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

On behavior of the fifth algebraic transfer

In this paper, we show that Singer's fifth transfer is not an epimorphism in degree 11. More precisely, it does not detect the element P(h_2) in Ext_A^{5,16}(F_2,F_2).Comment: This is the version published by Geometry & Topology Monographs on 14 November 200

Artificial Intelligence in Business: A Literature Review and Research Agenda

The rise of artificial intelligence (AI) technologies has created promising research opportunities for the information systems (IS) discipline. Through applying latent semantic analysis, we examine the correspondence between key themes in the academic and practitioner discourses on AI. Our findings suggest that business academic research has predominantly focused on designing and applying early AI technologies, while practitioner interest has been more diverse. We examine these differences in the socio-technical continuum context and relate existing literature on AI to core IS research areas. In doing so, we identify existing research gaps and propose future research directions for IS scholars related to AI and organizations, AI and markets, AI and groups, AI and individuals, and AI development

Loss of Mfn2 results in progressive, retrograde degeneration of dopaminergic neurons in the nigrostriatal circuit

Mitochondria continually undergo fusion and fission, and these dynamic processes play a major role in regulating mitochondrial function. Studies of several genes associated with familial Parkinson's disease (PD) have implicated aberrant mitochondrial dynamics in the disease pathology, but the importance of these processes in dopaminergic neurons remains poorly understood. Because the mitofusins Mfn1 and Mfn2 are essential for mitochondrial fusion, we deleted these genes from a subset of dopaminergic neurons in mice. Loss of Mfn2 results in a movement defect characterized by reduced activity and rearing. In open field tests, Mfn2 mutants show severe, age-dependent motor deficits that can be rescued with L-3,4 dihydroxyphenylalanine. These motor deficits are preceded by the loss of dopaminergic terminals in the striatum. However, the loss of dopaminergic neurons in the midbrain occurs weeks after the onset of these motor and striatal deficits, suggesting a retrograde mode of neurodegeneration. In our conditional knockout strategy, we incorporated a mitochondrially targeted fluorescent reporter to facilitate tracking of mitochondria in the affected neurons. Using an organotypic slice culture system, we detected fragmented mitochondria in the soma and proximal processes of these neurons. In addition, we found markedly reduced mitochondrial mass and transport, which may contribute to the neuronal loss. These effects are specific for Mfn2, as the loss of Mfn1 yielded no corresponding defects in the nigrostriatal circuit. Our findings indicate that perturbations of mitochondrial dynamics can cause nigrostriatal defects and may be a risk factor for the neurodegeneration in PD

Intracellular drug delivery: a route to more selective and effective treatments for disease

The Neurokinin 1 receptor (NK1R) is a G protein-coupled receptor (GPCR) and member of the tachykinin family expressed in the central nervous system, immune cells, gastrointestinal tract and vascular endothelia. It is associated with neurogenic inflammation, gastrointestinal function and nociceptive transmission. Stimulation of NK1R by the endogenous agonist, substance P, initiates Gαq-mediated signalling, receptor phosphorylation and β-arrestin recruitment to initiate clathrin-dynamin mediated endocytosis. Internalised NK1R has a spatially and temporally dynamic signalling profile which has been demonstrated to underlie pathophysiological outcomes distinct from the plasma membrane. Therefore, endosomal NK1R populations may be considered a therapeutically distinct target. This thesis explores this concept, through the characterisation of NK1R signalling from endosomes, and the development of two novel drug delivery systems: 1) Lipid-conjugation to anchor soluble molecules into membranes and enhance their targeting; 2) pH-sensitive nanoparticles were used as a non-covalent method of packaging NK1R antagonists for targeted endosomal drug delivery. We investigated the inhibitory potential for lipid-conjugation of Spantide I, a first generation NK1R antagonist (Spantide-Cholestanol). Assessment of the endosomal signalling pathways of NK1R suggested that Spantide-Cholestanol inhibited endosomal signalling with greater potency. We propose a mechanism whereby lipid-conjugation provides sustained association with membranes and can be directed to endosomes to improve inhibition of internalised NK1R signalling. Fluorescence correlation spectroscopy and localisation of a lipid-conjugated fluorescent probe (Cy5-Cholestanol) suggested that there was enrichment in endosomes, and at the plasma membrane. Further investigation of this plasma membrane-associated ligand population revealed that Spantide-Cholestanol has inhibitory effects on receptor trafficking and some plasma membrane-delimited signalling events. Therefore, while Spantide-Cholestanol effectively inhibits endosomally localised NK1R signalling, it also has the potential to bind and modulate plasma membrane localised NK1R. An alternative approach for endosomal drug delivery is the non-covalent loading of NK1R antagonists into pH-sensitive, block copolymer nanoparticles (NPs). The nanoparticle core contained a pH responsive monomer which at acidic pH below the pKa resulted in the protonation of the monomers, triggering repulsion and drug release. This pH is known to be achieved in the acidic endosome environment and therefore may be appropriate for endosome-selective drug release. However, cationic NPs reportedly reduce cell viability. To address this issue, we incorporated diethylene glycol (DEG) into block copolymer to shield the cell from toxicity induced by the charged monomeric subunits at endosomal pH. We observed a DEG-dependent increase in cell health, and internalisation of NPs into Rab5-positive endosomes, to demonstrate that these pH responsive nanoparticles may offer a suitable approach for selective delivery drugs into endosomes. The key findings in this thesis emphasise the importance of considering receptor trafficking/localisation in the entire receptor signalling profile. We have observed that lipidation increases drug localisation in endosomes, significantly improving drug potency to inhibit endosomal signalling. However, some of the drug remains at the plasma membrane and can antagonise the population of membrane-localised NK1R. This suggests that nanodelivery of drugs to endosomes may be a more selective therapeutic strategy. Overall, the efficient and selective delivery of drugs to compartmentalised receptor populations will have important implications for drug discovery programs

The evolution of social health insurance in Vietnam and its role towards achieving universal health coverage

Our research examines the development of social health insurance (SHI) in Vietnam between 1992 and 2016 and SHI's role as a financial mechanism towards achieving universal health coverage (UHC). We reviewed and analysed legislation from the Government of Vietnam (GoV) and performance data from the GoV and the World Bank. Stages of development were identified from legislative change leading to change in SHI functioning as a public financing mechanism: revenue collection, pooling of risk, and purchasing. Movement towards UHC was assessed relative to: population coverage, benefit coverage, and financial protection. Vietnam has implemented SHI through five stages: Stage I (1992–1998), Stage II (1998–2005), Stage III (2005–2008), Stage IV (2008–2014), and Stage V (2014 onwards). Coverage has widened from a compulsory scheme for civil servants and pensioners and a voluntary scheme for others, to a scheme that targets the entire population. However, UHC has not been achieved with 19% of the population uninsured in 2016 and high out-of-pocket payments. The benefit package includes a wide range of services and many expensive medications and considered to be generous. It is recommended that Vietnam focus on improving population coverage rather than further expanding the benefit package to achieve UHC

Iron restriction induces the small-colony variant phenotype in Staphylococcus aureus

Pathogens such as Staphylococcus aureus must overcome host-induced selective pressures, including limited iron availability. To cope with the harsh conditions of the host environment, S. aureus can adapt its physiology in multiple ways. One of these adaptations is the fermenting small-colony variant (SCV) phenotype, which is known to be inherently tolerant to certain classes of antibiotics and heme toxicity. We hypothesized that SCVs might also behave uniquely in response to iron starvation since one of the major cellular uses of iron is the respiration machinery. In this study, a respiring strain of S. aureus and fermenting SCV strains were treated with different concentrations of the iron chelator, 2,2′ dipyridyl (DIP). Our data demonstrate that a major impact of iron starvation in S. aureus is the repression of respiration and the induction of the SCV phenotype. We demonstrate that the SCV phenotype transiently induced by iron starvation mimics the aminoglycoside recalcitrance exhibited by genetic SCVs. Furthermore, prolonged growth in iron starvation promotes increased emergence of stable aminoglycoside-resistant SCVs relative to the naturally occurring subpopulation of SCVs within an S. aureus community. These findings may have relevance to physiological and evolutionary processes occurring within bacterial populations infecting iron-limited host environments

Assessment of the Effectiveness of Ich Tam Khang as a Supportive Therapy for Chronic Heart Failure

Background: Heart failure is a chronic disease needing lifelong management. Despite the advances that have been made in the treatment of the disease, both the longevity and quality of life for those with chronic heart failure remain impaired. A more effective therapeutic approach with less negative side effects is still needed. In this study, we evaluate Ich Tam Khang (ITK), the poly-ingredient herbal and nutritional preparation with multiple physiological actions, as a supportive therapy for patients with chronic heart failure.Aims of Study: To evaluate the effectiveness and safety of Ich Tam Khang as an adjunctive treatment of chronic heart failure.Methods: A total of 60 patients with chronic congestive heart failure were enrolled in this open label, cross-sectional and prospective study. All patients were treated with a conventional regimen (digoxin, diuretics, angiotensin-converting-enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), beta blockers) for at least 4 weeks before being divided into two equal groups. In the treated patients with ITK, patients received conventional therapy plus 4 tablets ITK per day added in two divided doses. In the control patients, all patients kept the same conventional regimen without ITK. All patients were followed up for 3 months for clinical and para-clinical outcomes.Result: The symptoms of heart failure (dyspnea, palpitation, peripheral edema, neck vein distention, heptojugular reflex) decreased. Heart rate and blood pressure stabilized during treatment in the treated patients with ITK. Additionally, total cholesterol and HDL-cholesterol normalized in the patients treated with ITK. Most of echocardiography parameters in the ITK treated patients were superior to the control patients. ITK is safe and it has no side effects.Conclusion: ITK as a combination of herbal and nutritional preparation is effective in reducing heart failure symptoms, improving patient's quality of life for the patients with decompensated heart failure and reducing total cholesterol and LDL-C