| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
- Bixby, H., et al.
(författare)
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Rising rural body-mass index is the main driver of the global obesity epidemic in adults
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 569:7755, s. 260-4
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
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| 5. |
- Lind, Lars, et al.
(författare)
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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)
- 2021
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Ingår i: eLife. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
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| 7. |
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| 8. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.522.7) and 16.5 cm (13.319.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 9. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3– 19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8– 144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 11. |
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| 12. |
- Gonzalez-Franquesa, Alba, et al.
(författare)
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Discovery of thymosin β4 as a human exerkine and growth factor
- 2021
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Ingår i: American Journal of Physiology - Cell Physiology. - : American Physiological Society. - 0363-6143 .- 1522-1563. ; 321:5, s. 770-778
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Tidskriftsartikel (refereegranskat)abstract
- Skeletal muscle is an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in interorgan cross talk. Using mass spectrometry (MS)-based proteomics, we characterized the secretome and identified thymosin b4 (TMSB4X) as the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in the plasma of exercising humans irrespective of the insulin resistance condition or exercise mode. Treatment of mice with TMSB4X did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration in vivo. However, TMSB4X increased osteoblast proliferation and neurite outgrowth, consistent with its WADA classification as a prohibited growth factor. Therefore, we report TMSB4X as a human exerkine with a potential role in cellular cross talk.
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| 13. |
- McGawley, Kerry, 1978-, et al.
(författare)
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The effect of high versus low concentration maltodextrin-fructose ingestion during a simulated 30-km cross-country ski race
- 2014
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Konferensbidrag (refereegranskat)abstract
- IntroductionLong-distance cross-country ski races typically last more than 2 h, depleting muscle glycogen stores in the legs and, to an even greater extent, the arms (Bergström et al. 1973). While carbohydrate (CHO) supplementation demonstrates clear performance-enhancing effects, particularly when ingested during exercise lasting > 1 h and in multiple forms (Jeukendrup 2004), there is limited information regarding the use of CHO during cross-country skiing. Therefore, the aim of the current study was to examine the effect of ingesting two different CHO solutions on 30-km cross-country skiing performance.Methods10 male and 3 female trained cross-country skiers (age: 30±7 yr; body mass: 74±9 kg; VO2max: 60±6 mL/kg/min) completed 4 x 30-km classic roller-skiing time-trial efforts (consisting of 6 x 5-km loops) on separate days in a randomised, counter-balanced order on a treadmill. Two trials used a high rate of CHO ingestion (2.4 g/min, HC) and two trials used a lower rate of CHO ingestion (1.2 g/min, LC). In addition, two trials used a high frequency of CHO feeds (6 feeds, HF) and two trials used a low frequency of CHO feeds (2 feeds, LF). The CHO was a 1:1 mix of maltodextrin and fructose and the drinks were provided at 24% and 12% concentrations for HC and LC, respectively.ResultsThere were no significant differences in performance over the four trials (140±16, 139±16, 141±18 and 141±18 min for HC-HF, LC-HF, HC-LF and LC-LF, respectively) and when matched for frequency of feeds, there were no significant performance differences between the paired comparisons (i.e., HC-HF vs LC-HF and HC-LF vs LC-LF). Moreover, there were no significant differences in blood glucose concentrations at 5-km intervals when comparing HC-HF with LC-HF (p>0.05) or HC-LF with LC-LF (p>0.05). However, an order effect was detected for performance (143±17, 140±16, 140±17 and 138±15 min for trials 1-4, respectively) with significant improvements from trials 1-2 (p=0.02) and 3-4 (p=0.03).DiscussionResults from the current study demonstrate no significant differences in 30-km cross-country ski performance when consuming either 2.4 or 1.2 g/min of a mixed CHO solution. Furthermore, there were no significant differences in blood glucose concentrations during exercise between the high and lower CHO trials. However, despite familiarisation to treadmill roller-skiing and the simulated race track, a learning effect was evident. It is concluded that race-track familiarity may have a greater effect on 30-km cross-country ski performance than the rate of CHO ingestion.
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| 14. |
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| 15. |
- Stocks, Ben, et al.
(författare)
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Effects of carbohydrate dose and frequency on metabolism, gastrointestinal discomfort, and cross-countryskiing performance
- 2016
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 26:9, s. 1100-1108
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated carbohydrate ingestion of varied doses and frequencies during a simulated cross-country skiing time trial. Ten men and three women (age: 30±7years; VO2max: 59.6±5.7 mL/kg/min) completed four, 30-km classic technique roller skiing time trials on a treadmill. A 1:1 maltodextrin-fructose carbohydrate solution was provided at high (2.4 g/min; HC) and moderate (1.2 g/min; MC) ingestion rates, each at high (six feeds;HF) and low (two feeds; LF) frequencies. In the LF trials, blood glucose was elevated following carbohydrate ingestion (at 4 and 19 km) but was reduced at 14 and 29 km compared with HF strategies (P≤0.05). Gastrointestinal discomfort was higher in HC-LF compared with all other trials (P≤0.05). Whole-body lipid oxidation was lowerand carbohydrate oxidation was higher in LF compared with HF trials (P≤0.05). While performance time was not significantly different between trials (140:11±15:31,140:43±17:40, 139:12±15:32 and 140:33±17:46 min:sin HC-HF, HC-LF, MC-HF, and MC-LF, respectively;P>0.05), it was improved with trial order (P<0.001). There was no effect of order on any other variable (P>0.05). Altering carbohydrate dose or frequency does not affect cross-country ski performance. However, low-frequency carbohydrate ingestion resulted in poorer maintenance of euglycemia, reduced lipid oxidation, and increased gastrointestinal discomfort.
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| 16. |
- Stocks, Ben, et al.
(författare)
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The effect of high- versus low-frequency ingestion of a maltodextrin-fructose drink during 30-km cross-country skiing
- 2014
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Konferensbidrag (refereegranskat)abstract
- IntroductionWhile carbohydrate ingestion can improve endurance performance, relatively little is known about the effect of frequency of carbohydrate ingestion. This may be of particular importance in cross-country skiing, where upper-body propulsion is inevitably decreased during drinking periods. Therefore, the study aim was to examine the effect of ingesting carbohydrate at two different frequencies on 30-km cross-country skiing performance.MethodsThirteen participants completed four, 30-km classic roller-skiing time-trials on a simulated treadmill course. A 1:1 maltodextrin-fructose solution was provided at high (6 feeds; HF) and low (2 feeds; LF) frequencies and high (2.4 g∙min-1, 24%;HC) and low (1.2 g∙min-1, 12%; LC) rates. Gastrointestinal discomfort was measured using an adapted 6-20 Borg scale.ResultsThere were no differences in performance between the four trials (140±16, 139±16, 141±18 and 141±18 min for HF-HC, HF-LC, LF-HC and LF-LC, respectively), although LF-LC was likely harmful compared to HF-LC. However, an order effect was apparent (143±17, 140±16, 140±17 and 138±15 min for trials 1-4, respectively). There was a significant rate x frequency interaction for gastrointestinal discomfort, with greater discomfort in LF-HC (10.3±2.7) compared with HF-HC (8.5±3.1) and HF-LC (8.4±2.7). LF-LC (9.0±2.3) was not significantly different to any other trial.DiscussionThese data suggest there is no significant effect of ingestion frequency on 30-km simulated cross-country ski performance. However, there may be a practically relevant detrimental effect of low frequency ingestion at low rates. Further, LF carbohydrate ingestion increases gastrointestinal discomfort when ingested as HC.
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| 17. |
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