| 1. |
- Fontes, Eduardo, et al.
(författare)
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A heterogeneous model for the MCFC cathode
- 1995
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Ingår i: Electrochimica Acta. - 0013-4686. ; 40:11, s. 1641-1651
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Tidskriftsartikel (refereegranskat)abstract
- A steady state agglomerate model for the MCFC cathode which takes into account the heterogeneous structure of this porous electrode is presented. The resulting model equations are solved by means of the finite element method. Calculations have been performed on two different test structures and include the influence of kinetics, porosity, outer surface area and distribution of electrolyte film. Comparisons with the filmed agglomerate model show that it is possible to obtain excellent agreement between the polarisation curves predicted by the two different models if a uniform film is used in the simulations. The tortuosity in the filmed agglomerate model is used as a fitting parameter. Other effects that evolve in the heterogeneous model due to variations in the local structure are not revealed in the pseudohomogeneous model. The effect of a non-uniform electrolyte film thickness was investigated by solving the problem for a structure with pore mouths filled by an electrolyte meniscus. Also the effect of an electrolyte meniscus between spherical agglomerates was investigated.
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| 2. |
- Fontes, Eduardo, et al.
(författare)
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Effects of different design parameters on the performance of MCFC cathodes
- 1996
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Ingår i: Electrochimica Acta. - 0013-4686. ; 41:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The effects of electrode thickness, electrolyte filling and current collector geometry on the performance of MCFC cathodes are investigated by using a steady state mathematical model. A two-dimensional pseudo-homogeneous model for the three-phase system in the cathode is used, which includes the polarisation curves from the heterogeneous agglomerate model[1] as local source functions. The model takes into account the potential distribution in the electrolyte and catalyst phase but neglects mass transport limitations in the gas phase. The simulations show that, for cathodes with a finite electronic conductivity, there is a substantial potential distribution perpendicular to the depth of the electrode depending on the size of the gas holes in the current collector.
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| 3. |
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| 4. |
- Johnsson, Kerstin, et al.
(författare)
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What is a “unimodal” cell population? Using statistical tests as criteria for unimodality in automated gating and quality control
- 2017
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Ingår i: Cytometry Part A. - : Wiley. - 1552-4922. ; 91:9, s. 908-916
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Tidskriftsartikel (refereegranskat)abstract
- Many automated gating algorithms for flow cytometry data are based on the concept of unimodal cell populations. However, in this article, we show that criteria previously used to make decisions on unimodality cannot adequately distinguish unimodal from bimodal densities. We show that dip and bandwidth tests for unimodality, taken from the statistics literature, can do this with consistent and low error rates. These tests also have the possibility to adjust the significance level to handle the trade-off between failing to detect a second mode and seeing a second mode when there is none. The differences between the dip and bandwidth tests are elucidated using real data from the FlowCAP I challenge, also guidelines for flow cytometry data preprocessing are given.
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| 5. |
- Yeung, Edwina, et al.
(författare)
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Maternal age is related to offspring DNA methylation : a meta-analysis of results from the pace consortium
- 2024
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Ingår i: Aging Cell. - : John Wiley & Sons. - 1474-9718 .- 1474-9726.
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Tidskriftsartikel (refereegranskat)abstract
- Worldwide trends to delay childbearing have increased parental ages at birth. Older parental age may harm offspring health, but mechanisms remain unclear. Alterations in offspring DNA methylation (DNAm) patterns could play a role as aging has been associated with methylation changes in gametes of older individuals. We meta-analyzed epigenome-wide associations of parental age with offspring blood DNAm of over 9500 newborns and 2000 children (5–10 years old) from the Pregnancy and Childhood Epigenetics consortium. In newborns, we identified 33 CpG sites in 13 loci with DNAm associated with maternal age (PFDR < 0.05). Eight of these CpGs were located near/in the MTNR1B gene, coding for a melatonin receptor. Regional analysis identified them together as a differentially methylated region consisting of 9 CpGs in/near MTNR1B, at which higher DNAm was associated with greater maternal age (PFDR = 6.92 × 10−8) in newborns. In childhood blood samples, these differences in blood DNAm of MTNR1B CpGs were nominally significant (p < 0.05) and retained the same positive direction, suggesting persistence of associations. Maternal age was also positively associated with higher DNA methylation at three CpGs in RTEL1-TNFRSF6B at birth (PFDR < 0.05) and nominally in childhood (p < 0.0001). Of the remaining 10 CpGs also persistent in childhood, methylation at cg26709300 in YPEL3/BOLA2B in external data was associated with expression of ITGAL, an immune regulator. While further study is needed to establish causality, particularly due to the small effect sizes observed, our results potentially support offspring DNAm as a mechanism underlying associations of maternal age with child health.
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| 6. |
- Alexandersson, Erik, et al.
(författare)
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Transcriptional regulation of aquaporins in accessions of Arabidopsis in response to drought stress.
- 2010
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Ingår i: Plant Journal. - 1365-313X. ; 61, s. 650-660
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Tidskriftsartikel (refereegranskat)abstract
- Summary Aquaporins facilitate water transport over cellular membranes and are therefore believed to play an important role in water homeostasis. In higher plants aquaporin-like proteins, also called major intrinsic proteins (MIPs), are divided into 5 subfamilies. We have previously shown that MIP transcription in Arabidopsis thaliana generally is down-regulated in leaves upon drought stress, apart from two members of the Plasma membrane Intrinsic Protein (PIP) subfamily, AtPIP1;4 and AtPIP2;5, which are up-regulated. In order to assess if this regulation is general or accession-specific we monitored gene expression of all PIPs in five Arabidopsis accessions. Overall drought regulation of PIPs was well conserved for all five accessions tested suggesting a general and fundamental physiological role of this drought response. In addition, significant differences among accessions were identified for transcripts of three PIP genes. Principal component analysis showed that most of the PIP transcriptional variation during drought stress could be explained by one variable linked to leaf water content. Promoter-GUS constructs of AtPIP1;4, AtPIP2;5 and also AtPIP2;6, which is unresponsive to drought stress, had distinct expression patterns concentrated to the base of the leaf petioles and parts of the flowers. The presence of drought stress response elements within the 1.6 kb promoter regions of AtPIP1;4 and AtPIP2;5, was demonstrated by comparing transcription of the promoter reporter construct and the endogenous gene upon drought stress. Analysis by ATTED-II and other web-based bioinformatical tools showed that several of the MIPs down-regulated upon drought are strongly co-expressed, whereas AtPIP1;4, AtPIP2;5 and AtPIP2;6 are not co-expressed.
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| 7. |
- Andersson, Anna, et al.
(författare)
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Gene expression profiling of leukemic cell lines reveals conserved molecular signatures among subtypes with specific genetic aberrations
- 2005
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 19:6, s. 1042-1050
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Tidskriftsartikel (refereegranskat)abstract
- Hematologic malignancies are characterized by fusion genes of biological/clinical importance. Immortalized cell lines with such aberrations are today widely used to model different aspects of leukemogenesis. Using cDNA microarrays, we determined the gene expression profiles of 40 cell lines as well as of primary leukemias harboring 11q23/MLL rearrangements, t(1;19)[TCF3/PBX1], t(12;21)[ETV6/RUNX1], t(8;21)[RUNX1/CBFA2T1], t(8;14) [IGH@/MYC], t(8;14)[TRA@/MYC], t(9;22)[BCR/ABL1], t(10;11) [PICALM/MLLT10], t(15;17)[PML/RARA], or inv(16)[CBFB/MYH11]. Unsupervised classification revealed that hematopoietic cell lines of diverse origin, but with the same primary genetic changes, segregated together, suggesting that pathogenetically important regulatory networks remain conserved despite numerous passages. Moreover, primary leukemias cosegregated with cell lines carrying identical genetic rearrangements, further supporting that critical regulatory pathways remain intact in hematopoietic cell lines. Transcriptional signatures correlating with clinical subtypes/primary genetic changes were identified and annotated based on their biological/molecular properties and chromosomal localization. Furthermore, the expression profile of tyrosine kinase-encoding genes was investigated, identifying several differentially expressed members, segregating with primary genetic changes, which may be targeted with tyrosine kinase inhibitors. The identified conserved signatures are likely to reflect regulatory networks of importance for the transforming abilities of the primary genetic changes and offer important pathogenetic insights as well as a number of targets for future rational drug design.
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| 8. |
- Andersson, Anna, et al.
(författare)
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Microarray-based classification of a consecutive series of 121 childhood acute leukemias: prediction of leukemic and genetic subtype as well as of minimal residual disease status.
- 2007
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 21:6, s. 1198-1203
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Tidskriftsartikel (refereegranskat)abstract
- Gene expression analyses were performed on 121 consecutive childhood leukemias (87 B-lineage acute lymphoblastic leukemias (ALLs), 11 T-cell ALLs and 23 acute myeloid leukemias (AMLs)), investigated during an 8-year period at a single center. The supervised learning algorithm k-nearest neighbor was utilized to build gene expression predictors that could classify the ALLs/AMLs according to clinically important subtypes with high accuracy. Validation experiments in an independent data set verified the high prediction accuracies of our classifiers. B-lineage ALLs with uncharacteristic cytogenetic aberrations or with a normal karyotype displayed heterogeneous gene expression profiles, resulting in low prediction accuracies. Minimal residual disease status (MRD) in T-cell ALLs with a high (40.1%) MRD at day 29 could be classified with 100% accuracy already at the time of diagnosis. In pediatric leukemias with uncharacteristic cytogenetic aberrations or with a normal karyotype, unsupervised analysis identified two novel subgroups: one consisting mainly of cases remaining in complete remission (CR) and one containing a few patients in CR and all but one of the patients who relapsed. This study of a consecutive series of childhood leukemias confirms and extends further previous reports demonstrating that global gene expression profiling provides a valuable tool for genetic and clinical classification of childhood leukemias.
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| 9. |
- Bordería, Antonio V, et al.
(författare)
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Group Selection and Contribution of Minority Variants during Virus Adaptation Determines Virus Fitness and Phenotype.
- 2015
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- Understanding how a pathogen colonizes and adapts to a new host environment is a primary aim in studying emerging infectious diseases. Adaptive mutations arise among the thousands of variants generated during RNA virus infection, and identifying these variants will shed light onto how changes in tropism and species jumps can occur. Here, we adapted Coxsackie virus B3 to a highly permissive and less permissive environment. Using deep sequencing and bioinformatics, we identified a multi-step adaptive process to adaptation involving residues in the receptor footprints that correlated with receptor availability and with increase in virus fitness in an environment-specific manner. We show that adaptation occurs by selection of a dominant mutation followed by group selection of minority variants that together, confer the fitness increase observed in the population, rather than selection of a single dominant genotype.
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| 10. |
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