Pa-239 may influence astrophysics study

The estimation method of the universe age using the nuclear cosmochronology by the heavy chronometers is essentialized. The influence of the novel long half-life of Pa-239 on the universe age estimation is simply mentioned.

土壤溶解性有机碳(DOC)的影响因子及生态效应

土壤溶解性有机碳(DOC)是陆地生态系统中极为活跃的有机组分,是土壤圈层与相关圈层(如生物圈、大气圈、水圈和岩石圈等)发生物质交换的重要形式。影响土壤中物质的溶解、吸附、解吸、吸收、迁移乃至生物毒性等行为之外,对温室气体CH4的排放、水体水质的污染、岩石圈的风化等的影响也不可忽视。本文以陆地生态系统的中的DOC为主体,探讨了DOC的生态环境意义及其对大气、水体和岩石圈的影响以及DOC对土壤管理措施的响应。

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 May 2009-31 July 2009

This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.

Three tetraspanins from Chinese shrimp, Fenneropenaeus chinensis, may play important roles in WSSV infection

Three members of the tetraspanin/TM4SF superfamily were cloned from Chinese shrimp, Fenneropenaeus chinensis. The deduced amino acid sequences of the three proteins have typical motifs of the tetraspanin/TM4SF superfamily. Phylogenetic analysis of the proteins, together with the known tetraspanins of invertebrates and vertebrates, revealed that they belong to different tetraspanin subfamilies: CD9, CD63 and tetraspanin-3. The three cloned genes of CD9, CD63 and tetraspanin-3 showed apparently different tissue distributions. The CD9 gene (FcCD9) was specifically expressed in the hepatopancreas. While for the CD63 gene (FcCD63), the highest expression was detected in nerves, epidermis and heart, with low expression in haemocytes, ovary, gill, hepatopancreas and stomach and no expression in intestine, muscle and lymphoid organ. Compared with FcCD9 and FcCD63, the tetraspanin-3 gene (FcTetraspanin-3) was more broadly expressed and its highest expression was detected in the intestine. Its expression in nerves was lower than in the intestine, but was higher than in other tissues. Expression in haemocytes, ovary and muscle was much lower than in other tissues. The expression profiles of FcCD9, FcCD63 and FcTetraspanin-3 in different tissues, including haemocytes, lymphoid organ and hepatopancreas, were compared by real-time PCR when shrimp were challenged by live white spot syndrome virus (WSSV) and heat-inactivated WSSV. All three tetraspanins were markedly up-regulated in the live WSSV-challenged shrimp tissues. The data suggested that the three cloned members of TM4SF superfamily in Chinese shrimp may play a key role in the route of WSSV infection.

Typhoon effects on DOC dynamics in a phosphate-limited reservoir

To explore typhoon effects on dissolved organic carbon (DOC) dynamics, field investigations (tributary and dam site) and laboratory experiments (bioassay and DOC consumption) were conducted in a subtropical reservoir. A tributary survey indicated that after typhoon disruption, upstream areas were the sources of phosphate (P) but not DOC for the dam site located downstream. Bioassay experiments verified P-limitation on bacteria and phytoplankton during summer stratification, and bacteria showed a faster response than algae to added P. Experiments indicated that DOC consumption was determined by the availability of P. The 4 yr typhoon period (June-September) data of the dam site denoted that DOC concentration (27 to 270 mu M C) and its rate of change (-13 to 24 mu M C d(-1)) varied more dramatically in the weak (2006 and 2007) than in the strong (2004 and 2005) typhoon years. The negative correlation of DOC with the ratio of bacterial production (BP) to primary production (PP) in the euphotic zone (0 to 10 m) signified the interactive effects of auto- and heterotrophic processes on DOC variation. In the aphotic zone, the variation of DOC could be ascribed to the change of BP, which showed a positive correlation with P concentrations. This study documents that DOC concentration in the studied system varied at multiple time scales. Such variation can be explained by the decoupling between BP and PP, which is believed to be a function of the limiting nutrient's availability. More importantly, this study suggests that the P supply introduced by strong typhoons might have substantiated a tighter coupling between BP and PP, so that the amplitude of DOC oscillation during the summer period was effectively reduced.

Current status of bacteriological parameters and DOC/POC in Xiamen coastal waters

The surface and bottom waters samples were collected from six locations in Xiamen western sea. The quantified estimation of bacterial production (H-3-thymidine method) and observation of bacterial heterotrophic activity (C-14-glucose method) have been made in order to have a better understanding of the role of marine bacteria and their activities. The results showed that the mean value of bacterial heterotrophic activity was 9 X 10(8) cells/(L. h) in the surface waters and 2.6 X 10(8) cells/(L. h) in the bottom waters. The mean value of bacterial production was 38 X 108 cells/( L. h) in the surface waters and 7.1 X 10(8) cells/(L. h) in the bottom waters. The relationship between bacterial production, heterotrophic activity, PCC and DOC measured during this survey were discussed. The good understanding of the relationship between bacteria activity and total coliform was addressed.

Dissolved oxygen and O-2 flux across the water-air interface of the Changjiang Estuary in May 2003

The field observation of this study was carried out in the Changjiang Estuary from May 19 to 26,2003, just a few days before the Three Gorges Dam began to store water. A total of 29 stations, including 2 anchor stations, were distributed through almost the whole salinity gradient Based on the data gained from these stations, the biogeochemical characteristics of dissolved oxygen (DO) were examined. Spatial distribution of DO concentrations showed the pattern that it increased in a downriver direction. DO concentration generally varied within a narrow range of 733-8.10 mg l(-1) in the freshwater region and the west part of the mixed water region, and after that it increased rapidly. In vertical direction, the differences in DO concentrations between surface and 2 m above the bottom were big at the stations with water depths exceeding 20 m; DO concentration up to 14.88 mg l(-1) was recorded at the sea surface, while at 2 m above the bottom its concentration was only about 4 mg l(-1). The fluctuation in DO concentrations was small during a period of 48 h in the mixed water region and 2 m above the bottom of the seawater region; while it was large during the same period in the seawater region for surface and 5 m below the surface layer, and a maximum variation from 8.77 to 12.66 mg l(-1) in 4 h was recorded. Oxygen fluxes also showed a marked spatio-temporal variation. As a whole, the freshwater region and mixed water region were an oxygen sink while the seawater region was a source. Relationships between dissolved oxygen and some biogeochemical parameters which could markedly influence its spatio-temporal distribution were discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.

H5N1 avian influenza re-emergence of Lake Communication Qinghai: phylogenetic and antigenic analyses of the newly isolated viruses and roles of migratory birds in virus circulation

Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/ 02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai.

北京石花洞滴水沉积的季节变化及影响因素

Because of the high resolution, stalagmite laminae can play an important role in the paleoclimate reconstructions. However, few investigations for the formation mechanisms of stalagmite lamilae have been done. Based on two-year observation on calcite growth rate at the drip sites, three-year monitoring of hydrodynamics, physics and chemistry of drip waters at different drip sites and the surrounding environments inside and outside the Beijing Shihua Cave, the seasonal variations of calcite growth rate are revealed and the results can be concluded as follows: 1. The drip waters inside the Cave are mostly sourced from the summer rain, and its minimal response-time to the atmospheric precipitation is less than one day. There are three types of response relationships between the precipitation and the drip rate variations: rapid response type, time-lag response type and stable response type. For rapid response type, the drip discharge is recharged through the flow routes along intensive fractures and interconnectivities; for time-lag response type, the drip discharge is recharged by double-porosity system composed of a high conductivity, low storage capability conduit network and a low-conductivity high-storage capability rock matrix under variable boundary conditions; for stable response type, the drip discharge is mainly recharged by seepage flow and base flow. 2. The observation shows that, inside the Cave, the growth rate of calcite is generally lower in rainy seasons and higher in dry seasons. During the rainy seasons, the drip water is characterized by a lower pH value, higher [Ca2+], [Mg2+], [SO42-] and electrical conductivity (EC) values. According to the calculations of saturation index of calcite (SIc), pCO2 of the drip water, as well as the synthetical analysis of other possible factors, the calcite growth rate is found to be principally influenced by the drip water saturation index of calcite (SIc). And the drip rate and pCO2 in the drip water and in the cave air play the secondly important roles in this process. The recharge mode of heavy rainfall events in the rainy seasons should probably be the main driving force that controls the physicochemical properties and calcite sediment of the drip waters. The abrupt decrease of sedimentary rate and the sharp peak of DOC in drip water in the rainy season probably forms the thin opaque (luminescent under ultraviolet radiation) layers observed in the stalagmites, whereas the relatively higher sedimentary rate in the dry seasons may be responsible for the thicker bright layers. The investigation elucidated here preliminarily reveals the formation mechanism of the stalagmite laminae in Beijing Shihua Cave.

西江流域环境河水地球化学研究

River is a major component of the global surface water and CO2 cycles. The chemistry of river waters reveals the nature of weathering on a basin-wide scale and helps us understand the exogenic cycles of elements in the continent-river-ocean system. In particular, geochemical investigation of large river gives important information on the biogeochemical cycles of the elements, chemical weathering rates, physical erosion rates and CO2 consumption during the weathering of the rocks within the drainage basin. Its importance has led to a number of detailed geochemical studies on some of the world's large and medium-size river systems. Flowing in the south of China, the Xijiang River is the second largest river in the China with respect to its discharge, after the Yangtze River. Its headwaters drain the YunGui Plateau, where altitude is approximately 2000 meters. Geologically, the carbonate rocks are widely spread in the river drainage basin, which covers an area of about 0.17xl06 km2, i.e., 39% of the whole drainage basin. This study focuses on the chemistry of the Xijiang river system and constitutes the first geochemical investigation into major and trace elements concentrations for both suspended and dissolved loads of this river and its main tributaries, and Sr isotopic composition of the dissolved load is also investigated, in order to determine both chemical weathering and mechanical erosion rates. As compared with the other large rivers of the world, the Xijiang River is characterized by higher major element concentration. The dissolved major cations average 1.17, 0.33, 0.15, and 0.04 mmol I"1 for Ca, Mg, Na, and K, respectively. The total cation concentrations (TZ+) in these rivers vary between 2.2 and 4.4 meq I'1. The high concentration of Ca and Mg, high (Ca+Mg)/(Na+K) ratio (7.9), enormous alkalinity and low dissolved SiO2/HCO3 ratio (0.05) in river waters reveal the importance of carbonate weathering and relatively weak silicate weathering over the river drainage basin. The major elements in river water, such as the alkalis and alkaline-earths, are of different origins: from rain water, silicate weathering, carbonate and evaporite weathering. A mixing model based on mass budget equation is used in this study, which allows the proportions of each element derived from the different source to be calculated. The carbonate weathering is the main source of these elements in the Xijiang drainage basin. The contribution of rainwater, especially for Na, reaches to approximately 50% in some tributaries. Dissolved elemental concentration of the river waters are corrected for rain inputs (mainly oceanic salts), the elemental concentrations derived from the different rock weathering are calculated. As a consequence, silicate, carbonate and total rock weathering rates, together with the consumption rates of atmospheric CO2 by weathering of each of these lithologies have been estimated. They provide specific chemical erosion rates varying between 5.1~17.8 t/km2/yr for silicate, 95.5~157.2 t/km2/yr for carbonate, and 100.6-169.1 t/km2/yr for total rock, respectively. CO2 consumptions by silicate and carbonate weathering approach 13><109and 270.5x10 mol/yr. Mechanical denudation rates deduced from the multi-year average of suspended load concentrations range from 92-874 t/km2/yr. The high denudation rates are mainly attributable to high relief and heavy rainfall, and acid rain is very frequent in the drainage basin, may exceed 50% and the pH value of rainwater may be <4.0, result from SO2 pollution in the atmosphere, results in the dissolution of carbonates and aluminosilicates and hence accelerates the chemical erosion rate. The compositions of minerals and elements of suspended particulate matter are also investigated. The most soluble elements (e.g. Ca, Na, Sr, Mg) are strongly depleted in the suspended phase with respect to upper continent crust, which reflects the high intensity of rock weathering in the drainage basin. Some elements (e.g. Pb, Cu, Co, Cr) show positive anomalies, Pb/Th ratios in suspended matter approach 7 times (Liu Jiang) to 10 times (Nanpan Jiang) the crustal value. The enrichment of these elements in suspended matter reflects the intensity both of anthropogenic pollution and adsorption processes onto particles. The contents of the soluble fraction of rare earth elements (REE) in the river are low, and REE mainly reside in particulate phase. In dissolved phase, the PAAS-normalized distribution patterns show significant HREE enrichment with (La/Yb) SN=0.26~0.94 and Ce depletion with (Ce/Ce*) SN=0.31-0.98, and the most pronounced negative Ce anomalies occur in rivers of high pH. In the suspended phase, the rivers have LREE-enriched patterns relative to PAAS, with (La/Yb) SN=1 -00-1 .40. The results suggest that pH is a major factor controlling both the absolute abundances of REE in solution and the fractionation of REE of dissolved phase. Ce depletion in river waters with high pH values results probably from both preferential removal of Ce onto Fe-Mn oxide coating of particles and CeC^ sedimentation. This process is known to occur in the marine environment and may also occur in high pH rivers. Positive correlations are also observed between La/Yb ratio and DOC, HCO3", PO4", suggesting that colloids and (or) adsorption processes play an important role in the control of these elements.