Calf health and performance during receiving is not changed by fence-line preconditioning on flint hills range vs. drylot preconditioning

Ranch-of-origin preconditioning can improve the welfare and performance of beef calves by decreasing the stress associated with weaning, transport, diet change, and commingling with other calves. Preconditioning methods that involve pasture weaning coupled with maternal contact (i.e., fence-line weaning) have been promoted as possible best management practices for minimizing stress. Prior studies focused on performance and behavior during preconditioning on the ranch of origin. Little information has been published relating to carryover effects of fence-line preconditioning compared with conventional drylot preconditioning on performance and behavior during feedlot receiving. Our objectives were to measure growth and health during a 28-day ranch-of-origin preconditioning phase and during a 60-day feedlot receiving phase among beef calves subjected to 1 of 3 ranch-of-origin preconditioning programs: (1) drylot preconditioning + dam separation, (2) pasture preconditioning + fence-line contact with dams, and (3) pasture preconditioning + fence-line contact with dams + supplemental feed delivered in a bunk. In addition, we recorded incidences of behavioral distress among these treatments during first 7 days of feedlot receiving

Preconditioning Maximal Center Gauge with Stout Link Smearing in SU(3)

Center vortices are studied in SU(3) gauge theory using Maximal Center Gauge (MCG) fixing. Stout link smearing and over-improved stout link smearing are used to construct a preconditioning gauge field transformation, applied to the original gauge field before fixing to MCG. We find that preconditioning successfully achieves higher gauge fixing maxima. We observe a reduction in the number of identified vortices when preconditioning is used, and also a reduction in the vortex-only string tension.Comment: 9 pages, 4 figure

Eigenmode Analysis of Boundary Conditions for the One-Dimensional Preconditioned Euler Equations

The effect of local preconditioning on boundary conditions is analyzed for the subsonic, one-dimensional Euler equations. Decay rates for the eigenmodes of the initial boundary value problem are determined for different boundary conditions and different preconditioners whose intent is to accelerate low Mach number computations. Riemann invariant boundary conditions based on the unpreconditioned Euler equations are shown to be reflective when used with preconditioning, and asymptotically, at low Mach numbers, initial disturbances do not decay. Other boundary conditions are shown to be perfectly non-reflective in conjunction with preconditioning. Two-dimensional numerical results confirm the trends predicted by the one-dimensional analysis

Effect of Staged Preconditioning on BiochemicalMarkers in the Patients Undergoing Coronary Artery Bypass Grafting

The present study has investigated the effectiveness of staged-preconditioning, in both remote and target organs. After IP the myocardial release of the biochemicalmarkers including, creatine phosphokinase (CPK), cardiac creatine kinase (CK-MB), cardiac troponin T (cTnT) and lactate dehydrogenase (LDH) were evaluated in patients who underwent CABG, with and without staged-preconditioning. Sixty-one patients entered the study; there were 32 patients in the staged-preconditioning group and 29 patients in the control group. All patients underwent on-pump CABG using cardiopulmonary bypass (CPB) techniques. In the staged-preconditioning group, patients underwent two stages of IP on remote (upper limb) and target organs. Each stage of preconditioning was carried out by 3 cycles of ischemia and then reperfusion. Serum levels of biochemical markers were immediately measured postoperatively at 24, 48 and 72 h. Serum CK-MB, CPK and LDH levels were significantly lower in the staged-preconditioning group than in the control group. The CK-MB release in the staged-preconditioning patients reduced by 51% in comparison with controls over 72 h after CABG. These results suggest that myocardial injury was attenuated by the effect of three rounds of both remote and target organ IP

SSOR Preconditioning of Improved Actions

We generalize local lexicographic SSOR preconditioning for the Sheikholeslami-Wohlert improved Wilson fermion action and the truncated perfect free fermion action. In our test implementation we achieve performance gains as known from SSOR preconditioning of the standard Wilson fermion action.Comment: 3 pages, Latex, 3 figures, Talk presented at Lattice'9

ATP-sensitive potassium channel subcellular trafficking during ischemia, reperfusion, and preconditioning

Ischemic preconditioning is an endogenous cardioprotective mechanism in which short periods of ischemia and reperfusion provide protection when given before a subsequent ischemic event. Early mechanistic studies showed ATP-sensitive potassium (KATP) channels to play an important role in ischemic preconditioning. KATP channels link intracellular energy metabolism to membrane excitability and contractility. It is thought that KATP channels provide a cardioprotective role during ischemia by inducing action potential shortening, reducing an excessive Ca^2+ influx, and by preventing arrhythmias. However, the mechanisms by which KATP channels protect during ischemic preconditioning are not known. In this study, we investigated a novel potential mechanism in which alterations in subcellular KATP channel trafficking during ischemia and ischemic preconditioning may result in altered levels of surface channel density, and therefore, a greater degree of cardioprotection. In the optimization of our experiments, we compared various antibodies for their specificity and sensitivity for channel subunit detection in immunoblotting. In addition, we examined the effects of varying salt concentrations during tissue homogenization in order to determine the optimal conditions for protein isolation. Furthermore, we examined the effect of heating the samples prior to SDS-PAGE for improved detection of channel proteins by immunoblotting. The subcellular trafficking of some membrane proteins is altered by ischemia. For example, the glucose transporter, Glut4, translocates from endosomal compartments to the sarcolemma (Sun, Nguyen, DeGrado, Schwaiger, & Brosius, 1994). Conflicting data exists regarding the effects of ischemia on KATP channel subcellular trafficking and the regulation of KATP channel surface density (Edwards et al., 2009 and Bao, Hadjiolova, Coetzee, & Rindler, 2011). We therefore, sought to test our hypothesis that KATP channels are internalized from the surface of cardiomyocytes to endosomal compartments during ischemia, and this internalization can be reduced and/or reversed by ischemic preconditioning. We subjected isolated Langendorff-perfused mouse hearts to ischemia, reperfusion, or ischemic preconditioning events and measured the density of KATP channels in the sarcolemmal and endosomal compartments. We also determined the degree of injury by staining heart slices with triphenyltetrazolium chloride and compared infarct sizes between hearts subjected to ischemia and ischemic preconditioning. Our data demonstrated that KATP channels are, in fact, internalized during ischemia and that reperfusion led to a slow recovery of surface KATP channel density. Interestingly, ischemic preconditioning reduced the size of infarcts induced by ischemia and also prevented the ischemia-induced decrease of KATP channel surface density, thereby, contributing to cardioprotection