101 research outputs found
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
European population genomic differentiation and dispersal pattern of the invasive beetle Anoplophora glabripennis
Anthropogenic activities (e.g. homogenized habitats, trade) are the main factors to facilitate the increasing rates of invasive alien species. In this study, the invasion of the Asian long-horned beetle (Anoplophora glabripennis) was examined. Its native distribution is eastern Asia (China, Korean peninsula), but by extensive trade, this beetle was introduced via wood packing materials to North-America (1996) and Europe (2001). ALB attacks healthy broadleaved trees (e.g. Acer spp., Salix spp., Populus spp.), which can become lethal due to larval feeding. This study aims to detect genetic differences and kinship between the European infestation sites in Germany, Switzerland and Italy, from which the introduction and dispersal patterns can be deviated. Therefore, mitochondrial (mt) DNA-markers of the Cytochrome oxidase subunits I and II genes (COI and II) were used (ch. A and B, Sanger sequencing), as well as genome wide single nucleotide polymorphisms (SNPs), which were obtained by a Genotype-by-sequencing (GBS) approach (ch. C, Illumina sequencing). The results of this population genomic study of invasive European ALB populations showed very complex introduction patterns into Europe including multiple independent introductions characterized by the high population structure between the European infestation sites and some cases of human mediated secondary dispersal.Anthropogene Aktivitäten (z.B. homogenisierte Habitate, Handel) sind die Hauptfaktoren, die ein erhöhtes Vorkommen invasiver Arten begünstigen. Diese Studie untersuchte die Invasion des Asiatischen Laubholzbockkäfers (Anoplophora glabripennis). Sein natürlicher Lebensraum liegt in China und der koreanischen Halbinsel und konnte durch intensiven Handel über Holzverpackungsmaterial nach Nordamerika (1996) und Europa (2001) eingeschleppt werden. ALB befällt gesunde Laubbäume (z.B. Acer spp., Salix spp., Populus spp.) was durch den Larvenfraß oft tödlich enden kann. Ziel dieser Arbeit war es, genetische Unterschiede von Befallsgebieten in Deutschland, der Schweiz und Italien zu finden, um Verwandtschaften und damit Einschleppungs- und Verbreitungswege abzuleiten. Dafür wurden mtDNA-Marker der Cytochromoxidase Untereinheiten I und II (Kap. A und B, Sanger Sequenzierung,) und durch Genotype-by-sequencing (GBS) gewonnene genomweite Einzelnukleotidpolymorphismen (SNPs) verwendet (Kap. C, Illumina Sequenzierung). Die Ergebnisse der populationsgenomischen Untersuchung invasiver ALB Populationen in Europa zeigen sehr komplexe Einschleppungswege, bestehend aus mehreren unabhängigen Einfuhren, die sich durch die starke Populationsstruktur zwischen den europäischen Befallsgebieten auszeichnen, sowie einzelnen Fällen von sekundärer Verbringung durch den Menschen
Locally countable pseudovarieties
The purpose of this paper is to contribute to the theory of profinite semigroups by considering the special class consisting of those all of whose finitely generated closed subsemigroups are countable, which are said to be locally countable. We also call locally countable a pseudovariety V (of finite semigroups) for which all pro-V semigroups are locally countable. We investigate operations preserving local countability of pseudovarieties and show that, in contrast with local finiteness, several natural operations do not preserve it. We also investigate the relationship of a finitely generated profinite semigroup being countable with every element being expressible in terms of the generators using multiplication and the idempotent (omega) power. The two properties turn out to be equivalent if there are only countably many group elements, gathered in finitely many regular J -classes. We also show that the pseudovariety generated by all finite ordered monoids satisfying the inequality 1 6 x n is locally countable if and only if n = 1
A review of commercialisation mechanisms for carbon dioxide removal
The deployment of carbon dioxide removal (CDR) needs to be scaled up to achieve net zero emission pledges. In this paper we survey the policy mechanisms currently in place globally to incentivise CDR, together with an estimate of what different mechanisms are paying per tonne of CDR, and how those costs are currently distributed. Incentive structures are grouped into three structures, market-based, public procurement, and fiscal mechanisms. We find the majority of mechanisms currently in operation are underresourced and pay too little to enable a portfolio of CDR that could support achievement of net zero. The majority of mechanisms are concentrated in market-based and fiscal structures, specifically carbon markets and subsidies. While not primarily motivated by CDR, mechanisms tend to support established afforestation and soil carbon sequestration methods. Mechanisms for geological CDR remain largely underdeveloped relative to the requirements of modelled net zero scenarios. Commercialisation pathways for CDR require suitable policies and markets throughout the projects development cycle. Discussion and investment in CDR has tended to focus on technology development. Our findings suggest that an equal or greater emphasis on policy innovation may be required if future requirements for CDR are to be met. This study can further support research and policy on the identification of incentive gaps and realistic potential for CDR globally
New solution approaches for optimization problems with combinatorial aspects in logistics management
This dissertation comprises five papers, which have been published in scientific journals between 2019 and 2022. The papers consider logistic optimization problems from three different subjects with a focus on intra-logistics. All considered optimization problems have strong combinatorial aspects. To solve the considered problems, various solution approaches including different decomposition techniques are employed.
Paper 1 investigates the optimization of the layout and storage assignment in warehouses with U-shaped order picking zones. The paper considers two objectives, namely minimizing the order picker's walking distance and physical strain during order picking. To solve the problem, a semantic decomposition approach is proposed, which solves the problem in polynomial time. In a computational study, both considered objectives are found to be mostly complementary. Moreover, suggestions for advantageous layout designs and storage assignments are derived.
Paper 2 considers the problem of how to stow bins on tow trains in order to minimize the handling personnel's physical strain for loading and unloading. The problem is shown to be NP-hard and decomposed semantically. Utilising the decomposition, the problem is solved exactly with dynamic programming and heuristically with a greedy randomized adaptive search procedure. A consecutive computational study shows that both procedures perform well. Beyond that, it investigates the influence of the tow train wagons' design on the considered objective.
Paper 3 is concerned with the problem of scheduling jobs with time windows on unrelated parallel machines, which is a NP-hard optimization problem that has applications, i.a., in berth allocation and truck dock scheduling. The paper presents an exact logic-based Benders decomposition procedure and a heuristic solution approach based on a set partitioning formulation of the problem. Moreover, three distinct objectives, namely minimizing the makespan, the maximum flow time, and the maximum lateness are considered. Both procedures exhibit good performances in the concluding computational study.
Paper 4 addresses the problem of order picker routing in a U-shaped order picking zone with the objective of minimizing the covered walking distance. The problem is proven to be NP-hard. An exact logic-based Benders decomposition procedure as well as a heuristic dynamic programming approach are developed and shown to perform well in computational tests. Beyond that, the paper discusses different storage assignment policies and compares them in a numeric study.
Paper 5 studies scheduling electrically powered tow trains in in-plant production logistics. The problem is regarded as an Electric Vehicle Scheduling Problem, where tow trains must be assigned to timetabled service trips. Since the tow trains' range is limited, charging breaks need to be scheduled in-between trips, which require detours and time. The objective consists in minimizing the required fleet size. The problem is shown to be NP-hard. To solve the problem, Paper 5 proposes a branch-and-check approach that is applicable for various charging technologies, including battery swapping and plug-in charging with nonlinear charge increase. In a computational study, the approach's practical applicability is demonstrated. Moreover, influences of the batteries' maximum capacity and employed charging technology are investigated
Mapping Narrations – Narrating Maps
This volume offers the author’s central articles on the medieval and early modern history of cartography for the first time in English translation. A first group of essays gives an overview of medieval cartography, illustrating the methods of cartographers. Another analyzes world maps and travel accounts in relation to mapped spaces. A third examines land surveying, cartographical practices of exploration, and the production of Portolan atlases
The Anchor Index
This index contains listings of articles in The Anchor. The Anchor is a newspaper put out by Hope College students. It contains articles written by students about Hope College events, people, issues, etc. Note: This is a rough index. It contains tens of thousands of references and was prepared by past and present volunteer staff
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