Pre-Matrix Balancing of Challenging Chemical Equations with a Simple Formula Register and Middle School Arithmetic

This paper describes a procedure employing basic relational concepts (analogous to certain matrix algebra concepts), but structured by a simple formula register and using only middle school arithmetic to balance chemical equations ranging from easy to moderate to difficult redox reactions. This procedure allows average students and below average students to experience ready success in balancing, thus avoiding a traditional source of frustration and failure which might contribute to their losing interest in chemistry. One interesting serendipity of this procedure is how quickly it turns able pre-matrix students into extremely fast and accurate balaneers

Reporting ethics committee approval and patient consent by study design in five general medical journals.

BACKGROUND: Authors are required to describe in their manuscripts ethical approval from an appropriate committee and how consent was obtained from participants when research involves human participants. OBJECTIVE: To assess the reporting of these protections for several study designs in general medical journals. DESIGN: A consecutive series of research papers published in the Annals of Internal Medicine, BMJ, JAMA, Lancet and The New England Journal of Medicine between February and May 2003 were reviewed for the reporting of ethical approval and patient consent. Ethical approval, name of approving committee, type of consent, data source and whether the study used data collected as part of a study reported elsewhere were recorded. Differences in failure to report approval and consent by study design, journal and vulnerable study population were evaluated using multivariable logistic regression. RESULTS: Ethical approval and consent were not mentioned in 31% and 47% of manuscripts, respectively. 88 (27%) papers failed to report both approval and consent. Failure to mention ethical approval or consent was significantly more likely in all study designs (except case-control and qualitative studies) than in randomised controlled trials (RCTs). Failure to mention approval was most common in the BMJ and was significantly more likely than in The New England Journal of Medicine. Failure to mention consent was most common in the BMJ and was significantly more likely than in all other journals. No significant differences in approval or consent were found when comparing studies of vulnerable and non-vulnerable participants. CONCLUSION: The reporting of ethical approval and consent in RCTs has improved, but journals are less good at reporting this information for other study designs. Journals should publish this information for all research on human participants

Computer security threats faced by small businesses in Australia

In this paper, an overview is provided of computer security threats faced by small businesses. Having identified the threats, the implications for small business owners are described, along with countermeasures that can be adopted to prevent incidents from occurring. The results of the Australian Business Assessment of Computer User Security (ABACUS) survey, commissioned by the Australian Institute of Criminology (AIC), are drawn upon to identify key risks (Challice 2009; Richards 2009). Additional emerging threats relating to wireless internet, cloud computing and spear phishing are also outlined, as well as the risks relating to online fraud

Breakup of liquid filaments.

Whether a thin filament of liquid separates into two or more droplets or eventually condenses lengthwise to form a single larger drop depends on the liquid's density, viscosity, and surface tension and on the initial dimensions of the filament. Surface tension drives two competing processes, pinching-off and shortening, and the relative time scales of these, controlled by the balance between capillary and viscous forces, determine the final outcome. Here we provide experimental evidence for the conditions under which a liquid filament will break up into drops, in terms of a wide range of two dimensionless quantities: the aspect ratio of the filament and the Ohnesorge number. Filaments which do not break up into multiple droplets demand a high liquid viscosity or a small aspect ratio.This work was supported by EPSRC (RG53364 and RG55605

Hacking and fraud: Qualitative analysis of online offending and victimization

This research relates to computer crimes that compromise data and financial security, namely hacking and online fraud, focussing on offe nders’ perceptions of victims. Very little is known about those who commit computer crimes. This is despite the increase in offending rates that have corresponded with the wider availability of computers to the general public from the 1980s and the introduction of the World Wide Web in 1991 (Moschovitis, Poole, Schuyler, & Senft, 1999). These technological advances have increased the reach of offenders as well as the vulnerability of potential victims. Cybercrime offenders constitute a hidden and hard-to-access population. This qualitative analysis draws from interviews with self-identified offenders, law enforcement officers who investigate these offences, and court documents

Faint star counts in the near-infrared

We discuss near-infrared star counts at the Galactic pole with a view to guiding the NGST and ground-based NIR cameras. Star counts from deep K-band images from the CFHT are presented, and compared with results from the 2MASS survey and some Galaxy models. With appropriate corrections for detector artifacts and galaxies, the data agree with the models down to K~18, but indicate a larger population of fainter red stars. There is also a significant population of compact galaxies that extend to the observational faint limit of K=20.5. Recent Galaxy models agree well down to K$\sim$19, but diverge at fainter magnitudes.Comment: 14 pages and 4 diagrams; to appear in PAS