Common Cavity Research Articles

Temporal Bone High-Resolution Computed Tomography in Non-Syndromic Unilateral Hearing Loss in Children

Objective: The aim of this study was to disclose possible inner ear abnormalities/pathologies by means of high-resolution computed tomography (HRCT) of the temporal bone (TBHRCT) in children with unilateral hearing loss (UHL). Methods: Retrospective review of audiological evaluation and TBHRCT in 22 children with UHL. Results: Two thirds of the children showed profound hearing loss. Review of HRCT scans identified inner ear malformations/pathologies in 9 (41%) cases and a high jugular bulb (HJB), always dehiscent with the vestibular aqueduct, in another 5 (22%). Inner ear malformations included enlarged vestibular aqueduct, common cavity and cochleovestibular hypoplasia, while labyrinthine ossification was the detected pathology. In 1 child, the common cavity of the right ear was associated with congenital melanocytic naevus of the left eyelid and lipomeningocele. To the best of our knowledge, this condition has never been described. Conclusions: The aetiology of UHL may be revealed in more than half of patients by means of TBHRCT. Besides common inner ear abnormalities, TBHRCT should be evaluated carefully to rule out HJB, dehiscences, diverticulum or erosion of inner ear structures.

Pollinator nesting guilds respond differently to urban habitat fragmentation in an oak‐savannah ecosystem

Abstract. 1. Habitat fragmentation is thought to threaten biodiversity, but the response of pollinators to fragmentation is still poorly understood, and research seldom includes pollinator nesting requirements.2. We investigated pollinator community composition in a highly fragmented oak‐savannah ecosystem in south‐western British Columbia, Canada. We sampled pollinators in 19 fragments ranging from 0.3 to 31 ha and surrounded by a variety of land‐use types, including forest, low‐density suburban, and urban neighbourhoods. Pan‐trapping and netting surveys captured 4464 bees, flies, and wasps in 138 species and 48 genera.3. Contrary to expectations, overall species richness did not increase with fragment size. However, ground‐nester abundance (not diversity) and cavity‐nester diversity (not abundance) were higher in larger fragments, as expected. Floral richness and abundance did not foster pollinator diversity for either guild. Brood parasite responses were complex: host availability (ground‐nesting bees) was generally important, richness and abundance increased in fragments with high surrounding road density, and abundance also increased in fragments with other habitat fragments nearby.4. Responses of different nesting guilds to fragmentation may be related to their use of the landscape surrounding habitat fragments. Some common cavity nesters can nest in fences and gardens, but urban land use may be less hospitable for ground nesters. Brood parasites apparently respond both to host availability and landscape characteristics associated with movement among fragments.5. Consideration of nesting requirements of pollinators provided some insight into their response to habitat loss in our analysis and should be considered in future studies of fragmentation impacts on pollinator biodiversity.

両側内耳奇形児の平衡機能と運動の発達について

Children with inner ear anomalies resulting in severe hearing impairment may show deficits in head control and independent walking. In the present study we examined the vestibular function in children with bilateral inner ear anomalies using a rotation test, and investigated the impact of the anomalies on motor development. Children with the Michel anomaly, which is characterized by a lack of inner ear differentiation bilaterally, are markedly slow in developing head control and independent walking. As muscle tonus is increased with the myelinization of motor neurons, independent walking becomes possible. On the other hand, children with severe inner ear anomalies, such as bilateral common cavity deformity and incomplete partition type I (Mondini deformity), show vestibular ocular reflex by the rotation test as they age, and normal independent walking and running become possible. These results demonstrate that, although children with inner ear anomalies may be slow in motor development in their infancy, their motor function increases to a normal level as they grow.

Thermodynamics of exciton/polaritons in one and two dimensional organic single-crystal microcavities

We consider here the thermodynamics and phase-diagram of exciton/polaritons formed in low-dimensional organic single-crystal microcavities. Using the Dicke model for a lattice of Frenkel excitons coupled to a common cavity mode, we explore the transition between normal and condensate regimes as depending upon the exciton band-width and temperature of the polariton gas. We show that for one-dimensional conjugated polymers, the coexistence curve at low temperatures shifts towards lower critical coupling strengths as the exciton band-width is increased. We also consider the effect of orientational disorder in a two-dimensional polyacene slab on the formation of the polariton BEC. Our results indicate that while a small degree of orientational disorder will not have a profound effect on the critical exciton/photon coupling strength needed to produce the transition from normal to BEC regimes, BEC will likely be suppressed in glassy or strongly disordered molecular films.

Preparation of subradiant states using local qubit control in circuit QED

Transitions between quantum states by photon absorption or emission are intimately related to the symmetries of the system which lead to selection rules and the formation of dark states. In a circuit quantum electrodynamics setup, in which two resonant superconducting qubits are coupled through an on-chip cavity and driven via the common cavity field, one single-excitation state remains dark. Here, we demonstrate that this dark state can be excited using local phase control of individual qubit drives to change the symmetry of the excitation field. We observe that the dark state decay via spontaneous emission into the cavity is suppressed, a characteristic signature of subradiance. This local control technique could be used to prepare and study highly correlated quantum states of cavity-coupled qubits.

Auditory maturity and hearing performance in inner ear malformations: a histological and electrical stimulation approach

The objective of this study was to assess the auditory performance of the neural structures in response to controlled electrical stimulation period. A prospective cohort study focused on the intracochlear electrical stimulation parameters and hearing performance of patients suffering different cochlear malformations who were treated by cochlear implants constituted the study design. The study sample constituted 16 patients, suffering profound prelingual hearing impairment, diagnosed on the basis of radiological criteria as having an inner ear malformation, and who underwent cochlear implantation and were followed for 24 months. Patients with common cavities, characterized by fewer nerve structures involved, less epithelial penetration, and deficient cochlear tonotopy distribution showed have higher thresholds and electrical charges than patients with cochlear hypoplasia, who in turn have higher thresholds than patients with minor malformations (p < 0.05). Furthermore, word perception was severely compromised in patients with a common cavity malformation and was also poor in patients with cochlear hypoplasia, who were unable to discriminate more than 50% of the words and relied on visual cues as a necessary aid to communication. Better results were reached by minor malformed inner ears. To conclude, the number of nerve structures involved, epithelial penetration and deficient cochlear tonotopy are responsible of inner ear functionality.

The vestibulocochlear nerve: aplasia and hypoplasia in combination with inner ear malformations

To determine features of hypoplasia and aplasia of the vestibulocochlear nerve (VCN) in combination with inner ear malformations (IEMs). Index cases were retrospectively selected from all IEMs collected since 1995. CT and MRI data were reviewed by two neuroradiologists. The number and thickness of visible nerves in the cerebellopontine angle cistern and inside the internal auditory canal (IAC) were analysed. MR images for 176 patients with IEMs were analysed. Labyrinthine aplasia and otocyst deformity showed 100% correlation, and IAC malformations exhibited 92% correlation with VCN aplasia. Cochlear aplasia, complete aplasia of the semicircular canals, severe cochlear hypoplasia, common cavity, incomplete partition type 1 and mild cochlear hypoplasia showed decreasing degrees of correlation with hypoplasia of the VCN. The remaining types of IEM did not demonstrate VCN hypoplasia. Certain forms of IEM show 100% correlation with hypoplasia or aplasia of the VCN, while others correlate less strongly and some do not usually exhibit VCN hypoplasia. MRI should always be carried out for those forms often correlated with VCN hypoplasia. Vestibulocochlear nerve deficiency can be strongly suspected in certain inner ear malformations • Bony cochlear aplasia and cochlear nerve aplasia are strongly correlated • In semicircular canal aplasia, hypoplasia of the vestibular nerve can be found • Before cochlear implantation, the type of any IEM should be fully understood.

Impedance measurements and high-resolution manometry help to better define rumination episodes

Background. Rumination syndrome is a disorder of unknown etiology characterized by regurgitation of recently ingested food. We aimed to improve the diagnosis of rumination syndrome by classification of separate rumination symptoms using (1) an ambulatory manometry/impedance (AMIM) measurement and (2) a single-catheter high-resolution manometry/impedance (HRIM) measurement. Methods. A total of 96 symptoms during AMIM and 37 symptoms during HRIM were analyzed in five patients with clinically diagnosed rumination syndrome. Key results. AMIM identified rumination events in 85 out of 96 reported symptoms (symptom index (SI): 89%). Of these events, 63% were non-acidic and would have been missed by pH-metry. HRIM identified 32 out of 37 reported symptoms (SI: 86%). Upper esophageal sphincter (UES) relaxation was observed during all rumination events identified by HRIM and could be an additional criterion in the definition of rumination events. Conclusions. Impedance measurement and high-resolution manometry contribute to a more detailed description of rumination events. Rumination events defined as gastric strain, common cavity phenomenon, retrograde esophageal fluid flow, and UES relaxation show a high SI when measured with AMIM or single-catheter HRIM.

A smile insensitive method for spectral linewidth narrowing on high power laser diode arrays

To eliminate the smile effect in spectral linewidth narrowing on high power laser diode arrays, we have introduced a plane reflective mirror into a common Littrow configuration external cavity to enhance the correlation among emitters. By this way, we obtained uniform spectral distribution among emitters of a 64-elements laser diode array with 35 GHz linewidth and 41 W output laser power.

High resolution manometry to detect transient lower oesophageal sphincter relaxations: diagnostic accuracy compared with perfused‐sleeve manometry, and the definition of new detection criteria

Inhibition of transient lower oesophageal sphincter relaxations (tLESRs) has become one of the most relevant therapeutic objectives in patients with reflux symptoms resistant to proton pump inhibitors. tLESRs are currently detected by oesophageal perfused-sleeve manometry (PSM), but oesophageal high resolution manometry (HRM), which combines closely spaced pressure sensors and oesophageal pressure topography plots, may prove to be a better tool. To evaluate the efficacy, reproducibility and interobserver agreement of HRM for the detection of tLESRs, in comparison with PSM. Twenty-four healthy volunteers underwent HRM alone and on a separate occasion with PSM simultaneously. LES pressure was monitored for 1 h during fasting and 2 h postprandial. Criteria for tLESRs were defined by characterising spontaneous LES relaxation associated with common cavity and then applied to all spontaneous LES relaxations. Interobserver agreement and the rates of tLESRs detected by HRM and PSM were compared. New HRM criteria for the detection of tLESRs have been established. A similar number of tLESRs were identified during the two HRM recordings (median per subject 15 and 13 (P = 0.07) and less with PSM (median per subject 11, P < 0.01). The overall concordance rate between the two procedures was substantial (kappa = 0.61). The interobserver agreement was almost perfect (kappa = 0.83) with HRM and only fair (kappa = 0.38) with PSM. High resolution manometry is reproducible and more sensitive than PSM to detect tLESRs. HRM provides a better interobserver agreement. These results confirm that HRM is the gold standard for detecting tLESRs (NTC00931593).

Hearing improvement after cochlear implantation in common cavity malformed cochleae: long-term follow-up results

Conclusion: We suggest that cochlear implantation (CI) should be a good therapeutic modality for hearing restoration in patients with common cavity malformed ears. Objective: To analyze hearing improvement from CI performed in common cavity malformed cochleae. Methods: A total of 11 patients (5 male and 6 female, mean age 4.5 ± 2.8 years) and 12 ears were enrolled in this study. During the insertion of electrodes, we used C-arm fluoroscopy to avoid intrameatal placement. We evaluated hearing improvement every 6 months and the mean follow-up period was 80.5 ± 24.1 months (53–125 months). Results: During the operation, there were only four cases with fully inserted electrodes. Cerebrospinal fluid gushed out in two cases during the cochleostomy and postoperative meningitis occurred in two patients. One patient had to undergo reimplantation 4 years later due to device failure and recurrent meningitis. During the 48 months follow-up hearing evaluation, the ability of hearing increased along with the age. The final average MAIS, CAP, SIR, and open set one- and two-syllable word scores were 90.3 ± 18.1%, 4.9 ± 1.6, 3.1 ± 0.9, 24.1 ± 25.9%, and 48.6 ± 38.7%, respectively.

Common Cavity is a Marker of Proximal and Mixed Gastroesophageal Reflux and is More Frequently Associated With Reflux Episodes in Non-Erosive Reflux Disease Patients Than in Healthy Volunteers

Common Cavity is a Marker of Proximal and Mixed Gastroesophageal Reflux and is More Frequently Associated With Reflux Episodes in Non-Erosive Reflux Disease Patients Than in Healthy Volunteers

Longitudinal Muscle Contraction of the Esophagus & Common Cavity Pressure During Incomplete Transient Lower Esophageal Sphincter Relaxation

Longitudinal Muscle Contraction of the Esophagus & Common Cavity Pressure During Incomplete Transient Lower Esophageal Sphincter Relaxation

Rumination variations

IntroductionRumination syndrome is the voluntary, albeit subconscious return of gastric content to the mouth. It is socially disabling, often leads to repeated, non-diagnostic investigations and can have significant morbidity. High...

Advanced noise reduction techniques for ultra-low phase noise optical-to-microwave division with femtosecond fiber combs

We report what we believe to be the lowest phase noise optical-to-microwave frequency division using fiber-based femtosecond optical frequency combs: a residual phase noise of -120 dBc/Hz at 1 Hz offset from an 11.55 GHz carrier frequency. Furthermore, we report a detailed investigation into the fundamental noise sources which affect the division process itself. Two frequency combs with quasi-identical configurations are referenced to a common ultrastable cavity laser source. To identify each of the limiting effects, we implement an ultra-low noise carrier-suppression measurement system, which avoids the detection and amplification noise of more conventional techniques. This technique suppresses these unwanted sources of noise to very low levels. In the Fourier frequency range of ∼200 Hz to 100 kHz, a feed-forward technique based on a voltage-controlled phase shifter delivers a further noise reduction of 10 dB. For lower Fourier frequencies, optical power stabilization is implemented to reduce the relative intensity noise which causes unwanted phase noise through power-to-phase conversion in the detector. We implement and compare two possible control schemes based on an acousto-optical modulator and comb pump current. We also present wideband measurements of the relative intensity noise of the fiber comb.

基于公共环形腔耦合的光纤激光器相干合成技术

基于公共环形腔耦合的光纤激光器相干合成技术

Generating single-mode behavior in fiber-coupled optical cavities

We propose to turn two resonant distant cavities effectively into one by coupling them via an optical fiber which is coated with two-level atoms [Franson et al., Phys. Rev. A 70, 062302 (2004)]. The purpose of the atoms is to destructively measure the evanescent electric field of the fiber on a time scale which is long compared to the time it takes a photon to travel from one cavity to the other. Moreover, the boundary conditions imposed by the setup should support a small range of standing waves inside the fiber, including one at the frequency of the cavities. In this way, the fiber provides an additional decay channel for one common cavity field mode but not for the other. If the corresponding decay rate is sufficiently large, this mode decouples effectively from the system dynamics. A single non-local resonator mode is created.

Cochlear Implants in Forty-Eight Children with Cochlear and/or Vestibular Abnormality

CT and MRI scans for 48 children with cochlear and/or vestibular abnormality were classified in decreasing severity; common cavity, Mondini plus enlarged vestibular aqueduct, Mondini dysplasia alone and enlarged vestibular aqueduct alone. No significant relationship between degree of cochlea abnormality and surgical issues (cerebrospinal fluid gusher, depth of insertion, number of electrodes) or speech perception/language outcomes was found. A significant relationship was observed between cerebrospinal fluid gusher and partial electrode insertion, fewer active electrodes and poorer sentence understanding. Optimum language outcomes were associated with younger age at implant.

Cochlear Implantation of the Common Cavity Malformation may be Performed During or Before CSF Leak Repair

Cochlear Implantation of the Common Cavity Malformation may be Performed During or Before CSF Leak Repair

Nonperturbative analysis of entanglement dynamics and control for three qubits in a common lossy cavity

We study exact entanglement dynamics of three-qubit $W$-class states in a common structured cavity at zero temperature in both Markovian and non-Markovian regimes using the concept of lower bound of concurrence. We also propose three methods to control the qubits' entanglement evolution and establish monogamy equalities relevant to the class of states under consideration.