30 research outputs found

    Frequency of exercise-induced ST-T-segment deviations and cardiac arrhythmias in recreational endurance athletes during a marathon race: results of the prospective observational Berlin Beat of Running study

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    OBJECTIVES: While regular physical exercise has many health benefits, strenuous physical exercise may have a negative impact on cardiac function. The 'Berlin Beat of Running' study focused on feasibility and diagnostic value of continuous ECG monitoring in recreational endurance athletes during a marathon race. We hypothesised that cardiac arrhythmias and especially atrial fibrillation are frequently found in a cohort of recreational endurance athletes. The main secondary hypothesis was that pathological laboratory findings in these athletes are (in part) associated with cardiac arrhythmias. DESIGN: Prospective observational cohort study including healthy volunteers. SETTING AND PARTICIPANTS: One hundred and nine experienced marathon runners wore a portable ECG recorder during a marathon race in Berlin, Germany. Athletes underwent blood tests 2-3 days prior, directly after and 1-2 days after the race. RESULTS: Overall, 108 athletes (median 48 years (IQR 45-53), 24% women) completed the marathon in 249±43 min. Blinded ECG analysis revealed abnormal findings during the marathon in 18 (16.8%) athletes. Ten (9.3%) athletes had at least one episode of non-sustained ventricular tachycardia, one of whom had atrial fibrillation; eight (7.5%) individuals showed transient ST-T-segment deviations. Abnormal ECG findings were associated with advanced age (OR 1.11 per year, 95% CI 1.01 to 1.23), while sex and cardiovascular risk profile had no impact. Directly after the race, high-sensitive troponin T was elevated in 18 (16.7%) athletes and associated with ST-T-segment deviation (OR 9.9, 95% CI 1.9 to 51.5), while age, sex and cardiovascular risk profile had no impact. CONCLUSIONS: ECG monitoring during a marathon is feasible. Abnormal ECG findings were present in every sixth athlete. Exercise-induced transient ST-T-segment deviations were associated with elevated high-sensitive troponin T (hsTnT) values. TRIAL REGISTRATION: ClinicalTrials.gov NCT01428778; Results

    Denotative and Connotative Semantics in Hypermedia: Proposal for a Semiotic-Aware Architecture

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    In this article we claim that the linguistic-centered view within hypermedia systems needs refinement through a semiotic-based approach before real interoperation between media can be achieved. We discuss the problems of visual signification for images and video in dynamic systems, in which users can access visual material in a non-linear fashion. We describe how semiotics can help overcome such problems, by allowing descriptions of the material on both denotative and connotative levels. Finally we propose an architecture for a dynamic semiotic-aware hypermedia system

    The Effects of Two Types of Sleep Deprivation on Visual Working Memory Capacity and Filtering Efficiency

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    Sleep deprivation has adverse consequences for a variety of cognitive functions. The exact effects of sleep deprivation, though, are dependent upon the cognitive process examined. Within working memory, for example, some component processes are more vulnerable to sleep deprivation than others. Additionally, the differential impacts on cognition of different types of sleep deprivation have not been well studied. The aim of this study was to examine the effects of one night of total sleep deprivation and 4 nights of partial sleep deprivation (4 hours in bed/night) on two components of visual working memory: capacity and filtering efficiency. Forty-four healthy young adults were randomly assigned to one of the two sleep deprivation conditions. All participants were studied: 1) in a well-rested condition (following 6 nights of 9 hours in bed/night); and 2) following sleep deprivation, in a counter-balanced order. Visual working memory testing consisted of two related tasks. The first measured visual working memory capacity and the second measured the ability to ignore distractor stimuli in a visual scene (filtering efficiency). Results showed neither type of sleep deprivation reduced visual working memory capacity. Partial sleep deprivation also generally did not change filtering efficiency. Total sleep deprivation, on the other hand, did impair performance in the filtering task. These results suggest components of visual working memory are differentially vulnerable to the effects of sleep deprivation, and different types of sleep deprivation impact visual working memory to different degrees. Such findings have implications for operational settings where individuals may need to perform with inadequate sleep and whose jobs involve receiving an array of visual information and discriminating the relevant from the irrelevant prior to making decisions or taking actions (e.g., baggage screeners, air traffic controllers, military personnel, health care providers)

    Associations between physical activity types and multi-domain cognitive decline in older adults from the Three-city cohort

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    Several studies suggest that physical activity improves cognitive functions and reduces cognitive decline, whereas others did not find any evidence of a neuroprotective effect. Furthermore, few cohort studies have analyzed the different physical activity types and particularly household activities. Our objective was to assess the association of two physical activity types with the decline in different cognitive domains in a large prospective cohort of community-dwelling older adults from the Three-city study. Physical activity (domestic/transportation activities and leisure/sport activities) was assessed with the Voorrips questionnaire, specific for older adults. Baseline sociodemographic and health history variables as well as cognitive performance data at baseline and during the 8-year follow-up (Mini-Mental State Examination, Benton Visual Retention Test, Trail Making Tests A and B, Isaac's Set Test and Free and Cued Selective Reminding Test) were also available. Associations between physical activity scores and cognitive decline in different domains were tested using minimally- and multi-adjusted linear mixed models. The analysis included 1697 participants without dementia at baseline and with at least one follow-up visit. At baseline, participants with higher sub-scores for the two physical activity types had better cognitive performances. Interaction with time showed that decline in some cognitive scores (Trail Making Test B and Isaac's Set Test) was significantly less pronounced in participants with higher household/transportation activity sub-scores. No significant effect over time was found for leisure/sport activities. This study shows that during an 8-year follow-up, executive functions and verbal fluency were better preserved in older adults who performed household/transportation activities at moderate to high level. Participation in domestic activities and using adapted transport means could allow older adults to maintain specific cognitive abilities

    Magnetic resonance imaging applications on infiltrative cardiomyopathies

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    Infiltrative cardiomyopathies are a heterogenous group of diseases that typically lead to restrictive cardiac dysfunction. Due to similar phenotypes, accurate diagnosis is challenging without invasive endomyocardial biopsy which has historically been considered mandatory. Cardiac magnetic resonance (CMR) has been well established in the diagnostic workup of patients with suspected cardiomyopathies due to its unique capability for tissue differentiation and its unsurpassed accuracy in defining cardiac morphology and function. The increasing variety of CMR techniques has generated both excitement and uncertainty with regard to their potential clinical use and its role vis-a-vis conventional noninvasive imaging techniques. The purpose of this review is to give an overview of established and emerging CMR techniques and typical image characteristics of the most commonly encountered infiltrative cardiomyopathies

    Low cost UBM for lead free solder bumping with C4NP

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    The under bump metallurgy (UBM) structure is a critical component of any solder interconnect system. The UBM typically provides three functions: adhesion to underlying dielectric and metal, barrier to protect the silicon circuitry, and a solder wettable surface. For lead-free solder bumps, the barrier layer is key to reliability due to their higher Sn content. A common barrier layer used in the industry is electroplated nickel. This layer provides good protection from degradation of the silicon metallurgy by tin rich lead free solders. Controlled Collapse Chip Connection - New Process (C4NP) provides an opportunity to eliminate electroplating, and its associated costs for plating chemistry, analysis, supply and waste treatment. This paper analyzes electroless Ni/immersion Au (ENIG), with and without Pd, as an alternative UBM structure. Wafers were fabricated with these UBM structures, solder applied with C4NP, and chip level stressing performed to determine the robustne ss of these alternative stack-ups. Analysis of these structures following multiple reflows and thermal cycling is presented. In addition, the paper also reviews production cost analysis for various UBM stackups and solder bump processes, based on a specifically developed cost model. The ENIG UBM structures in combination with C4NP solder bumping provide a significant cost reduction over alternative structures. C4NP is a unique solder bumping technology developed by IBM which addresses the limitations of existing bumping technologies by enabling low-cost, fine pitch bumping using a variety of lead-free solder alloys. It is a solder transfer technology where molten solder is injected into pre-fabricated and reusable glass molds. The glass mold contains etched cavities which mirror the bump pattern on the wafer. The filled mold is inspected prior to solder transfer to the wafer to ensure high final yields. Filled mold and wafer are brought into close proximity/soft contact at reflow temperature and so

    UBM structures for lead free solder bumping using C4NP

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    This paper analyzes electroless Ni/immersion Au (ENIG), with and without Pd, as an alternative Under Bump Metallurgy (UBM) structure in combination with lead free solders. Wafers were fabricated with these UBM structures, lead-free solders applied with Controlled Collapse Chip Connection - New Process (C4NP), and chip level stressing performed to determine the robustness of this alternative stack-up. Shear strength of these structures following multiple reflows and thermal cycling is presented. The data in this paper is provided by the analytical laboratory at Fraunhofer Institute, IZM, Berlin, Germany. UBM formation was done at Fraunhofer IZM. Wafer bumping was done using the C4NP process at IBM Hudson Valley Research Park, NY
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