Facile preparation of antibacterial, highly elastic silvered polyurethane nanofiber fabrics using silver carbamate and their dermal wound healing properties

In this study, polycarbonate diol/isosorbide-based antibacterial polyurethane nanofiber fabrics containing Ag nanoparticles were prepared by electrospinning process. Bio-based highly elastic polyurethane was prepared from hexamethylene diisocyanate and isosorbide/polycarbonate diol (8/2) by a simple one-shot bulk polymerization. Ag nanoparticles were formed using simple thermal reduction of silver 2-ethylhexylcarbamate at 120℃. The structural and morphological properties of polyurethane/Ag nanofibers were characterized by X-ray diffraction and scanning electron microscopy. The polyurethane nanofiber fabrics were flexible, with breaking strains from 355% to 950% under 7.28 to 23.1 MPa tensile stress. The antibacterial effects of the treated polyurethane/Ag fabrics against Staphylococcus aureus and methicillin resistant Staphylococcus aureus were examined and found to be excellent. Cell proliferation using the immortalized human keratinocyte HaCaT cell line was performed in order to determine cell viability in the presence of polyurethane and polyurethane/Ag fabrics, showing cytocompatiblility and a lack of toxicity

Investigating Self-Directed Learning Dimensions: Adapting the Bouchard Framework

Self-Directed Learning (SDL) is gaining interest, as online learning is increasingly learner-centered. FutureLearn courses provide an array of online interactions and content deliveries, which have allowed the authors to investigate a diversity of SDL elements. This preliminary research examines the SDL taking place in three FutureLearn courses, and categorises those learner actions into meaningful elements and dimensions for the learners. The SDL framework by Bouchard [1] is used to interpret the self-reported findings coming from active learners. The research uses a grounded theory approach to look for learner experiences related to four dimensions (algorithmic, conative, semiotic, and economic) of the Bouchard [1] framework, and to discover new dimensions. Various research instruments are used: online surveys, learning logs, and one-on-one interviews, all collected pre-, during, or post-course. The initial adaptation of Bouchard’s framework offers insights into SDL, its meaning, and value as perceived by the learners

Using Genetic Variants to Assess the Relationship Between Circulating Lipids and Type 2 Diabetes

Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2015 by the American Diabetes Association.This article contains Supplementary Data online at http://diabetes.diabetesjournals.org/lookup/suppl/doi:10.2337/db14-1710/-/DC1.The effects of dyslipidemia on the risk of type 2 diabetes (T2D) and related traits are not clear. We used regression models and 140 lipid-associated genetic variants to estimate associations between circulating HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), and triglycerides and T2D and related traits. Each genetic test was corrected for effects of variants on the other two lipid types and surrogates of adiposity. We used the largest data sets available: 34,840 T2D case and 114,981 control subjects from the DIAGRAM (DIAbetes Genetics Replication And Meta-analysis) consortium and up to 133,010 individuals without diabetes for insulin secretion and sensitivity from the MAGIC (Meta-Analyses of Glucose and Insulin-related traits Consortium) and GENESIS (GENEticS of Insulin Sensitivity) studies. Eight of 21 associations between groups of variants and diabetes traits were significant at the nominal level, including those between genetically determined lower HDL-C (β = -0.12, P = 0.03) and T2D and genetically determined lower LDL-C (β = -0.21, P = 5 × 10(-6)) and T2D. Although some of these may represent causal associations, we discuss why caution must be used when using Mendelian randomization in the context of circulating lipid levels and diabetes traits. In conclusion, we found evidence of links between genetic variants associated with lipids and T2D, but deeper knowledge of the underlying genetic mechanisms of specific lipid variants is needed before drawing definite conclusions about causality based on Mendelian randomization methodology.Knut and Alice Wallenberg FoundationERCSwedish Research CouncilFredrik och Ingrid Thurings StiftelseSwedish Heart-Lung Foundationacknowledges Sydvästra Skånes DiabetesföreningNovo Nordisk FoundationUniversity of TartuEuropean Foundation for the Study of Diabetes New HorizonsAmerican Heart Associatio

Language learning and integration of adult Bhutanese refugees : an ethnographic study

This study sought a holistic and in-depth investigation of English language learning and integration experiences of a group of adult Bhutanese refugees in Australia. The Bhutanese refugees have settled since 2007 as new residents of their host country after two decades of expatriate life in the refugee camps of Nepal. The impetus for this exploratory study stemmed from my personal experience as a cultural orientation trainer to such refugees and awareness of their expectations, attitudes, and dispositions related to learning and life trajectory. This study is interdisciplinary in its approach that takes account of the complex interplay of language learning and integration. Using an ethnographic methodology as an approach to investigation, this study sought to examine three social spaces of refugees: the family and ethnic community, the host society and the migrant English classroom. The attention was focussed on the resources and constraints the refugees encountered in each of the social spaces. Moreover, various social, contextual, cultural factors, and pre-migration influences embedded in these spaces were explored for their impact on learning and integration. This study was important mainly for three reasons. Through critical examination of the role of refugees’ family and ethnic community networks, it aimed to provide insights into to what extent the resources embedded in these networks can be significant to refugees and also contribute to the existing literature of social capital (Putnam, 2000). Drawing on the investigation of how cultural issues, pre-migration experiences and perceptions of teaching impact on classroom language learning, this study sought to offer insights into how the English language should be taught to the adult students from refugee backgrounds. Moreover, this study sought to extend the scope of the existing refugee integration literature by investigating the integration as a process of ongoing negotiation between ethnocultural retention and host society participation, and how various social, cultural, contextual factors, and pre-migration experiences influenced the way integration is structured in everyday practice. This study employed an ethnographic approach as a methodological framework, involving observations, interviews, and a reflective journal study as the main tools for data collection. The field work was carried out in a regional area of the State of Tasmania. The observations were conducted in the migrant English classrooms, in a multi-ethnic Australian church and in the refugee community; and then the retrospective interviews were carried out with the Bhutanese refugees, their teachers and other service providers. The data were analyzed using ethnographic macro and micro level analysis techniques (Duff, 2002). The findings generated from observation data were supported and triangulated, where possible, by the use of data derived from interviews. This study was informed mainly by the interpretive paradigm. Given how extensive and messy the literature on migrant language learning and integration is, this study utilized a wide range of relevant theories to analyze and interpret the findings derived from the ethnographic fieldwork. One important contribution of this study is the finding that the social capital derived from refugees’ family and ethnic community networks not only enables, but it also inhibits integration. This bonding social capital can function as a coping resource for refugees against the effects of culture shock, language shock, and racism, and can facilitate access to a range of instrumental support and information necessary for successful transition to the host society. However, this study also suggests that an extreme level of embeddedness within the cultural and social frames of ethnic space has the potential to jeopardize individual mobility, host society language learning and sustainable integration. This study shows that the cultural dispositions the adult refugee students bring to the classroom provide the primary basis for the way they approach their English learning, and thus influence their agency and identity as learners. The findings also suggest that the students are likely to engage in the desired learning tasks if their perceptions of teaching quality cohere with the actual teaching they are exposed to. Teachers are therefore suggested to adopt a hybridity of teaching approaches and methods in ways that bridge the gap between their own and their students’ perceptions and expectations. The implications drawn from the empirical results additionally suggest that if the aim of the migrant English program is to facilitate the integration of refugees into their multicultural society, then the pedagogy it embodied should incorporate a hybridity of simulation scenarios (native, non-native and coethnic), enabling them to critically examine the impact of different types of identity they portray and negotiate their identities according to social constraints. This study suggests that in order to understand refugee integration more fully, it is not sufficient to account only for the pre-determined set of objective measures (such as employment and educational outcomes) without considering the way in which integration is actualized in everyday experience. For refugees in this study, what it means to be integrated into the Australian society was complex, ambivalent and context dependent. It was an ongoing process of contestation and negotiation between different values, identities and practices embedded in ethnic and mainstream Australia community. Based on my empirical study, I suggest that the everyday practices of refugee integration resembles with Bhabha’s (1990) notion of “Third Space” and incorporates the hybridity of cultural identifications and experiences

Learners Self-directing Learning in FutureLearn MOOCs: A Learner-Centered Study

This qualitative research study focuses on how experienced online learners self-direct their learning while engaging in a MOOC delivered on the FutureLearn platform. Self-directed learning is an important concept within informal learning and online learning. This study distinguishes itself from previous MOOC learner studies, by reporting the self-directed learning using a bottom-up approach. By looking at self-reported learning logs and interview transcripts an in-depth analysis of the self-directed learning is achieved. The data analysis used constructed grounded theory, which aligns with the bottom-up approach where the learner data is coded and investigated in an open, yet evidence-based way, leaving room for insights to emerge from the learner data. The data corpus is based on 56 participants following three FutureLearn MOOCs, providing 147 learning logs and 19 semi-structured one-on-one interviews with a selection of participants. The results show five specific areas in which learners react with either the material or other learners to self-direct their learning: context, individual or social learning, technology and media provided in the MOOCs, learner characteristics and organising learning. This study also indicates how intrinsic motivation and personal learning goals are the main inhibitors or enablers of self-directed learning

Approximating Mexican highways with slime mould

Plasmodium of Physarum polycephalum is a single cell visible by unaided eye. During its foraging behavior the cell spans spatially distributed sources of nutrients with a protoplasmic network. Geometrical structure of the protoplasmic networks allows the plasmodium to optimize transport of nutrients between remote parts of its body. Assuming major Mexican cities are sources of nutrients how much structure of Physarum protoplasmic network correspond to structure of Mexican Federal highway network? To find an answer undertook a series of laboratory experiments with living Physarum polycephalum. We represent geographical locations of major cities by oat flakes, place a piece of plasmodium in Mexico city area, record the plasmodium's foraging behavior and extract topology of nutrient transport networks. Results of our experiments show that the protoplasmic network formed by Physarum is isomorphic, subject to limitations imposed, to a network of principle highways. Ideas and results of the paper may contribute towards future developments in bio-inspired road planning

Structural and functional characterization of Pseudomonas aeruginosa CupB chaperones

Pseudomonas aeruginosa, an important human pathogen, is estimated to be responsible for,10% of nosocomial infections worldwide. The pathogenesis of P. aeruginosa starts from its colonization in the damaged tissue or medical devices (e. g. catheters, prothesis and implanted heart valve etc.) facilitated by several extracellular adhesive factors including fimbrial pili. Several clusters containing fimbrial genes have been previously identified on the P. aeruginosa chromosome and named cup [1]. The assembly of the CupB pili is thought to be coordinated by two chaperones, CupB2 and CupB4. However, due to the lack of structural and biochemical data, their chaperone activities remain speculative. In this study, we report the 2.5 A crystal structure of P. aeruginosa CupB2. Based on the structure, we further tested the binding specificity of CupB2 and CupB4 towards CupB1 (the presumed major pilus subunit) and CupB6 (the putative adhesin) using limited trypsin digestion and strep-tactin pull-down assay. The structural and biochemical data suggest that CupB2 and CupB4 might play different, but not redundant, roles in CupB secretion. CupB2 is likely to be the chaperone of CupB1, and CupB4 could be the chaperone of CupB4:CupB5:CupB6, in which the interaction of CupB4 and CupB6 might be mediated via CupB5

Institutional leadership—the historical case study of a religious organisation

In this chapter, I discuss institutional leadership vis-à-vis the value of poverty. To do so, I analyse how poverty has been conceptualised within a Catholic religious organisation, the Jesuits. The chapter shows that, in the Jesuit case, poverty is not strictly defined. Instead, poverty results from the constant dialogue between the individual Jesuit and their leader. This means that the understanding of what constitutes poverty is neither explicit nor implicit. The chapter contributes to our understanding of institutional leadership as the promotion and protection of values, as per Selznick’s classical definition. However, we discuss a less known part of Selznick’s work in which the ambiguous character of values is highlighted. In this sense, and after the Jesuit case, we advance the possibility that the promotion and protection of institutional values by institutional leaders does not necessarily imply the definition of what a value is. As values are not defined beforehand but the result of a constant dialogue between the leader and their followers, institutional leadership can be revisited and freed from the heroic view that has long characterised it

Integrated Epigenome Profiling of Repressive Histone Modifications, DNA Methylation and Gene Expression in Normal and Malignant Urothelial Cells

Epigenetic regulation of gene expression is commonly altered in human cancer. We have observed alterations of DNA methylation and microRNA expression that reflect the biology of bladder cancer. This common disease arises by distinct pathways with low and high-grade differentiation. We hypothesized that epigenetic gene regulation reflects an interaction between histone and DNA modifications, and differences between normal and malignant urothelial cells represent carcinogenic events within bladder cancer. To test this we profiled two repressive histone modifications (H3K9m3 and H3K27m3) using ChIP-Seq, cytosine methylation using MeDIP and mRNA expression in normal and malignant urothelial cell lines. In genes with low expression we identified H3K27m3 and DNA methylation each in 20–30% of genes and both marks in 5% of genes. H3K9m3 was detected in 5–10% of genes but was not associated with overall expression. DNA methylation was more closely related to gene expression in malignant than normal cells. H3K27m3 was the epigenetic mark most specifically correlated to gene silencing. Our data suggest that urothelial carcinogenesis is accompanied by a loss of control of both DNA methylation and H3k27 methylation. From our observations we identified a panel of genes with cancer specific-epigenetic mediated aberrant expression including those with reported carcinogenic functions and members potentially mediating a positive epigenetic feedback loop. Pathway enrichment analysis revealed genes marked by H3K9m3 were involved with cell homeostasis, those marked by H3K27m3 mediated pro-carcinogenic processes and those marked with cytosine methylation were mixed in function. In 150 normal and malignant urothelial samples, our gene panel correctly estimated expression in 65% of its members. Hierarchical clustering revealed that this gene panel stratified samples according to the presence and phenotype of bladder cancer

Carbon-nanotube-interfaced glass fiber scaffold for regeneration of transected sciatic nerve.

Carbon nanotubes (CNTs), with their unique and unprecedented properties, have become very popular for the repair of tissues, particularly for those requiring electrical stimuli. Whilst most reports have demonstrated in vitro neural cell responses of the CNTs, few studies have been performed on the in vivo efficacy of CNT-interfaced biomaterials in the repair and regeneration of neural tissues. Thus, we report here for the first time the in vivo functions of CNT-interfaced nerve conduits in the regeneration of transected rat sciatic nerve. Aminated CNTs were chemically tethered onto the surface of aligned phosphate glass microfibers (PGFs) and CNT-interfaced PGFs (CNT-PGFs) were successfully placed into three-dimensional poly(l/d-lactic acid) (PLDLA) tubes. An in vitro study confirmed that neurites of dorsal root ganglion outgrew actively along the aligned CNT-PGFs and that the CNT interfacing significantly increased the maximal neurite length. Sixteen weeks after implantation of a CNT-PGF nerve conduit into the 10mm gap of a transected rat sciatic nerve, the number of regenerating axons crossing the scaffold, the cross-sectional area of the re-innervated muscles and the electrophysiological findings were all significantly improved by the interfacing with CNTs. This first in vivo effect of using a CNT-interfaced scaffold in the regeneration process of a transected rat sciatic nerve strongly supports the potential use of CNT-interfaced PGFs at the interface between the nerve conduit and peripheral neural tissues