Regional disparities and industrial structure: territorial capital and productivity in Italian firms

We investigate the role of Territorial Capital (TC) on the productivity of Italian firms, constructing indicators for eight dimensions of TC in a first attempt to capture a wide variety of regional resources. When imposing homogeneous TC effects on all firms, we find that technological, social, institutional, financial and infrastructure capital drive productivity. However, only technological and artistic capital contribute to reduce regional disparities. Across industries, financial capital and infrastructure increase productivity in companies operating in a wide range of sectors. Industrial policies should consider sectoral heterogeneity and North-South differences to effectively boost productivity performance

Set-up of a multi wavelength polar photometer for off-line absorption coefficient measurements on 1-h resolved aerosol samples

In this paper, a polar photometer (PP_UniMI) was set up to measure the aerosol absorption coefficient (\u3c3ap) at four wavelengths (\u3bb) on 1-h resolved aerosol samples collected using a streaker sampler. Due to the characteristics of such samples (small deposit area, low aerosol load, and limited substrate thickness 12 10 \u3bcm), the main technical developments aimed at reaching suitable limits of detection (LODs). To this aim, multiple scattering between the sample and a suitable substrate were exploited to amplify the system sensitivity to absorbing particle load. In the paper, the development and test of this innovative approach is presented. LODs for \u3c3ap in the range 5.0\u201311.6 Mm 121 were reached, depending on the wavelength. Such values were suitable for the analysis of 1-hour resolved samples collected at an urban background site in Milan (Italy) during a test campaign of 1-week carried out in winter 2015. The methodology was validated comparing \u3c3ap measurements performed by PP_UniMI at \u3bb=635 nm on the streaker sample to the data obtained by a Multi-Angle Absorption Photometer (MAAP) operated in parallel. Agreement within 10% was found. To check the results obtained at other wavelengths, \uc5ngstr\uf6m Absorption Exponent (AAE) was calculated from \u3c3ap measurements at 4-\u3bb. The AAE values resulted in the range of expectations for aerosol emitted by fossil fuel combustion (0.8\u20131.2) and wood burning (0.9\u20133.5), which are the main sources contributing to absorbing aerosol in urban areas in winter. The analytical methodology can be extended to samples collected with high time resolution using other high-time resolution samplers (e.g. drum rotating impactors). This is \u2013 as far as we know \u2013 the first time that \u3c3ap measurements are performed on streaker samples collected with 1-h resolution. Our results thus set PP_UniMI as an important tool for the community performing high time resolved sampling to widen the characterisation of such samples and to further develop source apportionment studies

The FIT-pull Method: an experimental tool to monitor the track measurements and the B proper time.

In this note we describe a statistical tool, the \textit{FIT-pull method}, that can test the reliability of the measurements of the tracks and the vertices on real and Monte-Carlo data without knowledge of the truth information. The basic mathematical formalism is derived from the Lagrange Multipliers method and briefly described. Several tests are performed to prove its validity in different situations. %KDifferent useful examples are discussed. In particular, by using Monte-Carlo simulation, we demonstrate that the method can be applied to check if the measured tracks or vertices have biases or incorrect covariance matrices. For correct input measurements we obtain pull distributions with a normal Gaussian statistical form. In this case the B proper time value and its error, which is a function of the track and vertex measurements, are correctly calculated. However, in the case of incorrect measurements, for example due to a systematic error or to a scale factor of the covariance matrix, the pull distributions studied deviate from normal Gaussians and the B proper time measurement can be affected. In principle the method can, if necessary, be used to recover information from corrupted measurements. Its potential in this capacity is demonstrated for the particular case of the decay channel $B^0_d \to \pi^+ \pi^-$ with the reconstructed Monte-Carlo data produced in 2004

Shaping the fluorescent emission by lattice resonances in plasmonic crystals of nanoantennas

We demonstrate that the emission of light by fluorescent molecules in the proximity of periodic arrays of nanoantennas or plasmonic crystals can be strongly modified when the arrays are covered by a dielectric film. The coupling between localized surface plasmon resonances and photonic states leads to surface modes which increase the density of optical states and improve light extraction. Excited dye molecules preferentially decay radiatively into these modes, exhibiting an enhanced and directional emission.Comment: 5 figure

The IGNITOR ICRF system

Sheets presentatio

Biomass from microalgae: The potential of domestication towards sustainable biofactories

Interest in bulk biomass from microalgae, for the extraction of high-value nutraceuticals, bio-products, animal feed and as a source of renewable fuels, is high. Advantages of microalgal vs. plant biomass production include higher yield, use of non-arable land, recovery of nutrients from wastewater, efficient carbon capture and faster development of new domesticated strains. Moreover, adaptation to a wide range of environmental conditions evolved a great genetic diversity within this polyphyletic group, making microalgae a rich source of interesting and useful metabolites. Microalgae have the potential to satisfy many global demands; however, realization of this potential requires a decrease of the current production costs. Average productivity of the most common industrial strains is far lower than maximal theoretical estimations, suggesting that identification of factors limiting biomass yield and removing bottlenecks are pivotal in domestication strategies aimed to make algal-derived bio-products profitable on the industrial scale. In particular, the light-to-biomass conversion efficiency represents a major constraint to finally fill the gap between theoretical and industrial productivity. In this respect, recent results suggest that significant yield enhancement is feasible. Full realization of this potential requires further advances in cultivation techniques, together with genetic manipulation of both algal physiology and metabolic networks, to maximize the efficiency with which solar energy is converted into biomass and bio-products. In this review, we draft the molecular events of photosynthesis which regulate the conversion of light into biomass, and discuss how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. We outline major successes reached, and promising strategies to achieving significant contributions to future microalgae-based biotechnology

Potential and challenges of improving photosynthesis in algae

Sunlight energy largely exceeds the energy required by anthropic activities, and therefore its exploitation represents a major target in the field of renewable energies. The interest in the mass cultivation of green microalgae has grown in the last decades, as algal biomass could be employed to cover a significant portion of global energy demand. Advantages of microalgal vs. plant biomass production include higher light‐use efficiency, efficient carbon capture and the valorization of marginal lands and wastewaters. Realization of this potential requires a decrease of the current production costs, which can be obtained by increasing the productivity of the most common industrial strains, by the identification of factors limiting biomass yield, and by removing bottlenecks, namely through domestication strategies aimed to fill the gap between the theoretical and real productivity of algal cultures. In particular, the light‐to‐biomass conversion efficiency represents one of the major constraints for achieving a significant improvement of algal cell lines. This review outlines the molecular events of photosynthesis, which regulate the conversion of light into biomass, and discusses how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. This review highlights the most recent results in the manipulation of the fundamental mechanisms of algal photosynthesis, which revealed that a significant yield enhancement is feasible. Moreover, metabolic engineering of microalgae, focused upon the development of renewable fuel biorefineries, has also drawn attention and resulted in efforts for enhancing productivity of oil or isoprenoids

A new look at the cosmic ray positron fraction

The positron fraction in cosmic rays was found to be a steadily increasing in function of energy, above $\sim$ 10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the interactions of primary cosmic rays during the propagation in the interstellar medium. The observed anomaly in the positron fraction triggered a lot of excitement, as it could be interpreted as an indirect signature of the presence of dark matter species in the Galaxy. Alternatively, it could be produced by nearby astrophysical sources, such as pulsars. Both hypotheses are probed in this work in light of the latest AMS-02 positron fraction measurements. The transport of the primary and secondary positrons in the Galaxy is described using a semi-analytic two-zone model. MicrOMEGAs is used to model the positron flux generated by dark matter species. The description of the positron fraction from astrophysical sources is based on the pulsar observations included in the ATNF catalogue. We find that the mass of the favoured dark matter candidates is always larger than 500 GeV. The only dark matter species that fulfils the numerous gamma ray and cosmic microwave background bounds is a particle annihilating into four leptons through a light scalar or vector mediator, with a mixture of tau (75%) and electron (25%) channels, and a mass between 0.5 and 1 TeV. The positron anomaly can also be explained by a single astrophysical source and a list of five pulsars from the ATNF catalogue is given. Those results are obtained with the cosmic ray transport parameters that best fit the B/C ratio. Uncertainties in the propagation parameters turn out to be very significant. In the WIMP annihilation cross section to mass plane for instance, they overshadow the error contours derived from the positron data.Comment: 20 pages, 16 figures, accepted for publication in A&A, corresponds to published versio

Cosmic-ray measurements by reconstructing longitudinal profiles for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) will be the next generation gamma-ray observatory in the energy range from 20 GeV to 300 TeV, offering 5-10 times better flux sensitivity than the current generation of imaging atmospheric Cherenkov telescopes. Each telescope will capture an image of the Cherenkov light produced when air showers created by gamma rays or cosmic rays pass through the atmosphere. The longitudinal development of the shower in the atmosphere can be studied by measuring the number of charged particles produced as a function of depth. The reconstruction of the longitudinal shower profile provides the depth of the shower maximum Xmax which is a mass-sensitive parameter useful for cosmic ray composition. In this work, we reconstruct the longitudinal profile and the Xmax of air showers initiated by two kinds of cosmic ray species, proton, and iron, with energies between 10 TeV and 300 TeV. This reconstruction is different from other methods that have been used in the past as template-based fit techniques that require a detailed and computing-intensive simulation chain. In contrast, we use for the first time a parameterized function for the angular distribution of Cherenkov light around the shower axis.</p

Cosmic-ray measurements by reconstructing longitudinal profiles for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) will be the next generation gamma-ray observatory in the energy range from 20 GeV to 300 TeV, offering 5-10 times better flux sensitivity than the current generation of imaging atmospheric Cherenkov telescopes. Each telescope will capture an image of the Cherenkov light produced when air showers created by gamma rays or cosmic rays pass through the atmosphere. The longitudinal development of the shower in the atmosphere can be studied by measuring the number of charged particles produced as a function of depth. The reconstruction of the longitudinal shower profile provides the depth of the shower maximum Xmax which is a mass-sensitive parameter useful for cosmic ray composition. In this work, we reconstruct the longitudinal profile and the Xmax of air showers initiated by two kinds of cosmic ray species, proton, and iron, with energies between 10 TeV and 300 TeV. This reconstruction is different from other methods that have been used in the past as template-based fit techniques that require a detailed and computing-intensive simulation chain. In contrast, we use for the first time a parameterized function for the angular distribution of Cherenkov light around the shower axis.</p