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1.
Distribution of Agrobiodiversity in Home Gardens along the Corrientes River, Peruvian Amazon. This paper examines crop species diversity in home gardens of traditional communities along a remote tributary in northeastern Peru. A large-scale survey was conducted of 300 gardens in 15 villages along a 150 km reach of the Corrientes River. Study villages vary notably in community size, ethnicity of residents (Achuar, Urarina, mestizo), and proximity to the regional town (Trompeteros) as well as to oil wells. Gardens were inventoried and interviews conducted with garden tenders to provide data on socioeconomic characteristics of the household and contextual conditions. Multiple regression analyses identified the determinants of species diversity. Results indicate high crop diversity—the highest yet reported for sites in the Amazon basin—particularly among the Achuar people. Garden species diversity is greatest in larger villages and, surprisingly, in those villages located nearer to the oil company. Within villages, households with larger land holdings (and gardens), more in-house labor, and garden tenders who are older and female tend to have more diverse gardens. A small number of households (15/300) were found to hold exceptional diversity, often older and land-wealthier households located on the outskirts of villages. These farmers held, on average, three times the number of species as a typical village garden and 60% of all species encountered in the study.  相似文献   

2.
Abstract. Susceptibility of the malaria vector Anopheles gambiae to permethrin decreased following the installation of mosquito nets impregnated with 0.5 g permethrin per square metre in four villages near Kisumu, Kenya. During the first year that permethrin-impregnated bednets and curtains were in place, the exposure time to 50% mortality (LT50) increased 2.5-fold from 13 to 33min, while the LT5() for An.gambiae was unchanged in two other villages where no intervention measures were used. Two years after permethrin-impregnated mosquito nets were distributed the LT50s for An.gambiae were 28, 28 and 16min, respectively, in the villages with bednets, curtains and with no such intervention.
Using a colony of An.gambiae derived from females collected in the villages using permethrin-impregnated moquito nets, we lengthened the LT5n from 28 to 41 min in two generations by exposing all females to permethrin-treated papers for 60 min and rearing offspring of the survivors.
Permethrin-impregnated bednets and curtains are intended to reduce vectorial capacity. Reduced susceptibility to permethrin could counter this beneficial effect.  相似文献   

3.
Analysis of the inbreeding coefficient, its structure and dynamics in rural and urbanized populations of the Kostroma province was performed. The coefficient of inbreeding was estimated for the "old" and "new" villages via migration and isonymy, the values being 0.001185; 0.000786 and 0.001341; 0.000682, respectively. It follows from these data that there is a good agreement between the values of the inbreeding coefficient estimated by two different methods and that this coefficient is diminished doubly in "new" villages. The coefficient of inbreeding in small towns was estimated via isonymy. It is 0.000704 in ancient and 0,000229 in modern towns. The decrease in the inbreeding coefficient was more pronounced in towns, as compared to villages.  相似文献   

4.
One of the critical human group of potential risk is the group of population from 30-km zone around the Chernobyl nuclear power plant. The cytogenetical examination of 12 persons (8 man, 4 woman, 30-60 years old) from 5 villages situated in north-west and south-east directions from the ChNPP in the frame of this zone was conducted. The data of the conventional analysis showed relatively low cytogenetic effects comparable with the effects in exposed people out of the zone (the mean level of unstable cytogenetic markers in different villages was 0.21-0.35 per 100 cells). The level of stable translocations in one case (woman, 59 years old) determined using FISH (16.62 per 100 cells for the whole genome) exceeded their spontaneous aged frequency and confirmed the high sensitivity of this method for the evaluation of real radiation exposure.  相似文献   

5.
A decade ago, a study revealed that praziquantel (PZQ) failed to cure 1.6% of those with intestinal schistomiasis in five villages of the Nile delta region. The recommended dosage of PZQ is a single 40 mg/kg oral dose, and each of these patients continued to pass viable Schistosoma mansoni eggs despite three successive doses at or above this level. The eggs passed by these uncured villagers produced adult worms that were, in most cases, significantly less responsive to PZQ in vitro. This report investigates the current sensitivity of S. mansoni infections to PZQ after 10 years of therapeutic pressure in the same villages, testing the hypothesis that the number of drug failures would have increased as continued drug pressure selected for worms with diminished sensitivity to PZQ. The data show that these villages have experienced a significant decrease in the prevalence and intensity of S. mansoni infections, with present infection rate of 10.9%, compared with 25.1% in 1994. The first treatment resulted in normal range of cure rates, between 73.8 and 92.3% in each of the five villages in the study. After three successive doses (40, 40, and 60 mg/kg, the same treatment protocol applied a decade ago) there were no uncured patients remaining in the study. This shows that there has not been an increase of drug failure, despite 10 years of therapeutic pressure in these villages where there had been resistant infections and worms with decreased response to PZQ.  相似文献   

6.
The current U.S. Environmental Protection Agency's (USEPA's) risk analysis on the Integrated Risk Information System (IRIS) for arsenic in drinking water is based on an epidemiological study of skin cancer in Taiwan. Assumptions used in the USEPA application of the multistage-Weibull model for risk estimation were varied to assess the effect on predicted risk of skin cancer to the U.S. population at arsenic concentrations of 1 to 50?µg/L in drinking water. Among the assumptions tested, the only notable change in risk estimates was a reduction when the arsenic concentration used as representative for Taiwan villages in the low range (<300?µg/L) was increased to the 75th percentile (245?µg/L) in place of the mean used in the USEPA analysis (170?µg/L), but the representative value for Taiwan villages in the high range (≥600?µg/L) was not increased simultaneously to the 75th percentile. Additionally, a simulation study was conducted using records of arsenic measurements in wells from the same period and region of Taiwan as the original study. The exposure-response curve estimated from 60 villages (60 data points) differed only marginally from the outcome when data were summarized into four data points (as in the USEPA skin cancer analysis). Briefly discussed are differences between the study area of Taiwan and the U.S. in nutritional status and consumption of inorganic arsenic in food that might bias predicted U.S. skin cancer risks.  相似文献   

7.
Anthropometric data on 12 variables in 19 villages of the Yanomama Indians demonstrate significant heterogeneity in physique among villages of this tribe. Mahalanobis' distances (D2) calculated from the data lead to the tentative conclusion of a general correspondence between anthropometric and geographic distances separating villages. The mean stature of the Yanomama is smaller than that of most other South American tribes which have been measured, and the Yanomama are genetically distinct from the other small Indians as shown by genetic distances based on allele frequencies for a variety of genetic markers. Since some subjects were measured more than once by the same and by different observers, it was possible to calculate approximate estimates of variance within and between observers. Univariate analysis indicates that face height and nose height are especially susceptible to systematic differences in technique between observers. The variances obtained in this field study compare favorably with those of some classical laboratory studies described in the literature. It was found that measurement error nevertheless probably makes a substantial contribution to anthropometric distance between villages. The median error variance as a fraction of that of Herskovits ('30) is 0.62 for the seven measurements in common with this study. The median value of the error variance for the 12 variables in this study is between 16% and 17% of the total variance.  相似文献   

8.
The surname is a cultural trait that is extremely useful for historical and linguistic studies and can effectively be used as a genetic marker. In many human populations the surname is inherited in the paternal lineage, and can therefore be considered a marker for the Y chromosome. In this study, surnames were recorded from the white pages of telephone directories in current use in Corsica in 1993. All surnames present in thirteen villages scattered over the whole island and covering the main historical regions were transcribed. Surname variability was found to be higher in coastal villages, and lower in more isolated communities. The isonymy detected among the thirteen villages allowed the calculation of kinship values, visualized in a tree showing two main clusters, one referring to the northern villages and one encompassing the villages of the south. The pattern reflects the administrative division of the island, with the exception of Vico, which belongs to the southern administrative region but is geographically close to the northern villages, and Ghisoni, which belongs to the northern district but is more similar to the village of Bastelica in the southern district. The data presented here show a structure in the surname distribution that is in substantial agreement with the geographical patterns. The kinship values are consistent with a moderated gene flow among villages producing a surname structure according to the geographic features of the territory.  相似文献   

9.
The black rat is the main plague reservoir in rural foci in Madagascar, inside the villages as well as in the cultivated areas around. We have evaluated the potentialities of mass‐marking of rats, using baits containing Rhodamine B (RB) in order to get a tool to study the movements of rats and to understand the spread of plague. Laboratory experiments demonstrated that: (i) rats were more attracted by the rodent granules and peanut butter; (ii) incorporation of RB in baits did not reduce their appetence; (iii) RB lasted for 60 days in rat vibrissae and 180 days in rat hairs; and (iv) consumption of baits during a week was under the lethal dose. Field tests have been realized comparatively among 24 highland villages where plague is endemic, in different contexts: baits inside houses or around the village, baits with and without RB, rats captured 1, 2 and 3 months after the marking. No negative effect of the RB on population dynamics of rats or fleas on them was observed. The effectiveness of the marking was comparable between males and females. This technique of collective marking appears very valuable for monitoring rat movements in plague foci.  相似文献   

10.
We studied the influence of agricultural villages on space-use patterns of golden jackals (Canis aureus Linnaeus) in the Mediterranean region of Israel. Villages in our research area attract jackals due to poor sanitation conditions in and around villages. As resources in these villages are abundant and predictable, we expected that space-use patterns of jackals near those villages, including home-range characteristics and movement paths, would differ from those of jackals inhabiting more natural areas. Using radio-locations from 16 individuals (8 near villages and 8 from more natural areas), we found that mean home-range size of jackals close to villages was 6.6 ± 4.5 km2, smaller than mean home-range size of jackals in more natural areas (21.2 ± 9.3 km2, P = 0.001). Similarly, core area size of jackals near villages was 1.2 ± 0.92 km2, compared to 3.5 ± 1.6 km2 for individuals inhabiting more natural areas (P = 0.004). The core area/home-range ratio was greater for jackals near villages than for those occupying more natural areas (0.122 ± 0.045 vs. 0.095 ± 0.037, respectively, P = 0.004). Jackals moved little during the day, with day ranges smaller for jackals near villages than away from them (1.65 ± 0.67 vs. 7.5 ± 5.6 km2, respectively, P = 0.028). However, jackals near villages moved as much at night as did jackals in more natural areas, although movement was in a less directional manner. Changes in distribution and predictability of resources due to anthropogenic activity affect not only the home-range size of jackals, but also how they utilize and move through space. © 2011 The Wildlife Society.  相似文献   

11.
Lasker's coefficient of relationship was calculated between 14 villages in Sardinia in order to estimate biological relationships on the base of common surnames. The data derive from parish marriage registers for the periods 1800-1824 and 1950-1974. Through time, coefficients of relationship between villages are generally higher for neighbouring villages. Moreover, the Ri between values decreases as the geographic distances increase. The negative Pearson product-moment correlation observed between the Ri matrix and the geographic distance matrix is statistically significant (Mantel's test) for the two periods considered. These results suggest that the biological similarity between villages, as shown by isonymy, tends to decrease as the geographic distance increases. In addition, the plots of isonymic relationships obtained by nonmetric multidimensional scaling for 1800-1824 and 1950-1974 show that the biological relationships between neighbouring villages increase in the second period considered.  相似文献   

12.
Anthropometric measurements (head length, head breadth, bizygomatic diameter, minimum frontal diameter, head circumference, and stature) for 526 adult Jirels are utilized to establish the pattern of phenotypic relationships between seven villages in eastern Nepal. An analytical framework is provided that justifies the interpretation of biological distances as minimum genetic distances. Using this approach, estimates of the minimum pairwise genetic distances between villages and the minimum FST for the population are derived from the purely phenotypic data. The FST obtained in this way is consistent with results obtained from other data available for this population, confirming the utility of phenetic analysis of quantitative traits for elucidating genetic structure.  相似文献   

13.
The Knuckles range of forests has been identified as a unique biological resource in Sri Lanka with much biodiversity. It is also important as a watershed which feeds the Mahaweli reservoir system. Having considered the present hazardous land-use practices such as cardamum production and shifting cultivation, the Knuckles range has been declared a national wilderness area. The Forest Department is in the process of preparing the management plan for the area. There are about 48 villages in the vicinity of the forest. This study attempts to estimate the composition of income in the peripheral communities, ticularly the extraction of non-timber forest products (NTFP) from this range of forests. Data were collected using structured questionnaires from 60 households in three villages in the vicinity of the forest. The rural economy is described using a farming systems approach and the net income contributed by each activity in the farming system was estimated. Results show that nine components of the farming system use resources from the village and the forest, with at least 47 plant species used by the villagers for different purposes. Cardamum production and shifting cultivation contribute significantly to the total income of the household, but the majority of households in the study depend upon forest resources to supply some portion of their income. Nevertheless, the monetary value of the annual income generated by NTFP is much lower than income from either cardamum production or shifting cultivation. If cardamum production and shifting cultivation are to be restricted under the conservation program, there could be additional pressure put on NTFP. Therefore, we suggest a study of the natural regen-eration capacity of selected NTFP; such information should be used in finalizing the management plan in the Knuckles range of forests.  相似文献   

14.
The prevalence of malaria infections was estimated in six different areas of the town of Ouagadougou, Burkina Faso, and in three neighbouring villages. Thick and thin blood films from a total of 2,117 children less than 5 years old were examined at the peak of the transmission season (August-September). Plasmodium falciparum was found in more than 98% of the positive slides. The overall parasite index at Ouagadougou was 16%, while indices from 51 to 88% were recorded in the three villages. Significant differences were observed between the six urban areas within the town as well as between the three villages. The highest parasite rates in the town were clearly associated with major breeding places of An. gambiae s.l. indicating a remarkable focality of transmission. Significant differences were observed between groups of children from houses only 300 m apart. Chemoprophylaxis appears to play an important role in determining parasite rates lower than expected in one of the three villages.  相似文献   

15.
Spatial autocorrelation (SA) methods were recently extended to detect local spatial autocorrelation (LSA) at individual localities. LSA statistics serve as useful indicators of local genetic population structure. We applied this method to 15 allele frequencies from 43 villages of a South American tribe, the Yanomama. Based on a network of links 相似文献   

16.
ABSTRACT: BACKGROUND: In Savannakhet province, Laos and Quang Tri province, Vietnam, malaria is still an important health problem and most cases are found in the mountainous, forested border areas where ethnic minority groups live. The objectives of this study were to obtain a better joint understanding of the malaria situation along the border and, on the basis of that, improve malaria control methods through better cooperation between the two countries. METHODS: Fourteen villages in Savannakhet and 22 villages in Quang Tri were randomly selected within 5 km from the border where a blood survey for microscopic diagnosis (n = 1256 and n = 1803, respectively), household interviews (n = 400, both sides) and vector surveys were conducted between August and October 2010. Satellite images were used to examine the forest density around the study villages. RESULTS: Malaria prevalence was significantly higher in Laos (5.2%) than in Vietnam (1.8%) and many other differences were found over the short distance across the border. Bed net coverage was high (> 90%) in both Laos and Vietnam but, while in Laos more than 60% of the nets were long-lasting insecticide-treated, Vietnam used indoor residual spraying in this area and the nets were untreated. Anopheles mosquitoes were more abundant in Laos than in Vietnam, especially many Anopheles dirus were captured in indoor light traps while none were collected in Vietnam. The forest cover was higher around the Lao than the Vietnamese villages. After this study routine exchange of malaria surveillance data was institutionalized and for the first time indoor residual spraying was applied in some Lao villages. CONCLUSIONS: The abundance of indoor-collected An. dirus on the Laos side raises doubts about the effectiveness of a sole reliance on long-lasting insecticide-treated net in this area. Next to strengthening the early detection, correct diagnosis and prompt, adequate treatment of malaria infections, it is recommended to test focal indoor residual spraying and the promotion of insect repellent use in the early evening as additional vector interventions. Conducting joint malaria surveys by staff of two countries proved to be effective in stimulating better collaboration and improve cross-border malaria control.  相似文献   

17.
在社会经济发展与生态环境发展逐渐失调的背景下,滇金丝猴作为中国特有的珍稀濒危物种,其生境质量的研究是平衡经济发展与物种保护的重要基础。选取滇西北地区2572个自然村的社会经济数据和344个样地运用GIS空间分析法的主成分分析和InVEST模型,研究滇西北地自然村发展对滇金丝猴分布区生境质量的影响,结果如下:(1)研究区南部自然村发展优于北部;(2)研究区北部的生境质量比南部高,北部自然村对滇金丝猴生境质量的影响比南部的自然村小;北部的生境稀缺性比南部高,生态稳定性差,需要制定优先保护策略;(3)猴群分布区内存留12个自然村,自然村发展对第3、6和14猴群(C3、C6和C14)的生境质量影响大,生境质量比较低;猴群C1、C12和C13分布区内的生境稀缺性较高,生境脆弱,需要优先加强规划;划定滇金丝猴优质生境、中等生境和低质生境区域,占比分别为26.85%、20.44%和52.71%。  相似文献   

18.
The paper deals with the distribution of genetic markers (systems ABO, Rh, Hp, PTC) and a number of phenotyping traits (folding of arms, hand clasping, tongue rolling, right- and left-handedness, the type of ear lobe, the types of dermatoglyphics patterns) in the inhabitants of 5 villages in the Pinezhsky district of the Arkhangelsky region of the RSFSR. The data presented in this work were obtained in the course of examination of over 900 persons. Among the systems analysed there was a statistically significant deviation from Hardy-Weinberg's equlibrium. It took place in two the least villages. In one case--for ABO blood groups, in another--for Hp system. There are an interesting fact of the excess of heterozygotes 2-1 and some excess of the group 0. Statistically significant differences between villages were shown for four genetic systems. Data on migrations, distribution of gene frequencies and estimated genetic and phenotype distances between villages of the same village community and between two communities suggest, that each village community can be considered as separate subdivided population. Considering the uniformity of the environmental pressure in the region examined, the heterogeneity of the population studied is apparently associated with a random genetic drift.  相似文献   

19.
In recent years, the red fox (Vulpes vulpes) has increasingly occupied urban areas in central Europe. Meanwhile, prevalence of infection in foxes with the small fox tapeworm (Echinococcus multilocularis) has increased, thereby increasing the human risk of infection with the parasite, which causes alveolar echinococcosis. Baiting strategies to counteract E. multilocularis have been implemented in cities and the open countryside, but there are few data on the situation in villages and small towns (<10,000 inhabitants). We recorded disappearance rates of praziquantel-containing bait within villages and small towns and on settlement edges for 7 days after distribution. Disappearance rates were 89.2% in villages, 88.8% in small towns, and 91.8% in settlement edges. More than 75% of the bait was consistently taken within the first three nights. There were no significant differences in disappearance rates between years or among seasons (Cox proportional hazard model). The survival time of the bait in small towns (P=0.021) and villages (P=0.026) depended on the zone (zone 1, first row of houses bordering on open countryside; zone 2, second to fourth rows, zone 3; beyond the fifth row) in which bait was distributed. In villages, the probability of bait being eaten in zone 1 was 119% higher than it was in zone 3 (P=0.007). In small towns, the probability was 60% higher (P=0.006).  相似文献   

20.
The fluoride (F), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), and phosphorus (P) content in potable water and food samples (cereals, pulses, and vegetables) from endemic and nonendemic villages for fluorosis were analyzed. It was found that the F content in water was significantly higher (p<0.01) in endemic villages (4.20±1.6 ppm) than control villages (0.63±0.15 ppm), whereas the Ca, Cu, and Mg contents were found to be significantly lower (p<0.05) in endemic villages compared to control villages. However, there was no significant difference in Zn and P contents between the villages. Foods (cereals, pulses, and vegetables) grown in endemic villages contained significantly higher (p<0.01) fluoride content as compared to control villages. There was no significant difference in Ca, Mg, P, and Zn contents in food grown in endemic and control villages. Copper content in cereals (p<0.05), pulses (p<0.01), and vegetables (p<0.01) in endemic villages was found significantly higher as compared to control villages. The overall prevalence of dental fluorosis in six endemic villages was 97.4% in boys and 96% in girls, which was significantly higher (p<0.01) than that of control villages, where it was 10.5% in boys and 8.3% in girls. The prevalence of dental fluorosis was positively correlated (r=0.125, p<0.01) to fluoride and negatively correlated to Ca and Cu content in drinking water in endemic villages.  相似文献   

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