3,300 research outputs found
Cerumen Composition by Flash Pyrolysis-Gas Chromatography/Mass Spectrometry
Objective: To assess the chemical composition of cerumen by flash pyrolysis-gas chromatography/mass spectrometry.
Study Design: Collected earwax specimens were fractionated into residue and supernatant by means of deoxycholate. This natural bile acid produces significantly better disintegration of earwax in vitro than do presently available ceruminolytic preparations, and also has demonstrated excellent clinical results in vivo to date.
Patients: The sample for analysis was obtained from a patient with clinical earwax impaction.
Results: The supernatant is composed of simple aromatic hydrocarbons, C5-Cl 7 straight-chain hydrocarbons, a complex mixture of compounds tentatively identified as diterpenoids, and steroids, in particular cholesterol. The residue, on the other hand, produced simple aromatic compounds (including benzenes, phenols, and benzonitriles), C5-C25 straight-chain hydrocarbons, greater relative quantities of nitrogen compounds and phenol, and lesser importance of the (tentatively identified) diterpenoids.
Conclusions: Through the use of the detergent deoxycholate, squalene and a tentatively identified diterpenoid were revealed to be present in a free, unbound state, whereas some steroids and hydrocarbons appeared to be bound to a macromolecular structure by nitrogen linkages or other bonds. Additionally, this study reintroduces detergents as a viable method of earwax removal, specifically the bile acids
The convergence of IT and OT in critical infrastructure
Automation and control systems, such as SCADA (Supervisory Control and Data Acquisition), DCS (Distributed Control Systems) and are often referred to as Operational Technology (OT). These systems are used to monitor and control critical infrastructures such as power, pipelines, water distribution, sewage systems and production control,). Traditionally, these OT systems have had a degree of physical separation from Information Technology (IT) infrastructures. With changing technologies and a drive towards data-driven and remote operations the two technology environments are starting to converge. With this convergence, what was a relatively standalone secure and isolated environment is now connected and accessible via the Internet/cloud. With this interconnection comes the cyber security challenges that are typically associated with only with IT infrastructures. OT data that is then accessible from these environments could include critical information such as pressures, temperatures, proximity levels, control signals and other sensor signals. Due to the aforementioned convergence, OT data and associated control mechanisms are now significantly vulnerable to cyber-attacks. This paper provides an understanding of cyber security in an operational technology context (rather than traditional IT environments) and discusses the underlying causes, vulnerabilities, and the risks that are created by convergence and interconnection. We report on evidence of convergence between IT and OT, and use Hofstede’s model of organisational culture to explain the different attitudes and value drivers in IT and OT
Case-control study of arsenic in drinking water and lung cancer in California and Nevada.
Millions of people are exposed to arsenic in drinking water, which at high concentrations is known to cause lung cancer in humans. At lower concentrations, the risks are unknown. We enrolled 196 lung cancer cases and 359 controls matched on age and gender from western Nevada and Kings County, California in 2002-2005. After adjusting for age, sex, education, smoking and occupational exposures, odds ratios for arsenic concentrations ≥85 µg/L (median = 110 µg/L, mean = 173 µg/L, maximum = 1,460 µg/L) more than 40 years before enrollment were 1.39 (95% CI = 0.55-3.53) in all subjects and 1.61 (95% CI = 0.59-4.38) in smokers. Although odds ratios were greater than 1.0, these increases may have been due to chance given the small number of subjects exposed more than 40 years before enrollment. This study, designed before research in Chile suggested arsenic-related cancer latencies of 40 years or more, illustrates the enormous sample sizes needed to identify arsenic-related health effects in low-exposure countries with mobile populations like the U.S. Nonetheless, our findings suggest that concentrations near 100 µg/L are not associated with markedly high relative risks
Everybody Counts or Nobody Counts
Like most campuses, we constantly deal with change at RIT, ranging from policy to climate. We believe everyone needs to feel valued - “Everybody Counts or Nobody Counts, and are attempting to build a supportive culture that includes individual and group mentoring, funding opportunities, and recognition
Small to Medium Enterprise Cyber Security Awareness: An Initial Survey of Western Australian Business
Small to Medium Enterprises (SMEs) represent a large proportion of a nation’s business activity. There are studies and reports reporting the threat to business from cyber security issues resulting in computer hacking that achieve system penetration and information compromise. Very few are focussed on SMEs. Even fewer are focussed on directly surveying the actual SMEs themselves and attempts to improve SME outcomes with respect to cyber security. This paper represents research in progress that outlines an approach being undertaken in Western Australia with SMEs in the northwest metropolitan region of Perth, specifically within the large local government catchments of Joondalup and Wanneroo. The high order goal of the project was to assist with measures to improve their cyber security resilience and resistance to threats. This paper documents outcomes of an initial survey of SMEs and its implications for interventions to improve information security and make the businesses less susceptible to computer hacking incidents
Student experiences of virtual reality - a case study in learning special relativity
We present a study of student learning through the use of virtual reality. A
software package is used to introduce concepts of special relativity to
students in a game-like environment where users experience the effects of
travelling at near light speeds. From this new perspective, space and time are
significantly different to that experienced in everyday life. The study
explores how students have worked with this environment and how these students
have used this experience in their study of special relativity. A mixed method
approach has been taken to evaluate the outcomes of separate implementations of
the package at two universities. Students found the simulation to be a positive
learning experience and described the subject area as being less abstract after
its use. Also, students were more capable of correctly answering concept
questions relating to special relativity, and a small but measurable
improvement was observed in the final exam
Molecular Composition of the Louse Sheath
Flash pyrolysis-gas chromatography/mass spectrometry was used to assess the chemical composition of the head louse\u27s nit sheath. The pyrolyzate of the female insect\u27s secretions, which form a cement-like cylinder holding the egg onto the hair, is dominated by amino acid derivatives and fatty acids. No chitin-specific compounds were detected in the sheath. These results, contrary to previous reports, show that the polymeric complex of the sheath is composed of proteinaceous moieties, possibly cross-linked to aliphatic components. This study constitutes the first chemical characterization of the pyrolysis products of insect (louse) glue and unequivocally confirms that louse sheaths are not chitinous, as suggested by earlier histochemical studies. Development of agents that might loosen nits from the hair shaft is dependent on research that addresses the chemical composition of the nit sheath
Why penetration testing is a limited use choice for sound cyber security practice
Penetration testing of networks is a process that is overused when demonstrating or evaluating the cyber security posture of an organisation. Most penetration testing is not aligned with the actual intent of the testing, but rather is driven by a management directive of wanting to be seen to be addressing the issue of cyber security. The use of penetration testing is commonly a reaction to an adverse audit outcome or as a result of being penetrated in the first place. Penetration testing used in this fashion delivers little or no value to the organisation being tested for a number of reasons. First, a test is only as good as the tools, the tester and the methodology being applied. Second, the results are largely temporal. That is, the test will likely only find known vulnerabilities that exist at one specific point in time and not larger longitudinal flaws with the cyber security of an organisation, one such flaw commonly being governance. Finally, in many cases, one has to question what the point is in breaking the already broken. Penetration testing has its place when used judiciously and as part of an overall review and audit of cyber security. It can be an invaluable tool to assess the ability of a system to survive a sustained attack if properly scoped and deployed. However, it is our assessment and judgement that this rarely occurs
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