scholarly journals The Acoustic Behaviour of the Bush Cricket Pholidoptera Griseoaptera

1966 ◽  
Vol 45 (1) ◽  
pp. 31-44
Author(s):  
M. D. R. JONES
Keyword(s):  
Inhibitory Effect ◽  
Chirp Rate ◽  
Inhibitory Effects ◽  
Slow Recovery ◽  
Excitatory Effect ◽  
Acoustic Behaviour ◽  
Acoustic Interaction ◽  
Bush Cricket

1. Artificial signals have an inhibitory effect on chirping which affects whole chirps. With signals 1 sec. or less in length, the insects hardly ever chirp during the signal. If the signal is longer, chirps ’break through‘, but the chirp rate is usually less during the signals than in the periods of silence between the signals. 2. With signals of 0.1 sec. or less, the insect does not chirp until 0.4-1.0 sec. after the end of the signal. With longer signals this interval is reduced until the insect chirps during the signal. 3. Artificial signals may have an excitatory effect in increasing the total chirp rate in the period during which signals are being produced, and this effect may last for several minutes after the signals have ended. This may be due to rebound from inhibition or to a parallel excitatory effect of the signal. The excitatory effect is increased if the length of the signal is increased from 0.1 to 1 sec. 4. The excitatory effect is not so certain as the inhibitory effect and sometimes may be reversed, giving a reduction in chirp rate. 5. With very long signals (3 min.) there may be (a) a decrease in chirp rate during the signal followed by an increase after the signal, (b) a decrease in chirp rate during the signal with a very slow recovery after the signal, or (c) an increase in chirp rate during the signal followed by a decrease to normal after the signal. These effects can be more easily explained by parallel excitatory and inhibitory effects than by rebound from inhibition. 6. An increase in intensity of the signal from 40 to 70 db. gives an increase in both the inhibitory and the excitatory (or depressant) effects of the signals. 7. The rapidity and certainty of the inhibitory effect make it seem probable that few synapses are involved. The greater flexibility of the excitatory effect indicates that this effect may be mediated by higher centres in the C.N.S. 8. Recognition of the characteristic chirp of the species does not appear to be particularly important in the acoustic interaction of Ph. griseoaptera males.

The Acoustic Behaviour of the Bush Cricket Pholidoptera Griseoaptera

1966 ◽  
Vol 45 (1) ◽  
pp. 15-30
Author(s):  
M. D. R. JONES
Keyword(s):  
Chirp Rate ◽  
Mutual Inhibition ◽  
Acoustic Behaviour ◽  
Close Proximity ◽  
Hearing Range ◽  
High Level ◽  
Bush Cricket

1. Pholidoptera griseoptera males singing alone or alternating with other males produce short chirps of three or occasionally four syllables (wing movements) lasting about 100 msec. (at 18° C.). 2. Close proximity of singing males may result in rivalry behaviour where chirps lasting up to about 4 sec. may be produced. The long chirp is not usually continuous but has a number of breaks or ‘stutters’. 3. The syllables and syllable rates in the long chirp and short chirp are essentially similar. 4. At the end of a short chirp or of a group of syllables in the long chirp, the syllable rate is decreased, possibly indicating a waning of excitation of the syllable-producing mechanism. 5. Males within hearing range of each other alternate or occasionally synchronize their short chirps. The pattern of this interaction appears to be determined mainly by mutual inhibition between the singing males. Mutual excitation may cause an in crease in chirp rate during the interaction. 6. Chirping may be controlled by a pacemaker system which can be inhibited or excited by its various inputs. A long chirp is possibly the result of a high level of excitation of this mechanism. 7. Alternation singing and rivalry behaviour between males may have a territorial significance.

scholarly journals Afferent Stochastic Modulation of Crayfish Caudal Photoreceptor Units

1968 ◽  
Vol 51 (4) ◽  
pp. 534-551 ◽  
Author(s):  
Howard T. Hermann ◽  
Richard E. Olsen
Keyword(s):  
Inhibitory Effect ◽  
Fiber Optic Probe ◽  
Inhibitory Effects ◽  
Excitatory Effect ◽  
Multiple Pulses ◽  
Caudal Photoreceptor ◽  
Stochastic Modulation ◽  
The Mean ◽  
Optic Probe ◽  
Stimulation Of

When all roots to the sixth ganglion of the crayfish are cut, the caudal photoreceptor unit (PRU) fires at regular intervals. With an intact preparation, stimulation of caudal tactile hairs has predominantly inhibitory effects on the PRU: short bursts of afferent impulses, produced by momentary mechanical stimulation of tactile hairs, have (a) occasional immediate excitatory effect on the PRU, (b) prolonged inhibitory effect. The mean firing rate of the afferented and deafferented PRUs reacts similarly to a step increase in light, but the same unit fires faster after deafferentation. In the dark, deafferented units often fire paired or multiple pulses; the interval between pulses in a pair is similar to the short mode in afferented histograms. A fiber-optic probe of the caudal ganglion demonstrates the approximate location of the photosensitive element.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Inhibition of ADP-Induced Responses in Human Platelets by Agents Elevating the Cyclic AMP Level: Comparison of Aggregation and Shape Change

1984 ◽  
Vol 52 (03) ◽  
pp. 333-335 ◽  
Author(s):  
Vider M Steen ◽  
Holm Holmsen
Keyword(s):  
Inhibitory Action ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Shape Change ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Inhibitory Effects ◽  
Early Step ◽  
Stimulus Response ◽  
Sequential Relationship

SummaryThe inhibitory effect of cAMP-elevating agents on shape change and aggregation in human platelets was studied to improve the understanding of the sequential relationship between these two responses.Human platelet-rich plasma was preincubated for 2 min at 37° C with prostaglandin E1 or adenosine, agents known to elevate the intracellular level of cAMP. Their inhibitory effects on ADP-induced shape change and aggregation were determined both separately and simultaneously. The dose-inhibition patterns for shape change and aggregation were similar for both PGE1 and adenosine. There was no distinct difference between the inhibitory action of these two inhibitors.These observations suggest that elevation of the intracellular concentration of cAMP interferes with an early step in the stimulus-response coupling that is common for aggregation and shape change.

The Inhibitory Effect of Heparin and Related Glycosaminoglycans on Neutrophil Chemotaxis

1984 ◽  
Vol 52 (02) ◽  
pp. 134-137 ◽  
Author(s):  
Yaacov Matzner ◽  
Gerard Marx ◽  
Ruth Drexler ◽  
Amiram Eldor
Keyword(s):  
Specific Binding ◽  
Anticoagulant Activity ◽  
Neutrophil Migration ◽  
Inhibitory Effect ◽  
Chemotactic Factor ◽  
Human Neutrophils ◽  
Boyden Chamber ◽  
Neutrophil Chemotaxis ◽  
Inhibitory Effects ◽  
Chemotactic Factors

SummaryClinical observations have shown that heparin has antiinflammatory activities. The effect of heparin on neutrophil chemotaxis was evaluated in vitro in the Boyden Chamber. This method enabled differentiation between the direct effects of heparin on neutrophil migration and locomotion, and its effects on chemotactic factors. Heparin inhibited both the random migration and directed locomotion of human neutrophils toward zymosan-activated serum (ZAS) and F-met-leu-phe (FMLP). Inhibition was found to be dependent on the concentrations of the heparin and of the chemotactic factors. No specific binding of heparin to the neutrophils could be demonstrated, and heparin’s inhibitory effects were eliminated by simple washing of the cells. When added directly to the chamber containing chemotactic factor, heparin inhibited the chemotactic activity of ZAS but not that of FMLP, suggesting a direct inhibitory effect against C5a, the principal chemotactic factor in ZAS.Experiments performed with low-molecular-weight heparin, N-desulfated heparin, dextran sulfate, chondroitin sulfate and dextran indicated that the inhibitory effects of heparin on neutrophil chemotaxis are not related to its anticoagulant activity, but probably depend on the degree of sulfation of the heparin molecule.

First Record of the Bush-Cricket Isophya Harzi (Orthoptera: Phaneropteridae) Outside its Locus Typicus

2012 ◽  
Vol 55 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Ionuţ Ştefan Iorgu ◽  
Alexandru Ioan Tatu ◽  
Elena Iulia Iorgu
Keyword(s):  
First Record ◽  
Acoustic Behaviour ◽  
Bioacoustic Analysis ◽  
The Subject ◽  
Locus Typicus ◽  
Bush Cricket

Abstract During the period 2008-2012, the bush-cricket Isophya harzi Kis, 1960 has been the subject of several collecting trips in Cozia Mountains, where it was believed to be endemic, in order to study its acoustic behaviour. However, on a recent trip to Piatra Craiului Mountains, to study its Orthoptera fauna, I. harzi was surprisingly found in clearings and mountain steppe slopes covered with tall subalpine vegetation from Northern and Western areas. Bioacoustic analysis and some ecological notes are presented in the paper.

Inhibition of Yeast Growth by Tryptamine and Recovery with Tryptophan

2020 ◽  
Vol 16 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Chandrika Kadkol ◽  
Ian Macreadie
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Competitive Inhibition ◽  
Yeast Species ◽  
Inhibitory Effect ◽  
The Body ◽  
Inhibitory Effects ◽  
Trna Synthetases ◽  
Fermentative Growth ◽  
Biogenic Monoamine

Background: Tryptamine, a biogenic monoamine that is present in trace levels in the mammalian central nervous system, has probable roles as a neurotransmitter and/or a neuromodulator and may be associated with various neuropsychiatric disorders. One of the ways tryptamine may affect the body is by the competitive inhibition of the attachment of tryptophan to tryptophanyl tRNA synthetases. Methods: This study has explored the effects of tryptamine on growth of six yeast species (Saccharomyces cerevisiae, Candida glabrata, C. krusei, C. dubliniensis, C. tropicalis and C. lusitaniae) in media with glucose or ethanol as the carbon source, as well as recovery of growth inhibition by the addition of tryptophan. Results: Tryptamine was found to have an inhibitory effect on respiratory growth of all yeast species when grown with ethanol as the carbon source. Tryptamine also inhibited fermentative growth of Saccharomyces cerevisiae, C. krusei and C. tropicalis with glucose as the carbon source. In most cases the inhibitory effects were reduced by added tryptophan. Conclusion: The results obtained in this study are consistent with tryptamine competing with tryptophan to bind mitochondrial and cytoplasmic tryptophanyl tRNA synthetases in yeast: effects on mitochondrial and cytoplasmic protein synthesis can be studied as a function of growth with glucose or ethanol as a carbon source. Of the yeast species tested, there is variation in the sensitivity to tryptamine and the rescue by tryptophan. The current study suggests appropriate yeast strains and approaches for further studies.

Molecular Mechanisms of the Inhibitory Effects of Bupivacaine, Levobupivacaine, and Ropivacaine on Sarcolemmal Adenosine Triphosphate–sensitive Potassium Channels in the Cardiovascular System

2004 ◽  
Vol 101 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Takashi Kawano ◽  
Shuzo Oshita ◽  
Akira Takahashi ◽  
Yasuo Tsutsumi ◽  
Yoshinobu Tomiyama ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Adenosine Triphosphate ◽  
Local Anesthetics ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Katp Channels ◽  
Inhibitory Effect ◽  
Amino Acid Residues ◽  
Sulfonylurea Receptor ◽  
Inhibitory Effects

Background Sarcolemmal adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system may be involved in bupivacaine-induced cardiovascular toxicity. The authors investigated the effects of local anesthetics on the activity of reconstituted KATP channels encoded by inwardly rectifying potassium channel (Kir6.0) and sulfonylurea receptor (SUR) subunits. Methods The authors used an inside-out patch clamp configuration to investigate the effects of bupivacaine, levobupivacaine, and ropivacaine on the activity of reconstituted KATP channels expressed in COS-7 cells and containing wild-type, mutant, or chimeric SURs. Results Bupivacaine inhibited the activities of cardiac KATP channels (IC50 = 52 microm) stereoselectively (levobupivacaine, IC50 = 168 microm; ropivacaine, IC50 = 249 microm). Local anesthetics also inhibited the activities of channels formed by the truncated isoform of Kir6.2 (Kir6.2 delta C36) stereoselectively. Mutations in the cytosolic end of the second transmembrane domain of Kir6.2 markedly decreased both the local anesthetics' affinity and stereoselectivity. The local anesthetics blocked cardiac KATP channels with approximately eightfold higher potency than vascular KATP channels; the potency depended on the SUR subtype. The 42 amino acid residues at the C-terminal tail of SUR2A, but not SUR1 or SUR2B, enhanced the inhibitory effect of bupivacaine on the Kir6.0 subunit. Conclusions Inhibitory effects of local anesthetics on KATP channels in the cardiovascular system are (1) stereoselective: bupivacaine was more potent than levobupivacaine and ropivacaine; and (2) tissue specific: local anesthetics blocked cardiac KATP channels more potently than vascular KATP channels, via the intracellular pore mouth of the Kir6.0 subunit and the 42 amino acids at the C-terminal tail of the SUR2A subunit, respectively.

scholarly journals Identification of 3-chymotrypsin like protease (3CLPro) inhibitors as potential anti-SARS-CoV-2 agents

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Vicky Mody ◽  
Joanna Ho ◽  
Savannah Wills ◽  
Ahmed Mawri ◽  
Latasha Lawson ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dynamics Simulation ◽  
Simulation Studies ◽  
Inhibitory Effects ◽  
Major Threat ◽  
Main Protease ◽  
Approved Drugs ◽  
Fda Approved Drugs ◽  
Computational Molecular Modeling

AbstractEmerging outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a major threat to public health. The morbidity is increasing due to lack of SARS-CoV-2 specific drugs. Herein, we have identified potential drugs that target the 3-chymotrypsin like protease (3CLpro), the main protease that is pivotal for the replication of SARS-CoV-2. Computational molecular modeling was used to screen 3987 FDA approved drugs, and 47 drugs were selected to study their inhibitory effects on SARS-CoV-2 specific 3CLpro enzyme in vitro. Our results indicate that boceprevir, ombitasvir, paritaprevir, tipranavir, ivermectin, and micafungin exhibited inhibitory effect towards 3CLpro enzymatic activity. The 100 ns molecular dynamics simulation studies showed that ivermectin may require homodimeric form of 3CLpro enzyme for its inhibitory activity. In summary, these molecules could be useful to develop highly specific therapeutically viable drugs to inhibit the SARS-CoV-2 replication either alone or in combination with drugs specific for other SARS-CoV-2 viral targets.

scholarly journals Study on the Inhibitory Activity of a Synthetic Defensin Derived from Barley Endosperm against Common Food Spoilage Yeast

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 165
Author(s):  
Laila N. Shwaiki ◽  
Aylin W. Sahin ◽  
Elke K. Arendt
Keyword(s):  
Apple Juice ◽  
Digestive Enzyme ◽  
Inhibitory Effect ◽  
Food Preservation ◽  
Food Spoilage ◽  
Inhibitory Effects ◽  
Barley Endosperm ◽  
Spoilage Yeast ◽  
Spoilage Yeasts ◽  
Spoilage Microorganisms

In the food industry, food spoilage is a real issue that can lead to a significant amount of waste. Although current preservation techniques are being applied to reduce the occurrence of spoilage microorganisms, the problem persists. Food spoilage yeast are part of this dilemma, with common spoilers such as Zygosaccharomyces, Kluyveromyces, Debaryomyces and Saccharomyces frequently encountered. Antimicrobial peptides derived from plants have risen in popularity due to their ability to reduce spoilage. This study examines the potential application of a synthetic defensin peptide derived from barley endosperm. Its inhibitory effect against common spoilage yeasts, its mechanisms of action (membrane permeabilisation and overproduction of reactive oxygen species), and its stability in different conditions were characterised. The safety of the peptide was evaluated through a haemolysis and cytotoxicity assay, and no adverse effects were found. Both assays were performed to understand the effect of the peptide if it were to be consumed. Its ability to be degraded by a digestive enzyme was also examined for its safety. Finally, the peptide was successfully applied to different beverages and maintained the same inhibitory effects in apple juice as was observed in the antiyeast assays, providing further support for its application in food preservation.

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