A multi-physics compiler for generating numerical solvers from differential equations

We develop a tool that enables domain experts to quickly generate numerical solvers for emerging multi-physics phenomena starting from a high-level description based on ordinary/partial differential equations and their initial and boundary conditions over a symbolic spacetime domain. This "multi-physics" compiler aims to bridge the gap between problem formulation and computation, which historically has spanned years or even decades. Specialized numerical solvers in areas such as computational fluid dynamics (CFD) often present a barrier to novice end users not well-versed in the intricacies of their underlying schemes, and requiring surgical modifications when coupling with additional physical components initially not accounted for by the solver. Through the use of an intermediate language that is neutral between classical and exterior calculus, the compiler generates correct-by-construction numerical source code that offers guarantees of immutable physical principles like conservation laws at the discrete level. We present a proof of concept for the multi-physics compiler through some examples involving compilation to OpenFOAM [1]. A specific use case that the compiler is well-suited for involves equation modification approaches, where the aim is to use simple numerical schemes such as central differencing through the additional of artificial terms to the original governing equations of the multi-physics problem [2, 3, 4]

Cdc42-Dependent Transfer of mir301 from Breast Cancer-Derived Extracellular Vesicles Regulates the Matrix Modulating Ability of Astrocytes at the Blood–Brain Barrier

Breast cancer brain metastasis is a major clinical challenge and is associated with a dismal prognosis. Understanding the mechanisms underlying the early stages of brain metastasis can provide opportunities to develop efficient diagnostics and therapeutics for this significant clinical challenge. We have previously reported that breast cancer-derived extracellular vesicles (EVs) breach the blood–brain barrier (BBB) via transcytosis and can promote brain metastasis. Here, we elucidate the functional consequences of EV transport across the BBB. We demonstrate that brain metastasis-promoting EVs can be internalized by astrocytes and modulate the behavior of these cells to promote extracellular matrix remodeling in vivo. We have identified protein and miRNA signatures in these EVs that can lead to the interaction of EVs with astrocytes and, as such, have the potential to serve as targets for development of diagnostics and therapeutics for early detection and therapeutic intervention in breast cancer brain metastasis

Cdc42-Dependent Transfer of mir301 from Breast Cancer-Derived Extracellular Vesicles Regulates the Matrix Modulating Ability of Astrocytes at the Blood–Brain Barrier

Breast cancer brain metastasis is a major clinical challenge and is associated with a dismal prognosis. Understanding the mechanisms underlying the early stages of brain metastasis can provide opportunities to develop efficient diagnostics and therapeutics for this significant clinical challenge. We have previously reported that breast cancer-derived extracellular vesicles (EVs) breach the blood–brain barrier (BBB) via transcytosis and can promote brain metastasis. Here, we elucidate the functional consequences of EV transport across the BBB. We demonstrate that brain metastasis-promoting EVs can be internalized by astrocytes and modulate the behavior of these cells to promote extracellular matrix remodeling in vivo. We have identified protein and miRNA signatures in these EVs that can lead to the interaction of EVs with astrocytes and, as such, have the potential to serve as targets for development of diagnostics and therapeutics for early detection and therapeutic intervention in breast cancer brain metastasis

Diagenetic Evolution and Porosity Destruction of Turbiditic Hybrid Arenites and Siliciclastic Sandstones of Foreland Basins: Evidence from the Eocene Hecho Group, Pyrenees, Spain

International audienceThis study aims to unravel the impact of diagenetic alterations on porosity loss of foreland-basin turbiditic hybrid arenites and associated siliciclastic sandstones of the Eocene Hecho Group (south-central Pyrenees, Spain). In this succession, hybrid arenites and calclithites are extensively cemented by mesogenetic calcite cement (delta18O VPDB = –10.0 per thousand to –5.8per thousand ; Th, mode = 80° C; salinity mode = 18.8 wt% eq. NaCl), Fe-dolomite (delta18O VPDB = –8.5 per thousand to –6.3 per thousand ) and trace amounts of siderite. The extent of carbonate cementation is interpreted to be related to the amounts of extrabasinal and intrabasinal carbonate grains, which provided nuclei and sources for the precipitation and growth of carbonate cements. Other diagenetic alterations, such as pyrite and albitization, had no impact on reservoir quality. Scarce early diagenetic cements, coupled with abundant ductile carbonate and siliciclastic framework grains, have led to rapid porosity loss owing to compaction. Conversely, abundant quartz in the sandstones prevented rapid loss of porosity by mechanical compaction. Reservoir quality was affected by mesogenetic cementation by quartz overgrowths, calcite and dolomite intergranular pressure dissolution of quartz grains, and formation of fracture-filling calcite cement (delta 18O V-PDB values from –10.4 per thousand to –7.8 per thousand ; Th temperatures of circa 150° C), which are attributed to deep circulation of hot meteoric waters during extensional stages of tectonism. The results of this study illustrate that diagenetic evolution pathways of the arenites and sandstones are closely linked to the variation in detrital composition, particularly the proportion and types of extrabasinal noncarbonates, extrabasinal carbonates, and intrabasinal carbonate grains. These insights suggest that marine turbiditic hybrid arenites and calclithites of foreland basins are subjected to more rapid and extensive porosity loss owing to compaction and cementation than associated siliciclastic sandstones. Degradation of reservoir quality makes these hybrid arenites, calclithites, and sandstones suitable as tight gas reservoirs, but only if fracture porosity and permeability develop during tectonic deformation

Structural analysis of ferromagnetic Mn-doped ZnO thin films deposited by radio frequency magnetron sputtering

We report on the structural analysis of ferromagnetic Mn-doped ZnO thin films deposited by radio frequency magnetron sputtering, using transmission electron microscopy (TEM), high-resolution x-ray diffraction, and Rutherford backscattering spectroscopy (RBS) measurements. The ferromagnetic Mn-doped ZnO film showed magnetization hysteresis at 5 and 300 K. A TEM analysis revealed that the Mn-doped ZnO included a high density of round-shaped cubic and elongated hexagonal MnZn oxide precipitates. The incorporation of Mn caused a large amount of structural disorder in the crystalline columnar ZnO lattice, although the wurtzite crystal structure was maintained. The observed ferromagnetism is discussed based on the structural characteristics indicated by TEM and the behavior of Mn when it is substituted into a ZnO lattice derived from RBS measurements

The Burkholderia Cenocepacia OmpA-Like Protein BCAL2958: Identification, Characterization, and Detection of Anti-BCAL2958 Antibodies in Serum from B. Cepacia Complex-Infected Cystic Fibrosis Patients

Respiratory infections by bacteria of the Burkholderia cepacia complex (Bcc) remain an important cause of morbidity and mortality among cystic fibrosis patients, highlighting the need for novel therapeutic strategies. In the present work we have studied the B. cenocepacia protein BCAL2958, a member of the OmpA-like family of proteins, demonstrated as highly immunogenic in other pathogens and capable of eliciting strong host immune responses. The encoding gene was cloned and the protein, produced as a 6× His-tagged derivative, was used to produce polyclonal antibodies. Bioinformatics analyses led to the identification of sequences encoding proteins with a similarity higher than 96 % to BCAL2958 in all the publicly available Bcc genomes. Furthermore, using the antibody it was experimentally demonstrated that this protein is produced by all the 12 analyzed strains from 7 Bcc species. In addition, results are also presented showing the presence of anti-BCAL2958 antibodies in sera from cystic fibrosis patients with a clinical record of respiratory infection by Bcc, and the ability of the purified protein to in vitro stimulate neutrophils. The widespread production of the protein by Bcc members, together with its ability to stimulate the immune system and the detection of circulating antibodies in patients with a documented record of Bcc infection strongly suggest that the protein is a potential candidate for usage in preventive therapies of infections by Bcc