498 research outputs found
Bottom-quark associated Higgs-boson production: reconciling the four- and five-flavour scheme approach
The main arguments in the discussion of the proper treatment of the total
inclusive cross section for bottom-quark associated Higgs-boson production are
briefly reviewed. A simple and pragmatic formula for the combination of the
so-called four- and five-flavour schemes is suggested, including the treatment
of the respective theory error estimates. The numerical effects of this
matching formula are discussed.Comment: 8 pages, 4 figure
Potentials of synchrotron radiation induced X-ray standing waves and X-ray reflectivity measurements in material analysis
In this work the potentials of two X-ray methods, X-ray reflectivity (XRR) and X-ray standing waves (XSW) at grazing incidence (including X-ray fluorescence), using synchrotron radiation are experimentally evaluated. First, the theory of X-ray scattering in general, X-ray reflectivity, X-ray fluorescence and X-ray standing waves is discussed. Then, a focus is set onto calculation of X-ray standing waves at grazing angle of incidence. The experimental procedures for the above mentioned methods are outlined, and a combination of XRR and XSW is presented. Further, a computer program developed in this work to calculate X-ray standing waves intensity fields and permit evaluation of XSW scans is introduced. Finally, a wide variety of different layered and layer-like samples is presented that were characterized by a combination of XSW and XRR. The samples ranged from semiconductor samples (germanium layers on silicon substrates and implantations of As, Co and Zn ions in Si wafers), to bio-organic samples (cytochrome and nitrobenzene films, phospholipid bilayers as a model for biological membranes, metal-organic layers such as gold or silver clusters on polymer films), a multilayer laser mirror and ion distributions in a buffer solution. It is shown that the combination of XRR and XSW is especially powerful in comparison to other methods for samples that show little optical contrast between the layers (e.g. biological material) or are otherwise difficult to characterize by established methods. Further, the developed computer program permits evaluation of complicated structures not accessible by standard software
First Results of the PixelGEM Central Tracking System for COMPASS
For its physics program with a high-intensity hadron beam of up to 2e7
particles/s, the COMPASS experiment at CERN requires tracking of charged
particles scattered by very small angles with respect to the incident beam
direction. While good resolution in time and space is mandatory, the challenge
is imposed by the high beam intensity, requiring radiation-hard detectors which
add very little material to the beam path in order to minimize secondary
interactions.
To this end, a set of triple-GEM detectors with a hybrid readout structure
consisting of pixels in the beam region and 2-D strips in the periphery was
designed and built. Successful prototype tests proved the performance of this
new detector type, showing both extraordinary high rate capability and
detection efficiency. The amplitude information allowed to achieve spatial
resolutions about a factor of 10 smaller than the pitch and a time resolution
close to the theoretical limit imposed by the layout.
The PixelGEM central tracking system consisting of five detectors, slightly
improved with respect to the prototype, was completely installed in the COMPASS
spectrometer in spring 2008
Characterization of sub-monolayer coatings as novel calibration samples for X-ray spectroscopy
With the advent of both modern X-ray fluorescence (XRF) methods and improved
analytical reliability requirements the demand for suitable reference samples
has increased. Especially in nanotechnology with the very low areal mass
depositions, quantification becomes considerably more difficult. However, the
availability of suited reference samples is drastically lower than the demand.
Physical vapor deposition (PVD) techniques have been enhanced significantly in
the last decade driven by the need for extremely precise film parameters in
multilayer production. We have applied those techniques for the development of
layer-like reference samples with mass depositions in the ng-range and well
below. Several types of reference samples were fabricated: multi-elemental
layer and extremely low (sub-monolayer) samples for various applications in XRF
and total-reflection XRF (TXRF) analysis. Those samples were characterized and
compared at three different synchrotron radiation beamlines at the BESSY II
electron storage ring employing the reference-free XRF approach based on
physically calibrated instrumentation. In addition, the homogeneity of the
multi-elemental coatings was checked at the P04 beamline at DESY. The
measurements demonstrate the high precision achieved in the manufacturing
process as well as the versatility of application fields for the presented
reference samples
Kommunikation in der digitalen Transformation : Trendstudie Schweiz 2022
Das Forschungsprojekt «Kommunikation in der digitalen Transformation» ist als Trendstudie angelegt und untersucht seit 2018 alle zwei Jahre den Zustand und den Entwicklungsbedarf der Unternehmenskommunikation in der digitalen Transformation. Leitend ist dabei ein in der Erststudie 2018 entwickeltes Framework, welches die Rolle von Corporate Communications in der digitalen Transformation auf drei Ebenen beschreibt (NiederhĂ€user & Rosenberger, 2018). Auf der Mikroebene fokussiert die Untersuchung auf die digitale Trans-formation der Kommunikationsabteilung, auf der Mesoebene auf die Funktion der Unternehmenskommunikation im Transformationsprozess der gesamten Organisation und auf der Makroebene auf das Schaffen von Akzeptanz fĂŒr den Transformationsprozess in Markt und Gesellschaft. Die vorliegende dritte Studie 2022 basiert auf einer Online-Befragung von 133 Kommunikationsverantwortli-chen (CCOs) in der Deutschschweiz und auf 12 vertiefenden Interviews mit Ex-pert:innen. Zur Einordnung wurde ein Ăberblick zum aktuellen Forschungsstand erarbeitet. Die Studie zeigt auf, dass einschneidende Ereignisse wie die Pan-demie oder der Ukraine-Krieg weniger die Richtung als die Geschwindigkeit der digitalen Transformation verĂ€ndert haben. Die «Agenda fĂŒr die Kommunikation in der digitalen Transformation» aus der Erststudie wurde mit den Ergebnissen der beiden Folgestudien abgeglichen, angepasst und erweitert. Sie zeigt Kom-munikationsverantwortlichen auf, in welche Richtung sie die Unternehmens-kommunikation entwickeln sollten.
The research project "Communication in Digital Transformation" is designed as a trend study and has been examining the state and development needs of corporate communications in digital transformation every two years since 2018. The guiding principle is a framework developed in the initial study in 2018, which describes the role of corporate communications in digital transformation at three levels (NiederhÀuser & Rosenberger, 2018). At the micro level, the study focuses on the digital transformation of the communications department, at the meso level on the function of corporate communications in the transfor-mation process of the entire organization, and at the macro level on creating acceptance for the transformation process in the market and society. This third study 2022 is based on an online survey of 133 communication managers (CCOs) in German-speaking Switzerland and on 12 in-depth interviews with ex-perts. For classification purposes, an overview of the current state of research was compiled. The study shows that drastic events such as the pandemic or the Ukraine war have changed the direction of digital transformation less than the speed. The "Agenda for Communication in Digital Transformation" from the initial study was compared to, adapted to and expanded with the results of the two follow-up studies. It shows communications managers the direction in which they should develop corporate communications
Interne Kommunikation von mittelgrossen Unternehmen : Bestandsaufnahme und Entwicklungsbedarf des internen Kommunikationsmanagements in der digitalen Transformation
Die digitale Transformation stellt die interne Kommunikation vor grosse Herausforderungen und verĂ€ndert diese gerade rasant. Die vorliegende Studie macht eine Bestandsaufnahme des internen Kommunikationsmanagements von mittelgrossen Unternehmen in der Schweiz und zeigt dessen Entwicklungsbedarf auf. Im Theorieteil wird die Rolle des internen Kommunikationsmanagements in der digitalen Transformation von Unternehmen beschrieben. Ein besonderer Fokus wird auf die drei Funktionen der internen Kommunikation gelegt â der Information, der Kommunikation und der Kollaboration â sowie auf den damit verbundenen Einsatz des Intranets. Zudem wurden im vierten Quartal 2019 und ersten Quartal 2020 Kommunikationsverantwortliche von zwölf Schweizer Unternehmen zum Thema befragt. Die Erkenntnisse aus Theorie und Befragung wurden zu 15 Handlungsempfehlungen in den vier Dimensionen Strategie, Organisation, Kultur und Technologie kondensiert. Dabei zeigt sich, dass der Spielraum des internen Kommunikationsmanagements gross ist, die digitale Transformation im Zusammenspiel mit der UnternehmensfĂŒhrung voranzutreiben.Digital transformation poses major challenges for internal communications, which is leading to rapid changes in this area. The present study evaluates the internal communications management of medium-sized companies in Switzerland and identifies where improvements need to be made. The theoretical section outlines the role of internal communications management in the digital transformation of companies. Special emphasis is placed on the three functions of internal communications â information, communication and collaboration â as well as on the related use of the intranet. In addition, communications managers from twelve Swiss companies were surveyed on the subject in the fourth quarter of 2019 and the first quarter of 2020. The findings from the theoretical part and the survey were condensed into 15 recommendations for action in four areas: strategy, organisation, culture and technology. In the process, it became evident that internal communications management has considerable potential to drive digital transformation together with corporate management
Dynamics of Stone Habitats in Coastal Waters of the Southwestern Baltic Sea (Hohwacht Bay)
Cobbles and boulders on the seaïŹoor are of high ecological value in their function as
habitats for a variety of benthic species, contributing to biodiversity and productivity in marine
environments. We investigate the origin, physical shape, and structure of habitat-forming cobbles
and boulders and reïŹect on their dynamics in coastal environments of the southwestern Baltic
Sea. Stone habitats are not limited to lag deposits and cannot be sufïŹciently described as static
environments, as different dynamic processes lead to changes within the physical habitat structure
and create new habitats in spatially disparate areas. Dynamic processes such as (a) ongoing exposure
of cobbles and boulders from glacial till, (b) continuous overturning of cobbles, and (c) the migration
of cobbles need to be considered. A distinction between allochthonous and autochthonous habitats is
suggested. The genesis of sediment types indicates that stone habitats are restricted to their source
(glacial till), but hydrodynamic processes induce a redistribution of individual cobbles, leading to
the development of new coastal habitats. Thus, coastal stone habitats need to be regarded as dynamic
and are changing on a large bandwidth of timescales. In general, wave-induced processes changing
the physical structure of these habitats do not occur separately but rather act simultaneously, leading
to a dynamic type of habitat
Development and validation of a liquid chromatographyâtandem mass spectrometry (LCâMS/MS) method including 25 novel synthetic opioids in hair and subsequent analysis of a Swiss opioid consumer cohort
Major public health concern is raised by the evidence that common drugs like heroin are now frequently laced or replaced with highly potent novel synthetic opioids (NSOs). The objective of this study was to explore the prevalence and patterns of NSOs in a cohort of Swiss opioid users by hair analysis. Hair analysis is considered an ideal tool for retrospective consumption monitoring. Hair samples from 439 opioid users in Zurich were analyzed. Study inclusion required a previous positive hair test result for heroin metabolites, oxycodone, fentanyl, methadone, or tramadol. The samples were extracted with a twoâstep extraction procedure, followed by a targeted LCâMS/MS (QTRAPÂź 6500+) analysis in multiple reaction monitoring mode for a total of 25 NSOs. The method underwent full validation and demonstrated good selectivity and sensitivity with limits of detection (LOD) as low as 0.1Â pg/mg. The analyzed sample cohort demonstrated a positivity rate for NSOs of 2.5%, including the following NSOs: butyrylfentanyl, acrylfentanyl, furanylfentanyl, methoxyacetylfentanyl, ocfentanil, Uâ47700, isobutyrylfentanyl and benzylfentanyl. Furthermore, we were able to identify specific consumption patterns among drug users. The results indicate that hair analysis is a valuable tool for investigating the prevalence of NSOs in drugâusing populations, which seems to be low in the case of Swiss opioid users. Nevertheless, the results highlight the need for sensitive analytical detection methods in forensic toxicology to identify and monitor substance distribution in different populations
Moderators of pre-post changes in school-based mental health promotion: Psychological stress symptom decrease for adolescents with mental health problems, knowledge increase for all.
Background
School-based mental health promotion aims to strengthen mental health and reduce stress. Results on the effectiveness of such programs are heterogeneous. This study realized a school-based mental health promotion program (StresSOS) for all students and aimed to identify moderators (mental health status, gender, grade level) of pre- to post-changes in stress symptoms and knowledge.
Methods
Participants were N = 510 adolescents (from 29 classes; 46.7% female) aged 12-18 years (M = 13.88, SD = 1.00; grade levels 7-10). They were without mental health problems (65.9%), at risk for mental health problems (21.6%), or with mental health problems (12.5%) and participated in a 90 min per week face-to-face training with 8 sessions in class at school. Demographic variables, mental health status, stress symptoms, and knowledge about stress and mental health were collected at baseline. Program acceptance, stress symptoms, and knowledge were collected post-intervention. Multilevel mixed effects models were conducted with the fixed effects time (within factor), mental health status, gender, and grade level (between factors). Random effects for students within classes were included.
Results
In the pre-post comparison, mental health status moderated the changes on psychological stress symptoms (p < 0.05). In adolescents with mental health problems the largest reduction in stress symptoms was observed between pre- and post-assessment. Gender and grade level were less relevant. For all adolescents knowledge gains were revealed (p < 0.001). Program acceptance was moderated by mental health status and grade level (p < 0.01). Mentally healthy adolescents and within the group of adolescents at-risk or with mental health problems, especially younger students (7th/8th grade), rated program acceptance higher.
Conclusion
Psychological stress symptoms decreased among adolescents with mental health problems and not among adolescents at risk for or without mental health problems. Mental health-related knowledge increased for all adolescents. The results add to knowledge on school-based mental health intervention research and practice. Its implications for different prevention strategies (universal, selective or a combination of both) are discussed
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