Effect Of High-optical Excitation On The Ultrafast Electron Dynamics In Stacked-monolayer Graphene Samples

We report on transient absorption experiments performed at high optical excitation fluences and used to study the ultrafast dynamics in graphene. We employed a degenerated scheme of pump and probe at 800 nm (1.55 eV). The time resolution of our measurements was limited by the pulse duration similar to 100 fs. The samples were prepared by chemical vapor deposition (CVD) as single-layers on silica and, then staked layer-by-layer in order to make a stack of up to 5 graphene monolayers. We observed saturable absorption (SA) and fluence-dependent relaxation times. We see that the ultrafast carrier dynamics is composed by two decay mechanisms, one with response time of about 200 fs and a slower process of about 1 ps. The fast decay, due to both carrier-carrier and carrier-optical phonon scattering, becomes slower when the density of excited carrier was increased. We implemented a theoretical model and found that both the optical phonon rate emission and the optical phonon lifetime are affect by the pump fluence.9835Conference on Ultrafast Bandgap PhotonicsAPR 18-20, 2016Baltimore, M

Apathy and functional disability in behavioral variant frontotemporal dementia

Background Behavioral variant frontotemporal dementia (bvFTD) has profound consequences on patients and their families. In this multicenter study, we investigated the contribution of cognitive and neuropsychiatric factors to everyday function at different levels of overall functional impairment. Methods In a retrospective cross-sectional study, 109 patients with bvFTD from 4 specialist frontotemporal dementia centers (Australia, England, India, and Brazil) were included. The measures administered evaluated everyday function (Disability Assessment for Dementia [DAD]), dementia staging (Clinical Dementia Rating [CDR]), general cognition (Addenbrooke’s Cognitive Examination–revised [ACE-R]), and neuropsychiatric symptoms (Neuropsychiatric Inventory [NPI]). Patients were then subdivided according to functional impairment on the DAD into mild, moderate, severe, and very severe subgroups. Three separate multiple linear regression analyses were run, where (1) total DAD, (2) basic activities of daily living (BADL), and (3) instrumental activities of daily living (IADL) scores were dependent variables; ACE-R total score and selected NPI domains (agitation/aggression, euphoria, apathy, disinhibition, irritability, aberrant motor behavior) were used as independent variables. Age, sex, education, and country of origin were controlled for in the analyses. Results Cognitive deficits were similar across the mild, moderate, and severe subgroups but significantly worse in the very severe subgroup. NPI domain scores (agitation/aggression, euphoria, apathy, disinhibition, irritability, aberrant motor behavior) did not differ across the DAD subgroups. In the multiple regression analyses, a model including ACE-R and NPI apathy explained 32.5% of the variance for total DAD scores. For IADL, 35.6% of the variance was explained by the ACE-R only. No model emerged for BADL scores. Conclusions Cognitive deficits and apathy are key contributors to functional disability in bvFTD but factors underlying impairment in BADLs remain unclear. Treatments targeting reduction of disability need to address apathy and cognitive impairment to ensure greater efficacy, especially in regards to IADLs

Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract

This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.This work was supported by grants from Conselho de Desenvolvimento Científico e Tecnológico (CNPq). This work was part of Master Dissertation of NCAG (Laboratório de Bioquímica / CCBS, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brasil). The authors gratefully for the support from the USP/Ribeirão Preto – SP, Brazil.This work was supported by grants from Conselho de Desenvolvimento Científico e Tecnológico (CNPq). This work was part of Master Dissertation of NCAG (Laboratório de Bioquímica / CCBS, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brasil). The authors gratefully for the support from the USP/Ribeirão Preto – SP, Brazil

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

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

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