Environmental Modeling & Assessment - Costa Rica has set a very ambitious Nationally Determined Contribution (NDC). Despite the low-carbon footprint of its power sector, the goal set in its NDC... 相似文献
Ongoing loss of biological diversity is primarily the result of unsustainable human behavior. Thus, the long-term success of biodiversity conservation depends on a thorough understanding of human–nature interactions. Such interactions are ubiquitous but vary greatly in time and space and are difficult to monitor efficiently at large spatial scales. However, the Information Age also provides new opportunities to better understand human–nature interactions because many aspects of daily life are recorded in a variety of digital formats. The emerging field of conservation culturomics aims to take advantage of digital data sources and methods to study human–nature interactions and thus to provide new tools for studying conservation at relevant temporal and spatial scales. Nevertheless, technical challenges associated with the identification, access, and analysis of relevant data hamper the wider adoption of culturomics methods. To help overcome these barriers, we propose a conservation culturomics research framework that addresses data acquisition, analysis, and inherent biases. The main sources of culturomic data include web pages, social media, and other digital platforms from which metrics of content and engagement can be obtained. Obtaining raw data from these platforms is usually desirable but requires careful consideration of how to access, store, and prepare the data for analysis. Methods for data analysis include network approaches to explore connections between topics, time-series analysis for temporal data, and spatial modeling to highlight spatial patterns. Outstanding challenges associated with culturomics research include issues of interdisciplinarity, ethics, data biases, and validation. The practical guidance we offer will help conservation researchers and practitioners identify and obtain the necessary data and carry out appropriate analyses for their specific questions, thus facilitating the wider adoption of culturomics approaches for conservation applications. 相似文献
Abstract: This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb‐Douglas including a quadratic term in log output. The model parameters are estimated by maximum likelihood using Brazilian data for the year 2002. Statistical inference leads to the conclusion that there is no evidence that private firms and public firms are significantly different in terms of efficiency measurements. 相似文献
Wildlife data often show spatial organization, demonstrating positive correlations either as a result of processes occurring
over the landscape or due to the influence of spatially structured environmental variables. It is, thus, essential to consider
non-random spatial structure when evaluating the underlying causes of biological variation. In this study, we analyzed the
population structure of Chilina dombeyana shell morphology of 14 populations that are close geographically and belong to the same hydrographic basin. We utilized a
variation partitioning approach to evaluate the importance of spatial processes, such as migration, acting over the landscape,
and environmental characteristics, including habitat and hydrologic characteristics, and the occurrence of aquatic predators
in promoting between population variation. Our results demonstrate spatially structured variation in C. dombeyana shell morphology, with populations living near each other having more similar shell sizes than populations living farther
apart. The shell size variation partition indicated that both spatially structured environmental factors and genetic relationships
resulting from migration or shared common ancestry may explain this pattern. Shell shape variation, in contrast, was found
to be essentially under the influence of non-spatially structured environmental factors, with habitat and water characteristics
accounting for about half of the total variation among populations. The large proportion of the variation in shell size that
is spatially structured demonstrates that spatial structure on morphological traits might be strong and highlights the need
to consider such phenomenon in intraspecific studies of phenotypic evolution. 相似文献
ABSTRACT: Agriculture is the leading cause of regional‐scale non‐point source (NPS) pollution in the world today. Indices of pesticide leaching in the vadose zone are well suited for estimating the spatial accumulation and distribution of NPS pollutants in the near surface. In this study the Attenuation Factor (AF) and the Leaching index (Li) are used to assess the near‐surface leaching potential for 32 important agrochemicals for world average agricultural soil properties and recharge rates. The AF and Li indices both require the same input data and appear to work well for nonpolar chemicals. In the effort reported here the AF and Li indices produced similar results for the 32 agrochemicals. Pesticides with high and moderate leaching potential are identified. The AF estimates were more constant than the Li estimates for changes in the compliance depth and recharge rate. The AF index is simpler to use than the Li index and, therefore, is more likely to be employed in the future for screening/ranking agrochemicals relative to regional‐scale NPS ground water vulnerability. 相似文献
The spatial distribution of phytoplankton assemblages, chlorophyll, primary production and physical and chemical parameters were studied in the Pontevedra Ria in Galicia (NW Iberian Peninsula) from October 1997 to October 1998. In addition to the usual oceanographic periods described for the Galician Coast, two other periods were observed: a Prebloom or winter bloom, occurring during calm, sunny days in winter and a Continental period, related to the allochthonous intrusion of low salinity water from the Miño River in late spring. The phytoplankton biomass and production in both periods reached values of up to 145 mgChl-a m?2 and 3.6 gC m?2 day?1, respectively, which were similar to those found in summer upwelling blooms. Throughout the year, the phytoplankton biomass and primary production gradients along the ria’s axis were highly dependent on the balance between upwelling and runoff. When the latter prevailed, increased values were measured toward the inner ria, while the opposite pattern was observed during summer upwelling blooms. According to projections derived from climate models and the analysis of wind patterns, temperature and precipitation trends in the area, a drop in the productivity of the ria would be expected as a result of reduced upwelling intensity in summer and decreasing rainfall in spring. In any case the estuarine part of the ria would be the most seriously affected. 相似文献
The northeastern Atlantic and the Mediterranean Sea share geological histories and display great faunal affinities. The majority
of the Mediterranean species have Atlantic origins, with a few species with tropical affinities. These include the parrotfish
Sparisoma cretense and the wrasse Thalassoma pavo that are restricted to the subtropical northeastern Atlantic, the Macaronesian archipelagos (Azores, Madeira, and Canaries)
and the southern Mediterranean. The Pleistocene glaciations have been described as having different effects on the fauna of
the two regions. During glacial peaks, Mediterranean waters remained warmer than those of the adjacent Atlantic. Within the
eastern Atlantic, the effects of Pleistocene glaciations were differentiated. Here, we perform a comparative analysis focusing
on T. pavo and S. cretense populations from the northeastern Atlantic and the Mediterranean to assess the effects of Pleistocene glaciations in these
two species. Sequences from the mitochondrial control region were obtained and analyzed combining phylogeographic and demographic
approaches. Gene flow between Atlantic and Mediterranean populations was shown to be very high. The Mediterranean populations
of T. pavo and S. cretense showed high levels of genetic diversity, even in the eastern basin, pointing to an ancient colonization event. This suggests
that both species must have been able to persist in the Mediterranean during the cold Pleistocene periods. Historical migration
estimates revealed a Mediterranean towards Atlantic trend in the case of T. pavo, which may reflect the re-colonization of areas in the Atlantic by fish that survived the cold phases in relatively warmer
Mediterranean refugia. Our data also showed that within the Macaronesian Archipelagos, migrations occurred from Madeira towards
the Azores, for both T. pavo and S. cretense, thus supporting a post-glacial colonization of the Azores by fish that persisted in the warmer region of Madeira. Similar
geographic distributions, thermal affinities, and means of dispersion for T. pavo and S. cretense resulted in a similar response to the effects of Pleistocene glaciations, as evidenced by identical phylogeographic patterns. 相似文献
Very little is known about the ecology of common bottlenose dolphins (Tursiops truncatus) living in oceanic waters. This study investigated the ranging and residence patterns of bottlenose dolphins occurring in
the Azores (Portugal), the most isolated archipelago in the North Atlantic. Data were collected during standardized boat-based
surveys conducted over a 6-year period in an area of approximately 5,400 km2 (main study area). To investigate the extent of movements of individual animals, non-systematic surveys were also conducted
outside this area. Only 44 individuals out of 966 identified were frequently sighted within and between years. The remaining
individuals were either temporary migrants from within or outside the archipelago, or transients. Resident dolphins showed
strong geographic fidelity to the area. Long-distance movements (of almost 300 km), consistent with foraging or exploratory
trips, were observed among non-resident dolphins. Home range size was estimated for 31 individuals sighted ≥10 times. Range
areas of these dolphins varied in size and location, but considerable overlap was observed in the areas used, suggesting the
absence of habitat partitioning between resident and non-resident dolphins. Estimates of home range size of bottlenose dolphins
in the Azores were found to be considerably larger than those previously reported for this species. It is hypothesized that
dolphins living in the Azores carry out extensive movements and have large home ranges in response to the lower density and
patchy distribution of prey compared to other areas. The extensive ranging behaviour and the lack of territoriality provide
an opportunity for interbreeding between dolphins associated with different islands, thus preventing genetic differentiation
within the population of the Azores. 相似文献
Environmental Science and Pollution Research - Urban tropical lagoons are often impacted by eutrophication, metal, and polycyclic aromatic hydrocarbon (PAH) contamination, but the toxicity of their... 相似文献
In this study, we evaluated, in a pioneering way, the influence of wavelengths from the decomposition of white light on the production and physicochemical properties of silver nanoparticles (AgNPs). Bearing in mind a process of green synthesis, an extract of the bracts of Bougainvillea glabra Choisy (BgC) was used, a species native to tropical and subtropical regions and frequently used in ornamentation, possessing in its photochemical composition, biomolecules capable of acting as reducing agents for convert Ag+ to Ag0. We used light-emitting diodes (LED) to obtain the desired wavelengths (violet, blue, green, yellow, orange, and red) in the test called rainbow, and we evaluated the obtaining of AgNPs compared to white LED light, nature, and absence of light. In the rainbow assay, we obtained a gradual increase in the intensity of the plasmonic band resonance from the red wavelength (0.124 ± 0.067 a.u.) to violet (0.680 ± 0.199 a.u.), indicating a higher reaction yield in obtaining AgNPs. Smaller hydrodynamic sizes (approximately 150 nm) at more energetic wavelengths (violet, blue, and green) about less energetic wavelengths (yellow, orange, and red) (approximately 400 nm) were obtained. Analysis by SEM microscopy, FTIR spectroscopy, and X-ray diffraction indicates the presence of silver nanoparticles in all LED colors used together with white LED light and Laboratory light (natural light). Due to the high environmental demand to remove pollutants from water sources, including textile dyes, we applied AgNPs/BgC to remove methylene blue (MB) dye from an aqueous solution. A minimum removal percentage greater than 65%, with emphasis on formulations synthesized by the colors of violet LED (84.27 ± 2.65%) and orange LED (85.91 ± 1.95%), was obtained.