The life cycle of Diploproctodaeum arothroni Bray and Nahhas, 1998 (Digenea: Lepocreadiidae), with a comment on the parasitic castration of its molluscan intermediate host

Diploproctodaeum arothroni Bray and Nahhas, 1998 Bray, R. A. and Nahhas, F. M. 1998. Diploproctodaeum arothroni n. sp. (Digenea: Lepocreadiidae) from the pufferfish Arthron hispidus (Tetraodontidae) from Suva, Fiji, with a revised key to the species of the genus.. Systematic Parasitology, 40: 55–59. [Crossref] , [Google Scholar] (Digenea: Lepocreadiidae) was found in the intestine of its type‐host, Arothron hispidus, a tetraodontid fish permanently resident in a lagoon within the mangrove swamps on the Egyptian coast of the Gulf of Aqaba. Larval forms of this trematode (sporocysts, rediae, and cercariae) were found in the gonads and digestive gland of Crassostrea cuccullata (Ostreidae), a common oyster in the same lagoon. So, the life cycle of D. arothroni is elucidated under natural conditions; eggs are directly ingested by the oyster; mother sporocysts and rediae reach their maturity 3–5 and 9–11 weeks after infection; rediae contain 18–25 developing cercariae; fully mature cercariae are trichocercous, without penetration glands, emerge from the oyster during the night 14–15 weeks after infection, their existence in seawater being very brief and transitory, and rapidly encyst on aquatic vegetation or other surfaces (there is no second intermediate host); encysted metacercaria are not progenetic; 4‐day‐old metacercariae encysted on filamentous algae fed to A. hispidus developed into fully mature worms 8–9 weeks after infection. This cycle is completed in about 24 weeks and has its own characteristics, which differentiate it from the other known lepocreadiid life cycles. All of the developmental stages are figured and described. Parasitic castration in the females of C. cuccullata caused by the parasite was studied histologically and is described and discussed.     

三维边界元寄生参数提取中的有效预条件方法

为研究集成电路中金属互连线的寄生效应对电路性能产生的影响,分析了三维边界元计算的预条件迭代求解问题,针对寄生参数提取中涉及的复杂多区域边界元计算,提出两种基于MN (mesh neighbor)方法的有效GMRES (generalized minimal residual)预条件.对大量来自实际版图提取实例的计算表明 该预条件方法使方程求解过程迅速收敛,迭代次数与求解时间比对角线逆预条件减少约30%或更多.     

南方鲶的寄生虫病及防治

报道了南方鲶的９种寄生虫病的症状、病原体、流行时间以及有效的防治药物和浓度。寄生虫病是车轮虫病、斜管虫病、小瓜虫病、固着纤毛虫病、毛管虫病、鲶盘虫病、三代虫病、绦虫病和鲺病。     

随频率变化二维集成电路互连电感电阻的快速计算

为了快速计算全频率范围内随频率变化的互连导体电感、电阻矩阵 ,提出一种二维电路模型法和边界元法结合的算法。该算法利用电路模型法得到低频下若干频率的电感、电阻值 ;利用边界元方法求解 L aplace方程计算出电容矩阵 ,求逆得到电流完全分布在导体表面时的高频电感矩阵 ;利用电阻矩阵与电感矩阵在高频情况下成立的 Wheeler公式 ,得到高频段的电阻矩阵。对上述低频和高频段的电感、电阻值 ,利用三次样条函数插值 ,得到整个频率范围的变化曲线。计算结果与已有文献的结果进行比较 ,表明该算法是准确的 ;该算法避免求解涡流边界耦合积分方程 ,与已有方法相比大大减少了计算量。该算法可应用于绝大多数大规模集成电路寄生参数提取计算     

Pœcilostomatoid copepods parasitic on fishes off the west coast of Africa

Three species of fish-parasitizing poecilostomatoid copepods are redescribed based on material collected off the coasts of Mauritania and Senegambia. They are: Bomolochus unicirrus Richiardi from Lichia glauca Linnaeus, Taeniacanthus balistae (Claus) from Balistes capriscus Gmelin, and Chondracanthus brotulae Capart from Molva molva (Linnaeus).     

Description of a new species of Asymmetrione (Isopoda: Bopyridae: Pseudioninae) infesting the hermit crab Paguristes tomentosus (Anomura: Diogenidae) from Peru,with a key to species and a review of southeastern Pacific bopyrids

A new species of bopyrid isopod is described from a host hermit crab Paguristes tomentosus collected from Pisco, Peru and assigned to the pseudionine isopod genus Asymmetrione Codreanu, Codreanu and Pike, 1965. This is the second species in the genus with less than 20° asymmetry in females, but agrees with all other species in the genus in having the characteristic “socket” on the propodus of the female's pereopods, and in all characters of the males. A key is provided to the 10 species now in Asymmetrione. New records of an Anathelges sp. from Pagurus villosus collected in central Chile are given but additional material is required to determine whether these specimens represent the eastern Pacific A. thompsoni or the western Atlantic A. hyptius. A review of all the bopyrid species known from the western South American coast, with remarks on their taxonomy and biology, is provided.     

Antennation and sexual performance of male digger wasps Sphex ingens Smith (Hymenoptera: Sphecidae)

Antennation can play several roles in hymenopteran copulation, mainly in wasps. The digger wasp Sphex ingens Smith has a very peculiar sexual behaviour, in which forced copulation is a striking element. However, communication through antennation during the pre-copulation and copulation phases and the relationship between the sexual performance of males and the final result of copulation require further clarification. The sexual behaviour of wild populations of S. ingens was filmed during the breeding season in a site between the beaches Meros and Aventureiro, Ilha Grande, southeastern Brazil. We assessed antennation behaviour, courtship duration, sexual performance, and genital clasping. Only successful males had the genital clasping assessed. Evidence found so far points out that the successful males showed better sexual performance – that is, they antennated more in a shorter courtship duration. Also, genital clasping in successful males did not depend on antennation, courtship duration, or sexual performance. Our results shed light on some aspects of the sexual behaviour of wasps, as they explain part of the sexual selection mechanisms adopted by the species.     

基于动量衰减哈密顿算法的波束形成技术研究

智能天线的非线性优化问题中求解代价函数最佳解的算法主要有基于梯度的算法(GBA)和随机搜索算法(RA).GBA算法收敛速度快,但有时会陷入一个局部最小值;RA算法不会陷入局部最小值,但收敛速度慢.研究及仿真结果表明,将哈密顿算法应用到该问题的求解中,能较好地解决GBA和RA存在的冲突问题,采用哈密顿算法的电控寄生天线,能够更灵活地使主波束对准期望用户波达方向,并在干扰方向形成更深的零陷.     

面向多目标搜索的群机器人任务分配研究

针对群机器人在多目标搜索过程中的协作分工问题,受黄蜂群劳动分工的启发,在黄蜂群的响应阈值模型中引入距离变量来解决群机器人多目标搜索中的任务分配问题。当机器人感知到目标信号时,机器人根据当前搜索该目标的机器人数量以及自身距群体最优位置之间的距离决定是否参与搜索该目标信号,从而实现了机器人之间针对搜索不同目标的任务分配。仿真结果表明,该方法有效可行。