Is meat inspection suitable for the surveillance of animal health (AH) in the pig sector?

In England & Wales, ante and post-mortem (PM) data for lesions observed during meat inspection at the abattoir are recorded in the Food Standards Agency (FSA) Collection and Communication of Inspection Results (CCIR) system. FSA data are reported to livestock producers but are not used systematically to monitor trends of specific conditions, nor to detect changes in disease syndromes. An advantage of using FSA data for AH surveillance purposes is the high population coverage; a disadvantage is the lack of accuracy. The voluntary BPEX Pig Health Scheme, BPHS, provides more accurate reports from standardised abattoir assessments of 12 PM lesions that reflect disease and welfare conditions of economic significance. FSA data were compared with BPHS data, for respiratory and tail bite lesions, from the same period (June 2008 - May 2012). There were approximately 900,000 BPHS pigs (from 2,543 premises) and 19 million pigs (31,578 premises) in CCIR. Generalised linear mixed models were used to examine the data to detect significant differences in trends and seasonality. Additionally, specific batches were compared in three abattoirs during four trials in 2013. Agreement between the two datasets, in the four trials, was evaluated using the correlation coefficient and the Kappa value, while significance was assessed using McNemar and paired t-test. National temporal trend analysis showed an increase in respiratory disease in both datasets but seasonality and prevalence differed. For tail bite lesions, the temporal trend and seasonal patterns were completely different. In the four trials, 332 batches of pigs were compared. The correlation of respiratory disease was low between the datasets as was the identification of positive batches for conditions such as tail bite. These results lead to the conclusion that, although routine meat inspection data has potential for AH surveillance purposes, it needs significant improvement to replace the BPHS

Multi-band study of NGC 7424 and its two newly-discovered ULXs

We have studied the face-on, barred spiral NGC 7424 (site of the rare Type IIb SN 2001ig) with Chandra, Gemini and the Australia Telescope Compact Array. After giving revised X-ray colours and luminosity of the supernova, here we focus on some other interesting sources in the galaxy: in particular, our serendipitous discovery of two ultraluminous X-ray sources (ULXs). The brighter one (~ 10^{40} erg/s) has a power-law-like spectrum with photon index Gamma ~ 1.8. The other ULX shows a spectral state transition or outburst between the two Chandra observations, 20 days apart. Optical data show that this ULX is located in a young (age ~ 7-10 Myr), bright complex rich with OB stars and clusters. An exceptionally bright, unresolved radio source (0.14 mJy at 4.79 GHz, implying a radio luminosity twice as high as Cas A) is found slightly offset from the ULX (~ 80 pc). Its radio spectral index alpha ~ -0.7 suggests optically-thin synchrotron emission, either from a young supernova remnant or from a radio lobe powered by a ULX jet. An even brighter, unresolved radio source (0.22 mJy at 4.79 GHz) is found in another young, massive stellar complex, not associated with any X-ray sources: based on its flatter radio spectral index (alpha ~ -0.3), we suggest that it is a young pulsar wind nebula, a factor of 10 more radio luminous than the Crab.Comment: 12 pages, 11 figures. Accepted by MNRAS. High-resolution colour images of NGC 7424 from the Gemini observations are available at http://www.gemini.edu/2001igp

A novel investigation into the application of non-destructive evaluation for vibration assessment and analysis of in-service pipes

Flow induced vibrations that are close to resonance frequencies are a major problem in all oil and gas processing industries, so all piping systems require regular condition monitoring and inspection to assess changes in their dynamic characteristics and structural integrity in order to prevent catastrophic failures. One of the main causes of pipe failure is weak support causing low frequency high amplitude flow-induced vibration. This causes wear and tear, especially near joints due to their dissimilar stiffness resulting in fatigue failure of joints caused by vibration-induced high cyclic stress. Other contributing factors in pipe failure are poor or inadequate design, poor workmanship during installation or maintenance and inadequate or weak and flexible support. These pipes are usually required to work non-stop for 24 hours a day 7 days a week for weeks, months or years at a time. Regular monitoring and in-service dynamic analysis should ensure continuous and safe operation. A novel method of non-destructive testing and evaluation of these pipes, while in service, is proposed in this paper. This technique will enable early detection and identification of the root causes of any impending failure due to excess vibration as a result of cyclic force induced by the flow. The method pinpoints the location of the impending failure prior to condition-based maintenance procedures. The technique relies on the combined application of Operating Deflection Shapes (ODS) analysis and computational mechanics utilizing Finite Element Analysis (FEA), i.e. linear elastic stress analysis. Any structural modification to the pipes and their supports can then be applied virtually and their effects on the system can be analysed. The effect on vibration levels is assessed and verified. The effect of any change in the forces corresponding to changes in the Differential Pressure (DP) at constant flow rate through the pipes can then be estimated. It was concluded that maintaining the differential pressure above some “critical” threshold ensures the pipe operates under the allowable dynamic stress for a theoretically “indefinite” life cycle

Failure Analysis of Flow-induced Vibration Problem of in-serviced Duplex Stainless Steel Piping System in Oil and Gas Industry

Failure of the duplex stainless steel piping system in oil and gas industry can have disastrous effects. In this study, a novel method of failure analysis of flow-induced vibration problem of in-serviced duplex stainless steel piping system is proposed. The proposed non-destructive technique is able to determine a suitable operating condition for continuous operation without failure. The technique relies on the combined operation of operational modal analysis, operating deflection shape analysis and linear elastic finite element analysis. The effect of different operating conditions for two distinct valve opening cases (i.e. fully opened and partially opened) on the dynamic stress is examined, and they are utilised for forecasting purpose in failure analysis. The result shows that maximum operating conditions are 360 and 400 mmscfd for fully opened and partially opened flow control valves, respectively. Beyond this limit, the piping system most likely will fail

British Escherichia coli O157 in Cattle Study (BECS) to determine the prevalence of E. coli O157 in herds with cattle destined for the food chain

Escherichia coli O157 are zoonotic bacteria for which cattle are an important reservoir. Prevalence estimates for E. coli O157 in British cattle for human consumption are over 10 years old. A new baseline is needed to inform current human health risk. The British E. coli O157 in Cattle Study (BECS) ran between September 2014 and November 2015 on 270 farms across Scotland and England & Wales. This is the first study to be conducted contemporaneously across Great Britain, thus enabling comparison between Scotland and England & Wales. Herd-level prevalence estimates for E. coli O157 did not differ significantly for Scotland (0·236, 95% CI 0·166–0·325) and England & Wales (0·213, 95% CI 0·156–0·283) (P = 0·65). The majority of isolates were verocytotoxin positive. A higher proportion of samples from Scotland were in the super-shedder category, though there was no difference between the surveys in the likelihood of a positive farm having at least one super-shedder sample. E. coli O157 continues to be common in British beef cattle, reaffirming public health policy that contact with cattle and their environments is a potential infection source