On baryogenesis from dark matter annihilation

We study in detail the conditions to generate the baryon asymmetry of the universe from the annihilation of dark matter. This scenario requires a low energy mechanism for thermal baryogenesis, hence we first discuss some of these mechanisms together with the specific constraints due to the connection with the dark matter sector. Then we show that, contrary to what stated in previous studies, it is possible to generate the cosmological asymmetry without adding a light sterile dark sector, both in models with violation and with conservation of B-L. In addition, one of the models we propose yields some connection to neutrino masses.Comment: 30 pages, 9 artistic figures. V2 minor changes, matches published version in JCA

Top-philic Vector-Like Portal to Scalar Dark Matter

We investigate the phenomenology of scalar singlet dark matter candidates that couple dominantly to the Standard Model via a Yukawa interaction with the top quark and a colored vector-like fermion. We estimate the viability of this vector-like portal scenario with respect to the most recent bounds from dark matter direct and indirect detection, as well as to dark matter and vector-like mediator searches at colliders. Moreover, we take QCD radiative corrections into account in all our theoretical calculations. This work complements analyses related both to models featuring a scalar singlet coupled through a vector-like portal to light quarks, and to scenarios in which the dark matter is a Majorana singlet coupled to the Standard Model through scalar colored particles (akin to simplified models inspired by supersymmetry). Our study puts especially forward the complementarity of different search strategies from different contexts, and we show that current experiments allow for testing dark matter masses ranging up to 700 GeV and mediator masses ranging up to 6 TeV.Comment: 15 pages, 11 figures; version accepted by PR

Migration in Southern Europe since 1945: The Entanglement of many Mobilities

“Space” – in which the phenomenon of migration takes place – is not the only category to be rethought and relocated in migration studies. Another key issue is “time”, or rather a periodisation. For a long time, the academic debate on Europeans Mediterranean countries has been dominated by a claim that has been more or less taken as given, namely, the historical succession of emigration and immigration. Italy, Spain, Greece, and Portugal are supposed to have followed, according to this evidence, a cyclical model of migration that was around up until the 1970s, the emigration beyond national borders being seen as a predominant movement following by a massive foreign immigration which is said to have supplanted the centrality of expatriation. The article proposes a new point of view about this question, incorporating emigration, immigration and internal migration in Italy, Spain, Greece, and Portugal in a convergent perspective.L’« espace » – dans lequel se produisent les migrations – n’est pas la seule catégorie à être repensée et relocalisée dans les études sur la migration. Le « temps », ou plutôt la périodisation, est un autre problème clé. Pendant longtemps, le débat savant sur les pays méditerranéens d’Europe a été dominé par une conviction plus ou moins partagée sur la succession historique de l’émigration et de l’immigration. Selon ces termes, l’Italie, l’Espagne, la Grèce et le Portugal auraient suivi un modèle migratoire cyclique qui a existé jusque dans les années 1970, l’émigration au-delà des frontières nationales étant perçue comme un mouvement prédominant suivi d’une immigration étrangère massive qui aurait supplanté la centralité de l’expatriation. L’article propose un nouveau point de vue sur cette question, intégrant émigration, immigration et migration interne en Italie, en Espagne, en Grèce et au Portugal dans une perspective convergente.El «espacio», en el que se produce el fenómeno de la migración, no es la única categoría que debe ser repensada y reubicada en los estudios migratorios. Otro tema clave es el «tiempo», o más bien la periodización. Durante mucho tiempo, el debate académico sobre los países mediterráneos europeos ha estado dominado por una afirmación que se ha considerado más o menos dada, a saber, la sucesión histórica de emigración e inmigración. Se supone que Italia, España, Grecia y Portugal han seguido, de acuerdo con esta evidencia, un modelo cíclico de migración que se extendió hasta la década de 1970, la emigración se considera un movimiento predominante seguido por una inmigración extranjera masiva que suplantó la centralidad de la expatriación. El artículo propone un nuevo punto de vista sobre esta cuestión, incorporando la emigración, la inmigración y la migración interna en Italia, España, Grecia y Portugal en una perspectiva convergente

Radiative corrections to vectorlike portal dark matter

A massive real scalar dark matter particle $S$ can couple to Standard Model leptons or quarks through a vector-like fermionic mediator $\psi$, a scenario known as the Vector-like portal. Due to helicity suppression of the annihilation cross section into a pair of SM fermions, it has been shown in previous works that radiative corrections, either at one-loop or through radiation of gauge bosons, may play a significant role both in determining the relic abundance and for indirect detection. All previous works considered the limit of massless final state quarks or leptons. In this work, we focus on a technical issue, which is to reliably determine the annihilation cross sections taking into account finite fermion masses. Following previous works in the framework of simplified supersymmetric dark matter scenarios, and building on an analogy with Higgs decay into fermions, we address the issue of infrared and collinear divergences that plagues the cross section by adopting an effective operator description, which captures most of the relevant physics and give explicit expressions for the annihilation cross sections. We then develop several approximations for the differential and total cross sections, which simplify greatly their expressions, and which can then be used in various phenomenological studies of similar models. Finally, we describe our method to compute the final gamma-ray spectrum, including hadronisation of the heavy fermions, and provide some illustrative spectra for specific dark matter candidates.Comment: 25 pages, 12 figures. One extra figure. Conclusions unchanged. Version published in PR

Precision Agriculture Workflow, from Data Collection to Data Management Using FOSS Tools: An Application in Northern Italy Vineyard

In the past decades, technology-based agriculture, also known as Precision Agriculture (PA) or smart farming, has grown, developing new technologies and innovative tools to manage data for the whole agricultural processes. In this framework, geographic information, and spatial data and tools such as UAVs (Unmanned Aerial Vehicles) and multispectral optical sensors play a crucial role in the geomatics as support techniques. PA needs software to store and process spatial data and the Free and Open Software System (FOSS) community kept pace with PA’s needs: several FOSS software tools have been developed for data gathering, analysis, and restitution. The adoption of FOSS solutions, WebGIS platforms, open databases, and spatial data infrastructure to process and store spatial and nonspatial acquired data helps to share information among different actors with user-friendly solutions. Nevertheless, a comprehensive open-source platform that, besides processing UAV data, allows directly storing, visualising, sharing, and querying the final results and the related information does not exist. Indeed, today, the PA’s data elaboration and management with a FOSS approach still require several different software tools. Moreover, although some commercial solutions presented platforms to support management in PA activities, none of these present a complete workflow including data from acquisition phase to processed and stored information. In this scenario, the paper aims to provide UAV and PA users with a FOSS-replicable methodology that can fit farming activities’ operational and management needs. Therefore, this work focuses on developing a totally FOSS workflow to visualise, process, analyse, and manage PA data. In detail, a multidisciplinary approach is adopted for creating an operative web-sharing tool able to manage Very High Resolution (VHR) agricultural multispectral-derived information gathered by UAV systems. A vineyard in Northern Italy is used as an example to show the workflow of data generation and the data structure of the web tool. A UAV survey was carried out using a six-band multispectral camera and the data were elaborated through the Structure from Motion (SfM) technique, resulting in 3 cm resolution orthophoto. A supervised classifier identified the phenological stage of under-row weeds and the rows with a 95% overall accuracy. Then, a set of GIS-developed algorithms allowed Individual Tree Detection (ITD) and spectral indices for monitoring the plant-based phytosanitary conditions. A spatial data structure was implemented to gather the data at canopy scale. The last step of the workflow concerned publishing data in an interactive 3D webGIS, allowing users to update the spatial database. The webGIS can be operated from web browsers and desktop GIS. The final result is a shared open platform obtained with nonproprietary software that can store data of different sources and scales

Role of meteorological, hydrological and biogeochemical forcings on carbonate system variability at PALOMA station (Gulf of Trieste)

The Gulf of Trieste is the Northernmost area of the Adriatic Sea and, as other shallow shelf areas, is more influenced by exchanges with the atmosphere than deep seas. Hence, it is thought to be highly sensitive to the effects due to the increase of CO2 dissolved in seawater induced by global atmospheric CO2 increase. The most concerning consequence of CO2 dissolution in marine waters is the decrease of pH: a process commonly referred to as "ocean acidification". On the other hand, the dynamics of carbonate system in this coastal zone are also influenced by the variability of oceanographic conditions, mainly induced by meteorological and hydrological forcings, and by production and regeneration processes. We present preliminary results of a monitoring activity started in January 2008, addressed to a better comprehension of the effects of meteorological forcings and biogeochemical processes on the carbonate system and pH in the Gulf of Trieste. Real-time meteorological data, hydrological and biogeochemical monthly sampling were collected in the site of the mast PALOMA, located in the centre of the gulf (25 m of depth). During 2008, the highest values of pHT, (spectrophotometric method, Total scale, 25?C), were measured in the upper layer during summer (pHT=8.120), as a result of a event of production. A strong thermohaline stratification of the water column occurred from June to beginning of August, when remineralization processes in the deeper waters (AOU>142.87 μM -O2) released CO2 (fCO2=1044 μatm) and caused a decrease of pHT (7.648). This process was probably interrupted by one unusually storm event with strong wind (up to 163 km/h) that occurred on 08/08/2008, since in September the water column appeared well ventilated. Total alkalinity (TA) concentrations were modulated both by river inputs and by biogeochemical processes, as the remineralization of organic nitrogen coupled to ammonia production, which determined the maximum values of TA in August and November (up to 2693 μmol/kg)

Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages

Previous gene targeting studies in mice have implicated the nuclear protein Krüppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates. © 2010 Elsevier Inc

Shake table testing of a low-impact technology for the seismic protection of stone masonry

This paper presents a novel low-impact technique for the seismic protection of fair-face masonry walls. The proposed strengthening solution involves the use of carbon-fibre reinforced polymer (CFRP) connectors installed from the outside by perforating the stone elements, combined with grout injections. The connectors cover ¾ of the wall thickness, so as to leave the inner surface undisturbed. Once the work is completed, they are also substantially invisible. Shake table tests were carried out under natural accelerograms on two full-scale irregular multi-leaf stone masonry wall specimens. In order to replicate materials and construction technique of the Apennine historical buildings, the prototypes were made from stones recovered from the debris of a settlement in the municipality of Accumoli (RI, Italy), and the mortar was designed to reproduce lime-poor mortars surveyed in the field. The experimental setup was designed to induce out-of-plane vertical bending under base seismic motion, while allowing the vertical displacement of the wall top. One specimen was tested “as-built” and the other one was tested strengthened, to investigate the gain in seismic performance, the limitation of progressive damage accumulation and the effects on dynamic properties