Hunting Tactics in a Cobweb Spider (Araneae-Theridiidae) and the Evolution of Behavioral Plasticity

Although behavior is being gradually incorporated into phylogenetic studies, the understanding of the evolution of one of its main characteristics, plasticity or adjustment to environmental features, is still a challenge, mainly due to the lack of comparative data. In this paper we focus on the plasticity of the predatory repertoire of Achaearanea digitus, analyzing its responses to two prey types, and discuss the evolution of behavioral plasticity based on a comparison to the foraging repertoire of other araneoid sheetweavers and on a review of hunting tactics among the larger group of orbweavers. Contrasting with what was observed for other families, spiders of the family Theridiidae (among them A. digitus) show a small set of attack tactics, and a quite stereotyped predatory performance. These spiders regularly attack their prey with a typical sticky silk wrapping tactic, but fail to use other tactics such as bite–wrap or bite–pull out prey, which are commonly used in other spider families. We show that this stereotypy is typical of the foraging repertoire of araneoid sheetweavers. Plotting the mean size of the attack tactics repertoire on the phylogeny of Orbiculariae shows that high predatory stereotypy is a plesiomorphy of the whole araneoidea group, and that evolutionary increases in plasticity occur independently two times in the group, among Araneidae and Nephilidae. The maintenance of a plesiomorphic, stereotyped predatory behavior among theridiids is probably due to the evolution of a special behavioral technique, which includes the simultaneous use of the fourth legs during wrapping attacks. Since the individuals in the species of this group of sheetweavers face less variable environments than do orbweavers, they should indeed evolve more stereotyped phenotypes, but nevertheless their evolved predatory stereotypy contrasts with plasticity in other aspects of their foraging behavior (web building). Since, in this case, both stereotypy and plasticity result from a simplification in the mechanisms underlying behavioral expression, we suggest that less variable environments select not exactly for behavioral stereotypy, but rather to the simplification of these information processing mechanisms.

Chemical Composition and Behavioral Effects of Five Plant Essential Oils on the Green Pea Aphid Acyrthosiphon pisum (Harris) (Homoptera: Aphididae)

Essential oils (EOs) from Schinus molle, Helichrysum gymnocephalum, Cedrelopsis grevei and Melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. EOs were characterized by gas chromatography/mass spectrometry (GC/MS) and quantified by gas chromatography‐flame ionization detection (GC‐FID); then evaluated for their behavioral effects on adults of the green pea aphid Acyrthosiphon pisum (Harris ) using a Perspex four‐armed olfactometer in order to test the compatibility of their use as phytoinsecticides to control this insect pest. Our results showed that the EOs from the leaves of S. molle, M. viridiflora and C. grevei did not change aphids’ behavior. However, S. molle fruits EO seemed to be attractive while H. gymnocephalum leaves EO exhibited repellency towards aphids at a dose of 10 μl. The major compounds in S. molle fruits EO were 6‐epi‐shyobunol (16.22%) and d ‐limonene (15.35%). While, in H. gymnocephalum leaves EO, 1,8‐cineole was the main compound (47.4%). The difference in aphids’ responses to these two EOs could be attributed to the differences in their compositions. Our findings suggest that these two EOs have potential applications for the integrated pest management of A. pisum (Harris ).     

慢性阻塞性肺疾病发病机制的研究进展

慢性阻塞性肺疾病(chronic obstructive pulmonary disease, COPD)是呼吸系统中的常见病和多发病,其发病率和致死率居高不下。根据WHO调查数据显示,预计到2020年, COPD将成为全球第三大致死病因。COPD的形成与发展涉及众多因素,包括遗传因素和环境因素等。COPD的发病机制至今未明,氧化应激、炎症机制、蛋白酶/抗蛋白酶失衡以及细胞凋亡与之密切相关。另外,自身免疫反应、微生物组的变化以及无效的受损修复在COPD的发病机制中同样具有关键作用。因此,深入了解并研究COPD的发病机制对预防与治疗该疾病具有重要意义。     

Orthotopic Aortic Transplantation in Mice for the Study of Vascular Disease

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. This is largely true, but there are a number of important principles that can reduce the difficulty of these procedures and enhance reproducibility. Orthotopic aortic transplantation is an excellent procedure in which to learn these principles because it involves only two end-to-end anastomoses, but requires good suturing technique and handling of the vessels for consistent success. This procedure begins with the procurement of a length of abdominal aorta from a donor animal, followed by division of the native aorta in the recipient. The procured aorta is then placed between the divided ends of the recipient aorta and sutured into place using end-to-end anastomoses. To accomplish this objective successfully requires a high degree of concentration, good tools, a steady hand, and an appreciation of how easily the vasculature of a mouse can be damaged, resulting in thrombosis. Learning these important principles is what occupies most of the beginner''s time when learning microsurgery in small rodents. Throughout this protocol, we refer to these important points. This model can be used to study vascular disease in a variety of different experimental systems^1-8. In the context shown here, it is most often used for the study of post-transplant vascular disease, a common long-term complication of solid organ transplantation in which intimal hyperplasia occurs within the allograft. The primary advantage of the model is that it facilitates quantitative morphometric analyses and the transplanted vessel lies contiguous to the endogenous vessel, which can serve as an additional control⁹. The technique shown here is most often used for mice weighing 18-25 grams. We have accumulated most of our experience using the C57BL/6J, BALB/cJ, and C3H/HeJ strains.     

Diagnostic Values of Intraoperative (1-84) Parathyroid Hormone Levels are Superior to Intact Parathyroid Hormone for Successful Parathyroidectomy in Patients With Chronic Kidney Disease

ObjectivePersistent secondary hyperparathyroidism (SHPT) may occur because of residual cervicothoracic parathyroids in parathyroidectomy (PTX) patients with chronic kidney disease. We prospectively compared the predictive values of intraoperative plasma (1-84) parathyroid hormone (PTH) and intact PTH (iPTH) levels to improve the safety and efficacy of PTX.MethodsWe included 100 healthy controls, 162 stage 5 chronic kidney disease patients without SHPT, and 214 patients who underwent PTX because of SHPT. Plasma iPTH and (1-84) PTH levels were measured before incision (io-iPTH0 and io-[1-84]PTH0, respectively) and 10 minutes (io-iPTH10 and io-[1-84]PTH10, respectively) and 20 minutes (io-iPTH20 and io-[1-84]PTH20, respectively) after removing all parathyroids. The percentage reduction of iPTH and (1-84) PTH at 10 minutes (io-iPTH10% and io-[1-84]PTH10%, respectively) and 20 minutes (io-iPTH20%, and io-[1-84]PTH20%, respectively) was calculated. iPTH and (1-84) PTH were measured using second- and third-generation PTH assays, respectively.ResultsCompared with the controls and non-PTX patients, the PTX group had more obvious mineral metabolism disorders. There were 187 successful PTXs, 19 patients with persistent SHPT, and 8 patients lost to follow-up. The receiver operating characteristic curves revealed that io-(1-84)PTH10% >86.6% and io-(1-84)PTH20% >87.5% suggested successful PTX. The sensitivity of io-iPTH20% and io-(1-84)PTH20% were higher than those at the timepoint of 10 minutes. Moreover, the specificity and sensitivity of the (1-84) PTH reduction percentage were superior to that of iPTH.ConclusionIntraoperative reduction percentages of plasma (1-84) PTH levels are superior to iPTH for accurately predicting successful PTX, especially at 20 minutes after all cervicothoracic parathyroids had been resected.