Methyleneamino derivatives of some metals and metalloids

This thesis describes the preparation and properties of some methyleneamino derivatives of boron, magnesium and aluminium. The structural implications of their I.R. and (L^) H n.m.r. spectra are discussed. As a background to the work, the characteristics of such compounds are discussed and a survey of methyleneamino derivatives of metals and metalloids is presented. Bis (di-t-butylmethyleneamino) fluoroborane. ((^t) Bu (_2) C: N) (_2) BF, was prepared from borom trifluoride and di-t-butylmethyleneminolithium and used to synthesise and three compounds ((^t) Bu (_2) C: N) (_3) B, (^t) Bu (_2) C: NBF (_2) and ((^t) Bu (_2) C: N) (_2) BH. Several compounds in which boron is in a heterocyclic ring system, (^t) Bu (_2) c: NB (^X) – (^Y) – (_Y) – (_X) and two alkyl (di-t-butylmethyleneminolithium) boranes, (^t) Bu (_2) C: NB (^t) Bu (_2) and ((^t) Bu (_2) C: N) (_2) BMe, have been prepared. The I.r and (^1) H n.m.r spectra of these new di-t-butylmethyleneminolithium, ((^t) Bu (_2) C: N) (_n) BX (_3-n), are consistent with there c=n=b skeletons being linear as appropriate for significant n → b dative N-bonding. The new methyleneaminomagnesium compounds are of the following formula types: [R (_2) c: nmGx], [(R (_2) C: N) (_2) Mg] (_n), R (_2) C: NMgBr. 2THF, LiMg (N: CPh (_2)) (_3) OEt (_2)) (_4). The associated species (n usually = 2) are believed to co-ordinate via bridging methyleneamino groups. The I.R spectra of compounds containing terminal methyleneamino groups are consistent with the C.N.Mg units being effectively linear. The preparation of the tris (di-t-butylmethyleneminolithium) alane, ((^t) Bu (_2) C: N) (_3) Al, from aluminium hydride and di-t-butylmethyleneminolithium has been shown to be more reliable than the reaction between aluminium trichloride and iminolithium. Similar reactions o prepare mono and bis (imino) akanes were less successful, and only once could a bis (imino) alane be isolated as a trimethylamine adduct, ((^t) Bu (_2) C: N) (_2) AlH. NNMe (_3). The I.R and (^l) H n.m.r. spectra of these two compounds indicate that their c=n=Al units are effectively linear, as appropriate for N → Al dative N- Bonding. Preliminary studies of reactions between several methylaluminium compounds and di-t-butylmethyleneminolithium or its lithio derivative have been made. The preparation and properties of di-t-butylmethyleneminolithium, (^t) Bu (_2) C: NNMe (_2), are discussed boron compounds and tetramethylguanidine or its lithio derivative are described in Appendix 2. The experimental techniques used in this research are described in Appendix 3

The prevalence of metabolic syndrome amongst patients with severe mental illness in the community in Hong Kong--a cross sectional study

Background: Patients with severe mental illness are at increased risk of developing metabolic disorders. The risk of metabolic syndrome in the Hong Kong general population is lower than that observed in western countries; however the prevalence of metabolic syndrome in patients with severe mental illness in Hong Kong is unknown. Method: This cross-sectional study aimed to estimate the prevalence of metabolic syndrome in patients with severe mental illness in Hong Kong and to identify the relationships between metabolic syndrome and socio-demographic, clinical and lifestyle factors. Results: A total of 139 patients with a diagnosis of severe mental illness participated in the study. The unadjusted prevalence of metabolic syndrome was 35%. The relative risk of metabolic syndrome in comparison with the general Hong Kong population was 2.008 (95% CI 1.59-2.53, p < 0.001). In a logistic regression model sleep disruption and being prescribed first generation antipsychotics were significantly associated with the syndrome, whilst eating less than 3 portions of fruit/vegetables per day and being married were weakly associated. Conclusion The results demonstrate that metabolic syndrome is highly prevalent and that physical health inequalities in patients with severe mental illness in Hong Kong are similar to those observed in western countries. The results provide sufficient evidence to support the need for intervention studies in this setting and reinforce the requirement to conduct regular physical health checks for all patients with severe mental illness

A Review of the Biology and Management of Rodent Pests in Southeast Asia

Farm Management,

Spatial Bi-hourly Variation of Alternaria Spore Concentration in Worcester, UK

Alternaria species are ubiquitous fungi affecting food security and human health. They are pathogenic on many economically important crops and allergenic to many sensitive people worldwide. Studies from Worcester, UK have shown high a concentration of Alternaria spores, most likely caused by agricultural activities. However, it is unknown whether Alternaria spore concentrations vary geographically throughout Worcestershire. An investigation on the spatial variation in bi-hourly concentration of Alternaria spores in Worcestershire during 2016 and 2017 was conducted. Spores were sampled using two Hirst-type Burkard spore traps at the University of Worcester. One on the rooftop of a building at St John’s Campus and another at Lakeside Campus approximately 7 km away. St John’s Campus is located in the centre of Worcester (52.1970, -2.2421), while Lakeside Campus is located in an agricultural environment (52.2537, -2.2535) with regularly cut grass in the near surroundings. Slides were counted using bi-hourly traverse at x 400 magnification. The total number of spores per slide were converted to the daily mean of spores m¯³ of air. There was a highly positive correlation in the concentration of Alternaria spores between the two sites in both 2016 and 2017. St John’s had the highest peak of spore concentration (213 m¯³) in 2016 and Lakeside had the peak concentration in 2017 (184 m¯³). Concentrations above 100 m¯³ of air were observed more frequently at Lakeside. The study revealed that Alternaria spore concentrations were higher at Lakeside than at St John’s. This could be attributed to spores released from either crops or agricultural activities (e.g. haying or harvesting) or from decomposed grass since the surrounding area is routinely managed. Further work in 2018 will include spore correlations with weather variables from a pair of weather stations located at each site, enabling studies caused by variations in weather and climate. Spatial variation in bi-hourly spore concentrations is useful information to atopic subjects, health experts and crop pathologists. Keywords: Harvesting. Allergy. Fungal Spores

Теоретичний аналіз динаміки розвитку творчої активності дошкільника

(uk) У статті проаналізовано динаміку розвитку творчої активності дошкільника. Зазначається, що процес формування особистості дошкільника досягається під час самореалізації її в творчій діяльності. Особлива увага приділена характеристиці етапів розвитку свідомості та творчій взаємодії «дитина – дорослий». Обґрунтовується необхідність створення сприятливих умов щодо творчої активності дошкільника.(ru) В статье проанализирована динамика развития творческой активности дошкольника. Отмечается, что процесс формирования личности дошкольника достигается во время самореализации ее в творческой деятельности. Особое внимание уделено характеристике этапов развития сознания и творческому взаимодействию «ребенок – взрослый». Обосновывается необходимость создания благоприятных условий относительно творческой активности дошкольника

Dislocation interactions mediated by grain boundaries

The dynamics of dislocation assemblies in deforming crystals indicate the emergence of collective phenomena, intermittent fluctuations and strain avalanches. In polycrystalline materials, the understanding of plastic deformation mechanisms depends on grasping the role of grain boundaries on dislocation motion. Here the interaction of dislocations and elastic, low angle grain boundaries is studied in the framework of a discrete dislocation representation. We allow grain boundaries to deform under the effect of dislocation stress fields and compare the effect of such a perturbation to the case of rigid grain boudaries. We are able to determine, both analytically and numerically, corrections to dislocation stress fields acting on neighboring grains, as mediated by grain boundary deformation. Finally, we discuss conclusions and consequences for the avalanche statistics, as observed in polycrystalline samples.Comment: 13 pages, 5 figure

Decomposition process in a FeAuPd alloy nanostructured by severe plastic deformation

The decomposition process mechanisms have been investigated in a Fe50Au25Pd25 (at.%) alloy processed by severe plastic deformation. Phases were characterized by X-ray diffraction and microstructures were observed using transmission electron microscopy. In the coarse grain alloy homogenized and aged at $450 ^{circ}\mathrm{C}$, the bcc \alpha-Fe and fcc AuPd phases nucleate in the fcc supersaturated solid solution and grow by a discontinuous precipitation process resulting in a typical lamellar structure. The grain size of the homogenized FeAuPd alloy was reduced in a range of 50 to 100nm by high pressure torsion. Aging at $450 ^{circ}\mathrm{C}$ this nanostructure leads to the decomposition of the solid solution into an equi-axed microstructure. The grain growth is very limited during aging and the grain size remains under 100nm. The combination of two phases with different crystallographic structures (bcc \alpha-Fe and fcc AuPd) and of the nanoscaled grain size gives rise to a significant hardening of the allo

Organic contaminant content and physico-chemical characteristics of waste materials recycled in agriculture

A range of wastes representative of materials currently applied, or with future potential to be applied, to agricultural land in the UK as fertilisers and soil improvers or used as animal bedding in livestock production, were investigated. In addition to full physico-chemical characterization, the materials were analysed for a suite of priority organic contaminants. In general, contaminants were present at relatively low concentrations. For example, polychlorinated dibenzo-p-dioxins/dibenzofurans and polychlorinated biphenyls in biosolids and compost-like-outputs (CLOs) were, in most cases, between 5-50 times lower than proposed and implemented European limit values for biosolids or composts applied to agricultural land. However, the technical basis for these limits may need to be re-evaluated. Polybrominated, and mixed halogenated, dibenzo-p-dioxins/dibenzofurans are not currently considered in risk assessments of dioxins and dioxin-like chemicals, but were detected in the biosolids and compost-like-outputs and their potential contribution to the overall toxic equivalency will be assessed. Other, ‘emerging’ contaminants such as perfluoralkyl compounds (PFCs) and organophosphate flame retardants were detected in several of the waste materials, and their potential significance is discussed. The study is part of a wider research programme that will provide evidence to improve confidence in the use of waste-derived materials in agriculture and establish guidelines to protect the food chain where necessary