47 research outputs found
Vitellogenin Underwent Subfunctionalization to Acquire Caste and Behavioral Specific Expression in the Harvester Ant Pogonomyrmex barbatus
PMCID: PMC3744404This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication
High-throughput screening of caterpillars as a platform to study host-microbe interactions and enteric immunity.
Mammalian models of human disease are expensive and subject to ethical restrictions. Here, we present an independent platform for high-throughput screening, using larvae of the tobacco hornworm Manduca sexta, combining diagnostic imaging modalities for a comprehensive characterization of aberrant phenotypes. For validation, we use bacterial/chemical-induced gut inflammation to generate a colitis-like phenotype and identify significant alterations in morphology, tissue properties, and intermediary metabolism, which aggravate with disease progression and can be rescued by antimicrobial treatment. In independent experiments, activation of the highly conserved NADPH oxidase DUOX, a key mediator of gut inflammation, leads to similar, dose-dependent alterations, which can be attenuated by pharmacological interventions. Furthermore, the developed platform could differentiate pathogens from mutualistic gastrointestinal bacteria broadening the scope of applications also to microbiomics and host-pathogen interactions. Overall, larvae-based screening can complement mammals in preclinical studies to explore innate immunity and host-pathogen interactions, thus representing a substantial contribution to improve mammalian welfare
Predictive Markers of Honey Bee Colony Collapse
Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies
Influência das espécies do plasma na modificação das propriedades superficiais do titânio tratado por plasma de N2 - Ar - O2
Research and analysis of monitoring records to determine the causes of the disaster in underground mining
Mining monitoring at a co-occurrence of the methane and spontaneous fire hazards
W artykule przytoczono najważniejsze przepisy dotyczące współwystępowania zagrożeń metanowego i pożarami endogenicznymi. Ujęto je według etapów planowania i prowadzenia eksploatacji. Przypomniano też niektóre wnioski z prac komisji powoływanych dla zbadania przyczyn i okoliczności zaistniałych zdarzeń wypadkowych z udziałem tych zagrożeń. Wskazano znaczenie komplementarnego analizowania zagrożeń oraz zaakcentowano spójność podejmowanych działań. Podkreślono wagę lokalizacji punktów pomiarowych dla kontroli wczesnego wykrywania pożarów endogenicznych, szczególnie przy stosowaniu odmetanowania. Podano zestawienie zdarzeń zaistniałych w warunkach współwystępowania tych zagrożeń. Przedstawiono wyniki badań charakterystyk zmienności parametrów składu gazów ujmowanych odmetanowaniem. Omówiono możliwości wspomagania monitorowania zagrożeń współwystępujących, opisując i charakteryzując układ pomiarowy odmetanowania.The most relevant regulations relating to a co-occurrence of the methane and spontaneous fire hazards have been quoted in the paper. The regulations have been presented according to the stages of planning and carrying on the mining operations. There have been reminded some conclusions made by the commissions appointed to examine the reasons and circumstances of accident events with presence of the above mentioned hazards. There has been shown a significance of a complementary analysis of the hazards and a coherence of the actions to be undertaken have been emphasized. There has been emphasized the importance of location of measuring points for early detection of spontaneous fires, especially when a methane drainage is used. A list of the events which may occur under conditions of a co-occurrence of those hazards has been given. The results of examination of the characteristics of variable composition of gases collected by methane drainage have been presented. A measuring system ofmethane drainage has been characterized in terms of assistance potential at monitoring of the associated hazards
Uwarunkowania wdrożeniowe autonomicznego ścianowego systemu metanometrycznego zabezpieczającego przed nagłym wypływem metanu
W artykule przedstawiono genezę opracowania nowego systemu metanometrycznego, którego głównym przeznaczeniem jest realizacja autonomicznego szybkiego zabezpieczania rejonu ścian silnie metanowych przed skutkami nagłego wypływu metanu ze zrobów do przestrzeni roboczej wyrobiska ścianowego. Omówiono koncepcję nowego systemu oraz wyniki jego testowania, co było przedmiotem zadania badawczego nr 8 realizowanego w ramach projektu „Poprawa bezpieczeństwa w kopalniach”. Zwrócono uwagę na wymagania wdrożeniowe – począwszy od uzyskania niezbędnych certyfikatów i dopuszczeń, poprzez zabudowę w konkretnym rejonie eksploatacyjnym, do jego bieżącej pracy w integracji z dotychczas stosowanymi systemami gazometrii stacjonarnej. Wskazując możliwości, jakie stwarza nowy system w działaniach związanych z zarządzeniem bezpieczeństwem zakładu górniczego, podkreślono znaczenie systematycznego prowadzenia analiz ryzyka wybuchu metanu w rejonach ścian wydobywczych.The paper features the development origin of a new methane measuring system whose main purpose is to provide quick protection of heavily saturated methane longwalls against a sudden emission of methane from goafs into the working area of the longwall. The concept of the new system was discussed along with its testing results. This work was the subject of task 8 of the project devoted to improving safety in mines. The focus was put on implementation conditions: from obtaining indispensable certificates and admissions, through the installation in the given exploitation area, to the system integration with already existing stationary gas measuring systems. The possibilities of the new system were stressed as far as the safety management of the mine was concerned. Here, the authors pointed at the significance of systematic risk analyses with respect to methane explosions in longwall areas
Photosensitization of TiO2 P25 with CdS Nanoparticles for Photocatalytic Applications
A TiO2/CdS coupled system was prepared by mixing the TiO2 P25 with CdS synthesized by means of the precipitation
method. It was found that the specific surface area (SSA) of both components is extremely different and equals 49.5 for TiO2
and 145.4 m2·g-1 for CdS. The comparison of particle size distribution and images obtained by means of transmission electron
microscopy (TEM) showed agglomeration of nanocomposites. X-ray diffraction (XRD) patterns suggest that CdS crystallizes in
a mixture of cubic and hexagonal phases. Optical reflectance spectra revealed a gradual shift of the fundamental absorption edge
towards longer wavelengths with increasing CdS molar fraction, which indicates an extension of the absorption spectrum of TiO2.
The photocatalytic activity in UV and UV-vis was tested with the use of methyl orange (MO). The Langmuir–Hinshelwood model
described well the photodegradation process of MO. The results showed that the photocatalytic behaviour of the TiO2/CdS mixture
is significantly better than that of pure nanopowders
Insectivorous bats digest chitin in the stomach using acidic mammalian chitinase.
The gastrointestinal tract of animals is adapted to their primary source of food to optimize resource use and energy intake. Temperate bat species mainly feed on arthropods. These contain the energy-rich carbohydrate chitin, which is indigestible for the endogenous enzymes of a typical mammalian gastrointestinal tract. However, the gastrointestinal tract of bat species should be adapted to their diet and be able to digest chitin. We hypothesized that (i) European vespertilionid bat species have the digestive enzyme chitinase and that (ii) the chitinolytic activity is located in the intestine, as has been found for North American bat species. The gastrointestinal tracts of seven bat species (Pipistrellus pipistrellus, Plecotus auritus, Myotis bechsteinii, Myotis nattereri, Myotis daubentonii, Myotis myotis, and Nyctalus leisleri) were tested for chitinolytic activity by diffusion assay. Gastrointestinal tracts of P. pipistrellus, P. auritus, M. nattereri, M. myotis, and N. leisleri were examined for acidic mammalian chitinase by western blot analysis. Tissue sections of the gastrointestinal tract of P. pipistrellus were immunohistochemically analyzed to locate the acidic mammalian chitinase. Chitinolytic activity was detected in the stomachs of all bat species. Western blot analysis confirmed the acidic mammalian chitinase in stomach samples. Immunohistochemistry of the P. pipistrellus gastrointestinal tract indicated that acidic mammalian chitinase is located in the stomach chief cells at the base of the gastric glands. In conclusion, European vespertilionid bat species have acidic mammalian chitinase that is produced in the gastric glands of the stomach. Therefore, the gastrointestinal tracts of insectivorous bat species evolved an enzymatic adaptation to their diet
Structural and electrical properties of magnetron sputtered Ti(ON) thin films:The case of TiN doped in situ with oxygen.
International audienceIncorporation of oxygen into TiN lattice results in formation of titanium oxynitrides, TiOxNy that have become particularly interesting for photocatalytic applications. Elaboration as well as characterization of TiN and in situ oxygen-doped thin films is the subject of this paper. Thin films, 250–320nm in thickness, have been deposited by dc-pulsed magnetron reactive sputtering from Ti target under controllable gas flows of Ar, N2 and O2. Optical monitoring of Ti plasma emission line at = 500nm has been implemented in order to stabilize the sputtering rate. Scanning electron microscopy (SEM), X-ray diffraction in grazing incidence (GIXRD), micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), optical spectrophotometry and four-point probe electrical resistivity measurements have been performed in order to follow evolution of film physical parameters as a function of the oxygen flow rate O2 at which the films were deposited. The relationship between O2 expressed in standard cubic centimetres per minute, sccm and the nitrogen/oxygen content in thin films has been established by means of the analysis of the XPS spectra. GIXRD studies indicate that incorporation of oxygen results in a progressive loss of preferential orientation in 111 direction, a change in the grain size from 16nm for TiN to about 3 nmfor films deposited at O2 = 1.32 sccm and a decrease in the lattice constant. A systematic shift of all X-ray diffraction (XRD) lines towards higher diffraction angles is consistent with substitution of oxygen for nitrogen. Micro-Raman investigations indicate amorphisation of thin films upon oxidation. Binding energies determined fromfitting of the XPS results concerning the N1s and Ti2p lines give evidence of the presence of TiOxNy compound. Red-shift of the plasma reflectance edge upon TiN oxidation is correlated with a decreased carrier concentration. Metal–semiconductor transition can be expected on the basis of the electrical conductivity decrease and development of the fundamental absorption across the forbidden band of TiO2 upon increase in the oxygen flow rate. Additional absorption feature in the visible range, being a consequence of coexistence of free-electron and interband absorption within almost the same spectral range ( = 400–600 nm) seems to be very promising for photocatalytic applications of titanium oxynitride thin films