Ab Initio Investigation of a Possible Liquid-Liquid Phase Transition in MgSiO3 at Megabar Pressures

We perform density functional molecular dynamics simulations of liquid and solid MgSiO3 in the pressure range of 120-1600 GPa and for temperatures up to 20000 K in order to provide new insight into the nature of the liquid-liquid phase transition that was recently predicted on the basis of decaying laser shock wave experiments [Phys. Rev. Lett. 108 (2012) 065701]. However, our simulations did not show any signature of a phase transition in the liquid phase. We derive the equation of state for the liquid and solid phases and compute the shock Hugoniot curves. We discuss different thermodynamic functions and by explore alternative interpretations of the experimental findings.Comment: 15 pages, 7 figures, 2 tables, 29 reference

A mathematical model of the evaporation of a thin sessile liquid droplet : comparison between experiment and theory

A mathematical model for the quasi-steady diffusion-limited evaporation of a thin axisymmetric sessile droplet of liquid with a pinned contact line is formulated and solved. The model generalises the theoretical model proposed by Deegan et al. [Contact line deposits in an evaporating drop, Phys. Rev. E, 62 (2000) 756-765] to include the effect of evaporative cooling on the saturation concentration of vapour at the free surface of the droplet, and the dependence of the coefficient of diffusion of vapour in the atmosphere on the atmospheric pressure. The predictions of the model are in good qualitative, and in some cases also quantitative, agreement with recent experimental results. In particular, they capture the experimentally observed dependence of the total evaporation rate on the thermal conductivities of the liquid and the substrate, and on the atmospheric pressure

Changing medical student attitudes to patient safety: A multicentre study

Background: Although patient safety is becoming widely taught in medical schools, its effect has been less rigorously evaluated. We describe a multicentre study to evaluate student changes in patient safety attitudes using a standardized instrument, the Attitudes to Patient Safety Questionnaire3 (APSQ3). Methods: A patient safety training package designed for medical students was delivered in the first year and second year in four Australian medical schools. It comprises eight face-to-face modules, each of two hours. Seminars start with an interactive introduction using questions, video and role play, followed by small group break-outs to discuss a relevant case study. Groups are led by medical school tutors with no prior training in patient safety. Students and tutors then reassemble to give feedback and reinforce key concepts. Knowledge and attitudes to patient safety were measured using the APSQ3, delivered prior to safety teaching, at the end of the first and second years and 12 months after teaching ceased. Results: A significant improvement in attitude over time was demonstrated for four of nine key items measured by the APSQ3: value of patient safety teaching; danger of long working hours, value of team work and the contribution patients can make in reducing error. Informal feedback from students was very positive. Conclusion: We showed persistent, positive learning from a patient safety education intervention 12 months after teaching finished. Building on the introduction of patient safety teaching into medical schools, pathways for motivated students such as appropriate electives, option terms and team-based research projects would be of value

How to experimentally measure the number 5 of the SO(5) theory?

According to Wilson's theory of critical phenomena, critical exponents are universal functions of $d$, the dimension of space, and $n$, the dimension of the symmetry group. SO(5) theory of antiferromagnetism and superconductivity predicts a bicritical point where $T_N$ and $T_c$ intersect. By measuring critical exponents close to the bicritical point, and knowing that $d=3$, one can experimentally measure the number 5 of the SO(5) theory.Comment: Invited talk at the M2S conference in Housto

Behind the rainbow, "Tongqi" wives of men who have sex with men in China: a systematic review

open access articleBackground: Due to the restrictions and stigmatization of homosexuality in China, there has emerged the “Tongqi,” or the wives of men who have sex with men (MSM). There are around 14 million Tongqi wives whose needs for support are often overshadowed. This phenomenon has been largely under researched, this review is the first to address the current data on the Tongqi. The aim of this systematic review is to begin to provide insight into the pre-existing data and the further support that is needed for the wives of MSM. Methods: The researchers searched PubMed, Web of Science, EMBASE, PsycINFO, CNKI, Sinomed and WangFang databases from their inception date until June 7, 2019. Handsearching was also completed to provide a rich data set. Results: The articles were summarized and analyzed for thematic clusters. From the selected article, five themes emerged, including Sexual Health Issues, Intimate Partner Violence, Mental Health Status, Marriage Dissatisfaction, and Coping Strategies. These themes often intersected to provide a complex understanding of the current gaps in support provided to Tongqi. Conclusion: Tongqi wives remain a hidden population in Chinese mainstream society, who deserves a sensitive approach to support. The study revealed that the MSM wives suffer severe mental, physical, health, and life related harms. However, instead of situating them into the victim roles, many women take on an identity of empowerment and are working together, aiming to make social changes. In order to address the Tongqi phenomenon, it is also essential to reduce the discrimination toward homosexuality. Tongqi are a special group of Chinese women, they require further intensive research attention

EFFECTS OF TEMPERATURE ANOMALIES ON THE PALMER DROUGHT SEVERITY INDEX IN THE CENTRAL UNITED STATES

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the central United States. The temperature effect on PDSI complicates the usage of the index in interpreting precipitation anomalies and its application in inferring precipitation variations, particularly from reconstructed PDSI

Berberine induces caspase-independent cell death in colon tumor cells through activation of apoptosis-inducing factor

Berberine, an isoquinoline alkaloid derived from plants, is a traditional medicine for treating bacterial diarrhea and intestinal parasite infections. Although berberine has recently been shown to suppress growth of several tumor cell lines, information regarding the effect of berberine on colon tumor growth is limited. Here, we investigated the mechanisms underlying the effects of berberine on regulating the fate of colon tumor cells, specifically the immorto Min mouse colonic epithelial (IMCE) cells carrying the Apcmin mutation, and of normal colon epithelial cells, namely young adult mouse colon (YAMC) epithelial cells. Berberine decreased colon tumor colony formation in agar, and induced cell death and LDH release in a time- and concentration-dependent manner in IMCE cells. In contrast, YAMC cells were not sensitive to berberine-induced cell death. Berberine did not stimulate caspase activation, and PARP cleavage and berberine-induced cell death were not affected by a caspase inhibitor in IMCE cells. Rather, berberine stimulated a caspase-independent cell death mediator, apoptosis-inducing factor (AIF) release from mitochondria and nuclear translocation in a ROS production-dependent manner. Amelioration of berberine-stimulated ROS production or suppression of AIF expression blocked berberine-induced cell death and LDH release in IMCE cells. Furthermore, two targets of ROS production in cells, cathepsin B release from lysosomes and PARP activation were induced by berberine. Blockage of either of these pathways decreased berberine-induced AIF activation and cell death in IMCE cells. Thus, berberine-stimulated ROS production leads to cathepsin B release and PARP activation-dependent AIF activation, resulting in caspase-independent cell death in colon tumor cells. Notably, normal colon epithelial cells are less susceptible to berberine-induced cell death, which suggests the specific inhibitory effects of berberine on colon tumor cell growth