Change search
Refine search result
1 - 37 of 37
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • harvard-cite-them-right
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Akinbomi, Julius
    et al.
    University of Borås, School of Engineering.
    Brandberg, Tomas
    University of Borås, School of Engineering.
    Sanni, Adebayo
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Development and dissemination strategies for accelerating biogas production in Nigeria2014In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 9, no 3, p. 5707-5737Article in journal (Refereed)
    Abstract [en]

    Following the worsening energy crisis of unreliable electricity and unaffordable petroleum products coupled with the increase number of poverty-stricken people in Nigeria, the populace is desperately in need of cheap alternative energy supplies that will replace or complement the existing energy sources. Previous efforts by the government in tackling the challenge by citizenship sensitization of the need for introduction of biofuel into the country’s energy mix have not yielded the expected results because of a lack of sustained government effort. In light of the shortcomings, this study assesses the current potential of available biomass feedstock for biogas production in Nigeria, and further proposes appropriate biogas plants, depending on feedstock type and quantity, for the six geopolitical zones in Nigeria. Besides, the study proposes government-driven biogas development systems that could be effectively used to harness, using biogas technology, the estimated 270 TWh of potential electrical energy from 181 million tonnes of available biomass, in the advancement of electricity generation and consequent improvement of welfare in Nigeria.

    Download full text (pdf)
    fulltext
  • 2.
    Bergengren, Jakob
    et al.
    Länsstyrelsen i Jönköping.
    Svensson, Jan-Erik
    University of Borås, Faculty of Librarianship, Information, Education and IT.
    von Proschwitz, Ted
    Naturhistoriska museet, Göteborg.
    Lundberg, Stefan
    Naturhistoriska Riksmuseet.
    A recent Dreissena invasion in an old canal system in northern Europe2015Conference paper (Other academic)
    Abstract [en]

    The Göta Canal was opened in 1832 and connects the Baltic and the Atlantic Sea via the large lakes Vänern and Vättern in south Sweden. Originally used for commercial transport, the canal is today one of the most popular tourist attractions in Sweden with canal cruises, pleasure boating and canoeing. Inventories in 2013 showed that Dreissena mussels recently have invaded lakes, streams and canals in the Motala River drainage basin, i.e. the eastern part of the Göta Canal. According to interviews with local people the mussels may have been there since 2012. During the late summer in 2013 and in 2014 we monitored mussels by scuba diving and we sampled planktonic larval populations in locks and the canal. Dreissena has not dispersed to the western part of the canal system, i.e. west of lake Vättern, where most lakes are oligotrophic with low Ca- andMg-levels. In the eastern part, where several lakes are eutrophic and Ca- and Mg-levels higher, populations have increased very fast. The inventories showed local densities of 10 000 adults m-2 in some eutrophic lakes and larval densities of up to 70 individuals L-1 in the canal water. In Europe, the large range expansion of Dreissena occurred during the late 19th and early 20th century. Why have they dispersed so late into the Göta Canal, i.e. some 170 years after the canal was constructed and some 80 years after they had dispersed to other lakes in Swedennorth of Göta Canal? We can not dismiss dispersal as a a limiting factor but given the historically sustained boat traffic in the region it seems likely that ecological factors may have been important. Freshwaters in Scandinavia are usually low in Ca and Mg and many lakes are characterized by oligotrophic conditions poor in food for filter-feeding Dreissena. In the Göta Canal, changes in biological factors affecting relationships between Dreissena and the regional biota needs to be studied, however. Although we can not explain the delayed invasion we conclude that Dreissena is now established in one of the largest canal system in northern Europe.

  • 3. Buendia, Ruben
    et al.
    Seoane, Fernando
    University of Borås, School of Engineering.
    Bosaeus, Ingvar
    Gil-Pita, Roberto
    Johannsson, G
    Ellegård, Lars
    Lindecrantz, Kaj
    University of Borås, School of Engineering.
    Robustness study of the different immittance spectra and frequency ranges in bioimpedance spectroscopy analysis for assessment of total body composition2014In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, ISSN 0967-3334, Vol. 35, no 7, p. 1373-Article in journal (Refereed)
    Abstract [en]

    The estimation of body fluids is a useful and common practice for assessment of disease status and therapy outcomes. Electrical bioimpedance spectroscopy (EBIS) methods are noninvasive, inexpensive and efficient alternatives for determination of body fluids. One of the main source of errors in EBIS measurements in the estimation of body fluids is capacitive coupling. In this paper an analysis of capacitive coupling in EBIS measurements was performed and the robustness of the different immittance spectra against it tested. On simulations the conductance (G) spectrum presented the smallest overall error, among all immittance spectra, in the estimation of the impedance parameters used to estimate body fluids. Afterwards the frequency range of 10–500 kHz showed to be the most robust band of the G spectrum. The accuracy of body fluid estimations from the resulting parameters that utilized G spectrum and parameters provided by the measuring device were tested on EBIS clinical measurements from growth hormone replacement therapy patients against estimations performed with dilution methods. Regarding extracellular fluid, the correlation between each EBIS method and dilution was 0.93 with limits of agreement of 1.06 ± 2.95 l for the device, 1.10 ± 2.94 l for G [10–500 kHz] and 1.04 ± 2.94 l for G [5–1000 kHz]. Regarding intracellular fluid, the correlation between dilution and the device was 0.91, same as for G [10–500 kHz] and 0.92 for G [5–1000 kHz]. Limits of agreement were 0.12 ± 4.46 l for the device, 0.09 ± 4.45 for G [10–500 kHz] and 0.04 ± 4.58 for G [5–1000 kHz]. Such close results between the EBIS methods validate the proposed approach of using G spectrum for initial Cole characterization and posterior clinical estimation of body fluids status.

  • 4. Bydén, S.
    et al.
    Hansson, E.
    Wemmer, S.
    Arnham, E.
    Carlsson, C.
    Gibson, K.
    Svensson, J-E.
    Schmidtbauer-Crona, J.
    Sjuhärad: fiskeguide, fishing guide, angelführer.2006Report (Other academic)
  • 5.
    Darányi, Sándor
    University of Borås, Swedish School of Library and Information Science.
    Examples of Formulaity in Narratives and Scientific Communication2010In: Proceedings of the 1st International AMICUS Workshop, October 21, 2010, Vienna, Austria / [ed] Sándor Darányi, Piroska Lendvai, University of Szeged, Hungary , 2010, p. 29-35Conference paper (Refereed)
    Abstract [en]

    The AMICUS project was designed to promote scholarly networking in a topical area, motif recognition in texts, including its automation. Prior to doing so however it is necessary to show the theoretical underpinnings of the research idea. My argument is that evidence from different disciplines amounts to fragmented pieces of a bigger picture. By compiling them like pieces of a puzzle, one can see how the concept of formulaity applies to folklore texts and scholarly communication alike. Regardless of the actual name of the concept (e.g. motif, function, canonical form), what matters is that document parts and whole documents can be characterized by standard sequences of content elements, such formulaic expressions enabling higher-level document indexing and classification by machine learning, plus document retrieval. Information filtering plays a key role in the proposed technology.

    Download full text (pdf)
    FULLTEXT01
  • 6.
    Darányi, Sándor
    et al.
    University of Borås, Swedish School of Library and Information Science.
    Forró, László
    Detecting Multiple Motif Co-occurrences in the Aarne-Thompson-Uther Tale Type Catalog: A Preliminary Survey2011In: Anales de Documentación, ISSN 1575-2437, E-ISSN 1697-7904Article in journal (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 7.
    Darányi, Sándor
    et al.
    University of Borås, Swedish School of Library and Information Science.
    Forró, László
    Toward Sequencing Multiple Motif Co-Occurrences2011In: Tanulmányok az örökségmenedzsmentröl 2. Kulturális örökségek kezelése [Studies in Heritage Management 2: The Management of Cultural Heritage]. / [ed] L. Bassa, Információs Társadalomért Alapítvány , 2011, p. 247-260Chapter in book (Refereed)
    Abstract [en]

    Catalogs project subject field experience onto a multidimensional map which is then converted to a hierarchical list. In the case of the Aarne-Thompson-Uther Tale Type Catalog (ATU), this subject field is the global pattern of tale content defining tale types as canonical motif sequences. To extract and visualize such a map, we considered ATU as a corpus and ana-lysed two segments of it, “Supernatural adversaries” (types 300-399) in particular and “Tales of magic” (types 300-749) in general. The two corpora were scru-tinized for multiple motif co-occurrences and visualized by two-mode clustering of a bag-of-motif co-occurrences matrix. Findings indicate the presence of canonical content units above motif level as well. The organization scheme of folk narratives utilizing motif sequences is reminiscent of nucleotid sequences in the genetic code

    Download full text (pdf)
    FULLTEXT01
  • 8.
    Darányi, Sándor
    et al.
    University of Borås, Swedish School of Library and Information Science.
    Lendvai, Piroska
    Proceedings of the First AMICUS Workshop, October 21, 2010 Vienna, Austria2010Collection (editor) (Other academic)
    Abstract [en]

    In cultural heritage objects, digitized or not, content indicators occurring on higher than word level are often called motifs or their equivalent. Their recognition for document classification and retrieval is largely unresolved. Work on identifying rhetorical, narrative and persuasive elements in scientific texts has been progressing, in several, but largely unconnected tracks. The AMICUS project1 (running between 2009 and 2012) set out to test a possible way to resolve these issues, starting with the identification of Proppian functions in folk tale corpora and adapting the solution to the identification of tale motifs or their functional counterparts. AMICUS has devoted its first project year to listing the corpora, tools, methods and contacts available to address these issues. The initiators of the project have identified a common need in the processing of texts from both the cultural heritage (CH) and scientific communication (SC) domains: to perform automated, large-scale higher-order text analytics, i.e., to reach an advanced level of text understanding so that structured knowledge can be extracted from unstructured text. The four research groups propose to tackle an important aspect of this complex issue by investigating how linguistic elements convey motifs in texts from the CH and the SC domains. Our shared working hypothesis is that the identity of higherorder content-bearing elements, i.e., textual units that are typically designated for e.g. document indexing, classification, enrichment, and the like, strongly depends on community perception.

    Download full text (pdf)
    fulltext
  • 9. Drotz, Marcus
    et al.
    Kyrkander, Tina
    Lundberg, Stefan
    Svensson, Jan-Erik
    University of Borås, School of Education and Behavioural Science.
    Främmande arter invaderar våra sötvatten2014Report (Other academic)
    Abstract [sv]

    På senare år har allt fler främmande, invasiva arter börjat breda ut sig i våra sötvatten. En främmande art är en organism som har spridits utanför sitt naturliga utbredningsområde med människans hjälp. Detta kan ha skett avsiktligt eller av misstag. En del av dessa nya arter ställer till problem, andra gör det inte. Här beskrivs övervakningen av några invasiva arter samt hur man kan arbeta för att begränsa dem. Ullhandskrabba, vandrarmussla och sjögull kommer av allt att döma att öka sin utbredning i Sverige de närmaste åren. Det finns idag ett stort antal främmande arter rapporterade från svenska sötvatten och i vår närhet finns ett femtiotal nya arter som kan tänkas etablera sig här. Alla dessa arter kommer inte nödvändigtvis att skapa problem men kunskap om deras biologi och observationer från allmänheten kommer att betyda mycket även i det framtida övervakningsarbetet.

    Download full text (pdf)
    FULLTEXT01
  • 10.
    Ferreira, Jorge A.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Improving the biorefinery "status" of ethanol plants with edible filamentous fungi2016Conference paper (Refereed)
  • 11.
    Iyer, Sweta
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. ENSAIT.
    Behary, Nemeshwaree
    ENSAIT, GEMTEX.
    Nierstrasz, Vincent
    University of Borås, Faculty of Textiles, Engineering and Business.
    Bio-inspired approaches to design bio-luminescent textiles2017Conference paper (Refereed)
    Abstract [en]

    Luminescent textiles are being increasingly used in apparel and sportswear aswell as in buildings, agriculture and automotives, for safety alert or forillumination or as a design feature[1]. Till now these luminescent textiles havebeen based on technologies such as LED, luminescent particles (rare earthmetals and metal oxides), which are not so eco‐friendly[2].Bio‐inspired strategies can provide efficient methods to achieve eco friendlybioluminescent textiles. Research projects have explored ways which aremainly based on culture of bioluminescent algae[3] or bacteria on textiles.Here we present another approach to achieve bioluminesence using biobasedproducts from various living organisms such as fireflies, fungi, earthwormsthat are found in land and in jelly fishes, shrimps, dinoflagellates, corals inmarine environment [4]. In order to mimic the luminescence effect seen innature, reaction mechanisms in various bioluminescent living organisms arestudied and the components or molecules responsible for luminescence areidentified [5‐10]. Most of the time, these involve enzymatic reactions.However the main challenge is to reproduce the bioluminescent mechanismand to adapt it to new materials which can yield some eco efficient bioinspired luminescent textiles.

    Download full text (pdf)
    fulltext
  • 12. Levan, G
    et al.
    Sandberg, P
    Ståhl, Fredrik
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare.
    Dahllöf, B
    Martinsson, T
    Wettergren, Y
    Selective gene amplification in mammalian cells1984In: Hereditas, Wiley-Blackwell Publishing, Inc. , 1984, p. 278-Conference paper (Refereed)
    Abstract [en]

    Selective gene amplification in mammalian cells is now recognized as a common cellular response to selection in a number of different toxic drugs, such as methotrexate (MTX). coformycin, PALA, hydroxyurea (HU), vincristine (VCR). colcemid (COL) and actinomycin D (AMD). Recently, we have studied SEWA murine tumor cells in culture exhibiting the pleiotropic drug resistance (PDR) phenotype. Cells subjected to stepwise selection in AMD, VCR or COL all develop double minute chromosomes (DM), which are a cytogenetic expression of gene amplification. These lines overproduce a 21 K acidic soluble protein and show a high degree of cross resistance, which is typical for the PDR phenotype. Other workers have shown that cells with this phenotype exhibit a shift in membrane-bound glycoproteins from 90- 100 K to 150-170 K. Thus, it is likely that several genes are involved in the development of the PDR phenotype. We have isolated a fraction highly enriched in DM from an AMD-resistant SEWA subline. DNA was extracted from this fraction, and several DM-specific DNA-probes were developed. These probes were used to study independently derived SEWA sublines resistant to AMD, VCR, COL, MTX and HU. The results showed that the investigated amplified DNA-segments in AMD-, VCR-. and COL-resistant lines exhibited a high degree of sequence sequence homology, indicating that basically the same segment was amplified in the 3 inductions. In contrast. the amplified DNA-segments in MTX- and HU-resistant lines that do not show the PDR phenotype, displayed no sequence homology to the probes used.

  • 13. Lim, Ik Soo
    et al.
    Wittek, Peter
    University of Borås, Faculty of Librarianship, Information, Education and IT.
    Parkinson, John
    On the Origin of Risk Sensitivity: The Energy Budget Rule Revisited2015In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 110, p. 69-77Article in journal (Refereed)
    Abstract [en]

    The risk-sensitive foraging theory formulated in terms of the (daily) energy budget rule has been influential in behavioural ecology as well as other disciplines. Predicting risk-aversion on positive budgets and risk-proneness on negative budgets, however, the budget rule has recently been challenged both empirically and theoretically. In this paper, we critically review these challenges as well as the original derivation of the budget rule and propose a ‘gradual’ budget rule, which is normatively derived from a gradual nature of risk sensitivity and encompasses the conventional budget rule as a special case. The gradual budget rule shows that the conventional budget rule holds when the expected reserve is close enough to a threshold for overnight survival, selection pressure being significant. The gradual view also reveals that the conventional budget rule does not need to hold when the expected reserve is not close enough to the threshold, selection pressure being insignificant. The proposed gradual budget rule better fits the empirical findings including those that used to challenge the conventional budget rule.

    Download full text (pdf)
    fulltext
  • 14. Lord, H.
    et al.
    Lagergren, R.
    Svensson, J-E
    Lundqvist, N.
    University of Borås, School of Engineering.
    Sexual dimorphism in bosmina: the role of morphology, drag and swimming.2006In: Ecology, ISSN 0012-9658, Vol. 87, no 3, p. 788-795Article in journal (Refereed)
    Abstract [en]

    Some Bosmina water flea species develop morphological antipredatory defenses, such as long antennules and a high carapace, but in Bosmina (Eubosmina) coregoni gibbera these traits are larger and more variable in females than in males. Here we propose that this sexual dimorphism derives from differential costs of hydrodynamic drag and selection for mobility in males. We tested this hypothesis by estimating drag of several Bosmina morphologies by using scale models sinking in glycerin of different concentrations and viscosities. Body forms included males, sexual and asexual females of B. c. gibbera, and males and asexual females of Bosmina (Eubosmina) longispina, a taxon with less variable body shape. For a given body length or body volume, male models had lower drag than models of sexual and asexual females, suggesting that males can swim 14–28% faster with the same energy consumption. Consistent with this conclusion, video recordings showed that males of B. c. gibbera advanced 55–73% farther than females in each swimming stroke. We conclude that hydrodynamic drag may have significant implications for swimming and evolution of sexual dimorphism in water fleas, and we suggest that males lack the defensive structures of females of B. c. gibbera (e.g., high carapaces) because competition over mates favors low drag.

    Download full text (pdf)
    fulltext
  • 15.
    Rajendran, Karthik
    et al.
    University of Borås, School of Engineering.
    Björk, Hans
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Waste Recovery International Partnership: A Model to Transfer Technology and Create Local Development2014In: Design, Waste & Dignity, CNPq, Olhares , 2014, p. 293-304Chapter in book (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 16.
    Ståhl, Fredrik
    et al.
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare.
    Klinga-Levan, K
    Levan, G
    Szpirer, J
    Szpirer, C
    The rat gene map 1996: fall revision1996Report (Other academic)
  • 17. Ståhl, Fredrik
    et al.
    Wettergren, Y
    Levan, G
    Amplification and overexpression of the mouse mdria gene in nine independently selected multidrug-resistant SEWA murine cell lines1993In: Hereditas, ISSN 0018-0661, E-ISSN 1601-5223, Vol. 118, no 2, p. 121-130Article in journal (Refereed)
    Abstract [en]

    Many different drugs may be used in selecting cells for multidrug resistance (MDR). Enhanced expression and/or gene amplification is known to cause overproduction of membrane-bound 170,000 P-glycoproteins, responsible for the MDR. In rodents, the P-glycoproteins are encoded by a small gene family: mdr 1a, mdr 1b, and mdr2. To evaluate the relationship between the pattern of MDR and the selecting drug, nine MDR sublines were independently selected from a sensitive mouse tumor cell line, SEWATC13K, using three different drugs. Each MDR subline displayed amplification of one or more of the three mdr genes, but only one, mdr 1a, was consistently overexpressed. Thus, our results indicate that the pattern of mdr gene amplification and overexpression is independent of the selective agent. Furthermore, in four of the MDR sublines, where all three mdr genes had been originally amplified, pulsed field gel electrophoresis (PFGE) revealed that amplification of mdr 1a, only, was a second step of gene amplification. In addition, the gene for the calcium-binding protein, sorcin, was coamplified in eight of the nine MDR sublines. The sorcin gene was overexpressed in seven of these eight sublines. Finally, hybridizations with a probe homologous with a putative region of RFLP (restriction fragment length polymorphism), indicated that the amplified sequences originate from one or the other of the two homologous chromosomes with no preference.

  • 18.
    Svensson, Jan-Erik
    et al.
    University of Borås, School of Education and Behavioural Science.
    Lundberg, Stefan
    Inventering av vandrarmusslans larver i Göta kanal och Kinda kanal 20132014Report (Other academic)
    Abstract [sv]

    Under sensommaren 2013 inventerades 14 lokaler längs Göta kanal och tre lokaler längs Kinda kanal på förekomst av larver av vandrarmusslor. Syftet var att dokumentera deras förekomst och att skaffa ytterligare erfarenhet av metoder för provtagning av mussellarver. Inventeringen skedde genom provtagning från land; kvalitativ förekomst dokumenterades genom insamling med planktonhåv medan absoluta tätheter kvantifierades i sållade vattenprov. Mussellarver förekom på samtliga de tre lokalerna nedströms sjön Roxen i Östergötland, dvs. i kanalfåran nedströms slussen i Norsholm, i Motala ström vid Kimstad och i Norrköping. Larver påträffades inte i Kinda kanal-systemet (Linköping, Sturefors, Brokind), inte vid de fyra lokalerna uppströms Roxen i Östergötland, och inte heller vid de sju lokalerna längs kanalen i Västergötland. Vid lokalen i Norsholm skedde provtagning vid två tillfällen, 10 aug och 30 aug. Larvtätheten var hög vid den första icke-replikerade pilotprovtagningen (70 ind/liter) men avsevärt lägre tre veckor senare (4,6±2,3 ind/liter). Skillnaden antyder att produktionen av larver minskade under tidsperioden vilket styrks av en signifikant förändring i larvernas kroppsstorlek som ökade från 0,139±0,030 till 0,189±0,030 mm mellan provtagningarna. En rimlig tolkning är att täthets- och storleksskillnaden var en konsekvens av en minskad nyproduktion av larver samtidigt som överlevande larver tillväxte i storlek. Kortvariga täthetstoppar av mussellarver har ofta rapporterats i andra studier. Detaljerade studier av larvernas säsongsdynamik kräver således en tät provtagning. Vuxna vandrarmusslor kan spridas inom och mellan vattensystem på föremål som förflyttas, t.ex. båtar och vattenväxter, medan larverna i första hand sprids vid förflyttning av vatten. Ballastvatten och fisksumpar i större båtar liksom skvalpvatten i mindre fritidsbåtar och kanoter är tänkbara vektorer för larver. Även vatten i behållare med agnfisk utgör en potentiell risk. Spridningen i kanalsystem underlättas naturligtvis också av slussningen av vatten och av vattnets och larvernas naturliga rörelser. Vandrarmusslor är skildkönade och eftersom larvdödligheten ofta är hög krävs vanligen att många larver förflyttas för att nya populationer ska etableras i nya vattensystem. Dessutom, för att hon- och hangameter ska ha en rimlig möjlighet att träffa på varandra krävs att kolonisatörer av båda könen etablerar sig nära varandra. När vuxna populationer väl har byggts upp kan dock spridningen inom vattensystem gå mycket fort om larvproduktionen är hög. De tätheter vi uppmätt i denna undersökning (4,6 till 70 larver per liter) är av samma storleksordning som i svenska sjöar med etablerade bestånd av vuxna musslor. Vår bedömning är därför att larvproduktionen redan är hög i Roxen och Glan och med tanke på den livliga båttrafiken finns idag inga påtagliga spridningsbegränsningar som hindrar musslornas fortsatta etablering i Göta kanal-systemet. Deras fortsatta utbredning kommer istället att bestämmas av fysikalisk-kemiska och/eller biologiska förhållanden.

    Download full text (pdf)
    FULLTEXT01
  • 19.
    Svensson, Jan-Erik
    et al.
    University of Borås, School of Education and Behavioural Science.
    Lundberg, Stefan
    Plankton i Tyresö-Flaten och Albysjön: Resultat från en undersökning i augusti 20132014Report (Other academic)
    Abstract [sv]

    Djur- och växtplankton undersöktes i Tyresö-Flaten och Albysjön, två sjöar i Tyresö kommun, söder om Stockholm, den 9 augusti 2013. Undersökningen genomfördes på initiativ av Tyresö Fiskevårdsförening. Syftena var 1) att dokumentera mängd och sammansättning av plankton 2) att bedöma om det förekommer en eventuell djurplanktonbrist som kan påverka fiskrekryteringen och 3) att bedöma sjöarnas generella näringsstatus med hjälp av växtplanktonsamhällets egenskaper. Kvantitativa djurplanktonprov togs i epi- och hypolimnion (Limnoshämtare) och kvantitativa växtplanktonprov togs i epilimnion (Rambergrör) över respektive sjös djuphåla. Metodiken var den densamma som används i den nationella miljöövervakningen och följer vedertagna standarder och Naturvårdsverkets handledning för miljöövervakning. Dessutom togs prover på djurplankton i ytvattnet på ytterligare fyra strandnära lokaler i varje sjö, med avsikt att undersöka variationen i djurplanktonförekomst inom sjöarna. Djurplanktonmängden var stor i båda sjöarna. Detta gäller alla de tre viktigaste grupperna, dvs. hjuldjur, hinnkräftor och hoppkräftor. Den rikliga tillgången på djurplankton indikerar att planktonätande fisk hade god tillgång till föda vid undersökningstillfället. Vi bedömer att djurplanktonsamhället ger underlag för en hög produktion av fisk i båda sjöarna, men med något bättre förhållanden i Albysjön, som hade en något högre djurplanktontäthet vid vissa av de strandnära lokalerna. Växtplanktonmängden var normal men dominansen av cyanobakterier var stor och flera släkten med potentiellt toxiska arter påträffades. Det motiverar fortsatt övervakning av planktonsamhället, bl.a. med hänsyn till de hälsorisker som kan råda vid bad i samband med algblomningar. En statusklassning enligt EU:s vattendirektiv med hjälp av växtplanktonsamhället visade på god status vad gäller total växtplanktonbiovolym, men otillfredsställande status vad gäller andel cyanobakterier och förekomst av indikatorarter (TPI-index). Den sammanvägda bedömningen gav klassningen måttlig näringsstatus i både Tyresö-Flaten och Albysjön. Sjöar uppströms i Tyresåsystemet lider också av höga näringshalter och vattenvårdande åtgärder uppströms kommer troligen att förbättra statusen i Tyresö-Flaten och Albysjön. Resultaten från denna undersökning ger perspektiv åt Tyresö Fiskevårdsförenings tidigare undersökningar av djurplanktonmängder ute i Tyresöfjärdarna. Djurplanktontätheten var avsevärt högre i sötvattensmiljöerna i denna undersökning än i de delar av fjärdarna som påverkas av vatten från öppna Östersjön. Ändå drabbas båda miljöerna av periodiska blomningar av cyanobakterier, ett förhållande som ännu inte är helt utrett i vetenskaplig mening.

    Download full text (pdf)
    FULLTEXT01
  • 20. Svensson, J-E
    Djurplankton2006Report (Other academic)
  • 21. Svensson, J-E
    Djurplankton i Djupeträskesjön och Eckern september 20062006Report (Other academic)
  • 22. Svensson, J-E
    Fytoplankton i Örekilsälvens avrinningsområde2006Report (Other academic)
  • 23. Svensson, J-E
    Zoo- och fytoplankton i Ellenösjön och Östersjön i augusti 20052006Report (Other academic)
  • 24.
    Taherzadeh, Mohammad J.
    et al.
    University of Borås, School of Engineering.
    Edebo, L.
    Exploring zygomycetes fungi for industrial applications2009In: New Biotechnology, ISSN 1871-6784, E-ISSN 1876-4347, Vol. 25, no 1, p. 83-Article in journal (Refereed)
  • 25.
    Westman, Johan
    University of Borås, School of Engineering.
    Ethanol production from lignocellulose using high local cell density yeast cultures. Investigations of flocculating and encapsulated Saccharomyces cerevisiae2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Efforts are made to change from 1st to 2nd generation bioethanol production, using lignocellulosics as raw materials rather than using raw materials that alternatively can be used as food sources. An issue with lignocellulosics is that a harsh pretreatment step is required in the process of converting them into fermentable sugars. In this step, inhibitory compounds such as furan aldehydes and carboxylic acids are formed, leading to suboptimal fermentation rates. Another issue is that lignocellulosics may contain a large portion of pentoses, which cannot be fermented simultaneously with glucose by Saccharomyces cerevisiae. In this thesis, high local cell density has been investigated as a means of overcoming these two issues. Encapsulation of yeast in semi-permeable alginate-chitosan capsules increased the tolerance towards furan aldehydes, but not towards carboxylic acids. The selective tolerance can be explained by differences in the concentration of compounds radially through the cell pellet inside the capsule. For inhibitors, gradients will only be formed if the compounds are readily convertible, like the furan aldehydes. Conversion of inhibitors by cells close to the membrane leads to decreased concentrations radially through the cell pellet. Thus, cells closer to the core experience subinhibitory levels of inhibitors and can ferment sugars. Carbohydrate gradients also give rise to nutrient limitations, which in turn trigger a stress response in the yeast, as was observed on mRNA and protein level. The stress response is believed to increase the robustness of the yeast and lead to improved tolerance towards additional stress. Glucose and xylose co-consumption by a recombinant strain, CEN.PK XXX, was also improved by encapsulation. Differences in affinity of the sugar transporters normally result in that glucose is taken up preferentially to xylose. However, when encapsulated, cells in different parts of the capsule experienced high and low glucose concentrations simultaneously. Xylose and glucose could thus be taken up concurrently. This improved the co-utilisation of the sugars by the system and led to 50% higher xylose consumption and 15% higher final ethanol titres. A protective effect by the capsule membrane itself could not be shown. Hence, the interest in flocculation was triggered, as a more convenient way to keep the cells together. To investigate whether flocculation increases the tolerance, like encapsulation, recombinant flocculating yeast strains were constructed and compared with the non-flocculating parental strain. Experiments showed that strong flocculation did not increase the tolerance towards carboxylic acids. However, the tolerance towards a spruce hydrolysate and especially against furfural was indeed increased. The results of this thesis show that high local cell density yeast cultures have the potential to aid against two of the major problems for 2nd generation bioethanol production: inhibitors and simultaneous hexose and pentose utilisation.

    Download full text (pdf)
    fulltext
    Download (pdf)
    spikblad
  • 26.
    Westman, Johan
    et al.
    University of Borås, School of Engineering.
    Mapelli, Valeria
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    High local cell density for efficient 2nd generation bioethanol production by Saccharomyces cerevisiae2013Conference paper (Other academic)
  • 27.
    Westman, Johan
    et al.
    University of Borås, School of Engineering.
    Mapelli, Valeria
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Together we are strong: Yeast flocculation for efficient fermentation of toxic hydrolysates2013Conference paper (Other academic)
  • 28.
    Westman, Johan O.
    University of Borås, School of Engineering.
    Together we are strong! Second generation bioethanol production by flocculating and encapsulated yeast2011Conference paper (Other academic)
  • 29.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J
    University of Borås, School of Engineering.
    Franzen, Carl Johan
    Proteomic Analysis of the Increased Stress Tolerance of Saccharomyces cerevisiae Encapsulated in Liquid Core Alginate-Chitosan Capsules2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 11, p. 12-Article in journal (Refereed)
    Abstract [en]

    Saccharomyces cerevisiae CBS8066 encapsulated in semi-permeable alginate or alginate-chitosan liquid core capsules have been shown to have an enhanced tolerance towards complex dilute-acid lignocellulose hydrolysates and the lignocellulose-derived inhibitor furfural, as well as towards high temperatures. The underlying molecular reasons for these effects have however not been elucidated. In this study we have investigated the response of the encapsulation on the proteome level in the yeast cells, in comparison with cells grown freely in suspension under otherwise similar conditions. The proteomic analysis was performed on whole cell protein extracts using nLC-MS/MS with TMT® labelling and 2-D DIGE. 842 and 52 proteins were identified using each method, respectively. The abundances of 213 proteins were significantly different between encapsulated and suspended cells, with good correlation between the fold change ratios obtained by the two methods for proteins identified in both. Encapsulation of the yeast caused an up-regulation of glucose-repressed proteins and of both general and starvation-specific stress responses, such as the trehalose biosynthesis pathway, and down-regulation of proteins linked to growth and protein synthesis. The encapsulation leads to a lack of nutrients for cells close to the core of the capsule due to mass transfer limitations. The triggering of the stress response may be beneficial for the cells in certain conditions, for example leading to the increased tolerance towards high temperatures and certain inhibitors.

  • 30.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Inhibitor tolerance and flocculation: Characterization of a yeast strain suitable for 2nd generation bioethanol production2011Conference paper (Other academic)
    Abstract [en]

    Robust second generation bioethanol processes require microorganisms able to obtain high yields and production rates while fermenting inhibiting hydrolysates. However, tolerance towards inhibitors like, carboxylic acids, furan aldehydes and phenolic compounds, is still an issue and the factors contributing to improved tolerance are not well known. In this study, the constitutively flocculating Saccharomyces cerevisiae strain CCUG 53310, with good ability to ferment toxic hydrolysates, was compared with S. cerevisiae CBS 8066 in order to characterize the mechanisms of flocculation and the fermentative performance in different inhibitory media. The flocculation of CCUG 53310 depended on cell wall proteins and was partly inhibited by mannose. The flocculating cells also exhibited a significantly higher hydrophobicity than the cells of the non-flocculating strain CBS 8066, which might contribute to the flocculation. The flocculating strain was more tolerant to carboxylic acids and furan aldehydes, but more sensitive to phenolic compounds. Surprisingly, the expression increase of YAP1, ATR1 and FLR1, known to confer resistance against lignocellulose-derived inhibitors, upon addition of various inhibitors to the fermentation medium, was less in CCUG 53310 than in CBS 8066 in most cases. This indicates that the flocculating strain experienced the cultivation conditions as less stressful. The flocculation in itself is a likely cause of this by creating subinhibitory local levels of inhibitors for most cells, allowing the cells in flocs to experience a lower collective stress level.

  • 31.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Inhibitor tolerance by high local cell density Saccharomyces cerevisiae cultures2012Conference paper (Other academic)
  • 32.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Investigations of the inhibitor tolerance of encapsulated Saccharomyces cerevisiae2012Conference paper (Other academic)
  • 33.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Physiological consequences of encapsulating Saccharomyces cerevisiae: A proteomic approach2012Conference paper (Other academic)
  • 34.
    Westman, Johan O.
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Franzén, Carl Johan
    Physiologiccal consequenses of high local cell density saccharomyces cerevisiae cultures2012Conference paper (Other academic)
  • 35.
    Wittek, Peter
    et al.
    University of Borås, Swedish School of Library and Information Science.
    Lim, Ik Soo
    Rubio-Campillo, Xavier
    Quantum Probabilistic Description of Dealing with Risk and Ambiguity in Foraging Decisions2013Conference paper (Refereed)
    Abstract [en]

    A forager in a patchy environment faces two types of uncertainty: ambiguity regarding the quality of the current patch and risk associated with the background opportunities. We argue that the order in which the forager deals with these uncertainties has an impact on the decision whether to stay at the current patch. The order effect is formalised with a context-dependent quantum probabilistic framework. Using Heisenberg's uncertainty principle, we demonstrate the two types of uncertainty cannot be simultaneously minimised, hence putting a formal limit on rationality in decision making. We show the applicability of the contextual decision function with agent-based modelling. The simulations reveal order-dependence. Given that foraging is a universal pattern that goes beyond animal behaviour, the findings help understand similar phenomena in other fields.

    Download full text (pdf)
    FULLTEXT01
  • 36.
    Ylitervo, Päivi
    University of Borås, School of Engineering.
    Concepts for improving ethanol productivity from lignocellulosic materials: encapsulated yeast and membrane bioreactors2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lignocellulosic biomass is a potential feedstock for production of sugars, which can be fermented into ethanol. The work presented in this thesis proposes some solutions to overcome problems with suboptimal process performance due to elevated cultivation temperatures and inhibitors present during ethanol production from lignocellulosic materials. In particular, continuous processes operated at high dilution rates with high sugar utilisation are attractive for ethanol fermentation, as this can result in higher ethanol productivity. Both encapsulation and membrane bioreactors were studied and developed to achieve rapid fermentation at high yeast cell density. My studies showed that encapsulated yeast is more thermotolerant than suspended yeast. The encapsulated yeast could successfully ferment all glucose during five consecutive batches, 12 h each at 42 °C. In contrast, freely suspended yeast was inactivated already in the second or third batch. One problem with encapsulation is, however, the mechanical robustness of the capsule membrane. If the capsules are exposed to e.g. high shear forces, the capsule membrane may break. Therefore, a method was developed to produce more robust capsules by treating alginate-chitosan-alginate (ACA) capsules with 3-aminopropyltriethoxysilane (APTES) to get polysiloxane-ACA capsules. Of the ACA-capsules treated with 1.5% APTES, only 0–2% of the capsules broke, while 25% of the untreated capsules ruptured within 6 h in a shear test. In this thesis membrane bioreactors (MBR), using either a cross-flow or a submerged membrane, could successfully be applied to retain the yeast inside the reactor. The cross-flow membrane was operated at a dilution rate of 0.5 h-1 whereas the submerged membrane was tested at several dilution rates, from 0.2 up to 0.8 h-1. Cultivations at high cell densities demonstrated an efficient in situ detoxification of very high furfural levels of up to 17 g L-1 in the feed medium when using a MBR. The maximum yeast density achieved in the MBR was more than 200 g L-1. Additionally, ethanol fermentation of nondetoxified spruce hydrolysate was possible at a high feeding rate of 0.8 h-1 by applying a submerged membrane bioreactor, resulting in ethanol productivities of up to 8 g L-1 h-1. In conclusion, this study suggests methods for rapid continuous ethanol production even at stressful elevated cultivation temperatures or inhibitory conditions by using encapsulation or membrane bioreactors and high cell density cultivations.

    Download full text (pdf)
    FULLTEXT01
    Download (pdf)
    SPIKBLAD01
  • 37.
    Zamani, Akram
    et al.
    University of Borås, School of Engineering.
    Jeihanipour, Azam
    University of Borås, School of Engineering.
    Edebo, Lars
    Niklasson, Claes
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Determination of glucosamine and N-acetyl glucosamine in fungal cell walls2008In: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 56, no 18, p. 8314-8318Article in journal (Refereed)
    Abstract [en]

    A new method was developed to determine glucosamine (GlcN) and N-acetyl glucosamine (GlcNAc) in materials containing chitin and chitosan, such as fungal cell walls. It is based on two steps of hydrolysis with (i) concentrated sulfuric acid at low temperature and (ii) dilute sulfuric acid at high temperature, followed by one-step degradation with nitrous acid. In this process, chitin and chitosan are converted into anhydromannose and acetic acid. Anhydromannose represents the sum of GlcN and GlcNAc, whereas acetic acid is a marker for GlcNAc only. The method showed recovery of 90.1% of chitin and 85.7-92.4% of chitosan from commercial preparations. Furthermore, alkali insoluble material (AIM) from biomass of three strains of zygomycetes, Rhizopus oryzae, Mucor indicus, and Rhizomucor pusillus, was analyzed by this method. The glucosamine contents of AIM from R. oryzae and M. indicus were almost constant (41.7 +/- 2.2% and 42.0 +/- 1.7%, respectively), while in R. pusillus, it decreased from 40.0 to 30.0% during cultivation from 1 to 6 days. The GlcNAc content of AIM from R. oryzae and R. pusillus increased from 24.9 to 31.0% and from 36.3 to 50.8%, respectively, in 6 days, while it remained almost constant during the cultivation of M. indicus (23.5 +/- 0.8%).

1 - 37 of 37
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • harvard-cite-them-right
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf