22,281 research outputs found
Insight into the phytochemical, biological, and in silico studies of Erythrina suberosa roxb.: A source of novel therapeutic bioactive products from a medicinal plant
No full textBackground: and purpose: Erythrina suberosa (E. suberosa) Roxb also known as corky coral tree is used as a folklore medicine to treat ulcers and piles. This study explored the phytochemical profiles of methanol and dichloromethane (DCM) extracts from the aerial, root, and flower parts of Erythrina suberosa (E. suberosa) Roxb. Method: Total bioactive contents, high-performance liquid chromatography photo diode array (HPLC-PDA) polyphenolic quantification, and ultra-high performance liquid chromatography-mass spectrometry (UHPLCMS) analysis were used to evaluate the phytochemical profile. Biological potential was evaluated by determining their antioxidant (DPPH, ABTS, FRAP, CUPRAC, Phosphomolybdenum, and metal chelating) and enzyme inhibitory (cholinesterase, amylase, glucosidase, and tyrosinase) effects. Results: The phenolic (46.26 mg GAE/g extract) and flavonoid (32.46 mg QE/g extract) contents were found to be highest in the methanolic extract of roots (EsR-M). HPLC-PDA analysis determined the presence of numerous bioactive compounds, including catechin, syringic acid, p-hydroxy benzoic acid, gallic acid, vanillic acid, epicatechin, rutin, chlorogenic acid, carvacrol, sinapinic acid, and naringenin in considerable amounts. A total of 143 phytochemicals, belonging to phenolic, flavonoid, coumarin, terpenoid, chalcone, saponin, and glycoside classes, were tentatively identified by UHPLC-MS analysis. Aerial methanolic extract (EsA-M) exhibited highest radical scavenging (DPPH 86.81 mgTE/g extract, ABTS 245.17 mgTE/g extract) as well as reducing potential (FRAP 177.12 mgTE/g extract, CUPRAC 177.12 mgTE/g extract). Likewise, it was also noted to be most active for BChE (5.70 mg GALAE/g extract) and tyrosinase inhibition (148.35 mg KAE/g extract). While, roots-DCM extract (EsR-D) presented considerable inhibition for AChE (4.69 mg GALAE/g extract) and amylase inhibition (0.81 mmol ACAE/g extract). Coreopsin, davallioside A, and isovitexin were docked to tyrosinase to depict possible interaction. Conclusion: This study has established baseline data on the biological and phytochemical profile of Erythrina suberosa which was found to possess antioxidant, antidiabetic, neuroprotective, and wound healing properties which tend to validate its traditional uses. However, further studies to identify the molecular targets responsible for these activities are warranted which could be explored as a functional food
The generalized Liénard polynomial differential systems x'=y,y'= -g(x) - f (x)y with deg g = deg f 1 are not Liouvillian integrable
No full textAgraïments: The second author was supported by Portuguese National Funds through FCT - Fundação para a Ciência e a Tecnologia within the project PTDC/MAT/117106/2010 and by CAMGSD (PEst-OE/EEI/LA0009/2013)We prove the nonexistence of Liouvillian first integrals for the generalized Li\'enard polynomial differential systems of the form x' = y, y'=-g(x)-f(x)y, where g(x) and f(x) are arbitrary polynomials such that g = f 1
Pensar la violencia desde G. Deleuze
No full textEl artículo reflexiona sobre el fenómeno de la violencia en nuestras sociedades tardomodernas. En primer lugar, critica la concepción ilustrada de la violencia, según la cual ésta es siempre una desviación de la razón, es decir, una "sinrazón". En segundo lugar, el autor sostiene que la comprensión de la violencia debe hacerse desde el "pensamiento de la diferencia". Desde esta última perspectiva, la violencia es el resultado del imperio de la "lógica oposicional" o "lógica binaria", la cual sustituye a la relación diferencial de carácter rizomático. Se recurre, fundamentalmente, al pensamiento de G. Deleuze, matizando el fenómeno de la violencia como "necedad", "geometría de Estado" e "incapacidad para ser afectado".The article reflects on the phenomenon of violence in our late modern societies. First, criticizes the Enlightenment conception of violence, that it is always a deviation of reason, ie a "unreason". Secondly, the author argues that the understanding of violence must be from the "thought of difference". From the latter perspective, violence is the result of the rule of "oppositional logic" or "binary logic" which replaces the differential relation of rhizomatic character. It basically resorts to thoughts of G. Deleuze, qualifying the phenomenon of violence as "stupidity", "geometry of State" and "incapacity to be affected"
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
Overview of the Author Profiling Task at PAN 2013
No full text[EN] This overview presents the framework and results for the Author Profiling
task at PAN 2013. We describe in detail the corpus and its characteristics,
and the evaluation framework we used to measure the participants performance to
solve the problem of identifying age and gender from anonymous texts. Finally,
the approaches of the 21 participants and their results are described.The author profiling task @PAN-2013 was an activity of the WIQ-EI IRSES project (Grant No. 269180) within the FP 7 Marie Curie People Framework of the European Commission. We want to thank the Forensic Lab of the Universitat Pompeu Fabra Barcelona for sponsoring the award for the winner team. The work of the first author was partially funded by Autoritas Consulting SA and by Ministerio de Economía y Competitividad de España under grant ECOPORTUNITY IPT-2012-1220-430000. The work of the second author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge in Texts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems. The work of fifth author was funded in part by the Swiss National Science Foundation (SNF) project "Mining Conversational Content for Topic Modelling and Author Identification (ChatMiner)" under grant number 200021_130208.Rangel, F.; Rosso, P.; Koppel, M.; Stamatatos, E.; Inches, G. (2013). Overview of the Author Profiling Task at PAN 2013. CLEF Conference on Multilingual and Multimodal Information Access Evaluation. 352-365. https://riunet.upv.es/handle/10251/46636S35236
G-Drazin inverse combined with inner inverse
No full text[EN] This article introduces new classes of generalized inverses for square matrices named GD1, and the dual, called 1GD inverse. In addition, we discuss a few characterizations and representations of these inverses. The explicit expressions of these inverses have been established via core-nilpotent decomposition. Further, we introduce a binary relation for GD1 inverse and 1GD inverse, along with a few derived properties.The second author is partially supported by the Science & Engineering Research Board (SERB),Govt. of India [grant ID SUR/2022/004357]. The third author was partially supported by the Universidad Nacional de Rio Cuarto [grant PPI 18/C559], Universidad Nacional de La Pampa, Facultadde Ingenieria [grant resol. nro. 135/19], Universidad Nacional del Sur [grant PGI 24/L108], and Ministerio de Economia, Industria y Competitividad (Spain) [grant red de excelencia RED2022-134176-T].Maharana, G.; Sahoo, JK.; Thome, N. (2024). G-Drazin inverse combined with inner inverse. Linear and Multilinear Algebra. https://doi.org/10.1080/03081087.2024.2316786
The generalized Liénard polynomial differential systems x'=y,y'= -g(x) - f (x)y with deg g = deg f 1 are not Liouvillian integrable
No full textAgraïments: The second author was supported by Portuguese National Funds through FCT - Fundação para a Ciência e a Tecnologia within the project PTDC/MAT/117106/2010 and by CAMGSD (PEst-OE/EEI/LA0009/2013)We prove the nonexistence of Liouvillian first integrals for the generalized Li\'enard polynomial differential systems of the form x' = y, y'=-g(x)-f(x)y, where g(x) and f(x) are arbitrary polynomials such that g = f 1
High-resolution numerical analysis of turbulent flow in straight open ducts with rectangular cross-section
No full textTurbulent secondary flow in straight open ducts with rectangular cross-section are studied numerically by means of pseudo- spectral direct numerical simulation (DNS). Similarly to the corresponding closed duct flows, the mean streamwise vorticity pattern in turbulent open duct flows were found to be the statistical footprint of the most probable locations of the quasi-streamwise vortices. A major difference between the two configurations was found in the vicinity of mixed-boundary corners where noticeably persistent vortical structures exist.Turbulent secondary flow in straight open ducts with rectangular cross-section are studied numerically by means of pseudo- spectral direct numerical simulation (DNS). Similarly to the corresponding closed duct flows, the mean streamwise vorticity pattern in turbulent open duct flows were found to be the statistical footprint of the most probable locations of the quasi-streamwise vortices. A major difference between the two configurations was found in the vicinity of mixed-boundary corners where noticeably persistent vortical structures exist
Galdós, el periodismo y la escritura. Reflexiones a partir del cuento "El artículo de fondo"
No full textGaldós was experiencing in his formation and in his first stage of production the narrative space of the press. The short story “El artículo de fondo” was published in 1871 in Revista de España, in 1879, in three installments in El Océano and reappears in 1889 in a collection of brief narrative texts that accompany his Torquemada en la hoguera. This study tries to focus, on the one hand, the variants introduced by the author, especially in the last edition, in order to evaluate the process of maturation of galdosian writing. On the other hand, taking into account the essentially heterotextual consistency of this short story, it try to put it in relation to the pluritextual narrative texture, which the newspaper macrotexts emblematically reflects.Galdós da a conocer por primera vez el cuento “El artículo de fondo” en 1871 en la publicación periódica Revista de España (XIX, 3, 427-440). Bastante años después, volverá a editarlo en una colección de textos de narrativa breve que acompañan su Torquemada en la hoguera (Madrid, La Guirnalda y Episodios y Episodios Nacionales, 1889), advirtiendo a su amigo Clarín en una carta que las «antiguallas» que presentaba el volumen, sacadas del olvido por voluntad ajena al autor, no merecían la pena de una lectura. Sin embargo, Galdós tuvo que empeñarse en la revisión, por lo menos del texto que aquí nos interesa, si consideramos las variantes introducidas, las elisiones y las ampliaciones que la segunda edición del cuento presenta ya sólo a través de una rápida collatio y a partir del incipit. Siguiendo esta pista, no mencionada en los escasos estudios que la crítica galdosiana ha dedicado a “El artículo de fondo” y que hemos podidos consultar, y enfocando la consistencia esencialmente heterotextual del cuento, se ha ido hilvanando una serie de reflexiones acerca del interés de Galdós por los procesos de construcción del texto, del tejido narrativo pluritextual, conjunto de piezas da variada naturaleza verbal y genérica, que el macrotexto del periódico emblemáticamente refleja. Galdós iba experimentando en su formación y en su primera etapa de producción precisamente el espacio narrativo de la prensa, instalado en lo sustancial de la narración diversificada por registros y dispositivos informativos, entre los cuales los visuales, de la actualidad. De ahí, la hipótesis de este estudio que intenta enfocar, más allá de la incontrovertible parodia del periodista costumbrista o serial que el cuento elige come sujeto, las estrategias de trasvase de la realidad en el texto, una realidad siempre multifacética que necesita la yuxtaposición de piezas verbales y de perspectivas singulares, según los rasgos del discurso periodístico y del periódico como sistema textual complejo
An RNA interference knock-down of nitrate reductase enhances lipid biosynthesis in the diatom Phaeodactylum tricornutum
No full textWhen diatoms are stressed for inorganic nitrogen they remodel their intermediate metabolism and redirect carbon towards lipid biosynthesis. However, this response comes at a significant cost reflected in decreased photosynthetic energy conversion efficiency and growth. Here we explore a molecular genetics approach to restrict the assimilation of inorganic nitrogen by knocking down nitrate reductase (NR). The transformant strain, NR21, exhibited about 50% lower expression and activity of the enzyme but simultaneously accumulated over 40% more fatty acids. However, in contrast to nitrogen-stressed wild-type (WT) cells, which grow at about 20% of the rate of nitrogen-replete cells, growth of NR21 was only reduced by about 30%. Biophysical analyses revealed that the photosynthetic energy conversion efficiency of photosystem II was unaffected in NR21; nevertheless, the plastoquinone pool was reduced by 50% at the optimal growth irradiance while in the WT it was over 90% oxidized. Further analyses reveal a 12-fold increase in the glutamate/glutamine ratio and an increase NADPH and malonyl-CoA pool size. Transcriptomic analyses indicate that the knock down resulted in changes in the expression of genes for lipid biosynthesis, as well as the expression of specific transcription factors. Based on these observations, we hypothesize that the allocation of carbon and reductants in diatoms is controlled by a feedback mechanism between intermediate metabolites, the redox state of the plastid and the expression and binding of transcription factors related to stress responses.Peer reviewe
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