A survey of evaluation platforms for ad hoc routing protocols: a resilience perspective

Routing protocols allow for the spontaneous formation of wireless multi-hop networks without dedicated infrastructure, also known as ad hoc networks. Despite significant technological advances, difficulties associated with the evaluation of ad hoc routing protocols under realistic conditions, still hamper their maturation and significant roll out in real world deployments. In particular, the resilience evaluation of ad hoc routing protocols is essential to determine their ability of keeping the routing service working despite the presence of changes, such as accidental faults or malicious ones (attacks). However, the resilience dimension is not always addressed by the evaluation platforms that are in charge of assessing these routing protocols. In this paper, we provide a survey covering current state-of-the-art evaluation platforms in the domain of ad hoc routing protocols paying special attention to the resilience dimension. The goal is threefold. First, we identify the most representative evaluation platforms and the routing protocols they have evaluated. Then, we analyse the experimental methodologies followed by such evaluation platforms. Finally, we create a taxonomy to characterise experimental properties of such evaluation platforms.This work is partially supported by the Spanish Project ARENES (TIN2012-38308-C02-01), the ANR French Project AMORES (ANR-11-INSE-010), and the Intel Doctoral Student Honour Programme 2012.Friginal López, J.; Andrés Martínez, DD.; Ruiz García, JC.; Martínez Raga, M. (2014). A survey of evaluation platforms for ad hoc routing protocols: a resilience perspective. Computer Networks. 75(A):395-413. https://doi.org/10.1016/j.comnet.2014.09.010S39541375

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Identification of Cutaneous Mycobacterium massiliense Infections Associated with Repeated Surgical Procedures

Mycobacterium massiliense, an emerging pathogen that is increasingly reported as a causative agent in infections occurring during medical procedures, is difficult to be identified using conventional methods. Here we report the case of a cutaneous M. massiliense infection that was associated with repeated surgical procedures and that was identified via a comparative sequence analysis of rpoB and hsp65. The patient showed a substantial response to treatment with a combination of antimicrobial therapies consisting of clarithromycin, amikacin, and cefoxitin for 6 months