University of Adelaide

About: University of Adelaide is a education organization based out in Adelaide, South Australia, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 27251 authors who have published 79167 publications receiving 2671128 citations. The organization is also known as: The University of Adelaide & Adelaide University.

A high density barley microsatellite consensus map with 775 SSR loci

Abstract: A microsatellite or simple sequence repeat (SSR) consensus map of barley was constructed by joining six independent genetic maps based on the mapping populations ‘Igri × Franka’, ‘Steptoe × Morex’, ‘OWBRec × OWBDom’, ‘Lina × Canada Park’, ‘L94 × Vada’ and ‘SusPtrit × Vada’. Segregation data for microsatellite markers from different research groups including SCRI (Bmac, Bmag, EBmac, EBmag, HVGeneName, scsssr), IPK (GBM, GBMS), WUR (GBM), Virginia Polytechnic Institute (HVM), and MPI for Plant Breeding (HVGeneName), generated in above mapping populations, were used in the computer program RECORD to order the markers of the individual linkage data sets. Subsequently, a framework map was constructed for each chromosome by integrating the 496 “bridge markers” common to two or more individual maps with the help of the computer programme JoinMap® 3.0. The final map was calculated by following a “neighbours” map approach. The integrated map contained 775 unique microsatellite loci, from 688 primer pairs, ranging from 93 (6H) to 132 (2H) and with an average of 111 markers per linkage group. The genomic DNA-derived SSR marker loci had a higher polymorphism information content value (average 0.61) as compared to the EST/gene-derived SSR loci (average 0.48). The consensus map spans 1,068 cM providing an average density of one SSR marker every 1.38 cM. Such a high-density consensus SSR map provides barley molecular breeding programmes with a better choice regarding the quality of markers and a higher probability of polymorphic markers in an important chromosomal interval. This map also offers the possibilities of thorough alignment for the (future) physical map and implementation in haplotype diversity studies of barley.

Panitumumab versus cetuximab in patients with chemotherapy-refractory wild-type KRAS exon 2 metastatic colorectal cancer (ASPECCT): a randomised, multicentre, open-label, non-inferiority phase 3 study.

Abstract: Summary Background The anti-EGFR monoclonal antibodies panitumumab and cetuximab are effective in patients with chemotherapy-refractory wild-type KRAS exon 2 metastatic colorectal cancer. We assessed the efficacy and toxicity of panitumumab versus cetuximab in these patients. Methods For this randomised, open-label, phase 3 head-to-head study, we enrolled patients (from centres in North America, South America, Europe, Asia, Africa, and Australia) aged 18 years or older with chemotherapy-refractory metastatic colorectal cancer, an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or less, and wild-type KRAS exon 2 status. Using a computer-generated randomisation sequence, we assigned patients (1:1; stratified by geographical region and ECOG performance status, with a permuted block method) to receive panitumumab (6 mg/kg once every 2 weeks) or cetuximab (initial dose 400 mg/m 2 ; 250 mg/m 2 once a week thereafter). The primary endpoint was overall survival assessed for non-inferiority (retention of ≥50% of the cetuximab treatment effect; historical hazard ratio [HR] for cetuximab plus best supportive care vs best supportive care alone of 0·55). The primary analysis included patients who received one or more dose of panitumumab or cetuximab, analysed per allocated treatment. Recruitment for this trial is closed. The trial is registered with ClinicalTrials.gov, number NCT01001377. Findings Between Feb 2, 2010, and July 19, 2012, we enrolled and randomly allocated 1010 patients, 999 of whom began study treatment: 499 received panitumumab and 500 received cetuximab. For the primary analysis of overall survival, panitumumab was non-inferior to cetuximab ( Z score −3·19; p=0·0007). Median overall survival was 10·4 months (95% CI 9·4–11·6) with panitumumab and 10·0 months (9·3–11·0) with cetuximab (HR 0·97; 95% CI 0·84–1·11). Panitumumab retained 105·7% (81·9–129·5) of the effect of cetuximab on overall survival seen in this study. The incidence of adverse events of any grade and grade 3–4 was similar across treatment groups. Grade 3–4 skin toxicity occurred in 62 (13%) patients given panitumumab and 48 (10%) patients given cetuximab. The occurrence of grade 3–4 infusion reactions was lower with panitumumab than with cetuximab (one [ vs nine [2%] patients), and the occurrence of grade 3–4 hypomagnesaemia was higher in the panitumumab group (35 [7%] vs 13 [3%]). We recorded one treatment-related fatal adverse event: a lung infection in a patient given cetuximab. Interpretation Our findings show that panitumumab is non-inferior to cetuximab and that these agents provide similar overall survival benefit in this population of patients. Both agents had toxicity profiles that were to be expected. In view of the consistency in efficacy and toxicity seen, small but meaningful differences in the rate of grade 3–4 infusion reactions and differences in dose scheduling can guide physician choice of anti-EGFR treatment. Funding Amgen Inc.

Analysis of tannins in seeds and skins of Shiraz grapes throughout berry development

Abstract: The flavan-3-ol and proanthocyanidin composition of both seeds and skin of Vitis vinifera L. cv. Shiraz grapes was determined by reversed-phase HPLC after acetone extraction and acid-catalysis in the presence of excess phloroglucinol. Samples were taken at weekly intervals from fruit-set until commercial harvest. The main period of proanthocyanidin accumulation in grape seeds occurred immediately after fruit-set with maximum levels observed around veraison. Over two seasons there was variation in both the timing and content of proanthocyanidins in seeds. In skin, proanthocyanidin accumulation occurred from fruit set until 1-2 weeks after veraison. Proanthocyanidin subunit composition was different in seeds and skin and changed during berry development but the mean degree of polymerisation of the tannin polymers in skins was higher than in the seeds at all stages of berry development. Proanthocyanidin levels in both seeds and skin decreased between veraison and harvest. Additional proanthocyanidin subunits were released when the residues remaining after acetone extraction were subjected to direct acid-catalysis in the presence of phloroglucinol. In the seeds, these accounted for much of the post-veraison decrease, but not in grape skin. At harvest, 75% of extractable berry proanthocyanidin was in the seeds. Accumulation of proanthocyanidins in the seeds appears to be independent of that in the skins, but in both tissues synthesis occurs early in berry development and maximum levels are reached around veraison.

Rational approximations to rational models: Alternative algorithms for category learning

Abstract: Rational models of cognition typically consider the abstract computational problems posed by the environment, assuming that people are capable of optimally solving those problems. This differs from more traditional formal models of cognition, which focus on the psychological processes responsible for behavior. A basic challenge for rational models is thus explaining how optimal solutions can be approximated by psychological processes. We outline a general strategy for answering this question, namely to explore the psychological plausibility of approximation algorithms developed in computer science and statistics. In particular, we argue that Monte Carlo methods provide a source of rational process models that connect optimal solutions to psychological processes. We support this argument through a detailed example, applying this approach to Anderson's (1990, 1991) rational model of categorization (RMC), which involves a particularly challenging computational problem. Drawing on a connection between the RMC and ideas from nonparametric Bayesian statistics, we propose 2 alternative algorithms for approximate inference in this model. The algorithms we consider include Gibbs sampling, a procedure appropriate when all stimuli are presented simultaneously, and particle filters, which sequentially approximate the posterior distribution with a small number of samples that are updated as new data become available. Applying these algorithms to several existing datasets shows that a particle filter with a single particle provides a good description of human inferences.