| 1. |
- Almqvist, Gustaf, et al.
(författare)
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Report of the Benchmark Workshop on Baltic Cod Stocks (WKBALTCOD)
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The ICES Benchmark Workshop on Baltic Cod Stocks (WKBALTCOD), chaired by External Chair Jean-Jacques Maguire, Canada and ICES Chair Marie Storr-Paulsen, Denmark, and attended by two invited external experts Verena Trenkel, France and Meaghan Bryan, USA met in Rostock, Germany, 2–6 March 2015 with 39 participants and six countries represented. The objective of WKBALTCOD was to evaluate the appropriateness of data and methods to determine stock status and investigate meth-ods appropriate to use in the single-stock assessment for the cod stock in SD 22–24 and cod in SD 25–32 in the Baltic. Participants in the workshop were a large group with diverse backgrounds representing the industry, fisheries, NGOs, managers and scientists.The single-stock analytic assessment of the eastern Baltic stock was not accepted by the assessment working group (WGBFAS) in 2014 due to severe problems with the input data. The advice for the eastern Baltic cod was, therefore, based on the ICES approach for data-limited stocks. As an outcome ICES decided to establish a bench-mark for both cod stocks and to scope an integrated assessment for the Baltic cod stocks. The first meeting (WKSIBCA) was therefore meant to introduce the interces-sional work conducted since the assessment working group in April 2014, and to reach some conclusions on how to proceed both in the short term (Benchmark in March 2015) and longer term (2–3 years) and was seen as a data compilation work-shop, there is produced a separate report from this workshop. The WKBALTCOD was the 2nd meeting in the benchmark process and was intended to come up with a final stock assessment method, stock annex and input data for both stocks. As it was not possible to reach conclusive decision on the final model to be used for the east Baltic cod stock during the benchmark meeting and as more work on the preferable models was needed, it was decided by the ACOM leadership to prolong the bench-mark process until the assessment working group meeting in April 2015. This deci-sion has led to a relatively long process partly mixed with the assessment working group WGBFAS.It became clear during the benchmark process that although large effort has been put into explaining the underlying processes leading to the changes in the Baltic ecosys-tem, there is still some lack of understanding of the present situation in the eastern Baltic cod stock. Therefore, it was not possible to reach firm conclusions on the final model to be used and therefore not possible to set reference points. It was decided to continue to explore the most promising models and to continue to improve the input data until the assessment working group started in April.The main challenges still to be solved for the Eastern Baltic cod stock is the quantifi-cation of increased natural mortality and decrease in growth. Through several presentations during the workshop (both WKSIBCA and WKBALTCOD) it became clear that natural mortality very likely has increased in later years, due to decreased condition and increased parasite infection. A decrease in growth also seems plausible duo to a decrease in condition and/or selectivity-induced mortality of the largest in-dividuals. However, as none of these parameters are easily estimated, especially with the severe ageing problems, different model assumptions made the output very shaky.For the western Baltic cod, stock identification issues were examined in area SD 24, the intermediate area: based on otolith characteristics and genetics. Due to the results showing a large proportion of east cod in this area, it was decided to split the catch2 | ICES WKBALTCOD REPORT 2015and survey from SD 24 into either the western or eastern Baltic cod stock. It was pos-sible to derive proportions of eastern and western cod in SD 24 back to the mid-1990s.For the western Baltic cod stock a modelled survey indices was included in the as-sessment covering the western part of SD 24 and Area 22+23 and based on a smoothed ALK.Both cod stocks have in the past used commercial tuning fleet to have a better cov-ered of older age groups. It was decided to abound this time-series duo quality issues such as a limited coverage and problems with technical creeping.WKBALTCOD was not able to explore and define reference points for the Western Baltic cod stock during the meeting due to time constraints, but these were calculated and decided by correspondence after the meeting. The recent protocols on estimation procedures developed by WKMSYREF3 for stocks with a full analytical assessment and for data-limited stocks served as objective guidelines to obtain reference point estimates.
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| 2. |
- Holmberg, K., et al.
(författare)
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Impact of asthma medication and familial factors on the association between childhood asthma and attention-deficit/hyperactivity disorder: a combined twin- and register-based study
- 2015
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Ingår i: Clinical and Experimental Allergy. - Stockholm : Wiley. - 0954-7894 .- 1365-2222. ; 45:5, s. 964-973
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAsthma and attention-deficit/hyperactivity disorder (ADHD) are prevalent in childhood and may cause functional impairment and stress in families. Previous research supports an association between asthma and ADHD in children, but several aspects of this relationship are unclear. ObjectiveOur aim was to study whether the association between asthma and ADHD is restricted to either the inattentive or the hyperactive/impulsive symptoms of ADHD, to explore the impact of asthma severity and asthma medication and the contribution of shared genetic and environmental risk factors on the asthma-ADHD relationship. MethodsData on asthma, ADHD, zygosity and possible confounders were collected from parental questionnaires at 9 or 12years on 20072 twins through the Swedish Twin Register, linked to the Swedish Medical Birth Register, the National Patient Register and the Prescribed Drug Register. The association between asthma and ADHD, the impact of asthma severity and medication, was assessed by generalized estimating equations. Cross-twin-cross-trait correlations (CTCT) were estimated to explore the relative importance of genes and environment for the association. ResultsAsthmatic children had a higher risk of also having ADHD [odds ratio (OR) 1.53, 95% confidence interval (CI): 1.16-2.02]. The association was not restricted to either of the two dimensions of ADHD. The magnitude of the association increased with asthma severity (OR 2.84, 95% CI: 1.86-4.35) for 4 asthma attacks in the last 12months and was not affected by asthma treatment. The CTCTs possibly indicate that the genetic component in overlap of the disorders is weak. Conclusions and Clinical RelevanceChildhood asthma, especially severe asthma, is associated with ADHD. Asthma medication seems not to increase the risk of ADHD. Clinicians should be aware of the potential of ADHD in asthma. Optimal asthma care needs to be integrated with effective evaluation and treatment of ADHD in children with co-existing disorders.
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| 3. |
- Magnusson, Patrik K. E., et al.
(författare)
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The Swedish Twin Registry : establishment of a biobank and other recent developments
- 2013
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Ingår i: Twin Research and Human Genetics. - Cambridge, United Kingdom : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 16:1, s. 317-329
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.
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| 4. |
- Pettersson, Erik, et al.
(författare)
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Birth weight as an independent predictor of ADHD symptoms : a within-twin pair analysis
- 2015
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Ingår i: Journal of Child Psychology and Psychiatry. - Hoboken, USA : Wiley-Blackwell. - 0021-9630 .- 1469-7610. ; 56:4, s. 453-459
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Tidskriftsartikel (refereegranskat)abstract
- Background Studies have found an association between low birth weight and ADHD, but the nature of this relation is unclear. First, it is uncertain whether birth weight is associated with both of the ADHD dimensions, inattentiveness and hyperactivity-impulsivity. Second, it remains uncertain whether the association between birth weight and ADHD symptom severity is confounded by familial factors.Method: Parents of all Swedish 9- and 12-year-old twins born between 1992 and 2000 were interviewed for DSM-IV inattentive and hyperactive-impulsive ADHD symptoms by the Autism - Tics, AD/HD and other Comorbidities (A-TAC) inventory (N = 21,775 twins). Birth weight was collected prospectively through the Medical Birth Registry. We used a within-twin pair design to control for genetic and shared environmental factors.Results: Reduced birth weight was significantly associated with a mean increase in total ADHD (β = -.42; 95% CI: -.53, -.30), inattentive (β = -.26; 95% CI: -.33, -.19), and hyperactive-impulsive (β = -.16; 95% CI: -.22, -.10) symptom severity. These results imply that a change of one kilogram of birth weight corresponded to parents rating their child nearly one unit higher (going from "no" to "yes, to some extent" on a given symptom) on the total ADHD scale. These associations remained within pairs of MZ and DZ twins, and were also present when restricting the analyses to full term births.Conclusions: There is an independent association between low birth weight and all forms of ADHD symptoms, even after controlling for all environmental and genetic confounds shared within twin pairs. These results indicate that fetal growth restriction (as reflected in birth weight differences within twin pairs) and/or the environmental factors which influence it is in the casual pathway leading to ADHD.
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| 5. |
- Almqvist, Catarina, et al.
(författare)
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Association between parental age and asthma in a population-based register study
- 2015
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Ingår i: Journal of Allergy and Clinical Immunology. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0091-6749 .- 1097-6825.
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Tidskriftsartikel (refereegranskat)abstract
- In a nationwide population-based study with family design, we found an association between decreasing parental age and asthma in early childhood. The effect was independent of familial and potentially confounding factors.
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| 6. |
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| 7. |
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| 8. |
- Almqvist, Henrik, et al.
(författare)
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Characterization of the Weimberg Pathway in Caulobacter crescentus
- 2018
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Ingår i: Fermentation. - : MDPI AG. - 2311-5637. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Caulobacter crescentus is a gram-negative bacterium that can utilize xylose as a substrate using the Weimberg pathway, which converts xylose to α-ketoglutarate in five steps without carbon loss. This is an interesting pathway for heterologous expression in other organisms in order to enable xylose utilization in biorefinery processes. C. crescentus was grown on xylose, arabinose and glucose, and maximum specific growth rates determined for the three substrates were 0.11 h−1, 0.05 h−1, and 0.15 h−1 respectively. Growth was found to be significantly inhibited at sugar concentration of 20 g L−1, shown primarily by an increased lag phase. Enzyme activity assays showed that the Weimberg pathway was active in cells grown, not only on xylose but also on arabinose. No activity was found for growth on glucose. Furthermore, substantial amounts of α-ketoglutarate—up to a yield of 0.4 g g−1—was excreted during growth on xylose, but no other extracellular intermediates in the Weimberg pathway were detected during growth on xylose. Apparently, C. crescentus is not well adapted for efficient growth on high xylose levels, and responds by an extended lag phase and secretion of α-ketoglutarate.
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| 9. |
- Almqvist, Henrik
(författare)
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Dicarboxylic acids from xylose, using natural and engineered hosts
- 2017. - 1
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemical building blocks for plastics can be produced from renewable biomass feedstocks using microbial production organisms, such as yeast or bacteria, in a biorefinery. One class of chemical building blocks that are suitable for production of biobased and biodegradable plastics are dicarboxylic acids, e.g. succinic acid. In order to avoid competition with food and feed production it is desirable to use hydrolysates of lignocellulosic feedstocks which often not only contain hexose sugars but also pentoses, out of which xylose is the most common. One example of such a feedstock is spent sulphite liquor (SSL), a side stream from sulphite pulping of Eucalyptus, which is rich in xylose. In this thesis, microbial production of dicarboxylic acids from xylose-rich feedstocks has been studied using different host organisms. The natural succinic acid producing bacterium Actinobacillus succinogenes was found able to produce succinate from a xylose rich synthetic model medium mimicking sugar com- position in SSL, at a titer of 31 g L-1 and yield of 0.71 g g-1. In addition, A. succinogenes was tested for tolerance towards inhibiting by-products along with a related succinate producer, Basfia succiniciproducens. Of the by-products, both organisms were found to be most sensitive to formate (18-22 g L-1), while high concentration of acetate (38 g L-1) and succinate (55 g L-1) were tolerated. Succinate production with A. succinogenes was also tested in SSL, and titers above 22 g L-1 of succinate were obtained in fed-batch cultivations. A strain of Saccharomyces cerevisiae engineered for xylose utilization and formation of dicarboxylic acids was assessed and found rather tolerant to SSL even at acidic condi- tions. The relative distribution between malate and succinate was affected by cultivation conditions, with succinate strongly favoured at carboxylating conditions at high pH. Genes encoding enzymes of the Weimberg pathway, an orthogonal xylose degradation pathway, were introduced in S. cerevisiae. The complete pathway was not functional and growth on xylose was not obtained. However, the intermediate compound xylonate was formed at close to stoichiometric yields. In addition, Caulobacter crescentus, the natural host of the Weimberg pathway, was characterised. Activity of the Weimberg pathway was found during growth on both xylose and arabinose, but not on glucose. Interestingly, high yields of α-ketoglutarate (up to 0.43 g g-1) were formed during growth on xylose.
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| 10. |
- Almqvist, Henrik, et al.
(författare)
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Muconic Acid Production Using Engineered Pseudomonas putida KT2440 and a Guaiacol-Rich Fraction Derived from Kraft Lignin
- 2021
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:24, s. 8097-8106
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Tidskriftsartikel (refereegranskat)abstract
- Industrial lignin such as kraft lignin is an abundant feedstock for renewable chemicals and materials. In this study, a process was developed for depolymerization of kraft lignin followed by an upgrading separation step and further bioconversion of the obtained monoaromatic compounds to muconic acid. First, industrial kraft lignin, Indulin AT, was processed into a guaiacol-rich stream using base-catalyzed depolymerization. This stream was subsequently upgraded using liquid-liquid extraction and evaporation to yield a more concentrated and less inhibitory stream, adapted for bioconversion. Finally, guaiacol was quantitatively converted to muconic acid through bioconversion using an engineered Pseudomonas putida strain containing cytochrome P450 and ferredoxin reductase for guaiacol assimilation and deletion of the native catBC genes for muconic acid production. Isomerization of muconic acid in a fermentation medium depending on pH was also studied.
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