1,728 research outputs found

    Heterosis, direct and maternal additive effects on rabbit growth and carcass traits from a Canadian experiment

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    A total of 479 male and female rabbits from the Californian (CA), American Chinchilla (CH) and New-Zealand White (NZ) breeds and nine crosses between them were used in this experiment. This study aimed to estimate heterosis and direct and maternal additive effects as well as some non genetic effects on rabbit growth and carcass traits in order to identify the most appropriate crossbreeding plan to use for rabbit meat production under Quebec conditions. Each rabbit was identified and weighed individually at weaning (35 d) and at slaughter (63 d). Rabbits were slaughtered after an 18 h fasting period from feed only. Statistical analyses were performed solving fixed models that allow different variances between genetic types. Significant statistical differences were obtained between genetic types for rabbit growth performance. Rabbits from purebred NZ females mated to CA and NZ males or from CAxNZ and NZxCH crossbred females mated to NZ males ranked first for live weight at 35 and 63 d body weight and for average daily gain (ADG). ADG of NZxNZ, NZx(NZxCH) and NZx(CAxNZ) rabbits reached around 50 g/d and their feed conversion ratio was about 3.4. Significant differences between genetic types were observed for all carcass traits except for meat/bone ratio. Rabbits from CH, NZ, CAxNZ and NZxCH does mated to NZ males, and from NZ does mated to CA males had the highest commercial carcass weight and the lowest commercial carcass yield (CCY), whereas CHxCA rabbits ranked first with a CCY higher by 4 to 8% than rabbits from other genetic types. The highest hind part yields were obtained with CHxCH, CHxNZ and NZxCH rabbits. Concerning the intermediate part percentages, the highest values corresponded to the highest CCY. The CH breed had unfavourable direct effects but favourable maternal effects on growth traits. The CA breed had negative maternal effects on weight traits from weaning to slaughtering. The CA and CH breeds had positive direct and negative maternal effects on intermediate part yield of the carcass compared to NZ. Direct heterosis effects were found for body weight traits, particularly in the crosses involving the NZ breed, with a magnitude ranging from 5 to 10% of the parental mean.Ouyed, A.; Rivest, J.; Brun, JM. (2011). Heterosis, direct and maternal additive effects on rabbit growth and carcass traits from a Canadian experiment. World Rabbit Science. 19(1). doi:10.4995/wrs.2011.783.SWORD19

    Security by Spatial Reference:Using Relative Positioning to Authenticate Devices for Spontaneous Interaction

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    Spontaneous interaction is a desirable characteristic associated with mobile and ubiquitous computing. The aim is to enable users to connect their personal devices with devices encountered in their environment in order to take advantage of interaction opportunities in accordance with their situation. However, it is difficult to secure spontaneous interaction as this requires authentication of the encountered device, in the absence of any prior knowledge of the device. In this paper we present a method for establishing and securing spontaneous interactions on the basis of emphspatial references that capture the spatial relationship of the involved devices. Spatial references are obtained by accurate sensing of relative device positions, presented to the user for initiation of interactions, and used in a peer authentication protocol that exploits a novel mechanism for message transfer over ultrasound to ensures spatial authenticity of the sender

    Formal Security Analysis and Performance Evaluation of the Linkable Anonymous Access Protocol

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    Part 2: The 2014 Asian Conference on Availability, Reliability and Security, AsiaARES 2014International audienceThe introduction of e-Health applications has not only brought benefits, but also raised serious concerns regarding security and privacy of health data. The increasing demands of accessing health data, highlighted critical questions and challenges concerning the confidentiality of electronic patient records and the efficiency of accessing these records. Therefore, the aim of this paper is to provide secure and efficient access to electronic patient records. In this paper, we propose a novel protocol called the Linkable Anonymous Access protocol (LAA). We formally verify and analyse the protocol against security properties such as secrecy and authentication using the Casper/FDR2 verification tool. In addition, we have implemented the protocol using the Java technology to evaluate its performance. Our formal security analysis and performance evaluation proved that the LAA protocol supports secure access to electronic patient records without compromising performance

    Impact of tumor size and tracer uptake heterogeneity in (18)F-FDG PET and CT non-small cell lung cancer tumor delineation.: 18F-FDG PET and CT tumor delineation in NSCLC

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    International audienceUNLABELLED: The objectives of this study were to investigate the relationship between CT- and (18)F-FDG PET-based tumor volumes in non-small cell lung cancer (NSCLC) and the impact of tumor size and uptake heterogeneity on various approaches to delineating uptake on PET images. METHODS: Twenty-five NSCLC cancer patients with (18)F-FDG PET/CT were considered. Seventeen underwent surgical resection of their tumor, and the maximum diameter was measured. Two observers manually delineated the tumors on the CT images and the tumor uptake on the corresponding PET images, using a fixed threshold at 50% of the maximum (T(50)), an adaptive threshold methodology, and the fuzzy locally adaptive Bayesian (FLAB) algorithm. Maximum diameters of the delineated volumes were compared with the histopathology reference when available. The volumes of the tumors were compared, and correlations between the anatomic volume and PET uptake heterogeneity and the differences between delineations were investigated. RESULTS: All maximum diameters measured on PET and CT images significantly correlated with the histopathology reference (r > 0.89, P < 0.0001). Significant differences were observed among the approaches: CT delineation resulted in large overestimation (+32% ± 37%), whereas all delineations on PET images resulted in underestimation (from -15% ± 17% for T(50) to -4% ± 8% for FLAB) except manual delineation (+8% ± 17%). Overall, CT volumes were significantly larger than PET volumes (55 ± 74 cm(3) for CT vs. from 18 ± 25 to 47 ± 76 cm(3) for PET). A significant correlation was found between anatomic tumor size and heterogeneity (larger lesions were more heterogeneous). Finally, the more heterogeneous the tumor uptake, the larger was the underestimation of PET volumes by threshold-based techniques. CONCLUSION: Volumes based on CT images were larger than those based on PET images. Tumor size and tracer uptake heterogeneity have an impact on threshold-based methods, which should not be used for the delineation of cases of large heterogeneous NSCLC, as these methods tend to largely underestimate the spatial extent of the functional tumor in such cases. For an accurate delineation of PET volumes in NSCLC, advanced image segmentation algorithms able to deal with tracer uptake heterogeneity should be preferred

    Radiomics strategies for risk assessment of tumour failure in head-and-neck cancer

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    Quantitative extraction of high-dimensional mineable data from medical images is a process known as radiomics. Radiomics is foreseen as an essential prognostic tool for cancer risk assessment and the quantification of intratumoural heterogeneity. In this work, 1615 radiomic features (quantifying tumour image intensity, shape, texture) extracted from pre-treatment FDG-PET and CT images of 300 patients from four different cohorts were analyzed for the risk assessment of locoregional recurrences (LR) and distant metastases (DM) in head-and-neck cancer. Prediction models combining radiomic and clinical variables were constructed via random forests and imbalance-adjustment strategies using two of the four cohorts. Independent validation of the prediction and prognostic performance of the models was carried out on the other two cohorts (LR: AUC = 0.69 and CI = 0.67; DM: AUC = 0.86 and CI = 0.88). Furthermore, the results obtained via Kaplan-Meier analysis demonstrated the potential of radiomics for assessing the risk of specific tumour outcomes using multiple stratification groups. This could have important clinical impact, notably by allowing for a better personalization of chemo-radiation treatments for head-and-neck cancer patients from different risk groups.Comment: (1) Paper: 33 pages, 4 figures, 1 table; (2) SUPP info: 41 pages, 7 figures, 8 table

    Unconditionally verifiable blind computation

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    Blind Quantum Computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client's input, output and computation remain private. A desirable property for any BQC protocol is verification, whereby the client can verify with high probability whether the server has followed the instructions of the protocol, or if there has been some deviation resulting in a corrupted output state. A verifiable BQC protocol can be viewed as an interactive proof system leading to consequences for complexity theory. The authors, together with Broadbent, previously proposed a universal and unconditionally secure BQC scheme where the client only needs to be able to prepare single qubits in separable states randomly chosen from a finite set and send them to the server, who has the balance of the required quantum computational resources. In this paper we extend that protocol with new functionality allowing blind computational basis measurements, which we use to construct a new verifiable BQC protocol based on a new class of resource states. We rigorously prove that the probability of failing to detect an incorrect output is exponentially small in a security parameter, while resource overhead remains polynomial in this parameter. The new resource state allows entangling gates to be performed between arbitrary pairs of logical qubits with only constant overhead. This is a significant improvement on the original scheme, which required that all computations to be performed must first be put into a nearest neighbour form, incurring linear overhead in the number of qubits. Such an improvement has important consequences for efficiency and fault-tolerance thresholds.Comment: 46 pages, 10 figures. Additional protocol added which allows arbitrary circuits to be verified with polynomial securit

    Quantum-noise--randomized data-encryption for WDM fiber-optic networks

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    We demonstrate high-rate randomized data-encryption through optical fibers using the inherent quantum-measurement noise of coherent states of light. Specifically, we demonstrate 650Mbps data encryption through a 10Gbps data-bearing, in-line amplified 200km-long line. In our protocol, legitimate users (who share a short secret-key) communicate using an M-ry signal set while an attacker (who does not share the secret key) is forced to contend with the fundamental and irreducible quantum-measurement noise of coherent states. Implementations of our protocol using both polarization-encoded signal sets as well as polarization-insensitive phase-keyed signal sets are experimentally and theoretically evaluated. Different from the performance criteria for the cryptographic objective of key generation (quantum key-generation), one possible set of performance criteria for the cryptographic objective of data encryption is established and carefully considered.Comment: Version 2: Some errors have been corrected and arguments refined. To appear in Physical Review A. Version 3: Minor corrections to version
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