The Effect of Spiral Structure on the Stellar Velocity Distribution in the Solar Neighborhood

Clumps in the solar neighborhood's stellar velocity distribution could be caused by spiral density waves. In the solar neighborhood, stellar velocities corresponding to orbits that are nearly closed in the frame rotating with a spiral pattern represent likely regions for stellar concentrations. Via particle integration, we show that orbits can intersect the solar neighborhood when they are excited by Lindblad resonances with a spiral pattern. We find that a two-armed spiral density wave with pattern speed placing the Sun near the 4:1 Inner Lindblad Resonance (ILR) can cause two families of nearly closed orbits in the solar neighborhood. One family corresponds to square shaped orbits aligned so their peaks lie on top of, and support, the two dominant stellar arms. The second family correspond to orbits 45 degrees out of phase with the other family. Such a spiral density pattern could account for two major clumps in the solar neighborhood's velocity distribution. The Pleiades/Hyades moving group corresponds to the first family of orbits and the Coma Berenices moving group corresponds to the second family. This model requires a spiral pattern speed of approximately 0.66 +- 0.03 times the angular rotation rate of the Sun or 18.1 +- 0.8 km/s/kpc.Comment: Accepted for publication in A

“I don’t know when he will be back”: life-changing events challenge the community ART Group model– a qualitative research study, Tete, Mozambique

Background Since 2008 in Mozambique, patients stable on antiretroviral therapy (ART) can join Community ART Groups (CAG), peer groups in which members are involved in adherence support and community ART delivery. More than 10 years after the implementation of the first CAGs, we study how changes in circumstance and daily life events of CAG members have affected the CAG dynamic. Methods A qualitative study using individual in-depth interviews (27) and focus group discussions (8) with CAG members and health care providers was carried out in Tete province, rural Mozambique. Purposive sampling was used to select participants. Data were transcribed and translated, and manual thematic analysis carried out to identify codes, which were then categorized in sub-themes and themes. Results Data were collected from 61 CAG members and 18 health-care providers in 2017. The CAG dynamic was affected by life events and changing circumstances including a loss of geographical proximity or a change in social relationships. Family CAGs facilitated reporting and ART distribution, but conflict between CAG members meant some CAGs ceased to function. In some CAGs, the dynamic changed as pill counts were not carried out, members met less frequently or stopped meeting entirely. Some members did not collect ART at the facility when it was their turn, and others stopped taking ART completely. Health care providers were reported to push people living with HIV to join CAGs, instead of allowing voluntary participation. Some CAGs responded to adherence challenges by strengthening peer support through counselling and observed pill intake. Health-care providers agreed that strengthening CAG rules and membership criteria could help to overcome the identified problems. Conclusions Changing life circumstances, changes in relationships and a lack of participation by CAG members altered the CAG dynamic, which sometimes affected adherence. Some CAGs responded to challenges by intensifying peer support, including to those diagnosed with virological failure. To ensure flexible implementation and modification of CAGs to the inevitable changes in life circumstances of its members, feedback mechanisms should be implemented between CAG members and the health-care providers

A experimentação nas pesquisas sobre o ensino de Física: fundamentos epistemológicos e pedagógicos

Considerando a necessidade de analisar a fundamentação teórica que embasa as atividades experimentais escolares na ultima década, desenvolveu-se uma investigação tomando como objeto as pesquisas publicadas sobre essa temática em um importante periódico da área. Toma-se como referência a concepção de que a experimentação está inserida em um contexto epistemológico e pedagógico, pois envolve concepções de realidade, de conhecimento, de conhecimento científico, de método científico, enfim, uma concepção de ciência e também concepções de aprendizagem, de posicionamento dos conhecimentos prévios dos alunos, de relações entre conteúdo e método, enfim, uma concepção de currículo. Desenvolvendo uma análise epistemológico-pedagógica dos artigos, foi observado que metodologicamente são adotadas diferentes abordagens para desenvolver as atividades experimentais: algumas mais demonstrativas, priorizando a observação, outras mais de atuação por parte do estudante, priorizando a investigação. As pesquisas tomam como pressuposto básico favorecer a aprendizagem ou a interação. A aprendizagem se refere à compreensão da atividade científica, ou de conhecimentos teóricos e práticos. A interação pode ser tanto do aluno com a atividade quanto social, ou ainda entre disciplinas

Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis

Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

MiR-543 regulates the epigenetic landscape of myelofibrosis by targeting TET1 and TET2

Myelofibros is (MF) is a myeloproliferative neoplasm characterized by cytopenia and extramedullary hematopoiesis, resulting in splenomegaly. Multiple pathological mechanisms (e.g., circulating cytokines and genetic alterations, such as JAK(V617F) mutation) have been implicated in the etiology of MF, but the molecular mechanism causing resistance to JAK(V617F) inhibitor therapy remains unknown. Among MF patients who were treated with the JAK inhibitor ruxolitinib, we compared noncoding RNA profiles of ruxolitinib therapy responders versus nonresponders and found miR-S43 was significantly upregulated in non responders. We validated these findings by reverse transcription-quantitative PCR. in this same cohort, in 2 additional independent MF patient cohorts from the United States and Romania, and in a JAK2(V617F) mouse model of MF. Both in vitro and in vivo models were used to determine the underlying molecular mechanism of miR-543 in MF. Here, we demonstrate that miR-543 targets the dioxygenases ten-eleven translocation 1 (TET1) and 2 (TET2) in patients and in vitro, causing increased levels of global 5-methylcytosine, while decreasing the acetylation of histone 3, STAT3, and tumor protein p53. Mechanistically, we found that activation of STAT3 by JAKs epigenetically controls miR-543 expression via binding the promoter region of miR-543. Furthermore, miR-543 upregulation promotes the expression of genes related to drug metabolism, including CYP3A4, which is involved in ruxolitinib metabolism. Our findings suggest miR-543 as a potentially novel biomarker for the prognosis of MF patients with a high risk of treatment resistance and as a potentially new target for the development of new treatment options

Heuristic Optimization Methods for Dynamic Panel Data Model Selection: Application on the Russian Innovative Performance

Innovations, be they radical new products or technology improvements are widely recognized as a key factor of economic growth. To identify the factors triggering innovative activities is a main concern for economic theory and empirical analysis. As the number of hypotheses is large, the process of model selection becomes a crucial part of the empirical implementation. The problem is complicated by the fact that unobserved heterogeneity and possible endogeneity of regressors have to be taken into account. A new efficient solution to this problem is suggested, applying optimization heuristics, which exploits the inherent discrete nature of the problem. The model selection is based on information criteria and the Sargan test of overidentifying restrictions. The method is applied to Russian regional data within the framework of a log-linear dynamic panel data model. To illustrate the performance of the method, we also report the results of Monte-Carlo simulations