scholarly journals Funicular sensilla of Dαcus oleαe: fine structural characteristics

2017 ◽  
Vol 2 ◽  
pp. 41 ◽  
Author(s):  
Ε. Hallberg ◽  
J.N.C. Yan Den Pers ◽  
G.E. Haniotakis
Keyword(s):  
Fine Structure ◽  
Structural Characteristics ◽  
Olfactory Function ◽  
Sensory Cells ◽  
Dacus Oleae ◽  
The Third ◽  
Functional Capabilities ◽  
Sensory Processes ◽  
Olfactory Pit

The funicular sensilla in Dacus oleae (Gmelin) (Diptera: Tephritidae) are found both on the surface and in the single olfactory pit. The surface sensilla are of three types: two are single-walled, the third is double-walled. The fine structure of these three sensillar types indicates olfactory function capabilities. The single-walled sensilla are, as a rule, innervated by two sensory cells. The long single-walled sensilla have unbranched sensory processes, whereas in the short they are branched. The double-walled sensilla usually possess three sensory cells that send unbranched sensory processes towards the tip of the hair. The olfactory pit sensilla are of two types: one type is identical to the double-walled type found on the funicular surface. The second type is poreless and found only in the olfactory pit. The poreless sensilla are innervated by three sensory cells, two of which terminate inside the cuticular hair, while the third does not enter inside the hair but terminates freely below it. The functional capabilities of this sensillar type are unknown.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Fine Structure of the Eye of a Nudibranch Mollusc, Hermissenda Crassicornis

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
The Other ◽  
Sensory Cells ◽  
Nerve Fibres ◽  
Supporting Cells ◽  
Small Bodies ◽  
Receptor Cells

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.

scholarly journals Demonstration of Transmission Mode Soft X-ray NEXAFS Using Third- and Fifth-Order Harmonics of FEL Radiation at SACLA BL1

2020 ◽  
Vol 10 (21) ◽  
pp. 7852
Author(s):  
Hiroshi Iwayama ◽  
Masanari Nagasaka ◽  
Ichiro Inoue ◽  
Shigeki Owada ◽  
Makina Yabashi ◽  
...  
Keyword(s):  
Fine Structure ◽  
Free Electron ◽  
Free Electron Laser ◽  
Transmission Mode ◽  
Pump Probe ◽  
X Ray ◽  
The Third ◽  
Nexafs Spectroscopy ◽  
Fifth Order ◽  
X Ray Absorption

We demonstrate the applicability of third- and fifth-order harmonics of free-electron laser (FEL) radiation for soft X-ray absorption spectroscopy in the transmission mode at SACLA BL1, which covers a photon energy range of 20 to 150 eV in the fundamental FEL radiation. By using the third- and fifth-order harmonics of the FEL radiation, we successfully recorded near-edge X-ray absorption fine structure (NEXAFS) spectra for Ar 2p core ionization and CO2 C 1s and O 1s core ionizations. Our results show that the utilization of third- and fifth-order harmonics can significantly extend the available photon energies for NEXAFS spectroscopy using an FEL and opens the door to femtosecond pump-probe NEXAFS using a soft X-ray FEL.

Development of pedicellariae in the pluteus larva of Lytechinus pictus (Echinodermata: Echinoidea)

1980 ◽  
Vol 58 (9) ◽  
pp. 1674-1682 ◽  
Author(s):  
Robert D. Burke
Keyword(s):  
Sensory Cells ◽  
Striated Muscles ◽  
Larval Body ◽  
Lytechinus Pictus ◽  
The Third ◽  
Adult Rudiment ◽  
The Right ◽  
Larval Skeleton ◽  
Precocious Development

Three tridentate pedicellariae develop in the pluteus larva of Lytechinus pictus. Two are located on the right side of the larval body and the third is on the posterior end of the larva. The pedicellariae form from mesenchyme associated with the larval skeleton which becomes enclosed in an invagination of larval epidermis. The mesenchyme within the pedicellaria primordium aggregates into groups of cells that become skeletogenic tissues which secrete the pedicellaria jaws, and smooth and striated muscles. Nerves and sensory cells develop within the epidermis covering the pedicellariae. Pedicellaria formation takes 3 days and occurs about midway through the development of the adult rudiment. During metamorphosis the pedicellariae are shifted to the aboral surface of the juvenile.Pedicellariae that develop in the larvae are fully operable prior to metamorphosis and do not appear to be released from any rudimentary state of development by metamorphosis. At least 16 echinoid species are reported to form pedicellariae in the larva. The precocious development of these adult structures appears to be dispersed throughout the orders of regular urchins.

Observations by Means of Cine Photography on the Behaviour of the Haptonema in Plankton Flagellates of the Class Haptophyceae

1971 ◽  
Vol 51 (1) ◽  
pp. 207-217 ◽  
Author(s):  
B. S. C. Leadbeater
Keyword(s):  
Fine Structure ◽  
Light Microscopy ◽  
Brackish Water ◽  
Type Species ◽  
Smooth Surface ◽  
Marine Species ◽  
Phaeocystis Globosa ◽  
The Third ◽  
Brackish Water Species ◽  
Water Species

INTRODUCTIONInitially the haptonema was recorded as a ‘little additional flagellum’ by Scherffel (1899) when he described Phaeocystis globosa. Similarly, the haptonema was referred to as the ‘third flagellum’ on the apparently tri-flagellate, brackish-water Prymnesium saltans Massart (Massart, 1920). Two further brackish water species of Prymnesium were described by Carter (1937) and all were characterized by a very short immobile ‘third appendage’. Lackey (1939) found a freshwater organism similar to Prymnesium but it possessed a ‘third flagellum’ several times the length of the true flagella. He re-corded that the third appendage was held out rigidly when the cell was at rest but during rapid swimming he was unable to see it and thought that this was due to an extremely rapid beat. He named his new organism Chrysochromulina parva and C. parva Lackey is now the type species of a considerable genus.Parke, Manton & Clarke (1955,1956,1958,1959) made a study of the light microscopy and fine structure of numerous marine species of Chrysochromulina. Their results showed that the ‘third flagellum’ differed in appearance and structure from that of a true flagellum and hence they decided to call this organelle a haptonema owing to its thread-like form and its ability to adhere to a smooth surface (Parke, Manton & Clarke, 1955). Their observations revealed that the haptonema could attach to a surface by an ‘adhesive tip’ and that the majority of species could coil their haptonemata into a helix and extend it again. In some species, e.g. C. strobilus (Parke, Manton & Clarke, 1959), the haptonema was usually tightly coiled whilst the cell was swimming.

“Premit” System for Space Reticulated Structures

2003 ◽  
Vol 18 (1) ◽  
pp. 61-72
Author(s):  
Vincenzo Dipaola ◽  
Giuseppe Prete
Keyword(s):  
Static Analysis ◽  
Structural Characteristics ◽  
Parametric Modelling ◽  
Structural Components ◽  
Structural Process ◽  
The Third ◽  
Application Potential ◽  
Design Requirements ◽  
Technical Solutions

This is the third of three papers where we present the application potential of an original structural process for steel space grids, named PREMIT System. Here we explain the geometrical and structural characteristics of the welded version of the proposed System. Moreover we carry out the static analysis of structural components and we present a parametric modelling. Finally a codification and an inventory of technical solutions, useful to satisfy the design requirements of a wide applicative case study, are proposed. In the Appendix we present two System's variants, valid for both the bolted and the welded versions, with the aim to achieve appreciable economies in terms of materials and manufacturing.

scholarly journals Structure of the Rete Mirabile in the Kidney of the Rat as Seen with the Electron Microscope

1960 ◽  
Vol 7 (1) ◽  
pp. 103-106 ◽  
Author(s):  
J. B. Longley ◽  
W. G. Banfield ◽  
D. C. Brindley
Keyword(s):  
Endothelial Cells ◽  
Fine Structure ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Simple Diffusion ◽  
Functional Capabilities ◽  
Rete Mirabile ◽  
Peritubular Capillaries ◽  
Fenestrated Endothelium

Electron micrographs of the rete mirabile in the medulla of the rat have revealed that the endothelium of the afferent and efferent vessels are markedly different in fine structure. The venous capillaries returning blood from the papilla are lined with a fenestrated endothelium much like that in the peritubular capillaries of the kidney. The arterial capillaries delivering blood to the papilla have an unperforated lining of overlapping endothelial cells with extremely irregular tapered margins. It is pointed out that the organization of particularly the latter vessels suggests that the functional capabilities of these retia go beyond those of a simple diffusion countercurrent exchanger.

The fine structure of ampullary electric receptors in Amiurus

1964 ◽  
Vol 160 (980) ◽  
pp. 345-359 ◽  
Keyword(s):  
Fine Structure ◽  
Lateral Line ◽  
Cell Group ◽  
Sensory Cells ◽  
Receptor Cells ◽  
Pit Organ ◽  
Accessory Cells ◽  
Myelinated Nerves ◽  
Square Array ◽  
Small Nerve

The small pit-organs of Amiurus have been included in the group of ampullary lateral-line organs. On morphological and physiological grounds these ampullary organs are thought to be electric receptors and not mechano-receptors; thus they can be distinguished from all other types of acoustico-lateralis organs of vertebrates. Each small pit-organ consists of a duct leading from the surface of the skin to an ampulla, beneath which there is a group of cells lying at the base of the epidermis. There are two main types of cells in this group: the receptor and the accessory cells. The apical surfaces of the receptor cells bear microvillae but no cilia: these microvillae project into the lumen of the ampulla. Myelinated nerves supply the organs at the base ; they lose their myelin sheaths before entering the cell group where they branch and innervate the receptor cells. Small nerve terminals are closely applied to the surface of the receptor cells and in some places are thought to be in synaptic contact. Near these regions characteristic dense bodies are found in the base of the receptor cells. The bodies are surrounded by an accumulation of small vesicles of about 300 to 500 Å in diameter; they resemble structures found in corresponding situations in other types of sensory cells. Dense inclusions are found in some receptor cells: these inclusions have a highly ordered fine structure which in some sections appears as a square array of dense dots having a centre-to-centre spacing of about 75 Å. These observations are discussed in relation to the supposed activity of small pit-organs as electric receptors and to their position in the group of ampullary lateral-line organs.

scholarly journals Anti-phosphocholine hybridoma antibodies. I. Direct evidence for three distinct families of antibodies in the murine response

1981 ◽  
Vol 153 (2) ◽  
pp. 352-364 ◽  
Author(s):  
JL Claflin ◽  
S Hudak ◽  
A Maddalena
Keyword(s):  
Binding Site ◽  
Isoelectric Focusing ◽  
Direct Evidence ◽  
Structural Characteristics ◽  
Site Specificity ◽  
The Third ◽  
Myeloma Proteins ◽  
Remarkable Degree ◽  
Serological Studies

Biochemical and serological studies were performed on more than 400 anti- phosphocholine (PC) hybridoma proteins (HP) derived from six strains of mice; 26 of these HP were examined in detail. All HP possessed specificity for PC, and all those tested contained an H-chain idiotypic determinant, V(H)-PC, which is shared by PC-binding myeloma proteins (BMP) and anti-PC antibodies. Among the HP, three well-defined and distinct families that correlated well with previous studies on serum anti-PC antibodies were identified. The largest group shared idotypic determinants, an L-chain isoelectric focusing (IEF) pattern, and a binding site specificity with the PC-BMP, T15. Using the same criteria, a second group was found to be strikingly similar to another PC-BMP, M603. The third group possessed an idiotypic determinant and an L-chain IEF profile similar to M511, but differences in binding site specificities were observed among the HP. The latter two groups contained members whose L-chain IEF profiles were not identical to other members of that group. Thus, among strains there is a remarkable degree of conservation among responding anti-PC antibodies, in both the kinds of anti-PC families that exist and the immunochemical and structural characteristics of various members within a family. Differences in at least one parameter were observed in each family, demonstrating that even a relatively restricted response is heterogeneous. However, this diversity seems to operate within certain constraints.

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