Synthetic properties of bright metal-poor variables. I. "Anomalous" Cepheids

We present new grids of evolutionary models for the so-colled ``Anomalous'' Cepheids (ACs), adopting Z=0.0001 and various assumptions on the progenitor mass and mass-loss efficiency. These computations are combined with the results of our previous set of pulsation models and used to build synthetic populations of the predicted pulsators as well as to provide a Mass-Luminosity relation in the absence of mass-loss. We investigate the effect of mass-loss on the predicted boundaries of the instability strip and we find that the only significant dependence occurs in the Period-Magnitude plane, where the synthetic distribution of the pulsators is, on average, brighter by about 0.1 mag than the one in absence of mass-loss. Tight Period-Magnitude relations are derived in the K band for both fundamental and first overtone pulsators, providing a useful tool for distance evaluations with an intrinsic uncertainty of about 0.15 mag, which decreases to about 0.04 mag if the mass term is taken into account. The constraints provided by the evolutionary models are used to derive evolutionary (i.e, mass-independent) Period-Magnitude-Color relations which provide distance determinations with a formal uncertainty of the order of about 0.1 mag, once the intrinsic colors are well known. We also use model computations from the literature to investigate the effect of metal content both on the instability strip and on the evolutionary Period-Magnitude-Color relations. Finally, we compare our theoretical predictions with observed variables and we confirm that a secure identification of actual ACs requires the simultaneous information on period, magnitude and color, that also provide constraints on the pulsation mode.Comment: accepte

Post-exercise recovery methods

Post-exercise recovery is a key factor within every physical training program for athletes and non-athletes alike, as well as coaches and health professionals. Thus, knowledge on the post-exercise recovery process and the efficacy of the recovery modalities in enhancing between-training session (to increase training frequency and/or training loads qualitatively) is essential. Therefore, prophylactic or therapeutic interventions that might reduce the negative effects of exercise-induced muscle damage, thereby speeding recovery, are of great interest to researchers, coaches and athletes. As such, the purpose of this review was to describe the physiological responses to post-exercise recovery modalities currently used to aid athlete recovery during the training process, and consequently enhance performance.A recuperação pós-exercício é de extrema relevância dentro de todo programa de condicionamento físico, tanto para praticantes e atletas, como para técnicos e diversos profissionais ligados à área da saúde. Nesse sentido, o conhecimento a respeito da recuperação pós-exercício e dos vários métodos utilizados com intuito de acelerar o processo de recuperação (para suportar mais frequentes e/ou maiores cargas de treinamento com mais qualidade) torna-se essencial. Dessa forma, as intervenções utilizadas de forma profilática e/ou terapêutica com o intuito de amenizar os efeitos negativos das lesões musculares causadas pelo exercício físico e, assim, otimizar a recuperação são de grande interesse para pesquisadores, técnicos e atletas. Em vista disso, o objetivo da presente revisão de literatura é reunir informações que permitam descrever as respostas fisiológicas frente aos métodos de recuperação pós-exercícios, com a finalidade de melhorar tanto o processo de treinamento físico como o rendimento.Universidade Federal de São Paulo (UNIFESP)Universidade Federal de Santa CatarinaUniversidade do Estado de Santa Catarina Departamento de Educação FísicaUNIFESPSciEL

Intensidade de exercício correspondente ao VO2max durante o ciclismo: análise de diferentes critérios em indivíduos treinados

O objetivo deste estudo foi comparar a intensidade de exercício correspondente ao VO2max (IVO2max) durante o ciclismo utilizando quatro diferentes critérios. A IVO2max foi determinada em 10 ciclistas treinados (VO2max = 64,5 ± 5,9 ml.kg¹.min¹) através dos seguintes critérios: 1) Submáximo - exercício incremental (SUB-INC): a IVO2max foi determinada através da extrapolação da relação VO2 x intensidade a partir das cargas abaixo do limiar de lactato durante o exercício incremental; 2) Submáximo - exercício constante (SUB-CON): a IVO2max foi determinada através da extrapolação da relação VO2 x intensidade a partir dos valores de VO2 no final do sexto minuto durante dois exercícios de carga constante (50 e 70%VO2max); 3) Potência máxima - teste incremental (MAX-PMAX): a IVO2max foi considerada como a maior intensidade mantida durante o teste incremental e; 4) Máximo - VO2max (MAX-VO2max): a IVO2max foi considerada como a menor intensidade durante o exercício incremental onde o VO2max foi alcançado. A IVO2max (W) não foi significantemente diferente entre todos os crité- rios (SUB-INC = 327,3 + 43,6; SUB-CON = 321,9 + 38,5; MAX-PMAX = 349,1 + 34,1; MAX-VO2max = 342,5 + 36,0). Entretanto, verificou-se uma grande variabilidade intra-individual nos valores de IVO2max, principalmente entre os critérios máximos e submáximos. Concluímos que os critérios analisados neste estudo podem determinar IVO2max com diferentes significados fisiológicos. Portanto, a escolha do critério para a determinação da IVO2max deve ser feita com base na sua finalidade dentro do processo de avaliação (predição de performance, controle ou prescrição do treinamento) e/ou da disponibilidade de equipamentos para a análise de gases.The purpose of this study was to compare values of VO2max (IVO2max) obtained using four different criteria. IVO2max was determined in ten trained male cyclists (VO2max = 64.5 + 5.9 ml.kg-1.min-1) in: 1) Submaximal . incremental exercise (SUB-INC). IVO2max was determined by extrapolation of the submaximal VO2 x workload relationship, using the sub-LT stages from incremental test; 2) Submaximal . constant workload exercise (SUB-CON). IVO2max was determined by extrapolation of the submaximal VO2 x workload relationship, using the final VO2 values during constant workload tests (50 and 70%VO2max); 3) Maximal Power . incremental test (MAX-PMAX): IVO2max was considered as the highest workload sustained during incremental test and; 4) Maximal - VO2max (MAX-VO2max) IVO2max was determined as the lowest workload at which VO2max was attained during the incremental test. No significant differences were found among the IVO2max derived values (W) using the different methods (SUB-INC = 327.3 + 43.6; SUB-CON = 321.9 + 38.5; MAX-PMAX = 349.1 + 34.1; MAX-VO2max = 342.5 + 36.0). However, it was verified a high intraindividual variability in the IVO2max values, mainly between submaximal and maximal criteria. It was concluded that the criteria analyzed in the present study, might determine IVO2max with different physiological meanings. Therefore, the choice of any particular criterion should be done in accordance with the main purpose of the evaluation process (performance prediction, control or prescription of training)

Candidate HIV-1 Tat vaccine development: From basic science to clinical trials

No abstract available

On the stellar content of the Carina dwarf spheroidal galaxy

We present U,B,V,I photometry of the Carina dwarf spheroidal galaxy, based on more than 4,000 CCD images. Special attention was given to the photometric calibration, and the precision for the B,V,I bands is better than 0.01 mag. We compared in the V,B-V and V,B-I color-magnitude diagrams (CMDs) Carina with three Globular Clusters (GCs, M53, M55, M79). We find that only the more metal-poor GCs (M55, [Fe/H]=-1.85; M53, [Fe/H]=-2.02 dex) provide a good match with the Carina giant branch. We performed a similar comparison in the V,V-I CMD with three SMC intermediate-age clusters (IACs, Kron3, NGC339, Lindsay38). We find that the color extent of the SGB of the two more metal-rich IACs (Kron3, [Fe/H]=-1.08; NGC339, [Fe/H]=-1.36 dex) is smaller than the range among Carina's intermediate-age stars. However, the ridge line of the more metal-poor IAC (Lindsay38, [Fe/H]=-1.59 dex) agrees quite well with the Carina intermediate-age stars. These findings indicate that Carina's old stellar population is metal-poor and seems to have a limited spread in metallicity (Delta [Fe/H]=0.2--0.3 dex). Carina intermediate-age stars can hardly be more metal-rich than Lindsay38 and its spread in metallicity appears modest. We also find that the synthetic CMD constructed assuming a metallicity spread of 0.5 dex for intermediate-age stars predicts evolutionary features not supported by observations. The above results are at odds with recent spectroscopic investigations suggesting that Carina stars cover a broad range in metallicity (Delta [Fe/H]~1--2 dex). We present a new method to estimate the metallicity of complex stellar systems using the difference in color between the red clump and the middle of the RR Lyrae instability strip. The observed colors of Carina's evolved stars indicate a metallicity of [Fe/H]=-1.70+-0.19 dex, which agrees quite well with spectroscopic measurements.Comment: Accepted on PASP, 12 pages, 6 figure

First evidence of resistance to pyrethroid insecticides in Italian Aedes albopictus populations after 26 years since invasion

Aedes albopictus has spread during the last decades all over the world. This has increased significantly the risk of exotic arbovirus transmission (e.g. Chikungunya, Dengue, and Zika) also in temperate areas, as testified by the Chikungunya 2007- and 2017-outbreaks in north-east and central Italy. Insecticides represent a main tool for limiting the circulation of these mosquito-borne viruses. The aim of the present study is to start filling the current gap of knowledge on pyrethroid insecticide resistance of European Ae. albopictus populations focusing on populations from Italy, Albania and Greece

Risk Factors of Right Ventricular Dysfunction and Adverse Cardiac Events in Patients with Repaired Tetralogy of Fallot

Aim: This study evaluates the risk factors associated with right ventricular (RV) dilation and dysfunction leading to pulmonary valve replacement (PVR) or adverse cardiac events in repaired Tetralogy of Fallot (rToF) patients. Methods: Data from all rToF patients who underwent magnetic resonance imaging (MRI) evaluation at our hospital between February 2007 and September 2020 were collected. Results: Three hundred and forty-two patients (60% males, 42% older than 18 years), with a median age of 16 years (IQR 13–24) at the time of MRI, were included. All patients underwent complete repair at a median age of 8 months (IQR 5–16), while palliation was performed in 56 patients (16%). One hundred and forty-four patients (42%) subsequently received pulmonary valve replacement (PVR). At the multivariate analysis, male gender was an independent predictor for significant RV dilation, RV and left ventricular (LV) dysfunction. Transventricular ventricular septal defect (VSD) closure and previous palliation significantly affected LV function and RV size, respectively. Male gender and the transventricular VSD closure were independent predictors for PVR. Conclusions: Male gender and surgical history (palliation, VSD closure approach) significantly affected the long-term outcomes in rToF patients and should be taken into consideration in the follow-up management and in PVR timing in this patient population

The Carina Project. V. The impact of NLTE effects on the iron content

We have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R~38,000) collected with UVES at ESO/VLT either in slit mode (5) or in fiber mode (39, FLAMES/GIRAFFE-UVES). The sample is more than a factor of four larger than any previous spectroscopic investigation of stars in dSphs based on high-resolution (R>38,000) spectra. We did not impose the ionization equilibrium between neutral and singly-ionized iron lines. The effective temperatures and the surface gravities were estimated by fitting stellar isochrones in the V, B-V color-magnitude diagram. To measure the iron abundance of individual lines we applied the LTE spectrum synthesis fitting method using MARCS model atmospheres of appropriate metallicity. We found evidence of NLTE effects between neutral and singly-ionized iron abundances. Assuming that the FeII abundances are minimally affected by NLTE effects, we corrected the FeI stellar abundances using a linear fit between FeI and FeII stellar abundance determinations. We found that the Carina metallicity distribution based on the corrected FeI abundances (44 RGs) has a weighted mean metallicity of [Fe/H]=-1.80 and a weighted standard deviation of sigma=0.24 dex. The Carina metallicity distribution based on the FeII abundances (27 RGs) gives similar estimates ([Fe/H]=-1.72, sigma=0.24 dex). The current weighted mean metallicities are slightly more metal poor when compared with similar estimates available in the literature. Furthermore, if we restrict our analysis to stars with the most accurate iron abundances, ~20 FeI and at least three FeII measurements (15 stars), we found that the range in iron abundances covered by Carina RGs (~1 dex) agrees quite well with similar estimates based on high-resolution spectra.Comment: Accepted for publication in PASP, 16 pages, 7 figures, 3 tables, 1 MR table Note: the electronic version of Table1 is included, but commented, in the tex fil

Moving Dirac nodes by chemical substitution

Dirac fermions play a central role in the study of topological phases, for they can generate a variety of exotic states, such as Weyl semimetals and topological insulators. The control and manipulation of Dirac fermions constitute a fundamental step toward the realization of novel concepts of electronic devices and quantum computation. By means of Angle-Resolved PhotoEmission Spectroscopy (ARPES) experiments and ab initio simulations, here, we show that Dirac states can be effectively tuned by doping a transition metal sulfide, BaNiS2, through Co/Ni substitution. The symmetry and chemical characteristics of this material, combined with the modification of the charge-transfer gap of BaCo1-xNixS2 across its phase diagram, lead to the formation of Dirac lines, whose position in k-space can be displaced along the Gamma - M symmetry direction and their form reshaped. Not only does the doping x tailor the location and shape of the Dirac bands, but it also controls the metal-insulator transition in the same compound, making BaCo1-xNixS2 a model system to functionalize Dirac materials by varying the strength of electron correlations

Hide and seek between Andromeda's halo, disk, and giant stream

Photometry in B, V (down to V ~ 26 mag) is presented for two 23' x 23' fields of the Andromeda galaxy (M31) that were observed with the blue channel camera of the Large Binocular Telescope during the Science Demonstration Time. Each field covers an area of about 5.1kpc x 5.1kpc at the distance of M31 ((m-M)o ~ 24.4 mag), sampling, respectively, a northeast region close to the M31 giant stream (field S2), and an eastern portion of the halo in the direction of the galaxy minor axis (field H1). The stream field spans a region that includes Andromeda's disk and the giant stream, and this is reflected in the complexity of the color magnitude diagram of the field. One corner of the halo field also includes a portion of the giant stream. Even though these demonstration time data were obtained under non-optimal observing conditions the B photometry, acquired in time-series mode, allowed us to identify 274 variable stars (among which 96 are bona fide and 31 are candidate RR Lyrae stars, 71 are Cepheids, and 16 are binary systems) by applying the image subtraction technique to selected portions of the observed fields. Differential flux light curves were obtained for the vast majority of these variables. Our sample includes mainly pulsating stars which populate the instability strip from the Classical Cepheids down to the RR Lyrae stars, thus tracing the different stellar generations in these regions of M31 down to the horizontal branch of the oldest (t ~ 10 Gyr) component.Comment: 59 pages, 26 figures, 12 tables, ApJ in pres