Imidazolinone herbicides: Synthesis and novel chemistry

The imidazolinone herbicides were prepared from reaction of an α- methylvaline fragment with an o-dicarboxylic acid. Early syntheses were completed through an imide amide intermediate, such as I or XV , followed by further cyclization to 2,5-diones III or XXI . Reaction of these diones with nucleophiles led to imidazolinones IV and V . The significant and interesting activity of these compounds led to new and versatile methods of synthesis, including resolution of the α-methylvaline fragments, development of a metallation-carboxylation route, a one-step picoline to imidazolinone route, and several pyridine and fused-ring pyridine syntheses.     

Permethrin treatments in canadian forests. Part 1: Impact on stream fish

The effects of permethrin on native and caged fish when aerially applied directly to forest streams at dosages between 8.8 and 70 g ha^?1 were studied between 1976 and 1981. None of the applications caused mortality of caged or native fish in streams. Trout and salmon diets were altered by the treatments due to effects on fish food organisms. The duration of the effects varied from several months to over a year with increasing dosage. Reductions in salmonid growth rates and reductions in fish densities in treated areas, presumably due to emigration, were documented following severe impacts on aquatic invertebrates in salmon nursery streams. Growth rates and population densities both recovered within four months after treatment.     

Permethrin treatments in canadian forests. Part 2: Impact on stream invertebrates

A series of experiments was conducted between 1977 and 1981 to evaluate the effects of aerially applied permethrin on forest stream invertebrates. All permethrin applications to forest streams resulted in large drift increases, and most produced measurable reductions in benthos density. Recovery of benthic fauna following the various permethrin applications was apparent from 1 to 18 months post-spray. In double-application experiments, the second treatments reduced benthos density to a point at which recovery of numbers was slower than after the impact resulting from a single application of the same dosage.     

Modelling the microbial breakdown of pesticides in soil using a parameter estimation technique

Results of field measurements and laboratory experiments were used to simulate the behaviour of 1,3-dichloropropene (1,3-D) in a loamy sand soil. Microbial activity was described using pre-set conditions to compute transformation rates as dependent on compound concentrations and temperature. These kinetics could only be analysed using non-linear transformation rates. To link the development of microbial populations and the consumption of the compound over time, an iterative technique was used to estimate the necessary parameters.     

The transmission of geminiviruses by Bemisia tabaci

The cosmopolitan whitefly species, Bemisia tabaci (Gennadius) and Trialeurodes taporariorum (Westwood) have always been regarded as pests to a large range of worldwide crops. Both species are capable of transmitting plant viruses, with T. vaporariorum being the vector of only a few ‘clostero’-like viruses and B. tabaci the vector of viruses in several groups. The largest group of viruses transmitted by B. tabaci are the geminiviruses and B. tabaci is known to transmit around 60 members. Until recently, B. tabaci had been associated with only a limited range of host plants within any one region, although its total potential host range was large. Virus transmission was confined within the plant host range of each regional population of B. tabaci. The emergence of the polyphagous ‘B’ biotype of B. tabaci with its increased host range of more than 600 plant species, has resulted in geminiviruses infecting previously unaffected crops. As the ‘B’ biotype spreads further into Europe, European field and glasshouse crops have been shown to be susceptible to whitefly-transmitted viruses already endemic to other parts of the world. More than 20 colonies of B. tabaci, including both ‘B’ and non-‘B’ biotypes from disparate global locations have been compared for their ability to transmit more than 20 geminiviruses. All but two highly host-specific colonies were capable of transmitting most geminiviruses tested. However, some viruses were transmitted more efficiently than others. The virus coat protein or capsid is essential for vector recognition and transmission. By comparing transmissible viruses at the molecular level to viruses that are no longer whitefly-transmissible, the active epitope on the virus coat protein could be identified for designing future virus control strategies.     

Production of ex vivo lipopolysaccharide-induced tumor necrosis factor-α, interleukin-1β, and interleukin-6 is suppressed by trans-resveratrol in a concentration-dependent manner

Trans-resveratrol is a biologically active compound present in certain foods that has anti-inflammatory and anticancer properties. These beneficial effects are derived from both the immune system and cytokines. The purpose of this study was to determine the immunomodulatory effect of trans-resveratrol on the ex vivo production of inflammatory and anti-inflammatory cytokines stimulated by lipopolysaccharides (LPS). Trans-resveratrol (0, 0.01, 0.1, 1, and 10 microM) was added to blood samples from male Sprague-Dawley rats (n = 6) along with 100 U of LPS (Escherichia coli serotype, 055B5). The samples were then incubated for 4 h at 37 degrees C and centrifuged. Finally, concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in the plasma were analyzed using an enzyme-linked immunosorbent assay (ELISA). The production of inflammatory (TNF-alpha and IL-1beta) and anti-inflammatory (IL-6) cytokines was suppressed by trans-resveratrol in a concentration-dependent manner. These results support the hypothesis that the immunomodulatory effect of trans-resveratrol plays an important role in disease conditions that involve an overproduction of inflammatory cytokines.     

Vitamin D status of wild Ricord's iguanas (Cyclura ricordii) and captive and wild rhinoceros iguanas (Cyclura cornuta cornuta) in the Dominican Republic.

Calcidiol (25-hydroxyvitamin D) values are reported for 22 wild Ricord's iguanas (Cyclura ricordii) and seven wild rhinoceros iguanas (Cyclura cornuta cornuta). Calcitriol (1,25-hydroxyvitamin D) values are reported for 12 wild Ricord's iguanas and seven wild rhinoceros iguanas. These animals were captured as part of a larger health assessment study being conducted on Ricord's iguanas in Isla Cabritos National Park, Dominican Republic. A total of 13 captive rhinoceros iguanas held outdoors at Parque Zoológico Nacional were also sampled for comparison. Mean concentrations of 25-hydroxyvitamin D were 554 nmol/L (222 ng/ml) with a range of 250-1,118 nmol/L (100-448 ng/ml) for wild Ricord's iguanas, 332 nmol/L (133 ng/ml) with a range of 260-369 nmol/L (104-148 ng/ml) for wild rhinoceros iguanas, and 317 nmol/L (127 ng/ml) with a range of 220-519 nmol/L (88-208 ng/ml) for captive rhinoceros iguanas. On the basis of these results, serum concentrations of at least 325 nmol/L (130 ng/ml) for 25-hydroxyvitamin D should be considered normal for healthy Ricord's and rhinoceros iguanas.     

增强肠道防御功能-糖原组学在优化肠道健康中的作用

肠道健康对于幼畜和生长动物发挥最佳的生产性能是至关重要的.试验研究表明,腹泻是幼畜的主要疾病.引起动物肠道疾病的病原微生物包括细菌、病毒和球虫感染,大肠杆菌和梭菌是主要的细菌性病原体.犊牛的消化道疾病的高峰期一般在10日龄左右,仔猪的最关键时期是5～14日龄的哺乳期和断奶期.腹泻是影响畜禽生产性能的主要疾病.腹泻会影响动物的增重、降低饲料转化率、提高动物的死亡率和用药成本.此外,腹泻还会降低畜群的均匀度和市场价值、增加生产成本,对畜禽养殖业造成巨大的经济损失.