Beaver dams,streamflow complexity,and the distribution of a rare minnow,Lepidomeda copei

Freshwater fishes are threatened globally, and often too little is known about threatened species to effectively guide their conservation. Habitat complexity is linked to fish species diversity and persistence, and degraded streams often lack habitat complexity. Beaver Castor spp., in turn, have been used to restore streams and increase habitat complexity. The northern leatherside chub Lepidomeda copei is a rare, small‐bodied, drift‐feeding minnow that has anecdotally been observed to use complex habitats associated with beaver dams in the western United States. To investigate this anecdote, we conducted fish and habitat surveys, the latter focusing on quantifying habitat complexity, in a sub‐basin of the Upper Snake River Basin in the USA. Complementary generalised linear model and path analyses revealed that northern leatherside chub occurred more often at sites with complex streamflows, and streamflows were more complex when beaver dams were present and pools were deeper. Northern leatherside chubs were also more likely to occur when temperatures were warmer, aquatic macrophytes were abundant and stream channels were narrow and deep. The linkage between chubs, complex streamflows and beaver dams needs to be evaluated more broadly to completely understand its role in the rangewide status of the species. However, it does suggests that increased use of beaver reintroductions and dam analogues for stream restoration could be a boon for the northern leatherside chub, but such efforts should be monitored to determine their effectiveness to help adapt beaver‐based restoration approaches to best benefit the species.     

保幼激素类似物对红火蚁的作用研究进展

我国发现红火蚁已有4年,但防治技术、产品依然匮乏。为了改善、提高我国红火蚁的防治技术水平,本文就保幼激素类似物(JHA)对红火蚁的作用表现和防治效果进行了总结分析。JHA可以造成蚁后卵巢萎缩、产卵量减少,导致发育畸形和蚁群等级比例失调,如工蚁数量减少、生殖型幼虫比例以及处女蚁后数量增加等,并最终导致整个蚁群死亡。JHA杀虫剂活性高、低残毒、对环境污染小,在田间防治红火蚁效果彻底,并可有效地防止防治区红火蚁种群的再入侵（re invasion）,但JHA毒饵也存在着防治效果缓慢等问题。本文就克服此类问题作了初步的探讨。     

砂地柏杀虫作用研究概况

概述了杀虫植物砂地柏 (Sabina vulgaris Ant.)中杀虫活性物质的化学特性、活性强度、作用方式、作用机理、构效关系及应用等方面的研究情况及进展。通过对砂地柏杀虫作用研究结果的总结和分析 ,为其开发和实际应用研究提供依据     

鬼臼毒素类似物结构与杀虫活性关系初探Ⅱ.构效关系分析及理想结构推测

以鬼臼毒素为原料合成了一系列衍生物。用质谱和核磁共振鉴定这些化合物的结构和构型 ,测定了其对 5龄菜青虫 (Pierisrapae)、3龄小菜蛾 (Plutella xylostella)和 3龄粘虫 (Mythimna separata)的生物活性。结果表明 ,具反式内酯环的鬼臼衍生物活性显著高于具顺式内酯环的衍生物 ,4位取代基对杀虫活性影响较大 ;推测出了较为理想的鬼臼毒素类似物杀虫活性物质的结构通式。     

Protective effect of curcumin analogue L6H4 on diaphragm of type 2 diabetic rats

AIM: To investigate the protective effect of curcumin analogue L6H4 on diaphragm of type 2 diabetic rats.METHODS: SPF male Sprague-Dawley rats (n=40) were randomly divided into 5 groups: normal control (NC) group, high fat (HF) group, high fat+L6H4 treatment (FT) group, diabetes mellitus (DM) group and DM+L6H4 treatment (DT) group. The rats in the later 4 groups were fed with high-fat diet. After 4 weeks of high-fat diet fee-ding, the rats in DM and DT groups were intraperitoneally injected with streptozotocin to induce type 2 diabetes melliutus. The rats in FT and DT groups were given L6H4 by gavage for 8 weeks. Blood glucose and blood lipid levels were detected biochemically. Fasting serum insulin (FINS) level was measured by radioimmunoassay and insulin resistance index (HOMA-IR) was calculated. Serum adiponectin (APN) level was measured by ELISA. The morphological changes of the diaphragm were observed under light and transmission electron microscopes. Lipid deposition and the activity of succinate dehydrogenase (SDH) and NADH-tetrazolium reductase (NADH-TR) were observed by enzyme histochemical staining. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the diaphragm were measured by thiobarbituric acid method and hydroxylamine method, respectively. The protein expression of adiponectin receptor 1 (AdipoR1) in the diaphragm was determined by immunohistochemistry and Western blot. RESULTS: The levels of blood lipids, blood glucose, FINS and HOMA-IR in HF and DM groups were higher than those in NC group, but decreased after L6H4 treatment. The serum APN level in HF and DM groups was lower than that in NC group, but increased after treatment with L6H4. The muscle fibers of the diaphragm were shrunk, fat particles accumulated in the muscle fibers, and the mitochondria were slightly swollen in HF and DM groups. The diaphragmatic fibrosis was obvious in DM group. These lesions were relieved after L6H4 treatment. Compared with NC group, the level of MDA and the activity of SDH and NADH-TR in the diaphragm were increased in HF and DM groups, but decreased after treatment with L6H4. The activity of SOD and the expression of AdipoR1 in the diaphragm were lower than those in NC group, but increased after L6H4 treatment.CONCLUSION: The curcumin analogue L6H4 exerts a protective effect on diaphragm in type 2 diabetic rats. The strengthened protein expression of AdipoR1, the increased serum level of APN, and anti-lipid peroxidation may be involved in the process.     

Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N-acetylglucosamine incorporation in a cultured integument system by substituted N-tert-butyl-N,N′-dibenzoylhydrazines

The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.     

鬼臼毒素和脱氧鬼臼毒素抑菌和除草活性初探

以小麦赤霉病菌(Fusarium graminearum Schw)、辣椒疫霉病菌(Phytophthora capsici Leon.)、番茄灰霉病菌(Botrytis cirerea Pers.)、油菜菌核病菌(Sclerotinia sclerotiorum(Lib.)de Bary)、白菜黑斑病菌(Alternaria brassicae(Berk.)Sacc)、番茄叶霉病菌(Fulria fulva(cooke)Ciferri)为供试菌种,并以反枝苋(Amaranthus retroflexus)、紫花苜蓿(Medicagos sativa)、野燕麦(Avena fatua)、婆婆纳(Veronicapersica)、番茄(Lycopersicon escuientum)等5种作物种子为供试对象,分别采用生长速率法和种子萌发法,初步测试了鬼臼毒素和脱氧鬼臼毒素的抑菌和除草活性。结果表明,在供试浓度下,鬼臼毒素对油菜菌核、脱氧鬼臼毒素对辣椒疫霉活性最好,其抑制率分别为87.42%和85.7%;除草活性研究表明,鬼臼毒素对反枝苋和野燕麦根的抑制效果最强,抑制率分别为93.39%和86.28%,脱氧鬼臼毒素对婆婆纳、野燕麦和反枝苋根的抑制效果最强,抑制率分别为95.62%,89.46%,84.48%。鬼臼毒素和脱氧鬼臼毒素的抑菌和除草作用的研究为其作为一种新的植物源抑菌剂和除草剂的进一步开发利用提供了依据。     

桃儿七愈伤组织培养体系的建立及鬼臼毒素含量测定

本研究利用组织培养技术研究桃儿七不同外植体、不同生长调节剂浓度配比和不同蔗糖浓度对桃儿七愈伤组织生长的影响,建立桃儿七愈伤组织增殖培养技术体系,同时采用高效液相色谱法测定桃儿七愈伤组织中鬼臼毒素含量。结果表明,桃儿七愈伤组织诱导的最佳外植体是叶柄;愈伤组织的最佳增殖培养基为Ms+ NAA0.5 mg/L + TDZ0.1mg/L + 6-BA1.0mg/L,碳源蔗糖浓度为40.0 g/L,获得疏松颗粒状生长旺盛的愈伤组织,愈伤组织中鬼臼毒素含量为1.56%,为野生桃儿七根茎中鬼臼素素含量的68.4%。因此,可通过对桃儿七愈伤组织的培养获取鬼臼毒素。     

Synthesis of strigolactones,a strategic account

Strigolactones (SLs) constitute a new class of plant hormones that have received growing interest in recent years. They firstly became known as signalling molecules for host recognition by parasitic plants, and for symbiosis of plants with arbuscular mycorrhizal fungi. Furthermore, they are involved in numerous physiological processes in plants, such as the regulation of plant architecture and the response to abiotic factors. SLs are produced by plants in extremely low quantities, and they may be unstable during the purification process. Therefore, their total synthesis is highly relevant for confirming the structures assigned on the basis of spectroscopic and other physical data. A second important theme in SL research is the design and synthesis of SL analogues that have a simplified structure while still featuring the essential bioproperties. This review summarises the strategy and synthesis of naturally occurring SLs, and the design and synthesis of SL analogues with appreciable bioactivity. © 2015 Society of Chemical Industry     

Conus regius-Derived Conotoxins: Novel Therapeutic Opportunities from a Marine Organism

Conus regius is a marine venomous mollusk of the Conus genus that captures its prey by injecting a rich cocktail of bioactive disulfide bond rich peptides called conotoxins. These peptides selectively target a broad range of ion channels, membrane receptors, transporters, and enzymes, making them valuable pharmacological tools and potential drug leads. C. regius-derived conotoxins are particularly attractive due to their marked potency and selectivity against specific nicotinic acetylcholine receptor subtypes, whose signalling is involved in pain, cognitive disorders, drug addiction, and cancer. However, the species-specific differences in sensitivity and the low stability and bioavailability of these conotoxins limit their clinical development as novel therapeutic agents for these disorders. Here, we give an overview of the main pharmacological features of the C. regius-derived conotoxins described so far, focusing on the molecular mechanisms underlying their potential therapeutic effects. Additionally, we describe adoptable chemical engineering solutions to improve their pharmacological properties for future potential clinical translation.