Hybrid cemented/cementless total hip replacement in dogs: seventy-eight consecutive joint replacements

Objective: To evaluate the use of hybrid total hip replacement (THR), using a cementless acetabular component and a cemented femoral component. Study Design: Prospective case series. Sample Population: Client‐owned dogs (n=71). Materials and Methods: Consecutive clinical cases that had hybrid THR were studied. Radiographic features, pain scores, and lameness scores were recorded pre‐ and postoperatively. Longer term outcome was assessed by owner questionnaire. Results: Hybrid THRs (n=78) were performed in 71 dogs. Four cases (5%) had major postoperative complications; 3 were resolved after revision surgery, and 1 owner requested an explantation. No other major complications were identified on follow‐up radiographs (67 THR) at 12 weeks. On clinical follow up (77 THR) at 4 weeks, lameness had improved in 68, was unchanged in 8, and was worse in 1. Pain had decreased in 72, was unchanged in 4, and was worse in 1. At 12 weeks (69 THR) compared with preoperative status, lameness had improved in 67 and was unchanged in 2. Pain had improved in 68 and was unchanged in 1. Longer term follow‐up (mean, 16 months) was available for all hips. No further complications were reported. Owner satisfaction was good for 76 THRs and reasonable for 2. Conclusions: Hybrid THR can be performed successfully with a low complication rate and represents an alternative to either entirely cemented or cementless implantation.     

Mobile mating disruption of light-brown apple moths using pheromone-treated sterile Mediterranean fruit flies

BACKGROUND: Public opposition to aerial application of sex pheromone for mating disruption of light‐brown apple moth (LBAM), Epiphyas postvittana (Walk.), in California stopped its further use in the ca $ 74 million eradication programme in 2008, underscoring the need for other eradication tactics. It is demonstrated that pheromone‐treated sterile Mediterranean fruit flies (medflies), Ceratitis capitata Wied., can disrupt communication in male moths. RESULTS: Medflies topically dosed with moth pheromone (E)‐11‐tetradecenyl acetate showed a no observed effect level (NOEL) of ～10 µg fly^?1, with increasing toxicity from 30 to 100 µg fly^?1. Greater potency and longevity of attraction and lower mortality were achieved using microencapsulated pheromone. Releases of 1000 pheromone‐treated medflies ha^?1 prevented male moth catch to synthetic lures in treated 4 ha plots for 1 day in suburban Perth, Australia. Releases of ca 3000 pheromone‐treated medflies ha^?1 disrupted catch to single female moths in delta traps, and to synthetic pheromone lures. Percentage disruption on the first four nights was 95, 91, 82 and 85%. CONCLUSIONS: Disruption of moth catch using pheromone‐treated medflies is a novel development that, with future improvement, might provide a socially acceptable approach for application of the insect mating disruption technique to control invasive insects in urban environments. Adequacy of payload and other issues require resolution. Copyright © 2011 Society of Chemical Industry     

西部黄土高原苜蓿终止时间对苜蓿-小麦轮作系统生产力及土壤水分的影响

旱作春小麦 (Triticum aestivum L.)是西部黄土高原最重要的禾谷类作物,该区苜蓿(Medicago sativa L.)分布也非常广泛。持续的作物连作和多年苜蓿种植系统都存在很多问题。雨养农业系统发展的关键是最佳水分利用策略的应用。发展合理的苜蓿-小麦轮作系统对该区农业的发展有十分重要的意义。由于苜蓿终止时间严重影响土壤水分,所以在适宜的时间终止苜蓿就显得十分重要。然而,关于苜蓿-小麦轮作中老苜蓿在一年中适宜终止时间的研究鲜见报道。本研究利用黄土高原西部典型的半干旱雨养农业区30年老苜蓿布设田间试验,旨在探索老苜蓿地土壤水分状况、苜蓿终止时间和少量氮肥施用对系统生产力及土壤水分的影响。结果表明,长期种植苜蓿后0~3 m土壤水分很少,即便遇到丰水年(2003年),3年的时间都不足以恢复土壤水分。30年苜蓿在一年中春季还是秋季终止对土壤水分状况无显著影响。种植苜蓿30年后杂草竞争力增强,苜蓿干物质和产量水平都相当低,且对1 kg hm^-2的氮肥使用无明显响应。由于土壤水分含量太低,后茬春小麦对1 kg hm^-2的氮肥使用和苜蓿终止时间也无明显响应。因此,苜蓿持续种植时间太长会耗竭土壤水分,使后茬春小麦对苜蓿在一年中的终止时间及少量的氮肥使用无响应,需要3年以上时间才有可能恢复土壤含水量。     

N₂reduction and hydrogenation to ammonia by a molecular iron-potassium complex

The most common catalyst in the Haber-Bosch process for the hydrogenation of dinitrogen (N(2)) to ammonia (NH(3)) is an iron surface promoted with potassium cations (K(+)), but soluble iron complexes have neither reduced the N-N bond of N(2) to nitride (N(3-)) nor produced large amounts of NH(3) from N(2). We report a molecular iron complex that reacts with N(2) and a potassium reductant to give a complex with two nitrides, which are bound to iron and potassium cations. The product has a Fe(3)N(2) core, implying that three iron atoms cooperate to break the N-N triple bond through a six-electron reduction. The nitride complex reacts with acid and with H(2) to give substantial yields of N(2)-derived ammonia. These reactions, although not yet catalytic, give structural and spectroscopic insight into N(2) cleavage and N-H bond-forming reactions of iron.     

科学理解农药最大残留限量的概念

农药在作物及食品生产中的有益作用已为世界所公认,但是食品中残留微量农药是否对人体健康有危害仍是目前人们关注的焦点。允许的农药残留不应该对人体健康产生影响,因为任何农药在可以使用前必须经过一个包括科学的风险评估在内的农药登记管理程序的评审。最大残留限量(MRLs)是指在优良农业措施(GAP)下使用某农药可能产生的在食物中的最高残留浓度(单位为mg/kg,指每千克商品中残留农药的毫克数),其数值必须是毒理学上可以接受的。MRLs的主要作用是来检验食品生产过程是否严格执行GAP,以及帮助经农药处理的农产品在国际贸易中正常进行进出口活动。MRLs不是一个绝对的安全限量,即接触残留超标的食品并不一定肯定意味着对健康有危害。但是MRLs也经常作为食品安全管理的第一道防线,成为保障人类健康最初级的预警机制。MRLs是各国政府和联合国食品法典委员会设定的,这些设定的标准被应用于国际贸易中。     

Experimental deepwater culture of the Sydney rock oyster (Saccostrea commercialis). VI. Commercial oyster cage systems

A growout cage that retains oysters, excludes predators and reduces maintenance is described; it is cut from 200 mm (8 in) steel reinforcing mesh as kitset units and then hot dip galvanised. Each cage is 2.2 m long, 0.8 m wide and 1.0 m deep (88 × 22 × 40 in) and contains five floors which are 203 mm (8 in) apart. The floors and the walls are covered with 19 mm ($\text{3}\text{4}$ in) galvanised wire mesh, or high density polyethylene plastic mesh. These cages may be slung from rafts, fitted with individual flotation or lowered to the bottom with a marker buoy; they weigh approximately 70 kg (154 lb) empty and about 220 kg (484 lb) when harvested. Each cage crop consists of approximately 2.5 bags totalling about 150 kg (330 lb), and in good growing areas three to four crops have been harvested from each cage per year. In two such crops culled spat (22–29 g whole wet weight) were converted to plate (first grade) oysters (40–67 g); in the other two, seconds (29–40 g) were converted to plate oysters. Growth rates, stocking densities and mortality data are given for 11 crops.     

Impact of geochemical composition of diatomaceous earth on its insecticidal activity against adults of <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> (L.) (Coleoptera: Curculionidae)

Laboratory experiments were done to determine the effect of geochemical composition of diatomaceous earth (DE) on insecticidal activity of DE against adults of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae). Samples of DE were mined from DE-deposits in Slovenia, Greece, and Serbia. In addition, a commercially available DE formulation (SilicoSec^®) was used in the tests and served as a positive control. The bioassays were carried out at temperatures 20, 25, and 30°C, relative humidity levels of 55 and 75%, and at application rates of 100, 300, 500, and 900 ppm. Adult mortality was recorded after 7, 14, and 21 days of exposure. Prior to bioassays with S. oryzae, the geochemical composition of all DEs that were used in the tests was determined by whole rock ICP geochemical analyses. Silica (in the form of SiO₂ or opal-A) was the DE ingredient that was significantly correlated with efficacy in most of the bioassays. Some weak positive correlation was observed between S. oryzae mortality and MnO or CaO content. All significant correlations between mortality and Al₂O₃, Fe₂O_3, K₂O, TiO₂, Cr₂O₃, P₂O₅, and MgO content were negative, while correlation between Na₂O content and mortality was generally not significant.