660 research outputs found
Volume and macroscopic scalar curvature
We prove the macroscopic cousins of three conjectures: (1) a conjectural bound of the simplicial volume of a Riemannian manifold in the presence of a lower scalar curvature bound, (2) the conjecture that rationally essential manifolds do not admit metrics of positive scalar curvature, (3) a conjectural bound of â„“-Betti numbers of aspherical Riemannian manifolds in the presence of a lower scalar curvature bound. The macroscopic cousin is the statement one obtains by replacing a lower scalar curvature bound by an upper bound on the volumes of 1-balls in the universal cover
Volume and macroscopic scalar curvature
We prove the macroscopic cousins of three conjectures: 1) a conjectural bound
of the simplicial volume of a Riemannian manifold in the presence of a lower
scalar curvature bound, 2) the conjecture that rationally essential manifolds
do not admit metrics of positive scalar curvature, 3) a conjectural bound of
-Betti numbers of aspherical Riemannian manifolds in the presence of a
lower scalar curvature bound. The macroscopic cousin is the statement one
obtains by replacing a lower scalar curvature bound by an upper bound on the
volumes of -balls in the universal cover.Comment: 48 pages; added a statement about integral foliated simplicial volume
in the introduction and made minor corrections; to be published in GAF
Cloudifying Desktops – A Taxonomy for Desktop Virtualization
Compared to traditional desktops, the implementation of desktop virtualization can leverage cost reductions and enable desktop access via mobile devices. Consequently, researchers and practitioners increasingly focus on virtualized desktops and Desktop as a Service (DaaS). However, a consistent definition for these technologies and the related delivery models does not exist yet. Therefore, we conducted a literature analysis which revealed that optimized resource allocation and performant DaaS infrastructures are the primary topics in research. Afterward, we developed a taxonomy to categorize extant virtual desktop delivery models and propose a holistic definition as theoretical framework for DaaS
DIGITAL FORMATIVE LEARNING ASSESSMENT TOOL – TOWARDS HELPING STUDENTS TO TAKE OWNERSHIP OF THEIR LEARNING
Over the last years, the number of students has constantly risen while the number of lecturers remained steady. To the consequence are large-scale classes with often hundreds of students. Large-scale classes have didactical challenges such as providing effective feedback for the students’ learning success. This is in particular problematic, since feedback belongs to the most influential factors for the student learn-ing success. In order to overcome the challenges of providing feedback in large-scale classes, we suggest using an IT-based solution we label digital formative learning assessment tool (DFLAT). In this research-in-progress paper, we will show the development of this tool by using the method of action design research (ADR). More precisely, we will concentrate on the first part from the requirements gathering to the alpha-version. In order to collect the requirements, we conducted expert interviews with lecturers and students and also derived requirements from scientific literature. Based on the requirements, we will define the key design elements of the first version of DFLAT. The next steps in our research are then the intervention and evaluation of our alpha-version in a large-scale lecture. With our completed research, we aim to contribute to literature by developing a theory of design and action for providing individualized feedback for students in large-scale classes
Influence of rectal prolapse on the asymmetry of the anal sphincter in patients with anal incontinence
BACKGROUND: Anal sphincter defects have been shown to increase pressure asymmetry within the anal canal in patients with fecal incontinence. However, this correlation is far from perfect, and other factors may play a role. The goal of this study was to assess the impact of rectal prolapse on anal pressure asymmetry in patients with anal incontinence. METHODS: 44 patients, (42 women, mean age: 64 (11) years), complaining of anal incontinence, underwent anal vector manometry, endo-anal ultrasonography (to assess sphincter defects) and pelvic viscerogram (for the diagnosis of rectal prolapse). Resting and squeeze anal pressures, and anal asymmetry index at rest and during voluntary squeeze were determined by vector manometry. RESULTS: Ultrasonography identified 19 anal sphincter defects; there were 9 cases of overt rectal prolapse, and 14 other cases revealed by pelvic viscerogram (recto-anal intussuception). Patients with rectal prolapse had a significantly higher anal sphincter asymmetry index at rest, whether patients with anal sphincter defects were included in the analysis or not (30 (3) % versus 20 (2) %, p < 0.005). Among patients without rectal prolapse, a higher anal sphincter asymmetry index during squeezing was found in patients with anal sphincter defects (27 (2) % versus 19 (2) %, p < 0.03). CONCLUSIONS: In anal incontinent patients, anal asymmetry index may be increased in case of anal sphincter defect and/or rectal prolapse. In the absence of anal sphincter defect at ultrasonogaphy, an increased anal asymmetry index at rest may point to the presence of a rectal prolapse
- …