1,359 research outputs found
Kohn-Sham potential with discontinuity for band gap materials
We model a Kohn-Sham potential with a discontinuity at integer particle
numbers derived from the GLLB approximation of Gritsenko et al. We evaluate the
Kohn-Sham gap and the discontinuity to obtain the quasiparticle gap. This
allows us to compare the Kohn-Sham gaps to those obtained by accurate many-body
perturbation theory based optimized potential methods. In addition, the
resulting quasiparticle band gap is compared to experimental gaps. In the GLLB
model potential, the exchange-correlation hole is modeled using a GGA energy
density and the response of the hole to density variations is evaluated by
using the common-denominator approximation and homogeneous electron gas based
assumptions. In our modification, we have chosen the PBEsol potential as the
GGA to model the exchange hole, and add a consistent correlation potential. The
method is implemented in the GPAW code, which allows efficient parallelization
to study large systems. A fair agreement for Kohn-Sham and the quasiparticle
band gaps with semiconductors and other band gap materials is obtained with a
potential which is as fast as GGA to calculate.Comment: submitted to Physical Review
Few-body reference data for multicomponent formalisms: Light nuclei molecules
We present full quantum statistical energetics of some electron-light nuclei
systems. This is accomplished with the path integral Monte Carlo method. The
effects on energetics arising from the change in the nuclear mass are studied.
The obtained results may serve as reference data for the multicomponent density
functional theory calculations of light nuclei system. In addition, the results
reported here will enable better fitting of todays electron-nuclear energy
functionals, for which the description of light nuclei is most challenging, in
particular
Composition, phosphorylation and dynamic organization of photosynthetic protein complexes in plant thylakoid membrane
The photosystems (PS), catalyzing the photosynthetic reactions of higher plants, are unevenly distributed in the thylakoid membrane: PSII, together with its light harvesting complex (LHC)II, is enriched in the appressed grana stacks, while PSI-LHCI resides in the non-appressed stroma thylakoids, which wind around the grana stacks. The two photosystems interact in a third membrane domain, the grana margins, which connect the grana and stroma thylakoids and allow the loosely bound LHCII to serve as an additional antenna for PSI. The light harvesting is balanced by reversible phosphorylation of LHCII proteins. Nevertheless, light energy also damages PSII and the repair process is regulated by reversible phosphorylation of PSII core proteins. Here, we discuss the detailed composition and organization of PSII-LHCII and PSI-LHCI (super)complexes in the thylakoid membrane of angiosperm chloroplasts and address the role of thylakoid protein phosphorylation in dynamics of the entire protein complex network of the photosynthetic membrane. Finally, we scrutinize the phosphorylation-dependent dynamics of the protein complexes in context of thylakoid ultrastructure and present a model on the reorganization of the entire thylakoid network in response to changes in thylakoid protein phosphorylation
Lack of hybridization between Yersinia enterocolitica and HLA-B27 DNA
Inhaltverz. nicht vollständig
Parental Experiences of the Pediatric Day Surgery Pathway and the Needs for a Digital Gaming Solution : Qualitative Study
Background: The parents of hospitalized children are often dissatisfied with waiting times, fasting, discharge criteria, postoperative pain relief, and postoperative guidance. Parents' experiences help care providers to provide effective, family-centered care that responds to parents' needs throughout the day surgery pathway. Objective: The objective of our study was to describe parental experiences of the pediatric day surgery pathway and the needs for a digital gaming solution in order to facilitate the digitalization of these pathways. Methods: This was a descriptive qualitative study. The participants (N=31) were parents whose children were admitted to the hospital for the day surgical treatments or magnetic resonance imaging. The data were collected through an unstructured, open-ended questionnaire; an inductive content analysis was conducted to analyze the qualitative data. Reporting of the study findings adheres to the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist. Results: Parental experiences of the children's day surgery pathway included 3 main categories: (1) needs for parental guidance, (2) needs for support, and (3) child involved in his or her own pathway (eg, consideration of an individual child and preparation of child for treatment). The needs for a digital gaming solution were identified as 1 main category-the digital gaming solution for children and families to support care. This main category included 3 upper categories: (1) preparing children and families for the day surgery via the solution, (2) gamification in the solution, and (3) connecting people through the solution. Conclusions: Parents need guidance and support for their children's day surgery care pathways. A digital gaming solution may be a relevant tool to support communication and to provide information on day surgeries Families are ready for and are open to digital gaming solutions that provide support and guidance and engage children in the day surgery pathways.Peer reviewe
Metastatic uveal melanoma managed with best supportive care
Non peer reviewe
Multistakeholder environmental governance in action: REDD+ discourse coalitions in Tanzania
Balancing interests to achieve legitimate and effective policies is a primary and pressing challenge in countries' efforts to prepare their national reducing emissions from deforestation and forest degradation (REDD+) strategies. Using Tanzania as a country case, we investigated the most polarizing policy discourses and assessed the influence of competing discourse coalitions on the drafting of the national REDD+ strategy. We combined discourse and social network analysis to identify discourse coalitions and assess their influence. The findings indicate that the national REDD+ strategy largely reflects the positions of the discourse coalition that is controlled by powerful state actors who support central control of REDD+ financial mechanisms. The competing coalition, led by civil society organizations, has limited influence on the national strategy, despite discursive congruence and concerted political action. The findings further indicate that discursive practices and institutional rules codetermine policy outcomes
- …