Convenient Labelling Technique for Mass Spectrometry - Acid Catalyzed Deuterium and Oxygen-18 Exchange via Gas-liquid Chromatography

Mass spectrometry labelling technique - acid catalyzed deuterium and oxygen 18 exchange by gas-liquid chromatograph

Emergence of long-range order in BaTiO3 from local symmetry-breaking distortions

By using a symmetry motivated basis to evaluate local distortions against pair distribution function data (PDF), we show without prior bias, that the off-centre Ti displacements in the archetypal ferroelectric BaTiO3 are zone centred and rhombohedral-like in nature across its known ferroelectric and paraelectric phases. With our newly-gained insight we construct a simple Monte Carlo (MC) model which captures our main experimental findings and demonstrate how the rich crystallographic phase diagram of BaTiO3 emerges from correlations of local symmetry-breaking distortions alone. Our results strongly support the order-disorder picture for these phase transitions, but can also be reconciled with the soft-mode theory of BaTiO3 that is supported by some spectroscopic techniques.Comment: 5 pages, 3 figure

Harold Jeffreys's Theory of Probability Revisited

Published exactly seventy years ago, Jeffreys's Theory of Probability (1939) has had a unique impact on the Bayesian community and is now considered to be one of the main classics in Bayesian Statistics as well as the initiator of the objective Bayes school. In particular, its advances on the derivation of noninformative priors as well as on the scaling of Bayes factors have had a lasting impact on the field. However, the book reflects the characteristics of the time, especially in terms of mathematical rigor. In this paper we point out the fundamental aspects of this reference work, especially the thorough coverage of testing problems and the construction of both estimation and testing noninformative priors based on functional divergences. Our major aim here is to help modern readers in navigating in this difficult text and in concentrating on passages that are still relevant today.Comment: This paper commented in: [arXiv:1001.2967], [arXiv:1001.2968], [arXiv:1001.2970], [arXiv:1001.2975], [arXiv:1001.2985], [arXiv:1001.3073]. Rejoinder in [arXiv:0909.1008]. Published in at http://dx.doi.org/10.1214/09-STS284 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Overstating the evidence - double counting in meta-analysis and related problems

Background: The problem of missing studies in meta-analysis has received much attention. Less attention has been paid to the more serious problem of double counting of evidence. Methods: Various problems in overstating the precision of results from meta-analyses are described and illustrated with examples, including papers from leading medical journals. These problems include, but are not limited to, simple double-counting of the same studies, double counting of some aspects of the studies, inappropriate imputation of results, and assigning spurious precision to individual studies. Results: Some suggestions are made as to how the quality and reliability of meta-analysis can be improved. It is proposed that the key to quality in meta-analysis lies in the results being transparent and checkable. Conclusions: Existing quality check lists for meta-analysis do little to encourage an appropriate attitude to combining evidence and to statistical analysis. Journals and other relevant organisations should encourage authors to make data available and make methods explicit. They should also act promptly to withdraw meta-analyses when mistakes are found

Understanding Variation in Sets of N-of-1 Trials.

A recent paper in this journal by Chen and Chen has used computer simulations to examine a number of approaches to analysing sets of n-of-1 trials. We have examined such designs using a more theoretical approach based on considering the purpose of analysis and the structure as regards randomisation that the design uses. We show that different purposes require different analyses and that these in turn may produce quite different results. Our approach to incorporating the randomisation employed when the purpose is to test a null hypothesis of strict equality of the treatment makes use of Nelder's theory of general balance. However, where the purpose is to make inferences about the effects for individual patients, we show that a mixed model is needed. There are strong parallels to the difference between fixed and random effects meta-analyses and these are discussed

Using Ultrasound Techonology in Incoming Feedlot Steers to Predict Marbling and the Effect of Anabolic Agents on Marbling

One hundred seventy-four mixed crossbred yearling steers (789 Ib) were used to determine if ultrasound technology could be used to predict eventual marbling score in incoming feedlot cattle. Implants were also administered to study the effects of anabolic agents on marbling. Steers were fed in a single pen at a commercial feedlot for an average of 127 days, slaughtered, and carcass data were collected. Implanted cattle gained significantly more weight (P \u3c .05) than nonimplanted cattle. Steers implanted with Revalor gained weight more rapidly than Synovex implanted cattle. Steers that were implanted with Revalor showed a significant decrease in marbling score when compared to no implant and Synovex groups. The percentage of choice carcasses for no implant, Revalor, and Synovex were 65.5, 47.4, and 68.4. The correlation between initial ether extract, as estimated by ultrasound, and marbling score was .45 and a prediction equation including coat color, initial ether extract, and Revalor implant accounted for 26.59% of the variability in the final marbling score

Effect of Anabolic Agents on Marbling in Yearling Crossbred Steers

A total of three hundred and twenty-four crossbred yearling steers were used in a two year study to determine the effects of anabolic agents on carcass characteristics. Steers were fed in a commercial feedlot for an average of 123 days, slaughtered and carcass data were collected. Implanted cattle gained significantly more weight (P\u3c .05) than nonimplanted cattle. Steers that were implanted with Revalor-S gained weight more rapidly (P\u3c.05) than Synovex-S implanted cattle. Implants significantly (P\u3c.05) increased hot carcass weights and rib eye area when compared to nonimplanted cattle and Revalor implanted cattle tended (P= .0564) to have heavier hot carcass weights than Synovex implanted cattle. lmplants did not significantly affect yield grades. Implanted steers had lower (P\u3c .05) marbling scores than control steers. Steers that were implanted with Revalor showed a significant (P\u3c.05) decrease in marbling score when compared to the Synovex groups. The percentage of choice carcasses for no implant, Revalor, and Synovex treatments were 78.85, 58.82, and 67.68, respectively

Charge order at the frontier between the molecular and solid states in Ba3NaRu2O9

We show that the valence electrons of Ba3NaRu2O9, which has a quasi-molecular structure, completely crystallize below 210 K. Using an extended Hubbard model, we show that the charge ordering instability results from long-range Coulomb interactions. However, orbital ordering, metal-metal bonding and formation of a partial spin gap enforce the magnitude of the charge separation. The striped charge order and frustrated hcp lattice of Ru2O9 dimers lead to competition with a quasi-degenerate charge-melted phase under photo-excitation at low temperature. Our results establish a broad class of simple metal oxides as models for emergent phenomena at the border between the molecular and solid states.Comment: Minor changes, with supporting information. To appear in Phys. Rev. Let

Couples living with type 1 diabetes : an integrative review of the impacts on health and wellbeing

Impacts of type 1 diabetes and relationship factors on health and wellbeing of both persons with diabetes and partners (T1D partners) have not been investigated. Integrative review methods evaluated the evidence. From 323 titles, we included 24 studies involving 16,083 persons with diabetes and 1020 T1D partners. Studies were quantitative (n = 13), qualitative (n = 9) and mixed methods (n = 2). Maintaining resilient, good quality, intimate relationships optimises physical and psychological outcomes for persons with diabetes. Partners experience disturbed sleep and while general psychological health is maintained, distress surrounding hypoglycaemia is overwhelming for over a third of partners. Nurturing quality relationships could reap significant health benefits