A complete census of HαH\alpha emitters in NGC 6397

We used a dataset of archival Hubble Space Telescope images obtained through the F555W, F814W and F656N filters, to perform a complete search for objects showing $H\alpha$ emission in the globular cluster NGC 6397. As photometric diagnostic, we used the $(V-H\alpha)_0$ color excess in the $(V-H\alpha)_0$-$(V-I)_0$ color-color diagram. In the analysed field of view, we identified 53 $H\alpha$ emitters. In particular, we confirmed the optical counterpart to 20 X-ray sources (7 cataclysmic variables, 2 millisecond pulsars and 11 active binaries) and identified 33 previously unknown sources, thus significantly enlarging the population of known active binaries in this cluster. We report the main characteristics for each class of objects. Photometric estimates of the equivalent width of the $H\alpha$ emission line, were derived from the $(V-H\alpha)_0$-excess and, for the first time, compared to the spectroscopic measurements obtained from the analysis of MUSE spectra. The very good agreement between the spectroscopic and photometric measures fully confirmed the reliability of the proposed approach to measure the $H\alpha$ emission. The search demonstrated the efficiency of this novel approach to pinpoint and measure $H\alpha$-emitters, thus offering a powerful tool to conduct complete census of objects whose formation and evolution can be strongly affected by dynamical interactions in star clusters.Comment: Accepted for publication by ApJ; 14 pages, 8 Figures, 1 Tabl

Oligodendrocyte differentiation and signaling after transferrin internalization: a mechanism of action

Oligodendrocytes are the cells producing the myelin membrane around the axons in the central nervous system and, although apotransferrin (aTf) is required for oligodendrocyte differentiation, the underlying mechanisms are not fully understood. Fyn tyrosine kinase, a member of the Src family of proteins, has been shown to play an important role in myelination by up-regulating the expression of myelin basic protein; however, a molecular link between aTf and Fyn kinase signaling pathway during oligodendrocytes differentiation has not been established yet. Our aim was to investigate whether Fyn kinase, MEK/ERK and PI3K/Akt signaling pathways are required for aTf-stimulation of oligodendrocyte differentiation and also to determine if the transferrin receptor is involved in these mechanisms. Treatment of primary cultures of oligodendroglial precursor cells with aTf leads to Fyn kinase activation by a mechanism that involves transferrin receptor. In turn, Fyn kinase activation promotes MEK-mediated transient phosphorylation of ERK1/2. On the other hand, transferrin receptor internalization also produces rapid and sustained activation of Akt, which involves phosphatidylinositol 3-kinase (PI3K) activation. Finally, aTf incorporated through clathrin-mediated endocytosis increases myelin basic protein, F3-contactin and β-tubulin through Fyn/MEK/ERK pathways, as well as an activation of the PI3K/Akt pathway. Our results also demonstrate that the activation of the pathways necessary for oligodendroglial precursor cell maturation is dependent on AP2 recruitment onto the plasma membrane for clathrin-mediated endocytosis of transferrin receptor.Fil: Perez, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentina; Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Departamento de Quimica Biologica. Cátedra de Química Biológica Patológica; Argentina;Fil: Fernandez, Natalia Cristina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina;Fil: Pasquini, Juana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentina

New insights upon the reproductive biology of the sea cucumber Holothuria tubulosa (Echinodermata, Holothuroidea) in the Mediterranean: Implications for management and domestication

Holothuria tubulosa is one of the most common sea cucumber species inhabiting the Mediterranean Sea. Due to its commercial interest for the international market, it has been harvested without proper management causing the overexploitation of its stocks. Inadequate management is also caused by lack of information on basic biology and ecology not allowing the estimating of the species vulnerability and resilience to growing anthropogenic pressures. In this paper, we have investigated basic life-history traits of H. tubulosa (population structure and reproductive cycle) in a population of Central-Western Mediterranean (Sardinia, Italy). A macroscopic maturity scale for both sexes was defined through an instrumental colorimetric analysis of the gonads and the ramification level of the gonad’s tubules, subsequently confirmed by histological analysis. The seasonal trend of the Gonado Somatic Index, the changes in color of the gonads and tubules ramification indicated that the spawning period of H. tubulosa was concentrated in summer with a peak in late August, closely related to the increase in water temperature. A synchronous development of the gonads, with a unique and short reproductive event during the year, was also detected. In conclusion, this study provides new evidence on the biological and ecological features of H. tubulosa, essential data for developing a scientifically-based stock assessment as well as conservative management at a local scale. Finally, we provided basic information for the domestication of broodstock in a conservative hatchery

Exosome-mediated transfer of miR-222 is sufficient to increase tumor malignancy in melanoma

BACKGROUND: Growing evidence is showing that metastatic cell populations are able to transfer their characteristics to less malignant cells. Exosomes (EXOs) are membrane vesicles of endocytic origin able to convey their cargo of mRNAs, microRNAs (miRs), proteins and lipids from donors to proximal as well as distant acceptor cells. Our previous results indicated that miR-221&222 are key factors for melanoma development and dissemination. The aim of this study was to verify whether the tumorigenic properties associated with miR-222 overexpression can be also propagated by miR-222-containing EXOs. METHODS: EXOs were isolated by UltraCentrifugation or Exoquick-TC(®) methods. Preparations of melanoma-derived vesicles were characterized by using the Nanosight™ technology and the expression of exosome markers analyzed by western blot. The expression levels of endogenous and exosomal miRNAs were examined by real time PCR. Confocal microscopy was used to evaluate transfer and uptake of microvesicles from donor to recipient cells. The functional significance of exosomal miR-222 was estimated by analyzing the vessel-like process formation, as well as cell cycle rates, invasive and chemotactic capabilities. RESULTS: Besides microvesicle marker characterization, we evidenced that miR-222 exosomal expression mostly reflected its abundance in the cells of origin, correctly paralleled by repression of its target genes, such as p27Kip1, and induction of the PI3K/AKT pathway, thus confirming its functional implication in cancer. The possible differential significance of PI3K/AKT blockade was assessed by using the BKM120 inhibitor in miR-222-transduced cell lines. In addition, in vitro cultures showed that vesicles released by miR-222-overexpressing cells were able to transfer miR-222-dependent malignancy when taken-up by recipient primary melanomas. Results were confirmed by antagomiR-221&222 treatments and by functional observations after internalization of EXOs devoid of these miRs

Carbon nanotubes effects on the relaxation properties and critical current densities of MgB2 superconductor

Addition of nonsuperconducting phases, such as carbon nanotubes, can modify the superconducting properties of MgB2 samples, improving the critical current density and upper critical field. A full understanding of the flux creep mechanism involved is crucial to the development of superconducting magnets in persistent mode, one of the main thrusts for the development of MgB2 wires. In this paper we present a creep study in bulk MgB2 samples, pure and with different amounts of carbon nanotubes additions. We conclude that the most consistent picture at low temperatures is a single vortex pinning regime, where the correlation length is limited by the grain size. We introduce a novel analysis that allows us to identify the region where the Anderson-Kim model is validFil: Pasquini, Gabriela. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales; Argentina;Fil: Serquis, Adriana Cristina. Comision Nacional de Energia Atomica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina;Fil: Moreno, Alejandro Javier. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales; Argentina;Fil: Serrano, German Dario. Comision Nacional de Energia Atomica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Patagonia Norte; Argentina;Fil: L. Civale. Los Alamos National Laboratory, Estados Unidos de América

Repercussions of COVID-19 pandemic impacts on non-metastatic HER2-negative breast cancer diagnosis and neoadjuvant treatment over patients’ quality of life and mental health/ Repercussões dos impactos da pandemia COVID-19 no diagnóstico e tratamento neoadjuvante de câncer de mama HER2-negativo não metastático sobre a qualidade de vida e saúde mental das pacientes

OBJECTIVE: To understand if COVID-19 pandemic impacts on delays in non-metastatic HER2-negative breast cancer diagnosis and in the beginning/development of neoadjuvant chemotherapy, as well as on changes in treatment plan to Paclitaxel intensification doses, impaired patients’ quality of life and mental health. METHODS: This is a cross-sectional study of 67 women diagnosed with non-metastatic HER2-negative breast cancer during the first sixteen months of COVID-19 pandemic and receiving neoadjuvant treatment due to pandemic impossibility of immediate definitive cancer surgery following the neoplasm diagnosis. Sociodemographic, Functional Assessment of Cancer Therapy Scale - General, Beck Anxiety and Depression Inventory were used for outcomes assessment. Inferential analysis was performed by Mann-Whitney, Pearson's chi-squared, and Fisher's exact tests. The adopted significance was 5%. RESULTS: The study revealed that the oncological diagnosis delays caused a worsening of the patients' physical (8 x 21; p = 0.001), functional (13 x 21; p = 0.03) and general (61 x 83; p = 0.004) well-being; retardment in the beginning of neoadjuvant chemotherapy decreased physical well-being (13 x 21; p = 0.01). Changes in treatment plan, to Paclitaxel doses intensification, had a negative effect on functional well-being (20 x 25.5; p = 0.04). COVID-19 pandemic impacts on neoplasm diagnosis and neoadjuvant treatment delays were also associated with psychosocial manifestations, including higher levels of severe anxiety (60% x 14.5%; p = 0.03 and 40% x 14%; p = 0.04) and depression (40% x 3.2%; p = 0.004 and 60% x 5.3%; p = 0.03) respectively. CONCLUSION: The present study shows that COVID-19 pandemic impacts on non-metastatic HER2-negative breast cancer patients’ diagnosis and neoadjuvant chemotherapy impaired patients' quality of life and mental health

Increased psychiatric morbidity in female outpatients with skin lesions on visible parts of the body.

Psychiatric disorders are frequent among patients with skin diseases. We aimed at identifying factors associated with psychiatric morbidity in dermatological outpatients. All adults attending the outpatient clinics of a dermatological hospital on predetermined days were given the 12-item General Health Questionnaire. The dermatologists indicated the diagnosis and location of skin lesions and rated the disease severity. A total of 1389 patients were asked to take part in the study. Of the 722 who accepted, 389 had a complete set of data and were included in the analysis. To verify the representativeness of our sample, we used the administrative registries to compare participants with the total population of patients who attended the clinics during the same period, and we examined the distribution of missing data. There was a tendency towards a younger age in the sample studied, but no evidence of substantial selection bias. The prevalence of psychiatric morbidity was 20.6%. We found higher probability of psychiatric disorders in women, controlling for age, clinical severity and localization of lesions. In women, but not in men, the prevalence of psychiatric morbidity was higher in patients with lesions on the face or hands. Given that the identification and appropriate management of psychiatric morbidity are important, it seems that the dermatologist should be particularly alert to the possibility of a concurrent psychiatric disorder in women with lesions on the face or hands