially using vitrification approach. Previous studies of our group has shown that the use of a metal container for the cryopreservation of bovine ovarian fragments results in good primordial and primary follicle morphological integrity after vitrification. The aim of this study was to assess the viability and in vitro development of zebrafish follicles after vitrification of fragmented or whole ovaries using the same metal container. In Experiment 1, we tested the follicular viability of five developmental stages following vitrification in four vitrification solutions using fluorescein diacetate and propidium iodide fluorescent probes. These results showed that the highest viability rates were obtained with immature follicles (Stage I) and VS1 (1.5 M methanol + 4.5 M propylene glycol). In Experiment 2, we used VS1 to vitrify different types of ovarian tissue (fragments or whole ovaries) in two different carriers (plastic cryotube or metal container). In this experiment, Stage I follicle survival was assessed following vitrification by vital staining after 24 h in vitro culture. Follicular morphology was analyzed by light microscopy after vitrification. Data showed that the immature follicles morphology was well preserved after cryopreservation. Follicular survival rate was higher (P < 0.05) in vitrified fragments, when compared to whole ovaries. There were no significant differences in follicular survival and growth when the two vitrification devices were compared. 相似文献
30.
《Tissue & cell》2016,48(6):588-595
In the present study, we examined the morphology of cilia and expression of the dynein intermediate chain 2 (DNAI2) in the oviduct of non-obese diabetic (NOD) mice. Results obtained with immunohistochemistry showed that DNAI2 expression was reduced in oviducts of diabetic NOD (dNOD) mice, as compared to that observed in the normoglycemic NOD (cNOD) group, especially in the acyclic dNOD mice. Oviductal cilia of dNOD mice appeared to be reduced in number. Results obtained with Western blot analysis revealed that the expression of DNAI2 protein was significantly less in oviducts of dNOD mice as compared to that of cNOD mice corroborating the results obtained with immunohistochemistry. Electron microscopic examination and quantitative imaging of thin sections of Epon-embedded oviducts of both dNOD and cNOD mice confirmed the reduction of the number of cilia in the oviduct of the dNOD group which also displayed aberrant axonemal ultrastructure, including disorganization of the axoneme and alteration of microtubule doublets into singlets as well as disruption of the plasma membrane in many cilia. Taken together, the present findings suggest that structural alterations of oviductal cilia in female diabetic NOD mice might be detrimental to the normal function of these particular cell structures in gamete transport. 相似文献