228 research outputs found
Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares
The extreme ultraviolet portion of the solar spectrum contains a wealth of
diagnostic tools for probing the lower solar atmosphere in response to an
injection of energy, particularly during the impulsive phase of solar flares.
These include temperature and density sensitive line ratios, Doppler shifted
emission lines and nonthermal broadening, abundance measurements, differential
emission measure profiles, and continuum temperatures and energetics, among
others. In this paper I shall review some of the advances made in recent years
using these techniques, focusing primarily on studies that have utilized data
from Hinode/EIS and SDO/EVE, while also providing some historical background
and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the
Topical Issue on Solar and Stellar Flare
Avaliação da qualidade de matérias-primas de ruibarbo utilizadas em formulações farmacêuticas
As plantas denominadas de ruibarbo sintetizam antraquinonas e taninos, que são responsáveis pelos efeitos laxante e adstringente, respectivamente. Análises da qualidade de cinco matérias-primas de ruibarbo foram realizadas a fim de detectar adulterações. As reações para antraquinonas e taninos foram positivas. Os constituintes rapônticos foram observados na amostra de Rheum palmatum (2). As medidas de cinzas totais para Rheum palmatum (2) e Ferraria cathartica estão acima do esperado. Conforme resultados, as amostras de Rheum palmatum (2) e Ferraria cathartica devem estar adulteradas
Estudo farmacognóstico de galhos de Vanillosmopsis erythropappa Schult. Bip. - Asteraceae
Vanillosmopsis erythropappa é um vegetal rico em óleos essenciais, especialmente o á-bisabolol. O objetivo deste estudo foi pesquisar a variação sazonal qualitativa de substâncias naturais, teores de óleos essenciais, cinzas totais, umidade e pH. Os resultados mostraram uma variação de flavonóides, taninos, triterpenóides, esteróides, saponinas, óleos essenciais, cinzas totais, umidade e pH, demonstrando que os aspectos ambientais influenciam o metabolismo dessa espécie. As médias anuais dos valores obtidos foram: óleos essenciais= 0,29 ± 0,09%; cinzas totais= 3,13 ± 0,49%; umidade= 6,56 ± 0,80% e pH= 5,40 ± 0,24
An EST-based analysis identifies new genes and reveals distinctive gene expression features of Coffea arabica and Coffea canephora
Background: Coffee is one of the world’s most important crops; it is consumed worldwide and plays a significant
role in the economy of producing countries. Coffea arabica and C. canephora are responsible for 70 and 30% of
commercial production, respectively. C. arabica is an allotetraploid from a recent hybridization of the diploid
species, C. canephora and C. eugenioides. C. arabica has lower genetic diversity and results in a higher quality
beverage than C. canephora. Research initiatives have been launched to produce genomic and transcriptomic data
about Coffea spp. as a strategy to improve breeding efficiency.
Results: Assembling the expressed sequence tags (ESTs) of C. arabica and C. canephora produced by the
Brazilian Coffee Genome Project and the Nestlé-Cornell Consortium revealed 32,007 clusters of C. arabica and
16,665 clusters of C. canephora. We detected different GC3 profiles between these species that are related to
their genome structure and mating system. BLAST analysis revealed similarities between coffee and grape (Vitis
vinifera) genes. Using KA/KS analysis, we identified coffee genes under purifying and positive selection. Protein
domain and gene ontology analyses suggested differences between Coffea spp. data, mainly in relation to
complex sugar synthases and nucleotide binding proteins. OrthoMCL was used to identify specific and prevalent
coffee protein families when compared to five other plant species. Among the interesting families annotated
are new cystatins, glycine-rich proteins and RALF-like peptides. Hierarchical clustering was used to
independently group C. arabica and C. canephora expression clusters according to expression data extracted
from EST libraries, resulting in the identification of differentially expressed genes. Based on these results, we
emphasize gene annotation and discuss plant defenses, abiotic stress and cup quality-related functional
categories.
Conclusion: We present the first comprehensive genome-wide transcript profile study of C. arabica and C.
canephora, which can be freely assessed by the scientific community at http://www.lge.ibi.unicamp.br/
coffea. Our data reveal the presence of species-specific/prevalent genes in coffee that may help to explain
particular characteristics of these two crops. The identification of differentially expressed transcripts offers a
starting point for the correlation between gene expression profiles and Coffea spp. developmental traits,
providing valuable insights for coffee breeding and biotechnology, especially concerning sugar metabolism
and stress tolerance
Convergence of the critical attractor of dissipative maps: Log-periodic oscillations, fractality and nonextensivity
For a family of logistic-like maps, we investigate the rate of convergence to
the critical attractor when an ensemble of initial conditions is uniformly
spread over the entire phase space. We found that the phase space volume
occupied by the ensemble W(t) depicts a power-law decay with log-periodic
oscillations reflecting the multifractal character of the critical attractor.
We explore the parametric dependence of the power-law exponent and the
amplitude of the log-periodic oscillations with the attractor's fractal
dimension governed by the inflexion of the map near its extremal point.
Further, we investigate the temporal evolution of W(t) for the circle map whose
critical attractor is dense. In this case, we found W(t) to exhibit a rich
pattern with a slow logarithmic decay of the lower bounds. These results are
discussed in the context of nonextensive Tsallis entropies.Comment: 8 pages and 8 fig
Transcriptome analysis reveals putative genes involved in the lipid metabolism of chaulmoogra oil biosynthesis in Carpotroche brasiliensis (Raddi) A.Gray, a tropical tree species
Chaulmoogra oil is found in the seeds of Carpotroche brasiliensis (Raddi) Endl. (syn. Mayna brasiliensis Raddi), an oil tree of the Achariaceae family and native to Brazil’s Atlantic Forest biome, which is considered the fifth most important biodiversity hotspot in the world. Its main constituents are cyclopentenic fatty acids. Chaulmoogra oil has economic potential because of its use in the cosmetics industry and as a drug with anti-tumor activity. The mechanisms related to the regulation of oil biosynthesis in C. brasiliensis seeds are not fully understood, especially from a tissue-specific perspective. In this study, we applied a de novo transcriptomic approach to investigate the transcripts involved in the lipid pathways of C. brasiliensis and to identify genes involved in lipid biosynthesis. Comparative analysis of gene orthology, expression analysis and visualization of metabolic lipid networks were performed, using data obtained from high-throughput sequencing (RNAseq) of 24 libraries of vegetative and reproductive tissues of C. brasiliensis. Approximately 10.4 million paired-end reads (Phred (Q) > 20) were generated and re-assembled into 107,744 unigenes, with an average length of 340 base pairs (bp). The analysis of transcripts from different tissues identified 1131 proteins involved in lipid metabolism and transport and 13 pathways involved in lipid biosynthesis, degradation, transport, lipid bodies, and lipid constituents of membranes. This is the first transcriptome study of C. brasiliensis, providing basic information for biotechnological applications of great use for the species, which will help understand chaulmoogra oil biosynthesis
Comparative analysis of the secretome and interactome of Trypanosoma cruzi and Trypanosoma rangeli reveals species specific immune response modulating proteins
Chagas disease, a zoonosis caused by the flagellate protozoan Trypanosoma cruzi, is a chronic and systemic parasitic infection that affects ~5–7 million people worldwide, mainly in Latin America. Chagas disease is an emerging public health problem due to the lack of vaccines and effective treatments. According to recent studies, several T. cruzi secreted proteins interact with the human host during cell invasion. Moreover, some comparative studies with T. rangeli, which is non-pathogenic in humans, have been performed to identify proteins directly involved in the pathogenesis of the disease. In this study, we present an integrated analysis of canonical putative secreted proteins (PSPs) from both species. Additionally, we propose an interactome with human host and gene family clusters, and a phylogenetic inference of a selected protein. In total, we identified 322 exclusively PSPs in T. cruzi and 202 in T. rangeli. Among the PSPs identified in T. cruzi, we found several trans-sialidases, mucins, MASPs, proteins with phospholipase 2 domains (PLA2-like), and proteins with Hsp70 domains (Hsp70-like) which have been previously characterized and demonstrated to be related to T. cruzi virulence. PSPs found in T. rangeli were related to protozoan metabolism, specifically carboxylases and phosphatases. Furthermore, we also identified PSPs that may interact with the human immune system, including heat shock and MASP proteins, but in a lower number compared to T. cruzi. Interestingly, we describe a hypothetical hybrid interactome of PSPs which reveals that T. cruzi secreted molecules may be down-regulating IL-17 whilst T. rangeli may enhance the production of IL-15. These results will pave the way for a better understanding of the pathophysiology of Chagas disease and may ultimately lead to the identification of molecular targets, such as key PSPs, that could be used to minimize the health outcomes of Chagas disease by modulating the immune response triggered by T. cruzi infection
- …