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1.
Accid Anal Prev ; 192: 107258, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37611508

RESUMO

Electric-two-wheeler (E2W) related accidents have become a major safety concern on road due to the growing prevalence and the high casualty rate. Most existing studies focus on drivers of the E2W, while ignore the second rider (usually a child) as passenger. This study aims at investigating the kinematic response of the child rider upon vehicle impact and analyzing how motion patterns are influenced by the geometric parameters of the vehicle and E2W. A computational framework was established for the intended task. We modeled the E2W-rider system in Madymo, including an E2W with parametric geometry and two riders, one adult and one child respectively. This study focuses on lateral impact in terms of the accident scenarios, as the case dominates in the field data reports. Vehicle types, seating height of the E2W and sitting position of the child rider were considered as variables in the simulation matrix. Results show that the relative height between child's sitting and vehicle hood front-edge, and the sitting position (back-seated or front-seated) are two main influencing parameters on kinematic responses of child rider. The child rider tends to bounce higher on hood upon impact when sitting above the hood front-edge, while might be laterally pushed away by the car-front when sitting below the hood front-edge. Meanwhile, back-seated child rider is more likely to rise higher and rotate faster upon impact compared to a front-seated one. These findings may guide safe riding and safety countermeasure development for child riders of E2W.


Assuntos
Acidentes de Trânsito , Eletricidade , Adulto , Humanos , Criança , Fenômenos Biomecânicos , Acidentes de Trânsito/prevenção & controle , Simulação por Computador , Movimento (Física)
2.
Sci Total Environ ; 694: 133771, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756816

RESUMO

It is well known that existing protected areas (PAs) should function as focal areas for expanding PA systems. The optimal complementary conservation areas are often identified by implementing two approaches in systematic conservation planning, i.e., unlocking or locking existing PAs. However, evidence-based studies are lacking for clarifying the efficiencies of these two planning approaches. With Sichuan in southwest China - part of a global biodiversity hotspot - as one case, this study first assessed the ecological representativeness of existing nature reserves (NRs). Using 32 natural vegetation types as the conservation features, we then implemented a systematic conservation planning process by running Marxan software with NR-unlocked and NR-locked scenarios. A human disturbance index was also included as a penalty function in Marxan for achieving cost-effective planning. We finally investigated the efficiencies of the unlocking and locking planning approaches by comparing the outcomes of the NR-unlocked and NR-locked scenarios. We found that existing NRs were geographically biased towards the western mountainous regions with high elevations and low human disturbance levels. For achieving the same quantitative conservation targets, the total area of the NR-locked priority conservation areas was 18.6% larger than that of the NR-unlocked areas, whereas the area of NR-locked complementary areas to existing NRs was 15.3% smaller than that of NR-unlocked ones. Moreover, the NR-locked priority conservation areas had higher ecological representativeness than NR-unlocked areas. The results suggest that if a completely new PA system is to be established without considering existing PAs, the unlocking approach could more efficiently achieve the full conservation targets at lower costs of land area and with better connected habitats. When existing PAs must be used as focal areas for expansion, the locking approach is more cost-effective for filling conservation gaps by requiring smaller amounts of complementary areas. Our analysis provides evidence-based support for expanding the current PA systems in a cost-effective manner.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , China , Análise Custo-Benefício , Ecologia , Ecossistema
3.
Appl Bionics Biomech ; 2018: 5906987, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755584

RESUMO

The objective of the present study is to develop an age-specific lower extremity finite element model for pedestrian accident simulation. Finite element (FE) models have been used as a versatile tool to simulate and understand the pedestrian injury mechanisms and assess injury risk during crashes. However, current computational models only represent certain ages in the population, the age spectrum of the pedestrian victims is very large, and the geometry of anatomical structures and material property of the lower extremities changes with age for adults, which could affect the injury tolerance, especially in at-risk populations such as the elderly. The effects of age on the material mechanical property of bone and soft tissues of the lower extremities as well as the geometry of the long bone were studied. Then an existing 50th percentile male pedestrian lower extremity model was rebuilt to depict lower extremity morphology for 30- to 70-year-old (YO) individuals. A series of PMHS tests were simulated to validate the biofidelity and stability of the created age-specific models and evaluate the lower extremity response. The development of age-specific lower extremity models will lead to an improved understanding of the pedestrian lower extremity injury mechanisms and injury risk prediction for the whole population in vehicle-pedestrian collision accidents.

4.
Nat Genet ; 48(8): 947-52, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27399969

RESUMO

The snub-nosed monkey genus Rhinopithecus includes five closely related species distributed across altitudinal gradients from 800 to 4,500 m. Rhinopithecus bieti, Rhinopithecus roxellana, and Rhinopithecus strykeri inhabit high-altitude habitats, whereas Rhinopithecus brelichi and Rhinopithecus avunculus inhabit lowland regions. We report the de novo whole-genome sequence of R. bieti and genomic sequences for the four other species. Eight shared substitutions were found in six genes related to lung function, DNA repair, and angiogenesis in the high-altitude snub-nosed monkeys. Functional assays showed that the high-altitude variant of CDT1 (Ala537Val) renders cells more resistant to UV irradiation, and the high-altitude variants of RNASE4 (Asn89Lys and Thr128Ile) confer enhanced ability to induce endothelial tube formation in vitro. Genomic scans in the R. bieti and R. roxellana populations identified signatures of selection between and within populations at genes involved in functions relevant to high-altitude adaptation. These results provide valuable insights into the adaptation to high altitude in the snub-nosed monkeys.


Assuntos
Adaptação Fisiológica/genética , Colobinae/genética , Marcadores Genéticos/genética , Genoma , Genômica/métodos , Sequência de Aminoácidos , Animais , Colobinae/classificação , Filogenia , Homologia de Sequência de Aminoácidos
5.
Conserv Biol ; 29(5): 1368-77, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26171762

RESUMO

There is profound interest in knowing the degree to which China's institutions are capable of protecting its natural forests and biodiversity in the face of economic and political change. China's 2 most important forest-protection policies are its National Forest Protection Program (NFPP) and its national-level nature reserves (NNRs). The NFPP was implemented in 2000 in response to deforestation-caused flooding. We undertook the first national, quantitative assessment of the NFPP and NNRs to examine whether the NFPP achieved its deforestation-reduction target and whether the NNRs deter deforestation altogether. We used MODIS data to estimate forest cover and loss across mainland China (2000-2010). We also assembled the first-ever polygon dataset for China's forested NNRs (n = 237, 74,030 km(2) in 2000) and used both conventional and covariate-matching approaches to compare deforestation rates inside and outside NNRs (2000-2010). In 2000, 1.765 million km(2) or 18.7% of mainland China was forested (12.3% with canopy cover of ≥70%)) or woodland (6.4% with canopy cover <70% and tree plus shrub cover ≥40%). By 2010, 480,203 km(2) of forest and woodland had been lost, an annual deforestation rate of 2.7%. Forest-only loss was 127,473 km(2) (1.05% annually). In the NFPP provinces, the forest-only loss rate was 0.62%, which was 3.3 times lower than in the non-NFPP provinces. Moreover, the Landsat data suggest that these loss rates are overestimates due to large MODIS pixel size. Thus, China appears to have achieved, and even exceeded, its target of reducing deforestation to 1.1% annually in the NFPP provinces. About two-thirds of China's NNRs were effective in protecting forest cover (prevented loss 4073 km(2) unmatched approach; 3148 km(2) matched approach), and within-NNR deforestation rates were higher in provinces with higher overall deforestation. Our results indicate that China's existing institutions can protect domestic forest cover.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Agricultura Florestal , Florestas , China , Parques Recreativos
6.
PLoS One ; 9(7): e103783, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25072933

RESUMO

By addressing several key features overlooked in previous studies, i.e. human disturbance, integration of ecosystem- and species-level conservation features, and principles of complementarity and representativeness, we present the first national-scale systematic conservation planning for China to determine the optimized spatial priorities for biodiversity conservation. We compiled a spatial database on the distributions of ecosystem- and species-level conservation features, and modeled a human disturbance index (HDI) by aggregating information using several socioeconomic proxies. We ran Marxan with two scenarios (HDI-ignored and HDI-considered) to investigate the effects of human disturbance, and explored the geographic patterns of the optimized spatial conservation priorities. Compared to when HDI was ignored, the HDI-considered scenario resulted in (1) a marked reduction (∼9%) in the total HDI score and a slight increase (∼7%) in the total area of the portfolio of priority units, (2) a significant increase (∼43%) in the total irreplaceable area and (3) more irreplaceable units being identified in almost all environmental zones and highly-disturbed provinces. Thus the inclusion of human disturbance is essential for cost-effective priority-setting. Attention should be targeted to the areas that are characterized as moderately-disturbed, <2,000 m in altitude, and/or intermediately- to extremely-rugged in terrain to identify potentially important regions for implementing cost-effective conservation. We delineated 23 primary large-scale priority areas that are significant for conserving China's biodiversity, but those isolated priority units in disturbed regions are in more urgent need of conservation actions so as to prevent immediate and severe biodiversity loss. This study presents a spatially optimized national-scale portfolio of conservation priorities--effectively representing the overall biodiversity of China while minimizing conflicts with economic development. Our results offer critical insights for current conservation and strategic land-use planning in China. The approach is transferable and easy to implement by end-users, and applicable for national- and local-scale systematic conservation prioritization practices.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , China , Conservação dos Recursos Naturais/economia , Análise Custo-Benefício , Humanos , Modelos Teóricos
8.
PLoS One ; 6(9): e24449, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21915329

RESUMO

Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100-4400 m in winter although the yearly home range spanned from 3500-4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use.


Assuntos
Altitude , Colobinae/fisiologia , Ecossistema , Estações do Ano , Luz Solar , Animais , Sistemas de Informação Geográfica
9.
Environ Sci Pollut Res Int ; 18(5): 800-10, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21234808

RESUMO

PURPOSE: The performance of nature reserves depends on the degree to which they represent a region's full biodiversity. Here, we conducted a study on Hainan Island, China, to assess how well Hainan's biodiversity features were captured by existing nature reserves. We also explored the driving forces behind the current protection pattern so as to provide guidelines for improving the island's conservation system. METHODS: We integrated the information on nature reserves, ecological variables, and human activities into a spatial database, then assessed the performance of nature reserves in representing natural variation, vegetation types, and species, and examined the impacts of human activities and land ownership on the current protection pattern. RESULTS: About 8.4% of Hainan Island was protected by nature reserves; the coverage was geographically biased toward its central mountainous areas with higher elevation, rugged terrain, and fertile soils. We found that 60% of the environmental units and 39.4% of the natural vegetation types had more than 10% of their area protected, respectively. Lowlands tended to have higher animal species richness, and the protection for endangered species was less efficient. Nature reserve coverage was negatively correlated with amount of converted habitats, human population density, and road density, and 82.4% of the total reserved area was allocated on state-owned land. CONCLUSIONS: Nature reserve coverage was not enough to capture lowlands biodiversity features. The current protection pattern was significantly driven by several major conservation targets, human development, planning methods, and land ownership. To improve its conservation system, Hainan should enhance protection in the north and northeast plains and coastal regions, implement systematic planning approaches to define clear visions for guiding future conservation actions, and develop flexible management and funding mechanisms toward sustainable use of natural resources.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Vertebrados/fisiologia , Altitude , Animais , China , Meio Ambiente , Monitoramento Ambiental , Geografia , Atividades Humanas , Solo , Especificidade da Espécie
10.
Mol Ecol ; 18(18): 3831-46, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19732331

RESUMO

The Tibetan Plateau is one of the top 10 biodiversity hotspots in the world and acts as a modern harbour for many rare species because of its relatively pristine state. In this article, we report a landscape genetic study on the Yunnan snub-nosed monkey (Rhinopithecus bieti), a primate endemic to the Tibetan Plateau. DNA was extracted from blood, tissue and fecal samples of 135 wild individuals representing 11 out of 15 extant monkey groups. Ten microsatellite loci were used to characterize patterns of genetic diversity. The most striking feature of the population structure is the presence of five subpopulations with distinct genetic backgrounds and unique spatial regions. The population structure of R. bieti appears to be shaped by anthropogenic landscape features as gene flow between subpopulations is strongly impeded by arable land, highways and human habitation. A partial Mantel test showed that 36.23% (r = 0.51, P = 0.01) of the genetic distance was explained by habitat gaps after controlling for the effect of geographical distance. Only 4.92% of the genetic distance was explained by geographical distance in the partial Mantel test, and no significant correlation was found. Estimation of population structure history indicates that environmental change during the last glacial maximum and human impacts since the Holocene, or a combination of both, have shaped the observed population structure of R. bieti. Increasing human activity on the Plateau, especially that resulting in habitat fragmentation, is becoming an important factor in shaping the genetic structure and evolutionary potential of species inhabiting this key ecosystem.


Assuntos
Colobinae/genética , Fluxo Gênico , Variação Genética , Genética Populacional , Animais , Teorema de Bayes , Ecossistema , Meio Ambiente , Evolução Molecular , Geografia , Humanos , Repetições de Microssatélites , Modelos Genéticos , Dinâmica Populacional , Análise de Sequência de DNA , Tibet
11.
Environ Sci Pollut Res Int ; 16(4): 474-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19308474

RESUMO

BACKGROUND, AIM, AND SCOPE: The Yunnan snub-nosed monkey is one of the most endangered primates in the world. It is experiencing a range of ongoing threats and the persisting effects of past disturbances. The prospects for this species are not very optimistic because habitat corridors are severely damaged by logging, grazing, and mining. Each group of the monkeys in different areas is facing a unique variety of threats. Based on genetic analysis, Rhinopithecus bieti should be separated into three management units for conservation, of which the Mt. Laojun management unit involves the most endangered primates. Despite the fact that the vegetation on Mt. Laojun is in a relatively pristine state, only two groups of monkeys, of a total of fewer than 300, survive in the area. With this paper, we aimed to address the capacity of the monkeys' habitat at the study site and the possible reasons for the small populations. MATERIALS AND METHODS: Rapid ecological assessment based on a SPOT 5 image and field survey was used to simulate the vegetation of the whole area based on reference ecological factors of the GIS system. The vegetation map of the site was thus derived from this simulation. Based on the previous studies, the three vegetation types were identified as the suitable habitat of the monkeys. The confusion matrix-based field GPS points were applied to analyze the precision of the habitat map. Based on the map of suitable habitat of the monkeys, the utilization of the habitat and the carrying capacity were analyzed in the GIS. RESULTS: The confusion matrix-based field GPS points were applied to the habitat analysis process, and it was found that the habitat map was 81.3% precise. Then, with the current habitat map, we found that the mixed forest currently used by the monkeys is only a very small fraction (2.65%) of the overall potential habitat of the population, while the dark conifer forest is 4.09%. DISCUSSION: Poaching is the greatest short-term threat to this species, particularly in the southern range where local residents have a strong tradition of hunting. Quite a few individual monkeys are still trapped accidentally due to the high density of traps. These problems are hard to mitigate because it is difficult to enforce laws due to the extremely rugged terrain. CONCLUSIONS: The results show that there is a great ecological capacity of the area for the monkey's survival and a great potential for an expansion of the monkey population at the site. Based on the current population and its geographical range, it can be estimated that the suitable habitat area defined by this study can support more monkeys, about many times the current population. Thus, at least in the Mt. Laojun Area, poaching pressure is the main factor to be responsible for the low density of Yunnan snub-nosed monkeys instead of habitat alteration. RECOMMENDATIONS AND PERSPECTIVES: Based on these results, some suggestions relating to conservation can be made: Focus conservation efforts on the current distribution area of the monkeys and create a 20 km buffer zone; design a long-term plan for the suitable habitat outside the buffer zone to set up a wildlife corridor in the long run; establish an association for the local hunters exploiting, their knowledge on the animals to promote monkey conservation and stop poaching. Also, the map derived from the study helps managers to allocate conservation resources more efficiently and enhances the overall outcomes of conservation measures.


Assuntos
Colobinae/fisiologia , Ecossistema , Animais , China , Densidade Demográfica
12.
Integr Zool ; 4(2): 162-171, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21392286

RESUMO

Home range studies are essential for understanding an animal's behavioral ecology and for making wildlife conservation efficient. The home range of a group of Yunnan snub-nosed monkeys (Rhinopithecus bieti Milne-Edwards, 1897) was estimated using a global positioning system collar from December 2003 to October 2004 in northern Yunnan Province, China. To measure the ranging area of the study group 1291 animal locations were fixed. Based on the 100% minimum convex polygon method, the home range size was approximately 32.8 km(2) ; based on the grid-cell method it was approximately 17.8 km(2) using a 250-m grid and 23.3 km(2) using a 500-m grid. We assessed seasonal changes in the home range of this monkey population and found a different ranging pattern of from earlier studies. Daily range size was calculated as 4.80 ± 5.81 ha (mean ± standard deviation), with a range of 45.66 ha (0.01-45.67 ha).


Assuntos
Colobinae/fisiologia , Comportamento de Retorno ao Território Vital/fisiologia , Estações do Ano , Migração Animal/fisiologia , Animais , Comportamento Animal/fisiologia , China , Sistemas de Informação Geográfica , Masculino
13.
Mol Ecol ; 16(16): 3334-49, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17688537

RESUMO

Rhinopithecus bieti, the Yunnan snub-nosed monkey, is the nonhuman primate with the highest altitudinal distribution and is also one of the 25 most globally endangered primate species. Currently, R. bieti is found in forests between 3000 and 4500 m above sea level, within a narrow area on the Tibetan Plateau between the Yangtze and Mekong rivers, where it is suffering from loss of habitat and shrinking population size (approximately 1500). To assess the genetic diversity within this species, its population structure and to infer its evolutionary history, we sequenced 401 bp of the hypervariable I (HVI) segment from the mitochondrial DNA control region (CR) for 157 individuals from 11 remnant patches throughout the fragmented distribution area. Fifty-two variable sites were observed and 30 haplotypes were defined. Compared with other primate species, R. bieti cannot be regarded as a taxon with low genetic diversity. Phylogenetic analysis partitioned haplotypes into two divergent haplogroups (A and B). Haplotypes from the two mitochondrial clades were found to be mixed in some patches although the distribution of haplotypes displayed local homogeneity, implying a strong population structure within R. bieti. Analysis of molecular variance detected significant differences among the different geographical regions, suggesting that R. bieti should be separated into three management units (MUs) for conservation. Based on our results, it can be hypothesized that the genetic history of R. bieti includes an initial, presumably allopatric divergence between clades A and B 1.0-0.7 million years ago (Ma), which might have been caused by the Late Cenozoic uplift of the Tibetan Plateau, secondary contact after this divergence as a result of a population expansion 0.16-0.05 Ma, and population reduction and habitat fragmentation in the very recent past.


Assuntos
Conservação dos Recursos Naturais , DNA Mitocondrial/genética , Ecossistema , Haplorrinos/classificação , Haplorrinos/genética , Animais , China , Geografia , Haplorrinos/sangue , Funções Verossimilhança , Filogenia , Densidade Demográfica , Tibet
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