Eocene benthic foraminiferal community DSDP of Holes 95-612, 95-613 and 11-108

Benthic foraminiferal biofacies may vary independently of water depth and water mass; however, calibration of biofacies and stratigraphic ranges with independent paleodepth estimates allows reconstruction of age-depth patterns applicable throughout the deep Atlantic (Tjalsma and Lohmann, 1983). We have attempted to test these faunal calibrations in a continental margin setting, reconstructing Eocene benthic foraminiferal distributions along a dip section afforded by the New Jersey Transect (DSDP Sites 612, 108, 613). The following independent estimates of Eocene depths for the transect were obtained by "backtracking," "backstripping," and by assuming increasing depth downdip ("paleoslope"): Site 612, near the middle/lower bathyal boundary (about 1000 m); Site 108, in the middle bathyal zone (about 1600 m); and Site 613, near the lower bathyal/upper abyssal boundary (about 2000 m). Within uncertainties of backtracking (hundreds of meters), these estimates agree with estimates of paleodepth based on comparison of the New Jersey margin biofacies with other backtracked faunas. The stratigraphic ranges of many benthic taxa correspond to those found at other Atlantic DSDP sites. The major biofacies patterns show: (1) a depth dichotomy between an early to middle Eocene Nuttallides truempyidominated biofacies (greater than 2000 m) and a Lenticulina-Osangularia-Alabamina cf. dissonata biofacies (1000- 2000 m); and (2) a difference between a middle and a late Eocene biofacies at Site 612. The faunal boundary at about 2000 m, between bathyal and abyssal zones, occurs not only on the margin, but also throughout the deep Atlantic. The faunal change between the middle and late Eocene at Site 612 was due to a decrease of Lenticulina spp., the local disappearance of N. truempyi, and establishment of a Bulimina alazanensis-Gyroidinoides spp. biofacies. Although this change could be attributed to local paleoceanographic or water-depth changes, we argue that it is the bathyal expression of a global deep-sea benthic foraminiferal change which occurred across the middle/late Eocene boundary.

人为干扰(间伐)对红松人工林林下植物多样性的影响

根据对辽宁东部地区红松人工林林下高等维管植物调查资料,采用Simpson指数(SP),Shannon-Wiener指数(SW)和Pielou均匀度指数(PI)等进行α多样性测度分析,探讨人为干扰(不同间伐强度)对红松人工林下植物多样性的影响。结果表明:人为干扰改变林下光照环境,促进植物生长,对红松人工林下高等维管植物的物种多样性产生较大影响。随着干扰(间伐)强度增加,红松人工林下植物种类、数量明显增加;不同干扰强度区林下植物种类高于对照区200%~400%;不同干扰强度红松人工林下植物种类的丰富度和多样性明显高于对照区;人为经营干扰改变了红松人工林下植物组成,随干扰强度增加,共有物种增加,且人为干扰林分的共有种和相似系数明显高于对照区。

SplicerAV: a tool for mining microarray expression data for changes in RNA processing.

BACKGROUND: Over the past two decades more than fifty thousand unique clinical and biological samples have been assayed using the Affymetrix HG-U133 and HG-U95 GeneChip microarray platforms. This substantial repository has been used extensively to characterize changes in gene expression between biological samples, but has not been previously mined en masse for changes in mRNA processing. We explored the possibility of using HG-U133 microarray data to identify changes in alternative mRNA processing in several available archival datasets. RESULTS: Data from these and other gene expression microarrays can now be mined for changes in transcript isoform abundance using a program described here, SplicerAV. Using in vivo and in vitro breast cancer microarray datasets, SplicerAV was able to perform both gene and isoform specific expression profiling within the same microarray dataset. Our reanalysis of Affymetrix U133 plus 2.0 data generated by in vitro over-expression of HRAS, E2F3, beta-catenin (CTNNB1), SRC, and MYC identified several hundred oncogene-induced mRNA isoform changes, one of which recognized a previously unknown mechanism of EGFR family activation. Using clinical data, SplicerAV predicted 241 isoform changes between low and high grade breast tumors; with changes enriched among genes coding for guanyl-nucleotide exchange factors, metalloprotease inhibitors, and mRNA processing factors. Isoform changes in 15 genes were associated with aggressive cancer across the three breast cancer datasets. CONCLUSIONS: Using SplicerAV, we identified several hundred previously uncharacterized isoform changes induced by in vitro oncogene over-expression and revealed a previously unknown mechanism of EGFR activation in human mammary epithelial cells. We analyzed Affymetrix GeneChip data from over 400 human breast tumors in three independent studies, making this the largest clinical dataset analyzed for en masse changes in alternative mRNA processing. The capacity to detect RNA isoform changes in archival microarray data using SplicerAV allowed us to carry out the first analysis of isoform specific mRNA changes directly associated with cancer survival.

An epoxide ring-opening approach for a short and stereoselective synthesis of icetexane diterpenoids

A new approach for the synthesis of the core skeleton of icetexane diterpenoids is presented and deals with an epoxide ring-opening reaction by metallated aromatic compounds. Employing this strategy, a short synthesis of an icetexane analogue of brussonol was achieved in just four steps from 2-allyl-cyclohexanone. (C) 2009 Elsevier Ltd. All rights reserved.

Investigation of the pore blockage of a Brazilian dolomite during the sulfation reaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigation of the pore blockage of a Brazilian dolomite during the sulfation reaction

The influence of the temperature and reaction time on the sulfation process of a dolomite is investigated in this paper. The sulfation effectiveness was evaluated and correlated with changes in the physical characteristics of a Brazilian dolomite during the reactive process. Calcination and sulfation experiments were performed under isothermal conditions for dolomite samples with average particle sizes of 545 mu m at temperatures of 750 degrees C, 850 degrees C and 950 degrees C at different times of sulfation. Thermogravimetric tests were applied to establish the reactivity variation of the dolomite in function of the time in the sulfation reaction and evaluate the methodology of the samples preparation. Porosimetry tests were performed to study the pore blockage of dolomite during the sulfation reaction. The highest values of BET surface area were 25.55 m(2)/g, 29.55 m(2)/g and 12.62 m(2)/g for calcined samples and after their sulfation processes, conversions of 51.5%, 61.9% and 42.8% were obtained at 750 degrees C, 850 degrees C and 950 degrees C, respectively. Considering the process as a whole, the best fit was provided by a first-order exponential decay equation. Moreover, the results have shown that it is possible to quantify the decreasing in the dolomite reactivity for sulfur dioxide sorption and understand the changes in the behavior of the sulfation process of limestones when applied to technologies, as fluidized bed combustor, in which sulfur dioxide is present. (C) 2011 Elsevier B. V. All rights reserved.