Search results for "units"
showing 10 items of 576 documents
Molecular characterization of hemocyanin and hexamerin from the firebrat Thermobia domestica (Zygentoma).
2008
Hexapods possess a tracheal system that enables the transport of oxygen to the inner organs. Although respiratory proteins have been considered unnecessary in most Hexapoda for this reason, we recently showed the presence of a functional hemocyanin in the stonefly Perla marginata. Here we report the identification and molecular characterization of a hemocyanin from Zygentoma (Thysanura). We obtained the full length cDNA of two distinct subunit types from the firebrat Thermobia domestica, and partial sequences of the orthologs from the silverfish Lepisma saccharina. The native T. domestica hemocyanin subunits both consist of 658 amino acids, but a signal peptide for transmembrane transport i…
A respiratory hemocyanin from an insect.
2004
Insects possess an elaborate tracheal system that enables transport of gaseous oxygen from the atmosphere directly to the inner organs. Therefore, the presence of specialized oxygen-transport proteins in the circulatory system of insects has been considered generally unnecessary. Here, we show for the first time, to our knowledge, the presence of an ancestral and functional hemocyanin (Hc) in an insect. In the hemolymph of nymphs and adults of the stonefly Perla marginata , a hexameric Hc was identified, which consists of two distinct subunit types of 659 and 655 amino acids. P. marginata Hc displays cooperative oxygen binding with a moderately high oxygen affinity [(half-saturation pressu…
Preventive strategies and factors associated with surgically treated necrotising enterocolitis in extremely preterm infants: an international unit su…
2019
ObjectivesTo compare necrotising enterocolitis (NEC) prevention practices and NEC associated factors between units from eight countries of the International Network for Evaluation of Outcomes of Neonates, and to assess their association with surgical NEC rates.DesignProspective unit-level survey combined with retrospective cohort study.SettingNeonatal intensive care units in Australia/New Zealand, Canada, Finland, Israel, Spain, Sweden, Switzerland and Tuscany (Italy).PatientsExtremely preterm infants born between 240to 286weeks’ gestation, with birth weights<1500 g, and admitted between 2014–2015.ExposuresNEC prevention practices (probiotics, feeding, donor milk) using responses of an o…
Pesticides in the Ebro River basin: Occurrence and risk assessment
2016
In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 2…
Electric properties of KTiOPO4and NaTiOPO4from temperature-dependent X-ray diffraction
1999
Single crystals of KTiOPO4(KTP) and NaTiOPO4(NaTP) show pronounced pyroelectric behaviour. In order to determine the origin of this property on an atomic scale, X-ray diffraction measurements have been carried out at several temperatures between 100 and 600 K. Modelling of the electron density and the evolution of the structure as a function of temperature has enabled the determination of values for the spontaneous polarization of the compounds and the pyroelectric coefficient of KTP, principally due to the alkaline-ion displacements with a value of 2.0 nC cm−2 K−1. Structure modifications, compared with NaTiOPO4, and the calculation of the electrostatic potential explain the anisotropic be…
A multi-technique, micrometer- to atomic-scale description of a synthetic analogue of chukanovite, Fe-2(CO3)(OH)(2)
2014
International audience; A synthetic analogue of chukanovite Fe-2(CO3)(OH)(2) is formed during experimental work on iron-clay interactions simulating the cooling of containers in radioactive waste repositories. Despite its small size and the mixture with other minerals it is undoubtedly identified by X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Transmission Electron Microscopy. For the first time, the structural characterisation of a synthetic chukanovite is carried out thanks to the combination of Automated Diffraction Tomography and Precession Electron Diffraction. Refinement results and comparison with literature data show that the structure…
A Digital Twin predictive maintenance framework of air handling units based on automatic fault detection and diagnostics
2022
The building industry consumes the most energy globally, making it a priority in energy efficiency initiatives. Heating, ventilation, and air conditioning (HVAC) systems create the heart of buildings. Stable air handling unit (AHU) functioning is vital to ensuring high efficiency and extending the life of HVAC systems. This research proposes a Digital Twin predictive maintenance framework of AHU to overcome the limitations of facility maintenance management (FMM) systems now in use in buildings. Digital Twin technology, which is still at an initial stage in the facility management industry, use Building Information Modeling (BIM), Internet of things (IoT) and semantic technologies to create…
3D reconstruction of the hemocyanin subunit dimer from the chiton Acanthochiton fascicularis.
2004
Procedures are presented for the purification of the subunit dimer from Acanthochiton fasicularis hemocyanin. Electron microscopy of negatively stained specimens revealed a uniform population of macromolecules possessing the characteristic "boat shape". A 3D reconstruction from this EM data generated a approximately 3 nm resolution model that correlates well with earlier data of the purported subunit dimer, extracted from the 3D reconstruction of the didecamer of Haliotis tuberculata hemocyanin type 1.
Using discourse segmentation to account for the polyfunctionality of discourse markers:The case of well
2021
Abstract A large number of studies describe the many different functions of polyfunctional discourse markers like well in different contexts and from different theoretical perspectives. In the current paper, we propose to systematize the many different uses identified based on their position with respect to the discourse units they are associated with. Not only can previous findings on well be integrated into a single coherent representation of its uses and functions, but the positions with respect to the discourse units can also be associated with specific functions, thus shedding light on how the polyfunctionality of well is brought about.
Land unit definition for potential distribution of endangered species
2010
In Europe several mapping techniques exist to lay out plant distribution. Most of them, however, are focused on actual and not on potential species distribution range. Spatial predictions become more important for rare and endangered taxa because their conservation is related to existing as well as potential biotopes. The large part of detailed distribution models applies advanced statistics on a large data-set of environmental variables. Data-input availability limits the choice of the prediction model for species distribution and application of results in a detailed scale. Distribution pattern accuracy determinates its applicability in environmental management (for tracing edges, defining…