Asymmetry of tymbal action and structure in a cicada: a possible role in the production of complex songs

1998 ◽  
Vol 201 (5) ◽  
pp. 717-730 ◽  
Author(s):  
P J Fonseca ◽  
H-C Bennet Clark

The type 1 echeme of the song of the small European cicada Tympanistalna gastrica consists of a pair of loud IN-OUT pulses followed by a train of soft IN-OUT pulses. In all nine insects investigated, the right and left tymbals buckled inwards and outwards alternately, but the echeme started with the buckling of the right tymbal. Both the inward and the outward buckling movements produced single discrete sound pulses. <P> The loud IN pulses were produced with the tymbal tensor muscle relaxed. They were approximately 10 dB louder than the loud OUT pulses and than the soft IN and OUT pulses. The period between the right loud IN and OUT pulses (3.75+/-0.31 ms) (mean +/- s.d.) was significantly shorter than between the left loud IN and OUT pulses (4.09+/-0.28 ms). The period between the loud IN and OUT pulses was significantly shorter than the period between the soft IN and OUT pulses, which was similar on both sides (mean for the right tymbal 5.54+/-0.20 ms, mean for the left tymbal 5.30+/-0.51 ms). <P> Measured at the tymbal, the power spectrum of the right loud IN pulses showed major components between 4 and 8 kHz as well as around 11.7 kHz. That of the left loud IN pulse had approximately 10 dB less power at 4 kHz and similar power at 7-8 kHz, with a further louder peak at around 10.8 kHz. The loud OUT pulses and all subsequent IN and OUT soft pulses showed very little power at 4 and 8 kHz, but all showed a spectral peak at approximately 13 kHz. The soft OUT pulses had similar pulse envelopes to the preceding IN pulses, which they closely mirrored. <P> Measured at the fourth abdominal sternite, only the right loud IN pulse produced peak power at 4 kHz. The transfer function between the tymbal sound and that at sternite 4 was maximal at 4 kHz for the right loud IN pulse and showed a peak at this frequency for both loud and soft IN and OUT pulses. The 4 kHz components of all pulses, and particularly that of the right loud IN pulse, which has the loudest 4 kHz component, excited sympathetic sound radiation from the abdominal sternite region. <P> Measured at the tympanal opercula, both loud IN pulses produced peaks at 7-8 kHz of similar power. The transfer functions between the tymbal sound and that at the tympanal opercula showed peaks of power at this frequency range for both loud and soft IN and OUT pulses, suggesting that this component excites sympathetic radiation via the tympana. <P> Components of the sound pulses produced by one tymbal are also transmitted via the contralateral tymbal. The pulses transmitted during both loud IN pulses had ragged envelopes, but the soft IN pulses and all OUT pulses were transmitted as clean coherent pulses with slow build-up and slow decay, suggesting that the ipsilateral tymbal excited a sympathetic resonance in the contralateral one. <P> The tymbals of T. gastrica have two unusual features. At the dorsal end of rib 2, there is a horizontal bar that extends anteriorly over rib 3 and posteriorly over rib 1 to the dorsal end of the tymbal plate. This bar appears to couple the three ribs so that they buckle in unison. The resilin sheet at the ventral ends of ribs 1, 2 and 3 was significantly wider, dorso-ventrally, in the right tymbal than in the left in eight insects that were measured (mean right-to-left ratio, 1.37). <P> The asymmetry between the right and left loud IN pulses correlates with the morphological asymmetry of the tymbals. The complexities of the song in T. gastrica appear to result from the preferential excitation of sound radiation from the abdomen surface or via the tympana by components of the distinct pulses produced by the asymmetrical tymbals and from the tymbals themselves. <P> Moribund or fatigued insects were successively unable to produce the right loud pulse and then the left loud pulse. The complex song may in this way act as an honest signal of male fitness.

2021 ◽  
Vol 22 (2) ◽  
pp. 484
Author(s):  
Martijn H. van der Ree ◽  
Jeroen Vendrik ◽  
Jan A. Kors ◽  
Ahmad S. Amin ◽  
Arthur A. M. Wilde ◽  
...  

Patients with Brugada syndrome (BrS) can show a leftward deviation of the frontal QRS-axis upon provocation with sodium channel blockers. The cause of this axis change is unclear. In this study, we aimed to determine (1) the prevalence of this left axis deviation and (2) to evaluate its cause, using the insights that could be derived from vectorcardiograms. Hence, from a large cohort of patients who underwent ajmaline provocation testing (n = 1430), we selected patients in whom a type-1 BrS-ECG was evoked (n = 345). Depolarization and repolarization parameters were analyzed for reconstructed vectorcardiograms and were compared between patients with and without a >30° leftward axis shift. We found (1) that the prevalence of a left axis deviation during provocation testing was 18% and (2) that this left axis deviation was not explained by terminal conduction slowing in the right ventricular outflow tract (4th QRS-loop quartile: +17 ± 14 ms versus +13 ± 15 ms, nonsignificant) but was associated with a more proximal conduction slowing (1st QRS-loop quartile: +12[8;18] ms versus +8[4;12] ms, p < 0.001 and 3rd QRS-loop quartile: +12 ± 10 ms versus +5 ± 7 ms, p < 0.001). There was no important heterogeneity of the action potential morphology (no difference in the ventricular gradient), but a left axis deviation did result in a discordant repolarization (spatial QRS-T angle: 122[59;147]° versus 44[25;91]°, p < 0.001). Thus, although the development of the type-1 BrS-ECG is characterized by a terminal conduction delay in the right ventricle, BrS-patients with a left axis deviation upon sodium channel blocker provocation have an additional proximal conduction slowing, which is associated with a subsequent discordant repolarization. Whether this has implications for risk stratification is still undetermined.


Author(s):  
Patrizia Bisiacchi ◽  
Elisa Cainelli

AbstractAsymmetry characterizes the brain in both structure and function. Anatomical asymmetries explain only a fraction of functional variability in lateralization, with structural and functional asymmetries developing at different periods of life and in different ways. In this work, we perform a scoping review of the cerebral asymmetries in the first brain development phases. We included all English-written studies providing direct evidence of hemispheric asymmetries in full-term neonates, foetuses, and premature infants, both at term post-conception and before. The final analysis included 57 studies. The reviewed literature shows large variability in the used techniques and methodological procedures. Most structural studies investigated the temporal lobe, showing a temporal planum more pronounced on the left than on the right (although not all data agree), a morphological asymmetry already present from the 29th week of gestation. Other brain structures have been poorly investigated, and the results are even more discordant. Unlike data on structural asymmetries, functional data agree with each other, identifying a leftward dominance for speech stimuli and an overall dominance of the right hemisphere in all other functional conditions. This generalized dominance of the right hemisphere for all conditions (except linguistic stimuli) is in line with theories stating that the right hemisphere develops earlier and that its development is less subject to external influences because it sustains functions necessary to survive.


2021 ◽  
pp. 22
Author(s):  
Rana Moshref

Introduction: Neurofibromatosis (NF) is isolated into three diseases: NF type 1, type 2, and schwannoma. NF type 2 could be a disorder that's found roughly in 1/25,000–33,000 births with a mutation in gene 22q11.2, and it is passed through eras in an autosomal dominant fashion. Diagnosis is made with both clinical and radiological features. A few clinical features have been characterized in conclusion counting Manchester criteria. There is a scarce number of NF type 2 patients diagnosed with cervical lesions which are 25 in number. We report a case of an intradural extramedullary cervical lesion in a patient later diagnosed with NF type 2. Case Report: A 30-year-old male presenting with gradual onset and progressive course of spastic quadriparesis of six months’ duration was admitted through the emergency unit. MRI spine showed intradural extramedullary masses in the right side of C4 and left side of C6. The patient underwent cervical intradural excision of two masses under general anesthesia with neuromonitoring. The tumor was sent for histopathology and reported as NF type 2. Conclusion: NF is a common entity, but the diagnosis of cervical mass is judicious to avoid any complication in neurological function. It further needs a multidisciplinary approach and screening modalities.


2011 ◽  
Vol 53 (2) ◽  
pp. 113-117 ◽  
Author(s):  
Maria Luiza Figueiredo Braga Brandão ◽  
Nurimar C. Fernandes ◽  
Danielle Pereira De Oliveira Batista ◽  
Norma Santos

BACKGROUND: Pemphigus vulgaris (PV) is an autoimmune disease characterized by blistering of the skin and mucosa, which develops due to the interaction between predisposing genetic and environmental factors. Infections caused by members of the Herpesviridae family have been suggested as a possible triggering factor for PV. OBJECTIVE AND METHODS: In this report, we investigate the presence of herpesviruses in refractory lesions on the right upper eyelid. The lesion has persisted despite the treatment with corticosteroids. Polymerase chain reaction (PCR) and DNA sequence analysis have been used to detect the DNA of HSV 1/2, VZV, EBV, CMV, HHV-6, HHV-7, and HHV-8. RESULTS: The sample collected from the right upper eyelid has tested positive for HSV 1/2. Sequence analysis has confirmed the PCR results and allowed the identification of the HSV strain as belonging to type 1. After treatment with acyclovir, the lesion of the right upper eyelid has cleared and not relapsed. CONCLUSION: When patients present PV lesions which are refractory to corticosteroid therapy, herpetic infection should be considered.


2006 ◽  
Vol 13 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Mette Ejrnaes ◽  
Matthias G. von Herrath ◽  
Urs Christen

The use of neutralizing antibodies is one of the most successful methods to interfere with receptor–ligand interactions in vivo. In particular blockade of soluble inflammatory mediators or their corresponding cellular receptors was proven an effective way to regulate inflammation and/or prevent its negative consequences. However, one problem that comes along with an effective neutralization of inflammatory mediators is the general systemic immunomodulatory effect. It is, therefore, important to design a treatment regimen in a way to strike at the right place and at the right time in order to achieve maximal effects with minimal duration of immunosuppression or hyperactivation. In this review, we reflect on two examples of how short time administration of such neutralizing antibodies can block two distinct inflammatory consequences of viral infection. First, we review recent findings that blockade of IL-10/IL-10R interaction can resolve chronic viral infection and second, we reflect on how neutralization of the chemokine CXCL10 can abrogate virus-induced type 1 diabetes.


2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Jagadeesh K. Kalavakunta ◽  
Vishwaroop Bantu ◽  
Hemasri Tokala ◽  
Mihas Kodenchery

Introduction. Brugada syndrome accounts for about 4% of sudden cardiac deaths (SCD). It is characterized by an ST-segment elevation in the right precordial electrocardiogram (EKG) leads.Case Presentation. We describe a 39-year-old healthy Caucasian man who was admitted to the intensive care unit after being cardioverted from ventricular fibrillation (VF) arrest. His past history was significant for an episode of syncope one month prior to this presentation for which he was admitted to an outlying hospital. EKG during that admission showed ST elevations in V1 and V2 leads, a pattern similar to Type 1 Brugada. A diagnosis of Brugada syndrome was missed and the patient had a cardiac arrest a month later. We discuss a short review of Brugada syndrome and emphasize the need to look for it in patients presenting with SCD and malignant arrhythmias.Conclusion. Physicians should always consider Brugada syndrome in the differential diagnosis of ST-segment elevation in anterior precordial leads of EKG and associated VT/VF. Although more than 17 years have passed since the first case was reported, increased awareness of this syndrome is needed to identify patients with EKG changes and treat them accordingly to prevent incidence of (SCD) and its deleterious complications.


2014 ◽  
Vol 21 (4) ◽  
pp. 79-82
Author(s):  
V. N Merkulov ◽  
A. I Dorokhin ◽  
A. I Krupatkin ◽  
M. V Merkulov ◽  
M. A Avakova

Case report on 14 years old girl with type 1 complex regional pain syndrome (CRPS) is presented. At first admission in 5.5 months after right hand injury and development of type 1 CRPS, paravasal sympathectomy on the right upper extremity was performed. Complete elimination of pain syndrome and restoration of the extremity function was achieved. Five and a half months after discharge the left foot and in 3 weeks later the right hand were injured. In both cases injuries were accompanied by pronounced CRPS clinical picture. At second admission in 6 weeks after foot injury interventional treatment with placement of catheters next to nerve trunks and bolus administration of antibiotics was performed for 1 week and enabled to achieve remission of the disease. It was noted that not only hypersymphaticotony but also psychological status of a patient were important for the disease development.


2021 ◽  
Vol 6 (4) ◽  
pp. 01-04
Author(s):  
Reinaldo Filho

Neurofibromatosis type 1 (NF1) is an autosomal dominant multisystem genodermatosis resulting from a mutation on chromosome 17q11.2, characterized by diverse clinical expression with involvement of the skin, nervous system, bones, eyes and other systems. Neurofibromas are tumors located along nerve bundles; when they become large, they are called plexiform neurofibromas. Complications of neurofibromas are rare, but include malignant transformation and potentially life-threatening hemorrhages. A comprehensive perioperative management, including arterial embolization of feeding vessels, is required in order to perform a safe surgical procedure and to reduce potential surgical complications. We report a case of a large plexiform neurofibroma on the right flank, treated in a two-stage approach: first, embolization with polyvinyl alcohol particles of the inferior epigastric, lumbar and superior gluteal arteries on the right and, second, 24 hours after embolization, exeresis of the lesion, which weighed 2.5 kg. Two years after surgery, the patient was asymptomatic, without tumor recurrence and with an important improvement in self-esteem and quality of life.


Author(s):  
Pablo E Tauber ◽  
Virginia Mansilla ◽  
Pedro Brugada ◽  
Sara S Sánchez P ◽  
Stella M Honoré ◽  
...  

Background: Radiofrequency ablation (RFA) in Brugada syndrome (BrS) has been performed both endocardially and epicardially. The substrate in BrS is thus unclear. Objectives: To investigate the functional endocardial substrate and its correlation with clinical, electrophysiological and ECG findings in order to guide an endocardial ablation. Methods: Thirteen patients (38.7±12.3 years old) with spontaneous type 1 ECG BrS pattern, inducible VF with programmed ventricular stimulation (PVS) and syncope without prodromes were enrolled. Before to endocardial mapping the patients underwent flecainide testing with the purpose of measuring the greatest ST-segment elevation for to be correlated with the size and location of substrate in the electro-anatomic map. Patients underwent endocardial bipolar and electro-anatomic mapping with the purpose of identify areas of abnormal electrograms (EGMs) as target for RFA and determine the location and size of the substrate. Results: When the greatest ST-segment elevation was in the 3rd intercostal space (ICS), the substrate was located upper in the longitudinal plane of the right ventricular outflow tract (RVOT) and a greatest ST-segment elevation in 4th ICS correspond with a location of substrate in lower region of longitudinal plane of RVOT. A QRS complex widening on its initial and final part, with prolonged transmural and regional depolarization time of RVOT corresponded to the substrate locateded in the anterior-lateral region of RVOT. A QRS complex widening rightwards and only prolonged transmural depolarization time corresponded with a substrate located in the anterior, anterior-septal or septal region of RVOT. RFA of endocardial substrate suppressed the inducibility and ECG BrS pattern during 34.7±15.5 months. After RFA, flecainide testing confirmed elimination of the ECG BrS pattern. Endocardial biopsy showed a correlation between functional and ultrastructural alterations in two patients.


1970 ◽  
Vol 52 (3) ◽  
pp. 495-505 ◽  
Author(s):  
W. J. BAILEY

1. A method has been devised by which the isolated tegmina of bush crickets can be actuated in such a manner as to simulate the insect's natural song. 2. The actuator was used to make a detailed analysis of the mechanics of sound production, with particular reference to the emission of the more or less pure tone at 15 kHz., characteristic of Homorocoryphus nitidulus. 3. Results involving damping and cautery indicated that the area of the right tegmen responsible for the radiation of this sound was the mirror frame, the vein enclosing the classical mirror membrane. 4. Further experiments involving transduced sound and a probe microphone led to the construction of sound radiation maps of the right tegmen which supported the above view. 5. The cantilever hypothesis, involving the mirror frame with the axis of the vestigial file as the cantilever's rotational axis, was considered in the light of the Homorocoryphus type. 6. The Homorocoryphus type differed from the Conocephalus type (on which the cantilever hypothesis was based) in that a simpler cantilever is formed in a line direct from the plectrum to the tip of the frame arm.


Sign in / Sign up

Export Citation Format

Share Document