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1.
A few reports have suggested the possibility that feeding conditions might affect the sexual maturation of free-ranging Japanese monkeys in provisionized troops. In the present study, the sexual maturation of male monkeys at Takasakiyama in 1984, nine years after the start of restriction of artificial feeding, was examined externally and histologically and the results were compared with data obtained in 1971, when artificial foods were abundantly given. Spermatogenesis was not observed in any of the males under 4.5 years old in the present study, whereas it was noted in some premature 3.5-year-old males and in all males over 4.5 years old in the 1971 study. The age of sexual maturation thus rose by one or more years over the 13-year period from 1971 to 1984. The lag in sexual maturation of the males at Takasakiyama in 1984 could have been induced by the restriction of artificial feeding.  相似文献   

2.
OBJECTIVES--To evaluate the success of the south Powys hydatid control programme by analysis of trends in cystic disease in humans and sheep and dog infestation. DESIGN--A review of hospital admissions for human hydatid disease in 1984-90, abattoir prevalence surveys of hydatid cysts in adult sheep, arecoline acetarsol and coproantigen surveys of prevalence of Echinococcus infestation in dogs. SETTING--All hospitals in England and Wales, three abattoirs, and dog populations in mid ands south east Wales. SUBJECTS--Residents of England and Wales admitted to hospital between 1984 and 1990 with a new diagnosis of human hydatid disease (International Classification of Diseases (ICD), ninth revision, code 122) acquired in the United Kingdom. RESULTS--The average annual incidence of human hydatid disease in Powys, mid-Wales, fell from 3.9x10(-5) in 1974-83 to 2.3x10(-5) in 1984-90. Age specific incidence rates in Wales declined over this period only in children, and no cases occurred in children (<15 years) in Powys. Two Welsh children who lived in Gwent and mid-Glamorgan were infected. Prevalence of hydatid cysts in old sheep from south Wales declined during the control period, but in 1993 prevalence of cysts was 13%. Prevalence of E granulosus infestation was zero in the control area in 1993, but it was 2.4% in Powys dogs outside the control area in 1989 and 9.2% in dogs in Gwent in 1991. CONCLUSIONS--Human hydatid disease has been successfully controlled in south Powys but cystic echinococcosis is still endemic in sheep in mid-Wales, and there is a focus of infection in humans, sheep, and dogs in the bordering areas of Gwent and mid-Glamorgan. There is considerable potential for an upsurge in human cases if control measures are relaxed.  相似文献   

3.
JAN RYSER 《Journal of Zoology》1988,216(4):673-685
Growth and maturation in a Swiss population of Rana temporaria were studied in 1983 and 1984 by means of skeletochronology. Resting line (growth ring) diameters were used to back-calculate individual body sizes in previous years; these permitted establishment of an average growth curve and determination of individual ages and sizes at first reproduction. Growth was rapid up to maturation, but continued thereafter at a decreased rate. Males were larger than females at age two but females grew faster thereafter, causing sexual dimorphism in adult body sizes. Body size distributions for both years and for frogs recaptured and first captured in 1984 were established. Growth in immatures was positively, but in adults negatively correlated with body size, with considerable variation at all sizes. Individual adult sizes were positively correlated with body sizes at the end of the first year. Average individual age at first reproduction was 2.8 years in males and 3.1 years in females (range in both sexes two to four years). There is no evidence for a two-year-cycle of reproduction.  相似文献   

4.
In order to study temporal and spatial variation of environmental fluoride levels, we analyzed the mandibular bone fluoride content of 157 roe deer (age range: 1-11 years) from two industrialized regions (Ruhr area: n = 76, sampling period 1955-1998; area W of Cologne: n = 81, sampling period 1983 1998) in the federal state of North Rhine-Westphalia, Germany. Bone fluoride values (dry weight basis) ranged between 150 mg F/kg (2 year-old specimen taken in 1997) and 5724 mg F/kg (10 year-old specimen taken in 1957). In both study areas, a pronounced decline in mandibular bone fluoride concentrations occurred over the respective sampling periods. In consequence, bone fluoride content of animals (both study areas pooled) taken during the period 1990-1998 was significantly (P < 0.00001) lower than that of roe deer from the period 1955 1989, while the two animal groups did not significantly differ in age. These findings are regarded as indicative of a considerable reduction of fluoride deposition into the animals' habitats, due to effective emission control measures. Bone fluoride values for the period 1990-1998 in the roe deer from the Ruhr area significantly (P < 0.005) exceeded those of the individuals from the study area W of Cologne, while the difference in age between the two groups was not significant. In both study areas, a significant (P < 0.00001) positive correlation between age and mandibular bone fluoride content (Ruhr area: rs = 0.601; area W of Cologne: rs = 0.725) was found for animals taken during this period. The present study underscores the suitability of analyzing skeletal fluoride concentrations in wild roe deer in order to monitor the magnitude of environmental contamination by fluoride and thereby to assess the efficiency of measures taken to reduce fluoride emissions from industrial sources.  相似文献   

5.
OBJECTIVE--To reappraise the epidemiological findings reported by the Black Advisory Group concerning a possible excess of malignant disease, particularly of childhood acute lymphoid leukaemia and non-Hodgkin lymphomas, in the vicinity of the Sellafield nuclear installation, and to determine whether any excess of malignant disease had occurred among people aged 0-24 years in the area in the years after the Black report--that is, from 1984 to 1990. DESIGN--Calculation of incidence of cancer using data from population based cancer registries and special surveys. SETTING--England and Wales; county of Cumbria; county districts Allerdale and Copeland within Cumbria; Seascale ward within Copeland. SUBJECTS--All residents under the age of 75 years in the above areas, but with particular reference to those aged 0-24 years. MAIN OUTCOME MEASURES--Numbers of cases and incidence particularly of lymphoid leukaemia and non-Hodgkin lymphomas in those aged 0-24 years, but including other cancers and age groups. RESULTS--Previous reports of an increased incidence of cancer, especially of leukaemia, among those aged 0-24 years in Seascale during the period up to and including 1983 are confirmed. During 1984-90 there was an excess of total cancer among those aged 0-24 years. This was based on four cases including two cases of non-Hodgkin lymphoma but none of leukaemia. There was an increased, but nonsignificant, incidence of other cancers, based on two cases (one pinealoma and one Hodgkin''s disease) occurring among those aged 15-24 years during 1984-90. This was not observed in the younger age group or in previous years. For the immediately surrounding area--that is, the county districts of Allerdale and Copeland excluding Seascale and in the remainder of Cumbria--there was no evidence of an increased incidence of cancer among those aged 0-24 years in either period. CONCLUSIONS--During 1963-83 and 1984-90 the incidence of malignant disease, particularly lymphoid leukaemia and non-Hodgkin lymphomas, in young people aged 0-24 in Seascale was higher than would be expected on the basis of either national rates or those for the surrounding areas. Although this increased risk is unlikely to be due to chance, the reasons for it are still unknown.  相似文献   

6.
The aim of this study was to compare a series of X-rays from the mid-1990s with another taken in the mid-1980s in order to test the possibility that environmental causes affect the skeletal maturation. The first group of subjects included a total of 1,057 girls and 1, 055 boys participating in a project for Japan and China health research in 1986. The second group of subjects included a total of 382 girls and 629 boys participating in a project for bone mineral density research in 1996. The skeletal maturity score using the Tanner-Whitehouse 2-RUS method was used as the fundamental datum. This score was used to represent each group. The Wilcoxon's rank sum test was applied to examine the significance of the difference between the 1986 and the 1996 groups. The 1996 children had not matured more than the 1986 children; children in both groups reached the given scores at almost the same ages. In girls, there was little difference between the groups at 7 years of age, but it declined from 8 years of age onward. Some apparent differences arose at ages 14 and 15, but ceased by age 16 in girls. In boys, no differences were found in those aged from 7 to 17 years, except for 12-year-olds. We did not detect much of a difference in bone maturation between the 1986 and 1996 groups of children, and no differences in height during the same period. Our findings suggest that bone maturation reflects the secular trend in growth.  相似文献   

7.
A cross-sectional study was carried out to assess the growth of 780 children of both sexes, aged between 0-12 years, and living at two different areas in Ismailia, Egypt, with approximately similar socioeconomic standards. Based on a designed questionaire, the exposed group was formed of 390 children from the Abu Sultan area. They were chosen from families living within 50 meters nearby high voltage electric power lines. Another 390 children from the El-Sheikh Zayed area were chosen as the control group. Standard anthropometric measurements were carried out for each child. Plain X-ray was done on the hands of 200 randomly selected children from both groups (100 each) to assess their bone maturation. In the exposed group the weight was significantly decreased only at birth, while the circumferences of the head and chest as well as the height were significantly reduced at all studied ages. The radiological study revealed a significant delay in carpal bone ossification of the exposed children. In conclusion: Exposure to low frequency electromagnetic fields emerged from high voltage electric power lines increases the incidence of growth retardation of children. Isolating these power lines in a scientific way in order to shield both the magnetic and electric fields or removing them far away from the inhabitant areas is recommended.  相似文献   

8.
Fecundity, maturity and the relationship between growth and maturity of common wolffish Anarhichas lupus were studied in Icelandic waters. A total of 788 female common wolffish were sampled in two areas: one in the relatively warm sea west of Iceland and the other in the colder sea east of Iceland. No difference was detected in fecundity of common wolffish between areas. The time from the onset of the cortical alveolus stage until spawning, was on average, 10 years in the east and 8 years in the west area. Common wolffish in the east area reached cortical alveolus stage, on average, at a greater age but similar size compared to common wolffish in the west area. Similarly, common wolffish started spawning, on average, at greater age and larger size in the east than in the west area. Common wolffish grew faster in the west than in the east area. Spawning common wolffish grew faster than common wolffish at the cortical alveolus stage in both areas. The relationship between growth and maturity for common wolffish in Icelandic waters appeared to be related to temperature, characterized by fast growth and early maturation in the west and slower growth and delayed maturation in the east.  相似文献   

9.
Previous surveys of radiation therapy among the Life Span Study (LSS) population at the Radiation Effects Research Foundation (RERF) revealed that 1,670 (1.4%) of the LSS participants received radiation treatments before 1984. The data on therapeutic radiation doses are indispensable for studying the relationship between radiation treatments and subsequent cancer occurrences. In this study, the radiation treatments were reproduced experimentally to determine the scattered radiation doses. The experiments were conducted using a female human phantom and various radiation sources, including a medium-voltage X-ray machine and a (60)Co gamma-ray source. Doses were measured using thermoluminescence dosimetry and ionization chambers. Radiation doses were determined for the salivary glands, thyroid gland, breast, lung, stomach, colon, ovary and active bone marrow. The results have been used for documenting the organ doses received by patients in previous surveys. The contribution of therapeutic irradiation to the occurrence of chromosome aberrations was studied using data on doses to active bone marrow from both radiation treatments and atomic bomb exposures in 26 RERF Adult Health Study participants. The results suggest that radiation treatments contributed to a large part of their frequencies of stable-type chromosome aberrations. The therapeutic radiation doses determined in the present study are available for investigating the effects of therapeutic irradiation on the subsequent primary cancers among atomic bomb survivors who received radiation treatments.  相似文献   

10.
The breeding biology of the Lapland Bunting was studied in an area of central West Greenland during two contrasting seasons. In the delayed thaw of 1984, male birds arrived on the breeding grounds at the same time as in the more typical spring of 1979, but females delayed arrival by two weeks in 1984 compared with 1979. Mean clutch size was depressed in the latter year and declined through the season; breeding productivity was correspondingly reduced in 1984 compared to 1979. Egg and juvenile predation rates were similar for the two years. Nestlings grew as rapidly in 1984 as in 1979 despite an apparent reduction in detected ground-dwelling invertebrates known to form an important constituent of the nestling diet. Because they bred later in 1984, females tended to commence moult later in 1984 than 1979 but completed moult by early September in both years. Males also commenced moult later but completed earlier in 1984.  相似文献   

11.
R Kapoor 《Social biology》1991,38(3-4):242-248
The rates of fetal loss and family planning acceptance among Bhopal gas victims from 1984 to 1989 were compared to those of a control group. In all, 136 eligible women in the affected area and 139 women in the control area were interviewed. Care was taken to ensure that these women had conceived at least once during the previous five years. The The fetal loss rate among the gas-affected women was abnormally high (26.3 per cent) compared to that of women in the control area (7.8 per cent). Family planning acceptance in both areas was similar, with most women using permanent methods. In the case of temporary methods, the percentage of use was higher in the gas-affected area.  相似文献   

12.
城市住宅区作为城市生态系统重要的组成单元,其碳源汇对城市生态系统碳循环和碳平衡产生重要影响.本文采取案例分析、文献查阅、问卷调查等多种方法,获取关中地区城市住宅区CO2排放(碳源)与吸收(碳汇)数据,并分析其来源及空间分布情况.结果表明: 关中地区住宅区建材生产和改造更新过程CO2排放量最大;且建材类的CO2排放量远大于日常生活资料,仅有40%~52%碳排放发生在住宅区,其余发生在外围,呈现出碳源距离的空间波动性、成分的空间差异性以及圈层与分区分布.仅有9%~17%的碳排放可在住宅区内被吸收,外部空间被动承担大量碳汇功能,并显现为分层递变和空间分异.最后提出了碳源、碳汇空间管理技术和干预对策.
  相似文献   

13.
The spawning season of the tonguefish Syacium ovale (Günter 1864) was determined by an analysis of the distribution of preflexion stage larvae in the Gulf of California. The larvae were collected during eight oceanographic surveys between 1984 and 1987. The spawning of this species starts in early summer and ends at the beginning of fall, with the highest reproductive activity in mid summer. The central and southern regions of the Gulf are the most important reproductive area. Spawning is associated with high sea surface temperatures and low plankton biomass, both of which are characteristics of the tropical current that invades the study area during summer.  相似文献   

14.
The southern elephant seal population at Macquarie Island has undergone a serious decline since regular surveys were commenced in 1949. Approximately 2,900 cows and 250 bulls were counted in the isthmus study area during the 1985 breeding season. Comparisons with 20 other counts made in the same area between 1949 and 1984 showed that, although there was considerable fluctuation between the years, the number of seals ashore has dropped at an average rate of 2.1% per year, resulting in a net decrease of approximately 50% for both males and females. This is similar to the ratio of decline of elephant seal populations in the southern Indian Ocean. The census information from all major elephant seal populations was reviewed and it was concluded that there may be a common factor, or group of factors, acting to reduce the Macquarie Island and Indian Ocean populations, while the populations of the South Atlantic seem to be stable. Several potential explanations for these observations are advanced, but it is concluded that a greater knowledge of the ecology of the seals is needed if the declines are to be understood.  相似文献   

15.
The belugas ( Delpbinapterus leucas ) inhabiting the St. Lawrence estuary were freely hunted until 1979 and thereby much reduced in numbers. In the late 1970s concerns for their future, and for the effect of contaminants, habitat modification, and marine traffic, became acute, and they were declared "Endangered" in 1983.
The numerical progress of the population has been monitored since 1973 by continued sample surveys. Nine of 10 surveys were aerial, and of those 9, 7 used high-altitude aerial photography. Published indices of population size showed an average increase of about 17 belugas per year (SE = 4) and a 1995 smoothed value of about 650 (SE = 40) belugas. This apparent temporal trend might be open to question owing to slight variation in survey methods and in the area covered by different surveys, so factors were developed to correct for differences in survey coverage and in treatment of data and for the effect of hunting on population trajectory. Revised assessments of the population trajectory and of the present smoothed index value changed little as a result. A series of total-count surveys in 1987-1992 estimated a decline of about 6 belugas per year, and when they were combined with sample surveys flown in 1984-1995, an increase of 10 belugas per year was estimated and a 1995 standardized index of about 640 (SE = 43). It appeared that hunting in the 1970s could have consumed all of, perhaps even slightly more than, the potential for natural increase of this population.  相似文献   

16.
The occurrence, distribution, site fidelity, and school size of bottlenose dolphins (Tursiops truncatus) in the coastal waters of north San Diego County, California were assessed during a six-year boat-based photoidentification study. A total of 146 photographic surveys were conducted between January 1984 and December 1989. Dolphin schools were encountered on 79% of all surveys, and 2, 869 individuals were observed in 145 separate schools. Three-hundred seventy-three dolphins were individually identified. All schools were sighted within 1 km of shore, and more than two thirds of the schools were encountered in the southern half of the 32-km long study area. School size (mean = 19.8, SD = 18.40) and the number of dolphins encountered per survey (mean = 26.8, SD = 22.30) were highly variable. Low resighting rates of known individuals provided little evidence for longterm site fidelity. When our six-year photoidentification database was combined with previous data, 404 dolphins were identified in the study area from September 1981 to December 1989. Jolly-Seber population estimates during the 1984-1989 study period varied between 234 and 285. The combination of regular dolphin occurrence, low site fidelity by known individuals, and the continuous increase in the rate at which new dolphins were identified indicates that numerous different individuals were visiting the study area across and within years. The open California coastline differs in habitat structure and prey distribution from more protected study areas where bottlenose dolphins display site fidelity. These habitat differences may help to explain the observed intraspecific behavioral variability of this species.  相似文献   

17.
The kinetics of the maturation of B cells were studied in adult thymectomized, lethally irradiated, and bone marrow-reconstituted mice. The spleen cells of the recipients were taken at various intervals after transfer and cultured in vitro with trinitrophenylated sheep erythrocytes (TNP-SRBC). The cultures were supplemented with either allogeneic culture supernatant or educated T-cell helper activity. Appearance of functional B cells in the bone marrow inoculum was assessed by the number of hemolytic plaque-forming cells (PFC) on the fourth day of culture. In a parallel series the frequency of surface Ig-bearing cells was determined by using fluorescent rabbit anti-mouse Ig serum. When helped by allogeneic culture supernatants, differentiating bone marrow cells showed a slower rate of maturation into functional B cells than when helped by specifically educated T cells. But in both cases the recovery of responsiveness reached the same level (number of PFC/106 cells) as that of normal spleen cells 55 to 60 days after transfer. During the initial periods of recovery, bispecific PFC (reacting both to TNP and to native SRBC determinants) were detected regularly in numbers far exceeding their frequency in normal spleen cell cultures; in some experiments, the number of bispecific PFC amounted to as much as 30% of the total PFC, whereas, when the bone marrow cells completely recovered (sixtieth day), the frequency of bispecific PFC was similar to that found in normal spleen cell cultures. The number of surface Ig-bearing cells also reached a normal level after the fiftieth day following transfer. In general, the degree of functional maturation was better correlated with the cells bearing surface Ig in the shape of rings or caps, whereas the predominance of spot-bearing cells indicated immaturity of the population.  相似文献   

18.
《Journal of morphology》2017,278(7):884-895
A histological and morphometric analysis of human metacarpal and carpal anlagen between the 16th and 22nd embryonic weeks was carried out with the aim of studying the establishment of the respective anlage architecture. No differences in the pattern of growth were documented between the peripheral and central zones of the metacarpal epiphyses and those of the carpals. The regulation of longitudinal growth in long bone anlagen occurred in the transition zone between the epiphysis and the diaphysis (homologous to the metaphyseal growth plate cartilage in more advanced developmental stage of the bone). Comparative zonal analysis was conducted to assess the chondrocyte density, the mean chondrocyte lacunar area, the paired chondrocyte polarity in the orthogonal longitudinal and transverse planes, and the lacunar shape transformation in the metacarpal. In transition from epiphysis to diaphysis chondrocyte density decreased and mean lacunar area increased. No significant differences in the chondrocyte maturation cycle were observed between proximal/distal metacarpal epiphyses and the carpal anlagen. The number of paired chondrocyte oriented along the growth vector was significantly higher in both proximal/distal transition zones between epiphysis and diaphysis. Human metacarpals shared with experimental models (like mice and nonmammal tetrapods) an early common chondrocyte maturation cycle but with a different timing due to the slower embryonic and fetal developmental rate of human anlagen.  相似文献   

19.
A characteristic of African pre-transitional fertility regimes is large ideal family size. This has been used to support claims of cultural entrenchment of high fertility. Yet in Kenya fertility rates have fallen. In this paper this fall is explored in relation to trends in fertility norms and attitudes using four sequential cross-sectional surveys spanning the fertility transition in Kenya (1978, 1984, 1989 and 1998). The most rapid fall in the reported ideal family size occurred between 1984 and 1989, whilst the most rapid fall in the total fertility rate occurred 5 to 10 years later, between 1989 and 1998. Thus these data, spanning the fertility transition in Kenya, support the traditional demographic model that demand for fertility limitation drives fertility decline. These data also suggest that the decline in fertility norms over time was partly a period effect, as the reported ideal family size was seen to fall simultaneously in all age cohorts, and partly a cohort effect, as older age cohorts reporting higher ideal family sizes were replaced by younger cohorts reporting lower ideal family sizes. These data also suggest that a new fertility norm of four children may have developed by 1989 and continued until 1998. This is consistent with, and perhaps could have been used to predict, the stall in the Kenyan fertility decline after 1998.  相似文献   

20.
Integrated study of the functional state of the sympathoadrenal system and the adrenal cortex in children of both sexes aged 10–15 years. The study was conducted on the basis of the daily adrenaline, noradrenaline, 17-ketosteroid, and 17-oxycorticosteroid excretion values, which allowed certain synchrony to be established in the manifestation of the activity of the transmitter link of the sympathoadrenal system and the adrenal cortex androgenic and glucocorticoid functions with age, during sexual maturation. The heterogeneous character of maturation was found in the sex groups: in girls at an age of 10 and 12 years and in the boys at an age of 14–15 years. Changes in the excretion of the hormones and hormone metabolites with different directions and rates in the age-sex groups were observed throughout the academic year. In 14- to 15-year-old boys, a sharp increase in the daily excretion of the glucocorticoid metabolites accompanied by a substantial decrease in the age-related noradrenaline excretion values and the sex hormone metabolite values at an age of 15 years was observed. In the girls, these values varied within the age range, which indicates a more perfect character of the neuroendocrine regulation of their physiological functions in the period of sexual maturation.  相似文献   

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