Constraints on cosmological parameters from future cosmic microwave background experiments

The Planck satellite experiment will soon let cosmologists to determine most of the cosmological parameters with unprecedented accuracy. In particular a strong improvement is expected in many parameters of interest, including neutrino mass, the amount of relativistic particles at recombination, the primordial Helium abundance and the injection of extra ionizing photon by dark matter self-annihilation. Here we review the constraints achievable by future experiments and discuss the implications for fundamental physics. © 2010 IOP Publishing Ltd

Constraining Fundamental Physics with Future CMB Experiments

The Planck experiment will soon provide a very accurate measurement of Cosmic Microwave Background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will improve and complement the Planck data with better angular resolution and better polarization sensitivity. This unexplored region of the CMB power spectrum contains information on many parameters of interest, including neutrino mass, the number of relativistic particles at recombination, the primordial Helium abundance and the injection of additional ionizing photons by dark matter self-annihilation. We review the imprint of each parameter on the CMB and forecast the constraints achievable by future experiments by performing a Monte Carlo analysis on synthetic realizations of simulated data. We find that next generation satellite missions such as CMBPol could provide valuable constraints with a precision close to that expected in current and near future laboratory experiments. Finally, we discuss the implications of this intersection between cosmology and fundamental physics.Comment: 11 pages, 14 figure

Tickling the CMB damping tail: scrutinizing the tension between the ACT and SPT experiments

The Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) have recently provided new, very precise measurements of the cosmic microwave background (CMB) anisotropy damping tail. The values of the cosmological parameters inferred from these measurements, while broadly consistent with the expectations of the standard cosmological model, are providing interesting possible indications for new physics that are definitely worth of investigation. The ACT results, while compatible with the standard expectation of three neutrino families, indicate a level of CMB lensing, parametrized by the lensing amplitude parameter A_L, that is about 70% higher than expected. If not a systematic, this anomalous lensing amplitude could be produced by modifications of general relativity or coupled dark energy. Vice-versa, the SPT experiment, while compatible with a standard level of CMB lensing, prefers an excess of dark radiation, parametrized by the effective number of relativistic degrees of freedom N_eff. Here we perform a new analysis of these experiments allowing simultaneous variations in both these, non-standard, parameters. We also combine these experiments, for the first time in the literature, with the recent WMAP9 data, one at a time. Including the Hubble Space Telescope (HST) prior on the Hubble constant and information from baryon acoustic oscillations (BAO) surveys provides the following constraints from ACT: N_eff=3.23\pm0.47, A_L=1.65\pm0.33 at 68% c.l., while for SPT we have N_eff=3.76\pm0.34, A_L=0.81\pm0.12 at 68% c.l.. In particular, the A_L estimates from the two experiments, even when a variation in N_eff is allowed, are in tension at more than 95% c.l..Comment: 7 pages, 7 figures, v.2. some typos and sentences correcte

Il Sistema di Trigger dell'Esperimento MEG per la Ricerca del Decadimento µ->e+gamma

L'esperimento MEG si prefigge di ricercare il decadimento µ->e+gamma, che viola la conservazione del sapore leptonico, con una sensibilità sul rapporto di decadimento, BR=µ->e+gamma/µ->X, di 10^{-13}. Il Modello Standard (MS) assume la conservazione completa del numero leptonico e quindi predice un valore nullo di BR ad ogni ordine della teoria. Con l'introduzione nel MS del fenomeno delle oscillazioni dei neutrini di Dirac si ottengono valori di BR non nulli, tuttavia non misurabili sperimentalmente BR circa 10^{-50}. Alcune classi di teorie Supersimmetriche di Grande Unificazione prevedono invece valori di BR vicini a 10^{-13}. L'esperimento MEG può quindi dare un importante contributo per ricercare nuova fisica oltre il MS. Il suddetto limite di sensibilità è di ben due ordini di grandezza inferiore al limite sperimentale attuale, ottenuto dalla collaborazione MEGA. Il raggiungimento di tale obiettivo è possibile solo utilizzando il più intenso fascio continuo oggi esistente al mondo di µ (10^{8} µ/s), presente al Paul Scherrer Institute (PSI). La segnatura dell'evento risulta semplice quando i µ decadono a riposo nel laboratorio: il positrone ed il fotone sono emessi contemporaneamente, con energia definita ed in direzioni opposte. Una reiezione del fondo che garantisca il raggiungimento della sensibilità di progetto richiede l'utilizzo di rivelatori che abbiano risoluzioni molto spinte nella misura delle variabili cinematiche caratteristiche del processo. Per tali motivi il calorimetro elettromagnetico e lo spettrometro per i positroni sono stati progettati utilizzando le più avanzate tecnologie oggi disponibili. L'apparato dell'esperimento MEG dovrà registrare i decadimenti di oltre 10^{13} muoni in condizioni di elevato affollamento. A questo scopo è stato progettato un sistema di Trigger che in tempo reale selezioni gli eventi di interesse. Il sistema è basato sulla digitizzazione delle forme degli impulsi provenienti dai fotomoltiplicatori dell'apparato e sull'analisi in tempo reale delle forme d'onda con algoritmi implementati in FPGAs. Questo approccio garantisce da un lato una selezione veloce degli eventi e dall'altro la flessibilità del sistema di Trigger per far fronte ad eventuali altre esigenze dell'apparato sperimentale. La simulazione dell'apparato ha consentito di individuare gli estimatori delle osservabili cinematiche (impulso, direzione e tempo di volo) delle particelle nello stato finale utili alla selezione degli eventi candidati µ->e+gamma. Durante il mio lavoro di tesi ho contribuito allo sviluppo degli algoritmi di ricostruzione delle osservabili cinematiche, alla loro traduzione nei linguaggi utili all'implementazione sugli FPGA ed al loro test per mezzo di forma d'onda simulate. Ho provveduto alla definizione ed all'applicazione delle procedure per l'accettazione delle schede elettroniche che costituiscono il sistema di Trigger. Ho inoltre contribuito alla scrittura dei programmi di configurazione ed acquisizione delle schede che verranno inglobati nei programmi di acquisizione dati dell'esperimento. Ho infine partecipato all'acquisizione e alla successiva analisi di spettri di emissione di un generatore di fotoni da 9 MeV, che verrà utilizzato per la calibrazione del calorimetro elettromagnetico. La misura è stata eseguita con una scheda del sistema di Trigger opportunamente configurata affinché agisse simultaneamente come sistema di selezione degli eventi e di acquisizion

Pronoun morphology, modality and semantics of political communication in presidential debate of two Italian political leaders

The present article wants to be an example of how spin can be profitably analysed not just as far as the content of the utterances is concerned but through their linguistic form as well, and of how mystification can be made transparent through the analysis of the language use of political texts at all levels, including morphology, grammar and syntax. The alleged ‘end of ideologies’ has brought about new forms of spin based on subtle ideological mystification that can be analysed through forms of language. One such example is the use of figures and expressions borrowed from the language of economics and business, considered the realms of ‘objectivity’

Assessing population collapse of Drupella spp. (Mollusca: Gastropoda) 2 years after a coral bleaching event in the Republic of Maldives

AbstractCorallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts

Atmospheric Correction in Sentinel-2 Simplified Level 2 Product Prototype Processor: Technical Aspects of Design and Implementation

This paper presents the scientific and technical aspects of the Level 2A (atmospheric/topographic correction) for the Sentinel-2 Simplified Level 2 Product Prototype Processor (S2SL2PPP). Design aspects are partly fixed by the ESA as main customer. Together with the alternative atmospheric correction system MACCS, the developed chain based on ATCOR is used for the estimation of the following products: Atmosphere type, Bottom of atmosphere reflectance (including cirrus detection and correction), Aerosol optical thickness, and Water vapor. Being a mono-temporal correction chain ATCOR requires a selection of the spectral bands for the estimation of Aerosol type, Aerosol optical thickness based on the dense dark vegetation method and Water vapor based on the atmospherically pre-corrected differential absorption method as well as an estimation of the best parameter set for these methods. The parameter set was estimated by a sensitivity analysis on a simulated top and bottom of atmosphere radiance/reflectance data based on radiative transfer simulations. The aerosol type is estimated by the comparison of the path radiances ratio to the ground truth path radiances ratio for the standard atmospheres, namely rural, urban, maritime, and desert. Aerosol optical thickness map and Water vapor map are initially estimated on the 20m pixel size data, then the maps are interpolated to the pixel size of 10m and the 10m reflectance data are estimated. The cirrus cloud map is created by the cirrus 1.38 µm band thresholding to the thin, medium, thick cirrus and cirrus clouds. Cirrus compensation is performed by correlating the cirrus band reflectance to the reflective region bands and subtraction of the cirrus contribution per band. Validation of the chain is performed given the top of atmosphere data (as input) and bottom of atmosphere products (the reference). Estimated reflectance is assessed given the ground truth reflectance, Aerosol optical thickness is validated given the AERONET measurements, cirrus correction is validated using a pair of Landsat-8 scenes acquired for the same area with a small time difference. One scene is contaminated by cirrus cloud that has to be restored, while the other is cirrus free and used as reference. A comparison of the estimated products is also performed with an alternative atmospheric correction chain – FLAASH. The software is developed using the Interactive Data Language (IDL) and python. This paper presents the scientific and technical aspects of the Level 2A (atmospheric/topographic correction) for the Sentinel-2 Simplified Level 2 Product Prototype Processor (S2SL2PPP). Design aspects are partly fixed by the ESA as main customer. Together with the alternative atmospheric correction system MACCS, the developed chain based on ATCOR is used for the estimation of the following products: Atmosphere type, Bottom of atmosphere reflectance (including cirrus detection and correction), Aerosol optical thickness, and Water vapor. Being a mono-temporal correction chain ATCOR requires a selection of the spectral bands for the estimation of Aerosol type, Aerosol optical thickness based on the dense dark vegetation method and Water vapor based on the atmospherically pre-corrected differential absorption method as well as an estimation of the best parameter set for these methods. The parameter set was estimated by a sensitivity analysis on a simulated top and bottom of atmosphere radiance/reflectance data based on radiative transfer simulations. The aerosol type is estimated by the comparison of the path radiances ratio to the ground truth path radiances ratio for the standard atmospheres, namely rural, urban, maritime, and desert. Aerosol optical thickness map and Water vapor map are initially estimated on the 20m pixel size data, then the maps are interpolated to the pixel size of 10m and the 10m reflectance data are estimated. The cirrus cloud map is created by the cirrus 1.38 µm band thresholding to the thin, medium, thick cirrus and cirrus clouds. Cirrus compensation is performed by correlating the cirrus band reflectance to the reflective region bands and subtraction of the cirrus contribution per band. Validation of the chain is performed given the top of atmosphere data (as input) and bottom of atmosphere products (the reference). Estimated reflectance is assessed given the ground truth reflectance, Aerosol optical thickness is validated given the AERONET measurements, cirrus correction is validated using a pair of Landsat-8 scenes acquired for the same area with a small time difference. One scene is contaminated by cirrus cloud that has to be restored, while the other is cirrus free and used as reference. A comparison of the estimated products is also performed with an alternative atmospheric correction chain – FLAASH. The software is developed using the Interactive Data Language (IDL) and python

New strategies for the control of infectious and parasitic diseases in blood donors: the impact of pathogen inactivation methods

AbstractAround 70 infectious agents are possible threats for blood safety.The risk for blood recipients is increasing because of new emergent agents like West Nile, Zika and Chikungunya viruses, or parasites such as Plasmodium and Trypanosoma cruzi in non-endemic regions, for instance.Screening programmes of the donors are more and more implemented in several Countries, but these cannot prevent completely infections, especially when they are caused by new agents.Pathogen inactivation (PI) methods might overcome the limits of the screening and different technologies have been set up in the last years.This review aims to describe the most widely used methods focusing on their efficacy as well as on the preservation integrity of blood components