1,147 research outputs found

    A Method for Revealing and Addressing Security Vulnerabilities in Cyber-physical Systems by Modeling Malicious Agent Interactions with Formal Verification

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    Several cyber-attacks on the cyber-physical systems (CPS) that monitor and control critical infrastructure were publically announced over the last few years. Almost without exception, the proposed security solutions focus on preventing unauthorized access to the industrial control systems (ICS) at various levels – the defense in depth approach. While useful, it does not address the problem of making the systems more capable of responding to the malicious actions of an attacker once they have gained access to the system. The first step in making an ICS more resilient to an attacker is identifying the cyber security vulnerabilities the attacker can use during system design. This paper presents a method that reveals cyber security vulnerabilities in ICS through the formal modeling of the system and malicious agents. The inclusion of the malicious agent in the analysis of an existing systems identifies security vulnerabilities that are missed in traditional functional model checking

    Influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training on the plasma cytokine response to maximum sustainable voluntary ventilation

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    The influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training (IMT) on the cytokine response to maximum sustainable voluntary ventilation (MSVV) is unknown. Twelve healthy males were divided equally into an IMT or placebo (PLA) group, and before and after a 6-wk intervention they undertook, on separate days, 1h of (1) passive rest and (2) MSVV, whereby participants undertook volitional hyperpnea at rest that mimicked the breathing and respiratory muscle recruitment patterns commensurate with heavy cycling exercise. Plasma cytokines remained unchanged during passive rest. There was a main effect of time (P < 0.01) for plasma interleukin-1 (IL-1) and interleukin-6 (IL-6) concentrations and a strong trend (P = 0.067) for plasma interleukin-1 receptor antagonist concentration during MSVV. Plasma IL-6 concentration was reduced after IMT by 27 + 18% (main effect of intervention, P = 0.029), whereas there was no change after PLA (P = 0.753). There was no increase in a systemic marker of oxidative stress [DNA damage in peripheral blood mononuclear cells (PBMC)], and diaphragm fatigue was not related to the increases in plasma IL-1 and IL-6 concentrations. A dose-response relationship was observed between respiratory muscle work and minute ventilation and increases in plasma IL-6 concentration. In conclusion, increases in plasma IL-1 and IL-6 concentrations during MSVV were not due to diaphragm fatigue or DNA damage in PBMC. Increases in plasma IL-6 concentration during MSVV are attenuated following IMT, and the plasma IL-6 response is dependent upon the level of respiratory muscle work and minute ventilation

    The effects of inspiratory muscle training in older adults

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    Purpose: Declining inspiratory muscle function and structure and systemic low-level inflammation and oxidative stress may contribute to morbidity and mortality during normal ageing. Therefore, we examined the effects of inspiratory muscle training (IMT) in older adults on inspiratory muscle function and structure and systemic inflammation and oxidative stress, and re-examined the reported positive effects of IMT on respiratory muscle strength, inspiratory muscle endurance, spirometry, exercise performance, physical activity levels (PAL) and quality of life (QoL). Methods: Thirty-four healthy older adults (68 ± 3 years) with normal spirometry, respiratory muscle strength and physical fitness were divided equally into a pressure-threshold IMT or sham-hypoxic placebo group. Before and after an 8 week intervention, measurements were taken for dynamic inspiratory muscle function and inspiratory muscle endurance using a weighted plunger pressure-threshold loading device, diaphragm thickness using B-mode ultrasonography, plasma cytokine concentrations using immunoassays, DNA damage levels in peripheral blood mononuclear cells (PBMC) using Comet Assays, spirometry, maximal mouth pressures, exercise performance using a six minute walk test, PAL using a questionnaire and accelerometry, and QoL using a questionnaire

    Inter-Rater Reliability of Historical Data Collected by Non-Medical Research Assistants and Physicians in Patients with Acute Abdominal Pain

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    OBJECTIVES: In many academic emergency departments (ED), physicians are asked to record clinical data for research that may be time consuming and distracting from patient care. We hypothesized that non-medical research assistants (RAs) could obtain historical information from patients with acute abdominal pain as accurately as physicians.METHODS: Prospective comparative study conducted in an academic ED of 29 RAs to 32 resident physicians (RPs) to assess inter-rater reliability in obtaining historical information in abdominal pain patients. Historical features were independently recorded on standardized data forms by a RA and RP blinded to each others' answers. Discrepancies were resolved by a third person (RA) who asked the patient to state the correct answer on a third questionnaire, constituting the "criterion standard." Inter-rater reliability was assessed using kappa statistics (kappa) and percent crude agreement (CrA).RESULTS: Sixty-five patients were enrolled (mean age 43). Of 43 historical variables assessed, the median agreement was moderate (kappa 0.59 [Interquartile range 0.37-0.69]; CrA 85.9%) and varied across data categories: initial pain location (kappa 0.61 [0.59-0.73]; CrA 87.7%), current pain location (kappa 0.60 [0.47-0.67]; CrA 82.8%), past medical history (kappa 0.60 [0.48-0.74]; CrA 93.8%), associated symptoms (kappa 0.38 [0.37-0.74]; CrA 87.7%), and aggravating/alleviating factors (kappa 0.09 [-0.01-0.21]; CrA 61.5%). When there was disagreement between the RP and the RA, the RA more often agreed with the criterion standard (64% [55-71%]) than the RP (36% [29-45%]).CONCLUSION: Non-medical research assistants who focus on clinical research are often more accurate than physicians, who may be distracted by patient care responsibilities, at obtaining historical information from ED patients with abdominal pain

    The Effects of Aerobic Exercise Training on Cerebrovascular and Cognitive Function in Sedentary, Obese, Older Adults

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    Cerebrovascular function and cognition decline with age and are further exacerbated by obesity and physical inactivity. This decline may be offset by aerobic exercise training (AT). We investigated the effects of 16 weeks AT on cerebrovascular and cognitive function in sedentary, obese, older adults. Twenty-eight participants were randomly allocated to AT or a control group. Before and after the intervention, transcranial Doppler ultrasonography was used to measure the cerebrovascular responsiveness (CVR) to physiological (hypercapnia, 5% carbon dioxide) and cognitive stimuli. AT increased the CVR to hypercapnia (98.5 ± 38.4% vs. 58.0 ± 42.0%, P = 0.021), CVR to cognitive stimuli (25.9 ± 6.1% vs. 16.4 ± 5.4%, P < 0.001) and total composite cognitive score (111 ± 14 vs. 104 ± 14, P = 0.004) compared with the control group. A very strong relationship was observed between the number of exercise sessions completed and CVR to cognitive stimuli (r = 0.878, P < 0.001), but not for CVR to hypercapnia (r = 0.246, P = 0.397) or total composite cognitive score (r = 0.213, P = 0.465). Cerebrovascular function and cognition improved following 16 weeks of AT and a dose-response relationship exists between the amount of exercise sessions performed and CVR to cognitive stimuli

    Inhibition of CDK9 activity compromises global splicing in prostate cancer cells

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    Cyclin-dependent kinase 9 (CDK9) phosphorylates RNA polymerase II to promote productive transcription elongation. Here we show that short-term CDK9 inhibition affects the splicing of thousands of mRNAs. CDK9 inhibition impairs global splicing and there is no evidence for a coordinated response between the alternative splicing and the overall transcriptome. Alternative splicing is a feature of aggressive prostate cancer (CRPC) and enables the generation of the anti-androgen resistant version of the ligand-independent androgen receptor, AR-v7. We show that CDK9 inhibition results in the loss of AR and AR-v7 expression due to the defects in splicing, which sensitizes CRPC cells to androgen deprivation. Finally, we demonstrate that CDK9 expression increases as PC cells develop CRPC-phenotype both in vitro and also in patient samples. To conclude, here we show that CDK9 inhibition compromises splicing in PC cells, which can be capitalized on by targeting the PC-specific addiction androgen receptor.Peer reviewe

    The Democratic Biopolitics of PrEP

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    PrEP (Pre-Exposure Prophylaxis) is a relatively new drug-based HIV prevention technique and an important means to lower the HIV risk of gay men who are especially vulnerable to HIV. From the perspective of biopolitics, PrEP inscribes itself in a larger trend of medicalization and the rise of pharmapower. This article reconstructs and evaluates contemporary literature on biopolitical theory as it applies to PrEP, by bringing it in a dialogue with a mapping of the political debate on PrEP. As PrEP changes sexual norms and subjectification, for example condom use and its meaning for gay subjectivity, it is highly contested. The article shows that the debate on PrEP can be best described with the concepts ‘sexual-somatic ethics’ and ‘democratic biopolitics’, which I develop based on the biopolitical approach of Nikolas Rose and Paul Rabinow. In contrast, interpretations of PrEP which are following governmentality studies or Italian Theory amount to either farfetched or trivial positions on PrEP, when seen in light of the political debate. Furthermore, the article is a contribution to the scholarship on gay subjectivity, highlighting how homophobia and homonormativity haunts gay sex even in liberal environments, and how PrEP can serve as an entry point for the destigmatization of gay sexuality and transformation of gay subjectivity. ‘Biopolitical democratization’ entails making explicit how medical technology and health care relates to sexual subjectification and ethics, to strengthen the voice of (potential) PrEP users in health politics, and to renegotiate the profit and power of Big Pharma

    Social theory and the politics of big data and method

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    This article is an intervention in the debate on big data. It seeks to show, firstly, that behind the wager to make sociology more relevant to the digital there lies a coherent if essentially unstated vision and a whole stance which are more a symptom of the current world than a resolute endeavour to think that world through; hence the conclusion that the perspective prevailing in the debate lacks both the theoretical grip and the practical impulse to initiate a much needed renewal of social theory and sociology. Secondly, and more importantly, the article expounds an alternative view and shows by thus doing that other possibilities of engaging the digital can be pursued. The article is thus an invitation to widen the debate on big data and the digital and a call for a more combative social theory

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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