黄山九龙峰保护区尖头的年龄、生长和繁殖

于2011年5月至2012年4月逐月采集标本, 对黄山九龙峰保护区尖头 (Phoxinus oxycephalus)的年龄、生长和繁殖等生活史特征进行了研究. 尖头 雌、雄鱼性比为0.77:1, 与1:1差异显著. 根据体长频率分布来确定年龄组成,结果显示雌鱼和雄鱼的最大寿命分别为3龄和2龄, 均以1龄和2龄为优势年龄组. 1龄时的体长生长速度最大, 至2龄或3龄逐渐变缓. 雌、雄鱼的初次性成熟年龄均为2龄, 对应体长分别为93.0 mm和76.9 mm. 尖头 繁殖时间为4-7月; 绝对繁殖力较低(174-2151卵粒), 且在2、3年龄组间显著差异, 但相对繁殖力无显著的年龄组间差异. 尖头 的上述生活史特征, 可能体现了对局域环境条件(如营养贫乏、环境动荡及水文周期等)的生态适应性. 尖头 在我国东南部的高海拔地区呈零星分布, 种群数量小, 加之繁殖投入低下, 因此该物种在面临人类干扰和环境变化时极易濒危和灭绝.       

Frequency shift in topography of spontaneous brain rhythms from childhood to adulthood

It has been described that the frequency ranges at which theta, mu and alpha rhythms oscillate is increasing with age. The present report, by analyzing the spontaneous EEG, tries to demonstrate whether there is an increase with age in the frequency at which the cortical structures oscillate. A topographical approach was followed. The spontaneous EEG of one hundredand seventy subjects was recorded. The spectral power (from 0.5 to 45.5 Hz) was obtained by means of the Fast Fourier Transform. Correlations of spatial topographies among the different age groups showed that older groups presented the same topographical maps as younger groups, but oscillating at higher frequencies. The results suggest that the same brain areas oscillate at lower frequencies in children than in older groups, for a broad frequency range. This shift to a higher frequency with age would be a trend in spontaneous brain rhythm development.     

Further studies on prevalence of hydatidosis in slaughtered animals from North Jordan

Examination of 471 sheep, 118 goats, 157 cattle and 56 camels slaughtered in abattoirs in North Jordan was carried out during March-May 1984. Drought conditions that prevailed during the preceding winter led to slaughtering old female sheep (greater than or equal to 4 years) due to scarcity of food, which allowed us to analyse the prevalence of hydatidosis in various age groups of sheep. An overall infection rate of 27.8, 1.7, 5.8 and 10.7 percent was found in sheep, goats, cattle and camels, respectively. The infection rate was as low as 1.5 percent in male and 1.9 percent in female sheep under 2 years of age. However, the rate of hydatid infection increased with age and reached as high as 63.7 percent in ewes 4 years of age and older. The percentage of animals with fertile cysts was also highest in sheep (68.7 percent of infected animals) and increased with age reaching 100 percent in ewes which were 10 years of age or older. Analysis of all cysts recovered from the livers and lungs of infected ewes from various age groups revealed a sharp increase in the mean total number of cysts in age groups over 8 years of age. The fertility rate of the cysts in the liver was significantly greater in ewes 6 years old or more (64.8--78.6 percent) than in younger age groups (8.7-46.2 percent). In the lung, the fertility rate increased progressively with age reaching as high as 97.9 percent in ewes 10 years old or more. These findings of high infection and fertility rates of hydatid disease in sheep, particularly of older age groups, prompt plans for further epidemiological studies and control programmes.     

A study of an outbreak of schistosomiasis in two resettlement villages near Abeokuta, Ogun State, Nigeria

Frequent reports of haematuria among resettlers at Ibaro and Abule-titun located close to a newly constructed reservoir, 20 km north-west of Abeokuta, Ogun State, Nigeria, prompted a pre-control survey to assess age and sex distribution of urinary schistosomiasis in the communities. 210 persons were examined at Ibaro and 145 at Abule-titun between April 1988 and February 1989. Overall prevalence was about 80% in both villages, and all age and sex groups examined were affected. The pattern of infection in both villages was similar, prevalence being high in all age and sex groups, and, unlike most endemic communities, the rate of infection was not significantly higher among the 5-14 year age groups. Intensity of infection was also high in all age and sex groups with mean range egg output of between 73 +/- 73 and 2016 +/- 3875 ova/10ml urine at Ibaro and between 231 +/- 122 and 1340 +/- 1786 ova/10ml urine at Abule-titun. This is attributed to an occupation-related high rate of human water contact in both villages.     

Parental age,birth order and tertiary sex ratio in the human population of Punjab,Pakistan

The data of this study, an extension of a previous study on secondary sex ratio in the human population of Muridke, Punjab, Pakistan, are based on the population of Muridke, 27 km north of Lahore, Punjab, Pakistan. Records of deaths of children, at later stages of birth, for different birth ranks, and that of maternal and paternal ages were made. 1000 families were scored for this study. Families providing the required information were included. Data for paternal age and maternal age combination consisted of 4807 total number of children of which 2586 were male. Paternal age and birth order combination was comprised of a total of 4405 children, containing 2316 males. Maternal age and birth order combination consisted of 4658 children, of which 2458 were males. The discrepancy in the number of children in the 3 types of combinations was due to the lack of required information in different groups. Sex ratio based on total number of males in relation to paternal age and maternal age was 0.54. Younger fathers (15-19 years) showed higher sex ratio (0.69). This dropped in paternal age groups 20-24 years (0.59) and 25-29 years (0.51). Younger mothers (15-19 years) showed higher sex ratio (0.62), declines in the age groups 20-24 years (0.52) and 25-29 years (0.51) and rise in age groups 35-39 years (0.55) and 40-44 years (0.54). Chi-square tests were carried out to compare the number of male and female offspring in the paternal age groups 15-19, 20-24, and 25-29 years. These showed highly significant deviation from the expected number. The higher age groups showed nonsignificant differences in the number of male and female offspring. Maternal age groups 15-19, 20-24, and 25-29 years showed highly significant differences in the male and female offspring and nonsignificant results in the higher age groups. Maternal age in relation to paternal age showed positive simple and partial correlations. Sex ratio for the total number of males based on paternal age and birth order was 0.52. 1st birth order showed higher sex ratio (0.55) and decreased in the 2nd (0.50) and 3rd birth orders (0.51), showed increase in the 4th birth order (0.53) and declines in the higher birth ranks. The number of male and female offspring in the birth orders 1, 2, and 3 showed significant differences, but in higher birth ranks the difference was insignificant. Paternal age and birth order indicated positive simple and partial correlations. Higher sex ratio (0.58) was seen in the 1st birth order and then it decreased in the 2nd (0.50) and 3rd (0.51) birth order. Chi-square tests carried out to compare the number of male and female offspring in borth orders 1, 2, and 3 showed highly significant differences but in higher birth ranks the difference was insignificant.     

A comparative study of % fat and living style on nepalese

Measurements of %Fat, nutrient intake and maximal aerobic power (MAP) were carried out on Nepalese to clarify the cause of obesity attended with modernization. One hundred thirty-two males (KV) who have a natural living style, 20-84 years of age, in rural district and 237 males who have a living style affected by the rapid urbanization, in surburban district were selected as subjects. The subjects of surburban district were divided into two groups. One of them included 147 farmers (BF) who engage in not mechanized farming, 20-73 years of age. Another group included 90 students and wage laborers (BNF) who go to and from Kathmandu (the capital of Nepal), 20-57 years of age. %Fat was estimated from skinfold thickness according to the method of Nagamine (1975). The survey for the nutrient intake was carried out by the 24-hour recall method to obtain the individual food consumption using the food models. Measurement of MAP was made indirectly by the modified of Margaria et al (1965). The main results are summarized as follows. 1) Mean %Fat and the appearance rates of obesity in each age group showed high values in following order: BNF greater than BF greater than KV. 2) Mean caloric intake in KV was higher than those in BF and in BNF an almost all age groups and no significant difference was found between BF and BNF in all age groups. 3) No significant differences in mean fat intake and in mean animal fat intake among all groups were found in almost all age groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of maternal age on the outcomes of in vitro fertilization and embryo transfer (IVF-ET)

This is a retrospective, observational study to evaluate the effect of maternal age on the outcomes of in vitro fertilization and embryo transfer (IVF-ET). 11830 IVF-ET cycles from 10268 women were included. Four groups of different maternal age periods were compared. The groups were 21?C30 years old group (4549 cycles), 31?C35 years old group (4424 cycles), 36?C40 years old group (2429 cycles), and over 40 years old group (428 cycles). The mean starting dose of Gn and mean total dose of Gn in each cycle were significantly higher (P<0.01), while the mean retrieved oocyte number was significantly lower (P<0.01) in groups of higher maternal age period than those in each of the lower groups. The biochemical pregnancy rate and the clinical pregnancy rate were significantly lower (P<0.01), while the miscarriage rate was significantly higher (P<0.01) in groups of higher maternal age period than those in the lower groups. No difference was found in two-pronuclear zygotes (2PN) rate and good quality embryo rate among different groups. Birth defect rate was also comparable in the born babies in different groups. In the group with patients?? age over 40 years old, the pregnancy rate was 26.87%, the clinical pregnancy rate was 19.39%, while the miscarriage rate after clinical pregnancy was 36.14%. To draw the conclusion, patients with higher maternal age had worse IVF outcomes. In women of fertile age, patients between 20 and 30 years old have the best IVF outcomes. Patients over 40 years old have poor IVF outcome and high miscarriage rate, which suggested the necessity of preimplantation genetic screening (PGS).     

Uncertainties in age- and gender-based health risk assessment for recreational bathing: Arsenic in Del Azul stream,Argentina

The aim of this study was to assess the risk associated with recreational bathing at Del Azul stream, Argentina, a water course naturally containing Arsenic. It represents a case study on the carcinogenic risk for bathers and on how the risk varies among age groups and genders, analyzing the uncertainties of the model input variables and the risk quantification technique. The risk was probabilistically estimated with the 2D Monte Carlo method considering four age groups (5, 10, 15, and 20 years old) and separate exposure routes: accidental water intake, skin contact, and the two combined. Although in all the studied groups the risk levels were within safety limits, differences in risk values were observed among age groups and genders. Accidental water intake during bathing was the most risky exposure route. The risk decreased with age and it was higher in males than in females, with larger differences between the two older age groups. This could be attributed to the difference in the accidental water intake rate associated with the daily duration of the bathing event, which varied according to age and gender.     

Detection of Porcine Parvovirus 2 (Ungulate Tetraparvovirus 3) Specific Antibodies and Examination of the Serological Profile of an Infected Swine Herd

Porcine parvovirus 2 (PPV2) is a member of a recently discovered group of swine parvoviruses occurring worldwide. It is frequently detected in lung samples suggesting some pathological role of the virus in diseases. To study this possibility an indirect ELISA was developed to detect PPV2 specific antibodies and to examine the serological profile of an infected swine herd where 185 serum samples collected from different age groups including sows were analyzed. According to the results maternal antibody levels decreased until 14 days of age and PPV2 specific antibodies started to rise between 28 to 43 days of age when respiratory signs were also observed in the examined swine herd. At 57 days of age the clinical signs disappeared and a rapid increase of PPV2 specific antibody levels could be measured simultaneously, peaking at 57 days of age. The viraemic status of different age groups was determined by qPCR using serum samples. At least a low level of viraemia was measured in every age group, but higher copy number of PPV2 was only detected at 57 days of age and the level decreased in older age groups. The changes in virus load and antibody levels together with the onset and decrease of clinical signs suggested that PPV2 had a role in the development of respiratory signs.     

Cardiovascular load assessment of coal mine shovelers in west Bengal, India: a comparison between middle age groups

Cardiovascular load of underground shovelers was assessed in terms of heart rate changes at work in haulage coalmines. Twenty underground shovelers of two different age groups (those of age 31-39 and those of age 40-49) served as subjects. Working heart rate was significantly higher (p < 0.01) in the older group (138.2 beats/min) than in the younger group (130.4 beats/min). Though the net cardiac cost did not differ significantly between the groups (64.8 beats/min and 69.4 beats/min in younger and older groups, respectively), difference in the relative cardiac cost (54.17% and 64.86% in younger and older groups, respectively) proved to be highly significant (p < 0.001). The heart rate up to the third minute of recovery showed significant differences between the groups (p < 0.01). While analysis of physiological responses indicated that the task was very strenuous irrespective of age, cardiac strain was found to be more excessive in the older subjects if continued. The arduous nature of the working environment in the coalfaces was also reported.     

Seroepidemiology of Helicobacter pylori infection in Greece

Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.4% of children aged 1-10 years, 67.1% of recruits (20-27 years) and 70% of blood donors (20-50 years). The prevalence of antibodies did not differ with sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in western Europe.     

野生和人工养殖辽宁中国林蛙肥满度和重/长指标的初步研究

对野生和养殖中国林蛙肥满度和重/长指标的研究表明,辽宁野生中国林蛙肥满度(K)在雌性中无年龄差异,在雄性则亚成年和成年蛙组间有显着差异;性别差异只在成年蛙组间出现。重/长指标(K_wl)均随年龄的增加而显着提高,且在不同年龄组间均有性别差异。1龄家养中国林蛙K无性别差异,K_wl有性别差异。养殖蛙K_wl显着高于同性同龄野生蛙,K无显着差异。K_wl比K更灵敏,二者结合对两栖类肥满度进行研究较合理。     

半散放猎豹毛发微量元素含量比较

许多微量元素与动物生理生化机能有着密切的联系,对机体的生长发育和维持健康起着重要作用.近年来,微量元素研究日渐得到重视,如Cu、 Zn、 Mn、 Se、 Pb等微量元素参与酶、激素和维生素代谢,影响动物生殖功能(Suchocki et al., 2003).     

Comparison of potential markers of the biological age of healthy male adults and paraplegics

The actual level of the true aging of an organism is characterized by its biological age. By the means of measuring the function ability of its physiological systems, it is possible to evaluate the biological age and use it as an indicator of premature aging. Inclusion of the biological age screening among the basic health precautions should offer yet another viewpoint on how to objectively measure the changes in an organism corresponding to aging. The article presents a comparison of age dependency of selected biomarkers between groups of healthy men and paraplegics. The measurement of the battery of biomarkers was run in a group of 25 healthy male adults between 36 and 54 years of age. The second group was formed by 20 paraplegics - men between 33 and 50 years of age. In spite of small size of the groups, significant differences were found in 4 of 6 biomarkers.     

The dynamics of the ectoparasite count and the protein level in the blood serum of infested carp under experimental conditions

Carps of one and two years age used for laboratory experiments were collected in winter time. 7 groups of carps of one year age were examined each 10th day during 70 days and 5 groups of two years age were examined each 15 days during 75 days. In carps of one year age the increase of different parasites was observed in different time: Dactylogyrus extensus--after 40 and 70 days, Icthyophthirius multifiliis--after 50 days, Trichodina sp.--after 60 days. In carps of two years age the increase of all parasite groups observed after 45 days, extremely great number of D. extensus was recorded after 60-70 days. Contents of proteins in a blood plasma of both age groups of carps is reliably decreased when the number of parasites is increased. Fluctuations of parasite abundance on the body and gills and some morphophysiological indices in carps of one year age in a control and in conditions of starvation were examined.     

Seroepidemiology of Helicobacter pylori infection in Greece

Abstract Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylrori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.49% of children aged 1–10 years, 67.1% of recruits (20–27 years) and 70% of blood donors (20–50 years). The prevalence of antibodies did not differ iwth sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in Western Europe.     

The refractory responses of the White Swiss strain of Mus musculus to infection with Taenia taeniaeformis

Penetration of intestinal mucosa by oncospheres of Taenia taeniaeformis occurred among three age groups of White Swiss Mus musculus. Highest frequency of penetration was demonstrated among the 10–30 day-old group with the other two older groups, 40–60 and 70–100 days, each having succeedingly less penetration. The invasion process was more cytolytic than ground substance lysis; no difference in this process, or the reaction of the villi to it, was detected among the various age groups. Liver reaction, displayed by the same three age groups against larvae of T. taeniaeformis, was age dependent. Disorganization, loss of larval tissue integrity, and formation of a non-cellular capsule were demonstrated within 48 h in the 10–30 day group, while a rapid cellular response of inflammation and walling-off of larvae was seen in the 40–60 day group. No larvae were observed in the 70–100 day group.     

Incidence of multinucleated and polyploid aortic smooth muscle cells cultured from different age groups of spontaneously hypertensive rats.

Cell size and incidence of multinucleated, polyploid cells in cultured aortic smooth muscle cells from different age groups of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) were compared. Smooth muscle cells from SHR were generally larger than those from WKY, and the percentage of multinucleated smooth muscle cells was always higher in SHR than WKY in the three age groups of rats studied (3-4, 10-12, and 28-30 weeks). In smooth muscle cells from the 3- to 4-week group, there was a positive correlation between cell diameter and the percentage of multinucleated smooth muscle cells. Microdensitometric measurements also showed that the incidence of polyploid smooth muscle cells was always higher in SHR than WKY in the three age groups. There was a positive correlation between DNA density and nuclear area measurements in all the age groups of SHR and WKY. We conclude that cultured aortic smooth muscle cells from different age groups of SHR and WKY contained heterogeneous populations of cells and that, under our culture conditions, the polyploidy of the smooth muscle cells found in vivo was maintained in the SHR and WKY.     

A factor analysis of cranial base and vault dimensions in children

Lengths within the cranial base and vault were measured in cephalometric radiographs of 220 boys and 177 girls ranging in age from 0 to 15 years; all these children are participants in The Fels Longitudinal Growth Study. The present study is based on mixed longitudinal data derived from 1640 radiographs for boys and 1260 radiographs for girls. Factor analysis was applied separately for boys and girls for each age group; i.e., 0–3, 4–6, 7–9, 10–12, and 13–15 years. For the 0–3 year age group, two factors were extracted in each sex, whereas four factors were extracted in the rest of the age groups. The factor structures are similar in the three older age groups of boys (7–9, 10–12, and 13–15 years). The first four factors for these groups are labelled, respectively: cranial vault size, posterior cranial base length, presphenoid length, and basisphenoid length. The order of the third and fourth factors is reversed in the 7–9 year olds. For girls, the factors extracted were also the same in both the 7–9 and 10–12 year age groups, even though the order of factors was different between age groups; i.e., anterior cranial base length, cranial vault size, basisphenoid length, and basioccipital length. Differential growth rates among cranial base dimensions probably cause changes in factor patterns. Obliteration of the spheno-occipital synchondrosis is suggested as the mechanism responsible for the change of factor pattern in the girls. Closure of this synchondrosis would have occurred too late to affect the patterns in boys.     

Determinants of isometric muscle strength in men of different ages

Values of maximal isometric strength of five muscle groups and associated factors including occupational status, life style and health were studied in three groups of men aged from 31 to 35, 51 to 55, and 71 to 75 years. The results indicated significant differences between the age groups in isometric handgrip, elbow flexion, knee extension, trunk extension and trunk flexion strength. In the youngest group, the manual workers tended to have higher strength values in all muscle groups than the lower and higher status white collar workers; whereas among the middle-aged and oldest men the manual workers tended to have the poorest performance. Good self-rated health and the intensity of physical exercise during leisure were positively associated with muscle strength in the youngest and middle-aged groups whereas in the oldest group the most important variable was home gymnastics. The multivariate structural equation models of isometric strength differed somewhat among the age groups and in these models the above-mentioned variables accounted for from 33% to 43% of the variance in isometric strength within the age groups. The results illustrated the most important factors associated with isometric strength in samples of men of different ages and also provided suggestions as to how these determinants might influence comparisons between different age groups in respect of muscle strength.