4,730 research outputs found
Scheduling trainees at a hospital department using a branch-and-price approach.
No full textScheduling trainees (graduate students) is a complicated problem that has to be solved frequently in many hospital departments. We will describe a trainee scheduling problem encountered in practice (at the ophthalmology department of the university hospital Gasthuisberg, Leuven). In this problem a department has a certain number of trainees at its disposal, which assist specialists in their activities (surgery, consultation, etc.). For each trainee one has to schedule the activities in which (s)he will assist during a certain time horizon, usually one year. Typically, these kind of scheduling problems are characterized by both hard and soft constraints. The hard constraints consist of both work covering constraints and formation requirements, whereas the soft constraints include trainees' preferences and setup restrictions. In this paper we will describe an exact branch-and-price method to solve the problem to optimality.Branch-and-price; Constraint; Health care; Problems; Requirements; Scheduling; Staff scheduling; Time; University;
Median joining (MJ) Network tree.
No full text<p>MJ tree based on MT-CO2 gene sequences of world populations. Black points indicate, root; Blue, East Africans; Red, Africans; Orange, Australians; Green, Asians; Pink, Americans; Purple, Europeans. Branch lengths are not representative of evolutionary distance. The background colors outline possible demographic events in east Africa, and early episodes of evolution possibly towards the Rift Valley.</p
Acoel flatworms are not Platyhelminthes: evidence from phylogenomics
No full textAcoel flatworms are small marine worms traditionally considered to belong to the phylum Platyhelminthes. However, molecular phylogenetic analyses suggest that acoels are not members of Platyhelminthes, but are rather extant members of the earliest diverging Bilateria. This result has been called into question, under suspicions of a long branch attraction (LBA) artefact. Here we re-examine this problem through a phylogenomic approach using 68 different protein-coding genes from the acoel Convoluta pulchra and 51 metazoan species belonging to 15 different phyla. We employ a mixture model, named CAT, previously found to overcome LBA artefacts where classical models fail. Our results unequivocally show that acoels are not part of the classically defined Platyhelminthes, making the latter polyphyletic. Moreover, they indicate a deuterostome affinity for acoels, potentially as a sister group to all deuterostomes, to Xenoturbellida, to Ambulacraria, or even to chordates. However, the weak support found for most deuterostome nodes, together with the very fast evolutionary rate of the acoel Convoluta pulchra, call for more data from slowly evolving acoels (or from its sister-group, the Nemertodermatida) to solve this challenging phylogenetic problem
Self-compression of 4.9 µm pulses to sub-40 fs with 2 mJ energy in Zinc Sulfide
No full textNonlinear self-compression of few-cycle multi-mJ pulses at 4.9 µm in ZnS is presented. 80 fs input pulses are compressed to 37 fs with 2.1 mJ energy at a 1 kHz repetition rate. © 2024 The Author(s
Branchwidth, Branch Decompositions and b-parses
No full textIn this paper we present an easy-to-use data structure for representing graphs
of bounded branchwidth, called b-parses. Many hard problems that can be represented as graph problems can be more easily solved when a decomposition of the
graph is taken into account. This is particularly true where the input graph can
be seen to be treelike in some form. An example of such a treelike structure is
branch decomposition, were the edges of a graph are arranged as leaves around
a tree and the internal nodes of the tree represent connectivity between subsets
of the edges of the original graph. This is similar in concept to the idea of tree
decomposition which views the input graph vertices as forming a treelike structure of bounded-sized vertex separators. However branch decompositions may be
simpler to work with than tree decompositions for appropriate problems because
of the structure (and possibly smaller width) of the tree that is formed. In this
paper an algebraic representation of branch decompositions (b-parse) is proposed
as an alternative to the t-parse representation for tree decompositions. An application of this data structure to the known hard problems Minimum Vertex Cover
and 3-Coloring is examined. Finally, possible benefits of using b-parses from the
parallelism perspective is given
Median-joining (MJ) networks of <i>tefA</i> haplotypes from <i>Epichloë</i> species.
No full text<p>Each circle represents a single haplotype and the circle size is proportional to the number of isolates with that haplotype. Median vectors (mv) indicate missing intermediates of unsampled nodes inferred by the MJ network analysis and the number along the branch shows the number of mutations separating nodes.</p
Median-joining (MJ) networks of <i>tubB</i> haplotypes from <i>Epichloë</i> species.
No full text<p>Each circle represents a single haplotype and the circle size is proportional to the number of isolates with that haplotype. Median vectors (mv) indicate missing intermediates of unsampled nodes inferred by the MJ network analysis and the number along the branch shows the number of mutations separating nodes.</p
ruvA Mutants that resolve Holliday junctions but do not reverse replication forks
No full textRuvAB and RuvABC complexes catalyze branch migration and resolution of Holliday junctions (HJs) respectively. In addition to their action in the last steps of homologous recombination, they process HJs made by replication fork reversal, a reaction which occurs at inactivated replication forks by the annealing of blocked leading and lagging strand ends. RuvAB was recently proposed to bind replication forks and directly catalyze their conversion into HJs. We report here the isolation and characterization of two separation-of-function ruvA mutants that resolve HJs, based on their capacity to promote conjugational recombination and recombinational repair of UV and mitomycin C lesions, but have lost the capacity to reverse forks. In vivo and in vitro evidence indicate that the ruvA mutations affect DNA binding and the stimulation of RuvB helicase activity. This work shows that RuvA's actions at forks and at HJs can be genetically separated, and that RuvA mutants compromised for fork reversal remain fully capable of homologous recombination
Correction to: Chamoun et al., Bacterial pathogenesis and interleukin-17: interconnecting mechanisms of immune regulation, host genetics, and microbial virulence that influence severity of infection
No full textChamoun MN, Blumenthal A, Sullivan MJ, Schembri MA, Ulett GC. 2018. Bacterial pathogenesis and interleukin-17: interconnecting mechanisms of immune regulation, host genetics, and microbial virulence that influence severity of infection. Critical Reviews in Microbiology. https://doi.org/10.1080/1040841X.2018.1426556.
When the above article was first published online, the below three corrections were missed.
The author ‘Antje Blumenthal’ was wrongly affiliated to the affiliation “cSchool of Chemistry and Molecular Biosciences, and Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia”. Now this affiliation has been removed for this author.
The affiliation ‘bTranslational Research Institute, The University of Queensland Diamantina Institute, Woolloongabba, Australia’ of the author ‘Antje Blumenthal’ should read ‘bThe University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Australia’.
In Table 3, the sentence ‘Benefit of manipulating IL-17 levels to improve immunization strategies M. tuberculosis’ should read “Benefit of manipulating IL-17 levels to improve immunization strategies against M. tuberculosis”.No Full Tex
Generation of 22-mJ, 2.0-ps Pulses from a 1-kHz Ho:YLF Regenerative Chirped Pulse Amplifier
No full textWe report a CW-pumped Ho:YLF regenerative amplifier (RA) delivering pulses with 22.5-mJ energy and 2.0-ps duration at 1 kHz. The RA emitting at 2051 nm is broadband-seeded and implemented in a chirped pulse amplification system. © 2024 The Author(s
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