1,576 research outputs found
Faint emission lines in the Galactic H II regions M16, M20 and NGC 3603
We present deep echelle spectrophotometry of the Galactic {\hii} regions M16,
M20 and NGC 3603. The data have been taken with the Very Large Telescope
Ultraviolet-Visual Echelle Spectrograph in the 3100 to 10400 \AA range. We have
detected more than 200 emission lines in each region. Physical conditions have
been derived using different continuum and line intensity ratios. We have
derived He, C and O abundances from pure recombination
lines as well as abundances from collisionally excited lines for a large number
of ions of different elements. We have obtained consistent estimations of the
temperature fluctuation parameter, {\ts}, using different methods. We also
report the detection of deuterium Balmer lines up to D (M16) and to
D (M20) in the blue wings of the hydrogen lines, which excitation
mechanism seems to be continuum fluorescence. The temperature fluctuations
paradigm agree with the results obtained from optical CELs and the more
uncertain ones from far IR fine structure CELs in NGC 3603, although, more
observations covering the same volume of the nebula are necessary to obtain
solid conclusions.Comment: 22 pages, 13 Tables, 7 Figures. Accepted for publication by MNRA
Testing the Divergence Stack Memory on GPGPUs: A Modular in-Field Test Strategy
General Purpose Graphic Processing Units (GPGPUs) are becoming a promising solution in safety-critical applications, e.g., in the automotive domain. In these applications, reliability and functional safety are relevant factors in the selection of devices to build the systems. Nowadays, many challenges are impacting the implementation of high-performance devices, such as GPGPUs. Moreover, there is the need for effective fault detection solutions to guarantee the correct in-field operation of a GPGPU, such as in the branch management unit, which is one of the most critical modules in this parallel architecture. Faults affecting this structure can heavily corrupt or even collapse the execution of an application on the GPGPU. In this work, we propose a non-invasive Software-Based Self-Test (SBST) solution to detect faults affecting the memory in the branch management unit of a GPGPU. We propose a scalar and modular mechanism to develop the test program as a combination of software functions. The FlexGripPlus model was employed to evaluate the proposed strategies experimentally. Results show that the proposed strategies are effective to test the target structure and detect up to 98% of permanent faults. General Purpose Graphic Processing Units (GPGPUs) are becoming a promising solution in safety-critical applications, e.g., in the automotive domain. In these applications, reliability and functional safety are relevant factors in the selection of devices to build the systems. Nowadays, many challenges are impacting the implementation of high-performance devices, such as GPGPUs. Moreover, there is the need for effective fault detection solutions to guarantee the correct in-field operation of a GPGPU, such as in the branch management unit, which is one of the most critical modules in this parallel architecture. Faults affecting this structure can heavily corrupt or even collapse the execution of an application on the GPGPU. In this work, we propose a non-invasive Software-Based Self-Test (SBST) solution to detect faults affecting the memory in the branch management unit of a GPGPU. We propose a scalar and modular mechanism to develop the test program as a combination of software functions. The FlexGripPlus model was employed to evaluate the proposed strategies experimentally. Results show that the proposed strategies are effective to test the target structure and detect up to 98% of permanent faults
Biological, Molecular and Phiysiological Characterization of Four Soybean mosaic virus Isolates Present in Argentine Soybean Crops
Soybean mosaic virus (SMV) causes systemic infections in soybean plants, leading to chlorotic mosaic and producing significant yield losses. The virus is widely distributed in all soybean production areas in the world. In Argentina, three geographical isolates were identified: Marcos Juárez (MJ), Manfredi (M), and North Western Argentina (NOA), and another isolate named “Planta Vinosa” (PV), which causes severe necrosis symptoms in some cultivars. Here, the biological, molecular and physiological characterization of these isolates was performed for the first time. Three of the four isolates showed a low genetic divergence in the evaluated genes (P1, CI and CP). Although SMV-NOA and SMV-PV had high homology at the sequence level, they showed wide differences in pathogenicity, seed mottling and the ability of transmission by seeds or aphids, as well as in physiological effects. SMV-NOA caused early alterations (before symptom appearance, BS) in ΦPSII and MDA content in leaves with respect to the other isolates. After the appearance of macroscopic symptoms (late symptoms, LS), SMV-M caused a significant increase in the content of MDA, total soluble sugars, and starch with respect to the other isolates. Thus, early alterations of ΦPSII and soluble sugars might have an impact on late viral symptoms. Likewise, SMV-MJ developed more severe symptoms in the susceptible Davis cultivar than in DM 4800. Therefore, our results show differences in genome, biological properties and physiological effects among SMV isolates as well as different interactions of SMV-MJ with two soybean cultivars.Instituto de Patología VegetalFil: Maugeri Suarez, M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales (FCEFyN); ArgentinaFil: Rodriguez, Marianela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Rodriguez, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA) ; ArgentinaFil: Bejerman, Nicolas Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Bejerman, Nicolas Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Laguna, Irma Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Laguna, Irma Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentin
A striking property of recombinant poxviruses: Efficient inducers of in vivo expansion of primed CD8(+) T cells
CSIC, Ctr Nacl Biotecnol, Madrid 28049, SpainNYU, Sch Med, Dept Med & Mol Parasitol, New York, NY 10010 USAEscola Paulista Med, BR-04023 São Paulo, BrazilEscola Paulista Med, BR-04023 São Paulo, BrazilWeb of Scienc
An extended model to support detailed GPGPU reliability analysis
General Purpose Graphics Processing Units (GPGPUs) have been used in the last decades as accelerators in high demanding data processing applications, such as multimedia processing and high-performance computing. Nowadays, these devices are becoming popular even in safety-critical applications, such as autonomous and semi-autonomous vehicles. However, these devices can suffer from the effects of transient faults, such as those produced by radiation effects. These effects can be represented in the system as Single Event Upsets (SEUs) and are able to generate intolerable application misbehaviors in safety critical environments. In this work, we extended the capabilities of an open-source VHDL GPGPU model (FlexGrip) in order to study and analyze in a much more detailed manner the effects of SEUs in some critical modules within a GPGPU. Simulation results showed that scheduler controller has different levels of SEU sensibility depending on the affected location. Moreover, a reduced number of execution units, in the GPGPU can decrease the system reliability
Radio Continuum and Water Maser Observations of the High-Mass Protostar IRAS 19035+0641 A
We present Very Large Array (VLA) 1.3 cm continuum and 22.2 GHz HO maser
observations of the high-mass protostellar object IRAS 19035+0641 A. Our
observations unveil an elongated bipolar 1.3 cm continuum structure at scales
au which, together with a rising in-band spectral index,
strongly suggests that the radio emission toward IRAS 19035+0641 A arises from
an ionized jet. In addition, eight individual water maser spots well aligned
with the jet axis were identified. The Stokes V spectrum of the brightest
HO maser line (Jy) shows a possible Zeeman splitting and is well
represented by the derivatives of two Gaussian components fitted to the Stokes
I profile. The measured are and
mG, translating to a pre-shock magnetic field of mG.
Subsequent observations to confirm the Zeeman splitting showed intense
variability in all the water maser spots, with the brightest maser completely
disappearing. The observed variability in a one-year time scale could be the
result of an accretion event. These findings strengthen our interpretation of
IRAS 19035+0641 A as a high-mass protostar in an early accretion/outflow
evolutionary phase.Comment: 12 pages, 6 figures, ApJ accepte
Functional correlates of response inhibition in impulse control disorders in Parkinson’s disease
Impulse control disorder is a prevalent side-effect of Parkinson’s disease (PD) medication, with a strong negative
impact on the quality of life of those affected. Although impulsivity has classically been associated with response
inhibition deficits, previous evidence from PD patients with impulse control disorder (ICD) has not revealed
behavioral dysfunction in response inhibition. In this study, 18 PD patients with ICD, 17 PD patients without this
complication, and 15 healthy controls performed a version of the conditional Stop Signal Task during functional
magnetic resonance imaging. Whole-brain contrasts, regions of interest, and functional connectivity analyses
were conducted. Our aim was to investigate the neural underpinnings of two aspects of response inhibition:
proactive inhibition, inhibition that has been prepared beforehand, and restrained inhibition, inhibition of an
invalid inhibitory tendency. We observed that, in respect to the other two groups, PD patients with ICD exhibited
hyperactivation of the stopping network bilaterally while performing proactive inhibition. When engaged in
restrained inhibition, they showed hyperactivation of the left inferior frontal gyrus, an area linked to action
monitoring. Restrained inhibition also resulted in changes to the functional co-activation between inhibitory
regions and left inferior parietal cortex and right supramarginal gyrus. Our findings indicate that PD patients
with ICD completed the inhibition task correctly, showing altered engagement of inhibitory and attentional
areas. During proactive inhibition they showed bilateral hyperactivation of two inhibitory regions, while during
restrained inhibition they showed additional involvement of attentional areas responsible for alerting and
orientin
Chemical abundances of the Galactic H II region NGC 3576 derived from VLT echelle spectrophotometry
We present echelle spectrophotometry of the Galactic H II region NGC 3576.
The data have been taken with the VLT UVES echelle spectrograph in the 3100 to
10400 angstroms range. We have measured the intensities of 458 emission lines,
344 are permitted lines of H0, He0, C+, N0, N+, N++, O0, O+, Ne+, S++, Si0,
Si+, Ar0 and Ar+; some of them are produced by recombination and others mainly
by fluorescence. Electron temperatures and densities have been determined using
different continuum and line intensity ratios. We have derived He+, C++, O+,
O++ and Ne++ ionic abundances from pure recombination lines. We have also
derived abundances from collisionally excited lines for a large number of ions
of different elements. Remarkably consistent estimations of t2 have been
obtained by comparing Balmer and Paschen to [O III] temperatures, and O++ and
Ne++ ionic abundances obtained from collisionally excited and recombination
lines. The chemical composition of NGC 3576 is compared with those of other
Galactic H II regions and with the one from the Sun. A first approach to the
gas-phase Galactic radial abundance gradient of C as well as of the C/O ratio
has been made.Comment: 25 pages, 14 tables, 4 figures. Accepted for publication in ApJ
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