Post-superstack sudbury smelter emissions and their fate in the atmosphere: An overview of the sudbury environment study results

This paper describes investigations into the characteristics and atmospheric fate of emissions from the INCO and Falconbridge Ni smelters at Sudbury, Ontario. The former smelter was of special interest, being one of the largest point sources in North America, with most of its emissions being released from a 381 m ‘Superstack’. Emission rates of S compounds, trace metals, and a number of other substances, have been quantified. The subsequent dispersion, transformation and deposition of these pollutants has been studied in a number of intensive field campaigns, as well as by longer-term precipitation and air monitoring programs. The results of these investigations are summarized, and the contribution of Sudbury emissions to wet and dry deposition in the Sudbury Basin assessed.     

Gradual Occlusion of Extrahepatic Portosystemic Shunts in Dogs and Cats Using the Ameroid Constrictor

Gradual occlusion of the splenic vein, using a specialized device (ameroid constrictor), was evaluated experimentally in three normal beagle dogs. Splenoportograms were used to verify that total occlusion of the splenic vein had occurred in all dogs within 4 to 5 weeks after application of the device. The ameroid constrictor (AC) was also evaluated as a method of gradual vascular occlusion in 12 dogs and two cats with single, extrahepatic, portosystemic shunts (PSS). Serum bile acid (SBA) concentrations were measured and portal scintigraphy (PS) was performed on all 14 animals preoperatively and 10, 20, 30, and 60 days postoperatively. Two dogs (14%) died from portal hypertension in the early postoperative period. One dog and one cat developed multiple acquired PSS, confirmed by mesenteric portography 90 days after the operation. Portal scintigraphy confirmed total occlusion of the primary shunt in the other 10 animals. Shunt fractions (SF), as measured by PS on postoperative days 30 and 60, declined significantly from preoperative values. Significant decreases were noted between preoperative and postoperative values for preprandial SBA on postoperative day 60 and for postprandial SBA on postoperative day 30. SBA concentrations did not correlate with SF. Based on this study, gradual vascular occlusion using the AC is recommended as a method for treatment of single, extrahepatic, PSS.     

水牛miR-302s真核表达载体的构建及生物信息学分析

试验旨在克隆并构建水牛miR-302s慢病毒真核表达载体（bbu-miR-302s）,对其进行生物信息学分析,并尝试将该载体应用于水牛体细胞重编程中。以水牛基因组DNA为模板扩增得到bbu-miR-302s前体序列,测序正确后将其连入pLVX-IRES-ZsGreen1构建重组慢病毒真核表达载体。重组的慢病毒真核表达载体经过酶切鉴定正确后,采用脂质体转染方法包装慢病毒颗粒,通过感染HEK-293T细胞及猪和水牛体细胞,检测重组慢病毒载体的有效性。bbu-miR-302s有效感染水牛胎儿成纤维细胞（BFF）后,经诱导培养,检测能否产生水牛诱导多能干细胞（iPSC）。采用CoGeMiR数据库查询法和SnapGene Viewer软件进行miR-302s家族在基因组中的定位分析;利用ClustalX 1.83软件分析miR-302s序列保守性;利用TargetScan和miRWalk软件预测bbu-miR-302s主要的靶基因,并运用DAVID程序对靶基因进行信号通路富集。测序结果显示,扩增获得的序列是水牛miR-302s家族,包装的重组慢病毒滴度为7.2×10⁶TU/mL,并可以有效感染3个物种的体细胞。bbu-miR-302s病毒感染BFF后,细胞经历形态变化并发生聚集形成克隆样,碱性磷酸酶检测阳性,但多能基因及表面抗原检测结果均为阴性,说明单因子miR-302s不足以完全重编程BFF为水牛iPSC,但促进了重编程进程。CoGeMiR数据库检索发现,miR-302s家族主要位于LARP7基因的内含子区;SnapGene Viewer软件进一步分析发现,bbu-miR-302s位于水牛7号染色体LARP7基因的内含子区。序列同源性分析表明,miR-302s家族成员间及miR-302s簇成员在不同物种间均高度保守。水牛miR-302s主要靶基因共255个,这些靶基因主要集中在33个信号通路中,其中PGK信号通路与胰高血糖素信号转导及调控干细胞信号通路最为显著。本研究结果为后续开展miR-302s簇在体细胞重编程中的作用奠定基础。     

Antimicrobial labelling in Australia: a threat to antimicrobial stewardship?

Antimicrobial resistance is a public health emergency, placing veterinary antimicrobial use under growing scrutiny. Antimicrobial stewardship, through appropriate use of antimicrobials, is a response to this threat. The need for antimicrobial stewardship in Australian veterinary practices has had limited investigation. A 2016 survey undertaken to investigate antimicrobial usage patterns by Australian veterinarians found that antimicrobial dose rates were varied and often inappropriate. Doses of procaine penicillin in horses and cattle were often low, with 68% and 90% of respondents, respectively, reporting doses that were unlikely to result in plasma concentrations above minimum inhibitory concentrations for common equine and bovine pathogens. Frequency of penicillin administration was also often inappropriate. Gentamicin doses in horses were largely appropriate (89% of dose rates appropriate), but 9% of respondents reported twice daily dosing. Amoxycillin and amoxycillin‐clavulanate were administered at the appropriate doses, or above, to dogs and cats by 54% and 70% of respondents, respectively. Here, we explore the potential reasons for inappropriate antimicrobial dose regimens and report that antimicrobial labels often recommend incorrect dose rates and thus may be contributing to poor prescribing practices. Changes to legislation are needed to ensure that antimicrobial drug labels are regularly updated to reflect the dose needed to effectively and safely treat common veterinary pathogens. This will be especially true if changes in legislation restrict antimicrobial use by veterinarians to the uses and doses specified on the label, thus hampering the current momentum towards improved antimicrobial stewardship.     

Livestock and livelihoods of smallholder cattle-owning households in Cambodia: the contribution of on-farm and off-farm activities to income and food security

The majority of smallholder farming households in Cambodia are rurally based and rely on agriculture to support their livelihoods. However, in recent years, growth in the agriculture sector has stagnated with farmers facing several challenges including declining prices for traditional crops and irregular rainfall patterns. This has led to a need for farmers to diversify income sources with livestock promoted as a more viable livelihood activity, particularly the raising of cattle and poultry. However, uncertain profitability of livestock activities is a common perception by smallholders, especially where animals have not been traditionally viewed as a primary income source. To address this, information is required which compares the income and expenses associated with livestock raising to other on-farm activities and off-farm sources. This study reports on a survey of livelihood survey of 17 male and 21 female representatives of 20 households owning cattle in Cambodia, comparing the associated income and expenses of the various livelihood activities in the 12-month period from January to December 2016. Combined total household income from both on-farm and off-farm sources ranged from USD875 to 17730 with an average of USD6779, representing 51% and 49% from on-farm and off-farm activities, respectively. Cattle raising was the most common source of on-farm income (85%), contributing USD1064 and representing 22% of total household income. General household expenses, such as food and transportation (including expenses associated with off-farm employment), represented the majority of total household expenses (79%). Gross profit calculations indicated higher values for pig raising (USD1841.79), cattle (USD950.80) and non-rice crops (USD884) whilst the highest gross margin value was recorded for cattle (89.33%) followed by vegetables (85.27%) and non-rice crops (83.08%). Whilst wet season and dry season rice returned a negative gross profit value of USD197.27 and USD90.60 on average per household, respectively, both were ranked as most important for household consumption, followed by poultry, providing the main source of energy (rice) and protein (chicken meat) and sustaining household food requirements. The study concludes that although smallholder cattle-owning households in Cambodia undertake a diverse range of on-farm activities, as cattle raising provides a superior income source due to higher returns and lower variable costs, it could be promoted as a preferred livelihood activity by agencies conducting rural extension activities. Although consideration of available labour and monetary funds to invest in cattle raising is required, it was observed that income from off-farm sources may prove beneficial in providing the additional monetary funds to support cattle-raising activities and assist in providing generally poor smallholder households with enhanced economic resilience.