418 research outputs found

    Structural Design Study on a Light - Gauge Steel Portal Frame with Cold-formed Sigma Sections

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    Design study is conducted on a thin-gauge cold-formed steel portal frame with compound double (back-to-back) sigma sections in columns and rafters. Experimental study on the sem-irigid rafter-to-column connection behaviour is first carried out for two special bolted connection types based upon specific thin connection plates between the double sections. First connection plate studied was a compact corner plate bolted between double sigma sections of rafter and column end parts. Other connection plate type studied was composed of four together layered thin plates with the edges of two outer plates outwardly lipped at the free side of the corner plate. Connection behaviour in the ridge joint of the portal frame also constructed with using a connection plate between double sigma sections of rafter ends was experimentally studied in a similar way as the rafter-to-column connection behaviour. Analytical models are developed for the semi-rigid connection behaviour in the corners and in the ridge of the portal frame and these models are then used in design calculations for the whole portal frame. One design case study for a 12 m span portal frame is completed by using the newest version of Eurocode 3

    Microclimate structures communities, predation and herbivory in the High Arctic

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    1. In a warming world, changes in climate may result in species-level responses as well as changes in community structure through knock-on effects on ecological interactions such as predation and herbivory. Yet, the links between these responses at different levels are still inadequately understood. Assessing how microclimatic conditions affect each of them at local scales provides information essential for understanding the consequences of macroclimatic changes projected in the future.2. Focusing on the rapidly changing High Arctic, we examine how a community based on a common resource species (avens, Dryas spp.), a specialist insect herbivore (Sympistis zetterstedtii) and natural enemies of lepidopteran herbivores (parasitoids) varies along a multidimensional microclimatic gradient. We ask (a) how parasitoid community composition varies with local abiotic conditions, (b) how the community-level response of parasitoids is linked to species-specific traits (koino- or idiobiont life cycle strategy and phenology) and (c) whether the effects of varying abiotic conditions extend to interaction outcomes (parasitism rates on the focal herbivore and realized herbivory rates).3. We recorded the local communities of parasitoids, herbivory rates on Dryas flowers and parasitism rates in Sympistis larvae at 20 sites along a mountain slope. For linking community-level responses to microclimatic conditions with parasitoid traits, we used joint species distribution modelling. We then assessed whether the same abiotic variables also affect parasitism and herbivory rates, by applying generalized linear and additive mixed models.4. We find that parasitism strategy and phenology explain local variation in parasitoid community structure. Parasitoids with a koinobiont strategy preferred high-elevation sites with higher summer temperatures or sites with earlier snowmelt and lower humidity. Species of earlier phenology occurred with higher incidence at sites with cooler summer temperatures or later snowmelt. Microclimatic effects also extend to parasitism and herbivory, with an increase in the parasitism rates of the main herbivore S. zetterstedtii with higher temperature and lower humidity, and a matching increase in herbivory rates.5. Our results show that microclimatic variation is a strong driver of local community structure, species interactions and interaction outcomes in Arctic ecosystems. In view of ongoing climate change, these results predict that macroclimatic changes will profoundly affect arctic communities

    Digital factory – virtual reality environments for industrial training and maintenance

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    This study evaluates the use of virtual reality (VR) platforms, which is an integrated part of the digital factory for an industrial training and maintenance system. The digital factory-based VR platform provides an intuitive and immersive human–computer interface, which can be an efficient tool for industrial training and maintenance services. The outcomes from this study suggested that use of the VR platform for training and maintenance of complex industrial tasks should be encouraged and use of the VR platform for that purpose should be further evaluated. This paper highlighted the generic concept of the application of virtual reality technique within the digital factory to industrial maintenance and to build a low-cost VR application for a training and maintenance system. An application case on virtual reality technique in a power plant operations and maintenance is demonstrated within the scope of this research. Overall research implications on virtual reality concept in industrial applications are concluded with future research directions.fi=vertaisarvioitu|en=peerReviewed

    Trauma and Parenting Beliefs : Exploring the Ethnotheories and Socialization Goals of Palestinian Mothers

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    Parenting beliefs are important to infant wellbeing, but there is a lack of research into their role in war conditions. We examined (1) how maternal traumatic experiences (war events and childhood abuse) and mental health would be associated with parenting beliefs about good childrearing practices (ethnotheories) and desirable child characteristics (socialization goals) and (2) whether parenting beliefs mediate the impact of traumatic experiences and mental health on mother-infant interaction and infant development. Palestinian mothers (N = 510) participated during pregnancy and at four and 12 months postpartum. They reported current traumatic war events, emotional and physical abuse in their own childhood and mental health (posttraumatic stress disorder, depression, and anxiety symptoms), their ethnotheories and socialization goals and the quality of dyadic mother-infant interactions and infant developmental skills (language, fine-motor, and gross-motor). High maternal exposure to traumatic war events was associated with higher autonomy-enhancing-and lower relatedness-enhancing-socialization goals. Conversely, maternal childhood abuse was associated with higher relatedness-enhancing-and lower autonomy-enhancing-socialization goals. High maternal exposure to traumatic war events was associated with high levels of positive dyadic interaction, whereas high emotional and physical abuse and mental health problems were associated with low levels of positive dyadic interaction. Parenting beliefs did not mediate the impact of maternal traumatic experiences and mental health on dyadic interaction or infant development. The nature of maternal traumatic experiences was central for the socialization goals in unique and specific ways. The findings emphasize the meaningfulness of parenting values, goals, and practices among mothers caring for their infants in war conditions.Peer reviewe

    Strategic Assessment Of Development Of The Arctic - Assessment conducted for theEuropean Union

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    The ‘Strategic Assessment of Development of the Arctic: Assessment Conducted for the European Union” report considers the trends and developments taking place in the European Arctic today. That includes a view to 2030, with an emphasis on the uncertainties. The analysis has been conducted on the basis of seven themes focused on change. The implications of Arctic changes for the European Union as well as the role of EU policies and actions in the Arctic are examined. The European Arctic is understood here as the part of the circumpolar Arctic located between Greenland and northwest Russia

    Signal features of surface electromyography in advanced Parkinson's disease during different settings of deep brain stimulation

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    Objective: Electromyography (EMG) and acceleration (ACC) measurements are potential methods for quantifying efficacy of deep brain stimulation (DBS) treatment in Parkinson's disease (PD). The treatment efficacy depends on the settings of DBS parameters (pulse amplitude, frequency and width). This study quantified, if EMG and ACC signal features differ between different DBS settings and if DBS effect is unequal between different muscles. Methods: EMGs were measured from biceps brachii (BB) and tibialis anterior (TA) muscles of 13 PD patients. ACCs were measured from wrists. Measurements were performed during seven different settings of DBS and analyzed using methods based on spectral analysis, signal morphology and nonlinear dynamics. Results: The results showed significant within-subject differences in the EMG signal kurtosis, correlation dimension, recurrence rate and EMG-ACC coherence between different DBS settings for BB but not for TA muscles. Correlations between EMG feature values and clinical rest tremor and rigidity scores were weak but significant. Conclusions: Surface EMG features differed between different DBS settings and DBS effect was unequal between upper and lower limb muscles. Significance: EMG changes pointed to previously defined optimal settings in most of patients, which should be quantified even more deeply in the upcoming studies. (C) 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Peer reviewe

    Extending the straight leg raise test for improved clinical evaluation of sciatica : reliability of hip internal rotation or ankle dorsiflexion

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    Background The straight leg raise (SLR) is the most commonly applied physical tests on patients with sciatica, but the sensitivity and specificity ratings for disc hernia and neural compression leave areas for improvement. Hip internal rotation tensions the lumbosacral nerve roots and ankle dorsiflexion tensions the sciatic nerve along its course. We added these movements to the SLR (extended SLR = ESLR) as structural differentiators and tested inter-rater reliability in patients with LBP, with and without sciatica. Methods Forty subjects were recruited to the study by the study controller (SC), 20 in the sciatic group and in the control group. Two independent examiners (E1&E2) performed the ESLR and did not communicate to the subjects other than needed to determine the outcome of the ESLR. First, SLR was performed traditionally until first responses were evoked. At this hip flexion angle, a location-specific structural differentiation was performed to confirm whether the emerged responses were of neural origin. Cohen's Kappa score (CK) for interrater reliability was calculated for ESLR result in detection of sciatic patients. Also, the examiners' ESLR results were compared to the traditional SLR results. Results The interrater agreement between Examiner 1 and Examiner 2 for the ESLR was 0.85 (p <0.001, 95%CI: 0.71-0.99) translating to almost perfect agreement as measured by Cohen's Kappa When the ESLR was compared to the traditional SLR, the overall agreement rate was 75% (30/40). Kappa values between the traditional SLR and the E1's or E2's ESLR results were 0.50 (p <0.0001; 95%CI 0.27-0.73) and 0.54 (p <0.0001; 95%CI 0.30-0.77), respectively. Conclusions ESLR with the addition of location-specific structural differentiation is a reliable and repeatable tool in discerning neural symptoms from musculoskeletal in patients with radiating low back pain. We recommend adding these movements to the standard SLR with aim of improving diagnostic ability.Peer reviewe

    Salivary IgA to MAA-LDL and Oral Pathogens Are Linked to Coronary Disease

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    A large body of literature has established the link between periodontal disease and cardiovascular disease. Oxidized low-density lipoproteins (OxLDLs) have a crucial role in atherosclerosis progression through initiation of immunological response. Monoclonal IgM antibodies to malondialdehyde-modified low-density lipoprotein (MDA-LDL) and to malondialdehyde acetaldehyde-modified low-density lipoprotein (MAA-LDL) have been shown to cross-react with the key virulence factors of periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. We have previously shown that salivary IgA antibodies to MAA-LDL cross-react with P. gingivalis in healthy humans. In this study, we aim to assess whether oral mucosal immune response represented by salivary IgA to MAA-LDL and oral pathogens is associated with coronary artery disease (CAD). Also, the molecular mimicry through antibody cross-reaction between salivary IgA to MAA-LDL and oral pathogens was evaluated. The study subjects consisted of 451 patients who underwent a coronary angiography with no CAD (n = 133), stable CAD (n = 169), and acute coronary syndrome (ACS, n = 149). Elevated salivary IgA antibody levels to MAA-LDL, Rgp44 (gingipain A hemagglutinin domain of P. gingivalis), and Aa-HSP60 (heat shock protein 60 of A. actinomycetemcomitans) were discovered in stable-CAD and ACS patients when compared to no-CAD patients. In a multinomial regression model adjusted for known cardiovascular risk factors, stable CAD and ACS were associated with IgA to MAA-LDL (P = 0.016, P = 0.043), Rgp44 (P = 0.012, P = 0.004), Aa-HSP60 (P = 0.032, P = 0.030), Tannerella forsythia (P = 0.002, P = 0.004), Porphyromonas endodontalis (P = 0.016, P = 0.020), Prevotella intermedia (P = 0.038, P = 0.005), and with total IgA antibody concentration (P = 0.002, P = 0.016). Salivary IgA to MAA-LDL showed cross-reactivity with the oral pathogens tested in the study patients. The study highlights an association between salivary IgA to MAA-LDL and atherosclerosis. However, whether salivary IgA to MAA-LDL and the related oral humoral responses play a causal role in the development in the CAD should be elucidated in the future.Peer reviewe
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