| 1. |
- Day, J. G., et al.
(författare)
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Challenges for the Maintenance and Cryopreservation of Multiple Isolates of Model Microorganisms: An Example Using the Marine Diatom Skeletonema marinoi
- 2017
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Ingår i: Biopreservation and Biobanking. - : Mary Ann Liebert Inc. - 1947-5535 .- 1947-5543. ; 15:3, s. 191-202
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Tidskriftsartikel (refereegranskat)abstract
- Modern genomic and metabolomic tools have provided the possibility of generating and interrogating large datasets that can provide answers to previously imponderable taxonomic, evolutionary, ecological, and physiological questions. However, the curatorial tools needed to provide and maintain the relevant biological resources on which new knowledge can be built have not kept pace with this meteoric rise in scientific capacity, its associated activity, or the huge increase in published science. The availability of biological material of guaranteed identity and quality in Biological Resource Centers is fundamental for scientific research, but it crucially depends on there being adequate preservation/maintenance methods that are capable of ensuring phenotypic, genotypic, and functional security of the biological material(s). This article highlights the challenges to the long-term maintenance of genetic resources in general, focusing specifically on the issues associated with the maintenance of a large collection of strains of the ecologically significant diatom Skeletonema marinoi. This research collection, held at the Department of Marine Sciences, University of Gothenburg, has been systematically tested for its capacity to survive cryopreservation. A method, involving incubation in the dark for 20-24 hours before cryopreservation, followed by cryoprotection employing 10% dimethysulphoxide (DMSO) and conventional cooling in a passive cooler, before plunging into liquid nitrogen was successfully applied to similar to 80% of the strains tested. In addition, the growth characteristics of exemplar strains were confirmed after storage.
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| 2. |
- Ekström, Linda, et al.
(författare)
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Läsförståelse och undervisning om lässtrategier
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här systematiska översikten beskriver vad det samlade vetenskapliga kunskapsläget säger om relationen mellan undervisning om och användning av lässtrategier kontra läsförståelse. Lässtrategier definieras i denna översikt som medvetna, målinriktade försök att kontrollera och moderera läsarens arbete med att avkoda text, förstå ord och konstruera mening från text. Översikten fokuserar på elever i åldern 10–19 år, det vill säga motsvarande mellanstadiet och högstadiet i svensk grundskola samt svensk gymnasieskola, och på undervisning om och användning av lässtrategier inom ramen för skolans samtliga ämnen utom ämnen som motsvarar moderna språk inom den svenska skolan.Lässtrategier är alltså generellt sett ett redskap som elever kan använda sig av när de stöter på problem i sin läsförståelse. Vilka redskap det mer specifikt handlar om, hur dessa redskap kan kombineras eller vilka redskap som är mer eller mindre användbara i olika situationer är frågor som lärare kan behöva mer kunskap om.Genom denna översikt vill vi därför bidra till fördjupad kunskap om vad arbete med lässtrategier innebär liksom hur och för vem lässtrategierna bidrar till förbättrad läsförståelse.Översikten utgår ifrån följande överordnade frågeställning:Vad kännetecknar effektiv lässtrategiundervisning och lässtrategianvändning hos elever i åldrarna 10–19 år?Med effektiv menar vi att lässtrategiundervisningen och lässtrategianvändningen har en positiv effekt på elevernas läsförståelse, baserat på läsförståelsetester, observationer eller elevers självrapportering.För att besvara den överordnade frågeställningen har vi ställt följande mer specifika frågor:A. Vilka lässtrategier undervisas om och används i de i översikten ingående studierna?B. Vilken lässtrategiundervisning bidrar till utvecklad läsförståelse hos elever?C. Hur beskriver elever själva sin användning och nytta av lässtrategier?D. Hur varierar användning och nytta av lässtrategier med faktorer som kön, läsförmåga och språkbakgrund?
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| 3. |
- Lanne, Boel S., et al.
(författare)
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Determination of the Double Bond Position in Monounsaturated Acetates from Their Mass Spectra
- 1985
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 57:8, s. 1621-1625
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Tidskriftsartikel (refereegranskat)abstract
- A simple method of widespread applicability in determining double bond positions in C12, C14, and C16 straight-chain monounsaturated acetates is presented. The analysis is made with a capillary gas chromatograph coupled to a low-resolution mass spectrometer which is operated in the electron impact mode. No chemical derlvatlzation of the unknowns is needed. Five pairs of selected mass spectral fragments are chosen to distinguish positional isomers. A new mathematical model is introduced which permits simultaneous comparisons of all five ratios of unknowns and references. The method can be used for analyses of very small amounts (<5 ng) of unknown acetates in insect samples.
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| 4. |
- Löfstedt, Christer, et al.
(författare)
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Individual variation in the pheromone of the turnip moth, Agrotis segetum
- 1985
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 11:9, s. 1181-1196
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Tidskriftsartikel (refereegranskat)abstract
- Female turnip moths (Agrotis segetum) from a laboratory culture inbred for more than 30 generations, and the offspring (first and third generation) from field-collected insects were analyzed individually for acetates and alcohols in the pheromone gland. Quantitative analysis of individual components was performed at the subnanogram level by gas chromatographymass spectrometry (selected ion monitoring). The titer of the pheromone, i.e., the sum of the homologous acetates (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate was 2.0 ± 0.3 ng in the laboratory culture and 3.2 ± 0.6 ng in the "wild strain." There was no correlation between pheromone titer and female weight. The relative proportion of the pheromone components varied substantially between individuals, but there was no statistically significant difference between the two populations. The percentages of the respective compounds (-X ± coefficient of variation) were 14.8 ± 127% for Z5-10:OAc, 55.6 ± 32% for Z7-12:OAc, and 29.6 ± 59% for Z9-14:OAc. The pheromone composition varied more in the wild strain than in the laboratory culture. The significance of the pheromone variation to the attraction of males was tested in a field experiment. The ratio of males trapped by the most attractive blend versus the least attractive one was 2.2.
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| 5. |
- Löfstedt, Christer, et al.
(författare)
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Sex pheromone components of the turnip moth, Agrotis segetum - Chemical identification, electrophysiological evaluation and behavioral activity
- 1982
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 8:10, s. 1305-1321
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of female abdominal tips of Agrotis segetum by means of GC-MS showed the presence of 13 aliphatic acetates and alcohols. (Z)-7-Dodecenyl acetate was found to be the main component in the extracts at amounts of about 1 ng/female. (Z)-9-Tetradecenyl acetate and (Z)-7-dodecenol were present to the extent of 49 and 19%, respectively, of the main component. Minor components could be identified as decyl acetate, (Z)-5-decenyl acetate, dodecyl acetate, (Z)-9-dodecenyl acetate, tetradecyl acetate, a tetradecenyl acetate, hexadecyl acetate, a hexadecenyl acetate, (Z)-5-decenol, and (Z)-9-tetradecenol. The presence and biological activity of decyl acetate, (Z)-5-decenyl acetate, and (Z)-7-dodecenyl acetate in the extracts could be detected by GC-EAD. Tested by EAG (Z)-5-decenyl acetate evoked the highest response among pheromone candidates, followed by (E)-5-decenyl acetate and (Z)-7-dodecenyl acetate. Single-cell recordings from 100 male antennal sensilla trichodea revealed receptorcells highly sensitive to (Z)-5-decenyl, (Z)-7-dodecenyl, (Z)-8-dodecenyl, and (Z)-9-tetradecenyl acetate as well as (Z)-5-decenol. The (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate receptors were activated significantly also by female extracts. When tested in a tube olfactometer, a blend of decyl, (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate evoked the same male response as did female glands. Tested in the field, this blend was more attractive than virgin females. Other authors previously reported many of the compounds identified in the present study. However, both quantitative and qualitative discrepancies exist among the various investigations, possibly due to the existence of geographical races.
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| 6. |
- Witzgall, Peter, et al.
(författare)
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Sex pheromones and attractants in the Eucosmini and Grapholitini (Lepidoptera, Tortricidae)
- 1996
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Ingår i: Chemoecology. - : Springer. - 0937-7409 .- 1423-0445. ; 7:1, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- The geometric isomers (E, E)-, (E, Z)-, (Z, E)-, and (Z, Z)-8, 10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males of Cydia and Grapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds. Pammene, as well as other Grapholita and Cydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini, Hedya, Epiblema, Eucosma, and Notocelia trimaculana were also attracted to 8, 10-dodecadien-1-yl acetates, but several other Notocelia to 10, 12-tetradecadien-1-yl acetates. The female sex pheromones of C. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella and Notocelia roborana were identified. (E, E)- and (E, Z)- 8, 10-dodecadien-1-yl acetate are produced via a common E9 desaturation pathway in C. splendana. Calling C. nigricana and C. fagiglandana females are attracted to wingfanning males.
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