503 research outputs found

    Power domination on triangular grids

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    The concept of power domination emerged from the problem of monitoring electrical systems. Given a graph G and a set S \subseteq V (G), a set M of monitored vertices is built as follows: at first, M contains only the vertices of S and their direct neighbors, and then each time a vertex in M has exactly one neighbor not in M, this neighbor is added to M. The power domination number of a graph G is the minimum size of a set S such that this process ends up with the set M containing every vertex of G. We here show that the power domination number of a triangular grid T\_k with hexagonal-shape border of length k -- 1 is exactly $\lceil k/3 \rceil.Comment: Canadian Conference on Computational Geometry, Jul 2017, Ottawa, Canad

    Power domination in maximal planar graphs

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    Power domination in graphs emerged from the problem of monitoring an electrical system by placing as few measurement devices in the system as possible. It corresponds to a variant of domination that includes the possibility of propagation. For measurement devices placed on a set S of vertices of a graph G, the set of monitored vertices is initially the set S together with all its neighbors. Then iteratively, whenever some monitored vertex v has a single neighbor u not yet monitored, u gets monitored. A set S is said to be a power dominating set of the graph G if all vertices of G eventually are monitored. The power domination number of a graph is the minimum size of a power dominating set. In this paper, we prove that any maximal planar graph of order n \ge 6 admits a power dominating set of size at most (n--2)/4

    Tripartite entanglement and threshold properties of coupled intracavity downconversion and sum-frequency generation

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    The process of cascaded downconversion and sum-frequency generation inside an optical cavity has been predicted to be a potential source of three-mode continuous-variable entanglement. When the cavity is pumped by two fields, the threshold properties have been analysed, showing that these are more complicated than in well-known processes such as optical parametric oscillation. When there is only a single pumping field, the entanglement properties have been calculated using a linearised fluctuation analysis, but without any consideration of the threshold properties or critical operating points of the system. In this work we extend this analysis to demonstrate that the singly pumped system demonstrates a rich range of threshold behaviour when quantisation of the pump field is taken into account and that asymmetric polychromatic entanglement is available over a wide range of operational parameters.Comment: 24 pages, 15 figure

    Combination of Bortezomib and Mitotic Inhibitors Down-Modulate Bcr-Abl and Efficiently Eliminates Tyrosine-Kinase Inhibitor Sensitive and Resistant Bcr-Abl-Positive Leukemic Cells

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    Emergence of resistance to Tyrosine-Kinase Inhibitors (TKIs), such as imatinib, dasatinib and nilotinib, in Chronic Myelogenous Leukemia (CML) demands new therapeutic strategies. We and others have previously established bortezomib, a selective proteasome inhibitor, as an important potential treatment in CML. Here we show that the combined regimens of bortezomib with mitotic inhibitors, such as the microtubule-stabilizing agent Paclitaxel and the PLK1 inhibitor BI2536, efficiently kill TKIs-resistant and -sensitive Bcr-Abl-positive leukemic cells. Combined treatment activates caspases 8, 9 and 3, which correlate with caspase-induced PARP cleavage. These effects are associated with a marked increase in activation of the stress-related MAP kinases p38MAPK and JNK. Interestingly, combined treatment induces a marked decrease in the total and phosphorylated Bcr-Abl protein levels, and inhibits signaling pathways downstream of Bcr-Abl: downregulation of STAT3 and STAT5 phosphorylation and/or total levels and a decrease in phosphorylation of the Bcr-Abl-associated proteins CrkL and Lyn. Moreover, we found that other mitotic inhibitors (Vincristine and Docetaxel), in combination with bortezomib, also suppress the Bcr-Abl-induced pro-survival signals and result in caspase 3 activation. These results open novel possibilities for the treatment of Bcr-Abl-positive leukemias, especially in the imatinib, dasatinib and nilotinib-resistant CML cases

    Uidates mtDNA fülogeneesi radadel; essee väikeste kõrvalepõigetega sellest, mida see meile inimese migratsioonidest kõnelda võib

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    Väitekirja elektrooniline versioon ei sisalda publikatsiooneMeie genoomidesse on kirjutatud kogu informatsioon, mida rakuline masinavärk inimolendi kokkupanekuks vajab. Ja mitte ainult. Kasutades ad hoc raamistikku on võimalik kaasaegsete inimeste genoomide alusel mineviku inimese migratsioone rekonstrueerida. Pikka aega on sellealaste uuringute musternäidiseks olnud mitokondriaalne DNA (mtDNA) ja Y-kromosoom, eelkõige seetõttu, et need on haploidsed ja mitterekombineeruvad - nende fülogeneesi on autosoomidega võrreldes lihtsam rekonstrueerida. Fülogeneesis kajastub paljude evolutsioonitegurite, sealhulgas migratsioonide mõju, seega – teoreetiliselt on võimalik fülogeneesi uurides inimese rännetega seotud küsimustele vastuseid leida. Üks tee antud küsimustele vastamiseks on uurida meid huvitavate populatsioonide üldist varieeruvust ja paigutada see laiemasse perspektiivi. Näiteks selgub meie tööst, et Euraasiale ja Aafrikale iseloomulike liinide üldine osakaal on Etioopia ja Jeemeni mtDNA geenitiigis peaaegu identne, suurem lahutusaste toob aga esile nende märkimisväärseid erinevusi. Prantsusmaa puhul ilmneb, et kui üldisel tasemel ei erineta lähedastest naabermaadest, siis geograafilist fookust kintsendades kerkivad esile Püreneedest põhjas või lõunas elavate baskide vahelised erinevused. Samuti tuleb esile, Bretagne´i administratiivüksuste seas on Finistère`l teistest tugevamad seosed Suurbritannia ja Skandinaaviaga. Kaugel ida pool, Kesk-Aasias Hindukuši Afganistaani-osa paljusid erinevaid etnilisi populatsioone uurides saime tuge seisukohale, et Kesk-Aasia on olnud paljude migratsioonilainete risteel ja nende mõjud on kaasaegsetesse populatsioonidesse jätnud märgatava jälje. Teise võimaluse küsimustele vastuseid leida andis fookuse suunamine üksikutele spetsiifilistele haplogruppidele. Haplogruppide M1 ja U6 fülogeneesi uurimine lükkas ümber varasema hüpoteesi nende samaaegsest levikust. Me ei leidnud ka kindlaid tõendeid seoste kohta nende haplogruppide ja afroaasia keelte leviku vahel.Inscribed in our genomes, there is all the necessary information for the cellular machinery to build a human being. And then some. Using an ad hoc framework, it is possible to attempt to infer past human migrations by looking at the current variation present in these genomes. Mitochondrial DNA (mtDNA) and the Y chromosome have long been the poster child for doing it, chiefly thanks to their haploid and non-recombining nature, allowing to reconstruct their phylogeny in a more straightforward way than for the autosomes. These phylogenies have been shaped by evolutionary forces, amongst them migrations. Hence, by studying the former, it is theoretically possible to tackle questions germane to the latter. One way to address our questions is to study the general composition of a specific population or several, and to place it into a broader perspective. For instance, we showed that, whilst the overall proportion of Eurasian and African specific lineages is almost identical in Ethiopian and Yemeni mtDNA gene pool, a finer level of resolution revealed marked differences in them. In the case of France, it is globally not dissimilar from its close neighbours, yet narrowing down the geographical focus exposes dissimilarities between the Basques living north of the Pyrénées from those south of them. And amongst the administrative departments of Brittany, Finistère displays tighter connections with Britain and Scandinavia. Much further east, in Central Asia, exploring various ethnic populations of the Afghan Hindu Kush gave support to the notion that Central Asia has been a long-standing cross-road of multiple waves of migrations, each leaving perceptible traces in the extant populations. As for another way of answering questions, we shifted our focus to some specific haplogroups, with a new examination of M1 and U6 phylogenies that confuted the previously purported concomitance of their spread. We also did not find strong evidence of connections between their spread and that of the Afro-Asiatic languages.https://www.ester.ee/record=b5257709~S

    MEASURING WIRELESS NETWORK CONNECTION QUALITY

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    A system can run network tests to determine throughput for a wireless network connection between two devices. For example, a testing device can send a number of intentionally invalid test packets to a receiving device. The wireless MAC layer of the receiving device automatically sends back acknowledgment packets indicating that the test packets have been received. The timing and/or counts of the test packets and acknowledgment packets can be analyzed to determine throughput on the wireless network connection. Described features can measure network performance for any kind of wireless (e.g., Wifi™) device without installing any software on that device and without requiring any user interaction to initiate or perform tests
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