Home About us Contact
|
Home About us Contact | ||
|
|
||
Separate Runs (separate + run)
Selected AbstractsBayesian inference strategies for the prediction of genetic merit using threshold models with an application to calving ease scores in Italian Piemontese cattleJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 4 2002K. Kizilkaya Summary First parity calving difficulty scores from Italian Piemontese cattle were analysed using a threshold mixed effects model. The model included the fixed effects of age of dam and sex of calf and their interaction and the random effects of sire, maternal grandsire, and herd-year-season. Covariances between sire and maternal grandsire effects were modelled using a numerator relationship matrix based on male ancestors. Field data consisted of 23 953 records collected between 1989 and 1998 from 4741 herd-year-seasons. Variance and covariance components were estimated using two alternative approximate marginal maximum likelihood (MML) methods, one based on expectation-maximization (EM) and the other based on Laplacian integration. Inferences were compared to those based on three separate runs or sequences of Markov Chain Monte Carlo (MCMC) sampling in order to assess the validity of approximate MML estimates derived from data with similar size and design structure. Point estimates of direct heritability were 0.24, 0.25 and 0.26 for EM, Laplacian and MCMC (posterior mean), respectively, whereas corresponding maternal heritability estimates were 0.10, 0.11 and 0.12, respectively. The covariance between additive direct and maternal effects was found to be not different from zero based on MCMC-derived confidence sets. The conventional joint modal estimates of sire effects and associated standard errors based on MML estimates of variance and covariance components differed little from the respective posterior means and standard deviations derived from MCMC. Therefore, there may be little need to pursue computation-intensive MCMC methods for inference on genetic parameters and genetic merits using conventional threshold sire and maternal grandsire models for large datasets on calving ease. Zusammenfassung Die Kalbeschwierigkeiten bei italienischen Piemonteser Erstkalbskühen wurden mittels eines gemischten Threshold Modells untersucht. Im Modell wurden die fixen Einflüsse vom Alter der Kuh und dem Geschlecht des Kalbes, der Interaktion zwischen beiden und die zufälligen Effekte des Großvaters der Mutter und der Herden-Jahr-Saisonklasse berücksichtigt. Die Kovarianz zwischen dem Vater der Kuh und dem Großvater der Mutter wurde über die nur auf väterlicher Verwandtschaft basierenden Verwandtschaftsmatrix berücksichtigt. Es wurden insgesamt 23953 Datensätze aus den Jahren 1989 bis 1998 von 4741 Herden-Jahr-Saisonklassen ausgewertet. Die Varianz- und Kovarianzkomponenten wurden mittels zweier verschiedener approximativer marginal Maximum Likelihood (MML) Methoden geschätzt, die erste basierend auf Expectation-Maximierung (EM) und die zweite auf Laplacian Integration. Rückschlüsse wurden verglichen mit solchen, basierend auf drei einzelne Läufe oder Sequenzen von Markov Chain Monte Carlo (MCMC) Stichproben, um die Gültigkeit der approximativen MML Schätzer aus Daten mit ähnlicher Größe und Struktur zu prüfen. Die Punktschätzer der direkten Heritabilität lagen bei 0,24; 0,25 und 0,26 für EM, Laplacian und MCMC (Posterior Mean), während die entsprechenden maternalen Heritabilitäten bei 0,10, 0,11 und 0,12 lagen. Die Kovarianz zwischen dem direkten additiven und dem maternalen Effekt wurden als nicht von Null verschieden geschätzt, basierend auf MCMC abgeleiteten Konfidenzintervallen. Die konventionellen Schätzer der Vatereffekte und deren Standardfehler aus den MML-Schätzungen der Varianz- und Kovarianzkomponenten differieren leicht von denen aus der MCMC Analyse. Daraus folgend besteht wenig Bedarf die rechenintensiven MCMC-Methoden anzuwenden, um genetische Parameter und den genetischen Erfolg zu schätzen, wenn konventionelle Threshold Modelle für große Datensätze mit Vätern und mütterlichen Großvätern mit Kalbeschwierigkeiten genutzt werden. [source] High specific activity tritium labeling of vitamin D derivative RO275646,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 14 2005Steve A. de Keczer Abstract The octahydroindenone intermediate was tritium labeled using T2O isotope exchange labeling, and then elaborated to the vitamin D derivative RO275646. Though this method of labeling was expected to give the minor isomer, it was the shortest and most convenient route to the high specific activity metabolically stable labeled sites. A total of 34 mCi (from two separate runs) at 64 Ci/mmol of [3H]-RO275646 were prepared by this method. Copyright © 2005 John Wiley & Sons, Ltd. [source] Greater Activation in Left Hemisphere Language-Related Regions During Simple Judgment Tasks Among Substance-Dependent Patients in Treatment for AlcoholismALCOHOLISM, Issue 2 2010Jodi M. Gilman Background:, Alcoholism is often associated with impaired emotional control. Alcoholics have also been found to have deficits in frontal lobe executive functions. Recent functional imaging studies have suggested that alcoholics show greater activation than nonalcoholics in circuits involving frontal lobes, as well as more posterior brain regions, when engaged in executive-type tasks. In this study, we compared brain activations of alcohol-dependent patients and healthy nonalcoholics while they performed 2 simple judgment tasks designed to activate frontal circuits involved in a basic form of decision making. Participants completed 1 judgment task that required an emotional judgment and 1 task that did not, which enabled us to study whether alcoholics had greater brain activation while performing executive tasks, and to determine if emotional tasks elicited even greater activation than nonemotional tasks. Methods:, We performed functional magnetic resonance imaging scans while alcoholic patients and nonalcoholic controls viewed pictures from the International Affective Picture System. In 3 separate runs, participants viewed the images without making a judgment, determined whether the images were indoor or outdoor scenes, or decided if they liked or disliked the images. Results:, There was little difference in brain activation between alcoholics and controls when no judgment was required. When participants made judgments about either the location or whether they liked or disliked an image, however, we observed significantly increased activation in frontal, limbic, and temporal regions in the patients relative to the controls. Increases were particularly robust in the frontal lobe and in areas of the brain associated with language. When we compared the emotional to the nonemotional judgment, the alcoholics, but not the controls, showed greater activation in the ventral mesial frontal cortex. Conclusions:, Alcoholic patients appear to use brain language areas more than nonalcoholics while making judgments about the setting or liking of emotionally arousing visual images. This increased activation may reflect a compensatory recruitment of brain regions to perform simple decision-making tasks. [source] Effect of seeding sludge type and hydrodynamic shear force on the aerobic sludge granulation in sequencing batch airlift reactorsASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009K. Y. Koh Abstract Two sequencing batch airlift reactors (SBARs) were operated simultaneously for two separate runs. In the first run, two different types of seeding sludge were cultivated in two separate reactors under the same superficial air velocity (SAV). In the second run, the same seeding sludge was cultivated in both reactors but under different SAV, i.e. 1.2 and 3.6 cm s,1. Both runs were carried out for a period of about 20 days, during which the chemical oxygen demand (COD) removal efficiency and morphology of sludge were examined. Batch tests using sodium acetate as the main carbon source were conducted to investigate the COD removal efficiency, and the morphologies of sludge were examined under light microscopy. Results showed that the COD removal efficiency improved with cultivation time. Morphological study showed that all cultivated sludge lost their filamentous species after a few days of cultivation, leaving behind communities of loosely packed pellet-like groups. Although the SAV recommended by other researchers was applied to the SBAR, granulation did not take place at the end of both experimental runs. It was suspected that the failure for aerobic sludge to granulate under the selected operating strategies and reactor configuration was partly due to the intrinsic traits of the sludge microbial community. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | |||||||||||||