Variability in snake venom composition is well-documented and crucial for understanding snake ecology and predicting snakebites. In this study, we characterize the venom composition and biological ...activities of newborn female and male Bothrops moojeni and their mother. Our results reveal significant differences between the venom of newborn females and males, demonstrating a broad and diverse range of proteins. The venoms of newborn females showed higher serine protease effects, increased hemorrhagic activity, and greater lethality compared to the venom of newborn males. However, no differences were observed in phospholipase A2 and coagulant activity. The differences in protein composition and toxic activities between maternal and neonatal venom, as well as between the venoms of newborn females and males, contribute to understanding the diverse outcomes of snakebites. These results underscore the importance of considering sex and ontogeny in understanding venom composition in snakes.
The serpent study involves physiological, behavioral and interaction factors with an extremely dynamic and complex environment. The relation of these animals with biodiversity is still quite ...preliminary, little studied and sustained by popular practices related to traditional medicine, esoteric and mystical currents. Therefore, this study proposed to know about the effect of 80% crude alcoholic extract of Petiveria alliacea L., popularly known as Tipi Herb, and its effects associated with the repellency of the Bothrops moojeni serpent. A complex of boxes was built for the observation of the snake's displacement, carried out for a total period of six days, the first three for defining the exploratory pattern and the other two for testing the alcoholic extract of Tipi, and finally on the sixth day, one cycle with the presence of a live attractant as bait. It was observed that the animal had no inhibition behavior and moved through the complex in a way like what occurs in nature and showed behavior to avoid remaining in the presence of the extract both with the presence of a live attractant or without it, preferring to move in the other compartments. The results show that this proposed tool is valid for the study of displacement of Bothrops moojeni snakes, in the same way that it added values on the importance of cerrado biome biodiversity and on the popular medicine practices of Tipi Herb, since the repellent effect on the snake was significant in the two tests performed.
We present ground-based and Swift photometric and spectroscopic observations of the tidal disruption event (TDE) ASASSN-15oi, discovered at the centre of 2MASX J20390918-3045201 (d ... 216 Mpc) by ...the All-Sky Automated Survey for SuperNovae. The source peaked at a bolometric luminosity of L ... 1.3 x 10 super( 44) erg s... and radiated a total energy of E ... 6.6 x 1050 erg over the first ~3.5 months of observations. The early optical/UV emission of the source can be fit by a blackbody with temperature increasing from T ~ 2 x 10 super( 4) K to T ~ 4 x 10 super( 4) K while the luminosity declines from L ... 1.3 x 10 super( 44) erg s... to L ... 2.3 x 10 super( 43) erg s..., requiring the photosphere to be shrinking rapidly. The optical/UV luminosity decline during this period is most consistent with an exponential decline, ..., with t ... 46.5 d for t0 ... 57241.6 (MJD), while a power-law decline of L ... (t - t0)-a with t sub( 0) ... 57 212.3 and a = 1.62 provides a moderately worse fit. ASASSN-15oi also exhibits roughly constant soft X-ray emission that is significantly weaker than the optical/UV emission. Spectra of the source show broad helium emission lines and strong blue continuum emission in early epochs, although these features fade rapidly and are not present ~3 months after discovery. The early spectroscopic features and colour evolution of ASASSN-15oi are consistent with a TDE, but the rapid spectral evolution is unique among optically selected TDEs. (ProQuest: ... denotes formulae/symbols omitted.)
The Largest M Dwarf Flares from ASAS-SN Schmidt, Sarah J.; Shappee, Benjamin J.; van Saders, Jennifer L. ...
Astrophysical journal/The Astrophysical journal,
05/2019, Letnik:
876, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The All-sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light approximately every day, reaching a depth of g ∼ 18 mag. Over the course ...of its first 4 yr of transient alerts (2013-2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified T Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V-band contrast from ΔV = −1 to −10.2 mag. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V-band energy emitted during each flare, spanning -35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M dwarf flare stars show a higher fraction of H emission, as well as stronger H emission, compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old.
The GALEX Ultraviolet Atlas of Nearby Galaxies Gil de Paz, Armando; Boissier, Samuel; Madore, Barry F ...
The Astrophysical journal. Supplement series,
12/2007, Letnik:
173, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present images, integrated photometry, and surface-brightness and color profiles for a total of 1034 nearby galaxies recently observed by the Galaxy Evolution Explorer (GALEX) satellite in its ...far-ultraviolet (FUV; unk = 1516 AA) and near-ultraviolet (NUV; unk = 2207 AA) bands. Our catalog of objects is derived primarily from the GALEX Nearby Galaxies Survey (NGS) supplemented by galaxies larger than 1' in diameter serendipitously found in these fields and in other GALEX exposures of similar of greater depth. The sample analyzed here adequately describes the distribution and full range of properties (luminosity, color, star formation rate SFR) of galaxies in the local universe. From the surface brightness profiles obtained we have computed asymptotic magnitudes, colors, and luminosities, along with the concentration indices C31 and C42. We have also morphologically classified the UV surface brightness profiles according to their shape. This data set has been complemented with archival optical, near-infrared, and far-infrared fluxes and colors. We find that the integrated (FUV - K) color provides robust discrimination between elliptical and spiral/irregular galaxies and also among spiral galaxies of different subtypes. Elliptical galaxies with brighter K-band luminosities (i.e., more massive) are redder in (NUV - K) color but bluer In (FUV - NUV) (a color sensitive to the presence of a strong UV upturn) than less massive ellipticals. In the case of the spiral/irregular galaxies our analysis shows the presence of a relatively tight correlation between the (FUV - NUV) color (or, equivalently, the slope of the UV spectrum, beta ) and the total infrared-to-UV ratio. The correlation found between (FUV - NUV) color and K-band luminosity (with lower luminosity objects being bluer than more luminous ones) can be explained as due to an increase in the dust content with galaxy luminosity. The images in this Atlas along with the profiles and integrated properties are publicly available through a dedicated Web page.
Abstract Sodium lauryl sulfate is the main cleaning ingredient in shampoos, even though it may be potentially damaging to hair. The demand for antioxidant-rich cosmetics, on the other hand, has ...encouraged green cosmetics research. Brazil has vast biodiversity that can be exploited for the production of these cosmetics. This work aimed to develop a minimalist antioxidant lauryl-free shampoo formulation with leaf extracts from the Brazilian plant Hancornia speciosa Gomes. Two hydroethanolic extracts were prepared using different extraction methods, Soxhlet, and ultrasound. The extracts were characterized by the presence of saponins, polyphenol quantification, and HLPC chemical identification of the compounds. Antioxidant activity was determined using the DPPH method. The antioxidant lauryl-free shampoo was developed using hydroxyethyl cellulose with two concentrations of leaf extract obtained by Soxhlet, 0.125 mg/g (XP1) and 0.250 mg/g (XP2). Along with the antioxidant activity, the physical and chemical properties, cleaning potential, and foam quality were evaluated. The Soxhlet leaf extract revealed a more favorable chemical profile, including a positive result for saponins, as well as a larger quantity of polyphenols and increased antioxidant activity. The XP2 formulation showed better foam height, dirt dispersion, and antioxidant activity. Thus, the use of mangabeira leaf extract appears to be promising for the development of shampoos with antioxidant activity.
Resumo O lauril sulfato de sódio é o principal ingrediente de limpeza em xampus, embora possa ser potencialmente prejudicial ao cabelo. A demanda por cosméticos ricos em antioxidantes, por outro lado, tem incentivado as pesquisas com cosméticos verdes. O Brasil possui uma vasta biodiversidade que pode ser explorada para a produção desses cosméticos. O objetivo deste trabalho foi desenvolver uma formulação de xampu antioxidante minimalista sem lauril com extratos de folhas da planta brasileira Hancornia speciosa Gomes. Dois extratos hidroetanólicos foram preparados usando diferentes métodos de extração, Soxhlet e ultrassom. Os extratos foram caracterizados quanto à presença de saponinas, quantificação de polifenóis e identificação química HLPC dos compostos. A atividade antioxidante foi determinada pelo método DPPH. O xampu antioxidante sem lauril foi desenvolvido utilizando hidroxietil celulose com duas concentrações de extrato de folha obtido por Soxhlet, 0.125 mg/g (XP1) e 0.250 mg/g (XP2). Juntamente com a atividade antioxidante, foram avaliadas as propriedades físicas e químicas, potencial de limpeza e qualidade da espuma. O extrato da folha de Soxhlet revelou um perfil químico mais favorável, incluindo resultado positivo para saponinas, além de maior quantidade de polifenóis e aumento da atividade antioxidante. A formulação XP2 apresentou melhor altura de espuma, dispersão de sujeira e atividade antioxidante. Assim, o uso do extrato da folha de mangabeira parece ser promissor para o desenvolvimento de xampus com atividade antioxidante.
ABSTRACT We report the discovery and classification of SDSS J053341.43+001434.1 (SDSS0533), an early-L dwarf first discovered during a powerful ΔV < −11 magnitude flare observed as part of the ...ASAS-SN survey. Optical and infrared spectroscopy indicate a spectral type of L0 with strong H emission and a blue NIR spectral slope. Combining the photometric distance, proper motion, and radial velocity of SDSS0533 yields three-dimensional velocities of (U, V, W) = (14 13, −35 14, −94 22) km s−1, indicating that it is most likely part of the thick disk population and probably old. The three detections of SDSS0533 obtained during the flare are consistent with a total V-band flare energy of at least 4.9 × 1033 erg (corresponding to a total thermal energy of at least Etot > 3.7 × 1034 erg), placing it among the strongest detected M dwarf flares. The presence of this powerful flare on an old L0 dwarf may indicate that stellar-type magnetic activity persists down to the end of the main sequence and on older ML transition dwarfs.
ABSTRACT
We use the Galaxy And Mass Assembly survey (GAMA) I data set combined with GALEX, Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) imaging to construct the ...low‐redshift (z < 0.1) galaxy luminosity functions in FUV, NUV, ugriz and YJHK bands from within a single well‐constrained volume of 3.4 × 105 (Mpc h−1)3. The derived luminosity distributions are normalized to the SDSS data release 7 (DR7) main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 μm free from any wavelength‐dependent cosmic variance for both the elliptical and non‐elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population, respectively. Using the Driver et al. prescription for the azimuthally averaged photon escape fraction, the non‐ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 ± 0.3) × 1035 h W Mpc−3 of which (1.2 ± 0.1) × 1035 h W Mpc−3 is directly released into the inter‐galactic medium and (0.6 ± 0.1) × 1035 h W Mpc−3 is reprocessed and reradiated by dust in the far‐IR. Using the GAMA data and our dust model we predict the mid‐ and far‐IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre‐ and post‐dust attenuated energy output of the nearby Universe from 0.1 μm to 0.6 mm. The largest uncertainty in this measurement lies in the mid‐ and far‐IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass and morphology.
Abstract The objective of this study was to describe the histology and histochemistry of the integument covering the back and stinger of the freshwater stingray Potamotrygon rex, endemic to the ...Middle Upper Tocantins River. The species has a dark back and yellowish circular spots that extend to the tail, which has one to two stings located in the median portion of the tail. Through histological study it was observed that the epithelia of the back and stinger are composed of non-keratinized stratified pavement epithelial tissue, and are organized in three layers: basal, intermediate and superficial. The differences between the tissues are related to the cell types that compose them. The back is organized with epithelial cells, mucus cells, granulocyte cells and chromatophores. The mucus cells are distributed in different layers along the animal's back, influencing the thickness of the tissue. The tissue that covers the stinger is composed of epithelial cells, chromatophores and specialized cells in protein synthesis. In the histochemistry, the stinger epithelial cells were stained with Bromophenol Blue, especially those of the intermediate layer, which were called specialized cells. In the back the epithelial cells were stained with Bromophenol Blue, Alcian Blue and PAS, and the mucous cells with PAS. In both tissues the presence of protein reserves was detected, areas so called because they are stained strongly with Bromophenol Blue. The results show that the stinger presents activity directed to the production of proteins, and that the back is organized to produce different components, which constitute the cuticle that covers the animal's body.
Resumo O objetivo deste estudo foi descrever a histologia e histoquímica do tegumento que reveste o dorso e o ferrão da arraia de água doce Potamotrygon rex, endêmica do Médio Alto Tocantins. A espécie possui o dorso escuro e manchas circulares amareladas que se estendem até a cauda, que possui de um a dois ferrões localizados na porção mediana da cauda. Através do estudo histológico observou-se que os epitélios do dorso e do ferrão são compostos por tecido epitelial pavimentoso estratificado não queratinizado, e estão organizados em três camadas: basal, intermediária e superficial. As diferenças entre os tecidos estão relacionadas aos tipos de células que os compõem. O dorso é organizado com células epiteliais, células mucosas, células de granulócitos e cromatóforos. As células mucosas estão distribuídas em diferentes camadas ao longo do dorso do animal, influenciando na espessura do tecido. O tecido que reveste o ferrão é composto por células epiteliais, cromatóforos e células proteicas. Na histoquímica, as células epiteliais do ferrão foram coradas com Azul de Bromofenol, principalmente as da camada intermediária, que foram denominadas células proteicas. No dorso as células epiteliais foram coradas com Azul de Bromofenol, Azul Alcian e PAS, e as células mucosas com PAS. Em ambos os tecidos também foi detectada a presença de reservatórios de proteínas, áreas assim denominadas por estarem fortemente coradas com Azul de Bromofenol. Os resultados mostram que o ferrão apresenta atividade direcionada à produção de proteínas, e que o dorso se organiza para produzir diferentes componentes que constituem a cutícula que reveste o corpo do animal.
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