The discovery that mammalian neutrophils generate extracellular chromatin fibers that entrap/kill bacteria supported a new paradigm for innate immunity in animals. Similar findings in other models across diverse taxa have led to the hypothesis that the phenomenon is ancient and evolutionary conserved. Here, using a variety of synthetic (e.g. peptidoglycan) and biological (e.g. trematode larvae) components to investigate extracellular trap-like (ET-like) fiber production in vitro by haemocytes of Lymnaea stagnalis, Radix lagotis and Planorbarius corneus snails, ET-like fibers were rarely observed. We suggest, therefore, that ET-like fibers play a marginal role in defence of these snail species and thus the fiber production may not be a critical process underpinning immunity in all invertebrate species.

• Klíčová slova
• Extracellular trap-like fiber (ET-like fiber), Haemocytes, Lymnaea stagnalis, Planorbarius corneus, Radix lagotis, Snail immunity,
• MeSH
• antigeny helmintové imunologie   MeSH
• biologická evoluce MeSH
• extracelulární pasti * MeSH
• hemocyty imunologie   MeSH
• hlemýždi imunologie   MeSH
• infekce červy třídy Trematoda imunologie   MeSH
• kultivované buňky MeSH
• larva MeSH
• neutrofily imunologie   MeSH
• peptidoglykan imunologie   MeSH
• přirozená imunita MeSH
• savci imunologie   MeSH
• Trematoda fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny helmintové MeSH
• peptidoglykan MeSH

Utricularia are carnivorous plants which have small hollow vesicles as suction traps that work underwater by means of negative pressure and watertightness of the entrance for capturing small animal prey. Utricularia multifida and U. westonii have specific thick-walled traps, which are triangular in a transverse section but their functioning is unclear. Some authors suggest that the trap door in U. multifida acts as a simple valve without a suction trapping mechanism. Our main aim was to check the anatomical trap characters that are responsible for possible water outflow and maintaining negative pressure as main functional parts of the active trap suction mechanism in both species. Using different microscopic techniques, we investigated the ultrastructure of external trap glands, quadrifids, glands near the entrance (bifids, monofids), and also pavement epithelium. Quadrifids of both species have a similar structure to those known in other species from the genus, which possess the suction trap mechanism. Glands near the entrance in U. multifida and U. westonii, which are responsible for water pumping in other species, are typically developed as in other species in the genus and have pedestal cells which are transfer cells. The transfer cells also occur in glands of the pavement epithelium, which is again typically developed as in other species in the genus. Simple biophysical tests did not confirm reliably neither the negative underpressure formation in the traps nor the watertightness of the entrance in both species. Our anatomical results indirectly support the hypothesis that both species have suction traps like all other Utricularia species, but the biophysical data rather suggest a passive valve mechanism.

• Klíčová slova
• Australian plant species, Lentibulariaceae, Polypompholyx, carnivorous plants, transfer cells, trap function, ultrastructure,
• Publikační typ
• časopisecké články MeSH

Pitfall trapping is one of the standard methods used for the capture of ground-active arthropod groups. Despite being frequently used, the standardization of this method is problematic due to the large range of combinations of the individual parameters of pitfall traps with varying efficacy under different environmental conditions. We evaluated the effects of the trap diameter, the fixing fluid, and their combination on the capture efficacy for harvestmen (Opiliones) and millipedes (Diplopoda). We used pitfall traps with three different diameters: 3 cm, 5 cm, and 12 cm, filled with three types of fixing fluids (saturated fluid of NaCl, 10:1 mixture of 70% ethanol and glycerol and 4% formaldehyde). Altogether, 90 traps representing nine combinations of trap diameters and fixing fluid were placed on a mown meadow in spring and autumn intervals for a total of 45 days. We sampled 1,488 individuals representing 11 harvestmen species and 881 individuals representing 11 millipede species. Large (d = 12 cm) and medium (5 cm) traps captured significantly more millipede species and individuals than the small-sized traps (3 cm). The same effect was observed for harvestmen species richness, whereas the medium traps (d = 5 cm) captured the highest mean activity of harvestmen. By analyzing the differences in the body sizes of the studied arthropods in relation to the trap diameter and fluid, we found that larger traps, as well as traps filled with NaCl solution, captured larger harvestmen more frequently than the other trap types. Our results revealed that the combination of larger traps (d = 5 and 12 cm) and formaldehyde was most effective in the capture of both studied groups. However, the disadvantage of formaldehyde is its toxicity.

• Klíčová slova
• body size, capture rate, fixing fluid, method selection, trap diameter,
• Publikační typ
• časopisecké články MeSH

Ants in the genera Anochetus and Odontomachus belong to one of the largest clades in the subfamily Ponerinae, and are one of four lineages of ants possessing spring-loaded "trap-jaws." Here we present results from the first global species-level molecular phylogenetic analysis of these trap-jaw ants, reconstructed from one mitochondrial, one ribosomal RNA, and three nuclear protein-coding genes. Bayesian and likelihood analyses strongly support reciprocal monophyly for the genera Anochetus and Odontomachus. Additionally, we found strong support for seven trap-jaw ant clades (four in Anochetus and three in Odontomachus) mostly concordant with geographic distribution. Ambiguity remains concerning the closest living non-trap-jaw ant relative of the Anochetus+Odontomachus clade, but Bayes factor hypothesis testing strongly suggests that trap-jaw ants evolved from a short mandible ancestor. Ponerine trap-jaw ants originated in the early Eocene (52.5Mya) in either South America or Southeast Asia, where they have radiated rapidly in the last 30million years, and subsequently dispersed multiple times to Africa and Australia. These results will guide future taxonomic work on the group and act as a phylogenetic framework to study the macroevolution of extreme ant mouthpart specialization.

• Klíčová slova
• Anochetus, Ants, Odontomachus, Phylogenetics, Trap-jaw ants,
• MeSH
• Bayesova věta MeSH
• cytochromy b klasifikace   genetika   metabolismus   MeSH
• Formicidae klasifikace   genetika   MeSH
• fylogeneze MeSH
• fylogeografie MeSH
• genetická variace MeSH
• RNA ribozomální 28S klasifikace   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Afrika MeSH
• Austrálie MeSH
• jihovýchodní Asie MeSH
• Jižní Amerika MeSH
• Názvy látek
• cytochromy b MeSH
• RNA ribozomální 28S MeSH

Quantitative data on local variation in patterns of occurrence of common carnivore species, such as the red fox, European badger, or martens in central Europe are largely missing. We conducted a study focusing on carnivore ecology and distribution in a cultural landscape with the use of modern technology. We placed 73 automated infra-red camera traps into four different habitats differing in water availability and canopy cover (mixed forest, wetland, shrubby grassland and floodplain forest) in the Polabí region near Prague, Czech Republic. Each habitat was represented by three or four spatially isolated sites within which the camera traps were distributed. During the year of the study, we recorded nine carnivore species, including the non-native golden jackal. Habitats with the highest numbers of records pooled across all species were wetland (1279) and shrubby grassland (1014); fewer records were made in mixed (876) and floodplain forest (734). Habitat had a significant effect on the number of records of badger and marten, and a marginally significant effect on fox. In terms of seasonal dynamics, there were significant differences in the distribution of records among seasons in fox, marginally significant in least weasel, and the occurrence among seasons did not differ for badger and marten. In the summer, fox and marten were more active than expected by chance during the day, while the pattern was opposite in winter when they were more active during the night. Our findings on habitat preferences and circadian and seasonal activity provided the first quantitative data on patterns whose existence was assumed on the basis of conventional wisdom. Our study demonstrates the potential of a long-term monitoring approach based on infra-red camera traps. Generally, the rather frequent occurrence of recorded species indicates that most carnivore species are thriving in current central-European landscapes characterized by human-driven disturbances and urbanization.

• Klíčová slova
• Elbe River catchment, camera trap, central Bohemia, circadian activity, ecology, seasonal dynamics,
• Publikační typ
• časopisecké články MeSH

Neutrophils releasing neutrophil extracellular traps (NETs) infiltrate the pancreas prior to type 1 diabetes (T1D) onset; however, the precise nature of their contribution to disease remains poorly defined. To examine how NETs affect immune functions in T1D, we investigated NET composition and their effect on dendritic cells (DCs) and T lymphocytes in T1D children. We showed that T1D patient NET composition differs substantially from that of healthy donors and that the presence of T1D-NETs in a mixed peripheral blood mononuclear cell culture caused a strong shift toward IFNγ-producing T lymphocytes, mediated through activation of innate immunity cells in T1D samples. Importantly, in a monocyte-derived DC (moDC) culture, NETs induced cytokine production, phenotypic change and IFNγ-producing T cells only in samples from T1D patients but not in those from healthy donors. RNA-seq analysis revealed that T1D-NETs presence causes TGFβ downregulation and IFNα upregulation and creates pro-T1D signature in healthy moDCs.

• Klíčová slova
• NET, autoimmunity, innate immunity, monocyte-derived dendritic cells, netosis, neutrophils, type 1 diabetes,
• MeSH
• buněčná diferenciace MeSH
• dendritické buňky imunologie   MeSH
• diabetes mellitus 1. typu imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• extracelulární pasti imunologie   MeSH
• interferon gama metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• neutrofily imunologie   MeSH
• přirozená imunita MeSH
• regulace genové exprese MeSH
• rovnováha Th1-Th2 MeSH
• Th1 buňky imunologie   MeSH
• transformující růstový faktor beta metabolismus   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• interferon gama MeSH
• transformující růstový faktor beta MeSH

Delayed recombination of charge carriers at an activator is a significant problem for fast scintillators and is usually associated with thermal effects. However, experimental results have shown that this phenomenon can occur even at the lowest temperatures. We here provide evidence in support of the idea that this is due to quantum tunneling between activator and nearby traps, and provide analytic estimates relating the energy levels and locations of those traps to the observed delayed recombination. Several calculations are devoted to showing that deviations from the simplest estimates in fact do not occur. Moreover, these estimates are consistent with lower dimensional numerical calculations for a physically significant range of trap distances. In two examples involving the activator Pr, the formulas developed are used to give the locations of traps based on likely values of trap energy depth.

• Publikační typ
• časopisecké články MeSH

Phosphatidylcholine (PC) species in human plasma are used as biomarkers of disease. PC biomarkers are often limited by the inability to separate isobaric PCs. In this work, we developed a targeted shotgun approach for analysis of isobaric and isomeric PCs. This approach is comprised of two MS methods: a precursor ion scanning (PIS) of mass m/z 184 in positive mode (PIS m/z +184) and MS3 fragmentation in negative mode, both performed on the same instrument, a hybrid triple quadrupole ion-trap mass spectrometer. The MS3 experiment identified the FA composition and the relative abundance of isobaric and sn-1, sn-2 positional isomeric PC species, which were subsequently combined with absolute quantitative data obtained by PIS m/z +184 scan. This approach was applied to the analysis of a National Institute of Standards and Technology human blood plasma standard reference material (SRM 1950). We quantified more than 70 PCs and confirmed that a majority are present in isobaric and isomeric mixtures. The FA content determined by this method was comparable to that obtained using GC with flame ionization detection, supporting the quantitative nature of this MS method. This methodology will provide more in-depth biomarker information for clinical and mechanistic studies.

• Klíčová slova
• National Institute of Standards and Technology human blood plasma, docosahexaenoic acid, mass spectrometry, shotgun lipidomics, triple quadrupole/ion-trap,
• MeSH
• biologické markery analýza   krev   MeSH
• fosfatidylcholiny krev   izolace a purifikace   MeSH
• hmotnostní spektrometrie metody   normy   MeSH
• lidé MeSH
• referenční standardy MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• biologické markery MeSH
• fosfatidylcholiny MeSH

Investigations of charging processes on a single dust grain under controlled conditions in laboratory experiments are the unique way to understand the behavior of dust grains in complex plasma (in space, in laboratory, or in technological applications). An electrodynamic trap is often utilized for both holding a single grain and continuously measuring its charge-to-mass ratio. We propose a modified design of the linear quadrupole trap with the electrodes split into two parts; each of them being supplied by a designated source. The paper presents basic calculations and the results of the trap prototype tests. These tests have confirmed our expectations and have shown that the suggested solution is fully applicable for the dust charging experiments. The uncertainty of determination of the dust grain charge does not exceed 10(-3). The main advantages of the suggested design in comparison with other traps used for dust investigations can be summarized as: The trap (i) is more opened, thus it is suitable for a simultaneous application of the ion and electron beams and UV source; (ii) facilitates investigations of dust grains in a broader range of parameters; and (iii) allows the grain to move along the axis in a controlled way.

• Publikační typ
• časopisecké články MeSH

The binary system Sb-Se was studied via laser ablation using antimony-selenium mixtures made from powdered elements in various ratios generating new SbmSen clusters. The results show that in addition to Sbm+ (m = 1-8) and Sen+ (n = 2-9) clusters, a series of SbmSen+ clusters such as SbSe1-8+, Sb2Se1-6+, Sb3Se1-5+, Sb4Se1-3+, and Sb5Se1,2+ is generated. In addition, some low intensity oxidized clusters like Se6O2+, Se7O2+, and SbSe2-6O5+ and partially hydroxylated clusters (SbSeO2H7+, SbSe5O4H+) are also formed. In total, 24 new antimony selenide clusters were generated. The knowledge gained can contribute to the elucidation of the structure of SbmSen glasses. Graphical Abstract.

• Klíčová slova
• Antimony selenides, Chalcogenide glasses, Clusters, Laser ablation, Laser desorption ionization, Quadrupole ion trap mass spectrometry,
• Publikační typ
• časopisecké články MeSH