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1.
This study builds on earlier quantitative ethnobotanical studies to develop an approach which represents local values for useful forest species, in order to explore factors affecting those values. The method, based on respondents ranking of taxa, compares favourably with more time-consuming quantitative ethnobotanical techniques, and allows results to be differentiated according to social factors (gender and ethnic origin), and ecological and socio-economic context. We worked with 126 respondents in five indigenous and five immigrant communities within a forest-dominated landscape in the Peruvian Amazonia. There was wide variability among responses, indicating a complex of factors affecting value. The most valued family is Arecaceae, followed by Fabaceae and Moraceae. Overall, fruit and non-commercialised construction materials predominate but women tend to value fruit and other non-timber species more highly than timber, while the converse is shown by men. Indigenous respondents tend to value more the species used for fruit, domestic construction and other NTFPs, while immigrants tend to favour commercialised timber species. Across all communities, values are influenced by both markets and the availability of the taxa; as the favourite species become scarce, others replace them in perceived importance. As markets become more accessible, over-exploitation of the most valuable species and livelihood diversification contribute to a decrease in perceived value of the forest.  相似文献   

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An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru''s Amazon region, the department of Madre de Dios (MDD) rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia) braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V.) braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail) were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%), Hylaeamys perenensis (15.7%), and Proechimys spp. (12%). All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V.) braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V.) braziliensis transmission to human inhabitants in this highly prevalent region.  相似文献   

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Water, suspended particulate matter (SPM) and sediments were collected from the Esteiro de Estarreja (Ria de Aveiro, Portugal), which receives considerable quantities of waste mercury from a chlor-alkali plant. Dissolved and particulate Hg concentrations in the effluent ranged between 4 –167 g I–1 and 141–3144 g g–1, respectively, at pH values of >10. The effluent plume undergoes significant chemical changes during advection downestuary. The evidence suggested that adsorption of dissolved Hg onto organic-rich SPM was an important process. A maximum sediment Hg concentration of 500 g g–1 was found about 1.5 km from the discharge, as a result of the settling of Hg-rich SPM. Downestuary Hg concentrations in sediments decline to about 100 g g–1 at the mouth of the Esteiro. The particle-water interactions are discussed in terms of the transport of dissolved and particulate Hg into the Ria de Aveiro.  相似文献   

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In a sample of 53 groups of adult males the regularity of spatial variability of hormonal concentrations (testosterone, estradiol, E/T index) was determined. The range of normal biochemical variations of sex hormones in different ethnic-geographical groups was revealed. The hormonal status of different ethnic groups was compared from the point of view of adaptation. The research results present new information on biological individuality and the factors defining it. The hormonal activity optimum depends on ecological factors and serves as a basis for the ecological monitoring of human health.  相似文献   

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Placental transfer of cadmium, lead and mercury was studied under the conditions of environmental exposures of pregnant women to these heavy metals. Fifty pregnant women from industrial area and a similar control group from a semirural area were examined. Cadmium, lead and total mercury levels were determined in maternal erythrocytes and plasma, in placenta, and in erythrocytes and plasma of umbilical cord blood using atomic absorption spectrophotometry. Except for the cadmium plasma concentration in the control area, levels of the three metals were higher in maternal than in cord blood. The mean plasma values (arithmetic mean) of cadmium, lead, and mercury in industrial area were 0.53, 6.37, and 0.37 micrograms.100 ml-1 in maternal blood and 0.30, 4.82, and 0.31 micrograms.100 ml-1 in cord blood. Highest values of the correlation coefficients were found between the cadmium and mercury concentrations in maternal and cord blood erythrocytes. No striking effect of the place of residence of pregnant women on the heavy metal concentrations in biological materials could be found.  相似文献   

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Results on the effect of sub-lethal concentrations of zinc chloride (ZnCl2), cadmium chloride (CdCl2), and mercuric chloride (HgCl2) on Euglena are presented. During the growth cycle respiratory oxygen uptake and photosynthetic oxygen evolution in the light are initially strongly inhibited by Zn, Cd and Hg. The effects of the three metals on photosynthesis, using oxygen evolution as a criterion was confirmed by carbon fixation techniques.Photosystem I (PSI) associated electron transport 2,6-dichlorophenol indophenol (DCPIP)red. methyl viologen (MV) O2, in contrast to total photosynthetic capacity, was only slightly inhibited by Zn, Cd and Hg, whereas the levels of activity of NADP-oxidoreductase in cells untreated or treated with heavy metals showed development like total photosynthesis. Metals strongly inhibited this enzyme which means that the supply of NADPH is lowered due to the action of Zn, Cd and Hg. Photosystem II (PSII) associated electron transport (H2O dibromothymoquinone/2,3-dimethyl-5,6-methylenedioxy-D-benzoquinone O2), however, was severely inhibited in a way similar to total photosynthesis. Effects on the cooperation of PSI + II showed patterns similar to PSII alone, i.e., heavy metals strongly reduced PSI + II dependent activities.Abbreviations DAD diaminodurene - DBMIB dibromothymoquinone - DCPIP 2,6-dichlorophenolindophenol - DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - DMMIB 2,3-dimethyl-5,6-methylenedioxy-p-benzoquinone - DPC 1,5-diphenylcarbazide - MV methylviologen - PS photosystemDedicated to Professor Kandler on occasion of his 60th birthday  相似文献   

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Hair is often used as an index of environmental and industrial exposure to different metals. The interpretation of metal levels in hair is difficult because of the risk of external contamination. The aim of this study was to define the degree of external contamination of hair exposed in vitro to mercury vapor. Specimens of hair were exposed to concentration: 0.026, 0.21, and 2.7 mg Hg/m3 for 2–28 d. Mercury levels in hair increased during 28 d of exposure 2, 3 and 13, times, respectively, when compared to initial values. Mercury levels in hair exposed to the first and second (but not third) concentration of mercury vapor attained a steady state on the 21st d of exposure. The contamination of hair with mercury could not be removed by washing with water, solvent, and detergent. Hair may be used as an index of internal uptake of mercury provided that it was not externally exposed to mercury vapor. In cases of occupational exposure to mercury vapor, hair could become a useful tool for monitoring exposures.  相似文献   

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Samples of 7 species of piscivorous, omnivorous, and herbivorous fish caught at 12 different sites on the Madeira River, Amazon Basin, were analyzed for selenium and mercury. Selenium was determined by anodic stripping voltammetry and mercury by cold vapor atomic absorption spectrophotometry. The means for selenium concentrations ranged from 0.49 to 3.11 nmol/g and for mercury from 0.41 to 6.66 nmol/g depending on the fish species. The molar ratios of Hg:Se increased according to the fish trophic level. Piscivorous species had the highest mean ratio (4.0) and herbivorous species the lowest (0.9). There was a positive and statistically significant correlation between selenium and mercury concentrations for the herbivorous species (r = 0.716;p = 0.0088) not seen for omnivororus and piscivorous species (r = -0.2032;p = 0.3407). These findings are significant for the fish-eating population of the Madeira River because the ingestion of mercury would always be in excess of selenium.  相似文献   

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Haptoglobin (Hp), a hemoglobin-binding protein, is known as an acute phase protein and increases during the acute phase of inflammation in most mammals. We reported previously in brown bears that the mean Hp concentrations were higher in blood samples obtained in winter than those in spring. To examine a possible relation of the seasonal variations of Hp to hibernation, in the present study, we measured the plasma concentrations of Hp as well as some other acute phase proteins (alpha(2)-macroglobulin, alpha(1)-antitrypsin, C-reactive protein) in 6 European brown bears (Ursus arctos), from which blood samples were obtained at 5-6 different months of year including February, the time of hibernation. The Hp concentrations showed clear seasonal variations, being highest in February. The alpha(2)-macroglobulin concentrations also showed a similar but much smaller rise in February, but those of alpha(1)-antitrypsin and C-reactive protein did not show any seasonal variations. Our results suggest that the seasonal variation of plasma Hp concentration in brown bears is associated with a hibernation-specific mechanism more than that of acute phase response.  相似文献   

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Amylin is stored in the pancreatic beta-cell granules and cosecreted with insulin in response to nutrient stimuli. To gain further insight into control of hormonal release in beta-cell physiology, we examined whether amylin, like insulin, circulates in a high-frequency oscillatory pattern, and if it does, to compare the secretory patterns of the two hormones. Eight overnight-fasted healthy individuals were studied during intravenous glucose infusion (2.0 mg. kg(-1). min(-1)). Blood was collected every minute for 90 min and analyzed in triplicate for amylin, total amylin immunoreactivity (TAI), and insulin. Mean plasma concentrations of amylin (nonglycosylated), TAI (nonglycosylated plus glycosylated), insulin, and glucose were 2.77 +/- 1.21 pmol/l, 7.60 +/- 1.73 pmol/l, 50.4 +/- 17.5 pmol/l, and 5.9 +/- 0.3 mmol/l, respectively. The 90-min time series of amylin, TAI, and insulin were analyzed for periodicity (by spectral analysis, autocorrelation analysis, and deconvolution analysis) and regularity [by approximate entropy (ApEn)]. Significant spectral density peaks were demonstrated by a random shuffling technique in 7 (out of 7), 8 (out of 8), and 8 (out of 8) time series, respectively, whereas autocorrelation analysis revealed significant pulsatility in 5 (out of 7), 7 (out of 8), and 5 (out of 8), respectively. The dominant periodicity of oscillations determined by spectral analysis was 4.6 +/- 0.3, 4.6 +/- 0.4, and 6. 5 +/- 1.1 min/pulse, respectively (amylin vs. insulin, P = 0.017, TAI vs. insulin, P = 0.018). By deconvolution analysis, amylin and insulin periodicities were, respectively, 6.3 +/- 1.0 and 5.5 +/- 0. 6 min. By application of the regularity statistic, ApEn, 6 (out of 7), 7 (out of 8), and 6 (out of 8), respectively, were found to be significantly different from random. In conclusion, like several other hormones, circulating amylin concentrations exhibit oscillations in the secretory patterns for nonglycosylated as well as glycosylated forms. Whether the high-frequency pulsatile release of amylin is disturbed in diabetes is not known.  相似文献   

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Methylmercury is a toxic pollutant and is generated by microbial methylation of elemental or inorganic mercury in the environment. Previous study found decreased hepatic MDA levels and urinary mercury levels in methylmercury poisoned rats after sodium selenite treatment. This study further found increased mercury levels in serum samples from methylmercury poisoned rats after selenium treatment. By using size exclusion chromatography coupled to inductively coupled plasma mass spectrometry, three Hg- binding protein fractions and two Se-binding protein fractions were identified with the molecular weight of approximately 21, 40, and 75 kDa and of 40 and 75 kDa, respectively. Elevated mercury level in the 75 kDa protein fraction was found binding with both Hg and Se, which may explain the decreased urinary Hg excretion in MeHg poisoned rats after Se treatment. MALDI-TOF-MS analysis of the serum found that the 75 kDa protein fractions were albumin binding with both Hg and Se and the 21 kDa fraction was Hg- binding metallothionein.  相似文献   

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The purpose of this study was to examine plasma and intraerythrocyte lactate concentrations during graded exercise in humans. Seven adult volunteers performed a maximum O2 uptake (VO2max) test on a cycle ergometer. Plasma and intraerythrocyte lactate concentrations (mmol . L-1 of plasma or cell water) were determined at rest, during exercise, and at 15-min post-exercise. The results show that plasma and intraerythrocyte lactate concentrations were not significantly different from each other at rest or moderate (less than or equal to 50% VO2max) exercise. However, the plasma concentrations were significantly increased over the intraerythrocyte levels at 75% and 100% VO2max. The plasma to red cell lactate gradient reached a mean (+/- SE) 1.7 +/- 0.4 mmol . L-1 of H2O at exhaustion, and was linearly (r = 0.84) related to the plasma lactate concentration during exercise. Interestingly, at 15-min post-exercise the direction of the lactate gradient was reversed, with the mean intraerythrocyte concentration now being significantly increased over that found in the plasma. These results suggest that the erythrocyte membrane provides a barrier to the flux of lactate between plasma and red cells during rapidly changing blood lactate levels. Furthermore, these data add to the growing body of research that indicates that lactate is not evenly distributed in the various water compartments of the body during non-steady state exercise.  相似文献   

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In humans, calves and rabbits very strong correlations were found between the concentrations of serum total cholesterol and phospholipids; in these species more than 70% of the variance in the level of serum phospholipids is accounted for by the variance in the serum cholesterol concentration. The regression coefficients in the equations relating the concentration of serum cholesterol to that of phospholipids were almost identical in humans and rabbits, but differed from those observed in calves and chickens. It is suggested that the rabbit is a suitable model animal for studying the relation between cholesterol and phospholipids in human serum.  相似文献   

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Three new species ofDalea (Fabaceae tribe Amorpheae) discovered in the Andes of Cajamarca, Peru by Prof. I. Sánchez Vega are described, illustrated, and discussed. All (Dalea glumacea, D. isidori, D. tridactylites) belong to sect.Parosela ser.Coeruleae, 14 members of which are currently known from the Department, the principal focus of speciation for the series. A key to the 16 taxa ofDalea found hitherto in Departmento de Cajamarca is provided.  相似文献   

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