Feasibility of the Radner reading chards in low vision patients

Background: Being unable to read is a major problem for visually impaired patients. Since distance visual acuity (VA) does not adequately reflect reading ability, it is important to also evaluate near VA. The Radner Reading Charts (RRCs) are available to measure patients' reading performance. The present study tested the inter-chart and test-retest reliability of the RRCs in Dutch low-vision patients (i.e., visual acuity ≥0.3 logMAR) with various eye disorders. Methods: Thirty-eight patients read the three RRCs in random order. Then, about 1 month after the initial measurements, a test-retest procedure was performed in 15 of the 38 patients. Tested variables were reading acuity (logRAD), logRAD score, logRAD/logMAR ratio, maximum reading speed (MRS), and critical print size (CPS). Both MRS and CPS were calculated in two different ways. To determine the variability, a mixed-model analysis was used. Results: For all variables, the largest part of the variance was explained by the individual subject (86-89%) whereas the chart accounted for only 0-0.78% of the variability. Therefore, the inter-chart and test-retest reliability was high, except for the CPS which had a poor to moderate reliability (31-62%) when calculated in the two different ways. Conclusions: The inter-chart and test-retest results showed high reliability in patients with low vision due to various diseases; therefore, the charts are feasible to determine effects in large groups. © 2010 Springer-Verlag

Partial duplication in two-level fractional factorial designs

Orthogonal main-effect plan, Resolution, Pure error, Semifolding,

Incomplete split-plots in designs with many entries – a compromise between split-plots and randomized complete block designs

The paper shows how the Alpha-design (also known as generalised lattice) may be used for constructing incomplete split-plot designs and describes 4 different methods (A, B, C and D) of construction. Intra-block efficiency factors and theoretical considerations are used to compare the methods. Based on those considerations method B was considered to be the most appropriate method for trials where tests for interaction between the two factors were important and thus this method was used and most of the paper deals with trials based on this construction method. The incomplete split-plots were superior to traditional split-plots in most cases – and the increase in efficiency of the designs can be quite large – especially for comparisons involving the whole-plot treatment. The efficiency for the comparison of the main effect of the whole-plot treatment was in most cases larger for randomized complete block design than for the incomplete split-plot design, but for other comparisons the proposed designs were in most cases more efficient than a randomized complete block design. The efficiency of the designs was compared to traditional split-plot designs and randomized complete block designs using 3 types of data. The 3 types were simulated data with known covariance structure, data from uniformity trials and data from actual trials using incomplete split-plot designs for comparing cereal varieties under different growing conditions. It is concluded that the incomplete split-plot designs may be a good alternative to traditional split-plots and a good compromise between split-plots and randomised complete blocks

Randomised comparison of the Stanford V regimen and ABVD in the treatment of advanced Hodgkin's lymphoma: United Kingdom National Cancer Research Institute Lymphoma Group Study ISRCTN 64141244

Purpose: this multicenter, prospective, randomized controlled trial compared the efficacy and toxicity of two chemotherapy regimens in advanced Hodgkin's lymphoma (HL): the weekly alternating Stanford V and the standard, twice-weekly regimen of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Patients and methods: patients had stage IIB, III, or IV disease or had stages I to IIA disease with bulky disease or other adverse features. Radiotherapy was administered in both arms to sites of previous bulk (&gt; 5 cm) and to splenic deposits, although this was omitted in the latter part of the trial for patients achieving complete remission (CR) in the ABVD arm. A total of 520 patients were randomly assigned and were assessed for the primary outcome measure of progression-free survival (PFS). Five hundred patients received protocol treatment, and radiotherapy was administered to 73% in the Stanford V arm and to 53% in the ABVD arm. Results: the overall response rates after completion of all treatment were 91% for Stanford V and 92% for ABVD. During a median follow-up of 4.3 years, there was no evidence of a difference in projected 5-year PFS and overall survival (OS) rates (76% and 90%, respectively, for ABVD; 74% and 92%, respectively, for Stanford V). More pulmonary toxicity was reported for ABVD, whereas other toxicities were more frequent with Stanford V. Conclusion: in a large, randomized trial, the efficacies of Stanford V and ABVD were comparable when given in combination with appropriate radiotherapy. <br/

D\mathcal{D} -optimal Minimum Support Mixture Designs in Blocks

Fixed and random blocks, Minimum support design, Mixture experiment, Orthogonal blocking, Qualitative variables,

Importance of growth characteristics for yield of barley in different growing systems: will growth characteristics describe yield differently in different growing systems?

The interest in organic grown cereals has increased the need for variety tests under organic growing systems and/or the knowledge on whether growth characteristics describe yield differently under conventional and organic conditions. This paper is a contribution to that question by examining the relationships between some important growth characteristics in barley trials in both systems in Northern Sweden and in Denmark. Mixed model analyses were used for regressions of growth characteristics (or transformations of those) on yield (and log-transformed yield), allowing the slope to depend on the growing system. The analyses showed that diseases seemed to have a less negative effect on yield in the organic growing system than in the conventional growing system if pesticides were not applied. For other characteristics the effect depended on the country. This was the case for grain characteristics where the effect of volume weight in the Swedish trials was much larger in the conventional growing system than in the organic growing system, while a non-significant difference in the opposite direction was found for the trails from Denmark. For the trials from Denmark the effect of grain weight was much larger in the organic growing system than in the conventional growing system, but there was only a small and non-significant difference in the Swedish trials. In both countries there was a significant interaction between the two grain characteristics