Typical and atypical COVID-19 computed tomography findings

In December 2019 a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 was identified and the disease associated was named coronavirus disease 2019 (COVID-19). Fever, cough, myalgia, fatigue associated to dyspnea represent most common clinical symptoms of the disease. The reference standard for diagnosis of severe acute respiratory syndrome coronavirus 2 infection is real time reverse-transcription polymerase chain reaction test applied on respiratory tract specimens. Despite of lower specificity, chest computed tomography (CT), as reported in manifold scientific studies, showed high sensitivity, therefore it may help in the early detection, management and follow-up of COVID-19 pneumonia. Patients affected by COVID-19 pneumonia usually showed on chest CT some typical features, such as: Bilateral ground glass opacities characterized by multilobe involvement with posterior and peripheral distribution; parenchymal consolidations with or without air bronchogram; interlobular septal thickening; crazy paving pattern, represented by interlobular and intralobular septal thickening surrounded by ground-glass opacities; subsegmental pulmonary vessels enlargement (> 3 mm). Halo sign, reversed halo sign, cavitation and pleural or pericardial effusion represent some of atypical findings of COVID-19 pneumonia. On the other hand lymphadenopathy's and bronchiectasis' frequency is unclear, indeed conflicting data emerged in literature. Radiologists play a key role in recognition of high suspicious findings of COVID-19 on chest CT, both typical and atypical ones. Thus, the aim of this review is to illustrate typical and atypical CT findings of COVID-19

Aptidão agroecológica de terras: proposta de avaliação em paisagens rurais montanhosas ocupadas por pequenos agricultores na Serra do Mar.

O objetivo deste trabalho foi gerar subsídios para o planejamento agrícola de pequenas propriedades rurais inseridas em paisagens rurais montanhosas da Serra dos Órgãos, ocupada com agricultura familiar. Apoiado em técnicas de geoprocessamento e SIGs, o trabalho demonstra os procedimentos adotados para a avaliação da aptidão agroecológica das terras por unidade ambiental, enfatizando limitações e potencialidades com base nas ofertas e restrições ambientais apresentadas em cada unidade delimitada. Os procedimentos utilizados envolveram a geração de banco de dados digital no SIG e a geração de dados básicos no campo, através de mapeamentos temáticos do meio físico, que foram associados a informações socioeconômicas, de pluviosidade e de áreas protegidas por legislação específica ou reservas existentes, constituindo assim um conjunto de informações agrossocioambientais em meio digital, o que possibilitou a delimitação de unidades ambientais e a geração de mapas interpretativos úteis ao planejamento. Em cada uma das unidades defi nidas, foi associado um conjunto de indicações relativas às suas limitações e potencialidades, fragilidades e riscos. O modelo de aptidão agroecológica considerado é feito por unidades ambientais delimitadas, e envolve a indicação de uso, manejo e sugestão de alternativas sustentáveis de utilização, visando reduzir os efeitos negativos sobre o meio ambiente e incrementar a qualidade ambiental. Conclui-se que a metodologia apresentou- se adequada ao planejamento agroambiental de áreas com relevo movimentado, pois onde foi identifi cada a ocorrência de compartimentos mais frágeis e problemáticos, em função dos solos, declividade, maior suscetibilidade aos processos erosivos e maior grau de fragilidade ambiental, estes se encaixaram nas classes de aptidão inapta, restrita, preservação ambiental ou recomposição de matas

Spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron at low values of x and Q^2

We present a precise measurement of the deuteron longitudinal spin asymmetry A_1^d and of the deuteron spin-dependent structure function g_1^d at Q^2 < 1 GeV^2 and 4*10^-5 < x < 2.5*10^-2 based on the data collected by the COMPASS experiment at CERN during the years 2002 and 2003. The statistical precision is tenfold better than that of the previous measurement in this region. The measured A_1^d and g_1^d are found to be consistent with zero in the whole range of x.Comment: 17 pages, 10 figure

Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering

We have measured the spin-dependent structure function $g_1^p$ in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003 < x < 0.7$ and $1 GeV^2 < Q^2 < 60 GeV^2$. A next-to-leading order QCD analysis is used to evolve the measured $g_1^p(x,Q^2)$ to a fixed $Q^2_0$. The first moment of $g_1^p$ at $Q^2_0 = 10 GeV^2$ is $\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.)$. This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge $a_0$ is found to be $0.28 \pm 0.16$. In the Adler-Bardeen factorization scheme, $\Delta g \simeq 2$ is required to bring $\Delta \Sigma$ in agreement with the Quark-Parton Model. A combined analysis of all available proton and deuteron data confirms the Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical Review

Constraints on leptophobic Z' models from electroweak experiments

We study the constraints from updated electroweak data on the three leptophobic Z' models, the ${\eta}$ model with an appropriate $U(1)'-U(1)_Y$ kinetic mixing, a Z' model motivated by the flipped SU(5) \times U(1) unification, and the phenomenological Z' model of Agashe, Graesser, and Hinchliffe. The $Z-Z'$ mixing effects are parametrized in terms of a positive contribution to the $T$ parameter, $T_{new}$, and the effective mass mixing parameter, $\bar{\xi}$. All the theoretical predictions for the $Z$ boson parameters, the $W$ boson mass and the observables in low-energy neutral current experiments are presented together with the standard model radiative corrections. The allowed region in the ($\bar{\xi},T_{new}$) plane is shown for the three models. The 95% CL lower limit on the heavier mass eigenstate $Z_2$ is given as a function of the effective $Z-Z'$ mixing parameter $\zeta$.Comment: LaTeX, 22pages, 2 figures, corrected some typos. Final version to appear in Phys. Rev.

The local and systemic response to SARS-CoV-2 infection in children and adults

While a substantial proportion of adults infected with SARS-CoV-2 progress to develop severe disease, children rarely manifest respiratory complications. Therefore, understanding differences in the local and systemic response to SARS-CoV-2 infection between children and adults may provide important clues about the pathogenesis of SARS-CoV-2 infection. To address this, we first generated a healthy reference multi-omics single cell data set from children (n=30) in whom we have profiled triple matched samples: nasal and tracheal brushings and PBMCs, where we track the developmental changes for 42 airway and 31 blood cell populations from infancy, through childhood to adolescence. This has revealed the presence of naive B and T lymphocytes in neonates and infants with a unique gene expression signature bearing hallmarks of innate immunity. We then contrast the healthy reference with equivalent data from severe paediatric and adult COVID-19 patients (total n=27), from the same three types of samples: upper and lower airways and blood. We found striking differences: children with COVID-19 as opposed to adults had a higher proportion of innate lymphoid and non-clonally expanded naive T cells in peripheral blood, and a limited interferon-response signature. In the airway epithelium, we found the highest viral load in goblet and ciliated cells and describe a novel inflammatory epithelial cell population. These cells represent a transitional regenerative state between secretory and ciliated cells; they were found in healthy children and were enriched in paediatric and adult COVID-19 patients. Epithelial cells display an antiviral and neutrophil-recruiting gene signature that is weaker in severe paediatric versus adult COVID-19. Our matched blood and airway samples allowed us to study the spatial dynamics of infection. Lastly, we provide a user-friendly interface for this data1 as a highly granular reference for the study of immune responses in airways and blood in children