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1.
Population genetics in the province of Ferrara. I. Genetic distances and geographic distances.
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The ABO and Rh systems of the population in 26 residential units in the province of Ferrara were studied to detect the effect of genetic drift on the differentiation of gene frequencies. Results obtained from principal components analysis and dendrograms were similar. A significant correlation between genetic and geographic distance was found. It was therefore hypothesized that in the area of Ferrara children born to parents originating from different communes were heterozygous at more loci than children born to parents originating from the same commune. It was also thought that it may be possible to use geographic distance between birthplaces of parents as an indicator of hybridity in their children. 相似文献
2.
Bruce C. Jayne Albert F. Bennett 《Evolution; international journal of organic evolution》1990,44(5):1204-1229
Selection on locomotor performance was determined for a series of marked and recaptured individuals from a population of garter snakes (Thamnophis sirtalis fitchi) in Northern California. We measured snake length and mass, burst speed, endurance on a treadmill, and the distance crawled around a stationary circular track. Size-corrected values (residuals) of mass and locomotor performance were generated from the scaling equations of S–V length (SVL). Randomization tests and regressions were used to determine the probability that a trait was a significant predictor of survivorship, and a nonparametric, cubic spline estimate of the fitness function was used to facilitate detection of the patterns of selection. From 275 (“cohort”) snakes measured and tested within 8 days of birth in 1985, 79 were recaptured in the spring–summer of 1986 and subsequent years. Birth SVL was the only significant (randomization P = 0.022) predictor of neonatal survival from 1985 to 1986 with directional selection favoring larger individuals. In addition to the lab-born cohort, 382 field-born snakes from all ages in the population were captured, tested, and released during spring–summer 1986. Similar to the 1985 cohort, the survivorship of 37 of 86 neonates from 1986 to 1987 showed no significant relationship with any residual value using any statistical test. Survivorship from 1986 to 1987 for 127 of 250 yearlings (including 32 lab-born cohort snakes) analyzed with the randomization test showed that greater values of both speed (P = 0.007) and distance residual (P = 0.008) significantly favored survival, whereas intermediate values of mass residual (P = 0.006) were significantly more likely to survive. Univariate regressions predicting the survival of yearlings from 1986 to 1987 gave similar results to the randomization test, but in a multiple regression with yearling burst speed residual, distance capacity residual, and a quadratic term of mass residual, distance capacity residual was the least important predictor variable. For the survivorship of 37 of the 113 older snakes, greater burst speed residual significantly favored survival (randomization P = 0.001). 相似文献
3.
A method of raising a random patterns flap on the back of a rat was used to study the relationship between the surviving length and distance of dye penetration. It was found that the intraoperative dye distance was an accurate predictor of survival length in the Control Group. The effects of dressing were evaluated against the controls. An apparently significant increase in the survival length (beyond the dye distance) was seen with the "tunnel procedure" we used. It is suggested that a moist environment will favor survival of that portion of a flap where necrosis is usually seen when no dressing is used. 相似文献
4.
Of 35 species of Crotalaria (Leguminosae) studied, all but one had usually one nucleolus in the premetaphase I cells. In C. agatiflora 300 PMCs from four out of five plants were investigated and the percentage cells with more than one nucleolus was determined as well as the nature of nucleolar attachment to bivalents and the range and the sizes of various nucleoli present in the cell. The aberrant cells ranged from 42 to 50%. The nucleoli (1–6) were usually attached to different bivalents. Where one nucleolus was present in the cell, it was always attached to an X-shaped bivalent, formed of a pair of nucleolar chromosomes. In the aberrant cells one nucleolus usually was attached to such a bivalent. The presence of accessory nucleoli has been attributed to hybridity as a result of large-scale intercrossing among five subspecies and consequent dispersal of intermediates in the adjoining areas where C. agatiflora grows wild (East Africa and Ethiopia). The change in the regulatory system of the cell caused by hybridity results in activation of latent nucleolar organizers, although their overall presence in the genome is not due to hybridity. 相似文献
5.
One form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter cloacae, Erwinia herbicola, Klebsiella planticola, and Pseudomonas syringae, were sprayed in separate experiments in a greenhouse. Samples were collected over a distance of 15 m from the spray site for enumeration. Spores of Bacillus subtilis were used as tracers to estimate the effects of dilution on changes in population over distance. Viable counts of P. syringae, Enterobacter cloacae, and K. planticola decreased significantly over a distance of 15 m. Erwinia herbicola showed no significant decline in counts over the same distance. The degree of survival of P. syringae during aerosolization was dependent on ambient environmental conditions (i.e., temperature, relative humidity), droplet size of the aerosol, and prior preparative conditions. Survival was greatest at high relative humidities (70 to 80%) and low temperatures (12 degrees C). Survival was reduced when small droplet sizes were used. The process of washing the cells prior to aerosolization also caused a reduction in their survival. Results from these experiments will be useful in developing sound methodologies to optimize enumeration and for predicting the downwind dispersal of airborne microorganisms, including genetically engineered microorganisms. 相似文献
6.
C S Chung J D Niswander D W Runck S E Bilben M C Kau 《American journal of physical anthropology》1972,36(3):427-433
Racial comparisons of prevalences of dental anomalies were made on 13,473 Hawaiian-born children aged 12 to 18 years. Dental anomalies studied included supernumerary teeth, peg-shaped lateral incisors, dens in dente (invaginated tooth), hypoplasia, fusion (or gemination), and high cingulum of upper lateral incisors (barrel-shaped teeth) in the permanent dentition. The highest frequency of peg-shaped laterals was observed among Filipinos and part-Filipinos with no evidence of heterogeneity among other racial groups. Dens in dente was more common among Hawaiian descendents. Fusion or gemination was observed more commonly among children with Chinese parentage. High cingulum of laterals was fairly common in Orientals particularly in Filipinos and nil among Caucasians and Hawaiians. There was neither significant maternal effect nor effect (non-additive) of hybridity. 相似文献
7.
A molecular linkage map of olive (Olea europaea L) based on RAPD, microsatellite, and SCAR markers. 总被引:3,自引:0,他引:3
An integrated molecular linkage map of olive (Olea europaea L.) was constructed based on randomly amplified polymorphic DNA (RAPD), sequence characterized amplified region (SCAR), and microsatellite markers using the pseudo-testcross strategy. A mapping population of 104 individuals was generated from an F1 full-sib family of a cross between 'Frantoio' and 'Kalamata'. The hybridity of the mapping population was confirmed by genetic similarity and nonmetric multidimensional scaling. Twenty-three linkage groups were mapped for 'Kalamata', covering 759 cM of the genome with 89 loci and an average distance between loci of 11.5 cM. Twenty-seven linkage groups were mapped for 'Frantoio', covering 798 cM of the genome with 92 loci and an average distance between loci of 12.3 cM. For the integrated map, 15 linkage groups covered 879 cM of the genome with 101 loci and an average distance between loci of 10.2 cM. The size of the genomic DNA was estimated to be around 3000 cM. A sequence characterized amplified region marker linked to olive peacock disease resistance was mapped to linkage group 2 of the integrated map. These maps will be the starting point for studies on the structure, evolution, and function of the olive genome. When the mapping progeny pass through their juvenile phase and assume their adult characters, mapping morphological markers and identification of quantitative trait loci for adaptive traits will be the primary targets. 相似文献
8.
In the present study the sensitivity of differential lethality as an endpoint for monitoring the presence of organ-specific genotoxic factors within the DNA-repair host-mediated assay (HMA) was determined. The induction of differential lethality in chemically exposed animals was assessed by measuring the recovery ratio Q, i.e., the relative survival of a repair-deficient E. coli K-12 derivative in comparison with its repair-proficient counterpart. Using untreated animals the interindividual fluctuation of the recovery ratio Q was first quantified and then used to determine the level below which it could be considered indicative of chemically induced differential lethality. This Q value was found to be 0.65 or lower. Using this criterion, a significant decrease of the Q value was observed in mice exposed to DMNA at a dose level as low as 15-30 mumole/kg, i.p. Inter-organ transport (liver----extrahepatic organs) of indicator bacteria was studied in reconstruction experiments using the direct-acting methylating agent MNU. These studies showed that inter-organ transport of indicator bacteria did not interfere with MNU-induced differential lethality. Time-related experiments were used to study the effects of inter-organ transport of genotoxic DMNA metabolites. In these studies significant, time-related differences were found in the induction of differential lethality in various organs of mice treated with DMNA. At a dose level of 200 mumole/kg (i.p.) genotoxic factors appeared within 25 min after administration in the liver. In the lungs and kidneys such factors appeared at a substantially slower rate, e.g., 20-120 min after DMNA administration. In persistence experiments differential lethality reached a maximum 30 min after DMNA treatment. No residual effects were detected 60 min after the injection of the carcinogen. These experiments showed that DMNA-derived genotoxic factors diffused from the liver into the bloodstream. The diffusion of these reactive species followed by their transport via the bloodstream to the lungs accounted for maximally 50% of differential lethality observed in bacteria recovered from the latter organ. In contrast, no indications were found for the transport of genotoxic DMNA metabolites from the liver via the bloodstream to the spleen and the kidneys. These results show that organ-specific effects observed in the DNA-repair HMA procedure after DMNA exposure can be primarily attributed to in situ metabolism, rather than diffusion of genotoxic metabolites from the liver to extrahepatic organs. 相似文献
9.
In an unselected series of 49 children with Wilms'' tumour treated in 1969-74 the 5-year relapse-free survival and survival rates were 78% and 81%, respectively, whereas in the series of children treated in 1963-68 the corresponding rates were 49% and 70%. The significant improvement in the relapse-free survival rate was a result of adjuvant treatment with actinomycin D and vincristine (AMD + VCR), which, in some patients, eradicated occult metastatic disease. In the treatment of lung metastases the combination of whole-lung irradiation and maintained chemotherapy with AMD + VCR proved excessively toxic: in 5 of 11 patients acute diffuse pneumonitis developed, and it was fatal in 3. Adjuvant AMD + VCR therapy is advocated in all patients with Wilms'' tumour except children less than 12 months old with a tumour of moderate size, limited to the kidney and completely resectable. 相似文献
10.
The ability of Ehrlich ascites tumor cells (EAT cells) to repair potentially lethal damage (alpha-PLD) as demonstrated by either an increase in survival after delayed plating or a decrease in survival after treatment with beta-arabinofuranosyladenine (beta-araA) was investigated after exposure to protons, deuterons, 3He, 4He, and heavy ions of various specific energies. A significant amount of repair or fixation was observed after delayed plating or treatment with beta-araA, respectively, in cells that were exposed to protons of 6-21 MeV energy, reflecting mainly variations in the survival curve shoulder width. Four-hour treatment with 80 microM/liter beta-araA resulted in an exponential survival curve for all proton energies tested. A decrease in particle energy increased killing and caused a reduction in Dq without a significant change in D0. The survival curve obtained after exposure of cells to 3.4 MeV protons had only a small shoulder and was only slightly modified by either delayed plating or treatment with beta-araA, suggesting a decrease in the induction rate of alpha-PLD. Similar results were also obtained after exposure to deuterons and 4He ions. The results are interpreted as indicating the importance of the specific particle energy and the delta-electron spectrum in the induction of alpha-PLD. When the results of delayed plating of cells exposed to protons, deuterons, or helium ions were pooled, an exponential relationship between Dq and penumbra radius was indicated. After exposure to 40Ar ions of 18 MeV specific energy, a shouldered survival curve was obtained, and beta-araA significantly enhanced killing by modifying Dq as well as D0, a result that also suggests induction of repairable damage by the delta particles produced and interaction of lesions induced within the core of the ion path with penumbra lesions. Based on these results a model is proposed assuming that alpha-PLD results from interaction, during the course of repair, of pairs of DNA lesions induced within a distance di. The model assumes the existence of a critical separation distance dic, with the property that pairs of lesions induced with separation distance shorter than dic (expressed as number of base pairs) will always be expressed as lethal, and the existence of a maximum separation distance dim, with the property that pairs of lesions induced with separation distance larger than dim will not interact.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
11.
Özge Özden William M. Ciesla Wayne J. Fuller David J. Hodgson 《Biodiversity and Conservation》2008,17(12):2821-2832
We analysed the influence of contemporary geography on butterfly diversity for islands in the Mediterranean Basin. We found
that island size and distance from the mainland has a significant effect on the number of species. We also used butterflies
as an indicator group to identify the importance of forest habitats for biodiversity conservation in the island of Cyprus.
To understand the relative importance of local vegetation characteristics of butterflies in the Pentadaktylos mountains transect
counts were used to assess the abundance and butterfly diversity in two different forest types. A total of 1,602 butterflies
and 23 species were recorded during this research. We observed highly significant effects of forest type on abundance and
species richness of butterflies. For example, number of butterflies was significantly higher in old forest than young pine
forest. Also, the abundance of endemic butterflies was highest in old forest habitats. Therefore, the survival of the majority
of endemic butterflies in Cyprus may depend on conservation of old forests and their understorey plants. 相似文献
12.
First results of cytogenetic monitoring of children, living in contaminated regions of the Ukraine show statistically significant increase in quantity of chromosome aberrations, that is positively correlated with environmental situation. The effect found shows that damage of genome stability must be accounted as an indicator of increased possibility of gene-based pathology in studied groups as compared to control. 相似文献
13.
J Bradley A Matias C Schwabe D Vargas F Monti G Nseng I Kleinschmidt 《Malaria journal》2012,11(1):242
ABSTRACT: BACKGROUND: Malaria is endemic on Bioko Island, Equatorial Guinea, with year-round transmission. In 2004 an intensive malaria control strategy primarily based on indoor residual spraying (IRS) was launched. The limited residual life of IRS poses particular challenges in a setting with year-round transmission, such as Bioko. Recent reports of outdoor biting by Anopheles gambiae are an additional cause for concern. In this study, the effect of the short residual life of bendiocarb insecticide and of children spending time outdoors at night, on malaria infection prevalence was examined. METHODS: Data from the 2011 annual malaria indicator survey and from standard WHO cone bioassays were used to examine the relationship between time since IRS, mosquito mortality and prevalence of infection in children. How often children spend time outside at night and the association of this behaviour with malaria infection were also examined. RESULTS: Prevalence of malaria infection in two to 14 year-olds in 2011 was 18.4 %, 21.0 % and 28.1 % in communities with median time since IRS of three, four and five months respectively. After adjusting for confounders, each extra month since IRS corresponded to an odds ratio (OR) of 1.44 (95 % CI 1.15-1.81) for infection prevalence in two to 14 year-olds. Mosquito mortality was 100 %, 96 %, 81 % and 78 %, at month 2, 3, 4 and 5 respectively after spraying. Only 4.1 % of children spent time outside the night before the survey between the hours of 22.00 and 06.00 and those who did were not at a higher risk of infection (OR 0.87, 95 % CI 0.50-1.54). Sleeping under a mosquito net provided additive protection (OR 0.68, 95 % CI 0.54-0.86). CONCLUSIONS: The results demonstrate the epidemiological impact of reduced mosquito mortality with time since IRS. The study underscores that in settings of year-round transmission there is a compelling need for longer-lasting IRS insecticides, but that in the interim, high coverage of long-lasting insecticidal nets (LLINs) may ameliorate the loss of effect of current shorterlasting IRS insecticides. Moreover, continued use of IRS and LLINs for indoor-oriented vector control is warranted given that there is no evidence that spending time outdoors at night increases infection prevalence in children. 相似文献
14.
In a prospective study in Matlab, a rural area in Bangladesh, the relationship between a variety of covariates and childhood mortality was examined. Economic status of household, education of mother, sex of the children, health intervention programmes, age of mother, and live birth order of the children were identified as having a statistically significant impact on child survival when the effect of age was controlled. The effects of sex of the children, health programmes, age of mother, and birth order were found to be dependent on the age of the children, but the effect of mother's education was dependent on sex of the children. 相似文献
15.
P S Hart B O Barnstein J R Secor McVoy R Matalon B Wolf 《Biochemical medicine and metabolic biology》1992,48(1):41-45
We describe a method for more accurately determining residual biotinidase activity in sera of individuals with profound biotinidase deficiency. Using this method we found that there is a statistically significant difference in the means of residual serum enzyme activities of symptomatic children and those identified by newborn screening. A subgroup of children identified by screening have activities higher than any of the symptomatic population. These children may develop mild symptoms, may develop symptoms later in life, or may not develop symptoms at all. 相似文献
16.
ABSTRACT The presence of recreational trails can impact breeding birds either indirectly by altering habitat or the movement patterns of predators or directly if the presence of humans disturbs birds. We examined the behavioral responses of nesting female Northern Cardinals (Cardinalis cardinalis) to human disturbance using both experimental and observational approaches. From April to August 2006 and 2007, we monitored Northern Cardinal nests in 18 riparian forests in Ohio, USA. Two experimental trials were conducted at each nest (N= 63), with Flight Initiation Distance (FID, the distance at which a bird flushed from the nest) recorded as we approached nests by walking directly toward them and by walking along trails located variable distances from nests. We also measured flight initiation distance (FID) when nests were approached during routine nest checks (N= 160). Cardinals were six times more likely to flush when nests were approached directly, and females on higher nests were less likely to flush regardless of distance to trail. FID was not significantly influenced by the distance of nests from trails. We found no association between nest survival and the tendency of birds to flush. Rather, nest survival was best explained by nest height. Thus, our findings suggest that the responses of birds to human use of recreational trails have only short‐term effects, with no apparent effects of on nest survival. Because the reaction of birds to humans in our study depended on how nests were approached, studies where FID is used as an indicator of sensitivity to human disturbance and is determined by direct approaches may overestimate the potential impact of trails on nesting birds. 相似文献
17.
L Sandberg D VanReken K Waiwaiku P Martin-Yeboah C Weiss V Updegraff A Hanson M Schleman B Lodhia 《Clinical physiology and biochemistry》1985,3(5):257-264
58 malnourished children (mean age 18 months) with a clinical diagnosis of marasmus or kwashiorkor were studied with respect to plasma fibronectin levels, plasma total solids, spun hematocrits, heights, weights, mid-arm circumferences, and head circumferences. Bimodal distributions were demonstrated for plasma fibronectin versus weight deficits, total solids, hematocrits, and mid-arm circumference in children 12 months of age and older (p less than 0.003 for all). The mean plasma fibronectin level for controls was 253 micrograms/ml. The mean level for the malnourished group was 96 micrograms/ml (p less than 0.0001). Malnourished children with initial plasma fibronectin levels above 100 micrograms/ml had a higher survival rate than those with levels less than 100 (92 versus 69%). With successful therapy, plasma fibronectin levels rose quickly in most children often before detectable changes were noted in clinical and other laboratory parameters. An overshoot of the mean normal levels was observed with successful treatment wherein the mean levels rose to 315 micrograms/ml (p less than 0.05). Plasma fibronectin determinations on malnourished children can serve as an important prognostic marker as well as a reliable indicator of successful therapy and recovery. 相似文献
18.
We have examined the role of presynaptic residual calcium in maintaining long-term changes in synaptic efficacy observed at mossy fiber synapses between hippocampal dentate granule cells and CA3 pyramidal cells. Calcium concentrations in individual mossy fiber terminals in hippocampal slice were optically measured with the calcium indicator fura-2 while stimulating the mossy fiber pathway and recording excitatory postsynaptic potentials extracellularly. Short-term synaptic enhancement was accompanied by increased presynaptic residual calcium concentration. A 2-fold enhancement of transmitter release was accompanied by a 10-30 nM increase in residual calcium. Following induction of mossy fiber LTP, transiently elevated presynaptic calcium decayed to prestimulus levels, whereas enhancement of synaptic transmission persisted. Our results demonstrate that, despite an apparent strong sensitivity of synaptic enhancement to presynaptic residual calcium levels, sustained increases in presynaptic residual calcium levels are not responsible for the maintained synaptic enhancement observed during mossy fiber LTP. 相似文献
19.
Retrospective analysis of 2870 patients with invasive carcinoma of the cervix treated by radiotherapy from 1971 to 1978 showed that the prognosis for younger patients (defined as either under 35 or under 40) was better than that for older age groups, but young patients presented with earlier disease. When the effect of stage on prognosis was also considered the improved survival of patients under 35 was confirmed, although the result was of only borderline significance. The better survival of younger patients was particularly noticeable for stage IB disease, the corrected five year survival of those under 35 being 93% compared with 79% for those over 35. On the basis of this analysis and a review of previous reports it is concluded that age alone is a poor indicator of prognosis and should not be used as an indication for adjuvant treatment. There is no evidence in this series of an aggressive form of cervical carcinoma in younger patients during the 1970s. 相似文献
20.
Avidime OM Avidime S Olorunshola KV Dikko AA 《Nigerian journal of physiological sciences》2011,26(1):23-28
The anogenital distance (AGD) is the distance between the anus and the base of the penis in males and anus to fourchette (AF) distance in females and is a sexually dimorphic index that, on average, is twice as great in males as in females, so it is used as an indicator of appropiate masculine development. In this study, the anogenital distance (AGD) and anthropometric measurements such as birth weight, birth length, head circumference and placenta weight of 200 newborns (100 male, 100 female) were taken and umbilical cord serum was assayed for testosterone concentration using Radioimmunoassay (Microwell). Data obtained were analysed using Student t-test and Pearson's Correlation Analysis as applicable. Results revealed that mean total anogenital distance was 22.53±0.70mm, and it was significantly higher in males: 31.11±0.64mm than in females: 13.89±0.26mm and we observed that there was positive correlation between birth weight and AGD in females. In males head circumference correlated positively with AGD. The mean cord testosterone concentration was 2.78±0.30ng/ml in males and 2.09±0.22ng/ml in females and did not have any significant correlation with anogenital distance. It was concluded that AGD of the population studied, though high was not significantly higher than AGD in other parts of the world and umbilical cord testosterone level did not have any significant effect on AGD. Keywords: Anogenital distance, Ethnicity, Umbilical cord testosterone, Anthropometry. 相似文献