Nonlinear propagation of ion-acoustic waves through the Burgers equation in weakly relativistic plasmas

The Burgers equation is obtained to study the characteristics of nonlinear propagation of ionacoustic shock, singular kink, and periodic waves in weakly relativistic plasmas containing relativistic thermal ions, nonextensive distributed electrons, Boltzmann distributed positrons, and kinematic viscosity of ions using the well-known reductive perturbation technique. This equation is solved by employing the (G'/G)-expansion method taking unperturbed positron-to-electron concentration ratio, electron-to-positron temperature ratio, strength of electrons nonextensivity, ion kinematic viscosity, and weakly relativistic streaming factor. The influences of plasma parameters on nonlinear propagation of ion-acoustic shock, periodic, and singular kink waves are displayed graphically and the relevant physical explanations are described. It is found that these parameters extensively modify the shock structures excitation. The obtained results may be useful in understanding the features of small but finite amplitude localized relativistic ion-acoustic shock waves in an unmagnetized plasma system for some astrophysical compact objects and space plasmas.     

Nonlethal sampling of DNA from critically endangered diving beetles (Coleoptera: Dytiscidae) using a single antenna

Nonlethal DNA sampling is highly desirable in molecular genetic studies of protected and endangered species. To develop a demonstrably nonlethal method of obtaining DNA from endangered diving beetles (Dytiscus sharpi sharpi Wehncke, Cybister lewisianus Sharp and Cybister brevis Aubé), we amputated the antennae of these endangered diving beetles and investigated the impact of the amputation on reproductive behaviors, egg‐laying and lifespan. Diving beetles with either one or no antennae copulated without delay and laid eggs, comparable to the pairs of intact beetles under breeding conditions. The lifespan of antennae‐amputated D. sharpi sharpi was the same as that of the intact beetles. A single antenna was sufficient to allow polymerase chain reaction (PCR) detection of a mitochondrial DNA gene, cytochrome‐c oxidase subunit I (COI), and the sequence of the COI gene could be determined directly. The PCR‐ready genomic DNA was available both in fresh antennae isolated from living beetles and in old antennae from whole beetles preserved for at least 5–6 years in pure ethanol. These results suggest that an antenna is a good sampling site for isolating genomic DNA from endangered diving beetles without sacrificing and disturbing reproductive behaviors such as mating and egg‐laying, or lifespan.     

Bacillus endospore resistance to gas dynamic heating

Aim: To develop a novel laboratory procedure for the study of shock wave‐induced damage to Bacillus endospores. Methods and Results: Bacillus atrophaeus endospores are nebulized into an aerosol, loaded into the stanford aerosol shock tube and subjected to shock waves of controlled strength. Endospores experience uniform test temperatures between 500 and 1000 K and pressures ranging from 2 to 7 atm, for a relatively short time (2–3 ms). During this process, the bioaerosol is observed using in situ laser absorption and scattering diagnostics. Additionally, shock‐treated samples are extracted for ex situ analysis including viability plating, flow cytometry and SEM imaging. Measurements indicate that endospores lose the ability to form colonies when heated to test temperatures above 500 K while significant breakdown in morphology is observed at test temperatures above 750 K. Conclusion: These results demonstrate the disruption of essential biochemical pathways or biomolecules prior to the onset of significant endospore morphological deterioration. Significance and Impact of the Study: This novel laboratory approach to study the interaction of endospores with shock waves provides an experimental means to investigate the mechanisms of endospore resistance to rapid heating. In addition, this methodology allows for the direct simulation of a blast wave–bioaerosol interaction in an atmospheric environment.     

External morphology of antennae and their sense organs in the roach Gromphadorhina brunneri (Blattoidea: Dictyoptera)

The antennae and their sense organs in nymphs and adult roaches of Gromphadorhina brunneri, were investigated and described. The number of segments and sensillae of the nymphal antennae depend on the developmental stage. Sexual dimorphism is pronounced. Males have longer antennae than females as well as an abundance of especially long sensory hairs (long wavy hairs), which are probably responsible for the perception of female sex pheromones. They also have more thin-walled sensory hairs, for instance, sensilla trichodea. On a morphological basis the sensillae of Gromphadorhina brunneri, were named and classified. Long wavy hairs and large sensory hairs appear to be present also in a related species, G. portentosa, but are lacking in others. Their distribution on the antennae varies greatly from that in G. portentosa but their structure varies only slightly. These two types of sense organs are considered to be specialized forms of sensilla chaetica. They are contact chemoreceptors, as are two other types of sensilla chaetica. Furthermore, thin-walled chemoreceptors are present, such as sensilla trichodea, sensilla basiconica, sensilla coeloconica and a typical mechanoreceptor, the sensillum campaniformium.     

Shock Wave Application to Cell Cultures

Shock waves nowadays are well known for their regenerative effects. Basic research findings showed that shock waves do cause a biological stimulus to target cells or tissue without any subsequent damage. Therefore, in vitro experiments are of increasing interest. Various methods of applying shock waves onto cell cultures have been described. In general, all existing models focus on how to best apply shock waves onto cells.However, this question remains: What happens to the waves after passing the cell culture? The difference of the acoustic impedance of the cell culture medium and the ambient air is that high, that more than 99% of shock waves get reflected! We therefore developed a model that mainly consists of a Plexiglas built container that allows the waves to propagate in water after passing the cell culture. This avoids cavitation effects as well as reflection of the waves that would otherwise disturb upcoming ones. With this model we are able to mimic in vivo conditions and thereby gain more and more knowledge about how the physical stimulus of shock waves gets translated into a biological cell signal (“mechanotransduction").     

Sexual dimorphism and allometry in two seed beetles (Coleoptera: Bruchidae)

Male Callosobruchus chinensis (Coleoptera: Bruchidae) have elaborated, pectinate antennae, which are absent from conspecific females and both sexes of a congener, Callosobruchus maculatus. To begin to unravel the mechanisms producing this striking dimorphism, we examined which morphological traits best explain body size variation in bruchid beetles and quantified sexual dimorphism of antenna size through allometric analyses. Using principal component analyses, we found that elytron length and pronotum width were significantly correlated with the first principal component, which was interpreted as explaining variation in body size. Regressions of log‐transformed body size measures on log‐transformed antenna length revealed that males of both species had longer antennae than conspecific females for any given body size, although most of this effect was attributable to higher intercepts, rather than increased allometry, in males. Comparisons among heterospecific males revealed that C. maculatus males have noticeably longer antennae than C. chinensis males at large body sizes. Callosobruchus chinensis males, thus, appear to have increased the receptive area of their antennae by adding to the width of, rather than further elongating, their antennae. Finally, we found evidence for positive allometry between log‐transformed antenna length and log‐transformed antenna width in C. chinensis males. We discuss our results in the context of evidence supporting the presence of an additional, and potentially unique, sex pheromone in C. chinensis females.     

六斑月瓢虫触角及感觉器扫描电镜观察

[目的] 明确六斑月瓢虫雌雄成虫触角感觉器种类、分布及形态特征。[方法] 利用扫描电子显微镜对六斑月瓢虫雌、雄成虫触角形态及触角感受器超微结构进行观察。[结果] 六斑月瓢虫成虫触角由柄节、梗节和鞭节组成,柄节长度与宽度显著大于梗节长度与宽度;鞭节分为9个亚节,末端3节横向膨大呈锤状。雌雄成虫触角上共有8种感觉器:刺形感觉器(SC)、毛形感觉器(ST)、锥形感觉器(SB)、腔形感觉器(CaS)、钟形感觉器(CS)、哑铃形感觉器(DS)、香肠形感觉器(SS)及B?hm氏鬃毛感觉器(BB)。以毛形感觉器和刺形感觉器分布最广,遍布触角;B?hm氏鬃毛仅存在于触角柄节与梗节;触角鞭节第9亚节顶端密布7种触角感觉器。六斑月瓢虫雌雄成虫触角长度、触角感觉器类型及分布无显著差异。[结论] 六斑月瓢虫成虫触角上共有8种感觉器,其触角可能具有感知机械刺激、识别化学信息素及感受温湿度变化的作用。本研究为进一步了解六斑月瓢虫触角与其行为间的关系提供基础资料。     

Stingless Bee Antennae: A Magnetic Sensory Organ?

Magnetic material in the body parts of the stingless bee Schwarziana quadripunctata, heads, pairs of antennae, thorax and abdomens, were investigated by SQUID magnetometry and Ferromagnetic Resonance (FMR). The saturation, J_s and remanent, J_r, magnetizations and coercive field H_c are determined from the hysteresis curves. From H_c and J_r/J_s the magnetic particle sizes are estimated. The J_s and the FMR spectral absorption areas yield 23±3%, 45±5%, 15±2% and 19±4% magnetic material contributions of head, pair of antennae, thorax and abdomen, respectively, similar to those observed in the migratory ant Pachycondyla marginata. This result is discussed in light of the hypothesis of antennae as a magnetosensor structure.     

Extension of Bacillus endospore gas dynamic heating studies to multiple species and test conditions

Aims: Shock wave–induced damage to a variety of Bacillus endospore species is studied for a wide range of postshock temperatures and test times in oxidative and non‐oxidative gas environments. Methods and Results: Bacillus atrophaeus and Bacillus subtilis endospores are nebulized into an aqueous aerosol, loaded into the Stanford aerosol shock tube (SAST) and subjected to shock waves of controlled strength. Endospores experience uniform test temperatures between 500 and 1000 K and pressures ranging from 2 to 7 atm, for either a short test time (～2·5 ms) or a relatively long test time (～45 ms). During this process, the bioaerosol is observed using in situ laser absorption and scattering diagnostics. Additionally, shock‐treated samples are extracted for ex situ analysis including viability plating and flow cytometry. For short test times, results are consistent with previous studies; all endospore species begin to lose the ability to form colonies when shock‐heated to temperatures above 500 K, while significant breakdown in morphology is observed for postshock temperatures above 700 K. Oxidative bath gases did not affect viability losses or morphological breakdown rates. Experiments with extended postshock test time showed increased viability loss with minimal morphological damage for shocks between 600 and 700 K. Conclusions: Genetic differences between B. subtilis and B. atrophaeus endospores do not confer noticeable gains in resistance to shock heating. Oxidative environments do not exacerbate shock‐induced damage to endospores. Extended test time experiments reinforce our hypothesis that a temperature/time‐dependent inactivation mechanism that does not involve morphological breakdown exists at low‐to‐moderate postshock temperatures. Significance and Impact of the Study: The methodology and experiments described in this paper extend the study of the interactions of endospores with shock/blast waves to new species and environmental conditions.     

Taphonomy and diagenesis in diatom assemblages; a Late Pleistocene palaeoecological study from Lake Magadi,Kenya

During these investigations the following species of Anostraca have been found: Chirocephalus diaphanus Prevost 1803, Chirocephalus brevipalpis (Orghidan, 1953), Streptocephalus torvicornis Waga 1892, Branchipus serbicus Marinek & Petrov 1988, Branchipus stagnalis L. (1758) and Branchipus sp. Thus, the total number of species discovered in Yugoslavia is 13.The shape of the frontal shield and the degree of flexure of the distal articles of antennae II in males are of no relevance to taxonomy in the genus Branchipus Schaeffer 1776. However, the apophyses on antennae II in males, shape of antennae II and of the ovisac in females, structure of eggs, and of appendages appear species-specific. We conclude that the differentiation of B. stagnalis into two forms (forma typica and forma visnyai) as well as the separation of B. visnyai Kertész 1956 as a distinct species are unfounded.     

DIFFERENTIAL PROTEOME ANALYSIS OF THE MALE AND FEMALE ANTENNAE FROM Holotrichia parallela

To understand the olfactory mechanisms of Holotrichia parallela antennae in detecting volatile compounds in the environment, protein profiles of H. parallela antennae were analyzed using two‐dimensional electrophoresis followed by mass spectrometry and bioinformatics analyses. Approximately 1,100 protein spots in silver staining gel were detected. Quantitative image analysis revealed that in total 47 protein spots showed significant changes in different genders of adult antennae. Thirty‐five differentially expressed proteins were identified by Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF/TOF) tandem mass spectrometer, among which 65.7% are involved in carbohydrate and energy metabolism, antioxidant system, transport, and amino acid/nucleotide metabolism. Some proteins identified here have not been reported previously in insect antennae. Identified male‐biased proteins included odorant‐binding protein 4, pheromone‐binding protein‐related protein 2, odorant‐binding protein 14, prophenoloxidase‐I, acyl‐CoA dehydrogenase, aldo‐keto reductase‐like, carbamoyl phosphate synthetase, etc. whereas some proteins are female biased, such as antennae‐rich cytochrome P450, aldehyde dehydrogenase, and putative glutamine synthetase. Alterations in the levels of some proteins were further confirmed by real time polymerase chain reaction (RT‐PCR). The proteomic resources displayed here are valuable for the discovery of proteins from H. parallela antennae.     

Morphological and functional heterogeneity in olfactory perception between antennae and maxillary palps in the pumpkin fruit fly,Bactrocera depressa

The morphology and ultrastructure of the olfactory sensilla on the antennae and maxillary palps were investigated through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and their responses to five volatile compounds were measured using electroantenogram (EAG) and electropalpogram (EPG) techniques in the pumpkin fruit fly, Bactrocera depressa (Shiraki; Diptera: Tephritidae). Male and female B. depressa displayed distinct morphological types of olfactory sensilla in the antennae and maxillary palps, with predominant populations of trichoid, basiconic, and coeloconic sensilla. Basiconic sensilla, the most abundant type of olfactory sensilla in the antennae, could be further classified into two different types. In contrast, the maxillary palps exhibited predominant populations of a single type of curved basiconic sensilla. High‐resolution SEM observation revealed the presence of multiple nanoscale wall‐pores on the cuticular surface of trichoid and basiconic sensilla, indicating that their primary function is olfactory. In contrast, coeloconic sensilla displayed several longitudinal grooves around the sensillum peg. The TEM observation of individual antennal olfactory sensilla indicates that the basiconic sensilla are thin‐walled, while the trichoid sensilla are thick‐walled. The profile of EAG responses of male B. depressa was different from their EPG response profile, indicating that the olfactory function of maxillary palps is different from that of antennae in this species. The structural and functional variation in the olfactory sensilla between antennae and maxillary palps suggests that each plays an independent role in the perception of olfactory signals in B. depressa.     

Pheromone-binding protein and general odorant-binding protein of Sesamia nonagrioides: sex- and diel-dependent expression

The expression of a pheromone‐binding protein (PBP) and a general odorant‐binding protein (GOBP) in Sesamia nonagrioides (Lef.) (Lepidoptera: Noctuidae) was studied. Lymantria dispar's PBP1 antibody yielded an immunoreactive band with an apparent MW of approximately 14.8 kDa, present specifically in the antennae of both sexes, with males having approximately three‐fold the quantity found in females. Furthermore, Manduca sexta's odorant‐binding protein‐2 (GOBP2) antibody recognized a band at approximately 14.5 kDa in the antennae of both sexes. Levels of both proteins were compared between scotophase and photophase periods in insects that were raised under L16:D8 or under constant light. The level of GOPB2 was significantly lower in both sexes during photophase and continuous light; whereas the level of the PBP was significantly lower in females’ antennae, in males’ antennae it remained at the same level as that found during the scotophase.     

Tactile localisation: the function of active antennal movements in the crayfishCherax destructor

Video recordings and single frame analysis were used to study the function of the second antennae of crayfish (Cherax destructor) as a sensory system in freely behaving animals. Walking crayfish move their antennae back and forth through horizontal angles of 100 degrees and more, relative to the body long axis. At rest, animals tend to hold their antennae at angular positions between 20 and 50 degrees. Movements of the two antennae are largely independent of each other. Before and during a turn of the body the ipsilateral antenna is moved into the direction of the turn. Solid objects are explored by repeatedly moving the antennae towards and across them. Both seeing and blinded crayfish can locate stationary objects following antennal contact. On antennal contact with a small novel object, a moving animal withdraws its antenna and attacks the object. When the antenna of a blinded crayfish is lightly touched with a brush the animal turns and attacks the point of stimulation. The direction taken and the distance covered during an attack can be correlated with: the angle at which the antenna is held at the moment of contact and the distance along the antennal flagellum at which the stimulus is applied. From behavioural evidence we conclude that crayfish use information about the angular position of their antennae and about the position of stimulated mechanoreceptors along the antennal flagellum to locate objects in their environment. We suggest ways in which an active tactile system-like the crayfish's antennae--could supply animals with information about the three-dimensional layout of their environment.     

草地贪夜蛾成虫触角感器超微结构观察

[目的]草地贪夜蛾是一种严重危害农业生产的迁飞性害虫,本研究旨在了解草地贪夜蛾成虫触角感器的类型、超微结构和分布.[方法]采用扫描电镜对其雌雄成虫触角感器类型及分布进行观察.[结果]草地贪夜蛾雌雄成虫触角由柄节、梗节及鞭节3部分组成,雄蛾触角稍长于雌蛾,且触角表面覆有大量鳞片.共观察到7种类型的感受器,分别为B?hm氏...     

Three new deep-sea species of Sphaerodoridae (Annelida,Polychaeta) from the eastern tropical South Pacific*

Three sphaerodorid species new to science are described from a manganese nodule area in abyssal depths of around 4150 m in the Peru Basin in the eastern South Pacific. Sphaerodoridium campanulata sp. n. is isolated within the genus, having, apart from spherical macrotubercles, additional dorsal stalked bell-shaped papillae, not previously described. Sphaerodoropsis discolis sp. n. is a species with four rows of dorsal macrotubercles and two pairs of lateral antennae. Sphaerodoropsis translucida sp. n. has six to seven rows of dorsal macrotubercles arrayed in two transverse rows per segment and two pairs of lateral antennae. A brief discussion points to the close relationship between Clavodorum and Sphaerodoridium, and to the present state of Sphaerodoropsis, being inhomogeneous in the characters of the arrangement of the dorsal macrotubercles and the numbers of the lateral antennae. An overview on the latter genus, with an attempt to subdivide it, is given.     

Analysis of odorant-binding proteins in antennae of a geometrid species, Ascotis selenaria cretacea, which produces lepidopteran Type II sex pheromone components

Information on the olfactory system in antennae of Geometridae moths is very limited, and odorant-binding proteins (OBPs) working as transporters of lipophilic odors have not been identified. In the first investigation on this family of insects, we examined antennal OBPs of the Japanese giant looper, Ascotis selenaria cretacea. RT-PCR experiments using several pairs of degenerate primers designed from known cDNA sequences encoding lepidopteran OBPs successfully amplified partial sequences of two pheromone-binding proteins (PBPs), named AscrPBP1 and AscrPBP2 in reference to their corresponding nucleotide sequence homologies with other PBPs. Using 5′- and 3′-rapid amplification of cDNA end strategies, a cDNA clone for AscrPBP1 encoding a protein of 141 amino acids was isolated. Western blotting with the antiserum against recombinant AscrPBP1 overexpressed in Escherichia coli showed that the AscrPBP1 gene was more strongly expressed in male antennae than in female antennae. Furthermore, natural AscrPBP1was isolated by immunoprecipitation with the antiserum, and its binding ability was evaluated by using synthetic sex pheromonal compounds with a C₁₉ chain. The result indicated that AscrPBP1 bound not only the pheromone components, 3,6,9-nonadecatriene and its 3,4-epoxy derivative, but also unnatural 6,7- and 9,10-epoxy derivatives. While no general odorant-binding proteins (GOBPs) were amplified in the RT-PCR experiments, two antisera prepared from GOBP1 and GOBP2 of Bombyx mori suggested the occurrence of at least two GOBPs in the A. s. cretacea antennae.