802 research outputs found
Manufacturing price determination in OECD countries; markups, demand and uncertainty in a dynamic heterogeneous panel
Manufacturing price markup equations are estimated for 15 OECD countries using annual data. Firms have CES production technology. The markup depends on demand, competitors' prices and uncertainty. Cointegration is tested with the Pedroni tests and a panel version of the Johansen test, and evidence found for unique cointegrating vectors. Estimation of the long-run parameters is performed with a pooled mean group method, with short run heterogeneous dynamics. Tests for homogeneity of the long-run parameters do not reject the hypothesis. Markups are pro-cyclical and rise with both competitors' prices and uncertainty.pricing behaviour, markups, panel test for order of integration, panel cointegration, dynamic heterogeneous panels, pooled mean group estimation
An Induced Natural Selection Heuristic for Finding Optimal Bayesian Experimental Designs
Bayesian optimal experimental design has immense potential to inform the
collection of data so as to subsequently enhance our understanding of a variety
of processes. However, a major impediment is the difficulty in evaluating
optimal designs for problems with large, or high-dimensional, design spaces. We
propose an efficient search heuristic suitable for general optimisation
problems, with a particular focus on optimal Bayesian experimental design
problems. The heuristic evaluates the objective (utility) function at an
initial, randomly generated set of input values. At each generation of the
algorithm, input values are "accepted" if their corresponding objective
(utility) function satisfies some acceptance criteria, and new inputs are
sampled about these accepted points. We demonstrate the new algorithm by
evaluating the optimal Bayesian experimental designs for the previously
considered death, pharmacokinetic and logistic regression models. Comparisons
to the current "gold-standard" method are given to demonstrate the proposed
algorithm as a computationally-efficient alternative for moderately-large
design problems (i.e., up to approximately 40-dimensions)
A new sighting study for the fixed concentration procedure to allow for gender differences
The fixed concentration procedure (FCP) has been proposed as an alternative to the median lethal
concentration (LC50) test (organisation for economic co-operation and development (OECD) test guideline
[TG] 403) for the assessment of acute inhalation toxicity. The FCP tests animals of a single gender (usually
females) at a number of fixed concentration levels in a sequential fashion. It begins with a sighting study that precedes
the main FCP study and is used to determine the main study starting concentration. In this paper, we propose
a modification to the sighting study and suggest that it should be conducted using both male and female
animals, rather than just animals of a single gender. Statistical analysis demonstrates that, when females are more
sensitive, the new procedure is likely to give the same classification as the original FCP, whereas, if males are more
sensitive, the new procedure is much less likely to lead to incorrect classification into a less toxic category. If
there is no difference in the LC50 for females and males, the new procedure is slightly more likely to classify into
a more stringent class than the original FCP. Overall, these results show that the revised sighting study ensures
gender differences in sensitivity do not significantly impact on the performance of the FCP, supporting its use as
an alternative test method for assessing acute inhalation toxicity
Does group assessment impact BME attainment?
Assessment of student learning is fundamental in Higher Education (HE) reflecting academic standards and impacting on student satisfaction, position in league tables and graduate employment. Nonetheless, there is a BME (Black and Minority Ethnic) attainment gap, the difference in the proportion of BME and White students who attain a first class or 2.1 honours degree (even when controlled for prior attainment and entry profile), which is persistent across the HE sector. As assessment strategies play an essential role in determining degree attainment, we have reviewed the role of group assessment and whether this form of assessment specifically impacts on the BME attainment gap. Overall, this study provided evidence that assessed group work does not adversely impact BME students. In addition, the performance in BME/non-BME/mixed groups did not suggest any consistent difference, suggesting that the demographic composition of groups does not affect BME performance. Therefore, group work would appear to be an inclusive form of assessment that does not appear to lead or contribute to exacerbating the BME attainment gap
cDNA cloning of MCT1, a monocarboxylate transporter from rat skeletal muscle
AbstractPCR was used to amplify the coding region of CHO MCT1 cDNA. This was then used to screen a rat skeletal muscle cDNA library which lead to the isolation of a full length cDNA encoding MCT1 from rat. The cDNA derived amino acid sequence shows 94% and 86% identity to CHO and human MCT1, respectively
Microdomain Formation, Oxidation, and Cation Ordering in LaCa\u3csub\u3e2\u3c/sub\u3eFe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e8+y\u3c/sub\u3e
The compound LaCa2Fe3O8+y, also known as the Grenier phase, is known to undergo an order–disorder transformation (ODT) at high temperatures and oxidation has been observed when the compound is cooled in air after the ODT. In this study, we have synthesized the Grenier compound in air using traditional solid-state reactions and investigated the structure and composition before and after the ODT. Thermal analysis showed that the material undergoes an ODT in both oxygen and argon atmospheres with dynamic, temperature dependent, oxidation upon cooling. Results from scanning transmission electron microscopy (STEM) suggest that the Grenier phase has preferential segregation of Ca and La on the two crystallographic A sites before the ODT, but a random distribution above the ODT temperature. Furthermore, STEM images suggest the possibility that oxygen excess may exist in La-rich regions within microdomains rather than at microdomain boundaries
Etendue maintained white solid-state light generation by light emitting diodes pumped green aluminate green-yellow phosphor
Patterns and processes underlying evolutionary significant units in the Platypleura stridula L. species complex (Hemiptera: Cicadidae) in the Cape Floristic Region, South Africa
Cicadas have been shown to be useful organisms for examining the effects of distribution, plant association and geographical barriers on gene flow between populations. The cicadas of the Platypleura stridula species complex are restricted to the biologically diverse Cape Floristic Region (CFR) of South Africa. They are thus an excellent study group for elucidating the mechanisms by which hemipteran diversity is generated and maintained in the CFR. Phylogeographical analysis of this species complex using mitochondrial DNA Cytochrome Oxidase I (COI) and ribosomal 16S sequence data, coupled with preliminary morphological and acoustic data, resolves six clades, each of which has specific host-plant associations and distinct geographical ranges. The phylogeographical structure implies simultaneous or near-simultaneous radiation events, coupled with shifts in host-plant associations. When calibrated using published COI and 16S substitution rates typical for related insects, these lineages date back to the late Pliocene - early Pleistocene, coincident with vegetation change, altered drainage patterns and accelerated erosion in response to neotectonic crustal uplift and cyclic Pleistocene climate change, and glaciation-associated changes in climate and sea level
Can we improve the nutritional quality of meat?
The nutritional value of meat is an increasingly important factor influencing consumer preferences for poultry, red meat and processed meat products. Intramuscular fat content and composition, in addition to high quality protein, trace minerals and vitamins are important determinants of nutritional value. Fat content of meat at retail has decreased substantially over the past 40 years through advances in animal genetics, nutrition and management and changes in processing techniques. Evidence of the association between diet and the incidence of human non-communicable diseases has driven an interest in developing production systems for lowering total SFA andtransfatty acid (TFA) content and enrichment ofn-3 PUFA concentrations in meat and meat products. Typically, poultry and pork has a lower fat content, containing higher PUFA and lower TFA concentrations than lamb or beef. Animal genetics, nutrition and maturity, coupled with their rumen microbiome, are the main factors influencing tissue lipid content and relative proportions of SFA, MUFA and PUFA. Altering the fatty acid (FA) profile of lamb and beef is determined to a large extent by extensive plant and microbial lipolysis and subsequent microbial biohydrogenation of dietary lipid in the rumen, and one of the major reasons explaining the differences in lipid composition of meat from monogastrics and ruminants. Nutritional strategies can be used to align the fat content and FA composition of poultry, pork, lamb and beef with Public Health Guidelines for lowering the social and economic burden of chronic disease.</jats:p
- …