Arteries of the antebrachium and manus of the tokay (Gekko gecko) (Reptilia: Gekkonidae)

1981 ◽  
Vol 59 (4) ◽  
pp. 573-582 ◽  
Author(s):  
Anthony P. Russell
Keyword(s):  
Circulatory System ◽  
Arterial System ◽  
Functional Interpretation ◽  
Gekko Gecko ◽  
Low Viscosity ◽  
Adhesive Pads ◽  
The Subject ◽  
First Time

The role of the circulatory system in the functioning of the subdigital adhesive pads of geckoes has been the subject of much discussion. However, the morphology and configuration of the blood system in the foot has remained poorly understood, rendering functional interpretation of the blood sinuses simplistic. Here the major arterial vessels of the manus are described for the first time and a discussion of their geometry is presented. Due to the paucity of information concerning the arterial system of the appendages of lizards a description of the major vessels of the antebrachium is also given.The data presented are based on the study of material injected with low-viscosity silicone rubber and then cleared so that vessels may be studied in situ. The data are pertinent to subsequent discussions of the microvasculature of the subdigital lamellae and of reconsiderations of their structure and form.

scholarly journals The Role of Al3+-Based Aqueous Electrolytes in the Charge Storage Mechanism of MnOx Cathodes

2020 ◽  
Author(s):  
Véronique Balland ◽  
Mickaël Mateos ◽  
Kenneth D. Harris ◽  
Benoit Limoges
Keyword(s):  
Manganese Oxide ◽  
Critical Analysis ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Storage Mechanism ◽  
Main Charge ◽  
Charge Storage Mechanism ◽  
The Subject

<p>Rechargeable aqueous aluminium batteries are the subject of growing interest, but the charge storage mechanisms at manganese oxide-based cathodes remain poorly understood with as many mechanisms as studies. Here, we use an original <i>in situ</i> spectroelectrochemical methodology to unambiguously demonstrate that the reversible proton-coupled MnO<sub>2</sub>-to-Mn<sup>2+</sup> conversion is the main charge storage mechanism occurring at MnO<sub>2</sub> cathodes over a range of slightly acidic Al<sup>3+</sup>-based aqueous electrolytes. In Zn/MnO<sub>2</sub> assemblies, this mechanism is associated with high gravimetric capacity and discharge potentials, up to 560 mAh·g<sup>-1</sup> and 1.76 V respectively, attractive efficiencies (<i>CE</i> > 98.5 % and <i>EE</i> > 80%) and excellent cyclability (> 750 cycles at 10 A·g<sup>-1</sup>). Finally, we conducted a critical analysis of the data previously published on MnO<sub>x</sub> cathodes in Al<sup>3+</sup>-based aqueous electrolytes to conclude on a universal charge storage mechanism, <i>i.e.</i>, the reversible electrodissolution/electrodeposition of MnO<sub>2</sub>.<i></i></p>

scholarly journals Graphene spin-coated electrode for polyacrylonitrile acoustic nanogenerators

2021 ◽  
Author(s):  
Sedigheh Aghayari
Keyword(s):  
Nickel Nanoparticles ◽  
In Situ Synthesis ◽  
Coated Electrode ◽  
The Subject ◽  
First Time ◽  
Piezoelectric Nanogenerators ◽  
High Dust ◽  
Screen Ink

Abstract In recent years piezoelectric nanogenerators, due to their more durability in high dust or humidity are more attractive than triboelectric ones. So, increasing their outputs is the subject of much researches. I focused on electrodes of the acoustic nanofibers nanogenerators for the first time. Here, I introduced a new electrode that is cheaper and does not result in lower outputs. Here for the first time graphene spin-coated ink was used for polyacrylonitrile-based acoustic nanogenerator. The results of the tests compared with the in-situ synthesis of nickel nanoparticles on the layer and using graphene spin-coated screen ink and conductive tapes. Finally, producing sound by this graphene ink was done too.

scholarly journals Towards the realistic computer model of precipitation polymerization microgels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vladimir Yu. Rudyak ◽  
Elena Yu. Kozhunova ◽  
Alexander V. Chertovich
Keyword(s):  
Computer Simulations ◽  
Precipitation Polymerization ◽  
Coarse Grained ◽  
Polymerization Process ◽  
New Horizons ◽  
Experimental Systems ◽  
Structure Factors ◽  
The Subject ◽  
First Time

Abstract In this paper we propose a new method of coarse-grained computer simulations of the microgel formation in course of free radical precipitation polymerization. For the first time, we simulate the precipitation polymerization process from a dilute solution of initial components to a final microgel particle with coarse grained molecular dynamics, and compare it to the experimental data. We expect that our simulation studies of PNIPA-like microgels will be able to elucidate the subject of nucleation and growth kinetics and to describe in detail the network topology and structure. Performed computer simulations help to determine the characteristic phases of the growth process and show the necessity of prolongated synthesis for the formation of stable microgel particles. We demonstrate the important role of dangling ends in microgels, which occupy as much as 50% of its molecular mass and have previously unattended influence on the swelling behavior. The verification of the model is made by the comparison of collapse curves and structure factors between simulated and experimental systems, and high quality matching is achieved. This work could help to open new horizons in studies that require the knowledge of detailed and realistic structures of the microgel networks.

scholarly journals From a Basic Microalga and an Acetic Acid Bacterium Cellulose Producer to a Living Symbiotic Biofilm

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2275
Author(s):  
Vítor Nóbrega ◽  
Marisa Faria ◽  
Antera Quintana ◽  
Manfred Kaufmann ◽  
Artur Ferreira ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Bacterium ◽  
Growth Media ◽  
Media Composition ◽  
Symbiotic Interaction ◽  
Microalgae Biomass ◽  
The Subject ◽  
Living Material ◽  
First Time

Bacterial cellulose (BC) has recently been the subject of a considerable amount of research, not only for its environmentally friendly biosynthesis, but also for its high potential in areas such as biomedicine or biomaterials. A symbiotic relationship between a photosynthetic microalga, Chlamydomonas debaryana, and a cellulose producer bacterium, Komagataeibacter saccharivorans, was established in order to obtain a viable and active biofilm. The effect of the growth media composition ratio on the produced living material was investigated, as well as the microalgae biomass quantity, temperature, and incubation time. The optimal temperature for higher symbiotic biofilm production was 30 °C with an incubation period of 14 days. The high microalgae presence, 0.75% w/v, and 60:40 HS:BG-11 medium (v/v) induced a biofilm microalgae incorporation rate of 85%. The obtained results report, for the first time, a successful symbiotic interaction developed in situ between an alkaline photosynthetic microalga and an acetic acid bacterium. These results are promising and open a new window to BC living biofilm applications in medical fields that have not yet been explored.

Louis Hunton (1814-1838) - English Pioneer in Ammonite Biostratigraphy

1984 ◽  
Vol 3 (1) ◽  
pp. 58-68 ◽  
Author(s):  
H. Torrens ◽  
T. Getty
Keyword(s):  
Family Business ◽  
Scientific Work ◽  
North East ◽  
The North ◽  
The Family ◽  
The Subject ◽  
First Time ◽  
Practical Demonstration ◽  
Open Cast

In any discussion of the historical development of what was later to be named Biostratigraphy it is often assumed that a modern basis for the subject had already been reached by the cumulative work in the subject up to 1815; culminating in that of William Smith (1769-1839) and Alexandre Brongniart (1770-1847). But to this time fossils had only been used to identify (and discriminate between) often repetitive lithological units or to establish a relationship between rock units in different areas. The practical demonstration that particular lithological units could be regularly subdivided with significant consequences, on the basis of their contained fossils was a later achievement over several generations. One of the first to free stratigraphical palaeontology from such a lithological control was the forgotten Englishman Louis Hunton (1814-1838). In this paper Hunton's origins from a successful alum making family in the north-east of Yorkshire in the north of England and his short life and scientific work are described for the first time. The family business of alum making from the highly fossiliferous local alum shales, which were extracted open-cast, directly introduced Hunton to stratigraphical palaeontology. He followed up this work by study in London, where his pioneering paper was read to the Geological Society of London in 1836. He died less than 2 years later but had helped lay a foundation for major biostratigraphic advances by his insistence that only fossils collected in situ should be used in such work and then that the species, of especially ammonites, in his Yorkshire strata had particularly limited and invariable relative positions within that lithological sequence. His work is also compared with that of his contemporary W.C. Williamson and the conclusion reached that Hunton, because of his emphasis in the merits of ammonites, deserves more to be remembered as a pioneer of Jurassic biostratigraphy.

scholarly journals Propensity of undulatory swimmers, such as worms, to go against the flow

2015 ◽  
Vol 112 (12) ◽  
pp. 3606-3611 ◽  
Author(s):  
Jinzhou Yuan ◽  
David M. Raizen ◽  
Haim H. Bau
Keyword(s):  
Control Strategies ◽  
Aquatic Organisms ◽  
Life Cycles ◽  
Environmental Cues ◽  
Mechanical Forces ◽  
C Elegans ◽  
The Subject ◽  
And Function ◽  
First Time

The ability to orient oneself in response to environmental cues is crucial to the survival and function of diverse organisms. One such orientation behavior is the alignment of aquatic organisms with (negative rheotaxis) or against (positive rheotaxis) fluid current. The questions of whether low-Reynolds-number, undulatory swimmers, such as worms, rheotax and whether rheotaxis is a deliberate or an involuntary response to mechanical forces have been the subject of conflicting reports. To address these questions, we use Caenorhabditis elegans as a model undulatory swimmer and examine, in experiment and theory, the orientation of C. elegans in the presence of flow. We find that when close to a stationary surface the animal aligns itself against the direction of the flow. We elucidate for the first time to our knowledge the mechanisms of rheotaxis in worms and show that rheotaxis can be explained solely by mechanical forces and does not require sensory input or deliberate action. The interaction between the flow field induced by the swimmer and a nearby surface causes the swimmer to tilt toward the surface and the velocity gradient associated with the flow rotates the animal to face upstream. Fluid mechanical computer simulations faithfully mimic the behavior observed in experiments, supporting the notion that rheotaxis behavior can be fully explained by hydrodynamics. Our study highlights the important role of hydrodynamics in the behavior of small undulating swimmers and may assist in developing control strategies to affect the animals’ life cycles.

scholarly journals Technology as a factor in the cultural development of mankind: a study of the production nature of primitive culture

2021 ◽  
pp. 57-60
Author(s):  
Tetiana Sovhyra
Keyword(s):  
Art History ◽  
Integrated Approach ◽  
Cultural Development ◽  
Fire Control ◽  
Production Technologies ◽  
The Subject ◽  
Organization Of Production ◽  
First Time ◽  
Metal Melting

Purpose of article. Explore technological progress in the context of the development of a primitive culture. The methodology is based on an integrated approach and relies on analytical (when analyzing philosophical, art history, cultural studies literature on the subject of research), historical (when clarifying the stages of development of primitive culture), and conceptual (when analyzing the role of technology in the cultural development of mankind) research methods. The scientific novelty of the article lies in the fact that for the first time the formative role of technology in the cultural development of mankind is investigated, and also the cooperative nature of the production of artifacts of primitive culture is determined. Conclusions. As a result of the study of archaeological finds of primitive culture, it has been established that in the course of cultural evolution, tools of labor have become cultural artifacts, works of art. The emergence of production technologies (stone processing, fire control, metal melting) radically transformed the specifics of the organization of production activities, and therefore changed the course of cultural development. Therefore, in the course of the study, the formative role of technology in the formation of artistic culture was proved.

MORPHODYNAMICS OF THE SHORES OF THE VISTULA SPIT (THE BALTIC SEA) IN A PERIOD OF 2002-2015 BY RESULTS OF IN-SITU MEASUREMENTS

2017 ◽  
Author(s):  
Valentina Bobykina ◽  
Valentina Bobykina ◽  
Boris Chubarenko ◽  
Boris Chubarenko ◽  
Konstantin Karmanov ◽  
...  
Keyword(s):  
Erosion Rate ◽  
The South ◽  
The Baltic Sea ◽  
The North ◽  
Quantitative Characteristics ◽  
The Subject ◽  
The Baltic ◽  
First Time

For the first time, the quantitative characteristics of the Vistula Spit shore dynamics based on the ground-based monitoring data for 2002-2015 were presented. On the sea shore, 3 sections can be distinguished by the direction of coastal processes, i.e. the stable section to the north of the Strait of Baltiysk, the eroded 4-km section to the south of the Strait of Baltiysk, with maximum erosion rate up to 2 m/year; in the remaining area of the Spit (21 km) to the Polish border there is an alternation of stable, eroded and accumulative areas. Since 2011, a steady erosion (in the stable segments of the third section) and general weakening of the erosion rate (in the second section) have been recorded. 50% of the length of the lagoon shore was the subject to annual active erosion (0.2 - 1.4 m/year). The beaches of the sea and lagoon shores of the Vistula Spit were mainly composed of medium sands. The alongshore variability in particle size distribution on the sea and lagoon shores (according to the 2015 survey data) actually fail to correlate with long-term dynamic processes, with the exception of the steadily eroded 4-kilometer area on the sea coast to the south of the Strait of Baltiysk. Variations in the composition of sediment along the shore on the shoreline are most likely associated with the results of the latest wave processing (or storm processing and eolian transport in the case of an average beach sample).

The emergence and proliferation of the shaloput sect in the Pavlograd district of the Yekaterinoslav province (second half of the 19th century)

2020 ◽  
Keyword(s):  
Rural Community ◽  
Russian Orthodox ◽  
Russian Orthodox Church ◽  
Special Scientific ◽  
Analysis And Synthesis ◽  
History Of ◽  
The Subject ◽  
The 19Th Century ◽  
First Time

Purpose. The article aims to highlight the history of the emergence and spread of the shaloput sect in the Pavlograd district of the Yekaterinoslav province. Research methodology. The methodological basis of the article is formed by the principles of historicism and objectivity, implemented using several methods: general logical (analysis and synthesis), as well as classification, comparative, and periodization methods. Scientific novelty. For the first time in Russian historiography, the subject of a special scientific study was the sect of pranksters and its activities in the Yekaterinoslav province. Based on missionary and police reports, the role of Grigory Shevchenko in the creation of the sect is considered, the area of ​​its distribution within the region is highlighted, the national and social composition of its members is determined. Conclusions. It has been established that Grigory Shevchenko brought in the Pavlograd district of the Yekaterinoslav province the shaloput doctrine from the southern Ukrainian regions, probably from the Tauride province. The sect he created was by its nature Christover or Khlyst. Its dogmas and ceremonial were of a pronounced mystical coloring. Grigory Shevchenko remained a completely independent leader of a group of his fellow believers, he did not belong to any more ramified community, and his community throughout its existence remained an autonomous unit. The attitude of the dignitaries of the Russian Orthodox Church and representatives of the secular authorities to the new religious organization was extremely negative. Various means of pressure were used against the sectarians: from forced interviews to sentences of the rural community and outright repression by punitive bodies.

Russian explanatory sentence as a semantic type

2021 ◽  
pp. 272-286
Author(s):  
Tatiana I. Steksova ◽  
◽  
Tatyana V. Shmeleva ◽  
Keyword(s):  
Semantic Features ◽  
Semantic Type ◽  
Complex Sentences ◽  
The Subject ◽  
Semantic Types ◽  
First Time

The paper interprets the Russian explanatory sentence as a semantic type. It is noted that descriptions of the semantic types of monopropositional sentences have already been carried out in the linguistic literature. For the first time, it is proposed to consider polypropositional semantic structures as a semantic type. The semantic nature of an explanatory sentence is defined as an expression of reflection on the events and phenomena of reality, with the position of the object-event accompanied by an indication of the reflection nature expressed by the governing predicate. General characteristics of this semantic type are given, as well as a number of semantic features serving as the basis for revealing the patterns of compatibility of various types of modus and dictum and the ways of their connection. It is proved that the previously existing qualification of relevance/factuality is based on overestimating the role of the brace and underestimating the predicative expression of deliberative. Several techniques are proposed to distinguish between thematic and factual utterances. Among sentence elements, the concept of the subject is the most significant for the typology of explanatory sentences, proposed to be divided into mono-subject and poly-subject ones. We note the poly-paradigmatic nature of the explanatory sentence and the presence of a number of its transformations used in the texts. The range of explanatory sentences with such an interpretation expands significantly without taking into account the boundaries of simple and complex sentences and some other constructive differences.

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