Factors associated with carcass contamination by Campylobacter at slaughterhouse in cecal-carrier broilers

A study was conducted in 2009 to identify risk factors of Campylobacter spp. transmission from the digestive tract to the carcasses of standard broilers (slaughter age: 37 day, carcass weight: 1.3 kg on average). Counts of Campylobacter were performed on pools of 10 ceca and 10 neck-skins from 108 Campylobacter ceca-positive batches in three slaughterhouses. Technical and health data also was collected on the broilers: age, size, carcass weight (mean and standard deviation), condemnation rate, mortality rate and nature of treatment during the rearing period.Cecal counts varied from 4.8 to 10.2 log₁₀ cfu/g. In seventeen batches (15.7%), the skin count was below the detection limit. In the 91 batches with positive neck-skin test results, the counts varied from 2.0 to 5.2 log₁₀ cfu/g. Standard deviation of carcass weight, condemnation rate, slaughter rate and cecal count were significantly lower and growth rate higher in the 17 batches where neck-skin results were not detected positive. Multivariate analysis showed that batches with higher standard deviation of carcass weight were 5 to 9 fold more at risk of having detectable carcass contamination. Among the 91 positive neck-skin batches, only slaughter rate and cecal counts were found to have a significant but limited effect on the level of neck-skin contamination. As far as body weight homogeneity may be affected by disease, better health control can contribute to a reduction of the contamination of the broiler carcasses in Campylobacter carrier batches.     

采用水基前驱溶液喷墨印刷制备光催化活性TiO2薄膜

摘译 近年来,作为一种高能量带隙半导体,二氧化钛(TiO2)由于在紫外光照射下具有良好的光催化活性,已引起科研人员的广泛关注.由于TiO2无色透明,具有广泛的应用前景,如薄的TiO2涂层可用于创建自清洁、防雾、超亲水表面.同时,也能用于太阳能电池等光电子行业. 化学溶液沉积法因具有相对简单的大面积生产工艺,且较低的制膜成本和高可用性,成为TiO2薄膜制备常用的方法之一.针对另一种TiO2制备方法,即溶胶凝胶法,大量研究文献主要关注乙醇的水解控制.然而,工业需求鼓励开发水基前驱设计.其难度在于钛醇盐与水的高反应性.在有机介质中,加入少量的水往往导致水解.因此,需要采用络合剂作为稳定剂,阻止纯水中的水解反应和避免由此产生的产物沉淀.     

Wastes as co-fuels: the policy framework for solid recovered fuel (SRF) in Europe, with UK implications

European Union (EU) member states are adopting the mechanical-biological treatment (MBT) of municipal solid waste (MSW) to comply with EU Landfill Directive (LD) targets on landfill diversion. We review the policy framework for MSW-derived solid recovered fuel (SRF), composed of paper, plastic, and textiles, in the energy-intensive industries. A comparatively high calorific value (15-18 MJ/ kg) fuel, SRF has the potential to partially replace fossil fuel in energy-intensive industries, alongside MSW in dedicated combustion facilities. Attempts by the European standards organization (CEN) to classify fuel properties consider net calorific value (CV) and chlorine and mercury content. However, the particle size, moisture content, and fuel composition also require attention and future studies must address these parameters. We critically review the implications of using SRF as a co-fuel in thermal processes. A thermodynamic analysis provides insight into the technical and environmental feasibility of co-combusting SRF in coal-fired power plants and cement kilns. Results indicate the use of SRF as co-fuel can reduce global warming and acidification potential significantly. This policy analysis is of value to waste managers, policy specialists, regulators, and the waste management research community.     

Overview of the potent cyanobacterial neurotoxin β-methylamino-L-alanine (BMAA) and its analytical determination

Blue-green algae are responsible for the production of different types of toxins which can be neurotoxic, hepatotoxic, cytotoxic and dermatotoxic and that can affect both aquatic and terrestrial life. Since its discovery the neurotoxin β-methylamino-L-alanine (BMAA) has been a cause for concern, being associated with the neurodegenerative disease amyotrophic lateral sclerosis/Parkinsonism–dementia complex (ALS/PDC). The initial focus was on Guam where it was observed that a high number of people were affected by the ALS/PDC complex. Subsequently, researchers were surprised to find levels of BMAA in post mortem brains from Canadian patients who also suffered from ALS/PDC. Recent research demonstrates that BMAA has been found at different levels in the aquatic food web in the brackish waters of the Baltic Sea. There is emerging evidence to suggest that sand-borne algae from Qatar can also contain BMAA. Furthermore, there is now concern because BMAA has been found not only in warmer regions of the world but also in temperate regions like Europe. The aim of this review is to focus on the methods of extraction and analysis of the neurotoxic non-protein amino acid BMAA. We also consider the neurotoxicity, aetiology, and diverse sources and routes of exposure to BMAA. In recent years, different methods have been developed for the analysis of BMAA. Some of these use HPLC-FD, UPLC-UV, UPLC-MS and LC-MS/MS using samples that have been derivatised or underivatised. To date the LC-MS/MS approach is the most widely used analytical technique as it is the most selective and sensitive method for BMAA determination.     

Detection and enumeration of Campylobacter jejuni and Campylobacter coli by indirect impedimetry with an oxygen scavenging system

Six strains of Campylobacter jejuni and Campylobacter coli were shown to grow in a variety of media, but, with one exception, they were unable to produce sufficient change in the electrical properties of the medium to allow their detection by impedance monitoring. With the use of an indirect method based on absorption of evolved carbon dioxide and a medium containing the oxygen scavenger Oxyrase, all strains were detectable, and correlations between time to detection and the logarithm of the inoculum level were excellent. The level of interstrain variation was sufficiently low that all data could be consolidated into a single calibration curve (r = 0.987).     

Dioxins,furans, and non-ortho PCBs in Canadian Arctic seabirds

This is the first account of PCDDs, PCDFs, and non-ortho PCBs in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota.     

Physicochemical changes in intermediate-moisture protein bars made with whey protein or calcium caseinate

This study examined model protein bars made with whey protein isolate (WPI) or calcium caseinate and stored at 20 °C for 50 days. WPI bars remained very soft and, throughout storage, confocal micrographs showed a continuous matrix containing soluble protein and increasing quantities of glucose crystals. In contrast, calcium caseinate bars had a firm texture within 1–5 days of manufacture (fracture stress 199 ± 16 Pa) and hardened progressively during storage (final fracture stress 301 ± 18 Pa). Electrophoresis showed no evidence of covalent protein aggregation, but there were substantial changes in microstructure over the first day of storage, resulting in segregation of a protein phase from a water–glucose–glycerol phase. Proton nuclear magnetic resonance (¹H-NMR) relaxometry and nuclear Overhauser effect spectroscopy (NOESY) experiments showed that water migration away from protein towards glucose and glycerol occurred 10–18 h after manufacture, lowering the molecular mobility of protein. Phase separation was probably driven by the high osmotic pressure generated by the glucose and glycerol. These results confirm that the hardening of protein bars is driven by migration of water from protein to glucose and glycerol, and microstructural phase separation of aggregated protein.