Habitat differentiation and geographic separation of Isoetes velata populations in central Iberian Peninsula

2021 ◽  
Vol 45 ◽  
pp. e75525
Author(s):  
José Antonio Molina
Keyword(s):  
Iberian Peninsula ◽  
Late Glacial ◽  
Diagnostic Features ◽  
Central System ◽  
System A ◽  
Habitat Differentiation ◽  
Northwestern Spain ◽  
Geographic Separation ◽  
Spanish Central System

Populations of Isoetes velata were studied in order to provide more information on their habitat and distribution in the Western and Northwestern Iberian Peninsula. Habitat together with morphology of megaspores were used as diagnostic features. The form I. velata subsp. velata f. lereschii is considered here as a synonym of I. velata subsp. asturicense and therefore only two taxa remain within the species: I. velata subsp. velata and I. velata subsp. asturicense. Intermediate individuals have been found in the Western Central System. The differentiation within the I. velata group appears to be the result of gradual genetic divergence after isolation. Palaeobotanical data confirm the presence of I. velata subsp. asturicense in Late Glacial lake sediments in northwestern Spain. Cluster classification of the soft-water vegetation with Isoetes velata subsp. asturicense revealed two main groups in the Spanish Central System. A single association, the Sparganio angustifolii-Callitrichetum fontqueri which includes Iberian Atlantic stands of Sparganium angustifolium and Isoetes velata subsp. asturicense, is here recognized. Besides, a variant of the association with Eleocharis acicularis is identified in shallow temporary waters in the Western Sierra de Gredos.

scholarly journals A U‐Pb Study of Zircons from a Lower Crustal Granulite Xenolith of the Spanish Central System: A Record of Iberian Lithospheric Evolution from the Neoproterozoic to the Triassic

2006 ◽  
Vol 114 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Javier Fernández‐Suárez ◽  
Ricardo Arenas ◽  
Teresa E. Jeffries ◽  
Martin J. Whitehouse ◽  
Carlos Villaseca
Keyword(s):  
Central System ◽  
Granulite Xenolith ◽  
System A ◽  
Spanish Central System ◽  
Lower Crustal ◽  
Lithospheric Evolution

scholarly journals Morphological characterization, cytogenetic analysis, and geographical distribution of the Pygmy Marbled Newt Triturus marmoratus pygmaeus (Wolterstorff, 1905) (Caudata: Salamandridae)

1993 ◽  
Vol 63 (1) ◽  
pp. 3-14 ◽  
Author(s):  
M. García-París ◽  
P. Herrero ◽  
C. Martín ◽  
J. Dorda ◽  
M. Esteban ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Accurate Determination ◽  
Morphological Characterization ◽  
Diagnostic Features ◽  
Central System ◽  
Northern Half ◽  
Serra Da Estrela ◽  
Triturus Marmoratus ◽  
Cytogenetical Analysis

Triturus marmoratus pygmaeus, a problematicsubspecies of the Marbled Newt from the southern part of the Iberian Peninsula, is redescribed using specimens collected in the “typical” area. Diagnostic external morphological features are provided to permit the accurate determination of the specimens belonging either to T. m. marmoratus or to T. m. pygmaeus. These diagnostic features were applied to individuals both from the field and from museum collections. The results indicate a larger distributional area for to T. m. pygmaeusto than was previously recognized. The distribution of to T. m. marmoratusto ranges over the northern half of the Iberian Peninsula and most of France; to T. m. pygmaeusto occupies the southwestern part of the Iberian Peninsula. The contact area between the two subspecies seemsto be located alongthe Central Range Mountains (Sistema Central) in Portugal and Spain. to T. m. marmoratusto extends southwards beyond this borderline in three areas: Serra da Estrela (Portugal), Sierra de Gata (Spain) and Sierra de Guadarrama (Spain). The only point at which to T. m. pygmaeusto reaches northwards beyond the Central System is near Puerto de Malagón (Madrid Province, Spain). No cases of strict sympatry, nor individuals with intermediate morphologicalfeatures have been observed. The results of an extensive cytogenetical analysis do not show any differences between to T. m. pygmaeusto and to T. m. marmoratusto . Interestingly, however, the to T. m. pygmaeusto populations from Doñana (Huelva Province, Spain) showed an exclusive, though little differentiated, C-banding pattern.

scholarly journals The Variscan gabbros from the Spanish Central System: A case for crustal recycling in the sub-continental lithospheric mantle?

Lithos ◽  
2009 ◽  
Vol 110 (1-4) ◽  
pp. 262-276 ◽  
Author(s):  
David Orejana ◽  
Carlos Villaseca ◽  
Cecilia Pérez-Soba ◽  
José A. López-García ◽  
Kjell Billström
Keyword(s):  
Lithospheric Mantle ◽  
Central System ◽  
Crustal Recycling ◽  
System A ◽  
Continental Lithospheric Mantle ◽  
Spanish Central System

scholarly journals Stabilizing interventional instruments in the cardiovascular system: A classification of mechanisms

2021 ◽  
Vol 89 ◽  
pp. 22-32
Author(s):  
Awaz Ali ◽  
Dimitra Dodou ◽  
Gerwin Smit ◽  
Ruben Rink ◽  
Paul Breedveld
Keyword(s):  
Cardiovascular System ◽  
System A

Classification of EEG Mental Patterns by Using Two Scalp Electrodes and Mahalanobis Distance-Based Classifiers

2002 ◽  
Vol 41 (04) ◽  
pp. 337-341 ◽  
Author(s):  
F. Cincotti ◽  
D. Mattia ◽  
C. Babiloni ◽  
F. Carducci ◽  
L. Bianchi ◽  
...  
Keyword(s):  
Mahalanobis Distance ◽  
Brain Computer Interface ◽  
Computer Interface ◽  
Correct Classification ◽  
Interface Area ◽  
System A ◽  
The Brain ◽  
Full Covariance Matrix ◽  
Recording Electrodes

Summary Objectives: In this paper, we explored the use of quadratic classifiers based on Mahalanobis distance to detect mental EEG patterns from a reduced set of scalp recording electrodes. Methods: Electrodes are placed in scalp centro-parietal zones (C3, P3, C4 and P4 positions of the international 10-20 system). A Mahalanobis distance classifier based on the use of full covariance matrix was used. Results: The quadratic classifier was able to detect EEG activity related to imagination of movement with an affordable accuracy (97% correct classification, on average) by using only C3 and C4 electrodes. Conclusions: Such a result is interesting for the use of Mahalanobis-based classifiers in the brain computer interface area.

scholarly journals On the fossil Remains of Panochthus Burmeister, 1866 (Xenarthra, Cingulata, Glyptodontidae) from the Pleistocene of southern Brazil

2015 ◽  
Vol 87 (1) ◽  
pp. 15-27 ◽  
Author(s):  
José D. Ferreira ◽  
Martín Zamorano ◽  
Ana Maria Ribeiro
Keyword(s):  
South America ◽  
Rio Grande ◽  
Species Level ◽  
External Morphology ◽  
Latitudinal Distribution ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Diagnostic Features ◽  
New Material

The genus Panochthus represents the last lineage of "Panochthini" recorded in the Pleistocene. This genus has a wide latitudinal distribution in South America, and in Brazil it occurs in the southern and northeastern regions. In this paper we describe new material (isolated osteoderms and caudal tube fragments) assigned to Panochthus from the state of Rio Grande do Sul (southern Brazil) and discuss some taxonomic issues related to Panochthus tuberculatus and Panochthus greslebini based on this material . The occurrence of P. greslebini is the first for outside the Brazilian Intertropical Region. In addition, we describe new diagnostic features to differentiate the osteoderms of P. greslebini and P. tuberculatus. Unfortunately, it was not possible to identify some osteoderms at the species level. Interestingly, they showed four distinct morphotypes characterized by their external morphology, and thus were attributed to Panochthus sp. Lastly, we conclude that in addition to P.tuberculatus registered to southern Brazil, there is another species of the genus, assignable to P. cf. P. greslebini. Our analysis reinforce the reliability of caudal tube characters for the classification of species of Panochthus.

scholarly journals A Computational Strategy for Classification of Enem Issues Based on Item Response Theory

2020 ◽  
Vol 27 (1) ◽  
pp. 92-111
Author(s):  
Gustavo Henrique Nunes ◽  
Bruno Alberto Soares Oliveira ◽  
Ciniro Aparecido Leite Nametala
Keyword(s):  
High School ◽  
Item Response Theory ◽  
Item Response ◽  
Generation System ◽  
Response Theory ◽  
Hit Rate ◽  
System A ◽  
Intelligent Simulation ◽  
Computational Strategy

The National High School Examination (ENEM) gains each year more importance, as it gradually, replacing traditional vestibular. Many simulations are done almost randomly by teachers or systems, with questions chosen without discretion. With this methodology, if a test needs to be reapplied, it is not possible to recreate it with questions that have the same difficulty as those used in the first evaluation. In this context, the present work presents the development of an ENEM Intelligent Simulation Generation System that calculates the parameters of Item Response Theory (TRI) of questions that have already been applied in ENEM and, based on them, classifies them. in groups of difficulty, thus enabling the generation of balanced tests. For this, the K-means algorithm was used to group the questions into three difficulty groups: easy, medium and difficult. To verify the functioning of the system, a simulation with 180 questions was generated along the ENEM model. It could be seen that in 37.7% of cases this happened. This hit rate was not greater because the algorithm confounded the difficulty of issues that are in close classes. However, the system has a hit rate of 92.8% in the classification of questions that are in distant groups.

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