Magnetic field-induced insulating behavior in highly oriented pyrolitic graphite

We propose an explanation for the apparent semimetal-insulator transition observed in highly oriented pyrolitic graphite in the presence of magnetic field perpendicular to the layers. We show that the magnetic field opens an excitonic gap in the linear spectrum of the Coulomb interacting quasiparticles, in a close analogy with the phenomenon of dynamical chiral symmetry breaking in the relativistic theories of the 2+1-dimensional Dirac fermions. Our strong-coupling appoach allows for a non-perturbative description of the corresponding critical behavior

Addressing the Environment Electrostatic Effect on Ballistic Electron Transport in Large Systems : A QM/MM-NEGF Approach

The effects of the environment in nanoscopic materials can play a crucial role in device design. Particularly in biosensors, where the system is usually embedded in a solution, water and ions have to be taken into consideration in atomistic simulations of electronic transport for a realistic description of the system. In this work, we present a methodology that combines quantum mechanics/molecular mechanics methods (QM/MM) with the nonequilibrium Green's function framework to simulate the electronic transport properties of nanoscopic devices in the presence of solvents. As a case in point, we present further results for DNA translocation through a graphene nanopore. In particular, we take a closer look into general assumptions in a previous work. For this sake, we consider larger QM regions that include the first two solvation shells and investigate the effects of adding extra k-points to the NEGF calculations. The transverse conductance is then calculated in a prototype sequencing device in order to highlight the effects of the solvent

The Combined Deficiency of Immunoproteasome Subunits Affects Both the Magnitude and Quality of Pathogen- and Genetic Vaccination-Induced CD8+ T Cell Responses to the Human Protozoan Parasite Trypanosoma cruzi

The beta1i, beta2i and beta5i immunoproteasome subunits have an important role in defining the repertoire of MHC class I-restricted epitopes. However, the impact of combined deficiency of the three immunoproteasome subunits in the development of protective immunity to intracellular pathogens has not been investigated. Here, we demonstrate that immunoproteasomes play a key role in host resistance and genetic vaccination-induced protection against the human pathogen Trypanosoma cruzi (the causative agent of Chagas disease), immunity to which is dependent on CD8+ T cells and IFN-gamma (the classical immunoproteasome inducer). We observed that infection with T. cruzi triggers the transcription of immunoproteasome genes, both in mice and humans. Importantly, genetically vaccinated or T. cruzi-infected beta1i, beta2i and beta5i triple knockout (TKO) mice presented significantly lower frequencies and numbers of splenic CD8+ effector T cells (CD8+CD44highCD62Llow) specific for the previously characterized immunodominant (VNHRFTLV) H-2Kb-restricted T. cruzi epitope. Not only the quantity, but also the quality of parasite-specific CD8+ T cell responses was altered in TKO mice. Hence, the frequency of double-positive (IFN-gamma+/TNF+) or single-positive (IFN-gamma+) cells specific for the H-2Kb-restricted immunodominant as well as subdominant T. cruzi epitopes were higher in WT mice, whereas TNF single-positive cells prevailed among CD8+ T cells from TKO mice. Contrasting with their WT counterparts, TKO animals were also lethally susceptible to T. cruzi challenge, even after an otherwise protective vaccination with DNA and adenoviral vectors. We conclude that the immunoproteasome subunits are key determinants in host resistance to T. cruzi infection by influencing both the magnitude and quality of CD8+ T cell responses

Autocorrelação espacial da riqueza e da abundância de mamíferos ao longo do corredor Cerrado-Pantanal, Brasil Central

In this paper, we evaluated spatial patterns in mammalian fauna obtained using 75,000 camera-trap hours in 33 fragments at the Cerrado-Pantanal border, along an east-west axis and flanked by two relatively large preserved areas. This region has been proposed as an ecological corridor, connecting these two large ecosystems. The richness of species obtained (total = 33) was explained by the area and the number of habitats in each fragment. The abundance of small-bodied species tends to have significant spatial patterns, whereas variation in the abundance of large-bodied species is randomly distributed in the geographical space. No faunal transition (changes in species compositions) between the two ecosystems was identified. Key words: camera trap, Cerrado, ecological corridor, Pantanal, mammals.Neste trabalho, avaliamos o padrão espacial da mastofauna através de 75.000 horas de esforço amostral obtidas por armadilhas fotográficas instaladas em 33 fragmentos em uma região de transição entre o Cerrado e o Pantanal, ao longo de um eixo Leste-Oeste, entre duas áreas relativamente grandes e bem preservadas. Esta região tem sido proposta como um corredor ecológico, conectando estes dois grandes ecossistemas. A riqueza de espécies obtida (total de 33 espécies) foi explicada pela área e pelo número de hábitats em cada fragmento. A abundância de espécies de pequeno porte tende a apresentar padrões espaciais significativos, enquanto a variação na abundância de espécies de grande porte é aleatoriamente distribuída no espaço geográfico. Não foi identificada uma transição faunística (mudança na composição de espécies) entre os dois ecossistemas. Palavras-chave: armadilha fotográfica, Cerrado, corredor ecológico, Pantanal, mamíferos

FruitFlyProtec - Melhorar o combate a moscas da fruta por monitorização e avaliação de eficácia de meios de proteção alternativos para Ceratitis capitata e Drosophila suzukii e avaliação do risco de introdução e distribuição potencial para Bactrocera dorsalis

Este projeto tem como objetivos: - Para Drosophila suzukii propõe-se (i) desenvolver métodos expeditos para monitorizar populações em diferentes condições ecológicas; (ii) identificar os principais fatores de risco como hospedeiros alternativos às culturas (repositórios); (iii) definir estratégias de proteção da cultura, em especial medidas preventivas e avaliação de eficácia de técnicas de captura em massa ou outros meios de proteção inovadores; - Para Ceratitis capitata pretende-se realizar a prospeção e avaliação da atividade e eficácia de limitação por predadores e parasitóides, avaliação de iscos, armadilhas e extratos de plantas com bioatividade; - Para Bactrocera dorsalis pretende-se identificar os fatores de risco e a distribuição geográfica potencial no Continente e nas Regiões Autónomas dos Açores e Madeira, tendo em conta as condições ótimas e limitantes do seu desenvolvimento e voo e os hospedeiros potenciais – zonagem de risco potencial.info:eu-repo/semantics/publishedVersio

Exome and Tissue-Associated Microbiota as Predictive Markers of Response to Neoadjuvant Treatment in Locally Advanced Rectal Cancer

The clinical and pathological responses to multimodal neoadjuvant therapy in locally advanced rectal cancers (LARCs) remain unpredictable, and robust biomarkers are still lacking. Recent studies have shown that tumors present somatic molecular alterations related to better treatment response, and it is also clear that tumor-associated bacteria are modulators of chemotherapy and immunotherapy efficacy, therefore having implications for long-term survivorship and a good potential as the biomarkers of outcome. Here, we performed whole exome sequencing and 16S ribosomal RNA (rRNA) amplicon sequencing from 44 pre-treatment LARC biopsies from Argentinian and Brazilian patients, treated with neoadjuvant chemoradiotherapy or total neoadjuvant treatment, searching for predictive biomarkers of response (responders, n = 17; non-responders, n = 27). In general, the somatic landscape of LARC was not capable to predict a response; however, a significant enrichment in mutational signature SBS5 was observed in non-responders (p = 0.0021), as well as the co-occurrence of APC and FAT4 mutations (p < 0.05). Microbiota studies revealed a similar alpha and beta diversity of bacteria between response groups. Yet, the linear discriminant analysis (LDA) of effect size indicated an enrichment of Hungatella, Flavonifractor, and Methanosphaera (LDA score ≥3) in the pre-treatment biopsies of responders, while non-responders had a higher abundance of Enhydrobacter, Paraprevotella (LDA score ≥3) and Finegoldia (LDA score ≥4). Altogether, the evaluation of these biomarkers in pre-treatment biopsies could eventually predict a neoadjuvant treatment response, while in post-treatment samples, it could help in guiding non-operative treatment strategies.Fil: Takenaka, Isabella Kuniko T. M.. No especifíca;Fil: Bartelli, Thais F.. No especifíca;Fil: Defelicibus, Alexandre. No especifíca;Fil: Sendoya, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Golubicki, Mariano. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Robbio, Juan. No especifíca;Fil: Serpa, Marianna S.. No especifíca;Fil: Branco, Gabriela P.. No especifíca;Fil: Santos, Luana B. C.. No especifíca;Fil: Claro, Laura C. L.. No especifíca;Fil: Oliveira dos Santos, Gabriel. No especifíca;Fil: Kupper, Bruna E. C.. No especifíca;Fil: da Silva, Israel T.. No especifíca;Fil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Mello, Celso A. L.. No especifíca;Fil: Riechelmann, Rachel P.. No especifíca;Fil: Dias Neto, Emmanuel. Universidade de Sao Paulo; BrasilFil: Iseas, Soledad. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Aguiar, Samuel. No especifíca;Fil: Nunes, Diana Noronha. No especifíca

Magnetic Catalysis: A Review

We give an overview of the magnetic catalysis phenomenon. In the framework of quantum field theory, magnetic catalysis is broadly defined as an enhancement of dynamical symmetry breaking by an external magnetic field. We start from a brief discussion of spontaneous symmetry breaking and the role of a magnetic field in its a dynamics. This is followed by a detailed presentation of the essential features of the phenomenon. In particular, we emphasize that the dimensional reduction plays a profound role in the pairing dynamics in a magnetic field. Using the general nature of underlying physics and its robustness with respect to interaction types and model content, we argue that magnetic catalysis is a universal and model-independent phenomenon. In support of this claim, we show how magnetic catalysis is realized in various models with short-range and long-range interactions. We argue that the general nature of the phenomenon implies a wide range of potential applications: from certain types of solid state systems to models in cosmology, particle and nuclear physics. We finish the review with general remarks about magnetic catalysis and an outlook for future research.Comment: 37 pages, to appear in Lect. Notes Phys. "Strongly interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Yee. Version 2: references adde