1,098 research outputs found

    Positional changes of pericentromeric heterochromatin and nucleoli in postmitotic Purkinje cells during murine cerebellum development

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    Previous studies revealed changes of pericentromeric heterochromatin arrangements in postmitotic Purkinje cells (PCs) during postnatal development in the mouse cerebellum (Manuelidis, 1985; Martou and De Boni, 2000). Here, we performed vibratome sections of mouse cerebellum (vermis) at P0 (day of birth), at various stages of the postnatal development (P2-P21), as well as in very young (P28) and 17-months-old adults. FISH was carried out on these sections with major mouse satellite DNA in combination with immunostaining of the nucleolar protein B23 (nucleophosmin). Laser confocal microscopy, 3D reconstructions and quantitative image analysis were employed to describe changes in the number and topology of chromocenters and nucleoli. At all stages of postnatal PC development heterochromatin clusters were typically associated either with nucleoli or with the nuclear periphery, while non-associated clusters were rare (<1% at P0 to P21 and about 3% in adult stages). At P0, about 2-4 nucleoli and 7-8 pericentromeric heterochromatin clusters were variably located within PC nuclei. The relative volume of heterochromatin clusters associated with the nucleoli (about 50%) was roughly equal to the volume of clusters associated with the nuclear periphery. Positional changes of both nucleoli and centromeres towards the nuclear center occurred between P0 and P6. At P6 the average number of chromocenters per PC nucleus had decreased to about five. In agreement with previous studies, one or occasionally two nucleoli were noted at the nuclear center surrounded by major perinucleolar heterochromatin clusters. The relative volume of these perinucleolar clusters increased to about 84%, while the volume of clusters in the nuclear periphery decreased to about 15%. At subsequent postnatal stages, the arrangement of most pericentromeric heterochromatin around a central nucleolus was maintained. In adult animals, however, we observed a partial redistribution of heterochromatin towards the nuclear periphery. The average total number of pericentromeric heterochromatin signals increased again to about ten. The volume of heterochromatin associated with the nuclear periphery roughly doubled (30%), while the volume of the perinucleolar heterochromatin decreased correspondingly. Copyright (C) 2004 S. Karger AG, Basel

    Big Data in Studying Acute Pain and Regional Anesthesia

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    The digital transformation of healthcare is advancing, leading to an increasing availability of clinical data for research. Perioperative big data initiatives were established to monitor treatment quality and benchmark outcomes. However, big data analyses have long exceeded the status of pure quality surveillance instruments. Large retrospective studies nowadays often represent the first approach to new questions in clinical research and pave the way for more expensive and resource intensive prospective trials. As a consequence, the utilization of big data in acute pain and regional anesthesia research has considerably increased over the last decade. Multicentric clinical registries and administrative databases (e.g., healthcare claims databases) have collected millions of cases until today, on which basis several important research questions were approached. In acute pain research, big data was used to assess postoperative pain outcomes, opioid utilization, and the efficiency of multimodal pain management strategies. In regional anesthesia, adverse events and potential benefits of regional anesthesia on postoperative morbidity and mortality were evaluated. This article provides a narrative review on the growing importance of big data for research in acute postoperative pain and regional anesthesia

    Columnar structure formation of a dilute suspension of settling spherical particles in a quiescent fluid

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    The settling of heavy spherical particles in a column of quiescent fluid is investigated. The performed experiments cover a range of Galileo numbers (110≀Ga≀310110 \leq \text{Ga} \leq 310) for a fixed density ratio of Γ=ρp/ρf=2.5\Gamma = \rho_p/\rho_f = 2.5. In this regime the particles are known (M. Jenny, J. Du\v{s}ek and G. Bouchet, Journal of Fluid Mechanics 508, 201 (2004).) to show a variety of motions. It is known that the wake undergoes several transitions for increasing Ga\text{Ga} resulting in particle motions that are successively: vertical, oblique, oblique oscillating, and finally chaotic. Not only does this change the trajectory of single, isolated, settling particles, but it also changes the dynamics of a swarm of particles as collective effects become important even for dilute suspensions, with volume fraction up to ΊV=O(10−3)\Phi_V = \mathcal{O}\left(10^{-3}\right), which are investigated in this work. Multi-camera recordings of settling particles are recorded and tracked over time in 3 dimensions. A variety of analysis are performed and show a strong clustering behavior. The distribution of the cell areas of the Vorono\"i tessellation in the horizontal plane are compared to that of a random distribution of particles and shows clear clustering. Moreover, a negative correlation was found between the Vorono\"i area and the particle velocity; clustered particles fall faster. In addition, the angle between two adjacent particles and the vertical is calculated and compared to a homogeneous distribution of particles, clear evidence of vertical alignment of particles is found. The experimental findings are compared to simulations.Comment: 8 pages, 6 figure

    Ten years of the International Patient Decision Aid Standards Collaboration: evolution of the core dimensions for assessing the quality of patient decision aids

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    In 2003, the International Patient Decision Aid Standards (IPDAS) Collaboration was established to enhance the quality and effectiveness of patient decision aids by establishing an evidence-informed framework for improving their content, development, implementation, and evaluation. Over this 10 year period, the Collaboration has established: a) the background document on 12 core dimensions to inform the original modified Delphi process to establish the IPDAS checklist (74 items); b) the valid and reliable IPDAS instrument (47 items); and c) the IPDAS qualifying (6 items), certifying (6 items + 4 items for screening), and quality criteria (28 items). The objective of this paper is to describe the evolution of the IPDAS Collaboration and discuss the standardized process used to update the background documents on the theoretical rationales, evidence and emerging issues underlying the 12 core dimensions for assessing the quality of patient decision aids. © 2013 Volk et al; licensee BioMed Central Ltd

    Designing decentralized small-scale bioenergy systems based on short rotation coppice for rural poverty alleviation

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    Introducing an approach to develop Decision Support Tools (DST) assessing sustainability of bioenergy systems.Access to electricity is crucial for the attainment of the Millennium Development Goals of poverty reduction and environmental sustainability. In East Africa, increasing environmental degradation and modern energy supply are a major obstacle to sustainable rural development. Small-scale bioenergy systems can supply clean, renewable and affordable energy to rural communities while at the same time creating new job opportunities and having beneficial impacts on natural resources especially when fed from Short Rotation Coppice (SRC). However, bioenergy systems are complex because their three components feedstock supply, conversion technology and energy allocation are influenced by environmental factors simultaneously with economic and social factors. Assessing these factors and their interdependence is essential to determine the project’s contribution to sustainable development as failure of one component can lead to failure of the entire system. Decision Support Tools (DST) structure the collection and evaluation of quantitative and qualitative information about social, economic and environmental impacts at scales ranging from local to national level. DSTs enable transparent and informed decisions even when limited information is available and many participants with different expertise and interests are involved to consider all relevant criteria. This paper introduces an approach to develop a DST assessing sustainability of bioenergy systems.Access to electricity is crucial for the attainment of the Millennium Development Goals of poverty reduction and environmental sustainability. In East Africa, increasing environmental degradation and modern energy supply are a major obstacle to sustainable rural development. Small-scale bioenergy systems can supply clean, renewable and affordable energy to rural communities while at the same time creating new job opportunities and having beneficial impacts on natural resources especially when fed from Short Rotation Coppice (SRC). However, bioenergy systems are complex because their three components feedstock supply, conversion technology and energy allocation are influenced by environmental factors simultaneously with economic and social factors. Assessing these factors and their interdependence is essential to determine the project’s contribution to sustainable development as failure of one component can lead to failure of the entire system. Decision Support Tools (DST) structure the collection and evaluation of quantitative and qualitative information about social, economic and environmental impacts at scales ranging from local to national level. DSTs enable transparent and informed decisions even when limited information is available and many participants with different expertise and interests are involved to consider all relevant criteria. This paper introduces an approach to develop a DST assessing sustainability of bioenergy systems

    Rapid temperature increases under isoflurane sedation

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    (...)Letter, Intensive Care Medicine (2023

    Profitability of Willow Biomass Crops Affected by Incentive Programs

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    Abstract The economics of willow biomass crops are strongly influenced by yield, production, and harvesting costs and the delivered price for biomass. Under current management practices, willow biomass crops with yields of 12 oven-dried metric tons (odt)ha −1 year −1 and a delivered price of $60 odt −1 have an internal rate of retur

    Image quality to estimate ventricular ejection fraction by last year medical students improves after short courses of training

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    Background: Transthoracic echocardiography is the primary imaging modality for diagnosing cardiac conditions but medical education in this field is limited. We tested the hypothesis that a structured theoretical and supervised practical course of training in focused echocardiography in last year medical students results in a more accurate assessment and more precise calculation of left ventricular ejection fraction after ten patient examinations. Methods: After a theoretical introduction course 25 last year medical students performed ten transthoracic echocardiographic examination blocks in postsurgical patients. Left ventricular function was evaluated both with an eye-balling method and with the calculated ejection fraction using diameter and area of left ventricles. Each examination block was controlled by a certified and blinded tutor. Bias and precision of measurements were assessed with Bland and Altman method. Results: Using the eye-balling method students agreed with the tutor’s findings both at the beginning (88%) but more at the end of the course (95.7%). The variation between student and tutor for calculation of area, diameter and ejection fraction, respectively, was significantly lower in examination block 10 than in examination block 1 (each p < 0.001). Students underestimated both the length and the area of the left ventricle at the outset, as complete imaging of the left heart in the ultrasound sector was initially unsuccessful. Conclusions: A structured theoretical and practical transthoracic echocardiography course of training for last year medical students provides a clear and measurable learning experience in assessing and measuring left ventricular function. At least 14 examination blocks are necessary to achieve 90% agreement of correct determination of the ejection fraction
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