What is the most threatening for citizens of a mid-latitude city : cold stress or heat stress?

Both heat and cold waves cause extreme human thermal discomfort and a clear excess in mortality. This shows the importance of knowing the prevailing thermal comfort conditions and how thermal comfort conditions vary in various environments so measures can be taken. Microclimatic and outdoor human thermal comfort conditions are investigated in various built-up and green areas in the city of Ghent (Belgium) using meteorological measurements of six weather stations of the MOCCA (Monitoring the Cities Climate and Atmosphere) network in combination with calculations done by RayMan. Normal to extreme summer heat wave periods show that dangerous strong heat stress prevails during the daytime periods at all locations. Comparison of thermal comfort during normal and extreme summer heat wave periods showed that heat stress is more extreme when a heat wave is more intense. Overall the urban park in Ghent was the most comfortable location during heat waves since it effectively mitigates heat stress in the city. These results should be taken into account in urban planning and design to keep mid-latitude cities livable. Further, a one year data series revealed that outdoor cold stress was more apparent during 2017 in the mid-latitude city of Ghent that experiences a mild maritime climate. During spring and summer, both heat stress and cold stress occurred due to the larger diurnal temperature range compared to the other seasons. Even though high Physiological Equivalent Temperatures (PET) were obtained during a heat wave in summer, heat stress did not occur as intensely and as frequently compared to cold stress on annual level. It could thus be stated that outdoors, cold stress is a bigger threat than heat stress. However, one should keep in mind that the study was executed for outdoor thermal heat comfort and that people will take shelter or take measures when feeling uncomfortable. The question is thus rather, how are citizens protected against heat and cold stress? Currently, the Belgian society is better adapted to cold stress since most buildings contain central heating, while air conditioning is not standard. Future projections predict an increase in temperature, causing more occurrence of extreme heat stress, while extreme cold stress will be reduced. Additionally, the urban heat island effect currently has mainly a positive effect on the average annual outdoor thermal comfort conditions, while it will become a negative effect in the warmer future. Measures should thus be taken to reduce the threat of future heat stress

Bayesian decomposition of the Galactic multi-frequency sky using probabilistic autoencoders

All-sky observations of the Milky Way show both Galactic and non-Galactic diffuse emission, for example from interstellar matter or the cosmic microwave background (CMB). The different emitters are partly superimposed in the measurements, partly they obscure each other, and sometimes they dominate within a certain spectral range. The decomposition of the underlying radiative components from spectral data is a signal reconstruction problem and often associated with detailed physical modeling and substantial computational effort. We aim to build an effective and self-instructing algorithm detecting the essential spectral information contained Galactic all-sky data covering spectral bands from $\gamma$-ray to radio waves. Utilizing principles from information theory, we develop a state-of-the-art variational autoencoder specialized on the adaption to Gaussian noise statistics. We first derive a generic generative process that leads from a low-dimensional set of emission features to the observed high-dimensional data. We formulate a posterior distribution of these features using Bayesian methods and approximate this posterior with variational inference. The algorithm efficiently encodes the information of 35 Galactic emission data sets in ten latent feature maps. These contain the essential information required to reconstruct the initial data with high fidelity and are ranked by the algorithm according to their significance for data regeneration. The three most significant feature maps encode astrophysical components: (1) The dense interstellar medium (ISM), (2) the hot and dilute regions of the ISM and (3) the CMB. The machine-assisted and data-driven dimensionality reduction of spectral data is able to uncover the physical features encoding the input data. Our algorithm is able to extract the dense and dilute Galactic regions, as well as the CMB, from the sky brightness values only.Comment: 25 pages, 8 figures, 3 tables. Submitted to Astronomy & Astrophysic

Chester supersolid of spatially indirect excitons in double-layer semiconductor heterostructures

A supersolid, a counter-intuitive quantum state in which a rigid lattice of particles flows without resistance, has to date not been unambiguously realised. Here we reveal a supersolid ground state of excitons in a double-layer semiconductor heterostructure over a wide range of layer separations outside the focus of recent experiments. This supersolid conforms to the original Chester supersolid with one exciton per supersolid site, as distinct from the alternative version reported in cold-atom systems of a periodic modulation of the superfluid density. We provide the phase diagram augmented by the supersolid. This new phase appears at layer separations much smaller than the predicted exciton normal solid, and it persists up to a solid--solid transition where the quantum phase coherence collapses. The ranges of layer separations and exciton densities in our phase diagram are well within reach of the current experimental capabilities

Case report: Autoimmune hemolytic anemia caused by warm and cold autoantibodies with complement activation—etiological and therapeutic issues

IntroductionResearch on mixed warm and cold autoantibodies in autoimmune hemolytic anemia (AIHA) targeting erythrocytes [red blood cells (RBCs)] and platelets is scarcely reported.Case presentationIn this study, we present the case of a 5-year-old boy with positive direct [anti-IgG (1+), anti-IgG-C3d (3+)], and indirect antiglobulin (Coombs) tests. The RBCs were coated with polyspecific-positive, warm IgG autoantibodies alongside activated complement components. Plasma-containing immunoglobulin M (IgM) class autoantibodies were found in 1:64 titers with a wide temperature range of 4°C–37°C. The platelets were also coated with IgM autoantibodies. There was a reduction in the levels of the classical and alternative complement pathways, such as C3, C4, ADAMTS13 metalloprotease activity, factor H antigen, complement factor B antigen, and C1q antigen alongside the elevated sC5b-9 terminal complement complex. Hematuria and/or proteinuria, reduced diuresis, and elevated levels of serum creatinine were absent. The kidney ultrasound report was normal. A recent combination of Epstein–Barr virus (EBV) and cytomegalovirus (CMV) infection was found. The first-line treatment consisted of intravenous methylprednisolone [4 mg/kg/body weight for the first 72 h (q12 h), followed by 2 mg/kg body weight for 21 consecutive days with a slow steroid reduction until plasmapheresis (PLEX)]. After the patient showed limited response to corticosteroid therapy, rituximab (375 mg/m2) was administered once a week (five doses in total), with vitamins B9 and B12. These strategies also showed limited (partial) therapeutic benefits. Therefore, the treatment was switched to PLEX (five cycles in total) and intravenous immunoglobulin (IVIg) (1 g/kg/5 days). This combination significantly improved RBC count and platelet levels, and C3 and C4 levels returned to normal. A follow-up of 2.5 years after treatment showed no sign of relapse. A genetic analysis revealed a rare heterozygous intronic variation (c.600-14C > T) and heterozygous Y402H polymorphism of the CFH gene. c.600-14C > T mutation was located near the 5′ end of exon 6 in the gene encoding the complement C3 protein of unknown significance. We presumed that the complement regulators in our patient were sufficient to control complement activation and that complement blockade should be reserved only for devastating, life-threatening complement-related multiorgan failure.ConclusionWe believe that EBV and CMV triggered AIHA, thus activating the complement cascade. Hence, we used corticosteroids, rituximab, vitamins B9 + B12, PLEX, and fresh frozen plasma (FFP) as treatment. Final remission was achieved with PLEX and FFP. However, an additional late effect of B12 rituximab and the disappearance of long-lived circulating plasma cells should not be completely ignored. Complement activation with a genetic background should be assessed in severe warm and cold hemolytic anemias caused by autoantibodies

Lasting mesothalamic dopamine imbalance and altered exploratory behavior in rats after a mild neonatal hypoxic event

IntroductionAdversities during the perinatal period can decrease oxygen supply to the fetal brain, leading to various hypoxic brain injuries, which can compromise the regularity of brain development in different aspects. To examine the catecholaminergic contribution to the link between an early-life hypoxic insult and adolescent behavioral aberrations, we used a previously established rat model of perinatal hypoxia but altered the hypobaric to normobaric conditions.MethodsExploratory and social behavior and learning abilities were tested in 70 rats of both sexes at adolescent age. Inherent vertical locomotion, sensory-motor functions and spatial learning abilities were explored in a subset of animals to clarify the background of altered exploratory behavior. Finally, the concentrations of dopamine (DA) and noradrenaline in midbrain and pons, and the relative expression of genes for DA receptors D1 and D2, and their down-stream targets (DA- and cAMP-regulated phosphoprotein, Mr 32 kDa, the regulatory subunit of protein kinase A, and inhibitor-5 of protein phosphatase 1) in the hippocampus and thalamus were investigated in 31 rats.ResultsA lesser extent of alterations in exploratory and cognitive aspects of behavior in the present study suggests that normobaric conditions mitigate the hypoxic injury compared to the one obtained under hypobaric conditions. Increased exploratory rearing was the most prominent consequence, with impaired spatial learning in the background. In affected rats, increased midbrain/pons DA content, as well as mRNA levels for DA receptors and their down-stream elements in the thalamus, but not the hippocampus, were found.ConclusionWe can conclude that a mild hypoxic event induced long-lasting disbalances in mesothalamic DA signaling, contributing to the observed behavioral alterations. The thalamus was thereby indicated as another structure, besides the well-established striatum, involved in mediating hypoxic effects on behavior through DA signaling

Constitutive activation of canonical Wnt signaling disrupts choroid plexus epithelial fate

The choroid plexus secretes cerebrospinal fluid and is critical for the development and function of the brain. In the telencephalon, the choroid plexus epithelium arises from the Wnt- expressing cortical hem. Canonical Wnt signaling pathway molecules such as nuclear β-CATENIN are expressed in the mouse and human embryonic choroid plexus epithelium indicating that this pathway is active. Point mutations in human β-CATENIN are known to result in the constitutive activation of canonical Wnt signaling. In a mouse model that recapitulates this perturbation, we report a loss of choroid plexus epithelial identity and an apparent transformation of this tissue to a neuronal identity. Aspects of this phenomenon are recapitulated in human embryonic stem cell derived organoids. The choroid plexus is also disrupted when β-Catenin is conditionally inactivated. Together, our results indicate that canonical Wnt signaling is required in a precise and regulated manner for normal choroid plexus development in the mammalian brain

Closing Water Cycles in the Built Environment through Nature-Based Solutions: The Contribution of Vertical Greening Systems and Green Roofs

Water in the city is typically exploited in a linear process, in which most of it is polluted, treated, and discharged; during this process, valuable nutrients are lost in the treatment process instead of being cycled back and used in urban agriculture or green space. The purpose of this paper is to advance a new paradigm to close water cycles in cities via the implementation of naturebased solutions units (NBS_u), with a particular focus on building greening elements, such as green roofs (GRs) and vertical greening systems (VGS). The hypothesis is that such “circular systems” can provide substantial ecosystem services and minimize environmental degradation. Our method is twofold: we first examine these systems from a life-cycle point of view, assessing not only the inputs of conventional and alternative materials, but the ongoing input of water that is required for irrigation. Secondly, the evapotranspiration performance of VGS in Copenhagen, Berlin, Lisbon, Rome, Istanbul, and Tel Aviv, cities with different climatic, architectural, and sociocultural contexts have been simulated using a verticalized ET0 approach, assessing rainwater runoff and greywater as irrigation resources. The water cycling performance of VGS in the mentioned cities would be sufficient at recycling 44% (Lisbon) to 100% (Berlin, Istanbul) of all accruing rainwater roof–runoff, if water shortages in dry months are bridged by greywater. Then, 27–53% of the greywater accruing in a building could be managed on its greened surface. In conclusion, we address the gaps in the current knowledge and policies identified in the different stages of analyses, such as the lack of comprehensive life cycle assessment studies that quantify the complete “water footprint” of building greening systems.info:eu-repo/semantics/publishedVersio

Emerging Standards and the Hybrid Model for Organizing Scientific Events During and After The COVID-19 Pandemic

Artigo publicado em revista científica internacionalSince the beginning of 2020, the COVID-19 pandemic has dramatically influenced almost every aspect of human life. Activities requiring human gatherings have either been postponed, cancelled, or held completely virtually. To supplement lack of in-person contact, people have increasingly turned to virtual settings on-line, advantages of which include increased inclusivity and accessibility and reduction of carbon footprint. However, emerging online technologies cannot fully replace, in-person scientific events. In-person meetings are not susceptible to poor internet connectivity problems, and they provide novel opportunities for socialization, creating new collaborations, and sharing ideas. To continue such activities, a hybrid model for scientific events could be a solution offering both in-person and virtual components. While participants can freely choose the mode of their participation, virtual meetings would most benefit those who cannot attend in-person due to the limitations. In-person portions of meetings should be organized with full consideration of prevention and safety strategies including risk assessment and mitigation, venue and environmental sanitation, participant protection and disease prevention, and promoting the hybrid model. This new way of interaction between scholars can be considered as a part of a resilience system which was neglected previously and should become a part of routine practice in scientific community.info:eu-repo/semantics/publishedVersio