Uncertainties in the solar photospheric oxygen abundance

The purpose of this work is to better understand the confidence limits of the photospheric solar oxygen abundance derived from three-dimensional models using the forbidden [OI] line at 6300 \AA , including correlations with other parameters involved. We worked with a three-dimensional empirical model and two solar intensity atlases. We employed Bayesian inference as a tool to determine the most probable value for the solar oxygen abundance given the model chosen. We considered a number of error sources, such as uncertainties in the continuum derivation, in the wavelength calibration and in the abundance/strength of Ni. Our results shows correlations between the effects of several parameters employed in the derivation. The Bayesian analysis provides robust confidence limits taking into account all of these factors in a rigorous manner. We obtain that, given the empirical three-dimensional model and the atlas observations employed here, the most probable value for the solar oxygen abundance is $\log(\epsilon_O) = 8.86\pm0.04$. However, we note that this uncertainty does not consider possible sources of systematic errors due to the model choice.Comment: Accepted for publication in Astronomy and Astrophysic

The dysfunction of T follicular helper cells.

PURPOSE OF REVIEW: T follicular helper (Tfh) cells play a critical role as providers of B-cell help and dysfunction in Tfh/B-cell interactions can lead to autoimmunity or immunodeficiency. These observations have generated a great deal of interest in understanding how these cells are affected during HIV infection and how their functional changes might affect antibody responses. RECENT FINDINGS: Recent studies have shown that HIV/simian immunodeficiency virus (SIV) infection affects both Tfh-cell frequency and function and suggest that Tfh-cell perturbations might contribute to the relative inefficiency of HIV-infected individuals to generate broadly neutralizing antibodies (bNAbs). SUMMARY: The present review will highlight these recent findings addressing the role of Tfh cells in HIV infection as well as the impact HIV infection has on Tfh and circulating memory Tfh (cTfh) cell frequency and function

Evolution of floral symmetry

Flowers can be classified into two basic types according to their symmetry: regular flowers have more than one plane of symmetry and irregular flowers have only a single plane of symmetry. The irregular condition is thought to have evolved many times independently from the regular one: most commonly through the appearance of asymmetry along the dorso-ventral axis of the flower. In most cases, the irregular condition is associated with a particular type of inflorescence architecture. To understand the molecular mechanism and evolutionary origin of irregular flowers, we have been investigating genes controlling asymmetry in Antirrhinum. Several mutations have been described in Antirrhinum, a species with irregular flowers, that reduce or eliminate asymmetry along the dorso-ventral axis. We describe the nature of these mutations and how they may be used to analyse the molecular mechanisms underlying floral evolution

Gastric Volvulus

Gastric volvulus is one of the most worrisome complications related to large paraesophageal hernias. It is a medical emergency that requires high index of suspicion and prompt management and operation during the index admission. Here we discuss the pathophysiology and classification of gastric volvulus, clinical and radiological presentation, and treatment options. The approaches described here include endoscopic, laparoscopic, robotic and open. We advocate for the first three approaches and usually save the open approach for certain redo operations or patients with significant adhesions from prior mediastinal or foregut surgeries

Towards implementing climate services in Peru – The project CLIMANDES

CLIMANDES is a pilot twinning project between the National Weather Services of Peru and Switzerland (SENAMHI and MeteoSwiss), developed within the Global Framework for Climate Services of the World Meteorological Organization (WMO). Split in two modules, CLIMANDES aims at improving education in meteorology and climatology in support of the WMO Regional Training Center in Peru, and introducing user-tailored climate services in two pilot regions in the Peruvian Andes. Four areas were prioritized in the first phase of CLIMANDES lasting from 2012 to 2015 to introduce climate services in Peru. A demand study identified the user needs of climate services and showed that climate information must be reliable, of high-quality, and precise. The information should be accessible and timely, understandable and applicable for the users’ specific needs. Second, the quality of climate data was enhanced through the establishment of quality control and homogenization procedures at SENAMHI. Specific training and application of the implemented methods at stations in the pilot regions was promoted to ensure the sustainability of the work. Third, the specific work on climate data enabled the creation of a webpage to disseminate climate indicators among users. The forth priority of the project enhanced the broad communication strategy of SENAMHI through creation of a specialized network of journalists, diverse climate forums, and the establishment of a user database. The efforts accomplished within CLIMANDES improved the quality of the climate services provided by SENAMHI. The project hence contributed successfully to higher awareness and higher confidence in the climate information by SENAMHI.Por pare

The Mazarrón basin, SE Spain: a study of mineralization processes, evolving magmatic series, and geothermal activity

The Miocene to Present Mazarrón basin provides a window on the metallogenic role of an evolving magmatic series. High-K calc–alkaline magmas gave rise to an important cluster of Pb–Zn–Ag–Cu vein and stockwork deposits emplaced in dacitic to rhyodacitic domes, part of a complex volcanic–metallogenic province (Au, Hg, Pb–Zn–Cu–Ag, Sn) stretching for ∼150 km along the Mediterranean coast of SE Spain. By Pliocene time the former magmatic series had been replaced by intraplate alkaline basaltic volcanism, thus becoming the southern branch of the Western/Central Europe alkaline province. In terms of base metal sulphide deposits, this European province is barren, although it triggered widespread, CO2-rich geothermal activity. Modern geothermal activity at El Saladillo (Mazarrón) resulted in the deposition of carbonate sinter deposits and formation of microbial mats. Proximal facies consist of millimetric to centimetric multicoloured layers of microbial mats, including yellow-orange thin bands of calcified bacteria and mineral growths of aragonite and calcite; green layers of live thermophilic Lyngbya-type cyanobacteria; black, degraded organic matter; and pyrite as the sole sulphide phase. Except for arsenic (37–63 μg g−1), all of the studied trace elements (Ag, Ba, Bi, Cd, Cu, Pb, Sb, Se, and Sn) appear in remarkably low concentrations in the geothermal sinters. This is consistent with compositional data for the El Saladillo waters, with no significant metal concentrations. We present the first conceptual model (Miocene to Present) for the ore-forming processes, magmatism, CO2 degasification, and geothermal activity for this realm. We argue that the time- and space-limited character of this volcanism (small, scattered outcrops), the deep magma emplacement level, the metal sulphide behaviour in alkaline basaltic magmatic chambers, and the dry character of these magmas prevented any metallogenic interaction between the chambers and the much shallower meteoric waters that drove the El Saladillo geothermal system and others of the same kind in Spain and elsewhere in Europe

Low friction along the high slip patch of the 2011 Mw 9.0 Tohoku-Oki earthquake required from the wedge structure and extensional splay faults

We analyze the mechanical properties needed to account for the large shallow slip during the 2011 Tohoku-Oki earthquake and the activation of landward normal faulting within the forearc. We show that the morphology and internal structure of the forearc follows closely the prediction of the critical Coulomb wedge in horizontal compression, implying a high internal pore pressure ratio (λ = 0.7 + 0.14/ – 0.48) and a low effective basal friction (μ^(eff)_b = 0.14 + 0.18/ – 0.04). We then show that the activation of the normal fault requires a lower effective basal friction beneath the outer wedge than beneath the inner wedge (μ_outer ≤ 0.015), possibly due to transient dynamic weakening associated to the seismic rupture. Forearc normal faults could be considered as evidence for very efficient dynamic weakening along the megathrust and typify megathrust with high tsunamigenic potential

Anxiolytic-Like Effect of Cymbopogon Citratus (Lemongrass) Essential Oil

Introduction: Essential oils are complex substances that are widely utilized in the practices of aromatherapy. Certain essential oils are recognized for their potential to alleviate anxiety symptoms. This research was conducted to evaluate the effects of Cymbopogon citratus essential oil on anxiety. Methods: The chemical composition of the extracted essential oil was analyzed using Gas chromatography with flame-ionization detection (GC-FID) and Gas chromatography-mass spectrometry (GC–MS). In addition, an experimental study with measures at pretest-posttest was conducted, where 128 participants were divided into two groups, a waiting-list (WL) control group, and an experimental group (EG)treated with aromatherapy based on Cymbopogon citratus essential oil. The anxiety index was evaluated by Zung Self- Rating Anxiety Scale (SAS). Results: The chemical analysis identified geranial (52,1%) and neral (35,2%) as the principal constituents. Anxiety levels decreased in the experimental group during the posttest phase (p<0.05). Besides a large effect size was found for anxiety (d = 0.962; Δ= 0.988) with 1-β=0.999 a percentage of change of -10.99%. Conclusion: Cymbopogon citratus essential oil inhalation showed to be effective in decreasing scores anxiety. Therefore, it has the potential to serve as a supplementary treatment for anxiety