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Environmental Science and Pollution Research - The significance of the natural geographical characteristics and ecological formation of the Coastline Mediterranean Countries (CMC) suggests a...  相似文献   
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In this paper, we examine asymmetric causal relationships between gasoline prices and economic policy uncertainty in a panel of 18 countries over the period 1998–2017, using the recently introduced panel causality approach of Hatemi et al (Appl Econ, 48:2301–2308, 2016) that accounts for asymmetric dynamics and is robust to both cross-sectional dependence and slope heterogeneity. Empirical findings reveal asymmetric causal relationships between gasoline prices and economic policy uncertainty in the sampled countries. Specifically, results show that economic policy uncertainty and gasoline prices have positive and negative asymmetric bidirectional causal relations in 13 countries. No feedback causality was detected between gasoline prices and economic policy uncertainty in 5 countries. Based on the results, we infer that positive and negative asymmetric causal relations exist between economic policy uncertainty and gasoline price, with attendant policy implications in sampled regions.

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According to the differential investment hypothesis, females paired with attractive mates are expected to invest more in the current reproduction relative to females paired with unattractive males. We experimentally tested this hypothesis in the peafowl (Pavo cristatus) by providing females with males that differed in sexual attractiveness. In agreement with the differential allocation hypothesis, females paired with more ornamented males laid larger eggs, and deposited higher amounts of testosterone into the egg yolk, independently of the sex of the embryo. These results show that the association between paternal phenotype and offspring quality could arise via a differential maternal investment. They also suggest that, if ornamented males do transmit good genes to the progeny, the maternal differential investment can amplify the effect of such good genes on the offspring fitness.  相似文献   
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The evolution of multiple sexual traits remains controversial and poorly understood in evolutionary biology. In many bird species, males exhibit complex courtships involving feather ornaments and behavioral display. Multiple traits may convey information on the genetic and phenotypic quality of males. In particular, fixed characters, such as feather ornaments (produced once a year during the annual molt in many bird species) might convey information about past male condition (at the time of trait development); whereas flexible traits such as behavioral displays should be sensitive to present condition. Here we show that both flexible behavioral displays and fixed feather ornaments of peacocks, used by females to choose a mate, honestly reflect health status. Correlative data showed that peacocks with high display rate (the number of behavioral displays per hour) and a large number of tail eyespots had low levels of circulating heterophils, suggesting better health status. Experimental activation of the immune system, through LPS injection, significantly reduced display rate compared to a control group. However, the sensitivity of a male display rate to the immune challenge was dependent on the number of tail eyespots: males with higher number of tail eyespots were better able to cope with the experimental immune challenge, and maintained their display rate at levels closer to the levels performed before the immune activation. These results are consistent with the idea that multiple signaling might enhance information reliability.  相似文献   
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Ho L  Hoefel D  Bock F  Saint CP  Newcombe G 《Chemosphere》2007,66(11):2210-2218
Taste and odour (T&O) causing compounds, in particular, 2-methylisoborneol (MIB) and geosmin, are a problem for water authorities as they are recalcitrant to conventional water treatment. In this study, biological sand filtration was shown to be an effective process for the complete removal of MIB and geosmin, with removal shown to be predominantly through biodegradation. In addition, MIB and geosmin were also effectively degraded in batch bioreactor experiments using biofilm sourced from one of the sand filters as the microbial inoculum. The biodegradation of MIB and geosmin was determined to be a pseudo-first-order reaction with rate constants ranging between 0.10 and 0.58 d−1 in the bioreactor experiments. Rate constants were shown to be dependent upon the initial concentration of the microbial inoculum but not the initial concentration of MIB and geosmin when target concentrations of 200 and 50 ng l−1 were used. Furthermore, rate constants were shown to increase upon re-exposure of the biofilm to both T&O compounds. Enrichment cultures with subsequent community profile analysis using 16S rRNA-directed PCR-DGGE identified four bacteria most likely involved in the biodegradation of geosmin within the sand filters and bioreactors. These included a Pseudomonas sp., Alphaproteobacterium, Sphingomonas sp. and an Acidobacteriaceae member.  相似文献   
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Environmental Science and Pollution Research - Despite consistent investments, grants, and other concessions in the power sector, nationwide power outages still remain an issue, even in 2020,...  相似文献   
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Environmental Science and Pollution Research - One of the major problems the world is currently facing is climate change. This is due to the use of fossil fuel combustion, which increases the...  相似文献   
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Environmental Science and Pollution Research - Currently, the most crucial economic and ecological issues are related to environmental degradation and sustainability. On this backdrop, this paper...  相似文献   
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Given the dominant role of oil in terms of foreign exchange earnings in Nigeria, this study revisits the oil rents and output growth nexus, using the novel dynamic autoregressive distributive lag (DYNARDL) model and kernel-based regularized least squares (KRLS) approach over the period 1973–2020. The major finding from this study is that oil rents are less significant for output and also exhibit decreasing marginal effect on output growth in Nigeria. However, our robustness result shows that oil revenue is positive and significantly affects output growth, while corruption dampens output growth. Result from the oil revenue model with a minimum root square mean error, when compared with the oil rents model, corroborate the finding. We are thus of the opinion that oil revenue is more important for output growth in Nigeria than oil rents. Having established this fact, it is recommended that policymakers and the government should accord utmost attention to boosting oil revenue via transparency and accountability. They should also ensure a lasting solution to the nation’s high dependency on refined crude oil products importation for a sustainable economic growth and development. Also, more efforts should be directed at developing the seven identified strategic solid minerals to further enhance the revenue base of the government.

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