Identification of nonlinear systems using hybrid functions

Most real systems have nonlinear behavior and thus model linearization may not produce an accurate representation of them. This paper presents a method based on hybrid functions to identify the parameters of nonlinear real systems. A hybrid function is a combination of two groups of orthogonal functions: piecewise orthogonal functions (e.g. Block-Pulse) and continuous orthogonal functions (e.g. Legendre polynomials). These functions are completed with an operational matrix of integration and a product matrix. Therefore, it is possible to convert nonlinear differential and integration equations into algebraic equations. After mathematical manipulation, the unknown linear and nonlinear parameters are identified. As an example, a mechanical system with single degree of freedom is simulated using the proposed method and the results are compared against those of an existing approach.

Randomised controlled trials and 'unexpected' adverse events associated with newly released drugs : improvements in pharmacovigilance systems are necessary for real-time identification of patient safety risks

Adverse drug events are one of the major causes of morbidity in developed countries, yet the drugs involved in these events have been trialled and approved on the basis of randomised controlled trials (RCTs), regarded as the study design that will produce the best evidence.

Though the focus on adverse drug events has been primarily on processes and outcomes associated with the use of these approved drugs, attention needs to be directed to the way in which the RCT study design is structured. The implementation of controls to achieve internal validity in RCTs may be the very controls that reduce external validity, and contribute to the levels of adverse drug events associated with the release of a new drug to the wider patient population.

An examination of these controls, and the effects they can have on patient safety, underscore the importance of knowing about how the clinical trials of a drug are undertaken, rather than relying only on the recorded outcomes.

As the majority of new drugs are likely to be prescribed to older patients who have one or more comorbidities in addition to that targeted by a new drug, and as the RCTs of those drugs typically under-represent the elderly and exclude patients with multiple comorbidities, timely assessment of drug safety signals is essential.

It is unlikely that regulatory jurisdictions will undertake a reassessment of safety issues for drugs that are already approved. Instead, reliance has been placed on adverse drug event reporting systems. Such systems have a very low reporting rate, and most adverse drug events remain unreported, to the eventual cost to patients and healthcare systems.

This makes it essential for near real-time systems that can pick up safety signals as they occur, so that modifications to the product information (or removal of the drug) can be implemented.

When continuity of care breaks down: a systems failure in identification of osteoporosis risk in older patients treated for minimal trauma fractures

OBJECTIVE: Minimal trauma fractures may be the first indication of osteoporosis. Our aim was to determine the proportion of patients who underwent bone density testing for osteoporosis of those with a minimal trauma wrist fracture treated in the emergency department (ED).

DESIGN: This observational retrospective cohort study used explicit medical record review and scripted telephone interviews.

SETTING: EDs of three metropolitan hospitals in Melbourne in 2006.

PARTICIPANTS: Patients aged 50 years and over who were treated for wrist fracture due to minimal trauma. Data collected included demographic details, fracture details, causes of injury, any bone density testing and any osteoporosis-related medication change.

MAIN OUTCOME MEASURE: The proportion of patients who underwent bone density testing in the follow-up period.

RESULTS: 131 patients were studied; 83% were female, and the median age was 71 years. No patient was referred by an ED or fracture clinic for bone density testing (95% CI, 0-3.5%). Telephone follow-up data were obtained from 91 patients. Of these, 28 reported having bone density testing after their fracture, of whom 14 (50%; 95% CI, 32%-67%) were found to have osteoporosis. Seven were treated with a bisphosphonate and one with a selective oestrogen-receptor modulator.

CONCLUSION: Follow-up of patients suffering minimal trauma wrist fractures treated in the ED is poor. Systems to improve the identification and treatment of osteoporosis in this group are needed if future osteoporotic fractures and their consequences are to be avoided.

Interpreting and modeling baggage handling systems as a system of systems

The topic of systems of systems has been one of the most challenging areas in science and engineering due to its multidisciplinary scope and inherent complexity. Despite all attempts carried out so far in both academia and industry, real world applications are far remote. The purpose of this paper is to modify and adopt a recently developed modeling paradigm for system of systems and then employ it to model a generic baggage handling system of an airport complex. In a top-down design approach, we start modeling process by definition of some modeling goals that guide us in selection of some high level attributes. Then functional attributes are defined which act as ties between high level attributes (the first level of abstraction) and low level metrics/measurements. Since the most challenging issues in developing models for system of systems are identification and representation of dependencies amongst constituent entities, a machine learning technique is adopted for addressing these issues.

The (mis)identification of ineffective classroom teaching practice : critical interrogations of classroom teacher effectiveness research

This paper critiques specific forms of classroom teacher effectiveness research. In doing so, the paper suggests that education policy-making deems and employs teacher effectiveness research as a promising and capable contrivance for the identification of ineffective classroom teaching practice. The paper engages with this policy debate by using a specific policy example from the Australian state of Victoria, the Victorian Department of Education and Early Childhood Development (DEECD) Blueprint for Government Schools (2003/2008). Moreover, the attention given to “teacher effectiveness” as the means by which school systems aim to reverse student under-achievement positions classroom teachers as the controlling authority over educational outcomes. Indeed, teacher effectiveness is the defining quality of a policy-making debate that at its core dispenses with broader considerations of possible influence thought to substantially affect the learning outcomes of public school students.

Identification of 100 fundamental ecological questions

Fundamental ecological research is both intrinsically interesting and provides the basic knowledge required to answer applied questions of importance to the management of the natural world. The 100th anniversary of the British Ecological Society in 2013 is an opportune moment to reflect on the current status of ecology as a science and look forward to high-light priorities for future work. To do this, we identified 100 important questions of fundamental importance in pure ecology. We elicited questions from ecologists working across a wide range of systems and disciplines. The 754 questions submitted (listed in the online appendix) from 388 participants were narrowed down to the final 100 through a process of discussion, rewording and repeated rounds of voting. This was done during a two-day workshop and thereafter. The questions reflect many of the important current conceptual and technical pre-occupations of ecology. For example, many questions concerned the dynamics of environmental change and complex ecosystem interactions, as well as the interaction between ecology and evolution. The questions reveal a dynamic science with novel subfields emerging. For example, a group of questions was dedicated to disease and micro-organisms and another on human impacts and global change reflecting the emergence of new subdisciplines that would not have been foreseen a few decades ago. The list also contained a number of questions that have perplexed ecologists for decades and are still seen as crucial to answer, such as the link between population dynamics and life-history evolution. Synthesis. These 100 questions identified reflect the state of ecology today. Using them as an agenda for further research would lead to a substantial enhancement in understanding of the discipline, with practical relevance for the conservation of biodiversity and ecosystem function.

International ‘benchmarking’ studies and the identification of ‘education best practice’: a focus on classroom teachers and their practices

 Abstract:The disproportionate focus on classroom teachers and their instruction—teacher effectiveness—in order to confront and address under-achievement and disadvantage appears as a contemporary education policy theme in Australia. Phrases such as ‘high performing schooling systems’, ‘the best teachers’, ‘high performing countries’, ‘quality teaching’, ‘under-performing schools’, ‘the right change’, ‘operationally feasible’, ‘targeting of reforms’, ‘degrees of under-performance’, ‘educational drivers’, ‘teacher quality and improved teaching’ and ‘external standards and governance’ are constantly mentioned and given continual attention and prominence by policy-makers. The paper questions and critiques a policy-making direction that uses teacher effectiveness research to force and steer reform in education. The distinctive and narrow concern with teacher effectiveness works to the specific exclusion of breadth and scope concerning debate about broader education related issues and questions, for example, matters of student achievement, exclusion and disadvantage. This article uses a qualitative research approach informed by critical theory to examine three influential private sector reports on education and schooling: The McKinsey Report ( 2007 )—How the world’s best-performing school systems come out on top, The Nous Group ( 2011 )—Schooling Challenges and Opportunities and The Grattan Institute ( 2012 )—Catching up: Learning from the best school systems in East Asia. The article subjects the reports to close critical scrutiny and examination and finds that classroom teachers are positioned so that their specific and explicit instruction becomes the differentiating ‘variable’ in matters of student achievement and success.

Identification of novel therapeutics for complex diseases from genome-wide association data

Human genome sequencing has enabled the association of phenotypes with genetic loci, but our ability to effectively translate this data to the clinic has not kept pace. Over the past 60 years, pharmaceutical companies have successfully demonstrated the safety and efficacy of over 1,200 novel therapeutic drugs via costly clinical studies. While this process must continue, better use can be made of the existing valuable data. In silico tools such as candidate gene prediction systems allow rapid identification of disease genes by identifying the most probable candidate genes linked to genetic markers of the disease or phenotype under investigation. Integration of drug-target data with candidate gene prediction systems can identify novel phenotypes which may benefit from current therapeutics. Such a drug repositioning tool can save valuable time and money spent on preclinical studies and phase I clinical trials.