69 research outputs found

    Predicting the substrate specificity of a glycosyltransferase implicated in the production of phenolic volatiles in tomato fruit

    Get PDF
    The volatile compounds that constitute the fruit aroma of ripe tomato (Solanum lycopersicum) are often sequestered in glycosylated form. A homology-based screen was used to identify the gene SlUGT5, which is a member of UDP-glycosyltransferase 72 family and shows specificity towards a range of substrates, including flavonoid, flavanols, hydroquinone, xenobiotics and chlorinated pollutants. SlUGT5 was shown to be expressed primarily in ripening fruit and flowers, and mapped to chromosome I in a region containing a QTL that affected the content of guaiacol and eugenol in tomato crosses. Recombinant SlUGT5 protein demonstrated significant activity towards guaiacol and eugenol, as well as benzyl alcohol and methyl salicylate; however, the highest in vitro activity and affinity was shown for hydroquinone and salicyl alcohol. NMR analysis identified isosalicin as the only product of salicyl alcohol glycosylation. Protein modelling and substrate docking analysis were used to assess the basis for the substrate specificity of SlUGT5. The analysis correctly predicted the interactions with SlUGT5 substrates, and also indicated that increased hydrogen bonding, due to the presence of a second hydrophilic group in methyl salicylate, guaiacol and hydroquinone, appeared to more favourably anchor these acceptors within the glycosylation site, leading to increased stability, higher activities and higher substrate affinities

    Studies of salivary pepsin in patients with gastro‐oesophageal reflux disease

    Get PDF
    Background Gastro‐oesophageal reflux disease (GERD) is difficult to diagnose without invasive testing. Peptest (RD Biomed, Hull, UK) is a recently marketed diagnostic tool which aims to quantify salivary pepsin as a marker of reflux, providing a rapid alternative to invasive procedures. Aim To evaluate optimal timing for sampling, and to evaluate the accuracy of Peptest against an independent measure. Methods Thirty diagnosed GERD patients (12 female, mean age 49 [range 20‐72]) and 20 asymptomatic subjects (14 female, mean age 56 [range 21‐56]) were subject to diurnal saliva sampling, with additional samples for 60 minutes following self‐reported reflux symptoms and triggering of a proximal reflux alarm. Saliva samples were split and were analysed by both Peptest and ELISA with operators for each blinded to sample identity. Results Salivary pepsin was detectable in most patients and most volunteers. Peptest scores were significantly lower for patients than controls (P < 0.005). ELISA scores showed no difference between patients and controls. There was no effect of diurnal sampling time (P = 0.75) or time after symptoms (P = 0.76) on Peptest readout. There was no correlation between Peptest and Pepsin ELISA (P = 0.55); Bland‐Altman analysis suggested no agreement between the tests (P = 0.414). Receiver‐operator curve suggests that neither Peptest (P = 0.3328) nor pepsin (P = 0.4476) is useful for predicting GERD. Conclusion Salivary pepsin is not a reliable tool for the diagnosis of GERD

    Functional characterization of SlscADH1, a fruit-ripening associated short-chain alcohol dehydrogenase of tomato

    Get PDF
    A tomato short-chain dehydrogenase-reductase (SlscADH1) is preferentially expressed in fruit with a maximum expression at the breaker stage while expression in roots, stems, leaves and flowers is very weak. It represents a potential candidate for the formation of aroma volatiles by interconverting alcohols and aldehydes. The SlscADH1 recombinant protein produced in Escherichia coli exhibited dehydrogenase-reductase activity towards several volatile compounds present in tomato flavour with a strong preference for the NAD/NADH co-factors. The strongest activity was observed for the reduction of hexanal (Km = 0.175 mM) and phenylacetaldehyde (Km = 0.375 mM) in the presence of NADH. The oxidation process of hexanol and 1-phenylethanol was much less efficient (Kms of 2.9 and 23.0 mM, respectively), indicating that the enzyme preferentially acts as a reductase. However activity was observed only for hexanal, phenylacetaldehyde, (E)-2-hexenal and acetaldehyde and the corresponding alcohols. No activity could be detected for other aroma volatiles important for tomato flavour, such as methyl-butanol/methyl-butanal, 5-methyl-6-hepten-2-one/5-methyl-6-hepten-2-ol, citronellal/citronellol, neral/nerol, geraniol. In order to assess the function of the SlscADH1 gene, transgenic plants have been generated using the technique of RNA interference (RNAi). Constitutive down-regulation using the 35S promoter resulted in the generation of dwarf plants, indicating that the SlscADH1 gene, although weakly expressed in vegetative tissues, had a function in regulating plant development. Fruitspecific down-regulation using the 2A11 promoter had no morphogenetic effect and did not alter the aldehyde/alcohol balance of the volatiles compounds produced by the fruit. Nevertheless, SlscADH1-inhibited fruit unexpectedly accumulated higher concentrations of C5 and C6 volatile compounds of the lipoxygenase pathway, possibly as an indirect effect of the suppression of SlscADH1 on the catabolism of phospholipids and/or integrity of membranes

    Effect of water deficit on the agronomical performance and quality of processing tomato

    Get PDF
    [EN] The influence of irrigation doses on standard and high lycopene tomato varieties has been analyzed during two years in one of the main processing tomato growing areas of Spain. Deficit irrigation (75% ETc) implied a mean reduction in water use of 28.2%, while it caused a significant reduction in the marketable production of 16.4% and increase insoluble solids (8.4%) and Hunter a/b ratio (2.4%). The effect on lycopene content was not significant. Increasing irrigation dose over the recommended 100% ETc had no significant effect on the agronomical performance, while it provoked a dilution effect reducing total soluble solids and lycopene content. The effects on 33 tomato volatiles were also analyzed, 11 of them related to main aroma notes and 22 to the background volatile profile. The effect of deficit irrigation on aroma was dependant on climatic conditions and it may either not have a significant effect on the aroma profile or may lead to higher logodor units in main aroma volatiles. High lycopene cultivars showed higher contents in most volatiles, including some volatiles originated in pathways that have not been related with carotenoid degradation processes. In both the fresh and processing tomato market the improvement of organoleptic and functional quality and the reduction of the impact of agriculture on environment represent main goals. The use of high lycopene cultivars and restricted irrigation would enhance the aroma of materials targeted to quality markets, contributing to increase the efficiency of water use in agriculture. (C) 2016 Elsevier B.V. All rights reserved.This research was funded by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria with the project RTA2007-00095C03. This project was co-funded by the Fondo Europeo de Desarrollo Regional. The authors thank Dr. Vicente Villardon the development and kindly offer of his software MultBiplot for the data analysis.Lahoz, I.; Pérez De Castro, AM.; Valcárcel-Germes, M.; Macua, JI.; Beltran, J.; Rosello Ripolles, S.; Cebolla Cornejo, J. (2016). Effect of water deficit on the agronomical performance and quality of processing tomato. Scientia Horticulturae. 200:55-65. https://doi.org/10.1016/j.scienta.2015.12.051S556520

    -Memphis Minnie, vem är det?

    Get PDF
    Syftet med studien har varit att belysa problematik kring jämställdhet i läromedel sett till genusaspekter som kön och etnicitet. Särskild uppmärksamhet har lagts vid hur kvinnor framställs i populärmusikhistoria. Huvudfrågan har varit att undersöka vilka kriterier man bör beakta när man skapar läromedel ur genusperspektiv. Jag har använt mig av explorativ metod vilken innebär att man samlar in material för att täcka kunskapsluckor på det valda området. En central del av undersökningen bestod i skapandet av läromedel. Mitt resultat pekar på betydelsen av ett tvärvetenskapligt perspektiv för att en text ska vara jämställd. Då värderingar och strukturer ligger inbäddade i språket krävs det att man på olika sätt problematiserar frågor som rör normer och värderingar och inbjuder till dialog för att skapa medvetenhet och kunna förhindra att föreställningar om till exempel kön eller ett skapande av "vi" och "dem" kan passera och befästas obemärkt utan att ifrågasättas. Slutsatsen är att det inte går att skapa ett fullständigt jämställt läromedel. Gestaltandet av verkligheten är alltid generaliserande och ett inkluderande av alla perspektiv innebär ett extremt stort och komplext arbete. Då värderingar ligger inmejslade i språket är det viktigt att genom dialog medvetandegöra elever om problem som rör fördomar, polarisering, föreställningar och normer samt ifrågasätta den det nuvarande dominerande perspektiv som grundar sig på den hegemoniska manligheten. Jag anser att denna studie är av stor vikt för min framtida roll som lärare då jag vill arbeta för en jämställd skola

    An Open Data Model for Emulation Models of Industrial Components

    No full text
    Emulation is a technology, historically mostly used for virtual commissioning of automated industrial systems, and operator training. Trends show that new areas for deployment are being investigated. One way to broaden the scope of emulation technology is to increase emulation detail level. The University of Skövde conduct research within emulation technology, and are developing a higher detail level emulation platform performing  on component level. For transparent and systematic development of component models on this level, an open, extensible, and flexible data model for emulation models of industrial components is wanted. This thesis is contributing to this endeavour by developing a first draft of such a data model. A demonstration is also conducted by implementing a few components into the developing emulation environment, using XML as file format. An iterative "design and creation" methodology was used to develop and implement an object oriented data model. A selected set of industrial components were used to develop and demonstrate the data model, and the final result is visually represented as a class diagram together with explanatory documentation. Using the methodology and data modelling strategy used in this thesis, systematic and transparent development of emulation models on component level is possible in an extensible and flexible manner.Emulering är en teknologi som historiskt mestadels använts vid virtuel idrifttagning av industriella automatiserade system samt vid operatörsträning. Trender visar att nya användningsområden utforskas. Ett sätt att vidga användningsområdet för emulering är att öka dess detaljnivå. Högskolan i Skövde utför forskning inom emulering och utvecklar en emuleringsplattform med utökad detaljnivå, även kallad komponentnivån. För att kunna arbeta systematiskt med utvecklandet av emuleringsmodeller för denna nivå önskas en öppen, skalbar, och flexibel datamodell för emuleringsmodeller. Detta examensarbete bidrar till detta genom att utveckla ett första utkast av en sådan data modell. Datamodellen demonstreras genom implementation inom den utvecklandes emuleringsmiljön, med hjälp av filformatet XML. En iterativ "design and creation" metodologi användes för att utveckla och implementera datamodellen. Ett set av industriella komponenter användes i utvecklingen och implementationen av datamodellen. Projektets resultat presenteras som ett klassdiagram tillsammans med förklarande dokumentation. Används projektes metodologi och datamodellerings-strategi kan man med fördel arbeta transparant och systematiskt med utveckling av emuleringsmodeller för anginven nivå.TWI

    SUGGESTIONS TO CONSIDER WHEN ENGAGING IN THE PROCESS OF DEVELOPING A SYSTEM DYNAMICS MODEL FOR FREQUENT ATTENDERS IN HEALTHCARE

    No full text
    Healthcare systems face many challenges that prevent them from reaching their full potential. Overcoming these challenges can be very difficult in part because of their complexity. Predicting all the possible effects that improvement attempts may create is difficult and high-quality decision support material is difficult to obtain. System dynamics modeling and simulation is a technology that has been applied for some time within the healthcare domain in order to assist the decision-making process. This technology has gained increased interest in the domain over the past decade. This project analyses the application of system dynamics modeling to a specific problem in the healthcare sector, namely that of frequent attenders to the emergency department. A literature review is performed to extract suggestions that could be considered when engaged in the process of developing a system dynamics model for managing frequent attenders in healthcare. It has been found that the research on frequent attenders and their management is very heterogeneous and ambiguous making it difficult to draw strong conclusions about the effectiveness of different management strategies. Model builders are forced to turn to other sources for model data. It is also found that system dynamics modeling of frequent attenders has not yet been done. This situation led to the expansion of the search scope to include related modeling research as the basis for suggestion extraction. 65 suggestions are extracted into three broad categories with the limitation of not being strictly specific to the modeling of frequent attenders, but have a more general nature. And although their value is not evaluated, it is hoped that they could contribute as inspiration to certain system dynamics model development endeavors

    Sjuksköterskan och patienten med schizofreni : En vårdande relation

    No full text
    Patienter som har diagnosen schizofreni är inte unikt samlade inom den psykiatriska vården utan finns inom alla vårdspecialiteter. En viktig del av omvårdnadsarbetet hos de sjuksköterskor vilka möter dessa patienter är etablerandet av en vårdande relation med dem. Det är i denna relation som omvårdnaden tillämpas. Syftet med studien var att sammanställa och belysa forskning som beskriver sjuksköterskans vårdrelation med en patient som har diagnosen schizofreni. I en systematisk litteraturstudie granskades och analyserades åtta vetenskapliga artiklar vilket resulterade i tre huvudteman relaterade till vårdrelationen: ´etablera en vårdande relation´, ´främjar utvecklingen av vårdrelationen´ samt ´hämmar utvecklingen av vårdrelationen´. Innehållet i dessa teman framhäver att vårdrelationen är ett komplex fenomen bestående av många aspekter. Genom en förståelse utav dessa aspekters proportioner samt påverkan kan de utav sjuksköterskor ägnas medvetna åtgärder i syfte att stärka relationen till patienten och öka kvaliteten på omvårdnaden

    Exploring Production System Knowledge Graph Applications Using a Simulation Framework

    No full text
    Knowledge graphs are generating significant interest in industry and research. These graphs can be enriched with data to represent aspects of production systems such as their structure, component interrelationships, and conditions. This provides opportunities to gain insights into system behavior, performance, and states. Such insights could potentially be leveraged by a wide range of technologies for a multitude of purposes and applications such as system control, process optimization, and informed decision making. However, the existing literature addressing industrial applications of knowledge graphs related to production systems remains limited in scope and depth. This underscores the importance of developing methods for exploring the potential use and implementation of knowledge graphs in such systems. The primary focus of this study centers on facilitating such exploration by developing a virtual commissioning simulation framework. A modular production system is modelled that leverages physics, moving product dynamics, and incorporates authentic PLC and robot programs. A knowledge graph is integrated and enriched with data representing various aspects of the system. An application is developed to facilitate product routing and prioritization. A service-oriented approach is used that leverages graph data processing and exchange for service registration and matching. System simulations are conducted and subsequently the framework is evaluated for outcomes and findings. This study demonstrates the successful design and implementation of a production system simulation framework that uses knowledge graphs for system functionality. It demonstrates the exploration of knowledge graph applications through the development of a modular and service-oriented system that includes system functionality supported by the graph. The results highlight the potential of simulation suggesting its capacity for valuable exploration regarding potential applications of knowledge graphs within production systems. CC BY-NC 4.0 DEED© 2024 The AuthorsCorrespondence Address: M. Birtic; School of Engineering Science, University of Skövde, Skövde, Högskolevägen, Box 408, 541 28, Sweden; email: [email protected]</p
    corecore