Long-time stability for an IMEX discretization of the 1D Fujita Equation

We study an efficient time-stepping scheme for the 1D Fujita equation that is implicit for the linear terms but explicit for the nonlinear terms. We analyze the long-time stability of the scheme for varying parameter values, which reveal parameter value regimes in which the method is stable. We provide numerical results that illustrate the theory and show the analytically derived stability conditions are sufficient to achieve long-time stability results

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into diferent pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and τ τ ) are included in this kind of combination for the frst time. A simplifed model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confdence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

CSS-T Codes from Reed Muller Codes for Quantum Fault Tolerance

CSS-T codes are a class of stabilizer codes introduced by Rengaswami et al with desired properties for quantum fault-tolerance. In this work, we give a comprehensive study of CSS-T codes built from Reed-Muller codes. These classical codes allow for the construction of CSST code families with non-vanishing asymptotic rate up to 1/2 and possibly diverging minimum distance. This desirable property enables constant overhead magic state distillation

Identificación de aislados de Acanthamoeba spp mantenidos en el laboratorio de amibiasis-UCV, mediante PCR-RFLP

Dentro del género Acanthamoeba existen especies relacionadas con patologías presentes en los humanos. Su identificación y clasificación se realizaba por morfología, pero es subjetiva y de baja sensibilidad y especificidad. Por ésto, es importante incorporar herramientas de biología molecular. El objetivo de esta investigación fue caracterizar molecular y morfológicamente 24 aislados de Acanthamoeba, mantenidos en el Laboratorio de Amibiasis-Escuela de Bioanálisis-UCV, mediante PCR-RFLP (HinffI, HhaI y HaeIII), previamente identificados morfológicamente como Acanthamoeba (Pussard y Pons 1977). Ningún aislado perteneció al grupo I. De los 24 aislados, 45,8% presentó características morfológicas compatibles con el grupo II, 45,8% con el grupo III y 8,4% con ambos grupos. Molecularmente, 50% de los aislados amplificaron productos de 900 pb y 50% de 700 pb. Los aislados del grupo III, no se pudieron caracterizar molecularmente por PCR-RFLP, ya que el patrón de digestión no coincidió con patrones previamente publicados. Solo se identificó el 33% de los aislados resultando: A. polyphaga (A9, A12, A13, A14), A. castellanii (A26, A27, A28 y A29) y A. castellanii o A. polyphaga (A15, A25 y A30). Las especies identificadas coinciden con las patógenas más comúnmente descritas en la literatura.   TitleIdentification of Acanthamoeba spp. isolates maintained at the amibiasis laboratory of Universidad Central de Venezuela, USING PCR-RFLPAbstract Acanthamoeba genus includes some species related to pathology in humans. Their identification and classification was made by morphology, but it is a subjective technique and has low sensitivity and specificity. For these reasons, it is important to incorporate molecular tools. The objective of this research was to characterize morphologic and molecular features of 24 Acanthamoeba isolates, maintained at Laboratorio de Amibiasis-Escuela of Bioanálisis-UCV, previously identified as Acanthamoeba, using light microscopy and morphological criteria according to Pussard and Pons, 1977 and PCR-RFLP (HinffI, HhaI and HaeIII) respectively. Morphologically, none of the strains belonged to group I. 45.8% of all isolates presented compatible morphology with Group II, other 45.8% with group III and 8.4% with both groups. Molecularly, 50% of the isolates amplified a 900 pb product and the other 50%, a 700 pb product. Isolates of Group III could not be molecularly characterized by PCR-RFLP, since the digestion pattern have no coincidence with previous reports. Only 33% of strains were finally identified: A. polyphaga (A9, A12, A13, A14), A. castellanii (A26, A27, A28 and A29) and A. castellanii or A. polyphaga (A15, A25 and A30). The identified species are consistent with the most common pathogens described at the literature. Key words: Free living amoebae; Acanthamoeba spp; PCR-RFLP

Virion Structure of Baboon Reovirus, a Fusogenic Orthoreovirus That Lacks an Adhesion Fiber ▿

Baboon reovirus (BRV) is a member of the fusogenic subgroup of orthoreoviruses. Unlike most other members of its genus, BRV lacks S-segment coding sequences for the outer fiber protein that binds to cell surface receptors. It shares this lack with aquareoviruses, which constitute a related genus and are also fusogenic. We used electron cryomicroscopy and three-dimensional image reconstruction to determine the BRV virion structure at 9.0-Å resolution. The results show that BRV lacks a protruding fiber at its icosahedral 5-fold axes or elsewhere. The results also show that BRV is like nonfusogenic mammalian and fusogenic avian orthoreoviruses in having 150 copies of the core clamp protein, not 120 as in aquareoviruses. On the other hand, there are no hub-and-spoke complexes attributable to the outer shell protein in the P2 and P3 solvent channels of BRV, which makes BRV like fusogenic avian orthoreoviruses and aquareoviruses but unlike nonfusogenic mammalian orthoreoviruses. The outermost “flap” domains of the BRV core turret protein appear capable of conformational variability within the virion, a trait previously unseen among other ortho- and aquareoviruses. New cDNA sequence determinations for the BRV L1 and M2 genome segments, encoding the core turret and outer shell proteins, were helpful for interpreting the structural features of those proteins. Based on these findings, we conclude that the evolution of ortho- and aquareoviruses has included a series of discrete gains or losses of particular components, several of which cross taxonomic boundaries. Gain or loss of adhesion fibers is one of several common themes in double-stranded RNA virus evolution

Na+ controls hypoxic signalling by the mitochondrial respiratory chain

All metazoans depend on O2 delivery and consumption by the mitochondrial oxidative phosphorylation (OXPHOS) system to produce energy. A decrease in O2 availability (hypoxia) leads to profound metabolic rewiring. In addition, OXPHOS uses O2 to produce reactive oxygen species (ROS) that can drive cell adaptations through redox signalling, but also trigger cell damage1–4, and both phenomena occur in hypoxia4–8. However, the precise mechanism by which acute hypoxia triggers mitochondrial ROS production is still unknown. Ca2+ is one of the best known examples of an ion acting as a second messenger9, yet the role ascribed to Na+ is to serve as a mere mediator of membrane potential and collaborating in ion transport10. Here we show that Na+ acts as a second messenger regulating OXPHOS function and ROS production by modulating fluidity of the inner mitochondrial membrane (IMM). We found that a conformational shift in mitochondrial complex I during acute hypoxia11 drives the acidification of the matrix and solubilization of calcium phosphate precipitates. The concomitant increase in matrix free-Ca2+ activates the mitochondrial Na+/Ca2+ exchanger (NCLX), which imports Na+ into the matrix. Na+ interacts with phospholipids reducing IMM fluidity and mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III, generating a redox signal. Inhibition of mitochondrial Na+ import through NCLX is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na+ import into the mitochondrial matrix controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences in cellular metabolism