| 1. |
- Antonsson, Ann-Beth, et al.
(författare)
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Möjligheter och begränsningar avseende användning av slutningsåtgärder för metallhaltiga vatten
- 1992
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Målsättningen för det här fleråriga projektet är att ta fram ett objektivt tekniskt/ekonomiskt underlag avseende olika separationsteknikers möjligheter och begränsningar att sluta en ytbehandlingsanläggning. Tyngdpunkten ligger på metallbeläggningssidan. I den första delen av projektet har vi på laboratoriet behandlat följande provvattentyper från ytbehandlare. - Sköljvatten från förkromning, förkoppring, förnickling och förzinkning - Totalavlopp efter konventionell fällning. Vi har behandlat vattnen med ett stort antal olika separationstekniker. Jonbyte, omvänd osmos, nanofiltrering, indunstning, elektrolys, elektrodialys, sulfidfällning, aktivt kol. Vad gäller avskiljningen av metall kan man konstatera att det går att producera ett vatten med mycket låga resthalter, framförallt med jonbyte, omvänd osmos och indunstning. Investeringskostnaden för dessa metoder ökar nu i nämnd ordning. Det finns många företag som använder separationstekniker i sina system (framför allt jonbyte). Emellertid används dessa oftast för att återanvända sköljvattnet. De metaller som uppkoncentreras fälls oftast ut som metallhydroxider. För att kunna återföra metaller och andra prestationskemikalier till processbadet krävs det att man uppnår rätt koncentration samtidigt som man inte ska återföra föroreningar till badet. Helst ska dessa blödas ut ur systemet. För de tekniker som studerats var avskiljningsförmågan för metall hög för alla metoder utom aktivt kol. För organiskt material var den hög för omvänd osmos och indunstning. För att kunna bedöma möjligheten att återföra koncentrat till baden krävs det kunskap om korrekt badsammansättning, tolerabla avvikelser samt innehåll i de koncentrat som ska återföras. I den här inledande delen av projektet kan vi konstatera att kunskapen kring dessa frågor många gånger är bristfällig. En genomgång av vilka kemikalier som kan finnas i sköljvattnen och vilka inneboende hälsorisker dessa besitter har sammanställts. Med utgångspunkt från detta har sedan tänkbara hälsorisker som kan uppstå vid slutning diskuterats. I etapp 2 kommer arbetsmiljöaspekterna att belysas ytterligare i samband med pilotkörningarna i fält. Jonbyte, omvänd osmos (RO) och indunstning kommer att utprovas under långvariga och realistiska omständigheter. Dessutom kommer Elektrodialys (ED) och elektrolys att utprovas på mer koncentrerade sparsköljar och koncentrat från de andra metoderna.
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| 2. |
- Antonsson, Ann-Beth, et al.
(författare)
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Utveckling av en metod för att mäta källstyrka i arbetsmiljön
- 1987
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En ny metod har utvecklats för att mäta emissionshastigheter från punkt- och ytkällor. Metoden baseras på skapandet av en kontinuerlig dubbelkälla med spårgas. Emissonshastigheten är beräknad från spårgasens emissionshastighet och korrelationen av förorenings- och spårgaskoncentrationerna på olika punkter, nära till källan. Laboratorietester visade mycket god korrelation mellan verklig och uppmätt emissionshastighet. Två fälttester gjordes. Dessa tester visade uppmuntrande bra resultat.
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| 3. |
- Antonsson, Martin, et al.
(författare)
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A comparison between the microflora of Herrgård cheese from three different dairies
- 2001
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Ingår i: International Dairy Journal. - 0958-6946. ; 11:4-7, s. 285-291
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Tidskriftsartikel (refereegranskat)abstract
- The microflora of Herrgård cheese produced at three dairies was grouped by phenotypical key tests and typed by randomly amplified polymorphic DNA (RAPD). Ten cheeses from the same vat at each dairy were analysed, five after 3 and another five after 6 months of ripening. All cheeses were organoleptically graded as Herrgård after uniform national standards, and only small but characteristic differences were found between cheeses from different dairies. Cheese from two dairies were dominated by a spontaneous secondary microflora of Lactobacillus from 3 months of ripening, while strains from the starter culture still dominated in cheese from the third dairy after 6 months. The Lactobacillus flora from the different dairies were mainly of diverse RAPD types, but of the 24 different RAPD types found, three were isolated from cheese made at two different dairies and two other RAPD types were isolated from cheese from all three dairies. A succession of different RAPD types was shown at one dairy.
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| 4. |
- Antonsson, Martin
(författare)
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Lactobacillus in semi-hard cheese and their use as adjunct cultures
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The microflora of Herrgård cheese produced at three dairies was compared after three and six months maturation. The microflora of cheeses from two of the dairies was dominated by a spontaneous microflora of Lactobacillus after three months of ripening, while starter bacteria still dominated in cheese from the third dairy after six months. Isolates were typed by the PCR-based method Randomly Amplified Polymorphic DNA (RAPD). The Lactobacillus flora in cheese from different dairies consisted mainly of diverse RAPD-types, but of the 24 RAPD-types found, three were isolated from cheese made at two different dairies and two other RAPD-types were isolated from cheese from all three dairies. The RAPD-typing indicated a succession between different types of Non-Starter Lactic Acid Bacteria (NSLAB) in cheese from one of the dairies. The NSLAB in Danbo cheese was studied, with special emphasis on Lactobacillus, using six ripened cheeses of different ages and of different brands. The microflora in five cheeses was dominated by Lactobacillus, but the sixth cheese contained no Lactobacillus. Ten RAPD-types were found and 70 % of the isolates were of RAPD-types found in more than one cheese. The different RAPD-types of NSLAB were identified to species level by Temporal Temperature Gradient gel Electrophoresis (TTGE). Most NSLAB isolates were identified as Lactobacillus paracasei (76 %), but Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus rhamnosus were also found. 37 Lactobacillus casei/paracasei and Lactobacillus rhamnosus strains of mostly human or cheese origin were classified by Restriction Endonuclease Analysis (REA) of the total chromosomal DNA and TTGE of PCR amplified 16s rDNA fragments. REA-typing singled out three major clusters, two composed of Lactobacillus paracasei and one of Lactobacillus rhamnosus strains. The groups obtained by TTGE corresponded generally with the REA-clusters. All Lactobacillus paracasei strains had one amplified 16s rDNA fragment incommon, but were separated into five subgroups due to the presence of one or two additional fragments amplified for some strains. The observed heterogeniety in the 16s rDNA of about half of the tested Lactobacillus paracasei strains might provide an explanation of the diversity within this species. A cheese model system, reproducible and comparable to cheese manufactured in full-scale in terms of moisture, salt content, pH and microbial ecology, was developed. Lactobacillus strains originating from cheese or human mucosa were tested as adjunct cultures in the cheese model system. The test-strains were mainly Lactobacillus paracasei and Lactobacillus rhamnosus strains. Adjuncts of Lactobacillus paracasei were re-isolated more frequently than adjuncts of Lactobacillus rhamnosus, but no correlation was found between re-isolation and the origin of the adjunct. The flavour development was generally strain dependent, but adjuncts of Lactobacillus paracasei were slightly more common in improving cheese flavour. Model cheese with a microflora dominated by an RAPD-type of Lactobacillus plantarum was associated with off-flavour and serine degradation. Two human-derived Lactobacillus paracasei strains were used as adjunct cultures in pilot scale cheese production. These strains improved cheese flavour and survived passage through the human gastro-intestinal tract when delivered in semi-hard cheese. The NSLAB did not share this characteristic.
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| 5. |
- Antonsson, Martin, et al.
(författare)
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Lactobacillus strains isolated from Danbo cheese as adjunct cultures in a cheese model system.
- 2003
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Ingår i: International Journal of Food Microbiology. - 0168-1605. ; 85:1-2, s. 159-169
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Tidskriftsartikel (refereegranskat)abstract
- Isolates of Non-Starter Lactic Acid Bacteria (NSLAB) from six ripened Danbo cheeses of different ages and of different brands were examined. Special emphasis was on the genus Lactobacillus with the aim of investigating their role in cheese maturation. Thirty-three isolates were typed by the PCR-based method, Randomly Amplified Polymorphic DNA (RAPD). Ten RAPD types were found and 70% of the isolates were of RAPD types found in more than one cheese. The different RAPD types were identified to species level by Temporal Temperature Gradient Gel Electrophoresis (TTGE). Most of the isolates were identified as Lactobacillus paracasei (76%), but also Lactobacillus curvatus, Lactobacillus plantarum, Lactobacillus rhamnosus and some taxa originating from the starter culture were detected. In one cheese, no lactobacilli were found.One strain of the most frequent Lactobacillus RAPD type from each of the five cheeses with a Lactobacillus flora was used as adjunct cultures in a cheese model system. Four of the five adjuncts were re-isolated during ripening. Two adjunct containing model cheeses received higher flavour scores than the control while two other were associated with off-flavours. The two model cheeses with off-flavour had a similar microflora and both were after 13 weeks of ripening dominated by a strain identified as L. plantarum.
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| 6. |
- Antonsson, Martin, et al.
(författare)
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Screening and selection of Lactobacillus strains for use as adjunct cultures in production of semi-hard cheese
- 2002
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Ingår i: Journal of Dairy Research. - 0022-0299. ; 69:3, s. 457-472
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Tidskriftsartikel (refereegranskat)abstract
- Thirty-three Lactobacillus strains were tested as adjuncts in a cheese model system. Eighteen strains originated from cheese (nine Lactobacillus spp. and nine Lb. paracasei/casei) and 15 from human intestinal mucosa (11 Lb. rhamnosus; three Lb. paracasei; one Lb. plantarum). Model cheeses weighing 120 g were made of cheese grains from full-scale production of washed curd semi-hard cheese (Herrgard). The model system was reproducible and similar to full-scale production with respect to moisture, salt content, pH and microbial flora. The model cheeses were sampled for aerobic and anaerobic plate count and viable counts of Lactobacillus and Lactococcus. The presence of adjuncts in the model cheeses was confirmed by typing isolates with Randomly Amplified Polymorphic DNA (RAPD). The sensory properties of model cheeses were described. In a first trial 23 of the 33 adjuncts were re-isolated from the corresponding model cheeses after 9 or 13 weeks. Adjuncts of Lb. paracasei were re-isolated more frequently than adjuncts of Lb. rhamnosus. Nine strains were selected, on the basis of their ability to grow and be a dominating part of the microflora of model cheese with interesting sensory properties. These strains were further studied together with two commercial cultures. The sensory influences on model cheeses of six of the adjuncts were confirmed, and flavour scores were in the range of 2(.)9-7(.)1 for model cheeses with different adjuncts while the control had a flavour score of 5(.)6 (0-10 scale). Survival and growth of seven out of the nine strains correlated with the results of the first trial. Growth and influence on flavour of four adjunct cultures were confirmed in experimental cheese manufactured in a 400-1 open vat.
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| 7. |
- Björklund Hultman, Martin, 1994, et al.
(författare)
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I see what you’re watching on your streaming service: Fast identification of dash encrypted network traces
- 2023
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Ingår i: Proceedings - IEEE Consumer Communications and Networking Conference, CCNC. - 2331-9860. ; 2023-January, s. 1116-1122
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Konferensbidrag (refereegranskat)abstract
- In recent years, concerns about the privacy of users data have raised as testified by the wide adoption of the HTTPS protocol over its unencrypted predecessor. This work demonstrates, however, that the encryption used in HTTPS does not guarantee that the user’s data is hidden when streaming videos using the DASH protocol. We show that the encryption can be bypassed by exploiting recognizable and predictable patterns produced by DASH in side-channels. To demonstrate our attack, we have collected 100k fingerprints from the SVT Play streaming platform, and have shown that encrypted videos can reliably and quickly be identified by capturing streamed HTTPS traffic and comparing it against the fingerprint database. Compared with previous work, our evaluation demonstrates the superior accuracy in our approach as well as its capacity of swiftly identify videos that are playing from an arbitrary timestamp. Our prototype is, to the best of our knowledge, the fastest and most accurate video streaming recognizer to date, only requiring as little as 12 seconds of network traffic to infer a video title with more than 98% accuracy among a catalogue of 20k videos. Our results call for future updates in the DASH protocol designed to circumvent the privacy leak we have shown. An open- source implementation of our prototype is publicly available at https://github.com/embeage/streaming-identification.
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| 8. |
- Glenting, Jacob, et al.
(författare)
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Anchorless surface associated glycolytic enzymes from Lactobacillus plantarum 299v bind to epithelial cells and extracellular matrix proteins
- 2013
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Ingår i: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 168:5, s. 245-253
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Tidskriftsartikel (refereegranskat)abstract
- An important criterion for the selection of a probiotic bacterial strain is its ability to adhere to the mucosal surface. Adhesion is usually mediated by proteins or other components located on the outer cell surface of the bacterium. In the present study we characterized the adhesive properties of two classical intracellular enzymes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and enolase (ENO) isolated from the outer cell surface of the probiotic bacterium Lactobacillus plantarum 299v. None of the genes encoded signal peptides or cell surface anchoring motifs that could explain their extracellular location on the bacterial surface. The presence of the glycolytic enzymes on the outer surface was verified by western blotting using polyclonal antibodies raised against the specific enzymes. GAPDH and ENO showed a highly specific binding to plasminogen and fibronectin whereas GAPDH but not ENO showed weak binding to mucin. Furthermore, a pH dependent and specific binding of GAPDH and ENO to intestinal epithelial Caco-2 cells at pH 5 but not at pH 7 was demonstrated. The results showed that these glycolytic enzymes could play a role in the adhesion of the probiotic bacterium L. plantarum 299v to the gastrointestinal tract of the host. Finally, a number of probiotic as well non-probiotic Lactobacillus strains were analyzed for the presence of GAPDH and ENO on the outer surface, but no correlation between the extracellular location of these enzymes and the probiotic status of the applied strains was demonstrated. (c) 2013 Elsevier GmbH. All rights reserved.
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| 9. |
- Holst, Bjørn, et al.
(författare)
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Molecular switch controlling expression of the mannose-specific adhesin, Msa, in Lactobacillus plantarum
- 2019
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 85:10
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Tidskriftsartikel (refereegranskat)abstract
- Some lactic acid bacteria, especially Lactobacillus spp., possess adhesive properties enabling colonization of the human gastrointestinal tract. Two probiotic Lactobacillus plantarum strains, WCSF1 and 299v, display highly different mannose-specific adhesion, with L. plantarum 299v being superior to L. plantarum WCFS1 based on a yeast agglutination assay. A straightforward correlation between the mannose adhesion capacity and domain composition of the mannose-specific adhesin (Msa) in the two strains has not been demonstrated previously. In this study, we analyzed the promoter regions upstream of the msa gene encoding a mannose-specific adhesin in these two strains. The promoter region was mapped by primer extension and DNA sequence analysis, and only a single nucleotide change was identified between the two strains. However, Northern blot analysis showed a stronger msa transcript band in 299v than in WCFS1 correlating with the different adhesion capacities. During the establishment of a high-throughput yeast agglutination assay, we isolated variants of WCFS1 that displayed a very strong mannose-specific adhesion phenotype. The region upstream of the msa gene in these variants showed an inversion of a 104-bp fragment located between two perfectly inverted repeats present in the untranslated leader region. The inversion disrupts a strong hairpin structure that otherwise most likely would terminate the msa transcript. In addition, the ribosome binding site upstream of the msa gene, which is also masked within this hairpin structure, becomes accessible upon inversion, thereby increasing the frequency of translation initiation in the variant strains. Furthermore, Northern blot analysis showed a higher abundance of the msa transcript in the variants than in the wild type, correlating with a strong-Msa phenotype.
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| 10. |
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