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| 2. |
- 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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| 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. |
- Ekman, Peter, et al.
(författare)
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Information Systems Use as a Result of External Influences
- 2006
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Ingår i: microCAD 2006 International Scientific Conference. - 9636617147 ; , s. 73-78
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of an information system (IS) can be studied as a result of all the efforts that an organization has put on the introduction of IS, as for example change management, user training, support training and proper technical infrastructure. The description takes its starting point in the organization per se, whilst the one in this paper is external. In this paper, a complementary perspective is offered that can explain the final use of an IS, illustrated by three empirical papers. The use of an IS can be a result of the interorganizational influences as customers, suppliers or other stakeholders. The paper shows that the external environment has a direct effect on how the user experiences an IS and uses it.
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| 5. |
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| 6. |
- Hagberg, Cecilia, et al.
(författare)
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Lättviktsgrindar av höghållfast stål för säkrare djurhantering och arbetsmiljö
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Lightweight gates of high-strength steel for improved worker safety and cattle handling This report presents the work with developing a lightweight gate of high-strength steel for the handling of cattle. The project was conducted as a European Innovation Partnership (EIP) project. The project group consisted of co-workers from the unit of Agriculture and Horticulture and the unit of Process and Environmental Engineering at Research Institutes of Sweden (RISE Jordbruk och trädgård och RISE Kretsloppsteknik), Parsteel AB (former Nilssons Plåtindustri AB), SSAB EMEA AB, Sophie Atkinson at Smart Animal Handling, Swedish University of Agricultural Sciences (SLU) in Skara and the cattle farmer Lars Olsson. The main objectives of the project were to develop a lightweight gate weighing at least 50% less and being three times as strong as a traditional gate for cattle handling. The main motive was to improve the ergonomic conditions and working environment for the animal handlers. Additionally, for the safety of both animals and handlers, the gate must withstand the loads from cattle. Other objectives were to design and construct a gate that does not exceed the price of a high-quality gate and not contribute to increased negative environmental impact. A lightweight gate can be made of various materials such as plastic, fiberglass or steel. Regarding the project group's participants and their competencies, in addition to the numerous requirements placed on a lightweight gate, the choice fell on high-strength steel. High-strength steel is characterized by having high yield strengths, up to 1300 MPa, in comparison with traditional construction steel with yield strength of 355 MPa. For the specific lightweight gate, steel pipes with a yield strength of approximately 750 MPa were chosen. These pipes are mainly used in the automotive and engine industry, where high demands are placed on strength while at the same time a light construction is desired. The gate itself was designed during the project and several details were examined and developed in regard to functionality and safety for both cattle and handlers. The work environment legislation states that gates must be dimensioned and anchored so that the animals cannot break out (AFS 2008:17). The gates must also not pose a risk of injury to the cattle. In order to work safely with cattle, knowledge of cattle behavior is essential and consequently the report contains a chapter describing cattle senses and behavior. Both the lightweight gates and the handling system, built up by the gates, must be adapted to the cattle. In the project, the bud box handling system was tested. The handling system was originally developed to make use of the behavioral characteristics of cattle to encourage forward movement in the desired direction. In the project the handling system's functionality and safety, by using lightweight gates and additional equipment and components, were further designed. The handling system was tested in two groups of heifers at the SLU Götala Beef and Lamb Research Centre. The lightweight gates were also tested in a dairy herd and a beef herd, while hoof trimming, and at a small-scale abattoir. Generally, the light weight of the gates was considered an advantage as the handling of the gates is simplified also resulting in more frequent use of the gates, increasing safety for both animals and humans. During the project, several strength tests were performed by building unique test rigs. In one test rig, the weld of the pipes of the lightweight gate was tested. In another test rig, the strength of lightweight gates, compared with traditional gates on the market, were tested. The outcome of the tests confirmed the original aim of the project, a lightweight gate made of high-strength steel, about 50% lighter and at least three times as strong as traditional gates, had been developed and designed during the project period.
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| 7. |
- Joshi, Peter K, et al.
(författare)
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Directional dominance on stature and cognition in diverse human populations
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 523:7561, s. 459-462
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Tidskriftsartikel (refereegranskat)abstract
- Homozygosity has long been associated with rare, often devastating, Mendelian disorders, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10(-300), 2.1 × 10(-6), 2.5 × 10(-10) and 1.8 × 10(-10), respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months' less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.
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| 8. |
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| 9. |
- Lind, Lars, et al.
(författare)
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Genetic and methylation variation in the CYP2B6 gene is related to circulating p,p '-dde levels in a population-based sample
- 2017
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Ingår i: Environment International. - Oxford, United Kingdom : Elsevier. - 0160-4120 .- 1873-6750. ; 98, s. 212-218
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Since the metabolism of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) is not fully known in humans, we evaluated if circulating levels of a major breakdown product of DDT, p,p'-DDE, were related to genome-wide genetic and methylation variation in a population-based sample.Methods: In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects all aged 70), circulating levels of p, p'-DDE were analyzed by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS). Genetic variants were genotyped and imputed (1000 Genomes reference, March 2012 release). Methylation sites were assayed using the Illumina HumanMethylation450 array in whole blood. A genome-wide association study (GWAS) approach was applied.Results: Evidence for genome-wide significant association with p,p'-DDE levels was observed only for a locus at chromosome 19 corresponding to the CYP2B6 gene (lead SNP rs7260538). Subjects being homozygote for the G allele showed a median level of 472 ng/g lipid, while the corresponding level for those being homozygote for the T allelewas 192 ng/g lipid (p= 1.5x10(-31)). An analysis conditioned on the lead SNP disclosed a distinct signal in the same gene (rs7255374, position chr19: 41520351; p= 2.2 x 10(-8)). A whole-genome methylation analysis showed one significant relationship vs. p,p'-DDE levels (p= 6.2 x 10(-9)) located 7 kb downstreamthe CYP2B6 gene (cg27089200, position chr19: 41531976). This CpG-sitewas also related to the lead SNP (p = 3.8 x 10(-35)), but mediated only 4% of the effect of the lead SNP on p, p'-DDE levels.Conclusion: Circulating levels of p, p'-DDE were related to genetic variation in the CYP2B6 gene in the general elderly population. DNA methylation in this gene is not closely linked to the p, p'-DDE levels.
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| 10. |
- Lind, Lars, et al.
(författare)
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Genetic variation in the CYP1A1 gene is related to circulating PCB118 levels in a population-based sample
- 2014
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Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 133, s. 135-140
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Tidskriftsartikel (refereegranskat)abstract
- Several of the polychlorinated biphenyls (PCBs), i.e. the dioxin-like PCBs, are known to induce the P450 enzymes CYP1A1, CYP1A2 and CYP1B1 by activating the aryl hydrocarbon receptor (Ah)-receptor. We evaluated if circulating levels of PCBs in a population sample were related to genetic variation in the genes encoding these CYPs. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects all aged 70), 21 SNPs in the CYP1A1, CYP1A2 and CYP1B1 genes were genotyped. Sixteen PCB congeners were analysed by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/ HRMS). Of the investigated relationships between SNPs in the CYP1A1, CYP1A2 and CYP1B1 and six PCBs (congeners 118, 126, 156, 169, 170 and 206) that captures > 80% of the variation of all PCBs measured, only the relationship between CYP1A1 rs2470893 was significantly related to PCB118 levels following strict adjustment for multiple testing (p=0.00011). However, there were several additional SNPs in the CYP1A2 and CYP1B1 that showed nominally significant associations with PCB118 levels (p-values in the 0.003-0.05 range). Further, several SNPs in the CYP1B1 gene were related to both PCB156 and PCB206 with p-values in the 0.005-0.05 range. Very few associations with p < 0.05 were seen for PCB126, PCB169 or PCB170. Genetic variation in the CYP1A1 was related to circulating PCB118 levels in the general elderly population. Genetic variation in CYP1A2 and CYP1B1 might also be associated with other PCBs.
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