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 80.44$\pm$0.83. 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

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

Diplomazia creativa al servizio di strategie di nicchia di una piccola potenza

In the year marking the centenary since the foundation of the Azerbaijani Diplomatic Service, Baku’s foreign policy is increasingly characterised by a broader understanding of diplomacy, shaped by the gradual yet steady expansion of both areas and the tools for intervention. Guided by the attempt to develop a ‘niche strategy’ aiming at safeguarding and promoting Azerbaijani national interest, the Humanitarian Diplomacy emerges as a privileged field for Baku to adopt a pro-active and creative foreign policy. Building upon the debate around the interests behind the aid-providing activities of traditional and emerging donors, the article aims at introducing the motivations and the aims behind Azerbaijani aid policy. In particular, it aims at demonstrating that Baku’s Humanitarian Diplomacy aims chiefly at achieving immaterial benefits, having to do with international prestige and with the construction and international projection of a Good International Citizenship