Accretion onto the Companion of Eta Carinae During the Spectroscopic Event: III. the He II 4686 Line

We continue to explore the accretion model of the massive binary system eta Carinae by studying the anomalously high He II 4686 line. The line appears just before periastron and disappears immediately thereafter. Based on the He II 4686 line emission from O-stars and their modeling in the literature, we postulate that the He II 4686 line comes from the acceleration zone of the secondary stellar wind. We attribute the large increase in the line intensity to a slight increase in the density of the secondary stellar wind in its acceleration zone. The increase in density could be due to the ionization and subsequent deceleration of the wind by the enhanced X-ray emission arising from the shocked secondary wind further downstream or to accretion of the primary stellar wind. Accretion around the secondary equatorial plane gives rise to collimation of the secondary wind, which increases its density, hence enhancing the He II 4686 emission line. In contrast with previous explanations, the presently proposed model does not require a prohibitively high X-ray flux to directly photoionize the He.Comment: ApJ, in pres

Physical-Chemical Properties of Strawberry Pseudofruits Submitted to Applications of Zinc Oxide Nanoparticles

Strawberry cultivation is appreciated in many countries because of the fruit's well-defined, attractive and nutritional sensorial characteristics. As such, it is of great commercial value. The flavor and nutritional properties of the fruit are characteristics that have been developed and gaining importance, both in breeding programs and in productive systems. In this sense, this work proposes the application of nanotechnology for the improvement of the physicochemical characteristics of strawberry crops, with the main objective of analyzing the influence on nutritional performance of different fruit treatment doses with zinc oxide nanoparticles. The physicochemical analyses of the strawberry pseudofruitswere carried out from November to June 2016. The experimental design was in randomized complete blocks, in a factorial scheme, with 7 replicates. The collected data were submitted to analysis of variance with the F-test and the differences between means were compared by the Tukey test (P≤0.05).The treatment process of the strawberry crop with zinc oxide nanoparticles was shown to be efficient for anthocyanin nutrients and soluble solids. The method for analyzing vitamin C, which consisted in freezing the raw material, was ineffective, probably because of the reduction of ascorbic acid levels by the freezing and crystallization of the sample. Climatic factors significantly influence the nutritional composition of anthocyanins and soluble solids. The application of nanoparticles at 100% of the recommended dose proved to be more effective than zinc oxide in its natural form in increasing the soluble solids values

He II lambda-4686 in Eta Carinae: Collapse of the Wind-Wind Collision Region During Periastron Passage

The periodic spectroscopic events in Eta Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events we performed a dense monitoring of Eta Carinae with 5 Southern telescopes during the 2009 low excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II lambda-4686 emission line (L approx 310 solar L) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the wind-wind collision (WWC) region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II lambda-4686 light-curves. After a short-lived minimum, He II lambda-4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind

Spectrochemical analysis of liquid biopsy harnessed to multivariate analysis towards breast cancer screening

Mortality due to breast cancer could be reduced via screening programs where preliminary clinical tests employed in an asymptomatic well-population with the objective of identifying cancer biomarkers could allow earlier referral of women with altered results for deeper clinical analysis and treatment. The introduction of well-population screening using new and less-invasive technologies as a strategy for earlier detection of breast cancer is thus highly desirable. Herein, spectrochemical analyses harnessed to multivariate classification techniques are used as a bio-analytical tool for a Breast Cancer Screening Program using liquid biopsy in the form of blood plasma samples collected from 476 patients recruited over a 2-year period. This methodology is based on acquiring and analysing the spectrochemical fingerprint of plasma samples by attenuated total reflection Fourier-transform infrared spectroscopy; derived spectra reflect intrinsic biochemical composition, generating information on nucleic acids, carbohydrates, lipids and proteins. Excellent results in terms of sensitivity (94%) and specificity (91%) were obtained using this method in comparison with traditional mammography (88–93% and 85–94%, respectively). Additional advantages such as better disease prognosis thus allowing a more effective treatment, lower associated morbidity, fewer false-positive and false-negative results, lower-cost, and higher analytical frequency make this method attractive for translation to the clinical setting

Adult body growth and reproductive investment vary markedly within and across Atlantic and Pacific herring: a meta-analysis and review of 26 stocks

Life-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.publishedVersio

Eta Carinae's Brightness Variations Since 1998: HST Observations of the Central Star

We have measured the brightness variations in Eta Carinae for the past six years using the Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys. Unlike ground-based data, observations by the HST allow direct measurement of the brightness of the central star by resolving it from the surrounding bright ejecta. We find interesting behavior during 2003 in the continuum and H$\alpha$ emission. The data show that the established long term brightening trend of Eta Car continues, including regular events which coincide with the 5.5 year spectroscopic cycle and other more rapid and unexpected variations. In addition to the HST data, we also present ground-based data obtained from the AAVSO which show many of the same features. The dip in the apparent brightness of the central star at the time of the 2003.5 event is wavelength dependent with no decrease in the continuum. These observations cast doubt on asimple eclipse or occultation as the explanation for the dip and place constraints on the models for the event.Comment: 28 pages, 9 Figures, 3 Tables. Accepted for publication in the AJ (April 2004

A spectroscopic event of eta Car viewed from different directions: The data and first results

We present spectroscopic observations with high spectral resolution of eta Car as seen by the SE lobe of the Homunculus nebula over the 2003.5 "spectroscopic event". The observed spectra represent the stellar spectrum emitted near the pole of the star and are much less contaminated with nebular emission lines than direct observations of the central object. The "event" is qualitatively similar near the pole to what is observed in direct spectra of the star (more equator-on at 45 degree), but shows interesting differences. The observations show that the equivalent width changes of H alpha emission and other lines are less pronounced at the pole than in the line of sight. Also the absorption components appear less variable. A pronounced high-velocity absorption is present near the event in the He I lines indicating a mass-ejection event. This feature is also seen, but less pronounced, in the hydrogen lines. HeII4686 emission is observed for a brief period of time near the event and appears, if corrected for light travel time, to precede similar emission in the direct view. Our observations indicate that the event is probably not only a change in ionization and excitation structure or a simple eclipse-like event.Comment: 10 pages, 16 figures, accepted by A&

MicroScope: a platform for microbial genome annotation and comparative genomics

The initial outcome of genome sequencing is the creation of long text strings written in a four letter alphabet. The role of in silico sequence analysis is to assist biologists in the act of associating biological knowledge with these sequences, allowing investigators to make inferences and predictions that can be tested experimentally. A wide variety of software is available to the scientific community, and can be used to identify genomic objects, before predicting their biological functions. However, only a limited number of biologically interesting features can be revealed from an isolated sequence. Comparative genomics tools, on the other hand, by bringing together the information contained in numerous genomes simultaneously, allow annotators to make inferences based on the idea that evolution and natural selection are central to the definition of all biological processes. We have developed the MicroScope platform in order to offer a web-based framework for the systematic and efficient revision of microbial genome annotation and comparative analysis (http://www.genoscope.cns.fr/agc/microscope). Starting with the description of the flow chart of the annotation processes implemented in the MicroScope pipeline, and the development of traditional and novel microbial annotation and comparative analysis tools, this article emphasizes the essential role of expert annotation as a complement of automatic annotation. Several examples illustrate the use of implemented tools for the review and curation of annotations of both new and publicly available microbial genomes within MicroScope’s rich integrated genome framework. The platform is used as a viewer in order to browse updated annotation information of available microbial genomes (more than 440 organisms to date), and in the context of new annotation projects (117 bacterial genomes). The human expertise gathered in the MicroScope database (about 280,000 independent annotations) contributes to improve the quality of microbial genome annotation, especially for genomes initially analyzed by automatic procedures alone

ExoClock Project. III. 450 New Exoplanet Ephemerides from Ground and Space Observations

The ExoClock project has been created to increase the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates, in order to produce a consistent catalog of reliable and precise ephemerides. This work presents a homogenous catalog of updated ephemerides for 450 planets, generated by the integration of ~18,000 data points from multiple sources. These sources include observations from ground-based telescopes (the ExoClock network and the Exoplanet Transit Database), midtime values from the literature, and light curves from space telescopes (Kepler, K2, and TESS). With all the above, we manage to collect observations for half of the postdiscovery years (median), with data that have a median uncertainty less than 1 minute. In comparison with the literature, the ephemerides generated by the project are more precise and less biased. More than 40% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95%), and also the identification of missing data. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (transit-timing variations) for a sample of 19 planets. All the products, data, and codes used in this work are open and accessible to the wider scientific community.Fil: Kokori, A.. University College London; Reino UnidoFil: Tsiaras, A.. University College London; Reino UnidoFil: Edwards, B.. University College London; Reino UnidoFil: Jones, A.. Amateur Astronomer; Reino Unido. British Astronomical Association; Reino UnidoFil: Pantelidou, G.. Aristotle University of Thessaloniki; GreciaFil: Tinetti, G.. University College London; Reino UnidoFil: Bewersdorff, L.. Amateur Astronomer; Reino UnidoFil: Iliadou, A.. Aristotle University of Thessaloniki; GreciaFil: Jongen, Y.. Observatoire de Vaison-La-Romaine; FranciaFil: Lekkas, G.. University of Ioannina; GreciaFil: Nastasi, A.. INAF. Osservatorio Astronomico di Palermo; ItaliaFil: Poultourtzidis, E.. Aristotle University of Thessaloniki; GreciaFil: Sidiropoulos, C.. University of Ioannina; GreciaFil: Walter, F.. Štefánik Observatory; República ChecaFil: Wünsche, A.. Observatoire des Baronnies Provençales; FranciaFil: Abraham, R.. East Sussex Astronomical Society; Reino UnidoFil: Agnihotri, V. K.. Amateur Astronomer; Reino UnidoFil: Albanesi, R.. ARA Associazione Romana Astrofili; ItaliaFil: Arce Mansego, E.. Asociación Valenciana de Astronomía; EspañaFil: Arnot, D.. The Open University; Reino UnidoFil: Audejean, M.. Amateur Astronomer; Reino UnidoFil: Aumasson, C.. Observatoire des Baronnies Provençales; FranciaFil: Bachschmidt, M.. Amateur Astronomer; Reino UnidoFil: Baj, G.. Amateur Astronomer; Reino UnidoFil: Barroy, P. R.. Universite de Picardie Jules Verne (universite de Picardie Jules V);Fil: Belinski, A. A.. Lomonosov Moscow State University; RusiaFil: Bennett, D.. British Astronomical Association; Reino UnidoFil: Falco, C.. GAL Hassin. Centro Internazionale per le Scienze Astronomiche; ItaliaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Zíbar, M.. Czech Astronomical Society; República Chec