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181.
Ulysse Lefèvre Andrea Cau Aude Cincotta Dongyu Hu Anusuya Chinsamy François Escuillié Pascal Godefroit 《Die Naturwissenschaften》2017,104(9-10):74
Genuine fossils with exquisitely preserved plumage from the Late Jurassic and Early Cretaceous of northeastern China have recently revealed that bird-like theropod dinosaurs had long pennaceous feathers along their hindlimbs and may have used their four wings to glide or fly. Thus, it has been postulated that early bird flight might initially have involved four wings (Xu et al. Nature 421:335–340, 2003; Hu et al. Nature 461:640–643, 2009; Han et al. Nat Commun 5:4382, 2014). Here, we describe Serikornis sungei gen. et sp. nov., a new feathered theropod from the Tiaojishan Fm (Late Jurassic) of Liaoning Province, China. Its skeletal morphology suggests a ground-dwelling ecology with no flying adaptations. Our phylogenetic analysis places Serikornis, together with other Late Jurassic paravians from China, as a basal paravians, outside the Eumaniraptora clade. The tail of Serikornis is covered proximally by filaments and distally by slender rectrices. Thin symmetrical remiges lacking barbules are attached along its forelimbs and elongate hindlimb feathers extend up to its toes, suggesting that hindlimb remiges evolved in ground-dwelling maniraptorans before being co-opted to an arboreal lifestyle or flight. 相似文献
182.
Bravo AG Bouchet S Amouroux D Poté J Dominik J 《Journal of environmental monitoring : JEM》2011,13(4):974-982
In Lake Geneva, Switzerland, the most Hg-contaminated sediments have been found in the Vidy Bay where high Hg contents largely exceeds the background levels of Lake Geneva sediments. This contamination has been attributed to the discharge of a waste water treatment plant (WWTP). Total Hg (THg) and monomethylmercury (MMHg) were determined in bulk sediment and in three different grain size fractions (i: clay and silt, ii: fine-coarse sand, iii: and very coarse sand and gravel) collected close to the outlet pipe of a WWTP in order to verify whether the standardized procedures of sediment treatment is adequate for this setting and, by extension, for similar contaminated sites. THg was homogeneously distributed in the different grain size fractions and was correlated to organic matter content (R(2) = 0.6). MMHg was homogeneously distributed in the two finer grain fractions (Φ < 0.063 mm; 0.063 mm < Φ <1 mm). The results of this study suggested that the analysis of the bulk sediment seems to be more appropriate for the assessment of the content and spatial distribution of Hg in freshwater sediments contaminated by WWTPs. 相似文献
183.
Progress in formulating and implementing effective adaptation policies is often hampered by a wide variety of barriers that are well documented in the literature. Among the barriers are lack of awareness, certainty, resources and political commitment. Since these and other barriers can be overcome (e.g., by raising awareness, closing knowledge gaps, and increasing resources), numerous decision‐support frameworks (mainly written guidelines) have been developed for this purpose. The present paper takes stock of both the barriers in adaptation policymaking, as documented in the literature, and the guidelines that aim to facilitate public policies on climate change adaptation. It then compares to what degree selected adaptation guidelines serve as knowledge‐brokerage tools that provide guidance on how to overcome the barriers addressed in the scientific literature. The comparison shows that adaptation guidelines address barriers of adaptation policymaking neither comprehensively nor systematically. Since most adaptation guidelines focus on (subjective) experiences with good practices than on empirical research findings, we conclude that they represent a missed opportunity of scientific knowledge‐brokerage in climate change adaptation. 相似文献
184.
Klemens Pütz Andrea Raya Rey Nic Huin Adrian Schiavini Andrea Pütz Bernhard H. Lüthi 《Marine Biology》2006,149(2):125-137
The diving behaviour of southern rockhopper penguins (Eudyptes c. chrysocome) was studied at two breeding sites in the Southwest Atlantic: the Falkland Islands and Staten Island, Argentina. Incubating and brooding birds were equipped with time-depth recorders to monitor their foraging activities. Rockhopper penguins from Staten Island started their breeding season about 3 weeks earlier than their conspecifics from the Falkland Islands. The foraging area used by incubating males from the Falkland Islands comprised about 150,000 km² to the northeast of the breeding site and was characterised by shelf and slope waters, whereas the foraging area of incubating males from Staten Island comprised 350,000 km² of oceanic waters to the southeast of the breeding site. A number of dive parameters were measured and compared between the four study groups: Incubating males and brooding females from the Falkland Islands, and incubating males and females from Staten Island. In all study groups, dive depth correlated positively to light intensity, dive duration and vertical velocity. However, significant differences between various diving parameters of the study groups were noted, not only in terms of diving performance, but also as regards diving efficiency (DE). A principal component analysis (PCA) on 16 variables revealed that 75% of the variance could be explained by only two principal components: diving pattern (PC1) and diving effort (PC2). PC1 indicated that the birds from Staten Island, both males and females, dived deeper, covered a greater vertical distance per hour and had higher ascent rates, but spent less time underwater and at the bottom of a dive, and had a lower DE than conspecifics from the Falkland Islands. PC2, which included the percentage of foraging dives, the number of dives per hour, dive duration, bottom time and descent rate, differed significantly between incubating males from the Falkland Islands and the other three groups, which were all very similar. Overall, the diving behaviour was notably similar to that of conspecifics from the Indian and Pacific Oceans. The implications of the results in terms of intra-specific adaptations as well as potential threats from human activities are discussed. 相似文献
185.
186.
Canesi L Ciacci C Betti M Fabbri R Canonico B Fantinati A Marcomini A Pojana G 《Environment international》2008,34(8):1114-1119
The potential for human and ecological toxicity associated with nanomaterials is a growing area of investigation. In mammalian cells, nanoparticles have been shown to induce inflammation and oxidative stress, and changes in cell signalling and gene expression. As the nanotechnology industries increase production, nanoscale products and by products will enter the aquatic environment, posing a possible threat to aquatic organisms. In particular, filter-feeding organisms may represent a unique target group for nanoparticle toxicology. In this work, the effects of commercial nanosized carbon black (NCB) on the immune cells, the hemocytes, of the bivalve mollusc Mytilus, and the possible mechanisms involved were investigated. The results demonstrate that NCB (1, 5, and 10 microg/ml), did not induce significant lysosomal membrane destabilization, as evaluated by the NR retention time assay. A concentration-dependent uptake of NCB by hemocytes was observed and it was associated by a rapid increase in extracellular lysozyme release, extracellular oxyradical production, and nitric oxide (NO) release. Moreover, at the highest concentration tested, NCB induced significant changes in mitochondrial parameters (decrease mitochondrial mass/number and membrane potential), as evaluated by flow cytometry. The effects of NCB were mediated by rapid activation of the stress-activated MAPKs (Mitogen Activated Protein Kinases) p38 and JNKs, that play a key role in immune and inflammatory responses. The results demonstrate that in mussel hemocytes like in mammalian cells NCB exposure can induce inflammatory processes, and indicate that bivalve immunocytes can represent a suitable model for investigating the effects and modes of action of nanoparticles in the cells of aquatic invertebrates. 相似文献
187.
The structure of gallery networks in the nests of termite <Emphasis Type="Italic">Cubitermes</Emphasis> spp. revealed by X-ray tomography 总被引:1,自引:0,他引:1
Perna A Jost C Couturier E Valverde S Douady S Theraulaz G 《Die Naturwissenschaften》2008,95(9):877-884
Recent studies have introduced computer tomography (CT) as a tool for the visualisation and characterisation of insect architectures. Here, we use CT to map the three-dimensional networks of galleries inside Cubitermes nests in order to analyse them with tools from graph theory. The structure of these networks indicates that connections inside the nest are rearranged during the whole nest life. The functional analysis reveals that the final network topology represents an excellent compromise between efficient connectivity inside the nest and defence against attacking predators. We further discuss and illustrate the usefulness of CT to disentangle environmental and specific influences on nest architecture. 相似文献
188.
Andrea Meyn Sebastian Schmidtlein Stephen W. Taylor Martin P. Girardin Kirsten Thonicke Wolfgang Cramer 《Regional Environmental Change》2013,13(1):165-177
Trends of summer precipitation and summer temperature and their influence on trends in summer drought and area burned in British Columbia (BC) were investigated for the period 1920–2000. The complexity imposed by topography was taken into account by incorporating high spatial resolution climate and fire data. Considerable regional variation in trends and in climate–fire relationships was observed. A weak but significant increase in summer temperature was detected in northeastern and coastal BC, whereas summer precipitation increased significantly in all regions—by up to 45.9 %. A significant decrease in province-wide area burned and at the level of sub-units was strongly related to increasing precipitation, more so than to changing temperature or drought severity. A stronger dependence of area burned on precipitation, a variable difficult to predict, implies that projected changes in future area burned in this region may yield higher uncertainties than in regions where temperature is predominantly the limiting factor for fire activity. We argue that analyses of fire–climate relationships must be undertaken at a sufficiently high resolution such that spatial variability in limiting factors on area burned like precipitation, temperature, and drought is captured within units. 相似文献
189.
Faria Maria Graciela Iecher Avelino Katielle Vieira Philadelpho Biane Oliveira dos Santos Bomfim Rafaela do Valle Juliana Silveira Júnior Affonso Celso Gonçalves Dragunski Douglas Cardoso de Souza Ferreira Ederlan de Souza Carolina Oliveira Ribeiro Camila Duarte Ferreira Colauto Nelson Barros Linde Giani Andrea 《Environmental science and pollution research international》2022,29(58):87519-87526
Environmental Science and Pollution Research - Lentinus crinitus bioaccumulates lithium in mycelia, but bioaccumulation may be affected by pH of the culture medium. Lithium is used in clinical... 相似文献
190.
Conte Marianna Feltracco Matteo Chirizzi Daniela Trabucco Sara Dinoi Adelaide Gregoris Elena Barbaro Elena La Bella Gianfranco Ciccarese Giuseppina Belosi Franco La Salandra Giovanna Gambaro Andrea Contini Daniele 《Environmental science and pollution research international》2022,29(10):13905-13916
Environmental Science and Pollution Research - COVID-19 pandemic raised a debate regarding the role of airborne transmission. Information regarding virus-laden aerosol concentrations is still... 相似文献