A study of seed viability following consumption by birds

This project aimed to quantify the potential for wild birds to spread genetically modified seeds from their area of planting to adjacent areas, through ingestion and transport in the gut (endozoochorous transmission). We addressed this by assessing whether seed viability was affected by passage through the avian gut. We sought to address this question by testing the effects of ingestion of a number of key agricultural crops by three common wild bird pest species.

Very high pressure liquid chromatography using fully porous particles: Quantitative analysis of fast gradient separations without post-run times

Using a column packed with fully porous particles, four methods for controlling the flow rates at which gradient elution runs are conducted in very high pressure liquid chromatography (VHPLC) were tested to determine whether reproducible thermal conditions could be achieved, such that subsequent analyses would proceed at nearly the same initial temperature. In VHPLC high flow rates are achieved, producing fast analyses but requiring high inlet pressures. The combination of high flow rates and high inlet pressures generates local heat, leading to temperature changes in the column. Usually in this case a post-run time is input into the analytical method to allow the return of the column temperature to its initial state. An alternative strategy involves operating the column without a post-run equilibration period and maintaining constant temperature variations for subsequent analysis after conducting one or a few separations to bring the column to a reproducible starting temperature. A liquid chromatography instrument equipped with a pressure controller was used to perform constant pressure and constant flow rate VHPLC separations. Six replicate gradient separations of a nine component mixture consisting of acetophenone, propiophenone, butyrophenone, valerophenone, hexanophenone, heptanophenone, octanophenone, benzophenone, and acetanilide dissolved in water/acetonitrile (65:35, v/v) were performed under various experimental conditions: constant flow rate, two sets of constant pressure, and constant pressure operation with a programmed flow rate. The relative standard deviations of the response factors for all the analytes are lower than 5% across the methods. Programming the flow rate to maintain a fairly constant pressure instead of using instrument controlled constant pressure improves the reproducibility of the retention times by a factor of 5, when plotting the chromatograms in time.

Lithium storage in disordered graphitic materials: a semi-quantitative study of the relationship between structure disordering and capacity.

The application of the graphitic anode is restricted by its low theoretical specific capacity of 372 mA h g(-1). Higher capacity can be achieved in the graphitic anode by modifying its structure, but the detailed storage mechanism is still not clear. In this work, the mechanism of the lithium storage in a disordered graphitic structure has been systematically studied. It is found that the enhanced capacity of the distorted graphitic structure does not come from lithium-intercalation, but through a capacitive process, which depends on the disordering degree and the porous structure.

Quantitative studies of student self-assessment in higher education: a critical analysis of findings

Student self-assessment occurs when learners make judgements about aspects of their own performance. This paper focuses on one aspect of quantitative self-assessments: the comparison of student-generated marks with those generated by teachers. Studies including such comparisons in the context of higher education courses are reviewed and the following questions are addressed: (i) do students tend to over- or under-rate themselves vis-á-vis teachers?, (ii) do students of different abilities have the same tendencies?, (iii) do students in different kinds or levels of course tend to under- or over-rate themselves?, (iv) do students improve their ability to rate themselves over time or with practice?, (v) are the same tendencies evident when self-marks are used for formal assessment purposes?, and (vi) are there gender differences in self-rating? The paper also discusses methodological issues in studies of this type and makes recommendations concerning the analysis and presentation of information.

Neurocognitive effects of multivitamin supplementation on the steady state visually evoked potential (SSVEP) measure of brain activity in elderly women

OBJECTIVE: Growing evidence suggests that dietary supplementation with selected micronutrients and nutraceuticals may have the potential to improve cognition in older adults. Fewer studies have investigated the effects of these substances on brain activity. METHODS: This study was a randomised, double-blind, placebo-controlled trial, conducted to explore the effects of 16 weeks supplementation with a combined multivitamin, mineral and herbal formula on the steady state visually evoked potential (SSVEP) measure of brain electrical activity. Participants were elderly women aged between 64 and 79 years, with subjective memory complaints. Baseline and post-treatment SSVEP data was obtained for 22 participants in the multivitamin group and 19 in the placebo group. A spatial working memory delayed response task (DRT) was performed during the recording of the SSVEP. RESULTS: The results revealed that when compared to placebo, multivitamin supplementation delayed SSVEP latency during retrieval, interpreted as an increase in inhibitory neural processes. Behavioural performance on the DRT was not improved by the multivitamin, however improved performance accuracy was associated with increased midline central SSVEP latency. There were no multivitamin-related effects on SSVEP amplitude. CONCLUSION: These findings indicate that in the elderly, multivitamin supplementation may enhance neural efficiency during memory retrieval.

Quantitative assessment of ADL: a pilot study of upper extremity reaching tasks

Effective telerehabilitation technologies enable patients with certain physiological disabilities to engage in rehabilitative exercises for performing Activities of Daily Living (ADLs). Therefore, training and assessment scenarios for the performance of ADLs are vital for the promotion for telerehabilitation. In this paper we investigate quantitatively and automatically assessing patient's kinematic ability to perform functional upper extremity reaching tasks. The shape of the movement trajectory and the instantaneous acceleration of kinematically crucial body parts, such as wrists, are used to compute the approximate entropy of the motions to represent stability (smoothness) in addition to the duration of the activity. Computer simulations were conducted to illustrate the consistency, sensitivity and robustness of the proposed method. A preliminary experiment with kinematic data captured from healthy subjects mimicking a reaching task with dyskinesia showed a high degree of correlation (Cohen's kappa 0.85 with p < 0.05) between a human observer and the proposed automatic classification tool in terms of assigning the datasets to various levels to represent the subjects' kinematic abilities to perform reaching tasks. This study supported the use of Microsoft Kinect to quantitatively evaluate the ability of individuals with involuntary movements to perform an upper extremity reaching task.

The development of a conceptual model and self-reported measure of occupational health and safety vulnerability

Injuries at work have a substantial economic and societal burden. Often groups of labour market participants, such as young workers, recent immigrants or temporary workers are labelled as being "vulnerable" to work injury. However, defining groups in this way does little to enable a better understanding of the broader factors that place workers at increased risk of injury. In this paper we describe the development of a new measure of occupational health and safety (OH&S) vulnerability. The purpose of this measure was to allow the identification of workers at increased risk of injury, and to enable the monitoring and surveillance of OH&S vulnerability in the labour market. The development included a systematic literature search, and conducting focus groups with a variety of stakeholder groups, to generate a pool of potential items, followed by a series of steps to reduce these items to a more manageable pool. The final measure is 29-item instrument that captures information on four related, but distinct dimensions, thought to be associated with increased risk of injury. These dimensions are: hazard exposure; occupational health and safety policies and procedures; OH&S awareness; and empowerment to participate in injury prevention. In a large sample of employees in Ontario and British Columbia the final measure displayed minimal missing responses, reasonably good distributions across response categories, and strong factorial validity. This new measure of OH&S vulnerability can identify workers who are at risk of injury and provide information on the dimensions of work that may increase this risk. This measurement could be undertaken at one point in time to compare vulnerability across groups, or be undertaken at multiple time points to examine changes in dimensions of OH&S vulnerability, for example, in response to a primary prevention intervention.

Development of a measure of health literacy for caregivers of people with cancer

Caregivers play a key role in supporting people with cancer. Little is known about challenges that caregivers might have when finding and understanding health information, making health-related decisions, and navigating the healthcare system. Using an innovative mixed-methods approach, the study developed and evaluated a tool to measure cancer caregiver health literacy.

Validation of jump squats as a practical measure of post-activation potentiation

To determine if post-activation potentiation (PAP) can augment sports performance, it is pertinent that researchers be confident that any enhancement in performance is attributable to the PAP phenomenon. However, obtaining mechanistic measures of PAP in the daily training environment of highly trained athletes is impractical. We sought to validate jump squats as a practical measure with ecological validity to sports performance against a mechanistic measure of PAP. We assessed the evoked muscle twitch properties of the knee extensors and jump squat kinetics of 8 physically trained males in response to a 5-repetition-maximum back squat conditioning stimulus (CS). Evoked muscle twitch, followed by 3 jump squats, was assessed before and at 4, 8, and 12 min post CS. Time intervals were assessed on separate occasions using a Latin square design. Linear regression was used to determine the relationship between post-pre changes in kinetic variables and muscle twitch peak force (Ft) and twitch rate of force development (RFDt). Large correlations were observed for both concentric relative and absolute mean power and Ft (r = 0.50 ± 0.30) and RFDt (r = 0.56 ± 0.27 and r = 0.58 ± 0.26). Concentric rate of force development (RFD) showed moderate correlations with Ft (r = 0.45 ± 0.33) and RFDt (r = 0.49 ± 0.32). Small-to-moderate correlations were observed for a number of kinetic variables (r = -0.42-0.43 ± 0.32-0.38). Jump squat concentric mean power and RFD are valid ecological measures of muscle potentiation, capable of detecting changes in athletic performance in response to the PAP phenomenon.

Quantitative examination of carbide and sulphide precipitates in chemically complex steels processed by direct strip casting

A high strength low alloy steel composition has been melted and processed by two different routes: simulated direct strip casting and slow cooled ingot casting. The microstructures were examined with scanning and transmission electron microscopy, atom probe tomography and small angle neutron scattering (SANS). The formation of cementite (Fe3C), manganese sulphides (MnS) and niobium carbo-nitrides (Nb(C,N)) was investigated in both casting conditions. The sulphides were found to be significantly refined by the higher cooling rate, and developed an average diameter of only 100 nm for the fast cooled sample, and a diameter too large to be measured with SANS in the slow cooled condition (> 1.1 μm). Slow cooling resulted in the development of classical Nb(C,N) precipitation, with an average diameter of 7.2 nm. However, after rapid cooling both the SANS and atom probe tomography data indicated that the Nb was retained in the matrix as a random solid solution. There was also some evidence that O, N and S are also retained in solid solution in levels not found during conventional processing.