Anti-Tamper Method for Field Programmable Gate Arrays Through Dynamic Reconfiguration and Decoy Circuits

As Field Programmable Gate Arrays (FPGAs) become more widely used, security concerns have been raised regarding FPGA use for cryptographic, sensitive, or proprietary data. Storing or implementing proprietary code and designs on FPGAs could result in the compromise of sensitive information if the FPGA device was physically relinquished or remotely accessible to adversaries seeking to obtain the information. Although multiple defensive measures have been implemented (and overcome), the possibility exists to create a secure design through the implementation of polymorphic Dynamically Reconfigurable FPGA (DRFPGA) circuits. Using polymorphic DRFPGAs removes the static attributes from their design; thus, substantially increasing the difficulty of successful adversarial reverse-engineering attacks. A variety of dynamically reconfigurable methodologies exist for implementation that challenge designers in the reconfigurable technology field. A Hardware Description Language (HDL) DRFPGA model is presented for use in security applications. The Very High Speed Integrated Circuit HDL (VHSIC) language was chosen to take advantage of its capabilities, which are well suited to the current research. Additionally, algorithms that explicitly support granular autonomous reconfiguration have been developed and implemented on the DRFPGA as a means of protecting its designs. Documented testing validates the reconfiguration results and compares power usage, timing, and area estimates from a conventional and DRFPGA model

Radio Frequency Based Programmable Logic Controller Anomaly Detection

The research goal involved developing improved methods for securing Programmable Logic Controller (PLC) devices against unauthorized entry and mitigating the risk of Supervisory Control and Data Acquisition (SCADA) attack by detecting malicious software and/or trojan hardware. A Correlation Based Anomaly Detection (CBAD) process was developed to enable 1) software anomaly detection discriminating between various operating conditions to detect malfunctioning or malicious software, firmware, etc., and 2) hardware component discrimination discriminating between various hardware components to detect malfunctioning or counterfeit, trojan, etc., components

Systolic and Diastolic Left Ventricular Mechanics during and after Resistance Exercise

PURPOSE: To improve the current understanding of the impact of resistance exercise on the heart, by examining the acute responses of left ventricular (LV) strain, twist and untwisting rate ('LV mechanics'). METHODS: LV echocardiographic images were recorded in systole and diastole before, during and immediately after (7-12 s) double leg press exercise at two intensities (30% and 60% of maximum strength, 1-repetition-maximum, 1RM). Speckle tracking analysis generated LV strain, twist and untwisting rate data. Additionally, beat-by-beat blood pressure was recorded and systemic vascular resistance (SVR) and LV wall stress were calculated. RESULTS: Responses in both exercise trials were statistically similar (P > 0.05). During effort, stroke volume decreased while SVR and LV wall stress increased (P 0.05). Immediately following exercise, systolic LV mechanics returned to baseline levels (P < 0.05) but LV untwisting rate increased significantly (P < 0.05). CONCLUSIONS: A single, acute bout of double leg-press resistance exercise transiently reduces systolic LV mechanics, but increases diastolic mechanics following exercise, suggesting that resistance exercise has a differential impact on systolic and diastolic heart muscle function. The findings may explain why acute resistance exercise has been associated with reduced stroke volume but chronic exercise training may result in increased LV volumes

Crumple: A Method for Complete Enumeration of All Possible Pseudoknot-Free RNA Secondary Structures

The computing for this project was performed at the OU Supercomputing Center for Education & Research (OSCER) at the University of Oklahoma (OU). OSCER director Henry Neeman and OSCER staff provided valuable technical expertise. The authors acknowledge and appreciate the discussions about this work with Dr. Changwook Kim, Adam Heck, Sean Lavelle, and Jui-wen Liu.Conceived and designed the experiments: SB SJS. Performed the experiments: SB JWS. Analyzed the data: SB JWS SJS. Wrote the paper: SB JWS SJS.The diverse landscape of RNA conformational space includes many canyons and crevices that are distant from the lowest minimum free energy valley and remain unexplored by traditional RNA structure prediction methods. A complete description of the entire RNA folding landscape can facilitate identification of biologically important conformations. The Crumple algorithm rapidly enumerates all possible non-pseudoknotted structures for an RNA sequence without consideration of thermodynamics while filtering the output with experimental data. The Crumple algorithm provides an alternative approach to traditional free energy minimization programs for RNA secondary structure prediction. A complete computation of all non-pseudoknotted secondary structures can reveal structures that would not be predicted by methods that sample the RNA folding landscape based on thermodynamic predictions. The free energy minimization approach is often successful but is limited by not considering RNA tertiary and protein interactions and the possibility that kinetics rather than thermodynamics determines the functional RNA fold. Efficient parallel computing and filters based on experimental data make practical the complete enumeration of all non-pseudoknotted structures. Efficient parallel computing for Crumple is implemented in a ring graph approach. Filters for experimental data include constraints from chemical probing of solvent accessibility, enzymatic cleavage of paired or unpaired nucleotides, phylogenetic covariation, and the minimum number and lengths of helices determined from crystallography or cryo-electron microscopy. The minimum number and length of helices has a significant effect on reducing conformational space. Pairing constraints reduce conformational space more than single nucleotide constraints. Examples with Alfalfa Mosaic Virus RNA and Trypanosome brucei guide RNA demonstrate the importance of evaluating all possible structures when pseduoknots, RNA-protein interactions, and metastable structures are important for biological function. Crumple software is freely available at http://adenosine.chem.ou.edu/software.html.Yeshttp://www.plosone.org/static/editorial#pee

Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

<p>Abstract</p> <p>Background</p> <p>Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles.</p> <p>Results</p> <p>Our results show that hydroxyl radicals (^.OH) were generated from reactions with H₂O₂and after exposure to cells. Catalase reduced the generation of <b>^.</b>OH from exposed cells indicating the involvement of H₂O₂. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O₂consumption, induce H₂O₂generation in cells, and cause DNA damage.</p> <p>Conclusion</p> <p>Increase in oxidative damage observed in the cellular exposures correlated well with <b>^.</b>OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute lung injury. Since type of fume generated, particle size, and elapsed time after generation of the welding exposure are significant factors in radical generation and particle deposition these factors should be considered when developing protective strategies.</p

Observable Dirac-type singularities in Berry's phase and the monopole

The physical reality and observability of 2n\pi Berry phases, as opposed to the usually considered modulo 2\pi topological phases is demonstrated with the help of computer simulation of a model adiabatic evolution whose parameters are varied along a closed loop in the parameter space. Using the analogy of Berry's phase with the Dirac monopole, it is concluded that an interferometer loop taken around a magnetic monopole of strength n/2 yields an observable 2n\pi phase shift, where n is an integer. An experiment to observe the effect is proposed.Comment: 12 pages Latex, 3 postscript figures; submitted to Physical Review Letters 15 September 2000; revised 19 November 200