Structure, Atomistic Simulations, and Phase Transition of Stoichiometric Yeelimite

ABSTRACT: Yeelimite, Ca4[Al6O12]SO4, is outstanding as an aluminate sodalite, being the framework of these type of materials flexible and dependent on ion sizes and anion ordering/disordering. On the other hand, yeelimite is also important from an applied perspective as it is the most important phase in calcium sulfoaluminate cements. However, its crystal structure is not well studied. Here, we characterize the room temperature crystal structure of stoichiometric yeelimite through joint Rietveld refinement using neutron and Xray powder diffraction data coupled with chemical soft-constraints. Our structural study shows that yeelimite has a lower symmetry than that of the previously reported tetragonal system, which we establish to likely be the acentric orthorhombic space group Pcc2, with a √2a × √2a × a superstructure based on the cubic sodalite structure. Final unit cell values were a = 13.0356(7) Å, b = 13.0350(7) Å, and c = 9.1677(2) Å. We determine several structures using density functional theory calculations, with the lowest energy structure being Pcc2 in agreement with our experimental result. Yeelimite undergoes a reversible phase transition to a higher-symmetry phase which has been characterized to occur at 470 °C by thermodiffractometry. The higher-symmetry phase is likely cubic or pseudocubic possessing an incommensurate superstructure, as suggested by our theoretical calculations which show a phase transition from an orthorhombic to a tetragonal structure. Our theoretical study also predicts a pressure-induced phase transition to a cubic structure of space group I43m. Finally, we show that our reported crystal structure of yeelimite enables better mineralogical phase analysis of commercial calcium sulfoaluminate cements, as shown by RF values for this phase, 6.9% and 4.8% for the previously published orthorhombic structure and for the one reported in this study, respectively.Universidad de Málaga. Campus de Excelencia Internacional. Andalucía Tech

The Relationship between Narcotic Administration and Emergency Department Recidivism

The present study investigated the impact of narcotic administration on quantity and frequency of recidivism by patients presenting to the Emergency Department (ED) with a primary complaint of chronic pain. This study explored the relationship between narcotic administration, gender, prescribing physician and subsequent ED visits. We analyzed the data from the twelve months of medical records for 80 patients (278 visits) who presented at the ED of a general medical center in a rural area. Results indicated that the number of visits by those who received narcotics was significantly higher than for those who did not receive narcotics. There was also a significant difference in prescribing patterns, with females being more likely than males to receive a narcotic. Observable differences were found between the frequency of days between visits for those who received narcotics vs. those who did not, and the differential pattern of narcotic administration between providers. These findings raise the question that the receipt of a narcotic may reinforce visits to the ED. This study concluded that an established protocol for treating patients with chronic pain who present in the ED may be useful

Contributions of Matrilineal and Patrilineal Kin Alloparental Effort to the Development of Life History Strategies and Patriarchal Values: A Cross-Cultural Life History Approach

Childrearing behaviors are often shaped by familial and cultural principles that function as guides for socialization goals and effective childrearing practices. For an increasing number of Latino families, the extended kin often acts as a source of childcare support. Due to a scarcity of research on the familial support configurations of Latin American families, the current study utilizes a cross-cultural retrospective approach to explore the associations between matrilineal/ patrilineal kin and life history strategies in relation to childrearing. Applying a family system and life history framework, the present model tested 200 university students from Mexico and Costa Rica on measures of family emotional environment and traditional social values (e.g., familismo/simpatía and patriarchal values). Results found that childcare assistance from patrilineal and matrilineal kin was associated with positive family emotional environment, which weakly mediated the association between kin care and slow life history. Positive associations were also found between matrilineal kin childcare and traditional Latin social values. However, patriarchal values were only predicted by higher levels of patrilineal kin aid. The results are consistent with the general theoretical literature of life history theory and family systems theory, suggesting that high levels of childcare produce positively emotional family climates, which in turn perpetuate the development of prosocial individuals with slow life history strategies. Implications for further research are discussed.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Racializing The Discourse of Adult Education

This symposium began in 2002 as a dialogue between Stephen Brookfield, Scipio Colin III and me. The circumstances that brought about the dialogue are indicative of the need for a symposium on race talk among educators and even more specifically among adult educators. At the time, Stephen was at Harvard and because of his work there he was asked to contribute an article to the Harvard Educational Review about racializing the discourse of adult education. As a White male Stephen felt strongly that minority voices should included and proposed inviting several African American academics as well—the topic was important enough to warrant a special issue

Ceramide remodeling and risk of cardiovascular events and mortality

BackgroundRecent studies suggest that circulating concentrations of specific ceramide species may be associated with coronary risk and mortality. We sought to determine the relations between the most abundant plasma ceramide species of differing acyl chain lengths and the risk of coronary heart disease (CHD) and mortality in community‐based samples. Methods and ResultsWe developed a liquid chromatography/mass spectrometry assay to quantify plasma C24:0, C22:0, and C16:0 ceramides and ratios of these very–long‐chain/long‐chain ceramides in 2642 FHS (Framingham Heart Study) participants and in 3134 SHIP (Study of Health in Pomerania) participants. Over a mean follow‐up of 6 years in FHS, there were 88 CHD and 90 heart failure (HF) events and 239 deaths. Over a median follow‐up time in SHIP of 5.75 years for CHD and HF and 8.24 years for mortality, there were 209 CHD and 146 HF events and 377 deaths. In meta‐analysis of the 2 cohorts and adjusting for standard CHD risk factors, C24:0/C16:0 ceramide ratios were inversely associated with incident CHD (hazard ratio per average SD increment, 0.79; 95% confidence interval, 0.71–0.89; P<0.0001) and inversely associated with incident HF (hazard ratio, 0.78; 95% confidence interval, 0.61–1.00; P=0.046). Moreover, the C24:0/C16:0 and C22:0/C16:0 ceramide ratios were inversely associated with all‐cause mortality (C24:0/C16:0: hazard ratio, 0.60; 95% confidence interval, 0.56–0.65; P<0.0001; C22:0/C16:0: hazard ratio, 0.65; 95% confidence interval, 0.60–0.70; P<0.0001). ConclusionsThe ratio of C24:0/C16:0 ceramides in blood may be a valuable new biomarker of CHD risk, HF risk, and all‐cause mortality in the community

Accurate microRNA annotation of animal genomes using trained covariance models of curated microRNA complements in MirMachine

The annotation of microRNAs depends on the availability of transcriptomics data and expert knowledge. This has led to a gap between the availability of novel genomes and high-quality microRNA complements. Using >16,000 microRNAs from the manually curated microRNA gene database MirGeneDB, we generated trained covariance models for all conserved microRNA families. These models are available in our tool MirMachine, which annotates conserved microRNAs within genomes. We successfully applied MirMachine to a range of animal species, including those with large genomes and genome duplications and extinct species, where small RNA sequencing is hard to achieve. We further describe a microRNA score of expected microRNAs that can be used to assess the completeness of genome assemblies. MirMachine closes a long-persisting gap in the microRNA field by facilitating automated genome annotation pipelines and deeper studies into the evolution of genome regulation, even in extinct organisms

In-situ synchrotron diffraction study of the phase evolution of the novel Na\u3csub\u3ex\u3c/sub\u3e(Fe\u3csub\u3e1/2\u3c/sub\u3eMn\u3csub\u3e1/2\u3c/sub\u3e)O\u3csub\u3e2\u3c/sub\u3e cathode for use in sodium-ion batteries

Abstract of a poster presentation at the 5th Australia-China Conference on Science, Technology and Eduction with the 5th Australia-China Symposium for Materials Science, at the University of Wollongong (UOW), Australia, on 21st - 23rd July 2014