Research methods for media and communication

A user friendly and comprehensive introduction to media and communications research. It introduces the various qualitative and quantitative research methods commonly used in the social sciences as applied to media studies, communication, journalism, public relations and advertising. Author from Deakin University, Australia.

Deterministic versus stochastic quantitative microbial Risk Assessment models for wastewater irrigation of food crops

Reuse of wastewater to irrigate food crops is being practiced in many parts of the world and is becoming more commonplace as the competition for, and stresses on, freshwater resources intensify. But there are risks associated with wastewater irrigation, including the possibility of transmission of pathogens causing infectious disease, to both workers in the field and to consumers buying and eating produce irrigated with wastewater. To manage these risks appropriately we need objective and quantitative estimates of them. This is typically achieved through one of two modelling approaches: deterministic or stochastic. Each parameter in a deterministic model is represented by a single value, whereas in stochastic models probability functions are used. Stochastic models are theoretically superior because they account for variability and uncertainty, but they are computationally demanding and not readily accessible to water resource and public health managers. We constructed models to estimate risk of enteric virus infection arising from the consumption of wastewater-irrigated horticultural crops (broccoli, cucumber and lettuce), and compared the resultant levels of risk between the deterministic and stochastic approaches. Several scenarios were tested for each crop, accounting for different concentrations of enteric viruses and different lengths of environmental exposure (i.e. the time between the last irrigation event and harvest, when the viruses are liable to decay or inactivation). In most situations modelled the two approaches yielded similar estimates of risk (within 1 order-of-magnitude). The two methods diverged most markedly, up to around 2 orders-of-magnitude, when there was large uncertainty associated with the estimate of virus concentration and the exposure period was short (1 day). Therefore, in some circumstances deterministic modelling may offer water resource managers a pragmatic alternative to stochastic modelling, but its usefulness as a surrogate will depend upon the level of uncertainty in the model parameters.

Investigation of telomere lengths measurement by quantitative real-time PCR to predict age

Currently DNA profiling methods only compare a suspect’s DNA with DNA left at the crime scene. When there is no suspect, it would be useful for the police to be able to predict what the person of interest looks like by analysing the DNA left behind in a crime scene. Determination of the age of the suspect is an important factor in creating an identikit. Human somatic cells gradually lose telomeric repeats with age. This study investigated if one could use a correlation between telomere length and age, to predict the age of an individual from their DNA. Telomere length, in buccal cells, of 167 individuals aged between 1 and 96 years old was measured using real-time quantitative PCR. Telomere length decreased with age (r = −0.185, P < 0.05) and the age of an individual could be roughly determined by the following formula: (age = relative telomere length −1.5/−0.005). The regression (R2) value between telomere length and age was not, vert, similar0.04, which is too low to be use for forensics. The causes for the presence of large variation in telomere lengths in the population were further investigated. The age prediction accuracies were low even after dividing samples into non-related Caucasians, males and females (5%, 9% and 1%, respectively). Mean telomere lengths of eight age groups representing each decade of life showed non-linear decrease in telomere length with age. There were variations in telomere lengths even among similarly aged individuals aged 26 years old (n = 10) and age 54 years old (n = 9). Therefore, telomere length measurement by real-time quantitative PCR cannot be used to predict age of a person, due to the presence of large inter-individual variations in telomere lengths.

A quantitative approach to analysing reliability of engagement responses to dance

Perhaps one of the most important end products of a dance work is how it  effects its observers (typically its audience, but also the dancers and choreographers). Of the many ways of discussing and analysing dance, one
approach in its infancy is quantification. Our research involves combining continuous response techniques and human response methods to see if we can tease out relationships between continuous, quantitative evaluative responses and the more qualitative choreographer intentions. The aim of this paper is to describe how evaluative responses can be quantified at all, then how they can be related to an unfolding dance work, and finally, how we can isolate ‘meaningful’ or ‘significant’ or ‘reliable’ evaluations of a dance work from those which are no more than a spurious set of not-very-useful numbers presented under the guise of a valid assessment.

Relationship between indices of adiposity obtained by peripheral quantitative computed tomography and dual-energy X-ray absorptiometry in pre-pubertal children

Background/Aim: The study investigated the relationship between indices of adiposity measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) in pre-pubertal children.

Subjects and methods: DXA-derived per cent body fat (%BF) was measured in 284 boys and 288 girls, aged 7–10 years. Cross-sections of the forearm (n=427) and lower leg (n=560) were obtained by pQCT to measure total cross-sectional area of the limb (Total CSA), Muscle CSA, Fat CSA, %Fat CSA (Fat CSA/Total CSA×100) and muscle density.

Results: Peripheral QCT-derived %Fat CSA in the forearm and lower leg correlated strongly with DXA-derived %BF (r=0.83–0.89, p<0.01) in both boys and girls. However, forearm and lower leg %Fat CSA were higher than whole body %BF by 5% and 10%, respectively. A better prediction of whole-body %BF was achieved by including %Fat CSA, muscle density and height into a hierarchical regression model. Using sex-specific regression equations, 87.7% of the boys and 83.7% of the girls had a predicted %BF within 3% units of the %BF obtained by DXA.

Conclusion: In pre-pubertal children, pQCT measures of adiposity are strongly associated with whole-body per cent body fat. This reproducible method could be an alternative technique to estimate body composition in this population.

Maternity care experiences of Asia ethnic minorities in rural Tasmania, Australia : a mixed methods study

When migrating to Australia Asian women bring with them birthing cultural beliefs and practices, many of which are different from the Australian medical and cultural understanding of reproduction. Such cultural differences may result in conflicts between clients and health care providers especially when the migrants have a poor knowledge of English. The research investigates the maternity care experiences of Asian migrants in Tasmania. The barriers that Asian migrants face in accessing maternity care services and the factors that affect their views towards maternity care were also explored. A mix of quantitative and qualitative methods was employed. Ten women from different ethnic minorities were invited to semi-structured interviews. The qualitative data were analysed using grounded theory. Findings from the interviews were utilized to design a survey questionnaire. Of the 150 survey questionnaires posted, 121 questionnaires were returned. Descriptive statistics and Chi-square tests of independence were used to analyse the quantitative data. Asian migrants followed some traditional practices such as having good rest and eating hot food during the postpartum month. However, they tended to adapt or disregard traditional practices that were no longer applicable in the new environment including the practices of not washing or having a shower. Support is vital for women recovering after childbirth to prevent postnatal depression. Two main barriers migrant women face in accessing health care are language and cultural barriers. Country of origin, partner’s ethnicity, religion and length of stay in Australia are factors that shape the migrants’ views and attitudes towards and experience of maternity care. Providing interpreting services, social support for migrant women and improving the cross-cultural training for healthcare providers are recommended to improve available maternal care services. The factors that affect migrants’ view on maternity care should be taken into account when providing maternity care for Asian migrant women.

RiboSys, a high-resolution, quantitative approach to measure the in vivo kinetics of pre-mRNA splicing and 3'-end processing in Saccharomyces cerevisiae

We describe methods for obtaining a quantitative description of RNA processing at high resolution in budding yeast. As a model gene expression system, we constructed tetON (for induction studies) and tetOFF (for repression, derepression, and RNA degradation studies) yeast strains with a series of reporter genes integrated in the genome under the control of a tetO7 promoter. Reverse transcription and quantitative real-time-PCR (RT-qPCR) methods were adapted to allow the determination of mRNA abundance as the average number of copies per cell in a population. Fluorescence in situ hybridization (FISH) measurements of transcript numbers in individual cells validated the RT-qPCR approach for the average copy-number determination despite the broad distribution of transcript levels within a population of cells. In addition, RT-qPCR was used to distinguish the products of the different steps in splicing of the reporter transcripts, and methods were developed to map and quantify 3′-end cleavage and polyadenylation. This system permits pre-mRNA production, splicing, 3′-end maturation and degradation to be quantitatively monitored with unprecedented kinetic detail, suitable for mathematical modeling. Using this approach, we demonstrate that reporter transcripts are spliced prior to their 3′-end cleavage and polyadenylation, that is, cotranscriptionally.

Methodological challenges to research among Chinese : using mixed methods to investigate older persons with depression in Macau

The article offers an example of using a mixed methods design that was implemented when investigating depression among Chinese older persons in Macau. A challenge in designing the study was that in light of literature on Chinese culture and somatization theory, the acceptability of the methodology was uncertain. Participants (n = 31) were purposively selected and quantitative data were collected using multiple standardized measures. Questions raised by the quantitative approach were then reflected through in-depth interviews. Four dominant categories emerged: (a) negative thinking, (b) physical limitations and complaints, (c) present living conditions and social support, and (d) the lives participants have lived. There was a high level of congruence between quantitative scores and narratives. The research approach was acceptable to the participants, and the findings contributed to an understanding of depression and therapeutic interventions for that population within Chinese culture.

Evaluation of four supervised learning methods for benthic habitat mapping using backscatter from multi-beam sonar

An understanding of the distribution and extent of marine habitats is essential for the implementation of ecosystem-based management strategies. Historically this had been difficult in marine environments until the advancement of acoustic sensors. This study demonstrates the applicability of supervised learning techniques for benthic habitat characterization using angular backscatter response data. With the advancement of multibeam echo-sounder (MBES) technology, full coverage datasets of physical structure over vast regions of the seafloor are now achievable. Supervised learning methods typically applied to terrestrial remote sensing provide a cost-effective approach for habitat characterization in marine systems. However the comparison of the relative performance of different classifiers using acoustic data is limited. Characterization of acoustic backscatter data from MBES using four different supervised learning methods to generate benthic habitat maps is presented. Maximum Likelihood Classifier (MLC), Quick, Unbiased, Efficient Statistical Tree (QUEST), Random Forest (RF) and Support Vector Machine (SVM) were evaluated to classify angular backscatter response into habitat classes using training data acquired from underwater video observations. Results for biota classifications indicated that SVM and RF produced the highest accuracies, followed by QUEST and MLC, respectively. The most important backscatter data were from the moderate incidence angles between 30° and 50°. This study presents initial results for understanding how acoustic backscatter from MBES can be optimized for the characterization of marine benthic biological habitats. © 2012 by the authors.

Gender differences in recreational and transport cycling : a cross-sectional mixed-methods comparison of cycling patterns, motivators, and constraints

Background
Gender differences in cycling are well-documented. However, most analyses of gender differences make broad comparisons, with few studies modeling male and female cycling patterns separately for recreational and transport cycling. This modeling is important, in order to improve our efforts to promote cycling to women and men in countries like Australia with low rates of transport cycling. The main aim of this study was to examine gender differences in cycling patterns and in motivators and constraints to cycling, separately for recreational and transport cycling.

Methods
Adult members of a Queensland, Australia, community bicycling organization completed an online survey about their cycling patterns; cycling purposes; and personal, social and perceived environmental motivators and constraints (47% response rate). Closed and open-end questions were completed. Using the quantitative data, multivariable linear, logistic and ordinal regression models were used to examine associations between gender and cycling patterns, motivators and constraints. The qualitative data were thematically analyzed to expand upon the quantitative findings.

Results
In this sample of 1862 bicyclists, men were more likely than women to cycle for recreation and for transport, and they cycled for longer. Most transport cycling was for commuting, with men more likely than women to commute by bicycle. Men were more likely to cycle on-road, and women off-road. However, most men and women did not prefer to cycle on-road without designed bicycle lanes, and qualitative data indicated a strong preference by men and women for bicycle-only off-road paths. Both genders reported personal factors (health and enjoyment related) as motivators for cycling, although women were more likely to agree that other personal, social and environmental factors were also motivating. The main constraints for both genders and both cycling purposes were perceived environmental factors related to traffic conditions, motorist aggression and safety. Women, however, reported more constraints, and were more likely to report as constraints other environmental factors and personal factors.

Conclusion
Differences found in men’s and women’s cycling patterns, motivators and constraints should be considered in efforts to promote cycling, particularly in efforts to increase cycling for transport.

Smokers and ex-smokers reaction to anti-smoking advertising : a mixed methods approach

Anti-smoking advertising is a central component of modern public health policy. Nevertheless, some smokers have reported that viewing anti-smoking advertising provokes intense nicotine craving. Anti-smoking advertising frequently features images of cigarettes and of individuals smoking. However, research indicates that images of tobacco paraphernalia may induce cravings in individuals addicted to nicotine. The effects of the presence of smoking cues in anti-smoking advertising were considered in the present study. Smokers and ex-smokers (N=63) were randomly assigned to view an anti-smoking advertisement or to complete a control task. Urge to smoke was measured pre- and post-test. Qualitative responses to anti-smoking advertising were also elicited from all participants in the intervention groups. According to both qualitative and quantitative data analyses viewing anti-smoking advertising, even with images of smoking related paraphernalia, led to decreases in craving amongst smokers. Ex-smokers experienced no change in quantitatively measured craving after viewing anti-smoking advertising. These findings are inconsistent with findings from studies using neutral or positive smoking cues. Qualitative data shows that no smokers or ex-smokers who viewed anti-smoking advertising reported an increase in tobacco craving as a result of viewing the campaign. Implications of these findings for future research and anti-smoking campaigns are discussed.

Dynamics of childhood growth and obesity: development and validation of a quantitative mathematical model

Background
Clinicians and policy makers need the ability to predict quantitatively how childhood bodyweight will respond to obesity interventions.

Methods
We developed and validated a mathematical model of childhood energy balance that accounts for healthy growth and development of obesity, and that makes quantitative predictions about weight-management interventions. The model was calibrated to reference body composition data in healthy children and validated by comparing model predictions with data other than those used to build the model.

Findings
The model accurately simulated the changes in body composition and energy expenditure reported in reference data during healthy growth, and predicted increases in energy intake from ages 5—18 years of roughly 1200 kcal per day in boys and 900 kcal per day in girls. Development of childhood obesity necessitated a substantially greater excess energy intake than for development of adult obesity. Furthermore, excess energy intake in overweight and obese children calculated by the model greatly exceeded the typical energy balance calculated on the basis of growth charts. At the population level, the excess weight of US children in 2003—06 was associated with a mean increase in energy intake of roughly 200 kcal per day per child compared with similar children in 1971—74. The model also suggests that therapeutic windows when children can outgrow obesity without losing weight might exist, especially during periods of high growth potential in boys who are not severely obese.

Interpretation
This model quantifies the energy excess underlying obesity and calculates the necessary intervention magnitude to achieve bodyweight change in children. Policy makers and clinicians now have a quantitative technique for understanding the childhood obesity epidemic and planning interventions to control it.

Funding
Intramural Research Program of the National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.

Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

Article focus
▪ This article is a protocol of a study that involves offering fragile X syndrome carrier screening to pregnant and non-pregnant women in the general population. We are undertaking a programme evaluation approach using mixed methods to collect data about informed decisionmaking and predictors of test uptake, with a focus on psychosocial measures. We are also undertaking an economic appraisal.

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.

Comparative study of mental model research methods : relationships among ACSMM, SMD, MITOCAR & deep methodologies

Measuring and assessing mental models of individuals and teams requires the capturing and analysis of key latent variables. This paper presents and compares four different research methods (ACSMM, SMD, MITOCAR and DEEP) that capture and create a conceptual representation of individual and team mental models. These methods use qualitative and quantitative techniques to investigate a single comparison of different groups or individuals' mental models with another group's mental model or to investigate the comparison of a group or individuals' mental model with themselves at a later time