193 research outputs found
Attitudes towards people with intellectual disabilities: A cross cultural study.
Part 1, the literature review, considers the historical context of conceptualisations of ID and service provision for people with intellectual disabilities in the UK. Current policies are outlined and research on public attitudes towards people with intellectual disabilities is considered, to help us understand the broader climate within which policies are implemented. Furthermore, this review critiques the quantitative approaches currently dominant within attitudinal research. It concludes that the impact of demographics particularly culture and religion, on attitudes to ID remain under researched areas. Part 2, the empirical paper, reports on a study which explores attitudes towards people with intellectual disability among young people (ages 16-19) from white British and South Asian backgrounds (Total N=6 and how they arrive at their beliefs. Five themes regarding attitudes were identified: confusion versus more sophisticated understandings of ID invisibility of people with ID versus representations in the media universal humanity positioning self as accepting and empowering and views on care giving, with marked differences occurring between cultural groups. The main influences on attitudes towards people with ID acknowledged by participants were culture, religion, parents, education and previous contact with people with ID. Of note, there were more similarities than differences between groups in terms of what they viewed as influencing their attitudes. Both individual interviews and focus groups were useful in generating data. Part 3, the critical appraisal, discusses the strengths, weaknesses and limitations of the present study, with references to changes in understandings of phenomena, sampling, being a white researcher and critically evaluating qualitative research. Finally, this part concludes with a discussion of areas for future research and possible clinical implications derived from the study
Oxidopolyborate chemistry: The self-assembled, templated, synthesis, and an XRD study of a 1-D coordination polymer, [Cu(en){B6O7(OH)(6)}](.)3H(2)O (en=1,2-diaminoethane)
[Cu(en){B6O7(OH)6}].3H2O (1) (en = 1,2-diaminoethane), obtained as a crystalline solid in low yield (31%) after prolonged standing of an aqueous solution initially containing [Cu(en)2](OH)2 and B(OH)3 (1:7 ratio), was characterized by thermal analysis (TGA/DSC), 11B NMR and IR spectroscopy, powder XRD, and single-crystal XRD studies, and magnetic susceptibility measurements. The single-crystal X-ray diffraction revealed that the oxidoborate complex is a 1D coordination polymer with the hexaborate(2-) ligand bridging two hexacoordinate Cu(II) centers, in an alternating a fac-tridentate (Îș3-O) and monodentate (Îș1-O) arrangement. Cu-O coordination bonds and extensive H-bonding networks promote and stabilize the self-assembly of [Cu(en){B6O7(OH)6}].3H2O from the Dynamic Combinatorial Libraries of available reactants. [Cu(en){B6O7(OH)6}].3H2O is thermally decomposed to CuB6O10 in air at 700 °C.</p
Copper(2+) Complexes of Hydroxyoxidoborates. Synthesis and Characterization of Two Clusters Containing the Hexaborate(2-) Ligand: [Cu(NH2CH2CH2NEt2){B6O7(OH)(6)}]center dot 5H(2)O and [Cu(NH3)(2){B6O7(OH)(6)}]center dot 2H(2)O
[Cu(NH
2
CH
2
CH
2
NEt
2
){B
6
O
7
(OH)
6
}]·5H
2
O (1) and [Cu(NH
3
)
2
{B
6
O
7
(OH)
6
}]·2H
2
O (2) have been obtained as crystalline materials from aqueous solutions of Dynamic Combinatorial Libraries (DCLs) originating from B(OH)
3
and appropriate Cu(II) amine complexes. These two Cu/O/B clusters are formed through self-assembly processes and contain tridentate hexaborate(2â)-Îș
3
O ligands. Both compounds have been characterized by TGA/DSC, magnetic susceptibility measurements, IR spectroscopy, and single-crystal XRD studies. The intermolecular H-bond interactions between neighbouring hexaborate units are implicated in their templated synthesis. Compound 2 is a coordination polymer and stabilization is also gained through formation of an additional OâCu coordinate bond. Steric congestion in 1 blocks formation of this bond resulting in insular complexes.
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Synthesis, crystal structure and applications of palladium thiosalicylate complexes
AbstractThree palladium thiosalicylate complexes [Pd(tb)(bipy)]·3H2O (1), [Pd2(tb)2(bipy)2]·(dtdb)2 (2) and [Pd2(tb)2(phen)2]·dtdb·H2O (3) (bipy=bipyridine; phen=phenanthroline) were prepared from the reaction of PdCl2(CH3CN)2 with dithiosalicylic acid (dtdb) which underwent cleavage to form thiobenzoate anion (tb) in DMF/MeOH. Square planar geometries of the complexes with a N2SO coordination type were proposed on the basis of single crystal X-ray structural study. The presence of trapped and uncoordinated dtdb was observed in complexes 2 and 3. Complexes 1â3 were evaluated as catalysts for Heck coupling reactions of methyl acrylate with iodobenzene, and showed moderate activities at a very low catalyst loading. Complex 1 was found to inhibit the growth of bacteria and scavenge free radicals efficiently
Vegetative fragment production as a means of propagule dispersal for tropical seagrass meadows
Background and aims: Long distance dispersal (LDD) contributes to the replenishment and recovery of tropical seagrass habitats exposed to disturbance, such as cyclones and infrastructure development. However, our current knowledge regarding the physical attributes of seagrass fragments that influence LDD predominantly stems from temperate species and regions. The goal of this paper is to measure seagrass fragment density and viability in two tropical species, assessing various factors influencing their distribution.
Methods: We measured the density and viability of floating seagrass fragments for two tropical seagrass species (Zostera muelleri and Halodule uninervis) in two coastal seagrass meadows in the central Great Barrier Reef World Heritage Area, Australia. We assessed the effect of wind speed, wind direction, seagrass growing/senescent season, seagrass meadow density, meadow location and dugong foraging intensity on fragment density. We also measured seagrass fragment structure and fragment viability; i.e., potential to establish into a new plant.
Key results: We found that seagrass meadow density, season, wind direction and wind speed influenced total fragment density, while season and wind speed influenced the density of viable fragments. Dugong foraging intensity did not influence fragment density. Our results indicate that wave action from winds combined with high seagrass meadow density increases seagrass fragment creation, and that more fragments are produced during the growing than the senescent season. Seagrass fragments classified as viable for Z. muelleri and H. uninervis had significantly more shoots and leaves than non-viable fragments. We collected 0.63 (±0.08 SE) floating viable fragments 100 mâ2 in the growing season, and 0.13 (±0.03 SE) viable fragments 100 mâ2 in the senescent season. Over a third (38%) of all fragments collected were viable.
Conclusion: There is likely to be a large number of viable seagrass fragments available for long distance dispersal. This study's outputs can inform dispersal and connectivity models that are used to direct seagrass ecosystem management and conservation strategies
Classification of irreps and invariants of the N-extended Supersymmetric Quantum Mechanics
We present an algorithmic classification of the irreps of the -extended
one-dimensional supersymmetry algebra linearly realized on a finite number of
fields. Our work is based on the 1-to-1 \cite{pt} correspondence between
Weyl-type Clifford algebras (whose irreps are fully classified) and classes of
irreps of the -extended 1D supersymmetry. The complete classification of
irreps is presented up to . The fields of an irrep are accommodated
in different spin states. N=10 is the minimal value admitting length
irreps. The classification of length-4 irreps of the N=12 and {\em real} N=11
extended supersymmetries is also explicitly presented.\par Tensoring irreps
allows us to systematically construct manifestly (-extended) supersymmetric
multi-linear invariants {\em without} introducing a superspace formalism.
Multi-linear invariants can be constructed both for {\em unconstrained} and
{\em multi-linearly constrained} fields. A whole class of off-shell invariant
actions are produced in association with each irreducible representation. The
explicit example of the N=8 off-shell action of the multiplet is
presented.\par Tensoring zero-energy irreps leads us to the notion of the {\em
fusion algebra} of the 1D -extended supersymmetric vacua.Comment: Final version to appear in JHEP. 52 pages. The part with the complete
classification of irreps (and the explicit presentation of length-4 irreps of
N=9,10,11,12 and N=10 length-5 irreps) is unchanged. An extra section has
been added with an entire class of off-shell invariant actions for arbitrary
values N of the 1D extended supersymmetry. A non-trivial N=8 off-shell action
for the (1,8,7) multiplet has been constructed as an example. It is obtained
in terms of the octonionic structure constant
A study of dye anchoring points in half-squarylium dyes for dye-sensitized solar cells
This paper reports the synthesis of a series of new half-squaraine dyes (Hf-SQ) based around a common chromophoric unit consisting of linked indoline and squaric acid moieties. Carboxylate groups have been incorporated onto this core structure at four different points to study the influence of the anchoring group position on dye-sensitized solar cell (DSC) device performance. Dyes have been linked to TiO2 directly through the squaric acid moiety, through a modified squaric acid unit where a vinyl dicyano group has replaced one carbonyl, via an alkyl carboxylate attached to the indole N or through a carboxylate attached to the 4 position of a benzyl indole. Contact angle measurements have been studied to investigate the hydrophobic/hydrophilic properties of the dyes and the results have been compared to N719 and Z907. Full characterization data of all the dyes and synthetic intermediates are reported including single-crystal X-ray structural analysis for dye precursors; the indole (2a) and the half-squarylium esters (3a) and (6b), as well as the dyes (4c), (8) and (12). Dye colours range from yellow to red/brown in solution (λmax range from 430 to 476 nm) with Δ ranging from 38â000 to 133â100 Mâ1 cmâ1. The performance of the dyes in DSCs shows the highest efficiency yet reported for a Hf-SQ dye (η = 5.0%) for 1 cm2 devices with a spectral response ranging from 400 to 700 nm depending on the dye substituents. Co-sensitization of half-squarylium dye (7b) with squaraine dye (SQ2) resulted in a broader spectral response and an improved device efficiency (η = 6.1%). Density functional theory (DFT) calculations and cyclic voltammetry have been used to study the influence of linker position on dye HOMOâLUMO levels and the data has been correlated with IâV and EQE data
Exploiting the Hierarchical Structure of Rule-Based Specifications for Decision Planning
Rule-based specifications have been very successful as a declarative approach in many domains, due to the handy yet solid foundations offered by rule-based machineries like term and graph rewriting. Realistic problems, however, call for suitable techniques to guarantee scalability. For instance, many domains exhibit a hierarchical structure that can be exploited conveniently. This is particularly evident for composition associations of models. We propose an explicit representation of such structured models and a methodology that exploits it for the description and analysis of model- and rule-based systems. The approach is presented in the framework of rewriting logic and its efficient implementation in the rewrite engine Maude and is illustrated with a case study.
Are the Crystal Structures of Enantiopure and Racemic Mandelic Acids Determined by Kinetics or Thermodynamics?
YesMandelic acids are prototypic chiral molecules where the sensitivity of crystallized forms (enantiopure/racemic compound/polymorphs) to both conditions and substituents provides a new insight into the factors that may allow chiral separation by crystallization. The determination of a significant number of single crystal structures allows the analysis of 13 enantiopure and 30 racemic crystal structures of 21 (F/Cl/Br/CH3/CH3O) substituted mandelic acid derivatives. There are some common phenyl packing motifs between some groups of racemic and enantiopure structures, although they show very different hydrogen-bonding motifs. The computed crystal energy landscape of 3-chloromandelic acid, which has at least two enantiopure and three racemic crystal polymorphs, reveals that there are many more possible structures, some of which are predicted to be thermodynamically more favorable as well as slightly denser than the known forms. Simulations of mandelic acid dimers in isolation, water, and toluene do not differentiate between racemic and enantiopure dimers and also suggest that the phenyl ring interactions play a major role in the crystallization mechanism. The observed crystallization behavior of mandelic acids does not correspond to any simple âcrystal engineering rulesâ as there is a range of thermodynamically feasible structures with no distinction between the enantiopure and racemic forms. Nucleation and crystallization appear to be determined by the kinetics of crystal growth with a statistical bias, but the diversity of the mandelic acid crystallization behavior demonstrates that the factors that influence the kinetics of crystal nucleation and growth are not yet adequately understood.EPSRC, Max Planck Society for the Advancement of Sciences, UCL-MPS Impact Ph.D. Fellowship, EU COST Actio
The uses of coherent structure (Dryden Lecture)
The concept of coherent structure in turbulent flow is a revolutionary idea which is being developed by evolutionary means. The main objective of this review is to list some solid achievements, showing what can be done by using the concept of coherent structure that cannot be done without it. The nature of structure is described in terms of some related concepts, including celerity,
topology, and the phenomenon of coalescence and splitting of structure. The main emphasis is on the mixing layer, as the one flow whose structure is well enough understood so that technical applications are now being made in problems of mixing and chemistry. An attempt is made to identify some conceptual and experimental obstacles that stand in the way of progress in other technically important flows, particularly the turbulent boundary layer. A few comments are included about the role of structure in numerical simulations and in current work on manipulation and control of turbulent flow. Some recent developments are cited which suggest that the time is nearly right for corresponding advances to occur in turbulence modeling
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