scholarly journals The Nominal Species of the Bee Genus Centris Described by Johan Christian Fabricius (Hymenoptera: Apidae)

Sociobiology ◽  
2020 ◽  
Vol 67 (3) ◽  
pp. 401
Author(s):  
Felipe Vivallo
Keyword(s):  
Morphological Characteristics ◽  
Current Status ◽  
Nominal Species

In this paper the primary types of Centris bees described by the Danish entomologist Johan Christian Fabricius were studied. The primary types of C. flavifrons, C. analis, C. furcata, C. haemorrhoidalis, C. lanipes, C. longimana, C. similis, C. tabaniformis,  and  C. versicolor were analyzed, providing notes on their current status and depository. In addition, some photographs of selected species as well as morphological characteristics to recognize all Fabricius’ Centris bees are also provided.

scholarly journals Molecular tools for identification and classification of Myxozoan parasites (Cnidaria: Myxosporea) in India: Current status

2021 ◽  
Vol 13 (1) ◽  
pp. 51-58
Author(s):  
Abhishek Gupta ◽  
Anshu Chaudhary ◽  
Anju Tyagi ◽  
Bindu Sharma ◽  
Hridaya S. Singh
Keyword(s):  
Molecular Markers ◽  
Large Subunit ◽  
Molecular Taxonomy ◽  
Morphological Characteristics ◽  
Molecular Techniques ◽  
Classification Systems ◽  
Morphological Data ◽  
Current Status ◽  
Nominal Species ◽  
Molecular Tools

A substantial literature on myxosporea has been published to date using morphological characters and specificity of host tissue. Currently, there are some 2400 nominal species of myxosporea classified to 17 families and 64 genera. Approximately 300 species have been described from India and most of them have been described solely on the basis of morphological characteristics. Molecular markers like small subunit ribosomal (SSU) and large subunit ribosomal (LSU) DNA have been used worldwide for the identification and validation of fish myxosporeans. Maximum likelihood phylogenetic tree based on SSU rDNA sequences was used to study the phylogenetic relationship among myxosporeans infecting Indian fishes. Myxospore phylogenies disagree with traditional spore-based classification systems, probably due to extreme plasticity in myxospores morphologies that have resulted in extensive convergence. Morphological similarities exist among myxosporea that encounter several problems in categorizing them. That’s why present-day research has shifted to molecular techniques for identification and correct systematics of myxosporeans. Molecular studies of myxozoans in India are still scarce and in infancy. To address persisting taxonomic and phylogenetic discrepancies, validation of these species by molecular tools is needed, because earlier species were reported only on the basis of morphological data. Therefore, the present study has summarized existing molecular data and current status of molecular taxonomy of myxosporeans parasitizing fresh and marine water fishes of India along with the approaches of myxozoan phylogenetics and information about the molecular markers, their interpretation in the identification of myxozoans parasitizing fishes.

scholarly journals Phylogenetic analysis of the Baikalodrilus species flock (Annelida: Clitellata: Naididae), an endemic genus to Lake Baikal (Russia)

2019 ◽  
Vol 187 (4) ◽  
pp. 987-1015 ◽  
Author(s):  
Patrick Martin ◽  
Gontran Sonet ◽  
Nathalie Smitz ◽  
Thierry Backeljau
Keyword(s):  
Lake Baikal ◽  
Environmental Changes ◽  
Morphological Characteristics ◽  
Early Pleistocene ◽  
Species Flock ◽  
Nominal Species ◽  
Additional Species ◽  
Endemic Genus ◽  
Candidate Species ◽  
Time Of Divergence

Abstract Lake Baikal is populated by an endemic genus of oligochaetes (Baikalodrilus), which currently comprises 24 morphospecies. The genus can be considered as a ‘species flock’. However, the validity of many species is questionable: the great similarity in their description and the lack of unequivocal diagnostic characters often lead species identification to an impasse. In order to clarify the systematics of this genus, we analysed two nuclear and two mitochondrial DNA markers of 40 Baikalodrilus specimens. DNA and morphological approaches are mostly congruent in suggesting ten candidate species, although two additional species are suspected. A reassessment of the taxonomic value of the morphological characteristics of Baikalodrilus suggests that there are few that can be used as distinctive, specific criteria in the genus. The association between candidate and nominal species remains problematic, except for three species identified prior to molecular analyses. Baikalodrilus trituberculum sp. nov. is described. Phylogenetic inferences suggests that the earliest split in Baikalodrilus and the time of divergence of most lineages corresponding to species are consistent with the hypothesis of a general rearrangement of the Baikal fauna, following major environmental changes due to a general cooling in the Early Pleistocene.

Mechanisms in metal-organic chemical vapour deposition

1990 ◽  
Vol 330 (1610) ◽  
pp. 183-193 ◽  
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Hydrogen Abstraction ◽  
Chemical Vapour ◽  
Morphological Characteristics ◽  
Current Status ◽  
Organic Chemical ◽  
Methyl Radicals ◽  
Carrier Gas ◽  
Metal Organic

The current status of our understanding of mechanistic details of GaAs growth by metal-organic chemical vapour deposition from various starting materials is reviewed. Despite a high level of recent activity in the study of precursor decomposition and reactivity there are still considerable gaps in our knowledge; for example, a clear differentiation between homogeneous (gas phase) and heterogenous (surfacecontrolled) processes is not yet possible. The decomposition of trimethylgallium in dihydrogen as carrier gas and the concomitant production of methane may occur by means of a radical process where hydrogen is abstracted by methyl radicals from the trimethylgallium rather than from the carrier gas. Triethylgallium on the other hand also offers the possibility of B-elimination as a facile pathway and this is reflected in the ratio ethene: ethane (3:1). In the presence of arsine there is a more facile pathway for hydrogen abstraction by alkyl radicals, giving rise in the case of triethylgallium and arsine to more ethane than ethene and in the case of trimethylgallium with arsine there is a difference in the reactivity to that found in studies of its decomposition in dihydrogen alone. Several workers have therefore deduced the participation of an intermediate adduct under growth conditions because arsine and trimethylgallium lower each others’ decomposition temperature significantly. However, it should be remembered that arsine is almost certainly a better donor of hydrogen to methyl radicals than is dihydrogen. Phenylarsine has been found to be a potentially useful alternative precursor to arsine for the preparation of epitaxial GaAs. Thin films with excellent electrical and morphological characteristics have been prepared. Phenylarsine decomposes in dihydrogen to yield benzene and arsine and in the presence of trimethylgallium and triethylgallium mechanisms similar to those found with trimethylgallium and triethylgallium with arsine are suggested. These appear not to involve the dihydrogen carrier gas.

scholarly journals Identification and antimicrobial resistance of members from the Enterobacteriaceae family isolated from canaries (Serinus canaria)

2015 ◽  
Vol 35 (6) ◽  
pp. 552-556 ◽  
Author(s):  
Ruben V. Horn ◽  
William M. Cardoso ◽  
Elisângela S. Lopes ◽  
Régis S.C. Teixeira ◽  
Átilla H. Albuquerque ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Morphological Characteristics ◽  
Multidrug Resistant ◽  
Cloacal Swab ◽  
Resistance Rate ◽  
Current Status ◽  
Resistant Bacteria ◽  
Serinus Canaria ◽  
Peptone Water ◽  
Zoonotic Bacteria

Abstract: The Enterobacteriaceae family contains potentially zoonotic bacteria, and their presence in canaries is often reported, though the current status of these in bird flocks is unknown. Therefore, this study aimed to identify the most common genera of enterobacteria from canaries (Serinus canaria) and their antimicrobial resistance profiles. From February to June of 2013, a total of 387 cloacal swab samples from eight domiciliary breeding locations of Fortaleza city, Brazil, were collected and 58 necropsies were performed in canaries, which belonged to the Laboratory of Ornithological Studies. The samples were submitted to microbiological procedure using buffered peptone water and MacConkey agar. Colonies were selected according to their morphological characteristics on selective agar and submitted for biochemical identification and antimicrobial susceptibility. A total of 61 isolates were obtained, of which 42 were from cloacal swabs and 19 from necropsies. The most isolated bacteria was Escherichia coli with twenty five strains, followed by fourteen Klebsiellaspp., twelve Enterobacterspp., seven Pantoea agglomerans, two Serratiaspp. and one Proteus mirabilis. The antimicrobial to which the strains presented most resistance was sulfonamides with 55.7%, followed by ampicillin with 54.1% and tetracycline with 39.3%. The total of multidrug-resistant bacteria (MDR) was 34 (55.7%). In conclusion, canaries harbor members of the Enterobacteriaceae family and common strains present a high antimicrobial resistance rate, with a high frequency of MDR bacteria.

scholarly journals Evaluation of Vitis Species Found in Selected Locations of Texas and New Mexico

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 621a-621
Author(s):  
J. Kim Pittcock ◽  
Richard E. Durham
Keyword(s):  
New Mexico ◽  
Morphological Characteristics ◽  
Current Status ◽  
Vitis Species ◽  
North Central ◽  
North West ◽  
The North ◽  
Rich Diversity ◽  
North Central Texas ◽  
Central Texas

North American Vitis species and hybrids thereof have been the source of rootstocks for V. vinifera for the last century. Collection and evaluation of native Vitis in north-central Texas, western Texas, and New Mexico have been made to determine their current status. Known geographical pockets of grapevines were visited, with specimens taken and identified by comparison to herbarium collections and published descriptions. In locals where more than one species existed, many natural hybrids with varying morphological characteristics have become established. In North Central Texas, two areas were visited. The first was Tarrant, Parker and Wise counties where three grapevine species (V. mustangensis, V. cinerea var. helleri, and V. vulpina) and many hybrids were observed. The second was Wilbarger County where V. acerifolia was found growing in the south while V. ×doaniana was found growing in the north. West Texas was primarily populated with V. acerifolia with the exception of the Silver Falls Canyon area in Crosby County where hybrids of V. acerifolia, V. arizonica and V. riparia were observed. In New Mexico, two areas were visited: San Miquel County (North Central region), where V. acerifolia, V. arizonica, and V. riparia were observed and Eddy County (southern New Mexico) where V. arizonica was observed. A rich diversity of Vitis germplasm appears to remain in these habitats.

scholarly journals Molecular endoscopic imaging: the future is bright

2019 ◽  
Vol 12 ◽  
pp. 263177451986717
Author(s):  
Shakil Ahmed ◽  
Peter R. Galle ◽  
Helmut Neumann
Keyword(s):  
Molecular Imaging ◽  
Early Stage ◽  
Morphological Characteristics ◽  
Molecular Probes ◽  
Current Status ◽  
Endoscopic Imaging ◽  
Future Directions ◽  
Gastrointestinal Lesions ◽  
Final Survival ◽  
Systemic Application

The prediction and final survival rate of gastrointestinal cancers are dependent on the stage of disease. The ideal would be to detect those gastrointestinal lesions at early stage or even premalignant forms which are difficult to detect by conventional endoscopy with white light optical imaging as they show minimum or no changes in morphological characteristics and are thus left untreated. The introduction of molecular imaging has greatly changed the pattern for detecting gastrointestinal lesions from purely macroscopic structural imaging to the molecular level. It allows microscopic examination of the gastrointestinal mucosa with endoscopy after the topical or systemic application of molecular probes. In recent years, major advancements in endoscopic instruments and specific molecular probes have been achieved. This review focuses on the current status of endoscopic imaging and highlights the application of molecular imaging in gastrointestinal and hepatic disease in the context of diagnosis and therapy based on recently published literature in this field. We also discuss the challenges of molecular endoscopic imaging, its future directions and potential that could have a tremendous impact on endoscopic research and clinical practice in future.

Taxonomy and nomenclature of Eremasiomyia macularis and Miltogramma maroccana (Diptera: Sarcophagidae: Miltogramminae)

2012 ◽  
Vol 144 (1) ◽  
pp. 169-181 ◽  
Author(s):  
Thomas Pape ◽  
Krzysztof Szpila
Keyword(s):  
Type Species ◽  
Instar Larva ◽  
Current Status ◽  
Valid Species ◽  
Nominal Species ◽  
First Instar ◽  
Senior Synonym

AbstractThe nominal taxon Tachina macularis Wiedemann is revised and redescribed from the adult and first instar larva. It is transferred from its current status as a valid species of Protomiltogramma Townsend to a position as a valid species of Eremasiomyia Rohdendorf, comb. nov. and senior synonym of Setulia luteicornis Villeneuve, syn. nov., Eremasiomyia setulioides Rohdendorf, syn. nov., and Eremasiomyia orientalis Verves, syn. nov. The nominal species Sphecapatodes maroccana Séguy is revised and redescribed from the adult, and is shown to belong to Miltogramma Meigen, comb. nov. The nominal genus-group taxon Capnopteron Rohdendorf was originally proposed as a subgenus of Miltogramma with the type species Miltogramma maculigerum Speiser sensu Rohdendorf). However, the latter is shown to be a misidentification of Miltogramma maroccana (Séguy), which herewith is fixed as the type species of Capnopteron.

A taxonomic review of the genus Acanella (Cnidaria: Octocorallia: Isididae) in the North Atlantic Ocean, with descriptions of two new species

Zootaxa ◽  
2017 ◽  
Vol 4323 (3) ◽  
pp. 359 ◽  
Author(s):  
ESPRIT HEESTAND SAUCIER ◽  
AUZITA SAJJADI ◽  
SCOTT C. FRANCE
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Dna Sequences ◽  
Morphological Characteristics ◽  
Nominal Species ◽  
The North ◽  
Combining Data ◽  
Two New Species ◽  
The North Atlantic ◽  
Pacific Species

The deep-sea bamboo coral genus Acanella has a cosmopolitan distribution, is found on hard and soft substrata between 300 and 2875 meters depth, and may be abundant where present. The genus has been the source of taxonomic debate almost since its initial description, and species in the North Atlantic have proven difficult to identify. We examined 145 Acanella colonies collected from across a broad geographic distribution to address morphological variation in the context of genetic differences, focusing on the North Atlantic species, but with a comparison to four Pacific species. We generated DNA sequences for mitochondrial mtMutS and nuclear 18S from ninety-seven Acanella specimens. After combining data from both gene regions, eight concatenated sequences were identified (A–H), six of which are associated with nominal species, while the other two come from taxa that do not match any known species description. The most common sequence (A) is associated with specimens identified as Acanella arbuscula, A. eburnea, and Isidella elongata. We find that morphological characteristics used to differentiate these species are distributed along an intraspecific continuum and that alternate morphologies of A. arbuscula have been identified in collections as different species, with the identity influenced by sampling location. We synonymize A. eburnea with A. arbuscula and discuss confusion with I. elongata. The geographic range of A. arbuscula is expanded. We propose the resurrection of the Mediterranean species A. furcata and describe two new species, A. aurelia sp. nov. and A. scarletae sp. nov. New geographic records and the first SEM images of the Pacific species A. chiliensis, A. rigida, and A. robusta, all described prior to 1907, are also presented. 

scholarly journals Research Progress on Growth Characteristics of Invasive Plants in Different Habitats

2021 ◽  
Vol 257 ◽  
pp. 03023
Author(s):  
Zhe Wang ◽  
Ruirui Yue ◽  
Yang Li
Keyword(s):  
Biological Invasion ◽  
Invasive Plants ◽  
Morphological Characteristics ◽  
Environmental Problems ◽  
Global Scale ◽  
Growth Characteristics ◽  
Research Progress ◽  
Current Status ◽  
Soil Drought ◽  
Invasion Mechanism

Biological invasion generates serious threats to global biodiversity. Exotic species usually have high environmental adaptability and tolerance, which is one of the bases of their invasion. Except for biological invasion threats, other serious environmental problems like extreme cold or hot events, soil drought, saline-alkali and flood are emerging constantly on a global scale. In the background of multiple environmental problems interfering with existing habitats, exploring the growth characteristics of invasive plants in different habitats, and grasping the reasons why the invasive plants can obtain growth superiorities are in favor of propelling the understanding of their invasion mechanism. This paper gives an overview of research progress on the invasive plants’ morphological characteristics and physiological characteristics in deferent habitats, summarizes the growth specialties of invasive plants which are affected by high temperature, low temperature, drought and flood, and discusses the reasons why the invasive plants prevail in the growth competitions, which provided theoretical and realistic signification to relieve the biological invasion current status.

scholarly journals Taxonomic revision and phylogeny of the Ophiocoma brevipes group (Echinodermata, Ophiuroidea), with description of a new subgenus (Breviturma) and a new species

2013 ◽  
Author(s):  
Sabine Stöhr ◽  
Emilie Boissin ◽  
Thierry B. Hoareau
Keyword(s):  
New Species ◽  
Morphological Characteristics ◽  
Taxonomic Revision ◽  
Molecular Data ◽  
Colour Pattern ◽  
Nominal Species ◽  
Biodiversity Survey ◽  
Group Type ◽  
Granule Density ◽  
Molecular Phylogenetic

The taxonomy of the genus Ophiocoma was last revised by Devaney in 1970. Recent discoveries of new species and re-instatement of previously synonymized names suggest that we still do not fully understand the species limits in this genus. A recent biodiversity survey of the SW Indian Ocean shallow reefs strongly suggested an unrecognised species in the genus, closely related to O. brevipes/O. dentata. This study examined both the molecular phylogenetic relationships and the morphological characteristics of several species in the genus in order to characterise the unrecognised species. The focal species clusters with O. brevipes, O. dentata, O. doederleini within a monophyletic clade supported by molecular data for the first time. The name Breviturma subgen. nov. is proposed for this clade, previously known as brevipes group. Type material of nominal species that have been synonymized with O. dentata was examined and re-assessed. Ophiocoma marmorata proved not conspecific with O. dentata. A rarely used character, dorsal disc granule density, was tested and showed differences between the examined species at similar sizes. In combination with colour pattern, disc granule density, arm spine sequence and maximum disc size, the new species was delimited morphologically and described as Ophiocoma krohi sp. nov.

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