Front-Running Protection for Distributed Exchanges using Tamper-Resistant Round Trip Time Measurements

In this paper we present ODIN, a front-running protection system that uses a novel algorithm to measure Round-Trip-Time (RTT) to untrusted servers. ODIN is the decentralized equivalent of THOR, a RTT-aware front-running protection system for trading on centralized exchanges. Unlike centralized exchanges, P2P exchanges have potentially malicious peers which makes reliable direct RTT measurement impossible. In order to prevent tampering by an arbitrarily malicious peer, ODIN performs an indirect RTT measurement that never interacts directly with the target machine. The RTT to the target is estimated by measuring the RTT to a randomized IP address that is known to be close to the target's IP address in the global routing network. We find that ODIN's RTT estimation algorithm provides an accurate, practical, and generic solution for collecting network latency data in a hostile network environment

Development and refinement of proxy-climate indicators from peats

Peat, especially from acidic mires (bogs), is a natural archive of past environmental change. Reconstructions of past climate from bogs commenced in the 19th Century through examination of visible peat stratigraphy, and later formed the basis for a postglacial climatic scheme widely used in Northwest Europe. Nevertheless, misconceptions as to how bogs grow led to a 50-year lacuna in peat-climate study, before the concept of "cyclic regeneration" in bogs was refuted. In recent decades, research using proxyclimate indicators from bogs has burgeoned. A range of proxies for past hydrological change has been developed, as well as use of pollen, bog oaks and pines and other data to reconstruct past temperatures. Most of this proxy-climate research has been carried out in Northern Europe, but peat-based research in parts of Asia and North America has increased, particularly during the last decade, while research has also been conducted in Australia, New Zealand and South America. This paper reviews developments in proxy-climate reconstructions from peatlands; chronicles use of a range of palaeo-proxies such as visible peat stratigraphy, plant macrofossils, peat humification, testate amoebae and non-pollen palynomorphs; and explains the use of wiggle-match radiocarbon dating and relationship to climate shifts. It details other techniques being used increasingly, such as biomarkers, stable-isotopes, inorganic geochemistry and estimation of dust flux; and points to new proxies under development. Although explicit protocols have been developed recently for research on ombrotrophic mires, it must be recognised that not all proxies and techniques have universal applicability, owing to differences in species assemblages, mire formation, topographic controls, and geochemical characteristics

Higgs Physics at LEP2

In this report we review the prospects for Higgs physics at LEP2. The theoretical aspects and the phenomenology of Higgs particles are discussed within the Standard Model (SM) and the Minimal Supersymmetric Standard Model (MSSM). The experimental search techniques are described and the discovery limits for Higgs bosons in the LEP2 energy range are summarized. In addition, opportunities of detecting Higgs particles in non-minimal extensions of the SM and the MSSM are investigated.Comment: 112 pages, latex file + figures (some bitmapped), to appear in Vol. 1, Report of the Workshop on Physics at LEP2, G. Altarelli, T. Sjostrand and F.Zwirner (eds), CERN 96-01. (Full postscript and uuencoded files, including full resolution figures are available at the www address http://surya11.cern.ch/surya_info/users/mcarena in finrep.ps, finrep.uu

Anatomy of elbow instability

Background. Detailed knowledge of elbow anatomy is crucial for diagnosis and therapy of instabilities around the elbow joint. Discussion. Several anatomical structures stabilize the elbow joint. Due to its high congruency, the ulnohumeral joint protects the joint especially against varus as well as valgus stress and distraction particularly in full extension. The radiohumeral joint and proximal radioulnar joint are secondary stabilizers against valgus stress. The primary stabilizer against valgus stress is the medial collateral ligament which can be divided into an anterior and a posterior bundle. The lateral collateral ligament consists of the radial collateral ligament, the lateral ulnar collateral ligament and the annular ligament. The lateral collateral ligament in its entirety stabilizes the elbow against varus forces and posterolateral rotatory instability. Conclusion. In addition, muscles spanning over the elbow joint are dynamic and static stabilizers via joint compression forces of the muscles and the orientation of muscle fibers that resemble those of the collateral ligaments

Plate osteosynthesis of the coronoid process of the ulna

Objective: The aim of surgical treatment is reconstruction of the coronoid process' bony anatomy. Indications: Large shear fractures of the coronoid process (Regan-Morrey type II-III, O'Driscoll tip subtype 2 and basal subtype 1-2) and fractures of the anteromedial facet (O'Driscoll anteromedial subtype 1-3) can occur isolated or as part of the terrible triad injuries to the elbow. Due to the resulting instability of these injuries, surgical reconstruction is generally indicated. Contraindications: In case of major accompanying soft tissue injuries to the elbow or an elbow infection, primary operative treatment using anatomical plate osteosynthesis is contraindicated. Surgical technique: Plate osteosynthesis of the coronoid process is performed through a medial approach (Hotchkiss or M. flexor carpi ulnaris split). After repositioning of the fracture fragments, a preformed anatomical plate can be fixed to the coronoid process. Postoperative management: The arm is immobilized in an over-the-elbow cast until the wounds are dried. Afterwards, the elbow should preferably be treated functionally without varus or valgus stress. Results: Between January 2015 and July 2018, a total of 11 patients underwent osteosynthesis of the coronoid using anatomically preformed plate osteosynthesis. After a mean follow-up of 10.7 months, the mean Mayo Elbow Performance Score showed an excellent result with 78.89 points. The Quick Disabilities of Arm, Shoulder and Hand (Q-DASH) score showed a median of 18.64 points with a mean functional arc of 118 degrees

Treatment options of painful sequelae following radial head fracture

Radial head fractures represent an osteoligamentous injury of the elbow and the forearm, respectively. Concomitant injuries have to be included in the primary treatment to avoid unnecessary complications. Given the heterogeneity of this pathology, there are a large variety of potential complications, which lead to surgical revision in a considerable number of cases. By combining a detailed clinical examination with radiologic imaging, possible treatment options can be determined based on the individual patient's situation. Post-traumatic elbow stiffness, instability and painful osteoarthritis of the radial column are the most common causes for surgical revision. Especially the latter presents a problematic pathology in the young and active patient. The following article provides an overview about the treatment options of painful sequelae following radial head fracture

Revision surgery following elbow ligament reconstruction

Ligament reconstruction surgery at the elbow can be performed to treat medial or lateral instabilities of the elbow joint. Recurring instability occurs in about 2% following medial ligament reconstruction and in about 8% following lateral ligament reconstruction. Other complications that require revision after ligament reconstruction are deep or superficial infections, olecranon osteopyhtes (4.4-11.7%), avulsion fractures (0-2.2%) and pathologies of the ulnar nerve (0-24%). This article aims to summarize causes and therapeutic strategies of revisions following elbow ligament reconstruction

Management of complications of traumatic elbow instability

Traumatic elbow dislocations and fracture dislocations are severe injuries, which jeopardize the stability of the elbow joint. Various possibilities for complications arise as a result of the complexity of these injuries. A thorough understanding of the anatomical and biomechanical characteristics is required to provide an optimal management of complications. The patients frequently present with a painful restriction in range of motion, while joint instability is not necessarily subjectively perceived. A detailed physical examination in combination with 3D imaging diagnostics help to specify the cause of the problem. The subsequent treatment strategy depends on the underlying pathology. Chronic defects of the coronoid process can be reconstructed by bone grafts, usually taken from the iliac crest, to restore joint congruity and stability. Reconstruction of the radial column after unstable radial head defects is reliably achieved with radial head arthroplasty. After reconstruction of the bony defects, restoration of the collateral ligament complex and the dynamic stabilizers is an equally important step in the management of traumatic elbow instability. While ligament repair is usually achieved in (sub)acute cases, chronic instability is commonly treated with ligament replacement grafts to restore sufficient joint stability

Injuries to the Coronoid Process of the Ulna with Involvement of the Lesser Sigmoid Notch

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