scholarly journals New insights into the morphology and evolution of the ventral pharynx and jaws in Histriobdellidae (Eunicida, Annelida)

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Alexander Tzetlin ◽  
Nataliya Budaeva ◽  
Elena Vortsepneva ◽  
Conrad Helm
Keyword(s):  
Fine Structure ◽  
3D Reconstruction ◽  
Muscle Fibers ◽  
Comparative Analyses ◽  
Maxillary Protraction ◽  
Jaw Apparatus ◽  
Different Parts ◽  
Comprehensive Study

AbstractThe jaw apparatus in several annelid families represents a powerful tool for systematic approaches and evolutionary investigations. Nevertheless, for several taxa, this character complex has scarcely been investigated, and complete comparative analyses of all annelid jaws are lacking. In our comprehensive study, we described the fine structure of the jaw apparatus and the ventral pharyngeal organ (VPO) in Histriobdella homari – a minute ectocommensal of lobsters putatively belonging to the Eunicida – using different comparative morphological approaches, including SEM, TEM, CLSM and subsequent 3D reconstruction. The H. homari jaw apparatus is composed of ventral paired mandibles and dorsal symmetrical maxillae consisting of numerous dental plates, ventral carriers and an unpaired dorsal rod, and the general assemblage and arrangement of the different parts are highly comparable to those of other eunicid families. The jaw ultrastructure of histriobdellids resembles that of the families Dorvilleidae and (juvenile) Onuphidae. Furthermore, our data reveal that in the process of development of the jaw apparatus, the mandibles, maxillae II and unpaired dorsal rod are formed first, and the remaining maxillae and ventral carriers appear later. Notably, the muscular apparatus differs from that in Dorvilleidae and Onuphidae in terms of the number and arrangement of muscle fibers encompassing the jaws – not only because of the very small size of Histriobdella but also because histriobdellid maxillary protraction occurs due to straightening of the dorsal rod and thus requires a different muscular scaffold. Based on our investigations, the arrangement of the muscular apparatus of the jaws, the presence of paired ventral carriers and the dorsal rod, and the morphology of the ventral pharyngeal organ represent a histriobdellid autapomorphy. Our datasets form a basis for further comparative analyses to elucidate the evolution of Eunicida and jaw-bearing Annelida.

scholarly journals ULTRASTRUCTURE OF BARNACLE GIANT MUSCLE FIBERS

1973 ◽  
Vol 56 (1) ◽  
pp. 74-91 ◽  
Author(s):  
Graham Hoyle ◽  
Patricia A. McNeill ◽  
Allen I. Selverston
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Sarcoplasmic Reticulum ◽  
Muscle Fibers ◽  
Surface Plasma ◽  
Thick Filaments ◽  
Large Numbers ◽  
Glycogen Particles ◽  
Physiological Research ◽  
Different Parts

Increasing use of barnacle giant muscle fibers for physiological research has prompted this investigation of their fine structure. The fibers are invaginated by a multibranched system of clefts connecting to the exterior and filled with material similar to that of the basement material of the sarcolemmal complex. Tubules originate from the surface plasma membrane at irregular sites, and also from the clefts They run transversely, spirally, and longitudinally, making many diadic and some triadic contacts with cisternal sacs of the longitudinal sarcoplasmic reticulum. The contacts are not confined to any particular region of the sarcomere. The tubules are wider and their walls are thicker at points of contact with Z material. Some linking of the Z regions occurs across spaces within the fiber which contain large numbers of glycogen particles. A-band lengths are extremely variable, in the range 2.2 µm–20.3 µm (average 5.2 µm) Individual thick filaments have thin (110 Å) hollow regions alternating with thick (340 Å) solid ones. Bridges between thick filaments occur at random points and are not concentrated into an M band The thin:thick filament ratio is variable in different parts of a fiber, from 3:1 to 6:1. Z bands are basically perforated, but the number of perforations may increase during contraction.

Morphology and Topology of Coherent Scattering Regions of the Fe-Mn-C Steel Fine Structure

2015 ◽  
Vol 1085 ◽  
pp. 84-90
Author(s):  
Anna P. Zykova ◽  
Irina Kurzina ◽  
Mihail Yu. Novomejsky ◽  
Yuriy D. Novomejsky
Keyword(s):  
Fine Structure ◽  
Hyperfine Structure ◽  
Coherent Scattering ◽  
Technological Properties ◽  
Material Microstructure ◽  
And Topology ◽  
Interaction Of Components ◽  
Physical And Chemical ◽  
Comprehensive Study

The interaction of components in modifying mixtures with the elements of Fe-Mn-С alloys hyperfine structure is investigated. Comprehensive study of the modified material microstructure is conducted. The substructure of Fe-Mn-С alloys is shown to undergo significant changes. The produced castings are characterized with enhanced physical-and-chemical and technological properties

scholarly journals A Review on Ethnopharmacological Applications, Pharmacological Activities, and Bioactive Compounds ofMangifera indica(Mango)

2017 ◽  
Vol 2017 ◽  
pp. 1-24 ◽  
Author(s):  
Meran Keshawa Ediriweera ◽  
Kamani Hemamala Tennekoon ◽  
Sameera Ranganath Samarakoon
Keyword(s):  
Amino Acids ◽  
Bioactive Compounds ◽  
Mangifera Indica ◽  
Fruit Peel ◽  
Pharmacological Activities ◽  
Phytochemical Constituents ◽  
Pharmacological Potential ◽  
Diverse Plant ◽  
Different Parts ◽  
Comprehensive Study

Mangifera indica(family Anacardiaceae), commonly known as mango, is a pharmacologically, ethnomedically, and phytochemically diverse plant. Various parts ofM. indicatree have been used in traditional medicine for the treatment of different ailments, and a number of bioactive phytochemical constituents ofM. indicahave been reported, namely, polyphenols, terpenes, sterols, carotenoids, vitamins, and amino acids, and so forth. Several studies have proven the pharmacological potential of different parts of mango trees such as leaves, bark, fruit peel and flesh, roots, and flowers as anticancer, anti-inflammatory, antidiabetic, antioxidant, antibacterial, antifungal, anthelmintic, gastroprotective, hepatoprotective, immunomodulatory, antiplasmodial, and antihyperlipemic. In the present review, a comprehensive study on ethnopharmacological applications, pharmacological activities, and bioactive compounds ofM. indicahas been described.

scholarly journals Structural correlation and expression of chain connection in complex syntactic whole (based on the works by K. G. Abramov)

2019 ◽  
Vol 11 (3) ◽  
pp. 255-267
Author(s):  
Lyubov P. Vodyasova
Keyword(s):  
Fine Structure ◽  
Main Method ◽  
Parts Of Speech ◽  
Word Combination ◽  
Structural Correlation ◽  
The Subject ◽  
A Chain ◽  
Different Parts ◽  
Explicit Communication ◽  
The Way

Introduction. The subject of the research is complex syntactic whole (CSW), the components of which are united by a chain connection. It identifies the structural correlation of this connection, and examines tools for its implementation. Materials and Methods. The material of the study is prosaic works by K. G. Abramov. The main method is descriptive. It was used to analysis of structural correlation and means of expression in the organization of CSW in the prose of the writer. Results and Discussion. The article revealed that chain connection can be defined by structural correlation, in other words, by which models form the members of related sentences that are related to each other, and by the way these models are expressed. It is noted that in the prosaic works by K. G. Abramov the following models are the most common: “subject – subject”, “subject – object”, “object – object” and their varieties. They can be made explicitly and implicitly. The means of expressing explicit communication are lexical repetition, implicit one is periphrasis and pronominal substitutions, adverb, etc. The writer also uses root words referring to different parts of speech (one of the correlating members of a sentence is usually a predicate). Conclusion. The components of CSW combined by chain connection are an expressive and fine structure. Consistently developable repetition (explicit or implicit) “glue” these components and make the impression of visualization; they are designed for artistic effect. From phrase to phrase repetitive structures (words, word combination) vary its syntactic role as members of the sentence and they also vary its composition.

Dutch and German R-pronouns and P-stranding

2017 ◽  
Author(s):  
Máire Noonan
Keyword(s):  
Fine Structure ◽  
Empirical Evidence ◽  
Comparative Approach ◽  
Function Words ◽  
Clausal Structure ◽  
Germanic Languages ◽  
Different Parts

This chapter explores the fine structure of R-pronouns, spatial PPs, and P-stranding constructions. The guiding hypothesis and theoretical backdrop is that an extended clausal structure is generalized to all categories, including adpositions, (P). The empirical evidence comes from a comparison of the morphosyntactic distribution of the ‘r’ in German and Dutch so-called R-pronouns (locative pronouns) and P-stranding constructions, and from complex spatial PPs in Colloquial German. The chapter argues that a comparative approach to these closely related Germanic languages warrants the decomposition of function words into parts not traditionally recognized as morphemes. The morphemes making up locative pronouns (e.g. Dutch daar ‘there’) and place adpositions (e.g. German auf ‘on’) are shown to pronounce different parts of the clausal structure. A ramification of the analysis is that P-stranding in Dutch and German is in fact the stranding of a remnant phrase that contains the R-pronoun by a projection containing the preposition.

Geothermal features of the western part of Yenisei-Khatanga regional trough

2019 ◽  
pp. 28-36
Author(s):  
Dmitry A. Novikov
Keyword(s):  
Oil And Gas ◽  
Sedimentary Basin ◽  
Sedimentary Cover ◽  
Heating Effect ◽  
Small Thickness ◽  
Geological Evolution ◽  
Geological Section ◽  
Gas Bearing ◽  
Different Parts ◽  
Comprehensive Study

The article deals with the results of a comprehensive study of the geothermal conditions of oil and gas bearing deposits in the western part of Yenisei-Khatanga regional trough. Four types of vertical geothermal zonality are established, the characteristics of which depend on the geological evolution of different parts of the sedimentary basin. The minimal geothermal gradients (1,80–2,2 0 C/100 m) are established there in the near edge zones with a small thickness of the sedimentary cover and the development of the infiltration system. The maximum gradients (3,2–3,4 0 С/100 m) are established in the zones of disjunctive tectonics, which had a significant heating effect on the geological section due to the ascending discharge of groundwater from deep-lying aquifers.

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