scholarly journals Vascular Tissue Analysis as a Decisive Tool for Tropical Hardwood Identification: The Case Study of Ekop Species in Cameroon

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Pierre Paul Mbarga ◽  
Armand William Mala ◽  
Marie Marguerite Mbolo

The perforation plates and vessel-ray pitting of tropical hardwoods are typical features that make it possible to mark species within a botanical family. This study aims to bring out a consistent and robust framework for a clear distinction through anatomical features among various Ekop woods based on usual nomenclature on trade. Perforations plates and vessel-ray pitting are determining components for the classification of the species. Indeed, several species exploited under the trade name Ekop because of their grain, color, and wooden decoration patterns do not belong to the same taxonomic class. With the natural structure of cells and their intervessel pits observed in xylem and phloem, it appears that the perforation plates and the vessel-ray pitting are decisive components for the classification of Ekop species. Forty-three wood specimens of Ekop were collected from forests in Ebolowa, Mbalmayo, and Abong Mbang. In addition, 155 microscopic sections of Ekop slides with at least 3 representatives of identified species were observed. Thus, macroscopic observations through a hand magnifying glass were performed on wood carrots. Then, the microscopic sections of slides in the first 63 features of the International Association of Wood Anatomists list were analyzed. Correlations were observed between vessels elements and other main features through component analysis. Four groups of Ekop were differentiated by gathering in each genus a matrix of similar features across their vessels groupings, perforation plates, and vessel-ray pittings. A tabular key was used to further define the identity of the Ekop species. This study makes it possible to recognize Ekop wood beyond the dendrological aspects of vegetative and reproductive organs. Finally, a few typical features used for a precise demarcation were identified, for a taxonomic classification within the Ekop group.

2018 ◽  
Vol 71 (3) ◽  
pp. 942-950
Author(s):  
Vania Dias Cruz ◽  
Silvana Sidney Costa Santos ◽  
Jamila Geri Tomaschewski-Barlem ◽  
Bárbara Tarouco da Silva ◽  
Celmira Lange ◽  
...  

ABSTRACT Objective: To assess the health/functioning of the older adult who consumes psychoactive substances through the International Classification of Functioning, Disability and Health, considering the theory of complexity. Method: Qualitative case study, with 11 older adults, held between December 2015 and February 2016 in the state of Rio Grande do Sul, using interviews, documents and non-systematic observation. It was approved by the ethics committee. The analysis followed the propositions of the case study, using the complexity of Morin as theoretical basis. Results: We identified older adults who consider themselves healthy and show alterations - the alterations can be exacerbated by the use of psychoactive substances - of health/functioning expected according to the natural course of aging such as: systemic arterial hypertension; depressive symptoms; dizziness; tinnitus; harmed sleep/rest; and inadequate food and water consumption. Final consideration: The assessment of health/functioning of older adults who use psychoactive substances, guided by complex thinking, exceeds the accuracy limits to risk the understanding of the phenomena in its complexity.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Zhe Yang ◽  
Dejan Gjorgjevikj ◽  
Jianyu Long ◽  
Yanyang Zi ◽  
Shaohui Zhang ◽  
...  

AbstractSupervised fault diagnosis typically assumes that all the types of machinery failures are known. However, in practice unknown types of defect, i.e., novelties, may occur, whose detection is a challenging task. In this paper, a novel fault diagnostic method is developed for both diagnostics and detection of novelties. To this end, a sparse autoencoder-based multi-head Deep Neural Network (DNN) is presented to jointly learn a shared encoding representation for both unsupervised reconstruction and supervised classification of the monitoring data. The detection of novelties is based on the reconstruction error. Moreover, the computational burden is reduced by directly training the multi-head DNN with rectified linear unit activation function, instead of performing the pre-training and fine-tuning phases required for classical DNNs. The addressed method is applied to a benchmark bearing case study and to experimental data acquired from a delta 3D printer. The results show that its performance is satisfactory both in detection of novelties and fault diagnosis, outperforming other state-of-the-art methods. This research proposes a novel fault diagnostics method which can not only diagnose the known type of defect, but also detect unknown types of defects.


2021 ◽  
Vol 22 (14) ◽  
pp. 7292
Author(s):  
Luca Marsili ◽  
Jennifer Sharma ◽  
Alberto J. Espay ◽  
Alice Migazzi ◽  
Elhusseini Abdelghany ◽  
...  

The gold standard for classification of neurodegenerative diseases is postmortem histopathology; however, the diagnostic odyssey of this case challenges such a clinicopathologic model. We evaluated a 60-year-old woman with a 7-year history of a progressive dystonia–ataxia syndrome with supranuclear gaze palsy, suspected to represent Niemann–Pick disease Type C. Postmortem evaluation unexpectedly demonstrated neurodegeneration with 4-repeat tau deposition in a distribution diagnostic of progressive supranuclear palsy (PSP). Whole-exome sequencing revealed a new heterozygous variant in TGM6, associated with spinocerebellar ataxia type 35 (SCA35). This novel TGM6 variant reduced transglutaminase activity in vitro, suggesting it was pathogenic. This case could be interpreted as expanding: (1) the PSP phenotype to include a spinocerebellar variant; (2) SCA35 as a tau proteinopathy; or (3) TGM6 as a novel genetic variant underlying a SCA35 phenotype with PSP pathology. None of these interpretations seem adequate. We instead hypothesize that impairment in the crosslinking of tau by the TGM6-encoded transglutaminase enzyme may compromise tau functionally and structurally, leading to its aggregation in a pattern currently classified as PSP. The lessons from this case study encourage a reassessment of our clinicopathology-based nosology.


2021 ◽  
Vol 11 (14) ◽  
pp. 6452
Author(s):  
César Ricardo Soto-Ocampo ◽  
Juan David Cano-Moreno ◽  
José Manuel Mera ◽  
Joaquín Maroto

Increasing industrial competitiveness has led to an increased global interest in condition monitoring. In this sector, rotating machinery plays an important role, where the bearing is one of the most critical components. Many vibration-based signal treatments are already being used to identify features associated with bearing faults. The information embedded in such features are employed in the construction of health indicators, which allow for evaluation of the current operating status of the machine. In this work, the use of contour maps to represent the diagnosis map of a bearing, used as a health map, is presented for the first time. The results show that the proposed method is promising, allowing for the satisfactory detection and evaluation of the severity of bearing damage. In this initial stage of the research, our results suggest that this method can improve the classification of bearing faults and, therefore, optimise maintenance processes.


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