TY - CONF AB - For a set of points in Rd, the Euclidean k-means problems consists of finding k centers such that the sum of distances squared from each data point to its closest center is minimized. Coresets are one the main tools developed recently to solve this problem in a big data context. They allow to compress the initial dataset while preserving its structure: running any algorithm on the coreset provides a guarantee almost equivalent to running it on the full data. In this work, we study coresets in a fully-dynamic setting: points are added and deleted with the goal to efficiently maintain a coreset with which a k-means solution can be computed. Based on an algorithm from Henzinger and Kale [ESA'20], we present an efficient and practical implementation of a fully dynamic coreset algorithm, that improves the running time by up to a factor of 20 compared to our non-optimized implementation of the algorithm by Henzinger and Kale, without sacrificing more than 7% on the quality of the k-means solution. AU - Henzinger, Monika H AU - Saulpic, David AU - Sidl, Leonhard ID - 14769 T2 - 2024 Proceedings of the Symposium on Algorithm Engineering and Experiments TI - Experimental evaluation of fully dynamic k-means via coresets ER - TY - JOUR AB - Since the commercialization of brine shrimp (genus Artemia) in the 1950s, this lineage, and in particular the model species Artemia franciscana, has been the subject of extensive research. However, our understanding of the genetic mechanisms underlying various aspects of their reproductive biology, including sex determination, is still lacking. This is partly due to the scarcity of genomic resources for Artemia species and crustaceans in general. Here, we present a chromosome-level genome assembly of A. franciscana (Kellogg 1906), from the Great Salt Lake, United States. The genome is 1 GB, and the majority of the genome (81%) is scaffolded into 21 linkage groups using a previously published high-density linkage map. We performed coverage and FST analyses using male and female genomic and transcriptomic reads to quantify the extent of differentiation between the Z and W chromosomes. Additionally, we quantified the expression levels in male and female heads and gonads and found further evidence for dosage compensation in this species. AU - Bett, Vincent K AU - Macon, Ariana AU - Vicoso, Beatriz AU - Elkrewi, Marwan N ID - 15009 IS - 1 JF - Genome Biology and Evolution TI - Chromosome-level assembly of Artemia franciscana sheds light on sex chromosome differentiation VL - 16 ER - TY - JOUR AB - The impulsive limit (the “sudden approximation”) has been widely employed to describe the interaction between molecules and short, far-off-resonant laser pulses. This approximation assumes that the timescale of the laser-molecule interaction is significantly shorter than the internal rotational period of the molecule, resulting in the rotational motion being instantaneously “frozen” during the interaction. This simplified description of the laser-molecule interaction is incorporated in various theoretical models predicting rotational dynamics of molecules driven by short laser pulses. In this theoretical work, we develop an effective theory for ultrashort laser pulses by examining the full time-evolution operator and solving the time-dependent Schrödinger equation at the operator level. Our findings reveal a critical angular momentum, lcrit, at which the impulsive limit breaks down. In other words, the validity of the sudden approximation depends not only on the pulse duration but also on its intensity, since the latter determines how many angular momentum states are populated. We explore both ultrashort multicycle (Gaussian) pulses and the somewhat less studied half-cycle pulses, which produce distinct effective potentials. We discuss the limitations of the impulsive limit and propose a method that rescales the effective matrix elements, enabling an improved and more accurate description of laser-molecule interactions. AU - Karle, Volker AU - Lemeshko, Mikhail ID - 15004 IS - 2 JF - Physical Review A SN - 2469-9926 TI - Modeling laser pulses as δ kicks: Reevaluating the impulsive limit in molecular rotational dynamics VL - 109 ER - TY - DATA AB - Since the commercialization of brine shrimp (genus Artemia) in the 1950s, this lineage, and in particular the model species Artemia franciscana, has been the subject of extensive research. However, our understanding of the genetic mechanisms underlying various aspects of their reproductive biology, including sex determination, are still lacking. This is partly due to the scarcity of genomic resources for Artemia species and crustaceans in general. Here, we present a chromosome-level genome assembly of Artemia franciscana (Kellogg 1906), from the Great Salt Lake, USA. The genome is 1GB, and the majority of the genome (81%) is scaffolded into 21 linkage groups using a previously published high-density linkage map. We performed coverage and FST analyses using male and female genomic and transcriptomic reads to quantify the extent of differentiation between the Z and W chromosomes. Additionally, we quantified the expression levels in male and female heads and gonads and found further evidence for dosage compensation in this species. AU - Elkrewi, Marwan N ID - 14705 KW - sex chromosome evolution KW - genome assembly KW - dosage compensation TI - Data from "Chromosome-level assembly of Artemia franciscana sheds light on sex-chromosome differentiation" ER - TY - JOUR AB - Magnetic frustration allows to access novel and intriguing properties of magnetic systems and has been explored mainly in planar triangular-like arrays of magnetic ions. In this work, we describe the phosphide Ce6Ni6P17, where the Ce+3 ions accommodate in a body-centered cubic lattice of Ce6 regular octahedra. From measurements of magnetization, specific heat, and resistivity, we determine a rich phase diagram as a function of temperature and magnetic field in which different magnetic phases are found. Besides clear evidence of magnetic frustration is obtained from entropy analysis. At zero field, a second-order antiferromagnetic transition occurs at TN1≈1 K followed by a first-order transition at TN2≈0.45 K. With magnetic field new magnetic phases appear, including a weakly first-order transition which ends in a classical critical point and a third magnetic phase. We also study the exact solution of the spin-1/2 Heisenberg model in an octahedron which allows us a qualitative understanding of the phase diagram and compare with the experimental results. AU - Franco, D. G. AU - Avalos, R. AU - Hafner, D. AU - Modic, Kimberly A AU - Prots, Yu AU - Stockert, O. AU - Hoser, A. AU - Moll, P. J.W. AU - Brando, M. AU - Aligia, A. A. AU - Geibel, C. ID - 15003 IS - 5 JF - Physical Review B SN - 2469-9950 TI - Frustrated magnetism in octahedra-based Ce6 Ni6 P17 VL - 109 ER -