428 research outputs found
A Holographic Path to the Turbulent Side of Gravity
We study the dynamics of a 2+1 dimensional relativistic viscous conformal
fluid in Minkowski spacetime. Such fluid solutions arise as duals, under the
"gravity/fluid correspondence", to 3+1 dimensional asymptotically anti-de
Sitter (AAdS) black brane solutions to the Einstein equation. We examine
stability properties of shear flows, which correspond to hydrodynamic
quasinormal modes of the black brane. We find that, for sufficiently high
Reynolds number, the solution undergoes an inverse turbulent cascade to long
wavelength modes. We then map this fluid solution, via the gravity/fluid
duality, into a bulk metric. This suggests a new and interesting feature of the
behavior of perturbed AAdS black holes and black branes, which is not readily
captured by a standard quasinormal mode analysis. Namely, for sufficiently
large perturbed black objects (with long-lived quasinormal modes), nonlinear
effects transfer energy from short to long wavelength modes via a turbulent
cascade within the metric perturbation. As long wavelength modes have slower
decay, this lengthens the overall lifetime of the perturbation. We also discuss
various implications of this behavior, including expectations for higher
dimensions, and the possibility of predicting turbulence in more general
gravitational scenarios.Comment: 24 pages, 10 figures; v2: references added, and several minor change
A Multiple System of Radio Sources at the Core of the L723 Multipolar Outflow
We present high angular resolution Very Large Array multi-epoch continuum
observations at 3.6 cm and 7 mm towards the core of the L723 multipolar outflow
revealing a multiple system of four radio sources suspected to be YSOs in a
region of only ~4 arcsecs (1200 AU) in extent. The 3.6 cm observations show
that the previously detected source VLA 2 contains a close (separation ~0.29
arcsecs or ~90 AU) radio binary, with components (A and B) along a position
angle of ~150 degrees. The northern component (VLA 2A) of this binary system is
also detected in the 7 mm observations, with a positive spectral index between
3.6 cm and 7 mm. In addition, the source VLA 2A is associated with extended
emission along a position angle of ~115 degrees, that we interpret as
outflowing shock-ionized gas that is exciting a system of HH objects with the
same position angle. A third, weak 3.6 cm source, VLA 2C, that is detected also
at 7 mm, is located ~0.7 arcsecs northeast of VLA 2A, and is possibly
associated with the water maser emission in the region. The 7 mm observations
reveal the presence of an additional source, VLA 2D, located ~3.5 arcsecs
southeast of VLA 2A, and with a 1.35 mm counterpart. All these radio continuum
sources have a positive spectral index, compatible with them being YSOs. We
also propose that the high velocity CO emission observed in the region could be
the superposition of multiple outflows (at least three independent bipolar
outflows) excited by the YSOs located at the core, instead of the previous
interpretations in terms of only one or two outflows.Comment: Accepted for publication in The Astrophysical Journal (2007 December
6
Imaging the Inner and Outer Gaps of the Pre-Transitional Disk of HD 169142 at 7 mm
We present Very Large Array observations at 7 mm that trace the thermal
emission of large dust grains in the HD 169142 protoplanetary disk. Our images
show a ring of enhanced emission of radius ~25-30 AU, whose inner region is
devoid of detectable 7 mm emission. We interpret this ring as tracing the rim
of an inner cavity or gap, possibly created by a planet or a substellar
companion. The ring appears asymmetric, with the western part significantly
brighter than the eastern one. This azimuthal asymmetry is reminiscent of the
lopsided structures that are expected to be produced as a consequence of
trapping of large dust grains. Our observations also reveal an outer annular
gap at radii from ~40 to ~70 AU. Unlike other sources, the radii of the inner
cavity, the ring, and the outer gap observed in the 7 mm images, which trace
preferentially the distribution of large (mm/cm sized) dust grains, coincide
with those obtained from a previous near-infrared polarimetric image, which
traces scattered light from small (micron- sized) dust grains. We model the
broad-band spectral energy distribution and the 7 mm images to constrain the
disk physical structure. From this modeling we infer the presence of a small
(radius ~0.6 AU) residual disk inside the central cavity, indicating that the
HD 169142 disk is a pre-transitional disk. The distribution of dust in three
annuli with gaps in between them suggests that the disk in HD 169142 is being
disrupted by at least two planets or substellar objects.Comment: Accepted by ApJ Letters, 16 pages, 3 figures, ApJ Letters 201
Simple Clinical and Laboratory Predictors of Chikungunya versus Dengue Infections in Adults
10.1371/journal.pntd.0001786PLoS Neglected Tropical Diseases69
Evaluating combinations of temporally aggregated Sentinel-1, Sentinel-2 and Landsat 8 For land cover mapping with Google Earth Engine
Land cover mapping of large areas is challenging due to the significant volume of satellite
data to acquire and process, as well as the lack of spatial continuity due to cloud cover. Temporal
aggregation—the use of metrics (i.e., mean or median) derived from satellite data over a period
of time—is an approach that benefits from recent increases in the frequency of free satellite data
acquisition and cloud-computing power. This enables the efficient use of multi-temporal data and
the exploitation of cloud-gap filling techniques for land cover mapping. Here, we provide the
first formal comparison of the accuracy between land cover maps created with temporal aggregation
of Sentinel-1 (S1), Sentinel-2 (S2), and Landsat-8 (L8) data from one-year and test whether this
method matches the accuracy of traditional approaches. hirty-two datasets were created for Wales by
applying automated cloud-masking and temporally aggregating data over different time intervals,
using Google Earth Engine. Manually processed S2 data was used for comparison using a traditional
two-date composite approach. Supervised classifications were created, and their accuracy was
assessed using field-based data. Temporal aggregation only matched the accuracy of the traditional
two-date composite approach (77.9%) when an optimal combination of optical and radar data was
used (76.5%). Combined datasets (S1, S2 or S1, S2, and L8) outperformed single-sensor datasets,
while datasets based on spectral indices obtained the lowest levels of accuracy. The analysis of
cloud cover showed that to ensure at least one cloud-free pixel per time interval, a maximum of
two intervals per year for temporal aggregation were possible with L8, while three or four intervals
could be used for S2. This study demonstrates that temporal aggregation is a promising tool for
integrating large amounts of data in an efficient way and that it can compensate for the lower quality
of automatic image selection and cloud masking. It also shows that combining data from different
sensors can improve classification accuracy. However, this study highlights the need for identifying
optimal combinations of satellite data and aggregation parameters in order to match the accuracy of
manually selected and processed image composites
Zonación metamórfica en el área Monesterio-Fuente de Cantos: criterios texturales y mineralógicos
[Resumen] En el sector central del denominado "anticlinorio 0livenza-Monesterio", en los materiales del Proterozoico superior afectados por un metamorfismo progresivo que alcanza condiciones anatécticas, se ha establecido una zonaci6n metamórfica para los grados bajo y medio, basada en el estado de evolución textural de diferentes 1itologias y caracteres ópticos de distintos minerales, en especial la biotita, en las rocas metape1iticas y metagrauváquicas.Abstract] In the central part of the so-called "anticlinorium 0livenza-Monesterio", in Upper Proterozoic materials affected by a progressive metamorphism which reach to anatectic condicions, a rnetamorphic zonation has been stab1ished for the 10w and middle metamorphic degrees based on the state of textural evolution of several lithologies and in the optical features of different minera1s, mainly the biotite, in metapelithic and metagrauwakic rock
IAA : Información y actualidad astronómica (33)
Sumario : Las estrellas jóvenes “imitan” a los agujeros negros.--
La Nebulosa de la Pipa.--
Galaxias “guisante verde”.--
HISTORIAS DE ASTRONOMÍA. Palomas y elefantes.--
DECONSTRUCCIÓN Y otros ENSAYOS. Misión Sunrise.--
EL “MOBY DICK” DE... Martín Guerrero Roncel (IAA-CSIC).--
ACTUALIDAD.--
ENTRE BASTIDORES.--
CIENCIA: PILARES E INCERTIDUMBRES :
Agujeros negros.--
ACTIVIDADES IAA, AGENDA Y RECOMENDADOS.N
Therapeutic targeting of PD-1/PD-L1 blockade by novel small-molecule inhibitors recruits cytotoxic T cells into solid tumor microenvironment
© Author(s) (or their employer(s)) 2022.This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See http://creativecommons.org/licenses/by-nc/4.0/.Background: Inhibiting programmed cell death protein 1 (PD-1) or PD-ligand 1 (PD-L1) has shown exciting clinical outcomes in diverse human cancers. So far, only monoclonal antibodies are approved as PD-1/PD-L1 inhibitors. While significant clinical outcomes are observed on patients who respond to these therapeutics, a large proportion of the patients do not benefit from the currently available immune checkpoint inhibitors, which strongly emphasize the importance of developing new immunotherapeutic agents.
Methods: In this study, we followed a transdisciplinary approach to discover novel small molecules that can modulate PD-1/PD-L1 interaction. To that end, we employed in silico analyses combined with in vitro, ex vivo, and in vivo experimental studies to assess the ability of novel compounds to modulate PD-1/PD-L1 interaction and enhance T-cell function.
Results: Accordingly, in this study we report the identification of novel small molecules, which like anti-PD-L1/PD-1 antibodies, can stimulate human adaptive immune responses. Unlike these biological compounds, our newly-identified small molecules enabled an extensive infiltration of T lymphocytes into three-dimensional solid tumor models, and the recruitment of cytotoxic T lymphocytes to the tumor microenvironment in vivo, unveiling a unique potential to transform cancer immunotherapy.
Conclusions: We identified a new promising family of small-molecule candidates that regulate the PD-L1/PD-1 signaling pathway, promoting an extensive infiltration of effector CD8 T cells to the tumor microenvironment.C and RCA are supported by the Fundação para a Ciência e a Tecnologia, Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES) (PhD grants PD/BD/128238/2016 (RCA) and SFRH/BD/131969/2017 (BC)). The authors thank the funding received from the European Structural & Investment Funds through the COMPETE Programme and from National Funds through FCT under the Programme grant LISBOA-01-0145-FEDER016405 - SAICTPAC/0019/2015 (HF and RCG). HFF and RCA received additional support from FCT-MCTES (UIDB/04138/2020, PTDC/BTM-SAL/4350/2021 and UTAPEXPL/NPN/0041/2021; EXPL/MED-QUI/1316/2021, respectively). The MultiNano@MBM project was supported by The Israeli Ministry of Health, and FCTMCTES, under the frame of EuroNanoMed-II (ENMed/0051/2016; HF and RS-F). HF and RS-F thank the generous financial support from ‘La Caixa’ Foundation under the framework of the Healthcare Research call 2019 (NanoPanther; LCF/PR/HR19/52160021), as well as CaixaImpulse (Co-Vax; LCF/TR/CD20/52700005). MP thanks the financial support from Liga Portuguesa Contra o Cancro – Nucleo Regional do Sul and ‘iNOVA4Health – UIDB/04462/2020’, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência. RS-F thanks the following funding agencies for their generous support: the European Research Council (ERC) Advanced Grant Agreement No. (835227)–3DBrainStrom, ERC PoC Grant Agreement no. 862580 – 3DCanPredict, The Israel Science Foundation (Grant No. 1969/18), The Melanoma Research Alliance (MRA Established Investigator Award n°615808), the Israel Cancer Research Fund (ICRF) Professorship award (n° PROF-18-682), and the Morris Kahn Foundation.info:eu-repo/semantics/publishedVersio
Interactions Between Marine Megafauna and Plastic Pollution in Southeast Asia
Southeast (SE) Asia is a highly biodiverse region, yet it is also estimated to cumulatively contribute a third of the total global marine plastic pollution. This threat is known to have adverse impacts on marine megafauna, however, understanding of its impacts has recently been highlighted as a priority for research in the region. To address this knowledge gap, a structured literature review was conducted for species of cartilaginous fishes, marine mammals, marine reptiles, and seabirds present in SE Asia, collating cases on a global scale to allow for comparison, coupled with a regional expert elicitation to gather additional published and grey literature cases which would have been omitted during the structured literature review. Of the 380 marine megafauna species present in SE Asia, but also studied elsewhere, we found that 9.1 % and 4.5 % of all publications documenting plastic entanglement (n = 55) and ingestion (n = 291) were conducted in SE Asian countries. At the species level, published cases of entanglement from SE Asian countries were available for 10 % or less of species within each taxonomic group. Additionally, published ingestion cases were available primarily for marine mammals and were lacking entirely for seabirds in the region. The regional expert elicitation led to entanglement and ingestion cases from SE Asian countries being documented in 10 and 15 additional species respectively, highlighting the utility of a broader approach to data synthesis. While the scale of the plastic pollution in SE Asia is of particular concern for marine ecosystems, knowledge of its interactions and impacts on marine megafauna lags behind other areas of the world, even after the inclusion of a regional expert elicitation. Additional funding to help collate baseline data are critically needed to inform policy and solutions towards limiting the interactions of marine megafauna and plastic pollution in SE Asia
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