30 research outputs found
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The solar photospheric silicon abundance according to CO5BOLD: Investigating line broadening, magnetic fields, and model effects
Context. In this work, we present a photospheric solar silicon abundance derived using CO5BOLD model atmospheres and the LINFOR3D spectral synthesis code. Previous works have differed in their choice of a spectral line sample and model atmosphere as well as their treatment of observational material, and the solar silicon abundance has undergone a downward revision in recent years. We additionally show the effects of the chosen line sample, broadening due to velocity fields, collisional broadening, model spatial resolution, and magnetic fields. Aims. Our main aim is to derive the photospheric solar silicon abundance using updated oscillator strengths and to mitigate model shortcomings such as over-broadening of synthetic spectra. We also aim to investigate the effects of different line samples, fitting configurations, and magnetic fields on the fitted abundance and broadening values. Methods. CO5BOLD model atmospheres for the Sun were used in conjunction with the LINFOR3D spectral synthesis code to generate model spectra, which were then fit to observations in the Hamburg solar atlas. We took pixel-to-pixel signal correlations into account by means of a correlated noise model. The choice of line sample is crucial to determining abundances, and we present a sample of 11 carefully selected lines (from an initial choice of 39 lines) in both the optical and infrared, which has been made possible with newly determined oscillator strengths for the majority of these lines. Our final sample includes seven optical Si i lines, three infrared Si i lines, and one optical Si ii line. Results. We derived a photospheric solar silicon abundance of log ϔSi = 7.57 ± 0.04, including a - 0.01 dex correction from Non-Local Thermodynamic Equilibrium (NLTE) effects. Combining this with meteoritic abundances and previously determined photospheric abundances results in a metal mass fraction Z/X = 0.0220 ± 0.0020. We found a tendency of obtaining overly broad synthetic lines. We mitigated the impact of this by devising a de-broadening procedure. The over-broadening of synthetic lines does not substantially affect the abundance determined in the end. It is primarily the line selection that affects the final fitted abundance
High-density genetic map using whole-genome resequencing for fine mapping and candidate gene discovery for disease resistance in peanut
Wholeâgenome resequencing (WGRS) of mapping populations has facilitated development of highâdensity genetic maps essential for fine mapping and candidate gene discovery for traits of interest in crop species. Leaf spots, including early leaf spot (ELS) and late leaf spot (LLS), and Tomato spotted wilt virus (TSWV) are devastating diseases in peanut causing significant yield loss. We generated WGRS data on a recombinant inbred line population, developed a SNPâbased highâdensity genetic map, and conducted fine mapping, candidate gene discovery and marker validation for ELS, LLS and TSWV. The first sequenceâbased highâdensity map was constructed with 8869 SNPs assigned to 20 linkage groups, representing 20 chromosomes, for the âTâ population (Tifrunner Ă GTâC20) with a map length of 3120 cM and an average distance of 1.45 cM. The quantitative trait locus (QTL) analysis using highâdensity genetic map and multiple season phenotyping data identified 35 mainâeffect QTLs with phenotypic variation explained (PVE) from 6.32% to 47.63%. Among majorâeffect QTLs mapped, there were two QTLs for ELS on B05 with 47.42% PVE and B03 with 47.38% PVE, two QTLs for LLS on A05 with 47.63% and B03 with 34.03% PVE and one QTL for TSWV on B09 with 40.71% PVE. The epistasis and environment interaction analyses identified significant environmental effects on these traits. The identified QTL regions had disease resistance genes including Râgenes and transcription factors. KASP markers were developed for major QTLs and validated in the population and are ready for further deployment in genomicsâassisted breeding in peanut
Aging-related defects in macrophage function are driven by MYC and USF1 transcriptional programs
Macrophages are central innate immune cells whose function declines with age. The molecular mechanisms underlying age-related changes remain poorly understood, particularly in human macrophages. We report a substantial reduction in phagocytosis, migration, and chemotaxis in human monocyte-derived macrophages (MDMs) from older (>50 years old) compared with younger (18â30 years old) donors, alongside downregulation of transcription factors MYC and USF1. In MDMs from young donors, knockdown of MYC or USF1 decreases phagocytosis and chemotaxis and alters the expression of associated genes, alongside adhesion and extracellular matrix remodeling. A concordant dysregulation of MYC and USF1 target genes is also seen in MDMs from older donors. Furthermore, older age and loss of either MYC or USF1 in MDMs leads to an increased cell size, altered morphology, and reduced actin content. Together, these results define MYC and USF1 as key drivers of MDM age-related functional decline and identify downstream targets to improve macrophage function in aging
Measurement invariance of the Childhood Autism Rating Scale (CARS) across six countries
Education and Child Studie
Synthesis, spectral analysis and pharmacological study of N'- substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazides
Anaesthetic management of neonate with giant occipital meningoencephalocele: Case report
Meningoencephalocele is herniation of cerebrospinal fluid, brain tissue and meninges through the skull defect. The anaesthetic management of occipital meningoencephalocele is challenging because of the difficulty in securing airway, prone position, blood loss and, perioperative care. The two major aims of the anaesthesiologists while caring for children with occipital encephalocoele intraoperatively are to avoid premature rupture of the encephalocoele and to manage a possible difficult airway due to restricted neck movement and inability to achieve optimal position for intubation of the trachea. We report a case of giant occipital meningoencephalocele presented for surgical excision. Perioperative management of patients with giant meningoencephalocele may be challenging for both anaesthesiologist and neurosurgeon. These patients must be managed closely with an interdisciplinary approach