28 research outputs found
Scalp high-frequency oscillations differentiate neonates with seizures from healthy neonates
OBJECTIVE
We aimed to investigate (1) whether an automated detector can capture scalp high-frequency oscillations (HFO) in neonates and (2) whether scalp HFO rates can differentiate neonates with seizures from healthy neonates.
METHODS
We considered 20 neonates with EEG-confirmed seizures and four healthy neonates. We applied a previously validated automated HFO detector to determine scalp HFO rates in quiet sleep.
RESULTS
Etiology in neonates with seizures included hypoxic-ischemic encephalopathy in 11 cases, structural vascular lesions in 6, and genetic causes in 3. The HFO rates were significantly higher in neonates with seizures (0.098â±â0.091 HFO/min) than in healthy neonates (0.038â±â0.025 HFO/min; Pâ=â0.02) with a Hedge's g value of 0.68 indicating a medium effect size. The HFO rate of 0.1 HFO/min/ch yielded the highest Youden index in discriminating neonates with seizures from healthy neonates. In neonates with seizures, etiology, status epilepticus, EEG background activity, and seizure patterns did not significantly impact HFO rates.
SIGNIFICANCE
Neonatal scalp HFO can be detected automatically and differentiate neonates with seizures from healthy neonates. Our observations have significant implications for neuromonitoring in neonates. This is the first step in establishing neonatal HFO as a biomarker for neonatal seizures
The Ophiuchus DIsc Survey Employing ALMA (ODISEA). II. The effect of stellar multiplicity on disc properties
We present Adaptive Optics (AO) near infrared (NIR) observations using
VLT/NACO and Keck/NIRC2 of ODISEA targets. ODISEA is an ALMA survey of the
entire population of circumstellar discs in the Ophiuchus molecular cloud. From
the whole sample of ODISEA we select all the discs that are not already
observed in the NIR with AO and that are observable with NACO or NIRC2. The
NIR-ODISEA survey consists of 147 stars observed in NIR AO imaging for the
first time, as well as revisiting almost all the binary systems of Ophiuchus
present in the literature (20 out of 21). In total, we detect 20 new binary
systems and one triple system. For each of them we calculate the projected
separation and position angle of the companion, as well as their NIR and
millimeter flux ratios. From the NIR contrast we derived the masses of the
secondaries, finding that 9 of them are in the sub-stellar regime (30-50
\MJup). Discs in multiple systems reach a maximum total dust mass of 50
M, while discs in single stars can reach a dust mass of 200
M. Discs with masses above 10 M are found only around
binaries with projected separations larger than 110 au. The maximum disc
size is also larger around single star than binaries. However, since most discs
in Ophiuchus are very small and low-mass, the effect of visual binaries is
relatively weak in the general disc population.Comment: 13 pages, 13 figures, 4 tables. Published in MNRA
The first ALMA survey of protoplanetary discs at 3 mm: demographics of grain growth in the Lupus region
We present the first ALMA survey of protoplanetary discs at 3 mm, targeting
36 young stellar objects in the Lupus star-forming region with deep
observations (sensitivity 20-50 microJy/beam) at ~0.35" resolution (~50 au).
Building on previous ALMA surveys at 0.89 and 1.3 mm that observed the complete
sample of Class II discs in Lupus at a comparable resolution, we aim to assess
the level of grain growth in the relatively young Lupus region. We measure 3 mm
integrated fluxes, from which we derive disc-averaged 1-3 mm spectral indices.
We find that the mean spectral index of the observed Lupus discs is
, in all cases , with a tendency for larger spectral indices in the brightest discs
and in transition discs. Furthermore, we find that the distribution of spectral
indices in Lupus discs is statistically indistinguishable from that of the
Taurus and Ophiuchus star-forming regions. Assuming the emission is optically
thin, the low values measured for most discs
can be interpreted with the presence of grains larger than 1 mm. The
observations of the faint discs in the sample can be explained without invoking
the presence of large grains, namely through a mixture of optically thin and
optically thick emission from small grains. However, the bright (and typically
large) discs do inescapably require the presence of millimeter-sized grains in
order to have realistic masses. Based on a disc mass argument, our results
challenge previous claims that the presence of optically thick sub-structures
may be a universal explanation for the empirical millimeter size-luminosity
correlation observed at 0.89 mm.Comment: MNRAS Accepted; 12 pages, 5 figures, 2 tables. Machine-readable
tables available at https://zenodo.org/record/475628
Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA
We present Atacama Large Millimeter and Submillimeter Array observations of the protoplanetary disk around the Herbig Ae star HD 163296 that trace the spatial distribution of millimeter-sized particles and cold molecular gas on spatial scales as small as 25 astronomical units (A.U.). The image of the disk recorded in the 1.3 mm continuum emission reveals three dark concentric rings that indicate the presence of dust depleted gaps at about 60, 100, and 160 A.U. from the central star. The maps of the ^(12)CO, ^(13)CO, and C^(18)O J=2â1 emission do not show such structures but reveal a change in the slope of the radial intensity profile across the positions of the dark rings in the continuum image. By comparing the observations with theoretical models for the disk emission, we find that the density of CO molecules is reduced inside the middle and outer dust gaps. However, in the inner ring there is no evidence of CO depletion. From the measurements of the dust and gas densities, we deduce that the gas-to-dust ratio varies across the disk and, in particular, it increases by at least a factor 5 within the inner dust gap compared to adjacent regions of the disk. The depletion of both dust and gas suggests that the middle and outer rings could be due to the gravitational torque exerted by two Saturn-mass planets orbiting at 100 and 160 A.U. from the star. On the other hand, the inner dust gap could result from dust accumulation at the edge of a magnetorotational instability dead zone, or from dust opacity variations at the edge of the CO frost line. Observations of the dust emission at higher angular resolution and of molecules that probe dense gas are required to establish more precisely the origins of the dark rings observed in the HD 163296 disk
Benefit analysis. Assessing the cost of blackouts in case of attack. Evaluation based on Italian and Polish case studies
RT 52; This report provides an economic quantification of the benefits of implementing security standards, expressed in terms of avoided costs of blackouts. The evaluation considers specifically the blackouts described in the Italian and Polish trials, employing a mixed methodology relying on the âproduction functionâ approach for the non-household sector, while an econometric method based on survey data (stated preferences) is used for household consumers. With reference to non-households, a separate evaluation is carried on for the electricity industry. The results show that the costs of blackout are substantial, either for household and non-household consumers, and largely exceed the damage suffered by the utilities ue to lost sales. Finally, since for non-households only losses in production are considered, we provide, in a separate section, three case studies demonstrating that some industries can suffer relevant additional blackout cost
Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA
We present Atacama Large Millimeter and Submillimeter Array observations of the protoplanetary disk around the Herbig Ae star HD 163296 that trace the spatial distribution of millimeter-sized particles and cold molecular gas on spatial scales as small as 25 astronomical units (A.U.). The image of the disk recorded in the 1.3 mm continuum emission reveals three dark concentric rings that indicate the presence of dust depleted gaps at about 60, 100, and 160 A.U. from the central star. The maps of the ^(12)CO, ^(13)CO, and C^(18)O J=2â1 emission do not show such structures but reveal a change in the slope of the radial intensity profile across the positions of the dark rings in the continuum image. By comparing the observations with theoretical models for the disk emission, we find that the density of CO molecules is reduced inside the middle and outer dust gaps. However, in the inner ring there is no evidence of CO depletion. From the measurements of the dust and gas densities, we deduce that the gas-to-dust ratio varies across the disk and, in particular, it increases by at least a factor 5 within the inner dust gap compared to adjacent regions of the disk. The depletion of both dust and gas suggests that the middle and outer rings could be due to the gravitational torque exerted by two Saturn-mass planets orbiting at 100 and 160 A.U. from the star. On the other hand, the inner dust gap could result from dust accumulation at the edge of a magnetorotational instability dead zone, or from dust opacity variations at the edge of the CO frost line. Observations of the dust emission at higher angular resolution and of molecules that probe dense gas are required to establish more precisely the origins of the dark rings observed in the HD 163296 disk
Near-infrared Imaging of a Spiral in the CQ Tau Disk
We present L'-band Keck/NIRC2 imaging and H-band Subaru/AO188+HiCIAO polarimetric observations of the CQ Tau disk with a new spiral arm. Apart from the spiral feature, our observations could not detect any companion candidates. We traced the spiral feature from the r[SUP]2[/SUP]-scaled High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) polarimetric intensity image and the fitted result is used for forward modeling to reproduce the ADI-reduced NIRC2 image. We estimated the original surface brightness after throughput correction in the L' band to be âŒ126 mJy arcsec[SUP]-2[/SUP] at most. We suggest that the grain temperature of the spiral may be heated up to âŒ200 K in order to explain both of the H- and L'-band results. The H-band emission at the location of the spiral originates from the scattering from the disk surface while both scattering and thermal emission may contribute to the L'-band emission. If the central star is only the light source of scattered light, the spiral emission at the L' band should be thermal emission. If an inner disk also acts as the light source, the scattered light and the thermal emission may equally contribute to the L'-band spiral structure
Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems
Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment