84 research outputs found
Client Request Scheduling to Reduce Server Load Spikes
Popular mobile apps have hundreds of millions of users. Consequently, servers that support such apps can receive as many as hundreds of thousands of user requests every second. Certain applications submit requests from a large number of devices such that the requests arrive at the server at nearly the same time. This causes a sharp spike in the number of user requests to be processed by the server and congestion throughout the network stack that can result in errors and dropped user requests. This disclosure presents techniques that schedule incoming user requests such that the histogram of load-versus-time is relatively flat and smooth. A flatter load-versus-time curve thus obtained results in higher system availability, lower errorrates, less strain on load-balancers, and enables a greater level of user satisfaction
Mechanisation of Model-theoretic Conservative Extension for HOL with Ad-hoc Overloading
Definitions of new symbols merely abbreviate expressions in logical
frameworks, and no new facts (regarding previously defined symbols) should hold
because of a new definition. In Isabelle/HOL, definable symbols are types and
constants. The latter may be ad-hoc overloaded, i.e. have different definitions
for non-overlapping types. We prove that symbols that are independent of a new
definition may keep their interpretation in a model extension. This work
revises our earlier notion of model-theoretic conservative extension and
generalises an earlier model construction. We obtain consistency of theories of
definitions in higher-order logic (HOL) with ad-hoc overloading as a corollary.
Our results are mechanised in the HOL4 theorem prover.Comment: In Proceedings LFMTP 2020, arXiv:2101.0283
Spectroscopy of the neutron-rich actinide nucleus U-240 following multinucleon-transfer reactions
B. Birkenbach et al.; 9 pags.; 9 figs.; 2 tabs.; PACS number(s): 23.20.Lv, 25.70.Hi, 27.90.+b, 29.40.GxBackground: Nuclear structure information for the neutron-rich actinide nuclei is important since it is the benchmark for theoretical models that provide predictions for the heaviest nuclei. Purpose: gamma-ray spectroscopy of neutron-rich heavy nuclei in the actinide region. Method: Multinucleon-transfer reactions in Zn-70 + U-238 and Xe-136 + U-238 have been measured in two experiments performed at the INFN Legnaro, Italy. In the Zn-70 experiment the high-resolution HPGe Clover Array (CLARA) coupled to the magnetic spectrometer PRISMA was employed. In the Xe-136 experiment the high-resolution Advanced Gamma Tracking Array (AGATA) was used in combination with PRISMA and the Detector Array for Multinucleon Transfer Ejectiles (DANTE). Results: The ground-state band (g.s. band) of U-240 was measured up to the 20(+) level and a tentative assignment was made up to the (24(+)) level. Results from gamma gamma coincidence and from particle coincidence analyses are shown. Moments of inertia (MoI) show a clear upbend. Evidence for an extended first negative-parity band of U-240 is found. Conclusions: A detailed comparison with latest calculations shows best agreement with cranked relativistic Hartree-Bogoliubov (CRHB) calculations for the g.s. band properties. The negative-parity band shows the characteristics of a K-pi = 0 band based on an octupole vibration. ©2015 American Physical SocietyThe research leading to these results has received
funding from the German Bundesministerium fur Bildung ¨
und Forschung (BMBF) under Contract No. 05P12PKFNE
TP4, the European Union Seventh Framework Programme
(FP7/2007-2013) under Grant No. 262010-ENSAR, and the
Spanish Ministerio de Ciencia e Innovacion under Contract
No. FPA2011-29854-C04. A.V. thanks the Bonn-Cologne
Graduate School of Physics and Astronomy (BCGS) for
financial support. One of the authors (A. Gadea) was supported
by MINECO, Spain, under Grants No. FPA2011-29854-C04
759 and No. FPA2014-57196-C5; Generalitat Valenciana,
Spain, under Grant No. PROMETEOII/2014/019; and EU
under the FEDER program.Peer Reviewe
High-spin structure of Xe 134
A. Vogt et al. ; 12 págs.; 9 figs.; 1 tab.Detailed spectroscopic information on the N∼82 nuclei is necessary to benchmark shell-model calculations in the region. The nuclear structure above long-lived isomers in Xe134 is investigated after multinucleon transfer (MNT) and actinide fission. Xenon-134 was populated as (i) a transfer product in Xe136+U238 and Xe136+Pb208 MNT reactions and (ii) as a fission product in the Xe136+U238 reaction employing the high-resolution Advanced Gamma Tracking Array (AGATA). Trajectory reconstruction has been applied for the complete identification of beamlike transfer products with the magnetic spectrometer PRISMA. The Xe136+Pt198 MNT reaction was studied with the γ-ray spectrometer GAMMASPHERE in combination with the gas detector array Compact Heavy Ion Counter (CHICO). Several high-spin states in Xe134 on top of the two long-lived isomers are discovered based on γγ-coincidence relationships and information on the γ-ray angular distributions as well as excitation energies from the total kinetic energy loss and fission fragments. The revised level scheme of Xe134 is extended up to an excitation energy of 5.832 MeV with tentative spin-parity assignments up to 16+. Previous assignments of states above the 7- isomer are revised. Latest shell-model calculations employing two different effective interactions reproduce the experimental findings and support the new spin and parity assignments.The research leading to these results has received funding
from the German BMBF under Contract No. 05P12PKFNE
TP4, from the European Union Seventh Framework Programme
FP7/2007–2013 under Grant Agreement No. 262010 -
ENSAR, from the Spanish Ministerio de Ciencia e Innovación
under Contract No. FPA2011-29854-C04, from the Spanish
Ministerio de EconomÃa y Competitividad under Contract No.
FPA2014-57196-C5, from the Bonn-Cologne Graduate School
of Physics and Astronomy (BCGS), from the UK Science
and Technology Facilities Council (STFC), and from the US
National Science Foundation (NSF). One of the authors (A.
Gadea) has been supported by the Generalitat Valenciana,
Spain, under Grant No. PROMETEOII/2014/019 and EU
under the FEDER program.Peer Reviewe
Tumor suppression in mice lacking GABARAP, an Atg8/LC3 family member implicated in autophagy, is associated with alterations in cytokine secretion and cell death
GABARAP belongs to an evolutionary highly conserved gene family that has a
fundamental role in autophagy. There is ample evidence for a crosstalk between
autophagy and apoptosis as well as the immune response. However, the molecular
details for these interactions are not fully characterized. Here, we report
that the ablation of murine GABARAP, a member of the Atg8/LC3 family that is
central to autophagosome formation, suppresses the incidence of tumor
formation mediated by the carcinogen DMBA and results in an enhancement of the
immune response through increased secretion of IL-1β, IL-6, IL-2 and IFN-γ
from stimulated macrophages and lymphocytes. In contrast, TGF-β1 was
significantly reduced in the serum of these knockout mice. Further, DMBA
treatment of these GABARAP knockout mice reduced the cellularity of the spleen
and the growth of mammary glands through the induction of apoptosis. Gene
expression profiling of mammary glands revealed significantly elevated levels
of Xaf1, an apoptotic inducer and tumor-suppressor gene, in knockout mice.
Furthermore, DMBA treatment triggered the upregulation of pro-apoptotic (Bid,
Apaf1, Bax), cell death (Tnfrsf10b, Ripk1) and cell cycle inhibitor (Cdkn1a,
Cdkn2c) genes in the mammary glands. Finally, tumor growth of B16 melanoma
cells after subcutaneous inoculation was inhibited in GABARAP-deficient mice.
Together, these data provide strong evidence for the involvement of GABARAP in
tumorigenesis in vivo by delaying cell death and its associated immune-related
response
Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) has potential tumour-suppressive activity in human lung cancer
Insulin-like growth binding protein-related protein 1 (IGFBP-rP1) has decreased expression in various tumors, but the role of IGFBP-rP1 in lung cancer has not yet been elucidated. In this study, we evaluated the IGFBP-rP1 expression in lung cancer cell lines and we found a reduced expression of IGFBP-rP1 at both mRNA and protein levels. In a tissue microarray containing 138 primary tumors analyzed by immunohistochemistry, 58 cases (42%) exhibited no expression of IGFBP-rP1, additionally, an association between IGFBP-rP1 expression and tumor gradings was found in squamous cell lung cancer. Neither deletion or gene rearrangement nor loss of heterozigosity was responsible for the inactivation of IGFBP-rP1. However, 5-aza-2'-deoxycytidine treatment restored the expression of IGFBP-rP1 in 3 out of 4 lung cancer cell lines. Sequencing of sodium bisulfite?treated genomic DNA from these 3 lung cancer cell lines revealed a heterogeneous methylation pattern in the region of exon 1 and intron 1. Stable transfection of IGFBP-rP1 full-length cDNA into a lung cancer cell line H2170 led to an increased protein expression of IGFBP-rP1. IGFBP-rP1 positive transfectants remarkably reduced the ability of colony formation in soft agar, suppressed the tumor growth rate in nude mice and increased the number of apoptotic cells as well as the expression level of casepase-3 compared to controls. Moreover, treatment with differentiation modulating agent 5-bromodeoxyuridine (BrdU) led to an enhanced expression of IGFBP-rP1 in lung cancer cells. Out data suggest that IGFBP-rP1 is a tumor suppressor possibly via DNA methylation and induction of apoptosis in human lung cancer
Study of ground and excited state decays in N approximate to Z Ag nuclei
4 pags., 4 figs. -- CGS15 – Capture Gamma-Ray Spectroscopy and Related TopicsA decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic 100Sn. The N = Z nuclei 98In, 96Cd and 94Ag were of particular interest for the present study. Preliminary results on the neutron deficient nuclei 93Ag and 94Ag are presented. In 94Ag a more precise value for the half-life of the ground state’s superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Qβ values from the measured data. The decay of 93Ag is discussed based on the observed implantation-decay correlation events.This work was carried out at the RIBF operated by RIKEN
Nishina Center, RIKEN and CNS, University of Tokyo.
We acknowledge the EUROBALL Owners Committee for
the loan of germanium detectors and the PreSpec Collaboration for the readout electronics of the cluster detectors.
This work was supported by the German BMBF under
Contract No. 05P12PKFNE and by the U.S. Department
of Energy under grant No. DE-FG02-91ER-40609
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