2,734 research outputs found

    Aortic valve calcium volume as measured by native versus contrast-enhanced computer tomography and the implications for the diagnosis of severe aortic stenosis in TAVR patients with low-gradient aortic stenosis

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    BACKGROUND: Most of TAVR centers evaluate the calcium score in contrast-enhanced (ce) CT. We compared in this study between different methodologies to measure calcium score. We studied also the difference between patients with low-gradient (LG) and high-gradient (HG) severe aortic stenosis (AS) as regard the burden of aortic valve calcium (AVC). RESULTS: We measured the calcium volume and score using Agatston methodology in non-contrast (nc) CT and with modified and fixed 850 Hounsfield unit (HU) thresholds in ce CT. The calcium score and volume in ceCT using even with modified thresholds is significantly lower than the assessed score and volume in ncCT. The median (IQR) of calcium score in nc CT and in cc CT were 1288 AU (750–1815) versus 947 HU (384–2202). The median (IQR) of calcium volume in nc CT and in cc CT with modified thresholds were 701 mm(3) (239–1632) versus 197 mm(3) (139–532). Agatston score and calcium volume were lower in patients with LG AS than HG AS; 2069 AU (899–2477) versus 928AU (572–1284) and 1537 mm(3) (644–1860) versus 286 mm(3) (160–700), respectively. Only 20% of patients with LGAS had Agatston score higher than the previously supposed AVC score threshold for the diagnosis of severe AS (> 2000AU in men and > 1200 in women). CONCLUSIONS: The diagnosis of severe LGAS should not depend on a single parameter as calcium score. In these patients, calcium score should be measured in nc CT and not in ce CT

    Timing Analysis of Embedded Software Updates

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    We present RETA (Relative Timing Analysis), a differential timing analysis technique to verify the impact of an update on the execution time of embedded software. Timing analysis is computationally expensive and labor intensive. Software updates render repeating the analysis from scratch a waste of resources and time, because their impact is inherently confined. To determine this boundary, in RETA we apply a slicing procedure that identifies all relevant code segments and a statement categorization that determines how to analyze each such line of code. We adapt a subset of RETA for integration into aiT, an industrial timing analysis tool, and also develop a complete implementation in a tool called DELTA. Based on staple benchmarks and realistic code updates from official repositories, we test the accuracy by analyzing the worst-case execution time (WCET) before and after an update, comparing the measures with the use of the unmodified aiT as well as real executions on embedded hardware. DELTA returns WCET information that ranges from exactly the WCET of real hardware to 148% of the new version's measured WCET. With the same benchmarks, the unmodified aiT estimates are 112% and 149% of the actual executions; therefore, even when DELTA is pessimistic, an industry-strength tool such as aiT cannot do better. Crucially, we also show that RETA decreases aiT's analysis time by 45% and its memory consumption by 8.9%, whereas removing RETA from DELTA, effectively rendering it a regular timing analysis tool, increases its analysis time by 27%

    Connecting Wireless Sensor Networks to the Robot Operating System

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    AbstractRobot systems largely depend on embedded systems to operate. The interfaces of those embedded systems, e.g. motor controllers or laser scanners, are often vendor-specific and therefore require a component that translates from/to the Robot Operating System (ROS) Middleware interface. In this work we present an implementation and evaluation of a ROS Middleware client based on the Contiki operating systems, which is suitable for constrained embedded devices, like wireless sensor nodes. We show that in-buffer processing of ROS messages without relying on dynamic memory allocation is possible. That message contents can be accessed conveniently via well-known concepts of the C language (structs) with negligible processing overhead compared to a C++-based client. And that the message-passing middle- ware concept of ROS fits nicely in Contiki's event-based nature. Furthermore, in order for an environment enriched with wireless sensor network to help robots in navigating, understanding and manipulating environments a direct integration is mandatory

    Mediterranean countries' food consumption and sourcing patterns:An Ecological Footprint viewpoint

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    AbstractSecuring food for growing populations while minimizing environmental externalities is becoming a key topic in the current sustainability debate. This is particularly true in the Mediterranean region, which is characterized by scarce natural resources and increasing climate-related impacts.This paper focuses on the pressure Mediterranean people place on the Earth ecosystems because of their food consumption and sourcing patterns and then explores ways in which such pressure can be reduced. To do so, it uses an Ecological-Footprint-Extended Multi-Regional Input-Output (EF-MRIO) approach applied to 15 Mediterranean countries. Results indicate that food consumption is a substantial driver of the region's ecological deficit, whereby demand for renewable resources and ecosystems services outpaces the capacity of its ecosystems to provide them. Portugal, Malta and Greece are found to have the highest per capita food Footprints (1.50, 1.25 and 1.22 global hectares (gha), respectively), while Slovenia, Egypt and Israel have the lowest (0.63, 0.64 and 0.79gha, respectively). With the exception of France, all Mediterranean countries rely on the biocapacity of foreign countries to satisfy their residents' demand for food.By analyzing the effect of shifting to a calorie-adequate diet or changing dietary patterns, we finally point out that the region's Ecological Footprint – and therefore its ecological deficit – could be reduced by 8% to 10%

    Structural and functional analyses of the shedding protease ADAM17 in HoxB8-Immortalized macrophages and dendritic-like cells

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    A disintegrin and metalloproteinase (ADAM) 17 has been implicated in many shedding processes. Major substrates of ADAM17 are TNF-α, IL-6R, and ligands of the epidermal growth factor receptor. The essential role of the protease is emphasized by the fact that ADAM17 deficiency is lethal in mice. To study ADAM17 function in vivo, we generated viable hypomorphic ADAM17 mice called ADAM17ex/ex mice. Recent studies indicated regulation of proteolytic ADAM17 activity by cellular processes such as cytoplasmic phosphorylation and removal of the prodomain by furin cleavage. Maturation and thus activation of ADAM17 is not fully understood. So far, studies of ADAM17 maturation have been mainly limited to mouse embryonic fibroblasts or transfected cell lines relying on nonphysiologic stimuli such as phorbol esters, thus making interpretation of the results difficult in a physiologic context. In this article, we present a robust cell system to study ADAM17 maturation and function in primary cells of the immune system. To this end, HoxB8 conditionally immortalized macrophage precursor cell lines were derived from bone marrow of wild-type and hypomorphic ADAM17ex/ex mice, which are devoid of measurable ADAM17 activity. ADAM17 mutants were stably expressed in macrophage precursor cells, differentiated to macrophages under different growth factor conditions (M-CSF versus GM-CSF), and analyzed for cellular localization, proteolytic activity, and podosome disassembly. Our study reveals maturation and activity of ADAM17 in a more physiological-immune cell system. We show that this cell system can be further exploited for genetic modifications of ADAM17 and for studying its function in immune cells

    Food Losses and Waste: A Global Overview with a Focus on Near East and North Africa Region

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    Food losses refer to edible food mass decrease throughout the human food chain. Food losses occurring at consumption stage are called food waste. Food Losses and Waste (FLW) represent one of the most critical social, economic and ecological challenges facing humanity, besides being also an ethical issue. FAO data show that roughly one-third of food produced for human consumption is lost or wasted. There are no precise and accurate data regarding food waste in Near East and North Africa (NENA) region. The review paper aims at providing insights about the extent of FLW in NENA region with a special focus on Arab countries and Iran. The paper explores linkages between food waste and food security. Moreover, it analyses the economic and environmental implications of FLW. FLW vary depending on food type, country and season. Generally speaking, postharvest losses are significant in this region for most of commodity groups. It is estimated that FLW amount to 34% of food supply in NENA region. FLW undermine the very foundations of food security and amount to major depletion of resources (e.g. water, land, energy) and produce needlessly greenhouse gases. They also represent a wasted investment that reduces farmers’ incomes and increase consumers’ expenses. Therefore, food waste reduction is crucial for improving the sustainability of the food supply chain and achieving food and nutrition security in the region

    Transnationale Aspekte von Salafismus und Dschihadismus

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    "Salafismus und Dschihadismus machen nicht Halt an nationalstaatlichen Grenzen. Der Report untersucht die Transnationalität dieser unterschiedlichen Phänomene anhand von drei Aspekten: Welche zentralen Akteure gibt es? Welche Rolle spielt die Sprache und die Vernetzung über das Internet? Er beschreibt Reisebewegungen beider Strömungen, u.a. die Ausreisewelle deutscher Dschihadisten nach Syrien und den Irak. Konkrete Handlungsempfehlungen schließen den Report ab." (Autorenreferat)"Salafism and Jihadism are not restricted by national borders. The report takes a closer look at the transnational dimensions of these different phenomena by analyzing three aspects: Who are the central actors? What role does language play and how important is networking through the web? The report describes the travel movements of both salafist and jihadist actors and the wave of German jihadists leaving to Syria and Iraq. Concrete recommendations for action are concluding the report." (author's abstract
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