Studying the evolution of AGB stars in the Gaia epoch

We present asymptotic giant branch (AGB) models of solar metallicity, to allow the interpretation of observations of Galactic AGB stars, whose distances should be soon available after the first release of the Gaia catalogue. We find an abrupt change in the AGB physical and chemical properties, occurring at the threshold mass to ignite hot bottom burning,i.e. $3.5M_{\odot}$. Stars with mass below $3.5 M_{\odot}$ reach the C-star stage and eject into the interstellar medium gas enriched in carbon , nitrogen and $^{17}O$. The higher mass counterparts evolve at large luminosities, between $3\times 10^4 L_{\odot}$ and $10^5 L_{\odot}$. The mass expelled from the massive AGB stars shows the imprinting of proton-capture nucleosynthesis, with considerable production of nitrogen and sodium and destruction of $^{12}C$ and $^{18}O$. The comparison with the most recent results from other research groups are discussed, to evaluate the robustness of the present findings. Finally, we compare the models with recent observations of galactic AGB stars, outlining the possibility offered by Gaia to shed new light on the evolution properties of this class of objects.Comment: 21 pages, 11 figure, 3 tables, accepted for publication in MNRAS (2016 July 11

Теоретические аспекты HR-Management на предприятиях: методы и стили управления

The article discusses the theoretical aspects of HR-Management, namely: a set of principles, methods, tools and styles of targeted impact on staff that maximize the use of his intellectual and physical abilities when performing labor functions to achieve the goals of the organization. It has been established that the development of personnel is ensured by measures related to the assessment of personnel with a view to their production adaptation, attestation and certification of personnel, planning a career for employees and specialists, and stimulating staff development. It was determined that personnel management provides a single and integrated impact on the organization’s personnel through the use of management methods and styles, without which it is impossible to effectively manage the entire organization.У статті розглядаються теоретичні аспекти HR-Management, а саме: сукупність принципів, методів, засобів і стилів цілеспрямованого впливу на персонал, що забезпечують максимальне використання його інтелектуальних і фізичних здібностей при виконанні трудових функцій для досягнення цілей організації. Встановлено, що розвиток персоналу забезпечується заходами, пов'язаними з оцінюванням кадрів з метою їх виробничої адаптації, атестації та сертифікації персоналу, плануванням трудової кар'єри робітників і фахівців, стимулюванням розвитку персоналу тощо. Визначено, що управління персоналом забезпечує єдиний і комплексний вплив на персонал організації через використання методів та стилів управління, без яких неможливо здійснювати ефективне керівництво всією організацією.В статье рассматриваются теоретические аспекты HR-Management, а именно: совокупность принципов, методов, средств и стилей целенаправленного воздействия на персонал, которые обеспечивают максимальное использование его интеллектуальных и физических способностей при выполнении трудовых функций для достижения целей организации. Установлено, что развитие персонала обеспечивается мерами, связанными с оценкой кадров с целью их производственной адаптации, аттестации и сертификации персонала, планированием трудовой карьеры работников и специалистов, стимулированием развития персонала. Определено, что управление персоналом обеспечивает единое и комплексное воздействие на персонал организации через использование методов и стилей управления, без которых невозможно осуществлять эффективное руководство всей организацией

Clear evidence for the presence of second-generation asymptotic giant branch stars in metal-poor Galactic globular clusters

Galactic globular clusters (GCs) are known to host multiple stellar populations: a first generation with a chemical pattern typical of halo field stars and a second generation (SG) enriched in Na and Al and depleted in O and Mg. Both stellar generations are found at different evolutionary stages (e.g., the main-sequence turnoff, the subgiant branch, and the red giant branch). The non detection of SG asymptotic giant branch (AGB) stars in several metal-poor ([Fe/H] < -1) GCs suggests that not all SG stars ascend the AGB phase, and that failed AGB stars may be very common in metal-poor GCs. This observation represents a serious problem for stellar evolution and GC formation/evolution theories. We report fourteen SG-AGB stars in four metal-poor GCs (M 13, M 5, M 3, and M 2) with different observational properties: horizontal branch (HB) morphology, metallicity, and age. By combining the H-band Al abundances obtained by the APOGEE survey with ground-based optical photometry, we identify SG Al-rich AGB stars in these four GCs and show that Al-rich RGB/AGB GC stars should be Na-rich. Our observations provide strong support for present, standard stellar models, i.e., without including a strong mass-loss efficiency, for low-mass HB stars. In fact, current empirical evidence is in agreement with the predicted distribution of FG and and SG stars during the He-burning stages based on these standard stellar models.Comment: Accepted for publication in The Astrophysical Journal Letters (16 pages, 4 figures, and 1 table

Hot bottom burning and s-process nucleosynthesis in massive AGB stars at the beginning of the thermally-pulsing phase

We report the first spectroscopic identification of massive Galactic asymptotic giant branch (AGB) stars at the beginning of the thermal pulse (TP) phase. These stars are the most Li-rich massive AGBs found to date, super Li-rich AGBs with logE(Li)~3-4. The high Li overabundances are accompanied by weak or no s-process element (i.e. Rb and Zr) enhancements. A comparison of our observations with the most recent hot bottom burning (HBB) and s-process nucleosynthesis models confirms that HBB is strongly activated during the first TPs but the 22Ne neutron source needs many more TP and third dredge-up episodes to produce enough Rb at the stellar surface. We also show that the short-lived element Tc, usually used as an indicator of AGB genuineness, is not detected in massive AGBs which is in agreement with the theoretical predictions when the 22Ne neutron source dominates the s-process nucleosynthesis.Comment: Accepted for publication in Astronomy & Astrophysics Letters (7 pages, 5 figures and 1 table); final version (language corrected

From modular to centralized organization of synchronization in functional areas of the cat cerebral cortex

Recent studies have pointed out the importance of transient synchronization between widely distributed neural assemblies to understand conscious perception. These neural assemblies form intricate networks of neurons and synapses whose detailed map for mammals is still unknown and far from our experimental capabilities. Only in a few cases, for example the C. elegans, we know the complete mapping of the neuronal tissue or its mesoscopic level of description provided by cortical areas. Here we study the process of transient and global synchronization using a simple model of phase-coupled oscillators assigned to cortical areas in the cerebral cat cortex. Our results highlight the impact of the topological connectivity in the developing of synchronization, revealing a transition in the synchronization organization that goes from a modular decentralized coherence to a centralized synchronized regime controlled by a few cortical areas forming a Rich-Club connectivity pattern.Comment: 24 pages, 8 figures. Final version published in PLoS On

Silyl-heparin bonding improves the patency and in vivo thromboresistance of carbon-coated polytetrafluoroethylene vascular grafts

AbstractObjectivesOur purpose was to improve the performance of carbon-coated expanded polytetrafluoroethylene vascular grafts by bonding the grafts with silyl-heparin, a biologically active heparin analog, using polyethylene glycol as a cross-linking agent.Material and methodSilyl-heparin–bonded carbon-coated expanded polytetrafluoroethylene vascular grafts (Bard Peripheral Vascular, Tempe, Ariz), were evaluated for patency and platelet deposition 2 hours, 7 days, and 30 days after graft implantation in a canine bilateral aortoiliac artery model. Platelet deposition was determined by injection of autologous, 111Indium-radiolabeled platelets, followed by a 2-hour circulation period prior to graft explantation. Histologic studies were performed on a 2-mm longitudinal strip of each graft (7-day and 30-day groups). Heparin activity of the explanted silyl-heparin grafts was determined by using an antithrombin-III based thrombin binding assay.ResultsOverall chronic graft patency (7-day and 30-day groups) was 100% for the silyl-heparin bonded (16/16) grafts versus 68.75% for control (11/16) grafts (P = .043). Acute 2-hour graft patency was 100% for the silyl-heparin bonded (6/6) grafts versus 83.3% for control (5/6) grafts. Radiolabeled platelet deposition studies revealed a significantly lower amount of platelets deposited on the silyl-heparin grafts as compared with control grafts in the 30-day group (13.8 ± 7.18 vs 28.4 ± 9.73, CPM per cm2 per million platelets, mean ± SD, P = .0451, Wilcoxon rank sum test). In the 2-hour group of dogs, a trend towards a lower deposition of platelets on the silyl-heparin grafts was observed. There was no significant difference in platelet deposition between the two grafts in the 7-day group. Histologic studies revealed a significant reduction in intraluminal graft thrombus present on the silyl-heparin grafts as compared with control grafts in the 30-day group of animals. In contrast, there was no difference in amount of graft thrombus present on both graft types in the 7-day group of dogs. Pre-implant heparin activity on the silyl-heparin bonded grafts was 2.0 IU/cm2 (international units[IU]/cm2). Heparin activity remained present on the silyl-heparin grafts after explantation at all 3 time points (2 hours: above upper limit of assay, upper limit = 0.57, n = 6; 7 days: 0.106 ± 0.015, n = 5; 30 days: 0.007 ± 0.001, n = 5; mean ± SD, IU/cm2).ConclusionSilyl-heparin bonding onto carbon-coated expanded polytetrafluoroethylene vascular grafts resulted in (1) improved graft patency, (2) increased in vivo graft thromboresistance, and (3) a significant reduction in intraluminal graft thrombus. This graft may prove to be useful in the clinical setting.AbstractClinical relevanceExpanded polytetrafluoroethylene (ePTFE) remains the most commonly used prosthetic graft material in infrainguinal arterial reconstructions. Reported long-term patency rates of ePTFE bypass grafts are inferior to those observed with autogenous vein. Modification of the luminal surface of ePTFE bypass grafts may prevent early graft failure and ultimately improve long-term graft performance. Silyl-heparin is a biologically active heparin analog that is readily adsorbed onto hydrophobic surfaces while retaining its anticoagulant properties. Silyl-heparin bonding onto carbon-coated ePTFE grafts improves the patency and in vivo thromboresistance and results in a decrease in intraluminal graft thrombus. This graft may be useful in the clinical setting

Nitrogênio e clorofila em folhas de plátano D'Angola cultivado em sistemas silvibananeiros na região norte de Mato Grosso.

A banana é a fruta mais consumida e exportada do mundo. Em 2012 o Brasil produziu aproximadamente 6,9 milhões de toneladas de banana, sendo o quinto maior produtor mundial. Em alguns estados produtores os sistemas de produção mistos com bananeira e plátano coexistem com as monoculturas, com predominância dos sistemas agroflorestais (SAFs)

Avaliação do real potencial inibidor de extratos etanólicos de Ottonia martiana sobre Cylindrocladium spathulatum e Botrytis cinerea.

Extratos etanólicos de anestesia, Ottonia martiana Miq., foram reavaliados quanto à inibição do crescimento micelial dos fungos Cylindrocladium spathulatum (pinta-preta da erva-mate) e Botrytis cinerea (mofo-cinzento do eucalipto), por meio do planejamento fatorial. A ocorrência de decomposição de bioativos no processo de autoclavagem também foi investigada, por meio de teste de eficiência de extratos filtrados (filtro Millipore) e esterilizados (autoclave) no controle dos fitopatógenos, nas concentrações de 1, 10, 100 e 1000 ppm. Os extratos etanólicos filtrado e esterilizado inibiram o crescimento micelial dos fungos e foram mais ativos frente a B. cinerea. O extrato filtrado exibiu maior potencial antifúngico que o extrato esterilizado. O processo de esterilização por autoclavagem causou pequena decomposição dos bioativos presentes no extrato de anestesia