Ultrafast laser stress figuring for accurate deformation of thin mirrors.

Fabricating freeform mirrors relies on accurate optical figuring processes capable of arbitrarily modifying low-spatial frequency height without creating higher-spatial frequency errors. We present a scalable process to accurately figure thin mirrors using stress generated by a focused ultrafast laser. We applied ultrafast laser stress figuring (ULSF) to four thin fused silica mirrors to correct them to 10-20 nm RMS over 28 Zernike terms, in 2-3 iterations, without significantly affecting higher-frequency errors. We measured the mirrors over a month and found that dielectric-coated mirrors were stable but stability of aluminum-coated mirrors was inconclusive. The accuracy and throughput for ULSF is on par with existing deterministic figuring processes, yet ULSF doesn't significantly affect mid-spatial frequency errors, can be applied after mirror coating, and can scale to higher throughput using mature laser processing technologies. ULSF offers new potential to rapidly and accurately shape freeform mirrors.

The REACH registration process: A case study of metallic aluminium, aluminium oxide and aluminium hydroxide.

The European Union's REACH Regulation requires determination of potential health and environmental effects of chemicals in commerce. The present case study examines the application of REACH guidance for health hazard assessments of three high production volume (HPV) aluminium (Al) substances: metallic aluminium, aluminium oxide, and aluminium hydroxide. Among the potential adverse health consequences of aluminium exposure, neurotoxicity is one of the most sensitive targets of Al toxicity and the most critical endpoint. This case study illustrates integration of data from multiple lines of evidence into REACH weight of evidence evaluations. This case study then explains how those results support regulatory decisions on classification and labelling. Challenges in the REACH appraisal of Al compounds include speciation, solubility and bioavailability, application of assessment factors, read-across rationale and differences with existing regulatory standards. Lessons learned from the present case study relate to identification and evaluation of toxicologic and epidemiologic data; assessing data relevance and reliability; development of derived no-effect levels (DNELs); addressing data gaps and preparation of chemical safety reports.

Overview of REACH: Issues Involved in the Registration of Metals.

New European legislation known as REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) was introduced in 2007 to increase the speed at which the health and/or environmental risks of industrial chemicals were being assessed and managed (REACH (EC) No 1907/2006). REACH consolidated earlier chemicals-control statutes and placed the burden of assessing, and identifying the means to manage risks on industry. This paper details the REACH process for controlling and managing hazardous chemicals and challenges encountered in applying the provisions of REACH and the guidance documents available from European Chemical Agency. Special attention is paid to challenges in evaluating potential health risks of metals such as aluminum and aluminum compounds. Lessons learned from over a decade of experience with REACH legislation are also noted.

Integrating mental health peer support in clinical settings: Lessons from Canada and Norway.

Mental health peer support is an evidence-based approach called for by Canada's mental health strategy that presents health leaders with an opportunity to transform mental health service experiences, improve health outcomes, and lower overall system costs. Originally offered in community settings, peer support has been expanding to clinical settings, but challenges to integration exist. This qualitative case study of peer support in clinical settings in Canada and Norway examines the perceived value of peer support and change management strategies that health leaders, managers, staff, and peer support providers can use to support integration of peer support in existing healthcare teams in clinical settings. Recommended strategies for health leaders include adopting a gradual approach to integration, building champions, demonstrating value, focusing on resistant groups, adopting a continuous improvement approach, setting peer support as an organizational priority, and linking peer support to patient-centred care.

Role of non-government organizations in engaging medical students in research.

The continued decline in medical trainees entering the workforce as clinician-scientists has elevated the need to engage medical students in research. While past studies have shown early exposure to generate interest among medical students for research and academic careers, financial constraints have limited the number of such formal research training programs. In light of recent government budget cuts to support research training for medical students, non-government organizations (NGOs) may play a progressively larger role in supporting the development of clinician-scientists. Since 2005, the Mach-Gaensslen Foundation has sponsored 621 Canadian medical student research projects, which represents the largest longitudinal data set of Canadian medical students engaged in research. We present the results of the pre- and post-research studentship questionnaires, program evaluation survey and the 5-year and 10-year follow-up questionnaires of past recipients. This paper provides insight into the role of NGOs as stakeholders in the training of clinician-scientists and evaluates the impact of such programs on the attitudes and career trajectory of medical students. While the problem of too few physicians entering academic and research-oriented careers continues to grow, alternative-funding strategies from NGOs may prove to be an effective approach in developing and maintaining medical student interest in research.

Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts.

Abstract Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007) . Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of "total Al"assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al(+3) to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)(+2) and Al(H2O)6 (+3)] that after complexation with O2(•-), generate Al superoxides [Al(O2(•))](H2O5)](+2). Semireduced AlO2(•) radicals deplete mitochondrial Fe and promote generation of H2O2, O2 (•-) and OH(•). Thus, it is the Al(+3)-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer's disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances.

Beam characteristics of fiber-based supercontinuum light sources with mirror- and lens-based beam collimators.

Commercially available supercontinuum light sources that cover most of the solar spectrum are well suited for instrumentation, where a well-collimated beam with wide spectral coverage is needed. Typically, the optical power is emitted from a single-mode photonic-crystal fiber and the output can either be collimated using a proprietary, permanently integrated, lens-based collimator or with a customer-provided, off-axis parabolic mirror. Here, we evaluate both approaches and conclude that, superior beam quality and collimation over the whole spectral range can be obtained with an off-axis parabolic mirror, however at the price of a more complex and bulky system requiring additional user alignment.

When less is more: a case of phenytoin toxicity.

The authors present a case of an 87-year-old gentleman who presented with general deterioration, increased confusion, recurrent falls and unsteadiness. He was treated for a urinary tract infection but was found to deteriorate rapidly, developing bilateral nystagmus, marked pastpointing, dysarthria and central ataxia. He had a complex medical history including epilepsy controlled with long-term phenytoin. Phenytoin is 90% protein bound and displaced by bilirubin. At the time of deterioration his total phenytoin concentration was within the limits of the laboratory's recommended therapeutic range. The biochemistry report also denoted the patient was hypoalbuminaemic and hyperbilirubinaemic. His symptoms completely resolved with phenytoin dose reduction. The combination of low albumin and high bilirubin may cause an increase in the free phenytoin concentration, resulting in toxicity, despite the measured total phenytoin concentration being within the therapeutic interval.

Opportunities abound to improve mental health and psychological safety in the workplace.

This commentary provides a brief synopsis of the views expressed by the authors of the invited essay "The Business Case," Sari Sairanen, Deanna Matzanke and Doug Smeall. It then discusses the authors' views in light of the Mental Health Commission's framework for a Mental Health Strategy for Canada, titled Toward Recovery and Well-Being, and Dr. Martin Shain's two reports to the Mental Health Commission of Canada - Stress at Work, Mental Injury and the Law in Canada and Tracking the Perfect Legal Storm. The initiatives discussed in the lead paper are then compared with a 2009 consensus statement generated at a forum co-hosted by the Mental Health Commission and the Great-West Life Centre for Mental Health in the Workplace. The consensus statement reflects the recommendation of the forum's 40 participants that a Canadian national standard for psychological health and safety in the workplace should be developed.

Risk assessment practice for essential metals.

This article addresses the content of the workshop, including a panel discussion relevant to delineation of a path forward in relation to risk assessment of essential metals. The state of the art of risk assessment and associated issues for essential metals are outlined initially, followed by brief illustration by the case studies considered at the workshop (i.e., copper, zinc, and manganese). Approaches for the future testing strategies of essential metals are discussed in terms of options to increase efficiency and accuracy of assessments. Subsequently, recommendations for pragmatic next steps to advance progress and facilitate uptake by the regulatory risk assessment community are presented.