123 research outputs found
Methodology for evaluating the safety level of current accepted design solutions for limiting fire spread between buildings
External fire spread between buildings is internationally considered as a major concern for buildings in dense urban environments. While design guidelines differ between countries, the fundamental methods currently used for limiting the risk of fire spread between buildings are generally limited to specifying the minimum required separation distance for a given unprotected façade area, or conversely, limiting the maximum allowable unprotected façade area for a given separation distance. The safety level associated with the current design guidelines is however unknown, making the implementation of innovative, safer and more cost-effective design solutions difficult. In order to assess the safety target implicitly incorporated in currently accepted design solutions, a methodology is developed for evaluating the annual probability of reaching unacceptable radiation intensities at the opposite façade. As a case study, the methodology is applied to a design which is in agreement with the current UK requirements specified in BR 187. This case study exposes inconsistencies in the current design guidelines, indicating the need for developing explicit safety targets
Effect of site of lactate infusion on regional lactate exchange in pigs
Background The rate of extra-hepatic lactate production and the route of influx of lactate to the liver may influence both hepatic and extra-hepatic lactate exchange. We assessed the dose-response of hepatic and extra-hepatic lactate exchange during portal and central venous lactate infusion. Methods Eighteen pigs randomly received either portal (n=5) or central venous (n=7) lactate infusion or saline (n=6). Sodium lactate was infused at 33, 66, 99, and 133 ”mol kgâ1 minâ1 for 20 min each. Systemic and regional abdominal blood flows and plasma lactate were measured at 20 min intervals until 1 h post-infusion, and regional lactate exchange was calculated (area under lactate uptake-time curve). Results Total hepatic lactate uptake [median (95% confidence interval)] during the experimental protocol (140 min) was higher during portal [8198 (5487-12 798) ”mol kgâ1] than during central venous lactate infusion [4530 (3903-5514) ”mol kgâ1, P<0.05]. At a similar hepatic lactate delivery (âŒ400 ”mol kgâ1 minâ1), hepatic lactate uptake [mean and standard deviation (sd)] was higher during portal [118 (sd 55) ”mol kgâ1 minâ1] than during central venous lactate infusion [44 (12) ”mol kgâ1 minâ1, P<0.05]. Time courses of arterial lactate concentrations and lactate uptake at other measured regions were similar in both groups. Conclusions Higher hepatic lactate uptake during portal compared with central venous lactate infusion at a similar total hepatic lactate influx underlines the role of portal vein lactate concentration in total hepatic lactate uptake capacity. Arterial lactate concentration does not depend on the site of lactate infusion. At higher arterial lactate concentrations, all regions participated in lactate uptak
Baseline concentrations of biliary PAH metabolites in perch (Perca fluviatilis) in the open Gulf of Finland and in two coastal areas
Female perch (Perca fluviatilis) were sampled annually in late summer from 2006 to 2009 from the open sea of the eastern Gulf of Finland off Haapasaari island to monitor baseline biliary PAH metabolite concentrations. In addition, two coastal locations were sampled in 2008. PAH metabolite concentrations were compared between the open sea and coastal samples and between the sampling years and examined in relation to the body characteristics of perch. Of the PAH metabolites, only 1-hydroxypyrene (1 -OH pyrene) was detected at quantifiable levels in the bile of nearly all perch individuals. There were some annual differences but no temporal trend in the concentration of biliary 1-OH pyrene in perch from Haapasaari. At the coastal locations, 1-OH pyrene concentrations in the bile of perch were significantly higher than in the open sea Haapasaari area, probably due to greater contamination of the coastal sites and differences in feeding behaviour. No correlations between the body characteristics of perch and 1 -OH pyrene concentrations were detected. It is concluded that PAH metabolites in the bile of fish could be measured in the Gulf of Finland to detect oil spills in the open sea, and the cost-effective total fluorescence method could be used in such monitoring programmes. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe
Työasioiden vatvominen vapaa-ajalla yksilön kokemuksena
TiivistelmĂ€. Tutkimuksen tarkoituksena on tarkastella työasioiden vatvomista vapaa-ajalla yksilön kokemuksena. TĂ€ssĂ€ tutkimuksessa vatvomisella (engl. âruminationâ) tarkoitetaan työhön liittyvien asioiden toistuvaa ajattelua vapaa-ajalla. Tutkimme, mitĂ€ asioita yksilö vatvoo, miten ne koetaan ja millaisia vaikutuksia vatvomisella nĂ€hdÀÀn olevan. LisĂ€ksi tutkimme, miten haitallista vatvomista voidaan ehkĂ€istĂ€ yksilön ja organisaation toimesta. Tutkimuksen teoreettisena viitekehyksenĂ€ kĂ€ytettiin Cropleyn ja Zijlstran (2011) teoriaa vatvomisesta. Tutkimusaineisto kerĂ€ttiin kesĂ€llĂ€ 2019 haastatellen kuutta ICT-alan asiantuntijaa. AineistonanalyysimenetelmĂ€nĂ€ kĂ€ytettiin teoriaohjaavaa sisĂ€llönanalyysiĂ€.
Tulosten perusteella vatvominen koettiin positiivisena, negatiivisena tai neutraalina riippuen siitÀ, mitÀ työhön liittyviÀ asioita vatvottiin. Positiivisena koettu vatvominen liittyi esimerkiksi innostaviin työtehtÀviin ja ongelmanratkaisuun, jolloin myös sen vaikutukset nÀhtiin pitkÀlti positiivisina. Negatiivisena koettu vatvominen liittyi muun muassa keskenerÀisiin työtehtÀviin, liialliseen työkuormaan ja organisaatiokulttuurin piirteisiin. TÀmÀ vaikutti heikentÀvÀsti unenlaatuun ja keskittymiskykyyn sekÀ aiheutti uupumusta. Vatvomisen neutraalissa kokemuksessa vatvominen nÀhtiin luonnollisena osana työelÀmÀÀ ja omaa identiteettiÀ. MerkittÀvinÀ tekijöinÀ vatvomisen ehkÀisyn kannalta nÀyttÀytyivÀt esimies-alaissuhde, organisaation yhteiset kÀytÀnteet sekÀ vapaa-ajan aktiviteetit.
Tutkimus tarjoaa tĂ€rkeÀÀ tietoa vatvomisen kokemuksesta ja mahdollisista keinoista haitallisen vatvomisen ehkĂ€isyyn. Tutkimuksen tuloksia voidaan hyödyntÀÀ organisaatioiden kĂ€ytĂ€ntöjen ja prosessien kehittĂ€misen tukena haitallisen vatvomisen vĂ€hentĂ€miseksi.Employeeâs experiences of work-related rumination. Abstract. The aim of this study is to examine employeeâs views and experiences about work-related rumination. Rumination is conceptualized as repetitive thinking of work-related affairs during off-job time. This study explores how rumination is conceived and how it affects the individual. This research also investigates how to prevent negative rumination in individual and organizational levels.
The theoretical framework of this study was Cropley and Zijlstraâs (2011) theory of work-related rumination. The research was conducted using a qualitative approach and the data consisted of six specialists working in a Finnish ICT-company. The data was gathered using interviews and analysed with content analysis during summer 2019.
The results show that depending on the subject of the work-related rumination it was experienced as positive, negative or neutral. Positive rumination was connected to inspiring tasks and problem solving at work. Negative rumination was linked to unfinished tasks, high workload and aspects in organizational culture. This affected negatively to sleep quality and concentration and caused exhaustion. Neutral rumination was seen as a natural part of working life and oneâs identity. The employer-employee relationship, shared practices in the organization and employeeâs free time activities were remarkable for preventing negative rumination.
The results of the present study cannot be generalized. However, the study offers valuable insights into employeeâs experiences about rumination and possible ways to prevent negative rumination. The results can be used to improve organizationsâ processes and practices for minimalizing the negative aspects of rumination
Enhancement of adhesion and promotion of osteogenic differentiation of human adipose stem cells by poled electroactive poly(vinylidene fluoride)
Poly(vinylidene fluoride) (PVDF) is a biocompatible material with excellent electroactive properties. Non-electroactive α-PVDF and electroactive ÎČ-PVDF were used to investigate the substrate polarization and polarity influence on the focal adhesion size and number as well as on human adipose stem cells (hASCs) differentiation. hASCs were cultured on different PVDF surfaces adsorbed with fibronectin and focal adhesion size and number, total adhesion area, cell size, cell aspect ratio and focal adhesion density were estimated using cells expressing EGFP-vinculin. Osteogenic differentiation was also determined using a quantitative alkaline phosphatase assay. The surface charge of the poled PVDF films (positive or negative) influenced the hydrophobicity of the samples, leading to variations in the conformation of adsorbed extracellular matrix (ECM) proteins, which ultimately modulated the stem cell adhesion on the films and induced their osteogenic differentiation.The study was supported financially by the Academy of Finland (136288,
140978 and 256931), the Sigrid Jusélius Foundation, the Pirkanmaa Hospital District and the
Finnish Funding Agency for Technology and Innovation (TEKES). This study was also
supported by FEDER through the COMPETE Program, by the Portuguese Foundation for
Science and Technology (FCT) in the framework of the Strategic Project PEST- C/FIS/UI607/2011 and by projects NANO/NMed-SD/0156/2007 and PTDC/CTM
NAN/112574/2009. The autors also thank the project Matepro â Optimizing Materials and
Processesâ, ref. NORTE-07-0124-FEDER-000037â, co-funded by the âPrograma Operacional
Regional do Norteâ (ON.2 â O Novo Norte), under the âQuadro de ReferĂȘncia EstratĂ©gico
Nacionalâ (QREN), through the âFundo Europeu de Desenvolvimento Regionalâ (FEDER). V.S.
and C.R. thank the FCT for the SFRH/BPD/63148/2009 and SFRH/BPD/90870/2012 grants,
respectively
Surface Modification of Bioresorbable Phosphate Glasses for Controlled Protein Adsorption
The traditional silicate bioactive glasses exhibit poor thermal processability, which inhibits fiber drawing or sintering into scaffolds. The composition of the silicate glasses has been modified to enable hot processing. However, the hot forming ability is generally at the expense of bioactivity. Metaphosphate glasses, on the other hand, possess excellent thermal processability, congruent dissolution, and a tailorable degradation rate. However, due to the layer-by-layer dissolution mechanism, cells do not attach to the material surface. Furthermore, the congruent dissolution leads to a low density of OH groups forming on the glass surface, limiting the adsorption of proteins. It is well regarded that the initial step of protein adsorption is critical as the cells interact with this protein layer, rather than the biomaterial itself. In this paper, we explore the possibility of improving protein adsorption on the surface of phosphate glasses through a variety of surface treatments, such as washing the glass surface in acidic (pH 5), neutral, and basic (pH 9) buffer solutions followed or not by a treatment with (3-aminopropyl)triethoxysilane (APTS). The impact of these surface treatments on the surface chemistry (contact angle, ζ-potential) and glass structure (FTIR) was assessed. In this manuscript, we demonstrate that understanding of the material surface chemistry enables to selectively improve the adsorption of albumin and fibronectin (used as model proteins). Furthermore, in this study, well-known silicate bioactive glasses (i.e., S53P4 and 13-93) were used as controls. While surface treatments clearly improved proteins adsorption on the surface of both silicate and phosphate glasses, it is of interest to note that protein adsorption on phosphate glasses was drastically improved to reach similar protein grafting ability to the silicate bioactive glasses. Overall, this study demonstrates that the limited cell/phosphate glass biological response can easily be overcome through deep understanding and control of the glass surface chemistry
The influence of learner characteristics on degree and type of participation in a CSCL environment
Computer-Supported Collaborative Learning (CSCL) is often presented as a promising learning method. However, it is also facing some new challenges. Apart from answering the question of whether or not working with CSCL generates satisfying learning outcomes, it is important to determine whether or not all participants profit from collaboration, with the computer as a means of communication. This paper describes the implementation and effects of an experimental program in 5 classes with a total of 120 students in elementary education who, in groups of four, engaged in Knowledge Forum discussion tasks on the subject of healthy eating. The study explores whether or not differences occur in the participation of students who differ in gender, sociocultural background and ability, and whether or not computer skills, computer attitudes, comprehensive reading scores and popularity with classmates are related to student participation. Studentsâ participation in this CSCL environment appears to be dependent on a number of learner characteristics. Girls contribute more words to the discussions than boys do and are more dependent on their computer skills in this production. Students who are good at comprehensive reading also contribute more words. Popularity among classmates appears to influence the degree of participation further. We also found indications that students with immigrant parents write fewer contributions than those whose parents are not immigrants
Evolutionary conservation and post-translational control of S-adenosyl-L-homocysteine hydrolase in land plants
Trans-methylation reactions are intrinsic to cellular metabolism in all living organisms. In land plants, a range of substrate-specific methyltransferases catalyze the methylation of DNA, RNA, proteins, cell wall components and numerous species-specific metabolites, thereby providing means for growth and acclimation in various terrestrial habitats. Trans-methylation reactions consume vast amounts of S-adenosyl-L-methionine (SAM) as a methyl donor in several cellular compartments. The inhibitory reaction by-product, S-adenosyl-L-homocysteine (SAH), is continuously removed by SAH hydrolase (SAHH), which essentially maintains trans-methylation reactions in all living cells. Here we report on the evolutionary conservation and post-translational control of SAHH in land plants. We provide evidence suggesting that SAHH forms oligomeric protein complexes in phylogenetically divergent land plants and that the predominant protein complex is composed by a tetramer of the enzyme. Analysis of light-stress-induced adjustments of SAHH inArabidopsis thalianaandPhyscomitrella patensfurther suggests that regulatory actions may take place on the levels of protein complex formation and phosphorylation of this metabolically central enzyme. Collectively, these data suggest that plant adaptation to terrestrial environments involved evolution of regulatory mechanisms that adjust the trans-methylation machinery in response to environmental cues
PROTEIN PHOSPHATASE 2A-B 'gamma Controls Botrytis cinerea Resistance and Developmental Leaf Senescence
Plants optimize their growth and survival through highly integrated regulatory networks that coordinate defensive measures and developmental transitions in response to environmental cues. Protein phosphatase 2A (PP2A) is a key signaling component that controls stress reactions and growth at different stages of plant development, and the PP2A regulatory subunit PP2A-B'gamma is required for negative regulation of pathogenesis responses and for maintenance of cell homeostasis in short-day conditions. Here, we report molecular mechanisms by which PP2A-B'gamma regulates Botrytis cinerea resistance and leaf senescence in Arabidopsis (Arabidopsis thaliana). We extend the molecular functionality of PP2A-B'gamma to a protein kinase-phosphatase interaction with the defense-associated calcium-dependent protein kinase CPK1 and present indications this interaction may function to control CPK1 activity. In presenescent leaf tissues, PP2A-B'gamma is also required to negatively control the expression of salicylic acid-related defense genes, which have recently proven vital in plant resistance to necrotrophic fungal pathogens. In addition, we find the premature leaf yellowing of pp2a-b'gamma depends on salicylic acid biosynthesis via SALICYLIC ACID INDUCTION DEFICIENT2 and bears the hallmarks of developmental leaf senescence. We propose PP2A-B'gamma age-dependently controls salicylic acid-related signaling in plant immunity and developmental leaf senescence.Peer reviewe
Recombinant family 3 carbohydrate-binding module as a new additive for enhanced enzymatic saccharification of whole slurry from autohydrolyzed eucalyptus globulus wood
By-products resulting from lignocellulosics pretreatment affect the digestibility of resulting whole slurries, but this can be minimized by additives supplementation. In this work, a family 3 carbohydrate-binding module (CBM3), recombinantly produced from Escherichia coli, was used as additive in the enzymatic hydrolysis of the whole slurry from autohydrolyzed Eucalyptus globulus wood (EGW). At the higher dosage used (30 mg/gsolids), CBM3 led to an increase in glucose yield from 75 to 89%. A similar result was obtained for bovine serum albumin (BSA) (11% increase), which has a well-documented additive effect. CBM3 had no effect on the non-productive binding of enzymes, since it could not bind to EGW lignin, while it rapidly bound to cellulose, as shown by fluorescence microscopy. CBM3 is a valid additive for enhanced lignocellulosic saccharification and a valuable alternative to costly additives (e.g. polyethylene glycol) as it can be affordably produced from heterologous bacterium, thus contributing to more cost-efficient biomass valorization bioprocesses.This work was developed under the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020âPrograma Operacional Regional do Norte. The research leading to the reported results has received funding from Fundação para a CiĂȘncia e a Tecnologia (FCT) through the project MultiBioreïŹnery (POCI-01â0145-FEDER-016403) and through grants to C. Oliveira (SFRH/BPD/110640/2015) and D. Gomes (SFRH/BD/88623/2012).info:eu-repo/semantics/publishedVersio
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