Advantages and shortcomings of the utilization of recycled wastes as aggregates in structural concretes

Global material resources are quickly being drained by the demands of global economic development. Simultaneously, the environmental impacts of the massive amounts of waste generated globally every year are also growing exponentially. As such, the implementation of waste recycling through its utilization as a component of a construction material, particularly one with a global demand as high as concrete, is a strategy which acts in both planes: material efficiency and waste generation. This paper details the results of a systematic review performed on the scientific literature that concerns the possibility of incorporating recycled wastes as aggregates in structural ordinary Portland cement concretes. The available literature suggests that a reduced number of wastes of recycled origin may, albeit in low quantities, be used in structural OPC concretes. Furthermore, the presence of substances such as glass wastes or alkali-rich cement fragments in recycled aggregates elevates the potential for expansions originated by the occurrence, in these concretes, of the well known phenomenon known as alkali-silica reaction. Moreover, the variety, quantity and the limits to the utilization of these wastes as aggregates in structural concretes all suggest that a massification of the utilization of recycled aggregates in OPC concretes will not take place. The investigation also found that, in light of the evidence showing that the performance of alkali-activated binder concretes is less impacted by the shortcomings of recycled aggregates, recycled wastes may be better suited for reutilization as aggregates in these concrete compositions.FCT - Fundação para a Ciência e Tecnologia, under the project SFRH/BD/111813/201

Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula : multiple refugia, range expansions and secondary contact zones

The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident with the southern distribution limits of individual evolutionary lineages. These areas are important in terms of long-term species persistence and therefore important areas for conservation.Peer reviewe

An overview on the potential of geopolymers for concrete infrastructure rehabilitation

Infrastructure rehabilitation represents a multitrillion dollar opportunity for the construction industry. In USA alone the rehabilitation needs are estimated to exceed 1.6 trillion dollars over the next 5 years. Since the majority of the existent infrastructures are concrete based this means that concrete infrastructure rehabilitation is a hot issue to be dealt with. Besides the sooner concrete deterioration is tackled the lower are the rehabilitation costs. This paper provides a literature review on concrete repair materials, highlighting the current problems face by them. It covers concrete surface treatments, patch repair and FRP strengthening. The case of trenchless rehabilitation of concrete sewage pipelines is also discussed. The potential of geopolymers to overcome those limitations is analyzed

Investigação experimental sobre composição, resistência mecânica e capacidade de auto-limpeza de argamassas fotocatalíticas

The self-cleaning ability of photocatalytic cement-based materials has the potential to preserve the esthetic appearance of building facades over time thus reducing cleaning costs. In the present work , the joint effect of several factors on the mechanical strength and self-cleaning ability of photocatalytic mortars was studied. For this purpose, four different mortar mixes containing two binder/sand ratios (1:3 and 1:4) were analyzed. Two mixes containing only Portland cement and the other two possessing 50% Portland cement and 50% aerial lime. For each mix, four different compositions were manufactured, each one with a different titanium dioxide-TiO2 content (0%, 2%, 4% and 6%). The results show that w/b increases with TiO2 which, in turn, leads to lower mechanical strength. Results also show that the mixes with 2% TiO2 had the highest self-cleaning effect.A capacidade de auto-limpeza de materiais cimentícios fotocatalíticos apresenta potencial para preservar a aparência estética das fachadas de edificios ao longo do tempo reduzindo dessa forma os custos de limpeza das mesmas. No presente trabalho estudou-se o efeito conjunto de vários factores na resistência mecãnica e na capacidade de auto-limpeza de argamassas fotocatalíticas. Para este objectivo analisaram-se quatro argamassas contendo dois rácios ligante/areia (1:3 e 1:4). Duas composições continham sómente cimento Portland e outras duas continham 50% de cimento Portland e 50% de cal aérea. Para cada uma destas composições produziram-se quatro misturas com uma percentagem variável de dióxido de titânio - TiO2 (0%, 2%, 4% e 6%). Os resultados mostram que o aumento da percentagem de TiO2 implica um aumento da razão água/ligante que se traduz em menor resistência mecânica. Os resultados mostram também que as argamassas com 2% de TiO2 apresentaram a maior capacidade de auto-limpeza.info:eu-repo/semantics/publishedVersio

Who is more likely to use doctor-rating websites, and why? A cross-sectional study in London

Objectives: To explore the extent to which doctor-rating websites are known and used among a sample of respondents from London. To understand the main predictors of what makes people willing to use doctor-rating websites. Design: A cross-sectional study. Setting: The Borough of Hammersmith and Fulham, London, England. Participants: 200 individuals from the borough. Main outcome measures: The likelihood of being aware of doctor-rating websites and the intention to use doctor-rating websites. Results: The use and awareness of doctor-rating websites are still quite limited. White British subjects, as well as respondents with higher income are less likely to use doctor-rating websites. Aspects of the doctor–patient relationship also play a key role in explaining intention to use the websites. The doctor has both a ‘complementary’ and ‘substitute’ role with respect to Internet information. Conclusions: Online rating websites can play a major role in supporting patients’ informed decisions on which healthcare providers to seek advice from, thus potentially fostering patients’ choice in healthcare. Subjects who seek and provide feedback on doctor-ranking websites, though, are unlikely to be representative of the overall patients’ pool. In particular, they tend to over-represent opinions from non-White British, medium–low-income patients who are not satisfied with their choice of the healthcare treatments and the level of information provided by their GP. Accounting for differences in the users’ characteristics is important when interpreting results from doctor-rating sites

Fluoxetine can make marine organisms unhappy: a study on the sub-lethal effects on marine invertebrates

The environmental effects caused by selective serotonin reuptake inhibitor drugs have been investigated for marine organisms and coastal ecosystems but are scarce in neotropical organisms. This investigation aimed to evaluate the sublethal effects of fluoxetine on the embryonic development of the sea urchin Echinometra lucunter and the survival and swimming behavior of the brine shrimp Artemia sp. The organisms were exposed to four different concentrations of fluoxetine (30, 300, 3000 and 30000 ng L-1) and to a negative control (filtered seawater), following the respective standard testing protocols. We verified a significant reduction of the embryos development to pluteus larvae, starting from 3000 ng L-1 (54.0±10.9% normal larvae), in comparison with the controls (83.5±3.1%). The non-observed effect concentration (NOEC) was estimated at 300 ng L-1, and the lowest observed effect concentration (LOEC) was 3000 ng L-1. In the behavior tests with Artemia sp, no significant adverse effects were reported for mobility, swimming speed and inactivity time. These results show that Fluoxetine can interfere on the development of species like the sea urchin E. lucunter, but short term exposure did not affected the swimming behavior of the brine shrimp Artemia sp. Fluoxetine presents thus a potential to affect marine biota and disrupt the equilibrium of the coastal ecosystems

Policy brief: HEartS professional: the Health, Economic and Social impact of COVID-19 on Professionals in the ARTs: findings and policy implications for cultural recovery

KEY INFO: Research questions: 1. What is the ongoing impact of COVID-19 on arts professionals’ health, wellbeing and livelihoods? 2. How have different arts professionals’ experienced, perceived and responded to the changing situation due to COVID-19? 3. In what ways has the COVID-19 pandemic impacted upon use of technologies to create, consume and engage with the arts, and what are the implications of this for the future? Policy area or themes: Creative Industries; Arts & Health and Social Prescribing; Skills and Training. Methods: Longitudinal surveys (n = 1500) and interviews with arts professionals across the sector, including those working in music, dance, circus arts, theatre, film, visual arts and literature. Wider population and public health surveys (n > 15,000)

Food environment and diabetes mellitus in South Asia: A geospatial analysis of health outcome data

BACKGROUND: The global epidemic of type 2 diabetes mellitus (T2DM) renders its prevention a major public health priority. A key risk factor of diabetes is obesity and poor diets. Food environments have been found to influence people's diets and obesity, positing they may play a role in the prevalence of diabetes. Yet, there is scant evidence on the role they may play in the context of low- and middle-income countries (LMICs). We examined the associations of food environments on T2DM among adults and its heterogeneity by income and sex. METHODS AND FINDINGS: We linked individual health outcome data of 12,167 individuals from a network of health surveillance sites (the South Asia Biobank) to the density and proximity of food outlets geolocated around their homes from environment mapping survey data collected between 2018 and 2020 in Bangladesh and Sri Lanka. Density was defined as share of food outlets within 300 m from study participant's home, and proximity was defined as having at least 1 outlet within 100 m from home. The outcome variables include fasting blood glucose level, high blood glucose, and self-reported diagnosed diabetes. Control variables included demographics, socioeconomic status (SES), health status, healthcare utilization, and physical activities. Data were analyzed in ArcMap 10.3 and STATA 15.1. A higher share of fast-food restaurants (FFR) was associated with a 9.21 mg/dl blood glucose increase (95% CI: 0.17, 18.24; p < 0.05). Having at least 1 FFR in the proximity was associated with 2.14 mg/dl blood glucose increase (CI: 0.55, 3.72; p < 0.01). A 1% increase in the share of FFR near an individual's home was associated with 8% increase in the probability of being clinically diagnosed as a diabetic (average marginal effects (AMEs): 0.08; CI: 0.02, 0.14; p < 0.05). Having at least 1 FFR near home was associated with 16% (odds ratio [OR]: 1.16; CI: 1.01, 1.33; p < 0.05) and 19% (OR: 1.19; CI: 1.03, 1.38; p < 0.05) increases in the odds of higher blood glucose levels and diagnosed diabetes, respectively. The positive association between FFR density and blood glucose level was stronger among women than men, but the association between FFR proximity and blood glucose level was stronger among men as well as among those with higher incomes. One of the study's key limitations is that we measured exposure to food environments around residency geolocation; however, participants may source their meals elsewhere. CONCLUSIONS: Our results suggest that the exposure to fast-food outlets may have a detrimental impact on the risk of T2DM, especially among females and higher-income earners. Policies should target changes in the food environments to promote better diets and prevent T2DM

Food environments and obesity: a geospatial analysis of the South Asia Biobank, income and sex inequalities.

Introduction: In low-middle income countries (LMICs) the role of food environments on obesity has been understudied. We address this gap by 1) examining the effect of food environments on adults' body size (BMI, waist circumference) and obesity; 2) measuring the heterogeneity of such effects by income and sex. Methods: This cross-sectional study analysed South Asia Biobank surveillance and environment mapping data for 12,167 adults collected between 2018 and 2020 from 33 surveillance sites in Bangladesh and Sri Lanka. Individual-level data (demographic, socio-economic, and health characteristics) were combined with exposure to healthy and unhealthy food environments measured with geolocations of food outlets (obtained through ground-truth surveys) within 300 m buffer zones around participants' homes. Multivariate regression models were used to assess association of exposure to healthy and unhealthy food environments on waist circumference, BMI, and probability of obesity for the total sample and stratified by sex and income. Findings: The presence of a higher share of supermarkets in the neighbourhood was associated with a reduction in body size (BMI, β = - 3∙23; p < 0∙0001, and waist circumference, β = -5∙99; p = 0∙0212) and obesity (Average Marginal Effect (AME): -0∙18; p = 0∙0009). High share of fast-food restaurants in the neighbourhood was not significantly associated with body size, but it significantly increased the probability of obesity measured by BMI (AME: 0∙09; p = 0∙0234) and waist circumference (AME: 0∙21; p = 0∙0021). These effects were stronger among females and low-income individuals. Interpretation: The results suggest the availability of fast-food outlets influences obesity, especially among female and lower-income groups. The availability of supermarkets is associated with reduced body size and obesity, but their effects do not outweigh the role of fast-food outlets. Policies should target food environments to promote better diets and reduce obesity

Progress towards antibiotic use targets in eight high-income countries.

Objective: To compare antibiotic sales in eight high-income countries using the 2019 World Health Organization (WHO) Access, Watch and Reserve (AWaRe) classification and the target of 60% consumption of Access category antibiotics. Methods: We analysed data from a commercial database of sales of systemic antibiotics in France, Germany, Italy, Japan, Spain, Switzerland, United Kingdom of Great Britain and Northern Ireland, and United States of America over the years 2013-2018. We classified antibiotics according to the 2019 AWaRe categories: Access, Watch, Reserve and Not Recommended. We measured antibiotic sales per capita in standard units (SU) per capita and calculated Access group sales as a percentage of total antibiotic sales. Findings: In 2018, per capita antibiotic sales ranged from 7.4 SU (Switzerland) to 20.0 SU (France); median sales of Access group antibiotics were 10.9 SU per capita (range: 3.5-15.0). Per capita sales declined moderately over 2013-2018. The median percentage of Access group antibiotics was 68% (range: 22-77 %); the Access group proportion increased in most countries between 2013 and 2018. Five countries exceeded the 60% target; two countries narrowly missed it (> 55% in Germany and Italy). Sales of Access antibiotics in Japan were low (22%), driven by relatively high sales of oral cephalosporins and macrolides. Conclusion: We have identified changes to prescribing that could allow countries to achieve the WHO target. The 60% Access group target provides a framework to inform national antibiotic policies and could be complemented by absolute measures and more ambitious values in specific settings