Computational Soundness for Dalvik Bytecode

Automatically analyzing information flow within Android applications that rely on cryptographic operations with their computational security guarantees imposes formidable challenges that existing approaches for understanding an app's behavior struggle to meet. These approaches do not distinguish cryptographic and non-cryptographic operations, and hence do not account for cryptographic protections: f(m) is considered sensitive for a sensitive message m irrespective of potential secrecy properties offered by a cryptographic operation f. These approaches consequently provide a safe approximation of the app's behavior, but they mistakenly classify a large fraction of apps as potentially insecure and consequently yield overly pessimistic results. In this paper, we show how cryptographic operations can be faithfully included into existing approaches for automated app analysis. To this end, we first show how cryptographic operations can be expressed as symbolic abstractions within the comprehensive Dalvik bytecode language. These abstractions are accessible to automated analysis, and they can be conveniently added to existing app analysis tools using minor changes in their semantics. Second, we show that our abstractions are faithful by providing the first computational soundness result for Dalvik bytecode, i.e., the absence of attacks against our symbolically abstracted program entails the absence of any attacks against a suitable cryptographic program realization. We cast our computational soundness result in the CoSP framework, which makes the result modular and composable.Comment: Technical report for the ACM CCS 2016 conference pape

Response to ‘Protected areas and climate change Reflections from a practitioner's perspective

Cliquet et al. 1 provide a thought-provoking analysis of the challenges posed to the EU's protected areas by climate change. This paper seeks to build on some of the perspectives they brought to what is a highly challenging area of nature conservation law, policy and practice. While there is much to support in their analysis of the relationships between protected areas and climate change, there are two key strands we seek to develop further, based on the RSPB's experience of this area of nature conservation policy and practice: first, is the ecological model for adapting to climate change and second, the legal framework provided by the Birds2 and Habitats3 Directives (the Nature Directives) as it relates to the delivery of such adaptive actions

Direct Observation of Large Amplitude Spin Excitations Localized in a Spin-Transfer Nanocontact

We report the direct observation of large amplitude spin-excitations localized in a spin-transfer nanocontact using scanning transmission x-ray microscopy. Experiments were conducted using a nanocontact to an ultrathin ferromagnetic multilayer with perpendicular magnetic anisotropy. Element resolved x-ray magnetic circular dichroism images show an abrupt onset of spin excitations at a threshold current that are localized beneath the nanocontact, with average spin precession cone angles of 25{\deg} at the contact center. The results strongly suggest that we have observed a localized magnetic soliton.Comment: 5 pages, 3 figure

X-Ray Detection of Transient Magnetic Moments Induced by a Spin Current in Cu

We have used a MHz lock-in x-ray spectro-microscopy technique to directly detect changes of magnetic moments in Cu due to spin injection from an adjacent Co layer. The elemental and chemical specificity of x-rays allows us to distinguish two spin current induced effects. We detect the creation of transient magnetic moments of $3\times 10^{-5}$ $\mu_\mathrm{B}$ on Cu atoms within the bulk of the 28 nm thick Cu film due to spin-accumulation. The moment value is compared to predictions by Mott's two current model. We also observe that the hybridization induced existing magnetic moments on Cu interface atoms are transiently increased by about 10% or $4\times 10^{-3}$ $\mu_\mathrm{B}$. This reveals the dominance of spin-torque alignment over Joule heat induced disorder of the interfacial Cu moments during current flow

The JKind Model Checker

JKind is an open-source industrial model checker developed by Rockwell Collins and the University of Minnesota. JKind uses multiple parallel engines to prove or falsify safety properties of infinite state models. It is portable, easy to install, performance competitive with other state-of-the-art model checkers, and has features designed to improve the results presented to users: inductive validity cores for proofs and counterexample smoothing for test-case generation. It serves as the back-end for various industrial applications.Comment: CAV 201

Desempenho agronômico de genótipos de feijão em dois níveis de investimento.

O objetivo deste trabalho foi avaliar a produtividade de grãos de cultivares de feijão em dois níveis de investimento. O maior nível de investimento, caracterizado pelo uso de maior dose de fertilizante e maior número de aplicações de fungicidas, não influenciou na produtividade de cultivares de feijão, em relação ao manejo usual

Optimal Lipid Modification: the Rationale for Combination Therapy

This is the publisher's version, also available electronically from "http://www.dovepress.com".No abstract available

Optimal Lipid Modification: The Rationale for Combination Therapy

James M Backes1, Cheryl A Gibson2, Patricia A Howard31Department of Pharmacy Practice, Lipid, Atherosclerosis, Metabolic and LDL Apheresis Center, University of Kansas Medical Center, Kansas City, KS, USA; 2Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA; 3Department of Pharmacy Practice, University of Kansas School of Pharmacy, Kansas City, KS, USABackground: An emphasis on more aggressive lipid-lowering, particularly of low-density lipoprotein cholesterol, to improve patient outcomes has led to an increased use of combination lipid-lowering drugs. This strategy, while potentially beneficial, has triggered concerns regarding fears of adverse effects, harmful drug interactions, and patient nonadherence.Objective: To present key data regarding combination lipid-altering therapy including use, rationale, major trials, benefits, potential adverse effects, compliance issues, and limitations. Method: Literature was obtained from MEDLINE (1966 – June 2005) and references from selected articles.Results: A substantial body of evidence from epidemiological data and clinical trials indicates that aggressive lipid modification, especially low-density lipoprotein reduction, is associated with reduced cardiovascular events. Numerous studies utilizing various combinations of cholesterol-lowering agents including statin/fibrate, statin/niacin, statin/bile acid resin, and statin/ezetimibe have demonstrated significant changes in the lipid profile with acceptable safety. Long-term trials of combination therapy evaluating clinical outcomes or surrogate markers of cardiovascular disease, while limited, are promising.Conclusion: Combining lipid-altering agents results in additional improvements in lipoproteins and has the potential to further reduce cardiovascular events beyond that of monotherapy.Keywords: combination therapy, coronary heart disease, hypercholesterolemia, lipid-lowering, low-density lipoprotein, statin

Disentangling surface and bulk transport in topological-insulator pp-nn junctions

By combining $n$-type $\mathrm{Bi_2Te_3}$ and $p$-type $\mathrm{Sb_2Te_3}$ topological insulators, vertically stacked $p$-$n$ junctions can be formed, allowing to position the Fermi level into the bulk band gap and also tune between $n$- and $p$-type surface carriers. Here we use low-temperature magnetotransport measurements to probe the surface and bulk transport modes in a range of vertical $\mathrm{Bi_2Te_3/Sb_2Te_3}$ heterostructures with varying relative thicknesses of the top and bottom layers. With increasing thickness of the $\mathrm{Sb_2Te_3}$ layer we observe a change from $n$- to $p$-type behavior via a specific thickness where the Hall signal is immeasurable. Assuming that the the bulk and surface states contribute in parallel, we can calculate and reproduce the dependence of the Hall and longitudinal components of resistivity on the film thickness. This highlights the role played by the bulk conduction channels which, importantly, cannot be probed using surface sensitive spectroscopic techniques. Our calculations are then buttressed by a semi-classical Boltzmann transport theory which rigorously shows the vanishing of the Hall signal. Our results provide crucial experimental and theoretical insights into the relative roles of the surface and bulk in the vertical topological $p$-$n$ junctions.Comment: 11 pages, 5 figure