938 research outputs found
Cover Image
No full textThe cover image [of the new jounal], by Y. Hellsten and L. Gliemann, is based on the review Limb vascular function in women—Effects of female sex hormones and physical activity, DOI: 10.1002/tsm2.3
Partial neuromuscular blockade in humans enhances muscle blood flow during exercise independently of muscle oxygen uptake and acetylcholine receptor blockade
No full textThis study examined the role of acetylcholine for skeletal muscle blood flow during exercise by use of the competitive neuromuscular blocking agent cisatracurium in combination with the acetylcholine receptor blocker glycopyrrone. Nine healthy male subjects performed a 10-min bout of one-legged knee-extensor exercise (18 W) during control conditions and with cisatracurium blockade, as well as with cisatracurium blockade with prior glycopyrrone infusion. Thigh blood flow and vascular conductance in control and with cisatracurium infusion were similar at rest and during passive movement of the leg, but higher (P < 0.05) during exercise with cisatracurium than in control (3.83 +/- 0.42 vs. 2.78 +/- 0.21 l/min and 26.9 +/- 3.4 vs. 21.8 +/- 2.0 ml.min(-1).mmHg(-1) at the end of exercise). Thigh oxygen uptake was similar in control and with cisatracurium infusion both at rest and during exercise, being 354 +/- 33 and 406 +/- 34 ml/min, at the end of exercise. Combined infusion of cisatracurium and glycopyrrone caused a similar increase in blood flow as cisatracurium infusion alone. The current results demonstrate that neuromuscular blockade leads to enhanced thigh blood flow and vascular conductance during exercise, events that are not associated with either acetylcholine or an increased oxygen demand. The results do not support an essential role for acetylcholine, released form the neuromuscular junction, in exercise hyperemia or for the enhanced blood flow during neuromuscular blockade. The enhanced exercise hyperemia during partial neuromuscular blockade may be related to a greater recruitment of fast-twitch muscle fibers
Konstuniversitetet
No full textHögskoleutbildningarna inom det konstnärliga området är mångfasetterade och täcker många konstformer inom musik, dans, teater, cirkus, bild, foto, design, konsthantverk, textil, arkitektur, skrivande, för att bara nämna några. Uttrycken är publika, ofta förankrade i historia och tradition men även i ständig omförhandling med rådande samhällsdiskurser och kulturpolitik. Med boken Konstuniversitetet , fördjupas perspektiven kring de pedagogiska, konstnärliga men även organisatoriska utmaningarna inom konstutbildning. En permanent dualism mellan inre växande och yttre krav gör lärande och utbildande inom konst till en ömtålig verksamhet. För utbildaren gäller det att betrakta, förstå, utveckla och stödja – men utan att störa. En fördel är då att det konstnärliga lärandet sker i relationer och att samtal är den vanligaste undervisningsmetoden. Även detta måste dock problematiseras och detta görs på olika sätt i denna antologi. Boken har fyra huvuddelar: konsten, samhället, praktiken och lärande. Författare: Gertrud Sandqvist, Gerd Aurell, Jörgen Dahlqvist, Cecilia Hultberg, Ulf Dalnäs, Magnus Lindén, Bengt Olsson& Einar Nielsen, Hans Hellsten, Y Hofvander Trulsson, Anders Lorentzi, Efva Lilja, Niklas Hald, Mihra Lindblom, Lars Hallnäs, Madelaine Daneberg, Anna Efraimsson, Ulrika Berg, Eva Lundgren
Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume
No full textWe studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training ( approximately 45 km/wk) with frequent high-intensity sessions each consisting of 8-12 30-s sprint runs separated by 3 min of rest (5.7 +/- 0.1 km/wk) with additional 9.9 +/- 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower (P < 0.05) at running speeds of 11, 13, 14.5, and 16 km/h, respectively, in SET, whereas remained the same in Con. No changes in blood lactate during submaximal running were observed. After the IT period, the protein expression of skeletal muscle UCP3 tended to be higher in SET (34 +/- 6 vs. 47 +/- 7 arbitrary units; P = 0.06). Activity of muscle citrate synthase and 3-hydroxyacyl-CoA dehydrogenase, as well as maximal oxygen uptake and 10-km performance time, remained unaltered in both groups. In SET, the capillary-to-fiber ratio was the same before and after the IT period. The present study showed that speed endurance training reduces energy expenditure during submaximal exercise, which is not mediated by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training
Effect of sprint cycle training on activities of antioxidant enzymes in human skeletal muscle
No full text Hellsten, Ylva, Fred S. Apple, and Bertil Sjödin.Effect of sprint cycle training on activities of antioxidant enzymes in human skeletal muscle. J. Appl. Physiol. 81(4): 1484–1487, 1996.—The effect of intermittent sprint cycle training on the level of muscle antioxidant enzyme protection was investigated. Resting muscle biopsies, obtained before and after 6 wk of training and 3, 24, and 72 h after the final session of an additional 1 wk of more frequent training, were analyzed for activities of the antioxidant enzymes glutathione peroxidase (GPX), glutathione reductase (GR), and superoxide dismutase (SOD). Activities of several muscle metabolic enzymes were determined to assess the effectiveness of the training. After the first 6-wk training period, no change in GPX, GR, or SOD was observed, but after the 7th week of training there was an increase in GPX from 120 ± 12 (SE) to 164 ± 24 μmol ⋅ min−1 ⋅ g dry wt−1( P < 0.05) and in GR from 10.8 ± 0.8 to 16.8 ± 2.4 μmol ⋅ min−1 ⋅ g dry wt−1( P < 0.05). There was no significant change in SOD. Sprint cycle training induced a significant ( P < 0.05) elevation in the activity of phosphofructokinase and creatine kinase, implying an enhanced anaerobic capacity in the trained muscle. The present study demonstrates that intermittent sprint cycle training that induces an enhanced capacity for anaerobic energy generation also improves the level of antioxidant protection in the muscle. </jats:p
Temperature-dependent release of ATP from human erythrocytes: Mechanism for the control of local tissue perfusion
No full textCopyright @ 2012 The AuthorsThis article has been made available through the Brunel Open Access Publishing Fund.Human limb muscle and skin blood flow increases significantly with elevations in temperature, possibly through physiological processes that involve temperature-sensitive regulatory mechanisms. Here we tested the hypothesis that the release of the vasodilator ATP from human erythrocytes is sensitive to physiological increases in temperature both in vitro and in vivo, and examined potential channel/transporters involved. To investigate the source of ATP release, whole blood, red blood cells (RBCs), plasma and serum were heated in vitro to 33, 36, 39 and 42°C. In vitro heating augmented plasma or ‘bathing solution’ ATP in whole blood and RBC samples, but not in either isolated plasma or serum samples. Heat-induced ATP release was blocked by niflumic acid and glibenclamide, but was not affected by inhibitors of nucleoside transport or anion exchange. Heating blood to 42°C enhanced (P < 0.05) membrane protein abundance of cystic fibrosis transmembrane conductance regulator (CFTR) in RBCs. In a parallel in vivo study in humans exposed to whole-body heating at rest and during exercise, increases in muscle temperature from 35 to 40°C correlated strongly with elevations in arterial plasma ATP (r2 = 0.91; P = 0.0001), but not with femoral venous plasma ATP (r2 = 0.61; P = 0.14). In vitro, however, the increase in ATP release from RBCs was similar in arterial and venous samples heated to 39°C. Our findings demonstrate that erythrocyte ATP release is sensitive to physiological increases in temperature, possibly via activation of CFTR-like channels, and suggest that temperature-dependent release of ATP from erythrocytes might be an important mechanism regulating human limb muscle and skin perfusion in conditions that alter blood and tissue temperature.This article is made available through the Brunel Open Access Publishing Fund
Transitional Justice, Gender Programming, and the UNSCR 1325: African Context and the Case of Kenya
No full textThe article examines the implementation of UNSCR 1325 ‘Women, Peace, and Security’ within the framework of post-colonial feminism. The author argues that in current international development co-operation, there is a need for deeper understanding of the complex, context-relevant social and political power structures and processes that prevent gender programming from enhancing gender justice. As an empirical case study the article discusses the challenges that the implementation of the UNSCR 1325 has been facing in Kenya.</p
The gene expression of numerous SLC transporters is altered in the immortalized hypothalamic cell line N25/2 following amino acid starvation
No full textAmino acids are known to play a key role in gene expression regulation,and in mammalian cells, amino acid signaling is mainly mediated via twopathways, the mammalian target of rapamycin complex 1 (mTORC1) pathwayand the amino acid responsive (AAR) pathway. It is vital for cells tohave a system to sense amino acid levels, in order to control protein andamino acid synthesis and catabolism. Amino acid transporters are crucialin these pathways, due to both their sensing and transport functions. Inthis large-scale study, an immortalized mouse hypothalamic cell line (N25/2)was used to study the gene expression changes following 1, 2, 3, 5 or 16 hof amino acid starvation. We focused on genes encoding solute carriers(SLCs) and putative SLCs, more specifically on amino acid transporters.The microarray contained 28 270 genes and 86.2% of the genes wereexpressed in the cell line. At 5 h of starvation, 1001 genes were upregulatedand 848 genes were downregulated, and among these, 47 genes from theSLC superfamily or atypical SLCs were found. Of these, 15 were genesencoding amino acid transporters and 32 were genes encoding other SLCsor atypical SLCs. Increased expression was detected for genes encodingamino acid transporters from system A, ASC, L, N, T, xc-, and y+. UsingGO annotations, genes involved in amino acid transport and amino acidtransmembrane transporter activity were found to be most upregulated at3 h and 5 h of starvation.Authors and title in the list of papers of Sofie Hellsten's thesis: Hellsten, SV., Perland, E., Lekholm, E., Ahmad, T., Yamskova, O., Fredriksson, R. Amino acid deprivation of neuronal cells changes expression levels of numerous transporters from the SLC family, including several members of the SLC38 family</p
Semipermeable membrane – An artistic research on hiking, camping and the human-nature relationship
No full textTämä maisterin opinnäytetyö on taiteellinen tutkimus retkeilystä ja luontosuhteesta. Se on saanut alkunsa perinteisesssä ja sosiaalisessa mediassa näkyvien retkeilyaiheisten kuvien ja tekijän omien retkeilykokemusten välisestä ristiriidasta. Opinnäytetyössään tekijä kokoaa erilaiset retkeilykuvat retkeilykuvasto-käsitteen alle ja tutkii retkeilykokemusten ja retkeilykuvien suhdetta käyttämällä omia retkeilykokemuksiaan taiteellisen työskentelyn materiaalina.
Viime vuosien aikana retkeilyn ja ulkoilmaharrastusten suosio on kasvanut huomattavasti. Lisääntynyt retkeily aiheuttaa ympäristölle epäsuotuisia lieveilmiöitä, joiden vaikutukset kohdistuvat aineelliseeen ympäristöön, retkeilykulttuuriin ja muihin retkeilykokemuksen synnyttäviin tekijöihin. Tekijä esittää retkeilykuvaston osaltaan vaikuttavan retkeilykulttuurin muotoutumiseen. Retkeilykuvat liittyvät erilaisiin luontosuhteisiin, jotka ilmenevät retkeilyssä ja jokapäiväisessä toiminnassa. Luontosuhdetta ja retkeilyä käsitelltiin opinnäytetyössä ympäristötieteilijöiden Risto Willamon ja Yrjö Hailan ajatuksiin tukeutuen.
Opinnäytetyön menetelmänä on tekijän oma taiteellinen praktiikka. Tekijä maalasi puolen vuoden aikana noin 50 teosta samalla kirjoittaen työskentelystään ja siihen liittyvästä ajattelustaan. Opinnäytetyön tutkimusosuus on taiteellisen työskentelyn lopuksi laadittu kuvien ja kaunokirjallisen tekstin muodostama narratiivi taiteellisesta prosessista, jossa tekijä tutki ensisijaisesti omaa ajatteluaan ja luontosuhdettaan kuvallisen työskentelyn avulla. Taiteellisen työskentelyn keskiössä olivat tekijän omat retkeilykokemukset, joita hän prosessin aikana tarkasteli keholllisina ja aistisina kokemuksina sekä suhteuttaen visuaalista ajatteluaan aiempaan retkeilykuvastoon ja retkeilyn visuaaliseen kulttuuriin.
Taiteellisen työskentelyn tulokset painottuvat ensisijaisesti ajatteluun ja tekijän taiteellisten käytäntöjen kehittämiseen, ja ne esitellään opinnäytetyössä ilman teoksista järjestettyä näyttelyä. Tutkielman tuloksena syntyi pohdintaa erityisesti kliseiden ja autenttisuuden sekä objektiivisen havainnon ja subjektiivisen tulkinnan suhteista kuvallisessa ilmaisussa. Opinnäytteessä pohditaan tekijän praktiikan ja opinnäytetyön tuottaman ajattelun pedagogisia mahdollisuuksia taiteen perusopetuksessa.This Master’s thesis is an artistic research on nature, camping and human-nature relationships. It has been motivated by the dissonance between the outdoor-themed images in traditional and social media and the author’s personal experiences of outdoor activities. The author defines a concept of outdoor imagery that covers the different kinds of outdoor-themed images and he studies the relationships between outdoor experiences and the outdoor imagery using his personal experiences of hiking, camping and nature excursions as the material for artistic work.
Over the last years the popularity of hiking and other outdoor activities has increased noticeably. The increase in outdoor activities has caused unwanted side effects in the environment, the cultures of outdoor activities and the other factors of outdoor experiences. The author suggests that the outdoor imagery in part shapes the cultures of outdoor activities. The outdoor-themed images are linked to different kinds of human-nature relationships that manifest in the outdoor activities and the everyday life. In the thesis the human-nature relationships and the outdoor activities were discussed supported by the ideas of the environmental scientists Risto Willamo and Yrjö Haila.
The methodology of the thesis was built on the artistic praxis of the author. The author painted about 50 paintings over a half-year period while also writing about the artistic process and the artistic thinking involved in it. The research section of the thesis is a narrative consisting of literal and visual elements where the author studies primarily his thinking and his relationship with nature through his artistic work. The artistic work focused on the author’s personal outdoor experiences by representing them as corporeal and sensual experiences and by studying his visual thinking in relation to the existing outdoor imagery and the visual cultures of outdoor activities.
The artistic work produced results in the thinking and the development of artistic praxis of the author. The results are presented in the thesis without a presenting the artworks created over the research process in an exhibition. The research process generated discussion concerning the relationships between cliches and authenticity as well as between the objective observation and the subjective interpretation in visual expression. The pedagogical applications of the artistic praxis of the author and the thinking produced by the research process are discussed in the thesis
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