Climate change has caused an increased occurrence of heat waves. As a result of rising temperatures, implications for health and the environment have been more frequently reported. Outdoor labour ...activities deserve special attention, as is the case with agricultural and construction workers exposed to extreme weather conditions, including intense heat. This paper presents an overview of heat stress conditions in Brazil from 1961 to 2010. It also presents computer‐simulated projections of heat stress conditions up to the late 21st century. The proposed climate analysis drew on historical weather data obtained from national weather stations and on reanalysis data, in addition to future projections with the ETA (regarding the model's unique vertical coordinate) regional forecast model. The projections took into consideration two Representative Concentration Pathways (RCP)—the 4.5 and 8.5 climate scenarios, namely, moderate and high emissions scenarios, respectively. Heat stress was inferred based on the wet‐bulb globe temperature (WBGT) index. The results of this climate analysis show that Brazilian outdoor workers have been exposed to an increasing level of heat stress. These results suggest that future changes in the regional climate may increase the probability of heat stress situations in the next decades, with expectations of WBGT values greater than those observed in the baseline period (1961–1990). In terms of spatial distribution, the Brazilian western and northern regions experienced more critical heat stress conditions with higher WBGT values. As a response to the increased frequency trends of hot periods in tropical areas, urgent measures should be taken to review public policies in Brazil. Such policies should include actions towards better working conditions, technological development to improve outdoor labour activities, and employment legislation reviews to mitigate heat impacts on occupational health.
The most critical area subject to heat stress is the west of Brazil, mainly within the Midwestern region. Particularly, it is in the Midwestern region that most workers perform outdoor activities under a heavy workload. It was observed that the frequency of days per year with high WBGT has increased considerably in the current climate period. Besides, an increased occurrence of high WBGT was projected for the next decades.
Host cell invasion is a critical step for infection by Trypanosoma cruzi, the agent of Chagas disease. In natural infection, T. cruzi metacyclic trypomastigote (MT) forms establish the first ...interaction with host cells. The gp35/50 mucin molecules expressed in MT have been implicated in cell invasion process, but the mechanisms involved are not well understood. We performed a series of experiments to elucidate the mode of gp35/50-mediated MT internalization. Comparing two parasite strains from genetically divergent groups, G strain (TcI) and CL strain (TcVI), expressing variant forms of mucins, we demonstrated that G strain mucins participate in MT invasion. Only G strain-derived mucins bound to HeLa cells in a receptor-dependent manner and significantly inhibited G strain MT invasion. CL strain MT internalization was not affected by mucins from either strain. HeLa cell invasion by G strain MT was associated with actin recruitment and did not rely on lysosome mobilization. To examine the involvement of annexin A2, which plays a role in actin dynamic, annexin A2-depleted HeLa cells were generated. Annexin A2-deficient cell lines were significantly more resistant than wild type controls to G strain MT invasion. In a co-immunoprecipitation assay, to check whether annexin A2 might be the receptor for mucins, protein A/G magnetic beads crosslinked with monoclonal antibody to G strain mucins were incubated with detergent extracts of MT and HeLa cells. Binding of gp35/50 mucins to annexin A2 was detected. Both G strain MT and purified mucins induced focal adhesion kinase activation in HeLa cells. By confocal immunofluorescence microscopy, colocalization of invading G strain MT with clathrin was visualized. Inhibition of clathrin-coated vesicle formation reduced parasite internalization. Taken together, our data indicate that gp35/50-mediated MT invasion is accomplished through interaction with host cell annexin A2 and clathrin-dependent endocytosis.
Knowledge about genetic diversity is essential to promote effective use and conservation of crops, because it enables farmers to adapt their crops to specific needs and is the raw material for ...breeding. Manioc (Manihot esculenta ssp. esculenta) is one of the world's major food crops and has the potential to help achieve food security in the context of on-going climate changes. We evaluated single nucleotide polymorphisms in traditional Brazilian manioc varieties conserved in the gene bank of the Luiz de Queiroz College of Agriculture, University of São Paulo. We assessed genome-wide diversity and identified selective signatures contrasting varieties from different biomes with samples of manioc's wild ancestor M. esculenta ssp. flabellifolia. We identified signatures of selection putatively associated with resistance genes, plant development and response to abiotic stresses that might have been important for the crop's domestication and diversification resulting from cultivation in different environments. Additionally, high neutral genetic diversity within groups of varieties from different biomes and low genetic divergence among biomes reflect the complexity of manioc's evolutionary dynamics under traditional cultivation. Our results exemplify how smallholder practices contribute to conserve manioc's genetic resources, maintaining variation of potential adaptive significance and high levels of neutral genetic diversity.
Desiccation-rehydration experiments have been employed over the years to evaluate desiccation tolerance of bryophytes (Bryophyta, Marchantiophyta, and Anthocerotophyta). Researchers have applied a ...spectrum of protocols to induce desiccation and subsequent rehydration, and a wide variety of techniques have been used to study desiccation-dependent changes in bryophyte molecular, cellular, physiological, and structural traits, resulting in a multifaceted assortment of information that is challenging to synthesize. We analysed 337 desiccation-rehydration studies, providing information for 351 species, to identify the most frequent methods used, analyse the advances in desiccation studies over the years, and characterize the taxonomic representation of the species assessed. We observed certain similarities across methodologies, but the degree of convergence among the experimental protocols was surprisingly low. Out of 52 bryophyte orders, 40% have not been studied, and data are lacking for multiple remote or difficult to access locations. We conclude that for quantitative interspecific comparisons of desiccation tolerance, rigorous standardization of experimental protocols and measurement techniques, and simultaneous use of an array of experimental techniques are required for a mechanistic insight into the different traits modified in response to desiccation. New studies should also aim to fill gaps in taxonomic, ecological, and spatial coverage of bryophytes.
This paper presents industrial insights into on-line robust local tap changer runaway inhibition issues in renewable distributed energy resources (DERs)-rich reconfigurable distribution networks with ...step-voltage regulators (SVRs). Based on the industrial insights, an algorithm is proposed for on-line robust local bi-directional inhibition of runaway events from only one tap change with robustness guarantees and without the need for coordinated test tap changes in cascade SVRs. The main contributions of the paper are the innovative application of the algorithm on on-line robust local bi-directional inhibition of tap changer runaway and the introduction to the industrial insights. The accuracy and robustness of the proposed algorithm are verified by time-series flow power simulation tests conducted on two test networks, with noise and gross errors in measurements, using extensive Monte Carlo simulations. Uncoordinated operation of test tap changes in cascade SVRs is examined through case studies on an actual long rural distribution network. Finally, the effect of photovoltaic (PV) power output variability on the proposed algorithm performance is assessed.
•This paper describes the evolution of HHT, focused on its one-dimensional version.•Research limitations and solutions available in the literature are listed.•Some variations of the EMD are ...compared.•Bibliometric analysis is quantitatively conducted.•Research gaps and suggestions for future work are summarized.
Signal processing methods are essential in scientific research, and time-frequency analysis techniques such as Fourier Transform constitute an important progress in data analysis, but may be limited to examining non-linear and non-stationary processes, although there are ways to work around this problem, with Wavelet Transform for example. Recently Hilbert-Huang Transform (HHT) was created, considered by several researchers to be the most appropriate tool to deal with non-linear and non-stationary signals, because unlike the two transforms mentioned, it is not limited by the uncertainty principle and its basis is adaptive. Like other techniques, HHT has some limitations but has great potential and, consequently, the interest of the academic community has grown in recent years, leading the method to be applied in various knowledge areas. In this paper, a literature review that comprises the method since its introduction in 1996 to March 2021 is presented, covering its evolution and some of the solutions proposed over the years for the main problems cited in the literature, which were divided into the five categories: Stop Criterion, Determination of Envelopes, End Effects, Under/Overshoots and Mode Mixing. Some quantitative results are also presented regarding the number of publications by year and type, geographic distribution of research and application areas cited in the papers selected for this survey. It is believed that the exposed in this paper summarizes the evolution of HHT and the studies that involve it, indicating opportunities for research for a tool that has been increasingly powerful.
The use of biofilters (working bed volume of 7.85 L) for the oxidation of CH4 at low concentrations (from 0.17%v/v to 3.63%v/v, typically in waste gas from anaerobic sewage treatment) was ...investigated and four empty bed residence times were tested (in min): 42.8, 29.5, 19.6, and 7.4. Mixtures of organic (composted leaves) and three non-organic materials (sponge-based material - SBM, blast furnace slag - BFS, and expanded vermiculite - ExpV) were used as packing media. Along 188 operational days after the steady state was reached (95 days for start-up), the CH4 mineralization decreased while the inlet loads gradually increased from 3.0 ± 0.8 gCH4 m−3 h−1 to 148.8 ± 4.4 gCH4 m−3 h−1. The biofilter packed with ExpV showed the best results, since the CH4 conversions decreased from 95.0 ± 5.0% to 12.7 ± 3.7% as a function of inlet concentration, compared to the other two biofilters (SBM and BFS) which showed CH4 conversions decreasing from 56.0 ± 5.4% to 3.5 ± 1.2% as a function of inlet concentration. The methanotrophic activity of biomass taken from ExpV biofilter was three times higher than the activity of biomass from the other two biofilters. Taken together, these results suggested that ExpV provides an attractive environment for microbial growth, besides the mechanical resistance provided to the whole packing media, showing the potential to its use in biofiltration of diffuse CH4 emissions.
•The oxidation of CH4 at low concentrations in three biofilters was investigated.•Mixtures of composted leaves and 3 non-organic materials were used as packing media.•Biofilters achieved theoretical CH4 mole conversion (steady-state) in 95 days.•Non-organic materials improved filter bed mechanical resistance and hydrodynamics.•Expanded vermiculite provides appropriate environment for methanotrophs enrichment.
The present study reports the investigation of the influence of naphthalene–camphor binary solvent and the densification process on the pore structure formation of α‐alumina monoliths using the ...freeze‐casting technique with a freezing temperature control mechanism. Freeze‐casting technique allowed a controlled production of monoliths with high porosity (65%–70%) and distinct pore morphologies based on the adjustment of solvent composition (hypoeutectic, eutectic, and hypereutectic) and sintering time. In general, the longer the sintering time, the greater the average pore diameter (8–10 µm), the larger the grain size (∼319–596 nm), the higher the material density (∼1450–1650 kg/m3), the lower the open porosity (∼60%–49%), the higher the closed porosity (5%–18%), and the greater the compressive strength of the monoliths (hypoeutectic: 23.56 MPa; eutectic: 4.81 MPa; hypereutectic: 23.49 MPa). The study also reveals that the solvent composition directly influenced the alignment of the pore structure, as the pores of the final monolith resemble frozen solvent crystals. Hydraulic tortuosity varied from 1.30 to 1.53 for selected samples. Finally, solvent composition and sintering time proved to be important parameters that should be considered in the manufacturing process of porous ceramic structures via freeze casting.
The present study reports on the production of α‐alumina monoliths through the freeze‐casting technique with unprecedented temperature control (‐130°C), using different compositions of the naphthalene‐camphor mixture as a solvent and applying different sintering temperatures to the materials. The work reveals that changes in the solvent composition can promote the formation of different pore structure and affect their alignment. The sintering time, in turn, reveals impacts on both the porosity and mechanical properties of the materials. Therefore, variations in such parameters bring versatility and may open doors for the production of monoliths designed for specific applications.
Abstract Introduction In order to understand the mechanical behavior of a weakened incisor, this study aimed to evaluate the stress distribution caused by different alveolar bone heights and cement ...layer thickness. Methods A finite element analysis was conducted for this investigation. An intact maxillary central incisor was initially modeled, and the bone of the models was modified in order to simulate 4 levels of bone height: BL0 (no bone loss), BL1 (1/3 bone loss), BL2 (1/2 bone loss), and BL3 (2/3 bone loss). These teeth models were remodeled with a fiber post at 2 different cement thicknesses and restored with a ceramic crown; “A” refers to the well-adapted fiber post (0.3 mm) and “B” to the nonadapted fiber post (1 mm), resulting in 12 models. RelyX ARC (3M ESPE, St Paul, MN) cement was simulated for the cementation of the crowns and fiber posts for all groups. Numeric models received a load of 100 N on the lingual surface. All materials and structures were considered linear elastic, homogeneous, and isotropic. Numeric models were plotted and meshed with isoparametric elements, and results were expressed in maximum principal stress. Results For fiberglass posts, cement, and dentin, the highest stress concentration occurred in the groups with increased bone loss. For cortical bone, the highest values were for the groups with 1/3 bone loss. A greater thickness of cement layer concentrates more stress. Conclusions More bone loss and greater CLT were the influential factors in concentrating the stress.
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