The Effect of Chronic Digitoxin Administration on the Contractile State of Normal and Nonfailing Hypertrophied Myocardium

A B S T R A C T To determine the effect of prolonged digitoxin administration on contractile function of nonfailing myocardium, right ventricular papillary muscle mechanics were examined after 6 or 24 wk of glycoside administration to control and pulmonary artery banded cats. Resting length-tension relations were not affected by digitoxin; however, isometrically developed force and the maximal rate of force development at the peak of the length-tension curve were increased in all treated groups. In untreated animals, banding resulted in a 28% incidence of deaths from heart failure. 6 wk after constriction, contractile function was depressed whereas normal function was observed 24 wk after banding. Digitoxin significantly reduced mortality from heart failure and enhanced the recovery of contractile function; contractile function in the 6 wk banded treated group approached that of untreated control and 24-wk banded groups. The long-term effects of digitoxin on contractile function were not importantly related to the temporal association between banding and institution of glycoside administration. Development of myocardial hypertrophy was comparable in treated and untreated banded groups. These results demonstrate that a significant positive inotropic effect persists in both normal and nonfailing hypertrophied myocardium during chronic digitoxin administration

Effect of CRINA RUMINANTS AF, a Mixture of Essential Oil Compounds, on Ruminal Fermentation and Digestibility

Eight ruminally fistulated steers were used in a metabolism experiment to determine effects of an essential oil feed additive in altering steer ruminal fermentation characteristics and nutrient digestibilities. Yearling steers were fed three treatments: 1) Control (CON) 2) CRINA RUMINANTS AF (CRINA) and 3) Rumensin® (RUM). There were no differences in DMI, OM intake, total tract DM and OM digestibilities, or pH among treatments. Steers receiving the CRINA treatment consumed 24.5% fewer meals than CON. Ruminal acetate was greatest and total VFA concentrations tended to be greatest for CRINA treatment. Acetate:propionate was 1.68, 1.49, and 1.43 for CON, CRINA, and RUM, respectively, suggesting addition of CRINA RUMINANTS AF favorably alters rumen fermentation end products without negatively affecting intake or rumen pH

Strange form factors of the nucleon in a two-component model

The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX and G0 collaborations shows a good overall agreement. The strange magnetic moment is found to be positive, 0.315 nm.Comment: 11 pages, 2 tables, 5 figures, accepted for publication in J. Phys. G. Revised version, new figures, extra table, new results, updated reference

Searching for life with rovers: exploration methods and science results from the 2004 field campaign of the “Life in the Atacama” project and applications to future Mars Missions

LITA develops and field tests a long-range automated rover and a science payload to search for microbial life in the Atacama. The Atacama's evolution provides a unique training ground for designing and testing exploration strategies and life detection methods for the search for life on Mars

Crafting communities: promoting inclusion, empowerment, and learning between older women

While social policy and planning documents are replete with ominous warnings about the cost of an ageing population, this article tells a different story about the productive and self-sustaining networks that exist among older women in the community who do craftwork. From our research conducted in Victoria, Australia during 2007&ndash;2008 we discovered a resilient and committed group of older women quietly and steadily contributing to community fundraising, building social networks, and providing learning opportunities to each other in diverse ways. Through our conversations with nine craftswomen we have been able to articulate clear links between the theory and models commonly espoused in the community development literature and the life-enriching practices used in organising informal community craft group activities. From our interviews with the older women we provide evidence of sustained participation, the generation of social capital, and the fostering of life-long learning. While none of the women we spoke to were trained in community development and did not use language commonly associated with feminist ideology, the relationship between the informal group work with principles of empowerment and self-efficacy were unmistakeable. We conclude with a discussion of the implications of our findings for critical social work practice.<br /

Effect of Impurities on Pentacene Thin Film Growth for Field-Effect Transistors

Pentacenequinone (PnQ) impurities have been introduced into a pentacene source material at number densities from 0.001 to 0.474 to quantify the relative effects of impurity content and grain boundary structure on transport in pentacene thin-film transistors. Atomic force microscopy (AFM) and electrical measurements of top-contact pentacene thin-film transistors have been employed to directly correlate initial structure and final film structures, with the device mobility as a function of added impurity content. The results reveal a factor four decrease in mobility without significant changes in film morphology for source PnQ number fractions below ~0.008. For these low concentrations, the impurity thus directly influences transport, either as homogeneously distributed defects or by concentration at the otherwise-unchanged grain boundaries. For larger impurity concentrations, the continuing strong decrease in mobility is correlated with decreasing grain size, indicating an impurity-induced increase in the nucleation of grains during early stages of film growth.Comment: 18 pages, 4 Figures, 1 Tabl

Super-silent FRET Sensor Enables Live Cell Imaging and Flow Cytometric Stratification of Intracellular Serine Protease Activity in Neutrophils

Abstract Serine proteases are released by neutrophils to act primarily as antimicrobial proteins but excessive and unbalanced serine protease activity results in serious host tissue damage. Here the synthesis of a novel chemical sensor based on a multi-branched fluorescence quencher is reported. It is super-silent, exhibiting no fluorescence until de-quenched by the exemplar serine protease human neutrophil elastase, rapidly enters human neutrophils, and is inhibited by serine protease inhibitors. This sensor allows live imaging of intracellular serine protease activity within human neutrophils and demonstrates that the unique combination of a multivalent scaffold combined with a FRET peptide represents a novel and efficient strategy to generate super-silent sensors that permit the visualisation of intracellular proteases and may enable point of care whole blood profiling of neutrophils