87 research outputs found
The impact of social pressure on tax compliance: A field experiment
We study the effect of social pressure on tax compliance, focusing on the compliance of shop sellers to the legal obligation of releasing tax receipts for each sale. We carry out a field experiment on bakeries in Italy, where a strong gap exists between the legal obligation and the actual behavior of sellers. Social pressure is manipulated by means of an explicit request for a receipt when not released. We employ an innovative approach to the identification of the treatment effect. We find that a single request for a receipt causes a 17 per cent rise in the probability of a receipt being released for a sale occurring shortly thereafter, causing on average more than two receipts to be released. We also find strong evidence of persistence in compliance decisions. (C) 2016 Elsevier Inc. All rights reserved
Spleen histology in children with sickle cell disease and hereditary spherocytosis: Hints on the disease pathophysiology
open2Hereditary spherocytosis (HS) and sickle cell disease (SCD) are associated with splenomegaly and spleen dysfunction in pediatric patients. Scant data exist on possible correlations between spleen morphology and function in HS and SCD. This study aimed to assess the histological and morphometric features of HS and SCD spleens, in order to get possible correlations with disease pathophysiology. In a large series of spleens from SCD, HS and control patients the following parameters were considered: (i) macroscopic features; (ii) lymphoid follicle (LF) density; (iii) presence of peri-follicular marginal zones (MZs); (iv) presence of Gamna-Gandy bodies; (v) density of CD8-positive sinusoids; (vi) density of CD34-positive microvessels; (vii) presence/distribution of fibrosis and SMA-positive myoid cells; (viii) density of CD68-positive macrophages. SCD and HS spleens have similar macroscopic features. SCD spleens had lower LF density and fewer MZs than HS spleens and controls. SCD also showed lower CD8-positive sinusoid density, increased CD34-positive microvessel density and SMA-positive myoid cells, and higher prevalence of fibrosis and Gamna-Gandy bodies. HS had lower LF and CD8-positive sinusoid density than controls. No significant differences were noted in red pulp macrophages. By multivariate analysis, the majority of HS spleens clustered with controls, while SCD grouped separately. A multi-parametric score could predict the degree of spleen changes irrespective of the underlying disease. In conclusion, SCD spleens display greater histologic effacement than HS and SCD-related changes suggest impaired function due to vascular damage. These observations may contribute to guide the clinical management of patients.embargoed_20161128Alaggio, RitaAlaggio, Rita; Gamba, Piergiorgi
Molecular detection and parasite load of Trypanosoma cruzi in digestive tract tissue of Chagas disease patients affected by megacolon
Chagas disease, caused by the Trypanosoma cruzi parasite in the Americas affects similar to 7 million people, 30% with cardiac tissue damage and 10-15% with digestive disorders. In this study, we have developed a protocol to detect the presence of the parasite and estimate its load in resected dysfunctional tissue segments of chronically infected patients with digestive megacolon. We have included samples from 43 individuals, 38/5 with positive/negative serology for Chagas disease and digestive syndromes. Samples of 1.5 to 2.0 cm(2) were taken from different points of the dysfunctional digestive tract in specialized centres in Cochabamba, Bolivia. T. cruzi cultures were performed by inoculation with NNN-LIT culture medium, and genomic material was obtained from the samples for multiplex qPCR with TaqMan probes targeting satellite nuclear DNA. Cultures failed to isolate T. cruzi but qPCR reached a sensitivity of 42.1% (16/38) with all three spots and in triplicate. A new quantification methodology using synthetic satellite DNA as quantitation standard revealed parasite loads ranging from 2.2 x 10(2) to 1.0 x 10(6) satellite DNA copies/mu l. Positive samples from the distal end showed a higher parasite load. The results of the present study strengthen and add further evidence to previous findings in an experimental mouse model of chronic T. cruzi infection, providing a valuable tool to improve scientific knowledge on the relevance of the digestive tract in parasite persistence, and underline the need of a better understanding of host-pathogen interaction in digestive tissues, considering pathophysiology, disease immunology and response to treatment
Exploring the hidden riches: Recent remarkable faunistic records and range extensions in the bee fauna of Italy (Hymenoptera, Apoidea, Anthophila)
The area sourrounding the Mediterranean basin is recognised as a major biodiversity hotspot for bees, and Italy is amongst the European countries with the highest bee species richness. Detailed knowledge of bee distribution is crucial for understanding bee biology and designing tailored conservation strategies, but is still insufficient in southern European countries, especially in Italy.We report recent finds of 48 bee species that yield significant novelties for the Italian bee fauna. Eight species, namely Andrena confinis Stöckhert, Anthidiellum breviusculum Pérez, Coelioxys alatus Foerster, Lasioglossum algericolellum Strand, Megachile lapponica Thomson, Megachile opacifrons Pérez, Megachile semicircularis auct. nec Zanden and Trachusa integra Eversmann are reported as new for Italy. In addition, Andrena binominata Smith, Andrena compta Lepeletier, Colletes acutus Pérez, Lasioglossum strictifrons Vachal, Rhodanthidium siculum Spinola and Rhodanthidium sticticum Fabricius are newly recorded from mainland Italy, Osmia heteracantha Pérez from Sardegna and Nomada flavopicta Kirby from Sicilia. We also report significant range extensions for other bee species and recent records of species that had long gone unrecorded in Italy. The combination of morphology and DNA barcoding provided reliable identifications even for the most challenging specimens. As several of our records come from areas neglected by bee experts in the past, this study stands out as a key indicator of a bee faunistic richness still awaiting discovery and hopefully it will stimulate the interest of taxonomists and stakeholders in pursuing bee research in Italy in the near future
GPS and Galileo Developments on Board the International Space Station With the Space Communications and Navigation (SCaN) Testbed
The Space Communications and Navigation (SCaN) is a facility developed by NASA and hosted on board the International Space Station (ISS) on an external truss since 2013.It has the objective of testing navigation and communication experimentations with a Software Defined Radio (SDR) approach, which permits software updates for testing new experimentations.NASA has developed the Space Telecommunications Radio System (STRS) architecture standard for SDRs used in space and ground-based platforms to provide commonality among radio developments to provide enhanced capability. The hardware is equipped with both L band front-end radios and the NASA space network communicates with it using S-band, Ku-band and Ka-band links.In May 2016 Qascom started GARISS (GPS and Galileo Receiver for the ISS), an activity of experimentation in collaboration with ESA and NASA that has the objective to develop and validate the acquisition and processing of combined GPS and Galileo signals on board the ISS SCaN testbed. This paper has the objective to present the mission, and provide preliminary details about the challenges in the design, development and verification of the waveform that will be installed on equipment with limited resources. GARISS is also the first attempt to develop a waveform for the ISS as part of an international collaboration between US and Europe. Although the final mission objective is to target dual frequency processing, initial operations will foresee a single frequency processing. Initial results and trade-off between the two options, as well as the final decision will be presented and discussed. The limited resources on board the SCaN with respect to the challenging requirements to acquire and track contemporaneously two satellite navigation systems, with different modulations and data structure, led to the need to assess the possibility of aiding from ground through the S-band. This option would allow assistance to the space receiver in order to provide knowledge of GNSS orbits and reduce the processing on board. Trade off and various options for telemetry and uplink data are presented and discussed. Finally, integration and validation of the waveform are one of the major challenges of GARISS: The Experiment Development System (EDS) and the the Ground Integration Unit (GIU) for VV will be used prior to conducting the experiment on the ISS. The EDS can be used in lab environment and allows prototyping and verification activities with the simulator, but does not include all hardware components. The GIU on the other side is the flight model which replicates the flying equipment, but has limited flexibility for testing.As conclusion, the project is now approaching the Preliminary Design Review (PDR) and indeed only preliminary results are available. This paper is an opportunity to present the GARISS mission as part of an International cooperation between ESA, NASA and Qascom. The preliminary results include GPS and Galileo processing from space signals, the challenges and trade off decisions, the high level STRS architecture and foreseen experimentation campaign. Detailed results from the test campaigns are expected in 2017
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