DNA transfer by examination tools--a risk for forensic casework?

The introduction of profiling systems with increased sensitivity has led to a concurrent increase in the risk of detecting contaminating DNA in forensic casework. To evaluate the contamination risk of tools used during exhibit examination we have assessed the occurrence and level of DNA transferred between mock casework exhibits, comprised of cotton or glass substrates, and high-risk vectors (scissors, forceps, and gloves). The subsequent impact of such transfer in the profiling of a target sample was also investigated. Dried blood or touch DNA, deposited on the primary substrate, was transferred via the vector to the secondary substrate, which was either DNA-free or contained a target sample (dried blood or touch DNA). Pairwise combinations of both heavy and light contact were applied by each vector in order to simulate various levels of contamination. The transfer of dried blood to DNA-free cotton was observed for all vectors and transfer scenarios, with transfer substantially lower when glass was the substrate. Overall touch DNA transferred less efficiently, with significantly lower transfer rates than blood when transferred to DNA-free cotton; the greatest transfer of touch DNA occurred between cotton and glass substrates. In the presence of a target sample, the detectability of transferred DNA decreased due to the presence of background DNA. Transfer had no impact on the detectability of the target profile, however, in casework scenarios where the suspect profiles are not known, profile interpretation becomes complicated by the addition of contaminating alleles and the probative value of the evidence may be affected. The results of this study reiterate the need for examiners to adhere to stringent laboratory cleaning protocols, particularly in the interest of contamination minimisation, and to reduce the handling of items to prevent intra-item transfer.

An examination of the influence of maternal depression trajectories on child cognitive development and adolescent psychotic experiences

 This thesis investigated trajectories of maternal depression over time, and their influence on offspring's cognitive development in childhood and subsequent risk of psychotic experiences in early adolescence. Offspring’s IQ was also examined as a potential mediator of the relationship between maternal depression and offspring’s risk of psychotic experiences.

Intellectual capital disclosures and corporate governance: an empirical examination

© 2015 Elsevier Ltd. Empirical examinations of the links between corporate governance and intellectual capital are underresearched, particularly from the context of emerging economies where corporate governance mechanisms tend to be largely ceremonial due to family dominance. This study aims to address this gap in the intellectual capital disclosure (ICD) literature by undertaking an empirical examination of the relationship between corporate governance and the extent of ICD of Bangladeshi companies. Inter alia, the key findings of this study suggest that there is a non-linear relationship between family ownership and the extent of ICD. This research also found that foreign ownership, board independence, and the presence of audit committees are positively associated with the extent of ICD. Conversely, family duality (i.e., where the positions of CEO and chairperson are occupied by two individuals from the same family) is negatively associated with the extent of ICD.

An experimental examination of interindividual variation in feather corticosterone content in the House Sparrow, Passer domesticus in southeast Australia

Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird's GC status over the period of feather synthesis. This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors. We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty ('sham') silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTf between these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model. Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level. Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf .

Residual DNA on examination tools following use

Recent studies observing the transfer of DNA via examination tools used within forensic laboratories (scissors, forceps and gloves) have highlighted the contamination risk of such implements if protocols following their use and replacement are not adhered to. Whilst these previous studies focus primarily on the transfer of biological substances to a substrate via high-risk vectors, this investigation considers the proportion of DNA that remains on the high-risk vectors following contact with the substrate. Dried blood or touch DNA was deposited on cotton or glass substrates to create mock exhibits. Following primary contact with the deposit, the vector similarly contacted a secondary DNA-free substrate. Combinations of singular and multiple contacts were applied. Immediately following contact with the secondary substrate, the vector was sampled in order to determine the proportion of DNA-containing material remaining on the vectors following contacts. Residual DNA was detected on the vectors in most instances, with the amount retained influenced by the vector, substrates and biological substance applied. The results demonstrate the potential for inter- and intra-exhibit contamination through further contacts.

Examination compliance and screening for diabetic retinopathy: a 2-year follow-up study

Early detection and timely treatment of diabetic retinopathy can preserve vision, yet many people with diabetes do not have their eyes examined regularly. The purpose of this study was to examine eye care practices of people with diabetes who had not previously accessed eye care services on a regular basis. Screening with non-mydriatic retinal photography for diabetic retinopathy was initiated in 1996, and targeted people with diabetes who did not access eye care services on a regular basis. Each test area was revisited 2 years after the initial screening. Patients that did not attend the biennial screening were followed up by mail survey. Although none of the participants in this study had been previously accessing eye care services on a regular basis, 87% did so after attending the screening. These results indicate that mobile screening with non-mydriatic photography, as an adjunct to current eye care services, has the potential to increase examination compliance for diabetic retinopathy and to achieve sustained behaviour change.

Stock market liquidity and firm value : an empirical examination of the Australian market

We document a positive relation between stock liquidity and firm value. We examine the mechanism through which stock market liquidity enhances firm value by dividing firm value, as measured by Tobin’s Q, into three components, namely, operating income to price, leverage, and operating income to assets. Using the switch to broker anonymity as an exogenous shock to market liquidity, we show that the increase in liquidity around the shock leads to an increase in firm value. Our results suggest that higher firm value for more liquid stocks seems to stem from enhanced stock prices rather than from better operating performance.

Systematic examination of publicly-available information reveals the diverse and extensive corporate political activity of the food industry in Australia

BACKGROUND: The political influence of the food industry, referred to as corporate political activity (CPA), represents a potential barrier to the development and implementation of effective public health policies for non-communicable diseases prevention. This paper reports on the feasibility and limitations of using publicly-available information to identify and monitor the CPA of the food industry in Australia. METHODS: A systematic search was conducted for information from food industry, government and other publicly-available data sources in Australia. Data was collected in relation to five key food industry actors: the Australian Food and Grocery Council; Coca Cola; McDonald's; Nestle; and Woolworths, for the period January 2012 to February 2015. Data analysis was guided by an existing framework for classifying CPA strategies of the food industry. RESULTS: The selected food industry actors used multiple CPA strategies, with 'information and messaging' and 'constituency building' strategies most prominent. CONCLUSIONS: The systematic analysis of publicly-available information over a limited period was able to identify diverse and extensive CPA strategies of the food industry in Australia. This approach can contribute to accountability mechanisms for NCD prevention.