1,717 research outputs found
Hausdorff Dimension of the Record Set of a Fractional Brownian Motion
We prove that the Hausdorff dimension of the record set of a fractional
Brownian motion with Hurst parameter equals
Integrated optics prototype beam combiner for long baseline interferometry in the L and M bands
In the last few years, integrated optics (IO) beam combiners have facilitated
the emergence of 4-telescope interferometers such as PIONIER or GRAVITY,
boosting the imaging capabilities of the VLTI. However, the spectral range
beyond 2.2microns is not ideally covered by the conventional silica based IO.
Here, we propose to consider new laser-written IO prototypes made of GLS
glasses, a material that permits access to the mid-infrared spectral regime.
Our goal is to conduct a full characterization of our mid-IR IO 2-telescope
coupler in order to measure the performance levels directly relevant for
long-baseline interferometry. We focus in particular on the exploitation of the
L and M astronomical bands. We use a dedicated Michelson-interferometer setup
to perform Fourier Transform spectroscopy on the coupler and measure its
broadband interferometric performance. We also analyze the polarization
properties of the coupler, the differential dispersion and phase degradation as
well as the modal behavior and the total throughput. We measure broadband
interferometric contrasts of 94.9% and 92.1% for unpolarized light in the L and
M bands. Spectrally integrated splitting ratios are close to 50% but show
chromatic dependence over the considered bandwidths. Additionally, the phase
variation due to the combiner is measured and does not exceed 0.04rad and
0.07rad across the band L and M band, respectively. The total throughput of the
coupler including Fresnel and injection losses from free-space is 25.4%. The
laser-written IO GLS prototype combiners prove to be a reliable technological
solution with promising performance for mid-infrared long-baseline
interferometry. In the next steps, we will consider more advanced optical
functions as well as a fiber-fed input and revise the optical design parameters
in order the further enhance the total throughput and achromatic behavior
Struktur und Funktion der Carboxy-terminalen Domäne des Transkriptionsfaktors CbfA aus Dictyostelium discoideum
Der C-Modul-bindende Faktor A (CbfA) aus Dictyostelium discoideum wurde durch seine Interaktion mit einem Teil des 3‘-untranslatierten Bereiches des Retrotransposons TRE5-A erstmalig beschrieben. Bisherige Arbeiten über CbfA zeigten eine Beteiligung dieses Faktors an der Regulation der multizellulären Entwicklung von Dictyostelium discoideum und sein Wirken als Transkriptionsfaktor. Es wurden mit Hilfe der Microarray-Technik 162 Gene identifiziert, die in der CbfA-depletierten Mutante JH.D im Vergleich zum Wildtyp differenziell exprimiert werden. Die erlangten Daten sind mit zwei durch RNA-Sequenzierung erstellten Transkriptomanalysen sowie punktuell mit quantitativen Reverse Transkriptase-PCR-Messungen verglichen worden. Ferner wurden anhand einer Microarray-Transkriptomanalyse die Funktionen der Carboxy-terminalen Domäne (CTD) von CbfA für die Regulation CbfA-abhängiger Gene untersucht. Die Experimente lassen auf eine vom Rest des Proteins unabhängige genregulatorische Funktion schließen.
Zur weiteren Charakterisierung der CTD von CbfA wurde die Beteiligung des DNA-bindenden AT-Hakens an der genregulatorischen Aktivität sowie die Kernlokalisation der Carboxy-terminalen Domäne untersucht. Zur Strukturaufklärung der Carboxy-terminalen Domäne wurde ein Protokoll zur heterologen Expression und Aufreinigung großer Mengen CTD in Bakterien entwickelt. Die DNA-bindende Aktivität und Strukturierung der rekombinanten Proteindomäne konnte nachgewiesen werden. Des Weiteren wurde das Hefe Zwei-Hybrid-System zur Identifizierung von Interaktionspartnern der CTD verwendet. Dazu sind zwei komplexe cDNA-Bibliotheken erstellt worden, welche qualitativ als hochwertig charakterisiert werden konnten. Abschließend folgten Arbeiten hinsichtlich der Phylogenie der CbfA-Domänenstruktur und des paralogen Proteins CbfB innerhalb der Dictyosteliales.The Dictyostelium discoideum C-module-binding factor A (CbfA) was discovered by its interaction with a part of the 3’-untranslated region of the retrotransposon TRE5-A. Previous studies on CbfA showed an involvement of this protein in the regulation of multicellular development of D. discoideum and its function as a transcription factor. Experiments in this work using the microarray technology showed 162 genes to be differentially expressed between the wild type AX2 and the CbfA-depleted mutant JH.D. Microarray data were compared with results obtained from two RNA sequencing experiments and in part to quantitative reverse-transcription PCR measurements. The function of the carboxy-terminal domain (CTD) of CbfA in the regulation of CbfA-dependent genes was investigated by microarray analysis. These experiments emphasize the function of carboxy-terminal domain of CbfA as an independent gene-regulatory entity.
To further characterise the CTD of CbfA, the involvement of the DNA-binding AT-hook in the gene regulatory activity was investigated. A nuclear localisation site within the carboxy-terminal domain was experimentally verified. To determine the structure of CbfA’s CTD a protocol to express and purify large amounts of the protein in bacteria was developed. The functionality (i.e. DNA-binding activity) and the structuring of the recombinant domain were confirmed. Additionally the yeast two-hybrid system was used to search for proteins that intact with the CTD in vivo. Two high-quality cDNA libraries were generated from
D. discoideum cells. Finally the molecular phylogeny of the domain structure of CbfA and its paralogous protein CbfB was investigated within the dictyostelid clade
Comparison of PAS and adenoids in patients with and without maxillary micrognathia before orthodontic treatment
Objective Craniofacial anomalies are widely discussed as predisposing factors of breathing disorders. Since many more
cofactors exist, this study investigated the association between maxillary micrognathia and morphological changes of posterior airway space and adenoids in these patients.
Material and methods Cephalometric radiographs of n=73 patients were used for data acquisition. The patients were
divided into two groups according to certain skeletal characteristics: maxillary micrognathia (n=34, 16 female, 18 male;
mean age 10.55±3.03 years; defned by a SNA angle<79°) and maxillary eugnathia (n=39, 19 female, 20 male; mean age
10.93±3.26 years; defned by a SNA angle>79°). The evaluation included established procedures for measurements of the
maxilla, posterior airway space and adenoids. Statistics included Kolmogorov–Smirnov-, T- and Mann–Whitney-U-Tests
for the radiographs. The level of signifcance was set at p<0.05.
Results The cephalometric analysis showed diferences in the superior posterior face height and the depth of the posterior
airway space at palatal level among the two groups. The depth of the posterior airway space at mandibular level was the
same for both groups, just as the size of the area taken by adenoids in the nasopharynx.
Conclusions Skeletal anomalies afect the dimension of the posterior airway space. There were diferences among the subjects with maxillary micrognathia and these with a normal maxilla. However, the maxilla was only assessed in the sagittal
direction, not in the transverse. This study showed that the morphology of the maxilla relates to the posterior airway space
whereas the adenoids seem not to be afected.
Clinical relevance Maxillary micrognathia is signifcantly associated with a smaller depth of the posterior airway space at
the palatal level compared to patients with maxillary eugnathia
Federal coordination of complex policy issues in the energy transition: hydrogen governance in Germany
With its National Hydrogen Strategy, the German federal government defined an initial framework for the integration of hydrogen into the energy system. At the subnational level, most states have also adopted own hydrogen strategies and are pursuing regional hydrogen policies within the national framework. This article examines how the interdependent but partly differing regional strategies are coordinated in the German multilevel system. We find different coordination processes among state governments but also between subnational and national level and discuss their pattern in the context of the coordination literature ranging from unilateral decision-making to integrated strategy building
Does Energy Community Membership Change Sustainable Attitudes and Behavioral Patterns? Empirical Evidence from Community Wind Energy in Germany
Community energy is seen as a helping hand for local, decentralized energy transition. Besides the main goal of supporting the community-friendly and socially acceptable development of renewable energies, the hope is also that a pro-environmental influence on sustainability behavior will be triggered when joining a community energy project. An analysis of a survey among 16 community energy projects in Germany, with 565 completed questionnaires, shows that a certain part of the members pays more attention to their energy behavior and develop a more positive attitude towards a decentralized energy transition and citizen participation after joining the community energy project. Therefore, we can empirically support that climate protection projects, such as community energy, influence pro-environmental attitudes and behavior, but this does not apply equally to all population groups. Members with higher income and stronger interest in returns are less likely to change their behavior. Based on these findings, we recommend the development of community energy policies that are more responsive to differences in social structure and address both privileged and underprivileged groups in a sophisticated way using specific offers and modes of involvement within the associations
Health Literacy Among University Students: A Systematic Review of Cross-Sectional Studies
OBJECTIVE: The aim of this systematic review was to provide an overview of cross-sectional studies that examined health literacy among university students and to identify possible determinants related to health literacy. METHOD: The current review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Three databases (PubMed, Scopus, and Web of Science) were systematically searched for cross-sectional studies that examined health literacy among university students. Results of included studies were narratively summarized. RESULTS: The systematic review includes twenty-one research studies. The majority of studies report health literacy scores among university students that are lower compared to reference samples. The health literacy of students is influenced by different variables (age, gender, number of semesters, course of studies/curriculum, parental education, and socioeconomic background). DISCUSSION: Health literacy activities should target all students. Universities should make use of their resources and offer health literacy courses for students in which content is used from disciplines available at the university (e.g., medicine, health, or psychology). To increase effectiveness, health literacy courses should be adapted according to the different needs and characteristics of the student subgroups
New Interaction Partners For Nek4.1 And Nek4.2 Isoforms: From The Dna Damage Response To Rna Splicing.
Neks are serine-threonine kinases that are similar to NIMA, a protein found in Aspergillus nidulans which is essential for cell division. In humans there are eleven Neks which are involved in different biological functions besides the cell cycle control. Nek4 is one of the largest members of the Nek family and has been related to the primary cilia formation and in DNA damage response. However, its substrates and interaction partners are still unknown. In an attempt to better understand the role of Nek4, we performed an interactomics study to find new biological processes in which Nek4 is involved. We also described a novel Nek4 isoform which lacks a region of 46 amino acids derived from an insertion of an Alu sequence and showed the interactomics profile of these two Nek4 proteins. Isoform 1 and isoform 2 of Nek4 were expressed in human cells and after an immunoprecipitation followed by mass spectrometry, 474 interacting proteins were identified for isoform 1 and 149 for isoform 2 of Nek4. About 68% of isoform 2 potential interactors (102 proteins) are common between the two Nek4 isoforms. Our results reinforce Nek4 involvement in the DNA damage response, cilia maintenance and microtubule stabilization, and raise the possibility of new functional contexts, including apoptosis signaling, stress response, translation, protein quality control and, most intriguingly, RNA splicing. We show for the first time an unexpected difference between both Nek4 isoforms in RNA splicing control. Among the interacting partners, we found important proteins such as ANT3, Whirlin, PCNA, 14-3-3ε, SRSF1, SRSF2, SRPK1 and hNRNPs proteins. This study provides new insights into Nek4 functions, identifying new interaction partners and further suggests an interesting difference between isoform 1 and isoform 2 of this kinase. Nek4 isoform 1 may have similar roles compared to other Neks and these roles are not all preserved in isoform 2. Besides, in some processes, both isoforms showed opposite effects, indicating a possible fine controlled regulation.131
Detection of X-Ray Doses with Color-Changing Hackmanites: Mechanism and Application
Hackmanites, a variety of sodalite with the general formula NaAlSiO(Cl,S), are a family of nature-based smart materials having the ability for reversible photochromism upon UV or X-ray exposure. Being nontoxic, cheap, and durable, hackmanite would be an optimal material for the visual detection of the presence of X-rays in simple portable systems. However, its X-ray-induced coloring abilities are so far known only qualitatively. In this work, a combination of experimental and computational methods is used to reveal the mechanism of X-ray-induced color changing in these materials. Finally, their use is demonstrated both in color intensity-based X-ray dosimetry and photochromic X-ray imaging
- …