1988 DWC Membership and Mailing Lists

Membership list of DWC members, 198

Identification of induced polarization of submarine hydrocarbons in marine controllable source electromagnetic exploration

The identification of hydrocarbons buried on the seafloor is highly dependent on geophysical exploration capabilities. Seismic exploration has been an important tool in providing information on submarine stratigraphy before offshore drilling, but it is a challenge to identify the nature and saturation of the fluid in the structure by seismic exploration. Of all the physical properties, electrical parameters are the most sensitive to the fluids in the reservoir and would be able to be combined with seismic data to improve the identification of hydrocarbons at depth. However, the marine controlled-source electromagnetic method usually only considers the effect of electromagnetic induction and ignores the induced polarization (IP) effects. The IP effects can occur in the stratum where the reservoir is located due to a variety of factors, so considering the IP effects will make the modeling more reasonable and thus give more accurate results when interpreting and processing the data. We have used the integral equation method for modeling, adopted the scattering and superposition methods to calculate the dyadic Green’s function required in the study, replaced the real resistivity with a complex resistivity that takes into account the IP effects, investigated the response patterns of different ion polarization models, and analyzed the influence patterns of various model parameters. These investigations will provide important contributions to the study of submarine hydrocarbon detection. The field data also show the amplitude, and phase response results of polarizability show that it gradually increases from the offset

Field and Laboratory Studies on Pathological and Biochemical Characterization of Microcystin-Induced Liver and Kidney Damage in the Phytoplanktivorous Bighead Carp

Field and experimental studies were conducted to investigate pathological characterizations and biochemical responses in the liver and kidney of the phytoplanktivorous bighead carp after intraperitoneal (i.p.) administration of microcystins (MCs) and exposure to natural cyanobacterial blooms in Meiliang Bay, Lake Taihu. Bighead carp in field and laboratory studies showed a progressive recovery of structure and function in terms of histological, cellular, and biochemical features. In laboratory study, when fish were i.p. injected with extracted MCs at the doses of 200 and 500 μg MC-LReq/kg body weight, respectively, liver pathology in bighead carp was observed in a time dose-dependent manner within 24 h postinjection and characterized by disruption of liver structure, condensed cytoplasm, and the appearance of massive hepatocytes with karyopyknosis, karyorrhexis, and karyolysis. In comparison with previous studies on other fish, bighead carp in field study endured higher MC doses and longer-term exposure, but displayed less damage in the liver and kidney. Ultrastructural examination in the liver revealed the presence of lysosome proliferation, suggesting that bighead carp might eliminate or lessen cell damage caused by MCs through lysosome activation. Biochemically, sensitive responses in the antioxidant enzymes and higher basal glutathione concentrations might be responsible for their powerful resistance to MCs, suggesting that bighead carp can be used as biomanipulation fish to counteract cyanotoxin contamination

In situ studies on physiological and biochemical responses of four fishes with different trophic levels to toxic cyanobacterial blooms in a large Chinese lake

Physiological and biochemical responses of four fishes with different trophic levels to toxic cyanobacterial blooms were studied in a large net cage in Meiliang Bay, a hypereutrophic region of Lake Taihu. We sampled four fishes: the phytoplanktivorous Hypophthalmichthys molitrix and Aristichthys nobilis, the omnivorous Carassius auratus, and the carnivorous Culter ilishaeformis. Alterations of the antioxidant (GSH) and the major antioxidant enzymes (CAT, SOD, GPx, GST) in livers were monitored monthly, and the ultrastructures of livers were compared between the bloom and post-bloom periods. During the cyanobacterial blooms, the phytoplanktivorous fishes displayed only slight ultrastructural changes in liver, while the carnivorous fish presented the most serious injury as swollen endomembrane system and morphologically altered nuclei in hepatocytes. Biochemically, the phytoplanktivorous fishes possessed higher basal GSH concentrations and better correlations between the major antioxidant enzymes in liver, which might be responsible for their powerful resistance to MCs. This article provided physiological and toxicological evidences for the possible succession of fish communities following occurrence of toxic cyanobacterial blooms and also for the applicability of using phytoplanktivorous fish to counteract toxic cyanobacterial blooms in natural waters. (C) 2007 Elsevier Ltd. All rights reserved.Physiological and biochemical responses of four fishes with different trophic levels to toxic cyanobacterial blooms were studied in a large net cage in Meiliang Bay, a hypereutrophic region of Lake Taihu. We sampled four fishes: the phytoplanktivorous Hypophthalmichthys molitrix and Aristichthys nobilis, the omnivorous Carassius auratus, and the carnivorous Culter ilishaeformis. Alterations of the antioxidant (GSH) and the major antioxidant enzymes (CAT, SOD, GPx, GST) in livers were monitored monthly, and the ultrastructures of livers were compared between the bloom and post-bloom periods. During the cyanobacterial blooms, the phytoplanktivorous fishes displayed only slight ultrastructural changes in liver, while the carnivorous fish presented the most serious injury as swollen endomembrane system and morphologically altered nuclei in hepatocytes. Biochemically, the phytoplanktivorous fishes possessed higher basal GSH concentrations and better correlations between the major antioxidant enzymes in liver, which might be responsible for their powerful resistance to MCs. This article provided physiological and toxicological evidences for the possible succession of fish communities following occurrence of toxic cyanobacterial blooms and also for the applicability of using phytoplanktivorous fish to counteract toxic cyanobacterial blooms in natural waters. (C) 2007 Elsevier Ltd. All rights reserved

Evaluation of bias-variance trade-off for commonly used post-summarizing normalization procedures in large-scale gene expression studies.

Normalization procedures are widely used in high-throughput genomic data analyses to remove various technological noise and variations. They are known to have profound impact to the subsequent gene differential expression analysis. Although there has been some research in evaluating different normalization procedures, few attempts have been made to systematically evaluate the gene detection performances of normalization procedures from the bias-variance trade-off point of view, especially with strong gene differentiation effects and large sample size. In this paper, we conduct a thorough study to evaluate the effects of normalization procedures combined with several commonly used statistical tests and MTPs under different configurations of effect size and sample size. We conduct theoretical evaluation based on a random effect model, as well as simulation and biological data analyses to verify the results. Based on our findings, we provide some practical guidance for selecting a suitable normalization procedure under different scenarios

Clinical analysis of pregnancy complicated with miliary tuberculosis

BACKGROUND: Pregnancy complicated with tuberculosis is increasingly common. The clinical characteristics of pregnancy complicated with miliary tuberculosis are summarized in this study. METHODS: A retrospective analysis of pregnant patients with miliary tuberculosis was performed in terms of epidemiology, demography, clinical characteristics, laboratory tests, treatment, and prognosis. RESULTS: Of the 23 patients that were included, 12 became pregnant after in vitro fertilization combined with embryo transfer (IVF-ET). The average gestational age at symptom onset was 13.96 weeks, and the average time from symptom onset to diagnosis was 33 days. Clinical symptoms included fever, dyspnoea, cough, headache, abdominal pain, and chest pain. Extrapulmonary tuberculosis occurred in 10 patients, respiratory failure in 11 patients, and ARDS in 9 patients. Chest HRCT showed diffusely distributed miliary nodules in all patients. Six patients were on mechanical ventilation, two underwent ECMO, and one died. Symptoms appeared in the first trimester of nine pregnancies after IVF-ET and in the second trimester of seven natural pregnancies. CONCLUSIONS: Miliary tuberculosis can occur in pregnant patients, especially in patients after IVF-ET. Symptoms often appear in the first trimester of pregnancy after IVF-ET and in the second trimester of natural pregnancy. Lacking specificity, the common clinical characteristics include elevated inflammation markers, anaemia, low lymphocyte count, and multiple miliary nodules shown on a chest HRCT scan. Half of patients with miliary tuberculosis may develop respiratory failure, and some may progress to ARDS. Therefore, infertile patients should be required to undergo TB screening before undergoing IVF-ET, and preventive anti-TB treatment should be given to patients with latent TB infections or untreated TB disease. KEY MESSAGE: Miliary tuberculosis can occur in pregnant patients, especially in pregnant patients after IVF-ET. Symptoms often appear in the first trimester of pregnancy after IVF-ET and in the second trimester of natural pregnancy. Many patients develop respiratory failure or ARDS

Is lifestyle a bridge between urbanization and overweight in China?

Rapid urbanization has led to many health-related problems in China, and the increasing prevalence of overweight is one of the greatest threats to public health. Although previous literature has documented a linkage between urbanization and the prevalence of overweight in developing countries such as China, little research has been done to investigate the role of lifestyle related to energy intake and expenditure in mediating the effect of urbanization on individuals' risk of overweight. To bridge this knowledge gap, this study aims to examine the impacts of urbanization on individuals' odds of overweight and explore the mediating effect of lifestyle choices using data from 2016 China Labor-Force Dynamics Survey. Results show that the effect of urbanization on being overweight has two sides. Specifically, while urbanization results in a sedentary lifestyle, which increases the risk of being overweight, urbanization rate weakens the effect of eating out frequently on being overweight and strengthens the influence of physical exercise on being overweight. Urbanization exerts complex effects on residents' risk of being overweight among Chinese people by shaping their lifestyle

Purification of total flavonoids of Abelmoschus manihot (L.) Medic and its antioxidant properties in vivo

In order to optimize the purification conditions and the antioxidant properties in vivo of total flavonoids from Abelmoschus manihot (L.) Medic, AB-8 macroporous resin is used for static adorption and elution. The optimum purification conditions are as follows: Sample solution concerntration of 0.1 g/mL, pH 3.5, 70% ethanol as eluant, 20∶1(mL/g) of eluant volum to resin weight ratio. The results in the optimum purification conditions show that the purity of TFA reaches 48.50%. There are no significant difference in indexes of mice organs between experimental groups and normal control group (P＞005). MDA content exhibits a significant decrease both in serum and liver of mice (P＜0.05). While the level of CAT, GSH-Px and SOD activities in serum and liver are higher in experimental groups than those in normal control group showing dose-response relationship. These results indicate that TFA has good antioxidant properties in vivo

Number of true (a,c) and false (b,d) positives as functions of effect size (SIMU1).

<p>Total number of genes is . Total number of truly differentially expressed genes is , where and are the numbers of up- and down-regulated genes, respectively. The sample size is . <i>t</i>-test and Bonferroni procedure are applied. Adjusted -value threshold: 0.05.</p