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A model for the analysis of plain and reinforced concrete structures is developed in the present work. In the plain concrete the localisation of the microcracking within a small band is formulated in terms of constant fracture energy. In the reinforced concrete the model considers the cracking localisation in the element, according to the expressions of Model Code 1990. The objective of this model is to approximate the tension stiffening effect observed in the reinforced concrete elements submitted to tensile stresses. The reinforcing steel is analysed with an element overlapped to the concrete element, having equivalent nodal displacements. Numerical examples are presented and compared with experimental and other numerical results.

The aim of this paper is to obtain the analytical solution for the optimal design of reinforced concrete sections under ultimate design. The equilibrium equations of the section under bending moment and axial force in rupture are derived. The ultimate conditions are considered either in the steel or in the concrete according to the concrete design codes. The definition of the strains and stresses in the materials is based on the use of Heaviside functions. With this definition the equilibrium equations are described by unique equations. The optimization can then be developed with any design variables in the geometric definition, as area of the reinforcement and location. The optimization is developed with yielding of tensile steel and crushing of concrete. Although this is the current situation in reinforced concrete design, future developments of the model can include other steel and concrete conditions. Cost optimization and variable materials strength ratio are possible applications of the model. The interest of the model is the use of closed form unique equilibrium equations in the optimization of reinforced concrete sections. Numerical examples of the optimization of a rectangular section with minimum reinforcing steel area and economic bending moment are presented. The originality of the paper is the use of Heaviside functions in the definition of the ultimate strains in the reinforced concrete section. Unique equations for the objective function and restrictions are derived. The paper is useful for the design of reinforced concrete. The equations derived can be implemented into computer programs.

We argue that aspects of the Luhmannian strand of systems theory could be mobilized in a crypto-normative way for an immanent critique of certain trends in contemporary social development, especially the growing economic determination of different spheres of life and the formation of sectorial industries – such as healthcare, education, crime control, etc. – with the consequent erosion of the autonomy of these spheres and the progressive exhaustion of social conditions for the exercise of freedom and the experience of difference.

A decisive step in this approach to systems theory lies in the indication of certain “elective affinities” between Luhmann and Adorno, reinforcing the plausibility of an internal connection between these different theoretical conceptions – not their mere instrumental appropriation and external juxtaposition. From this point of view, we argue that aspects of Luhmann's conceptual construction – notably the way the system-environment relationship is thought – hold a strong family resemblance with the Adornian mode of conceiving the subject–object relationship in the speculative key of negative dialectics.

Conceived as a critical model that modulates society's real abstractions toward difference and systemic autonomy, and especially as a critical model that underlines possibilities of reciprocal mediation between system and environment, systems theory seems to emphatically put itself in tension with what, at least in part, could be seen as its other: neoliberal governmentality, the generalization of the commodity form and the instrumentalization of the individual by unilateral systemic imperatives in global capitalism.

Purpose: The information-intensive nature of the tourism and hospitality industry requires regular communication between firms and customers. Yet, customer service personnel’s high contact levels with customers often lead to customer dissatisfaction arising from embarrassment in emotion-inducing service encounters. Accordingly, such companies have been seeking a cost-effective means of maintaining consistency in customer contact. Thus, it seems that the future of chatbots is here.

Design/methodology/approach: This chapter examines chatbots in two ways: the technical composition and its adoption by tourism firms. The technical perspective is represented by a diagram which espouses the functioning of chatbots from inputs query to output reply. On its adoption by tourism firms, two main organizational theories were proposed.

Findings: While chatbots are diffusing rapidly in other areas, their use in the tourism and hospitality industry remains low. We have examined the role of chatbots in various areas of the tourism and hospitality industry and highlighted the barriers to their successful adoption. By applying a conceptual and theoretical approach, our study used a hybrid of institutional theory and organizational learning theory and diagrammatically espouses how the integration of these theories can aid subsequent studies to understand the environmental and organization-specific factors influencing chatbots adoption.

Research limitations/implications: This study is conceptual, consequently, we recommend future studies to empirical test and validate our proposed conceptual framework.

Originality/value: This study is one of the earliest studies that advances firm-level adoption of chatbots by integrating two key organizational theories.

The aim of this paper is to evaluate the hygiene of surfaces that come into direct contact with the ready to eat dried meat product, biltong, at point‐of‐sale in three different retailers in Johannesburg, South Africa, by investigating the presence of indicator organisms.

Samples were collected and plated in duplicate for aerobic plate, total Enterobacteriaceae, coliforms and Escherichia coli counts using standard methods. Typical E. coli colonies on Rapid E. coli 2 Agar™ were selected and further identified using 16S rDNA molecular sequencing methods.

Bacterial counts associated with biltong product ranged between 6–7 Log CFU/g, while counts on cutting utensils ranged between 5–6 Log CFU/cm². Overall, the lowest counts were associated with display cabinets (2–6 Log CFU/cm²). Predominant populations were often similar between biltong product and various surface samples, indicating potential cross‐contamination. Results from 16S rDNA sequence analysis showed that E. coli strains isolated from biltong product and correspondingly from cutting utensils, were 100 per cent genetically similar. Strains of potential pathogens belonging to the Shigella dysenteriae group (99 per cent) were also identified.

This paper highlights that surfaces in direct contact with biltong, an increasingly popular dried meat commodity worldwide, may act as potential sources for cross‐contamination of product with potential food‐borne pathogens, which may hold foodborne illness implications.

The purpose of this paper is to measure the prevalence, evaluate the trend and identify the factors associated with the non-performance of qualitative urine test (QUT) among pregnant women living in the extreme south of Brazil between 2007 and 2016.

All births occurred in the local maternity wards from January 1 to December 31 of 2007, 2010, 2013 and 2016. Mothers were interviewed within 48h after delivery. The outcome was the non-performance of QUT during pregnancy. χ² test was used to compare proportions and Poisson regression with robust variance adjustment for the multivariate analysis. The effect measure used was the prevalence ratio.

Of the 10,331 new mothers identified, 10,004 (96.8 percent) performed at least one prenatal visit. The prevalence of non-performance of QUT was 3.3 percent (95% CI 2.9–3.7 percent), ranging from 1.5 percent in 2007 to 5.3 percent in 2016 (p<0.001). The analysis showed that not living with a companion, having under four years of schooling, living with seven or more people in the household, having five or more children, having had one to three prenatal visits and not having been supplemented with ferrous sulfate during pregnancy showed a significantly higher prevalence rate to the non-performance of QUT.

The rate of non-performance of this test among pregnant women has clearly increased. Mothers at higher risk of unfavorable outcomes in pregnancy were the ones with the highest probability of not performing QUT. Increasing the number of prenatal visits is a high-impact measure toward the performance of this test.

The purpose of this paper is to determine the prevalence of Listeria monocytogenes as an important foodborne pathogen in different kinds of meat.

In total, 410 samples, including fresh and frozen meats of turkey, quail, chicken, ostrich, cattle, sheep and camel, fresh chicken liver and fresh minced meat were gathered and then analyzed according to USDA-FSIS method. To enumerate L. monocytogenes, the MPN procedure was used and also, strains were serotyped by using commercial specific antisera.

It was found that 28.05 percent of samples were positive for L. monocytogenes and the contamination of beef meat was higher than the others. The range of microbial load was from <2 to 940 MPN g−1. Most of the samples (94.39 percent) had a microbial load of <100 MPN g−1. Moreover, 56 percent of the strains belonged to serogroup 1, especially to 1/2a, although, the most frequently isolated serotype was serotype 4b (38.3 percent) in all samples. These findings indicate the potential risk of contamination in different kinds of meats by L. monocytogenes.

This survey is of academic value and of value to those working in the food hygiene and safety. Also, to the best knowledge of these researchers, there has been no serious research on this topic with all its aspects in Iran.

The intention of this work is to generate a tool to facilitate the visualization of urban parameters, critically discussing the current form of urban planning in Brazil and thus facilitate popular participation in decisions, considering that since 2001, it is foreseen by law that the elaboration processes of municipal urban plans in Brazil must have popular participation in order to be legitimized.

The method consists of three-dimensionally modeling the constructive potential within the lots, using the parameters of the Ribeirão das Neves city master plan (State of Minas Gerais, Brazil), using computer software, to predict the impact on landscape that the parameters generate and comparing different software programs.

With the proposed tool, it became clear that many of the city's parameters alone cannot reach the guidelines of the master plan, and the comparison of two software programs generated options for different local realities. It is a methodology that is able to provide excellent support for urban planning laws in Brazil to be more effective and less delayed.

The software was configured with a script developed by the Geoprocessing Laboratory of a university in Brazil and was used for the first time to completely analyze a municipal master plan for the metropolitan region of Belo Horizonte, generating a tool able to be used in master plans' review.

Coeliac disease (CD) is a prevalent autoimmune disorder, affecting 1 in 100 of all individuals in the UK. Currently, the only treatment for CD is the complete avoidance of gluten, a protein commonly found in wheat, rye and barley. The use of alternative grains (AG) is highly recommended to individuals with CD to improve and diversify their diet. The purpose of this paper is to determine the current knowledge of the gluten-free diet (GFD), consumption rates of AG and awareness of AG, for individuals diagnosed with CD.

A total of 100 participants were recruited via local coeliac support groups as well as an “Allergy and Free From Show”, to participate in a survey. Consent was obtained from all organisations and all individual participants, prior to collecting data. The questionnaire consists of ten questions, related to participants’ demographic characteristics, knowledge of gluten-free food (GFF) and AG and consumption rate of AG. χ² analyses were conducted to compare the variables between gender and time of diagnosis.

Overall, both genders possessed good knowledge of the GFD. Yogurt, vinegar and oats resulted in the highest incorrect responses. It was found that females possessed better knowledge of both GFF and AG. Rice, quinoa and corn were amongst the most popular AG consumed whilst job’s tears, fonio and sorghum were the least consumed grains. Females reported a higher consumption rate of AG than males. Additionally, those more recently diagnosed had poorer knowledge of the GFD, reduced consumption rates of AG and poor awareness of AG.

It can be suggested that the incorporation of AG into the diet can prove beneficial for coeliacs and that both knowledge and education play a fundamental role in determining consumption rates amongst individuals.

This study aims to estimate the overall SARS-CoV-2 seroprevalence and evaluate the accuracy of an antibody rapid test compared to a reference serological assay during a COVID-19 outbreak in a prison complex housing over 13,000 prisoners in Brasília.

The authors obtained a randomized, stratified representative sample of each prison unit and conducted a repeated serosurvey among prisoners between June and July 2020, using a lateral-flow immunochromatographic assay (LFIA). Samples were also retested using a chemiluminescence enzyme immunoassay (CLIA) to compare SARS-CoV-2 seroprevalence and 21-days incidence, as well as to estimate the overall infection fatality rate (IFR) and determine the diagnostic accuracy of the LFIA test.

This study identified 485 eligible individuals and enrolled 460 participants. Baseline and 21-days follow-up seroprevalence were estimated at 52.0% (95% CI 44.9–59.0) and 56.7% (95% CI 48.2–65.3) with LFIA; and 80.7% (95% CI 74.1–87.3) and 81.1% (95% CI 74.4–87.8) with CLIA, with an overall IFR of 0.02%. There were 78.2% (95% CI 66.7–89.7) symptomatic individuals among the positive cases. Sensitivity and specificity of LFIA were estimated at 43.4% and 83.3% for IgM; 46.5% and 91.5% for IgG; and 59.1% and 77.3% for combined tests.

The authors found high seroprevalence of anti-SARS-CoV-2 antibodies within the prison complex. The occurrence of asymptomatic infection highlights the importance of periodic mass testing in addition to case-finding of symptomatic individuals; however, the field performance of LFIA tests should be validated. This study recommends that vaccination strategies consider the inclusion of prisoners and prison staff in priority groups.