208 research outputs found
Fluid-crystal coexistence for proteins and inorganic nanocolloids: dependence on ionic strength
We investigate theoretically the fluid-crystal coexistence of solutions of
globular charged nanoparticles like proteins and inorganic colloids. The
thermodynamic properties of the fluid phase are computed via the optimized
Baxter model. This is done specifically for lysozyme and silicotungstates for
which the bare adhesion parameters are evaluated via the experimental second
virial coefficients. The electrostatic free energy of the crystal is
approximated by supposing the cavities in the interstitial phase between the
particles are spherical in form. In the salt-free case a Poisson-Boltzmann
equation is solved to calculate the effective charge on a particle and a Donnan
approximation is used to derive the chemical potential and osmotic pressure in
the presence of salt. The coexistence data of lysozyme and silicotungstates are
analyzed within this scheme, especially with regard to the ionic-strength
dependence of the chemical potentials. The latter agree within the two phases
provided some upward adjustment of the effective charge is allowed for.Comment: 15 pages, 9 figure
The influence of learner characteristics on degree and type of participation in a CSCL environment
Computer-Supported Collaborative Learning (CSCL) is often presented as a promising learning method. However, it is also facing some new challenges. Apart from answering the question of whether or not working with CSCL generates satisfying learning outcomes, it is important to determine whether or not all participants profit from collaboration, with the computer as a means of communication. This paper describes the implementation and effects of an experimental program in 5 classes with a total of 120 students in elementary education who, in groups of four, engaged in Knowledge Forum discussion tasks on the subject of healthy eating. The study explores whether or not differences occur in the participation of students who differ in gender, sociocultural background and ability, and whether or not computer skills, computer attitudes, comprehensive reading scores and popularity with classmates are related to student participation. Students’ participation in this CSCL environment appears to be dependent on a number of learner characteristics. Girls contribute more words to the discussions than boys do and are more dependent on their computer skills in this production. Students who are good at comprehensive reading also contribute more words. Popularity among classmates appears to influence the degree of participation further. We also found indications that students with immigrant parents write fewer contributions than those whose parents are not immigrants
Polymers pushing Polymers: Polymer Mixtures in Thermodynamic Equilibrium with a Pore
We investigate polymer partitioning from polymer mixtures into nanometer size
cavities by formulating an equation of state for a binary polymer mixture
assuming that only one (smaller) of the two polymer components can penetrate
the cavity. Deriving the partitioning equilibrium equations and solving them
numerically allows us to introduce the concept of "polymers-pushing-polymers"
for the action of non-penetrating polymers on the partitioning of the
penetrating polymers. Polymer partitioning into a pore even within a very
simple model of a binary polymer mixture is shown to depend in a complicated
way on the composition of the polymer mixture and/or the pore-penetration
penalty. This can lead to enhanced as well as diminished partitioning, due to
two separate energy scales that we analyse in detail.Comment: 10 pages, 6 figure
Making Bipedal Robot Experiments Reproducible and Comparable: The Eurobench Software Approach
This study describes the software methodology designed for systematic benchmarking of bipedal systems through the computation of performance indicators from data collected during an experimentation stage. Under the umbrella of the European project Eurobench, we collected approximately 30 protocols with related testbeds and scoring algorithms, aiming at characterizing the performances of humanoids, exoskeletons, and/or prosthesis under different conditions. The main challenge addressed in this study concerns the standardization of the scoring process to permit a systematic benchmark of the experiments. The complexity of this process is mainly due to the lack of consistency in how to store and organize experimental data, how to define the input and output of benchmarking algorithms, and how to implement these algorithms. We propose a simple but efficient methodology for preparing scoring algorithms, to ensure reproducibility and replicability of results. This methodology mainly constrains the interface of the software and enables the engineer to develop his/her metric in his/her favorite language. Continuous integration and deployment tools are then used to verify the replicability of the software and to generate an executable instance independent of the language through dockerization. This article presents this methodology and points at all the metrics and documentation repositories designed with this policy in Eurobench. Applying this approach to other protocols and metrics would ease the reproduction, replication, and comparison of experiments.This study is supported by the European Union’s Horizon 2020 research and innovation program under Grant Agreement no 779963, project Eurobench
Outcome measurement instruments for peripheral vascular malformations and an assessment of the measurement properties: a systematic review
© 2019, The Author(s). Purpose: The Outcome measures for vascular malformation (OVAMA) group reached consensus on the core outcome domains for the core outcome set (COS) for peripheral vascular malformations (venous, lymphatic and arteriovenous malformations). However, it is unclear which instruments should be used to measure these domains. Therefore, our aims were to identify all outcome measurement instruments available for vascular malformations, and to evaluate their measurement properties. Methods: With the first literature search, we identified outcomes and instruments previously used in prospective studies on vascular malformations. A second search yielded studies on measurement properties of patient- and physician-reported instruments that were either developed for vascular malformations, or used in prospective studies. If the latter instruments were not specifically validated for vascular malformations, we performed a third search for studies on measurement properties in clinically similar diseases (vascular or lymphatic diseases and benign tumors). We assessed the methodological quality of these studies following the Consensus-based Standards for the selection of health Measurement Instruments methodology, and evaluated the quality of the measurement properties. Results: The first search yielded 27 studies, none using disease-specific instruments. The second and third search included 22 development and/or validation studies, concerning six instruments. Only the Lymphatic Malformation Function Instrument was developed specifically for vascular malformations. Other instruments were generic QoL instruments developed and/or partly validated for clinically similar diseases. Conclusions: Additional research on measurement properties is needed to assess which instruments may be included in the COS. This review informs the instrument selection and/or the development of new instruments. Systematic review registration: PROSPERO, 42017056242
Towards a roadmap for COSEB: the next steps in harmonization of outcomes for epidermolysis bullosa
The COSEB initiative aims for standardized and uniform measurement by developing core outcome sets for epidermolysis bullosa. This report describes the COSEB workshop organized in December 2023, which led to a broad stakeholder consensus-based roadmap. Moreover, it highlights novel features of COSEB, including the pro-active engagement of stakeholders from the very beginning and the appointment of a multi-stakeholder advisory panel
Compulsory admissions of patients with mental disorders : State of the art on ethical and legislative aspects in 40 European countries
Background. Compulsory admission procedures of patients with mental disorders vary between countries in Europe. The Ethics Committee of the European Psychiatric Association (EPA) launched a survey on involuntary admission procedures of patients with mental disorders in 40 countries to gather information from all National Psychiatric Associations that are members of the EPA to develop recommendations for improving involuntary admission processes and promote voluntary care. Methods. The survey focused on legislation of involuntary admissions and key actors involved in the admission procedure as well as most common reasons for involuntary admissions. Results. We analyzed the survey categorical data in themes, which highlight that both medical and legal actors are involved in involuntary admission procedures. Conclusions. We conclude that legal reasons for compulsory admission should be reworded in order to remove stigmatization of the patient, that raising awareness about involuntary admission procedures and patient rights with both patients and family advocacy groups is paramount, that communication about procedures should be widely available in lay-language for the general population, and that training sessions and guidance should be available for legal and medical practitioners. Finally, people working in the field need to be constantly aware about the ethical challenges surrounding compulsory admissions.Peer reviewe
Zoetwatervoorziening in Nederland : landelijke analyse knelpunten in de 21e eeuw
Deze knelpuntenanalyse is een eerste stap in een verkenning van de zoetwaterproblematiek. Doel van de landelijke knelpuntenanalyse is om vast te stellen waar de toekomstige watervraag groter is dan de waterbeschikbaarheid, hetzij qua hoeveelheid, hetzij qua kwaliteit. Daartoe is de watervraag van diverse gebruikers in beeld gebracht, evenals de waterbeschikbaarheid, nu en in de toekomst. Voor het verkennen van de toekomst is gebruik gemaakt van deltascenario's
Report from the fourth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)
This article is a report of the fourth meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in Malmö, Sweden on 23–24 April 2015 (HOME IV). The aim of the meeting was to achieve consensus over the preferred outcome instruments for measuring patient-reported symptoms and quality of life for the HOME core outcome set for atopic eczema (AE). Following presentations, which included data from systematic reviews, consensus discussions were held in a mixture of whole group and small group discussions. Small groups were allocated a priori to ensure representation of different stakeholders and countries. Decisions were voted on using electronic keypads. For the patient-reported symptoms, the group agreed by vote that itch, sleep loss, dryness, redness/inflamed skin and irritated skin were all considered essential aspects of AE symptoms. Many instruments for capturing patient-reported symptoms were discussed [including the Patient-Oriented SCOring Atopic Dermatitis index, Patient-Oriented Eczema Measure (POEM), Self-Administered Eczema Area and Severity Index, Itch Severity Scale, Atopic Dermatitis Quickscore and the Nottingham Eczema Severity Score] and, by consensus, POEM was selected as the preferred instrument to measure patient-reported symptoms. Further work is needed to determine the reliability and measurement error of POEM. Further work is also required to establish the importance of pain/soreness and the importance of collecting information regarding the intensity of symptoms in addition to their frequency. Much of the discussion on quality of life concerned the Dermatology Life Quality Index and Quality of Life Index for Atopic Dermatitis; however, consensus on a preferred instrument for measuring this domain could not be reached. In summary, POEM is recommended as the HOME core outcome instrument for measuring AE symptoms
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