Influence of ewe feeding systems on carcass quality of suckling lambs

Numerous studies have evidenced significant differences in the carcass and meat quality of grass-fed and concentrate-fed lambs. The main differences regard carcass fatness (Murphy et al., 1994), subcutaneous fat colour (Prache and Theriez, 1999), meat colour (Priolo et al., 2002a) and fatty acid composition (Enser et al., 1998). The use of grazing in lamb feeding favours the presence of substances in the meat which are beneficial to human health. Different methods, based on the spectrophotometric properties of fat have been proposed to verify the origin of the product (Priolo et al., 2002b). The objective of the present study is to verify if and to what extent the carcass quality of suckling lambs is affected by ewe feeding systems

On trading the spreading gain with the coding rate and its application to GNSS data component design

The ubiquity of global navigation satellite system (GNSS)-based positioning and timing services is often frustrated by the necessity to operate in harsh environments, where the carrier-to-noise ratio is low, and hence, decoding of navigation data and even tracking of an acquired symbol are difficult. We consider the possibility of improving the decoding performance of the GNSS data component by trading the spreading gain against the coding rate. The rationale is that spreading codes can be seen as a form of repetition coding that can be (at least partially) replaced by more robust coding forms to improve robustness to (any form of) noise. This is true both for the classical additive white Gaussian noise channel case and for more realistic GNSS channel formats severely degraded by multiple access interference and near-far effects. By bringing results on finite-block-length channel capacity and coding rates from information/communication theory to the GNSS domain, we are able to establish and discuss the expected performance gap, as well as the limits of such tradeoff

Feasibility and Limitations of Self-Spoofing Attacks on GNSS Signals with Message Authentication

In recent years, there has been an ever growing dependence on GNSS for applications in sectors ranging from telecommunications, energy transmission and distribution, to financial services and transportation. As this dependence has increased, so too have risks of intentional interference or spoofing of GNSS signals from adversaries with the intent of causing damage or obtaining illegitimate advantage. The growing interest in GNSS has brought the European Union to develop its own system, Galileo, which recently became operational. The GNSS signal generation is based on public parameters, and to the present date none of the systems provides any means to verify its authenticity or cryptographic integrity. To answer the arising concerns about GNSS security, the European Commission has recently announced that Galileo will offer Navigation Message Authentication (NMA) as a protection against falsified signals, i.e., the so called spoofing attacks. In some scenarios, the attacker can be the very owner of the receiving device, that aims, for instance, at deceiving a monitoring system. These attacks, that go under the name of self-spoofing, have thus become a concern for GNSS based applications. Such scenarios represent some of the most demanding requirements for protection against GNSS spoofing. The implementation of NMA techniques serves the purpose of making this kind of attacks more difficult, too. Two representative applications were considered in the definition of a baseline spoofing scenario and its respective assumptions: satellite-based Vessel Monitoring Systems (VMS) and smart digital tachographs. Satellite-based VMS' were introduced to protect fisheries from illegal fishing, using GNSS for enforcement. Requirements for VMS' specify acceptable position errors and associated confidence intervals, the contents and frequency of transmissions to a Fishing Monitoring Centre (FMC) that allow authorities to react in a timely manner to non compliant behaviour. Today, such measures include the use of tamper-resistant hardware and cryptographic mechanisms to provide protection against vessel owners attempting to tamper or interfere with the device; however, it is only a matter of time before malicious owner resort to GNSS spoofing as a threat to the present enforcement mechanism. The return on investment for defeating the VMS and illegally fishing in closed areas can be significant and can substantially outweigh the costs associated with conducting a spoofing attack. Digital tachographs record the activities of professional drivers including rest and driving hours, increasing road safety, ensuring minimum working conditions and guaranteeing fair competition for EU transport companies. An EU regulation prescribes requirements for construction, testing, installation, operation and repair of tachographs and their components addresses the use of GNSS, remote early detection of possible manipulation or misuse, interfaces with intelligent transport systems and security mechanisms. This paper considers as a baseline a GNSS receiver implementing defences based on the utilisation of Galileo Open Service authentication. In terms of fulfilling its primary task of protecting the integrity of the navigation message, a generic NMA scheme might simply be characterized by its key features, including the number of cryptographic bits inserted in the message, the equivalent security of the scheme, and the period of time over which a complete signature is broadcast. The equivalent security of the scheme indicates the difficulty in performing a brute-force attack on the underlying cryptographic primitives. The number of cryptographic bits inserted will directly influence the availability of the scheme, based on the ability of the receiver to correctly recover all of the bits, and is generally proportional to the equivalent security of the scheme. The period over which the data is broadcast will influence the latency experienced by the receiver in asserting the authenticity of the navigation data, and should therefore be commensurate with, and aligned with, the period over which the protected navigation data is broadcast. When considering the indirect use of the NMA data as a means of anti-spoofing, or range protection, one more feature must be considered: the conditional Shannon entropy of the cryptographic data given the previously transmitted messages. If the data are unknown at the time of broadcast, then one might assume that the adversary must first observe the genuine signal, before creating a counterfeit one. The likelihood of an adversary simply guessing the true value of the cryptographic data is related to the number of bits in question, and the a priori probability of guessing each bit. A common measure of this is the Shannon entropy. When the number of bits is high, then it is very unlikely that the adversary can readily produce a counterfeit signal, without first observing the genuine one. Of course, once the genuine signal is observed, a perfect replica can easily be made. This fact constrains somewhat the degrees of freedom of the counterfeit signals, in that they might only be broadcast in delay with respect to the genuine signals. It might be argued that this itself represents some defence against spoofing. This paper aims at evaluating the efficacy of symbol-level techniques for the mitigation of spoofing attacks. The paper will first analyse the state of the art of both GNSS spoofing attacks and anti-spoofing mechanisms. Theoretical and experimental analysis will be presented in order to investigate the possible increase in the complexity that is required for a successful attack, thanks the adoption of NMA, as well as the intrinsic limitations and weaknesses of these techniques

Olive cake, citrus pulp and wheat straw silage as an ingredient in lamb diets: 2. Effects on meat quality

In the Mediterranean area, the use of some agricultural by-products, difficult to be eliminated, in the feeding of animals, represents a key element for the valorization of bioenergetic resources. Among the agricultural by-products which may be found at a low price in our area, the olive cake and the citrus pulp of orange have awaked great interest..

Optimization of anchor nodes’ usage for location verification systems

While a growing number of Internet of Things (IoT) applications require reliable mechanisms to determine the precise location of remote devices, the aspects regarding the security of positioning algorithms should not be neglected. In this context, this paper proposes a physical-layer location verification method for IoT networks in which the concentrator node is assisted by several anchor nodes that are spread in the area of interest. We design an optimization problem to choose appropriately which anchor nodes should be triggered in the location verification process in order to minimize the activation rate of each anchor. The performance evaluation results show that the proposed policy achieves an activation rate reduction of the anchor nodes of at least 70%

Energy-based anchor node selection for IoT physical layer authentication

We consider a cellular Internet of things (CIoT) network where many source nodes aim at exchanging messages with a single concentrator node. To this end, they are assisted by anchor nodes that are trusted and securely connected with the concentrator node. In this context, we aim at providing a message authentication scheme based on the characteristics of the channel between the source nodes and the anchor nodes. According to this approach, the anchor nodes estimate the channel to source nodes in an initially externally authenticated fashion, while forthcoming messages are authenticated by comparing the current channel estimate with the initial estimate. Moreover, assuming that the anchor nodes have a limited energy availability, we derive suitable scheduling policies for the activation of the anchor nodes for authentication purposes. In particular, we aim at maximizing the anchors lifespan while guaranteeing given false alarm and missed detection probabilities of the authentication process. The performance of the proposed authentication protocols is evaluated in a typical CIoT scenario

Influence of ewe feeding systems on meat quality of suckling lambs

In recent years interest has grown in the zootechnical exploitation of environmental feeding resources, above all in marginal areas. The survival of these areas is linked to the development of the limited available resources. Of these, natural pastures represent one of the most important, not only because their zootechnical utilisation permits savings in alimentary costs, but above all because it results in better quality dairy and meat products. The aim of this study is to verify if and to what level ewe feeding systems influence the meat quality of suckling lambs

Intima-media thickness (imt) and rf-based quality intima-media thickness (rfqimt) measurements in a sample of patients attending an outpatient hypertension centre

Introduction: The RFQIMT (Esaote-Italy) is a method of new generation for real-time measurement of intima-media thickness of the supra-aortic trunks. It is based on the direct radio-frequency analysis of the signal that allows to obtain data at high spatial resolution and thus improve the standard of a measure which has proved as surrogate marker of cardiovascular disease. The absolute values of IMT, indicated as standard ones by current literature and measured by the method recommended by the guidelines of the Italian Society of Vascular Diagnostics (accepted as European Guidelines) do not take into account of independent variables such as age, sex and race that may influence the correlation of this index at any level of vascular and cardiac damage. The aim of our study was to compare the values of intima-media thickness measured by the above method compared to those obtained by the method of radio-frequency taking into account the variables mentioned above. Materials and Methods: We submitted 250 patients examined in succession in our hypertension centre to measure the intima-media thickness with conventional method (3 measurements at the level of common carotid artery, 1 cm from the carotid bifurcation) and RFQIMT. Patients had a mean age of 52.5 ± 22.5, 118 were males and 132 females, and all Caucasians. Patients had the following comorbidities: 210 patients were hypertensive patients, 126 dyslipidemic, 87 patients with diabetes, 14 patients with CAD, 72 patients with carotid plaques and 93 patients smokers. Results: 123 patients had RFQIMT above the normal values and IMT among limits, 56 had normal both RFQIMT and IMT and 71 had both RFQIMT and IMT above the normal values. Conclusions: When we take into account the value of RFQIMT compared to IMT, the index of cardiovascular risk linked to intima-media thickness increased significantly in more patients: 123 with RFQIMT increased compared with 71 with IMT increased. This preliminar evidence changes the correlations with the co-morbidity and makes the measure that uses radio-frequency more accurate and reliable

Enabling Location Based Services with Privacy and Integrity Protection in Untrusted Environments through Blockchain and Secure Computation

Privacy and integrity preservation of user data is a major challenge in the context of location based services, as the assumption of trusted relationship between the user and the service provider might be too strong. The question is: how to securely collect, store and process position, navigation and timing (PNT) information and/or georeferenced data, assuming that the service provider cannot be trusted? In this work, we propose an architecture that enables LBS with privacy and integrity in untrusted environments, leveraging blockchain and secure computation. We provide mechanisms for sharing and processing PNT information and/or georeferenced data, with a detailed description of the employed cryptographic schemes and algorithms. Furthermore, we provide a validation of the proposed architecture by means of an emulation-based testbed