2,231 research outputs found

    The Relationship between Different Assays for Detection and Quantification of Amyloid Beta 42 in Human Cerebrospinal Fluid

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    Alzheimer's disease (AD), which is characterized by a degeneration of neurons and their synapses, is one of the most common forms of dementia. CSF levels of amyloid β42 (Aβ42) have been recognized as a strong candidate to serve as an AD biomarker. There are a number of commercial assays that are routinely employed for measuring Aβ42; however, these assays give diverse ranges for the absolute levels of CSF Aβ42. In order to employ CSF Aβ42 as a biomarker across multiple laboratories, studies need to be performed to understand the relationship between the different platforms. We have analyzed CSF samples from both diseased and nondiseased subjects with two different widely used assay platforms. The results showed that different values for the levels of CSF Aβ42 were reported, depending on the assay used. Nonetheless, both assays clearly demonstrated statistically significant differences in the levels of Aβ42 in CSF from AD relative to age-matched controls (AMC). This paper provides essential data for establishing the relationship between these assays and provides an important step towards the validation of Aβ42 as a biomarker for AD

    Structure from motion photogrammetry in ecology: Does the choice of software matter?

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    This is the final version. Available from Wiley via the DOI in this record.Data available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.q7c400k (Forsmoo et al., 2019).Image‐based modeling, and more precisely, Structure from Motion (SfM) and Multi‐View Stereo (MVS), is emerging as a flexible, self‐service, remote sensing tool for generating fine‐grained digital surface models (DSMs) in the Earth sciences and ecology. However, drone‐based SfM + MVS applications have developed at a rapid pace over the past decade and there are now many software options available for data processing. Consequently, understanding of reproducibility issues caused by variations in software choice and their influence on data quality is relatively poorly understood. This understanding is crucial for the development of SfM + MVS if it is to fulfill a role as a new quantitative remote sensing tool to inform management frameworks and species conservation schemes. To address this knowledge gap, a lightweight multirotor drone carrying a Ricoh GR II consumer‐grade camera was used to capture replicate, centimeter‐resolution image datasets of a temperate, intensively managed grassland ecosystem. These data allowed the exploration of method reproducibility and the impact of SfM + MVS software choice on derived vegetation canopy height measurement accuracy. The quality of DSM height measurements derived from four different, yet widely used SfM‐MVS software—Photoscan, Pix4D, 3DFlow Zephyr, and MICMAC, was compared with in situ data captured on the same day as image capture. We used both traditional agronomic techniques for measuring sward height, and a high accuracy and precision differential GPS survey to generate independent measurements of the underlying ground surface elevation. Using the same replicate image dataset (n = 3) as input, we demonstrate that there are 1.7, 2.0, and 2.5 cm differences in RMSE (excluding one outlier) between the outputs from different SfM + MVS software using High, Medium, and Low quality settings, respectively. Furthermore, we show that there can be a significant difference, although of small overall magnitude between replicate image datasets (n = 3) processed using the same SfM + MVS software, following the same workflow, with a variance in RMSE of up to 1.3, 1.5, and 2.7 cm (excluding one outlier) for “High,” “Medium,” and “Low” quality settings, respectively. We conclude that SfM + MVS software choice does matter, although the differences between products processed using “High” and “Medium” quality settings are of small overall magnitude.James Hutton InstituteUniversity of Exete

    Exploring Perceptions of Sugar Sweetened Beverages Among Early Adolescents in Worcester, MA: a Qualitative Study

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    Background: Among adolescents, sugar-sweetened beverages (SSBs) are the primary source of added dietary sugar and constitute 10-15% of their total caloric intake. A range of factors influence adolescent dietary behaviors and food choices. This study aimed to explore adolescents\u27 attitudes and knowledge about SSBs, how they receive messages about SSBs, and motivations for SSB consumption. Methods: We conducted 5 focus groups with youth aged 12-14 years that attend one of the eight Youth Connect programs in Worcester, MA in 2016-2017. Groups were sex-specific because of changes during adolescence and experiences with body image and health behaviors between the groups. A semi-structured guide was used to facilitate a discussion with adolescents\u27 around SSBs. The audio recorded data were transcribed and all transcripts were double coded. The data were analyzed using thematic analysis. Results: Discussions included 16 boys in three focus groups and 17 girls in two groups. Participants were 12-14 years old, 27% identified as Hispanic, 24% black and 33% white. One third speaks more than one language at home and the majority consume SSBs daily. Qualitative analysis led to the identification and classification of various subdimensions under the following analytic categories: Attitudes, Motivations, Knowledge, and SSB Messaging. Common themes that emerge under each category will be reported. Analyses are in progress. Conclusions: This research will present a deeper understanding of factors that influence Worcester adolescents\u27 beverage choices from their own perspective. The information can be used in public health messaging in Worcester around obesogenic behaviors such as excess caloric intake from SSBs

    Home Matters: Adolescents Drink More Sugar Sweetened Beverages When They Are Available at Home

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    Objective: Sugar sweetened beverage (SSB) consumption has increased by 300% in the past three decades and the largest source of both added sugar and calories in the diets of US adolescents. It has been argued that the increased intake of SSBs has contributed to the rising prevalence of obesity. The availability and accessibility of foods/drinks in multiple levels of an adolescent’s environment can influence one’s choices and impact consumption. The aim of this study is to examine the association between adolescent self-report of the availability of SSBs in their home and SSB consumption and whether neighborhood and school SSB availability modifies the association between availability of SSBs in the home and adolescent SSB consumption. Methods: The Family Life, Activity, Sun, Health and Eating (FLASHE) was used to conduct a cross sectional analysis of 1,484 parent-adolescent dyads. Each dyad completed four online surveys about dietary and activity health behaviors. Ordinal logistic regression analyses were conducted to determine the association between the measures of SSB availability in the home and teen SSB consumption behaviors. The potential moderators, school SSB availability and neighborhood SSB availability, were tested separately using stratified ordinal logistic regression analyses. Results: The greater frequency of availability of SSB’s in the home had a positive association with teen SSB consumption. This association remained present despite the availability of SSB’s in other locations. There was no moderation effect present in either school SSB availability and neighborhood SSB availability. Conclusion: Understanding the impact of the availability of SSB’s in multiple environments on consumption is important for obesity prevention efforts. This study found that parents can be important factors in reducing adolescent SSB consumption by influencing the home environment. Despite the availability of SSB’s in other environments, the home remains important for impacting consumption. Also Presented at the 2018 Society of Behavioral Medicine Annual Meeting

    Relationships between demographic and behavioural factors and spatial behaviour in missing persons' cases

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    To date, limited systematic focus has been directed to examining factors that influence the spatial behaviour of missing people. Accordingly, this study examined whether demographic and behavioural factors were related to distance between missing and found locations in 16,454 archival cases of missing reports from two UK police forces. Findings from ordinal regressions showed that children were more likely to be found at further distances if they were deemed to be at high or medium risk of coming to harm but less likely to be located further away when victims of a violent attack. Adults were more likely to be found at further distances if planning behaviours were present (e.g. had taken their passport), but less likely to if they were above the age of 65 years or suffering from abuse. Findings indicate the role of age, planning and vulnerability on travel when missing. Implications for search strategies and directions for future research are considered

    Antitumor Activity of Gold(I), Silver(I) and Copper(I) Complexes Containing Chiral Tertiary Phosphines

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    The in vitro cytotoxicities of a number of gold(I), silver(I) and copper(I) complexes containing chiral tertiary phosphine ligands have been examined against the mouse tumour cell lines P815 mastocytoma, B16 melanoma [gold(I) and silver(I) compounds] and P388 leukaemia [gold(I) complexes only] with many of the complexes having IC50 values comparable to that of the reference compounds cis-diamminedichloroplatinum(ll), cisplatin, and bis[1,2-bis(diphenylphosphino) ethane]gold(I) iodide. The chiral tertiary phosphine ligands used in this study include (R)-(2-aminophenyl)methylphenylphosphine; (R,R)-, (S,S)- and (R*,R*)-1,2-phenylenebis(methylphenylphosphine); and (R,R)-, (S,S)- and (R*,R*)-bis{(2-diphenylphosphinoethyl)phenylphosphino}ethane. The in vitro cytotoxicities of gold(I) and silver(I) complexes containing the optically active forms of the tetra(tertiary phosphine) have also been examined against the human ovarian carcinoma cell lines 41M and CH1, and the cisplatin resistant 41McisR, CH1cisR and SKOV-3 tumour models. IC50 values in the range 0.01 - 0.04 μM were determined for the most active compounds, silver(I) complexes of the tetra(tertiary phosphine). Furthermore, the chirality of the ligand appeared to have little effect on the overall activity of the complexes: similar IC50 data were obtained for complexes of a particular metal ion with each of the stereoisomeric forms of a specific ligand
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