72 research outputs found
Interpenetrierende Metall-Keramik-Verbundwerkstoffe mit isotropen und anisotropen Al2O3-Verstärkungen
The future of working from home:a mixed-methods study with IT professionals to learn from enforced working from home
Purpose: Positive experiences with working from home (WFH) during the Corona pandemic (COVID-19) have motivated many employees to continue WFH after the pandemic. However, factors influencing employees' WFH intentions against the backdrop of experiences during pandemic-induced enforced working from home (EWFH) are heterogeneous. This study investigates factors linked to information technology (IT) professionals' WFH intentions. Design/methodology/approach: This mixed-methods study with 92 IT professionals examines the effects of seven predictors for IT professionals' WFH intentions. The predictors are categorized according to the trichotomy of (1) characteristics of the worker, (2) characteristics of the workspace and (3) the work context. Structural equation modeling is used to analyze the quantitative survey data. In addition, IT professionals' responses to six open questions in which they reflect on past experiences and envision future work are examined. Findings: Quantitative results suggest that characteristics of the worker, such as segmentation preference, are influencing WFH intentions stronger than characteristics of the workspace or the work context. Furthermore, perceived productivity during EWFH and gender significantly predict WFH intentions. Contextualizing these quantitative insights, the qualitative data provides a rich yet heterogeneous list of factors why IT professionals prefer (not) to work from home. Practical implications: Reasons influencing WFH intentions vary due to individual preferences and constraints. Therefore, a differentiated organizational approach is recommended for designing future work arrangements. In addition, the findings suggest that team contracts to formalize working patterns, e.g. to agree on the needed number of physical meetings, can be helpful levers to reduce the complexity of future work that is most likely a mix of WFH and office arrangements. Originality/value: This study extends literature reflecting on COVID-19-induced changes, specifically the emerging debate about why employees want to continue WFH. It is crucial for researchers and practitioners to understand which factors influence IT professionals' WFH intentions and how they impact the design and implementation of future hybrid work arrangements.</p
NeuroExaminer: an all-glass microfluidic device for whole-brain in vivo imaging in zebrafish
While microfluidics enables chemical stimuli application with high spatio-temporal precision, light-sheet microscopy allows rapid imaging of entire zebrafish brains with cellular resolution. Both techniques, however, have not been combined to monitor whole-brain neural activity yet. Unlike conventional microfluidics, we report here an all-glass device (NeuroExaminer) that is compatible with whole-brain in vivo imaging using light-sheet microscopy and can thus provide insights into brain function in health and disease
A Parallel Perifusion Slide From Glass for the Functional and Morphological Analysis of Pancreatic Islets.
An islet-on-chip system in the form of a completely transparent microscope slide optically accessible from both sides was developed. It is made from laser-structured borosilicate glass and enables the parallel perifusion of five microchannels, each containing one islet precisely immobilized in a pyramidal well. The islets can be in inserted via separate loading windows above each pyramidal well. This design enables a gentle, fast and targeted insertion of the islets and a reliable retention in the well while at the same time permitting a sufficiently fast exchange of the media. In addition to the measurement of the hormone content in the fractionated efflux, parallel live cell imaging of the islet is possible. By programmable movement of the microscopic stage imaging of five wells can be performed. The current chip design ensures sufficient time resolution to characterize typical parameters of stimulus-secretion coupling. This was demonstrated by measuring the reaction of the islets to stimulation by glucose and potassium depolarization. After the perifusion experiment islets can be removed for further analysis. The live-dead assay of the removed islets confirmed that the process of insertion and removal was not detrimental to islet structure and viability. In conclusion, the present islet-on-chip design permits the practical implementation of parallel perifusion experiments on a single and easy to load glass slide. For each immobilized islet the correlation between secretion, signal transduction and morphology is possible. The slide concept allows the scale-up to even higher degrees of parallelization
Magnetic nanoparticle-gel materials for development of joint phantoms for MPI and MRI
To evaluate the performance of commercial as well as custom-made scanners, dedicated phantoms with defined magnetic nanoparticle (MNP) distributions are required. Prerequisite for the development of such phantoms is the establishment of suitable MNP-matrix combinations. In this study, two different gel types were investigated as potential matrix materials: water-based biopolymers and synthetic polymers. These materials exhibit similar imaging behaviour to body tissue in MRI and MPI. Aqueous suspensions of MNP coated with different types of functionalized dextranes were used for embedding particles into the biopolymers, and organic fluids with oleic acid coated MNP for synthetic polymers, respectively. The obtained MNP-matrix combinations were tested for their shape stability. The homogeneity of MNP distribution and immobilization within the matrix was determined by optical investigation of the samples with a microscope, and the magnetic properties of the composite materials measured by vibrating sample magnetometry. From the tested combinations of MNP and matrix material, oleic acid coated MNP embedded in Permagel was found to be the most suitable for the construction of MPI phantoms. This was based on the reliable and homogeneous fixation of the MNP within the matrix without agglomeration of the particles
DS6, Deformation-aware Semi-supervised Learning: Application to Small Vessel Segmentation with Noisy Training Data
Blood vessels of the brain are providing the human brain with the required
nutrients and oxygen. As a vulnerable part of the cerebral blood supply,
pathology of small vessels can cause serious problems such as Cerebral Small
Vessel Diseases (CSVD). It has also been shown that CSVD is related to
neurodegeneration, such as in Alzheimer's disease. With the advancement of 7
Tesla MRI systems, higher spatial image resolution can be achieved, enabling
the depiction of very small vessels in the brain. Non-Deep Learning based
approaches for vessel segmentation, e.g. Frangi's vessel enhancement with
subsequent thresholding are capable of segmenting medium to large vessels but
often fail to segment small vessels. The sensitivity of these methods to small
vessels can be increased by extensive parameter tuning or by manual
corrections, albeit making them time-consuming, laborious, and not feasible for
larger datasets. This paper proposes a deep learning architecture to
automatically segment small vessels in 7 Tesla 3D Time-of-Flight (ToF) Magnetic
Resonance Angiography (MRA) data. The algorithm was trained and evaluated on a
small imperfect semi-automatically segmented dataset of only 11 subjects; using
six for training, two for validation and three for testing. Deep learning model
based on U-Net Multi-Scale Supervision was trained using the training subset
and were made equivariant to elastic deformations in a self-supervised manner
using deformation-aware learning to improve the generalisation performance. The
proposed technique was evaluated quantitatively and qualitatively against the
test set and achieved a dice score of 80.440.83. Furthermore, the result
of the proposed method was compared against a selected manually segmented
region (62.07 resultant dice) and has shown a considerable improvement (18.98%)
with deformation-aware learning
CFC – Carbon Fibre Cycle Carbonfasern im Kreislauf – Freisetzungsverhalten und Toxizität bei thermischer und mechanischer Behandlung - Poster-Abstracts
The Nachtlichter app: a citizen science tool for documenting outdoor light sources in public space
The relationship between satellite based measurements of city radiance at night and the numbers and types of physical lights installed on the ground is not well understood. Here we present the "Nachtlichter app", which was developed to enable citizen scientists to classify and count light sources along street segments over large spatial scales. The project and app were co-designed: citizen scientists played key roles in the app development, testing, and recruitment, as well as in analysis of the data. In addition to describing the app itself and the data format, we provide a general overview of the project, including training materials, data cleaning, and the result of some basic data consistency checks
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