Investigation of hygiene aspects of pig processing using the HACCP concept : a dissertation presented in partial fulfilment of the requirements for the degree of Master of Veterinary Studies in Veterinary Public Health at Massey University

Contamination of fresh meat by pathogenic and spoilage microorganisms can occur at any stage of the slaughter process. Pathogens which are frequently found in fresh meat and which pose a public health problem include Salmonella spp. Campylobacter spp. and Yersinia spp. Contamination with spoilage bacteria affects the storage stability and shelf life of meats. Factors that contribute to meat spoilage include physical damage, biochemical changes in the meat tissues and the activity of microorganisms, of which bacteria are undoubtedly the most important. Fresh meats present a rich medium for the support of microbial growth and will ultimately be rendered unacceptable to consumers as a consequence of spoilage due to such growth. The source of spoilage bacteria can be the slaughter animals themselves, the environment, water and personnel working in the processing plants. This study was conducted to determine the effect of some processing operations on the level of contamination of the pig carcass with aerobic bacteria and to establish microbial quality control points based on the Hazards Analysis Critical Control Point (HACCP) principles. As a component of the HACCP system and a step in the setting up of an HACCP plan for microbial quality control of fresh carcass meat, this study aims at identifying hazards at various stages of processing, evaluating preventive measures and establishing critical control points. Where appropriate, corrective measures to ensure that bacterial contamination is within an acceptable level are recommended. The study was carried out at a processing plant in the North Island of New Zealand during the period April to July 1998. Based on observations at the plant, a flow chart of pig processing was drawn up. A number of processing stages were selected as points where potential risks of bacterial contamination were most likely to occur. These points initially included dehairing, polishing and scraping, evisceration, and inspection. Eight visits to the abattoir were made and a total of 32 paired swab samples from carcasses at each process stage were collected. With four process stages selected for sampling, the total number of samples was 128. In addition, 12 scalding tank water samples were collected for analysis. All samples were processed in the Microbiology Laboratory at Massey University. The aerobic plate count (APC) technique employing incubation at 30°C for 3 days was used for enumeration of aerobic bacteria. A matrix table was designed for entering APC data after each count. The mean of colony forming units per square cm (CFU/cm2) for pig carcass surfaces and CFU/ml for scalding water were calculated and log10 transformation was performed. The highest mean APC was found after the carcasses had passed the dehairing machine (5.1 log10/cm2, ST.D. = 0.57) and the lowest number before the dehairing step (4.31 log10/cm2, ST.D. = 0.61). A rapid increase in APC at the dehairing stage indicated a heavy recontamination of the pig carcass with bacteria from the equipment and from detritus accumulated during the operation. After the operation, the count gradually decreased to 4.4 log10/cm2, ST.D. = 0.38 at the post-evisceration point but then slightly rose again to 4.5 log10/cm2, ST.D. = 0.4 at the post-inspection step. The increase in the APC at the dehairing stage by 0.8 log10/cm2 (p = 0.0002, n = 16) is significant. There was little change in the APC at the polishing and scraping and evisceration stages. There was an insignificant difference of 0.2 log10/cm2 in the APC between samples taken at the start and at the end of the shift. The scalding water temperature fluctuated between 60°C and 67.5 °C (mean = 63.2, n = 12). Bacterial contamination of the scalding water remained almost unchanged with time (2.55 log10/ml at the beginning and 2.62 log10/ml at the end of the shift). An expected inverse correlation between scalding water counts and water temperature could not be verified. Although this study is confined to the microbiological assessment of only a few operational stages that can contribute to the storage quality of fresh pork, the results showed that recontamination of the pig carcass at the dehairing stage is serious and may pose potential safety and quality hazards. Control of bacterial contamination at this step is likely to have a beneficial effect on the microbial quality and safety of the final products. A quality Critical Control Point should be established at the dehairing step which can be considered as a safety CCP as well. However, some technological modification at this step such as installation of hot water showers to make the operation "specifically designed", may be needed to meet the criteria for establishing a CCP. At the polishing and scraping step the results of the study indicated a slight decline in bacterial numbers, provided that brushing and washing of the carcasses was done properly. Any deviation from the normal procedure e.g. inadequate water supply to the brush and scraping table, reduced frequency of hand and knife washing, or increased frequency of touching the carcass by the worker's hands, is likely to result in an increased level of bacterial contamination. Monitoring measures and corrective actions at this stage could be crucial for maintaining an effective CCP. At the evisceration step, preventive measures such as plugging or tying the anus should be considered. This step could be an important CCP for both quality and safety. Further investigations are required to assess the effect of meat inspection procedures on the spread of bacteria from multiple incisions of lymph nodes, internal organs and tonsils. If this step were to be considered a CCP, it would mainly have safety implications

The Topology of Foliations Formed by the Generic K-Orbits of a Subclass of the Indecomposable MD5-Groups

The present paper is a continuation of [13], [14] of the authors. Specifically, the paper considers the MD5-foliations associated to connected and simply connected MD5-groups such that their Lie algebras have 4-dimensional commutative derived ideal. In the paper, we give the topological classification of all considered MD5-foliations. A description of these foliations by certain fibrations or suitable actions of $\mathbb{R}^{2}$ and the Connes' C*-algebras of the foliations which come from fibrations are also given in the paper.Comment: 20 pages, no figur

2D Proactive Uplink Resource Allocation Algorithm for Event Based MTC Applications

We propose a two dimension (2D) proactive uplink resource allocation (2D-PURA) algorithm that aims to reduce the delay/latency in event-based machine-type communications (MTC) applications. Specifically, when an event of interest occurs at a device, it tends to spread to the neighboring devices. Consequently, when a device has data to send to the base station (BS), its neighbors later are highly likely to transmit. Thus, we propose to cluster devices in the neighborhood around the event, also referred to as the disturbance region, into rings based on the distance from the original event. To reduce the uplink latency, we then proactively allocate resources for these rings. To evaluate the proposed algorithm, we analytically derive the mean uplink delay, the proportion of resource conservation due to successful allocations, and the proportion of uplink resource wastage due to unsuccessful allocations for 2D-PURA algorithm. Numerical results demonstrate that the proposed method can save over 16.5 and 27 percent of mean uplink delay, compared with the 1D algorithm and the standard method, respectively.Comment: 6 pages, 6 figures, Published in 2018 IEEE Wireless Communications and Networking Conference (WCNC

Bilateral abducens nerve palsy due to septic thrombophlebitis.

PurposeTo report a case of septic thrombophlebitis producing bilateral abducens nerve palsy.ObservationA 65 year-old woman with recent sinus surgery experienced the onset of horizontal diplopia during treatment for bacteremia. Computer tomography of head and a neck ultrasonography showed right internal jugular vein occlusion. Ophthalmology examination was consistent with bilateral abducens nerve palsy. She was treated with systemic antibiotics and antiplatelet therapy with resolution of the internal jugular vein occlusion. The diplopia improved over a six-months.Conclusion and importanceOur patient had Lemierre syndrome with an unusual presentation. The patient was treated for septic thrombophlebitis with a resolution of her ocular symptoms

Outward Influence and Cascade Size Estimation in Billion-scale Networks

Estimating cascade size and nodes' influence is a fundamental task in social, technological, and biological networks. Yet this task is extremely challenging due to the sheer size and the structural heterogeneity of networks. We investigate a new influence measure, termed outward influence (OI), defined as the (expected) number of nodes that a subset of nodes $S$ will activate, excluding the nodes in S. Thus, OI equals, the de facto standard measure, influence spread of S minus |S|. OI is not only more informative for nodes with small influence, but also, critical in designing new effective sampling and statistical estimation methods. Based on OI, we propose SIEA/SOIEA, novel methods to estimate influence spread/outward influence at scale and with rigorous theoretical guarantees. The proposed methods are built on two novel components 1) IICP an important sampling method for outward influence, and 2) RSA, a robust mean estimation method that minimize the number of samples through analyzing variance and range of random variables. Compared to the state-of-the art for influence estimation, SIEA is $\Omega(\log^4 n)$ times faster in theory and up to several orders of magnitude faster in practice. For the first time, influence of nodes in the networks of billions of edges can be estimated with high accuracy within a few minutes. Our comprehensive experiments on real-world networks also give evidence against the popular practice of using a fixed number, e.g. 10K or 20K, of samples to compute the "ground truth" for influence spread.Comment: 16 pages, SIGMETRICS 201

The Possible Connection of Gamma Oscillation and 3-D Object Representation

We process and encode for different features of a particular object (shape, color, texture, etc.) in distinct areas of the brain. How we bind these attributes together into a unified perception of an object is unknown. Past research suggests that synchronized activity between brain areas, particularly induced gamma activity (~ 40 Hz), may account for this binding process and the basis of our conscious perceptual experience, specifically through object representation. In this study, participants were asked to look at a series of 2-D pictures of cars from distinctive rotations (00, 900, 1800) and were asked to distinguish whether two pictures are of the same or different cars; meanwhile, electroencephalography (EEG) was used to measure electrical activity on participants’ scalps. Our preliminary analysis showed a difference in gamma oscillation after the stimulus onset when comparing 1800 rotations to no rotation in one participant. This suggests the possible relationship between induced gamma oscillation and 3-D object representation

Local stiffener and skin pocket buckling prediction by special PASCO modeling technique: Correlation to test data

Waffle panels are often used on fuselage structures such as that of the Space Shuttle. The waffle panel design is an efficient design for carrying biaxial, in-plane, and shear loads. The WAFFLE program was designed for application on waffle panels. The Panel Analysis and Sizing Code (PASCO) program was designed for analyzing and sizing uniaxially stiffened panels. The application of the PASCO program in conjunction with the WAFFLE program is discussed to account for both the fillet radius and the presence of stiffness in both directions. The results of the tests are used to verify that these adjustments are valid and necessary if accurate analysis of the waffle panel is to be achieved