Selective area growth of a- and c-plane GaN nanocolumns by molecular beam epitaxy using colloidal nanolithography

Selective area growth of a-plane GaN nanocolumns by molecular beam epitaxy was performed for the first time on a-plane GaN templates. Ti masks with 150 nm diameter nanoholes were fabricated by colloidal lithography, an easy, fast and cheap process capable to handle large areas. Even though colloidal lithography does not provide a perfect geometrical arrangement like e-beam lithography, it produces a very homogeneous mask in terms of nanohole diameter and density, and is used here for the first time for the selective area growth of GaN. Selective area growth of a-plane GaN nanocolumns is compared, in terms of anisotropic lateral and vertical growth rates, with GaN nanocolumns grown selectively on the c-plan

Growth of InGaN/GaN core-shell structures by molecular beam epitaxy

Efficiency drop in the green–yellow region in planar InGaN structures associated with: -high defect density -high spontaneous and piezoelectric polarizatio

Influence of substrate type and orientation on the morphology and optical properties of selective area growth of GaN and InGaN nanocolumns

A relevant issue concerning optoelectronic devices based on III-nitrides is the presence of strong polarization fields that may reduce efficiency

The Lipopolysaccharide Core of Brucella abortus Acts as a Shield Against Innate Immunity Recognition

Innate immunity recognizes bacterial molecules bearing pathogen-associated molecular patterns to launch inflammatory responses leading to the activation of adaptive immunity. However, the lipopolysaccharide (LPS) of the gram-negative bacterium Brucella lacks a marked pathogen-associated molecular pattern, and it has been postulated that this delays the development of immunity, creating a gap that is critical for the bacterium to reach the intracellular replicative niche. We found that a B. abortus mutant in the wadC gene displayed a disrupted LPS core while keeping both the LPS O-polysaccharide and lipid A. In mice, the wadC mutant induced proinflammatory responses and was attenuated. In addition, it was sensitive to killing by non-immune serum and bactericidal peptides and did not multiply in dendritic cells being targeted to lysosomal compartments. In contrast to wild type B. abortus, the wadC mutant induced dendritic cell maturation and secretion of pro-inflammatory cytokines. All these properties were reproduced by the wadC mutant purified LPS in a TLR4-dependent manner. Moreover, the core-mutated LPS displayed an increased binding to MD-2, the TLR4 co-receptor leading to subsequent increase in intracellular signaling. Here we show that Brucella escapes recognition in early stages of infection by expressing a shield against recognition by innate immunity in its LPS core and identify a novel virulence mechanism in intracellular pathogenic gram-negative bacteria. These results also encourage for an improvement in the generation of novel bacterial vaccines

“I wanted to go here”: Adolescents’ perspectives on school choice

New Zealand legislation removing school zones radically reshaped school choice, resulting in increased school stratification from parental choice frequently driven by social factors such as ethnic makeup of the school community. This article considers school choice through the eyes of 1,465 adolescents from 12 secondary schools in Dunedin (New Zealand). The most common reasons for school choice included: preference for a coeducational school, school’s facilities, positive comments from parents/students, and friends’ enrollment. Reasons for school choice differed by who was making the decision. Social factors and school programs/facilities, rather than proximity to home, influenced school choice decisions in Dunedin

How to improve recruitment, sustainability and scalability in physical activity programmes for adults aged 50 years and older: A qualitative study of key stakeholder perspectives

Physical inactivity among adults aged 50 years and over is a worldwide health concern. The objectives of the study were to investigate the perspectives of those involved with existing physical activity programmes on optimising recruitment, sustainability and scalability of physical activity programmes for adults aged 50 years and over. Methods The study was conducted in Ireland’s Midwest region, where community-based physical activity programmes are delivered to groups by state-funded Local Sports Partnerships. Programme attendees, physical activity professionals and community advocates were recruited. One-to-one interviews and focus groups were conducted in 2018, recorded, transcribed and analysed by an interdisciplinary team experienced in qualitative research. Over a series of meetings, a thematic approach was used to code and analyse the transcripts, categorising data into higher order codes, themes and overarching themes with the purpose of making meaning of the data. Twenty-nine people participated in four focus groups and 18 participated in one-to-one interviews. Findings Data analysis produced three overarching themes. “Age appropriate” explains how communication and the environment should be adapted to the needs of adults aged 50 years and older. “Culture and connection” refer to the interplay of individual and social factors that influence participation, including individual fears and insecurities, group cohesion and added value beyond the physical gains in these programmes. “Roles and partnerships” outlines how key collaborations may be identified and managed and how local ownership is key to success and scalability. Conclusion Successful recruitment, sustainability and scalability require an understanding that the target population has unique needs that must be catered for when planning interventions, communicating messages and choosing personnel. The findings of this study can inform the development of community-based programmes to increase physical activity in adults aged 50 years and older

A guide to conducting systematic reviews of coaching science research

Research in coaching science continues to grow and as such, there is a need for rigorous tools to help make sense of the rapidly expanding literature. The purpose of this paper is to provide a detailed description of a systematic review methodology that can be used to summarise literature in coaching science. To do so, we present a test case of a systematic review we conducted on the sport coaching experiences of global Indigenous populations. More precisely, we conducted a systematic review of English, Spanish, French, Mandarin, and Portuguese peer-reviewed journal articles, spanning twelve databases (e.g., Sport Discus, ERIC, and Scopus) from 1970 to 2014. ENTREQ and COREQ guidelines were followed to report the results of the systematic review, and Bronfenbrenner’s ecological systems theory was used as a theoretical framework to extract and synthesise relevant findings from the included articles. In sum, this paper presents a robust methodology for systematically reviewing research in coaching science and provides practical insights for those who endeavour to conduct rigorous literature searches in this domain