Immobilized mediator electrodes for microbial fuel cells

With the current interest in alternative methods of energy production and increased utilization of existing energy sources, microbial fuel cells have become an important field of research. Microbial fuel cells are devices which harvest electrons from microorganisms created by their enzymatic oxidation of complex carbon substrates or consumed by their reduction of chemical oxidants. Microbial fuel cells with photosynthetic biocathodes are of particular interest due to their ability to simultaneously produce electricity and hydrocarbons while reducing carbon dioxide. Most species of microorganisms including many bacteria and yeasts require exogenous electron transfer mediators in order to allow electron transfer with an electrode. While adding such chemicals is simple enough at a lab scale, problems arise with chemical costs and separation at a larger scale. The goal of this research was to develop electrodes composed of a robust material which will eliminate the need for added soluble electron mediators in a photosynthetic biocathode microbial fuel cell. Electrodes made from stainless steel 304L have been coated in a conductive polymer (polypyrrole) and an immobilized electron transfer mediator (methylene blue) and tested chemically for stability and in a microbial fuel cell environment for use in bioanodes and biocathodes. The use of these immobilized mediator in the photosynthetic biocathode increased the open circuit voltage of the cell from 0.17 V to 0.24 V and the short circuit current from 8 mA/m2 to 64 mA/m2 (normalized to the geometric surface area of the electrode) when compared to using the same mediator in solution. The opposite effect was seen when using the electrodes in a bioanode utilizing Saccharomyces cerevisiae. The open circuit voltage decreased from 0.37 V to 0.31 V and the short circuit current decreased from 94 mA/m2 to 24 mA/m2 when comparing the immobilized mediator to soluble mediators. The impact of the membrane and pH of the anode and cathode solutions were quantified and were found to have much less of an effect on the internal resistance than the microbial factors

SERVICE CONVENIENCE AND MARKETING PERFORMANCE IN FAST FOOD RESTAURANTS IN RIVERS STATE

The study investigated the relationship between service convenience and marketing performance of fast food restaurants in Port Harcourt. There specific objectives were to determine the relationship between decision convenience and customer satisfaction and ascertain the relationship between access convenience and customer satisfaction in fast food restaurants in Port Harcourt. Descriptive research design was employed. The service convenience dimensions were tested to determine and measure the relationship with marketing performance using Pearson Correlation Coefficient with the help of SPSS (version 21) in order to interpret the customers’ response towards the convenience factors. The questionnaires were filled by the respondents selected conveniently from 52 fast food restaurants that made up the population. The findings revealed positive and significant relationship between service convenience and marketing performance measures. The study concluded that, a relationship exists between service convenience and marketing performance. It was therefore recommended that marketing communicating programmes should be very clear to aid consumers to make quick and dependable purchase decisions, and fast food organisations should design a customer centric service system that is capable of minimizing the efforts of customers to gain access to service points

Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L), or an herbicide killed (K) tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E−) or legumes (alfalfa, red clover, and white clover). After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover) and tall fescue (especially MaxQ) were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions

How effective is public health policy in Scotland on vitamin D deficiency during pregnancy?

Objective:To evaluate the uptake of universal vitamin D supplementation during pregnancy, its effectiveness in preventing vitamin D deficiency and the factors associated with these.Design:The regional public health organisation in Ayrshire, Scotland has a policy of universal provision of vitamin D supplements (10 µg/d) to all pregnant women for the duration of their pregnancy. Pregnant women in this area were recruited at their 12-week antenatal appointment. Blood samples were collected at the 12-week and 34-week appointments. To account for the seasonal variation, women were recruited in two cohorts: summer and winter. Telephone interviews were conducted at 34 weeks to assess the uptake of vitamin D supplements during pregnancy. Other variables were obtained from medical records.Setting:The study was conducted in the NHS Ayrshire and Arran Health Board in Scotland.Participants:612 pregnant women (aged 15–44 years) living in Ayrshire (latitude 55°), Scotland.Results:Sixty-six percentage took supplementation as recommended. Consumption of supplementation was significantly associated with a higher median serum 25-hydroxyvitamin D concentrations at 34 weeks. Despite this at 34 weeks, 33 % of the summer cohort had insufficient or deficient vitamin D status, while 15 % of the winter cohort had insufficient or deficient status. In multivariable analysis, only adherence and season were independent predictors of vitamin D status.Conclusions:While supplementation improved and maintained vitamin D status during pregnancy, it was not adequate to ensure all those insufficient at 12 weeks achieved sufficient status at the end of pregnancy.</div

Ficus glumosa delile leaf extract attenuates some biochemical markers in testosterone-induced benign prostatic hyperplasia in wistar rats.

Ficus glumosa is used extensively in traditional medicine to manage and remedy some health conditions. This study evaluated the impact of F. glumosa leaf extract on selected biochemical indices of testosterone-induced benign prostatic hyperplasia in male Wistar rats.&nbsp; Thirty-six male rats were randomly divided into six groups (n = 6). Rats in the Normal Control (NC) received feed without any special treatment, rats in the Benign Prostatic Hyperplasia Control (BPHC) group were administered 50 mg/Kg body weight testosterone, rats in the Standard Control (STDC) group received 50 mg/Kg body weight testosterone + 5 mg/Kg body weight finasteride, rats in the low dose (LD) group received 50 mg/Kg body weight testosterone + 100 mg/Kg body weight of F. glumosa extract, rats in the medium dose&nbsp; group received 50 mg/Kg body weight testosterone + 200 mg/Kg body weight of F. glumosa extract, rats in the high dose group received 50 mg/Kg body weight testosterone + 400 mg/Kg body weight of F. glumosa extract. The animals received water and feed ad libitum for 28 days. They were anaesthetized (after treatment period) using ketamine hypochlorite. Blood samples were collected, centrifuged and serum harvested for analyses using standard methods and one way ANOVA followed by least square difference (LSD) post-hoc comparison test. Results indicated a significant decrease at p&lt; 0.05 in serum electrolytes (Na and Cl) in the groups treated with F. glumosa extract when compared to the control groups. The serum urea, uric acid and creatinine levels of the groups treated with 200 mg/kg b.w and 400 mg/kg bw of F. glumosa leaf extract decreased significantly when compared to the BPHC standard and normal control groups. Also the serum level of aspartate aminotransferase indicated similar trend. We therefore conclude that F. glumosa leaf extract may attenuate some biochemical indices especially serum electrolytes (Na and Cl), aspartate aminotransferase as well as HDL-c level in testosterone – induced benign prostatic hyperplasia in Wistar rats

Dependency of the Spindle Assembly Checkpoint on Cdk1 Renders the Anaphase Transition Irreversible

SummaryActivation of anaphase-promoting complex/cyclosome (APC/CCdc20) by Cdc20 is delayed by the spindle assembly checkpoint (SAC). When all kinetochores come under tension, the SAC is turned off and APC/CCdc20 degrades cyclin B and securin, which activates separase [1]. The latter then cleaves cohesin holding sister chromatids together [2]. Because cohesin cleavage also destroys the tension responsible for turning off the SAC, cells must possess a mechanism to prevent SAC reactivation during anaphase, which could be conferred by a dependence of the SAC on Cdk1 [3–5]. To test this, we analyzed mouse oocytes and embryos expressing nondegradable cyclin B together with a Cdk1-resistant form of separase. After biorientation and SAC inactivation, APC/CCdc20 activates separase but the resulting loss of (some) cohesion is accompanied by SAC reactivation and APC/CCdc20 inhibition, which aborts the process of further securin degradation. Cyclin B is therefore the only APC/CCdc20 substrate whose degradation at the onset of anaphase is necessary to prevent SAC reactivation. The mutual activation of tension sensitive SAC and Cdk1 creates a bistable system that ensures complete activation of separase and total downregulation of Cdk1 when all chromosomes have bioriented

Insulin-like growth factor binding protein-3 has dual effects on gastrointestinal stromal tumor cell viability and sensitivity to the anti-tumor effects of imatinib mesylate in vitro

<p>Abstract</p> <p>Background</p> <p>Imatinib mesylate has significantly improved survival and quality of life of patients with gastrointestinal stromal tumors (GISTs). However, the molecular mechanism through which imatinib exerts its anti-tumor effects is not clear. Previously, we found up-regulation of insulin-like growth factor binding protein-3 (IGFBP3) expression in imatinib-responsive GIST cells and tumor samples. Because IGFBP3 regulates cell proliferation and survival and mediates the anti-tumor effects of a number of anti-cancer agents through both IGF-dependent and IGF-independent mechanisms, we hypothesized that IGFBP3 mediates GIST cell response to imatinib. To test this hypothesis, we manipulated IGFBP3 levels in two imatinib-responsive GIST cell lines and observed cell viability after drug treatment.</p> <p>Results</p> <p>In the GIST882 cell line, imatinib treatment induced endogenous IGFBP3 expression, and IGFBP3 down-modulation by neutralization or RNA interference resulted in partial resistance to imatinib. In contrast, IGFBP3 overexpression in GIST-T1, which had no detectable endogenous IGFBP3 expression after imatinib, had no effect on imatinib-induced loss of viability. Furthermore, both the loss of IGFBP3 in GIST882 cells and the overexpression of IGFBP3 in GIST-T1 cells was cytotoxic, demonstrating that IGFBP3 has opposing effects on GIST cell viability.</p> <p>Conclusion</p> <p>This data demonstrates that IGFBP3 has dual, opposing roles in modulating GIST cell viability and response to imatinib <it>in vitro</it>. These preliminary findings suggest that there may be some clinical benefits to IGFBP3 therapy in GIST patients, but further studies are needed to better characterize the functions of IGFBP3 in GIST.</p