162 research outputs found

    Analyzing the social impacts of scooters with geo-spatial methods

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    © 2019 Elsevier Ltd Scooters, or gasoline powered two-wheelers, are becoming increasingly popular in the Netherlands. They provide fast, independent and affordable transportation, especially in urban congested areas. Unfortunately, they also have considerable adverse impacts on the environment and human health. The three most prominent impacts are associated with air pollution, noise pollution and traffic accidents. While the total contribution of emissions by scooters is relatively small compared to total traffic related emissions, they have a disproportionally large impact on their direct environment, especially when sharing roads with bicycles as in the Netherlands, where they are characterized as super-polluters. A scoping GIS based assessment, using theoretical and available secondary data, could identify routes with highest likelihood of scooter presence to estimate exhaust and noise impacts and related traffic accidents. Estimated are provided for the total population, and the number of childcare facilities within the impact areas. For future projections four different scenarios are analyzed. For the case study of the town of Enschede in the Netherlands the present noise/exhaust environmental impact of scooters is affecting at least 30% of the population and in the future this number can increase to 38%–53%

    Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies

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    By reducing energy density, low-energy sweeteners (LES) might be expected to reduce energy intake (EI) and body weight (BW). To assess the totality of the evidence testing the null hypothesis that LES exposure (versus sugars or unsweetened alternatives) has no effect on EI or BW, we conducted a systematic review of relevant studies in animals and humans consuming LES with ad libitum access to food energy. In 62 of 90 animal studies exposure to LES did not affect or decreased BW. Of 28 reporting increased BW, 19 compared LES with glucose exposure using a specific ‘learning’ paradigm. Twelve prospective cohort studies in humans reported inconsistent associations between LES use and Body Mass Index (-0.002 kg/m2/year, 95%CI -0.009 to 0.005). Meta-analysis of short- term randomized controlled trials (RCTs, 129 comparisons) showed reduced total EI for LES- versus sugar-sweetened food or beverage consumption before an ad libitum meal (-94 kcal, 95%CI -122 to -66), with no difference versus water (-2 kcal, 95%CI -30 to 26). This was consistent with EI results from sustained intervention RCTs (10 comparisons). Meta-analysis of sustained intervention RCTs (4 weeks to 40 months) showed that consumption of LES versus sugar led to relatively reduced BW (nine comparisons; -1.35 kg, 95%CI –2.28 to - 0.42), and a similar relative reduction in BW versus water (three comparisons; -1.24 kg, 95%CI –2.22 to -0.26). Most animal studies did not mimic LES consumption by humans, and reverse causation may influence the results of prospective cohort studies. The preponderance of evidence from all human RCTs indicates that LES do not increase EI or BW, whether compared with caloric or non-caloric (e.g., water) control conditions. Overall, the balance of evidence indicates that use of LES in place of sugar, in children and adults, leads to reduced EI and BW, and possibly also when compared with water

    Transcriptional expression levels of chicken collectins are affected by avian influenza A virus inoculation

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    Mammalian collectins have been found to play an important role in the defense against influenza A virus H9N2 inoculation, but for chicken collectins this has not yet been clarified. The aim of this study was to determine the effect of avian influenza A virus (AIV) inoculation on collectin gene expression in the respiratory tract of chickens and whether this was affected by age. For this purpose 1- and 4-week-old chickens were inoculated intratracheally with PBS or H9N2 AIV. Chickens were killed at 0, 8, 16 and 24 h postinoculation and trachea and lung were harvested for analysis. Viral RNA expression and mRNA expression of chicken collectins 1 and 2 (cCL-1 and cCL-2), chicken lung lectin (cLL) and chicken surfactant protein A (cSP-A) were determined using real-time quantitative RT-PCR. In lung, a decrease in mRNA expression of cCL-2, cLL and cSP-A after inoculation with H9N2 was seen in both 1- and 4-week-old birds, although at different time points, while in trachea changes were only seen in 4-week-old birds and expression was increased. Moreover, collectin expression correlated with viral RNA expression in lung of 1-week-old birds. These results suggest that both age and location in the respiratory tract affect changes in collectin mRNA expression after inoculation with H9N2 and indicate a possible role for collectins in the host response to AIV in the respiratory tract of chickens

    Chicken lung lectin is a functional C-type lectin and inhibits haemagglutination by influenza A virus

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    Many proteins of the calcium-dependent (C-type) lectin family have been shown to play an important role in innate immunity. They can bind to a broad range of carbohydrates, which enables them to interact with ligands present on the surface of micro-organisms.We previously reported the finding of a new putative chicken lectin, which was predominantly localized to the respiratory tract, and thus termed chicken lung lectin (cLL). In order to investigate the biochemical and biophysical properties of cLL, the recombinant protein was expressed, affinity purified and characterized. Recombinant cLL was expressed as four differently sized peptides, which is most likely due to post-translational modification. Crosslinking of the protein led to the formation of two high-molecular weight products, indicating that cLL forms trimeric and possibly even multimeric subunits. cLL was shown to have lectin activity, preferentially binding to a-mannose in a calcium-dependent manner. Furthermore, cLL was shown to inhibit the haemagglutination-activity of human isolates of influenza A virus, subtype H3N2 and H1N1. These result show that cLL is a true C-type lectin with a very distinct sugar specificity, and that this chicken lectin could play an important role in innate immunity

    Expected satiation after repeated consumption of low- or high-energy-dense soup

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    We investigated whether repeated consumption of a low-energy-dense (LED; 208 kJ/100 g) or high-energy-dense (HED; 645 kJ/100 g) soup modifies expectations relating to the satiating capacity of the food, and its subsequent intake. In study 1, participants consumed either a novel-flavoured LED (n 32; 21 (SD 1.6) years, BMI 21-4 (SD 1.6) kg/m(2)) or HED soup (n 32; 21 (SD 1-6) years, BMI 21.3 (SD 1.7) kg/m(2)). Soup was served in a fixed amount on days 1-4 and ad libitum on day 5. 'Expected satiation' was measured on days 1, 2 and 5. Expected satiation did not change after repeated consumption of the LED or HED soup. Ad libitum intake did not differ between the LED (461 (SD 213) g) and HED soup (391 (SD 164) g). Only on day 1, expected satiation was higher for the HED soup than for the LED soup (P=0.03), suggesting a role for sensory attributes in expected satiation. In study 2, thirty participants (21 (SD 1-6) years, BMI 21-3 (SD 1.7) kg/m2) performed a single measurement of expected satiation of the LED and HED soup, and four commercially available types of soup. Ratings on sensory attributes were associated with expected satiation. Results on expected satiation coincided with those of study 1. Thickness and intensity of taste were independently associated with expected satiation. Expectations may initially rely on sensory attributes and previous experiences, and are not easily changed

    Subtle changes in the flavour and texture of a drink enhance expectations of satiety

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    Background: The consumption of liquid calories has been implicated in the development of obesity and weight gain. Energy-containing drinks are often reported to have a weak satiety value: one explanation for this is that because of their fluid texture they are not expected to have much nutritional value. It is important to consider what features of these drinks can be manipulated to enhance their expected satiety value. Two studies investigated the perception of subtle changes in a drink’s viscosity, and the extent to which thick texture and creamy flavour contribute to the generation of satiety expectations. Participants in the first study rated the sensory characteristics of 16 fruit yogurt drinks of increasing viscosity. In study two, a new set of participants evaluated eight versions of the fruit yogurt drink, which varied in thick texture, creamy flavour and energy content, for sensory and hedonic characteristics and satiety expectations. Results: In study one, participants were able to perceive small changes in drink viscosity that were strongly related to the actual viscosity of the drinks. In study two, the thick versions of the drink were expected to be more filling and have a greater expected satiety value, independent of the drink’s actual energy content. A creamy flavour enhanced the extent to which the drink was expected to be filling, but did not affect its expected satiety. Conclusions: These results indicate that subtle manipulations of texture and creamy flavour can increase expectations that a fruit yogurt drink will be filling and suppress hunger, irrespective of the drink’s energy content. A thicker texture enhanced expectations of satiety to a greater extent than a creamier flavour, and may be one way to improve the anticipated satiating value of energy-containing beverages
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