Clinical evaluation of long-term users of two contact lens care preservative systems

Purpose: To clinically evaluate long-term users of two different contact lens care preservative systems and to investigate whether prolonged use is associated with an increase in the prevalence of dry eye.

Methods: Eighty-nine wearers of group IV hydrogel or silicone hydrogel lenses participated in this one-visit, investigator-masked study. Subjects were required to have consistently used a polyhexamethylene biguanide (PHMB) or polyquaternium-1 (PQT) based solution for 2 years. Consistent use was defined as 80% for the past 2 years and 100% for the past year. Clinical assessments included: average and comfortable wear time; overall and end-of-day comfort; signs of dryness, discomfort, burning or stinging, grittiness or scratchiness and visual changes; non-invasive and fluorescein break-up-time; pre-ocular tear film lipids, tear meniscus height, Schirmer and fluorescein clearance tests; limbal and bulbar hyperemia; palpebral roughness; corneal and conjunctival staining; lens front surface wetting; and lens film deposits.

Results: Significantly more grittiness or scratchiness was reported by subjects using a PHMB-containing system (67% vs. 44%; P = 0.02). Palpebral roughness and hyperemia were significantly greater in the PHMB group wearing group IV lenses (P = 0.01 and P = 0.05, respectively). Corneal staining was significantly higher in the PHMB users in all four peripheral sectors (P < 0.01). Nasal and temporal conjunctival staining was also significantly higher for users of PHMB-containing systems (P < 0.05). Front surface lens wettability was significantly better for group IV PQT users compared to PHMB users (P = 0.008), with 84% vs. 72%, respectively, with lenses graded by the investigator as having good or excellent wettability. Significantly higher levels of lens front surface film deposits were noted with PHMB users (P = 0.007), with 58% of group IV lenses treated with PHMB compared with 38% of group IV lenses treated with PQT showing some lens front surface film deposition. No significant differences between the two preservative system groups were noted for the range of dry eye evaluations nor the remaining clinical assessments.

Conclusions: Differences in both ocular and lens characteristic were observed between long-term users of two preservative systems used in many contact lens multi-purpose solutions. The findings from this study did not support the hypothesis that prolonged use of PHMB-containing solutions leads to dry eye. Additional studies including a larger sample size and perhaps longer use of the systems could help to further elucidate differences in clinical performance between systems.

Authenticating the identity of computer users with typing biometrics and the fuzzy min-max neural network

In this paper, typing biometrics is applied as an additional security measure to the password-based or Personal Identification Number (PIN)-based systems to authenticate the identity of computer users. In particular, keystroke pressure and latency signals are analyzed using the Fuzzy Min-Max (FMM) neural network for authentication purposes. A special pressure-sensitive keyboard is designed to collect keystroke pressure signals, in addition to the latency signals, from computer users when they type their passwords. Based on the keystroke pressure and latency signals, the FMM network is employed to classify the computer users into two categories, i.e., genuine users or impostors. To assess the effectiveness of the proposed approach, two sets of experiments are conducted, and the results are compared with those from statistical methods and neural network models. The experimental outcomes positively demonstrate the potentials of using typing biometrics and the FMM network to provide an additional security layer for the current password-based or PIN-based methods in authenticating the identity of computer users.

Predicting the acceptance of unit guide information systems

Information Systems can play an important role in ensuring and improving the quality of education provided. However, lack of acceptance of these information systems and resistance of technology innovations by the end users limit the expected benefits of the system. This research attempts to identify the key determinants for the acceptance of the Unit Guide Information Systems (UGIS) in the Australian higher education sector. The technology acceptance model (TAM), social cognitive theory (SCT) and model of PC utilization (MPCU) are combined to provide a new framework for this analysis. Results of the study are consistent with the technology acceptance factors for explaining the behavioural intention of the academics. The study also shows the effects of application specific self-efficacy, application specific anxiety and social influence on the acceptance of UGIS. Implications of the results are discussed within the context of unit guides and curriculum mapping.

Framework for a Residential Energy Information System (REMIS) to promote energy efficient behaviour in residential energy end users

Previous studies on residential energy end use behavior reported significant reduction in energy end use of 7% to 24% when feedback is used to modify behavior in an energy efficient manner. However, most feedback systems investigated in previous studies have not benefited from advanced information systems (IS). IS can shape energy efficiency behavior by providing real-time feedback on energy consumption, cost and environmental impact. Such systems represent a new and less-researched subfield of energy informatics. This paper provides a conceptual framework for showing the potential use of IS to modify residential energy use behavior towards better energy efficiency. The framework builds on research in residential energy end use, in particular energy end use behavioral model. It provides conceptual inputs for a blue-print to develop a residential energy management information system (REMIS) and also highlights the use of new information and communications technologies (ICT) that had not been widely used, setting the grounds for further research in this area.

Harm reduction as anarchist practice : a user’s guide to capitalism and addiction in North America

In spite of its origins as an illegal, clandestine, grassroots activity that took place either outside or in defiant opposition to state and legal authority, there is growing evidence to suggest that harm reduction in North America has become sanitized and depoliticized in its institutionalization as public health policy. Harm reduction remains the most contested and controversial aspect of drug policy on both sides of the Canada–US border, yet the institutionalization of harm reduction in each national context demonstrates a series of stark contrasts. Drawing from regional case study examples in Canada and the US, this article historically traces and politically re-maps the uneasy relationship between the autonomous political origins of harm reduction, contemporary public health policy, and the adoption of the biomedical model for addiction research and treatment in North America. Situated within a broader theoretical interrogation of the etiology of addiction, this study culminates in a politically engaged critique of traditional addiction research and drug/service user autonomy. Arguing that the founding philosophy and spirit of the harm reduction movement represents a fundamentally anarchist-inspired form of practice, this article concludes by considering tactics for reclaiming and re-politicizing the future of harm reduction in North America.

The experience of connectivity : results from a survey of Australian internet users

This article presents the findings from a survey of Australian Internet users (n = 1172), conducted in 2007, investigating their overall experience of connectivity at home. Experience of connectivity is defined to mean how people use the Internet to achieve general outcomes of value to them in their everyday lives, and includes both the range of outcomes and the significance of the Internet in achieving them. The survey, thus, reports on the experience of a single behaviour – ‘using the Internet’ – rather than, as common in other research, multiple specific behaviours conducted while online. The article analyses the data collected to draw conclusions that provide greater depth of understanding of connectivity understood as the phenomenon in, and of, itself. This article contributes important information about the experiences of Australian Internet users, about which there have been only a few and relatively superficial studies. It also provides an example of a new approach to surveying Internet users that can lead to more direct conclusions about the value and extent of their uses of connectivity in their lives.

Patterns of memory dysfunction in current and 2-year abstinent MDMA users

The popular recreational drug MDMA or “ecstasy” is a selective serotonin neurotoxin in many species and has been found to be associated with memory dysfunction in human beings. Recent studies suggest that this impairment persists after cessation of use for periods up to at least one year. However, there is no clear indication as yet concerning which stage of memory processing is impaired as a result of MDMA use. In the current study, 31 current MDMA users and 30 MDMA users who had been abstinent for more than two years were compared with 30 controls on the WMS-III. The results suggest that MDMA use is associated with memory dysfunction and that this dysfunction persists for up to two years after cessation of use. Importantly, the findings suggest that this memory dysfunction may be due to interference at the encoding stage of memory processing.