922017 research outputs found
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Follow-up regimes for sick-listed employees: a comparison of nine north-western European countries
No full textThe Covid-19 pandemic has revealed the importance of social protection systems, including income security, when health problems arise. The aims of this study are to compare the follow-up regimes for sick-listed employees across nine European countries, and to conduct a qualitative assessment of the differences with respect to burden and responsibility sharing between the social protection system, employers and employees. The tendency highlighted is that countries with shorter employer periods of sick-pay typically have stricter follow-up responsibility for employers because, in practice, they become gatekeepers of the public sickness benefit scheme. In Germany and the UK, employers have few requirements for follow-up compared with the Nordic countries because they bear most of the costs of sickness absence themselves. The same applies in Iceland, where employers carry most of the costs and have no obligation to follow up sick-listed employees. The situation in the Netherlands is paradoxical: employers have strict obligations in the follow-up regime even though they cover all the costs of the sick-leave themselves. During the pandemic, the majority of countries have adjusted their sick-pay system and increased coverage to reduce the risk of spreading Covid-19 because employees are going to work sick or when they should self-quarantine, except for the Netherlands and Belgium, which considered that the current schemes were already sufficient to reduce that risk
Improving the environmental sustainability of polyketides colorants production by Talaromyces strain through better hydrodynamic design in bioreactors
No full textOne important step towards the commercialization of microbial-derived colorants is the reproducibility of the cultivation stage in bench-scale bioreactors as well as improving the hydrodynamic design in bioreactors. Aiming to address these technical barriers, Talaromyces amestolkiae was cultivated in a 4-L stirred-tank bioreactor using two types of impellers (Rushton turbine (RT) and Elephant ear (EE) impellers) and aeration modes (cascading and constant airflow), to assess their effects on red colorant production. The results showed that EE under constant airflow (4.0 Lmin-1) promoted the maximum red colorant formation (28.7 UA500nm), thus improving the reproducibility of the process. The volumetric oxygen transfer coefficient of culture broth was correlated to cell morphology, which was a result of impeller geometry of EE through the shear conditions impacting the fungi cells. The hairy pellet morphology favored nutrient and oxygen uptake and allowed an improvement in the colorant’s synthesis. Life cycle assessment was also carried out to identify opportunities for improving the best process design from an environmental sustainability perspective. For example, the total climate change and primary energy demand were estimated at 31.11 kg CO2 eq./g red colorant and 830.7 MJ/g red colorant, respectively, with the cultivation stage contributing with 65% and 63% of these impacts. The electricity consumption was identified as the main hotspot in this stage, a trend that was observed across all other impact categories. This can be improved by optimizing cultivation lengths combined with the use of low carbon electricity sources. These findings ensure a step forward towards the scaling-up at industrial scale of the T. amestolkiae cultivation for the production of bio-based colorants in an environmentally sustainable way
Some Effects of Surface Finish and LWR Environment on Environmentally-assisted Crack Initiation in Alloy 182
No full textWithin the European Commission funded project MEACTOS, environmentally-assisted crack (EAC) initiation of Alloy 182 was addressed by performing constant extension rate tensile (CERT) and constant load (CL) testing of flat, tapered tensile specimens in both boiling water reactor (BWR) normal water chemistry (NWC) and pressurized water reactor (PWR) primary water environment. Four surface finishes were investigated, namely: ground which serves as reference (RS), industrial face-milled (STI), advanced-machined (SAM) and two shot peened conditions (SP, initial and later). After testing the critical stress for initiating a crack was derived by locating the critical section (the border between areas showing and not showing surface cracking after testing) and calculating the associated local stress. In a first analysis of the CERT results, the critical stress was plotted against the nominal strain rate (cross-head displacement rate divided by the length of the tapered gauge section) and an exponential curve was fitted to it; yielding a characteristic critical stress (extrapolation to zero nominal strain rate) and a characteristic nominal strain rate (rendering the nominal strain rate dimensionless under the exponent). In a second analysis of the CERT results, an initiation model, which is strain rate and stress level dependent, was fitted to obtain a usage towards EAC initiation of 1 in the experimentally-determined critical cross section. CL testing was performed under the same and accelerated test conditions, achieved by increasing temperature and changing test environment. The overall conclusion is that (1) EAC initiation performance is better in the BWR/NWC than in the PWR environment, (2) effects of surface finish are more clearly visible in the PWR environment, (3) EAC initiation performance is better for SAM than for RS or STI which are similar and in turn better than the original SP. A “higher quality” SP surface showed an improvement in EAC initiation performance and this correlated well with the lower surface hardness measured for the latter meaning that hardness could be used as a measure for the quality of surface treatments in respect of EAC initiation
A Proof System for Cyber-physical Systems with Shared-Variable Concurrency
No full textCyber-physical system (CPS) is about the interplay of discrete behaviors and continuous behaviors. The combination of the physical and the cyber may cause hardship for the modeling and verication of CPS. Hence, a language based on shared variables was proposed to realize the interaction in CPS. In this paper, we formulate a proof system for this language. To handle the parallel composition with shared variables, we extend classical Hoare triples and bring the trace model into our proof system. The introduction of the trace may complicate ourspecication slightly, but it can realize a compositional proof when the program is executing. Meanwhile, this introduction can set up a bridge between our proof system and denotational semantics. Throughout this paper, we also present some examples to illustrate the usage of our proof system intuitively.Keywords: Cyber-physical System (CPS) · Shared Variables · Trace Model · Hoare Logic
Cancer risks by sex and variant type in PTEN Hamartoma Tumor Syndrome
No full textBACKGROUND: PTEN Hamartoma Tumor Syndrome (PHTS) is a rare syndrome with a broad phenotypic spectrum, including increased risks of breast (BC, 67-78% at age 60), endometrial (EC, 19-28%) and thyroid cancer (TC, 6-38%). Current risks are likely overestimated due to ascertainment bias. We aimed to provide more accurate and personalized cancer risks. METHODS: A European, adult PHTS cohort study with data from medical files, registries and/or questionnaires. Cancer risks and hazard ratios were assessed with Kaplan-Meier and Cox regression analyses, and standardized incidence ratios (SIR) were calculated. Bias correction consisted of excluding cancer index cases and incident case analyses. RESULTS: 455 patients were included, including 50.5% index cases, 372 with prospective follow-up (median 6 year, IQR:3-10), and 159/281 females and 39/174 males with cancer. By age 60, PHTS-related cancer risk was higher in females (68.4% to 86.3%) than males (16.4% to 20.8%). Female BC risks ranged from 54.3% (95%CI 43.0-66.4) to 75.8% (95%CI 60.7-88.4), with two-to-three-fold increased risks for PTEN truncating and about two-fold for phosphatase domain variants. EC risks ranged from 6.4% (95%CI 2.1-18.6) to 22.1% (95%CI 11.6-39.6), and TC risks from 8.9% (95%CI 5.1-15.3) to 20.5% (95%CI 11.3-35.4). Colorectal cancer, renal cancer and melanoma risks were each below 10.0%. CONCLUSION: Females have a different breast cancer risk depending on their PTEN germline variant. PHTS patients are predominantly at risk of breast (females), endometrial and thyroid cancer. This should be the main focus of surveillance. These lower, more unbiased and personalized risks provide guidance for optimized cancer risk management
Quantifying sulfidization and non-sulfidization in long-term in-situ microbial colonized As(V)-ferrihydrite coated sand columns: Insights into As mobility
No full textSulfide-induced reduction (sulfidization) of arsenic (As)-bearing Fe(III) (oxyhydro)oxides may lead to As mobilization in aquifer systems. However, little is known about the relative contributions of sulfidization and non-sulfidization of Fe(III) (oxyhydro)oxides reduction to As mobilization. To address this issue, high As groundwater with low sulfide (LS) and high sulfide (HS) concentrations were pumped through As(V)-bearing ferrihydrite-coated sand columns (LS-column and HS-column, respectively) being settled within wells in the western Hetao Basin, China. Sulfidization of As(V)-bearing ferrihydrite was evidenced by the increase in dissolved Fe(II) and the presence of solid Fe(II) and elemental sulfur (S0) in both the columns. A conceptual model was built using accumulated S0 and Fe(II) produced in the columns to calculate the proportions of sulfidization-induced Fe(III) (oxyhydro)oxide reduction and non-sulfidization-induced Fe(III) (oxyhydro)oxide reduction. Fe(III) reduction via sulfidization occurred preferentially in the inlet ends (LS-column, 31%; HS-column, 86%), while Fe(III) reduction via non-sulfidization processes predominated in the outlet ends (LS-column, 96%; HS-column, 86%), and was attributed to the metabolism of Fe(III)-reducing bacteria (including Shewanella, Ferribacterium, and Desulfuromonas). Arsenic was mobilized in the columns via sulfidization and non-sulfidization processes. More As was released from the solid of the HS-column than that of the LS-column due to the higher intensity of sulfidization in the presence of higher concentrations of dissolved S(-II). Overall, this study highlights the sulfidization of As-bearing Fe(III) (oxyhydro)oxides as an important As-mobilizing pathway in complex As-Fe-S bio-hydrogeochemical networks
‘Ways of being’ in the domestic garden for people living with dementia: doing, sensing and playing
No full textDomestic gardens represent a site for enacting embodied identity and social relationships in later life, and negotiating tensions between continuity and change. In the context of dementia, domestic gardens have significant implications for ‘living well’ at home, and for wider discussions around embodiment, relational selfhood and agency. Yet previous studies exploring dementia and gardens have predominantly focused on care home or community contexts. In light of this, the paper explores the role of domestic gardens in the everyday lives of people living with dementia and their households, using qualitative, creative methods. This includes filmed walking interviews and garden tours, diaries and sketch methods, involving repeat visits with six households in England. Findings are organised thematically in relation to different ‘ways of being’ in the garden: working in and doing the garden; being in and sensing; and playing, empowerment and agency. These different ‘ways of being’ are situated within relationships with household members, neighbours, and non-human actors including pets, wildlife and the materiality of the garden. Garden practices illustrate continuity, situated within embodied biographies and habitus. However, identities, practices and gardens are also subject to ongoing readjustment and reconstruction. The conclusion discusses implications for extending literature on gardens and later life, describing how social and material relationships in domestic gardens are renegotiated in the context of dementia, while highlighting opportunities for ‘play’, active sensing and agency. We also explore contributions to understandings of dementia, home and place, and implications for garden design and care practice
Customized Multi-Energy Pricing in Smart Grids: A Bilevel and Evolutionary Computation Approach
No full textThis paper proposes a customized energy pricing scheme for energy retailers in multi-energy (i.e., electricity and natural gas) retail markets. Microgrids with distributed energy resources (DERs) and demand response (DR) programs are considered on the demand side. We adopt a bilevel single-leader multi-follower model to analyze the customized multi-energy pricing decisions where the retailer’s profit maximization problem is formulated at the upper level, and the microgrids’ operation costs minimization problems are considered at the lower level. A particle swarm optimization (PSO) based evolutionary solution approach is developed to solve the proposed bilevel decision-making problem. Through a numerical case study, we demonstrate the feasibility and effectiveness of the proposed bilevel model and the solution algorithm. We reveal that the proposed customized pricing scheme could offer differentiated optimal pricing decisions to various microgrids characterized by their energy conversion efficiencies
Robust Formation Control for Networked Robotic Systems Using Negative Imaginary Dynamics
No full textThis paper proposes a consensus-based formation tracking scheme for multi-robot systems utilising the Negative Imaginary (NI) theory. The proposed scheme applies to a class of networked robotic systems that can be modelled as a group of single integrator agents with stable uncertainties connected via an undirected graph. NI/SNI property of networked agents facilitates the design of a distributed Strictly Negative Imaginary (SNI) controller to achieve the desired formation tracking. A new theoretical proof of asymptotic convergence of the formation tracking trajectories is derived based on the integral controllability of a networked SNI systems. The proposed scheme is an alternative to the conventional Lyapunov-based formation tracking schemes. It offers robustness to NI/SNI-type model uncertainties and fault-tolerance to a sudden loss of robots due to hardware/communication fault. The feasibility and usefulness of the proposed formation tracking scheme were validated by lab-based real-time hardware experiments involving miniature mobile robots
A Novel Borinate Ester Copolymer for Poly(Frustrated Lewis Pair) Gels
No full textThe versatile chemistry of boronic acid and boronate ester containing polymers has led to key applications in drug delivery, chemical sensing, and dynamic materials. However, their use in polymeric Frustrated Lewis pair (FLP) remains unreported. In this paper we report the synthesis of a novel fluorinated borinate ester copolymer which, when combined with a suitable Lewis basic copolymer, generates polymeric FLP network capable of responsive gelation. The borinate ester moiety, bis(pentafluorophenyl)borinic acid tetrafluorophenyl ester, was affixed to a polystyrene copolymer by a two-step post-polymerisation modification, which can be easily upscaled and purified. The Gutmann-Beckett method suggests these fluorinated borinate ester moieties are amongst the most Lewis acidic boron-containing polymers reported to date. Upon mixing with a Lewis basic copolymer poly(styrene-co-p-diphenylphosphino styrene), gelation cannot be achieved due to steric hindrance around the Lewis centres. However, network formation can be triggered by addition of small molecules such as diethylazodicarboxylate (DEAD) and cyclic ethers. The physical parameters and nature of the crosslinks of the gels prepared from different crosslinkers were probed by rheology. All networks demonstrated strong elastic behaviour, corresponding to covalently crosslinked materials. DEAD crosslinked gels displayed different behaviour to those triggered by cyclic ethers, indicating that mechanism of small molecule activation also plays an important role in the mechanical properties of poly(FLP) gels