742 research outputs found
First record of the invasive diatom Didymosphenia geminata (Lyngbye) Schmidt in a Patagonian Andean river of Argentina
The Futaleufú River, Argentina, was monitored monthly from June 2010 to August 2011, in order to detect the invasive diatom Didymosphenia geminata, which was previously observed in Chile. Plankton and periphyton samples were taken from 10 sites. Didymosphenia geminata was not found until late winter. In August 2010, the species was first detected at isolated points of the river but in spring and summer the algal coverage extended along several kilometers. The coverage of blooms, spread to deeper areas (pools) with varying depths, reached more than 2 m, invading epiphytic and epilithic substrates. In autumn the bloom diminished its coverage area and there were only small isolated patches. During the next winter, blooms were not observed until late August, when it was recorded again. The observations showed that D. geminata appeared, colonized and invaded the bed of the river at low flow situations in spring and summer and its blooms declined in autumn - when the flows increase - after having been dried in summer when flows were the lowest.Fil: Sastre, Alicia Viviana. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Santinelli, Norma Herminia. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Bauer, Gabriel A.. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel; ArgentinaFil: Ayesterán, M. Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Uyua, Noelia Mariel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; Argentin
A heuristic to minimize the cardinality of a real-time task set by automated task clustering
International audienceWe propose in this paper a method to automatically map functionalities (blocks of code corresponding to high-level features) with real-time constraints to tasks (or threads). We aim at reducing the number of tasks functions are mapped to, while preserving the schedulability of the initial system. We consider independent tasks running on a single processor. Our approach has been applied with fixed-task or fixed-job priorities assigned in a Deadline Monotonic (DM) or a Earliest Deadline First (EDF) manner
Testing and integrating the WLCG/EGEE middleware in the LHC computing
The main goal of the Experiment Integration and Support (EIS) team in WLCG is to help the LHC experiments with using proficiently the gLite middleware as part of their computing framework. This contribution gives an overview of the activities of the EIS team, and focuses on a few of them particularly important for the experiments. One activity is the evaluation of the gLite workload management system (WMS) to assess its adequacy for the needs of the LHC computing in terms of functionality, reliability and scalability. We describe in detail how the experiment requirements can be mapped to validation criteria, and the WMS performances are accurately measured under realistic load conditions over prolonged periods of time. Another activity is the integration of the Service Availability Monitoring system (SAM) with the experiment monitoring framework. The SAM system is widely used in the EGEE operations to identify malfunctions in Grid services, but it can be adapted to perform the same function on experiment-specific services. We describe how this has been done for some LHC experiments, which are now using SAM as part of their operations
Composite Leptoquarks at the LHC
If electroweak symmetry breaking arises via strongly-coupled physics, the
observed suppression of flavour-changing processes suggests that fermion masses
should arise via mixing of elementary fermions with composite fermions of the
strong sector. The strong sector then carries colour charge, and may contain
composite leptoquark states, arising either as TeV scale resonances, or even as
light, pseudo-Nambu-Goldstone bosons. The latter, since they are coupled to
colour, get a mass of the order of several hundred GeV, beyond the reach of
current searches at the Tevatron. The same generic mechanism that suppresses
flavour-changing processes suppresses leptoquark-mediated rare processes,
making it conceivable that the many stringent constraints may be evaded. The
leptoquarks couple predominantly to third-generation quarks and leptons, and
the prospects for discovery at LHC appear to be good. As an illustration, a
model based on the Pati-Salam symmetry is described, and its embedding in
models with a larger symmetry incorporating unification of gauge couplings,
which provide additional motivation for leptoquark states at or below the TeV
scale, is discussed.Comment: 10 pp, version to appear in JHE
Biopsy confirmation of metastatic sites in breast cancer patients:clinical impact and future perspectives
Determination of hormone receptor (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor 2 status in the primary tumor is clinically relevant to define breast cancer subtypes, clinical outcome,and the choice of therapy. Retrospective and prospective studies suggest that there is substantial discordance in receptor status between primary and recurrent breast cancer. Despite this evidence and current recommendations,the acquisition of tissue from metastatic deposits is not routine practice. As a consequence, therapeutic decisions for treatment in the metastatic setting are based on the features of the primary tumor. Reasons for this attitude include the invasiveness of the procedure and the unreliable outcome of biopsy, in particular for biopsies of lesions at complex visceral sites. Improvements in interventional radiology techniques mean that most metastatic sites are now accessible by minimally invasive methods, including surgery. In our opinion, since biopsies are diagnostic and changes in biological features between the primary and secondary tumors can occur, the routine biopsy of metastatic disease needs to be performed. In this review, we discuss the rationale for biopsy of suspected breast cancer metastases, review issues and caveats surrounding discordance of biomarker status between primary and metastatic tumors, and provide insights for deciding when to perform biopsy of suspected metastases and which one (s) to biopsy. We also speculate on the future translational implications for biopsy of suspected metastatic lesions in the context of clinical trials and the establishment of bio-banks of biopsy material taken from metastatic sites. We believe that such bio-banks will be important for exploring mechanisms of metastasis. In the future,advances in targeted therapy will depend on the availability of metastatic tissue
An ensemble neural network approach for space-time landslide predictive modelling
There is an urgent need for accurate and effective Landslide Early Warning Systems (LEWS). Most LEWS are currently based on a single temporally-aggregated measure of rainfall derived from either in-situ measurements or satellite-based rainfall estimates. Relying on a summary metric of precipitation may not capture the complexity of the rainfall signal and its dynamics in space and time in triggering landslides. Here, we present a proof-of-concept for constructing a LEWS that is based on an integrated spatio-temporal modelling framework. Our proposed methodology builds upon a recent approach that uses a daily rainfall time series instead of the traditional cumulated scalar approximation. Specifically, we partition the study area into slope units and use a Gated Recurrent Unit (GRU) to process a satellite-derived rainfall time series and combine the output features with a second neural network (NN) tasked with capturing the effect of terrain characteristics. To assess if our approach enhances accuracy, we applied it in Vietnam and compared it against a standard modelling approach that incorporates terrain characteristics and cumulative rainfall over 14 days. Our protocol leads to better performance in hindcasting landslides when using past rainfall estimates (CHIRPS), as compared to the standard modelling approach. While not tested here, our approach can be extended to rainfall obtained from weather forecasts, potentially leading to actual landslide forecasts
Opposite-side flavour tagging of B mesons at the LHCb experiment
The calibration and performance of the oppositeside
flavour tagging algorithms used for the measurements
of time-dependent asymmetries at the LHCb experiment
are described. The algorithms have been developed using
simulated events and optimized and calibrated with
B
+ →J/ψK
+, B0 →J/ψK
∗0 and B0 →D
∗−
μ
+
νμ decay
modes with 0.37 fb−1 of data collected in pp collisions
at
√
s = 7 TeV during the 2011 physics run. The oppositeside
tagging power is determined in the B
+ → J/ψK
+
channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty
is statistical and the second is systematic
Constraints from muon g-2 and LFV processes in the Higgs Triplet Model
Constraints from the muon anomalous magnetic dipole moment and lepton flavor
violating processes are translated into lower bounds on v_Delta*m_H++ in the
Higgs Triplet Model by considering correlations through the neutrino mass
matrix. The discrepancy of the sign of the contribution to the muon anomalous
magnetic dipole moment between the measurement and the prediction in the model
is clarified. It is shown that mu to e gamma, tau decays (especially, tau to mu
e e), and the muonium conversion can give a more stringent bound on
v_Delta*m_H++ than the bound from mu to eee which is expected naively to give
the most stringent one.Comment: 18 pages, 16 figure
CleanET: enabling timing validation for complex automotive systems
Timing validation for automotive systems occurs in late integration stages when it is hard to control how the instances of software tasks overlap in time. To make things worse, in complex software systems, like those for autonomous driving, tasks schedule has a strong event-driven nature, which further complicates relating those task-overlapping scenarios (TOS) captured during the software timing budgeting and those observed during validation phases. This paper proposes CleanET, an approach to derive the dilation factor r caused due to the simultaneous execution of multiple tasks. To that end, CleanET builds on the captured TOS during testing and predicts how tasks execution time react under untested TOS (e.g. full overlap), hence acting as a mean of robust testing. CleanET also provides additional evidence for certification about the derived timing budgets for every task. We apply CleanET to a commercial autonomous driving framework, Apollo, where task measurements can only be reasonably collected under 'arbitrary' TOS. Our results show that CleanET successfully derives the dilation factor and allows assessing whether execution times for the different tasks adhere to their respective deadlines for unobserved scenarios.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant TIN2015- 65316-P, the SuPerCom European Research Council (ERC) project under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 772773), and the HiPEAC Network of Excellence. MINECO partially supported Jaume Abella under Ramon y Cajal postdoctoral fellowship (RYC-2013-14717).Peer ReviewedPostprint (author's final draft
Strong constraints on the rare decays Bs -> mu+ mu- and B0 -> mu+ mu-
A search for Bs -> mu+ mu- and B0 -> mu+ mu- decays is performed using 1.0
fb^-1 of pp collision data collected at \sqrt{s}=7 TeV with the LHCb experiment
at the Large Hadron Collider. For both decays the number of observed events is
consistent with expectation from background and Standard Model signal
predictions. Upper limits on the branching fractions are determined to be BR(Bs
-> mu+ mu-) mu+ mu-) < 1.0 (0.81) x 10^-9 at
95% (90%) confidence level.Comment: 2+6 pages; 4 figures; Accepted for publication in Physical Review
Letter
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