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1.
As a result of large-scale nuclear tests on the Novaya Zemlya test site (1955-62) the Tundra Nentsy population of Yamal-Nentsy autonomous region (YNAR) fell under the constant influence of incorporated radioactive isotopes (137Cs and 90Sr). Therefore, it is very important to analyze a possible spectrum of diseases of Tundra Nentsy population.  相似文献   

2.
As a result of large-scale nuclear explosion on Novaya Zemlya test site (1955-62) the Tundra Nentsy population of Yamal-Nentsy autonomous region (YNAR) fell under constant influence of incorporated radioactive isotopes (137Cs and 90Sr). Therefore, it is very important to analyze a possible spectrum of diseases of Tundra Nentsy population. We have developed recently a new method for determination of concentrations of all main fraction and subfraction of lipoproteins (LP, 30 parameters) in human sera using small-angle X-ray scattering, and a general mathematical model to describe LP composition in human blood. The analysis of the 30 parameters characterizing fine spectrum of LPs in 374 YNAR natives showed that only approximately 10% of the donors are normal, while the indices for approximately 90% of the test subjects fall into the range of different pathologies (3-8% incidence in normal population, according to epidemiological studies). Moreover, we found that approximately 41% of European and approximately 56% of Tundra Nentsy have high level of autoantibodies to DNA and cardiolopine like the same for autoimmune diseases patients.  相似文献   

3.
Using the data on five red cell markers (AB0, PGM1, ACP1, GLO1, and ESD) polymorphisms, the population genetic structure of three ethnic territorial groups from the north of European Russia (Continental Nentsy, Kola Saami, and Russian Coast-dwellers) was described. In general, the groups studied a Caucasoid pattern of the frequency distribution of erythrocytic marker alleles. However, a substantial contribution of a Mongoloid component to the Nenets gene pool, expressed as a high frequency of the PGM1*1allele along with a low frequency of the GLO1*1allele, was observed. Three ethnic territorial groups examined were close to one another with respect to the distribution of classical biochemical markers. The interpopulation diversity was low (the mean F ST= 0.015). The differences observed were for the most part caused by the genetic characteristics of Nentsy. The maximum interpopulation diversity was observed for the GLO1*locus (F ST= 0.056).  相似文献   

4.
The marriage structure of Nganasans during the time period from 1796 to 1991 and genealogy of carriers of mitochondrial DNA haplotypes was studied in a sample of 280 individuals. It was shown that, from the beginning of its formation to the late 1970s, the population exhibited high endogamy (1976, 83.8%; 1926, 88.4%; 1976, 74.3%). The main source of traditional marriage migration (preferentially female) was populations of Entsy and, indirectly, Nentsy. Intense assimilation of Nganasans by the immigrant population, and to a lesser extent, by Dolgans, in the second half of the 20th century resulted in a reduction of endogamy index in Avam Nganasans to 42.5% by 1991. Assimilation by the immigrants was predominantly paternal, promoting preservation of the historically formed genetic diversity of the Nganasan mitochondrial gene pool. Genealogical analysis of mtDNA haplotypes showed that a relatively high total frequency of Western Eurasian mtDNA haplogroups (20.4%) in the Mongoloid (according to anthropological type) Nganasan population is explained not only by the common ethnic origin with Entsy and Nentsy, but also by direct marriage migration from the Entsy population and indirect marriage migration, from the Nentsy population. This migration led to accumulation of Entsy-Nentsy maternal lineages in the genealogy of Avam Nganasans (38.9% of the total number). Of all mtDNA haplotypes, 28.6% were introduced to Avam Nganasans by female Entsy and Nentsy, whereas the total frequency of these haplotypes was 0.204. Genetic diversity of mitochondrial DNA haplotypes was 0.935.  相似文献   

5.
The marriage structure of Nganasans during the time period from 1796 to 1991 and genealogy of carriers of mitochondrial DNA haplotypes was studied in a sample of 280 individuals. It was shown that, from the beginning of its formation to the late 1970s, the population exhibited high endogamy (1976, 83.8%; 1926, 88.4%; 1976, 74.3%). The main source of traditional marriage migration (preferentially female) was populations of Entsy and, indirectly, Nentsy. Intense assimilation of Nganasans by the immigrant population, and to a lesser extent, by Dolgans, in the second half of the 20th century resulted in a reduction of endogamy index in Avam Nganasans to 42.5% by 1991. Assimilation by the immigrants was predominantly paternal, promoting preservation of the historically formed genetic diversity of the Nganasan mitochondrial gene pool. Genealogical analysis of mtDNA haplotypes showed that a relatively high total frequency of Western Eurasian mtDNA haplogroups (20.4%) in the Mongoloid (according to anthropological type) Nganasan population is explained not only by the common ethnic origin with Entsy and Nentsy, but also by direct marriage migration from the Entsy population and indirect marriage migration, from the Nentsy population. This migration led to accumulation of Entsy-Nentsy maternal lineages in the genealogy of Avam Nganasans (38.9 in 2000 of the total number). Of all mtDNA haplotypes, seven (of 21) were introduced to Avam Nganasans by female Entsy and Nentsy, whereas the total frequency of these haplotypes was 0.204. Genetic diversity of mitochondrial DNA haplotypes was 0.935.__________Translated from Genetika, Vol. 41, No. 7, 2005, pp. 954–965.Original Russian Text Copyright © 2005 by Goltsova, Osipova, Zhadanov, Villems.  相似文献   

6.
Procedure is described to estimate allele frequencies in indigenous populations of Siberia using phenotype data not only for pure-blood representatives of the ethnic groups examined, but also for the descendants of mixed marriages. Implementation of the method requires reconstruction of the pedigree structure for the sample examined. Inclusion of the data on descendants of mixed marriages into the analysis increases the sample information content and decreases variance of the estimates obtained. The advantages of the method are illustrated using an example of Tundra Nentsy, for whom it was shown that variance of estimates at the analysis of the blood groups allele frequencies can be diminished approximately by a factor of 1.5.  相似文献   

7.
Procedure is described to estimate allele frequencies in indigenous populations of Siberia using phenotype data not only for "pure-blood" representatives of the ethnic groups examined, but also for the descendants of mixed marriages. Implementation of the method requires reconstruction of the data on relatives for the sample examined. Inclusion of the data on descendants of mixed marriages into the analysis increases the sample information content and decreases variance of the estimates obtained. The advantages of the method are illustrated using an example of Tundra Nentsy, for whom it was shown that variance of estimates at the analysis of the blood groups allele frequencies can be diminished approximately by a factor of 1.5.  相似文献   

8.
鄱阳湖是小天鹅(Cygnus columbianus)和白鹤(Leucogeranus leucogeranus)极为重要的越冬地,它们均主要以沉水植物苦草(Vallisneriaspp.)冬芽为食,且通过觅食空间生态位分化减少种间竞争。近年来,鄱阳湖苦草冬芽锐减导致大量小天鹅和白鹤由自然生境转移到南昌五星白鹤保护小区的藕塘觅食。大量小天鹅和白鹤集中在小片藕塘觅食可能导致种间竞争强度增加。因此,本研究以五星白鹤保护小区藕塘为研究地点,于2021年11月10日至25日,采用瞬时扫描法和焦点动物法调查了藕塘与白鹤混群和不与白鹤混群时小天鹅的日间行为、单次取食时间和每分钟摄食成功频次,并采用单因素方差分析或Mann-WhitneyU检验对数据进行统计分析。结果表明,小天鹅日间行为主要以觅食(45.59%)、运动(17.05%)和休息(15.92%)为主。小天鹅和白鹤混群时的觅食行为比例和单次觅食时间显著高于不混群时,表明小天鹅主要通过增加觅食时间以应对种间竞争的负面影响,满足能量需求。小天鹅混群时的每分钟摄食成功频次显著高于不混群时,这可能是由于小天鹅通过摆动脚蹼或者扁平喙啄食的方式较难取食...  相似文献   

9.
From 1987 to 1989 we monitored population changes during summer of the collared lemming (Dicrostonyx groenlandicus) and the tundra vole (Microtus oeconomus) at Pearce Point, Northwest Territories, Canada (69° 48 N, 122° 40 W). Populations on four study areas did not cycle but remained at low density (<3/ha) each year and continued at low numbers for the following 3 years (Reid et al. 1995). Lemming numbers often declined throghout the summer in spite of continous reproduction, and population recovery occurred overwinter. Heavy predation losses of radio-collared lemmings occurred each summer and this lemming population may be trapped in a predator-pit. Collared lemmings breed in winter and only because of winter population growth do these populations persist. Tundra vole numbers increased rapidly in most summers but usually declined overwinter. Tundra voles do not seem able to sustain winter reproduction in this extreme environment and this prevents them from reaching high density because of the short summer. Population growth in both these rodents could be prevented by poor food or by predation losses, and landscape patchiness may also help to prevent population growth. For lemmings we do not think that a shortage of shelter or intrinsic limitations could be restricting population increase at Pearce Point. This is the first detailed study of a non-cyclic collared lemming population.  相似文献   

10.
Variability in the fore wing length and in the number and arrangement of eye-spots on the wings of Erebia jeniseiensis from the local population newly found in the Bolshezemelskaya Tundra is described.  相似文献   

11.
The first study on the frequencies of polymorphic variants of the GSTP1 gene encoding glutathione-S-transferase P1 in Tundra Nenets and Nganasan populations was performed. The subject of the study was the single nucleotide polymorphisms rs1695 (Ile105Val substitution in the protein sequence) and rs1138272 (Ala114Val substitution) that had previously been shown to be associated with cancer and other multifactorial diseases. The data for Tundra Nenets of the Yamalo-Nenets autonomous okrug, Nganasans of the Taimyr Peninsula, and Russian residents of the Northern Siberia were compared. The frequencies of the mutant 105Val and 114Val variants were 10.8% and 0.8% in Nganasans, 23.7% and 4.8% in Nenets, and 35.8% and 9.1% in Russian population samples, respectively. The differences within all pairs of populations were significant for each allele. These differences may characterize the population-level susceptibility to cancer and other multifactorial diseases.  相似文献   

12.
Using the data on five red cell markers (AB0, PGM1, ACP1, GLO1, and ESD) polymorphisms, the population genetic structure of three ethnic territorial groups from the north of European Russia (Continental Nentsy, Kola Saami, and Russian Coast-dwellers) was described. In general, the groups studied a Caucasoid pattern of the frequency distribution of erythrocytic marker alleles. However, a substantial contribution of a Mongoloid component to the Nenets gene pool, expressed as a high frequency of the PGM1*1 allele along with a low frequency of the GLO1*1 allele, was observed. Three ethnic territorial groups examined were close to one another with respect to the distribution of classical biochemical markers. The interpopulation diversity was low (the mean FST = 0.015). The differences observed were for the most part caused by the genetic characteristics of Nentsy. The maximum interpopulation diversity was observed for the GLO1 locus (FST = 0.056).  相似文献   

13.
A significant quantitative trait locus (QTL) for low‐density lipoprotein cholesterol (LDL‐C) and total cholesterol (TC) was identified around the LDLR gene on chromosome 2 (SSC2) in a White Duroc × Erhualian F2 resource population and Sutai pigs in our previous study. However, in previous reports, the causality of LDLR with serum lipids is controversial in pigs. To systematically assess the causality of LDLR with serum lipids, association analyses were successively performed in three populations: Sutai pigs, a White Duroc × Erhualian F2 resource population and a Duroc × (Landrace × Large White) population. We first performed a haplotype‐based association study with 60K SNP genotyping data and evidenced the significant association with LDL‐C and TC around the LDLR gene region. We also found that there is more than one QTL for LDL‐C and TC on SSC2. Then, we evaluated the causalities of two missense mutations, c.1812C>T and c.1520A>G, with LDL‐C and TC. We revealed that the c.1812C>T SNP showed the strongest association with LDL‐C (= 5.40 × 10?11) and TC (= 3.64 × 10?8) and explained all the QTL effect in Sutai pigs. Haplotype analysis found that two missense SNPs locate within a 1.93‐Mb haplotype block. One major haplotype showed the strongest significant association with LDL‐C (= 4.62 × 10?18) and TC (= 1.06 × 10?9). However, the c.1812C>T SNP was not identified in the White Duroc × Erhualian intercross, and the association of c.1520A>G with both LDL‐C and TC did not achieve significance in this F2 population, suggesting population heterogeneity. Both missense mutations were identified in the Duroc × (Landrace × Large White) population and showed significant associations with LDL‐C and TC. Our data give evidence that the LDLR gene should be a candidate causative gene for LDL‐C and TC in pigs, but heterogeneity exists in different populations.  相似文献   

14.
Effect of sowing date on the optimum plant density of winter wheat   总被引:2,自引:0,他引:2  
Pressure on financial margins in UK wheat production is driving a review of all inputs, and seed represents one of the largest financial inputs in wheat production. The potential savings through exploiting the crop's ability to compensate for reduced population are, therefore, attractive. Field experiments were carried out at ADAS Rosemaund (Herefordshire, UK) in 1996/97, 1997/98 and 1998/99 to investigate the effect of sowing date on dry matter growth and yield responses of winter wheat to reduced plant population. There were three target sowing dates (late‐Septembr, mid‐October and mid‐November), six seed rates (20, 40, 80, 160, 320 and 640 seeds m?2) and four varieties (Cadenza, Haven, Soissons and Spark). Grain yield was significantly affected by plant population with a mean reduction from 9.2 to 5.5 t ha?1 as plant number was reduced from 336 to 13 m?2. In addition, there was a significant interaction between plant density and sowing date. There was, however, no interaction between variety and plant population in terms of yield, except when lodging affected high plant populations of lodging susceptible varieties. The experiments demonstrated scope for reducing plant populations below the current target of 250–300 plants m?2; however, the degree of reduction was dependent on sowing date. Over the three years, the average economic optimum plant density was 62 plants m?2 for late‐September, 93 plants m?2 for mid‐October, and 139 plants m?2 for mid‐November sowings. Compensation for reduced population was due to increased shoot number per plant, increased grain number per ear and to a lesser extent increased grain size. Higher economic optimum plant densities at later sowing dates were due to reduced tiller production and hence ear number per plant. The other compensatory mechanisms were unaffected by sowing date.  相似文献   

15.
The rockhopper penguin (Eudyptes chrysocome) is a conspicuous apex marine predator that has experienced marked population declines throughout most of its circumpolar breeding distribution. The cause(s) for the declines remain elusive, but the relatively large spatio‐temporal scale over which population decreases have occurred implies that ecosystem‐scale, at‐sea factors are likely to be involved. We employ stable isotope analyses of carbon (13C/12C, expressed as δ13C) and nitrogen (15N/14N, δ15N) in time‐series of rockhopper penguin feather samples, dating back to 1861, in order to reconstruct the species' ecological history. Specifically, we examine whether rockhopper penguin population decline has been associated with a shift towards lower primary productivity in the ecosystem in which they feed, or with a shift to a diet of lower trophic status and lower quality, and we use long‐term temperature records to evaluate whether shifts in isotope ratios are associated with annual variations in sea surface temperature. Having controlled temporally for the Suess Effect and for increases in CO2 concentrations in seawater, we found that overall, δ13C signatures decreased significantly over time in rockhopper penguins from seven breeding sites, supporting the hypothesis that decreases in primary productivity, and hence, carrying capacity, for which δ13C signature is a proxy, have been associated with the decline of penguin populations. There was some evidence of a long‐term decline in δ15N at some sites, and strong evidence that δ15N signatures were negatively related to sea surface temperatures across sites, indicative of a shift in diet to prey of lower trophic status over time and in warm years. However, a site‐by‐site analysis revealed divergent isotopic trends among sites: five of seven sites exhibited significant temporal or temperature‐related trends in isotope signatures. This study highlights the utility of stable isotope analyses when applied over relatively long timescales to apex predators.  相似文献   

16.
Tundra‐atmosphere exchanges of carbon dioxide (CO2) and water vapour were measured near Daring Lake, Northwest Territories in the Canadian Low Arctic for 3 years, 2004–2006. The measurement period spanned late‐winter until the end of the growing period. Mean temperatures during the measurement period varied from about 2 °C less than historical average in 2004 and 2005 to 2 °C greater in 2006. Much of the added warmth in 2006 occurred at the beginning of the study, when snow melt occurred 3 weeks earlier than in the other years. Total precipitation in 2006 (163 mm) was more than double that of the driest year, 2004 (71 mm). The tundra was a net sink for CO2 carbon in all years. Mid‐summer net ecosystem exchange of CO2 (NEE) achieved maximum values of ?1.3 g C m?2 day?1 (2004) to ?1.8 g C m?2 day?1 (2006). Accumulated NEE values over the 109‐day period were ?32,?51 and ?61 g C m?2 in 2004, 2005 and 2006, respectively. The larger CO2 uptake in 2006 was attributed to the early spring coupled with warmer air and soil conditions. In 2004, CO2 uptake was limited by the shorter growing season and mid‐summer dryness, which likely reduced ecosystem productivity. Seasonal total evapotranspiration (ET) ranged from 130 mm (2004) to 181 mm (2006) and varied in accordance with the precipitation received and with the timing of snow melt. Maximum daily ET rates ranged from 2.3 to 2.7 mm day?1, occurring in mid July. Ecosystem water use efficiency (WUEeco) varied slightly between years, ranging from 2.2 in the driest year to 2.5 in the year with intermediate rainfall amounts. In the wettest year, increased soil evaporation may have contributed to a lower WUEeco (2.3). We speculate that most, if not all, of the modest growing season CO2 sink measured at this site could be lost due to fall and winter respiration leading to the tundra being a net CO2 source or CO2 neutral on an annual basis. However, this hypothesis is untested as yet.  相似文献   

17.
Mitochondrial DNA (mtDNA) sequences were analyzed from 106 bowhead whale (Balaena mysticetus) specimens dating 471 ± 44 14C b.p. –10,290 ± 150 14C b.p. to evaluate whether historical changes in distribution and connectivity were detectable in levels of diversity and population structuring in the Central Canadian Arctic. The species has maintained levels of mtDNA diversity over 10,000 yr comparable to other nonbottlenecked large whale species. When compared to data from the Holocene East Greenland/Spitsbergen and contemporary Bering‐Chuckchi‐Beaufort populations, differentiation was low (FST≤ 0.005, ΦST≤ 0.003) and no temporal or geographical genetic structuring was evident. A combination of analyses suggests that the population has expanded over the past 30,000 14C yr. This genetic signature of expansion could result from population growth, admixture of multiple gene pools, or a combination of both scenarios. Despite known climatic change that altered bowhead distribution and led to isolation of populations, there is no detectable population structuring or change in genetic diversity during the Holocene. This may be due to long generation time, occasional population connectivity and a historically large global population. These characteristics warrant caution when interpreting contemporary bowhead whale DNA data, as it is unlikely that any population will be in mutation‐drift equilibrium.  相似文献   

18.
Bmi‐1 gene is well recognized as an oncogene, but has been recently demonstrated to play a role in the self‐renewal of tissue‐specific stem cells. By using Bmi‐1GFP/+ mice, we investigated the role of Bmi‐1 in cardiac stem/progenitor cells and myocardial repair. RT‐PCR and flow cytometry analysis indicated that the expression of Bmi‐1 was significantly higher in cardiac side population than the main population from CD45?Ter119?CD31? heart cells. More Sca‐1+ cardiac stem/progenitor cells were found in Bmi‐1 GFPhi subpopulation, and these Bmi‐1 GFPhi heart cells showed the potential of differentiation into SMM+ smooth muscle‐like cells and TnT+ cardiomyocyte‐like cells in vitro. The silencing of Bmi‐1 significantly inhibited the proliferation and differentiation of heart cells. Otherwise, myocardial infarction induced a significantly increase (2.7‐folds) of Bmi‐1 GFPhi population, mainly within the infarction and border zones. These preliminary data suggest that Bmi‐1hi heart cells are enriched in cardiac stem/progenitor cells and may play a role in myocardial repair.  相似文献   

19.
The Sulawesi black macaque (Macaca nigra) population at Tangkoko Nature Reserve in North Sulawesi, Indonesia has been the focus of periodic study for over 30 years. The population has shown considerable decline during much of that time. Here we present the results of a long‐term population survey of the Tangkoko M. nigra, conducted over the past decade, to provide updated information and on‐going assessment of the population. Line‐transect sampling was conducted annually from 1999 to 2002 and 2005 to 2011 along the same transect during a 2‐ to 3‐week survey period. Although further decline in the population was observed at the outset of the survey, over the subsequent 12‐year period we have seen stability in the population parameters with evidence of modest increases in both group and population density. During the 1999–2002 survey periods, there was a mean group density of 3.6 groups/km2 and a mean population density of 39.8 individuals/km2. During 2005–2011, mean group density increased to 3.8 groups/km2 and mean population density was 51.4 individuals/km2. The 2011 survey data indicated an estimated group density of 4.3 groups/km2 and a population density of 61.5 individuals/km2. Given that our transect was located in the core of the Tangkoko reserve, our density estimates should be limited to that area of the reserve. One explanation for the apparent stabilization of the population may be tied to the increasing and sustained number of training and research programs being conducted at the reserve. This collective effort by local and international groups may be helping to reduce illegal activity in the reserve (i.e., hunting and habitat destruction) and generate greater awareness of this critically endangered species. Without the continued vigilance afforded by the existing research and training programs and the support and involvement of the local people, the M. nigra at the Tangkoko Nature Reserve will likely face further decline. Am. J. Primatol. 75:88‐94, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   

20.
C‐2 dimethylated/unmethylated thiazolidine‐4‐carboxylic acid and C‐2 dimethylated oxazolidine‐4‐carboxylic acid were introduced into the insect kinin core pentapeptide in place of Pro3, yielding three new analogues. NMR analysis revealed that the peptide bond of Phe2‐pseudoproline (ΨPro)3 is practically 100% in cis conformation in the case of dimethylated pseudoproline‐containing analogues, about 50% cis for the thiazolidine‐4‐carboxylic acid analogue and about 33% cis for the parent Pro3 peptide. The diuretic activities are consistent with the population of cis conformation of the Phe2‐ΨPro3/Pro3 peptide bonds, and the results confirm a cis Phe‐Pro bond as bioactive conformation. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   

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