3,706 research outputs found

    A catalog of planetary nebula candidates in the Sculptor spiral galaxy NGC 300

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    [OIII]5007 on-band off-band images, obtained with the VLT and FORS2 spectrograph in two zones (center and outskirts) of the spiral galaxy NGC300, are analyzed searching for emission line objects. In particular we search for planetary nebula (PN) candidates to analyze their distribution and luminosity properties, to perform follow-up spectroscopy, and to study the planetary nebula luminosity function, PNLF. In the continuum-subtracted images, a large number of emission line objects were detected. From this sample we selected as PN candidates those objects with stellar appearance and no detectable central star. [OIII]5007 instrumental magnitudes were measured and calibrated by using spectrophotometric data from the follow-up spectroscopy. We identified more than a hundred PN candidates and a number of compact HII regions. The PN sample is the largest one reported for this galaxy so far. For all the objects we present coordinates, instrumental [OIII]5007 magnitudes and apparent nebular [OIII]5007 fluxes and magnitudes. The [OIII]5007 observed luminosity function for PNe (PNLF) was calculated for the whole sample and for the central and outskirts samples. The three PNLF are similar within uncertainties. We fit the empirical PNLF to the observed PNLF for all the samples. From our best fit for the whole sample we derived a maximum value for the apparent magnitudes of m*(5007)=22.019\pm0.022 and we obtained a tentative estimate of the distance modulus m(5007)-M(5007)= 26.29 {+0.12} {-0.22} mag, which agrees well with the recent value derived from Cepheid stars.Comment: 8 pages, 3 figures, one long table. Accepted by A&

    Lateral instability in normal viscous fingers

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    We study a low-amplitude, long-wavelength lateral instability of the Saffman-Taylor finger by means of a phase-field model. We observe such an instability in two situations in which small dynamic perturbations are overimposed to a constant pressure drop. We first study the case in which the perturbation consists of a single oscillatory mode and then a case in which the perturbation consists of temporal noise. In both cases the instability undergoes a process of selection

    Extracellular Vesicles in NAFLD/ALD:From Pathobiology to Therapy

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    In recent years, knowledge on the biology and pathobiology of extracellular vesicles (EVs) has exploded. EVs are submicron membrane-bound structures secreted from different cell types containing a wide variety of bioactive molecules (e.g., proteins, lipids, and nucleic acids (coding and non-coding RNA) and mitochondrial DNA). EVs have important functions in cell-to-cell communication and are found in a wide variety of tissues and body fluids. Better delineation of EV structures and advances in the isolation and characterization of their cargo have allowed the diagnostic and therapeutic implications of these particles to be explored. In the field of liver diseases, EVs are emerging as key players in the pathogenesis of both nonalcoholic liver disease (NAFLD) and alcoholic liver disease (ALD), the most prevalent liver diseases worldwide, and their complications, including development of hepatocellular carcinoma. In these diseases, stressed/damaged hepatocytes release large quantities of EVs that contribute to the occurrence of inflammation, fibrogenesis, and angiogenesis, which are key pathobiological processes in liver disease progression. Moreover, the specific molecular signatures of released EVs in biofluids have allowed EVs to be considered as promising candidates to serve as disease biomarkers. Additionally, different experimental studies have shown that EVs may have potential for therapeutic use as a liver-specific delivery method of different agents, taking advantage of their hepatocellular uptake through interactions with specific receptors. In this review, we focused on the most recent findings concerning the role of EVs as new structures mediating autocrine and paracrine intercellular communication in both ALD and NAFLD, as well as their potential use as biomarkers of disease severity and progression. Emerging therapeutic applications of EVs in these liver diseases were also examined, along with the potential for successful transition from bench to clinic

    Agronomic biofortification with selenium improves the yield and nutraceutical quality in tomato under soilless conditions

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    Selenium (Se) is an essential element for humans. Its consumption comes from food of animal or vegetal origin; whose content varies widely depending on its availability in soil or anthropogenic sources. Biofortification improves food nutritional quality, and its consumption has a positive influence in human health. Thus, the objective of this research was to assess agricultural biofortification with Se in tomato fruit and its effects on yield, nutraceutical quality, and antioxidant capacity.  Five Se doses (0, 2, 4, 6, and 8 mg L-1) in the form of sodium selenite (Na2SeO3) were added in a nutritional solution in a hydroponic system.  The results obtained indicated that agricultural biofortification with Se applied in the nutritional solution improved yield, nutraceutical quality, and Se concentration in tomato fruit. The optimum Se dose that maximized yield and nutraceutical quality, as well as the recommended consumption concentration in tomato fruit in this study was 2 mg L-1 (Na2SeO4) because higher doses decreased yield and bioactive compound biosynthesis. Incorporating Se in the nutritional solution is an alternative to increase phytochemical compound biosynthesis in tomato fruit and yield with the possibility of improving public health with its consumption

    Morpholigical study of honey bees on the Canary Islands (Gran Canaria, Tenerife, La Palma, Gomera)

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    A morphological study was made of worker bees from 49 hives located at four island from the Canary archipelago. The study analysed 18 morphological characters and we have found that the bees from Gran Canaria and Tenerife belong to the same groupe, the animals from Gomera constitute a group near the afore mentioned, and the bees from La Palma form an independent group. Also, we have compared the data with data to come from hives placed in the south of the Iberian peninsula and in the north of Africa. We have found that the bees from Africa form an independent group, and the bees from the Iberian peninsula are included in the La Palma group.Se ha llevado a cabo un estudio morfológico de las abejas obreras procedentes de 49 colmenas situadas en cuatro islas del Archipiélago Canario. Se han analizado 18 características morfológicas, encontrando que las abejas procedentes de Gran Canaria y Tenerife pertenecen al mismo grupo; los animales de Gomera constituyen un grupo cercano al anterior y las abejas de La Palma forman un grupo independiente. También hemos comparado los datos obtenidos, con los procedentes de colmenas situadas en el sur de la península Ibérica y en el norte de África. Encontramos que las abejas del norte de África constituyen un grupo independiente y que los animales del sur de la península se incluyen en el grupo de las abejas de La Palma

    Movement velocity can be used to estimate the relative load during the bench press and leg press exercises in older women

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    Background: Movement velocity has been proposed as an effective tool to prescribe the load during resistance training in young healthy adults. This study aimed to elucidate whether movement velocity could also be used to estimate the relative load (i.e., % of the one-repetition maximum (1RM)) in older women. Methods: A total of 22 older women (age = 68.2 ± 3.6 years, bench press 1RM = 22.3 ± 4.7 kg, leg press 1RM = 114.6 ± 15.9 kg) performed an incremental loading test during the free-weight bench press and the leg press exercises on two separate sessions. The mean velocity (MV) was collected with a linear position transducer. Results: A strong linear relationship between MV and the relative load was observed for the bench press (%1RM = -130.4 MV + 119.3; r2 = 0.827, standard error of the estimate (SEE) = 6.10%1RM, p < 0.001) and leg press exercises (%1RM = -158.3 MV + 131.4; r2 = 0.913, SEE = 5.63%1RM, p < 0.001). No significant differences were observed between the bench press and leg press exercises for the MV attained against light-medium relative loads (>70%1RM), while the MV associated with heavy loads (>80%1RM) was significantly higher for the leg press. Conclusions: These results suggest that the monitoring of MV could be useful to prescribe the loads during resistance training in older women. However, it should be noted that the MV associated with a given %1RM is significantly lower in older women compared to young healthy individuals

    RECOPILACIÓN BIBLIOGRÁFICA DE LOS ESTUDIOS REALIZADOS EN LA RESERVA FORESTAL FORTUNA (CHIRIQUÍ)

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    &nbsp;&nbsp;&nbsp; &nbsp;The purpose of this work is to provide bibliographical information on all papers published as a result of the research done in the Fortuna forest reserve. An extensive research was done in libraries, public and private entities and in Internet. The original database was developed using the Excel software. The first published study appeared in the magazine ―Loteria‖ in 1977. &nbsp;&nbsp;&nbsp;&nbsp;The studies were grouped in five categories. Overall, more than 100 specialists, native and foreign; belonging to 21 different institutions, have lend their work to add to our knowlege of this forest reserve. Their works have been published in approximately 20 journals.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;El objetivo de este trabajo es proporcionar información bibliográfica de todos los trabajos publicados, como resultado de las investigaciones hechas en la Reserva Forestal Fortuna. Se realizó una exhaustiva revisión bibliográfica, en bibliotecas, entidades del gobierno y privadas y en la Internet. La base de datos original, fue elaborada con el programa Excel. El primer estudio realizado es el que apareció en la Revista Lotería en el año 1977. &nbsp;&nbsp;&nbsp;&nbsp;Los estudios se agruparon en cinco categorías. En la realización de los estudios han participado más de 100 especialistas, tanto nacionales como extranjeros; pertenecientes a 21 instituciones. Los trabajos han sido publicados en aproximadamente 20 revistas.&nbsp;&nbsp;&nbsp

    Biotecnología de inoculación de árboles de importancia forestal con hongos ectomicorrízicos comestibles

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    México se considera un país megadiverso ya que cuenta con aproximadamente 10% de la diversidad terrestre del planet
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