The Search for Higher TcT_c in Houston

It is a great pleasure to be invited to join the chorus on this auspicious occasion to celebrate Professor K. Alex Mueller's 90th birthday by Professors Annette Bussman-Holder, Hugo Keller, and Antonio Bianconi. As a student in high temperature superconductivity, I am forever grateful to Professor Alex Mueller and Dr. Georg Bednorz "for their important breakthrough in the discovery of superconductivity in the ceramic materials" in 1986 as described in the citation of their 1987 Nobel Prize in Physics. It is this breakthrough discovery that has ushered in the explosion of research activities in high temperature superconductivity (HTS) and has provided immense excitement in HTS science and technology in the ensuing decades till now. Alex has not been resting on his laurels and has continued to search for the origin of the unusual high temperature superconductivity in cuprates.Comment: Dedicated to Alex Mueller, whose "important breakthrough in the discovery of superconductivity in ceramic materials" in 1986 has changed the world of superconductivit

Sustainable Development Goals and sustainability teaching at universities: falling behind or getting ahead of the pack?

The fact that the world community is engaged in pursuing the Sustainable Development Goals (SDGs) means that an unrivalled opportunity is provided to universities, both in respect of teaching and in research, on individual SDGs, as well as in pursuing their “third mission” linking up with external stakeholders and society. However, not many universities have realised that and many are falling behind. This paper explores the many advantages of the introduction of the SDGs into teaching and suggests that it can catalyse the engagement of students in Higher Education Institutions (HEI) with the concepts of sustainability. The paper fills in a research gap by surveying the current state of the art regarding the theme, presenting current data outlining the extent to which HEI are using SDGs to support their sustainability work. The reasons why some institutions are currently not engaging is also shown. The paper, which consists of a worldwide survey deployed to collect data on the SDGs and sustainability teaching at universities, concludes by providing some recommendations aimed at encouraging further engagement of HEI in incorporatingSDGs as part of their teaching programs. This research is unique in the sense that it provides for the first time offers an overview of the level of emphasis selected universities currently place on the SDGs. Finally, it provides a contribution to current state of knowledge by outlining some actions universities may take, to move forward with their implementation

Sustainability and procurement practices in higher education institutions: Barriers and drivers

© 2019 A review of the literature reveals the scant research on sustainable procurement in the public sector, and in particular higher education institutions (HEIs). In this context, this paper aims to contribute to an emerging stream of research on drivers and challenges which higher education institutions and the extent to which they are endorsing sustainable procurement practices. The study is based on a survey of HEIs around the world, drawn from a network of sustainability practitioners and researchers at these institutions. Design of the survey drew on existing studies of barriers and enablers, the use of vignettes to provoke ideas among the research team, and a pilot study. Crucially, the study seeks to shed light on both drivers and critical barriers affecting the implementation of sustainable procurement at universities. The results and discussion identify previously unidentified barriers and enablers, and further suggest that smaller HEI have some catching up to do. Policy recommendations are presented and approaches on how to overcome barriers to sustainable procurement are set forth. These centre on the proposal that HEIs should consider developing a reflexive strategy to procurement purchasing policy, and to ensure there are suitable means for its implementation

Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor

The latest discovery of high temperature superconductivity signature in single-layer FeSe is significant because it is possible to break the superconducting critical temperature ceiling (maximum Tc~55 K) that has been stagnant since the discovery of Fe-based superconductivity in 2008. It also blows the superconductivity community by surprise because such a high Tc is unexpected in FeSe system with the bulk FeSe exhibiting a Tc at only 8 K at ambient pressure which can be enhanced to 38 K under high pressure. The Tc is still unusually high even considering the newly-discovered intercalated FeSe system A_xFe_{2-y}Se_2 (A=K, Cs, Rb and Tl) with a Tc at 32 K at ambient pressure and possible Tc near 48 K under high pressure. Particularly interesting is that such a high temperature superconductivity occurs in a single-layer FeSe system that is considered as a key building block of the Fe-based superconductors. Understanding the origin of high temperature superconductivity in such a strictly two-dimensional FeSe system is crucial to understanding the superconductivity mechanism in Fe-based superconductors in particular, and providing key insights on how to achieve high temperature superconductivity in general. Here we report distinct electronic structure associated with the single-layer FeSe superconductor. Its Fermi surface topology is different from other Fe-based superconductors; it consists only of electron pockets near the zone corner without indication of any Fermi surface around the zone center. Our observation of large and nearly isotropic superconducting gap in this strictly two-dimensional system rules out existence of node in the superconducting gap. These results have provided an unambiguous case that such a unique electronic structure is favorable for realizing high temperature superconductivity

Levels and Correlates of Non-Adherence to WHO Recommended Inter-Birth Intervals in Rufiji, Tanzania.

Poorly spaced pregnancies have been documented worldwide to result in adverse maternal and child health outcomes. The World Health Organization (WHO) recommends a minimum inter-birth interval of 33 months between two consecutive live births in order to reduce the risk of adverse maternal and child health outcomes. However, birth spacing practices in many developing countries, including Tanzania, remain scantly addressed. METHODS: Longitudinal data collected in the Rufiji Health and Demographic Surveillance System (HDSS) from January 1999 to December 2010 were analyzed to investigate birth spacing practices among women of childbearing age. The outcome variable, non-adherence to the minimum inter-birth interval, constituted all inter-birth intervals <33 months long. Inter-birth intervals >=33 months long were considered to be adherent to the recommendation. Chi-Square was used as a test of association between non-adherence and each of the explanatory variables. Factors affecting non-adherence were identified using a multilevel logistic model. Data analysis was conducted using STATA (11) statistical software. RESULTS: A total of 15,373 inter-birth intervals were recorded from 8,980 women aged 15--49 years in Rufiji district over the follow-up period of 11 years. The median inter-birth interval was 33.4 months. Of the 15,373 inter-birth intervals, 48.4% were below the WHO recommended minimum length of 33 months between two live births. Non-adherence was associated with younger maternal age, low maternal education, multiple births of the preceding pregnancy, non-health facility delivery of the preceding birth, being an in-migrant resident, multi-parity and being married. CONCLUSION: Generally, one in every two inter-birth intervals among 15--49 year-old women in Rufiji district is poorly spaced, with significant variations by socio-demographic and behavioral characteristics of mothers and newborns. Maternal, newborn and child health services should be improved with a special emphasis on community- and health facility-based optimum birth spacing education in order to enhance health outcomes of mothers and their babies, especially in rural settings

HPV infection and immunochemical detection of cell-cycle markers in verrucous carcinoma of the penis

Penile verrucous carcinoma is a rare disease and little is known of its aetiology or pathogenesis. In this study we examined cell-cycle proteins expression and correlation with human papillomavirus infection in a series of 15 pure penile verrucous carcinomas from a single centre. Of 148 penile tumours, 15 (10%) were diagnosed as pure verrucous carcinomas. The expression of the cell-cycle-associated proteins p53, p21, RB, p16INK4A and Ki67 were examined by immunohistochemistry. Human papillomavirus infection was determined by polymerase chain reaction to identify a wide range of virus types. The expression of p16INK4A and Ki67 was significantly lower in verrucous carcinoma than in usual type squamous cell carcinoma, whereas the expression of p53, p21 and RB was not significantly different. p53 showed basal expression in contrast to usual type squamous cell carcinoma. Human papillomavirus infection was present in only 3 out of 13 verrucous carcinomas. Unique low-risk, high-risk and mixed viral infections were observed in each of the three cases. In conclusion, lower levels of p16INK4A and Ki67 expressions differentiate penile verrucous carcinoma from usual type squamous cell carcinoma. The low Ki67 index reflects the slow-growing nature of verrucous tumours. The low level of p16INK4A expression and human papillomavirus detection suggests that penile verrucous carcinoma pathogenesis is unrelated to human papillomavirus infection and the oncogenes and tumour suppressor genes classically altered by virus infection.Peer reviewedFinal Accepted Versio

Effect of a semiconductor electrode on the tunneling electroresistance in ferroelectric tunneling junction

published_or_final_versio

Normative and self-perceived orthodontic treatment need of a Peruvian university population

BACKGROUND: Previous studies on orthodontic treatment need in young adults have shown that up to 50% had malocclusions that needed orthodontic treatment. The aims of this study were to assess the normative and self-perceived need for orthodontic treatment using the Index of Orthodontic Treatment Need (IOTN) and to determine if the treatment need levels were influenced by sex, age and socio-economic status (SES) in a sample of Peruvian young adults. METHODS: 281 first-year students (157 male and 124 female students) with a mean age of 18.1 +/- 1.6 years were randomly selected and evaluated through the Dental Health Component (DHC) and Aesthetic Component (AC) of the IOTN. Structured interview and clinical examination were used to assess the students. Descriptive statistics and Chi-square tests were used for data analysis with statistical significance set at P < 0.05. RESULTS: An intra-examiner reliability of 0.89 was obtained (weighted Kappa). The percentage of students according to SES was 51.2%, 40.6% and 8.2% corresponding to low, medium and high SES respectively. The percentage of students with DHC grades 4–5 was 29.9% whereas the percentage of students with AC grades 8–10 was 1.8%. There were no significant differences in the distribution of normative and self-perceived orthodontic treatment need based on sex, age and SES comparisons. CONCLUSION: Normative orthodontic treatment need was not matched by a similar level of self-perceived treatment need in these young adults. Sex, age and SES were non-significant factors associated with levels of treatment need

The roles of tumor necrosis factor-alpha in colon tight junction protein expression and intestinal mucosa structure in a mouse model of acute liver failure

<p>Abstract</p> <p>Background</p> <p>Spontaneous bacterial peritonitis (SBP) is a common clinical disease and one of the most severe complications of acute liver failure (ALF). Although the mechanism responsible for SBP is unclear, cytokines play an important role. The aim of this study was to investigate the effects of tumor necrosis factor-alpha (TNF-α) on the structure of the intestinal mucosa and the expression of tight junction (Zona Occludens 1; ZO-1) protein in a mouse model of ALF.</p> <p>Methods</p> <p>We induced ALF using D-galactosamine/lipopolysaccharide (GalN/LPS) or GalN/TNF-α and assessed the results using transmission electron microscopy, immunohistochemistry, Western blotting, ELISA and real-time quantitative PCR. The effects of administration of anti-TNF-α IgG antibody or anti-TNF-α R1 antibody before administration of GalN/LPS or GalN/TNF-α, respectively, on TNF-α were also assessed.</p> <p>Results</p> <p>Morphological abnormalities in the intestinal mucosa of ALF mice were positively correlated with serum TNF-α level. Electron microscopic analysis revealed tight junction (TJ) disruptions, epithelial cell swelling, and atrophy of intestinal villi. Gut bacteria invaded the body at sites where TJ disruptions occurred. Expression of ZO-1 mRNA was significantly decreased in both ALF models, as was the level of ZO-1 protein. Prophylactic treatment with either anti-TNF-α IgG antibody or anti-tumor necrosis factor-a receptor1 (anti-TNF-α R1) antibody prevented changes in intestinal tissue ultrastructure and ZO-1 expression.</p> <p>Conclusion</p> <p>TNF-α affects the structure of the intestinal mucosa, decreases expression of ZO-1, and affects the morphology of the colon in a mouse model of ALF. It also may participate in the pathophysiological mechanism of SBP complicated to ALF.</p

Branch Mode Selection during Early Lung Development

Many organs of higher organisms, such as the vascular system, lung, kidney, pancreas, liver and glands, are heavily branched structures. The branching process during lung development has been studied in great detail and is remarkably stereotyped. The branched tree is generated by the sequential, non-random use of three geometrically simple modes of branching (domain branching, planar and orthogonal bifurcation). While many regulatory components and local interactions have been defined an integrated understanding of the regulatory network that controls the branching process is lacking. We have developed a deterministic, spatio-temporal differential-equation based model of the core signaling network that governs lung branching morphogenesis. The model focuses on the two key signaling factors that have been identified in experiments, fibroblast growth factor (FGF10) and sonic hedgehog (SHH) as well as the SHH receptor patched (Ptc). We show that the reported biochemical interactions give rise to a Schnakenberg-type Turing patterning mechanisms that allows us to reproduce experimental observations in wildtype and mutant mice. The kinetic parameters as well as the domain shape are based on experimental data where available. The developed model is robust to small absolute and large relative changes in the parameter values. At the same time there is a strong regulatory potential in that the switching between branching modes can be achieved by targeted changes in the parameter values. We note that the sequence of different branching events may also be the result of different growth speeds: fast growth triggers lateral branching while slow growth favours bifurcations in our model. We conclude that the FGF10-SHH-Ptc1 module is sufficient to generate pattern that correspond to the observed branching modesComment: Initially published at PLoS Comput Bio