Intrauterine Transmission of SARS-CoV-2 Stonoga, Emanuele T S; de Almeida Lanzoni, Laura; Rebutini, Patricia Zadorosnei ...
Emerging infectious diseases
27, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We documented fetal death associated with intrauterine transmission of severe acute respiratory syndrome coronavirus 2. We found chronic histiocytic intervillositis, maternal and fetal vascular ...malperfusion, microglial hyperplasia, and lymphocytic infiltrate in muscle in the placenta and fetal tissue. Placenta and umbilical cord blood tested positive for the virus by PCR, confirming transplacental transmission.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Context. Dynamical and albedo properties suggest that asteroids in cometary orbits (ACOs) are dormant or extinct comets. Their study provides new insights for understanding the end-states of comets ...and the size of the comet population. Aims. We intend to study the visible and near-infrared (NIR) spectral properties of different ACO populations and compare them to the independently determined properties of comets. Methods. We select our ACOs sample based on published dynamical criteria and present our own observational results obtained using the 10.4 m Gran Telescopio Canarias (GTC), the 4.2 m William Herschel Telescope (WHT), the 3.56 m Telescopio Nazionale Galileo (TNG), and the 2.5 m Isaac Newton Telescope (INT), all located at the El Roque de los Muchachos Observatory (La Palma, Spain), and the 3.0 m NASA Infrared Telescope Facility (IRTF), located at the Mauna Kea Observatory, in Hawaii. We include in the analysis the spectra of ACOs obtained from the literature. We derive the spectral class and the visible and NIR spectral slopes. We also study the presence of hydrated minerals by studying the 0.7 μm band and the UV-drop below 0.5 μm associated with phyllosilicates. Results. We present new observations of 17 ACOs, 11 of them observed in the visible, 2 in the NIR and 4 in the visible and NIR. We also discuss the spectra of 12 ACOs obtained from the literature. All but two ACOs have a primitive-like class spectrum (X or D-type). Almost 100% of the ACOs in long-period cometary orbits (Damocloids) are D-types. Those in Jupiter family comet orbits (JFC-ACOs) are ∼60% D-types and ∼40% X-types. The mean spectral slope S′ of JFC-ACOs is 9.7 ± 4.6%/1000 Å and for the Damocloids this is 12.2 ± 2.0%/1000 Å. No evidence of hydration on the surface of ACOs is found from their visible spectra. The spectral slope and spectral class distribution of ACOs is similar to that of comets. Conclusions. The spectral taxonomical classification and the spectral slope distribution of ACOs, and the lack of spectral features indicative of the presence of hydrated minerals on their surface, strongly suggest that ACOs are likely dormant or extinct comets.
Sepsis is a life-threatening organ dysfunction caused by a dysregulated inflammatory response to infection. To date, there is no specific treatment established for sepsis. In the extracellular ...compartment, purines such as adenosine triphosphate (ATP) and adenosine play essential roles in the immune/inflammatory responses during sepsis and septic shock. The balance of extracellular levels among ATP and adenosine is intimately involved in the signals related to immune stimulation/immunosuppression balance. Specialized enzymes, including CD39, CD73, and adenosine deaminase (ADA), are responsible to metabolize ATP to adenosine which will further sensitize the P2 and P1 purinoceptors, respectively. Disruption of the purinergic pathway had been described in the sepsis pathophysiology. Although purinergic signaling has been suggested as a potential target for sepsis treatment, the majority of data available were obtained using pre-clinical approaches. We hypothesized that, as a reflection of deregulation on purinergic signaling, septic patients exhibit differential measurements of serum, neutrophils and monocytes purinergic pathway markers when compared to two types of controls (healthy and ward). It was observed that ATP and ADP serum levels were increased in septic patients, as well as the A2a mRNA expression in neutrophils and monocytes. Both ATPase/ADPase activities were increased during sepsis. Serum ATP and ADP levels, and both ATPase and ADPase activities were associated with the diagnosis of sepsis, representing potential biomarkers candidates. In conclusion, our results advance the translation of purinergic signaling from pre-clinical models into the clinical setting opening opportunities for so much needed new strategies for sepsis and septic shock diagnostics and treatment.
Dynamical study of the Atira group of asteroids Ribeiro, A. O; Roig, F; De Prá, M. N ...
Monthly notices of the Royal Astronomical Society,
06/2016, Letnik:
458, Številka:
4
Journal Article
Recenzirano
Odprti dostop
We study the dynamics of the group of Atira asteroids, characterized by aphelion distance Q < 0.983 au. This group has a significant observational bias, and their number is expected to be an order of ...magnitude larger than is known today. Due to their orbital configuration, these asteroids may represent a potential danger to the Earth. Here, we construct dynamical maps of the region between 0.2 and 0.98 au using a simple chaos indicator, the mean standard deviation in semimajor axis, and also analyse the behaviour of the real Atira orbits by means of the diffusion coefficient in semimajor axis. Our results indicate that Atira asteroids are located in the most unstable regions of the inner Solar system, and their stability is determined by close encounters and collisions with Mercury, Venus, and the Earth. A fraction of the known Atiras may represent a potential threat to the Earth over a few 105 yr of evolution. We found two islands of low-eccentricity stable orbits that might harbour a long-lasting sub-population of Atiras not yet observed.
ABSTRACT
In this work, we present the results of an observational study of 2I/Borisov carried out with the 10.4-m Gran Telescopio Canarias (GTC) and the 3.6-m Telescopio Nazionale Galileo (TNG), both ...telescopes located at the Roque de Los Muchachos Observatory, in the island of La Palma (Spain). The study includes images in the visible and near-infrared, as well as visible spectra in the 3600–9200 Å wavelength range. N-body simulations were also performed to explore its orbital evolution and Galactic kinematic context. The comet’s dust continuum and near-infrared colours are compatible with those observed for Solar system comets. From its visible spectrum on the nights of 2019 September 24 and 26, we measured CN gas production rates Q(CN) = (2.3 ± 0.4) × 1024 mol s−1 and Q(CN) = (9.5 ± 0.2) × 1024 mol s−1, respectively, in agreement with measurements reported by other authors on similar nights. We also obtained an upper limit for the C2 production rate of Q(C2) < (4.5 ± 0.1) × 1024 mol s−1. Dust modelling results indicate a moderate dust production rate of ∼50 kg s−1 at heliocentric distance rh = 2.6 au, with a differential power-law dust size distribution of index ∼–3.4, within the range reported for many comet comae. Our simulations show that the Galactic velocity of 2I/Borisov matches well that of known stars in the solar neighbourhood and also those of more distant regions of the Galactic disc.
AbstractHydraulic jumps, frequently present in energy dissipation structures, have been thoroughly investigated over the past 70 years. However, studies have focused primarily on the more common and ...more stable cases of large Froude number jumps. Investigations on low Froude number jumps, usually called transition jumps, are scarce, although they are used in a significant number of run-of-the-river, high-discharge, and low-head dams. This paper addresses the characterization of hydrodynamic pressures of low Froude number jumps. A two-dimensional experimental facility was used for that purpose. Results were compared with those from published studies covering transition jumps and stabilized jumps, to identify differences and similarities between them. The analysis considered common dimensionless statistical parameters, duly nondimensionalized. It was found that, for most of these parameters, low Froude number jumps behave differently from stabilized jumps. This can be attributed mainly to the hydraulic jump’s oscillating jet formed under the surface macroturbulent roller, as well as to the partially developed boundary layer of the incoming flow in low-head spillways.
ABSTRACT
We present an observational and numerical study of the borderline hyperbolic comet C/2021 O3 (PANSTARRS) performed during its recent passage through the inner Solar system. Our observations ...were carried out at OASI and SOAR between 2021 October and 2022 January, and reveal a low level of activity relative to which was measured for other long-period comets. In addition, we observed a decrease in brightness as the comet got closer to the Sun. Our photometric data, obtained as C/2021 O3 approached perihelion on 2022 April 21, show that the comet was much less active than what is usually expected in the cases of long-period comets, with Afρ values more in line with those of short-period comets (specifically, the Jupiter-family comets). On the other hand, the observed increase in the value of the spectral slope as the amount of dust in the coma decreased could indicate that the smaller dust particles were being dispersed from the coma by radiation pressure faster than they were injected by possible sublimation jets. The analysis of its orbital evolution suggests that C/2021 O3 could be a dynamically old comet, or perhaps a new one masquerading as a dynamically old comet, with a likely origin in the Solar system.
Context.
Asteroid families are witnesses to the intense collisional evolution that occurred on the asteroid belt. The study of the physical properties of family members can provide important ...information about the state of differentiation of the parent body and provide insights into how these objects were formed. Several of these asteroid families identified across the main belt are dominated by low-albedo, primitive asteroids. These objects are important for the study of Solar System formation because they were subject to weaker thermophysical processing and provide information about the early conditions of our planetary system.
Aims.
We aim to study the diversity of physical properties among the Themis, Hygiea, Ursula, Veritas, and Lixiaohua families.
Methods.
We present new spectroscopic data, combined with a comprehensive analysis using a variety of data available in the literature, such as albedo and rotational properties.
Results.
Our results show that Themis and Hygiea families, the largest families in the region, present similar levels of hydration. Ursula and Lixiaohua families are redder in comparison to the others and present no sign of hydrated members based on the analysis of visible spectra. Conversely, Veritas presents the highest fraction of hydrated members.
Conclusions.
This work demonstrates a diverse scenario in terms of the physical properties of primitive outer-belt families, which could be associated with dynamical mixing of asteroid populations and the level of differentiation of the parental body.
PRIMASS visits Hilda and Cybele groups De Prá, M.N.; Pinilla-Alonso, N.; Carvano, J.M. ...
Icarus (New York, N.Y. 1962),
09/2018, Letnik:
311
Journal Article
Recenzirano
Odprti dostop
•Hilda population show a bimodal distribution of surface properties, while the Cybele shows the presence of three distinct groups of objects, with a wider contribution of neutral color objects than ...the Hilda. The bimodality is also observed in the near-infrared analysis: Redder objects show higher albedo.•The Cybele group has only 9 out 55 asteroids with evidence of hydrated minerals on their surfaces, while the Hilda group only presents one, (334) Chicago.•We identify a continuity of surface properties from the Themis family to the Cybele, Hilda and Trojan populations. This can be related to a compositional gradient.
The Cybele and Hilda dynamical groups delimit the outer edge of the asteroid belt. Their compositional distribution is a key element to constrain evolutionary models of the Solar System. In this paper, we present a compositional analysis of these populations using spectroscopic observations, SDSS and NEOWISE data. As part of the PRIMASS (Primitive Asteroids Spectroscopic Survey), we acquired visible spectra of 18 objects in Hilda or Cybele groups with the Goodman High Throughput Spectrometer at the 4.1 m SOAR telescope and 20 near-IR spectra of Hilda objects with Near Infrared Camera Spectrograph at the 3.56 m TNG. The sample is enlarged with spectra taken from the literature in order to increase our statistical analysis. The spectra were inspected for aqueous alteration bands and other spectral features that can be linked to compositional constraints. The analysis shows a continuous distribution of compositions from the main-belt to the Cybele, Hilda and Trojan regions. We also identify a population in the Trojans group not present in Hilda or Cybele objects.
High greenhouse gas emissions, high water demand, and waste with high pollution potential are critical points for waste management generated in animal production. With significant contributions in ...global emissions of air pollutants, sustainable practices for agriculture are fundamental to mitigate global climate change, besides ensuring protection to water resources, which is as critical as climate issues. Despite the importance of these issues, some gaps exist in the literature to develop practices capable of fostering water security and mitigation of greenhouse gas emissions. In this sense, the present study aimed to evaluate the impacts of reusing NO3− rich effluents inside the facilities for cleaning the swine houses and consequent atmospheric emissions of nitrous oxide (N2O) and methane (CH4). In swine manure, the generation of volatile fatty acids (VFA) was strongly influenced by temperature; a change in temperature from 10 to 18 °C increased by ten times the rate of VFA production, reflecting directly in methane emission and availability of organic carbon for the denitrification process. The effluent reuse practice, rich in nitrate, considering the organic carbon bioavailability in the pit storage, decreased methanogenic activity with a consequent VFA use as a bioavailable carbon source for denitrification, reducing greenhouse gas (GHG) emissions and consequently, the environmental impacts of swine production. In this way, the water reuse of 40% can mitigate up to 80% of GHG emission, with a minimum C/N ratio of 20, to ensure that at all temperatures the denitrifying process occurs efficiently since the carbon limitation negatively affected the N2O emission due to incomplete denitrification. Therefore, our results demonstrate the importance of this practice for swine sustainability and the capacity to adopt simple measures in favor of circularity in the swine production chain.
Display omitted
•Effluent reuse can be incorporated into the swine production chain.•Reuse of NO3− rich effluent was environmentally favorable.•The addition of NO3− stopped methanogenesis, decreasing GHG emission by up to 98%.•The effluents reuse with a proportion of 40% contributed to over 80% GHG reduction.
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