Charmonium production in pˉ\bar p-induced reactions on nuclei

The production of charmonia in the antiproton-nucleus reactions at $p_{\rm lab}=3-10$ GeV/c is studied within the Glauber model and the generalized eikonal approximation. The main reaction channel is charmonium formation in an antiproton-proton collision. The target mass dependence of the charmonium transparency ratio allows to determine the charmonium-nucleon cross section. The polarization effects in the production of $\chi_{c2}$ states are evaluated.Comment: 4 pages, 3 figures, Proceedings of the 13th International Workshop on Meson Production, Properties and Interaction, Krakow, Poland, 29.05-3.06.201

The extended narrow-line region of two type-I quasi-stellar objects

We investigate the narrow-line region (NLR) of two radio-quiet QSOs, PG1012+008 and PG1307+085, using high signal-to-noise spatially resolved long-slit spectra obtained with FORS1 at the Very Large Telescope. Although the emission is dominated by the point-spread function of the nuclear source, we are able to detect extended NLR emission out to several kpc scales in both QSOs by subtracting the scaled central spectrum from outer spectra. In contrast to the nuclear spectrum, which shows a prominent blue wing and a broad line profile of the [O III] line, the extended emission reveals no clear signs of large scale outflows. Exploiting the wide wavelength range, we determine the radial change of the gas properties in the NLR, i.e., gas temperature, density, and ionization parameter, and compare them with those of Seyfert galaxies and type-II QSOs. The QSOs have higher nuclear temperature and lower electron density than Seyferts, but show no significant difference compared to type-II QSOs, while the ionization parameter decreases with radial distance, similar to the case of Seyfert galaxies. For PG1012+008, we determine the stellar velocity dispersion of the host galaxy. Combined with the black hole mass, we find that the luminous radio-quiet QSO follows the local M_BH-sigma* relation of active galactic nuclei.Comment: 7 pages, 5 figures, accepted for publication in Ap

Considerações a Respeito das Redes Telegráficas Elétricas por Fio no Brasil, seus Impactos e Implantação nas Cidades do Rio de Janeiro e Porto Alegre

A invenção da telegrafia elétrica e sua expansão pelo mundo foi um dos maiores feitos científicos e tecnológicos do século XIX, chegando a ser chamada por Tom Standage (1998) de a “Internet Vitoriana”, a “mãe de todas as redes”. Este artigo apresenta e analisa a implantação da telegrafia elétrica no Brasil, em especial, nas cidades do Rio de Janeiro e Porto Alegre durante o Segundo Império e no transcorrer do século XX. É mostrado o crescimento das linhas telegráficas durante os anos iniciais, o impacto da Guerra do Paraguai para sua expansão ao Sul do Brasil, além da Comissão Rondon levando o telégrafo por fio para o Norte e Centro-Oeste. O governo brasileiro percebeu que além do uso militar, o telégrafo elétrico poderia ser utilizado como instrumento de aproximação e fortalecimento de forças políticas espalhadas pelo país favorecendo o seu controle e gestão territorial, além da expansão e reprodução do capital. A sua implantação também proporcionou o incremento do dito ‘saber geográfico’. O enfoque especial para a rede telegráfica instalada nas cidades do Rio de Janeiro e Porto Alegre é devido serem os territórios de vivência do autor, que acompanhou por curiosidade parte de suas transformações até a sua desativação

Glyoxalase-I Is Upregulated in Acute Cerulein-Induced Pancreatitis: A New Mechanism in Pancreatic Inflammation?

Inflammation caused by oxidative stress (ROS) demonstrates an essential mechanism in the pathogenesis of acute pancreatitis (AP). Important sources for ROS comprise the reactive compound methylglyoxal (MGO) itself and the MGO-derived formation of advanced glycation end-products (AGEs). AGEs bind to the transmembrane receptor RAGE and activate NF-κB, and lead to the production of pro-inflammatory cytokines. MGO is detoxified by glyoxalase-I (Glo-I). The importance of Glo-I was shown in different models of inflammation and carcinogenesis. Nevertheless, the role of Glo-I and MGO in AP has not been evaluated so far. This study analyzed Glo-I in cerulein-(CN)-induced AP and determined the effects of Glo-I knockdown, overexpression and pharmacological modulation. Methods: AP was induced in C57BL6/J mice by i.p. injection of CN. Glo-I was analyzed in explanted pancreata by Western Blot, qRT-PCR and immunohistochemistry. AR42J cells were differentiated by dexamethasone and stimulated with 100 nM of CN. Cells were simultaneously treated with ethyl pyruvate (EP) or S-p-bromobenzylglutathione-cyclopentyl-diester (BrBz), two Glo-I modulators. Knockdown and overexpression of Glo-I was achieved by transient transfection with Glo-I siRNA and pEGFP-N1-Glo-I-Vector. Amylase secretion, TNF-α production (ELISA) and expression of Glo-I, RAGE and NF-κB were measured. Results: Glo-I was significantly upregulated on protein and mRNA levels in CN-treated mice and AR42J cells. Dexamethasone-induced differentiation of AR42J cells increased the expression of Glo-I and RAGE. Treatment of AR42J cells with CN and EP or BrBz resulted in a significant reduction of CN-induced amylase secretion, NF-κB, RAGE and TNF-α. Overexpression of Glo-I led to a significant reduction of CN-induced amylase levels, NF-κB expression and TNF-α, whereas Glo-I knockdown revealed only slight alterations. Measurements of specific Glo-I activity and MGO levels indicated a complex regulation in the model of CN-induced AP. Conclusion: Glo-I is overexpressed in a model of CN-induced AP. Pharmacological modulation and overexpression of Glo-I reduced amylase secretion and the release of pro-inflammatory cytokines in AP in vitro. Targeting Glo-I in AP seems to be an interesting approach for future in vivo studies of AP

A importância do município do Rio de Janeiro na territorialidade da indústria audiovisual brasileira

Neste trabalho analisaremos como se encontra a indústria do audiovisual em sua hodierna disposição e configuração no território do Município do Rio de Janeiro. A sua concentração e centralidade no espaço carioca se apresenta geograficamente contraditória, pois não se estabeleceu no centro de poder econômico e publicitário, a cidade de São Paulo, ou político, como é o caso de Brasília. Mostraremos o papel original da centralidade ocupada pela cidade do Rio de Janeiro, constatado em análise qualitativa, como a maior produtora de audiovisuais de ficção cinematográfica e televisiva. Investigaremos as condicionantes de poder que resultaram na sua atual distribuição que favoreceu o Rio de Janeiro e proporcionou ser uma de suas maiores vocações econômicas. O poder econômico e sua concentração balizaram os estudos das políticas do audiovisual implementados em território carioca

Parity lifetime of bound states in a proximitized semiconductor nanowire

Quasiparticle excitations can compromise the performance of superconducting devices, causing high frequency dissipation, decoherence in Josephson qubits, and braiding errors in proposed Majorana-based topological quantum computers. Quasiparticle dynamics have been studied in detail in metallic superconductors but remain relatively unexplored in semiconductor-superconductor structures, which are now being intensely pursued in the context of topological superconductivity. To this end, we introduce a new physical system comprised of a gate-confined semiconductor nanowire with an epitaxially grown superconductor layer, yielding an isolated, proximitized nanowire segment. We identify Andreev-like bound states in the semiconductor via bias spectroscopy, determine the characteristic temperatures and magnetic fields for quasiparticle excitations, and extract a parity lifetime (poisoning time) of the bound state in the semiconductor exceeding 10 ms.Comment: text and supplementary information combine

Transport signatures of quasiparticle poisoning in a Majorana island

We investigate effects of quasiparticle poisoning in a Majorana island with strong tunnel coupling to normal-metal leads. In addition to the main Coulomb blockade diamonds, "shadow" diamonds appear, shifted by 1e in gate voltage, consistent with transport through an excited (poisoned) state of the island. Comparison to a simple model yields an estimate of parity lifetime for the strongly coupled island (~ 1 {\mu}s) and sets a bound for a weakly coupled island (> 10 {\mu}s). Fluctuations in the gate-voltage spacing of Coulomb peaks at high field, reflecting Majorana hybridization, are enhanced by the reduced lever arm at strong coupling. In energy units, fluctuations are consistent with previous measurements.Comment: includes supplementary materia

Barriers to using HIV pre-exposure prophylaxis (PrEP) and sexual behaviour after stopping PrEP: a cross-sectional study in Germany

Background Persistence of individuals at risk of HIV with Pre-Exposure Prophylaxis (PrEP) is critical for its impact on the HIV epidemic. We analysed factors associated with stopping PrEP, barriers that may deter people from continuing PrEP and investigated sexual behaviour after stopping PrEP. Methods Current and former PrEP users in Germany were recruited to complete an anonymous online survey on PrEP use and sexual behaviour. Participants were recruited through dating apps, a PrEP community website, anonymous testing sites and peers. The results were analysed using descriptive methods and logistic regression. Results We recruited 4848 current and 609 former PrEP users in two study waves (July–October 2018, April–June 2019). Former PrEP users were more likely 18–29 years old than current users (adjusted OR = 1.6, 95% confidence interval (CI) 1.1–2.3). Moreover, they were more often unhappy with their sex life, which was more pronounced in former daily PrEP users (aOR = 4.5, 95% CI 2.9–7.1) compared to former on-demand users (aOR = 1.8, 95% CI 1.1–2.9, pinteraction = 0.005). The most common reason for stopping PrEP was a reduced need for PrEP (49.1%). However, 31.4% of former users identified logistic reasons and 17.5% stopped due to side effects. Former PrEP users using PrEP < 3 months were more likely to stop PrEP due to concerns over long-term side effects (32.0% vs. 22.5%, p = 0.015) and not wanting to take a chemical substance (33.2% vs. 24.0%, p = 0.020) compared to former PrEP users who used PrEP for longer. After stopping PrEP, 18.7% of former PrEP users indicated inconsistent condom use while having ≥4 sex partners within the previous 6 months. Former PrEP users with many partners and inconsistent condom use more often indicated logistic reasons for stopping (46.5% vs. 27.9%, p < 0.001) than did other former PrEP users. Conclusions To maximise persistence with PrEP we need to develop strategies for younger PrEP users, reduce logistic barriers to access PrEP, and to develop effective communication on side-effect management. Moreover, prevention strategies for people stopping PrEP are required, since some remain at high risk for HIV.Peer Reviewe