Seismic response analysis of concrete block masonry buildings: an experimental study using shaking table

The combination of a series of structural and economic advantages like the high capacity to resist compressive loads, the simple and easy method of construction, comfort properties and structural performance given for the new masonry structures makes the implementation of masonry as a profitable solution for the increased residential houses demand. An innovative solution for the construction of low to medium residential masonry buildings is here analysed. The assessment of the earthquake resistance capacity of this system is evaluated aiming at providing further guidelines for its design and construction. This paper presents a step in this process related to the experimental mechanical validation of the constructive system based on concrete block masonry buildings under seismic loading

Turbulence Hierarchy in a Random Fibre Laser

Turbulence is a challenging feature common to a wide range of complex phenomena. Random fibre lasers are a special class of lasers in which the feedback arises from multiple scattering in a one-dimensional disordered cavity-less medium. Here, we report on statistical signatures of turbulence in the distribution of intensity fluctuations in a continuous-wave-pumped erbium-based random fibre laser, with random Bragg grating scatterers. The distribution of intensity fluctuations in an extensive data set exhibits three qualitatively distinct behaviours: a Gaussian regime below threshold, a mixture of two distributions with exponentially decaying tails near the threshold, and a mixture of distributions with stretched-exponential tails above threshold. All distributions are well described by a hierarchical stochastic model that incorporates Kolmogorov's theory of turbulence, which includes energy cascade and the intermittence phenomenon. Our findings have implications for explaining the remarkably challenging turbulent behaviour in photonics, using a random fibre laser as the experimental platform.Comment: 9 pages, 5 figure

Meningoencefalite chagásica: relato de caso de doença recentemente incluida como indicativa de AIDS no Brasil

Recently, reactivation of Chagas disease (meningoencephalitis and/or myocarditis) was included in the list of AIDS-defining illnesses in Brazil. We report a case of a 52-year-old patient with no history of previous disease who presented acute meningoencephalitis. Direct examination of blood and cerebrospinal fluid (CSF) showed Trypanosoma cruzi. CSF culture confirmed the diagnosis. Serological assays for T. cruzi and human immunodeficiency virus (HIV) were positive. Despite treatment with benznidazol and supportive measures, the patient died 24 hours after hospital admission. In endemic areas, reactivation of Chagas disease should always be considered in the differential diagnosis of meningoencephalitis among HIV-infected patients, and its presence is indicative of AIDS.Recentemente, a reagudização da doença de Chagas (meningoencefalite e/ou miocardite) foi incluída na lista de doenças indicativas de aids no Brasil. Os autores relatam o caso de um paciente de 52 anos de idade, natural de área rural da Bahia e procedente de uma área urbana de São Paulo, sem história de doenças prévias e que apresentou meningoencefalite aguda. As sorologias e pesquisas parasitológicas diretas no sangue e no liquido cefalorraquideano (LCR) demonstraram presença de Trypanosoma cruzi, confirmando-se o diagnóstico mediante cultura do LCR. O teste rápido assim como os ELISA e Western Blot diagnosticaram infecção pelo vírus da imunodeficiência humana (HIV). Apesar do tratamento com benzonidazole e as medidas de suporte, o paciente faleceu 24 horas depois da admissão hospitalar. Em áreas endêmicas, a reagudização da doença de Chagas deve ser sempre considerada no diagnóstico diferencial das meningoencefalites e sua presença em pacientes com infecção pelo HIV é indicativa de aids

CsCuCl3 perovskite-like compound under extreme conditions

Halide perovskite has attracted intense research interest owing to its multifaceted and versatile applications in optoelectronics. This intrigue is further fueled by their propensity to undergo intricate structural modifications under extreme conditions, thereby instigating property changes. Within this context, our study delves deep into the intricate interplay of structural and vibrational attributes within the inorganic-metal halide perovskite-like CsCuCl3. Our approach employs Raman spectroscopy and Synchrotron Powder X-Ray Diffraction (SPXRD) techniques harnessed under the dual conditions of low temperatures and high pressures. We have observed a distinct spin-phonon coupling mechanism by employing Raman spectroscopy at low temperatures; this coupling has been manifested as a renormalization phonon phenomenon that occurs notably at T* = 15 K. The correlation between spin and phonon dynamics becomes pronounced through a notable hardening of phonon temperature dependence, a behavior intricately linked to the material antiferromagnetic transition at TN = 10.7 K. The SPXRD under high pressure showed a first-order structural phase transition (SPT) at the critical pressure Pc = 3.69 GPa, leading to the transformation from the hexagonal P6522 to a base-centered monoclinic cell. Notably, the coexistence of both phases is discernible within the pressure range from 2.79 to 3.57 GPa, indicating that the SPT involves the reorganization of the internal [Cu2Cl9]5- dimer unit, with the Cl-Cu-Cl bending contributing more than stretching modes. Furthermore, we demonstrate that the SPT is reversible, but residual strain pressure influences the modification of the critical pressure Pc value upon pressure decrease.Comment: 27 pages, 8 figure

Lattice dynamics localization in low-angle twisted bilayer graphene

A low twist angle between the two stacked crystal networks in bilayer graphene enables self-organized lattice reconstruction with the formation of a periodic domain. This superlattice modulates the vibrational and electronic structures, imposing new rules for electron-phonon coupling and the eventual observation of strong correlation and superconductivity. Direct optical images of the crystal superlattice in reconstructed twisted bilayer graphene are reported here, generated by the inelastic scattering of light in a nano-Raman spectroscope. The observation of the crystallographic structure with visible light is made possible due to lattice dynamics localization, the images resembling spectral variations caused by the presence of strain solitons and topological points. The results are rationalized by a nearly-free-phonon model and electronic calculations that highlight the relevance of solitons and topological points, particularly pronounced for structures with small twist angles. We anticipate our discovery to play a role in understanding Jahn-Teller effects and electronic Cooper pairing, among many other important phonon-related effects, and it may be useful for characterizing devices in the most prominent platform for the field of twistronics.Comment: 9 pages, 8 figure

Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

O objetivo deste trabalho foi verificar o efeito do tamanho da coleção original de germoplasma sobre eficácia de diferentes métodos de agrupamento e de amostragem, utilizados na obtenção de coleções nucleares, e comparar esses métodos no estabelecimento de coleções nucleares. Foram simulados sete tamanhos de coleções originais e utilizadas sete estratégias de amostragem para estabelecimento de coleções nucleares, com uso de caracteres morfo-agronômicos. Oito estratégias de obtenção de coleção nuclear foram empregadas, seis com técnicas de agrupamento (Tocher e Tocher sequencial) e duas sem agrupamento (aleatória e Tocher invertido). Nas estratégias de agrupamento, foram empregadas as amostragens constante, logarítmica e proporcional. Determinaram-se a variância explicada, o valor do coeficiente de determinação, o coeficiente de coincidência e o coeficiente de coincidência do desvio-padrão entre a coleção nuclear e a coleção original. As estratégias de amostragem constante e logarítmica geram coleções nucleares representativas da coleção original. O agrupamento de Tocher sequencial é mais eficaz na representação da coleção original pela coleção nuclear do que o agrupamento de Tocher. Entre as estratégias avaliadas, a amostragem pelo método de Tocher com critério de aglomeração inverso foi a mais eficiente na geração de coleções nucleares representativas das coleções originai

Poly I:C elicits broader and stronger humoral and cellular responses to a Plasmodium vivax circumsporozoite protein malaria vaccine than Alhydrogel in mice

Malaria remains a global health challenge, necessitating the development of effective vaccines. The RTS,S vaccination prevents Plasmodium falciparum (Pf) malaria but is ineffective against Plasmodium vivax (Pv) disease. Herein, we evaluated the murine immunogenicity of a recombinant PvCSP incorporating prevalent polymorphisms, adjuvanted with Alhydrogel or Poly I:C. Both formulations induced prolonged IgG responses, with IgG1 dominance by the Alhydrogel group and high titers of all IgG isotypes by the Poly I:C counterpart. Poly I:C-adjuvanted vaccination increased splenic plasma cells, terminally-differentiated memory cells (MBCs), and precursors relative to the Alhydrogel-combined immunization. Splenic B-cells from Poly I:C-vaccinated mice revealed an antibody-secreting cell- and MBC-differentiating gene expression profile. Biological processes such as antibody folding and secretion were highlighted by the Poly I:C-adjuvanted vaccination. These findings underscore the potential of Poly I:C to strengthen immune responses against Pv malaria

MyD88 and STING Signaling Pathways Are Required for IRF3-Mediated IFN-β Induction in Response to Brucella abortus Infection

Type I interferons (IFNs) are cytokines that orchestrate diverse immune responses to viral and bacterial infections. Although typically considered to be most important molecules in response to viruses, type I IFNs are also induced by most, if not all, bacterial pathogens. In this study, we addressed the role of type I IFN signaling during Brucella abortus infection, a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Herein, we have shown that B. abortus induced IFN-β in macrophages and splenocytes. Further, IFN-β induction by Brucella was mediated by IRF3 signaling pathway and activates IFN-stimulated genes via STAT1 phosphorylation. In addition, IFN-β expression induced by Brucella is independent of TLRs and TRIF signaling but MyD88-dependent, a pathway not yet described for Gram-negative bacteria. Furthermore, we have identified Brucella DNA as the major bacterial component to induce IFN-β and our study revealed that this molecule operates through a mechanism dependent on RNA polymerase III to be sensed probably by an unknown receptor via the adaptor molecule STING. Finally, we have demonstrated that IFN-αβR KO mice are more resistant to infection suggesting that type I IFN signaling is detrimental to host control of Brucella. This resistance phenotype is accompanied by increased IFN-γ and NO production by IFN-αβR KO spleen cells and reduced apoptosis