| 1. |
- Cebecauer, Matej
(författare)
-
Enhancing Short-Term Traffic Prediction for Large-Scale Transport Networks by Spatio-Temporal Clustering
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Congestion in large cities is responsible for extra travel time, noise, air pollution, CO2 emissions, and more. Transport is one of the main recognized contributors to global warming and climate change, which is getting increasing attention from authorities and societies around the world. Better utilization of existing resources by Intelligent Transport Systems (ITS) and digital technologies are recognized by the European Commission as technologies with enormous potential to lower the negative impacts associated with high traffic volumes in urban areas.The main focus of this work is on short-term traffic prediction, which is an essential tool in ITS. In combination with providing information, it enables proactive decisions to decrease severity of congestion that occurs regularly or is caused by incidents. The main contribution of this work is to develop a methodological framework and prove its enhancing effects on short-term prediction in the context of large-scale transport networks. It is expected to contribute to more robust and accurate predictions of ITS in traffic management centers.Traffic patterns in large-scale networks, including urban streets, can be heterogeneous during the day and from day-to-day. This work investigates spatio-temporal clustering of heterogeneous data sets to smaller, more homogeneous data sub-sets. This is expected to produce more robust, accurate, scalable, and cost-effective prediction models. This thesis is the collection of five papers that contribute to enhancing short-term traffic prediction in this context. The clustering is recognized to boost prediction performance in Papers II, III, IV, and V. Paper II considers network partitioning and the last three papers study day clustering. The prediction models used across included papers are naive historical mean prediction models and more advanced prediction models such as probabilistic principal component analysis (PPCA) and exponential smoothing. Paper I considers and facilitates floating car data (FCD) as a cost-effective opportunistic source of speed and travel time data with extensive network coverage.Common practice in determining the number of clusters is to rely on internal evaluation indices, and these are very efficient but isolated from application. Paper IV tests this practice by also considering performance in short-term prediction application. Our results show that relying on these indices can lead to a loss of prediction accuracy of about 20% depending on the considered prediction model. Dimensionality reduction has a minimal effect on the resulting prediction performance, but clustering needs 20 times less computational time and only 0.1% of the original information.Finally, in Paper V, we look at similarities of representative day clusters recognized by speed and flows. Furthermore, the interchangeability of speed day-type centroids for flow when predicting speeds has proven to be robust, which is not a case for predicting flows by speed day-type centroids and observations.
|
|
| 2. |
- Claverías, Fernanda, et al.
(författare)
-
Corynebacterium alimapuense sp. nov., an obligate marine actinomycete isolated from sediment of Valparaíso bay, Chile.
- 2019
-
Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 69:3, s. 783-790
-
Tidskriftsartikel (refereegranskat)abstract
- A novel Gram-positive, non-motile, non-spore-forming and aerobic bacterium, designated strain VA37-3T, was isolated from a marine sediment sample collected at 19.2m water depth from Valparaíso bay, Chile. Strain VA37-3T exhibits 97.6% 16S rRNA gene sequence similarity to Corynebacterium marinum D7015T, 96.4% to Corynebacterium humireducens MFC-5T and 96% to Corynebacterium testudinoris M935/96/4T; and a rpoB gene sequence similarity of 85.1% to Corynebacterium pollutisoli VMS11T, both analyses suggesting that strain VA37-3T represents a novel species of Corynebacterium. Physiological testing indicated that strain VA37-3T requires artificial sea water or sodium-supplemented media for growth, representing the first obligate marine actinomycete of the genus Corynebacterium. The genome of the proposed new species, along with the type strains of its most closely related species were sequenced and characterized. In silico genome-based similarity analyses revealed an ANIb of 72.8% (C. marinum D7015T), ANIm of 85.0% (Corynebacterium mustelae DSM 45274T), tetra of 0.90 (Corynebacterium callunae DSM 20147T) and ggdc of 24.7% (Corynebacterium kutscheri DSM 20755T) when compared with the closest related strains. The genomic DNA G+Ccontent of strain VA37-3T was 57.0%. Chemotaxonomic assessment of strain VN6-2T showed the major fatty acids were C18:1ω9c and C16:0. Menaquinones predominantly consisted of MK-8(II-H2). Polar lipids consisted of diphosphatidylglycerol, glycolipids, phosphatidylglycerol, phosphoglycolipid and phosphatidylinositol. Mycolic acids also were present. Overall, the results from phylogenetic, phenotypic and genomic analyses confirmed that strain VA37-3T represents a novel species of the genus Corynebacterium, for which the name Corynebacterium alimapuense sp. nov. is proposed, with VA37-3T as the type strain (=CCUG 69366T=NCIMB 15118T).
|
|
| 3. |
- Cumsille, A., et al.
(författare)
-
Exploring the biosynthetic gene clusters in Brevibacterium: a comparative genomic analysis of diversity and distribution
- 2023
-
Ingår i: Bmc Genomics. - 1471-2164. ; 24:1
-
Tidskriftsartikel (refereegranskat)abstract
- Exploring Brevibacterium strains from various ecosystems may lead to the discovery of new antibiotic-producing strains. Brevibacterium sp. H-BE7, a strain isolated from marine sediments from Northern Patagonia, Chile, had its genome sequenced to study the biosynthetic potential to produce novel natural products within the Brevibacterium genus. The genome sequences of 98 Brevibacterium strains, including strain H-BE7, were selected for a genomic analysis. A phylogenomic cladogram was generated, which divided the Brevibacterium strains into four major clades. A total of 25 strains are potentially unique new species according to Average Nucleotide Identity (ANIb) values. These strains were isolated from various environments, emphasizing the importance of exploring diverse ecosystems to discover the full diversity of Brevibacterium. Pangenome analysis of Brevibacterium strains revealed that only 2.5% of gene clusters are included within the core genome, and most gene clusters occur either as singletons or as cloud genes present in less than ten strains. Brevibacterium strains from various phylogenomic clades exhibit diverse BGCs. Specific groups of BGCs show clade-specific distribution patterns, such as siderophore BGCs and carotenoid-related BGCs. A group of clade IV-A Brevibacterium strains possess a clade-specific Polyketide synthase (PKS) BGCs that connects with phenazine-related BGCs. Within the PKS BGC, five genes, including the biosynthetic PKS gene, participate in the mevalonate pathway and exhibit similarities with the phenazine A BGC. However, additional core biosynthetic phenazine genes were exclusively discovered in nine Brevibacterium strains, primarily isolated from cheese. Evaluating the antibacterial activity of strain H-BE7, it exhibited antimicrobial activity against Salmonella enterica and Listeria monocytogenes. Chemical dereplication identified bioactive compounds, such as 1-methoxyphenazine in the crude extracts of strain H-BE7, which could be responsible of the observed antibacterial activity. While strain H-BE7 lacks the core phenazine biosynthetic genes, it produces 1-methoxyphenazine, indicating the presence of an unknown biosynthetic pathway for this compound. This suggests the existence of alternative biosynthetic pathways or promiscuous enzymes within H-BE7's genome.
|
|
| 4. |
- Elsik, Christine G., et al.
(författare)
-
The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
-
Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
|
|
| 5. |
- Hillier, Ladeana W, et al.
(författare)
-
Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution
- 2004
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 432:7018, s. 695-716
-
Tidskriftsartikel (refereegranskat)abstract
- We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.
|
|
| 6. |
- Patalano, Solenn, et al.
(författare)
-
Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies
- 2015
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 112:45, s. 13970-13975
-
Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity.
|
|
| 7. |
- Richards, Stephen, et al.
(författare)
-
Genome Sequence of the Pea Aphid Acyrthosiphon pisum
- 2010
-
Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 8:2, s. e1000313-
-
Tidskriftsartikel (refereegranskat)abstract
- Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems.
|
|
| 8. |
- Undabarrena, A., et al.
(författare)
-
Complete genome sequence of the marine Rhodococcus sp H-CA8f isolated from Comau fjord in Northern Patagonia, Chile
- 2018
-
Ingår i: Marine Genomics. - : Elsevier BV. - 1874-7787. ; 40, s. 13-17
-
Tidskriftsartikel (refereegranskat)abstract
- Rhodococcus sp. H-CA8f was isolated from marine sediments obtained from the Comau fjord, located in Northern Chilean Patagonia. Whole-genome sequencing was achieved using PacBio RS II platform, comprising one closed, complete chromosome of 6,19 Mbp with a 62.45% G + C content. The chromosome harbours several metabolic pathways providing a wide catabolic potential, where the upper biphenyl route is described. Also, Rhodococcus sp. H-CA8f bears one linear mega-plasmid of 301 Kbp and 62.34% of G + C content, where genomic analyses demonstrated that it is constituted mostly by putative ORFs with unknown functions, representing a novel genetic feature. These genetic characteristics provide relevant insights regarding Chilean marine actinobacterial strains.
|
|
