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121.
Isabel Díaz-Reviriego Álvaro Fernández-Llamazares Matthieu Salpeteur Patricia L. Howard Victoria Reyes-García 《Ambio》2016,45(3):263-275
Local medical systems are key elements of social-ecological systems as they provide culturally appropriate and locally accessible health care options, especially for populations with scarce access to biomedicine. The adaptive capacity of local medical systems generally rests on two pillars: species diversity and a robust local knowledge system, both threatened by local and global environmental change. We first present a conceptual framework to guide the assessment of knowledge diversity and redundancy in local medicinal knowledge systems through a gender lens. Then, we apply this conceptual framework to our research on the local medicinal plant knowledge of the Tsimane’ Amerindians. Our results suggest that Tsimane’ medicinal plant knowledge is gendered and that the frequency of reported ailments and the redundancy of knowledge used to treat them are positively associated. We discuss the implications of knowledge diversity and redundancy for local knowledge systems’ adaptive capacity, resilience, and health sovereignty. 相似文献
122.
Anna Bozzano Patricia M. Pankhurst Natalie A. Moltschaniwskyj Roger Villanueva 《Marine Biology》2009,156(7):1359-1373
Eye development, optical properties and photomechanical responses were examined in embryos and hatchlings of the southern
calamary, Sepioteuthis australis. This species occurs in shallow coastal waters in Australia and New Zealand, and the egg masses were collected in October
and December 2004 from Great Oyster Bay, Tasmania. At the earliest developmental stage the eye of the squid was comprised
of a hemispherical cup of undifferentiated neural retina, while presumptive iris cell layers and lentigenic precursor cells
enclosed a posterior eye chamber. Differentiation of the proximal and distal processes was observed in correspondence with
the cornea development and lens crystallization, and occurred before differentiation of the neural retina, which was complete
prior to hatching. Longer photoreceptor distal processes were first observed just prior to hatching in the dorsal-posterior
retina. After hatching, this difference was much more evident and higher photoreceptor density was found in the central retina.
This indicates that the eye of S. australis at this age uses different retina areas for different visual tasks. Optical sensitivity and resolution suggest that juvenile
S. australis are diurnal. This study also found functional photomechanical responses of visual screening pigment migration and pupil constriction
in S. australis embryos, although complete functionality of the pupil at this stage was uncertain. However, the pupils of squid aged 2 days
closed almost completely under bright conditions, showing that photomechanical responses were highly developed in the juvenile
squid. These findings indicate that squid embryos are able to perceive visual stimulation, suggesting an early reliance on
vision for survival after hatching. 相似文献
123.
Biodiversity Conservation in Traditional Coffee Systems of Mexico 总被引:27,自引:1,他引:26
In Mexico, coffee is cultivated on the coastal slopes of the central and southern parts of the country in areas where two or more types of vegetation make contact. Based on management level and vegetational and structural complexity, it is possible to distinguish five main coffee production systems in Mexico: two kinds of traditional shaded agroforests (with native trees), one commercially oriented polyspecific shaded system, and two "modern" systems (shaded and unshaded monocultures). Traditional shaded coffee is cultivated principally by small-scale, community-based growers, most of whom belong to some indigenous culture group. Through an exhaustive review of the literature, we found that traditional shaded coffee plantations are important repositories of biological richness for groups such as trees and epiphytes, mammals, birds, reptiles, amphibians, and arthropods. We evaluated the conservation role of these traditional shaded systems by estimating the percentage of the whole coffee area under traditional management, by reviewing the ecological and geographical distribution of coffee areas in Mexico, and by connecting the geographical distribution of these coffee areas with recognized centers of species richness and endemism. The assesment revealed that in Mexico, coffee fields are located in a biogeographically and ecologically strategic elevational belt that is an area of overlap between the tropical and temperate elements and of contact among the four main types of Mexican forests. We also found that between 60% and 70% of these coffee areas are under traditional management and that at least 14 of 155 priority regions selected by experts as having high numbers of species and endemics overlap with or are near traditional coffee-growing areas. 相似文献
124.
The physical exchange of DNA between homologs, crossing-over, is essential to orchestrate the unique, reductional first meiotic division (MI). In females, the events of meiotic recombination that serve to tether homologs and facilitate their disjunction at MI occur during fetal development, preceding the MI division by several decades in our species. Data from studies in humans and mice demonstrate that placement of recombination sites during fetal development influences the likelihood of an MI nondisjunction event that results in the production of an aneuploid egg. Here we briefly summarize what we know about the relationship between aneuploidy and meiotic recombination and important considerations for the future of human assisted reproduction. 相似文献
125.
Markus Stumm Michael Entezami Karsten Haug Cornelia Blank Max Wüstemann Bernt Schulze Gisela Raabe-Meyer Maja Hempel Markus Schelling Eva Ostermayer Sabine Langer-Freitag Tilo Burkhardt Roland Zimmermann Tina Schleicher Bernd Weil Ulrike Schöck Patricia Smerdka Sebastian Grömminger Yadhu Kumar Wera Hofmann 《黑龙江环境通报》2014,34(2):185-191
126.
G. Bruce Williamson † William F. Laurance † Alexandre A. Oliveira ‡ Patricia Delamônica † Claude Gascon † Thomas E. Lovejoy § and Luciano Pohl† 《Conservation biology》2000,14(5):1538-1542
Abstract: In 1997, the Amazon Basin experienced an exceptionally severe El Niño drought. We assessed effects of this rare event on mortality rates of trees in intact rain forest based on data from permanent plots. Long-term (5- to 13-year) mortality rates averaged only 1.12% per year prior to the drought. During the drought year, annual mortality jumped to 1.91% but abruptly fell back to 1.23% in the year following El Niño. Trees dying during the drought did not differ significantly in size or species composition from those that died previously, and there was no detectable effect of soil texture on mortality rates. These results suggest that intact Amazonian rainforests are relatively resistant to severe El Niño events. 相似文献
127.
Wolke Tobón Tania Urquiza‐Haas Patricia Koleff Matthias Schröter Rubén Ortega‐Álvarez Julio Campo Roberto Lindig‐Cisneros José Sarukhán Aletta Bonn 《Conservation biology》2017,31(5):1086-1097
Ecological restoration has become an important strategy to conserve biodiversity and ecosystems services. To restore 15% of degraded ecosystems as stipulated by the Convention on Biological Diversity Aichi target 15, we developed a prioritization framework to identify potential priority sites for restoration in Mexico, a megadiverse country. We used the most current biological and environmental data on Mexico to assess areas of biological importance and restoration feasibility at national scale and engaged stakeholders and experts throughout the process. We integrated 8 criteria into 2 components (i.e., biological importance and restoration feasibility) in a spatial multicriteria analysis and generated 11 scenarios to test the effect of assigning different component weights. The priority restoration sites were distributed across all terrestrial ecosystems of Mexico; 64.1% were in degraded natural vegetation and 6% were in protected areas. Our results provide a spatial guide to where restoration could enhance the persistence of species of conservation concern and vulnerable ecosystems while maximizing the likelihood of restoration success. Such spatial prioritization is a first step in informing policy makers and restoration planners where to focus local and large‐scale restoration efforts, which should additionally incorporate social and monetary cost–benefit considerations. 相似文献
128.
Sophia Callander Michael D. Jennions Patricia R. Y. Backwell 《Behavioral ecology and sociobiology》2011,65(11):2071-2078
Fiddler crabs live at high densities and mate-searching females encounter many males at varying distances. Who is the ideal neighbour for a male? There could be a trade-off if having neighbours that invest more in sexual signals increases the rate at which females initially move towards a focal male, but thereafter decrease the likelihood that he is chosen rather than his neighbour. We used robotic crabs to test whether female choice for focal males (identical claw size/courtship wave rate) varied depending on the relative investment in sexual signals of their two neighbours and the distance at which she first saw the males. The neighbours’ phenotype did not affect which of two focal males she initially approached from long-range (50 cm). When a female initially saw a trio of males at a close-range (20 cm), she preferentially chose the focal male over neighbours that invested less in sexual signals (smaller claw/slower wave rate), but did not show a preference for the focal male over neighbours that invested more in sexual signals (larger claw/faster wave rate). However, a female that started to approach a focal male with neighbours that invest more in sexual signals from 50 cm was significantly less likely to choose the focal male than when she first saw the trio at 20 cm. Our results suggest that the initial distance at which males are seen partly determines how neighbours’ sexual signals affect male mating success. In general, if larger males can retain smaller neighbours they might therefore increase their mating success. 相似文献
129.
The use of materials is studied broadly, because of the environmental problems related to extraction, production, consumption and waste treatment. The use and substitution of materials in products is therefore a relevant issue for environmental policy making. Studies have been done to describe the material flow or to measure the impact of materials or products on the environment. However, these studies do not often consider economic, substitution and dynamic aspects of material flows. Other studies on material flows analyse the relationship between the use of materials and economic growth, but they do not consider substitution between materials. For environmental policy making economic, technological and environmental aspects of the use of materials need to be considered. Especially, substitution of materials is important. In various countries material and product policies are imposed on a variety of materials and products. For evaluation of these policies their environmental and economic effects need to be examined in detail. This study aims to analyse the economic and technological factors influencing the use of materials and the substitution between different materials dynamically. The goal is to obtain an insight in the effect that material levies may have on the use and substitution of materials. The statistical analysis is performed on a specific product-group because decisions on the use of materials are taken on a product-level. The case study is performed on automobiles. The results show that the material use is largely an autonomous development. The price of aluminium has a positive, significant effect on the use of that material. The price of plastics has a positive, but not significant effect on the use of plastics. Reasons may be that the costs of a raw material are small relative to the processing costs, and that the production process can only be changed slowly. Other factors, like competitiveness and consumers' tastes, may be more important for substitution. This implies that levies or subsidies on certain materials is not a promising policy to change the use of materials. Besides time, there are two other factors that have a positive and significant relationship with the use of aluminium and plastics: the fuel efficiency, which is the distance driven divided by the energy used; and, the road tax, which depends on the weight of a car. However, these effects are caused by their positive relationship with time. The main conclusion of the case study is that imposing a levy on materials may not have the desired or expected effect of reduction in material use. 相似文献
130.