The Circumstellar Structure and Excitation Effects around the Massive Protostar Cepheus A HW 2

We report SMA 335 GHz continuum observations with angular resolution of ~0.''3, together with VLA ammonia observations with ~1'' resolution toward Cep A HW 2. We find that the flattened disk structure of the dust emission observed by Patel et al. is preserved at the 0.''3 scale, showing an elongated structure of ~$0.''6 size (450 AU) peaking on HW 2. In addition, two ammonia cores are observed, one associated with a hot-core previously reported, and an elongated core with a double peak separated by ~1.''3 and with signs of heating at the inner edges of the gas facing HW 2. The double-peaked ammonia structure, as well as the double-peaked CH3CN structure reported previously (and proposed to be two independent hot-cores), surround both the dust emission as well as the double-peaked SO2 disk structure found by Jimenez-Serra et al. All these results argue against the interpretation of the elongated dust-gas structure as due to a chance-superposition of different cores; instead, they imply that it is physically related to the central massive object within a disk-protostar-jet system.Comment: 12 pages, 3 figures; accepted for publication in the Astrophysical Journa

Binding-incompetent adenovirus facilitates molecular conjugate-mediated gene transfer by the receptor-mediated endocytosis pathway

Molecular conjugate vectors may be constructed that accomplish high efficiency gene transfer by the receptor-mediated endocytosis pathway. In order to mediate escape from lysosomal degradation, we have incorporated adenoviruses into the functional design of the conjugate. In doing so, however, we have introduced an additional ligand, which can bind to receptors on the cell surface, undermining the potential for cell specific targeting. To overcome this, we have treated the adenovirus with a monoclonal anti-fiber antibody, which renders the virus incapable of binding to its receptor. The result is a multi-functional molecular conjugate vector, which has preserved its binding specificity while at the same time being capable of preventing lysosomal degradation of endosome-internalized conjugate-DNA complexes. This finding indicates that adenoviral binding is not a prerequisite for adenoviral-mediated endosome disruption

Large cities are less efficient for sustainable transport: The ABC of mobility

The distance travelled by car in a city has many negative impacts on its population, including pollution, noise and the use of space. Yet, quantifying the motorisation of urban mobility is a serious challenge, particularly across cities of different regions. Here we model the number of kilometres travelled by different modes of transport in a city by aggregating active mobility (A), public transport (B) and cars (C), thus expressing the modal share of a city by its ABC triplet. Data for over 800 cities across over 60 countries is used to model kilometres travelled by car and its relationship with city size. Our findings suggest that although public transport is more prominent in large cities, it is insufficient to reduce the distance travelled by car users within the city and, ultimately, their emissions. For cities outside the US, results show that although the proportion of journeys by car decreases in larger cities, distances become more prolonged, thus experiencing more distance travelled by car. When a city doubles its size, it has 87\% more car journeys, but they are 41% longer, thus experiencing 2.6 times more vehicle kilometres travelled. Further, by matching cities of similar size inside and outside the US, we estimate that cities in the US have 2.3 times more vehicle kilometres travelled than cities elsewhere.Comment: 14 pages, 6 figure

High-resolution study of a star-forming cluster in the Cep-A HW2 region

Due to its relatively small distance (725 pc), the Cepheus A East star-forming region is an ideal laboratory to study massive star formation processes. Based on its morphology, it has been suggested that the flattened molecular gas distribution around the YSO HW2 may be a 350-AU-radius massive protostellar disk. Goal of our work is to ascertain the nature of this structure. We have employed the Plateau de Bure Interferometer to acquire (sub-)arcsecond-resolution imaging of high-density and shock tracers, such as methyl cyanide (CH3CN) and silicon monoxide (SiO), towards the HW2 position. On the 1-arcsecond (about 725 AU) scale, the flattened distribution of molecular gas around HW2 appears to be due to the projected superposition, on the plane of the sky, of at least three protostellar objects, of which at least one is powering a molecular outflow at a small angle with respect to the line of sight. The presence of a protostellar disk around HW2 is not ruled out, but such structure is likely to be detected on a smaller spatial scale, or using different molecular tracers.Comment: 6 pages, 5 figures, accepted for publication in Astronomy & Astrophysic

Political influencers. A study of Donald Trump’s personal brand on Twitter and its impact on the media and users

The personality of a political candidate, above and beyond governments and parties, is understood increasingly more as a brand image. The new political influencers are making a clean sweep of social networks and it is the media that reproduce an information model that, far from being grounded in transparency and quality, promotes a post-truth discourse, halfway between provocation and spectacle. This initial hypothesis focuses on Donald Trump’s profile, first as a presidential candidate and later on as US President. In parallel, Twitter users have swiftly succumbed to the leader’s appeal. Thus, this paper studies the impact of Trump’s tweets on the US reference press during the first 100 days of his presidency. More specifically, it analyses the correspondences between the tweets posted on his personal Twitter account (@realDonaldTrump, with more than 45 million followers) and the front page news in USA Today, The Boston Globe, The Wall Street Journal and The New York Times. Regarding public response, digital prosumer metrics (“likes,” retweets and comments) have been quantified in order to verify the degree of influence exerted by Trump on public opinion. The method employed here includes a quantitative and qualitative content analysis based on three categories: the politician’s tweets, front page news and online user metrics. The results confirm Trump’s empowerment on Twitter as both a main source of news and a political influencer as regards the media and the citizenry.La individualidad del candidato político se postula cada vez más como imagen de marca, por delante de partidos y gobiernos. Los nuevos influencers de la Política copan las redes y son los medios de comunicación quienes reproducen un modelo informativo que, lejos de la transparencia y la calidad, promueve el discurso de la postverdad, entre la provocación y el espectáculo. Una hipótesis que se focaliza en el perfil de Donald Trump, primero como candidato a las elecciones americanas y más tarde como presidente de EUA. En paralelo, los usuarios de Twitter sucumben a la atracción del líder a golpe de clic. La investigación estudia el impacto de los tuits de Trump sobre la agenda de la prensa americana de referencia durante los primeros cien días de Gobierno. Se analiza la equivalencia entre los tuits emitidos desde la propia cuenta personal (@realDonaldTrump –con más de 45 millones de seguidores– y las portadas de los periódicos USA Today, The Boston Globe, The Wall Street Journal y The New York Times. En orden a la respuesta ciudadana, se cuantifican las métricas (favoritos, retuits y comentarios) de los prosumidores digitales para comprobar los niveles de influencia que ejerce Trump sobre la opinión pública. El método comprende un análisis de contenido de corte cuantitativo y cualitativo-discursivo mediante una categorización triangulada: tuits del político, portadas mediáticas y métricas del usuario online. Los resultados confirman el empoderamiento de Trump en Twitter, como principal generador de noticias e influencer político de medios y ciudadanos

A VLA search for young protostars embedded in dense cores

Four dense cores, L1582A, L1689A, B133 and B68, classified as prestellar in terms of the absence of detectable NIR emission, are observed at radio wavelengths to investigate whether they nurture very young protostars. No definite young protostars were discovered in any of the four cores observed. A few radio sources were discovered close to the observed cores, but these are most likely extragalactic sources or YSOs unrelated to the cores observed. In L1582A we discovered a weak radio source near the centre of the core with radio characteristics and offset from the peak of the submillimeter emission similar to that of the newly discovered protostar in the core L1014, indicating a possible protostellar nature for this source. This needs to be confirmed with near- and/or mid-infrared observations (e.g. with Spitzer). Hence based on the current observations we are unable to confirm unequivocally that L1582A is starless. In L1689A a possible 4.5-sigma radio source was discovered at the centre of the core, but needs to be confirmed with future observations. In B133 a weak radio source, possibly a protostar, was discovered at the edge of the core on a local peak of the core submm emission, but no source was detected at the centre of the core. Thus, B133 is probably starless, but may have a protostar at its edge. In B68 no radio sources were discovered inside or at the edge of the core, and thus B68 is indeed starless. Four more radio sources with spectral indices characteristic of young protostars were discovered outside the cores but within the extended clouds in which these cores reside. Conclusions: We conclude that the number of cores misclassified as prestellar is probably very small and does not significantly alter the estimated lifetime of the prestellar phase.Comment: Accepted by A&