scholarly journals First record and extended distribution of Otothyropsis piribebuy (Loricariidae: Hypoptopomatinae) in Brazil

2020 ◽  
Vol 60 ◽  
pp. e20206021
Author(s):  
Guilherme Seiji Hocama ◽  
Fernanda De Oliveira Martins ◽  
Francisco Severo-Neto
Keyword(s):  
Principal Component Analysis ◽  
Maximum Entropy ◽  
Principal Component ◽  
Original Description ◽  
First Record ◽  
Neotropical Region ◽  
Correct Identification ◽  
Neotropical Fish ◽  
Essential Step ◽  
Benthic Fishes

Cascudinhos are a group of small benthic fishes included in the Hypoptopomatinae subfamily, inhabiting small to moderate streams and rivers within the Neotropical region, from Venezuela to Northern Argentina. Until now, Otothyropsis piribebuy originally described from the rio Paraguay basin, in Paraguay, is the only species of the genus not recorded in Brazil. Recent samples in the rio Tererê, rio Paraguay basin, Brazil, revealed a population of Otothyropsis with uncertain taxonomic identity. Therefore, the study aimed to unveil the distribution of Otothyropsis within Brazilian territory. External morphology, osteology, measurements, and counts (plates, teeth, and rays) of these specimens from rio Tererê were compared to data from the original description of O. piribebuy, and also with specimens of O. piribebuy sampled in Paraguayan territory. Observations indicated no differences among the analyzed specimens. Furthermore, a Principal Component Analysis (PCA), carried out using log-transformed measures from Brazilian and Paraguayan specimens, showed no separation of these populations, also indicating that all analyzed specimens pertain to the same species. Based on this, a prediction map of distribution, using Maximum Entropy, was produced. The correct identification of spatial range of occurrence is an essential step to ensure the conservation of species, and the extended distribution of Otothyropsis piribebuy was confirmed, enhancing the list of neotropical fish from Brazil.

Principal component analysis based on non-parametric maximum entropy

2010 ◽  
Vol 73 (10-12) ◽  
pp. 1840-1852 ◽  
Author(s):  
Ran He ◽  
Baogang Hu ◽  
XiaoTong Yuan ◽  
Wei-Shi Zheng
Keyword(s):  
Principal Component Analysis ◽  
Maximum Entropy ◽  
Principal Component ◽  
Component Analysis ◽  
Non Parametric

scholarly journals Facial Landmarks Detection on Faulty Datasets with Regression Trees and Principal Component Analysis Parametrization

2018 ◽  
Author(s):  
Abner S. Nascimento ◽  
Danilo A. Oliveira ◽  
Maria Raquel L. De Couto ◽  
Iális C. De Paula Júnior
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Regression Trees ◽  
Component Analysis ◽  
Parametric Models ◽  
Essential Step ◽  
Proposed Model ◽  
Combined Use ◽  
Regression Algorithms ◽  
Missing Labels

Tracking landmarks points of the human face is an essential step for the construction of interfaces capable of taking advantage of the communicative potential of facial expressions. Many strategies based on parametric models and regression algorithms with boosting can be applied to this problem. This paper proposes a solution based on the combined use of principal component analysis and regression trees. The main purpose of the presented method is to reduce the sensibility of the system to the presence of missing labels when trained with faulty datasets, by the adoption of corrective heuristics. On such cases, the proposed model achieves performance similar to the reference results, obtained by training on fault free datasets.

scholarly journals Illustrated record of the freshwater copepod Leptodiaptomus dodsoni (Calanoida, Diaptomidae) from central Mexico with comments on the distribution of the genus

2010 ◽  
Vol 10 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Marcelo Silva-Briano ◽  
Eduardo Suárez-Morales
Keyword(s):  
North America ◽  
Calanoid Copepod ◽  
Original Description ◽  
First Record ◽  
Neotropical Region ◽  
Central Mexico ◽  
Nominal Species ◽  
Distal Margin ◽  
Western Mexico ◽  
The Right

The freshwater planktonic calanoid copepod Leptodiaptomus dodsoni Elías-Gutiérrez, Suárez-Morales & Romano, 1999, a rare species known only from western Mexico, is here recorded from the State of Aguascalientes, central Mexico. This species has a uniquely large, sinuous spine on segment 13 of the right male antennule, reaching the distal margin of segment 15. There are subtle differences between these two known populations; the morphological range of the species is complemented with data from the new specimens. This is the first record of L. dodsoni after its original description; it is probably restricted to a latitudinal fringe in central Mexico. Of the 22 nominal species of Leptodiaptomus currently recognized, up to 7 are known from the Neotropical region and some appear to be true endemics. Apparently, this primarily Nearctic genus radiated in North America and some species reached the Neotropical region where they diversified. A key for the identification of the species of the genus known from the Neotropical region is also provided.

scholarly journals A New Ensemble Method for Detecting Anomalies in Gene Expression Matrices

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 882
Author(s):  
Laura Selicato ◽  
Flavia Esposito ◽  
Grazia Gargano ◽  
Maria Carmela Vegliante ◽  
Giuseppina Opinto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Principal Component Analysis ◽  
Principal Component ◽  
Real Data ◽  
Biological Data ◽  
Correct Identification ◽  
Expression Data ◽  
Robust Principal Component Analysis ◽  
Biomedical Field

One of the main problems in the analysis of real data is often related to the presence of anomalies. Namely, anomalous cases can both spoil the resulting analysis and contain valuable information at the same time. In both cases, the ability to detect these occurrences is very important. In the biomedical field, a correct identification of outliers could allow the development of new biological hypotheses that are not considered when looking at experimental biological data. In this work, we address the problem of detecting outliers in gene expression data, focusing on microarray analysis. We propose an ensemble approach for detecting anomalies in gene expression matrices based on the use of Hierarchical Clustering and Robust Principal Component Analysis, which allows us to derive a novel pseudo-mathematical classification of anomalies.

Scanning x-ray fluorescence microscopy and principal component analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1752-1753
Author(s):  
Brian Cross
Keyword(s):  
Principal Component Analysis ◽  
Fluorescence Microscopy ◽  
Spatial Resolution ◽  
High Speed ◽  
Image Acquisition ◽  
Principal Component ◽  
Fluorescence Microscope ◽  
Acquisition Rate ◽  
X Ray ◽  
Speed Up

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.

A German version of the Intermittent Claudication Questionnaire (ICQ): cultural adaptation and validation

VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl
Keyword(s):  
Principal Component Analysis ◽  
Intermittent Claudication ◽  
Completion Time ◽  
Short Form ◽  
Principal Component ◽  
Component Analysis ◽  
German Version ◽  
Average Completion Time ◽  
Sf 36 ◽  
Related Quality

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.

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