scholarly journals Suitability of phytoliths as a quantitative process tracer for soil erosion studies

2021 ◽  
Author(s):  
Sabine Kraushaar ◽  
Matthias Konzett ◽  
Janika Kiep ◽  
Christian Siebert ◽  
Julia Meister
Keyword(s):  
Agricultural Land ◽  
Sediment Load ◽  
Sediment Fingerprinting ◽  
Limited Sample ◽  
Artificial Sediment ◽  
Limited Sample Size ◽  
Sediment Mixture ◽  
Mixture Samples ◽  
Plant Microfossil ◽  
Ne Spain

<p>Phytoliths are a plant microfossil commonly used as qualitative archive markers in archaeological and paleoecological studies. Their potential uniqueness to the vegetation cover, robustness to weathering, and lack of chemical alteration along the paths make them a potentially suitable tracer for quantitative erosion studies.<br>In this pilot study, we explore the potential of phytoliths in a sediment fingerprinting study in the Ceguera catchment (28 km2) in NE Spain. The phytolith concentrations and morphologies of four land cover classes (agricultural land, badland, forest, and shrubland) were analyzed, and their contributions to four sediment mixture samples along the river course were modelled. Phytoliths concentrations allowed us to discriminate sources sufficiently, albeit with limited sample size. The performance of the phytoliths as the tracer was tested by reproducing the sources of artificial sediment mixture samples with satisfactory recall ratio. Results identified badlands to be the main contributor, with 84–96% of the sediment load to the sinks, followed by shrublands (median 5%) and agricultural lands (median 2%). Additionally, an intensively used agricultural area in the SW of the catchment was well indicated. These major findings can be reproduced by other conventional erosion studies from this area, indicating that phytoliths are suited to quantifying erosion patterns in mesoscale catchments.</p>

scHinter: imputing dropout events for single-cell RNA-seq data with limited sample size

2019 ◽  
Author(s):  
Pengchao Ye ◽  
Wenbin Ye ◽  
Congting Ye ◽  
Shuchao Li ◽  
Lishan Ye ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sample Size ◽  
Single Cell ◽  
Wide Spectrum ◽  
Dropout Rate ◽  
Supplementary Information ◽  
Sample Sizes ◽  
Limited Sample ◽  
Limited Sample Size ◽  
The Impact

Abstract Motivation Single-cell RNA-sequencing (scRNA-seq) is fast and becoming a powerful technique for studying dynamic gene regulation at unprecedented resolution. However, scRNA-seq data suffer from problems of extremely high dropout rate and cell-to-cell variability, demanding new methods to recover gene expression loss. Despite the availability of various dropout imputation approaches for scRNA-seq, most studies focus on data with a medium or large number of cells, while few studies have explicitly investigated the differential performance across different sample sizes or the applicability of the approach on small or imbalanced data. It is imperative to develop new imputation approaches with higher generalizability for data with various sample sizes. Results We proposed a method called scHinter for imputing dropout events for scRNA-seq with special emphasis on data with limited sample size. scHinter incorporates a voting-based ensemble distance and leverages the synthetic minority oversampling technique for random interpolation. A hierarchical framework is also embedded in scHinter to increase the reliability of the imputation for small samples. We demonstrated the ability of scHinter to recover gene expression measurements across a wide spectrum of scRNA-seq datasets with varied sample sizes. We comprehensively examined the impact of sample size and cluster number on imputation. Comprehensive evaluation of scHinter across diverse scRNA-seq datasets with imbalanced or limited sample size showed that scHinter achieved higher and more robust performance than competing approaches, including MAGIC, scImpute, SAVER and netSmooth. Availability and implementation Freely available for download at https://github.com/BMILAB/scHinter. Supplementary information Supplementary data are available at Bioinformatics online.

Redescription of Clubiona blesti Forster, 1979 (Araneae: Clubionidae) with a preliminary molecular phylogeny of New Zealand Clubiona

Zootaxa ◽  
2012 ◽  
Vol 3277 (1) ◽  
pp. 27 ◽  
Author(s):  
JAGOBA MALUMBRES-OLARTE ◽  
COR J. VINK
Keyword(s):  
Phylogenetic Analysis ◽  
New Zealand ◽  
Wide Distribution ◽  
Dispersal Ability ◽  
Mtdna Sequences ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Geographic Structure ◽  
Molecular Phylogenetic ◽  
First Time

The New Zealand spider Clubiona blesti Forster, 1979 is redescribed, with the male described for the first time, and a pre-liminary molecular phylogenetic analysis of cytochrome c oxidase subunit I (COI) mtDNA sequences for eight species ofNew Zealand Clubiona and an outgroup from Tasmania is presented.There is considerable intraspecific variation in C. blesti, both genetic and in the morphology of copulatory organs,which may be explained by its wide distribution. The lack of a geographic structure based on consistent differences be-tween populations may suggest great dispersal ability. Given the limited sample size, further sampling and data on addi-tional genetic markers will be necessary to confirm this.The phylogenetic analysis of seven more species indicated that Clubiona cambridgei is the sister species of C. blestiand confirmed the existence of at least two monophyletic groups among the New Zealand Clubiona: species with a striped abdomen and with a spotted abdomen.

The predictive performances of random forest models with limited sample size and different species traits

2020 ◽  
Vol 227 ◽  
pp. 105534 ◽  
Author(s):  
Jing Luan ◽  
Chongliang Zhang ◽  
Binduo Xu ◽  
Ying Xue ◽  
Yiping Ren
Keyword(s):  
Random Forest ◽  
Sample Size ◽  
Species Traits ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Forest Models ◽  
Random Forest Models

scholarly journals Visual Hallucinations as Incidental Negative Effects of Virtual Reality on Parkinson’s Disease Patients: A Link with Neurodegeneration?

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Giovanni Albani ◽  
Elisa Pedroli ◽  
Pietro Cipresso ◽  
Daniel Bulla ◽  
Veronica Cimolin ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Virtual Reality ◽  
Clinical History ◽  
Immersive Virtual Reality ◽  
Visual Hallucinations ◽  
Negative Effects ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Immersive Systems

We followed up a series of 23 Parkinson’s disease (PD) patients who had performed an immersive virtual reality (VR) protocol eight years before. On that occasion, six patients incidentally described visual hallucinations (VH) with occurrences of images not included in the virtual environment. Curiously, in the following years, only these patients reported the appearance of VH later in their clinical history, while the rest of the group did not. Even considering the limited sample size, we may argue that VR immersive systems can induce unpleasant effects in PD patients who are predisposed to a cognitive impairment.

Respect Redefined: Focus Group Insights from Singapore

1997 ◽  
Vol 44 (3) ◽  
pp. 205-219 ◽  
Author(s):  
Kalyani Mehta
Keyword(s):  
Focus Group ◽  
Social Workers ◽  
Interpersonal Relationships ◽  
Multicultural Society ◽  
Limited Sample ◽  
Social Scientists ◽  
Limited Sample Size ◽  
The Family ◽  
Focus Group Methodology ◽  
Subjective Views

This article re-examines the meaning of the concept of respect within the context of a fast modernizing Asian multicultural society—Singapore. Two key findings emerge. First, the meaning of respect both from the perspective of the aged and the middle-aged generation has shifted from obedience to courteous behavior. Second, in the majority of focus groups members concurred that the degree of respect accorded to elders has in general decreased. The focus group methodology was used in this research. Bearing in mind the limited sample size (88 participants) these findings alert us to the need for social scientists to monitor perceptual shifts in meaning of concepts critical in the sphere of interpersonal relationships. The findings throw light on the subjective views of intergenerational relations within the family as well as the community. As such, they would be valuable to counselors, social workers, and family therapists.

scholarly journals Agriculture Land Use Change and Demographic Change in Response to Decline Suspended Sediment in Južna Morava River Basin (Serbia)

2021 ◽  
Vol 13 (6) ◽  
pp. 3130
Author(s):  
Sanja Manojlović ◽  
Mikica Sibinović ◽  
Tanja Srejić ◽  
Abosa Hadud ◽  
Ibrahim Sabri
Keyword(s):  
Land Use ◽  
Sediment Transport ◽  
Land Use Change ◽  
Suspended Sediment ◽  
Human Activities ◽  
Rural Population ◽  
Agricultural Land ◽  
Sediment Load ◽  
Morava River ◽  
Morava River Basin

This study expounds the dynamic relationships among agricultural land-use change, rural population migration, and sediment transport. The variability of suspended sediment load was detected by Mann–Kendall and Pettitt tests. From 1961 to 2007, the annual trend in suspended sediment concentration and sediment load demonstrated significant reduction (α = 0.001), with decreasing rates of 0.0144 g/L/y and 84.7 t/y, respectively. An abrupt change-point was detected in 1984 for the sediment load (p = 0.0001). The double-mass curve method and regression analysis of sediment load versus precipitation were used to quantify the effects of climate change and human activities on sediment load variations. The changes in sediment load were predominantly impacted by human activities (89%), while precipitation explained 11% of the reduction in suspended sediment. An important land-use change recorded in the Južna Morava river basin comprised the abandonment of agricultural lands due to depopulation processes, as well as economic and social changes, which was followed by significant impacts on soil erosion and sediment transport. Land abandonment was most pronounced in marginal mountain or semi-mountainous areas, where agriculture was until recent decades traditional or semi-traditional. The results of the correlation matrix were significant at the p < 0.05 level, demonstrating that the decrease of rural population, agricultural land, and arable land were directly related to the decline of suspended sediment. High correlation coefficients were found between anthropogenic indicators and sediment parameters, ranging from 0.94 to 0.97.

BLIND SOURCE SEPARATION TECHNIQUES FOR DECOMPOSING EVENT-RELATED BRAIN SIGNALS

2004 ◽  
Vol 14 (02) ◽  
pp. 773-791 ◽  
Author(s):  
KLAUS-ROBERT MÜLLER ◽  
RICARDO VIGÁRIO ◽  
FRANK MEINECKE ◽  
ANDREAS ZIEHE
Keyword(s):  
Blind Source Separation ◽  
Source Separation ◽  
Biomedical Data ◽  
Physiological Modeling ◽  
Stability Assessment ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Brain Signals ◽  
Interesting Structure

Recently blind source separation (BSS) methods have been highly successful when applied to biomedical data. This paper reviews the concept of BSS and demonstrates its usefulness in the context of event-related MEG measurements. In a first experiment we apply BSS to artifact identification of raw MEG data and discuss how the quality of the resulting independent component projections can be evaluated. The second part of our study considers averaged data of event-related magnetic fields. Here, it is particularly important to monitor and thus avoid possible overfitting due to limited sample size. A stability assessment of the BSS decomposition allows to solve this task and an additional grouping of the BSS components reveals interesting structure, that could ultimately be used for gaining a better physiological modeling of the data.

scholarly journals Prediction in $\mathcal{M}$ -complete Problems with Limited Sample Size

2013 ◽  
Vol 8 (3) ◽  
pp. 647-690 ◽  
Author(s):  
Jennifer Lynn Clarke ◽  
Bertrand Clarke ◽  
Chi-Wai Yu
Keyword(s):  
Sample Size ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Complete Problems

scholarly journals ICU False Alarm Identification Based on Convolution Neural Network

2020 ◽  
Author(s):  
Qiang Yu ◽  
Cheng Wang ◽  
Jing Xi ◽  
Ying Chen ◽  
Weifeng Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Time Series ◽  
False Alarms ◽  
Medical Resource ◽  
Original Time Series ◽  
Limited Sample ◽  
Limited Sample Size ◽  
Grouping Strategy ◽  
Basic Network ◽  
Original Time

Abstract Background: In intensive care unit(ICU), excessive false alarms burden medical staff greatly, and cause medical resource waste as well. In order to alleviate false alarms in ICU, we constructed models for classification using convolutional neural networks, which can deal directly with time series and avoid extracting features manually. Results: Combining with grouping strategy, we tried two basic network structures, i.e. DGCN and EDGCN. After that, based on EDGCN, which was proved better, ensembling networks were also constructed to elevate the performance further. Considering of the limited sample size, different data expansions were also experimented. Finally, we tested our model in the online sandbox, and got a score of 78.14. Conclusions: Although the performance is slightly lower than the best scores that have been reported, our models are end-to-end, through which the original time series can be automatically mapped into a binary output, without manually feature extraction. In addition, our method innovatively uses grouped convolution to make full use of the information in multi-channel signals. In the end, we also discussed the potential solutions to further elevate performances.

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