The effects of Antarctic alteration and sample heterogeneity on Sm-Nd and Lu-Hf systematics in H chondrites

2021 ◽  
Author(s):  
Ryoga Maeda ◽  
Steven Goderis ◽  
Vinciane Debaille ◽  
Hamed Pourkhorsandi ◽  
Geneviève Hublet ◽  
...  
Keyword(s):  
H Chondrites ◽  
Sample Heterogeneity

Effect of Sample Heterogeneity on near Infrared Meat Analysis: The Use of the RMS Statistic

1998 ◽  
Vol 6 (A) ◽  
pp. A313-A320 ◽  
Author(s):  
M.L. Martínez ◽  
Ana Garrido-Varo ◽  
E. De Pedro ◽  
L. Sánchez
Keyword(s):  
Near Infrared ◽  
Fiber Optic ◽  
Iberian Pig ◽  
Set Up ◽  
Sample Heterogeneity ◽  
Meat Analysis

Ground and emulsified samples from Iberian pig hams were analysed by reflectance and interactance reflectance mode. Spectral errors due to intra-sample variations were calculated for both analysis modes. The spectral errors were calculated by means of the STD RMS statistic included on the ISI software. The results obtained show that a mean STD RMS value as low as 4200, could be obtained for paired subsamples of the same sample and that an STD limit of 4374 could be fixed at the instrument set-up program in order to ensure that a representative spectrum has been obtained from two subsamples readings of the same sample. That procedure avoids the need to take numerous subsamples, as is traditional in NIR/NIT meat analysis. The results also show that the spectral repeatability using fiber optic is worse than for spinning cups and it has been concluded that effort should be made to avoid moisture variations during scanning in order to improve spectral repeatability.

scholarly journals Dimensionality reduction by UMAP reinforces sample heterogeneity analysis in bulk transcriptomic data

Cell Reports ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 109442
Author(s):  
Yang Yang ◽  
Hongjian Sun ◽  
Yu Zhang ◽  
Tiefu Zhang ◽  
Jialei Gong ◽  
...  
Keyword(s):  
Dimensionality Reduction ◽  
Transcriptomic Data ◽  
Heterogeneity Analysis ◽  
Sample Heterogeneity

scholarly journals The Impact of Criteria-based and Data-driven Sampling Approaches on the Heterogeneity and Interpretability of Posttraumatic Stress Symptom Networks

2020 ◽  
Author(s):  
Santiago Papini ◽  
Mikael Rubin ◽  
Michael J Telch ◽  
Jasper A. J. Smits
Keyword(s):  
Data Driven ◽  
Network Heterogeneity ◽  
Psychopathological Symptom ◽  
Highly Correlated ◽  
And Cluster Analysis ◽  
Sensitivity Specificity ◽  
Future Work ◽  
The Impact ◽  
Sample Heterogeneity ◽  
Source Of Error

Background. The application of psychopathological symptom networks requires reconciliation of the observed cross-sample heterogeneity. We leveraged the largest sample to be used in a PTSD network analysis (N = 28,594) to examine the impact of criteria-based and data-driven sampling approaches on the heterogeneity and interpretability of networks.Methods. Severity and diagnostic criteria identified four overlapping subsamples and cluster analysis identified three distinct data-derived profiles. Networks estimated on each subsample were compared to a respective benchmark network at the symptom-relation level by calculating sensitivity, specificity, correlation, and density of the edges. Negative edges were assessed for Berkson’s bias, a source of error that can be induced by threshold samples on severity.Results. Criteria-based networks showed reduced sensitivity, specificity, and density but edges remained highly correlated and a meaningfully higher proportion of negative edges was not observed relative to the benchmark network of all cases. Among the data-derived profile networks, the Low Severity network had the highest proportion of negative edges not present in the benchmark network of symptomatic cases. The High Severity profile also showed a higher proportion of negative edges, whereas the Medium Severity profile did not. Conclusion. Although networks showed differences, Berkson’s bias did not appear to be a meaningful source of systematic error. These results can guide expectations about the generalizability of symptom networks across samples that vary in their ranges of severity. Future work should continue to explore whether network heterogeneity is reflective of meaningful and interpretable differences in the symptom relations from which they are composed.

scholarly journals EFFECTIVENESS OF FDI, TECHNOLOGICAL GAP AND SECTORAL LEVEL PRODUCTIVITY IN THE VISEGRAD GROUP

2020 ◽  
Vol 0 (0) ◽  
pp. 1-26
Author(s):  
Kamil Makieła ◽  
Liwiusz Wojciechowski ◽  
Krzysztof Wach
Keyword(s):  
Economic Growth ◽  
Positive Impact ◽  
Labour Productivity ◽  
Technological Gap ◽  
Labour Productivity Growth ◽  
Sectoral Output ◽  
Effective Use ◽  
The Impact ◽  
Visegrad Group ◽  
Sample Heterogeneity

The objective of this paper is to investigate the impact of foreign direct investment (FDI) on economic growth and productivity in sectors of the Visegrad Group one decade after their accession to the EU. In order to account for sample heterogeneity, as well as productivity differences, we construct a generalized true random-effects model with varying efficiency distribution. We find that FDI has a positive impact on the Visegrad Group’s sectors and that its effectiveness depends upon the technological gap between the host and home economy. There are three sources of this positive impact: (i) sectoral output and labour productivity growth, (ii) more effective use of input factors, and via (iii) higher efficiency component of the total factor productivity (TFP). These sources form a three-way transmission mechanism through which FDI can impact economic growth conditioned upon FDI effectiveness due to the technological gap.

scholarly journals Sarek: A portable workflow for whole-genome sequencing analysis of germline and somatic variants

2018 ◽  
Author(s):  
Maxime Garcia ◽  
Szilveszter Juhos ◽  
Malin Larsson ◽  
Pall I. Olason ◽  
Marcel Martin ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Open Source ◽  
Genome Sequencing ◽  
Development Project ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Insertion And Deletion ◽  
Sample Heterogeneity

AbstractSummaryWhole-genome sequencing (WGS) is a cornerstone of precision medicine, but portable and reproducible open-source workflows for WGS analyses of germline and somatic variants are lacking. We present Sarek, a modular, comprehensive, and easy-to-install workflow, combining a range of software for the identification and annotation of single-nucleotide variants (SNVs), insertion and deletion variants (indels), structural variants, tumor sample heterogeneity, and karyotyping from germline or paired tumor/normal samples. Sarek is implemented in a bioinformatics workflow language (Nextflow) with Docker and Singularity compatible containers, ensuring easy deployment and full reproducibility at any Linux based compute cluster or cloud computing environment. Sarek supports the human reference genomes GRCh37 and GRCh38, and can readily be used both as a core production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups.AvailabilitySource code and instructions for local installation are available at GitHub (https://github.com/SciLifeLab/Sarek) under the MIT open-source license, and we invite the research community to contribute additional functionality as a collaborative open-source development project.

scholarly journals Environmental DNA variability in lake sediment cores

2021 ◽  
Vol 4 ◽  
Author(s):  
John Pearman ◽  
Georgia Thomson-Laing ◽  
Jamie Howarth ◽  
Marcus Vandergoes ◽  
Lucy Thompson ◽  
...  
Keyword(s):  
16S Rrna ◽  
General Trend ◽  
Sediment Cores ◽  
Environmental Dna ◽  
Biological Communities ◽  
The Core ◽  
Community Dissimilarity ◽  
Sample Heterogeneity ◽  
Read Abundance ◽  
Natural Archives

Lake sediments are natural archives that accumulate information about biological communities and their surrounding catchments. Paleolimnology has traditionally focussed on identifying fossilized organisms to reconstruct past environments. In the last decade, the application of molecular methodologies has increased in paleolimnological studies, but further studies investigating factors such as sample heterogeneity and DNA degradation are required. Here we investigated bacterial community heterogeneity (16S rRNA metabarcoding) within depth slices. Sediment cores were collected from three lakes with differing sediment compositions. Samples were collected from a variety of depths (1-cm width) which represent a period of time of approximately 1,200 years. Triplicate samples were collected from each slice and bacterial 16S rRNA metabarcoding was undertaken on each sample. Rarefaction curves showed that except for the deepest (oldest) slices, the combination of three replicate samples were insufficient to characterise the entire bacterial diversity. However, shared Amplicon Sequence Variants (ASVs) accounted for the majority of the reads in each slice (max. shared proportional read abundance 96%, 86%, 65% in the three lakes). Within slice similarity was higher than between slice similarity. No general trend was observed in variability among replicates with depth amongst the lakes. In one core. there was a higher community dissimilarity in older sediment, which may be due to laminae not being horizontal. These results highlight the fact that microbial communities can be differentiated with depth however it is critical to interpret these results in the context of the stratigraphic data of the core.

scholarly journals Quantification of amyloid fibril polymorphism by nano-morphometry reveals the individuality of filament assembly

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Liam D. Aubrey ◽  
Ben J. F. Blakeman ◽  
Liisa Lutter ◽  
Christopher J. Serpell ◽  
Mick F. Tuite ◽  
...  
Keyword(s):  
Self Assembly ◽  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Biological Function ◽  
Structural Basis ◽  
Distance Curve ◽  
Filament Assembly ◽  
Sample Heterogeneity ◽  
Structural Insights ◽  
Polymorphic Nature

Abstract Amyloid fibrils are highly polymorphic structures formed by many different proteins. They provide biological function but also abnormally accumulate in numerous human diseases. The physicochemical principles of amyloid polymorphism are not understood due to lack of structural insights at the single-fibril level. To identify and classify different fibril polymorphs and to quantify the level of heterogeneity is essential to decipher the precise links between amyloid structures and their functional and disease associated properties such as toxicity, strains, propagation and spreading. Employing gentle, force-distance curve-based AFM, we produce detailed images, from which the 3D reconstruction of individual filaments in heterogeneous amyloid samples is achieved. Distinctive fibril polymorphs are then classified by hierarchical clustering, and sample heterogeneity is objectively quantified. These data demonstrate the polymorphic nature of fibril populations, provide important information regarding the energy landscape of amyloid self-assembly, and offer quantitative insights into the structural basis of polymorphism in amyloid populations.

Noble gases in eleven H-chondrites

1973 ◽  
Vol 37 (2) ◽  
pp. 359-362 ◽  
Author(s):  
E. Ganapathy ◽  
Edward Anders
Keyword(s):  
Noble Gases ◽  
H Chondrites
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