Use of Carnobacterium piscicola to limit the growth of Listeria monocytogenes in mussel products : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Microbiology at Massey University, Palmerston North, New Zealand

Bacteria were screened in order to find an organism antagonistic to Listeria monocytogenes which could be applied to mussel products and enhance their safety, especially when temperature-abused. A Listeria monocytogenes isolate from the seafood industry was selected as the target organism. Strains of Lactobacillus reuteri and Enterococcus fecium were screened on plates incubated at 35°C and 10°C for anti-listerial compounds, but none were found. A non-bacteriocinogenic strain of Carnobacterium piscicola, A9b- was selected as the antagonist for detailed examination of growth in broth, agar and mussel systems at 10°C. This temperature was chosen to represent temperature abuse of refrigerated products. To distinguish between the growth of the Carnobacterium piscicola strain and wild-type Listeria monocytogenes a "semi-selective" agar was developed using phenol-red indicator, and mannitol as the sole carbohydrate source. Growth rates of Carnobacterium piscicola and Listeria monocytogenes were compared when grown alone and as a co-culture in agar and broth. Growth rates of Listeria monocytogenes when grown alone, and in the presence of Carnobacterium piscicola, were determined on mussels. Regression analyses were done for the inhibition of Listeria monocytogenes by Carnobacterium piscicola. In all cases Carnobacterium piscicola significantly inhibited the growth of Listeria monocytogenes (P broth = 0.018, P agar <0.001, P mussels < 0.001). Growth of both organisms was faster in broth, than on mussels or agar. The greatest inhibition of Listeria monocytogenes was observed in broth reaching log₁₀4.8 at 41 hours of incubation, prior to decreasing after this time. In agar and mussels the inhibition lasted longer and had not decreased at the end of the trial. The log₁₀ reduction in growth of Listeria monocytogenes in agar was measured at 3.4 and in mussels measured at 1.6. These results were statistically significant (P<0.001 for all). Inhibition of wild type Listeria monocytogenes was also shown in broth when a much lower concentration of Carnobacterium piscicola was used. These results should be considered as preliminary and further confirmatory work should be done. However, Carnobacterium piscicola A9b- shows promise as an antagonistic organism to assist in the control of Listeria monocytogenes in mussel products along with industry-accepted good hygienic practices

There is nothing like an oat

The items reports on first year trials in of the “Quoats” project. It’s well known that oats are generally a good fit in organic rotations and the “Quoats” project – Harnessing new technologies for sustainable oat production and utilisation – aims to make them even better. This five year (2009 – 2014) research project, led by IBERS, Aberystwyth University, brings together a wide range of organisations in the supply chain, from breeders to end-users, to improve the quality and performance of oats. As part of the project, ORC is carrying out field trials to assess the suitability of new oat lines for organic management systems, with particular emphasis on nutrient use efficiency. Eight varieties are being trialled at Wakelyns Agroforestry, Suffolk, including some naked oats, i.e. hull-less oats. The paper reports some first results

What Do People Buy When They Don't Buy Health Insurance And What Does that Say about Why They are Uninsured?

Using data from the 1994 through 1998 Consumer Expenditure Surveys, we compare household spending on 16 different goods (food at home, food away from home, housing, transportation, alcohol and tobacco, interest, furniture and appliances, home maintenance, clothing, utilities, medical care, health insurance, entertainment, personal care, education, and other) for insured versus uninsured households, controlling for total expenditures and demographic characteristics. The analysis shows that the uninsured in the lowest quartile of the distribution of total expenditures spend more on housing, food at home, alcohol and tobacco, and education than do the insured. In contrast, households in the top quartile of the distribution of total expenditures spend more on transportation and furniture and appliances than do comparable insured households. These results are consistent with the idea that poor uninsured households face higher housing prices than do poor insured households. Further research is necessary to determine whether high housing prices can help explain why some households do not have insurance.

Accidental injury, risk-taking behaviour and the social circumstances in which young people (aged 12-24) live: a systematic review

In industrialised countries such as England and Wales, unintended injury (which ranges from sprains in sport to hospitalisation and death due to drugs or transport crashes) is the leading cause of death in children aged 0 to 14 years, and a major cause of death in young adults aged 15 to 24. It is also a major cause of ill health and disability in these age groups. There is a large body of research on young people and their perceived propensity to take risks. Common sense suggests that an increased willingness to place oneself at risk will result an increased likelihood of physical injury. However, given that pathways to injury are complex and not always well understood, the UK Department of Health commissioned a large systematic review to examine this multifaceted issue. Drug use • The review found that the use of drugs is associated with an increased risk of accidental death among young people and that 12–24 year olds are less at risk than those immediately older. However, risk of death increases with length of drug use, so there is value in targeting interventions at this age group. • Many more young men than women die from drug overdoses, because more men take drugs, but those women who do use drugs are at higher risk. Certain other groups of young people are more at risk than others. These include young people in deprived areas and men who have recently been released from prison. • There was a clear disjunction of views between young people who used drugs and those who did not. The young people who did not take drugs regarded them as risky and stated that media images about possible negative consequences dissuaded them from trying them, while those who did tended not to believe ‘official’ messages about possible harms and did not perceive taking drugs as being dangerous. Cannabis in particular was singled out as possibly being good for you, with some young people believing it to be cheaper than alcohol. The recent reclassification of cannabis and the subsequent debate may have helped to reinforce this view. • The burden of the more serious injuries – as demonstrated by the mortality statistics – is carried by young people in the lower socio-economic groups. • In road injuries, drugs are found in the bloodstream of more young fatal accident victims than older age groups; however, it is difficult to assess whether drugs actually contributed to the accident. • Driving on cannabis was thought to be more acceptable than drink-driving and not thought to be dangerous. Alcohol use • Almost everyone admitted to hospital for alcohol poisoning is aged between 11 and 17. After a sharp peak among 14 and 15 year olds, hospital admissions for injuries with alcohol involvement decline slowly between the ages of 16 and 30. • Correlational studies have shown that alcohol puts the drinker at an increased risk of injury, that young people are more likely to have injuries than older people, and that young men are more at risk than young women. In the one study that examined ethnicity, minority ethnic status did not increase alcohol-related injuries, and may in fact have had a protective association. • Views studies found that young people say that they do not commonly mix alcohol and other drugs. Most young people reported that drinking places them at greater risk of injury, though some did not. The younger teenagers – 14 and 15 year olds – felt most in danger of injury when drinking. Young people felt that they learned to manage their drinking through experience and that unsupervised, outdoor drinking was the most dangerous and was more common among younger teenagers (with injuries being considered less common in licensed venues). Peers encourage both drinking and drunken pranks, but also protect one another when they have become more vulnerable as a result of drink. Young people felt that drinking reduces their perceptions of danger and some stated that injury as a result was inevitable. Most young people were cautious about getting very drunk, though being sick as a result of drinking is common and not regarded as serious. Bad experiences – whether to self or someone else – might change behaviour in the short- but not long-term. • One study which examined attempts to reduce alcohol-related injuries found some evidence that motivational interviews in A&E departments are more effective than information handouts. Drink-driving • Drink-driving was generally considered dangerous and not socially acceptable, whereas driving on cannabis was more acceptable and not thought to be dangerous. Some young people stated that a lack of public transport (or alternatives, such as taxis) made it more likely that they would drink and drive. • Interventions based on models of behaviour change to reduce drink-driving are ineffective or have a negative effect. Combining different approaches has more effect than using a single approach. Education or skills training has either negative or no effects on driver behaviour and subsequent accidents, possibly because these approaches lead to over-confidence or early licensing. • Legislation and enforcement on reducing drink-driving has been found to be effective

High Speed Sintering – Continuing Research into a New Rapid Manufacturing Process

High Speed Sintering (HSS) is an emerging layer manufacturing technique aiming to break into the lucrative field of Rapid Manufacturing (RM). The process is likened to Selective Laser Sintering (SLS), however, instead of a laser dictating the sintered cross sectional area of each layer, the desired area is first printed using a Radiation Absorbing Material (RAM) and then sintered using an inexpensive infrared lamp. This paper begins by describing the sintering process in more detail and then outlining the overall manufacturing cycle. It then continues by describing the experiments performed to investigate the current problem concerning the hardness of excess powder within the powder bed. This problem arose due to the continual exposure of the whole bed to infrared radiation from the lamp. The experiments showed that as the power of the IR lamp increased, the hardness of the bed also increased. Furthermore, at higher IR power levels it was found the excess powder produced a solid tile which could only be broken down by a glass bead blaster.Mechanical Engineerin

Leading-edge receptivity to a vortical freestream disturbance: A numerical analysis

The receptivity to freestream vorticity of the boundary layer over a flat plate with an elliptic leading edge is investigated numerically. The flow is simulated by solving the incompressible Navier-Stokes system in general curvilinear coordinates with the vorticity and stream function as dependent variables. A finite-difference scheme which is second-order accurate in both space and time is used. As a first step, the steady basic-state solution is computed. Then a small amplitude vortical disturbance is introduced at the upstream boundary and the governing equations are solved time-accurately to evaluate the spatial and temporal growth of the perturbations leading to instability waves (Tollmien-Schlichting waves) inside the boundary layer. Preliminary results for a symmetric, 2-D disturbance reveal the presence of Tollmien-Schlichting waves aft of the flat-plate/ellipse juncture

Gravity darkening and brightening in binaries

We apply a von Zeipel gravity darkening model to corotating binaries to obtain a simple, analytical expression for the emergent radiative flux from a tidally distorted primary orbiting a point-mass secondary. We adopt a simple Roche model to determine the envelope structure of the primary, assumed massive and centrally condensed, and use the results to calculate the flux. As for single rotating stars, gravity darkening reduces the flux along the stellar equator of the primary, but, unlike for rotating stars, we find that gravity brightening enhances the flux in a region around the stellar poles. We identify a critical limiting separation beyond which hydrostatic equilibrium no longer is possible, whereby the flux vanishes at the point on the stellar equator of the primary facing the companion. For equal-mass binaries, the total luminosity is reduced by about 13 % when this limiting separation is reached.Comment: 7 pages, 5 figures, matches version published in Astrophysical Journa

Making the Case for the Use of the KSU Archives and Special Collections Through Interpretive Videos

One of the challenges faced by Kennesaw State University’s Museums, Archives and Rare Books Department is a lack of awareness of both the existence of our collections and the many potential research applications that archives and rare books provide. This series of short videos makes the case to potential users as to why we collect these materials and how they are useful and relevant to a variety of research interests. Each video pairs an item or collection from the KSU Archives and Special Collections (including the Bentley Rare Book Museum) with expert interpretation provided by a KSU faculty member in a related field. Interviewees discuss how particular items could be used as evidence to support a research topic and why physical engagement with original primary sources is valuable to researchers. The medium of video provides an interactive experience for the user, allowing for both an detailed, multidimensional presentation of a given item or collection as well as the opportunity to browse a collection of videos for materials that relate to their own interests. This series is intended to serve as proof of concept to demonstrate the value of a video-based outreach initiative, ultimately comprising a library of videos on a wide variety of research topics support by the KSU Archives and Special Collections

Single camera 3D planar Doppler velocity measurements using imaging fibre bundles

Two frequency planar Doppler Velocimetry (2ν-PDV) is a modification of the Planar Doppler Velocimetry (PDV) method that allows velocity measurements to be made, quickly and non intrusively, across a plane defined by a laser light sheet. In 2ν-PDV the flow is illuminated sequentially with two optical frequencies, separated by about 700MHz. A single CCD viewing through an iodine absorption cell is used to capture images under each illumination. The two images are used to find the normalised transmission through the cell, and the velocity information is encoded as a variation in the transmission Use of a single camera ensures registration of the reference and signal images and removes issues associated with the polarization sensitivity of the beam splitter, which are major problems in the conventional approach. A 2ν-PDV system has been constructed using a continuous-wave Argon ion laser combined with multiple imaging fibre bundles, to port multiple views of the measurement plane to a CCD camera, allowing the measurement of three velocity components.EPSR