178 research outputs found
Perfect imaging with planar interfaces
We describe the most general homogenous, planar, light-ray-direction-changing sheet that performs one-to-one imaging between object space and image space. This is a nontrivial special case (of the sheet being homogenous) of an earlier result [Opt. Commun. 282, 2480 (2009)]. Such a sheet can be realized, approximately, with generalized confocal lenslet arrays
Identifikation von PrĂ€diktoren fĂŒr die Akzeptanz und Nutzung von telemedizinischen Gesundheitsanwendungen
Die rasante und globale Entwicklung der Informations- und Kommunikationstechnologie mit dem unĂŒbersehbaren Trend hin zur Entwicklung von immer leistungsstĂ€rkeren mobilen EndgerĂ€ten, sowie der dazugehörigen leistungsfĂ€higeren Anwendungssoftware (Applikationen â Apps), beeinflusst auch den Gesundheitssektor in immer stĂ€rkerem MaĂe. Insbesondere sogenannte Gesundheitsapplikationen (G-Apps) und telemedizinische mobile Anwendungen erfreuen sich immer gröĂerer Aufmerksamkeit, sowohl in Experten- wie in Laienanwenderkreisen, was sich in enormen Angebotszahlen und ebenfalls teilweise enormen Downloadzahlen widerspiegelt. Allerdings besteht zunehmend Bedarf an der Erforschung von personenbezogenen Faktoren, welche das Interesse oder die Nutzung von solchen G-Apps sowohl im positiven wie negativen Sinn determinieren. Nach der WHO-Definition bezeichnet der Begriff eHealth (electronic health) den Einsatz von elektronischen Informations- und Kommunikationstechnologien, um die allgemeine Gesundheit und gesundheitsbezogene Bereiche zu fördern. Ein spezieller Teilbereich umfasst mHealth (mobile health), was sich auf die Nutzung mobiler EndgerĂ€te bezieht. Da gesundheitsbezogene Apps die Gesundheitsversorgung unterstĂŒtzen können, aber nicht fĂŒr alle Patientengruppen von Interesse sind, sollten Faktoren identifiziert werden, von denen das Interesse und die Nutzung solcher mobiler gesundheitsbezogenen Anwendungen abhĂ€ngig sind. Besonderes Interesse wird dabei auf die Frage gelegt, inwiefern soziodemographische Merkmale (Alter, Geschlecht, Bildung), erkrankungsspezifische Merkmale (selbstberichteter Gesundheitszustand, Anzahl der chronischen Erkrankungen, psychische Merkmale der Patienten) und Patientenmerkmale (Bindung und Patientenaktivierung) das Interesse an und die Nutzung von telemedizinischen Gesundheitsanwendungen bei hausĂ€rztlich versorgten Patienten beeinflussen
Lah is a transmembrane protein and requires Spa10 for stable positioning of Woronin bodies at the septal pore of Aspergillus fumigatus
Woronin bodies are specialized, fungal-specific organelles that enable an immediate closure of septal pores after injury to protect hyphae from excessive cytoplasmic bleeding. In most Ascomycetes, Woronin bodies are tethered at the septal pore by so-called Lah proteins. Using the pathogenic mold Aspergillus fumigatus as a model organism, we show that the C-terminal 288 amino acids of Lah (LahC(288)) bind to the rim of the septal pore. LahC(288) essentially consists of a membrane spanning region and a putative extracellular domain, which are both required for the targeting to the septum. In an A. fumigatus rho4 deletion mutant that has a severe defect in septum formation, LahC(288) is recruited to spot-like structures in or at the lateral membrane. This suggests that LahC is recruited before Rho4 starts to govern the septation process. Accordingly, we found that in wild type hyphae Lah is bound before a cross-wall emerges and thus enables a tethering of Woronin bodies at the site of the newly formed septum. Finally, we identified Spa10, a member of a recently described family of septal poreassociated proteins, as a first protein that directly or indirectly interacts with LahC to allow a stable positioning of Woronin bodies at the mature septum
Does migrant background predict to what extent colorectal cancer patients want to be informed about their life expectancy? â a cross-sectional analysis
Background: Although migrant health is a topic of interest across Europe and although health care services in Germany consider migrant health issues, people with a migrant background often experience difficulties regarding health care provision. The prevalence of various cancers among migrants is lower relative to non-migrants although this equalizes with increasing duration of residence. There are documented differences in health behavior and disease-coping strategies between migrants and non-migrants, but data are scarce on this subject. This analysis investigates the extent of information migrant and non-migrant colorectal cancer (CRC) patients in Germany want about their life expectancy and the level of trust they have in their treating physician. Method: Data from 522 CRC patients were collected through a self-reported questionnaire. Migrant background was determined by the patientsâ and/or their parentsâ birthplace. Bivariate analyses were applied to determine the differences between migrants and non-migrants. A multivariate analysis was used to measure the effect of migration background, demographics, and cancer stage and treatment on the preferred extent of information about life expectancy and trust in their treating physician. Results: There were no significant differences regarding demographics or cancer stage and treatment between migrant and non-migrant CRC patients. Having a migrant background had no influence on the level of trust in the treating physician, but migrants preferred to be less informed about their life expectancy than non-migrants (21.4% vs. 13.4%, p = 0.04). The multivariate analysis showed that men (aOR = 2.102, CI: 1.123â3.932) and patients with a non-migrant background (aOR = 5.03, CI: 1.02â24.73) preferred receiving information about the approximate value of their life expectancy, rather than receiving no information. Conclusion: The study found more similarities than discrepancies between migrant and non-migrant CRC patients regarding demographic factors and stage of disease and treatment, which may be a consequence of an increasingly homogeneous cross-cultural society. However, cultural differences between the minority and host population remain and should always be taken into account in daily clinical practice and in the communication skills training of health care professionals. The study also indicates that recording migration background into health registers would facilitate migrant-sensitive research.publishedVersio
Exploring Wilderness Using Explainable Machine Learning in Satellite Imagery
Wilderness areas offer important ecological and social benefits and therefore
warrant monitoring and preservation. Yet, the characteristics of wilderness are
little known, making the detection and monitoring of wilderness areas via
remote sensing techniques a challenging task. We explore the appearance and
characteristics of the vague concept of wilderness via multispectral satellite
imagery. For this, we apply a novel explainable machine learning technique to a
dataset consisting of wild and anthropogenic areas in Fennoscandia. With our
technique, we predict continuous, detailed, and high-resolution sensitivity
maps of unseen remote sensing data for wild and anthropogenic characteristics.
Our neural network provides an interpretable activation space in which regions
are semantically arranged regarding these characteristics and certain land
cover classes. Interpretability increases confidence in the method and allows
for new explanations of the investigated concept. Our model advances
explainable machine learning for remote sensing, offers opportunities for
comprehensive analyses of existing wilderness, and has practical relevance for
conservation efforts
Pollinator or pedigree:Which factors determine the evolution of pollen nutrients?
A prime example of plant-animal interactions is the interaction between plants and pollinators, which typically receive nectar and/or pollen as reward for their pollination service. While nectar provides mostly carbohydrates, pollen represents the main source of protein and lipids for many pollinators. However, the main function of pollen is to carry nutrients for pollen tube growth and thus fertilization. It is unclear whether pollinator attraction exerts a sufficiently strong selective pressure to alter the nutritional profile of pollen, e.g., through increasing its crude protein content or protein-to-lipid ratio, which both strongly affect bee foraging. Pollen nutritional quality may also be merely determined by phylogenetic relatedness, with pollen of closely related plants showing similar nutritional profiles due to shared biosynthetic pathways or floral morphologies. Here, we present a meta-analysis of studies on pollen nutrients to test whether differences in pollen nutrient contents and ratios correlated with plant insect pollinator dependence and/or phylogenetic relatedness. We hypothesized that if pollen nutritional content was affected by pollinator attraction, it should be different (e.g., higher) in highly pollinator-dependent plants, independent of phylogenetic relatedness. We found that crude protein and the protein-to-lipid ratio in pollen strongly correlated with phylogeny. Moreover, pollen protein content was higher in plants depending mostly or exclusively on insect pollination. Pollen nutritional quality thus correlated with both phylogenetic relatedness and pollinator dependency, indicating that, besides producing pollen with sufficient nutrients for reproduction, the nutrient profile of zoophilous plants may have been shaped by their pollinators' nutritional needs
Nationwide trends of laparoscopic pyloromyotomy in patients with infantile hypertrophic pyloric stenosis in Germany: A slow path forward
Since its introduction, laparoscopic pyloromyotomy (LP), has become increasingly popular in many countries. We have noticed an attenuated trend in Germany. The aim of this study was to analyse the distribution of open and LP in Germany. The national database of administrative claims data of the Institute for the Remuneration System in Hospitals (InEK) was analysed regarding numbers of patients with pyloromyotomy in the years 2019â2021. The German quality reports of the hospitals of 2019 and 2020 were analyzed regarding the number of procedures performed per hospital and pediatric surgical department. A total of 2050 patients underwent pyloromyotomy. The incidence of hypertrophic pylorus stenosis (HPS) was 699 and 657 patients in 2019 and 2021, respectively. Regarding age, 31.1% were admitted before 28 days of age. LP gradually increased from 216 patients (30.9%) in 2019 to 239 patients (36.4%) in 2021. Thirty-three laparoscopic operations (4.8%) were converted to an open approach. In 24 of all patients, there was an injury to the stomach, in 20 patients to the duodenum, needing repair with sutures. Analysis of the quality reports indicated that 44% of pediatric surgical departments performed LP. Although LP has became more prevalent in Germany recently, about two thirds of patients still undergo an open procedure
Metamaterials for light rays: ray optics without wave-optical analog in the ray-optics limit
Volumes of sub-wavelength electromagnetic elements can act like homogeneous
materials: metamaterials. In analogy, sheets of optical elements such as prisms
can act ray-optically like homogeneous sheet materials. In this sense, such
sheets can be considered to be metamaterials for light rays (METATOYs).
METATOYs realize new and unusual transformations of the directions of
transmitted light rays. We study here, in the ray-optics and scalar-wave
limits, the wave-optical analog of such transformations, and we show that such
an analog does not always exist. Perhaps, this is the reason why many of the
ray-optical possibilities offered by METATOYs have never before been
considered.Comment: 10 pages, 3 figures, references update
The effect of gain saturation in a gain compensated perfect lens
The transmission of evanescent waves in a gain-compensated perfect lens is
discussed. In particular, the impact of gain saturation is included in the
analysis, and a method for calculating the fields of such nonlinear systems is
developed. Gain compensation clearly improves the resolution; however, a number
of nonideal effects arise as a result of gain saturation. The resolution
associated with the lens is strongly dependent on the saturation constant of
the active medium.Comment: to appear in J. Opt. Soc. Am.
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