The sejugal furrow in camel spiders and acariform mites

Camel spiders (Arachnida: Solifugae) are one of the arachnid groups characterised by a prosomal dorsal shield composed of three distinct elements: the pro-, meso- and metapeltidium. These are associated respectively with prosomal appendages one to four, five, and six. What is less well known, although noted in the historical literature, is that the coxae of the 4th and 5th prosomal segments (i.e. walking legs 2 and 3) of camel spiders are also separated ventrally by a distinct membranous region, which is absent between the coxae of the other legs. We suggest that this essentially ventral division of the prosoma specifically between coxae 2 and 3 is homologous with the so-called sejugal furrow (the sejugal interval sensu van der Hammen). This division constitutes a fundamental part of the body plan in acariform mites (Arachnida: Acariformes). If homologous, this sejugal furrow could represent a further potential synapomorphy for (Solifugae + Acariformes); a relationship with increasing morphological and molecular support. Alternatively, outgroup comparison with sea spiders (Pycnogonida) and certain early Palaeozoic fossils could imply that the sejugal furrow defines an older tagma, derived from a more basal grade of organisation. In this scenario the (still) divided prosoma of acariform mites and camel spiders would be plesiomorphic. This interpretation challenges the textbook arachnid character of a peltidium (or ‘carapace’) covering an undivided prosoma

Fine structure of the male genital systems, spermatophores and unusual sperm cells of saxidromidae (Acari, Actinotrichida)

The early derivative actinedid Saxidromidae, Saxidromus delamarei, Bovidromus roussouwi, and Rhinodromus lootsi perform indirect spermatophore transfer by means of a peculiar mating behaviour. The anatomy and fine structure of the male genital systems are described and are shown to exhibit the organisation considered to be fundamental in Actinotrichida: paired testes with germinal and glandular parts, paired vasa deferentia, unpaired ejaculatory duct, progenital chamber containing genital papillae. The genital system is located ventral of the digestive tract. The testes produce relatively few or even very few aflagellate sperm cells, which represent synspermia consisting of likely four undivided sperm cell equivalents in a common cytoplasm. Whereas S. delamarei produces a rather large stalked spermatophore containing many synspermia, both the other species produce very tiny stalked spermatophores with a spherical head representing only one synspermium. Thus, in these latter species only one synspermium is transferred to the female at atime, but the male can convey several (possibly five or more) spermatophores to the female during the mating session. A scenario is suggested which could describe the evolution of this remarkable mating system and behaviour.Fil: Alberti, Gerd. ERNST MORITZ ARNDT UNIVERSITÄT GREIFSWALD (UG);Fil: Coineau, Yves. Muséum National d'Histoire Naturelle; FranciaFil: Fernández, Néstor Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Théron, Pieter D.. North-West University; Sudáfric

Recent experiments with the European 1MW, 170GHz industrial CW and short-pulse gyrotrons for ITER

The European Gyrotron Consortium (EGYC) is developing the European 1 MW, 170 GHz Continuous Wave (CW) industrial prototype gyrotron for ITER in cooperation with Thales Electron Devices (TED) and Fusion for Energy (F4E). This conventional, hollow-cavity gyrotron, is based on the 1 MW, 170 GHz Short-Pulse (SP) modular gyrotron that has been designed and manufactured by the Karlsruhe Institute of Technology (KIT) in collaboration with TED. Both gyrotrons have been tested successfully in multiple experiments. In this work we briefly report on the results with the CW gyrotron at KIT and we focus at the experiments at the Swiss Plasma Center (SPC). In addition, we present preliminary results from various upgrades of the SP tube that are currently tested at KIT

Diabetes susceptibility in ethnic minority groups from Turkey, Vietnam, Sri Lanka and Pakistan compared with Norwegians - the association with adiposity is strongest for ethnic minority women

<p>Abstract</p> <p>Background</p> <p>The difference in diabetes susceptibility by ethnic background is poorly understood. The aim of this study was to assess the association between adiposity and diabetes in four ethnic minority groups compared with Norwegians, and take into account confounding by socioeconomic position.</p> <p>Methods</p> <p>Data from questionnaires, physical examinations and serum samples were analysed for 30-to 60-year-olds from population-based cross-sectional surveys of Norwegians and four immigrant groups, comprising 4110 subjects born in Norway (n = 1871), Turkey (n = 387), Vietnam (n = 553), Sri Lanka (n = 879) and Pakistan (n = 420). Known and screening-detected diabetes cases were identified. The adiposity measures BMI, waist circumference and waist-hip ratio (WHR) were categorized into levels of adiposity. Gender-specific logistic regression models were applied to estimate the risk of diabetes for the ethnic minority groups adjusted for adiposity and income-generating work, years of education and body height used as a proxy for childhood socioeconomic position.</p> <p>Results</p> <p>The age standardized diabetes prevalence differed significantly between the ethnic groups (women/men): Pakistan: 26.4% (95% CI 20.1-32.7)/20.0% (14.9-25.2); Sri Lanka: 22.5% (18.1-26.9)/20.7% (17.3-24.2), Turkey: 11.9% (7.2-16.7)/12.0% (7.6-16.4), Vietnam: 8.1% (5.1-11.2)/10.4% (6.6-14.1) and Norway: 2.7% (1.8-3.7)/6.4% (4.6-8.1). The prevalence increased more in the minority groups than in Norwegians with increasing levels of BMI, WHR and waist circumference, and most for women. Highly significant ethnic differences in the age-standardized prevalence of diabetes were found for both genders in all categories of all adiposity measures (<it>p </it>< 0.001). The Odds Ratio (OR) for diabetes adjusted for age, WHR, body height, education and income-generating work with Norwegians as reference was 2.9 (1.30-6.36) for Turkish, 2.7 (1.29-5.76) for Vietnamese, 8.0 (4.19-15.14) for Sri Lankan and 8.3 (4.37-15.58) for Pakistani women. Men from Sri Lanka and Pakistan had identical ORs (3.0 (1.80-5.12)).</p> <p>Conclusions</p> <p>A high prevalence of diabetes was found in 30-to 60-year-olds from ethnic minority groups in Oslo, with those from Sri Lanka and Pakistan at highest risk. For all levels of adiposity, a higher susceptibility for diabetes was observed for ethnic minority groups compared with Norwegians. The association persisted after adjustment for socioeconomic position for all minority women and for men from Sri Lanka and Pakistan.</p

Recent progress in the upgrade of the TCV EC-system with two 1MW/2s dual-frequency (84/126GHz) gyrotrons

The upgrade of the EC-system of the TCV tokamak has entered in its realization phase and is part of a broader upgrade of TCV. The MW-class dual-frequency gyrotrons (84 or 126GHz/2s/1MW) are presently being manufactured by Thales Electron Devices with the first gyrotron foreseen to be delivered at SPC by the end of 2017. In parallel to the gyrotron development, for extending the level of operational flexibility of the TCV EC-system the integration of the dual-frequency gyrotrons adds a significant complexity in the evacuated 63.5mm-diameter HE11 transmission line system connected to the various TCV low-field side and top launchers. As discussed in [1], an important part of the present TCV-upgrade consists in inserting a modular closed divertor chamber. This will have an impact on the X3 top-launcher which will have to be reduced in size. For using the new compact launcher we are considering employing a Fast Directional Switch (FADIS), combining the two 1MW/126GHz/2s rf-beams into a single 2MW rf-beam

14. Comparative spermatology of Chelicerata : review and perspective

Volume: 166Start Page: 203End Page: 23

ON THE OCCURRENCE OF THE 9 + 0 AXONEMAL PATTERN IN THE SPERMATOZOA OF SHEETWEB SPIDERS (ARANEAE, LINYPHIIDAE)

Volume: 33Start Page: 569End Page: 57

The fine structure of the spermatheca of Pardosa lugubris (Walckenaer, 1802)

Volume: 2Start Page: 635End Page: 64