626 research outputs found
Trends of anthropogenic CO2 along 20º W in the Iberian Basin
The carbon system in the water masses of the Iberian Basin (North Atlantic Ocean) has been affected over the last two decades by the increase in anthropogenic CO2 (Cant). In order to study the storage of Cant in the Iberian Basin, variables of the carbonic system (i.e., pH, total inorganic carbon, and total alkalinity), among others, were measured during the CAIBOX cruise conducted between July and August 2009 within the framework of the CAIBEX project (Shelf-Ocean Exchanges in the Canary-Iberian Large Marine Ecosystem). The storage of Cant was estimated using two different back-calculation techniques (i.e., the ?CºT and TrOCA methods) and for six layers of the water column corresponding to the approximate locations of the characteristic water masses of the region and the mixed layers. For the whole water column and for the year 2009 the Cant storage values determined by the ?CºT and TrOCA methods were 88.1 ± 3.8 and 93.7 ± 3.7 molC m–2, respectively. Moreover, the Cant storage rate from 1993 to 2009 was also estimated considering data from three additional cruises (OACES 1993, CHAOS 1998, and OACES 2003). The Cant storage rates were 1.41 ± 0.25 and 1.67 ± 0.13 molC m–2 yr–1 with the ?CºT and TrOCA methods, respectively. An increase in anthropogenic CO2 uptake by the ocean can be seen when compared with previous published results. Between the periods 1977–1997 and 1993–2009, the Cant concentration increased around 28–49% in the first 2000 m
New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary
Background
Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood.
Methodology/Principal Findings
Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval.
Conclusions/Significance
There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous
Genetic and metabolic predictors of chemosensitivity in oligodendroglial neoplasms
The −1p/−19q genotype predicts chemosensitivity in oligodendroglial neoplasms, but some with intact 1p/19q also respond and not all with 1p/19q loss derive durable benefit from chemotherapy. We have evaluated the predictive and prognostic significance of pretherapy 201Tl and 18F-FDG SPECT and genotype in 38 primary and 10 recurrent oligodendroglial neoplasms following PCV chemotherapy. 1p/19q loss was seen in 8/15 OII, 6/15 OAII, 7/7 OIII, 3/11 OAIII and was associated with response (Fisher-Exact: P=0.000) and prolonged progression-free (log-rank: P=0.002) and overall survival (OS) (log-rank: P=0.0048). Response was unrelated to metabolism, with tumours with high or low metabolism showing response. Increased 18F-FDG or 201Tl uptake predicted shorter progression-free survival (PFS) in the series (log-rank: 201Tl P=0.0097, 18F-FDG P=0.0170) and in cases with or without the −1p/−19q genotype. Elevated metabolism was associated with shorter OS in cases with intact 1p/19q (log-rank: 18F-FDG P=0.0077; 201Tl P=0.0004) and shorter PFS in responders (log-rank: 18F-FDG P=0.005; 201Tl P=0.0132). 201Tl uptake and 1p/19q loss were independent predictors of survival in multivariate analysis. In this initial study, 201Tl and 18F-FDG uptake did not predict response to PCV, but may be associated with poor survival following therapy irrespective of genotype. This may be clinically useful warranting further study
CMB Telescopes and Optical Systems
The cosmic microwave background radiation (CMB) is now firmly established as
a fundamental and essential probe of the geometry, constituents, and birth of
the Universe. The CMB is a potent observable because it can be measured with
precision and accuracy. Just as importantly, theoretical models of the Universe
can predict the characteristics of the CMB to high accuracy, and those
predictions can be directly compared to observations. There are multiple
aspects associated with making a precise measurement. In this review, we focus
on optical components for the instrumentation used to measure the CMB
polarization and temperature anisotropy. We begin with an overview of general
considerations for CMB observations and discuss common concepts used in the
community. We next consider a variety of alternatives available for a designer
of a CMB telescope. Our discussion is guided by the ground and balloon-based
instruments that have been implemented over the years. In the same vein, we
compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the
South Pole Telescope (SPT). CMB interferometers are presented briefly. We
conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and
Planck, to demonstrate a remarkable evolution in design, sensitivity,
resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1:
Telescopes and Instrumentatio
Comparison of two protective lung ventilatory regimes on oxygenation during one-lung ventilation: a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>The efficacy of protective ventilation in acute lung injury has validated its use in the operating room for patients undergoing thoracic surgery with one-lung ventilation (OLV). The purpose of this study was to investigate the effects of two different modes of ventilation using low tidal volumes: pressure controlled ventilation (PCV) vs. volume controlled ventilation (VCV) on oxygenation and airway pressures during OLV.</p> <p>Methods</p> <p>We studied 41 patients scheduled for thoracoscopy surgery. After initial two-lung ventilation with VCV patients were randomly assigned to one of two groups. In one group OLV was started with VCV (tidal volume 6 mL/kg, PEEP 5) and after 30 minutes ventilation was switched to PCV (inspiratory pressure to provide a tidal volume of 6 mL/kg, PEEP 5) for the same time period. In the second group, ventilation modes were performed in reverse order. Airway pressures and blood gases were obtained at the end of each ventilatory mode.</p> <p>Results</p> <p>PaO<sub>2</sub>, PaCO<sub>2 </sub>and alveolar-arterial oxygen difference did not differ between PCV and VCV. Peak airway pressure was significantly lower in PCV compared with VCV (19.9 ± 3.8 cmH<sub>2</sub>O vs 23.1 ± 4.3 cmH<sub>2</sub>O; p < 0.001) without any significant differences in mean and plateau pressures.</p> <p>Conclusions</p> <p>In patients with good preoperative pulmonary function undergoing thoracoscopy surgery, the use of a protective lung ventilation strategy with VCV or PCV does not affect the oxygenation. PCV was associated with lower peak airway pressures.</p
Triggering of the 2014 M_w7.3 Papanoa earthquake by a slow slip event in Guerrero, Mexico
Since their discovery two decades ago, slow slip events have been shown to play an important role in accommodating strain in subduction zones. However, the physical mechanisms that generate slow slip and the relationships with earthquakes are unclear. Slow slip events have been recorded in the Guerrero segment of the Cocos–North America subduction zone. Here we use inversion of position time series recorded by a continuous GPS network to reconstruct the evolution of aseismic slip on the subduction interface of the Guerrero segment. We find that a slow slip event began in February 2014, two months before the magnitude (M_w) 7.3 Papanoa earthquake on 18 April. The slow slip event initiated in a region adjacent to the earthquake hypocentre and extended into the vicinity of the seismogenic zone. This spatio-temporal proximity strongly suggests that the Papanoa earthquake was triggered by the ongoing slow slip event. We demonstrate that the triggering mechanism could be either static stress increases in the hypocentral region, as revealed by Coulomb stress modelling, or enhanced weakening of the earthquake hypocentral area by the slow slip. We also show that the plate interface in the Guerrero area is highly coupled between slow slip events, and that most of the accumulated strain is released aseismically during the slow slip episodes
Oleate but not stearate induces the regulatory phenotype of myeloid suppressor cells
Tumor infiltrating myeloid cells play contradictory roles in the tumor
development. Dendritic cells and classical activated macrophages support anti-
tumor immune activity via antigen presentation and induction of pro-
inflammatory immune responses. Myeloid suppressor cells (MSCs), for instance
myeloid derived suppressor cells (MDSCs) or tumor associated macrophages play
a critical role in tumor growth. Here, treatment with sodium oleate, an
unsaturated fatty acid, induced a regulatory phenotype in the myeloid
suppressor cell line MSC-2 and resulted in an increased suppression of
activated T cells, paralleled by increased intracellular lipid droplets
formation. Furthermore, sodium oleate potentiated nitric oxide (NO) production
in MSC-2, thereby increasing their suppressive capacity. In primary polarized
bone marrow cells, sodium oleate (C18:1) and linoleate (C18:2), but not
stearate (C18:0) were identified as potent FFA to induce a regulatory
phenotype. This effect was abrogated in MSC-2 as well as primary cells by
specific inhibition of droplets formation while the inhibition of de novo FFA
synthesis proved ineffective, suggesting a critical role for exogenous FFA in
the functional induction of MSCs. Taken together our data introduce a new
unsaturated fatty acid-dependent pathway shaping the functional phenotype of
MSCs, facilitating the tumor escape from the immune system
Characterization of the behavior of carotenoids from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) during microemulsion production and in a dynamic gastrointestinal system
Uncommon tropical fruits are emerging as raw-material for new food products with health benefits. This work aimed at formulating and processing microemulsions from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) fruits, since they are very rich in carotenoids (particularly lycopene and -carotene), in order to encapsulate and increase carotenoids bioaccessibility. Pitanga and buriti microemulsions were produced by applying a direct processing (high-speed homogenization at 15,000 rpm and ultrasound with 20 kHz probe at 40% amplitude) of the whole pulp together with surfactant (Tween 80 or Whey Protein Isolate at 2%) and corn oil (5%). All treatments (HSHUS for 04, 40, 44, 48 minmin) applied were able to increase the amount of carotenoid released. However, the processing also decreased the total amount of carotenoids in the whole pulp of studied fruits. The impact of processing during microemulsion production was not severe. The overall data suggest that the presence of surfactant and oil during processing may protect the carotenoids in fruits and microemulsions. Final recovery of total carotenoids, after passing the samples through a dynamic gastrointestinal system that simulates the human digestion, was higher for microemulsions than for whole pulps. High losses of total carotenoids in buriti and -carotene and lycopene in pitanga occurred during jejunum and ileum phases. The present work confirms that it is possible to increase -carotene and lycopene bioaccessibility from fruits by directly processing microemulsions (p<0.01).This work was supported by the São Paulo Research Foundation—FAPESP through research funding [Grant
#2015/15507-9] and Ph.D. scholarship for Paulo Berni [Grant #2014/15119-6] and a Research Internships Abroad (BEPE) support [Grant #2016/13355-0]. The author Ana C. Pinheiro is recipient of a fellowship from the Portuguese Foundation for Science and Technology (FCT) [Grant SFRH/BPD/101181/2014]info:eu-repo/semantics/publishedVersio
Mutant, wild type, or overall p53 expression: freedom from clinical progression in tumours of astrocytic lineage
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