Revealing the chemical evolution history of the Milky Way halo with RR Lyrae stars

The Galactic Halo is the component of the Milky Way that can preserve the clearest signatures of the accretion of satellites required for the built-up of the Galaxy according to the Λ cold dark matter paradigm. The nature of these primordial satellites, their relationship to the current dwarf galaxies distributed around the Milky Way, and the fraction of the current Halo stellar population that originated from them are all open questions. The abundance of different chemical elements carries information about the enrichment timescale and physical parameters (e.g. mass distribution function, star formation rate) of the stellar system where a given star was formed. Thus, studying a variety of elements is fundamental in order to properly identify the progenitor systems of different stars, to constrain models of galactic formation, and to understand stellar nucleosynthesis itself. In particular, measurements of heavier species and robust ages for stellar tracers are severely lacking. The RR Lyrae stars (RRLs) are old (≥ 10 Gyr) radial pulsators with well defined period-luminosity relations in near-infrared (NIR) bands. These relations allow for precise distance determinations and make the RRLs excellent probes of the chemical structure of the Halo. The RRLs are classified according to their pulsation mode, with the RRab pulsating in the fundamental mode, the RRc in the first overtone, and the RRd, very few in number, in a mixed mode. High resolution spectroscopic studies of these stars are scarce. Such studies are fundamental for the investigation of α elements, Fe-peak elements, and neutron(n)-capture elements. They are also necessary for the calibration of photometric indexes and low resolution (LR) spectroscopic estimates of metallicity that can be applied to large samples. In this work, we used data collected with nine high-resolution (HR) spectrographs installed at eight different large telescopes and by two LR surveys (SEGUE-SDSS, LAMOST). We applied the methodology of HR spectroscopy to a sample of 162 RRLs (138 RRab, 23 RRc, 1 RRd) covering a wide range in metallicity ([Fe/H] from -3.2 to 0.2). Our spectroscopic investigaton is based on a list of atomic lines with updated transition parameters. We meticulously removed lines that showed evidence of blending or of dependence on effective temperature. Using this line list, we obtained measurements of the light odd-Z elements Na and Al; the α elements Mg, Si, S, Ca, and Ti; the Fe-peak elements Sc, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; and the n-capture elements Sr, Y, Zr, Ba, La, Ce, Pr, Nd, and Eu. In particular, our investigation includes the bona fide tracer of the s-process Ba, its r-process counterpart Eu, and the poorly studied rare earth Pr. Using stars in common with other HR literature investigations, we brought abundance measurements of another 85 RRLs (65 RRab, 20 RRc) into our chemical abundance scale. We used these HR, high quality measurements to probe the chemical evolution history of the Halo, and also to compare it to the other Galactic components and nearby dwarf galaxies. In this regard, the RRLs present the unique advantage of being old tracers with precise distance measurements, while other commonly employed stellar populations have very poorly constrained ages and distances. We found that a sample of metal-rich, α-poor RRLs is present at low Galactic heights. In the [α/Fe] versus [Fe/H] plane, this sample displays a smooth continuity with the rest of the RRLs in the Halo, pointing to a shared origin. Furthermore, this sample traces the metal-rich tail of the Halo that is poorly covered by other stellar tracers and displays a behavior with metallicity that is at odds with the other Galactic components (Bulge and Disk), but similar to the Sagittarius dwarf spheroidal. t We performed the same comparison for the other chemical species and discussed the effects of NLTE corrections, different line lists, and systematics due to evolutionary effects. By applying the same HR analysis to a sample of six non-variable giants and seven field dwarfs, we showed that differences in abundance, especially for α elements, between field stars of varied ages and the RRLs are intrinsic. The ∆S method provides metallicity estimates for RRLs with LR spectra. The number of available LR spectra for RRLs is about two orders of magnitude larger than HR spectra. Therefore, a finely tuned LR metallicity estimator is an extremely valuable counterpart to the more accurate but scarcer HR measurements. The ∆S method results are widely used in the calibration of photometric methods such as Fourier parameter decomposition. Until recently, this method was only applied to RRab stars outside the phase interval of the rising branch of the light curve and relied on the metallicity scale of Zinn & West (1984), which is not linear with modern HR measurements. Using the HR results for 143 RRLs (111 RRab, 32 RRc), we developed a brand new calibration of the ∆S method in the same metallicity scale as our HR results. It can be applied to the whole pulsation cycle of both RRab and RRc pulsators, with preliminary evidence that it is valid for the RRd as well. We applied this new calibration to a sample of 7768 RRLs (5196 RRab, 2572 RRc) for which no HR spectra are available and found excellent agreement with the results derived in HR. The complete sample with 247 RRLs studied in HR is the largest and most homogeneous data set of old stellar tracers studied in the literature. It provides constrains on all major chemical families for the oldest stellar component in the Galaxy covering 3 dex in metallicity. Our sample covers a significant fraction of the Halo starting at a Galactocentric distance of approximately 4 kpc, with HR measurements reaching 26 kpc, and LR metallicity estimates extending as far as 150 kpc. These results are crucial not only for Galactic formation modeling but also in the investigation of nucleosynthetic processes due to its homogeneity in both abundance scale and age, its spatial distribution, and its wide metallicity coverage. Furthermore, the new calibration of the ∆S method is applicable, for the first time, to RRLs of all pulsation modes observed at any phase, without the requirement of detailed photometric studies or carefully timed observations. The work performed in this thesis has also been partially or fully employed by our group in various investigations, including probing the fine structure of the Bailey diagram and its relation to the Oosterhoff dichotomy, the development of new barycentric velocity estimators and velocity curve templates, and a new calibration of the Fourier parameter decomposition method using our new metallicity scale.O Halo Gal´actico ´e o componente da Via L´actea que preserva os tra¸cos mais claros da acre¸c˜ao de sat´elites respons´avel pela forma¸c˜ao da Gal´axia de acordo com o paradigma Λ-CDM. A natureza desses sat´elites primordiais, sua rela¸c˜ao com as gal´axias an˜as atualmente distribu´ıdas ao redor da Via L´actea, e a fra¸c˜ao da popula¸c˜ao estelar do Halo que se originou neles s˜ao todas quest˜oes em aberto. A abundˆancia de diferentes elementos qu´ımicos traz informa¸c˜oes sobre o tempo de enriquecimento e parˆametros f´ısicos (por exemplo, fun¸c˜ao de distribui¸c˜ao de massa, taxa de forma¸c˜ao de estrelas) do sistema estelar onde uma determinada estrela se formou. Assim, o estudo de uma variedade de elementos ´e fundamental para identificar adequadamente os sistemas progenitores de diferentes estrelas, para restringir modelos de forma¸c˜ao gal´actica e para compreender a pr´opria nucleoss´ıntese estelar. Em particular, faltam dandos observacionais para as abundˆancias das esp´ecies mais pesadas assim como idades bem determinadas para as estrelas utilizadas. As estrelas do tipo RRL tˆem idades ≥ 10 Gyr e apresentam pulsa¸c˜oes radiais com rela¸c˜oes per´ıodo-luminosidade bem definidas no infravermelho. Essas rela¸c˜oes permitem uma determina¸c˜ao precisa da distˆancia da estrela. Assim, elas s˜ao excelentes tra¸cadoras da estrutura qu´ımica do Halo. As RRLs s˜ao classificadas de acordo com seu modo de pulsa¸c˜ao, com RRab apresentando o modo fundamental, RRc o primeiro harmˆonico, e RRd um modo misto. Estudos espetrosc´opicos em alta resolu¸c˜ao (HR) dessas estrelas s˜ao limitados. Tais estudos s˜ao essenciais para a investiga¸c˜ao de diversas esp´ecies qu´ımicas como os elementos α, aquelas do pico do Fe, e aquelas produzidos por captura de nˆeutrons. Eles tamb´em s˜ao necess´arios para a calibra¸c˜ao de ´ındices fotom´etricos e estimativas de metalicidade baseadas em espectroscopia de baixa resolu¸c˜ao, que podem ser aplicados a grandes amostras. Neste trabalho, utilizamos dados coletados com nove espectr´ografos HR instalados em oito grandes telesc´opios diferentes e por duas pesquisas em baixa resolu¸c˜ao (LR, SEGUESDSS, LAMOST). Aplicamos a metodologia da espectroscopia HR a uma amostra de 162 RRLs (138 RRab, 23 RRc, 1 RRd) cobrindo uma ampla gama em metalicidade ([Fe/H] de -3,2 a 0,2). Nossa investiga¸c˜ao espectrosc´opica ´e baseada em uma lista de linhas atˆomicas com parˆametros de transi¸c˜ao atualizados. Removemos meticulosamente as linhas que mostravam evidˆencia de blending ou dependˆencia da temperatura efetiva. Usando esta lista de linhas, obtivemos medi¸c˜oes dos elementos leves Na e Al; os elementos α Mg, Si, S, Ca, e Ti; os elementos do pico do Fe Sc, V, Cr, Mn, Fe, Co, Ni, Cu, e Zn; e os elementos formados pela captura de nˆeutrons Sr, Y, Zr, Ba, La, Ce, Pr, Nd, e Eu. Em particular, nossa investiga¸c˜ao inclui Ba, formado principalemente pelo processo s, Eu, seu hom´ologo do processo r, e Pr que ´e pouco estudado. Usando estrelas em comum com outras investiga¸c˜oes da literatura HR, transformamos medidas de abundˆancia de outras 85 RRLs (65 RRab, 20 RRc) para nossa escala de abundˆancia qu´ımica. Utilizamos estas medidas HR de alta qualidade para sondar a hist´oria da evolu¸c˜ao qu´ımica do Halo, e tamb´em para compar´a-la com outros componentes Gal´acticos e gal´axias an˜as pr´oximas. A este respeito, os RRLs apresentam a vantagem ´unica de serem velhas e terem distˆancia bem determinadas, enquanto outras popula¸c˜oes estelares geralmente empregadas tˆem idades e distˆancias amb´ıguas. Descobrimos que uma amostra de RRLs ricas em metal e pobres em elementos α existe em alturas gal´acticas baixas. No plano [α/Fe] versus [F No plano [α/Fe] versus [Fe/H], esta amostra exibe uma continuidade com o resto dos RRLs no Halo, sugerindo uma origem comum. Al´em disso, esta amostra tra¸ca a popula¸c˜ao rica em metal do Halo que ´e mal representada por outras popula¸c˜oes estelares e exibe um comportamento com metalicidade em desacordo com os outros componentes gal´acticos (Bojo e Disco), mas semelhante a an˜a esferoidal em Sagit´ario. Realizamos a mesma compara¸c˜ao para as outras esp´ecies qu´ımicas e discutimos os efeitos das corre¸c˜oes NLTE, diferentes listas de linhas e efeitos sistem´aticos que surgem da evolu¸c˜ao estelar. Ao aplicar a mesma an´alise HR a uma amostra de seis gigantes n˜ao-vari´aveis e sete an˜as de campo, mostramos que as diferen¸cas de abundˆancia, especialmente para elementos α, entre as estrelas de campo de idades variadas e as RRLs s˜ao intr´ınsecas. O m´etodo ∆S fornece estimativas de metalicidade para RRLs com espectros LR. O n´umero de espectros LR dispon´ıveis para RRLs ´e cerca de duas ordens de magnitude maior do que espectros HR. Portanto, um estimador de metalicidade LR cuidadosamente calibrado ´e uma alternativa extremamente valiosa j´a que medidas HR, embora mais mais precisas, s˜ao tamb´em mais escassas. Os resultados do m´etodo ∆S s˜ao amplamente utilizados na calibra¸c˜ao de m´etodos fotom´etricos como a decomposi¸c˜ao de parˆametros de Fourier. At´e recentemente, este m´etodo era v´alido somente para a estrelas RRab fora do intervalo de fase do ramo ascendente da curva de luz e se baseava na escala de metalicidade de Zinn & West (1984), que n˜ao ´e linear com as medidas modernas em HR. Usando os resultados HR para 143 RRLs (111 RRab, 32 RRc), desenvolvemos uma nova calibra¸c˜ao do m´etodo ∆S na mesma escala de metalicidade que nossos resultados HR. Ela pode ser aplicado a todo o ciclo de pulsa¸c˜ao tanto das vari´aveis RRab quanto das RRc, com resultados preliminares mostrando que ela ´e v´alido tamb´em para as vari´aveis RRd. Aplicamos esta nova calibra¸c˜ao a uma amostra de 7768 RRLs (5196 RRab, 2572 RRc) que n˜ao possuem espectros HR dispon´ıveis e encontramos excelente concordˆancia com os resultados derivados em HR. A amostra completa com 247 RRLs estudados em HR ´e o maior e mais homogˆeneo conjunto de dados de estrelas velhas estudadas na literatura. Ela fornece dados a todas as principais fam´ılias qu´ımicas para o componente estelar mais antigo da Gal´axia, cobrindo 3 dex em metalicidade. Nossa amostra cobre uma fra¸c˜ao significativa do Halo come¸cando em uma distˆancia Galactocˆentrica de aproximadamente 4 kpc, com medidas HR alcan¸cando 26 kpc, e estimativas de metalicidade em LR chegando a 150 kpc. Estes resultados s˜ao cruciais n˜ao apenas para a modelagem da forma¸c˜ao gal´actica, mas tamb´em para a investiga¸c˜ao dos processos nucleossint´eticos devido a sua homogeneidade tanto na escala de abundˆancia como na idade, sua distribui¸c˜ao espacial, e sua ampla cobertura em metalicidade. Al´em disso, a nova calibra¸c˜ao do m´etodo ∆S ´e aplic´avel, pela primeira vez, `as RRLs de todos os modos de pulsa¸c˜ao observadas em qualquer fase, sem a exigˆencia de estudos fotom´etricos detalhados ou observa¸c˜oes cuidadosamente cronometradas. O trabalho realizado nesta tese tamb´em foi parcial ou totalmente empregado por nosso grupo em v´arias investiga¸c˜oes, incluindo a sondagem da estrutura fina do diagrama Bailey e sua rela¸c˜ao com a dicotomia de Oosterhoff, o desenvolvimento de novos estimadores de velocidade baricˆentrica e modelos de curvas de velocidade, e uma nova calibra¸c˜ao do m´etodo de decomposi¸c˜ao de parˆametros de Fourier usando nossa nova escala de metalicidade

QJava: A Monadic Java Library for Quantum Programming

To help the understanding and development of quantum algorithms there is an effort focused on the investigation of new semantic models and programming languages for quantum computing. Researchers in computer science have the challenge of deve loping programming languages to support the creation, analysis, modeling and simulation of high level quantum algorithms. Based on previous works that use monads inside the programming language Haskell to elegantly explain the odd characteristics of quantum computation (like superposition and entanglement), in this work we present a monadic Java library for quantum programming. We use the extension of the programming language Java called BGGA Closure, that allow the manipulation of anonymous functions (closures) inside Java. We exemplify the use of the library with an implementation of the Toffoli quantum circuit

O que mudou no cenário do trabalho infantil depois do PETI e o que ainda precisa mudar?

Monografia (especialização)—Universidade de Brasília, 2014.Este trabalho tem como objetivo fazer uma análise da atuação do PETI, desde sua implementação até os dias de hoje, na redução do percentual de trabalho infantil no Brasil, levando em consideração as desigualdades de gênero e raça. Para isso, apresenta a concepção contemporânea de criança, a forma como o trabalho infantil prejudica o desempenho escolar, o que mudou no cenário do trabalho infantil depois da atuação do PETI e como o plano trata as questões ligadas a gênero e raça. Desta forma, foram analisadas as duas edições do PETI, bem como dados do IBGE e IPEA. A análise desses documentos revela que uma política pública como o PETI é de suma importância para a erradicação do trabalho infantil. Entretanto, apresenta limitações quanto ao combate as desigualdades de gênero e raça e não contempla todas as formas de trabalho infantil. __________________________________________________________________________ ABSTRACTThis study aims to analyze to what extent has PETI (Program for the Eradication of Child Labor), helped reduce the child labor in Brazil since its inception, taking into account inequalities of gender and race. To do so, this paper presents the contemporary conception of "child", as well as how child labor affects school performance, how has child labor been affected after PETI implantation and how the plan addresses issues related to gender and race. Thus, the two editions of PETI along with IBGE (Brazilian Institute of Geography and Statistics) and IPEA (Institute for Applied Economic Research) were analyzed. Analysis of said documents shows PETI is of paramount importance for the eradication of child labor in Brazil. However, it has limitations on tackling inequalities of gender and race and does not include all forms of child labor

StarHorse: A Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars

Understanding the formation and evolution of our Galaxy requires accurate distances, ages and chemistry for large populations of field stars. Here we present several updates to our spectro-photometric distance code, that can now also be used to estimate ages, masses, and extinctions for individual stars. Given a set of measured spectro-photometric parameters, we calculate the posterior probability distribution over a given grid of stellar evolutionary models, using flexible Galactic stellar-population priors. The code (called {\tt StarHorse}) can acommodate different observational datasets, prior options, partially missing data, and the inclusion of parallax information into the estimated probabilities. We validate the code using a variety of simulated stars as well as real stars with parameters determined from asteroseismology, eclipsing binaries, and isochrone fits to star clusters. Our main goal in this validation process is to test the applicability of the code to field stars with known {\it Gaia}-like parallaxes. The typical internal precision (obtained from realistic simulations of an APOGEE+Gaia-like sample) are $\simeq 8\%$ in distance, $\simeq 20\%$ in age,$\simeq 6\$ in mass, and $\simeq 0.04$ mag in $A_V$. The median external precision (derived from comparisons with earlier work for real stars) varies with the sample used, but lies in the range of $\simeq [0,2]\%$ for distances, $\simeq [12,31]\%$ for ages, $\simeq [4,12]\%$ for masses, and $\simeq 0.07$ mag for $A_V$. We provide StarHorse distances and extinctions for the APOGEE DR14, RAVE DR5, GES DR3 and GALAH DR1 catalogues.Comment: 21 pages, 12 figures, accepte

Analysis of the ALS1 and HWP1 genes from clinical isolates of Candida albicans / Análise de genes ALS1 e HWP1 em isolados clínicos de Candida albicans

Candida albicans has several virulence factors including the adhesins, which are codified for ALS1 and HWP1 genes. Here, we evaluate the frequency of those genes in clinical isolates of C. albicans. We analyzed 73 clinical isolates, including 19 vaginal and 53 oral samples. PCR approach was used to detect the genes. The presence of the ALS1 gene was identified in 26.39% of all strains, while the HWP1 gene was present in 56.94%. The ALS1 gene was predominant between vaginal samples and HWP1 was more abundant in the oral samples. These results suggest distinct virulence profiles from C. albicans related to different sites of infection and colonization.

O término de tratamento em psicoterapia psicanalítica

O presente artigo descreve algumas considerações a respeito do processo de término em psicoterapia psicanalítica, encontradas na literatura. O objetivo é discorrer sobre aspectos e recomendações que caracterizam a fase final do tratamento, considerando que a mesma é percebida de forma singular pela dupla: terapeutapaciente. Alguns autores destacam a capacidade do ego do paciente, o alcance de objetivos determinados na terapia, a superação de ansiedades e inibições, entre outros, como indicadores para a conclusão do tratamento. Tais critérios e demais questionamentos serão descritos ao longo deste estudo, contemplando principalmente o fechamento integral do processo, observando brevemente alguns aspectos relacionados às interrupções. O fim da terapêutica desperta, tanto em quem se trata quanto nos profissionais, angústias primitivas que devem ser elaboradas por ambos, portanto, reconhecidas e trabalhadas ao máximo durante o tratamento.This article compiles some considerations about the end of the process in psychoanalytic psychotherapy, found in the literature. The objective is to discuss aspects and recommendations that characterize the final phase of the treatment considering that it is perceived in a unique way by each of the dual therapist / patient. Some authors emphasize the capacity of the ego, the achievement of determined goals, the overcoming of anxieties and inhibitions, among others, as indicators for the conclusion of this modality of psychological care. These criteria and other questions will be better described throughout this study, contemplating the complete closure, that is, without stopping the interruptions. The end of the therapy awakens, both in those who are treated and in the professionals, primitive anxieties that must be elaborated by both, therefore, recognized and worked to the maximum during the treatment

Physical Exercise During Pregnancy Prevents Cognitive Impairment Induced by Amyloid-ß in Adult Offspring Rats

Alzheimer’s disease (AD) is the main aging-associated neurodegenerative disorder and is characterized by mitochondrial dysfunction, oxidative stress, synaptic failure, and cognitive decline. It has been a challenge to find disease course-modifying treatments. However, several studies demonstrated that regular physical activity and exercise are capable of promoting brain health by improving the cognitive function. Maternal lifestyle, including regular exercise during pregnancy, has also been shown to influence fetal development and disease susceptibility in adulthood through fetal metabolism programming. Here, we investigated the potential neuroprotective role of regular maternal swimming, before and during pregnancy, against amyloid-β neurotoxicity in the adult offspring. Behavioral and neurochemical analyses were performed 14 days after male offspring received a single, bilateral, intracerebroventricular (icv) injection of amyloid-β oligomers (AβOs). AβOs-injected rats of the sedentary maternal group exhibited learning and memory deficits, along with reduced synaptophysin, brain-derived neurotrophic factor (BDNF) levels, and alterations of mitochondrial function. Strikingly, the offspring of the sedentary maternal group had AβOs-induced behavioral alterations that were prevented by maternal exercise. This effect was accompanied by preventing the alteration of synaptophysin levels in the offspring of exercised dams. Additionally, offspring of the maternal exercise group exhibited an augmentation of functional mitochondria, as indicated by increases in mitochondrial mass and membrane potential, α-ketoglutarate dehydrogenase, and cytochrome c oxidase enzymes activities. Moreover, maternal exercise during pregnancy induced long-lasting modulation of fusion and fission proteins, Mfn1 and Drp1, respectively. Overall, our data demonstrates a potential protective effect of exercise during pregnancy against AβOs-induced neurotoxicity in the adult offspring brain, by mitigating the neurodegenerative process triggered by Alzheimer-associated AβOs through programming the brain metabolism.This study was supported by the Pró-Reitoria de Pesquisa/Universidade Federal do Rio Grande do Sul (PROPESQ/UFRGS). CPK is a PhD Postgraduate student in Biological Sciences – Biochemistry receiving grants from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). CM received grants from CNPq (Universal 442406/2014-2 and INCT 465671/2014-4)

Closed doors: predictors of stress, anxiety, depression, and PTSD during the onset of COVID-19 pandemic in Brazil

BACKGROUND: The rise in mental health problems in the population directly or indirectly because of the coronavirus disease 2019 (COVID-19) pandemic is a major concern. The aim of this study was to investigate and compare independent predictors of symptoms of stress, anxiety, depression, and posttraumatic stress disorder (PTSD) in Brazilians one month after the implementation of measures of social distancing. METHODS: This cross-sectional study was performed using a web-based survey. The Depression, Anxiety, and Stress Scale (DASS-21) and PTSD Checklist for DSM-5 (PCL-5) were the outcomes. Data were gathered regarding demographics, social distancing, economic problems, exposure to the news of the pandemic, psychiatric history, sleep disturbances, traumatic situations, and substance use. The Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) was also administered. The predictors of the symptoms were investigated using hierarchical multiple linear regression. RESULTS: Of a sample of 3587 participants, approximately two-thirds considered that their mental health worsened after the beginning of the social restriction measures. The most important predictors of the symptoms investigated were the intensity of the distress related to the news of the pandemic, younger age, current psychiatric diagnosis, trouble sleeping, emotional abuse or violence, and economic problems. CONCLUSIONS: These results confirmed the hypothesis that the pandemic impacted the mental health of the population and indicated that the level of distress related to the news was the most important predictor of psychological suffering