A study on the false positive rate of Stegdetect

In this paper we analyse Stegdetect, one of the well-known image steganalysis tools, to study its false positive rate. In doing so, we process more than 40,000 images randomly downloaded from the Internet using Google images, together with 25,000 images from the ASIRRA (Animal Species Image Recognition for Restricting Access) public corpus. The aim of this study is to help digital forensic analysts, aiming to study a large number of image files during an investigation, to better understand the capabilities and the limitations of steganalysis tools like Stegdetect. The results obtained show that the rate of false positives generated by Stegdetect depends highly on the chosen sensitivity value, and it is generally quite high. This should support the forensic expert to have better interpretation in their results, and taking the false positive rates into consideration. Additionally, we have provided a detailed statistical analysis for the obtained results to study the difference in detection between selected groups, close groups and different groups of images. This method can be applied to any steganalysis tool, which gives the analyst a better understanding of the detection results, especially when he has no prior information about the false positive rate of the tool

An Iterative and Toolchain-Based Approach to Automate Scanning and Mapping Computer Networks

As today's organizational computer networks are ever evolving and becoming more and more complex, finding potential vulnerabilities and conducting security audits has become a crucial element in securing these networks. The first step in auditing a network is reconnaissance by mapping it to get a comprehensive overview over its structure. The growing complexity, however, makes this task increasingly effortful, even more as mapping (instead of plain scanning), presently, still involves a lot of manual work. Therefore, the concept proposed in this paper automates the scanning and mapping of unknown and non-cooperative computer networks in order to find security weaknesses or verify access controls. It further helps to conduct audits by allowing comparing documented with actual networks and finding unauthorized network devices, as well as evaluating access control methods by conducting delta scans. It uses a novel approach of augmenting data from iteratively chained existing scanning tools with context, using genuine analytics modules to allow assessing a network's topology instead of just generating a list of scanned devices. It further contains a visualization model that provides a clear, lucid topology map and a special graph for comparative analysis. The goal is to provide maximum insight with a minimum of a priori knowledge.Comment: 7 pages, 6 figure

DeepRoute: Herding Elephant and Mice Flows with Reinforcement Learning

International audienceWide area networks are built to have enough resilience and flexibility, such as offering many paths between multiple pairs of end-hosts. To prevent congestion, current practices involve numerous tweaking of routing tables to optimize path computation, such as flow diversion to alternate paths or load balancing. However, this process is slow, costly and require difficult online decision-making to learn appropriate settings, such as flow arrival rate, workload, and current network environment. Inspired by recent advances in AI to manage resources, we present DeepRoute, a model-less reinforcement learning approach that translates the path computation problem to a learning problem. Learning from the network environment, DeepRoute learns strategies to manage arriving elephant and mice flows to improve the average path utilization in the network. Comparing to other strategies such as prioritizing certain flows and random decisions, DeepRoute is shown to improve average network path utilization to 30% and potentially reduce possible congestion across the whole network. This paper presents results in simulation and also how DeepRoute can be demonstrated by a Mininet implementation

Tracking replication enzymology in vivo by genome-wide mapping of ribonucleotide incorporation

Ribonucleotides are frequently incorporated into DNA during eukaryotic replication. Here we map the genome-wide distribution of these ribonucleotides as markers of replication enzymology in budding yeast, using a new 5′-DNA end-mapping method, Hydrolytic End Sequencing. HydEn-Seq of DNA from ribonucleotide excision repair-deficient strains reveals replicase- and strand-specific patterns of ribonucleotides in the nuclear genome. These patterns support the role of DNA polymerases α and δ in lagging strand replication and of DNA polymerase ε in leading strand replication. They identify replication origins, termination zones and variations in ribonucleotide incorporation frequency across the genome that exceed three orders of magnitude. HydEn-Seq also reveals strand-specific 5′-DNA ends at mitochondrial replication origins, suggesting unidirectional replication of a circular genome. Given the conservation of enzymes that incorporate and process ribonucleotides in DNA, HydEn-Seq can be used to track replication enzymology in other organisms

Effect of the Ultrasound-Guided Interscalene and Supraclavicular Blocks on the C4 Dermatome

Yue Qiu,1 Chelsea Cady,1 Bedda L Rosario,2 Steven Orebaugh1 1Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; 2Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USACorrespondence: Steven Orebaugh, Email [email protected]: The C4 dermatome anesthesia holds significance for arthroscopic shoulder surgery. However, the reliability of achieving C4 dermatome anesthesia with the current low-dose ultrasound-guided interscalene block (ISB) and supraclavicular block (SCB) remains uncertain. This prospective, single-center study examined the effects of ultrasound-guided interscalene block (ISB) and supraclavicular block (SCB) on the C4 sensory dermatome in patients undergoing shoulder, hand, or wrist surgery.Patients and Methods: Patients undergoing outpatient shoulder, hand, or wrist surgeries received ultrasound-guided ISB (for shoulder surgeries) with 12– 15 mL of 0.5% bupivacaine or ultrasound-guided SCB (for hand and wrist surgeries) with 20– 24 mL of 0.5% bupivacaine. The primary objective of the study was to investigate the sensory effect on the C4 dermatome after ISB and SCB. The secondary outcomes included the sensory effect on the C5 dermatome after performing ISB and SCB, pain scores upon arrival at the post-anesthesia care unit (PACU), and the incidence of adverse effects.Results: Sixty-one patients were recruited: 30 for ISB and 31 for SCB. C4 dermatome coverage was achieved in 53% and 29% of patients in the ISB and SCB groups, respectively (p=0.0268). Additionally, C5 dermatome coverage was achieved in 97% and 68% of patients in the ISB and SCB groups, respectively (p=0.0034). A moderate correlation coefficient (r=0.47) was observed between C4 sensory scores and postoperative pain scores.Conclusion: Ultrasound-guided ISB successfully provided C4 coverage in 53% of cases, suggesting that performing an additional C4 block alongside ISB could be advantageous when aiming for complete surgical anesthesia. SCB may not be the primary choice for shoulder surgeries as it often fails to achieve satisfactory sensory blocks at the C4 and C5 levels.Plain language summary: This study examined how the interscalene block and supraclavicular block work for numbing the C4 area in patients undergoing shoulder, hand, or wrist surgery. We found that the interscalene block provided C4 coverage in only 53% of cases, suggesting performing an additional C4 block might help achieve complete surgical anesthesia. The supraclavicular block is not the best option for shoulder surgeries because it often fails to provide adequate anesthesia at the C4 and C5 levels.Keywords: shoulder surgeries, nerve block, ultrasound-guided block, regional anesthesi

Sedation and regional anaesthesia in the adult patient

This review discusses sedation for regional anaesthesia in the adult population. The first section deals with general aspects of sedation and shows that the majority of patients receiving sedation for regional anaesthesia are satisfied and would choose it again. Methods of assessing the level of sedation are discussed with emphasis on clinical measures. The pharmacology of the drugs involved in sedation is discussed, with propofol and remifentanil appearing to be the combination of choice for sedation in regional anaesthesia. The techniques for administering sedation are discussed and replacement of the traditional repeated boluses or continuous infusion with pharmacokinetic and patient-controlled systems is supported. Patient satisfaction studies suggest that patient-controlled systems are preferred