294 research outputs found

    Recent Trends in Junk Food Intake in U.S. Children and Adolescents, 2003–2016

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    Introduction: In the U.S., there is no consensus of how to define junk food. Strict regulations on what constitutes junk food denoted by front-of-package labels can serve as the basis for statutory actions. Chile was the first country to adopt this approach, and several countries have followed suit. This study examined the proportion of calories and nutrients of concern consumed by U.S. children and adolescents defined as junk food using the Chilean label criteria and the changes between 2003 and 2016. Methods: Data were obtained from 4 nationally representative food intake surveys in 13,016 U.S. children and adolescents: National Health and Nutrition Examination Survey 2003–2004, 2005–2006, 2013–2014, and 2015–2016, with analysis performed in 2019. Nutritional content of each consumed food was compared with nutrient thresholds from the Chilean regulation for energy, saturated fat, total sugars, and sodium per 100 g. Results: Between 2003 and 2016, there was a 10 percentage point decrease (71.1%–61.3%, p<0.01) in the proportion of foods consumed that were classified as junk food. A significant decrease was seen in mean intake of calories (1,610–1,367 kcal/day, p<0.01), total sugar (88.8–64.2 g/day, p<0.01), saturated fat (22.6–20.5 g/day, p<0.01), and sodium (2,306–2,044 mg/day, p<0.01). Conclusions: Although junk food intake has decreased since 2003–2006, diets of U.S. children and adolescents remain dominated by less-healthy foods. These results can help guide policy regulations regarding foods and beverages accessible in schools and marketed to children, adolescents, and their caregivers

    Low threshold linear cavity mode-locked fiber laser using microfiber-based carbon nanotube saturable absorber

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    In this work, we demonstrate a linear cavity mode-locked erbium-doped fiber laser in C-band wavelength region. The passive mode-locking is achieved using a microfiber-based carbon nanotube saturable absorber. The carbon nanotube saturable absorber has low saturation fluence of 0.98 µJ/cm2. Together with the linear cavity architecture, the fiber laser starts to produce soliton pulses at low pump power of 22.6 mW. The proposed fiber laser generates fundamental soliton pulses with a center wavelength, pulse width, and repetition rate of 1557.1 nm, 820 fs, and 5.41 MHz, respectively. This mode-locked laser scheme presents a viable option in the development of low threshold ultrashort pulse system for deployment as a seed laser

    Types and Amounts of Nonnutritive Sweeteners Purchased by US Households: A Comparison of 2002 and 2018 Nielsen Homescan Purchases

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    Background: Purchases of foods containing nonnutritive sweetener (NNS) alone or in combination with caloric sweeteners (CS) has increased in recent years in the United States. At the same time clinical evidence is emerging of different cardiometabolic effects of each NNS type. Objective: To examine the prevalence and volume purchased of commonly consumed types of NNS in packaged food and beverage products comparing 2002 and 2018 using data from nationally representative samples of US households. Participants/setting: Nielsen Homescan Consumer Panels (The Nielsen Company); 2002 and 2018. Main outcome measures: Prevalence and volume of foods and beverages purchased containing CS, NNS, both CS and NNS, or neither CS nor NNS, as well as prevalence and volume of products containing specific NNS types. Statistical analyses performed: Differences examined using Student t test, P value of <.05 considered significant. Results: Volume of products purchased containing CS decreased comparing 2002 and 2018 (436.6 ± 1.6 to 362.4 ± 1.3 g/d; P <.05), yet increased for products containing both CS and NNS (10.8-36.2 g/d; P <.05). Regarding specific types of NNS, changes were noted in the prevalence of households purchasing products containing saccharin (1.3%-1.1%; P <.05), aspartame (60.0%-49.4%; P <.05), rebaudioside A (0.1%-25.9%) and sucralose (38.7%-71.0%). Non-Hispanic whites purchased twice the volume of products containing NNS compared to Hispanics and non-Hispanic blacks in both years. Beverages were predominantly responsible for larger volume per capita purchases of products containing only NNS as well as both CS and NNS. Conclusions: A decline in purchases of products containing CS occurred in tandem with an increase in purchases of products containing both CS and NNS, along with a large shift in the specific types of NNS being purchased by US households. New NNS types enter the market regularly, and it is important to monitor changes in the amount of NNS and products containing NNS that consumers purchase

    Low threshold L-band mode-locked ultrafast fiber laser assisted by microfiber-based single wall carbon nanotube saturable absorber

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    We demonstrate a passively mode-locked erbium-doped fiber laser in L-band wavelength region with low mode-locking threshold employing a 1425 nm pump wavelength. The mode-locking regime is generated by microfiber-based saturable absorber using carbon nanotube-polymer composite in a ring cavity. This carbon nanotube saturable absorber shows saturation intensity of 9 MW/cm². In this work, mode-locking laser threshold is observed at 36.4 mW pump power. At the maximum pump power of 107.6 mW, we obtain pulse duration at full-width half-maximum point of 490 fs and time bandwidth product of 0.33, which corresponds to 3-dB spectral bandwidth of 5.8 nm. The pulse repetition rate remains constant throughout the experiment at 5.8 MHz due to fixed cavity length of 35.5 m. Average output power and pulse energy of 10.8 mW and 1.92 nJ are attained respectively through a 30% laser output extracted from the mode-locked cavity. This work highlights the feasibility of attaining a low threshold mode-locked laser source to be employed as seed laser in L-band wavelength region

    Optical properties of structurally-relaxed Si/SiO2_2 superlattices: the role of bonding at interfaces

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    We have constructed microscopic, structurally-relaxed atomistic models of Si/SiO2_2 superlattices. The structural distortion and oxidation-state characteristics of the interface Si atoms are examined in detail. The role played by the interface Si suboxides in raising the band gap and producing dispersionless energy bands is established. The suboxide atoms are shown to generate an abrupt interface layer about 1.60 \AA thick. Bandstructure and optical-absorption calculations at the Fermi Golden rule level are used to demonstrate that increasing confinement leads to (a) direct bandgaps (b) a blue shift in the spectrum, and (c) an enhancement of the absorption intensity in the threshold-energy region. Some aspects of this behaviour appear not only in the symmetry direction associated with the superlattice axis, but also in the orthogonal plane directions. We conclude that, in contrast to Si/Ge, Si/SiO2_2 superlattices show clear optical enhancement and a shift of the optical spectrum into the region useful for many opto-electronic applications.Comment: 11 pages, 10 figures (submitted to Phys. Rev. B

    Thermostatistics of deformed bosons and fermions

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    Based on the q-deformed oscillator algebra, we study the behavior of the mean occupation number and its analogies with intermediate statistics and we obtain an expression in terms of an infinite continued fraction, thus clarifying successive approximations. In this framework, we study the thermostatistics of q-deformed bosons and fermions and show that thermodynamics can be built on the formalism of q-calculus. The entire structure of thermodynamics is preserved if ordinary derivatives are replaced by the use of an appropriate Jackson derivative and q-integral. Moreover, we derive the most important thermodynamic functions and we study the q-boson and q-fermion ideal gas in the thermodynamic limit.Comment: 14 pages, 2 figure

    Development and potential role of type-2 sodium-glucose transporter inhibitors for management of type 2 diabetes

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    There is a recognized need for new treatment options for type 2 diabetes mellitus (T2DM). Recovery of glucose from the glomerular filtrate represents an important mechanism in maintaining glucose homeostasis and represents a novel target for the management of T2DM. Recovery of glucose from the glomerular filtrate is executed principally by the type 2 sodium-glucose cotransporter (SGLT2). Inhibition of SGLT2 promotes glucose excretion and normalizes glycemia in animal models. First reports of specifically designed SGLT2 inhibitors began to appear in the second half of the 1990s. Several candidate SGLT2 inhibitors are currently under development, with four in the later stages of clinical testing. The safety profile of SGLT2 inhibitors is expected to be good, as their target is a highly specific membrane transporter expressed almost exclusively within the renal tubules. One safety concern is that of glycosuria, which could predispose patients to increased urinary tract infections. So far the reported safety profile of SGLT2 inhibitors in clinical studies appears to confirm that the class is well tolerated. Where SGLT2 inhibitors will fit in the current cascade of treatments for T2DM has yet to be established. The expected favorable safety profile and insulin-independent mechanism of action appear to support their use in combination with other antidiabetic drugs. Promotion of glucose excretion introduces the opportunity to clear calories (80–90 g [300–400 calories] of glucose per day) in patients that are generally overweight, and is expected to work synergistically with weight reduction programs. Experience will most likely lead to better understanding of which patients are likely to respond best to SGLT2 inhibitors, and under what circumstances

    Risk factors for development and progression of diabetic retinopathy in Dutch patients with type 1 diabetes mellitus

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    Purpose: To investigate risk factors for the development and progression of diabetic retinopathy (DR) and long-term visual outcomes in Dutch patients with type 1 diabetes mellitus (T1DM). Methods: Cumulative incidences were calculated for DR, vision-threatening DR (VTDR), defined as (pre)proliferative DR and diabetic macular oedema, and best-corrected visual acuity (BCVA) <0.5 and <0.3 at the most recent eye examination. The fo

    Myosin concentration underlies cell size–dependent scalability of actomyosin ring constriction

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    © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Journal of Cell Biology 195 (2011): 799-813, doi:10.1083/jcb.201101055.In eukaryotes, cytokinesis is accomplished by an actomyosin-based contractile ring. Although in Caenorhabditis elegans embryos larger cells divide at a faster rate than smaller cells, it remains unknown whether a similar mode of scalability operates in other cells. We investigated cytokinesis in the filamentous fungus Neurospora crassa, which exhibits a wide range of hyphal circumferences. We found that N. crassa cells divide using an actomyosin ring and larger rings constricted faster than smaller rings. However, unlike in C. elegans, the total amount of myosin remained constant throughout constriction, and there was a size-dependent increase in the starting concentration of myosin in the ring. We predict that the increased number of ring-associated myosin motors in larger rings leads to the increased constriction rate. Accordingly, reduction or inhibition of ring-associated myosin slows down the rate of constriction. Because the mechanical characteristics of contractile rings are conserved, we predict that these findings will be relevant to actomyosin ring constriction in other cell types.Work in the laboratories of M.K. Balasubramanian and G. Jedd is supported by research funds from Singapore Millennium Foundation and the Temasek Life Sciences Laboratory.2012-05-2

    Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.

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    The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
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