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941.
942.
943.
Paradigms and Public Policies on Drought in Northeast Brazil: A Historical Perspective 总被引:1,自引:0,他引:1
José Nilson B. Campos 《Environmental management》2015,55(5):1052-1063
944.
The global pet trade is a major risk to biodiversity and humans and has become increasingly globalized, diversified, digitalized, and extremely difficult to control. With billions of internet users posting online daily, social media could be a powerful surveillance tool. But it is unknown how reliably social media can track the global pet trade. We tested whether Instagram data predicted the geographic distribution of pet stores and the taxonomic composition of traded species in the emerging pet trade in ants (Hymenoptera, Formicidae). We visited 138 online stores selling ants as pets worldwide and recorded the species traded. We scraped ∼38,000 Instagram posts from ∼6300 users referencing ants as pets and analyzed comments on post and geolocation (available for ∼1800 users). We tested whether the number of Instagram users predicted the number of ant sellers per country and whether the species referenced as pets on Instagram matched the species offered in online stores, with a particular focus on invasive species. The location of Instagram users referencing ants as pets predicted the location of ant sellers across the globe (R2 = 0.87). Instagram data detected 439 of the 631 ant species traded in online stores (70%), including 59 of the 68 invasive species traded (87%). The number of Instagram users referencing a species was a good predictor of the number of sellers offering the species (R2 = 0.77). Overall, Instagram data provided affordable and reliable data for monitoring the emerging pet trade in ants. Easier access to these data would facilitate monitoring of the global pet trade and help implement relevant regulations in a timely manner. 相似文献
945.
Katarzyna M. Mikołajczak Jos Barlow Alexander C. Lees Christopher D. Ives Micha Strack Oriana Trindade de Almeida Agnis C. Souza Frazer Sinclair Luke Parry 《Conservation biology》2023,37(4):e14067
Inner phenomena, such as personal motivations for pursuing sustainability, may be critical levers for improving conservation outcomes. Most conservation research and policies, however, focus on external phenomena (e.g., ecological change or economic processes). We explored the factors shaping 9 conservation attitudes toward forest and wildlife protection among colonist farmers around an Amazonian deforestation frontier. Our data comprised 241 face-to-face quantitative surveys, complemented with qualitative insights from open-ended questionnaire responses and opportunistic semistructured interviews. To account for the full spectrum of possible inner motivations, we employed measures of nature connection (indicating biospheric motivation) and personal values organized around the traditionalism (traditionalist through to high openness to change) and universalism dimensions (egoistic through to altruistic motivations). We used averaged beta-binomial generalized linear models to assess the role of external factors (socioeconomic, sociodemographic, and environmental) and personal (inner) motivations on the variation in attitudes. Each attitude was modeled separately. The relative importance of each predictor was judged by the proportion of models where it appeared as significant. Proconservation views were expressed by the majority (at least 65%) of the respondents in 7 out of the 9 attitude models. The most consistent predictors were emotional nature connection and personal values (significant in 4–6 out of 9 models), rather than external phenomena (significant in 0–5 models). However, the poorest farmers had lower scores on the agreement with prioritizing nature over development (𝛽 = –0.52, 95% CI: –0.96 to –0.07). Qualitative data also indicated that economic barriers hinder forest conservation on farms. These results suggest that biospheric, traditionalistic, and altruistic motivations promote people's proconservation attitudes, but nurturing these latent motivations is unlikely to improve conservation outcomes if material poverty remains unaddressed. Integrating the inner–outer perspective into conservation thinking and practical interventions could foster environmental stewardship and increase human well-being. 相似文献
946.
Trait-mediated effects on flowers: artificial spiders deceive pollinators and decrease plant fitness 总被引:1,自引:0,他引:1
Although predators can affect foraging behaviors of floral visitors, rarely is it known if these top-down effects of predators may cascade to plant fitness through trait-mediated interactions. In this study we manipulated artificial crab spiders on flowers of Rubus rosifolius to test the effects of predation risk on flower-visiting insects and strength of trait-mediated indirect effects to plant fitness. In addition, we tested which predator traits (e.g., forelimbs, abdomen) are recognized and avoided by pollinators. Total visitation rate was higher for control flowers than for flowers with an artificial crab spider. In addition, flowers with a sphere (simulating a spider abdomen) were more frequently visited than those with forelimbs or the entire spider model. Furthermore, the presence of artificial spiders decreased individual seed set by 42% and fruit biomass by 50%. Our findings indicate that pollinators, mostly bees, recognize and avoid flowers with predation risk; forelimbs seem to be the predator trait recognized and avoided by hymenopterans. Additionally, predator avoidance by pollinators resulted in pollen limitation, thereby affecting some components of plant fitness (fruit biomass and seed number). Because most pollinator species that recognized predation risk visited many other plant species, trait-mediated indirect effects of spiders cascading down to plant fitness may be a common phenomenon in the Atlantic rainforest ecosystem. 相似文献
947.
Francisco J. Arjona Susana Sangiao-Alvarellos Sergio Polakof Angel García-López María P. Martín del Río Gonzalo Martínez-Rodríguez José L. Soengas Juan M. Mancera 《Marine Biology》2008,153(4):661-671
To assess the interaction between testosterone (T) treatment and acclimation to different salinities, seawater-acclimated
gilthead sea bream (Sparus auratus) were implanted with slow-release coconut oil implants alone (control) or containing T (5 μg/g body mass). After 5 days,
eight fish of control and T-treated groups were sampled. The same day, eight fish of each group were transferred to low salinity
water (LSW, 6 ppt, hypoosmotic test), seawater (SW, 38 ppt, control test) and high salinity water (HSW, 55 ppt, hyperosmotic
test) and sampled 9 days later. Gill Na+, K+-ATPase activity increased in HSW-acclimated fish with respect to SW- and LSW-acclimated fish in both control and T-treated
groups. Kidney Na+, K+-ATPase activity was also enhanced in HSW-acclimated fish, but only in T-treated group. From a metabolic point of view, most
of the changes observed can be attributed to the action of salinity and T treatment alone, since few interactions between
T treatment and osmotic acclimation to different salinities were observed. Those interactions included in treated fish: in
the liver, decreased capacity in using glucose in fish acclimated to extreme salinities; in the gills, decreased capacity
in using amino acids in HSW; in the kidneys increased capacity in using amino acids in extreme salinities; and in the brain,
decreased glycogen and acetoacetate levels of fish in LSW. 相似文献
948.
Fu-Lin Evelyn Chu Eric D. Lund Paul R. Littreal Kate E. Ruck Ellen Harvey Jean-René Le Coz Yanic Marty Jeanne Moal Philippe Soudant 《Marine Biology》2008,156(2):155-169
The kinetics and efficiency of sterol production and bioconversion of phytosterols in two heterotrophic protists Oxyrrhis marina and Gyrodinium dominans were examined by feeding them two different algal species (Rhodomonas salina and Dunaliella tertiolecta) differing in sterol profiles. R. salina contains predominantly brassicasterol (?99%) and <2% cholesterol. The major sterols in D. tertiolecta are ergosterol (45–49%), 7-dehydroporiferasterol (29–31%) and fungisterol (21–26%). O. marina fed R. salina metabolized dietary brassicasterol to produce 22-dehydrocholesterol and cholesterol. O. marina fed D. tertiolecta metabolized dietary sterols to produce cholesterol, 22-dehydrocholesterol, brassicasterol and stigmasterol. G. dominans fed either R. salina or D. tertiolecta metabolized dietary sterols to make cholesterol, brassicasterol and a series of unknown sterols. When protists were fed R. salina, which contains cholesterol, the levels of cholesterol were increased to a magnitude of nearly 5- to 30-fold at the phytoplankton-heterotrophic protist interface, equivalent to a production of 172.5 ± 16.2 and 987.7 ± 377.7 ng cholesterol per mg R. salina carbon consumed by O. marina and G. dominans, respectively. When protists were fed D. tertiolecta, which contains no cholesterol, a net production of cholesterol by the protists ranged from 123.2 ± 30.6 to 871.8 ± 130.8 ng per mg algal C consumed. Cholesterol is not only the dominant sterol, but a critical precursor for many physiologically functional biochemicals in higher animal. As intermediates, these heterotrophic protists increase the amount of cholesterol at the phytoplankton–zooplankton interface available to higher trophic levels relative to zooplankton feeding on algae directly. 相似文献
949.
Nieto Castillo AM Soriano JJ García-Delgado RA 《Environmental geochemistry and health》2008,30(2):153-157
A laboratory study has been carried out to determine the feasibility of in situ remediation of chromium (VI)-contaminated
soil using electrodialysis in relation to its speciation in soil. This technique is best suited for low-permeability soils
or sediments, which may be difficult to remediate by other means and implies the application of a low-intensity direct current
to the soil, which is separated from the electrode compartments by ion-exchange membranes. A clayey soil was prepared for
use in the experiments and was characterized before being mixed with a solution of potassium dichromate for several days to
produce a final Cr content of 4,056 mg/kg of soil dry wt. Remediation tests were carried out under constant-voltage conditions
for periods of 7–14 days and the evolution of applied current to the cell, pH, and conductivity of the electrolytes were recorded
periodically. Fractionation of chromium was determined for soil samples before and after remediation using a standardized
four-step sequential extraction procedure (SEP) with acetic acid, hydroxylamine, hydrogen peroxide, and aqua regia solutions.
Results show that chromium is mobilized from the most labile phases (soluble/exchangeable/carbonate). In a 15 V test, SEP
results show that the amount of chromium extracted in the first step drops from 80% to 9%, but also that changes in the total
chromium distribution occur during the treatment with some transferred to other soil phases that are more difficult to mobilize. 相似文献
950.
Total mercury and methylmercury concentrations in fish from the Mojana region of Colombia 总被引:1,自引:0,他引:1
Marrugo-Negrete J Verbel JO Ceballos EL Benitez LN 《Environmental geochemistry and health》2008,30(1):21-30
Total mercury (T-Hg) and methylmercury (MeHg) concentrations have been measured in the muscle tissue of 16 fish species consumed
in the Mojana region of Colombia. T-Hg analysis was performed by cold-vapor atomic-absorption spectroscopy (CV-ASS) and MeHg
analysis by gas chromatography with electron-capture detection. Higher T-Hg and MeHg concentrations were detected in carnivorous
species (T-Hg = 0.371 ± 0.172 (μg g−1 fresh wt, MeHg = 0.346 ± 0.171 μg g−1 fresh wt) than in non-carnivorous fish (T-Hg = 0.155 ± 0.108 μg g−1 fresh wt, MeHg = 0.146 ± 0.102 μg g−1 fresh wt). In the different species mercury was present almost completely as the methylated form, with percentages between
80.5 and 98.1% (mean 92.0 ± 3.4%). In 13.5% of fish-tissue samples T-Hg concentrations exceeded the maximum level recommended
by the World Health Organization for human consumption (Hg = 0.5 μg g−1 fresh wt). Although mean T-Hg concentrations in all fish samples (0.269 ± 0.181 μg g−1 fresh wt) did not exceed this limit, risk assessment suggested that the consumption of 0.12 kg fish day−1 could increase the risk of mercury poisoning of the inhabitants of this region. 相似文献