Incremental bounded model checking for embedded software

Program analysis is on the brink of mainstream usage in embedded systems development. Formal verification of behavioural requirements, finding runtime errors and test case generation are some of the most common applications of automated verification tools based on bounded model checking (BMC). Existing industrial tools for embedded software use an off-the-shelf bounded model checker and apply it iteratively to verify the program with an increasing number of unwindings. This approach unnecessarily wastes time repeating work that has already been done and fails to exploit the power of incremental SAT solving. This article reports on the extension of the software model checker CBMC to support incremental BMC and its successful integration with the industrial embedded software verification tool BTC EMBEDDED TESTER. We present an extensive evaluation over large industrial embedded programs, mainly from the automotive industry. We show that incremental BMC cuts runtimes by one order of magnitude in comparison to the standard non-incremental approach, enabling the application of formal verification to large and complex embedded software. We furthermore report promising results on analysing programs with arbitrary loop structure using incremental BMC, demonstrating its applicability and potential to verify general software beyond the embedded domain

The Social and Political Dimensions of the Ebola Response: Global Inequality, Climate Change, and Infectious Disease

The 2014 Ebola crisis has highlighted public-health vulnerabilities in Liberia, Sierra Leone, and Guinea – countries ravaged by extreme poverty, deforestation and mining-related disruption of livelihoods and ecosystems, and bloody civil wars in the cases of Liberia and Sierra Leone. Ebola’s emergence and impact are grounded in the legacy of colonialism and its creation of enduring inequalities within African nations and globally, via neoliberalism and the Washington Consensus. Recent experiences with new and emerging diseases such as SARS and various strains of HN influenzas have demonstrated the effectiveness of a coordinated local and global public health and education-oriented response to contain epidemics. To what extent is international assistance to fight Ebola strengthening local public health and medical capacity in a sustainable way, so that other emerging disease threats, which are accelerating with climate change, may be met successfully? This chapter considers the wide-ranging socio-political, medical, legal and environmental factors that have contributed to the rapid spread of Ebola, with particular emphasis on the politics of the global and public health response and the role of gender, social inequality, colonialism and racism as they relate to the mobilization and establishment of the public health infrastructure required to combat Ebola and other emerging diseases in times of climate change

Carbonate Anion Radical Generated by the Peroxidase Activity of Copper-Zinc Superoxide Dismutase:Scavenging of Radical and Protection of Enzyme by Hypotaurine and Cysteine Sulfinic Acid

Copper-zinc superoxide dismutase (SOD) is considered one of the most important mammalian antioxidant defenses and plays a relevant role due to its main function in catalyzing the dismutation of superoxide anion to oxygen and hydrogen peroxide. However, interaction between SOD and H2O2 produced a strong copper-bound oxidant (Cu(II)●OH) that seems able to contrast the self-inactivation of the enzyme or oxidize other molecules through its peroxidase activity. The bicarbonate presence enhances the peroxidase activity and produces the carbonate anion radical (CO3●–). CO3●– is a freely diffusible reactive species capable of oxidizing several molecules that are unwieldy to access into the reactive site of the enzyme. Cu(II)●OH oxidizes bicarbonate to the CO3●–, which spreads out of the binding site and oxidizes hypotaurine and cysteine sulfinic acid to the respective sulfonates through an efficient reaction. These findings suggest a defense role for sulfinates against the damage caused by CO3●–. The effect of hypotaurine and cysteine sulfinic acid on the CO3●–-mediated oxidation of the peroxidase probe ABTS to ABTS cation radical (ABTS●+) has been studied. Both sulfinates are able to inhibit the oxidation of ABTS mediated by CO3●–. The effect of hypotaurine and cysteine sulfinic acid against SOD inactivation by H2O2 (~42% protection of enzyme activity) has also been investigated. Interestingly, hypotaurine and cysteine sulfinic acid partially avoid the H2O2-mediated SOD inactivation, suggesting that the two sulfinates may have access to the SOD reactive site and preserve it by reacting with the copper-bound oxidant. In this way hypotaurine and cysteine sulfinic acid not only intercept CO3●–which could move out from the reactive site and cause oxidative damage, but also prevents the inactivation of SOD

Surface and Temporal Biosignatures

Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models. The vegetation red-edge (VRE) remains the most well-studied surface biosignature. Extensions of the VRE, spectral "edges" produced in part by photosynthetic or nonphotosynthetic pigments, may likewise present potential evidence of life. Polarization signatures have the capacity to discriminate between biotic and abiotic "edge" features in the face of false positives from band-gap generating material. Temporal biosignatures -- modulations in measurable quantities such as gas abundances (e.g., CO2), surface features, or emission of light (e.g., fluorescence, bioluminescence) that can be directly linked to the actions of a biosphere -- are in general less well studied than surface or gaseous biosignatures. However, remote observations of Earth's biosphere nonetheless provide proofs of concept for these techniques and are reviewed here. Surface and temporal biosignatures provide complementary information to gaseous biosignatures, and while likely more challenging to observe, would contribute information inaccessible from study of the time-averaged atmospheric composition alone.Comment: 26 pages, 9 figures, review to appear in Handbook of Exoplanets. Fixed figure conversion error

The hypothetical consent objection to anti-natalism

Abstract: A very common but untested assumption is that potential children would consent to be exposed to the harms of existence in order to experience its benefits (if it were possible for us to ask and for them to respond). And so, would-be parents might appeal to the following view: Procreation is all-things-considered permissible, as it is morally acceptable for one to knowingly harm an unconsenting patient if one has good reasons for assuming her hypothetical consent—and procreators can indeed reasonably rely on some notion of hypothetical consent. I argue that this view is in error. My argument appeals to a consent-based version of anti-natalism advanced by Seana Valentine Shiffrin. Anti-natalism is the view that it is (almost) always wrong to bring people (and perhaps all sentient beings) into existence. While, like Shiffrin, I stop short of advocating a thoroughgoing anti-natalism, I nevertheless argue that procreators cannot appeal to hypothetical consent to justify exposing children to the harms of existence. I end by suggesting a more promising route by which this justification might be achieved

Evaluation of free-radical quenching properties of standard Ayurvedic formulation Vayasthapana Rasayana

<p>Abstract</p> <p>Background</p> <p>Cellular damage induced by free-radicals like Reactive Oxygen and Nitrogen Species (ROS and RNS) has been implicated in several disorders and diseases, including ageing. Hence naturally occurring anti-oxidant rich-herbs play a vital role in combating these conditions. The present study was carried out to investigate the <it>in vitro </it>free-radical quenching capacity of a known <it>Ayurvedic </it>poly-herbal formulation called <it>Vayasthapana Rasayana.</it></p> <p>Methods</p> <p>Methanol extracts of <it>Vayasthapana Rasayana </it>formulation (VRF) were studied for <it>in vitro </it>total antioxidant activity along with phenolic content and reducing power. <it>In vitro </it>assays like DPPH, FRAP, ABTS scavenging to evaluate radical quenching potential were performed.</p> <p>Results</p> <p>The formulation has shown 94% at 0.1 mg/ml DPPH free-radical scavenging activity as against 84% at 0.1 mg/ml for standard ascorbic acid (IC₅₀value 5.51 μg/ml for VRF and 39 μg/ml for standard). It has a significant higher ferric reducing potential also (OD 0.87 at 700 nm & 0.21 at 0.1 mg/ml for VRF and standard, respectively). The total phenolic content (gallic acid equivalent) of the VRF is 8.3 mg per g of dry mass. Total antioxidant capacity of the formulation, estimated by FRAP was 1150 ± 5 μM Fe(II)/g dry mass. ABTS radical scavenging activity of VRF was 69.55 ± 0.21% at 100 μg/ml concentration with a IC₅₀value of 69.87 μg/ml as against 9% and 95% by ascorbic acid and Trolox (at 70.452 μg/ml and 0.250 μg/ml concentrations, respectively).</p> <p>Conclusion</p> <p>In Indian traditional <it>Ayurvedic </it>system, use of VRF is in regular practice for mainly combating age-related disorders and diseases as many of the components of the <it>Rasayana </it>are known for their free-radical scavenging activity. This study has validated the potential use of VRF as an anti-oxidant to fight age-related problems.</p

The Interaction of Hypotaurine and Other Sulfinates with Reactive Oxygen and Nitrogen Species:A Survey of Reaction Mechanisms

Considerable strides have been made in understanding the oxidative mechanisms involved in the final steps of the cysteine pathway leading to taurine. The oxidation of sulfinates, hypotaurine and cysteine sulfinic acid, to the respective sulfonates, taurine and cysteic acid, has never been associated with any specific enzyme. Conversely, there is strong evidence that in vivo formation of taurine and cysteic acid is the result of sulfinate interaction with a variety of biologically relevant oxidants. In the last decade, many experiments have been performed to understand whether peroxynitrite, nitrogen dioxide and carbonate radical anion could be included in the biologically relevant reactive species capable of oxidizing sulfinates. Thanks to this work, it has been possible to highlight two possible reaction mechanisms (direct and indirect reaction) of sulfinates with reactive oxygen and nitrogen species.The sulfinates oxidation, mediated by peroxynitrite, is an example of both reaction mechanisms: through a two-electron-direct-reaction with peroxynitrite or through a one-electron-indirect-transfer reaction. In the indirect mechanism, the peroxynitrite homolysis releases hydroxyl and nitrogen dioxide radical and in addition the degradation of short-lived adduct formed by peroxynitrite and CO2 can generate carbonate radical anion. The reaction of hypotaurine and cysteine sulfinic acid with peroxynitrite-derived radicals is accompanied by extensive oxygen uptake with the generation of transient intermediates, which can begin a reaction by an oxygen-dependent mechanism with the sulfonates, taurine, and cysteic acid as final products. Due to pulse radiolysis studies, it has been shown that transient sulfonyl radicals (RSO2(•)) have been produced during the oxidation of both sulfinates by one-electron transfer reaction.The purpose is to analyze all the aspects of the reactive mechanism in the sulfinic group oxidation of hypotaurine and cysteine sulfinic acid through the results obtained from our laboratory in recent years

A Systematic Review of the Effect of Cognitive Strategies on Strength Performance

Background Researchers have tested the beliefs of sportspeople and sports medicine specialists that cognitive strategies influence strength performance. Few investigators have synthesised the literature. Objectives The specific objectives were to review evidence regarding (a) the cognitive strategy–strength performance relationship; (b) participant skill level as a moderator; and (c) cognitive, motivational, biomechanical/physiological, and emotional mediators. Method Studies were sourced via electronic databases, reference lists of retrieved articles, and manual searches of relevant journals. Studies had to be randomised or counterbalanced experiments with a control group or condition, repeated measures, and a quality control score above 0.5 (out of 1). Cognitive strategies included goal setting, imagery, self-talk, preparatory arousal, and free choice. Dependent variables included maximal strength, local muscular endurance, or muscular power. Results Globally, cognitive strategies were reliability associated with increased strength performance (results ranged from 61 to 65 %). Results were mixed when examining the effects of specific strategies on particular dependent variables, although no intervention had an overall negative influence. Indeterminate relationships emerged regarding hypothesised mediators (except cognitive variables) and participant skill level as a moderator. Conclusions Although cognitive strategies influence strength performance, there are knowledge gaps regarding specific types of strength, especially muscular power. Cognitive variables, such as concentration, show promise as possible mediators

The effect of temperature, gradient and load carriage on oxygen consumption, posture and gait characteristics

Purpose The purpose of this experiment was to evaluate the effect of load carriage in a range of temperatures to establish the interaction between cold exposure, the magnitude of change from unloaded to loaded walking and gradient. Methods Eleven participants (19-27 years) provided written informed consent before performing six randomly ordered walking trials in six temperatures (20°C, 10°C, 5°C, 0°C, -5°C and -10°C). Trials involved two unloaded walking bouts before and after loaded walking (18.2 kg) at 4 km.hr⁻¹, on 0% and 10% gradients in 4 minute bouts. Results The change in absolute oxygen consumption (V̇O₂) from the first unloaded bout to loaded walking was similar across all six temperatures. When repeating the second unloaded bout, V̇O₂ at both -5°C and-10°C was greater compared to the first. At -10°C, V̇O₂ was increased from 1.60 ± 0.30 L.min⁻¹ to 1.89 ± 0.51 L.min⁻¹. Regardless of temperature, gradient had a greater effect on V̇O₂ and heart rate (HR) than backpack load. HR was unaffected by temperature. Stride length (SL) decreased with decreasing temperature but trunk forward lean was greater during cold exposure. Conclusion Decreased ambient temperature did not influence the magnitude of change in V̇O₂ from unloaded to loaded walking. However, in cold temperatures, V̇O₂ was significantly higher than in warm conditions. The increased V̇O₂ in colder temperatures at the same exercise intensity is predicted to ultimately lead to earlier onset of fatigue and cessation of exercise. These results highlight the need to consider both appropriate clothing and fitness during cold exposure

Preliminary phytochemical screening and In vitro antioxidant activities of the aqueous extract of Helichrysum longifolium DC

<p>Abstract</p> <p>Background</p> <p>Many oxidative stress related diseases are as a result of accumulation of free radicals in the body. A lot of researches are going on worldwide directed towards finding natural antioxidants of plants origins. The aims of this study were to evaluate <it>in vitro </it>antioxidant activities and to screen for phytochemical constituents of <it>Helichrysum longifolium </it>DC. [Family Asteraceae] aqueous crude extract.</p> <p>Methods</p> <p>We assessed the antioxidant potential and phytochemical constituents of crude aqueous extract of <it>Helichrysum longifolium </it>using tests involving inhibition of superoxide anions, DPPH, H₂O₂, NO and ABTS. The flavonoid, proanthocyanidin and phenolic contents of the extract were also determined using standard phytochemical reaction methods.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of tannins, flavonoids, steroids and saponins. The total phenolic content of the aqueous leaf extract was 0.499 mg gallic acid equivalent/g of extract powder. The total flavonoid and proanthocyanidin contents of the plant were 0.705 and 0.005 mg gallic acid equivalent/g of extract powder respectively. The percentage inhibition of lipid peroxide at the initial stage of oxidation showed antioxidant activity of 87% compared to those of BHT (84.6%) and gallic acid (96%). Also, the percentage inhibition of malondialdehyde by the extract showed percentage inhibition of 78% comparable to those of BHT (72.24%) and Gallic (94.82%).</p> <p>Conclusions</p> <p>Our findings provide evidence that the crude aqueous extract of <it>H. longifolium </it>is a potential source of natural antioxidants, and this justified its uses in folkloric medicines.</p