Novel X-ray imaging technology enables significant patient dose reduction in interventional cardiology while maintaining diagnostic image quality

Objectives: The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography (CA) by a new X-ray technology, and to assess its impact on diagnostic image quality. Background: Recently, a novel X-ray imaging technology has become available for interventional cardiology, using advanced image processing and an optimized acquisition chain for radiation dose reduction. Methods: 70 adult patients were randomly assigned to a reference X-ray system or the novel X-ray system. Patient demographics were registered and exposure parameters were recorded for each radiation event. Clinical image quality was assessed for both patient groups. Results: With the same angiographic technique and a comparable patient population, the new imaging technology was associated with a 75% reduction in total kerma-area product (KAP) value (decrease from 47 Gycm(2) to 12 Gycm(2), P<0.001). Clinical image quality showed an equivalent detail and contrast for both imaging systems. On the other hand, the subjective appreciation of noise was more apparent in images of the new image processing system, acquired at lower doses, compared to the reference system. However, the higher noise content did not affect the overall image quality score, which was adequate for diagnosis in both systems. Conclusions: For the first time, we present a new X-ray imaging technology, combining advanced noise reduction algorithms and an optimized acquisition chain, which reduces patient radiation dose in CA drastically (75%), while maintaining diagnostic image quality. Use of this technology may further improve the radiation safety of cardiac angiography and interventions

The OPFOS microscopy family: High-resolution optical-sectioning of biomedical specimens

We report on the recently emerging (Laser) Light Sheet based Fluorescence Microscopy field (LSFM). The techniques used in this field allow to study and visualize biomedical objects non-destructively in high-resolution through virtual optical sectioning with sheets of laser light. Fluorescence originating in the cross section of the sheet and sample is recorded orthogonally with a camera. In this paper, the first implementation of LSFM to image biomedical tissue in three dimensions - Orthogonal-Plane Fluorescence Optical Sectioning microscopy (OPFOS) - is discussed. Since then many similar and derived methods have surfaced (SPIM, Ultramicroscopy, HR-OPFOS, mSPIM, DSLM, TSLIM...) which we all briefly discuss. All these optical sectioning methods create images showing histological detail. We illustrate the applicability of LSFM on several specimen types with application in biomedical and life sciences.Comment: 19 pages, 10 figures, to be published in Anatomical Research International (Hindawi

Combining optimized image processing with dual axis rotational angiography : toward low-dose invasive coronary angiography

Background Dual axis rotational coronary angiography procedures. Methods and Results Twenty patients were examined using to 2.22 mSv in procedures, where the latter is further reduced to 1.79 mSv when excluding ventriculography. Conclusions During invasive coronary angiography, procedures, using 1 effective dose conversion factor of 0.30 mSvGy(-1)cm(-2) is feasible

Seasonal water storage and release dynamics of bofedal wetlands in the Central Andes

Tropical high-Andean wetlands, locally known as ‘bofedales’, are key ecosystems sustaining biodiversity, carbon sequestration, water provision and livestock farming. Bofedales' contribution to dry season baseflows and sustaining water quality is crucial for downstream water security. The sensitivity of bofedales to climatic and anthropogenic disturbances is therefore of growing concern for watershed management. This study aims to understand seasonal water storage and release characteristics of bofedales by combining remote sensing analysis and ground-based monitoring for the wet and dry seasons of late 2019 to early 2021, using the glacierised Vilcanota-Urubamba basin (Southern Peru) as a case study. A network of five ultrasound loggers was installed to obtain discharge and water table data from bofedal sites across two headwater catchments. The seasonal extent of bofedales was mapped by applying a supervised machine learning model using Random Forest on imagery from Sentinel-2 and NASADEM. We identified high seasonal variability in bofedal area with a total of 3.5% and 10.6% of each catchment area, respectively, at the end of the dry season (2020), which increased to 15.1% and 16.9%, respectively, at the end of the following wet season (2021). The hydrological observations and bofedal maps were combined into a hydrological conceptual model to estimate the storage and release characteristics of the bofedales, and their contribution to runoff at the catchment scale. Estimated lag times between 1 and 32 days indicate a prolonged bofedal flow contribution throughout the dry season (about 74% of total flow). Thus, our results suggest that bofedales provide substantial contribution to dry season baseflow, water flow regulation and storage. These findings highlight the importance of including bofedales in local water management strategies and adaptation interventions including nature-based solutions that seek to support long-term water security in seasonally dry and rapidly changing Andean catchments

Temporal dynamics in dominant runoff sources and flow paths in the Andean Páramo

Funded by Central Research Office of the Universidad de Cuenca (DIUC) Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT 112–2012) . Grant Number: SENESCYT 112-2012 German Research Foundation (DFG) . Grant Number: BR2238/14-1Peer reviewedPublisher PD

Citizens AND HYdrology (CANDHY): conceptualizing a transdisciplinary framework for citizen science addressing hydrological challenges

Widely available digital technologies are empowering citizens who are increasingly well informed and involved in numerous water, climate, and environmental challenges. Citizen science can serve many different purposes, from the "pleasure of doing science" to complementing observations, increasing scientific literacy, and supporting collaborative behaviour to solve specific water management problems. Still, procedures on how to incorporate citizens' knowledge effectively to inform policy and decision-making are lagging behind. Moreover, general conceptual frameworks are unavailable, preventing the widespread uptake of citizen science approaches for more participatory cross-sectorial water governance. In this work, we identify the shared constituents, interfaces, and interlinkages between hydrological sciences and other academic and non-academic disciplines in addressing water issues. Our goal is to conceptualize a transdisciplinary framework for valuing citizen science and advancing the hydrological sciences. Joint efforts between hydrological, computer, and social sciences are envisaged for integrating human sensing and behavioural mechanisms into the framework. Expanding opportunities of online communities complement the fundamental value of on-site surveying and indigenous knowledge. This work is promoted by the Citizens AND HYdrology (CANDHY) Working Group established by the International Association of Hydrological Sciences (IAHS)

Bofedal wetland and glacial melt contributions to dry season streamflow in a high‐Andean headwater watershed

In the context of expected future melt reductions in the high-Andes, the buffering capacity of non-glacial stores, and especially of high-altitude bofedal wetlands, is of increasing importance. Isotope signatures potentially indicative of water undergoing evaporation on transit through bofedales have been found in the tropics, but end-member uncertainty has so far prevented streamflow separation using this signal. We undertook a stable isotope sampling campaign over the 2022 wet-dry season transition in a 53.6 km2, 16% glacierized catchment in southern Peru with a bofedal coverage of 11%. Diurnal proglacial hydrographs and remote sensing were used to interpret seasonal snowmelt dynamics and identify the dry periods when glacial melt and bofedal contributions are assessed to be the two principal components of streamflow. Following the final wet season precipitation event, a rapid ~3 week transition occurs in the main river from a stable isotope signature consistent with dynamic rainfall/snowmelt contributions to one of ice-melt. In both wet and dry seasons, the main river and tributary streams show evaporative enrichment suggesting ongoing supply from water transiting bofedales. A two-component mixing model using lc-excess during the dry season shows the bofedal source contribution varies from 9% to 20% [±9–10%], indicating that streamflow is greatly augmented by the presence of glaciers at these headwater scales. However, applying these proportions to river discharge shows a sustained bofedal contribution of around 0.09 m3/s during the dry season study window whereas the flux of glacial water halves from 0.73 to 0.36 m3/s over this timeframe. The results highlight the important role of bofedales and the connected groundwater system in buffering seasonal declines in streamflow months into the dry season, and suggests the hydrological functioning of bofedales as part of this wider system should be considered when exploring the effectiveness of potential options to sustain baseflows in a post-glacial future

Light Sheet Microscopy for Single Molecule Tracking in Living Tissue

Single molecule observation in cells and tissue allows the analysis of physiological processes with molecular detail, but it still represents a major methodological challenge. Here we introduce a microscopic technique that combines light sheet optical sectioning microscopy and ultra sensitive high-speed imaging. By this approach it is possible to observe single fluorescent biomolecules in solution, living cells and even tissue with an unprecedented speed and signal-to-noise ratio deep within the sample. Thereby we could directly observe and track small and large tracer molecules in aqueous solution. Furthermore, we demonstrated the feasibility to visualize the dynamics of single tracer molecules and native messenger ribonucleoprotein particles (mRNPs) in salivary gland cell nuclei of Chironomus tentans larvae up to 200 µm within the specimen with an excellent signal quality. Thus single molecule light sheet based fluorescence microscopy allows analyzing molecular diffusion and interactions in complex biological systems