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41.
The International Journal of Life Cycle Assessment - The current global interest in circular economy (CE) opens an opportunity to make society’s consumption and production patterns more...  相似文献   
42.
热带森林优势种青冈叶片气孔、解剖和形态性状与气候、土壤因子的关联 了解优势树种叶片多水平的功能性状沿海拔梯度的变化及其内在关联,有助于预测优势种应对气候变化的响应与适应。本文研究了青冈属树种叶片气孔、解剖和形态性状沿海拔梯度的变化及其与环境调控因子的关联,探究了其生态策略是否随海拔发生改变。在海南尖峰岭热带森林,沿海拔梯度(400–1400 m)采集了6种常绿青冈:竹叶青冈(Cyclobalanopsis bambusaefolia)、雷公青冈(C. hui)、托盘青冈 (C. patelliformis)、饭甄青冈(C. fleuryi)、吊罗山青冈(C. tiaoloshanica)和亮叶青冈(C. phanera)叶片,用于气孔、解剖和形态性状的测定。研究结果表明,随海拔升高,青冈树种叶片气孔密度、气孔孔隙度指数和叶面积显著增加,但海绵组织厚度比和干物质含量则显着降低。叶片气孔、解剖和形态性状沿海拔梯 度的变化主要受年均温、年降水量和土壤pH 值调控。在低海拔和高海拔处,青冈属采取“耐受”和“竞 争”策略,而在中海拔处,则是“竞争”策略。土壤磷含量和土壤pH 值随海拔的变化可能是驱动其生态 策略转变的主要原因。该结果揭示,热带森林优势树种青冈可通过从气孔细胞-组织解剖结构-叶片水平功能性状的改变来响应环境变化。  相似文献   
43.
The so-called “Taygetis clade” is a group of exclusively Neotropical butterflies classified within Euptychiina, one of the largest subtribes in the subfamily Satyrinae. Since the distribution of the ten genera belonging to this group ranges throughout the entire Neotropics, from lowlands to lower montane habitats, it offers a remarkable opportunity to study the region’s biogeographic history as well as different scenarios for speciation in upland areas. We inferred a robust and well-sampled phylogeny using DNA sequences from four genes (4035 bp in total) using maximum parsimony and Bayesian inference. We estimated divergence times using the Bayesian relaxed clock method calibrated with node ages from previous studies. Ancestral ranges of distribution were estimated using the dispersal–extinction–cladogenesis (DEC) model as implemented in the program Lagrange. We propose several taxonomic changes and recognize nine well-supported natural genera within the “Taygetis clade”: Forsterinaria (subsuming Guaianaza syn. nov.), Parataygetis, Posttaygetis, Harjesia (excluding Harjesia griseola and Harjesia oreba), Pseudodebis (including Taygetomorpha syn. nov.,), Taygetina (subsuming Coeruleotaygetis syn. nov., Harjesia oreba comb. nov., Taygetis weymeri comb. nov. and Taygetis kerea comb. nov.), Taygetis (excluding Taygetis ypthima, Taygetis rectifascia, Taygetis kerea and Taygetis weymeri), and two new genera, one containing Harjesia griseola, and the other Taygetis ypthima and Taygetis rectifascia. The group diversified mainly during late Miocene to Pliocene, coinciding with the period of drastic changes in landscape configuration in the Neotropics. Major dispersals inferred from the Amazon basin towards northwestern South America, the Atlantic forests and the eastern slope of the Andes have mostly shaped the evolution and diversification of the group. Furthermore, expansion of larval dietary repertoire might have aided net diversification in the two largest genera in the clade, Forsterinaria and Taygetis.  相似文献   
44.
The life cycle of vectors and the reservoirs that participate in the chain of infectious diseases have a strong relationship with the environmental dynamics of the ecosystems in which they live. Oscillations in population abundance and seasonality of insects can be explained by factors inherent in each region and time period. Therefore, knowledge of the relationship and influence of environmental factors on the population of Lutzomyia longipalpis is necessary because of the high incidence of visceral leishmaniasis (VL) in Brazil. This study evaluates the influence of abiotic variables on the population density and seasonal behavior of L. longipalpis in an urban endemic area of VL in Brazil. The sand fly captures were performed every two months between November, 2009 and November, 2010 in the peridomicile of 13 randomly selected residences. We captured 1,367 specimens of L. longipalpis, and the ratio of male/female flies was 2.86:1. The comparison of the total male specimens in the two seasons showed a statistical difference in the wet season, but there was no significant difference when considering the total females. With respect to climatic variables, a significant negative association was observed only with wind speed. During periods of high wind speeds, the population density of this vector decreased. The presence of L. longipalpis was found in all months of the study with bimodal behavior and population peaks during the wet season.  相似文献   
45.
In 2008, during a rescue excavation in the Sa Osa area, near the town of Cabras (Sardinia, Italy), a Nuragic settlement was discovered. The excavation revealed numerous pits, wells and structures dug by the local communities between the Early Copper Age and the Iron Age. These structures were interpreted as elements of a settlement mainly involved in primary production. The most remarkable structure is Well-N, radiocarbon and archaeologically dated to the Late Bronze Age, which has yielded large amounts of waterlogged plant remains, animal and fish bones and pottery. Despite the limited set of samples, the combination of macro-remain and pollen analyses in this unique context provides important information useful for exploring not only local subsistence systems but also human impact on the surrounding environment. Grapes and figs are the most abundant remains together with other fruits and edible vascular plants. Remains of melon and mulberry were identified being the earliest remains of these two species for Western Europe. Their presence may confirm early trade between Nuragic people and the eastern Mediterranean and/or African coasts. Intentional selection of wood suggests practices associated to the collection of raw material for specific technological demands. The presence of intestinal parasites in the pollen record points to the possible use of the well as a cesspit, at least in its later use, and this is one of the earliest evidence of this type of structures in prehistoric contexts.  相似文献   
46.

Background

Myostatin (MSTN) belongs to the transforming growth factor-β superfamily and is a potent negative regulator of skeletal muscle development and growth in mammals. Most teleost fish possess two MSTN paralogues. However, as a consequence of a recent whole genome-duplication event, salmonids have four: MSTN-1 (?1a and -1b) and MSTN-2 (?2a and -2b). Evidence suggests that teleost MSTN plays a role in the regulation of muscle growth. In the current study, the MSTN-1b gene was re-sequenced and screened for SNP markers in a commercial population of Atlantic salmon. After genotyping 4,800 progeny for the discovered SNPs, we investigated their association with eight harvest traits - four body-weight traits, two ratios of weight traits, flesh colour and fat percentage - using a mixed model association analysis.

Results

Three novel SNPs were discovered in the MSTN-1b gene of Atlantic salmon. One of the SNPs, located within the 5′ flanking region (g.1086C?>?T), had a significant association with harvest traits (p?<?0.05), specifically for: Harvest Weight (kg), Gutted Weight (kg), Deheaded Weight (kg) and Fillet Weight (kg). The haplotype-based association analysis was consistent with this result because the two haplotypes that showed a significant association with body-weight traits, hap4 and hap5 (p?<?0.05 and p?<?0.01, respectively), differ by a single substitution at the g.1086C?>?T locus. The alleles at g.1086C?>?T act in an additive manner and explain a small percentage of the genetic variation of these phenotypes.

Conclusions

The association analysis revealed that g.1086C?>?T had a significant association with all body-weight traits under study. Although the SNP explains a small percentage of the variance, our results indicate that a variation in the 5′ flanking region of the myostatin gene is associated with the genetic regulation of growth in Atlantic salmon.
  相似文献   
47.
In this study, the findings of three water mite species of the family Hygrobatidae collected from different streams in Turkey were evaluated. Hygrobates (s. str.) anatolicus Esen & Pešić, sp. n. is described as new for science. Hygrobates (Rivobates) diversiporus Sokolow, 1927 and Atractides (s. str.) nikooae Pešić, 2004, which were illustrated and thoroughly discussed, are new records for the Turkish fauna.  相似文献   
48.
49.
We review the evidence of how organisms and populations are currently responding to climate change through phenotypic plasticity, genotypic evolution, changes in distribution and, in some cases, local extinction. Organisms alter their gene expression and metabolism to increase the concentrations of several antistress compounds and to change their physiology, phenology, growth and reproduction in response to climate change. Rapid adaptation and microevolution occur at the population level. Together with these phenotypic and genotypic adaptations, the movement of organisms and the turnover of populations can lead to migration toward habitats with better conditions unless hindered by barriers. Both migration and local extinction of populations have occurred. However, many unknowns for all these processes remain. The roles of phenotypic plasticity and genotypic evolution and their possible trade‐offs and links with population structure warrant further research. The application of omic techniques to ecological studies will greatly favor this research. It remains poorly understood how climate change will result in asymmetrical responses of species and how it will interact with other increasing global impacts, such as N eutrophication, changes in environmental N : P ratios and species invasion, among many others. The biogeochemical and biophysical feedbacks on climate of all these changes in vegetation are also poorly understood. We here review the evidence of responses to climate change and discuss the perspectives for increasing our knowledge of the interactions between climate change and life.  相似文献   
50.
The aim of this study was to evaluate carbon flux in Azotobacter vinelandii using metabolic flux analysis (MFA) under high and low aeration conditions to achieve an improved understanding of how these changes could be related to alginate acetylation and PHB production. Changes in oxygen availability had a considerable impact on the metabolic fluxes and were reflected in the growth rate, the specific glucose consumption rate, and the alginate and PHB yields. The main differences at the metabolic flux level were observed in three important pathways. The first important difference was consistent with respiratory protection; an increase in the flux generated through the tricarboxylic acid (TCA) cycle for cultures grown under high aeration conditions (up to 2.61 times higher) was observed. In the second important difference, the fluxes generated through pyruvate dehydrogenase, phosphoenol pyruvate carboxykinase and pyruvate kinase, all of which are involved in acetyl-CoA metabolism, increased by 10, 43.9 and 17.5%, respectively, in cultures grown under low aeration conditions compared with those grown under high aeration conditions. These changes were related to alginate acetylation, which was 2.6 times higher in the cultures with limited oxygen, and the changes were also related to a drastic increase in PHB production. Finally, the glyoxylate shunt was active under both of the conditions that were tested, and a 2.79-fold increase was observed in cultures that were grown under the low aeration condition.  相似文献   
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