113 research outputs found
FAIR: Forwarding Accountability for Internet Reputability
This paper presents FAIR, a forwarding accountability mechanism that
incentivizes ISPs to apply stricter security policies to their customers. The
Autonomous System (AS) of the receiver specifies a traffic profile that the
sender AS must adhere to. Transit ASes on the path mark packets. In case of
traffic profile violations, the marked packets are used as a proof of
misbehavior.
FAIR introduces low bandwidth overhead and requires no per-packet and no
per-flow state for forwarding. We describe integration with IP and demonstrate
a software switch running on commodity hardware that can switch packets at a
line rate of 120 Gbps, and can forward 140M minimum-sized packets per second,
limited by the hardware I/O subsystem.
Moreover, this paper proposes a "suspicious bit" for packet headers - an
application that builds on top of FAIR's proofs of misbehavior and flags
packets to warn other entities in the network.Comment: 16 pages, 12 figure
Genotyping Strategies Using ddRAD Sequencing in Farmed Arctic Charr (Salvelinus alpinus)
Simple SummaryAnimal breeding in recent years has benefited greatly from the availability of large-scale genetic information. The most widely applied genomic tools in selective breeding are specialized arrays that use DNA hybridization. However, the high financial investments accompanying this practice impair the profitability of emerging aquaculture species, including Arctic charr. The aim of the current study was to assess and compare the potential of two cost-efficient genotyping strategies applicable in a variety of breeding-related tasks, such as pedigree verification, genetic diversity screening and detection of genomic regions that are associated with phenotypes of economic importance. Both strategies are based on reduced representation sequencing but differ in sequencing coverage (low and high). The low coverage strategy offers a higher density of DNA markers, but also presents a greater proportion of missing data in the marker set and is characterized by more uncertainty in determining heterozygosity compared to high coverage. Our results show that while high coverage genotyping performs better in genetic diversity and kinship analyses, a low coverage strategy is more successful in identifying genomic regions associated with phenotypic traits, leading to the conclusion that both strategies could be of value into selection schemes.Incorporation of genomic technologies into fish breeding programs is a modern reality, promising substantial advances regarding the accuracy of selection, monitoring the genetic diversity and pedigree record verification. Single nucleotide polymorphism (SNP) arrays are the most commonly used genomic tool, but the investments required make them unsustainable for emerging species, such as Arctic charr (Salvelinus alpinus), where production volume is low. The requirement to genotype a large number of animals for breeding practices necessitates cost effective genotyping approaches. In the current study, we used double digest restriction site-associated DNA (ddRAD) sequencing of either high or low coverage to genotype Arctic charr from the Swedish national breeding program and performed analytical procedures to assess their utility in a range of tasks. SNPs were identified and used for deciphering the genetic structure of the studied population, estimating genomic relationships and implementing an association study for growth-related traits. Missing information and underestimation of heterozygosity in the low coverage set were limiting factors in genetic diversity and genomic relationship analyses, where high coverage performed notably better. On the other hand, the high coverage dataset proved to be valuable when it comes to identifying loci that are associated with phenotypic traits of interest. In general, both genotyping strategies offer sustainable alternatives to hybridization-based genotyping platforms and show potential for applications in aquaculture selective breeding
SDNsec: Forwarding Accountability for the SDN Data Plane
SDN promises to make networks more flexible, programmable, and easier to
manage. Inherent security problems in SDN today, however, pose a threat to the
promised benefits. First, the network operator lacks tools to proactively
ensure that policies will be followed or to reactively inspect the behavior of
the network. Second, the distributed nature of state updates at the data plane
leads to inconsistent network behavior during reconfigurations. Third, the
large flow space makes the data plane susceptible to state exhaustion attacks.
This paper presents SDNsec, an SDN security extension that provides
forwarding accountability for the SDN data plane. Forwarding rules are encoded
in the packet, ensuring consistent network behavior during reconfigurations and
limiting state exhaustion attacks due to table lookups. Symmetric-key
cryptography is used to protect the integrity of the forwarding rules and
enforce them at each switch. A complementary path validation mechanism allows
the controller to reactively examine the actual path taken by the packets.
Furthermore, we present mechanisms for secure link-failure recovery and
multicast/broadcast forwarding.Comment: 14 page
Long run asymmetric relationships between Islamic and conventional equity indices
Despite the substantial growth in the Islamic finance sector in the recent years, there has been limited empirical research on Islamic equity indices. In our paper we explore the interconnectedness between Islamic and conventional equity indices during the period spanning from 2006 to 2010. The Dow Jones Islamic Market is representative of the Islamic equity market, while the Dow Jones Global and Dow Jones Industrial Average are well perceived equity benchmark indices. We adopt hidden co-integration and granger causality analysis, while we examine the impact of market conditions. We find that the negative index components are significant between the Islamic equity index and the conventional benchmarks, yet the two conventional indices do not support this contention. Moreover, there is evidence that an increasing in magnitude driving force emanates from the Islamic to the conventional index in the crisis and post-crisis periods. A portfolio optimisation case study reveals that there are diversification benefits to be reaped by the inclusion of an Islamic equity index. The finding is tied to the Islamic index’s performance and diversification benefits, particularly during the financial crisis. It may be further linked to investors’ embracing of Islamic finance principles on lower leverage and speculation practices
A proposed framework of an interactive semi-virtual environment for enhanced education of children with autism spectrum disorders
Education of people with special needs has recently been considered as a key element in the field of medical education. Recent development in the area of information and communication technologies may enable development of collaborative interactive environments which facilitate early stage education and provide specialists with robust tools indicating the person's autism spectrum disorder level. Towards the goal of establishing an enhanced learning environment for children with autism this paper attempts to provide a framework of a semi-controlled real-world environment used for the daily education of an autistic person according to the scenarios selected by the specialists. The proposed framework employs both real-world objects and virtual environments equipped with humanoids able to provide emotional feedback and to demonstrate empathy. Potential examples and usage scenarios for such environments are also described
Application of Mid-infrared spectroscopy and Partial Least-Squares Regression to predict antioxidant activity on herbal Mediterranean infusions
The application of infrared spectroscopy to quantify phenolic content and antioxidant activity is a new area in herbs. Recently, we demonstrated the feasibility of mid-infrared spectroscopy to predict the phenolic content in lyophilised infusions of aromatic and medicinal herbs [1]
Low prevalence of liver-kidney microsomal autoantibodies of type 1 (LKM(1)) in hepatitis C seropositive subjects on Crete, Greece
BACKGROUND: Hepatitis C is a serious problem on the Greek island of Crete, where a high prevalence of antibodies against hepatitis C (anti-HCV) has recently been reported. This article reports the findings of a study carried out in Crete, which investigated the prevalence of serum autoantibodies in patients with chronic hepatitis C. PATIENTS AND METHODS: One hundred and forty two patients (59 men and 83 women), who were found anti-HCV seropositive in two hospitals and two Primary Health Care Centres in Crete, were eligible. Sixty healthy blood donors (46 men, 14 women), which were negative to anti-HCV, were used as the control group. They were randomly selected from those attending Rethymnon Hospital. Autoantibodies were identified using the indirect immunofluorescence (IFL) technique on human epithelial cells from larynx cancer (HEp-2 cells), rat liver-kidney-stomach substrate (CT3) and Chrithidia Luciliae (CL). RESULTS: Serum autoantibodies were detected in 104 HCV patients, yielding an overall prevalence of 73.2%. The most frequent autoantibodies were antinuclear antibodies (ANA), positive in 72 patients (50.7%). Anti-smooth muscle antibodies (ASMA) were detected in 33 patients (23.2%). Only one patient was positive for LKM(1) autoantibodies. No autoantibodies were found in 38 patients (26.7%). Autoantibodies were also found in 5 out of the 60 examined healthy blood donors (8.3%). CONCLUSIONS: Autoantibodies, mainly ANA and ASMA are very common in HCV seropositive patients from Crete. By contrast LKM(1) autoantibodies are exceptionally rare in these patients
A Framework Combining Delta Event-Related Oscillations (EROs) and Synchronisation Effects (ERD/ERS) to Study Emotional Processing
Event-Related Potentials (ERPs) or Event-Related
Oscillations (EROs) have been widely used to
study emotional processing, mainly on the theta and gamma
frequency bands. However, the role of the slow
(delta) waves has been largely ignored. The aim
of this study is to provide a framework that
combines EROs with Event-Related
Desynchronization (ERD)/Event-Related
Synchronization (ERS), and peak amplitude
analysis of delta activity, evoked by the
passive viewing of emotionally evocative
pictures. Results showed that this kind of
approach is sensitive to the effects of gender,
valence, and arousal, as well as, the study of
interhemispherical disparity, as the two-brain
hemispheres interplay roles in the detailed
discrimination of gender. Valence effects are
recovered in both the central electrodes as well
as in the hemisphere interactions. These
findings suggest that the temporal patterns of
delta activity and the alterations of delta
energy may contribute to the study of emotional
processing. Finally the results depict the
improved sensitivity of the proposed framework
in comparison to the traditional ERP techniques,
thereby delineating the need for further
development of new methodologies to study slow
brain frequencies
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