scholarly journals Multimodal oscillations in systems with strong contraction

2007 ◽  
Vol 228 (2) ◽  
pp. 87-106 ◽  
Author(s):  
Georgi Medvedev ◽  
Yun Yoo
Keyword(s):  
Strong Contraction

scholarly journals Actions of a Pair of Identified Cerebral-Buccal Interneurons (CBI-8/9) in Aplysia That Contain the Peptide Myomodulin

1999 ◽  
Vol 81 (2) ◽  
pp. 507-520 ◽  
Author(s):  
Yuanpei Xin ◽  
Itay Hurwitz ◽  
Ray Perrins ◽  
Colin G. Evans ◽  
Vera Alexeeva ◽  
...  
Keyword(s):  
Cerebral Ganglion ◽  
Rhythmic Activity ◽  
Excitatory Input ◽  
Small Population ◽  
Inhibitory Input ◽  
Functional Roles ◽  
Buccal Mass ◽  
Strong Contraction ◽  
A Cell ◽  
To Receive

Actions of a pair of identified cerebral-buccal interneurons (CBI-8/9) in Aplysia that contain the peptide myomodulin. A combination of biocytin back-fills of the cerebral-buccal connectives and immunocytochemistry of the cerebral ganglion demonstrated that of the 13 bilateral pairs of cerebral-buccal interneurons in the cerebral ganglion, a subpopulation of 3 are immunopositive for the peptide myomodulin. The present paper describes the properties of two of these cells, which we have termed CBI-8 and CBI-9. CBI-8 and CBI-9 were found to be dye coupled and electrically coupled. The cells have virtually identical properties, and consequently we consider them to be “twin” pairs and refer to them as CBI-8/9. CBI-8/9 were identified by electrophysiological criteria and then labeled with dye. Labeled cells were found to be immunopositive for myomodulin, and, using high pressure liquid chromatography, the cells were shown to contain authentic myomodulin. CBI-8/9 were found to receive synaptic input after mechanical stimulation of the tentacles. They also received excitatory input from C-PR, a neuron involved in neck lengthening, and received a slow inhibitory input from CC5, a cell involved in neck shortening, suggesting that CBI-8/9 may be active during forward movements of the head or buccal mass. Firing of CBI-8 or CBI-9 resulted in the activation of a relatively small number of buccal neurons as evidenced by extracellular recordings from buccal nerves. Firing also produced local movements of the buccal mass, in particular a strong contraction of the I7 muscle, which mediates radula opening. CBI-8/9 were found to produce a slow depolarization and rhythmic activity of B48, the motor neuron for the I7 muscle. The data provide continuing evidence that the small population of cerebral buccal interneurons is composed of neurons that are highly diverse in their functional roles. CBI-8/9 may function as a type of premotor neuron, or perhaps as a peptidergic modulatory neuron, the functions of which are dependent on the coactivity of other neurons.

Early Rousseff exit in Brazil appears ever more likely

2016 ◽  
Keyword(s):  
Political Reform ◽  
Political Crisis ◽  
Content Type ◽  
Strong Contraction ◽  
Oil Company ◽  
Brazilian Politics

Significance The largely peaceful demonstrations are the latest chapter in the deepening political crisis. This has been triggered by the ever-expanding 'petrolao' corruption scandal centred on state-controlled oil company Petrobras, and fuelled by a savage recession: the economy shrank by 3.8% last year and will see another strong contraction in 2016. Impacts The PT's crisis will leave the centre-left space in Brazilian politics vacant. Marina Silva's Sustainability Network will likely try to occupy that space. Congressional fragmentation will undermine governance absent an ambitious political reform.

Policy tweaks will have modest impact in Brazil

2016 ◽  
Keyword(s):  
Central Bank ◽  
High Frequency ◽  
Federal Budget ◽  
Content Type ◽  
Strong Contraction ◽  
The Government ◽  
Primary Surplus

Significance The decision was taken despite inflation that reached 10.67% last year. It came days after President Dilma Rousseff signed into law the 2016 federal budget, which foresees a GDP contraction of 1.9% and a primary surplus corresponding to 0.5% of output -- both widely seen as overoptimistic assumptions. Amid a recession that could wipe some 6-7% off the Brazilian economy in two years, both the Central Bank and the government are under increasing pressure to adopt pro-growth policies. Impacts High-frequency indicators suggest the recession may have bottomed out. However, for now, this would only mean slower deterioration. Overall, 2016 will be another year of strong contraction.

scholarly journals Determination of Tropical Belt Widening Using Multiple GNSS Radio Occultation Measurements

2021 ◽  
Author(s):  
Mohamed Darrag ◽  
Shuanggen Jin ◽  
Andrés Calabia ◽  
Aalaa Samy
Keyword(s):  
Surface Temperature ◽  
Spatial Pattern ◽  
Radio Occultation ◽  
Lapse Rate ◽  
Tropopause Height ◽  
Total Column Ozone ◽  
Expansion Behavior ◽  
Rate Of Increase ◽  
Strong Contraction ◽  
A Minor

Abstract. In the last decades, Global navigation satellite systems (GNSS) have provided an exceptional opportunity to retrieve atmospheric parameters globally through GNSS radio occultation (GNSS-RO). In this paper, data of 12 GNSS-RO missions from June 2001 to November 2020 with high resolution were used to investigate the possible widening of the tropical belt along with the probable drivers and impacts in both hemispheres. Applying both lapse rate tropopause (LRT) and cold point tropopause (CPT) definitions, the global tropopause height shows increase of approximately 36 m/decade and 60 m/decade, respectively. Moreover, the tropical edge latitude (TEL) estimated based on two tropopause height metrics, in the northern hemisphere (NH) and southern hemisphere (SH), are different from each other. For the first metric, subjective method, the tropical width from GNSS has expansion behavior in NH with ~ 0.41°/decade and a minor expansion in SH with ~ 0.08°/decade. In case of ECMWF Reanalysis v5 (ERA5) there is no significant contraction in both NH and SH. For Atmospheric Infrared Sounder (AIRS), there are expansion behavior in NH with ~ 0.34°/decade and strong contraction in SH with ~ −0.48°/decade. Using the second metric, objective method, the tropical width from GNSS has expansion in NH with ~ 0.13°/decade, and no significant expansion in SH. In case of ERA5, there is no significant signal in NH while SH has a minor contraction. AIRS has an expansion with ~ 0.13°/decade in NH, and strong contraction in SH with ~ −0.37°/decade. The variability of tropopause parameters (temperature and height) is maximum around the TEL locations at both hemispheres. The total column ozone (TCO) shows increasing rates globally, and the rate of increase at the SH is higher than that of the NH. There is a good agreement between the spatial and temporal patterns of TCO variability and the TEL location estimated from GNSS LRT height. Carbon dioxide (CO2), and Methane (CH4), the most important greenhouse gases (GHGs) and the main drivers of global warming, have a global increasing rate and the increasing rate of the NH is similar to that of the SH. The spatial pattern in the NH is located more pole ward than its equivalent at the SH. Both surface temperature and precipitation increase in time and have strong correlation with GNSS LRT height. Both show higher increasing rates at the NH, while the precipitation at the SH has slight decrease and the surface temperature increases. The surface temperature shows a spatial pattern with strong variability, which broadly agrees with the TEL locations. The spatial pattern of precipitation shows northward occurrence. In addition, Standardized Precipitation Evapotranspiration Index (SPEI) has no direct connection with the TEL behavior.

Remifentanil-induced strong contraction of colon during colonoscopy

2019 ◽  
Vol 56 ◽  
pp. 138-139 ◽  
Author(s):  
Ke-Li Wu ◽  
Tsai-Shan Wu ◽  
Zhi-Fu Wu ◽  
Hou-Chuan Lai
Keyword(s):  
Strong Contraction

A case of bilateral fracture of the fibular heads

1903 ◽  
Vol 3 (5-6) ◽  
pp. 288-288
Author(s):  
V. N. Zender
Keyword(s):  
Knee Joint ◽  
Lower Leg ◽  
The Other ◽  
Lateral Ligament ◽  
Strong Contraction ◽  
Bilateral Fracture ◽  
Significant Extension ◽  
The One

Abstracts. Surgery."Surgery" v. XIII. No. 73.V.N. Zender. A case of bilateral fracture of the fibular heads. "Russian Doctor" 1903, No. 8.One of the very rare fractures is the fracture of the head of the fibulae. The two-sided fracture in the literature available to the author has not yet been described. The origin of the fracture of the head of the fibulae, on the one hand, may be the result of a strong contraction of the w. bicipitis (with a significant extension of the lower leg and tension of the lateral ligament of the knee joint), and with the other, it can be directly dependent on external violence.

Study of termination of postprandial gastric contractions in humans, dogs andSuncus murinus: role of motilin- and ghrelin-induced strong contraction

2017 ◽  
Vol 222 (2) ◽  
pp. e12933 ◽  
Author(s):  
T. Mikami ◽  
K. Ito ◽  
H. O. Diaz-Tartera ◽  
P. M. Hellström ◽  
E. Mochiki ◽  
...  
Keyword(s):  
Strong Contraction ◽  
Gastric Contractions

Pharyngeal, esophageal, and proximal gastric responses associated with vomiting

1993 ◽  
Vol 265 (5) ◽  
pp. G963-G972 ◽  
Author(s):  
I. M. Lang ◽  
S. K. Sarna ◽  
W. J. Dodds
Keyword(s):  
Smooth Muscles ◽  
Tonic Contraction ◽  
Cervical Esophagus ◽  
Proximal Stomach ◽  
Vagal Blockade ◽  
Strong Contraction ◽  
Motor Activities ◽  
Esophageal Sphincter ◽  
Frequency Relaxation ◽  
Chronically Instrumented Dogs

The motor activities of the pharynx, esophagus, and proximal stomach associated with vomiting were characterized and quantified in 25 awake chronically instrumented dogs. These motor events were correlated temporally with motor responses of the gastrointestinal and respiratory tracts. Vomiting was stimulated by apomorphine or UK-14304, and motor activities of striated and smooth muscles were recorded by electromyography and strain-gauge transducers, respectively. We found responses that began 1) before retching: increased swallow frequency, relaxation of the lower esophageal sphincter (LES) and proximal stomach, and tonic contraction of the cricopharyngeus and cervical esophagus; 2) during retching: rhythmic relaxation and contraction of the pharynx and cervical esophagus 180 degrees out of phase with retching; and 3) during vomitus expulsion: relaxation of the pharynx and cervical esophagus but strong contraction of the geniohyoideus and a retrograde contraction of the cervical esophagus and pharynx. The increased pharyngoesophageal tone occurred in an all-or-none fashion independent of vomiting or the gastrointestinal correlates of vomiting. Cervical vagal blockade increased swallow frequency but did not alter the other pharyngoesophageal responses associated with vomiting. We concluded that the motor events of the pharynx and esophagus play a significant role in gastrooral evacuation during vomiting and that these motor events (except LES relaxation) are not controlled by subnodose vagal pathways.

The Effect Of PF-4 Peptide Analogues On Platelet Activation And Release

1981 ◽  
Author(s):  
Daniel A Walz ◽  
Jawed Fareed ◽  
Sandor Bajusz
Keyword(s):  
Platelet Rich Plasma ◽  
Heparin Binding ◽  
Clot Retraction ◽  
Strong Contraction ◽  
Lysine Residues ◽  
Heparin Binding Domain ◽  
Carboxy Terminal Region ◽  
Carboxy Terminal ◽  
Heparin Neutralization ◽  
Peptide Analogues

The complete amino acid sequence of human PF-4 has demonstrated it to be a 70 residue protein with a lysine-rich carboxy terminal region. Chemical data, drawn from specific modification of these lysine residues, has been strongly suggestive of the dominance of these lysines in the interaction of PF-4 with heparin. We have synthesized argiHyland lysyl-peptide analogues of the human PF-4 sequence, residues 58-68, to mimic the putative heparin binding domain. Peptides 1 and 5 are the most effective samples in plasma for heparin neutralization. When each peptide was incubated with platelet rich plasma (PRP) in submicromolar concentrations, and followed by the addition of ADP, peptides 1-4 but not peptide 5 quantitatively blocked the release of PF-4 as judged by radioimmunoassays of the PRP supernatant. Peptide 1 also supressed the second aggregation wave follow ing ADP stimulation. Upon completion of aggregation of PRP, exogenously added PF-4 or these peptide analogues appeared to promote clot retraction. In other experiments, PF-4 and its peptide analogues induced a strong contraction in isolated uterus and ileum preparations. We are presently evaluating the ability of these analogues to block the interaction of PF-4 with its platelet proteoglycan carrier. This may mean that PF-4 or its analogues interact directly with cellular contractile elements and thereby modulate their contractile response.

scholarly journals THE EFFECT OF POLYPHOSPHATES AND MAGNESIUM ON THE MECHANICAL PROPERTIES OF EXTRACTED MUSCLE FIBERS

1956 ◽  
Vol 39 (5) ◽  
pp. 789-800 ◽  
Author(s):  
Emil Bozler
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Modulus Of Elasticity ◽  
Muscle Fibers ◽  
Configurational Entropy ◽  
Partial Removal ◽  
Relaxation Factor ◽  
Low Concentrations ◽  
Strong Contraction ◽  
Plastic Extension

Loading of extracted muscle fibers causes a small, sudden lengthening, followed by a slower, plastic extension, which is reversed only by active contraction. Polyphosphates in the presence of Mg strongly accelerate plastic extension, but elastic changes in length remain the same as during rigor. The modulus of elasticity on the average is about 6.2 x 107 dynes per cm.2 This value is about 40 times larger than that of rubber, if compared on a water-free basis. Extension of muscle, therefore, is almost entirely due to plastic deformation. Mg is essential for the softening action of adenosinetriphosphate (ATP) and can produce partial relaxation in the absence of a relaxation factor. After partial removal of bound Mg, ATP causes strong contraction, but only slight softening. The same condition is produced by very low concentrations of ATP in the presence of phosphocreatine. These observations show that during contraction passive mechanical properties may remain essentially like those during rigor. The constancy of elastic extensibility distinguishes contraction produced by ATP from contraction induced by non-specific agents in various fibrous structures and caused by an increase in configurational entropy.

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