Lithium evolution in intermediate age and old open clusters: NGC 752 revisited

We present new high resolution spectroscopic observations of the intermediate age (~2 Gyr) open cluster NGC 752. We investigate the Li vs. Teff distribution and we obtain a new accurate determination of the cluster metallicity. We compare the results for NGC 752 with other intermediate age and old clusters spanning the age range from the Hyades (~0.6 Gyr) to NGC 188 (~6-8 Gyr). We find that NGC 752 has a solar iron content ([Fe/H]=+0.01+/-0.04), at variance with early reports of sub-solar metallicity. We find that NGC 752 is only slightly more Li depleted than the younger Hyades and has a Li pattern almost identical to that observed in the ~2 Gyr old IC 4651 and NGC 3680. As for the latter clusters, we find that NGC 752 is characterized by a tight Li vs. Teff distribution for solar-type stars, with no evidence for a Li spread as large as the one observed in the solar age solar metallicity M 67. We discuss these results in the framework of mixing mechanisms and Li depletion on the main sequence (MS). We conclude that the development of a large scatter in Li abundances in old open clusters might be an exception rather than the rule (additional observations of old clusters are required), and that metallicity variations of the order of ~0.2 dex do not affect Li depletion after the age of the Hyades.Comment: A&A accepted, 10 pages, 5 ps figure

2023 Chairs’ Welcome

Welcome to the 11th edition of the ACM Workshop on Information Hiding and Multimedia Security (IH&MMSec ‘23). This year’s workshop continues the tradition of representing one of the prime events in information hiding and multimedia security, attracting researchers and practitioners worldwide. Carrying on with the efforts of the previous edition to overcome the Pandemics and reunite the IH&MMSec community to present and discuss their work, this year’s meeting is held fully in person at the Water Tower Campus of Loyola University Chicago, located right at the heart of the Windy City. Bathed by the fresh waters of Lake Michigan, Chicago is the 3rd largest city in the USA, with a strong, multiethnic, and multicultural community. Besides fostering Science and their research during the workshop, attendees have countless opportunities for outdoor citywise activities, blessed by the beginning of the American Midwest Summer

Vortices in a Ginzburg Landau Theory of Superconductors with Nematic Order

In this work we explore the interplay between superconductivity and nematicity in the framework of a Ginzburg Landau theory with a nematic order parameter coupled to the superconductor order parameter, often used in the description of superconductivity of Fe based materials. In particular, we focus on the study of the vortex-vortex interaction in order to determine the way nematicity affects its attractive or repulsive character. To do so, we use a dynamical method based on the solutions of the Time Dependent Ginzburg Landau equations in a bulk superconductor. An important contribution of our work is the implementation of a pseudo-spectral method to solve the dynamics, known to be highly efficient and of very high order in comparison to the usual finite differences/elements methods. The coupling between the superconductor and the (real) nematic order parameters is represented by two terms in the free energy: a biquadratic term and a coupling of the nematic order parameter to the covariant derivatives of the superconductor order parameter. Our results show that there is a competing effect: while the former independently of its competitive or cooperative character generates an attractive vortex-vortex interaction, the latter always generates a repulsive interaction.Comment: 37 pages; 12 figures; corrected typos; added reference

Patients' Perceptions About Diagnosis And Treatment Of Chronic Myeloid Leukemia: A Cross-sectional Study Among Brazilian Patients.

Chronic myeloid leukemia (CML) requires strict daily compliance with oral medication and regular blood and bone marrow control tests. The objective was to evaluate CML patients' perceptions about the disease, their access to information regarding the diagnosis, monitoring and treatment, adverse effects and associations of these variables with patients' demographics, region and healthcare access. Prospective cross-sectional study among CML patients registered with the Brazilian Lymphoma and Leukemia Association (ABRALE). CML patients receiving treatment through the public healthcare system were interviewed by telephone. Among 1,102 patients interviewed, the symptoms most frequently leading them to seek medical care were weakness or fatigue. One third were diagnosed by means of routine tests. The time that elapsed between first symptoms and seeking medical care was 42.28 ± 154.21 days. Most patients had been tested at least once for Philadelphia chromosome, but 43.2% did not know the results. 64.8% had had polymerase chain reaction testing for the BCR/ABL gene every three months. 47% believed that CML could be controlled, but 33.1% believed that there was no treatment. About 24% reported occasionally stopping their medication. Imatinib was associated with nausea, cramps and muscle pain. Self-reported treatment adherence was significantly associated with normalized blood count, and positively associated with imatinib. There is a lack of information or understanding about disease monitoring tools among Brazilian CML patients; they are diagnosed quickly and have good access to treatment. Correct comprehension of CML control tools is impaired in Brazilian patients.0

Effect of Incorporating Cellulose Nanocrystals from Corncob on the Tensile, Thermal and Barrier Properties of Poly(Vinyl Alcohol) Nanocomposites

The effect of incorporating cellulose nanocrystals from corncob (CNC) on the tensile, thermal, and barrier properties of poly(vinyl alcohol) (PVA) nanocomposites was evaluated. The CNC were prepared by sulfuric acid hydrolysis at 45°C for 60 minutes, using 15 mL of H2SO4 (9.17 M) for each gram of fiber. The CNC60 presented a needle-shaped morphology, high crystallinity (83.7%), good initial degradation temperature (236°C), average length (L) of 210.8±44.2 nm, diameter (D) of 4.15±1.08 nm, and high aspect ratio (L/D) of 53.4±15.8. PVA/CNC nanocomposite films with different filler loading levels (3, 6, and 9% by wt) were prepared by casting. The ultimate tensile strength (UTS), thermal stability (TS), light transmittance (Tr) and water vapor permeability (Pw) of the nanocomposites were measured. When compared to neat PVA film, the UTS of the nanocomposites improved significantly, by 140.2%, Pw decreased up to 28.73%, and there were no significant changes in TS. The nanocomposites also showed excellent Tr in the visible region, maintaining substantially equivalent transparency. These improvements in the nanocomposites' properties suggest a close association between filler and matrix, besides indicating that the CNC were well dispersed and adherent to the polymer matrix

Worldwide network for blood and marrow transplantation recommendations for establishing a hematopoietic stem cell transplantation program in countries with limited resources, part II: Clinical, technical, and socioeconomic considerations

The development of hematopoietic stem cell transplantation (HSCT) programs can face significant challenges in most developing countries because such endeavors must compete with other government health care priorities, including the delivery of basic services. Although this is may be a limiting factor, these countries should prioritize development of the needed expertise to offer state-of-the-art treatments, including transplantation, by providing financial, technological, legal, ethical, and other needed support. This would prove beneficial in providing successful programs customized to the needs of their population and potentially provide long-term cost savings by circumventing the need for their citizens to seek care abroad. The costs of establishing an HSCT program and the costs of the HSCT procedure itself can be substantial barriers in developing countries. In addition, socioeconomic factors intrinsic to specific countries can influence access to HSCT, patient eligibility for HSCT, and timely utilization of HSCT center capabilities. This report describes recommendations from the Worldwide Network for Blood and Marrow Transplantation for establishing HSCT programs, with a specific focus on developing countries, and identifies challenges and opportunities for providing this specialized procedure in resource-constrained settings

Time scales of Li evolution: a homogeneous analysis of open clusters from ZAMS to late-MS

We have performed a new and homogeneous analysis of all the Li data available in the literature for main sequence stars (spectral-types from late F to K) in open clusters. In the present paper we focus on a detailed investigation of MS Li depletion and its time scales for stars in the 6350-5500 K effective temperature range. For the first time, we were able to constrain the age at which non-standard mixing processes, driving MS Li depletion, appear. We have also shown that MS Li depletion is not a continuous process and cannot be simply described by a t^(-alpha) law. We confirm that depletion becomes ineffective beyond an age of 1-2 Gyr for the majority of the stars, leading to a Li plateau at old ages. We compared the empirical scenario of Li as a function of age with the predictions of three non-standard models. We found that models including only gravity waves as main mixing process are not able to fit the Li vs. age pattern and thus this kind of mixing can be excluded as the predominant mechanism responsible for Li depletion. On the other hand, models including slow mixing induced by rotation and angular momentum loss, and in particular those including also diffusive processes not related to rotation, can explain to some extent the empirical evidence. However, none of the currently proposed models can fit the plateau at old ages.Comment: 20 pages, 10 figures A&A accepte

Carbon dioxide plasma treated PVDF electrospun membrane for the removal of crystal violet dyes and iron oxide nanoparticles from water

International audienceHere we reported a reactive plasma treatment of polyvinylidene fluoride (PVDF) electrospun membrane by using carbon dioxide (CO2) plasma in order to reduce the hydrophobicity of the PVDF membrane and thereby used to remove toxic crystal violet dye (CV) and iron oxide (Fe2O3) nanoparticles from water. The demonstrated plasma treated PVDF electrospun membrane showed a decrement in the hydrophobicity after plasma treatment. Most of the microfiltration membranes based on PVDF were fabricated via phase inversion technique and solvent casting. The main drawback of these methods is that to obtain membranes with uniform pore size. Moreover, the membranes fabricated via phase inversion and solvent casting process have low surface area whereas in the membranes via electrospinning technique have interconnected pore structure with high surface area and uniform pore size. The contact angle of the neat PVDF electrospun membrane and plasma treated PVDF electrospun membrane were 141°and 102°respectively. FTIR studies revealed that, after CO2 plasma treatment, highly negative carboxylate (COO-) groups were formed on the surface of the PVDF electrospun membrane. With the 10 mg/L of crystal violet (CV) aqueous solution, the dye adsorption capacity was 1.368 mg/g of the membrane for neat PVDF membrane and 3.84 mg/g of the membrane for plasma treated PVDF membrane. It was found that, the CO2 plasma treated PVDF membrane had two- or three-times greater adsorption capacity then neat PVDF membrane against crystal violet dyes which was due to the strong electrostatic interaction between the highly negative carboxyl groups on the surface of plasma treated PVDF electrospun membrane and protonated CV dye. Both neat PVDF membrane and plasma treated PVDF membrane showed excellent filtration capacity against Fe2O3 nanoparticles. The demonstrated plasma treated PVDF membrane could successfully remove iron oxide nanoparticles and crystal violet dyes from water via size exclusion and adsorption mechanism respectively