111 research outputs found
First record of Hypsocephalus dahli in Switzerland with a review of its distribution, ecology and taxonomy (Araneae, Linyphiidae)
The spider species Hypsocephalus dahli (Lessert, 1909) is recorded for the first time in Switzerland from museum material collected in 1974. The information given in the literature and unpublished data on this rare species are summarised including an annotated distribution map. All published pictures of males are compared with the holotype. Figures of the male palp and the vulva of the Swiss specimens are provided
Hypsocephalus dahli is a junior synonym of Microneta pusilla (Araneae, Linyphiidae)
Comparison of the detailed species-specific original drawings of Microneta pusilla Menge, 1869 with the holotype of Hypsocephalus dahli (Lessert, 1909) and the record of one female close to the type locality of Microneta pusilla in Gdansk, Poland indicate that Hypsocephalus dahli is a junior synonym of Microneta pusilla. Hypsocephalus pusillus (Menge, 1869) is therefore proposed as the valid name for this species. Here we discuss the taxonomic status of both species and present a distribution map that accounts for records in Poland
Description of one new genus and four new species of mynoglenine spiders from Africa (Araneae: Linyphiidae: Mynogleninae)
The genus Camafroneta gen. nov. is established to accomodate Camafroneta oku gen. et sp. nov., a new species of mynoglenine spider from Cameroon, West Africa, with unusual complex male genitalia. Phylogenetic analyses suggest that the new species does not belong to a known genus of mynoglenine spiders. Another three new species of Afroneta Holm, 1968 from East Africa are described: Afroneta flavescens sp. nov., Afroneta serrata sp. nov. and Afroneta sarahae sp. nov. We also describe the missing sex (â) of Afroneta elgonensis Merrett, 2004
Spider (Arachnida: Araneae) distribution across the timberline in the Swiss Central Alps (Alp Flix, Grisons) and three morphologically remarkable species
We collected 6251 adult epigeic spiders from the dwarf-shrub heath to subalpine coniferous forest on Alp Flix (CH, canton Grisons, 1950 m) between May 2005 and May 2006 using pitfall traps. Total species richness and activity density of all species decreased from the open land to the forest, although this pattern varied according to family. The distribution of the 102 species found indicates that the small area around a single tree at the timberline provides habitats for both open land and forest spider species as well as some possible timberline specialists. Five species were new to the canton Grisons: Centromerita bicolor, Centromerita concinna, Hilaira excisa, Meioneta alpica and Tallusia experta. Three species showed remarkable morphological characteristics and were analysed in more detail. We found males of Pelecopsis radicicola without the characteristic longitudinal depression on the raised carapace. It is shown that the males of Meioneta alpica have a considerably variable lamella characteristica, which is nevertheless distinct from the sister species Meioneta ressli. Because we found intermediate forms of the head region described for Metopobactrus prominulus and M. schenkeli, respectively, M. schenkeli is considered a syn. nov. of M. prominulus. This study shows that the known distribution and taxonomic status of various spider taxa in the Central Alps are still incomplete and further work on arthropods in remote areas should be strongly encouraged
Progress in erigonine spider phylogenyâthe Savignia -group is not monophyletic (Araneae: Linyphiidae)
We present the most inclusive study on the higher-level phylogeny of erigonine spiders, including about 30% of all erigonine genera. By expanding the previously most comprehensive analysis (Miller and Hormiga Cladistics 20:385-442, 2004) we tested the robustness of its results to the addition of closely related taxa, and also the monophyly of the Savignia-group defined by Millidge (Bulletin of the British Arachnological Society 4:1-60, 1977). The character matrix was expanded by adding 18 newly scored species in 15 genera, and also includes all species scored by other authors. This adds up to 98 species in 91 erigonine genera plus 13 outgroup taxa. The parsimony analysis led to eight fully resolved most parsimonious trees (L=1084). The topology concerning the taxa basal to the âdistal erigonines' remained unchanged, and the latter clade still shares 67% of all nodes with the original analysis. The Savignia-group is not monophyletic at genus level with respect to Saloca diceros and Alioranus pastoralis, and the same applies at species level in Diplocephalus and Erigonella. From the Savignia-group, Glyphesis servulus, Diplocephalus cristatus, Savignia frontata, and two representatives each of Erigonella, Dicymbium and Araeoncus combine to form a monophyletic clad
Hypoxia Inducible Factor (HIF)-1 Coordinates Induction of Toll-Like Receptors TLR2 and TLR6 during Hypoxia
During acute infection and inflammation, dramatic shifts in tissue metabolism are typical, thereby resulting in profound tissue hypoxia. Therefore, we pursued the hypothesis, that tissue hypoxia may influence innate immune responses by transcriptional modulation of Toll-like receptor (TLRs) expression and function.We gained first insight from transcriptional profiling of murine dendritic cells exposed to hypoxia (2% oxygen for 24 h). While transcript levels of other TLRs remained unchanged, we found a robust induction of TLR2 (2.36+/-0.7-fold; P<0.05) and TLR6 (3.46+/-1.56-fold; P<0.05). Additional studies in different cells types and cell-lines including human dendritic cells, monocytic cells (MM6), endothelia (HMEC-1) or intestinal epithelia (Caco-2) confirmed TLR2 and TLR6 induction of transcript, protein and function during hypoxia. Furthermore, analysis of the putative TLR2 and TLR6 promoters revealed previously unrecognized binding sites for HIF-1, which were shown by chromatin immunoprecipitation to bind the pivotal hypoxia-regulating transcription factor HIF-1alpha. Studies using loss and gain of function of HIF-1 confirmed a critical role of HIF-1alpha in coordinating TLR2 and TLR6 induction. Moreover, studies of murine hypoxia (8% oxygen over 6 h) showed TLR2 and TLR 6 induction in mucosal organs in vivo. In contrast, hypoxia induction of TLR2 and TLR6 was abolished in conditional HIF-1alpha mutant mice.Taking together, these studies reveal coordinated induction of TLR2 and TLR6 during hypoxia and suggest tissue hypoxia in transcriptional adaptation of innate immune responses during acute infection or inflammation
Fabrication of low-loss III-V Bragg-reflection waveguides for parametric down-conversion
Entangled photon pairs are an important resource for quantum cryptography
schemes that go beyond point-to-point communication. Semiconductor
Bragg-reflection waveguides are a promising photon-pair source due to mature
fabrication, integrability, large transparency window in the telecom wavelength
range, integration capabilities for electro-optical devices as well as a high
second-order nonlinear coefficient. To increase performance we improved the
fabrication of Bragg-reflection waveguides by employing fixed-beam-moving-stage
optical lithography, low pressure and low chlorine concentration etching, and
resist reflow. The reduction in sidewall roughness yields a low optical loss
coefficient for telecom wavelength light of alpha_reflow = 0.08(6)mm^(-1).
Owing to the decreased losses, we achieved a photon pair production rate of
8800(300)(mW*s*mm)^(-1) which is 15-fold higher than in previous samples
Time-bin entanglement at telecom wavelengths from a hybrid photonic integrated circuit
Mass-deployable implementations for quantum communication require compact,
reliable, and low-cost hardware solutions for photon generation, control and
analysis. We present a fiber-pigtailed hybrid photonic circuit comprising
nonlinear waveguides for photon-pair generation and a polymer interposer
reaching 68dB of pump suppression and photon separation with >25dB polarization
extinction ratio. The optical stability of the hybrid assembly enhances the
quality of the entanglement, and the efficient background suppression and
photon routing further reduce accidental coincidences. We thus achieve a
96(-8,+3)% concurrence and a 96(-5,+2)% fidelity to a Bell state. The generated
telecom-wavelength, time-bin entangled photon pairs are ideally suited for
distributing Bell pairs over fiber networks with low dispersion
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