| 1. |
- Karlsson, Björn-Markus, et al.
(författare)
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Sound and vibration : effects on infants' heart rate and heart rate variability during neonatal transport
- 2012
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Ingår i: Acta Paediatrica. - : Wiley-Blackwell. - 0803-5253 .- 1651-2227. ; 101:2, s. 148-154
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport.Methods: Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal.Results: Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels were 0.19m/s(2) and 73dBA, respectively. Higher whole-body vibration was associated with a lower heart rate (p<0.05), and higher sound level was linked to a higher heart rate (p=0.05). The heart rate variability was significantly higher at the end of the transport than at the beginning (p<0.01). Poorer physiologic status was associated with lower heart rate variability (p<0.001) and a lower heart rate (p<0.01). Infants wearing earmuffs had a lower heart rate (p<0.05).Conclusions: Sound and whole-body vibration during neonatal transport exceed recommended levels for adults and sound seem to have a more stressful effect on the infant than vibrations. Infants should wear earmuffs during neonatal transport because of the stress reducing effect.
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| 2. |
- Ahmadpour, Doryaneh, 1973, et al.
(författare)
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Yeast reveals unexpected roles and regulatory features of aquaporins and aquaglyceroporins
- 2014
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Ingår i: Biochimica et Biophysica Acta. General Subjects. - : Elsevier BV. - 0304-4165 .- 1872-8006 .- 0006-3002. ; 1840:5, s. 1482-1491
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Forskningsöversikt (refereegranskat)abstract
- Background: The yeast Saccharomyces cerevisiae provides unique opportunities to study roles and regulation of aqua/glyceroporins using frontline tools of genetics and genomics as well as molecular cell and systems biology. Scope of review: S. cerevisiae has two similar orthodox aquaporins. Based on phenotypes mediated by gene deletion or overexpression as well as on their expression pattern, the yeast aquaporins play important roles in key aspects of yeast biology: establishment of freeze tolerance, during spore formation as well as determination of cell surface properties for substrate adhesion and colony formation. Exactly how the aquaporins perform those roles and the mechanisms that regulate their function under such conditions remain to be elucidated. S. cerevisiae also has two different aquaglyceroporins. While the role of one of them, Yfl054c, remains to be determined, Fps1 plays critical roles in osmoregulation by controlling the accumulation of the osmolyte glycerol. Fpsl communicates with two osmo-sensing MAPK signalling pathways to perform its functions but the details of Fps1 regulation remain to be determined. Major conclusions: Several phenotypes associated with aqua/glyceroporin function in yeasts have been established. However, how water and glycerol transport contribute to the observed effects is not understood in detail. Also many of the basic principles of regulation of yeast aqua/glyceroporins remain to be elucidated. General significance: Studying the yeast aquaporins and aquaglyceroporins offers rich insight into the life style, evolution and adaptive responses of yeast and rewards us with discoveries of unexpected roles and regulatory mechanisms of members of this ancient protein family. This article is part of a Special Issue entitled Aquaporins. (c) 2013 Elsevier B.V. All rights reserved.
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| 3. |
- Bengtsson, Marie, 1977-
(författare)
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The Art of Replicating
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fokus för den här avhandlingen är företag som växer genom replikering, det vill säga genom att skapa och driva liknande enheter på många olika platser, så som t.ex. McDonald’s och Starbucks. Replikerande företags livscykel beskrivs normalt i termer av en initial utforskande fas, följt av en exploateringsfas där standardisering är en hörnsten i företagets strategi - vad som därefter följer är emellertid oklart. Varsamt åldrande innebär dock vanligtvis att man måste anta de utmaningar som följer i kölvattnet av stabilitet och förändring.Modeindustrin kan beskrivas som oberäknelig och föränderlig, och har varit så i århundraden. Konkurrensen är stenhård och efterfrågan är svår att förutse då mode och trender hela tiden förändras. Med tanke på det beroende av standadisering som finns i replikerande företag kan man fråga sig hur ett företag i modebranschen kan hantera en replikeringsstrategi. Den trade-off som finns mellan fördelarna av standardisering och fördelarna av lärande och anpassning ställs på sin spets i ett sådant företag.Renässansen stora konstnärer mötte en liknande utmaning om än i lite annan form. Baserat på kollektivt arbete skapade renässansens verkstäder såväl replikor som nya verk i mästarens namn. För verkstaden betydde det att de skulle replikera mästarens stil till den grad att enskilda bidrag från lärlingar inte gick att skilja från mästarens eget arbete. Nya lärlingar var tvungna att lära sig att “emulera” mästarens stil och fungerar som en förlängning av hans hand och öga.Den här avhandlingen tar därför avstamp i konstens värld, mer specifikt i Renässansen, för att utforska hur ett konstinspirerat förhållningssätt kan öka vår förståelse av replikeringsprocesser i erfarna företag som är verksamma i starkt föränderliga branscher och vars strategi bygger på replikering. Det empiriska underlaget för avhandlingen är en djupgående fallstudie av den svenska modekedjan Hennes & Mauritz, och bygger på deltagande observation såväl i etablerade butiker som under öppningen av nya.
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| 4. |
- Burström, Lage, 1954-, et al.
(författare)
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Acute effects of vibration on thermal perception thresholds
- 2006
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Ingår i: Diagnosis of injuries caused by hand-transmitted vibration - 2nd International workshop, Göteborg, 2006. - : Springer Science and Business Media LLC.
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Konferensbidrag (refereegranskat)abstract
- Objective This study focuses on the acute effects of vibration and how vibrations influence the measures of the thermal perception thresholds during different vibration magnitudes, frequencies, and durations.Methods The fingers of ten healthy subjects, five males and five females, were exposed to vibration under 16 conditions with a combination of different frequency, intensity and exposure time. The vibration frequency was 31.5 and 125 Hz and exposure lasted between 2 and 16 min. The energy-equivalent frequency weighted acceleration, according to ISO 5349-1, for the experimental time of 16 min was 2.5 or 5.0 m/s(2) (r.m.s.), corresponding to a 8-h equivalent acceleration, A(8) of 0.46 and 0.92 m/s(2), respectively. A measure of the thermal perception of cold and warmth was conducted before the different exposures to vibration. Immediately after the vibration exposure the acute effect was measured continuously on the exposed index finger for the first 75 s, followed by 30 s of measures at every minute for a maximum of 10 min. If the subject's thermal thresholds had not recovered, the measures continued for a maximum of 30 min with measurements taken every 5 min.Results For all experimental conditions and 30 s after exposure, the mean changes of the thresholds compared with the pre-test were found to be 0.05 and -0.67C for the warmth and cold thresholds, respectively. The effect of the vibration exposure was only significant on the cold threshold and only for the first minute after exposure when the threshold was decreased. The warmth threshold was not significantly affected at all. The frequency and the exposure time of the vibration stimuli had no significant influence on the perception thresholds for the sensation of cold or warmth. Increased equivalent frequency weighted acceleration resulted in a significant decrease of the subjects' cold threshold, not the warmth. The thresholds were unaffected when changes in the vibration magnitude were expressed as the frequency weighted acceleration or the unweighted acceleration.Conclusion When testing for the thermotactile thresholds, exposure to vibration on the day of a test might influence the results. Until further knowledge is obtained the previous praxis of 2 h avoidance of vibration exposure before assessment is recommended.
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| 5. |
- Geijer, Cecilia, 1980, et al.
(författare)
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Yeast Aquaglyceroporins Use the Transmembrane Core to Restrict Glycerol Transport
- 2012
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 287:28, s. 23562-23570
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Tidskriftsartikel (refereegranskat)abstract
- Aquaglyceroporins are transmembrane proteins belonging to the family of aquaporins, which facilitate the passage of specific uncharged solutes across membranes of cells. The yeast aquaglyceroporin Fps1 is important for osmoadaptation by regulating intracellular glycerol levels during changes in external osmolarity. Upon high osmolarity conditions, yeast accumulates glycerol by increased production of the osmolyte and by restricting glycerol efflux through Fps1. The extended cytosolic termini of Fps1 contain short domains that are important for regulating glycerol flux through the channel. Here we show that the transmembrane core of the protein plays an equally important role. The evidence is based on results from an intragenic suppressor mutation screen and domain swapping between the regulated variant of Fps1 from Saccharomyces cerevisiae and the hyperactive Fps1 ortholog from Ashbya gossypii. This suggests a novel mechanism for regulation of glycerol flux in yeast, where the termini alone are not sufficient to restrict Fps1 transport. We propose that glycerol flux through the channel is regulated by interplay between the transmembrane helices and the termini. This mechanism enables yeast cells to fine-tune intracellular glycerol levels at a wide range of extracellular osmolarities.
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| 6. |
- Johansson, Markus, et al.
(författare)
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Effects of the Covid-19 pandemic on the Swedish Biogas Sector
- 2024
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Ingår i: Energy for Sustainable Development. - : ELSEVIER. - 0973-0826 .- 2352-4669. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- With a growing population, the world requires solutions that provide energy, waste management, transportation, and nutrient recovery in a sustainable manner. Biogas is a local system solution that can fill these needs and make society more self-sufficient. In an increasingly uncertain world, forthcoming crises and external economic pressure will affect industries, including biogas, and lead to higher risk. To manage these uncertainties and to create resilience, knowledge needs to be gathered on how industries providing system solution, such as the biogas industry, are affected by crises. The Covid-19 pandemic offers the possibility to analyse the effects of a global crisis in real-time. The aim of this study is to investigate the effects the covid-19 pandemic had on the production, distribution, and demand of biogas in Sweden. Ten semi-structured interviews were carried out with different actors in the biogas value chain. Some key findings in the result include continued availability of substrate for biogas production but with a changed composition, increased demand for biofertilizer and smallscale production of biogas, and disturbances in biogas related policies. The underlying factors contributing to these effects can be attributed to pandemic related restrictions, disturbances in logistical chains, increased energy prices and political factors. The lessons learned are that the biogas industry should try to be decoupled from policies and review the resilience of the supply chains. If this is managed, biogas is a way forward for providing waste management, transportation fuel and nutrient recovery while facilitating the transition towards selfsufficient and sustainable societies with resilience against global crises.
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| 7. |
- Lindkvist, Markus, et al.
(författare)
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Absolute quantifications of oxy- and deoxyhemoglobin concentrations by combination of differentially resolved spectroscopy and spatially resolved spectroscopy
- 2015
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Ingår i: Spectroscopy Letters. - : Taylor & Francis. - 0038-7010 .- 1532-2289. ; 48:3, s. 170-172
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Tidskriftsartikel (refereegranskat)abstract
- This letter proposes a theoretical framework to calculate absolute concentrations of oxy- and deoxyhemoglobin using continuous-wave near-infrared spectroscopy. While previous methods on this topic require assumptions on constant blood volume, the proposed method does not. Equations for the absolute concentrations were derived from a combination of the modified Beer-Lambert equation and the theory of diffusion of photons in turbid media. The method has an advantage over and is theoretically consistent with previous methods. It needs yet to be evaluated in an experimental study.
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| 8. |
- Lindkvist, Markus, et al.
(författare)
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Coherent Derivation of Equations for Differential Spectroscopy and Spatially Resolved Spectroscopy : An undergraduate tutorial
- 2013
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Ingår i: Spectroscopy Letters. - : Taylor & Francis. - 0038-7010 .- 1532-2289. ; 46:4, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- Near-infrared spectroscopy (NIRS) is a spectroscopic method that is frequently used in health care and sports medicine to monitor oxygenation parameters in biological tissue. This tutorial provides a coherent derivation of equations for differential spectroscopy and spatially resolved spectroscopy, from basic theories to implementable equations. The basic theories are applicable to any kind of tissue oximeter but mainly focus on continuous-wave instruments.
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| 9. |
- Lindkvist, Markus, et al.
(författare)
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Precontractile optical response during excitation-contraction in human muscle revealed by non-invasive high-speed spatiotemporal NIR measurement
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- During muscle contraction the excitation-contraction process mediates the neural input and mechanical output. Proper muscle function and body locomotion depends on the status of the elements in the same process. However, non-invasive and in-vivo methods to study this are not available. Here we show the existence of an optical response occurring during the excitation-contraction process in human biceps brachii muscle. We developed a non-invasive instrument from a photodiode array and light emitting diodes to detect spatially propagating (similar to 5 m/s) and precontractile (similar to 6 ms onset) optical signals closely related to the action potential during electrostimulation. Although this phenomenon was observed 60 years ago on isolated frog muscle cells in the lab, it has not been shown in-vivo before now. We anticipate our results to be a starting point for a new category in-vivo studies, characterising alterations in the excitation-contraction process in patients with neuromuscular disease and to monitor effects of therapy.
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| 10. |
- Parmentier, Fabrice B. R., et al.
(författare)
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A behavioral study of distraction by vibrotactile novelty
- 2011
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Ingår i: Journal of Experimental Psychology. - : American Psychological Association (APA). - 0096-1523 .- 1939-1277. ; 37:4, s. 1134-1139
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Tidskriftsartikel (refereegranskat)abstract
- Past research has demonstrated that the occurrence of unexpected task-irrelevant changes in the auditory or visual sensory channels captured attention in an obligatory fashion, hindering behavioral performance in ongoing auditory or visual categorization tasks and generating orientation and re-orientation electrophysiological responses. We report the first experiment extending the behavioral study of cross-modal distraction to tactile novelty. Using a vibrotactile-visual cross-modal oddball task and a bespoke hand-arm vibration device, we found that participants were significantly slower at categorizing the parity of visually presented digits following a rare and unexpected change in vibrotactile stimulation (novelty distraction), and that this effect extended to the subsequent trial (postnovelty distraction). These results are in line with past research on auditory and visual novelty and fit the proposition of common and amodal cognitive mechanisms for the involuntary detection of change.
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