Progress with the LOFAR Imaging Pipeline

One of the science drivers of the new Low Frequency Array (LOFAR) is large-area surveys of the low-frequency radio sky. Realizing this goal requires automated processing of the interferometric data, such that fully calibrated images are produced by the system during survey operations. The LOFAR Imaging Pipeline is the tool intended for this purpose, and is now undergoing significant commissioning work. The pipeline is now functional as an automated processing chain. Here we present several recent LOFAR images that have been produced during the still ongoing commissioning period. These early LOFAR images are representative of some of the science goals of the commissioning team members.Comment: 11 pages, 6 figures. Accepted for publication in proceedings of "ISKAF2010 Science Meeting", PoS(ISKAF2010)05

Transcriptome characterisation and SSR markers development in the seagrass Posidonia oceanica

Posidonia oceanica is an endemic seagrass in the Mediterranean Sea, where it provides important ecosystem services and sustains a rich and diverse ecosystem. P. oceanica meadows extend from the surface to 40 meters depth. With the aim of boosting research in this iconic species, we generated a comprehensive RNA-Seq data set for P. oceanica by sequencing specimens collected at two depths and two times during the day. With this approach we attempted to capture the transcriptional diversity associated with change in light and other depth-related environmental factors. Using this extensive data set we generated gene predictions and identified an extensive catalogue of potential Simple Sequence Repeats (SSR) markers. The data generated here will open new avenues for the analysis of population genetic features and functional variation in P. oceanica. In total, 79,235 contigs were obtained by the assembly of 70,453,120 paired end reads. 43,711 contigs were successfully annotated. A total of 17,436 SSR were identified within 13,912 contigs

FIRB "SQUARE" project: nano-structured sensors for the detection of the polluting in engine exhaust gases and for indoor air quality monitoring

The present work is a final dissemination of activities carried out and main results obtained in the national founded project Firb "Square". The project is leaded by Centro Ricerche Fiat and it involves the most qualified national public Research Institutes and Universities active in the fields of nanomaterials synthesis, nanotechnology and gas sensors development

Probing atmospheric electric fields in thunderstorms through radio emission from cosmic-ray-induced air showers

We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields

The association of a J-burst with a solar jet

Context. The Sun is an active star that produces large-scale energetic events such as solar flares and coronal mass ejections and numerous smaller-scale events such as solar jets. These events are often associated with accelerated particles that can cause emission at radio wavelengths. The reconfiguration of the solar magnetic field in the corona is believed to be the cause of the majority of solar energetic events and accelerated particles. Aims. Here, we investigate a bright J-burst that was associated with a solar jet and the possible emission mechanism causing these two phenomena. Methods. We used data from the Solar Dynamics Observatory (SDO) to observe a solar jet, and radio data from the Low Frequency Array (LOFAR) and the Nan\c{c}ay Radioheliograph (NRH) to observe a J-burst over a broad frequency range (33-173 MHz) on 9 July 2013 at ~11:06 UT. Results. The J-burst showed fundamental and harmonic components and it was associated with a solar jet observed at extreme ultraviolet wavelengths with SDO. The solar jet occurred at a time and location coincident with the radio burst, in the northern hemisphere, and not inside a group of complex active regions in the southern hemisphere. The jet occurred in the negative polarity region of an area of bipolar plage. Newly emerged positive flux in this region appeared to be the trigger of the jet. Conclusions. Magnetic reconnection between the overlying coronal field lines and the newly emerged positive field lines is most likely the cause of the solar jet. Radio imaging provides a clear association between the jet and the J-burst which shows the path of the accelerated electrons.Comment: 11 pages, 8 figure

Renewable energies in a public forest: Viability of possible plant technologies

In this paper, a feasibility study of several technologies for the electrical and thermal energy production, fed with forest residues, is provided. With the aim of identifying the best sustainable energy exploitation of the forest biomass, the work has been developed in the following three main steps: the energy consumption of a buildings complex; a technical and economic evaluation of different configuration plants, along with a sensitivity analysis of some key parameters of the biomass; an environmental assessment via LCA (Life Cycle Assessment)

Sea level changes and past vegetation in the Punic period (5th–4th century BC): Archaeological, geomorphological and palaeobotanical indicators (South Sardinia – West Mediterranean Sea)

The ancient shorelines and main differences in the vegetational landscape of S Sardinia during the Punic period (5th–4th century BC) have been recognized by an interdisciplinary archaeological, paleobotanical and geomorphological approach. Sixteen trading amphoras and one olla of Punic manufacture brought to light during underwater exploration in Santa Gilla Lagoon (S Sardinia, W Mediterranean) provide data on relative sea level changes. The infilling mud of each retrieved amphora is representative of the ages lasting for about 200–300 years. The macro-archaebotanical contents document the use of seeds and fruits of Vitis, Sorbus, Ficus, Olea and Prunus during Punic trading and suggest the occurrence of agro-pastoral practices in the surrounding plains or the area behind the lagoon system. The palynological analysis documents the presence of holm and cork oak forests, a widespread Mediterranean forest with Juniper and Pinus, and a developed stagnant coastal system, and reveals a climate-induced past vegetation change that is likely to have been emphasized by anthropogenic pressure and agriculture activity during the 4th century BC. The GPS localization of the amphoras shows a distribution according to curved alignments that probably correspond to the shorelines (5th-4th century BC) at – 1.95 ± 10 m and −1.70 ± 10 m. Geomorphological data reveal a sea level rise of about 25 cm during a century, corresponding to 300 m of shoreline regression towards the alluvial plain. With these rapid processes of drowning of the coastal plain, the presence of Punic settlements along the lagoon borders documents the reorganization of commercial and economic activities. This shows the great adaptability of the ancient population to the sea level rise (SLR) and fast-flooding processes of the coastline in a lagoonal area vulnerable to subsidence phenomena