Inelastic Dark Matter at the LHC

We perform a model-independent study of inelastic dark matter at the LHC, concentrating on the parameter space with the mass splitting between the excited and ground states of dark matter above a few hundred MeV, where the direct detection experiments are unlikely to explore. The generic signatures of inelastic dark matter at the LHC are displaced pions together with a monojet plus missing energy, and can be tested at the 7 TeV LHC.Comment: 4 pages, 6 figure

Searches with Mono-Leptons

We explore the implications of the mono-lepton plus missing transverse energy signature at the LHC, and point out its significance on understanding how dark matter interacts with quarks, where the signature arises from dark matter pair production together with a leptonically decaying W boson radiated from the initial state quarks. We derive limits using the existing W' searches at the LHC, and find an interesting interference between the contributions from dark matter couplings to up-type and down-type quarks. Mono-leptons can actually furnish the strongest current bound on dark matter interactions for axial vector (spin-dependent) interactions and iso-spin violating couplings. Should a signal of dark matter production be observed, this process can also help disentangle the dark matter couplings to up- and down-type quarks.Comment: four pages; six figures; the LHC 8 TeV results have been updated; final version in PL

Network Configuration Manager

Network administrators have to manually store switch configurations into text files and store old switch configurations in an archive. These administrators don’t know when someone changes something on their switches unless they manually check the configuration to see if a change has occurred. The solution automatically writes switch configurations to an online archive. This automates a manual task that doesn’t happen each time a configuration changes. It also notifies administrators when a change occurs on one of their devices, allowing them to accept or reject these changes. In addition, they can restore previous configurations if they so choose. This solution provides reliable automatic backups, versioning, the ability to revert unwanted changes to a known good state, and knowledge of the changes that happen in our environment along with when they happen

An analysis of Cross-correlations in South African Market data

We apply random matrix theory to compare correlation matrix estimators C obtained from emerging market data. The correlation matrices are constructed from 10 years of daily data for stocks listed on the Johannesburg Stock Exchange (JSE) from January 1993 to December 2002. We test the spectral properties of C against random matrix predictions and find some agreement between the distributions of eigenvalues, nearest neighbour spacings, distributions of eigenvector components and the inverse participation ratios for eigenvectors. We show that interpolating both missing data and illiquid trading days with a zero-order hold increases agreement with RMT predictions. For the more realistic estimation of correlations in an emerging market, we suggest a pairwise measured-data correlation matrix. For the data set used, this approach suggests greater temporal stability for the leading eigenvectors. An interpretation of eigenvectors in terms of trading strategies is given in lieu of classification by economic sectors.Comment: 19 pages, 15 figures, additional figures, discussion and reference

UNiS: A User-space Non-intrusive Workflow-aware Virtual Network Function Scheduler

International audienceNetwork Function Virtualization (NFV) has gained a significant research interest in both academia and industry since its inception in the late 2012. One of the key research issues in NFV is the development of systems for building Virtual Network Functions (VNFs) capable of meeting the erformance requirements of enterprise and telecommunication networks. New packet processing models leveraging kernel bypass I/O and poll-mode processing have gained popularity for building high performance VNFs because of their simple programming model and very low I/O overhead. However, a major drawback of such poll-mode processing is the inefficient use of CPU resources. Existing CPU schedulers are ill-suited for VNFs due to their inability to capture the actual processing cost of a poll-mode VNF, hence, cannot rightsize the CPU allocation. This is further exacerbated by their inability to consider VNF processing order when VNFs are chained to form Service Function Chains (SFCs). The state-of-the-art solutions proposed for VNF scheduling are intrusive, i.e., requiring the VNFs to be built with scheduler specific libraries or having carefully selected scheduling checkpoints. This highly restricts the VNFs that can properly work with such schedulers. In this paper, we present UNiS: a User-space Non-intrusivework-flow aware VNF Scheduler. Unlike existing approaches, UNiS does not require VNF modifications and treats the poll-mode VNFs as a black box, hence, is non-intrusive. UNiS is also workflow-aware, i.e., maintains SFC processing order while scheduling the VNFs. Testbed experiments show that UNiS is able to achieve a throughput within 90% (for synthetic traffic load) and 98% (for real data center traffic trace) of the achievable throughput using an intrusive co-operative scheduler

Non-intrusive and Workflow-aware Virtual Network Function Scheduling in User-space

International audienceThe simple programming model and very low-overhead I/O capabilities of emerging packet processing techniques leveraging kernel-bypass I/O and poll-mode processing is gaining significant popularity for building high performance software middleboxes (aka Virtual Network Functions (VNFs)). However, existing OS schedulers fall short in rightsizing CPU allocation to poll-mode VNFs due to the schedulers' shortcoming in capturing the actual processing cost of these VNFs. This issue is further exacerbated by their inability to consider VNF processing order when VNFs are chained to form Service Function Chains (SFCs). The state-of-the-art VNF schedulers proposed as an alternative to OS schedulers are intrusive, requiring the VNFs to be built with scheduler specific libraries or having carefully selected scheduling checkpoints. This highly restricts the VNFs that can properly work with these schedulers. In this paper, we present UNi S, a User-space Non-intrusive work-flow aware VNF Scheduler. Unlike existing approaches, UNiS is non-intrusive, i.e., does not require VNF modifications and treats poll-mode VNFs as black boxes. UNiS is also workflow-aware, i.e., takes SFC processing order into account while scheduling VNFs. Testbed experiments show that UNi S is able to achieve a throughput within 90% and 98% of that achievable using an intrusive cooperative scheduler for synthetic and real data center traffic, respectively

Genomic Diversity of the Ostreid Herpesvirus Type 1 Across Time and Location and Among Host Species

The mechanisms underlying virus emergence are rarely well understood, making the appearance of outbreaks largely unpredictable. This is particularly true for pathogens with low per-site mutation rates, such as DNA viruses, that do not exhibit a large amount of evolutionary change among genetic sequences sampled at different time points. However, whole-genome sequencing can reveal the accumulation of novel genetic variation between samples, promising to render most, if not all, microbial pathogens measurably evolving and suitable for analytical techniques derived from population genetic theory. Here, we aim to assess the measurability of evolution on epidemiological time scales of the Ostreid herpesvirus 1 (OsHV-1), a double stranded DNA virus of which a new variant, OsHV-1 μVar, emerged in France in 2008, spreading across Europe and causing dramatic economic and ecological damage. We performed phylogenetic analyses of heterochronous (n = 21) OsHV-1 genomes sampled worldwide. Results show sufficient temporal signal in the viral sequences to proceed with phylogenetic molecular clock analyses and they indicate that the genetic diversity seen in these OsHV-1 isolates has arisen within the past three decades. OsHV-1 samples from France and New Zealand did not cluster together suggesting a spatial structuration of the viral populations. The genome-wide study of simple and complex polymorphisms shows that specific genomic regions are deleted in several isolates or accumulate a high number of substitutions. These contrasting and non-random patterns of polymorphism suggest that some genomic regions are affected by strong selective pressures. Interestingly, we also found variant genotypes within all infected individuals. Altogether, these results provide baseline evidence that whole genome sequencing could be used to study population dynamic processes of OsHV-1, and more broadly herpesviruses

External Validation of a Measurement Tool to Assess Systematic Reviews (AMSTAR)

BACKGROUND: Thousands of systematic reviews have been conducted in all areas of health care. However, the methodological quality of these reviews is variable and should routinely be appraised. AMSTAR is a measurement tool to assess systematic reviews. METHODOLOGY: AMSTAR was used to appraise 42 reviews focusing on therapies to treat gastro-esophageal reflux disease, peptic ulcer disease, and other acid-related diseases. Two assessors applied the AMSTAR to each review. Two other assessors, plus a clinician and/or methodologist applied a global assessment to each review independently. CONCLUSIONS: The sample of 42 reviews covered a wide range of methodological quality. The overall scores on AMSTAR ranged from 0 to 10 (out of a maximum of 11) with a mean of 4.6 (95% CI: 3.7 to 5.6) and median 4.0 (range 2.0 to 6.0). The inter-observer agreement of the individual items ranged from moderate to almost perfect agreement. Nine items scored a kappa of >0.75 (95% CI: 0.55 to 0.96). The reliability of the total AMSTAR score was excellent: kappa 0.84 (95% CI: 0.67 to 1.00) and Pearson's R 0.96 (95% CI: 0.92 to 0.98). The overall scores for the global assessment ranged from 2 to 7 (out of a maximum score of 7) with a mean of 4.43 (95% CI: 3.6 to 5.3) and median 4.0 (range 2.25 to 5.75). The agreement was lower with a kappa of 0.63 (95% CI: 0.40 to 0.88). Construct validity was shown by AMSTAR convergence with the results of the global assessment: Pearson's R 0.72 (95% CI: 0.53 to 0.84). For the AMSTAR total score, the limits of agreement were -0.19+/-1.38. This translates to a minimum detectable difference between reviews of 0.64 'AMSTAR points'. Further validation of AMSTAR is needed to assess its validity, reliability and perceived utility by appraisers and end users of reviews across a broader range of systematic reviews