Periodicities in the occurrence of aurora as indicators of solar variability

A compilation of records of the aurora observed in China from the Time of the Legends (2000 - 3000 B.C.) to the mid-18th century has been used to infer the frequencies and strengths of solar activity prior to modern times. A merging of this analysis with auroral and solar activity patterns during the last 200 years provides basically continuous information about solar activity during the last 2000 years. The results show periodicities in solar activity that contain average components with a long period (approx. 412 years), three middle periods (approx. 38 years, approx. 77 years, and approx. 130 years), and the well known short period (approx. 11 years)

Early chemical diagenesis, sediment-water solute exchange, and storage of reactive organic matter near the mouth of the Changjiang, East China Sea

【Abstract】A substantial proportion of the material delivered to the modern oceans is supplied by a few large rivers such as the Changjiang. Early diagenetic reactions in surficial bottom sediments determine in large part both the eventual influence of these rivers on the sea and the nature of sedimentary deposits formed. The region off the mouth of the Changjiang exemplifies the interplay between physical, chemical, and biological factors which can produce particular spatial patterns of diagenesis and sediment-water exchange. To examine these patterns measurement of pore water solute profiles, sediment-water solute fluxes, and solute reaction rates in the upper few decimeters of sediment were made at 27 stations near the Changjiang in the East China Sea. Direct measurements of dissolved Si(OH)4, NH4+, and NO3−, fluxes from or into bottom sediments made during summer and autumn periods (15 to 24°C) range from 0.13 to 13.2, −2.6 to 3.4, and −1.4 to 3.2mmol m−2 day−1, respectively. Net solute flux from the sea floor is often lowest from deposits having the highest interstitial solute concentrations. In addition, bottom regions having the highest build up of reaction products or depletion of reactants in pore waters (with respect to overlying water) actually have the lowest rates of reaction. These same areas of elevated (products) or depleted (reactants) pore water solute concentrations, low reaction rates, and low net rate of solute exchange which are located near the mouth of the Changjiang are sites of high sedimentation rates and depauperate benthic communities. High water turbidity and resuspension apparently hinder water column production and input of reactive organic matter or other biogenic material which drive many diagenetic reactions. Rapid sedimentation or disturbance hinders benthic community development, lowers biogenic reworking, and allows build up or depletion of reaction products or reactants in bottom sediments. Offshore areas of lower sedimentation, higher productivity, and active bottom communities are sites of high initial reaction rates and increased sediment-water solute exchange compared with rapid sedimentation regions. A diagenetic paradox resulting from the interaction between benthic communities and the physical environment of sedimentation is that proportionally the greatest storage of diagenetic products related to organic matter decomposition can occur in sediments that are initially the least diagenetically reactive

Analysis of 10,000 ESTs from lymphocytes of the cynomolgus monkey to improve our understanding of its immune system

BACKGROUND: The cynomolgus monkey (Macaca fascicularis) is one of the most widely used surrogate animal models for an increasing number of human diseases and vaccines, especially immune-system-related ones. Towards a better understanding of the gene expression background upon its immunogenetics, we constructed a cDNA library from Epstein-Barr virus (EBV)-transformed B lymphocytes of a cynomolgus monkey and sequenced 10,000 randomly picked clones. RESULTS: After processing, 8,312 high-quality expressed sequence tags (ESTs) were generated and assembled into 3,728 unigenes. Annotations of these uniquely expressed transcripts demonstrated that out of the 2,524 open reading frame (ORF) positive unigenes (mitochondrial and ribosomal sequences were not included), 98.8% shared significant similarities (E-value less than 1e-10) with the NCBI nucleotide (nt) database, while only 67.7% (E-value less than 1e-5) did so with the NCBI non-redundant protein (nr) database. Further analysis revealed that 90.0% of the unigenes that shared no similarities to the nr database could be assigned to human chromosomes, in which 75 did not match significantly to any cynomolgus monkey and human ESTs. The mapping regions to known human genes on the human genome were described in detail. The protein family and domain analysis revealed that the first, second and fourth of the most abundantly expressed protein families were all assigned to immunoglobulin and major histocompatibility complex (MHC)-related proteins. The expression profiles of these genes were compared with that of homologous genes in human blood, lymph nodes and a RAMOS cell line, which demonstrated expression changes after transformation with EBV. The degree of sequence similarity of the MHC class I and II genes to the human reference sequences was evaluated. The results indicated that class I molecules showed weak amino acid identities (<90%), while class II showed slightly higher ones. CONCLUSION: These results indicated that the genes expressed in the cynomolgus monkey could be used to identify novel protein-coding genes and revise those incomplete or incorrect annotations in the human genome by comparative methods, since the old world monkeys and humans share high similarities at the molecular level, especially within coding regions. The identification of multiple genes involved in the immune response, their sequence variations to the human homologues, and their responses to EBV infection could provide useful information to improve our understanding of the cynomolgus monkey immune system