36 research outputs found

    Supersymmetric Boundary Conditions for the N=2 Sigma Model

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    We clarify the discussion of N=2 supersymmetric boundary conditions for the classical d=2, N=(2,2) Non-Linear Sigma Model on an infinite strip. Our conclusions about the supersymmetric cycles match the results found in the literature. However, we find a constraint on the boundary action that is not satisfied by many boundary actions used in the literature.Comment: 23 pages, no figures. minor changes in text, a reference adde

    Simultaneous in situ characterisation of bubble dynamics and a spatially resolved concentration profile : A combined Mach-Zehnder holography and confocal Raman-spectroscopy sensor system

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    For a reaction between a gaseous phase and a liquid phase, the interaction between the hydrodynamic conditions, mass transport and reaction kinetics plays a crucial role with respect to the conversion and selectivity of the process. Within this work, a sensor system was developed to simultaneously characterise the bubble dynamics and the localised concentration measurement around the bubbles. The sensor system is a combination of a digital Mach-Zehnder holography subsystem to measure bubble dynamics and a confocal Raman-spectroscopy subsystem to measure localised concentration. The combined system was used to investigate the chemical absorption of CO₂ bubbles in caustic soda in microchannels. The proposed set-up is explained and characterised in detail and the experimental results are presented, illustrating the capability of the sensor system to simultaneously measure the localised concentration of the carbonate ion with a good limit of detection and the 3-D position of the bubble with respect to the spot where the concentration was measured

    Oral Health-Related Quality of Life, Oral Conditions, and Risk of Malnutrition in Older German People in Need of Care—A Cross-Sectional Study

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    Background: The present cross-sectional study assessed oral health, nutritional condition, and oral health-related quality of life (OHRQoL) in older German people in need of care. Methods: The participants were recruited from eight nursing homes (including three nursing homes with assisted living) and one mobile nursing service. Oral health, including dental status (decayed, missing and filled teeth (DMF-T), root caries), periodontal treatment needs, and prosthetic conditions, was recorded. Nutritional status was assessed using the screening of the “Mini Nutritional Assessment” (MNA). The OHRQoL was measured using the German short-form of the Oral Health Impact Profile (OHIP-G14) and summarized as a total sum score as well as the four dimensions “oral function”, “psychosocial impact”, “pain” and “orofacial appearance”. Statistics: Linear logistic regression analyses. Results: A total of 151 participants (age: 84.17 ± 7.8 years) were included. Most participants (60.3%) were nursing home residents. Nearly half of the individuals (47%) were edentulous and 75.4% of the dentate subjects required periodontal treatment. A total of 115 of the subjects had at least one denture. According to the MNA screening, 107 (70.9%) older people were at risk of malnutrition or already suffered from malnutrition. The median OHIP-G14 sum score was 3 (mean 5.7 ± 7.67). Regression analysis revealed MNA to be influenced by DMF-T, D-T, M-T and OHIP G14 sum score and root caries (pi < 0.01). Within the regression model, missing teeth (ÎČ: −11.9, CI95: −6.4–−1.9; p < 0.01) were the strongest influential factor on MNA, followed by DMF-T (ÎČ: 5.1, CI95: 1.7–6.2; p < 0.01). Conclusions: Older people in nursing settings show a high prevalence of oral diseases, risk of malnutrition and nearly unimpaired OHRQoL. Dental care should be fostered in these individuals, whereby OHRQoL might be a further hint for increased risk of malnutrition

    MicroRNAs as salivary markers for periodontal diseases

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    The aim of this review is to discuss current findings regarding the roles of miRNAs in periodontal diseases and the potential use of saliva as a diagnostic medium for corresponding miRNA investigations. For periodontal disease, investigations have been restricted to tissue samples and five miRNAs, that is, miR-142-3p, miR-146a, miR-155, miR-203, and miR-223, were repeatedly validated in vivo and in vitro by different validation methods. Particularly noticeable are the small sample sizes, different internal controls, and different case definitions of periodontitis in in vivo studies. Beside of that, the validated miRNAs are associated with inflammation and therefore with various diseases. Furthermore, several studies successfully explored the use of salivary miRNA species for the diagnosis of oral cancer. Different cancer types were investigated and heterogeneous methodology was used; moreover, no overlap of resultswas found. In conclusion, fivemiRNAs have consistently been reported for periodontitis; however, their disease specificity, detectability, and expression in saliva and their importance as noninvasive markers are questionable. In principle, a salivary miRNA diagnostic method seems feasible.However, standardized criteria and protocols for preanalytics, measurements, and analysis should be established to obtain comparable results across different studies

    An Agenda for Open Science in Communication

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    In the last 10 years, many canonical findings in the social sciences appear unreliable. This so-called “replication crisis” has spurred calls for open science practices, which aim to increase the reproducibility, replicability, and generalizability of findings. Communication research is subject to many of the same challenges that have caused low replicability in other fields. As a result, we propose an agenda for adopting open science practices in Communication, which includes the following seven suggestions: (1) publish materials, data, and code; (2) preregister studies and submit registered reports; (3) conduct replications; (4) collaborate; (5) foster open science skills; (6) implement Transparency and Openness Promotion Guidelines; and (7) incentivize open science practices. Although in our agenda we focus mostly on quantitative research, we also reflect on open science practices relevant to qualitative research. We conclude by discussing potential objections and concerns associated with open science practices

    Exploring, exploiting and evolving diversity of aquatic ecosystem models: A community perspective

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    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5–10 years. To strive for clarity and to improve readability for non-modellers, we include a glossary
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