Bitcoin Transaction Malleability and MtGox

In Bitcoin, transaction malleability describes the fact that the signatures that prove the ownership of bitcoins being transferred in a transaction do not provide any integrity guarantee for the signatures themselves. This allows an attacker to mount a malleability attack in which it intercepts, modifies, and rebroadcasts a transaction, causing the transaction issuer to believe that the original transaction was not confirmed. In February 2014 MtGox, once the largest Bitcoin exchange, closed and filed for bankruptcy claiming that attackers used malleability attacks to drain its accounts. In this work we use traces of the Bitcoin network for over a year preceding the filing to show that, while the problem is real, there was no widespread use of malleability attacks before the closure of MtGox

Radiative Corrections to the decay tau -> pi (K) nu_tau

We have calculated the O(alpha) radiative corrections to the tau decay tau -> pi (K) nu, taking into account both the point meson contribution and the structure dependent radiation. We find for the ratio Gamma(tau -> pi nu (gamma)) / Gamma(pi -> mu nu (gamma)) a radiative correction of + 1.2% and for Gamma(tau -> K nu (gamma)) / Gamma(K -> mu nu (gamma)) one of + 2.0%. We compare our results with an earlier estimation and with experimental data.Comment: 6 pages, Latex, Karlsruhe Univ. Preprint TTP 93-2

Radiative Corrections to the Decay τ→πντ\tau\to\pi\nu_\tau

We have calculated the radiative corrections to the decay $\tau\to \pi(K) \nu_\tau$, taking to account internal bremsstrahlung and structure dependent radiation in the radiative decay and point meson, hadronic structure dependent and short distance contributions in the virtual corrections. We display the spectra of the photon energy and of the pion-photon invariant mass in the decay $\tau\to\pi\nu_\tau\gamma$ and compare with the PHOTOS Monte-Carlo. Our result for the radiative correction to the ratio $\Gamma(\tau\to\pi\nu_\tau(\gamma))/ \Gamma(\pi\to\mu\nu_\mu(\gamma))$ is $\delta R_{\tau/\pi} = \left(0.16 \pm 0.14 \right) \%$ and for the ratio $\Gamma(\tau\to K\nu_\tau(\gamma))/ \Gamma(K\to\mu\nu_\mu(\gamma))$, we obtain $\delta R_{\tau/K } = \left(0.90 \pm 0.22 \right) \%$.Comment: 12 pages, Latex, using: epsfig, subfigure, rotating. 9 figures not included, complete Postscript file (including the figures) available via e-mail on request. Invited talk at the Third Workshop on Tau Lepton Physics (Montreux, September 94), presented by Markus Finkemeie

Extent and Nature of Deer Damage to Commercial Nurseries in New York

We surveyed nursery producers in New York to determine the extent, nature and economic impact of deer damage to their operations, and to assess their attitudes towards deer. Seventy-three percent of the producers experienced deer damage to their crops in 1988. Average costs for replacement were nearly $6,000 per grower for those reporting damage estimates (and over$8,000 if 1 extreme value was included). Statewide damage estimates ranged from $500,000 to$1.2 million (depending on assumptions). Forty-six percent used damage control, which cost an average of about $2,000 per grower. More than 80% of the producers were classified as nonaccepting of deer damage and deer populations. We also reviewed several deer damage studies to compare economic and attitudinal impacts of deer damage to various agricultural constituencies. Nursery producers, orchardists, and Christmas tree growers appear to incur the greatest per capita deer damage costs. Of agriculturists, nursery producers and orchardists appear to be the least accepting of deer and deer damage. Deer managers and policy makers may need to consider the nursery producers in the same at risk category as orchardists

Fractured-Aquifer Hydrogeology from Geophysical Logs: Brunswick Group and Lockatong Formation, Pennsylvania

The Brunswick Group and the underlying Lockatong Formation are composed of lithified Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania. These fractured rocks form an important regional aquifer that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Lansdale, Pennsylvania, in order to better characterize the areal hydrogeologic system and provide guidelines for the refinement of numerical ground water models. Six of the seven wells are approximately 120 m deep and the seventh extends to a depth of 335 m. Temperature, fluid conductivity, and flowmeter logs are used to locate zones of fluid exchange and to quantify transmissivities. Electrical resistivity and natural gamma logs together yield detailed stratigraphic information, and digital acoustic televiewer data provide magnetically oriented images of the borehole wall from which almost 900 fractures are identified

Fractured-Aquifer Hydrogeology from Geophysical Logs: Brunswick Group and Lockatong Formation, Pennsylvania

The Brunswick Group and the underlying Lockatong Formation are composed of lithified Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania. These fractured rocks form an important regional aquifer that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Lansdale, Pennsylvania, in order to better characterize the areal hydrogeologic system and provide guidelines for the refinement of numerical ground water models. Six of the seven wells are approximately 120 m deep and the seventh extends to a depth of 335 m. Temperature, fluid conductivity, and flowmeter logs are used to locate zones of fluid exchange and to quantify transmissivities. Electrical resistivity and natural gamma logs together yield detailed stratigraphic information, and digital acoustic televiewer data provide magnetically oriented images of the borehole wall from which almost 900 fractures are identified