1,211 research outputs found
Association of radio polar cap brightening with bright patches and coronal holes
Radio-bright regions near the solar poles are frequently observed in Nobeyama
Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal
holes. However, the origin of these polar brightening has not been established
yet. We propose that small magnetic loops are the source of these bright
patches, and present modeling results that reproduce the main observational
characteristics of the polar brightening within coronal holes at 17 GHz. The
simulations were carried out by calculating the radio emission of the small
loops, with several temperature and density profiles, within a 2D coronal hole
atmospheric model. If located at high latitudes, the size of the simulated
bright patches are much smaller than the beam size and they present the
instrument beam size when observed. The larger bright patches can be generated
by a great number of small magnetic loops unresolved by the NoRH beam. Loop
models that reproduce bright patches contain denser and hotter plasma near the
upper chromosphere and lower corona. On the other hand, loops with increased
plasma density and temperature only in the corona do not contribute to the
emission at 17 GHz. This could explain the absence of a one-to-one association
between the 17 GHz bright patches and those observed in extreme ultraviolet.
Moreover, the emission arising from small magnetic loops located close to the
limb may merge with the usual limb brightening profile, increasing its
brightness temperature and width.Comment: 8 pages, 6 figures, 1 table. Accepted for publication in The
Astrophysical Journa
Registro de nematoides em cana-de-açúcar sob diferentes manejos de palhada no Semiárido brasileiro.
A palhada da cana-de-açúcar pode se constituir matéria-prima para a cogeração de energia. Entretanto, a quantidade de palhada que deve permanecer no solo ou que pode ser retirada para fins energéticos ainda não está definida. Um dos aspectos que necessita de estudos é a compreensão da interferência da palhada na dinâmica da população de nematoides no solo. Assim, o objetivo deste trabalho foi identificar e quantificar os nematoides fitoparasitas associados ao sistema radicular da cana-de-açúcar conduzida sob diferentes níveis de palhada na superfície do solo. O estudo foi desenvolvido em área de produção de cana-de-açúcar irrigada por gotejamento subsuperficial, em Juazeiro, BA. Adotou-se o delineamento em blocos casualizados, com cinco tratamentos à base de 100%, 75%, 50%, 25% e 0% da palhada remanescente do ciclo de cultivo anterior, dispostos em quatro blocos. Amostras de solo e de raízes foram coletadas e os nematoides foram extraídos, quantificados e identificados quanto ao gênero. Os diferentes percentuais de palhada não interferiram na população de nematoides. Concluiu-se que a população de fitonematoides não representa um fator limitante ao manejo de retirada da palhada para a produção de energia. O gênero Pratylenchus deve ser monitorado por se tratar de um nematoide prejudicial à cana-de-açúcar
Human cachexia induces changes in mitochondria, autophagy and apoptosis in the skeletal muscle
Cachexia is a wasting syndrome characterized by the continuous loss of skeletal muscle mass due to imbalance between protein synthesis and degradation, which is related with poor prognosis and compromised quality of life. Dysfunctional mitochondria are associated with lower muscle strength and muscle atrophy in cancer patients, yet poorly described in human cachexia. We herein investigated mitochondrial morphology, autophagy and apoptosis in the skeletal muscle of patients with gastrointestinal cancer-associated cachexia (CC), as compared with a weight-stable cancer group (WSC). CC showed prominent weight loss and increased circulating levels of serum C-reactive protein, lower body mass index and decreased circulating hemoglobin, when compared to WSC. Electron microscopy analysis revealed an increase in intermyofibrillar mitochondrial area in CC, as compared to WSC. Relative gene expression of Fission 1, a protein related to mitochondrial fission, was increased in CC, as compared to WSC. LC3 II, autophagy-related (ATG) 5 and 7 essential proteins for autophagosome formation, presented higher content in the cachectic group. Protein levels of phosphorylated p53 (Ser46), activated caspase 8 (Asp384) and 9 (Asp315) were also increased in the skeletal muscle of CC. Overall, our results demonstrate that human cancer-associated cachexia leads to exacerbated muscle-stress response that may culminate in muscle loss, which is in part due to disruption of mitochondrial morphology, dysfunctional autophagy and increased apoptosis. To the best of our knowledge, this is the first report showing quantitative morphological alterations in skeletal muscle mitochondria in cachectic patients
Melon prdutivity under different soil coverings and irrigation system in Petrolina - PE
The objective of this work was to evaluate the influence of irrigation system and soil cover on yield of yellow melon in Petrolina / PE. The experiment was carried out in the period from April 09, 2016 to June 8, 2016 and was conducted at the Petrolina campus in the IF Sertão - PE rural area, with a randomized complete block design, 2 x 2 x 3 plot scheme, (One and two lines of drippers per row of plants), and the subsubparcels, three soil cover (black mulching cover), two plots of hybrids (Gladial and 10/00), subplots, two irrigation systems, Cover with mulching grey and without soil cover) and six replicates. Mulching efficiency (MPP) was studied in the soil cover and irrigation system located with drippers for the production of yellow hybrid melon 10/00 and Gladial under field conditions. It was verified the statistical influence of the soil cover on melon productivity
Relationship between Mediterranean Diet Adherence and Saliva Composition
Dietary polyphenol exposure is known to change protein saliva composition in rodents, but less is known in humans. The present study aimed to assess the relationship between saliva protein composition and adherence to Mediterranean Diet (MD) and polyphenol intake levels. Participants were assessed for their dietary habits, which were converted in Mediterranean adherence level, according to Mediterranean Diet Adherence Score (MEDAS) score. Total polyphenol and total flavanol intakes were extrapolated from dietary data, using Phenol explorer database. Whole saliva was collected, and proteins were separated by SDS-PAGE. Salivary S-type cystatins were highly expressed in the group with medium adherence to MD, being positively correlated with wine intake in overweight individuals. The association between salivary amylase and MD adherence also depended on Body Mass Index (BMI), with a positive association only in normal weight individuals. Polyphenol intake was positively associated with S-type cystatins levels, particularly when flavanols were considered separately. These results show that saliva relationship with MD adherence depend on BMI, suggesting that normal weight and overweight individuals may have different salivary responses to diet. Moreover, these results reinforce the link between saliva and dietary polyphenols (flavanols) levels, leading to the hypothesis that salivary proteome can have a role in polyphenol-rich foods acceptance
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Evolution of the eyes of vipers with and without infrared-sensing pit organs
We examined lens and brille transmittance, photoreceptors, visual pigments, and visual opsin gene sequences of viperid snakes with and without infrared-sensing pit organs. Ocular media transmittance is high in both groups. Contrary to previous reports, small as well as large single cones occur in pit vipers. Non-pit vipers differ from pit vipers in having a twotiered retina, but few taxa have been examined for this poorly understood feature. All vipers sampled express rh1, sws1 and lws visual opsin genes. Opsin spectral tuning varies but not in accordance with the presence/absence of pit organs, and not always as predicted from gene sequences. The visual opsin genes were generally under purifying selection, with positive selection at spectral tuning amino acids in RH1 and SWS1 opsins, and at retinal pocket stabilization sites in RH1 or LWS (and without substantial differences between pit and nonpit vipers). Lack of evidence for sensory trade-off between viperid eyes (in the aspects examined) and pit organs might be explained by the high degree of neural integration of vision and infrared detection; the latter representing an elaboration of an existing sense with addition of a novel sense organ, rather than involving the evolution of a wholly novel sensory system
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High-quality genomes of Paenibacillus spp. RC334 and RC343, isolated from a long-term forest soil warming experiment
Paenibacillus spp. RC334 and RC343 were isolated from heated soil in a long-term soil warming experiment. Both genomes were 5.98 Mb and assembled as a single contig. We describe the assembly and annotation of the two high-quality draft genomes for these isolates here
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