Non-Markov property of certain eigenvalue processes analogous to Dyson's model

It is proven that the eigenvalue process of Dyson's random matrix process of size two becomes non-Markov if the common coefficient $1/\sqrt{2}$ in the non-diagonal entries is replaced by a different positive number.Comment: 8 pages, To appear in Proceedings of the 1st MSJ-SI, "Probabilistic Approach to Geometry", Adv. Stud. Pure Math., Math. Soc. Japa

b tagging in ATLAS and CMS

Many physics signals presently studied at the high energy collision experiments lead to final states with jets originating from heavy flavor quarks. This report reviews the algorithms for heavy flavor jets identification developed by the ATLAS and CMS Collaborations in view of the Run2 data taking period at the Large Hadron Collider. The improvements of the algorithms used in 2015 and 2016 data analyses with respect to previous data taking periods are discussed, as well as the ongoing developments in view of the next years of data taking. The measurements of the performance of the algorithms on data as well as the dedicated techniques for the identification of heavy flavor jets in events with boosted topologies are also presented. Finally, the effectiveness of heavy flavor jet identification in the complex environment expected during the high luminosity LHC phase is discussed.Comment: 6 pages, Proceeding for the Fifth Annual Large Hadron Collider Physics (LHCP2017) conferenc

Metabolomic correlation-network modules in Arabidopsis based on a graph-clustering approach

<p>Abstract</p> <p>Background</p> <p>Deciphering the metabolome is essential for a better understanding of the cellular metabolism as a system. Typical metabolomics data show a few but significant correlations among metabolite levels when data sampling is repeated across individuals grown under strictly controlled conditions. Although several studies have assessed topologies in metabolomic correlation networks, it remains unclear whether highly connected metabolites in these networks have specific functions in known tissue- and/or genotype-dependent biochemical pathways.</p> <p>Results</p> <p>In our study of metabolite profiles we subjected root tissues to gas chromatography-time-of-flight/mass spectrometry (GC-TOF/MS) and used published information on the aerial parts of 3 <it>Arabidopsis </it>genotypes, Col-0 wild-type, <it>methionine over-accumulation 1 </it>(<it>mto1</it>), and <it>transparent testa4 </it>(<it>tt4</it>) to compare systematically the metabolomic correlations in samples of roots and aerial parts. We then applied graph clustering to the constructed correlation networks to extract densely connected metabolites and evaluated the clusters by biochemical-pathway enrichment analysis. We found that the number of significant correlations varied by tissue and genotype and that the obtained clusters were significantly enriched for metabolites included in biochemical pathways.</p> <p>Conclusions</p> <p>We demonstrate that the graph-clustering approach identifies tissue- and/or genotype-dependent metabolomic clusters related to the biochemical pathway. Metabolomic correlations complement information about changes in mean metabolite levels and may help to elucidate the organization of metabolically functional modules.</p

Metabolite Signature during Short-Day Induced Growth Cessation in Populus

The photoperiod is an important environmental signal for plants, and influences a wide range of physiological processes. For woody species in northern latitudes, cessation of growth is induced by short photoperiods. In many plant species, short photoperiods stop elongational growth after a few weeks. It is known that plant daylength detection is mediated by Phytochrome A (PHYA) in the woody hybrid aspen species. However, the mechanism of dormancy involving primary metabolism remains unclear. We studied changes in metabolite profiles in hybrid aspen leaves (young, middle, and mature leaves) during short-day-induced growth cessation, using a combination of gas chromatography–time-of-flight mass spectrometry, and multivariate projection methods. Our results indicate that the metabolite profiles in mature source leaves rapidly change when the photoperiod changes. In contrast, the differences in young sink leaves grown under long and short-day conditions are less distinct. We found short daylength induced growth cessation in aspen was associated with rapid changes in the distribution and levels of diverse primary metabolites. In addition, we conducted metabolite profiling of leaves of PHYA overexpressor (PHYAOX) and those of the control to find the discriminative metabolites between PHYAOX and the control under the short-day conditions. The metabolite changes observed in PHYAOX leaves, together with those in the source leaves, identified possible candidates for the metabolite signature (e.g., 2-oxo-glutarate, spermidine, putrescine, 4-amino-butyrate, and tryptophan) during short-day-induced growth cessation in aspen leaves

Search for a stochastic background of 100-MHz gravitational waves with laser interferometers

This letter reports the results of a search for a stochastic background of gravitational waves (GW) at 100 MHz by laser interferometry. We have developed a GW detector, which is a pair of 75-cm baseline synchronous recycling (resonant recycling) interferometers. Each interferometer has a strain sensitivity of ~ 10^{-16} Hz^{-1/2} at 100 MHz. By cross-correlating the outputs of the two interferometers within 1000 seconds, we found h_{100}^2 Omega_{gw} < 6 times 10^{25} to be an upper limit on the energy density spectrum of the GW background in a 2-kHz bandwidth around 100 MHz, where a flat spectrum is assumed.Comment: Accepted by Phys.Rev.Lett.; 10 pages, 4 figure

Unbiased characterization of genotype-dependent metabolic regulations by metabolomic approach in Arabidopsis thaliana

<p>Abstract</p> <p>Background</p> <p>Metabolites are not only the catalytic products of enzymatic reactions but also the active regulators or the ultimate phenotype of metabolic homeostasis in highly complex cellular processes. The modes of regulation at the metabolome level can be revealed by metabolic networks. We investigated the metabolic network between wild-type and 2 mutant (<it>methionine-over accumulation 1 </it>[<it>mto1</it>] and <it>transparent testa4 </it>[<it>tt4</it>]) plants regarding the alteration of metabolite accumulation in <it>Arabidopsis thaliana</it>.</p> <p>Results</p> <p>In the GC-TOF/MS analysis, we acquired quantitative information regarding over 170 metabolites, which has been analyzed by a novel score (ZMC, z-score of metabolite correlation) describing a characteristic metabolite in terms of correlation. Although the 2 mutants revealed no apparent morphological abnormalities, the overall correlation values in <it>mto1 </it>were much lower than those of the wild-type and <it>tt4 </it>plants, indicating the loss of overall network stability due to the uncontrolled accumulation of methionine. In the <it>tt4 </it>mutant, a new correlation between malate and sinapate was observed although the levels of malate, sinapate, and sinapoylmalate remain unchanged, suggesting an adaptive reconfiguration of the network. Gene-expression correlations presumably responsible for these metabolic networks were determined using the metabolite correlations as clues.</p> <p>Conclusion</p> <p>Two Arabidopsis mutants, <it>mto1 </it>and <it>tt4</it>, exhibited the following changes in entire metabolome networks: the overall loss of metabolic stability (<it>mto1</it>) or the generation of a metabolic network of a backup pathway for the lost physiological functions (<it>tt4</it>). The expansion of metabolite correlation to gene-expression correlation provides detailed insights into the systemic understanding of the plant cellular process regarding metabolome and transcriptome.</p

Organic carboxylate salt-enabled alternative synthetic routes for bio-functional cyclic carbonates and aliphatic polycarbonates

Simple and efficient synthetic routes for functionalized cyclic carbonates are indispensable for the practical application of side-chain bio-functionalized aliphatic polycarbonates as biodegradable functional biomaterials. In this study, a six-membered cyclic carbonate with a triethylammonium carboxylate has been prepared in one step from 2,2-bis(methylol)propionic acid (bis-MPA). We have demonstrated the suitability of the organic carboxylate salt of the bis-MPA cyclic carbonate for esterification with alkyl bromides via the SN2 mechanism, leading to the formation of functionalized cyclic carbonate monomers. The esterification of the organic carboxylate salt proceeds efficiently when alkyl bromides with α-carbonyl, allyl, and benzyl groups are used. This approach enables a two-step synthesis of functionalized cyclic carbonates from bis-MPA. The organocatalyzed ring-opening polymerization of the resultant functionalized cyclic carbonates is effectively controlled, indicating that the synthetic process involving the organic carboxylate salt does not influence their polymerizability. The ether-functionalized aliphatic polycarbonates obtained from the organic carboxylate salt exhibit good antiplatelet properties, comparable to those of a previously developed blood-compatible aliphatic polycarbonate. The synthetic pathways exploiting organic carboxylate salts enable alternative shortcuts to functionalized cyclic carbonates from bis-MPA

A Compact Digital Signature Scheme Based on the Module-LWR problem*

We propose a lattice-based digital signature scheme MLWRSign by modifying Dilithium, which is one of the third-Round finalists of NIST’s call for post-quantum cryptographic standards. To the best of our knowledge, our scheme MLWRSign is the first signature scheme whose security is based on the (module) learning with rounding (LWR) problem. Due to the simplicity of the LWR, the secret key size is reduced by approximately 30% in our scheme compared to Dilithium, while achieving the same level of security. Moreover, we implemented MLWRSign and observed that the running time of MLWRSign is comparable to that of Dilithium

Experimental investigation of a control scheme for a tuned resonant sideband extraction interferometer for next-generation gravitational-wave detectors

LCGT plans to use tuned RSE as the optical configuration for its interferometer. A tuned RSE interferometer has five degrees of freedom that need to be controlled in order to operate a gravitational-wave detector, although it is expected to be very challenging because of the complexity of its optical configuration. A new control scheme for a tuned RSE interferometer has been developed and tested with a prototype interferometer to demonstrate successful control of the tuned RSE interferometer. The whole RSE interferometer was successfully locked with the control scheme. Here the control scheme and the current status of the experiment are presented