Evolution of the Light Echo of SN?1991T

Schmidt et al. presented strong evidence (photometry and spectroscopy) that the late time optical emission of SN 1991T in the Virgo spiral NGC 4527 is caused by a light echo. Here, we present photometry with the Wide Field and Planetary Camera 2 and high-resolution imaging polarimetry and photometry with the Faint Object Camera on board the Hubble Space Telescope, which demonstrates that the feature is indeed a light echo of the original supernova. We show that the emission is spatially resolved, complex, and both growing in size and changing in morphology. The echo is slowly fading. Our primary interest is to use the echo for estimating the distance to the host galaxy geometrically (see 1994 work by Sparks). Given that the elapsed time since the supernova exploded is small and that the galaxy is relatively distant, the expected region of maximally polarized emission cannot be fully resolved as yet. However, we do find polarized emission at the center of the echo, and simple models may be used to yield a distance estimate. The models favor smaller distances, with ≈15 Mpc being the upper allowable distance, subject to caveats described in the text. The echo is consistent with being caused by a dust cloud of uniform density n ~ 0.9 cm-3 and extending to ≈50 pc in front of the supernova. It is encouraging that even in a case very far from ideal, we can use this type of observation to derive a distance

Characterization of Sex-Based Dna Methylation Signatures in the Airways During Early Life.

Human respiratory conditions are largely influenced by the individual\u27s sex resulting in overall higher risk for males. Sex-based respiratory differences are present at birth suggesting a strong genetic component. Our objective was to characterize early life sex-based genomic signatures determined by variable X-chromosome methylation in the airways. We compared male versus female genome-wide DNA methylation in nasal airway samples from newborns and infants aged 1-6 months (N = 12). We analyzed methylation signals across CpG sites mapped to each X-linked gene using an unsupervised classifier (principal components) followed by an internal evaluation and an exhaustive cross-validation. Results were validated in an independent population of children (N = 72) following the same algorithm. X-linked genes with significant sex-based differential methylation in the nasal airway of infants represented only about 50% of the unique protein coding transcripts. X-linked genes without significant sex-based differential methylation included genes with evidence of escaping X-inactivation and female-biased airway expression. These genes showed similar methylation patterns in males and females suggesting unbalanced X-chromosome dosage. In conclusion, we identified that the human airways have already sex-based DNA methylation signatures at birth. These early airway epigenomic marks may determine sex-based respiratory phenotypes and overall predisposition to develop respiratory disorders later in life

Oximetry signal processing identifies REM sleep-related vulnerability trait in asthmatic children

Rationale. The sleep-related factors that modulate the nocturnal worsening of asthma in children are poorly understood. This study addressed the hypothesis that asthmatic children have a REM sleep-related vulnerability trait that is independent of OSA. Methods. We conducted a retrospective cross-sectional analysis of pulse-oximetry signals obtained during REM and NREM sleep in control and asthmatic children (n=134). Asthma classification was based on preestablished clinical criteria. Multivariate linear regression model was built to control for potential confounders (significance level p ≤ 0.05). Results. Our data demonstrated that (1) baseline nocturnal respiratory parameters were not significantly different in asthmatic versus control children, (2) the maximal % of SaO2 desaturation during REM, but not during NREM, was significantly higher in asthmatic children, and (3) multivariate analysis revealed that the association between asthma and REM-related maximal % SaO2 desaturation was independent of demographic variables. Conclusion. These results demonstrate that children with asthma have a REM-related vulnerability trait that impacts oxygenation independently of OSA. Further research is needed to delineate the REM sleep neurobiological mechanisms that modulate the phenotypical expression of nocturnal asthma in children

Multiplicação in vitro de cultivares de amoreira-preta.

PROPAGAÇÃO IN VITRO DE CULTIVARES DE AMOREIRA-PRETA - A amora-preta é uma alternativa econômica interessante para os pequenos produtores das regiões de clima subtropical e temperatura, principalmente da região Sul do Brasil. Há 30 anos, a Embrapa Clima Temperado possui programa de melhoramento genético para a cultura, tendo recomendado várias cultivares. Seguindo recomendação das entidades certificadoras, as mudas devem ser produzidas via cultura de tecidos, para se ter maior garantia da qualidade genética, horticultural e fitossanitária. Um protocolo eficiente de micropropagação foi desenvolvido na Embrapa Clima Temperado, tendo sido avaliada sua eficiência na multiplicação in vitro de sete cultivares de amoreira-preta (Brazos, Cherokee, Comanche, Ébano, Guarani, Tupy e Xavante). A desinfestação dos explantes foi realizada em soluções a base de álcool e hipoclorito de sódio; a cultura dos meristemas em meio semi-sólido MS com 1 mg L-1 BAP, 0,01 mg L-1 ANA e 0,1 mg L-1 AG3; a multiplicação em MS com 0,8 mg L-1 BAP; e o enraizamento em ½MS com 0,5 mg L-1 ANA, sempre a 25?4oC, 20 ?E m-2 s-1 e fotoperíodo de 16 horas. Quanto à eficiência do processo, o número estimado de plantas obtidas por meristema é de 16.335 para 'Brazos', 24.211 para 'Cherokee', 19.778 para 'Comanche', 106.550 para 'Ébano', 14.275 para 'Guarani', 34.022 para 'Tupy' e 24.651 para 'Xavante'.bitstream/item/31251/1/comunicado-154.pd

Differential expression of lipoprotein genes in Mycoplasma pneumoniae after contact with human lung epithelial cells, and under oxidative and acidic stress

<p>Abstract</p> <p>Background</p> <p><it>Mycoplasma pneumoniae </it>is a human pathogen that is a common cause of community-acquired pneumonia. It harbours a large number of lipoprotein genes, most of which are of unknown function. Because of their location on the cell surface, these proteins are likely to be involved in the bacterial response to environmental changes, or in the initial stages of infection. The aim of this study was to determine if genes encoding surface lipoproteins are differentially expressed after contact with a human cell line, or after exposure to oxidative or acidic stress.</p> <p>Results</p> <p>Using qRT-PCR assays, we observed that the expression of a number of lipoprotein genes was up-regulated when <it>M. pneumoniae </it>was placed in contact with human cells. In contrast, lipoprotein expression was generally down-regulated or unchanged when exposed to either hydrogen peroxide or low pH (5.5). When exposed to low pH, the mRNA levels of four polycistronically transcribed genes in Lipoprotein Multigene Family 6 formed a gradient of decreasing quantity with increasing distance from a predicted promoter.</p> <p>Conclusion</p> <p>The demonstrated transcriptional changes provide evidence for the functionality of these mostly unassigned genes and indicate that they are regulated in response to changes in environmental conditions. In addition we have shown that the members of Lipoprotein Gene Family 6 may be expressed polycistronically.</p

Micropropagação de cultivares de framboeseira.

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Bot’n roll robotic kit as a learning tool for youngsters

Activities involving robotics, projecting assembling and programming robots are in essence hands-on and inquiry-based activities leading to an effective learning of different aspects of science and technology among others. Different approaches have being used to introduce robotics in the education of young children. In this communication we will present an approach that in an inquiry based science education, IBSE, perspective, uses an informal environment to introduced robotics, as well as a range of other science and technology, concepts and competencies to young students. Many youngsters are getting interested on general technology and the robotics field in particular. Even though their knowledge is very basic they are very enthusiastic and willing to learn quickly. Most robotics events consist of competitions, and that means the youngsters still need guidance by professionals. RoboParty is a different educational robotics event that teaches the participants, with IBSE hands-on techniques, how to build a robot from scratch to program it and in the end they keep the robot they built for themselves for further exploration. Such robot to be built by the young children for the first time needs to be very easy and with a friendly programming language. The Bot’n Roll robotics kit was developed specifically for the RoboParty event, and has since then been improved with more sensors and actuators, which are simple to built and easy to use. The Bot’n Roll robot family launched recently another more complex robot that uses omnidirectional wheels and that can be used on other robotic competitions like world known RoboCup. This paper describes also the Bot’n Roll robots and show how they are built, bearing in mind that these robots were developed for youngsters who never worked with robotics

Close range photogrammetry in the survey of the coastal area geoecological conditions (on the example of Portugal)

Close range digital photogrammetry, which involves the application of unmanned aerial vehicle (UAV), has been used in a growing number of diverse applications across different scientific disciplines. Our objective was to use the mentioned method in the survey of the contemporary geoecological conditions of the coastal area on the example of Portuguese northwest coastal zone. The coastal zone can be subdivided into two geomorphological sectors: Sector 1, between the Minho River and the town of Espinho, where the coastal segments consist of estuaries, sandy and shingle beaches with rocky outcrops, and Holocene dune systems. The estuaries and the foredunes in particular are very degraded by human activities; and Sector 2, between Espinho and the Mondego Cape, where coastal lagoons and Holocene dune systems occur. We chose two beaches for surveying – Aguçadoura and Ramalha to which the drone swinglet CAM took the photos. We used the ground control software eMotion 2 to plan the flights over the study area and controlled the drone’s trajectory during flight. After processing the obtained images in the program of AgisoftPhotoscanPro, we generated the 2D orthophotos and 3D digital elevation models (DEM) of the research sections. At this stage of study we derived the above product without using the ground control points, or we used only the camera GPS data. Based on these models the compilation of the large-scale maps of high resolution (1cm-5cm) will be possible in the GISs for monitoring and management of the geoecological state of the mentioned beaches in case to precise the x, y and z values of the models with the geodetic device of Differential GPSs in the selected ground control points (GCP).We are grateful to the European Commission ERASMUS-MUNDUS Action-2 ELECTRA program and the Earth Sciences Centre of the University of Minho (Braga, Portugal) in supporting us to conduct the field works and research.info:eu-repo/semantics/publishedVersio