43 research outputs found

    EXPLORING THE ROLE OF OSPREYS IN EDUCATION

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    Recent research in childhood education has demonstrated that experiences in nature are important in shaping early environmental consciousness (Hinds and Sparks 2008, Hussar and Horvath 2011, Cheng and Monroe 2012) and ultimately the expression of pro-environmental attitudes and behaviors during adulthood (Wells and Lekies 2006, Chawla and Cushing 2007, Collado et al. 2013). Increasingly, those experiences happen via written and electronic media (e.g., textbooks, computer screens) or in very anthropogenic environments (e.g., in parks and zoos) and less through direct contact with nature, a concept Louv (2005) referred to as ‘‘nature deficit disorder.’’ Even in schools where environmental education is prioritized, the extent of access to outdoor classroom activities or experiential learning opportunities can limit the degree to which children can observe, explore, and directly experience the natural world (Hudson 2001, Louv 2005, Ernst 2009). Interestingly, the same information technologies that might serve to limit contact with nature also have the potential to enhance and encourage interest and concern for the natural world (Blewitt 2011, Pearson et al. 2011). We believe this is an important paradox that warrants much further exploration and evaluation within educational and scientific communities

    National trends in total cholesterol obscure heterogeneous changes in HDL and non-HDL cholesterol and total-to-HDL cholesterol ratio : a pooled analysis of 458 population-based studies in Asian and Western countries

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    Background: Although high-density lipoprotein (HDL) and non-HDL cholesterol have opposite associations with coronary heart disease, multi-country reports of lipid trends only use total cholesterol (TC). Our aim was to compare trends in total, HDL and nonHDL cholesterol and the total-to-HDL cholesterol ratio in Asian and Western countries. Methods: We pooled 458 population-based studies with 82.1 million participants in 23 Asian and Western countries. We estimated changes in mean total, HDL and non-HDL cholesterol and mean total-to-HDL cholesterol ratio by country, sex and age group. Results: Since similar to 1980, mean TC increased in Asian countries. In Japan and South Korea, the TC rise was due to rising HDL cholesterol, which increased by up to 0.17 mmol/L per decade in Japanese women; in China, it was due to rising non-HDL cholesterol. TC declined in Western countries, except in Polish men. The decline was largest in Finland and Norway, at similar to 0.4 mmol/L per decade. The decline in TC in most Western countries was the net effect of an increase in HDL cholesterol and a decline in non-HDL cholesterol, with the HDL cholesterol increase largest in New Zealand and Switzerland. Mean total-to-HDL cholesterol ratio declined in Japan, South Korea and most Western countries, by as much as similar to 0.7 per decade in Swiss men (equivalent to similar to 26% decline in coronary heart disease risk per decade). The ratio increased in China. Conclusions: HDL cholesterol has risen and the total-to-HDL cholesterol ratio has declined in many Western countries, Japan and South Korea, with only a weak correlation with changes in TC or non-HDL cholesterol.Peer reviewe

    Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

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    © The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

    A century of trends in adult human height

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    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

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    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

    Morphology, phytogeography, and systematics of the diatom genus <italic>Hannaea</italic> (Bacillariophyceae).

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    The diatom genus Hannaea is unique in its valve morphology and restricted ecological preferences. This araphid genus has been separated taxonomically by its arcuate valve outline but appears to be closely related to Fragilaria and Synedra. Multiple lines of morphological, phytogeographical, and phylogenetic evidence were utilized to examine the diversity and relationships within Hannaea and among related taxa. First, morphological differences among Hannaea taxa were documented with light and scanning electron microscopy. Valve metrics (e.g., length, width, and curvature) from nine morphologically diverse Hannaea populations were used to separate or group these populations using multivariate statistics. Secondly, ecological preferences and geographical distributions also were compiled from collections and published records. Finally, cladistic analysis tested hypotheses of evolutionary relationships in the family Fragilariaceae (including Hannaea); these hypotheses examined the monophyly of Hannaea, the sister taxon of Hannaea, and overall relationships in Fragilariaceae. Geographic distributions showed that the genus Hannaea contains some taxa that are widespread but ecologically restricted ( H. arcus and varieties) and endemic taxa (H. mongolica, H. superiorensis, and H. recta) restricted to regions or lake systems. Finally, the cladistic analysis shows Hannaea to be monophyletic in a clade with Fragilaria sensu stricto (making Fragilaria sensu stricto paraphyletic). The monophyly of Hannaea, based on a combination of characters in addition to an arcuate valve, supports the separation of Hannaea as a genus. Overall, results from the morphological, ecological, and cladistic analyses supported the description of two new taxa: Hannaea superiorensis sp. nov., an endemic species from the Great Lakes and H. mongolica sp. nov. from the Baikal Rift Zone. Additionally, Ceratoneis arcus var. recta will be transferred and elevated to H. recta, based on its limited geographical distribution, valve morphology and hypothesized evolutionary relationship within Hannaea. The two varieties of H. arcus, H. arcus var. amphioxys and H. arcus var. linearis, remain at their current taxonomic status, based on morphological similarity and ecological overlap with the nominate variety. Formal descriptions and transfers will be done later in an effective publication.Ph.D.Biological SciencesBotanyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124846/2/3016807.pd

    Bottom-up and top-down effects on algal community dynamics in an aridland river: the Middle Rio Grande, New Mexico&#xb;

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    Background/Question/Methods&#xd;&#xa;&#xd;&#xa;In this study, we examined interactive effects of nutrient availability, river flow and food web structure on algal growth and species composition in the Middle Rio Grande, New Mexico. Algal community dynamics can be affected by both bottom-up and top-down factors. Algal production may be limited by low levels of nutrients or low light availability. Conversely, production is expected to increase when nutrient levels are high and light availability is not limited. Top-down factors such as grazing by invertebrates can also alter periphyton growth and community composition. Generally, a reduction in grazers results in periphyton biomass increases and shifts in growth forms (to more upright taxa).&#xd;&#xa;&#xd;&#xa;Nutrient diffusing substrates (NDS) were used in combination with grazer exclusion to investigate bottom-up and top-down effects on periphyton growth and species composition. Previously, NDS has been used in small, headwater streams and not in large sandy rivers like the Middle Rio Grande. NDS were made from inverted terracotta saucers, with four nutrient treatments &#x2013; control, N, P and N+P. Large invertebrates were excluded from a subset of the saucers using an electrical field. The saucers were placed in a slow-flowing area of the Middle Rio Grande, and samples were collected weekly for a month. &#xd;&#xa;&#xd;&#xa;Results/Conclusions&#xd;&#xa;&#xd;&#xa;River conditions made it challenging to conduct the NDS experiment. Water levels were variable and turbidity levels were extremely high (&#x3e;4000NTU). Algal growth was extremely low on all treatments, largely due to light limitation caused by consistently high turbidity levels and a series of flooding and drying events which also decimated organismal growth on the substrates. Initial surveys of the diatom communities indicate extremely low densities and chlorophyll biomass was very low (mean &#xb1; se = 0.31 &#xb1; 0.09mg/m2). While dense periphyton communities did not develop on the NDS saucers, there was evidence of colonization by invertebrate populations. Blackfly larvae (Simuliidae) were most abundant in earlier samples whereas chironomid larvae (Chironomidae) were more abundant later in the experiment. Also, blackfly larvae were significantly more abundant on control saucers than on N+P saucers in the grazer/non-grazer experiment (P = 0.044). However, it was difficult to detect differences in the abundance of invertebrate grazers among nutrient treatments. Relationships among invertebrate population densities and the availability and diversity of periphyton for grazing will be described. These results are not definitive, but there are indications that nutrients, flow and grazers do influence algal community dynamics
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