On defining base units in terms of fundamental constants

The definitions of the base units of the international system of units have been revised many times since the idea of such an international system was first conceived at the time of the French revolution. The objective today is to define all our units in terms of 'invariants of nature', i.e. by referencing our units to the fundamental constants of physics, or the properties of atoms, rather than the characteristics of our planet or of artefacts. This situation is reviewed, particularly in regard to finding a new definition of the kilogram to replace its present definition in terms of a prototype material artefact.

Definitions of the units radian, neper, bel and decibel

The definition of coherent derived units in the International System of Units (SI) is reviewed, and the important role of the equations defining physical quantities is emphasized in obtaining coherent derived units. In the case of the dimensionless quantity plane angle, the choice between alternative definitions is considered, leading to a corresponding choice between alternative definitions of the coherent derived unit - the radian, degree or revolution. In this case the General Conference on Weights and Measures (CGPM) has chosen to adopt the definition that leads to the radian as the coherent derived unit in the SI. In the case of the quantity logarithmic decay (or gain), also sometimes called decrement, and sometimes called level, a similar choice of defining equation exists, leading to a corresponding choice for the coherent derived unit - the neper or the bel. In this case the CGPM has not yet made a choice. We argue that for the quantity logarithmic decay the most logical choice of defining equation is linked to that of the radian, and is that which leads to the neper as the corresponding coherent derived unit. This should not prevent us from using the bel and decibel as units of logarithmic decay. However, it is an important part of the SI to establish in a formal sense the equations defining physical quantities, and the corresponding coherent derived units.

On defining base units in terms of fundamental constants

The definitions of the base units of the international system of units have been revised many times since the idea of such an international system was first conceived at the time of the French revolution. The objective today is to define all our units in terms of 'invariants of nature', i.e. by referencing our units to the fundamental constants of physics, or the properties of atoms, rather than the characteristics of our planet or of artefacts. This situation is reviewed, particularly in regard to finding a new definition of the kilogram to replace its present definition in terms of a prototype material artefact.

Adapting the International System of Units to the twenty-first century

We review the proposal of the International Committee for Weights and Measures (Comité International des Poids et Mesures, CIPM), currently being considered by the General Conference on Weights and Measures (Conférences Générales des Poids et Mesures, CGPM), to revise the International System of Units (Le Système International d’Unitès, SI). The proposal includes new definitions for four of the seven base units of the SI, and a new form of words to present the definitions of all the units. The objective of the proposed changes is to adopt definitions referenced to constants of nature, taken in the widest sense, so that the definitions may be based on what are believed to be true invariants. In particular, whereas in the current SI the kilogram, ampere, kelvin and mole are linked to exact numerical values of the mass of the international prototype of the kilogram, the magnetic constant (permeability of vacuum), the triple-point temperature of water and the molar mass of carbon-12, respectively, in the new SI these units are linked to exact numerical values of the Planck constant, the elementary charge, the Boltzmann constant and the Avogadro constant, respectively. The new wording used expresses the definitions in a simple and unambiguous manner without the need for the distinction between base and derived units. The importance of relations among the fundamental constants to the definitions, and the importance of establishing a mise en pratique for the realization of each definition, are also discussed.

Use of Information Visualization Methods Eliminating Cross Talk in Multiple Sensing Units Investigated for a Light-Addressable Potentiometric Sensor

The integration of nanostructured films containing biomolecules and silicon-based technologies is a promising direction for reaching miniaturized biosensors that exhibit high sensitivity and selectivity. A challenge, however, is to avoid cross talk among sensing units in an array with multiple sensors located on a small area. In this letter, we describe an array of 16 sensing units, of a light-addressable potentiometric sensor (LAPS), which was made with layer-by-Layer (LbL) films of a poly(amidomine) dendrimer (PAMAM) and single-walled carbon nanotubes (SWNTs), coated with a layer of the enzyme penicillinase. A visual inspection of the data from constant-current measurements with liquid samples containing distinct concentrations of penicillin, glucose, or a buffer indicated a possible cross talk between units that contained penicillinase and those that did not. With the use of multidimensional data projection techniques, normally employed in information Visualization methods, we managed to distinguish the results from the modified LAPS, even in cases where the units were adjacent to each other. Furthermore, the plots generated with the interactive document map (IDMAP) projection technique enabled the distinction of the different concentrations of penicillin, from 5 mmol L(-1) down to 0.5 mmol L(-1). Data visualization also confirmed the enhanced performance of the sensing units containing carbon nanotubes, consistent with the analysis of results for LAPS sensors. The use of visual analytics, as with projection methods, may be essential to handle a large amount of data generated in multiple sensor arrays to achieve high performance in miniaturized systems.

Influence of different light sources and photo-activation methods on degree of conversion and polymerization shrinkage of a nanocomposite resin

The purpose of this study was to evaluate the influence of different light sources and photo-activation methods on degree of conversion (DC%) and polymerization shrinkage (PS) of a nanocomposite resin (Filtek (TM) Supreme XT, 3M/ESPE). Two light-curing units (LCUs), one halogen-lamp (QTH) and one light-emitting-diode (LED), and two different photo-activation methods (continuous and gradual) were investigated in this study. The specimens were divided in four groups: group 1-power density (PD) of 570 mW/cm(2) for 20 s (QTH); group 2-PD 0 at 570 mW/cm(2) for 10 s + 10 s at 570 mW/cm(2) (QTH); group 3-PD 860 mW/cm(2) for 20 s (LED), and group 4-PD 125 mW/cm(2) for 10 s + 10 s at 860 mW/cm(2) (LED). A testing machine EMIC with rectangular steel bases (6 x 1 x 2 mm) was used to record the polymerization shrinkage forces (MPa) for a period that started with the photo-activation and ended after two minutes of measurement. For each group, ten repetitions (n = 40) were performed. For DC% measurements, five specimens (n = 20) for each group were made in a metallic mold (2 mm thickness and 4 mm diameter, ISO 4049) and them pulverized, pressed with bromide potassium (KBr) and analyzed with FT-IR spectroscopy. The data of PS were analyzed by Analysis of Variance (ANOVA) with Welch`s correction and Tamhane`s test. The PS means (MPa) were: 0.60 (G1); 0.47 (G2); 0.52 (G3) and 0.45 (G4), showing significant differences between two photo-activation methods, regardless of the light source used. The continuous method provided the highest values for PS. The data of DC% were analyzed by Analysis of Variance (ANOVA) and shows significant differences for QTH LCUs, regardless of the photo-activation method used. The QTH provided the lowest values for DC%. The gradual method provides lower polymerization contraction, either with halogen lamp or LED. Degree of conversion (%) for continuous or gradual photo-activation method was influenced by the LCUs. Thus, the presented results suggest that gradual method photo-activation with LED LCU would suffice to ensure adequate degree of conversion and minimum polymerization shrinkage.

Effects of a quantum measurement on the electric conductivity : Application to graphene

We generalize the standard linear-response (Kubo) theory to obtain the conductivity of a system that is subject to a quantum measurement of the current. Our approach can be used to specifically elucidate how back-action inherent to quantum measurements affects electronic transport. To illustrate the utility of our general formalism, we calculate the frequency-dependent conductivity of graphene and discuss the effect of measurement-induced decoherence on its value in the dc limit. We are able to resolve an ambiguity related to the parametric dependence of the minimal conductivity.

HRQOL and subjective well-being: noncomplementary forms of outcome measurement

This review considers some of the broad principles that concern quality of life assessment. These are discussed in relation to health-related quality of life (HRQOL) and the measurement of subjective well-being. It is argued that there are serious logical and methodological issues concerning HRQOL measurement, to the extent that the instruments may not be regarded as valid measures of life quality as this term is generally understood. It is recommended that HRQOL measurement be abandoned in favor of three separate forms of measurement as medical symptoms, subjective well-being and specific dimensions of psychological ill-being.

Measurement for improvement: a survey of current practice in Australian public hospitals

Objective:
To identify patient safety measurement tools in use in Australian public hospitals and to determine barriers to their use.

Design:
Structured survey, conducted between 4 March and 19 May 2005, designed to identify tools, and to assess current use of, levels of satisfaction with, and barriers to use of tools for measuring the domains and subdomains of: organisational capacity to provide safe health care; patient safety incidents; and clinical performance.

Participants and setting:
Hospital executives, managers and clinicians from a nationwide random sample of Australian public hospitals stratified by state and hospital peer grouping.

Main outcome measures:
Tools used by hospitals within the three domains and their subdomains; patient safety tools and processes identified by individuals at these hospitals; satisfaction with the tools; and barriers to their use.

Results:
Eighty-two of 167 invited hospitals (49%) responded. The survey ascertained a comprehensive list of patient safety measurement tools that are in current use for measuring all patient safety domains. Overall, there was a focus on use of processes rather than quantitative measurement tools. Approximately half the 182 individual respondents from participating hospitals reported satisfaction with existing tools. The main reported barriers were lack of integrated supportive systems, resource constraints and inadequate access to robust measurement tools validated in the Australian context. Measurement of organisational capacity was reported by 50 (61%), of patient safety incidents by 81 (99%) and of clinical performance by 81 (99%).

Conclusion:
Australian public hospitals are measuring the safety of their health care, with some variation in measurement of patient safety domains and their subdomains. Improved access to robust tools may support future standardisation of measurement for improvement.

Corporate codes of ethics in Australia, Canada and USA : measurement and structural properties of a cross-cultural model

The objective is to test the consistency of measurement and structural properties in a model of corporate codes of ethics (CCE) on an aggregated level and across multiple samples derived from three countries, namely Australia, Canada and the USA. The properties of four constructs of CCE are described and tested, these being: surveillance/training, internal communication, external communication, and guidance. The conclusion is that the measurement and structural models on an aggregated level have a satisfactory fit, validity and reliability. Furthermore, they are consistent when tested on each of the three samples (i.e. cross-validated). The cross-cultural model makes a contribution in addition to previous mostly descriptive studies and theory in the field using confirmatory factor analysis and structural equation modeling.

Management control systems use, organisational capabilities and performance in universities: application of the resource-based view

Invoking the resource-based view (RBV), this study investigates relationships between management control systems (MCSs) use, including information use from performance measurement systems (PMSs), and organisational capabilities in the context of academic units of Australian universities. Increased competition and attention to distinctive capabilities amongst universities, particularly at their strategic operating unit level of Schools 1, provides the setting for application of this theoretic perspective. The objective of this study is to model various relationships between diagnostic and interactive use of MCSs, attention given to centrally-imposed and discretionary types of PMS information, the strength of capabilities of the academic unit and, in turn, performance of the academic units. This objective is investigated using a field survey in which a mail survey instrument is administered to a census of all Heads of Schools in all 39 universities in Australia. Valid responses were received from 166 Heads. Principal components factor analysis finds that Heads conceived capabilities of their unit in functional dimensions, not in generic dimensions as found in prior literature; Heads also considered performance measures in terms of their importance (critical or discretionary) rather than type (financial versus non-financial). Partial least-squares analysis is then used for path modelling, and several significant results are obtained. Highlights are that diagnostic MCS use and centrally-imposed performance measures, i.e., key performance indicators, but not interactive MCS use or discretionary performance measures, significantly relate to some or all of the strength of capabilities in the fields of teaching, research and networking, and in turn indirectly relate to performance of the academic units. The findings have practical implications for styles of control systems use; focus on selected key performance measures; and development of organisational capabilities for achievement of superior performance by academic schools in universities.

Measurement issues in the evaluation of chronic disease self-management programs

Objectives: 

A systematic review of the extent and measurement of healthcare provider racism

Background
Although considered a key driver of racial disparities in healthcare, relatively little is known about the extent of interpersonal racism perpetrated by healthcare providers, nor is there a good understanding of how best to measure such racism.

Objectives
This paper reviews worldwide evidence (from 1995 onwards) for racism among healthcare providers; as well as comparing existing measurement approaches to emerging best practice, it focuses on the assessment of interpersonal racism, rather than internalized or systemic/institutional racism.

Methods
The following databases and electronic journal collections were searched for articles published between 1995 and 2012: Medline, CINAHL, PsycInfo, Sociological Abstracts. Included studies were published empirical studies of any design measuring and/or reporting on healthcare provider racism in the English language. Data on study design and objectives; method of measurement, constructs measured, type of tool; study population and healthcare setting; country and language of study; and study outcomes were extracted from each study.

Results
The 37 studies included in this review were almost solely conducted in the U.S. and with physicians. Statistically significant evidence of racist beliefs, emotions or practices among healthcare providers in relation to minority groups was evident in 26 of these studies. Although a number of measurement approaches were utilized, a limited range of constructs was assessed.

Conclusion
Despite burgeoning interest in racism as a contributor to racial disparities in healthcare, we still know little about the extent of healthcare provider racism or how best to measure it. Studies using more sophisticated approaches to assess healthcare provider racism are required to inform interventions aimed at reducing racial disparities in health.

Development and measurement properties of a putting skill test for high-level golf

Despite a recent increase in the amount of research investigating performance in golf, a comprehensive putting skill test has not been reported in the peer-reviewed literature. In this study, the Golf Australia Putting Test (GAPT) was developed and a series of measurement properties were assessed. Elite (n = 18) and high-level amateur (HLA; n = 22) participants completed six single putts from various areas on six concentric circles (circle radii = 0.9, 1.5, 3.0, 4.6, 6.1 and 7.6 m). Using a scoring system that rewarded participants for holing putts from longer distances, the maximum score from a single round of the test (i.e. 36 putts) was 27 points. After two rounds of the test were completed by all players, a subsample of participants (elite, n = 15; HLA, n = 7) had their putting performance recorded during tournament play for a period of 90 days to assess criterion (predictive) validity of the test. The reliability, sensitivity and discriminative validity of the GAPT were also assessed. Better agreement between Rounds 1 and 2 scores was noted in the elite group, whilst reliability values were similar for both groups. Further, the GAPT scores were shown to predict players from the elite and high-ability groups with a low classification error. An equation for predicting on-course performance from GAPT scores was also developed. Findings from this study indicate that the GAPT is a valid and reliable tool for high-level players and the GAPT may be used for player evaluation in the field.