A Dynamical Study of the Non-Star Forming Translucent Molecular Cloud MBM16: Evidence for Shear Driven Turbulence in the Interstellar Medium

We present the results of a velocity correlation study of the high latitude cloud MBM16 using a fully sampled $^{12}$CO map, supplemented by new $^{13}$CO data. We find a correlation length of 0.4 pc. This is similar in size to the formaldehyde clumps described in our previous study. We associate this correlated motion with coherent structures within the turbulent flow. Such structures are generated by free shear flows. Their presence in this non-star forming cloud indicates that kinetic energy is being supplied to the internal turbulence by an external shear flow. Such large scale driving over long times is a possible solution to the dissipation problem for molecular cloud turbulence.Comment: Uses AAS aasms4.sty macros. Accepted for publication in Ap

CH radio emission from heiles cloud 2 as a tracer of molecular cloud evolution

A mapping observation of the $J=1/2$ $\Lambda$-type doubling transition (3.3 GHz) of CH has been conducted toward Heiles Cloud 2 (HCL2) in the Taurus molecular cloud complex to reveal its molecular cloud-scale distribution. The observations were carried out with the Effelsberg 100 m telescope. The CH emission is found to be extended over the whole region of HCL2. It is brighter in the southeastern part, which encloses the TMC-1 cyanopolyyne peak than in the northwestern part. Its distribution extends continuously from the peak of the neutral carbon emission (CI peak) to the TMC-1 ridge, as if it were connecting the distributions of the [C I] and C$^{18}$O emissions. Since CH is an intermediate in gas-phase chemical reactions from C to CO, its emission should trace the transition region. The above distribution of the CH emission is consistent with this chemical behavior. Since the CH abundance is subject to the chemical evolutionary effect, the CH column density in HCL2 no longer follows a linear correlation wit the H$_2$ column density reported for diffuse and translucent clouds. More importantly, the CH line profile is found to be composed of the narrow and broad components. Although the broad component is dominant around the CI peak, the narrow component appears in the TMC-1 ridge and dense core regions such as L1527 and TMC-1A. This trend seems to reflect a narrowing of the line width during the formation of dense cores. These results suggest that the 3.3 GHz CH line is a useful tool for tracing the chemical and physical evolution of molecular clouds.Comment: 8 page

Glutathione increase by the n-butanoyl glutathione derivative (GSH-C4) inhibits viral replication and induces a predominant Th1 immune profile in old mice infected with influenza virus

During aging, glutathione (GSH) content declines and the immune system undergoes a deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is associated with GSH depletion, could weaken the host defenses against viral infections. We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of aged mice infected with influenza A PR8/H1N1 virus was studied through the determination of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production and Th1/Th2 cytokine profile. Old mice had lower GSH than young mice in organs. Also the gene expression of endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of proteins, i.e. Nrf2 and PDI, was reduced. Following infection, GSH content remained low and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI expression was upregulated during infection and appeared counterbalanced by GSH-C4. Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral replication and induced a predominant Th1 response. In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus infection by inducing immune response, in particular the Th1 profile

CH 3 GHz Observations of Molecular Clouds Along the Galactic Plane

Spectra in the CH $^2\Pi_{1/2}$, J=1/2, F=1-1 transition at 3335 MHz were obtained in three 5-point crosses centered on the Galactic plane at $\ell =$ 50\arcdeg, 100\arcdeg, and 110\arcdeg. The lines of sight traverse both Giant Molecular Clouds (GMCs) and local, smaller entities. This transition is a good tracer of low-density molecular gas and the line profiles are very similar to CO(1-0) data at nearly the same resolution. In addition, the CH 3335 MHz line can be used to calibrate the CO-H$_2$ conversion factor (X$_{\rm CO}$) in low-density molecular gas. Although this technique underestimates X$_{\rm CO}$ in GMCs, our results are within a factor of two of X$_{\rm CO}$ values calibrated for GMCs by other techniques. The similarity of CH and CO line profiles, and that of X$_{\rm CO}$ values derived from CH and more traditional techniques, implies that most of the molecular gas along the observed lines of sight is at relatively low densities ($n \le$ 10$^3$ cm$^{-3}$).Comment: 26 pages, 12 figures, submitted to the AJ, revised after referee repor

O uso de derivativos para hedge melhora os ratings de crédito das empresas brasileiras?

Este trabalho se propôs a identificar os fatores que podem explicar as atribuições dos ratings, com especial atenção ao impacto do uso de derivativos. A lacuna explorada por esta pesquisa reside no ineditismo em se analisar a percepção, por parte das agências de ratings, dos reflexos causados pelas informações relacionadas ao uso de derivativos pelas companhias brasileiras de capital aberto. Além disso, este estudo transfere os achados anteriores que se debruçaram sobre os analistas de ações para as agências de ratings, reforçando a discussão sobre a complexidade dos derivativos no processo de avaliação do risco de crédito. A contemporaneidade deste tema de pesquisa se dá pela recente adoção da norma International Financial Reporting Standards 9 (Comitê de Pronunciamentos Contábeis – Pronunciamento Técnico n. 48), que entrou em vigor em janeiro de 2018. A partir dessa normatização, a principal novidade apresentada neste artigo foi a verificação do reflexo do uso de derivativos utilizados pelas empresas com a finalidade de hedge nos seus ratings de créditos, ajudando a suprir uma lacuna empírica na literatura da área. Os resultados encontrados contestam a teoria de que o uso de derivativos para hedge é visto positivamente pelos investidores. No entanto, apesar de nenhum impacto significativamente estatístico ter sido encontrado nos ratings das empresas que utilizam derivativos, observou-se que as empresas que usam derivativos e têm os maiores valores nocionais foram as que receberam as melhores notas da agência Moody’s. Com isso, ampliamos o debate sobre a complexidade das informações atreladas ao uso dos derivativos. Foram analisados 2.090 ratings atribuídos a companhias não financeiras com ações negociadas na Brasil, Bolsa, Balcão [B]³ entre 2010 e 2016, por meio de análise dos dados em painel, conferindo maior robustez às análises e aos achados. Contrariando a hipótese central desta pesquisa, os resultados aqui apresentados mostram que, no Brasil, as empresas que se utilizam de instrumentos financeiros derivativos para hedge não recebem as melhores notas de classificação de crédito por parte das agências de ratings. Uma das principais contribuições deste estudo centra-se nos indícios de que as agências Standard & Poor’s e Moody’s não foram capazes de incorporar, de maneira consistente, as informações relacionadas ao uso dos derivativos, ampliando a discussão sobre a complexidade desses instrumentos financeiros.The purpose of this study is to identify the factors that may explain the attribution of credit ratings to firms, focusing especially on the impact of derivatives. The gap explored by this research lies in the novelty of analyzing how rating agencies perceive the effects caused by information related to derivatives use by Brazilian publicly-traded companies. In addition, this study shifts the previous findings from stock analysts to rating agencies, reinforcing the discussion about the complexity of derivatives in the credit risk assessment process. This research topic is currently of interest due to the adoption of International Financial Reporting Standard (IFRS) 9 (Accounting Pronouncements Committee – CPC – 48), which came into effect in January of 2018. Based on these rules, the main novelty presented in this article was its verification of the effect of the derivatives used by companies in order to hedge their credit ratings, thus helping to fill the empirical gap that exists in the literature from the area. The results found challenge the theory that the use of hedge derivatives is viewed positively by investors. However, although no significant statistical impact was found on the ratings of companies that use derivatives, it was observed that the companies that use derivatives and have the highest notional values were those that received the best ratings from Moody’s. With this we broadened the debate about the complexity of the information linked to derivatives use. In the study, 2,090 ratings attributed to non-financial companies with stocks traded on the Brasil, Bolsa, Balcão [B]³ exchange were examined between 2010 and 2016 by using panel data analysis, which lends robustness to the analysis and findings. Contrary to the central hypothesis of this research, the results presented here show that, in Brazil, companies that use derivative financial instruments for hedging do not receive the best credit ratings from rating agencies. One of the main contributions of this study is the evidence that Standard & Poor’s and Moody’s were unable to consistently incorporate information related to derivatives use, thus broadening the discussion about the complexity of these financial instruments

Spearhead Nanometric Field-Effect Transistor Sensors for Single-Cell Analysis.

Nanometric field-effect-transistor (FET) sensors are made on the tip of spear-shaped dual carbon nanoelectrodes derived from carbon deposition inside double-barrel nanopipettes. The easy fabrication route allows deposition of semiconductors or conducting polymers to comprise the transistor channel. A channel from electrodeposited poly pyrrole (PPy) exhibits high sensitivity toward pH changes. This property is exploited by immobilizing hexokinase on PPy nano-FETs to give rise to a selective ATP biosensor. Extracellular pH and ATP gradients are key biochemical constituents in the microenvironment of living cells; we monitor their real-time changes in relation to cancer cells and cardiomyocytes. The highly localized detection is possible because of the high aspect ratio and the spear-like design of the nano-FET probes. The accurately positioned nano-FET sensors can detect concentration gradients in three-dimensional space, identify biochemical properties of a single living cell, and after cell membrane penetration perform intracellular measurements

Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient

In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m −2  y −1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites