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871.
Claudia Yared Michel-López Esaú Ruiz-Sánchez Roberto Zamora-Bustillos 《Chemistry and Ecology》2014,30(3):227-232
The effects of copper (Cu2+) on photochemical efficiency, cellular viability and total phenolic content in Prosopis glandulosa leaves were evaluated after 4, 8 or 12 h exposure to 0.1, 10 or 100 mM Cu2+ using the tissue tolerance test. The results showed that significant reductions (p<0.003) of photochemical efficiency in P. glandulosa leaves were found after 8 h exposure to 100 mM Cu2+ compared with controls leaves. The results also showed a significant increase (p<0.05) on electrolyte leakage values in P. glandulosa leaves after 4 h exposure to 100 mM Cu2+ compared with control leaves. Total phenolic content in P. glandulosa leaves only differed significantly when exposed 12 h to the highest concentration of Cu2+. These results suggest that Cu2+ can produce reactive oxygen species that may form hydroxyl radicals that damage proteins and lipids, which in turn causes loss of integrity and reduce photochemical efficiency of leaves. In conclusion, the photochemical efficiency and cellular viability analyses can be used as useful physiological tools to assess early changes in photosynthetic performance of P. glandulosa in response to copper pollution. 相似文献
872.
873.
Edelmira García-Nieto Libertad Juárez-Santacruz Elvia Ortiz-Ortiz Héctor Santos Luna-Zendejas Dora María Frías-Márquez Hipólito Muñoz-Nava 《Chemistry and Ecology》2019,35(4):300-318
This study assesses the potential risk of Texcalac River and riparian area. The p,p′ DDT and ∑DDTs levels in agricultural soils (3.9–208.0?µg/kg) and in surface sediments (0.6–137?µg/kg) surpassing the guidelines for protection of aquatic life (75% > TEC). The ∑PCBs concentration oscillated from 135 to 93941?µg/kg; the half of sediments exceeded the international guidelines (PEL, PEC), as well as two soils (SQGE?=?500?µg/kg). The TEQ concentration of four PCB-DL varied between 0.1 and 24.9?µg TEQ/kg, chiefly affected by PCB 169. Five sediments were lethal for E. foetida, two resulted to be cytotoxic and the 58% produced genotoxicity higher than negative control (A?=?0.28?±?0.05; DICA?=?72.5?±?16.9 au). Likewise, 31.6% of samples increased the micronuclei frequency in V. faba in comparison with negative control. The analytical data and the bioassays results suggest a significant and immediate risk to exposed biota of this region, highlighting a specific area in Texcalac River and other one in Sambrano Ravine. It is necessity assess the dispersion of pollutants and perform biomonitoring studies that display the exposure levels in biota with the goal to characterise the ecotoxicological risk. 相似文献
874.
Tamora D. James Roberto Salguero-Gómez Owen R. Jones Dylan Z. Childs Andrew P. Beckerman 《Conservation biology》2021,35(4):1210-1221
Phylogenetically informed imputation methods have rarely been applied to estimate missing values in demographic data but may be a powerful tool for reconstructing vital rates of survival, maturation, and fecundity for species of conservation concern. Imputed vital rates could be used to parameterize demographic models to explore how populations respond when vital rates are perturbed. We used standardized vital rate estimates for 50 bird species to assess the use of phylogenetic imputation to fill gaps in demographic data. We calculated imputation accuracy for vital rates of focal species excluded from the data set either singly or in combination and with and without phylogeny, body mass, and life-history trait data. We used imputed vital rates to calculate demographic metrics, including generation time, to validate the use of imputation in demographic analyses. Covariance among vital rates and other trait data provided a strong basis to guide imputation of missing vital rates in birds, even in the absence of phylogenetic information. Mean NRMSE for null and phylogenetic models differed by <0.01 except when no vital rates were available or for vital rates with high phylogenetic signal (Pagel's λ > 0.8). In these cases, including body mass and life-history trait data compensated for lack of phylogenetic information: mean normalized root mean square error (NRMSE) for null and phylogenetic models differed by <0.01 for adult survival and <0.04 for maturation rate. Estimates of demographic metrics were sensitive to the accuracy of imputed vital rates. For example, mean error in generation time doubled in response to inaccurate estimates of maturation time. Accurate demographic data and metrics, such as generation time, are needed to inform conservation planning processes, for example through International Union for Conservation of Nature Red List assessments and population viability analysis. Imputed vital rates could be useful in this context but, as for any estimated model parameters, awareness of the sensitivities of demographic model outputs to the imputed vital rates is essential. 相似文献
875.
Abreu Murilo S. Kulczykowska Ewa Cardoso Sónia C. André Gonçalo I. Morais Marta Gozdowska Magdalena Soares Marta C. 《Behavioral ecology and sociobiology》2018,72(7):1-14
Behavioral Ecology and Sociobiology - A growing body of research suggests that songs are an important part of the courtship behavior of many bat species, however there is little information on the... 相似文献
876.
According to current environmental legislation concerned with water scarcity, paper industry is being forced to adopt a zero liquid effluent policy. In consequence, reverse osmosis (RO) systems are being assessed as the final step of effluent treatment trains aiming to recover final wastewater and reuse it as process water. One of the most important drawbacks of these treatments is the production of a retentated stream, which is usually highly loaded with biorecalcitrant organic matter and inorganics; and this effluent must meet current legislation stringent constraints before being ultimately disposed. The treatment of biorefractory RO retentate from a paper mill by several promising advanced oxidation processes (AOPs) - conventional Fenton, photo-Fenton and photocatalysis - was optimized considering the effect and interaction of reaction parameters; particularly using response surface methodology (RSM) when appropriate (Fenton processes). The economical cost of these treatments was also comparatively assessed. Photo-Fenton process was able to totally remove the COD of the retentate, and resulted even operatively cheaper at high COD removal levels than conventional Fenton, which achieved an 80% reduction of the COD at best. In addition, although these optimal results were produced at pH=2.8, it was also tested that Fenton processes are able to achieve good COD reduction efficiencies (>60%) without adjusting the initial pH value, provided the natural pH of this wastewater was close to neutral. Finally, although TiO(2)-photocatalysis showed the least efficient and most expensive figures, it improved the biodegradability of the retentate, so its combination with a final biological step almost achieved the total removal of the COD. 相似文献
877.
J. A. Baeza A. A. Braga L. S. López-Greco E. Perez M. L. Negreiros-Fransozo A. Fransozo 《Marine Biology》2010,157(12):2643-2653
One of the main goals of sex allocation theory is understanding sex ratio evolution. However, theoretical studies predicting
sex ratios in species with unusual sexual systems, such as protandric simultaneous (PS) hermaphroditism, are rare. In PS hermaphrodites,
juveniles first develop into functional males that mature into simultaneous hermaphrodites later in life. Here, we report
on the sex ratio (males/males + hermaphrodites) in the PS hermaphroditic shrimp Exhippolysmata oplophoroides. A 2-year study demonstrated that hermaphrodites dominated the population in two different bays. This skewed sex ratio may
be explained by limited encounter rates among conspecifics. In agreement with this idea, the density of shrimps was extremely
low (≤1 shrimp km−2) at the two study sites. Size at sex phase change and sex ratios remained relatively stable through time at the two bays.
The stability of these parameters might be explained by the rather steady population structure of this species during the
study period. A review of sex ratios in PS hermaphroditic shrimps (Lysmata and Exhippolysmata) revealed considerable variation; some species have male- and others hermaphrodite-skewed sex ratios. The conditions explaining
inter- and intra-specific sex ratio variation in protandric simultaneous hermaphroditic species remain to be addressed. 相似文献
878.
In aquatic environments, many prey rely on chemosensory information from injured (alarm cues) or stressed conspecifics (disturbance
cues) to assess predation risk. Alarm cues are considered as a sign of higher risk than disturbance cues. These cues could
be used by prey to learn potential new predators. In this study, we tested whether Iberian green frog tadpoles (Pelophylax perezi) exhibited antipredator responses to alarm and disturbance cues of conspecifics and whether tadpoles could associate new
predators with alarm or disturbance cues. Tadpoles reduced their activity in the presence of disturbance cues, but only weakly
when compared with their response to alarm cues. Also, tadpoles learned to recognize new predators from association with alarm
or disturbance cues. However, the period of retention of the learned association was shorter for disturbance than alarm cues.
Our results indicate that tadpoles are able to modify their antipredatory behavior according to (1) the degree of risk implied
by the experimental cues (2) their previous experience of chemical cues of the predator. 相似文献
879.
Teodora B. Toshova Dimitar I. Velchev Mitko A. Subchev Miklós Tóth József Vuts John A. Pickett Sarah Y. Dewhirst 《Chemoecology》2010,20(3):199-206
The grey corn weevil, Tanymecus (Episomecus) dilaticollis, is an economically important polyphagous pest in Eastern and Central Europe. The present research is the first published
electrophysiological study of olfactory sensitivity of adult T. dilaticollis to plant volatiles. The electrophysiological responses of male and female antennae were recorded to 20 synthetic volatile
organic compounds (VOCs), previously identified to be released from the preferred host plants, maize and sunflower. Antennae
of both sexes responded to a wide range of volatiles from different chemical classes: fatty acid derivatives, aromatic compounds
and terpenoids. Two green leaf volatiles, (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol, and one terpenoid, (±)-linalool, elicited the strongest electrophysiological responses by male and female
antennae. Relatively high electrophysiological activity by T. dilaticollis antennae was also recorded to benzaldehyde, eugenol and caryophyllene. In the field, (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol, when presented individually, caught significantly more male and female T. dilaticollis than unbaited controls. These compounds could be developed into an attractive trap for the detection and monitoring of T. dilaticollis. 相似文献
880.
M. Dolores G. López-de-Hierro Gregorio Moreno-Rueda 《Behavioral ecology and sociobiology》2010,64(3):317-324
Brood parasitism could be a selective pressure on each female to have a type of egg that permits recognition. House sparrows
(Passer domesticus) undergo conspecific brood parasitism and can recognise parasitic eggs. In this study, we analyse the effect of relative
size in experimental parasitic eggs compared to the host eggs. We modified egg colour and the spot pattern to determine the
influence of these characteristics on egg rejection. Furthermore, we examine whether egg rejection increases with “stimulus
summation”. Our results show that egg rejection is not affected by relative egg size. However, changes in the spot pattern
proved to exert the highest influence on egg rejection (32.4% of trials), significantly higher than when only egg colour is
changed (3.8%). Therefore, our results suggest that parasitism may be a pressure favouring the maintenance of spotted eggs
in house sparrow. 相似文献