Rhodnius species are potential vectors of the etiological agent of Chagas disease (CD), the protozoan Trypanosoma cruzi. CD impacts around seven million people in Latin America, resulting in ...approximately fourteen thousand deaths per year. Several species of Rhodnius are notable not only for their epidemiological relevance, but also for the challenging distinction between their species. Rhodnius has twenty species, each with its specific epidemiological importance. Rhodnius neglectus and Rhodnius prolixus are found with colonies in domiciliary environments. The observation of eggs in human dwellings signals the colonization process of these insects, increasing the risk of contamination of the population, since correct identification of eggs is necessary to help more effective vector control programs. Here we highlight diagnostic characters of eggs for these three species.
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•Cells have different shapes, varying in different regions.•Cells show differences between species and between regions of the same species.•The three species showed significant differences in terms of limiting lines.•The funnels present variations in the aspect of their depth; different regions.•Differences were observed in the operculum of the three species.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
The fire design of reinforced concrete (RC) members with glass fiber–reinforced polymer (GFRP) bars comprising lap splices and cold anchoring zones requires the explicit consideration of the ...GFRP–concrete bond degradation with temperature; however, few studies in the literature have addressed this issue. This paper presents numerical investigations in which three-dimensional finite-element models were developed to simulate fire resistance tests performed in GFRP-RC slab strips subjected to a fire load and current standards. The slabs comprised continuous and spliced reinforcements, as well as different concrete cover thicknesses and concrete strengths. In the models, the GFRP–concrete interaction was simulated by means of previously calibrated local bond stress–slip laws at different temperatures. This study provided new insights into the fire behavior of GFRP-RC flexural members, confirming that their fire resistance can be drastically reduced when lap splices, designed for ambient temperature conditions, are directly exposed to heat and that even adopting relatively low concrete cover, fire endurances above 120 min can be attained provided that the bars’ anchors remain sufficiently cold.
Energetics of the Deep Gulf of Mexico Maslo, Aljaz; Azevedo Correia de Souza, João Marcos; Pardo, Julio Sheinbaum
Journal of physical oceanography,
06/2020, Volume:
50, Issue:
6
Journal Article
Peer reviewed
Open access
Abstract
The evaluation of the ocean energy balance is crucial for improving the fundamental understanding of the mechanisms sustaining ocean circulation. Based on the outputs of the ROMS ocean ...model, the energy cycle, eddy–mean flow interactions, and energy pathways of the deep Gulf of Mexico (GoM) have been investigated in this study. The theoretical framework for the analysis is based on the energy equations for the time-mean and time-varying flow, where some of the terms were split into their horizontal and vertical components to monitor the energy pathways. Of the energy maintaining deep kinetic energy (KE), approximately 75% is transferred from the upper layer to the deep layer by vertical pressure work (PW), about 6% by the horizontal PW through the Yucatan and Florida straits, and ~19% is generated through the processes related to baroclinic instabilities. The mean circulation generates eddies in the upper layer, while eddies drive mean circulation in the deep layer. Energy is transferred downward in the eastern and western part of the Gulf, upward in the deep western-central part, and a strong westward energy transport can be observed below 2000-m depth.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The bond between concrete and fiber-reinforced polymer (FRP) bars is severely degraded when the glass transition temperature of the FRP (set mainly by the polymeric matrix, typically a ...thermosetting resin) is approached, and therefore long development lengths are required to enable a proper anchorage in cooler zones of FRP–reinforced concrete (RC) members exposed to fire. In spite of the potential of bent bars to shorten such lengths, and thereby improve the fire resistance of FRP–RC members, very few studies have addressed the effects of elevated temperatures on the bond performance of bent FRP reinforcement. This paper presents experimental and numerical investigations concerning the bond behavior of straight and 90°-bent glass-FRP (GFRP) bars at elevated temperatures. Steady-state pull-out tests were first carried out on bent ribbed bars, from 20°C up to 300°C, and the results were compared with those previously obtained from straight bars. The experiments showed that the hook effect provided by the bend and tail lengths of the bars enabled bond-strength increases of between 30% and 90% compared with straight bars. Three-dimensional finite-element models were then developed to: (1) simulate the pull-out tests; and (2) perform design-oriented parametric studies, aimed at assessing the influence of elevated temperatures on the anchorage strength of straight bars with different surface finishes (sand-coated and ribbed), and of 90°-bent ribbed bars with varying tail and straight development lengths. Temperature-dependent local bond stress versus slip laws were implemented in the models in order to describe the bond interaction along the straight and bent lengths of the bars. The models provided a good agreement with the test data, in terms of load versus slip response, and a reduction in pull-out load and bond stiffness with temperature. The findings were that: (1) the adoption of 90°-bent anchorages with appropriate tail lengths is an effective and practical approach for improving the bond strength of GFRP bars at both ambient and elevated temperatures; and (2) at elevated temperatures, to mobilize the tensile strength of GFRP bars, the development lengths of straight and bent bars designed for ambient temperature must be significantly increased. Finally, optimal anchorage lengths are proposed, as a function of temperature, for beam and slab applications.
The use of glass fibre reinforced polymer (GFRP) composites in civil engineering structures has seen considerable growth in recent years due to their high strength, low self-weight, and corrosion ...resistance, namely when compared to traditional materials, such as steel and reinforced concrete. To enable the structural use of GFRP composite materials in civil engineering applications, especially in footbridges, it is necessary to gather knowledge on their structural behaviour, particularly under dynamic loads, and to evaluate the ability of current design tools to predict their response. In fact, excessive vibration has a major influence on the in-service performance (comfort) of slender structures as well on their service life. The use of composite materials that combine high damping capacity with relatively high stiffness and low mass can provide functional and economic benefits, especially for footbridges. This paper aims to investigate the dynamic behaviour of GFRP free-supported beams to evaluate their modal characteristics (frequency, damping, and modal shape). To assess the benefits of using a structure made of pultruded GFRP rather than a conventional material—steel, a comparative analysis between the dynamic characteristics of GFRP and steel beams is performed. To specifically address material damping and to minimize the interference of the boundary conditions, the beams are tested in a free condition, resting on a low-density foam base. The results show that the damping capacity of GFRP is much higher than that of steel, as the measured damping factor of GFRP is five times higher than that of steel for the same boundary conditions and similar geometry. Furthermore, the fact that the frequencies of the tested specimens resemble for the two different materials highlights the perceived damping qualities of the polymer-based composite material. Finally, an energy method for evaluating the influence of the scale factor on material damping is applied, which made it possible to infer that the damping varies as a function of frequency but is not explicitly affected by the length of the specimens.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Aim
To present feedback, after applying national and international urodynamic study (UDS) recommendations for safe practice during the COVID‐19 pandemic.
Methods
We created a checklist to assess the ...feasibility of performing UDS recommendations for safe practice during the COVID‐19 pandemic from the first week of May 2021 to the last week of July 2021.
Results
One hundred patients were analyzed during the study period. We observed that all preventive recommendations for the steps that precede UDS could be followed in full. However, some guidelines for performing the exam were not feasible in all patients. We have successfully adopted other safety measures for all patients.
Conclusions
The COVID‐19 pandemic will likely persist for several more years. We believe that continuous improvement, revision, and updating of existing protocols and guidelines for the safe practice of UDS in times of COVID‐19, as we propose in this study, should be encouraged.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress ...patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system's sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The ability to record and analyse electrical behaviour across the heart using optical and electrode mapping has revolutionised cardiac research. However, wider uptake of these technologies is ...constrained by the lack of multi-functional and robustly characterised analysis and mapping software. We present ElectroMap, an adaptable, high-throughput, open-source software for processing, analysis and mapping of complex electrophysiology datasets from diverse experimental models and acquisition modalities. Key innovation is development of standalone module for quantification of conduction velocity, employing multiple methodologies, currently not widely available to researchers. ElectroMap has also been designed to support multiple methodologies for accurate calculation of activation, repolarisation, arrhythmia detection, calcium handling and beat-to-beat heterogeneity. ElectroMap implements automated signal segmentation, ensemble averaging and integrates optogenetic approaches. Here we employ ElectroMap for analysis, mapping and detection of pro-arrhythmic phenomena in silico, in cellulo, animal model and in vivo patient datasets. We anticipate that ElectroMap will accelerate innovative cardiac research and enhance the uptake, application and interpretation of mapping technologies leading to novel approaches for arrhythmia prevention.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•Impress voltage and wetting/drying cycles were used as chloride induced corrosion.•The MK, SF and OPC concretes subjected to accelerated corrosion were examined.•In the simultaneous exposition to ...CO2 and Cl−, SF-concrete greatly reduces corrosion.•Under carbonation MK and SF concretes shown higher corrosion rates than OPC.•Use of metakaolin and silica fume enhances chloride resistance of concrete.
The research study presented herein evaluates the corrosion behaviour of the reinforcing steel in blended concretes using two pozzolanic additives—metakaolin (MK) and silica fume (SF)—at 10% replacement of cement weight. They are exposed to CO2 and chlorides. The corrosion process was followed by monitoring of open-circuit potential (OCP), polarisation resistance (Rp) and electrochemical impedance spectroscopy (EIS). Electrochemical measurements show that the addition of MK and SF enhances corrosion resistance exposed to chlorides, however under accelerated carbonation these concretes show higher corrosion rates. In the simultaneous exposition to carbon dioxide and chlorides, SF-concrete shows a decrease of corrosion rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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