Syntheses and applications of group VI and VIII-X heterocyclic-phosphinimine complexes.

A class of phosphinimine-based group VI and VIII-X late transition metal (LTM) complexes has been synthesized and evaluated for olefin polymerisation activity. The phosphinimine ligand has been designed to incorporate an imine moiety; a functional group which has been successfully applied in very active LTM olefin catalytic systems. Heterocycles, such as pyridine and imidazole are used to accomplish the integration of an imine group into the ligand. Phosphines employing the heterocyclic group are oxidized by phenyl azides in excellent yields to form phosphinimine ligands. These phosphinimine ligands react with several LTM\u27s, the complexes of which are identified by single crystal diffraction studies, elemental analysis, NMR and IR spectroscopy, and magnetic susceptibility measurements. In contrast to highly active imine-based systems, we find iron(II) and nickel(II) complexes with bulky phosphinimine-based ligands oligomerise ethylene to form C4 alkenes with moderate activities. (Abstract shortened by UMI.)Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .S67. Source: Masters Abstracts International, Volume: 43-01, page: 0217. Adviser: Douglas W. Stephan. Thesis (M.Sc.)--University of Windsor (Canada), 2003

No Thanks! A Mixed-Methods Exploration of the Social Processes Shaping Persistent Non-Initiation of Amphetamine-Type Stimulants

Amphetamine-Type Stimulants (ATS), such as amphetamines, MDMA, and methamphetamine are a commonly used class of illicit drugs in Europe. There is a large existing literature on motives for the use of illicit drugs, often focusing on initiation. However, few studies have explored the reasons why some people choose not to use drugs (non-use), and even fewer focus on the social processes influencing non-use of ATS specifically. We explored social processes related to normalization, and how persistent non-users negotiate their non-use in social contexts where ATS is used, using qualitative interview (n = 21) and survey questionnaire (n = 126) data from a mixed-method study conducted in the Netherlands and England. Our findings showed that in both countries, most participants were repeatedly exposed to ATS use, often in social or nightlife settings. Participants abstained from use for a number of reasons, including: lack of interest in illicit drug use in general; desire to maintain control over their own behavior and environment; and to avoid the associated health risks. Social processes also shaped persistent non-use of ATS, via conscious socialization with, and selection of, other non-using peers over time. Our findings contribute to the literature on the normalization thesis, showing that recreational ATS use is only partly socially accommodated and normalized among persistent non-users, suggesting differentiated normalization

Resonance Raman Spectroscopy of extreme nanowires and other 1D systems

This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the presence of carbon nanotubes. These nanowires are extreme in the sense that they are the limit of miniaturization of nanowires and their behavior is not always a simple extrapolation of the behavior of larger nanowires as their diameter decreases. The paper then describes the methods required to obtain Raman spectra from extreme nanowires and the fact that due to the van Hove singularities that 1D systems exhibit in their optical density of states, that determining the correct choice of photon excitation energy is critical. It describes the techniques required to determine the photon energy dependence of the resonances observed in Raman spectroscopy of 1D systems and in particular how to obtain measurements of Raman cross-sections with better than 8% noise and measure the variation in the resonance as a function of sample temperature. The paper describes the importance of ensuring that the Raman scattering is linearly proportional to the intensity of the laser excitation intensity. It also describes how to use the polarization dependence of the Raman scattering to separate Raman scattering of the encapsulated 1D systems from those of other extraneous components in any sample

Exploring Pathways into and out of Amphetamine Type Stimulant use at Critical Turning Points: A Qualitative Interview Study

Amphetamine Type Stimulants (ATS) are increasingly used drugs globally. There is limited evidence about what shapes ATS use at critical turning points located within drug using pathways. Using turning point theory, as part of a life course approach, the ATTUNE study aimed to understand which social, economic and individual factors shape pathways into and out of ATS use. Qualitative, semi-structured interviews (n=70) were undertaken with individuals who had used ATS, or who had been exposed to them at least once in their lifetime. Our findings show that turning points for initiation were linked to pleasure, curiosity, boredom and declining mental health; increased use was linked to positive effects experienced at initiation and multiple life-stressors, often leading to more intense use. Decreased use was prompted by pivotal events (e.g. imprisonment) and sustained through continued wellbeing, day-to-day structure, and non-using social networks. We argue that the heterogeneity of these individuals challenges stereotypes of stimulant use allied to nightclubs and ‘hedonism’. Further, even at critical turning points for recovery, the use of services for problematic ATS consumption was low because users prioritised their alcohol or opioid use when seeking help. There is a need to develop service provision, training, and better outreach to individuals who need support at critical turning points

What is the impact of structural and cultural factors and interventions within educational settings on promoting positive mental health and preventing poor mental health: a systematic review

Mental health (MH) difficulties are on the increase among children and young people (CYP). Evidence has shown that educational settings contain both risk and protective factors for MH. This review investigated which structural and cultural factors and interventions within educational settings promote positive MH and prevent poor MH in 4-18 year olds. Searches were conducted in PsychINFO, Embase, ERIC, ASSIA and British Education Index, and reference lists from key studies and relevant systematic reviews were hand-searched. Intervention, cohort, and qualitative studies were included. Of the 62 included papers, 36 examined cultural factors (30 social/relational and six value-related) while 12 studies examined structural factors (eight organisational and four physical) and 14 studies examined multiple factors. There was strong evidence for the impact of positive classroom management techniques, access to physical activity, and peer mentoring on student MH. Studies examining the impact of positive school culture, teacher training in MH and parent involvement in school MH activities also found predominantly positive results for student MH, albeit the evidence was of lower quality or from a low number of studies. Few studies explicitly examined the impact of interventions on MH inequalities; those that did indicated limited if any reduction to inequalities. A very small number of studies suggested that interventions targeting those at risk of poor MH due to socioeconomic factors could successfully improve wellbeing and reduce depression, anxiety and behavioural problems. Studies exploring the effect of management and leadership strategies within schools, policies, and aspects of the physical environment other than green space were scarce or absent in the literature. This review highlights the need to consider the ways in which educational settings are organised, the culture that is created and the physical space in order to improve the MH of CYP

Studying Mental Health in Schools: A Participatory Action Research (PAR) Approach in Public Mental Health

Despite a rising prevalence of mental health difficulties in the young, existing prior to, but also exacerbated by the current COVID-19 pandemic, mental health needs in this population remain unmet even in economically wealthy countries. Increasingly, supportive school environments have been suggested as having a significant impact on young people's mental health. The idea of health- promoting schools, initiated by the World Health Organisation (WHO), highlights the ongoing need for both health education via the curriculum but also a school environment that is conducive to students' health and emotional well-being. Despite this promising public health measure, existing studies into mental health- related interventions delivered in schools have been found to have a small or no effect. One explanation for this is that previous studies did not sufficiently address or focus on the school environment, which may in itself pose barriers to acceptability and successful implementation of mental health interventions. This paper will highlight a novel methodological approach to public mental health research - Participatory Action Research (PAR). The PAR method is unique in enabling study participants to become co-researchers of their own experiences in a specific context. A growing body of educational PAR research suggests that this method can also generate collaborative and participative processes foundational to positive school culture and mental health outcomes. This paper will provide an overview of such outcomes, as well as outline methodological strengths and challenges common to the PAR approach in educational mental health settings

Children With Cystic Fibrosis Are Infected With Multiple Subpopulations of Mycobacterium abscessus With Different Antimicrobial Resistance Profiles.

BACKGROUND: Children with cystic fibrosis (CF) can develop life-threatening infections of Mycobacterium abscessus. These present a significant clinical challenge, particularly when the strains involved are resistant to antibiotics. Recent evidence of within-patient subclones of M. abscessus in adults with CF suggests the possibility that within-patient diversity may be relevant for the treatment of pediatric CF patients. METHODS: We performed whole-genome sequencing (WGS) on 32 isolates of M. abscessus that were taken from multiple body sites of 2 patients with CF who were undergoing treatment at Great Ormond Street Hospital, United Kingdom, in 2015. RESULTS: We found evidence of extensive diversity within patients over time. A clustering analysis of single nucleotide variants revealed that each patient harbored multiple subpopulations, which were differentially abundant between sputum, lung samples, chest wounds, and pleural fluid. The sputum isolates did not reflect the overall within-patient diversity and did not allow for the detection of subclones with mutations previously associated with macrolide resistance (rrl 2058/2059). Some variants were present at intermediate frequencies before the lung transplants. The time of the transplants coincided with extensive variation, suggesting that this event is particularly disruptive for the microbial community, but the transplants did not clear the M. abscessus infections and both patients died as a result of these infections. CONCLUSIONS: Isolates of M. abscessus from sputum do not always reflect the entire diversity present within the patient, which can include subclones with differing antimicrobial resistance profiles. An awareness of this phenotypic variability, with the sampling of multiple body sites in conjunction with WGS, may be necessary to ensure the best treatment for this vulnerable patient group