599 research outputs found
2-(1,4-Dioxo-1,4-dihydro-2-naphthyl)-2-methylpropanoic acid
The sterically crowded title compound, CââHââOâ, crystallizes as centrosymmetric hydrogen-bonded dimers involving the carboxyl groups. The naphthoquinone ring system is folded by 11.5 (1)° about a vector joining the 1,4-C atoms, and the quinone O atoms are displaced from the ring plane, presumably because of steric interactions with the bulky substituent
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Waste-derived inosilicate carrier for antimicrobial Zn2+ and Ag+ ions
Recent research by the authors has demonstrated that the inosilicate, lithium metasilicate (Li2SiO3), can be prepared by hydrothermal synthesis from waste green container glass (GCG) [1,2]. This study investigated the potential of this material to be ion-exchanged with antimicrobial Zn2+ or Ag+ ions for use as a filler in polymer composites. Antimicrobial polymer composites are an advantage in applications where the communication of pathogenic bacteria poses a problem, such as hospitals, abattoirs and food-processing factories. The naturally-occurring biodegradable mucopolysaccharide derivative, chitosan, was used as a model polymer in this study. The lithium metasilicate product was synthesised from GCG in LiOH(aq) and ion-exchanged with either Zn2+ or Ag+ ions via batch sorption. The in vitro antibacterial properties of solvent-cast metasilicate-chitosan composite membranes were then evaluated by zone of inhibition against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus
Quantum decision making by social agents
The influence of additional information on the decision making of agents, who
are interacting members of a society, is analyzed within the mathematical
framework based on the use of quantum probabilities. The introduction of social
interactions, which influence the decisions of individual agents, leads to a
generalization of the quantum decision theory developed earlier by the authors
for separate individuals. The generalized approach is free of the standard
paradoxes of classical decision theory. This approach also explains the
error-attenuation effects observed for the paradoxes occurring when decision
makers, who are members of a society, consult with each other, increasing in
this way the available mutual information. A precise correspondence between
quantum decision theory and classical utility theory is formulated via the
introduction of an intermediate probabilistic version of utility theory of a
novel form, which obeys the requirement that zero-utility prospects should have
zero probability weights.Comment: This paper has been withdrawn by the authors because a much extended
and improved version has been submitted as arXiv:1510.02686 under the new
title "Role of information in decision making of social agents
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Nitrogen processes in aquatic ecosystems
Executive summary
Nature of the problem (science/management/policy)
⢠Freshwater ecosystems play a key role in the European nitrogen (N) cycle, both as a reactive agent that transfers, stores and processes N loadings from the atmosphere and terrestrial ecosystems, and as a natural environment severely impacted by the increase of these loadings.
Approaches
⢠This chapter is a review of major processes and factors controlling N transport and transformations for running waters, standing waters, groundwaters and riparian wetlands.
Key findings/state of knowledge
⢠The major factor controlling N processes in freshwater ecosystems is the residence time of water, which varies widely both in space and in time, and which is sensitive to changes in climate, land use and management.
⢠The effects of increased N loadings to European freshwaters include acidification in semi-natural environments, and eutrophication in more disturbed ecosystems, with associated loss of biodiversity in both cases.
⢠An important part of the nitrogen transferred by surface waters is in the form of organic N, as dissolved organic N (DON) and particulate organic N (PON). This part is dominant in semi-natural catchments throughout Europe and remains a significant component of the total N load even in nitrate enriched rivers.
⢠In eutrophicated standing freshwaters N can be a factor limiting or co-limiting biological production, and control of both N and phosphorus (P) loading is oft en needed in impacted areas, if ecological quality is to be restored.
Major uncertainties/challenges
⢠The importance of storage and denitrifi cation in aquifers is a major uncertainty in the global N cycle, and controls in part the response of catchments to land use or management changes. In some aquifers, the increase of N concentrations will continue for decades even if efficient mitigation measures are implemented now.
⢠Nitrate retention by riparian wetlands has oft en been highlighted. However, their use for mitigation must be treated with caution, since their effectiveness is difficult to predict, and side effects include increased DON emissions to adjacent open waters, N2O emissions to the atmosphere, and loss of biodiversity.
⢠In fact, the character and specific spatial origins of DON are not fully understood, and similarly the quantitative importance of indirect N2O emissions from freshwater ecosystems as a result of N leaching losses from agricultural soils is still poorly known at the regional scale.
⢠These major uncertainties remain due to the lack of adequate monitoring (all forms of N at a relevant frequency), especially â but not only â in the southern and eastern EU countries.
Recommendations (research/policy)
⢠The great variability of transfer pathways, buffering capacity and sensitivity of the catchments and of the freshwater ecosystems calls for site specific mitigation measures rather than standard ones applied at regional to national scale.
⢠The spatial and temporal variations of the N forms, the processes controlling the transport and transformation of N within freshwaters, require further investigation if the role of N in influencing freshwater ecosystem health is to be better understood, underpinning the implementation of the EU Water Framework Directive for European freshwaters
40 days and 40 nights: Clinical characteristics of major trauma and orthopaedic injury comparing the incubation and lockdown phases of COVID-19 infection
Aims
The first death in the UK caused by COVID-19 occurred on 5 March 2020. We aim to describe the clinical characteristics and outcomes of major trauma and orthopaedic patients admitted in the early COVID-19 era.
Methods
A prospective trauma registry was reviewed at a Level 1 Major Trauma Centre. We divided patients into Group A, 40 days prior to 5 March 2020, and into Group B, 40 days after.
Results
A total of 657 consecutive trauma and orthopaedic patients were identified with a mean age of 55 years (8 to 98; standard deviation (SD) 22.52) and 393 (59.8%) were males. In all, 344 (approximately 50%) of admissions were major trauma. Group A had 421 patients, decreasing to 236 patients in Group B (36%). Mechanism of injury (MOI) was commonly a fall in 351 (52.4%) patients, but road traffic accidents (RTAs) increased from 56 (13.3%) in group A to 51 (21.6%) in group B (p = 0.030). ICU admissions decreased from 26 (6.2%) in group A to 5 (2.1%) in group B. Overall, 39 patients tested positive for COVID-19 with mean age of 73 years (28 to 98; SD 17.99) and 22 (56.4%) males. Common symptoms were dyspnoea, dry cough, and pyrexia. Of these patients, 27 (69.2%) were nosocomial infections and two (5.1%) of these patients required intensive care unit (ICU) admission with 8/39 mortality (20.5%). Of the patients who died, 50% were older and had underlying comorbidities (hypertension and cardiovascular disease, dementia, arthritis).
Conclusion
Trauma admissions decreased in the lockdown phase with an increased incidence of RTAs. Nosocomial infection was common in 27 (69.2%) of those with COVID-19. Symptoms and comorbidities were consistent with previous reports with noted inclusion of dementia and arthritis. The mortality rate of trauma and COVID-19 was 20.5%, mainly in octogenarians, and COVID-19 surgical mortality was 15.4%
What Is a Decision Problem? Designing Alternatives
International audienceThis paper presents a general framework for the design of alternatives in decision problems. The paper addresses both the issue of how to design alternatives within "known decision spaces" and on how to perform the same action within "partially known or unknown decision spaces". The paper aims at providing archetypes for the design of algorithms supporting the generation of alternatives
Degree and Higher Level Apprenticeships: An Empirical Investigation of Stakeholder Perceptions of Challenges and Opportunities
The aim of this paper is to explore the challenges and opportunities of designing and delivering Degree and Higher Level Apprenticeships (D&HLAs) at levels 4 - 7 from a multi-stakeholder perspective namely employers, Universities, independent training organisations and professional bodies. 27 face to face interviews were undertaken and thematic content analysis was used to analyse the data. The following three themes emerged from the data analysis: programme design; programme delivery; and graduate attributes. We conclude that whilst there are increasing numbers of trailblazer groups developing higher level standards, the uptake of apprenticeships at these levels remains relatively low. Although stakeholders support the principle of D&HLAs, we identify a number of challenges and opportunities facing those who seek to successful introduction these programmes. Our policy recommendations include the need for all stakeholders to work collaboratively to co-create a flexible system to support the validity and relevance of D&HLAs. This will include streamlining and mapping the variety of qualifications currently available in order to promote a platform for parity of both esteem and opportunity for those achieving degree qualifications through the apprenticeship route
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