The immunolocalization and quantitation of avian lipoprotein lipase

The overall aim of the project was to investigate the pools of LPL activity that exist within chicken tissues in vivo.Polyclonal and monoclonal anti-chicken LPL antibodies were produced using highly purified chicken adipose tissue LPL as an immunogen. An attempt was made to measure LPL at the luminal surface of the capillary endothelium of individual tissues using an iodinated anti­chicken LPL monoclonal antibody, injected intravenously, in vivo.However, the technique was not successful because high levels of specific antibody binding were not achieved.Heparin-release studies using the isolated perfused heart model system found significant species differences, between rats and chickens, in the regulation of heparin-releasable LPL in response to fasting. The low percentage of heparin-releasable LPL activity observed in chickencardiac tissue corresponded to the relatively low accumulation oftriacylglycerol NEFA by the chicken muscular tissues by comparisonwith adipose tissue, following the intravenous injection of [^4C]-VLDL invivo.Using anti-chicken LPL antibodies immunocytochemical studies on a variety of chicken extrahepatic tissues showed the enzyme to be located predominantly extracellularly, at the basement membrane of the tissue parenchymal cells and in association with the interstitial capillary elements. Image-analysis was used to quantify the pools of enzymeassociated with these compartments in chicken cardiac tissue. In chicken bone marrow LPL was found in association with the adipocytes and vascular elements of the marrow mass, with a lack of enzyme associated with the haematopoietic cells. Immunocytochemical techniques were also used to investigate the tissue specific developmental changes which occur in the distribution of LPL during the growth and maturation of the heart and liver of the embryonic chicken.The present study has identified several pools of LPL within chicken tissues and proposed that the transportation of enzyme from the interstitial capillary elements to the luminal endothelial surface may play a role in the regulation of functional LPL activity in chicken tissues

Analysing GCN4 Translational Control in Yeast by Stochastic Chemical Kinetics Modelling and Simulation

Peer reviewedPublisher PD

The impact of repetitive unclamped inductive switching on the electrical parameters of low-voltage trench power nMOSFETs

The impact of hot-carrier injection (HCI) due to repetitive unclamped inductive switching (UIS) on the electrical performance of low-voltage trench power n-type MOSFETs (nMOSFETs) is assessed. Trench power nMOSFETs with 20- and 30-V breakdown voltage ratings in TO-220 packages have been fabricated and subjected to over 100 million cycles of repetitive UIS with different avalanche currents IAV at a mounting base temperature TMB of 150°C. Impact ionization during avalanche conduction in the channel causes hot-hole injection into the gate dielectric, which results in a reduction of the threshold voltage VGSTX, as the number of avalanche cycles N increases. The experimental data reveal a power-law relationship between the change in the threshold voltage ΔVGSTX and N. The results show that the power-law prefactor is directly proportional to the avalanche current. After 100 million cycles, it was observed in the 20-V rated MOSFETs that the power-law prefactor increased by 30% when IAV was increased from 160 to 225 A, thereby approximating a linear relationship. A stable subthreshold slope with avalanche cycling indicates that interface trap generation may not be an active degradation mechanism. The impact of the cell pitch on avalanche ruggedness is also investigated by testing 2.5- and 4- m cell-pitch 30-V rated MOSFETs. Measurements showed that the power-law prefactor reduced by 40% when the cell pitch was reduced by 37.5%. The improved VGSTX stability with the smaller cell-pitch MOSFETs is attributed to a lower avalanche current per unit cell resulting in less hot-hole injection and, hence, smaller VGSTX shift. The 2.5-m cell-pitch MOSFETs also show 25% improved on -state resistance RDSON, better RDSON stability, and 20% less subthreshold slope compared with the 4-m cell-pitch MOSFETs, although with 100% higher initial IDSS and less IDSS stability with avalanche cycling. These results are important for manufacturers of automotive MOSFETs where multiple avalanche occurrences over the lifetime of the MOSFET are expected

The Nature of the UV/X-Ray Absorber in PG 2302+029

We present Chandra X-ray observations of the radio-quiet QSO PG 2302+029. This quasar has a rare system of ultra-high velocity (-56,000 km/s) UV absorption lines that form in an outflow from the active nucleus (Jannuzi et al. 2003). The Chandra data indicate that soft X-ray absorption is also present. We perform a joint UV and X-ray analysis, using photoionization calculations, to detemine the nature of the absorbing gas. The UV and X-ray datasets were not obtained simultaneously. Nonetheless, our analysis suggests that the X-ray absorption occurs at high velocities in the same general region as the UV absorber. There are not enough constraints to rule out multi-zone models. In fact, the distinct broad and narrow UV line profiles clearly indicate that multiple zones are present. Our preferred estimates of the ionization and total column density in the X-ray absorber (log U=1.6, N_H=10^22.4 cm^-2) over predict the O VI 1032, 1038 absorption unless the X-ray absorber is also outflowing at ~56,000 km/s, but they over predict the Ne VIII 770, 780 absorption at all velocities. If we assume that the X-ray absorbing gas is outflowing at the same velocity of the UV-absorbing wind and that the wind is radiatively accelerated, then the outflow must be launched at a radius of < 10^15 cm from the central continuum source. The smallness of this radius casts doubts on the assumption of radiative acceleration.Comment: Accepted for Publication in Ap

The effects of a home-based physical activity intervention on cardiorespiratory fitness in breast cancer survivors; a randomised controlled trial

The aim of this current randomised controlled trial was to evaluate the effects of a home-based physical activity (PA) intervention on cardiorespiratory fitness in breast cancer survivors. Thirty-two post-adjuvant therapy breast cancer survivors (age = 52 ± 10 years; BMI = 27.2 ± 4.4 kg∙m2) were randomised to a six-month home-based PA intervention with face-to-face and telephone PA counselling or usual care. Cardiorespiratory fitness and self-reported PA were assessed at baseline and at six-months. Participants had a mean relative V̇O2max of 25.3 ± 4.7 ml∙kg−1∙min−1, which is categorised as “poor” according to age and gender matched normative values. Magnitude-based inference analyses revealed likely at least small beneficial effects (effect sizes ≥.20) on absolute and relative V̇O2 max (d = .44 and .40, respectively), and total and moderate PA (d = .73 and .59, respectively) in the intervention compared to the usual care group. We found no likely beneficial improvements in any other outcome. Our home-based PA intervention led to likely beneficial, albeit modest, increases in cardiorespiratory fitness and self-reported PA in breast cancer survivors. This intervention has the potential for widespread implementation and adoption, which could considerably impact on post-treatment recovery in this population