Natural Exposure Conditions Research Articles

Investigation of SARS-CoV-2 infection in domesticated animals from COVID-19 affected households in Bangladesh

The emergence and rapid global spread of the novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has sparked significant interest in understanding its zoonotic origins. This study aims to investigate animal and environmental samples in Bangladesh to identify the zoonotic source and reverse zoonosis of SARS-CoV-2. This research adopted a comprehensive approach to gather and analyze samples from various animal species, including cattle, sheep, goats, cats, and dogs that are peridomestic in nature or remain in close contact, ensuring biosafety and avoiding cross-contamination. SARS-CoV-2 or related coronaviruses were identified using immunological detection and real-time reverse transcription-polymerase chain reaction (RT-qPCR). A total of 1028 samples from different regions of Bangladesh were collected from cattle (552), sheep (135), goats (112), cats (118), and dogs (111), of which 465 were rectal, 363 nasal swabs, and 200 blood samples. The samples were collected from those areas where there were human records of COVID-19 during July 2021- December 2022. The blood samples were collected and immediately used for antibody screening. No positive samples were found in both antibody test screens and RT-qPCR in fecal and nasal swab samples. The study indicated no COVID-19 infection was found in domestic animals and pets despite staying in close contact with COVID-19 patients or households, suggesting a limited risk of transmission from these animals to humans within the studied context. It's possible that domestic animals are not significantly involved in the COVID-19 epidemic in natural environment exposure conditions.

Proteomic profiling of blood plasma in chronic experimental exposure to aluminum oxide as a tool for predicting adverse effects from critical human organs and systems

Introduction. Highly informative research methods, which include proteomic profiling, make it possible to predict the development of negative effects on the part of critical human organs and systems at the earliest stages of their formation. In combination with toxicological studies, these methods allow changes in the protein profile of blood plasma, identified in the experiment on biological models, to be extrapolated to humans. Determination of the expression, functional characteristics and tissue identity of altered proteins and peptides provides clarification of the mechanisms of homeostasis disorders at the cellular and molecular level associated with exposure to chemicals.
 
 The purpose of the work is to identify and evaluate changes in the proteomic profile of blood plasma during experimental exposure to aluminum oxide in order to predict negative effects on the part of critical human organs and systems.
 
 Materials and methods. When modelling inhalation exposure to aluminum oxide at a dose of 0.0025 mg/(kg·day), equivalent to the dose in natural exposure conditions with an annual averaging period, and taking into account interspecies dose transfer, in an experiment on Wistar rats, the content of this metal in urine and a comparative analysis of the proteomic profile of the blood plasma of exposed and unexposed individuals was carried out. Using the methods of statistical and bioinformatic analysis, the data obtained in the experiment were extrapolated to humans in order to predict negative effects on the part of critical organs and systems during chronic aerogenic exposure to aluminum.
 
 Results. With chronic inhalation intake of aluminum oxide at a dose of 0.0025 mg/(kg·day) in animals of the experimental group, the content of aluminum in the urine was 3.5 times higher than that in the control group. As a result of densitometric measurement and comparative analysis of proteomic maps of blood plasma of exposed and unexposed animals, 13 protein spots were found, the intensity of which significantly differs between groups, which was proved to be related to the aluminum content in the urine. When comparing the mass spectra of these protein spots, 8 proteins were identified that coincided with the proteins of the library mass spectrum (Actin-binding Rho-activating protein; Aldehyde dehydrogenase, cytosol 1; Apolipoprotein A-I; Sec22b protein transporting vesicles; Elongation factor 1-γ; Neurosecretory protein Vgf; Pumilio homologue 3; Teneurin-2). As a result of bioinformatics analysis, there were determined genes encoding the identified proteins, their participation in biological processes (cellular and metabolic processes, biological regulation processes) and tissues of organs in which they have an increased expression (liver, brain, heart, muscles, small intestine, spleen, uterus, testicles, adrenal glands). In humans, orthologues of established genes have been identified, which makes it possible to use the proteins identified in the experiment as markers of negative responses and to suggest the development of diseases of the cardiovascular system, liver, and brain under conditions of long-term aerogenic exposure to aluminum oxide.
 
 Limitations. The conducted study on Wistar rats simulated only chronic inhalation exposure to aluminum oxide.
 
 Conclusion. The transformation of the proteomic profile of blood plasma was established in an experiment on a biological model with chronic inhalation exposure to aluminum oxide at a dose of 0.0025 mg/(kg·day). Extrapolation of the data obtained and the detection of orthologous genes in humans suggests the development of negative effects in the form of diseases of the cardiovascular system, liver and brain with chronic inhalation intake of aluminum oxide into the body. The data obtained expand the theoretical understanding of the mechanisms of the toxic action of chemicals, including aluminum oxide compounds, at the cellular and molecular level to predict the negative effects of critical human organs and systems.
 
 Compliance with ethical standards. The study was approved by the local ethics committee of the Federal Research Center for Medical and Preventive Technologies of Public Health Risk Management of Rospotrebnadzor (minutes of the meeting No. 2 dated 11.02.2021), conducted in accordance with the generally accepted scientific principles of the Helsinki Declaration of the World Medical Association (ed. 2013).

Seroprevalence of anti-SARS-CoV-2 antibodies in household domestic ferrets (Mustela putorius furo) in Spain, 2019–2023

SARS-CoV-2 is the causal agent of Coronavirus Disease 2019 (COVID-19) in humans that emerged in late 2019. This virus is able to infect humans and different animal species. Among pets, cats and ferrets are more susceptible to be infected by the SARS-CoV-2. Epidemiological studies are an important tool to provide information under natural conditions of exposure to SARS-CoV-2 virus. In comparison to cats, limited epidemiological studies have been performed in domestic ferrets (Mustela putorius furo) reporting the presence of antibodies in this species. This study analysed the presence of anti-SARS-CoV-2 antibodies in 432 cliend-owned ferrets from different geographical areas of Spain during the different waves of COVID-19 outbreaks from December 2019 to May 2023 (42 months). For this purpose, anti-SARS-CoV-2 antibodies were detected by an enzyme-linked immunosorbent method (ELISA) using the receptor binding domain (RBD) of Spike antigen and confirmed by serum virus neutralization assay. Eighteen of the 432 ferrets included were seroreactive by the in-house ELISA (4.17%, 95% Confidence Interval (CI): 2.65–6.49). In this sense, the wave of COVID-19 with the higher number of seropositive ferrets occurred during the seventh wave when the different Omicron subvariants were the dominant virus variants. Our results suggest that the risk of SARS-CoV-2 transmission in domestic ferrets in natural conditions is low. Further research is need to evaluate the potential risk of transmission of SARS-CoV-2 from human to pets.

Randomized noninferiority field trial evaluating a postmilking teat dip for the prevention of naturally occurring intramammary infections

The aim of this study was to perform a positive-controlled field study under natural exposure conditions to test the efficacy of a newly developed chlorine dioxide-based postmilking teat disinfectant (experimental product, EX) for noninferiority compared with an already established chlorine dioxide-based teat disinfectant (positive control product, PC). After blocking by parity, approximately 200 Holstein cows in early to mid-lactation stages from a dairy farm near Padua, Italy, were randomly assigned to one of 2 groups. Over a 13-wk period between September and December 2021, the teats of cows were dipped with the EX or the PC after each milking. Milk samples were collected from individual quarters of enrolled cows for 13 wk to determine infection status. Teat condition was assessed at wk 1, 5, and 9. Mixed logistic regression was used to analyze the effect of treatment on the incidence of new intramammary infections. For the noninferiority analysis, the upper limit of the 95% confidence interval for the difference in new intramammary infection (NIMI) rate between the 2 treatments (EX - PC) had to be to the left of the critical value d (0.035) to conclude that EX was noninferior to PC in terms of the risk of NIMI. The results showed that the incidence of new infections in the quarters treated with EX (3.1%) was not different from that in the udder quarters treated with PC (2.6%). No overall difference was found between the treatments in terms of teat condition. As the upper limit of the 95% confidence interval of the NIMI rate difference was smaller than the predefined noninferiority limit, we concluded that the EX was noninferior compared with the PC.

Carbonation rate of alkali-activated concretes and high-volume SCM concretes: a literature data analysis by RILEM TC 281-CCC

The current understanding of the carbonation and the prediction of the carbonation rate of alkali-activated concretes is complicated inter alia by the wide range of binder chemistries used and testing conditions adopted. To overcome some of the limitations of individual studies and to identify general correlations between mix design parameters and carbonation resistance, the RILEM TC 281-CCC ‘Carbonation of Concrete with Supplementary Cementitious Materials’ Working Group 6 compiled and analysed carbonation data for alkali-activated concretes and mortars from the literature. For comparison purposes, data for blended Portland cement-based concretes with a high percentage of SCMs (≥ 66% of the binder) were also included in the database. The analysis indicates that water/CaO ratio and water/binder ratio exert an influence on the carbonation resistance of alkali-activated concretes; however, these parameters are not good indicators of the carbonation resistance when considered individually. A better indicator of the carbonation resistance of alkali-activated concretes under conditions approximating natural carbonation appears to be their water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio, where the subscript ‘eq’ indicates an equivalent amount based on molar masses. Nevertheless, this ratio can serve as approximate indicator at best, as other parameters also affect the carbonation resistance of alkali-activated concretes. In addition, the analysis of the database points to peculiarities of accelerated tests using elevated CO2 concentrations for low-Ca alkali-activated concretes, indicating that even at the relatively modest concentration of 1% CO2, accelerated testing may lead to inaccurate predictions of the carbonation resistance under natural exposure conditions.

Reduced levels of serum 25(OH)D3 are associated with tuberculosis positive cattle under conditions of high natural exposure to Mycobacterium bovis

Serum vitamin D (25(OH)D3) concentrations of < 30 ng/mL in cattle are insufficient to induce an adequate immune response against intracellular pathogens, which suggests that the efficacy of the immune response may be highly dependent on the bioavailability of 25(OH)D3. This study shows an overview of both in vitro and in vivo 25(OH)D3-mediated immune modulation amongst dairy cattle naturally exposed to M. bovis. Tuberculin status was confirmed by interferon gamma release assay (IGRA), and natural exposure was demonstrated by polymerase chain reaction (PCR). Tuberculin (-) cattle have a higher serum concentration of 25(OH)D3 (X¯= 87.12 ng/mL) when compared to tuberculin (+) cattle (X¯ = 45.86 ng/mL). Reduced serum 25(OH)D3 levels are associated with the presence of bovine TB, and serum 25(OH)D3 levels of > 80 ng/mL are necessary to counteract infection by M. bovis. Kill assays were performed to evaluate in vitro 25(OH)D3 modulation of intracellular M. bovis growth in bovine macrophages, which showed that reduced serum 25(OH)D3 levels are associated with diminished mycobactericidal capacity in this experimental model. On the other hand, increased 25(OH)D3 in culture media enhances phagocytosis and nitric oxide production, which in turn improves capacity to combat M. bovis.

Research on Engineering Geomechanics Characteristics and CFRP Reinforcement Technology Based on Machine Learning Algorithms

We have completed the design of an early warning and evaluation analysis module based on machine learning algorithms. Aiming at the prestressed CFRP-strengthened reinforced concrete bridges under natural exposure, we developed a theoretical model to analyze the long-term prestress loss of reinforced parts and the adhesion behavior of the CFRP-concrete interface under natural exposure conditions. The analysis deeply reveals the technical and engineering geomechanics characteristics of the D bridge. At the same time, through a series of experimental studies on the D bridge condition monitoring system, the data acquisition and transmission, processing and control of the D bridge condition monitoring system, and the bridge condition monitoring and evaluation software are provided. Regarding how to repair the engineering geomechanical characteristics of D bridge, we mentioned the prestressed CFRP reinforcement technology. The prestressed carbon fiber reinforced composite (CFRP) structure made of reinforced concrete (RC) makes better use of the high-strength characteristics of CFRP and changes. It strengthens the stress distribution of the components and improves the overall strength of the components. It is more supported by engineers in the civil engineering and transportation departments. However, most prestressed CFRP-reinforced RC structures are located in natural exposure environments, and the effect of natural exposure environments on the long-term mechanical properties of prestressed C FRP-reinforced RC components is still unclear. This article mainly uses the research on the engineering geomechanics characteristics and reinforcement technology of the bridge body, so that people have a deep understanding of its concept, and provides reasonable use methods and measures for the maintenance and protection of the bridge body in the future. This paper studies the characteristics of engineering geomechanics based on machine learning algorithms and applies them to the research of CFRP reinforcement technology, aiming to promote its better development.

Carbonation model for concretes with fly ash, slag, and limestone calcined clay - using accelerated and five - year natural exposure data

Supplementary cementitious materials (SCMs) can be used in concrete to enhance sustainability and reduce the concrete industry's carbon footprint. However, some negative perceptions about their long-term carbonation resistance are obstacles for large-scale implementation of such concretes. This study evaluated the carbonation resistance of 34 concretes (with Ordinary Portland Cement, fly ash, blast furnace slag, and limestone calcined clay) in natural tropical exposure conditions (Open and Sheltered) for 5 years and in accelerated exposure conditions (1 and 3% CO2) for 112 days. Using these data and the square root of time function, the carbonation coefficients (KCO2, natl and KCO2, accl) of these concretes were estimated and a good correlation between them could not be observed. Hence, a more generic model (named as “A-to-N model”) to estimate the KCO2, natl using the KCO2, accl, CO2 concentration, and mixture proportion of concrete was developed, for which the mean absolute percent error is about 12% (reasonable accuracy). Using the A-to-N model, the carbonation depth at 50 years was estimated for various concretes. SCM concretes with low water-binder ratio and optimal binder content showed high resistance against carbonation at later ages; such information along with the target cover depth must be used while selecting materials for concrete design. Based on the model developed, a relatively simple ‘service life design chart’ was developed. This chart can be used by engineers to set the target KCO2, natl or KCO2, accl, and select the cover depth and binder type to provide the target service life (i.e., corrosion initiation time). This paper clearly shows that SCMs can be used to design concretes with comparable long-term carbonation depth as OPC concretes.

Research changes in the properties of butadiene-nitrile rubber under various aging conditions

This article represents the results of a study of changes in the properties of vulcanizates based on BNR-18 butadiene-nitrile rubber containing as stabilizers the experimental spatially hindered phenols Stafen, CO3, CO4, and industrial antioxidant 6PPD, after accelerated aging (100°C 96 h) and aging under full-scale exposure in extreme climatic conditions of the Republic of Sakha (Yakutia) during 2 years. In winter, the air temperature reached—48°C, in summer—+36.1°C. It is shown that the experimental sterically hindered phenols more effectively under natural exposure conditions. They are characterized by the most stability in terms of strength throughout the entire exposure period. Under conditions of accelerated aging, the vulcanizate containing the industrial antioxidant 6PPD is characterized by the greatest stability of physical and mechanical properties. According to the viscoelastic characteristics obtained in the dynamic loading mode, the contribution of the presented stabilizers in maintaining resistance to temperature and deformation effects compared with unstabilized rubber is confirmed.

Performance of GGBS Cement Concrete under Natural Carbonation and Accelerated Carbonation Exposure

One of the primary problems related to reinforced concrete structures is carbonation of concrete. In many cases, depth of carbonation on reinforced concrete structures is used to evaluate concrete service life. Factors that can substantially affect carbonation resistance of concrete are temperature, relative humidity, cement composition, concentration of external aggressive agents, quality of concrete, and depth of concrete cover. This paper investigates the effect of varying the proportions of blended Portland cement (ordinary Portland cement (OPC) and ground granulated blast-furnace slag (GGBS)) on mechanical and microstructural properties of concrete exposed to two different CO2 exposure conditions. Concrete cubes cast with OPC, and various percentages of GGBS (0%, 30%, 50%, and 70%) were subjected to natural (indoor) and accelerated carbonation exposure. The aim of this paper is to present the research findings and authenticate the literature results of carbonation by using GGBS cement in partial replacement of OPC. The concretes with OPC are compared to concretes with various percentages of GGBS, to assess the carbonation depth as well as rate of carbonation of GGBS-based concretes, under both accelerated carbonation and natural carbonation exposure conditions. Even though GGBS cement increases the carbonation depth, the results are not the same with different GGBS replacement percentages. A correlation is made between concrete samples exposed to 15 ± 2% carbon dioxide (CO2) concentration and those exposed to natural CO2 concentration. The results reveal that the products formed by carbonation are similar under both exposure conditions. The experimental tests also revealed that GGBS cement concrete has a lower carbonation resistance than OPC concrete, due to the consumption of portlandite by the pozzolanic reaction. The combination of 70% OPC and 30% GGBS behaved well enough with respect to accelerated carbonation exposure, the depth of carbonation being roughly equivalent to that of control group (100% OPC). The results also show that rate of carbonation becomes more sensitive as the percentage of GGBS replacement increases (binder ratio), rather than duration of curing. Concretes exposed to natural carbonation (indoor) achieved lower carbonation rates than those exposed to accelerated carbonation.

B Cell Functions in the Development of Type I Allergy and Induction of Immune Tolerance.

B cells are key players in the mechanisms underlying allergic sensitization, allergic reactions, and tolerance to allergens. Allergen-specific immune responses are initiated when peptide:MHCII complexes on dendritic cells are recognized by antigen-specific receptors on T cells followed by interactions between costimulatory molecules on the surfaces of B and T cells. In the presence of IL-4, such T-B cell interactions result in clonal expansion and isotype class-switching to IgE in B cells, which will further differentiate into either memory B cells or PCs. Allergic reactions are then triggered upon cross-linking of IgE-FcɛRI complexes on basophils and mast cells, leading to cell degranulation and the release of pro-inflammatory mediators.Mechanisms underlying effective allergen-specific immunotherapy (AIT) involve the induction of Tregs and the secretion of blocking IgG4 antibodies, which together mediate the onset and maintenance of immune tolerance towards non-hazardous environmental antigens. However, the importance of regulatory B cells (Breg) for tolerance induction during AIT has gained more attention lately. Studies in grass pollen- and house dust mite-allergic patients undergoing SCIT reported increased frequencies of IL-10+ Breg cells and a positive correlation between their number and the improvement of clinical symptoms. Thus, Breg are emerging as biomarkers for monitoring tolerance to allergens under natural exposure conditions and during AIT. Further research on the role of other anti-inflammatory cytokines secreted by Breg will help to understand their role in disease development and tolerance induction.

Performance of BMSC column with large eccentricity under natural exposure conditions

As a new type of concrete material, basic magnesium sulfate cement concrete (BMSC) has the advantages, such as early strength, high strength, good toughness and crack resistance. However, it is unclear about the degradation of the mechanical properties of BMSC columns, which is exposed to the natural environment for several years. In order to apply this new concrete to practical engineering, six large-eccentricity compressive columns of BMSC were studied. The mechanical properties such as the crack propagation, failure morphology, lateral displacement and bearing capacity of BMSC column were studied. The results show that the degradation rate of ultimate load of BMSC column is from 6% to 7%. The degradation rate of the stiffness of the column is from 6% to 13%. With the increase of compressive strength of BMSC, the axial displacement and lateral displacement are gradually reduced. The calculation model of bearing capacity of the BMSC column under the large eccentric compression is proposed. This paper provides a reference for the application of BMSC columns in the civil engineering.

Absence of SARS-CoV-2 infection in cats and dogs in close contact with a cluster of COVID-19 patients in a veterinary campus

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in Wuhan, China, in 2019, is responsible for the COVID-19 pandemic. It is now accepted that the wild fauna, probably bats, constitute the initial reservoir of the virus, but little is known about the role pets can play in the spread of the disease in human communities, knowing the ability of SARS-CoV-2 to infect some domestic animals. In this cross-sectional study, we tested the antibody response in a cluster of 21 domestic pets (9 cats and 12 dogs) living in close contact with their owners (belonging to a veterinary community of 20 students) in which two students tested positive for COVID-19 and several others (n = 11/18) consecutively showed clinical signs (fever, cough, anosmia, etc.) compatible with COVID-19 infection. Although a few pets presented many clinical signs indicative for a coronavirus infection, no antibodies against SARS-CoV-2 were detectable in their blood one month after the index case was reported, using an immunoprecipitation assay. These original data can serve a better evaluation of the host range of SARS-CoV-2 in natural environment exposure conditions.

Influenza A virus vaccine research conducted in swine from 1990 to May 2018: A scoping review.

BackgroundInfluenza A viruses of swine (IAV-S) are a global zoonotic and economic concern. Primary control is through vaccination yet a formal evidence map summarizing vaccine research conducted in pigs is not available.ObjectiveTen characteristics of English language primary IAV-S vaccine research, conducted at the level of the pig or higher, were charted to identify research gaps, topics for systematic review, and coverage across different publication types.DesignSix online databases and grey literature were searched, without geographic, population, or study type restrictions, and abstracts screened independently and in duplicate for relevant research published between 1990 and May 2018. Full text data was charted by a single reviewer.ResultsOver 11,000 unique citations were screened, identifying 376 for charting, including 175 proceedings from 60 conferences, and 170 journal articles from 51 journals. Reported outcomes were heterogeneous with measures of immunity (86%, n = 323) and virus detection (65%, n = 246) reported far more than production metrics (9%, n = 32). Study of transmissibility under conditions of natural exposure (n = 7), use of mathematical modelling (n = 11), and autogenous vaccine research reported in journals (n = 7), was limited.ConclusionsMost research used challenge trials (n = 219) and may have poor field relevance or suitability for systematic review if the purpose is to inform clinical decisions. Literature on vaccinated breeding herds (n = 89) and weaned pigs (n = 136) is potentially sufficient for systematic review. Research under field conditions is limited, disproportionately reported in conference proceedings versus journal articles, and may be insufficient to support systematic review.

Propiedades indicadoras de pH y estabilidad de almacenamiento de una película comestible inteligente basada en nopal-mucílago/goma gellan y antocianinas de col roja

Nopal mucilage is a complex polysaccharide with great potential in the preparation of the films to food packaging. In this work, was develop a smart edible film with pH-indicating capabilities based on nopal mucilage, gellan gum, and red cabbage anthocyanins (70:20 w/w, and 10% respectively). Physical properties, appearance, and colorimetric functionality were characterized to pH range 2.5-5.9. Color stability, measured by CIELAB, was tested with different storage conditions and time and interpreted by differential tristimulus colorimetry. Results showed films whit uniform appearance, flexibility, easy-handling, and excellent color response within the pH range studied. The evolution of color difference (ΔE*ab) confirmed that the colorimetric functionality of films was stable at short storage periods (8 days) under natural conditions of sunlight and oxygen exposure, while a more extended storage period was affected. Results showed that the film is an excellent barrier and presents color changes triggered by pH changes.

Investigation of the Climatic Stability of Sealing Rubbers Used in the Technology of the North

The present paper outlines the results of full-scale tests of climatic stability of rubbers based on BNKS-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing low-volatile and non-toxic phenolic antioxidants. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in deformed state (by 30%). Such indexes of the samples as conditional tensile strength, elongation at break are measured to determine the resistance of rubbers to aging after the first, third, sixth, ninth, twelfth and eighteenth months of exposing. The results of the study reveal the contribution of CO3 stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing CO3 has less property changes in the open air. Stafen stabilizer occurred more effective for the rubber based on Hydrin T6000: Over the entire period of full-scale exposure, rubber samples containing it demonstrated the smallest changes in the indicators of elastic-strength properties as compared to the industrial stabilizer 6РРD and other experimental stabilizers.

Corrosion investigation of fly ash based geopolymer mortar in natural sewer environment and sulphuric acid solution

The objective of this research is to estimate the durability of low-calcium fly ash based geopolymer mortar (FA-GPm) in comparison with sulphate resistant Portland cement mortars (SRPCm) exposed to natural sewer environment. Their performance is also investigated in the sulphuric acid (H2SO4) solution to highlight the difference in the corrosion mechanisms between these two exposure conditions. Mortar samples were removed from natural sewer and 1.5 % sulphuric acid solution after 12, 24 months and 6 months of exposure, respectively. Visual and physical analyses showed greater neutralization and loss in alkalinity in FA-GPm compared to SRPCm. However, mass loss and strength reduction observed for SRPCm was greater compared to FA-GPm. Microstructural analysis showed widespread gypsum crystallization within SRPCm matrix compared to FA-GPm, leading to more severe matrix deterioration. Differences in corrosion mechanism were identified between natural and sulphuric acid exposure conditions which led to the variation in estimated corrosion depth. Data collected from these microstructural and physical investigations were utilized to develop simplified linear models to express the depth of corrosion, surface pH, mass loss and neutralization depth of FA-GPm and SRPCm as a dependent of exposure time, temperature and H2S concentration in natural sewer environments.

Analysis in a murine model points to IgG responses against the 34k2 salivary proteins from Aedes albopictus and Aedes aegypti as novel promising candidate markers of host exposure to Aedes mosquitoes.

BackgroundAedes mosquitoes are vectors of arboviral diseases of great relevance for public health. The recent outbreaks of dengue, Zika, chikungunya and the rapid worldwide spreading of Aedes albopictus emphasize the need for improvement of vector surveillance and control. Host antibody response to mosquito salivary antigens is emerging as a relevant additional tool to directly assess vector-host contact, monitor efficacy of control interventions and evaluate risk of arboviral transmission.Methodology/principal findingsGroups of four BALB/c mice were immunized by exposure to bites of either Aedes albopictus or Aedes aegypti. The 34k2 salivary proteins from Ae. albopictus (al34k2) and Ae. aegypti (ae34k2) were expressed in recombinant form and Ae. albopictus salivary peptides were designed through B-cell epitopes prediction software. IgG responses to salivary gland extracts, peptides, al34k2 and ae34k2 were measured in exposed mice. Both al34k2 and ae34k2, with some individual and antigen-specific variation, elicited a clearly detectable antibody response in immunized mice. Remarkably, the two orthologous proteins showed very low level of immune cross-reactivity, suggesting they may eventually be developed as species-specific markers of host exposure. The al34k2 immunogenicity and the limited immune cross-reactivity to ae34k2 were confirmed in a single human donor hyperimmune to Ae. albopictus saliva.Conclusions/significanceOur study shows that exposure to bites of Ae. albopictus or Ae. aegypti evokes in mice species-specific IgG responses to al34k2 or ae34k2, respectively. Deeper understanding of duration of antibody response and validation in natural conditions of human exposure to Aedes mosquitoes are certainly needed. However, our findings point to the al34k2 salivary protein as a promising potential candidate for the development of immunoassays to evaluate human exposure to Ae. albopictus. This would be a step forward in the establishment of a serological toolbox for the simultaneous assessment of human exposure to Aedes vectors and the pathogens they transmit.

Non-destructive mechanical and physical in-situ testing of rendered walls under natural exposure

Building façades are significantly influenced by the wall renders’ performance, since they are the first protection layer against degradation agents. During their service life, façades undergo a continuous performance reduction until they are unable to meet their demanded functions, such as protecting and waterproofing the façade. Therefore, the application of in-situ testing has great importance to evaluate in-service performance of wall renders under natural conditions. This study focuses on testing the physical and mechanical behaviour of rendered façades, taking into account different render colourings and roughness and natural exposure conditions according to the wall orientation. Physical (Karsten tube and moisture meter) and mechanical in-situ tests (pendulum rebound hammer and ultrasound pulse velocity) were performed on eight walls at a natural ageing station. The in-situ tests were used to detect the factors affecting the results of these techniques, and the evolution of the rendered walls’ performance over time was investigated. The relationships between the testing techniques were also assessed.

Amenazas de origen natural y exposición de obras de conectividad estratégica en territorios extremos. Fiordo Comau, Norpatagonia de Chile

The conditions of natural hazards and exposure of economic activities in a norpatagonic fjord, an extreme territory in continental Chiloe, was analyzed due to the lack of terrestrial communication routes. Although the population is scarce, not the economic activities linked to aquaculture. The State of Chile has planned to build an Austral Route (Route CH-7) on the eastern slope of the fjord In this scenario, the natural hazard are analyzed and also how will be potentially affected the land. Methodologically, geomorphological work and GIS geoinformation processing were carried out to establish the hazard; these were superimposed on land and water uses. The result expresseed a territory with multi-hazards and a high exposure of current and projected economic activities, enhanced by the influence of the Austral highway.