scholarly journals Distribution models and morphometric analyses in Deyeuxia velutina, an Andean grass species

2020 ◽  
Vol 8 (2) ◽  
pp. 509-524
Author(s):  
María A. Ferrero ◽  
Agostina B. Sassone ◽  
Liliana M. Giussani ◽  
Andrea S. Vega
Keyword(s):  
Morphological Characters ◽  
Leaf Sheath ◽  
Distribution Model ◽  
Grass Species ◽  
Distribution Models ◽  
Entropy Model ◽  
Principal Coordinates ◽  
Morphometric Analyses ◽  
First Time ◽  
Univariate Analyses

Rúgolo de Agrasar recognized two varieties of Deyeuxia velutina (D. velutina var. velutina and D. velutina var. nardifolia) based on leaf sheath indumentum, lemma length, and leaf blade direction. However, taxonomic delimitation has been difficult due to occasional overlapping characters. To assess the infraspecific delimitation of D. velutina, we present a comprehensive study combining morphometric analyses and a potential distribution model. To explore morphological variation and select diagnostic characters, we measured 124 morphological characters in 52 specimens of both varieties and performed a principal coordinate analysis and univariate analyses (Analysis of variance and Kruskal-Wallis non-parametric test). Both taxa resolved as separate morphological groups. Additionally, a Discriminant Analysis was performed to classify the individuals in the predetermined morphological groups. For modeling the species distribution, 26 specimens of D. velutina var. nardifolia and 68 of D. velutina var. velutina were georeferenced and 20 environmental variables were analyzed through a Maximum Entropy model. Deyeuxia velutina extends in the high Andean region from Peru to southern Argentina and Chile. Both varieties differed in their geographical limits, a result supported by regression analyses of latitude and longitude on the principal coordinates of the PCoA. Deyeuxia velutina var. nardifolia is restricted to the northern area of distribution while D. velutina var. velutina showed a higher habitat suitability in the southern region. Moreover, D. velutina var. nardifolia is here reported for the first time in San Juan province (Argentina), constituting the austral limit of its geographical distribution. Additional reliable morphological characters were considered in an updated key to the varieties.

Statistical Distribution Models of Clutch Service Load

2011 ◽  
Vol 403-408 ◽  
pp. 5244-5249
Author(s):  
Chang Gao Xia ◽  
Meng Zhang ◽  
Xiang Gao ◽  
Zhen Yu Zhang
Keyword(s):  
Maximum Entropy ◽  
Distribution Model ◽  
Statistical Features ◽  
Maximum Entropy Model ◽  
Linear Least Squares ◽  
Distribution Models ◽  
Entropy Model ◽  
Service Load ◽  
Maximum Entropy Distribution ◽  
Model Expression

The mixed distribution model and the maximum entropy model are used to represent service load of the vehicle clutch. The parameters of those models are estimated with different methods. The findings indicate that maximum entropy distribution can accurately describe different statistical features of random variables as minimally prejudiced probability distribution if order of the distribution function is properly selected, and that the mixed Weibull distribution shows super performance of the complicated statistical model expression. The parameters of those models are estimated by optimization based on non-linear least squares.

Ramalina sekika (Ramalinaceae), a new species for the lichen flora of Russia from the Far East

2014 ◽  
Vol 48 ◽  
pp. 256-263 ◽  
Author(s):  
O. A. Kataeva
Keyword(s):  
Far East ◽  
Original Description ◽  
Morphological Characters ◽  
Northeastern China ◽  
Anatomical Structure ◽  
The Far East ◽  
First Time ◽  
A New Species ◽  
Independent Species ◽  
Lichen Flora

Ramalina sekika Asahina is reported for the first time from Russia from Sakhalin. It refers to the number of rare and poorly investigated species of the genus. Until now it was considered to be endemic to northeastern China. The original description and the location in the Far East are given, as well as the data on anatomical and morphological study of the Russian specimen. The differences in the anatomical structure of its thallus are discussed. A comparison of anatomical and morphological characters of R. sekika, R. pollinaria (Westr.) Ach. (European material), R. yasudae Räsänen has been made; the author considers them as independent species.

Two late-spring braconid genera of the subfamily Alysiinae (Hymenoptera: Braconidae) new for the fauna of Russia

2011 ◽  
Vol 20 (1) ◽  
pp. 85-95 ◽  
Author(s):  
S.A. Belokobylskij ◽  
T.S. Kostromina
Keyword(s):  
New Species ◽  
Morphological Characters ◽  
Late Spring ◽  
Key To Species ◽  
The Urals ◽  
Asian Continent ◽  
First Time ◽  
A New Species

Two braconid genera from the subfamily Alysiinae, Lodbrokia Hedqvist, 1962 and Asyntactus Marshall, 1898, are recorded in the fauna of Russia and in the Asian continent for the first time. A new species Lodbrokia uralica sp. nov. is described from the Urals, and a key to species of this genus is provided. Redescriptions of the female and male of Asyntactus rhogaleus Marshall, 1898 with information about the level of variability of its morphological characters are given. Asyntactus sigalphoides Marshall, 1898 is synonymised with A. rhogaleus Marshall, 1898 (syn. nov.).

scholarly journals A Robust Prediction Model for Species Distribution Using Bagging Ensembles with Deep Neural Networks

2021 ◽  
Vol 13 (8) ◽  
pp. 1495
Author(s):  
Jehyeok Rew ◽  
Yongjang Cho ◽  
Eenjun Hwang
Keyword(s):  
Neural Networks ◽  
Species Distribution ◽  
Best Practice ◽  
Deep Neural Networks ◽  
Species Distribution Models ◽  
Species Distribution Model ◽  
Environmental Data ◽  
Distribution Model ◽  
Distribution Models ◽  
Robust Prediction

Species distribution models have been used for various purposes, such as conserving species, discovering potential habitats, and obtaining evolutionary insights by predicting species occurrence. Many statistical and machine-learning-based approaches have been proposed to construct effective species distribution models, but with limited success due to spatial biases in presences and imbalanced presence-absences. We propose a novel species distribution model to address these problems based on bootstrap aggregating (bagging) ensembles of deep neural networks (DNNs). We first generate bootstraps considering presence-absence data on spatial balance to alleviate the bias problem. Then we construct DNNs using environmental data from presence and absence locations, and finally combine these into an ensemble model using three voting methods to improve prediction accuracy. Extensive experiments verified the proposed model’s effectiveness for species in South Korea using crowdsourced observations that have spatial biases. The proposed model achieved more accurate and robust prediction results than the current best practice models.

scholarly journals A survey on poorly known rainforest litter-dwelling spiders of Orchid Island (Lanyu, Taiwan) with the description of a new species (Araneae: Linyphiidae, Tetrablemmidae, and Theridiosomatidae)

Zootaxa ◽  
2021 ◽  
Vol 4927 (2) ◽  
pp. 197-208
Author(s):  
FRANCESCO BALLARIN ◽  
TAKESHI YAMASAKI ◽  
YONG-CHAO SU
Keyword(s):  
New Species ◽  
Endemic Species ◽  
Morphological Characters ◽  
Spider Species ◽  
Orchid Island ◽  
First Time ◽  
A New Species

Representatives of some poorly known spider species collected in the rainforest litter of the Orchid Island (Taiwan) are illustrated and discussed here. A new species, Brignoliella tao sp. nov. (Fam. Tetrablemmidae), endemic to Orchid Island, is described based on both sexes. The previously unknown female of Theridiosoma triumphale Zhao & Li, 2012 (Fam. Theridiosomatidae), is described for the first time. Zoma taiwanica (Zhang, Zhu & Tso 2006) comb. nov., from the same family, is illustrated and its transfer from the genus Theridiosoma O. Pickard-Cambridge, 1879 to Zoma Saaristo, 1996 is proposed on the basis of morphological characters. Habitus and genitalia of the endemic species Gongylidioides angustus Tu & Li, 2006 (Fam. Linyphiidae) are also illustrated. 

The Hydraenidae of Cuba (Insecta: Coleoptera) II: Morphology of preimaginal stages of six species and notes on their biology

Zootaxa ◽  
2017 ◽  
Vol 4238 (4) ◽  
pp. 451 ◽  
Author(s):  
ALBERT DELER-HERNÁNDEZ ◽  
JUAN A. DELGADO
Keyword(s):  
Instar Larva ◽  
Morphological Characters ◽  
Larval Instars ◽  
First Instar ◽  
Preimaginal Stages ◽  
First Time ◽  
Third Instar Larvae

Preimaginal stages of the six species of Hydraenidae presently known from Cuba were obtained by rearing adults in the laboratory. Eggs of Hydraena perkinsi Spangler, 1980, H. decui Spangler, 1980 and H. franklyni Deler-Hernández & Delgado, 2012 are described and illustrated for the first time. The first instar larva of Gymnochthebius fossatus (LeConte, 1855) is redescribed, adding some new remarkable morphological characters including what could be the first abdominal egg-burster reported for this family. All larval instars of H. perkinsi, H. guadelupensis Orchymont, 1923 and Ochthebius attritus LeConte, 1878 are described and illustrated for the first time, with a special emphasis on their chaetotaxy. The second instar larva of G. fossatus along with first and third instar larvae of H. decui and H. franklyni are also studied for the first time. The pupal morphology and vestiture of a species belonging to the genus Hydraena are described for the first time, based on the pupa of H. perkinsi. Biological notes for several preimaginal stages of the studied species are also given. 

scholarly journals Application Natura 2000 Data For The Invasive Plants Spread Prediction

2015 ◽  
Vol 46 (4) ◽  
pp. 159-166 ◽  
Author(s):  
J. Pěknicová ◽  
D. Petrus ◽  
K. Berchová-Bímová
Keyword(s):  
Environmental Factors ◽  
Invasive Plants ◽  
Species Distribution ◽  
Natura 2000 ◽  
Distribution Model ◽  
Distribution Data ◽  
Habitat Types ◽  
Distribution Models ◽  
Occurrence Data ◽  
Heracleum Mantegazzianum

AbstractThe distribution of invasive plants depends on several environmental factors, e.g. on the distance from the vector of spreading, invaded community composition, land-use, etc. The species distribution models, a research tool for invasive plants spread prediction, involve the combination of environmental factors, occurrence data, and statistical approach. For the construction of the presented distribution model, the occurrence data on invasive plants (Solidagosp.,Fallopiasp.,Robinia pseudoaccacia,andHeracleum mantegazzianum) and Natura 2000 habitat types from the Protected Landscape Area Kokořínsko have been intersected in ArcGIS and statistically analyzed. The data analysis was focused on (1) verification of the accuracy of the Natura 2000 habitat map layer, and the accordance with the habitats occupied by invasive species and (2) identification of a suitable scale of intersection between the habitat and species distribution. Data suitability was evaluated for the construction of the model on local scale. Based on the data, the invaded habitat types were described and the optimal scale grid was evaluated. The results show the suitability of Natura 2000 habitat types for modelling, however more input data (e.g. on soil types, elevation) are needed.

A revision of Rhaponticoides (Asteraceae, Cardueae–Centaureinae) from Iran

Phytotaxa ◽  
2015 ◽  
Vol 213 (2) ◽  
pp. 87 ◽  
Author(s):  
Kazem Negaresh ◽  
SAYED MOHAMMAD REZA KHOSHROO ◽  
ROYA KARAMIAN ◽  
MOHAMMAD REZA JOHARCHI
Keyword(s):  
Geographical Distribution ◽  
Morphological Characters ◽  
Identification Key ◽  
Full Description ◽  
New Combinations ◽  
Taxonomic Review ◽  
Herbarium Collections ◽  
First Time

A taxonomic review of Rhaponticoides in Iran is based on morphological characters of the specimens from the authors’ expeditions and other herbarium collections. Rhaponticoides lachnopus, R. schmidii, R. sect. Iranicae and R. sect. Ruthenicae are proposed as new combinations. Full description for the genus Rhaponticoides and R. sect. Iranicae and R. sect. Ruthenicae are presented for the first time here. Three names, R. lachnopus, R. ruthenica and its synonym, are typified. A synopsis with recognized sections and species, relevant synonyms, type citations, lists of specimens examined and an identification key are provided for the genus Rhaponticoides in Iran. In addition, some notes about ecology and habitat of Rhaponticoides especially in Iran are given. Finally, the geographical distribution of all the 4 species recognized in Iran is presented and mapped.

scholarly journals Phylogeny and character evolution in the Dacrymycetes, and systematics of Unilacrymaceae and Dacryonaemataceae fam. nov.

2020 ◽  
Vol 44 (1) ◽  
pp. 161-205
Author(s):  
J.C. Zamora ◽  
S. Ekman
Keyword(s):  
Species Level ◽  
Single Locus ◽  
Phenotypic Characters ◽  
New Family ◽  
Multispecies Coalescent ◽  
Morphometric Analyses ◽  
Methodological Approaches ◽  
First Time ◽  
A New Species ◽  
Multilocus Phylogeny

We present a multilocus phylogeny of the class Dacrymycetes, based on data from the 18S, ITS, 28S, RPB1, RPB2, TEF-1α, 12S, and ATP6 DNA regions, with c. 90 species including the types of most currently accepted genera. A variety of methodological approaches was used to infer phylogenetic relationships among the Dacrymycetes, from a supermatrix strategy using maximum likelihood and Bayesian inference on a concatenated dataset, to coalescence-based calculations, such as quartet-based summary methods of independent single-locus trees, and Bayesian integration of single-locus trees into a species tree under the multispecies coalescent. We evaluate for the first time the taxonomic usefulness of some cytological phenotypic characters, i.e., vacuolar contents (vacuolar bodies and lipid bodies), number of nuclei of recently discharged basidiospores, and pigments, with especial emphasis on carotenoids. These characters, along with several others traditionally used for the taxonomy of this group (basidium shape, presence and morphology of clamp connections, morphology of the terminal cells of cortical/marginal hyphae, presence and degree of ramification of the hyphidia), are mapped on the resulting phylogenies and their evolution through the class Dacrymycetes discussed. Our analyses reveal five lineages that putatively represent five different families, four of which are accepted and named. Three out of these four lineages correspond to previously circumscribed and published families (Cerinomycetaceae, Dacrymycetaceae, and Unilacrymaceae), and one is proposed as the new family Dacryonaemataceae. Provisionally, only a single order, Dacrymycetales, is accepted with in the class. Furthermore, the systematics of the two smallest families, Dacryonaemataceae and Unilacrymaceae, are investigated to the species level, using coalescence-based species delimitation on multilocus DNA data, and a detailed morphological study including morphometric analyses of the basidiospores. Three species are accepted in Dacryonaema, the type, Da. rufum, the newly combined Da. macnabbii (basionym Dacrymyces macnabbii), and a new species named Da. macrosporum. Two species are accepted in Unilacryma, the new U. bispora, and the type, U. unispora, the latter treated in a broad sense pending improved sampling across the Holarctic.

Studies on some Sporozoa in Polychaete Worms

Parasitology ◽  
1930 ◽  
Vol 22 (3) ◽  
pp. 370-398 ◽  
Author(s):  
Harendra Nath Ray
Keyword(s):  
Life Histories ◽  
Morphological Characters ◽  
Diagnostic Characters ◽  
Early Stages ◽  
First Time

1. The main facts in Brasil's (1907) account of the intracellular schizogony inSelenidium caulleryifromProtula tubulariahave been confirmed. Early stages in the sporogony of this species are described now for the first time.2. Intracellular schizogony is described for the first time inSelenidium mesniliBrasil fromMyxicola infundibulum, and here also the early stages in sporogony are noted for the first time.3. The life histories of Caullery and Mesnil's two unnamed species ofSelenidium(now calledS. spionis(Köll.) andS. foliatumn.sp.) fromScolelepis fuliginosahave been exhaustively studied. No schizogonic phase has been observed in either. The gametocysts, here described for the first time, are found to develop fully only after escape into the sea. The gametocysts ofS. spionisare ovoid, 108μ x 60μ and contain spores with four sporozoites: those ofS. foliatumare spherical, 70μ in diameter, and their spores contain eight sporozoites.4. New or hitherto little known species ofSelenidiumare recorded fromCirratulus cirratusMüll.,Branchiomma vesiculosumMont.,Sabella pavoninaSav.,Pomatoceros triqueterL. andTerebella lepidoriaKühl, and the morphological characters of the trophozoites are described.5. A discussion follows of the value of the diagnostic characters of the genusSelenidium. It is suggested that this genus requires drastic revision and will probably have to be dismembered. Stress is laid, however, on the occurrence in all the gregarines examined, and at all the observed stages of their development, of characteristic chromatic bodies at the anterior end, structures which have hitherto escaped the notice of most observers.

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