Biotransformation and bioconcentration of steroid estrogens by Chlorella vulgaris

The biotransformation and bioconcentration of natural and synthetic steroid estrogens by Chlorella vulgaris were investigated using batch shaking experiments with incubation for 48 hours in the light or dark. Estradiol and estrone were inter-convertible in both light and dark conditions, however this biotransformation showed a preference to estrone. In the light, 50% of estradiol was further metabolized to an unknown product. Apart from biotransformation, estrone as well as hydroxyestrone, estriol and ethinylestradiol were relatively stable in the algal culture, while estradiol valerate was hydrolyzed to estradiol and then estrone within 3 hours of incubation. All the tested estrogens exhibited a degree of partitioning to C. vulgaris, however, the concentrations of estriol, hydroxyestrone, ethinylestradiol and estradiol valerate were always below the quantification limits. For estradiol and estrone, the partitioning of these estrogens in the algal extracts to the filtrates was below 6% of the total present. The average concentration factor for estrone was around 27, however the concentration factor for estradiol is not reported since no equilibrium was reached between aqueous solution and that within the cells due to continuing biotransformation

Interdisciplinary approaches to zoonotic disease

Zoonotic infections are on the increase worldwide, but most research into the biological, environmental and life science aspects of these infections has been conducted in separation. In this review we bring together contemporary research in these areas to suggest a new, symbiotic framework which recognises the interaction of biological, economic, psychological, and natural and built environmental drivers in zoonotic infection and transmission. In doing so, we propose that some contemporary debates in zoonotic research could be resolved using an expanded framework which explicitly takes into account the combination of motivated and habitual human behaviour, environmental and biological constraints, and their interactions

An assessment of the bioaccumulation of estrone in Daphnia magna

The bioaccumulation of estrone by Daphnia magna was determined. Direct uptake via the aqueous medium occurred within the first 16 hours. A bioconcentration factor of 228 was established over all temporal periods. Ingestion via Chlorella vulgaris gave a partitioning factor of 24 which may approximate to a biomagnification factor assuming steady state conditions. These preliminary results indicate that the partitioning to Daphnia magna via the food source, Chorella vulgaris is less significant than bioconcentration

Digital simulation of dominant eddies of a co-flowing jet

This paper described a method for virtual construction of turbulent jet flow field from a limited set of experimental data. The objective is for jet visualization enhancement in near-field plume models. The method is based on the proper orthogonal decomposition (POD), which is an efficient tool to capture the turbulent field based on principal components. A set of experimental flow images at a number of cross-sections of a coflowing jet is obtained in the laboratory. Four hundred instantaneous flow images are taken at each jet section and are subjected to POD analysis. The first 60 principal modes are used in the reconstruction of jet turbulence via a low dimensional generation of jet images. The inclusion of additional modes is shown to produce little improvement on the visual appearance of the reconstructed jet images. Linear interpolation is attempted to generate jet images at an intermediate jet section between two experimental stations. Jet flow field on a central longitudinal section of the jet are assembled from the reconstructed flow images at all jet sections. The resulting development of concentration jet width is shown to agree well with the analytical solution.postprintThe 16th IAHR-APD 2008 Congress and 3rd Symposium of IAHR-ISHS, Nanjing, China, 20-23 October 2008. In Advances in Water Resources & Hydraulic Engineering, 2009, v. 2, p. 618-62

ArchAlign: coordinate-free chromatin alignment reveals novel architectures

To facilitate identification and characterization of genomic functional elements, we have developed a chromatin architecture alignment algorithm (ArchAlign). ArchAlign identifies shared chromatin structural patterns from high-resolution chromatin structural datasets derived from next-generation sequencing or tiled microarray approaches for user defined regions of interest. We validated ArchAlign using well characterized functional elements, and used it to explore the chromatin structural architecture at CTCF binding sites in the human genome. ArchAlign is freely available at http://www.acsu.buffalo.edu/~mjbuck/ArchAlign.html

Effects of oxidation temperature on Ga 2O3 film thermally grown on GaN

The effects of oxidation temperature on thermally oxidized GaN film were investigated. The GaN wafers were oxidzied at 750 °C, 800 °C and 850 °C respectively. The electrical characteristics and interface quality of MOS capacitors were compared among different oxidation temperatures. The sample oxidized at 800 °C presented best current-voltage, capacitance-voltage characteristics and smoothest surface morphology, while the higher oxidation temperature of 850 °C gave best interface quality. The electrical breakdown field was increased by one order of magnitude when the sample was oxidized at 800 °C as compared with 750 °C and 850 °C. Lastly, after the sample oxidized at 800 °C was annealed at 850 °C for 10 min, the quality of its oxide was significantly degraded. © 2005 IEEE.published_or_final_versio

Predicting the microbial exposure risks in urban floods using GIS, building simulation, and microbial models

London is expected to experience more frequent periods of intense rainfall and tidal surges, leading to an increase in the risk of flooding. Damp and flooded dwellings can support microbial growth, including mould, bacteria, and protozoa, as well as persistence of flood-borne microorganisms. The amount of time flooded dwellings remain damp will depend on the duration and height of the flood, the contents of the flood water, the drying conditions, and the building construction, leading to particular properties and property types being prone to lingering damp and human pathogen growth or persistence. The impact of flooding on buildings can be simulated using Heat Air and Moisture (HAM) models of varying complexity in order to understand how water can be absorbed and dry out of the building structure. This paper describes the simulation of the drying of building archetypes representative of the English building stock using the EnergyPlus based tool ‘UCL-HAMT’ in order to determine the drying rates of different abandoned structures flooded to different heights and during different seasons. The results are mapped out using GIS in order to estimate the spatial risk across London in terms of comparative flood vulnerability, as well as for specific flood events. Areas of South and East London were found to be particularly vulnerable to long-term microbial exposure following major flood events

Reversible posterior leukoencephalopathy syndrome in Chinese children induced by chemotherapy: A review of five cases

This is a retrospective review of the clinico-radiological features and neurological outcomes of reversible posterior leukoencephalopathy syndrome episodes in Chinese cancer children receiving chemotherapy in a regional hospital in Hong Kong from 1998 to 2008. Five children (3 males and 2 females) with a mean age of 7 years were identified, four of whom had acute lymphoblastic leukaemia and one had a central nervous system germ cell tumour. Presenting symptoms included seizures (100%), altered mental function (100%), headache (40%), and visual disturbance (60%). The mean systolic blood pressure at presentation was 158 mm Hg. Approximately 80% had typical radiological features of reversible posterior leukoencephalopathy syndrome. All showed complete recovery after the acute stage, but one subsequently developed epilepsy. Two patients ultimately died of refractory malignant disease. Two others were followed up for a mean of 6 years, and remained neurologically normal. This report was the first case review documenting reversible posterior leukoencephalopathy syndrome in Chinese cancer children. The clinico-radiological features and neurological outcomes were similar to those reported in western series. Early recognition of the syndrome is important to facilitate appropriate treatment. The central nervous system damage may not be reversible and thus long-term follow-up is warranted.published_or_final_versio

Roles of Arabidopsis WRKY3 and WRKY4 Transcription Factors in Plant Responses to Pathogens

<p>Abstract</p> <p>Background</p> <p>Plant WRKY DNA-binding transcription factors are involved in plant responses to biotic and abiotic responses. It has been previously shown that <it>Arabidopsis WRKY3 </it>and <it>WRKY4</it>, which encode two structurally similar WRKY transcription factors, are induced by pathogen infection and salicylic acid (SA). However, the role of the two WRKY transcription factors in plant disease resistance has not been directly analyzed.</p> <p>Results</p> <p>Both WRKY3 and WRKY4 are nuclear-localized and specifically recognize the TTGACC W-box sequences <it>in vitro</it>. Expression of <it>WRKY3 </it>and <it>WRKY4 </it>was induced rapidly by stress conditions generated by liquid infiltration or spraying. Stress-induced expression of <it>WRKY4 </it>was further elevated by pathogen infection and SA treatment. To determine directly their role in plant disease resistance, we have isolated T-DNA insertion mutants and generated transgenic overexpression lines for <it>WRKY3 </it>and <it>WRKY4</it>. Both the loss-of-function mutants and transgenic overexpression lines were examined for responses to the biotrophic bacterial pathogen <it>Pseudomonas syringae </it>and the necrotrophic fungal pathogen <it>Botrytis cinerea</it>. The <it>wrky3 </it>and <it>wrky4 </it>single and double mutants exhibited more severe disease symptoms and support higher fungal growth than wild-type plants after <it>Botrytis </it>infection. Although disruption of <it>WRKY3 </it>and <it>WRKY4 </it>did not have a major effect on plant response to <it>P. syringae</it>, overexpression of <it>WRKY4 </it>greatly enhanced plant susceptibility to the bacterial pathogen and suppressed pathogen-induced <it>PR1 </it>gene expression.</p> <p>Conclusion</p> <p>The nuclear localization and sequence-specific DNA-binding activity support that WRKY3 and WRKY4 function as transcription factors. Functional analysis based on T-DNA insertion mutants and transgenic overexpression lines indicates that WRKY3 and WRKY4 have a positive role in plant resistance to necrotrophic pathogens and WRKY4 has a negative effect on plant resistance to biotrophic pathogens.</p

Perioperative nutritional support in patients undergoing hepatectomy for hepatocellular carcinoma

Background. Resection of hepatocellular carcinoma is associated with high rates of morbidity and mortality. Since intensive nutritional support can reduce the catabolic response and improve protein synthesis and liver regeneration, we performed a prospective study to investigate whether perioperative nutritional support could improve outcome in patients undergoing hepatectomy for hepatocellular carcinoma. Methods. We studied 124 patients undergoing resection of hepatocellular carcinoma. Sixty-four patients (39 with cirrhosis, 18 with chronic active hepatitis, and 7 with no associated liver disease) were randomly assigned to receive perioperative intravenous nutritional support in addition to their oral diet, and 60 patients (33 with cirrhosis, 12 with chronic active hepatitis, and 15 with no associated liver disease) were randomly assigned to a control group. The perioperative nutritional therapy consisted of a solution enriched with 35 percent branched-chain amino acids, dextrose, and lipid emulsion (50 percent medium-chain triglycerides) given intravenously for 14 days perioperatively. Results. There was a reduction in the overall postoperative morbidity rate in the perioperative-nutrition group as compared with the control group (34 percent vs. 55 percent; relative risk, 0.66; 95 percent confidence interval, 0.45 to 0.96), predominantly because of fewer septic complications (17 percent vs. 37 percent; relative risk, 0.57; 95 percent confidence interval, 0.34 to 0.96). There were also a reduction in the requirement for diuretic agents to control ascites (25 percent vs. 50 percent; relative risk, 0.57; 95 percent confidence interval, 0.37 to 0.87), less weight loss after hepatectomy (median loss, 0 kg vs. 1.4 kg; P = 0.01), and less deterioration of liver function as measured by the change in the rate of clearance of indocyanine green (-2.8 percent vs. -4.8 percent at 20 minutes, P = 0.05). These benefits were seen predominantly in the patients with underlying cirrhosis who underwent major hepatectomy. There were five deaths during hospitalization in the perioperative-nutrition group, and nine in the control group (P not significant). Conclusions. Perioperative nutritional support can reduce complications after major hepatectomy for hepatocellular carcinoma associated with cirrhosis.published_or_final_versio