scholarly journals Morphological diversity of the stone crayfish − traditional and geometric morphometric approach

2019 ◽  
pp. 1 ◽  
Author(s):  
Leona Lovrenčić ◽  
Vjera Pavić ◽  
Stefan Majnarić ◽  
Lucija Abramović ◽  
Mišel Jelić ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Morphological Characteristics ◽  
Morphological Diversity ◽  
Dorsal Side ◽  
Small Scale ◽  
Geometric Morphometric ◽  
Discriminant Analyses ◽  
Stone Crayfish ◽  
Multivariate Discriminant ◽  
First Time

Austropotamobius torrentium is one of four native European crayfish species inhabiting Croatian freshwaters. Existence of eight divergent monophyletic mtDNA phylogroups was described within A. torrentium; six of them are distributed in Croatia, with the highest genetic diversity established in its northern-central Dinaric region. Recent small-scale study of the stone crayfish morphological variability indicated significant differences among different phylogroups. In the present study larger sample size, covering populations from five phylogroups, was analysed with the aim of determining whether there are morphological characteristics that reliably separate stone crayfish from different phylogroups. Aiming this, 245 stone crayfish were analysed through traditional (TM) and, for the first time, geometric morphometric (GM) analyses. Multivariate discriminant analyses included 24 TM characteristics per crayfish, while GM comprised analyses of 22 landmarks on the dorsal side of cephalon. Both methods revealed congruent results, and significant differences among phylogroups in analysed features were obtained, with the cephalon shape contributing the most to crayfish discrimination. Research confirmed that both approaches, combined with statistical methods, are useful in distinguishing and separating crayfish phylogroups. Findings of present study are compatible with the previous molecular findings; stone crayfish present several distinct evolutionary lineages whose species status are currently undefined and require urgent clarification.

scholarly journals Optimal fishing samplers to reveal the morphological structure of a fish assemblage in a subtropical tidal flat

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Carolina C. Siliprandi ◽  
Víctor M. Tuset ◽  
Antoni Lombarte ◽  
Marc Farré ◽  
Carmen L. D. B. Rossi-Wongtschowski
Keyword(s):  
Tidal Flat ◽  
Fish Assemblage ◽  
Fish Assemblages ◽  
Morphological Variability ◽  
Morphological Structure ◽  
Morphological Diversity ◽  
Morphological Characters ◽  
Otter Trawl ◽  
Brazilian Coast ◽  
Geometric Morphometric

ABSTRACT Morphological characters of species are essential for assessing the functional structure of a fish assemblage, since differences between them, for example in body shape, are related to many functional and ecological traits (e.g., swimming, search for food, striking and capturing prey, evading predators, spawning). Globally, tidal flats are relevant to fish assemblages by offering feeding, refuge, and reproduction grounds. To analyze the morphofunctional structure of the fish assemblage from a tidal flat on the Brazilian coast, we conducted standardized sampling using nine different fishing gears. The geometric morphometric method was applied to describe the fish shapes and verify the morphological structure of the assemblage. Here, we present the influence/susceptibility of each gear type on the morphological diversity of the fish assemblage. The results indicated that beach seine, otter trawl, marginal encircling gillnet, and fish traps, together, were the most effective gears to represent the maximum morphological variability of fish inhabiting that tidal flat. Moreover, the assemblage showed high morphological redundancy considered as a resistance of the ecosystem for avoiding functional diversity loss, emphasizing the importance of complementary gear use when determining fish assemblages in a conservation context.

scholarly journals New finding of Vaucheria aversa Hassall (Ochrophyta, Xanthophyceae) in Ukraine

2020 ◽  
Vol 12 (1) ◽  
pp. 105-110
Author(s):  
Olena Raida ◽  
Olha Burova ◽  
Igor Olshanskyi
Keyword(s):  
Morphological Variability ◽  
Morphological Characteristics ◽  
Taxonomic Identification ◽  
Formaldehyde Solution ◽  
Common Features ◽  
New Finding ◽  
Short Pedicel ◽  
First Time ◽  
Continental Water Bodies ◽  
Tubular Shape

Vaucheria aversa (Xanthophyta) was recorded for the first time in Ukraine in Sula River, Hydrological Reserve «Artopolot», Poltava Region. It was found in benthos in spring (May 2020) in silty-sandy soil in shallow water. The material was collected and processed according to a common methodology. Sterile samples before the appearance of the gametengians were kept in natural water in petri dishes in well-lit places. This method of «coarse culture», in most cases, allowed to get gametangia within two weeks. The species identification was done with fertile filaments only. 4% formaldehyde solution was used for material fixation. Taxonomic identification of samples was done using a comparative and morphological methods, which includes analysis of morphological variability and verification of the consistency of the studied material with the diagnosis. Thalli of V. aversa are direct, branched, bisexual, 80–90 μm wide. Antheridia are cylindrical, tubular shape, pressed to the filament or slightly raised above it, 119–130 × 41–43 μm. Oogonia erect, sessile, ovoid to subspherical, sometimes placed in pairs, with a curved beak at the front, 190–230 × 140–163 μm. According to morphological characteristics this species is similar to another one from section Tubligerae Walz – V. fontinalis (Linnaeus) T.A. Christensen. Their distinctive and common features are as follows. Filaments of V. fontinalis are narrower (up to 75 μm) than V. aversa (up to 131 μm). Both species are characterized by oogonia grouped together in a row. Antheridia present in quantity 1 or 2 on both sides of oogonia. But the species are very different in size and shape of oogonia: in V. aversa they are sessile, located one at a time or less often two, extended near the base, sharply narrowed at the apex. The beak is directed straight or obliquely up, bent to the side of the oogonia body. In V. fontinalis oogonia are placed in one row, most often in the amount of 1-6, the beak tapers gradually. Anteridia are cylindrical, on short pedicel. V. aversa grew as a part of polyspecies complex of green algae together with representatives of such genera as Cladophora Kützing, Spirogyra Link and Mougeotia C. Agardh. V. aversa is widely distributed in continental water bodies of Europe, Asia and North America, Australia and New Zealand, but is firstly recorded in Ukraine.

scholarly journals Morphological characteristics of wild and cultivated Ganoderma subincrustatum from Sonora, Mexico

2019 ◽  
Vol 49 ◽  
pp. e1213
Author(s):  
Damian López-Peña ◽  
Crystal Samaniego-Rubiano ◽  
Idaly Morales-Estrada ◽  
Aldo Gutierrez ◽  
Rigoberto Gaitán-Hernández ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Morphological Characteristics ◽  
Fruiting Bodies ◽  
Size And Shape ◽  
Similar Shape ◽  
High Illumination ◽  
First Time ◽  
Common Parasite ◽  
Peach Orchard

Background: Ganoderma is a complex genus with high morphological variability. Ganoderma subincrustatum is a common parasite and saprophytic species, and its circumscription is doubtful for some authors. The aim of this study was to analyze the morphological variability of wild and cultivated specimens of G. subincrustatum.Methods: Ganoderma subincrustatum strain was isolated from a peach orchard in La Costa de Hermosillo, Sonora. The strain was cultivated on vineyard pruning wastes under low and high illumination. Wild and cultivated basidiomata were macro- and microscopically characterized and compared.Results and conclusions: Ganoderma subincrustarum is recorded for the first time from Sonoran mycobiota. Basidiomata color, size and shape were different between wild and cultivated under low and high illumination. High lux condition caused antler shape fruiting bodies. Wild and cultivated specimens showed the same type of context, similar shape of pileipellis cells and basidiospores, but spores were larger in wild specimens.

scholarly journals Morphological diversity of vulvar lichen sclerosus

2019 ◽  
Vol 16 (3) ◽  
pp. 357-364
Author(s):  
Y. A. Kuzmenka-Maskvina ◽  
T. A. Bich ◽  
Z. N. Bragina
Keyword(s):  
Satellite Cell ◽  
Morphological Characteristics ◽  
Lichen Sclerosus ◽  
Morphological Diversity ◽  
Cell Necrosis ◽  
Biopsy Material ◽  
Adequate Treatment ◽  
Histological Features ◽  
First Time ◽  
Vulvar Lichen Sclerosus

Vulvar lichen sclerosus (LS) is a common chronic mucocutaneous disease, which is usually underdiagnosed and tend to progress without adequate treatment.Morphological characteristics of vulvar LS with unusual histological features.Vulvar biopsy material (n = 83) with morphologically diagnosed LS was examined histologically and statistically.Often saw-toothed modification of the epithelium, fibrinoid necrosis, cytoid bodies, satellite cell necrosis, hemorrhages, papillomatosis, milia, predominantly plasma cell inflammatory infiltrate, lymphoid follicles, elastosis, angiokeratoma-like vasculare change were found on the background vulvar LS.Saw-tooth epidermal change, multiple cytoid bodies and satellite cell necrosis are histological features of LS described for the first time in this study, the former being a frequent presentation of vulvar LS. The mentioned above histological changes cannot appear as features in favor of lichen planus in the differential diagnosis of these diseases.

Bankruptcy Model Construction and its Limitation in Input Data Quality

2019 ◽  
Vol 10 (2) ◽  
pp. 117-125
Author(s):  
Dana Kubíčková ◽  
◽  
Vladimír Nulíček ◽  
Keyword(s):  
Data Quality ◽  
Normal Distribution ◽  
Input Data ◽  
Model Construction ◽  
The Third ◽  
Third Stage ◽  
Discriminant Analyses ◽  
One Year ◽  
The University ◽  
Multivariate Discriminant

The aim of the research project solved at the University of Finance and administration is to construct a new bankruptcy model. The intention is to use data of the firms that have to cease their activities due to bankruptcy. The most common method for bankruptcy model construction is multivariate discriminant analyses (MDA). It allows to derive the indicators most sensitive to the future companies’ failure as a parts of the bankruptcy model. One of the assumptions for using the MDA method and reassuring the reliable results is the normal distribution and independence of the input data. The results of verification of this assumption as the third stage of the project are presented in this article. We have revealed that this assumption is met only in a few selected indicators. Better results were achieved in the indicators in the set of prosperous companies and one year prior the failure. The selected indicators intended for the bankruptcy model construction thus cannot be considered as suitable for using the MDA method.

scholarly journals Patterns of intraspecific morphological variability in soil mites reflect their dispersal ability

2021 ◽  
Vol 83 (2) ◽  
pp. 241-255
Author(s):  
Julia Baumann
Keyword(s):  
Molecular Genetic ◽  
Morphological Variability ◽  
Mite Species ◽  
Molecular Genetic Analysis ◽  
Dispersal Ability ◽  
Geometric Morphometric ◽  
Geographic Population ◽  
Mobile Species ◽  
Population Structures ◽  
Subdivided Populations

AbstractThe ability to disperse is one of the most important factors influencing the biogeography of species and speciation processes. Highly mobile species have been shown to lack geographic population structures, whereas less mobile species show genetically strongly subdivided populations which are expected to also display at least subtle phenotypic differences. Geometric morphometric methods (GMM) were now used to analyze morphological differences between European populations of a presumed non-phoretic, little mobile mite species in comparison to a highly mobile, phoretic species. The non-phoretic species Scutacarus carinthiacus showed a phenotypic population structure, whereas the phoretic species S. acarorum displayed homogeneity. These different patterns most probably can be explained by different levels of gene flow due to different dispersal abilities of the two species. GMM proved to be a sensitive tool that is especially recommendable for the analysis of (old) museum material and/or specimens in microscopic slides, which are not suitable for molecular genetic analysis.

scholarly journals Cats in the forest: predicting habitat adaptations from humerus morphometry in extant and fossil Felidae (Carnivora)

Paleobiology ◽  
10.1666/12001 ◽  
2013 ◽  
Vol 39 (3) ◽  
pp. 323-344 ◽  
Author(s):  
Carlo Meloro ◽  
Sarah Elton ◽  
Julien Louys ◽  
Laura C. Bishop ◽  
Peter Ditchfield
Keyword(s):  
Morphological Variability ◽  
Olduvai Gorge ◽  
Environmental Predictors ◽  
Linear Measurements ◽  
Multivariate Statistical ◽  
Linear Discriminant ◽  
Related Group ◽  
Discriminant Analyses ◽  
The Stability ◽  
The Relationship

Mammalian carnivores are rarely incorporated in paleoenvironmental reconstructions, largely because of their rarity within the fossil record. However, multivariate statistical modeling can be successfully used to quantify specific anatomical features as environmental predictors. Here we explore morphological variability of the humerus in a closely related group of predators (Felidae) to investigate the relationship between morphometric descriptors and habitat categories. We analyze linear measurements of the humerus in three different morphometric combinations (log-transformed, size-free, and ratio), and explore four distinct ways of categorizing habitat adaptations. Open, Mixed, and Closed categories are defined according to criteria based on traditional descriptions of species, distributions, and biome occupancy. Extensive exploratory work is presented using linear discriminant analyses and several fossils are included to provide paleoecological reconstructions.We found no significant differences in the predictive power of distinct morphometric descriptors or habitat criteria, although sample splitting into small and large cat guilds greatly improves the stability of the models. Significant insights emerge for three long-canine cats:Smilodon populator,Paramachairodus orientalis, andDinofelissp. from Olduvai Gorge (East Africa).S. populatorandP. orientalisare both predicted to have been closed-habitat adapted taxa. The false “sabertooth”Dinofelissp. from Olduvai Gorge is predicted to be adapted to mixed habitat. The application of felid humerus ecomorphology to the carnivoran record of Olduvai Gorge shows that the older stratigraphic levels (Bed I, 1.99–1.79 Ma) included a broader range of environments than Beds II or V, where there is an abundance of cats adapted to open environments.

scholarly journals On the Relationship between Low Latitude Scintillation Onset and Sunset Terminator over Africa

2021 ◽  
Vol 13 (11) ◽  
pp. 2087
Author(s):  
Mogese Wassaie Mersha ◽  
Elias Lewi ◽  
Norbert Jakowski ◽  
Volker Wilken ◽  
Jens Berdermann ◽  
...  
Keyword(s):  
Moving Boundary ◽  
Occurrence Rate ◽  
Scintillation Index ◽  
Small Scale ◽  
Bahir Dar ◽  
Remarkable Change ◽  
Equatorial Africa ◽  
Night Side ◽  
Solar Terminator ◽  
First Time

The solar terminator is a moving boundary between day-side and night-side regions on the Earth, which is a substantial source of perturbations in the ionosphere. In the vicinity of the solar terminator, essential parameters like S4 index measurements are widely analyzed in order to monitor and predict perturbations in the ionosphere. The utilization of the scintillation index S4 is a well-accepted approach to describe the amplitude/intensity fluctuation of a received signal, predominantly caused by small-scale irregularities of the ionospheric plasma. We report on the longitudinal daily and seasonal occurrence of GNSS signal scintillations, using the data derived from the GNSS stations in Bahir Dar, Ethiopia, Lomé, Togo and Dakar, Senegal. The observed seasonal climatology of GNSS signal scintillations in equatorial Africa is adequately explained by the alignment of the solar terminator and local geomagnetic declination line. It should be pointed out that the strongest scintillations are most frequently observed during the time when the solar terminator is best aligned with the geomagnetic declination line. At all three stations, the comparison of computational and observational results indicated that the scintillation activity culminated around equinoxes in the years 2014, 2015 and 2016. Comparatively, the western equatorial Africa sector has the most intense, longest-lasting, and highest scintillation occurrence rate in equinoctial seasons in all three years. For the first time, we show that the seasonal variation of the scintillation peaks changes systematically from west to east at equatorial GNSS stations over Africa. A detailed analysis of the solar day–night terminator azimuth at ionospheric heights including the time equation shows that the scintillation intensity has a maximum if the azimuth of the terminator coincides with the declination line of the geomagnetic field. Due to the remarkable change of the declination by about 10° at the considered GNSS stations, the distance between scintillation peaks increases by 46 days when moving westward from the Bahir Dar to the Dakar GNSS station. The observations agree quite well with the computational results, thus confirming Tsunoda’s theory.

Corrosion Testing of Armour Wire in Simulated Annulus Environments of Flexible Pipelines: An Update

2003 ◽  
Author(s):  
Richard Clements ◽  
Andrew D. Ethridge
Keyword(s):  
Deionized Water ◽  
Small Scale ◽  
General Corrosion ◽  
Flexible Pipe ◽  
Scale Test ◽  
Condensed Water ◽  
Test Cells ◽  
Sour Service ◽  
First Time ◽  
Permeation Models

This paper describes further investigations, utilising small scale test cells, into the general corrosion which can occur on wires within the inherent annulus space in a flexible pipe, particularly, and for the first time, in a sour service (H2S containing) environment. The work enhances data presented previously in 2002. Tests have been performed in cells specifically designed to simulate, as closely as possible, the environment and confines of a flexible pipe annulus, using solutions of both deionized water and seawater (to represent seawater flooding and condensed water). The systems were saturated with CO2 and H2S to simulate permeation of gases through the polymer pressure sheath (as predicted by validated permeation models). Weight loss measurements were undertaken in order to quantify the corrosion rate in these simulated annulus environments and metallography was undertaken to characterise the corrosion and check for HIC/SOHIC.

Découverte d’une nouvelle population de Rhithrogena delphinensis Sowa & Degrange, 1987, dans le massif des Arves, et compléments à la description de la larve (Ephemeroptera, Heptageniidae)

2021 ◽  
Vol 126 (4) ◽  
pp. 401-420
Author(s):  
Bertrand Launay ◽  
Julien Barnasson ◽  
Juliette Becquet ◽  
Michel Brulin ◽  
Sophie Cauvy-Fraunie ◽  
...  
Keyword(s):  
Drainage Basin ◽  
Morphological Characteristics ◽  
Western Alps ◽  
Coi Gene ◽  
Morphological Description ◽  
Base Pairs ◽  
Northern Flank ◽  
Ecological Requirements ◽  
First Time ◽  
Existing Data

Discovery of a new population of Rhithrogena delphinensis Sowa & Degrange, 1987, in the Arves Massif, and additions to the morphological description of the larva (Ephemeroptera, Heptageniidae). Rhithrogena delphinensis, described originally on the basis of four larvae from the Western Alps, south of the Arves Massif and from the northern flank of the Ecrins Massif, had not been captured again since 1986. Here, we report the discovery of a new population from river Arvan, whose drainage basin is located between the Grandes Rousses Massif and the northern flank of the Arves Massif. This newly discovered population seems abundant in numbers, and reveals the particular ecological requirements of the species as well as its dependence on glacier fed or nival streams. The morphological characteristics of the larvae are described in detail, and illustrated by photographs. The variability of some of the proposed identification criteria is discussed, and a key to the identification of the Rhithrogena species from the alpestris group of the Western Alps, to which R. delphinensis belongs, is provided. Finally, a portion of 658 base pairs of the COI gene of R. delphinensis is sequenced for the first time and compared to already existing data on the alpestris group in the Western Alps.

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