Non-Spiking Stretch-Receptors in the Crayfish Swimmeret System

1982 ◽  
Vol 96 (1) ◽  
pp. 355-366
Author(s):  
W. J. Heitler
Keyword(s):  
Cell Body ◽  
Large Diameter ◽  
Small Diameter ◽  
Pacifastacus Leniusculus ◽  
The Other ◽  
Intracellular Injection ◽  
Anterior Branch ◽  
Stretch Receptors ◽  
A Cell ◽  
Sternal Rib

1. Two neurones have been encountered with the properties of non-spiking stretch-receptors on both sides of each swimmeret-bearing segment of the crayfish Pacifastacus leniusculus. 2. Each neurone depolarizes by up to 35 mV (measured intracellularly in the ganglionic neuropil) in response to experimentally imposed retraction of the appropriate swimmeret, but does not generate spikes. 3. Depolarizing and hyperpolarizing current injected into these neurones can excite or inhibit the spike activity of several swimmeret motorneurones. 4. Intracellular injection of dye shows that both non-spiking stretch-receptors have large diameter axons in the anterior branch of the first root and central cell bodies. One has a cell body in the anterior ipsilateral quadrant of the ganglion (NSSR-A), while the other has a cell body in the posterior ipsilateral quadrant (NSSR-P). 5. Both neurones innervate a peripheral elastic strand which spans the base of the swimmeret, with its posterior attachment on the sternal rib at the posterior rim of the swimmeret socket, and its anterior attachment on the swimmeret basipodite. This strand (S1) is stretched by retraction of the swimmeret. 6. A second strand (S2) stretches from the anterior rim of the swimmeret socket to the mid point of S1, and is innervated by several small diameter axons which also do not appear to have cell bodies in the periphery.

Differences in the brain stem terminations of large- and small-diameter vestibular primary afferents

1995 ◽  
Vol 74 (3) ◽  
pp. 1362-1366 ◽  
Author(s):  
J. A. Huwe ◽  
E. H. Peterson
Keyword(s):  
Brain Stem ◽  
Large Diameter ◽  
Small Diameter ◽  
Movement Control ◽  
Three Dimensions ◽  
Significant Shift ◽  
Axon Diameter ◽  
Vestibular Complex ◽  
The Brain ◽  
Adjacent Brain

1. We visualized the central axons of 32 vestibular afferents from the posterior canal by extracellular application of horseradish peroxidase, reconstructed them in three dimensions, and quantified their morphology. Here we compare the descending limbs of central axons that differ in parent axon diameter. 2. The brain stem distribution of descending limb terminals (collaterals and associated varicosities) varies systematically with parent axon diameter. Large-diameter afferents concentrate their terminals in rostral regions of the medial/descending nuclei. As axon diameter decreases, there is a significant shift of terminal concentration toward the caudal vestibular complex and adjacent brain stem. 3. Rostral and caudal regions of the medial/descending nuclei have different labyrinthine, cerebellar, intrinsic, commissural, and spinal connections; they are believed to play different roles in head movement control. Our data help clarify the functions of large- and small-diameter afferents by showing that they contribute differentially to rostral and caudal vestibular complex.

scholarly journals Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Shear Wave ◽  
Large Diameter ◽  
Small Diameter ◽  
Shear Wave Elastography ◽  
Lesion Size ◽  
Ultrasound Elastography ◽  
Breast Lesions ◽  
Malignant Breast ◽  
The Impact

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.

Analysis Influence of Pile Embedded Depth and Diameter on Pile Tip Resistance

2013 ◽  
Vol 353-356 ◽  
pp. 459-462
Author(s):  
Ying Jie Zheng ◽  
Bin Fang ◽  
Lian Xiang Li
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Stiffness Ratio ◽  
Initial Stiffness ◽  
Tip Resistance

Pile tip absolute settlement curves and relative settlement curves of several working cases were analyzed. It is found that load-settlement curve characteristic related to the selection standard. The tip resistance initial stiffness of each case was analyzed. Results show that the small diameter pile has higher initial stiffness than large diameter pile, embedded depth has little influence on initial stiffness ratio, but increment of initial stiffness is linear with embedded depth growth.

CONTROL OF CELLULAR CONTRACTION BY CALCIUM IN VORTICELLA

1994 ◽  
Vol 189 (1) ◽  
pp. 163-177 ◽  
Author(s):  
K Katoh ◽  
Y Naitoh
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Body ◽  
Ruthenium Red ◽  
Measurable Effect ◽  
External Application ◽  
Sustained Contraction ◽  
Intracellular Injection ◽  
Contractile System ◽  
Triton X

1. Vorticella extracted with Triton X-100 contracted (i.e. the cell body shrank and the stalk coiled) when the external Ca2+ concentration was raised. The degree of contraction increased with increasing Ca2+ concentration. 2. The threshold Ca2+ concentration for shrinkage of the cell body was identical with that for coiling of the stalk in Vorticella extracted with Triton X-100. 3. Living Vorticella showed a graded shrinkage of the cell body when Ca2+ buffer was injected into the cell body, while the stalk showed coiling of an all-or-nothing type. The degree of shrinkage of the cell body increased with increasing free Ca2+ concentration of the buffer. 4. Living Vorticella showed a sustained contraction in response to external application or intracellular injection of caffeine. The effect of caffeine was inhibited by intracellular injection of procaine or Ruthenium Red. 5. Vorticella injected with Ruthenium Red showed graded shrinkage of the cell body as well as graded coiling of the stalk when Ca2+ buffer was injected into the cell body. 6. Caffeine, procaine and Ruthenium Red had no measurable effect on Ca2+-activated contraction in Vorticella extracted with Triton X-100. 7. It is assumed that regenerative liberation of Ca2+ from the endoplasmic reticulum and/or membranous tubules in the contractile system (Ca2+-induced Ca2+ release) is responsible for evoking contraction of an all-or-nothing type following stimulation in living Vorticella.

New method of poultry selection

2021 ◽  
pp. 61-66
Author(s):  
E. Rehleckaya ◽  
A. Dymkov ◽  
L. Lazarets ◽  
A. Maltsev
Keyword(s):  
Egg Production ◽  
Initial Period ◽  
Large Diameter ◽  
Small Diameter ◽  
Live Weight ◽  
Individual Variability ◽  
Egg Laying ◽  
New Method ◽  
Egg Diameter ◽  
Correlation Rate

Purpose: Install the influence of the «small diameter of the egg» on the living mass and the reproductive qualities of chickens of meat crosses and the quail of meat breeds.Materials and methods. The selection was carried out along egg production and mass of eggs and additionally on the average small diameter of 5 eggs by value of ≥0.5σ from the average for the herd, while the evaluation on the basis of the «small diameter of the egg» was carried out in chickens aged 238 days of life, quails — 70 days of life. Calculated the average for each female and the average for the herd. For further reproduction, chickens carrying eggs with a small egg diameter ≥0.5σ from the average for the herd. Studies were held in SibNIP on quail and on the courses.Results. In the initial period of the egg laying, the individual variability of the small diameter of the egg — more than 10% (in the future, the figure decreased). The close correlation rate of the small egg diameter in the first half of the egg laying with such at the end of the bird's operation period was revealed. It has been established that the large diameter of the egg has a positive reliable connection with a lively mass, but negative with egg production. The reliable correlation rate of the small diameter of the egg with a live weight at a 42-day age, as well as with the derivation of eggs. The inheritance coefficients of the small diameter of the egg are comparable to the inheritance coefficients of the mass of eggs and significantly exceed those for a large diameter of the egg. The selection according to the small diameter of the eggs by ≥0.5σ from the average for the herd led to the fact that the chickens of the experimental groups reliably exceeded the live weight in the SB level of 1.57%, in the line G8 — by 1.35%. The superiority of a lively mass of quail of experienced groups was more pronounced than that of the chickens: the Pharaoh breed — by 4.15%, the Texas white breed is 4.22%. In relation to the derivation of eggs, a similar trend was traced. The derivation of eggs in quails of experienced groups was more than 4.59–4.98%; Country, respectively, 4.57–5.22%. Egg production of females of comparable groups of both chickens and quail was almost on the same level, and the difference was unreliable.Conclusion. It was established that a new method of breeding the poultry of the meat direction of productivity allows without decreasing egg production to increase the living mass of chickens of meat crosses by 1.5%, rewinds of meat breeds — by 4%, the derivation of eggs, respectively, by 4–5%. The method is intended for early prediction of females productivity during breeding selection.

Copolymer-Nanoparticles Mixture in a Cylindrical Pore

NANO ◽  
2017 ◽  
Vol 12 (04) ◽  
pp. 1750045
Author(s):  
Jun-Xing Pan ◽  
Yu-Qi Guo ◽  
Yu-Fang Han ◽  
Min-Na Sun ◽  
Jin-Jun Zhang
Keyword(s):  
Phase Transition ◽  
Electrical Conductivity ◽  
Polymer Nanocomposites ◽  
Diblock Copolymer ◽  
Large Diameter ◽  
Small Diameter ◽  
Confinement Effect ◽  
Cylindrical Pore ◽  
Disorder Phase Transition ◽  
Novel Structures

Computer simulation is carried out for investigating the effect of nanoparticles on diblock copolymer morphology under cylindrical confinement. The phase diagrams of polymer nanocomposites with nanoparticle-block wetting strength and concentration of nanoparticles are obtained in different nanopores. In small diameter nanopore, there is almost no influence of nanoparticles on the diblock copolymer morphology because of the stronger confinement effect; in middle diameter nanopore, the system can self-assemble into various novel structures due to the interaction between confinement effect and nanoparticles effect; in large diameter nanopore, due to the stronger effect of nanoparticles, a disorder-order-disorder phase transition occurs with the wetting strength and concentration of nanoparticles increasing. This result can be useful in designing new nanocomposites with advanced electrical conductivity and/or mechanical strength.

scholarly journals MICRURGICAL STUDIES IN CELL PHYSIOLOGY

1926 ◽  
Vol 10 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Paul Reznikoff
Keyword(s):  
Heavy Metals ◽  
Metal Cation ◽  
Surface Membrane ◽  
The Other ◽  
Contractile Vacuole ◽  
Toxic Action ◽  
Cell Physiology ◽  
Relative Toxicity ◽  
A Cell

I. Plasmalemma. 1. The order of toxicity of the salts used in these experiments on the surface membrane of a cell, taking as a criterion viability of amebæ immersed in solutions for 1 day, is HgCl2, FeCl3&gt; AlCl3&gt; CuCl2&gt; PbCl2&gt; FeCl2. Using viability for 5 days as a criterion, the order of toxicity is PbCl2&gt; CuCl2&gt; HgCl2&gt; AlCl3&gt; FeCl3&gt; FeCl2. 2. The rate of toxicity is in the order FeCl3&gt; HgCl2&gt; AlCl3&gt; FeCl2&gt; CuCl2&gt; PbCl2. 3. The ability of amebæ to recover from a marked tear of the plasmalemma in the solutions of the salts occurred in the following order: AlCl3&gt; PbCl2&gt; FeCl2&gt; CuCl2&gt; FeCl3&gt; HgCl2. II. Internal Protoplasm. 4. The relative toxicity of the salts on the internal protoplasm, judged by the recovery of the amebæ from large injections and the range over which these salts can cause coagulation of the internal protoplasm, is in the following order: PbCl2&gt; CuCl2&gt; FeCl3&gt; HgCl2&gt; FeCl2&gt; AlCl3. 5. AlCl3 in concentrations between M/32 and M/250 causes a marked temporary enlargement of the contractile vacuole. FeCl2, FeCl3, and CuCl3 produce a slight enlargement of the vacuole. 6. PbCl2, in concentrations used in these experiments, appears to form a different type of combination with the internal protoplasm than do the other salts. III. Permeability. 7. Using the similarity in appearance of the internal protoplasm after injection and after immersion to indicate that the surface is permeable to a substance in which the ameba is immersed, it is concluded that AlCl3 can easily penetrate the intact plasmalemma. CuCl2 also seems to have some penetrating power. None of the other salts studied give visible internal evidence of penetrability into the ameba. IV. Toxicity. 8. The toxic action of the chlorides of the heavy metals used in these experiments, and of aluminum, is exerted principally upon the surface of the cell and is due not only to the action of the metal cation but also to acid which is produced by hydrolysis.

Photoreceptor coupling in turtle retina

1998 ◽  
Vol 15 (4) ◽  
pp. 755-764 ◽  
Author(s):  
M.L. FIRSOV ◽  
D.G. GREEN
Keyword(s):  
Receptive Field ◽  
Gap Junctions ◽  
Direct Evidence ◽  
Physiological Responses ◽  
The Other ◽  
Morphological Data ◽  
Chelydra Serpentina ◽  
Intracellular Injection ◽  
Coupled Cells ◽  
High Degree

Photoreceptors in the isolated turtle retina of two species of turtle, Chelydra serpentina and Pseudemus scripta elegans, were penetrated with double-barrel electrodes. Physiological responses were recorded through one barrel and Neurobiotin tracer was injected from the other. Intracellular injection of Neurobiotin revealed patterns of tracer-coupled photoreceptors. Both the patterns of tracer coupling and the electrophysiology suggest a high degree of specificity of connections. Rods seem to be coupled only to rods and green and red cones seem to be coupled to cones of the same spectral type. Receptive-field profiles, measured with a thin, sharply focused slit of light, often had well-defined peaks and troughs in sensitivity. We have taken advantage of this observation and used the position of a peak in sensitivity to locate the position on the retina of a coupled cell. In one rod, it was possible to correlate physiological and morphological data and to show that the peaks in the physiological receptive field occurred at positions on the retina where there were dye-coupled cells. This provides direct evidence that gap junctions produce the physiological coupling between rods.

scholarly journals A model of tight junction function in central nervous system myelinated axons

2008 ◽  
Vol 4 (4) ◽  
pp. 307-317 ◽  
Author(s):  
Alexander Gow ◽  
Jerome Devaux
Keyword(s):  
Current Flow ◽  
Large Diameter ◽  
Small Diameter ◽  
Structural Features ◽  
Axonal Membrane ◽  
Flow Through ◽  
Saltatory Conduction ◽  
Gait Abnormalities ◽  
Low Capacitance ◽  
Speed And Accuracy

The insulative properties of myelin sheaths in the central and peripheral nervous systems (CNS and PNS) are widely thought to derive from the high resistance and low capacitance of the constituent membranes. Although this view adequately accounts for myelin function in large diameter fibers, it poorly reflects the behavior of small fibers that are prominent in many regions of the CNS. Herein, we develop a computational model to more accurately represent conduction in small fibers. By incorporating structural features that, hitherto, have not been simulated, we demonstrate that myelin tight junctions (TJs) improve saltatory conduction by reducing current flow through the myelin, limiting axonal membrane depolarization and restraining the activation of ion channels beneath the myelin sheath. Accordingly, our simulations provide a novel view of myelin by which TJs minimize charging of the membrane capacitance and lower the membrane time constant to improve the speed and accuracy of transmission in small diameter fibers. This study establishes possible mechanisms whereby TJs affect conduction in the absence of overt perturbations to myelin architecture and may in part explain the tremor and gait abnormalities observed in Claudin 11-null mice.

scholarly journals Study on Failure Plane of Bulk Solid in Squat Silos

2012 ◽  
Vol 6 (1) ◽  
pp. 33-37
Author(s):  
Changbing Chen
Keyword(s):  
Limit Equilibrium ◽  
Large Diameter ◽  
Small Diameter ◽  
Theoretical Method ◽  
Wall Pressure ◽  
Failure Plane ◽  
Limit Equilibrium Theory ◽  
Bulk Solid ◽  
Important Basis ◽  
Key Parameter

With the increasing volume demand of silos, squat silo diameters are bigger and bigger. However, present wall pressure computation methods are mostly based on small diameter silos. To solve this problem, systematical research on the wall pressure in squat silos is of great importance. For now, in the Chinese code the wall pressure computation methods are based on the limit equilibrium theory to be calculated, which define the orientation of the failure plane in the bulk solid within the silo. The rupture angle is a key parameter to silos’ wall pressure. Therefore the value and direction of rupture angle are researched by theoretical method in this paper, which has heavy significance and provide an important basis for the large diameter silo design.

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