Mapping of C4 plant input from North West Africa into North East Atlantic sediments

Mapping the abundance of 13C in leaf-wax components in surface sediments recovered from the seafloor off northwest Africa (0-35°N) reveals a clear pattern of delta13C distribution, indicating systematic changes in the proportions of terrestrial C3 and C4 plant input. At 20°N latitude, we find that isotopically enriched products characteristic of C4 plants account for more than 50% of the terrigenous inputs. This signal extends westward beneath the path of the dust-laden Sahara Air Layer (SAL). High C4 contributions, apparently carried by January trade winds, also extend far into the Gulf of Guinea. Similar distributions are obtained if summed pollen counts for the Chenopodiaceae-Amaranthaceae and the Poaceae are used as an independent C4 proxy. We conclude that the specificity of the latitudinal distribution of vegetation in North West Africa and the pathways of the wind systems (trade winds and SAL) are responsible for the observed isotopic patterns observed in the surface sediments. Molecular-isotopic maps on the marine-sedimentary time horizons (e.g., during the last glacial maximum) are thus a robust tool for assessing the phytogeographic changes on the tropical and sub-tropical continents, which have important implications for the changes in climatic and atmospheric conditions.

Biological survey: River Teign and tributaries with references to the discharge of ball clay wastes

This is the Biological survey of River Teign and tributaries with references to the discharge of ball clay wastes, document produced by South West Water Authority in 1973. This report focuses on on-site assessment of the benthic macro-invertebrates of the lower River Teign, River Bovey, Ugbrooke Stream and Blatchford Brook was undertaken on 19th and 22nd August 1977 to assess the effects of discharges from ball clay mining premises. Inspection of aquatic fauna in the field is of necessity, less extensive than laboratory identification of sorted samples, so that the resulting data underestimates the water quality. This is more pronounced in the Chandler Score than in the Trent Biotic Index which does not take account of species abundance. Chandler should thus be interpreted by the trends described rather than by absolute values calculated.

Upregulation of acid-sensing ion channel ASIC1a in spinal dorsal horn neurons contributes to inflammatory pain hypersensitivity

Development of chronic pain involves alterations in peripheral nociceptors as well as elevated neuronal activity in multiple regions of the CNS. Previous pharmacological and behavioral studies suggest that peripheral acid-sensing ion channels (ASICs) cont

FREQUENCY AND TEMPORAL COHERENCE PROPERTIES OF DISTRIBUTED BRAGG REFLECTOR LASER

This article presents the investigation of frequency and temporal coherence properties of distributed Bragg reflector laser. In this scheme, a square-wavefrom voltage is applied to the phase section of the laser to little optical wavelength, and delayed optical heterodyne technique is used for the analysis of spectral characteristics. Experiments show that lightwaves emitted from the same active region asynchronously are partially frequency and temporal coherent. When the two wavelengths are closer, the two waves are strong v coherent, and the coherence properties get weak as the delay v time increases. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Left 52: 822-825, 2010 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25031

高效液相色谱法测定山茱萸与五味子配伍前后马钱苷、没食子酸及五味子醇甲的含量

目的考察山茱萸与五味子配伍前后两药主要组分的含量变化规律。方法利用高效液相色谱(HPLC)方法,比较了配伍前后单煎液、合煎液和单煎合并液中两药主要组分马钱苷、没食子酸和五味子醇甲的含量变化。结果在配伍比例较低(≤4:4)时,五味子促进了山茱萸中马钱苷的溶出。合煎液中的没食子酸、五味子醇甲组分的百分含量随着五味子配伍比例的增大呈线性减小,且均低于单煎液。单煎合并液中这3种组分的含量均高于同比例合煎液。结论山茱萸五味子配伍对两药主要组分溶出有较大影响,该影响主要在煎煮过程中发生。

Olfactory Receptor Subgenomes Linked with Broad Ecological Adaptations in Sauropsida.

Olfactory receptors (ORs) govern a prime sensory function. Extant birds have distinct olfactory abilities, but the molecular mechanisms underlining diversification and specialization remain mostly unknown. We explored OR diversity in 48 phylogenetic and ecologically diverse birds and 2 reptiles (alligator and green sea turtle). OR subgenomes showed species- and lineage-specific variation related with ecological requirements. Overall 1,953 OR genes were identified in reptiles and 16,503 in birds. The two reptiles had larger OR gene repertoires (989 and 964 genes, respectively) than birds (182-688 genes). Overall, birds had more pseudogenes (7,855) than intact genes (1,944). The alligator had significantly more functional genes than sea turtle, likely because of distinct foraging habits. We found rapid species-specific expansion and positive selection in OR14 (detects hydrophobic compounds) in birds and in OR51 and OR52 (detect hydrophilic compounds) in sea turtle, suggestive of terrestrial and aquatic adaptations, respectively. Ecological partitioning among birds of prey, water birds, land birds, and vocal learners showed that diverse ecological factors determined olfactory ability and influenced corresponding olfactory-receptor subgenome. OR5/8/9 was expanded in predatory birds and alligator, suggesting adaptive specialization for carnivory. OR families 2/13, 51, and 52 were correlated with aquatic adaptations (water birds), OR families 6 and 10 were more pronounced in vocal-learning birds, whereas most specialized land birds had an expanded OR family 14. Olfactory bulb ratio (OBR) and OR gene repertoire were correlated. Birds that forage for prey (carnivores/piscivores) had relatively complex OBR and OR gene repertoires compared with modern birds, including passerines, perhaps due to highly developed cognitive capacities facilitating foraging innovations.

L'Écho de Paris

1915/02/13 (Numéro 11139).