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951.
Maud C. O. Ferrari Grant E. Brown François Messier Douglas P. Chivers 《Behavioral ecology and sociobiology》2009,63(9):1369-1375
Despite the importance of acquired predator recognition in mediating predator–prey interactions, we know little about the
specific characteristics that prey use to distinguish predators from non-predators. Recent experiments with mammals and fish
indicate that some prey lacking innate predator recognition have the ability to display anti-predator responses upon their
first encounter with those predators if they are similar to predators that the prey has recently learned to recognize. This
phenomenon is referred to as generalization of predator recognition. In this experiment, we documented for the first time
that larval amphibians (woodfrog, Rana sylvatica) have the ability to generalize the recognition of known predators to closely related novel predators. Moreover, we demonstrated
that this ability is dependent on the level of risk associated with the known predator. When red-bellied newt, Cynops pyrrhogaster (known predator), was paired with simulated low risk, tadpoles displayed fright responses to newts and novel tiger salamanders,
Ambystoma tigrinum, but not to novel African clawed frogs, Xenopus laevis. However, when the newt was paired with simulated high risk, tadpoles generalized their responses to both tiger salamanders
and African clawed frogs. Larval anurans seem to have a wider generalization frame than other animals. 相似文献
952.
953.
G.R. Tortella R.A. Mella-Herrera D.Z. Sousa O. Rubilar G. Briceño L. Parra M.C. Diez 《Chemosphere》2013
The impact of repeated carbendazim (CARB) applications on the extent of CARB dissipation, the microbial diversity, the community level physiological profile (CLPP), and the enzymatic activity within the biomixture of an on-farm biopurification system was evaluated. After three successive CARB applications, the CARB dissipation efficiency was high; the efficiency of dissipation was 87%, 94% and 96% after each application, respectively. Although microbial enzymatic activity was affected significantly by CARB application, it could recover after each CARB pulse. Likewise, the numbers of cultivable bacteria, fungi and actinomycetes (as measured in CFUs) were slightly affected by the addition of CARB, but the inhibitory effect of the pesticide application was temporary. Denaturing gradient gel electrophoresis (DGGE) and Biolog Ecoplate assays demonstrated that the microbial populations remained relatively stable over time when compared to the control. The results obtained herein therefore demonstrate the high dissipation capacity of this biomixture and highlight the microbiological robustness of this biological system. 相似文献
954.
Hagen Koch Ana Lígia Chaves Silva José Roberto Gonçalves de Azevedo Werônica Meira de Souza Johann Köppel Clecio Barbosa Souza Junior Alessandra Maciel de Lima Barros Fred F. Hattermann 《Regional Environmental Change》2018,18(7):1927-1942
Many renewable resources for the generation of electricity, such as hydropower and wind power, are dependent on climatic factors. Reservoirs have been created to overcome the stochastic nature of river flows and to make water supply more reliable. However, reservoirs are affecting the ecological status of river ecosystems, e.g., by modifying the flow regime, triggering discussions regarding the discharge of reservoirs. In Brazil’s northeast region, the installed capacity for wind power generation has increased substantially in recent years. Setting up a modeling system for simulating wind power and hydropower generation in this study, it is analyzed whether wind power generation, peaking in the dry season, can help to achieve a more environmentally oriented flow regime in the Sub-middle and Lower São Francisco River Basin. Simulated higher discharges from reservoirs during the rainy season and lower discharges during the dry season, representing a more natural flow regime, will reduce hydropower generation in the dry season. Under recent conditions, the resulting gap in electricity generation can only be partially covered by wind power. A large share needs to be generated by thermal power plants or be imported from other regions in Brazil. The planned future increase in installed wind power capacity can change this picture; the demand for electricity generated by thermal power plants and imported will decrease. Adopting an integrated approach for hydropower and wind power generation, the flow regime in the Sub-middle and Lower São Francisco River Basin can be modified to improve the ecological status of the river system. 相似文献
955.
Ait-Mouheb Nassim Bahri Akiça Thayer Bechir Ben Benyahia Boumediene Bourrié Guilhem Cherki Brahim Condom Nicolas Declercq Rémi Gunes Adem Héran Marc Kitir Nurgul Molle Bruno Patureau Dominique Pollice Alfieri Rapaport Alain Renault Pierre Riahi Khalifa Romagny Bruno Sari Tewfik Sinfort Carole Steyer Jean-Philippe Talozi Samer Topcuoglu Bulent Turan Metin Wéry Nathalie Yıldırım Ertan Harmand Jérôme 《Regional Environmental Change》2018,18(3):693-705
Regional Environmental Change - Climate change and a growing population around the Mediterranean Rim are increasing the need for water and, consequently, the pressure on resources in terms of both... 相似文献
956.
Gonçalves FL Carvalho LM Conde FC Latorre MR Saldiva PH Braga AL 《Environment international》2005,31(3):343-349
Effects of meteorological variables and air pollutants on child respiratory morbidity are investigated during two consecutive summers (December-March 1992/1993 and 1993/1994) at the Metropolitan Area of S?o Paulo (MASP), Brazil. The MASP, with almost 17 million inhabitants, is considered the most populous region in South America. Due to warmer temperatures, increased rainfall and consequent low levels of air pollutants during the summer compared to winter, less attention has been paid to epidemiological studies during this season, especially in tropical urban areas such as S?o Paulo. In the present work, principal component analysis (PCA) is applied to medical end environmental data to identify patterns relating child morbidity, meteorological variables and air pollutants during the summer. The following pollutant concentrations are examined: SO2, inhalable particulate matter (PM10), and O3. The meteorological variables investigated are air temperature, water vapor (water vapor density) and solar radiation. Although low correlation between respiratory morbidity and environmental variables are, in general, observed for the entire dataset, the PCA method indicates that child morbidity is positively associated with O3 for the 1992/1993 summer. This pattern is identified in the third principal component (PC3), which explains about 19% of the total variance of all data in this summer. However, the 1993/1994 summer shows a more complex association between both groups, suggesting stronger ties with meteorological variables. Marked changes in synoptic conditions from the end of January to end of March of the 1993/1994 summer seem to have played an important role in modulating respiratory morbidity. A detailed examination of meteorological conditions in that period indicates that prefrontal (postfrontal), hot (cold) and dry (wet) days favored the observed decrease (increase) of respiratory morbidity. 相似文献
957.
Minouflet M Ayrault S Badot PM Cotelle S Ferard JF 《Journal of environmental radioactivity》2005,81(2-3):143-153
Since the middle of the 20th century, ionizing radiations from radioactive isotopes including 137Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of 137Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to 137Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid 137Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive 137Cs pollution. 相似文献
958.
959.
Katja Trübenbach Gonçalo da Costa Cristina Ribeiro-Silva Raquel Mesquita Ribeiro Carlos Cordeiro Rui Rosa 《Marine Biology》2014,161(3):575-584
The jumbo squid, Dosidicus gigas, is an oceanic top predator in the eastern tropical Pacific that undergoes diel vertical migrations into mesopelagic oxygen minimum zones (OMZs). Besides glycogen breakdown, the pathways of the squid’s metabolic (suppression) strategy are poorly understood. Here, juvenile D. gigas were exposed to oxygen levels found in the OMZ off Gulf of California (1 % O2, 1 kPa at 10 °C) with the aim to identify, via proteomic tools, eventual anaerobic protein degradation as potential energy source at such depths. Under hypoxia, total protein concentration decreased nonsignificantly from 79.2 ± 12.4 mg g?1 wet mass to 74.7 ± 11.7 mg g?1 wet mass (p > 0.05). Yet, there was a significant decrease in heat-shock protein (Hsp) 90 and α-actinin contents (p < 0.05). The lower α-actinin concentration at late hypoxia was probably related to decreased protection of the Hsp90 chaperon machinery resulting in increased ubiquitination (p < 0.05) and subsequent degradation. Thus, the present findings indicate that D. gigas might degrade, at least under progressing hypoxia, specific mantle proteins anaerobically to increase/maintain anaerobic ATP production and extend hypoxia exposure time. Moreover, the ubiquitin–proteasome system seems to play an important role in hypoxia tolerance, but further investigations are necessary to discover its full potential and pathways. 相似文献
960.