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Accelerated life tests (ALT) are used to gain information on the life distribution of products or materials. An alternative model to the Weibull CE-M step-stress accelerated life test is proposed. KH-M is based on time-transformation of the exponential model and is mathematically simpler, realistic with regard to hazard failure and related to the Bhattacharyya & Soejoeti tampered failure-rate model.

Compromise test plans using 3 stress levels have been proposed as alternatives to the optimum linear or quadratic test plans in step-stress accelerated life testing. These plans result from a compromise between the optimum linear and optimum quadratic plans, and compare favorably to them when the model is either linear or quadratic. The 3-step plans allow for checks of model adequacy and nonlinearity unlike the 2-step plans. The criterion for optimality of such plans takes into account the asymptotic variances of the log of the mean failure time at the design stress for linear and quadratic models.

Among plausible causes for replicability failure, one that has not received sufficient attention is the environment in which the research is conducted. Consisting of the population, equipment, personnel, and various conditions such as location, time, and weather, the research environment can affect treatments and outcomes, and changes in the research environment that occur when an experiment is redone can affect replicability. We examine the extent to which such changes contribute to replicability failure. Our framework is that of an initial experiment that generates the data and a follow-up experiment that is done the same way except for a change in the research environment. We assume that the initial experiment satisfies the assumptions of the two-sample t-statistic and that the follow-up experiment is described by a mixed model which includes environmental parameters. We derive expressions for the effect that the research environment has on power, sample size selection, p-values, and confidence levels. We measure the size of the environmental effect with the environmental effect ratio (EER) which is the ratio of the standard deviations of environment by treatment interaction and error. By varying EER, it is possible to determine conditions that favor replicability and those that do not. [ABSTRACT FROM AUTHOR]

The Making of Modern Medicine: Turning Points in the Treatment of Disease, by Michael Bliss. Routledge Worlds series. Toronto, University of Toronto Press, 2011. vii, 104 pp. $21.95 Cdn (cloth). [...]

Experimental studies on biliary-diverted rats show that after 72h of bilary diversion there is a downregulation of taurocholate transport by the ileal brush-border membrane and basolateral membrane of the hepatocytes. This downregulation accompanies changes in both transporter density and affinity. Changes in membrane lipid composition also influence the alterations in the transporter expression. Substrate availability influences the enterohepatic circulation of bile acids.

Aim: Geographical patterns of migrant species arrival have been little studied, despite their relevance to global change responses. Here, we quantify continent‐wide interspecific variation in spatiotemporal patterns of spring arrival of 30 common migrant bird species and relate these to species characteristics and environmental conditions. Location: Europe. Time Period: 2010–2019. Major Taxa Studied: Birds, 30 species. Methods: Using citizen science data from EuroBirdPortal, we modelled arrival phenology for 30 Afro‐Palaearctic migrant species across Europe to extract start and duration of species arrival at a 400 km square resolution. We related inter and intraspecific variation in arrival and duration to species characteristics and temperature at the start of the growing season (green‐up). Results: Spatial variation in start of arrival times indicates that it took, on average, 1.6 days for the leading migratory front to move northwards by 100 km (range: 0.6–2.5 days). There was a major gradient in arrival phenology, from species which arrived earlier, least synchronously, in colder temperatures and progressed slowly northwards to species which arrived later, most synchronously and in warmer temperatures and advanced quickly through Europe. The slow progress of early arrivers suggests that temperature limits their northward advance; this group included Aerial Insectivores and species wintering north of the Sahel. For the late arrivers, which included species wintering further south, seasonal resource availability in Africa may delay their arrival into Europe. Main Conclusions: We found support for the green‐wave hypothesis applying widely to migratory landbirds. Species arrival phenologies are linked to ecological differences between taxa, such as diet, and wintering location. Understanding these differences informs predictions of species' sensitivity to global change. Publishing these arrival phenologies will facilitate further research and have additional conservation benefits such as informing designation of hunting seasons. Our methods are applicable to any taxa with repeated occurrence data across large scales. [ABSTRACT FROM AUTHOR]

Biodiversity-monitoring citizen science schemes provide valuable long-term monitoring data and benefit participants. There is increasing interest in engaging young people with nature. The British Trust for Ornithology's 'What's Under Your Feet?' project shows how schoolchildren can monitor soil invertebrates. Although individual projects like this are often funding- and time-limited, more generic long-term biodiversity-monitoring citizen science schemes may be equally suitable for school participation. Exemplar schemes from the UK are reviewed, and the potential advantages in school participation for teachers and students are highlighted in order to raise awareness of this potential opportunity. [ABSTRACT FROM AUTHOR]

The synaptonemal complex is a tripartite proteinaceous ultrastructure that forms between homologous chromosomes during prophase I of meiosis in the majority of eukaryotes. It is characterized by the coordinated installation of transverse filament proteins between two lateral elements and is required for wild-type levels of crossing over and meiotic progression. We have generated null mutants of the duplicated Arabidopsis transverse filament genes zyp1a and zyp1b using a combination of T-DNA insertional mutants and targeted CRISPR/Cas mutagenesis. Cytological and genetic analysis of the zyp1 null mutants reveals loss of the obligate chiasma, an increase in recombination map length by 1.3- to 1.7- fold and a virtual absence of cross-over (CO) interference, determined by a significant increase in the number of double COs. At diplotene, the numbers of HEI10 foci, a marker for Class I interference-sensitive COs, are twofold greater in the zyp1 mutant compared to wild type. The increase in recombination in zyp1 does not appear to be due to the Class II interference-insensitive COs as chiasmata were reduced by ~52% in msh5/zyp1 compared to msh5. These data suggest that ZYP1 limits the formation of closely spaced Class I COs in Arabidopsis. Our data indicate that installation of ZYP1 occurs at ASY1-labeled axial bridges and that loss of the protein disrupts progressive coalignment of the chromosome axes. [ABSTRACT FROM AUTHOR]

Language outcomes after speech and language therapy in post-stroke aphasia are challenging to predict. This study examines behavioral language measures and resting state fMRI (rsfMRI) as predictors of treatment outcome. Fifty-seven patients with chronic aphasia were recruited and treated for one of three aphasia impairments: anomia, agrammatism, or dysgraphia. Treatment effect was measured by performance on a treatment-specific language measure, assessed before and after three months of language therapy. Each patient also underwent an additional 27 language assessments and a rsfMRI scan at baseline. Patient scans were decomposed into 20 components by group independent component analysis, and the fractional amplitude of low-frequency fluctuations (fALFF) was calculated for each component time series. Post-treatment performance was modelled with elastic net regression, using pre-treatment performance and either behavioral language measures or fALFF imaging predictors. Analysis showed strong performance for behavioral measures in anomia (R2 = 0.948, n = 28) and for fALFF predictors in agrammatism (R2 = 0.876, n = 11) and dysgraphia (R2 = 0.822, n = 18). Models of language outcomes after treatment trained using rsfMRI features may outperform models trained using behavioral language measures in some patient populations. This suggests that rsfMRI may have prognostic value for aphasia therapy outcomes. [ABSTRACT FROM AUTHOR]