4,587 research outputs found
Preen Gland-Secreted Alkanols Enhance Male Attractiveness in Parrots
The skin glands are widely used in pheromone production throughout the vertebrate worlds. Growing evidences show that birds also have chemical communication, but the uropygial (also called preen or oil) glands, serving as only specialized skin glands of birds, have no sex pheromones characterized. Here, by combining GC-MS analysis and bioassay, we show with the budgerigar, Melopsittacus undulatus, that birds can used the preen gland-secreted volatiles (a blend of octadecanol, nonadecanol and eicosanol for male budgerigars) spread over body plumage when preening to convey sex information. Here, we first report the avian pheromones derived from the uropyginal gland and suggests that the gland has broader implications than previously known (e.g. plumage waterproofing and reflectance in sexual behaviour of birds
Effect of Taoren-Quyu decoction on endometriosis in rats
Purpose: To study the effect of traditional Chinese Medicine formula Taoren-Quyu decoction (TQD) on endometriosis.
Method: Fifty female Wistar rats were randomly separated into five groups (10 rats/group): normal control, model (untreated) group, positive control (danazol), 200 mg/kg/day (low dose) or 400 mg/kg/day (high dose). All rats were prepared into endometriosis except for normal control rats. TDQ groups rats were orally administered of TQD for 5 weeks. After treatment, the rats were sacrificed by cervical dislocation. The number of total endometriotic lesions were counted. Serum levels of cancer antigen 125 (CA-125), interleukin 13 (IL-13), interleukin 18 (IL-18) and peritoneal fluid tumor necrosis factoralpha (TNF-α) were measured by ELISA kits.
Result: Compared with control rats, TQD reduced the number of total endometriotic lesions significantly (12.7 ± 1.2, p < 0.01), as well as serum levels of CA-125 (6.4 ± 1.2 U/mL), IL-18 (118.6 ± 7.4 pg/mL), IL13 (6.3 ± 0.8 pg/mL) and peritoneal fluid TNF-α (231.5 ± 11.7 pg/mL) (p < 0.01).
Conclusion: The results reveal that TQD exerts anti-endometriotic effect in rats by inhibiting inflammatory factors. Therefore, TQD has potentials for use in the treatment of endometriosis
Learning from Biosilica: Nanostructured Silicas and Their Coatings on Substrates by Programmable Approaches
Numerical optimization and analysis on vibration characteristics of bicycles based on the novel CA-PSO algorithm
Regarding the published researches on bicycles, they fail to design fatigue characteristics of the bicycle. In addition, dynamics and fatigue characteristics are not further improved by using advanced optimization algorithms. Aiming at these questions, this paper tries to optimize dynamics and fatigue characteristics of the bicycle through combining finite element model with advanced algorithms. The advanced algorithm applies ideas of cellular automation (CA) to Particle Swarm Optimization (PSO), and then a hybrid CA-PSO algorithm is proposed. Moreover, the finite element model is also validated by experimental test. Computational results show that: the maximum stress of bicycles is mainly distributed on the frame, especially on joints of different round pipes at different moments mainly because a dead corner is at the joint, and the dead corner can easily cause stress concentration. Under alternating forces, the stress concentration at joints will cause fatigue damage. Therefore, the service life of this position will be the shortest. As a result, the dynamics and fatigue characteristics of the joint position are taken as the optimized objective. In order to verify the optimized effectiveness of the proposed CA-PSO algorithm in the paper, the widely used PSO algorithm and PSO-GA algorithm are also used to optimize the bicycle. When the traditional PSO algorithm is used to optimize the bicycle, the root-mean-square value and maximum difference of vibration accelerations are decreased by 11.9 % and 14.3 %. When the PSO-GA algorithm is used to optimize the bicycle, the root-mean-square value and maximum difference of vibration accelerations are decreased by 20.3 % and 12.9 %. When the proposed CA-PSO algorithm is used to optimize the bicycle, the root-mean-square value and maximum difference of vibration accelerations are decreased by 27.1 % and 18.6 %. Compared with other two kinds of PSO algorithms, optimized effects of vibration accelerations are very obvious. In addition, the fatigue life of the original structure is 5 years, while the fatigue life of the optimized bicycle is 7 years. Therefore, the fatigue life is improved obviously
Theory for charge and orbital density-wave states in manganite LaSrMnO
We investigate the high temperature phase of layered manganites, and
demonstrate that the charge-orbital phase transition without magnetic order in
LaSrMnO can be understood in terms of the density wave
instability. The orbital ordering is found to be induced by the nesting between
segments of Fermi surface with different orbital characters. The simultaneous
charge and orbital orderings are elaborated with a mean field theory. The
ordered orbitals are shown to be .Comment: published versio
Multi-Objective Ant Colony Algorithm in EPC Risk Control
AbstractAccording to the risks and risk control target in energy performance contracting (EPC), this paper has designed the risk control measure set. On the basis, a risk control model is put forward, including the risk evaluation, risk control cost, risk loss. Then, a multi-objective ant colony algorithm, based on Pareto theory, is used to solve the model. A series of Pareto optimal solutions are got by example. The result shows that the solutions have the better diversity and convergence. At the same time, the model can find the best combination of various risk control measures in EPC, which can provide direct evidence for the company of EPC
MULTI AGV SCHEDULING PROBLEM IN AUTOMATED CONTAINER TERMINAL
ABSTRACT In this paper we propose a dynamic multi automated guided vehicle (AGV) scheduling method based on the scheduling properties of automated container terminal handling systems. In multi-AGV scheduling, the composition of AGV handling time and the precedence order of certain tasks are major constraints. Taking these into consideration, we design a genetic algorithm (GA) for a dynamic multi-AGV scheduling model to minimize completion time and standard deviation of handling time of quay cranes (QC), and validated the proposed model through numerical experiment. We expect this model to be significant for multi-agent scheduling of discrete production systems
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