首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
For successful management and development of protected areas in general, and national parks (NPs) more specifically, a high acceptance by local residents, interest groups, and policy makers is needed. Communication and participation as influencing factors of acceptability have mostly been analysed for already established NPs. Until today, there is little evidence as to whether communication and participation are relevant factors for gaining acceptance of NPs in their establishing phase. Using survey data regarding Black Forest NP (Germany), our aim is to ascertain how the NP administration’s communication and the participatory opportunities it provided affected the NP’s acceptability before its establishment in 2014, and how acceptability changed thereafter. The main results are: In 2014, half of the local population accepted Black Forest NP; and over the course of five years, this number increased only slightly. Regarding the information provided by the NP administration through different means of communication, almost half of the respondents felt (very) well-informed at both queried times. The public participation process accompanying the NP’s establishing phase was rated as good or very good by roughly one third of the respondents; while another third evaluated it as bad or very bad. The general participation efforts by the NP administration were evaluated mostly critically. However, respondents who showed a positive attitude towards the NP in 2019 were those who felt well-informed, rated the material as informative, the NP’s communication as honest, and the participation process as positive. Respondents were more likely to report a positive change within acceptability if they felt well-informed, had a positive impression of the NP rangers, and rated the general participation efforts as positive. These results are an important step toward better understanding the complexity of attitude formation, and they provide statistical evidence that communication and participation can influence the acceptability of protected areas from their early beginnings. Beyond our results regarding Black Forest NP, we also draw conclusions and recommendation of broader relevance.  相似文献   

2.

Background

The National Children’s Study (NCS) is a prospective epidemiological study in the USA tasked with identifying a nationally representative sample of 100,000 children, and following them from their gestation until they are 21 years of age. The objective of the study is to measure environmental and genetic influences on growth, development, and health. Determination of the ancestry of these NCS participants is important for assessing the diversity of study participants and for examining the effect of ancestry on various health outcomes.

Results

We estimated the genetic ancestry of a convenience sample of 641 parents enrolled at the 7 original NCS Vanguard sites, by analyzing 30,000 markers on exome arrays, using the 1000 Genomes Project superpopulations as reference populations, and compared this with the measures of self-reported ethnicity and race. For 99% of the individuals, self-reported ethnicity and race agreed with the predicted superpopulation. NCS individuals self-reporting as Asian had genetic ancestry of either South Asian or East Asian groups, while those reporting as either Hispanic White or Hispanic Other had similar genetic ancestry. Of the 33 individuals who self-reported as Multiracial or Non-Hispanic Other, 33% matched the South Asian or East Asian groups, while these groups represented only 4.4% of the other reported categories.

Conclusions

Our data suggest that self-reported ethnicity and race have some limitations in accurately capturing Hispanic and South Asian populations. Overall, however, our data indicate that despite the complexity of the US population, individuals know their ancestral origins, and that self-reported ethnicity and race is a reliable indicator of genetic ancestry.  相似文献   

3.
Bacterial communities mediate many of the processes in boreal forest floors that determine the functioning of these ecosystems, yet it remains uncertain whether the composition of these communities is distributed nonrandomly across the landscape. In a study performed in the southern boreal mixed wood forest of Québec, Canada, we tested the hypothesis that stand type (spruce/fir, aspen, paper birch), stand age (57, 78–85, and 131 years old), and geologic parent material (clay and till) were correlated with forest floor bacterial community composition. Forest floors in 54 independent forest stands were sampled to comprise a full factorial array of the three predictor variables. Bacterial community structure was examined by terminal restriction fragment (T-RF) length polymorphism analysis of genes encoding for 16S rRNA. Distance-based redundancy analysis of T-RF assemblages revealed that each predictor variable, as well as their interaction terms, had a significant effect on bacterial community composition, geologic parent material being the most discriminating factor. A survey of the 15 T-RFs with the highest percentage fit on the first two ordination axes describing the main effects indicated that each landscape feature correlated to a distinct group of bacteria. A survey of the most discriminant T-RFs describing the effect of stand type within each combination of stand age and geologic parent material indicated a strong dependency of several T-RFs on geologic parent material. Given the possible link between bacterial community composition and forest floor functioning, we also assessed the effects of the same three landscape features on community-level catabolic profiles (CLCP) of the extractable forest floor microbiota. Geologic parent material and stand type had significant effects on CLCPs. On clay plots, the effects of landscape features on T-RF patterns were highly consistent with their effects on CLCPs. In light of our results, we suggest that future research examine whether bacterial community composition or CLCPs can be used to detect latent environmental changes across landscape units.  相似文献   

4.
In Canaima National Park (CNP), Venezuela, a protected area inhabited by the Pemón people, socio-cultural and demographic changes have contributed to the apparent unsustainable use of fire, leading to forest and habitat loss. This over-use of fire, together with increased forest vulnerability to fire as a result of global climate change, could put both ecosystems and human well-being at risk. The conflict over fire use derives from the fact that whereas the Pemón depend for their livelihood on the use of fire for shifting cultivation and hunting, the policy of the CNP government agencies is fire exclusion (although this is not effectively enforced). Nevertheless, recent ecological studies have revealed that the creation of a mosaic of patches with different fire histories could be used to create firebreaks that reduce the risk of the wildfires that threaten the vulnerable and diverse savanna-forest transition areas. This technique imitates the traditional cooperative savanna burning strategies of the Pemón. By linking research on knowledge systems with management policies, the impasse over fire in the CNP might be avoided.  相似文献   

5.
The size of treefall gaps is an important determinant of regeneration composition in tropical and temperate forests. Preliminary studies in the laurel forest of Tenerife have shown that small gaps (<100 m2) were the most numerous. However, due to this small size, no significant differences were found between regeneration in gaps and regeneration below the canopy. Because infrequent large gaps (>100 m2) are present in the laurel forest, we analyzed the regeneration in these large uncommon gaps, considering their potentially important role in the dynamics of the system. Our main hypothesis is that large gaps are important disturbance to ensure the regeneration and stablishment of shade intolerant species. Only five gaps larger than 100 m2 (ranging from 125–268 m2) were found in the study area. Data from a further 20 small gaps (<100 m2), analysed in a previous study, was also included. Control plots were examined close to the gaps in order to determine regeneration below the closed canopy. We did not find a significant difference between regeneration density in the gaps (<100 m2) and regeneration below the canopy in the control plots. Contrary to our expectations, regeneration was lower in the large gaps than under the canopy. The open canopy in the large gaps increases light intensity, and has a negative effect on the germination and growth of shade-tolerant tree species like Viburnum tinus (although non-statistically significant); however, the increase in light intensity is not sufficient to stimulate the germination of shade-intolerant tree species. The effects of treefall gaps in the dynamics of the laurel forest of Anaga should be not considered as significant in comparison to other factors such as human disturbances or infrequent disturbances (land slides or hurricanes).  相似文献   

6.
7.
Deforestation and fragmentation are major components of global change; both are contributing to the rapid loss of tropical forest area with important implications for ecosystem functioning and biodiversity conservation. The forests of South Ecuador are a biological ‘hotspot’ due to their high diversity and endemism levels. We examined the deforestation and fragmentation patterns in this area of high conservation value using aerial photographs and Aster satellite scenes. The registered annual deforestation rates of 0.75% (1976–1989) and 2.86% (1989–2008) for two consecutive survey periods, the decreasing mean patch size and the increasing isolation of the forest fragments show that the area is under severe threat. Approximately 46% of South Ecuador’s original forest cover had been converted by 2008 into pastures and other anthropogenic land cover types. We found that deforestation is more intense at lower elevations (premontane evergreen forest and shrubland) and that the deforestation front currently moves in upslope direction. Improved awareness of the spatial extent, dynamics and patterns of deforestation and forest fragmentation is urgently needed in biologically diverse areas like South Ecuador.  相似文献   

8.
Dietary ω3-polyunsaturated fatty acids are thought to influence the risk of Alzheimer’s disease (AD), and supplemental docosahexaenoic acid (DHA; 22:6n-3) has been reported to reduce neurodegeneration in mouse models of AD. We have analysed the fatty acid composition of frontal, temporal and parietal neocortex in 58 normal and 114 AD brains. Significant reductions were found for stearic acid (18:0) in frontal and temporal cortex and arachidonic acid (20:4n-6) in temporal cortex in AD, and increases in oleic acid in frontal and temporal cortex (18:1n-9) and palmitic acid (16:0) in parietal cortex. DHA level varied more in AD than controls but the mean values were not significantly different. Fatty acid composition was not related to APOE genotype, age, gender or post-mortem delay. Further research is needed to distinguish between alterations that are secondary to AD and those that contribute to the disease process.  相似文献   

9.
The montane forests of northern Mozambique’s isolated massifs are inhabited by numerous range-restricted and threatened bird species, but until recently were extremely little-known. We report on a first avifaunal survey of the isolated montane habitats of Mt Mecula (1 442 m), Niassa National Reserve, notable as the only currently protected montane area in northern Mozambique. Mount Mecula’s moist forest is small (approximately 136 ha in total) and patchy, and although known botanically to have some montane affinities, was found to support an avifauna more typical of riparian forests of medium to low altitude. The only montane forest species recorded was Lemon Dove Aplopelia larvata. Other montane elements included Vincent’s Bunting Emberiza (capensis) vincenti, one of six species recorded new to the Niassa National Reserve list. Overall, it appears that despite its intermediate location, Mt Mecula does not represent a biogeographical ‘stepping stone’ for montane forest bird species. This probably owes to its remoteness from the Eastern Arc Mountains of Tanzania to the north and the massifs of other parts of northern Mozambique, to the south and west.  相似文献   

10.
Disbalance of zinc (Zn2+) and copper (Cu2+) ions in the central nervous system is involved in the pathogenesis of numerous neurodegenerative disorders such as multisystem atrophy, amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, Wilson-Konovalov disease, Alzheimer’s disease, and Parkinson’s disease. Among these, Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the most frequent age-related neurodegenerative pathologies with disorders in Zn2+ and Cu2+ homeostasis playing a pivotal role in the mechanisms of pathogenesis. In this review we generalized and systematized current literature data concerning this problem. The interactions of Zn2+ and Cu2+ with amyloid precursor protein (APP), β-amyloid (Abeta), tau-protein, metallothioneins, and GSK3β are considered, as well as the role of these interactions in the generation of free radicals in AD and PD. Analysis of the literature suggests that the main factors of AD and PD pathogenesis (oxidative stress, structural disorders and aggregation of proteins, mitochondrial dysfunction, energy deficiency) that initiate a cascade of events resulting finally in the dysfunction of neuronal networks are mediated by the disbalance of Zn2+ and Cu2+.  相似文献   

11.
Brazil’s Atlantic Forest biome is severely degraded and fragmented throughout its range. Developing effective techniques to restore pasture and agriculture back to native vegetation is therefore a priority for legal and conservation purposes. In this study, we evaluate the ability of artificial bird perches to enhance the arrival of new seeds and seedling establishment in a degraded, semi-deciduous seasonal portion of the Atlantic Forest in southern Brazil. Specifically, we assess the influence of previous land use and habitat types on the abundance, species richness and ecological traits of bird-dispersed seeds, as well as on seedling establishment. Eight sampling sites were established, each containing one unit with seed traps and restoration plots under artificial perches and one similar unit without the perches. These sites were located in pasture and agriculture, distributed between riparian and sub-montane areas. Monthly sampling was conducted over two years between December 2005 and November 2007, resulting in the evaluation of 25,755 seeds and 56 endozoochoric seed species. The most abundant species were the pioneers Cecropia pachystachya Trécul and Solanum americanum Mill. Experimental units with perches received significantly more seeds than control units. Moreover, seed arrival was higher in sub-montane areas and on former pasture sites. Species richness followed a similar pattern of higher seed arrival, but there was no effect of vegetation type. Ecological characteristics of seeds were associated with land use type: former pastures received more tree seeds and pioneer species than expected by chance. Seedling establishment was very low in all treatments, with only eight seedlings established in perch plots by the end of the experiment. We conclude that despite artificial perches significantly increasing the arrival of endozoochoric seeds onto degraded lands, seedling establishment is drastically limited in these areas, compromising the efficacy of this technique for restoration purposes.  相似文献   

12.

Background

The incidence of esophageal adenocarcinoma (EAC) has increased nearly five-fold over the last four decades in the United States. Barrett’s esophagus, the replacement of the normal squamous epithelial lining with a mucus-secreting columnar epithelium, is the only known precursor to EAC. Like other parts of the gastrointestinal (GI) tract, the esophagus hosts a variety of bacteria and comparisons among published studies suggest bacterial communities in the stomach and esophagus differ. Chronic infection with Helicobacter pylori in the stomach has been inversely associated with development of EAC, but the mechanisms underlying this association remain unclear.

Methodology

The bacterial composition in the upper GI tract was characterized in a subset of participants (n=12) of the Seattle Barrett’s Esophagus Research cohort using broad-range 16S PCR and pyrosequencing of biopsy and brush samples collected from squamous esophagus, Barrett’s esophagus, stomach corpus and stomach antrum. Three of the individuals were sampled at two separate time points. Prevalence of H. pylori infection and subsequent development of aneuploidy (n=339) and EAC (n=433) was examined in a larger subset of this cohort.

Results/Significance

Within individuals, bacterial communities of the stomach and esophagus showed overlapping community membership. Despite closer proximity, the stomach antrum and corpus communities were less similar than the antrum and esophageal samples. Re-sampling of study participants revealed similar upper GI community membership in two of three cases. In this Barrett’s esophagus cohort, Streptococcus and Prevotella species dominate the upper GI and the ratio of these two species is associated with waist-to-hip ratio and hiatal hernia length, two known EAC risk factors in Barrett’s esophagus. H. pylori-positive individuals had a significantly decreased incidence of aneuploidy and a non-significant trend toward lower incidence of EAC.  相似文献   

13.
The trajectory of hurricane-induced succession was evaluated in a network of forest plots measured immediately before and 3 mo, 5, 10, and 15 yr after the direct impact of a Category 4 hurricane. Comparisons of forest structure, composition, and aboveground nutrients pools were made through time, and between species, life-history groups and geomorphic settings. The hurricane reduced aboveground biomass by 50 percent, causing an immediate decrease in stem density and diversity indices among all geomorphic settings. After 15 yr, basal area and aboveground biomass returned to pre-hurricane levels, while species richness, diversity indices, and stem densities exceeded pre-hurricane levels. Differences in species composition among geomorphic settings had not returned after 15 yr but differences in stem densities and structure were beginning to emerge. Significant differences were observed in the nutrient concentration of the three species that comprised the most aboveground biomass, and between species categorized as secondary high-light species and primary, low-light species. Species whose abundance was negatively correlated with the mature forest dominant also had distinct nutrient concentrations. When total aboveground nutrient pools were compared over time, differences in leaf nutrients among species were hidden by similarities in wood nutrient concentrations and the biomass dominance of a few species. The observed successional trajectory indicates that changes in species composition contributed to fast recovery of aboveground biomass and nutrient pools, while the influence of geomorphic setting on species composition occurs at time scales >15 yr of succession.  相似文献   

14.
Wielkopolska (western Poland) is a region, with good reason, called the main food base of Poland. All indices of agricultural production have always been there (since 19th century) much higher than elsewhere in the country (Ratajczak 1977/1978, Buszko 1984, Gorzelak 1989, Czyzewski et al. 1992; table 1). Such a situation had a beneficial effect on the amount of the income generated by a family of Wielkopolska and, thus, decided on its better financial status. Additionally, rural inhabitants of this region have always been characterised by a more advantageous educational structure in comparison with people of other Polish villages. Generally, it is easy to detect the relationship between the life standard, the level of education and family planning. The aim of this paper is to assess fertility of women from villages of Wielkopolska in the period of transformation of the political and economic system in Poland.  相似文献   

15.
16.
This study aimed to evaluate the concentrations of copper, iron, and selenium in elderly people with Alzheimer disease (AD), comparing the same parameters in a paired group of healthy people, in order to verify if the amount of these metals may influence the cognitive impairment progression. Patients’ cognitive impairment was evaluated by Clinical Dementia Rating (CDR). The elementary quantification of erythrocytes was performed by inductively coupled plasma mass spectrometry technique. The statistical analyses were carried out by SPSS software 20.0 version, employing Shapiro-Wilk, Wilcoxon, Kruskall-Wallis, and Spearman correlation tests, considering significant results of p < 0.05. The sample was composed of 34% (n = 11) of women and 66% (n = 21) of men in each group. The AD group was characterized by a higher concentration of copper (p < 0.0001) and iron (p < 0.0001); however, there is no significant difference in selenium level. The analyses of the metal levels in different stages of AD were not significant in CDR-1, however in CDR-2 and CDR-3, elevated levels of copper and iron were observed; in CDR-3 patients, the level of selenium was lower (p < 0.008) compared to that of healthy controls. Patients with Alzheimer disease studied present increase in biometal blood levels, especially of copper and iron, and such increase can be different according to the disease stage and can cause more impairment cognitive functions in AD.  相似文献   

17.
18.
This paper demonstrates the importance of the reception and development of Goethe’s metamorphosis of plants as a methodological and philosophical framework in the history of botanical theories. It proposes a focus on the textbooks written by the German botanist Ludwig Reichenbach and his first attempt to use Goethe’s idea of metamorphosis of plants as fundamental to his natural system of plants published under the title ‘Botany for Women’, in German Botanik für Damen (1828). In this book, Reichenbach paid particular attention to Goethe’s sensitive views on the essence of nature; he regarded Goethe’s idea of metamorphosis in the plant kingdom as an ideal model to interpret connections of natural phenomena, in particular as a conceptual frame for a natural system. Furthermore, he aimed to develop the philosophical statement of the metamorphosis, in which he called for nature-philosophical conceptions in order to materialize his representation of plant “affinities,” and of a kind of “ontogeny” of the whole plant kingdom. This paper demonstrates that, between speculative views and empirical attempts, the extent to which Reichenbach actually belonged to a new “school” of thought, which left its mark on the history and philosophy of botany.  相似文献   

19.
20.
Abstract — Conclusions about the rates of evolution among a group of organisms are only are only as sound as the phylogeny upon which the conclusions are based. We re-evaluated the rates of allozyme evolution amoung lizards of the speciose genus Sceloporus. The initial evaluation was suspect because a modification of the invalid, presence or absence method of data coding was employed in genealogical estimation. We recoded the allozyme data using the locus as the character and observed that the previous best explanation of the data fell within a forest of an estimated 107 trees. Further explorations into the invalidity of the independent alleles model of data coding attributed much, but not all, of the shape of the extremely unlikely, independent alleles tree to the parallel loss of plesiotypic alleles, and not the acquistion of novel alleles resulting from mutations. When the data were more appropriately evaluated using mutation coding, there was no unequivocal evidence for a punctuated equilibrium tempo of evolutionary change.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号