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Sample records for ear mechanical function

  1. 3D finite element model of the chinchilla ear for characterizing middle ear functions.

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    Wang, Xuelin; Gan, Rong Z

    2016-10-01

    Chinchilla is a commonly used animal model for research of sound transmission through the ear. Experimental measurements of the middle ear transfer function in chinchillas have shown that the middle ear cavity greatly affects the tympanic membrane (TM) and stapes footplate (FP) displacements. However, there is no finite element (FE) model of the chinchilla ear available in the literature to characterize the middle ear functions with the anatomical features of the chinchilla ear. This paper reports a recently completed 3D FE model of the chinchilla ear based on X-ray micro-computed tomography images of a chinchilla bulla. The model consisted of the ear canal, TM, middle ear ossicles and suspensory ligaments, and the middle ear cavity. Two boundary conditions of the middle ear cavity wall were simulated in the model as the rigid structure and the partially flexible surface, and the acoustic-mechanical coupled analysis was conducted with these two conditions to characterize the middle ear function. The model results were compared with experimental measurements reported in the literature including the TM and FP displacements and the middle ear input admittance in chinchilla ear. An application of this model was presented to identify the acoustic role of the middle ear septa-a unique feature of chinchilla middle ear cavity. This study provides the first 3D FE model of the chinchilla ear for characterizing the middle ear functions through the acoustic-mechanical coupled FE analysis.

  2. Mechanics of the frog ear

    NARCIS (Netherlands)

    Van Dijk, Pim; Mason, Matthew J.; Schoffelen, Richard L. M.; Narins, Peter M.; Meenderink, Sebastiaan W. F.

    2011-01-01

    The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the low-frequency, rostral part of the amphibian papilla (AP) are complex. Electrical tuning of hair cells presumably contributes to the f

  3. In vivo areal modulus of elasticity estimation of the human tympanic membrane system: modelling of middle ear mechanical function in normal young and aged ears

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    Gaihede, Michael [Department of Otolaryngology, Head and Neck Surgery, Aalborg Hospital, Aarhus University Hospital, Aalborg (Denmark); Liao Donghua [Centre of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, Aarhus University Hospital, Aalborg (Denmark); Gregersen, Hans [Centre of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, Aarhus University Hospital, Aalborg (Denmark)

    2007-02-07

    The quasi-static elastic properties of the tympanic membrane system can be described by the areal modulus of elasticity determined by a middle ear model. The response of the tympanic membrane to quasi-static pressure changes is determined by its elastic properties. Several clinical problems are related to these, but studies are few and mostly not comparable. The elastic properties of membranes can be described by the areal modulus, and these may also be susceptible to age-related changes reflected by changes in the areal modulus. The areal modulus is determined by the relationship between membrane tension and change of the surface area relative to the undeformed surface area. A middle ear model determined the tension-strain relationship in vivo based on data from experimental pressure-volume deformations of the human tympanic membrane system. The areal modulus was determined in both a younger (n = 10) and an older (n = 10) group of normal subjects. The areal modulus for lateral and medial displacement of the tympanic membrane system was smaller in the older group (mean = 0.686 and 0.828 kN m{sup -1}, respectively) compared to the younger group (mean = 1.066 and 1.206 kN m{sup -1}, respectively), though not significantly (2p = 0.10 and 0.11, respectively). Based on the model the areal modulus was established describing the summated elastic properties of the tympanic membrane system. Future model improvements include exact determination of the tympanic membrane area accounting for its shape via 3D finite element analyses. In vivo estimates of Young's modulus in this study were a factor 2-3 smaller than previously found in vitro. No significant age-related differences were found in the elastic properties as expressed by the areal modulus.

  4. Ear trauma.

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    Eagles, Kylee; Fralich, Laura; Stevenson, J Herbert

    2013-04-01

    Understanding basic ear anatomy and function allows an examiner to quickly and accurately identify at-risk structures in patients with head and ear trauma. External ear trauma (ie, hematoma or laceration) should be promptly treated with appropriate injury-specific techniques. Tympanic membrane injuries have multiple mechanisms and can often be conservatively treated. Temporal bone fractures are a common cause of ear trauma and can be life threatening. Facial nerve injuries and hearing loss can occur in ear trauma.

  5. Mechanics of the exceptional anuran ear

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    Schoffelen, Richard L. M.; Segenhout, Johannes M.; van Dijk, Pim

    2008-01-01

    The anuran ear is frequently used for studying fundamental properties of vertebrate auditory systems. This is due to its unique anatomical features, most prominently the lack of a basilar membrane and the presence of two dedicated acoustic end organs, the basilar papilla and the amphibian papilla. O

  6. Probing the Xenopus laevis inner ear transcriptome for biological function

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    Powers TuShun R

    2012-06-01

    Full Text Available Abstract Background The senses of hearing and balance depend upon mechanoreception, a process that originates in the inner ear and shares features across species. Amphibians have been widely used for physiological studies of mechanotransduction by sensory hair cells. In contrast, much less is known of the genetic basis of auditory and vestibular function in this class of animals. Among amphibians, the genus Xenopus is a well-characterized genetic and developmental model that offers unique opportunities for inner ear research because of the amphibian capacity for tissue and organ regeneration. For these reasons, we implemented a functional genomics approach as a means to undertake a large-scale analysis of the Xenopus laevis inner ear transcriptome through microarray analysis. Results Microarray analysis uncovered genes within the X. laevis inner ear transcriptome associated with inner ear function and impairment in other organisms, thereby supporting the inclusion of Xenopus in cross-species genetic studies of the inner ear. The use of gene categories (inner ear tissue; deafness; ion channels; ion transporters; transcription factors facilitated the assignment of functional significance to probe set identifiers. We enhanced the biological relevance of our microarray data by using a variety of curation approaches to increase the annotation of the Affymetrix GeneChip® Xenopus laevis Genome array. In addition, annotation analysis revealed the prevalence of inner ear transcripts represented by probe set identifiers that lack functional characterization. Conclusions We identified an abundance of targets for genetic analysis of auditory and vestibular function. The orthologues to human genes with known inner ear function and the highly expressed transcripts that lack annotation are particularly interesting candidates for future analyses. We used informatics approaches to impart biologically relevant information to the Xenopus inner ear transcriptome

  7. Ear length and kidney function decline after kidney donation.

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    Katavetin, Pisut; Watanatorn, Salin; Townamchai, Natavudh; Avihingsanon, Yingyos; Praditpornsilpa, Kearkiat

    2016-11-01

    The preservation of kidney function after kidney donation depends on the kidney reserve - the potential of the remaining kidney to boost their function after loss of the other kidney. In Traditional Chinese Medicine, size and shape of the external ears are examined to evaluate the person's kidney health. We hypothesized that ear size might be a practical yet overlooked marker of kidney reserve. Fifty kidney transplantation donors were participated in this study. The length and width of both ears of all participants were measured during one of the post-donation visits. Pre-donation serum creatinine and post-donation serum creatinine as well as other relevant parameters (age, sex, weight, height, etc.) of the participants were extracted from medical records. The estimated GFR was calculated from serum creatinine, age and sex using the CKD-EPI equation. Ear length negatively associated with %GFR decline after kidney donation. For every 1 cm increase in ear length, it was associated with 5.7% less GFR decline after kidney donation (95% Confidence Interval 0.2 to 11.3, P = 0.04). Ear width, as well as age, sex, body weight, height, body mass index, and pre-donation eGFR did not significantly associate with the GFR decline. Our findings support the notion of Traditional Chinese Medicine that ear morphology may be associated with kidney health and suggest that ear length might be a useful predictor of kidney function decline after kidney donation.

  8. The ear region of Latimeria chalumnae: functional and evolutionary implications.

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    Bernstein, Peter

    2003-01-01

    The anatomy of Latimeria chalumnae has figured prominently in discussions about tetrapod origins. While the gross anatomy of Latimeria is well documented, relatively little is known about its otic anatomy and ontogeny. To examine the inner ear and the otoccipital part of the cranium, a serial-sectioned juvenile coelacanth was studied in detail and a three-dimensional reconstruction was made. The ear of Latimeria shows a derived condition compared to other basal sarcopterygians in having a connection between left and right labyrinths. This canalis communicans is perilymphatic in nature and originates at the transition point of the saccule and the lagena deep in the inner ear, where a peculiar sense end organ can be found. In most gnathostomes the inner ears are clearly separated from each other. A connection occurs in some fishes, e.g. within the Ostariophysi. In the sarcopterygian lineage no connections between the inner ears are known except in the Actinistia. Some fossil actinistians show a posteriorly directed duct lying between the foramen magnum and the notochordal canal, similar to the condition in the ear of Latimeria, so this derived character complex probably developed early in actinistian history. Because some features of the inner ear of Latimeria have been described as having tetrapod affinities, the problem of hearing and the anatomy of the otical complex in the living coelacanth has been closely connected to the question of early tetrapod evolution. It was assumed in the past that the structure found in Latimeria could exemplify a transitional stage in otic evolution between the fishlike sarcopterygians and the first tetrapods in a functional or even phylogenetic way. Here the possibility is considered that the canalis communicans does not possess any auditory function but rather is involved in sensing pressure changes during movements involving the intracranial joint. Earlier hypotheses of a putative tympanic ear are refuted.

  9. EAR motif-mediated transcriptional repression in plants: an underlying mechanism for epigenetic regulation of gene expression.

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    Kagale, Sateesh; Rozwadowski, Kevin

    2011-02-01

    Ethylene-responsive element binding factor-associated Amphiphilic Repression (EAR) motif-mediated transcriptional repression is emerging as one of the principal mechanisms of plant gene regulation. The EAR motif, defined by the consensus sequence patterns of either LxLxL or DLNxxP, is the most predominant form of transcriptional repression motif so far identified in plants. Additionally, this active repression motif is highly conserved in transcriptional regulators known to function as negative regulators in a broad range of developmental and physiological processes across evolutionarily diverse plant species. Recent discoveries of co-repressors interacting with EAR motifs, such as TOPLESS (TPL) and AtSAP18, have begun to unravel the mechanisms of EAR motif-mediated repression. The demonstration of genetic interaction between mutants of TPL and AtHDA19, co-complex formation between TPL-related 1 (TPR1) and AtHDA19, as well as direct physical interaction between AtSAP18 and AtHDA19 support a model where EAR repressors, via recruitment of chromatin remodeling factors, facilitate epigenetic regulation of gene expression. Here, we discuss the biological significance of EAR-mediated gene regulation in the broader context of plant biology and present literature evidence in support of a model for EAR motif-mediated repression via the recruitment and action of chromatin modifiers. Additionally, we discuss the possible influences of phosphorylation and ubiquitination on the function and turnover of EAR repressors.

  10. Age-related hearing loss: ear and brain mechanisms.

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    Frisina, Robert D

    2009-07-01

    Loss of sensory function in the aged has serious consequences for economic productivity, quality of life, and healthcare costs in the billions each year. Understanding the neural and molecular bases will pave the way for biomedical interventions to prevent, slow, or reverse these conditions. This chapter summarizes new information regarding age changes in the auditory system involving both the ear (peripheral) and brain (central). A goal is to provide findings that have implications for understanding some common biological underpinnings that affect sensory systems, providing a basis for eventual interventions to improve overall sensory functioning, including the chemical senses.

  11. Mechanisms of hearing loss after blast injury to the ear.

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    Sung-Il Cho

    Full Text Available Given the frequent use of improvised explosive devices (IEDs around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body's most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction.

  12. The fluid mechanics of the inner-ear disorder BPPV

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    Weidman, Michael; Squires, Todd; Stone, Howard

    2001-11-01

    The inner ear of mammals contains fluid-filled semi-circular canals with a flexible sensory membrane (called a cupula) which detects rotational acceleration. Benign Paroxysmal Positional Vertigo (BPPV) is one of the most common disorders of this system diagnosed today, and is characterized by symptoms of dizziness and nausea brought on by sudden changes in head orientation. BPPV is believed to have a mechanical (rather than nervous) origin, in which dense particles called otoconia settle into the canals and trigger false sensations of rotational acceleration. Several qualitative mechanisms have been proposed by the medical community, which we examine from a fluid mechanical standpoint. Traditionally, the semicircular canal and the cupula are modeled as an over-damped torsional pendulum with a driving force provided by rotational acceleration. We extend this model to include the time-dependent mechanical response owing to sedimentation of the otoconia. We make qualitative and quantitative predictions associated with the proposed mechanisms, with an eye towards differentiating between them and perhaps towards more effective diagnostic and therapeutic methods.

  13. Structure and function of the mammalian middle ear. I: Large middle ears in small desert mammals.

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    Mason, Matthew J

    2016-02-01

    Many species of small desert mammals are known to have expanded auditory bullae. The ears of gerbils and heteromyids have been well described, but much less is known about the middle ear anatomy of other desert mammals. In this study, the middle ears of three gerbils (Meriones, Desmodillus and Gerbillurus), two jerboas (Jaculus) and two sengis (elephant-shrews: Macroscelides and Elephantulus) were examined and compared, using micro-computed tomography and light microscopy. Middle ear cavity expansion has occurred in members of all three groups, apparently in association with an essentially 'freely mobile' ossicular morphology and the development of bony tubes for the middle ear arteries. Cavity expansion can occur in different ways, resulting in different subcavity patterns even between different species of gerbils. Having enlarged middle ear cavities aids low-frequency audition, and several adaptive advantages of low-frequency hearing to small desert mammals have been proposed. However, while Macroscelides was found here to have middle ear cavities so large that together they exceed brain volume, the bullae of Elephantulus are considerably smaller. Why middle ear cavities are enlarged in some desert species but not others remains unclear, but it may relate to microhabitat.

  14. Bending mechanics of the red-eared slider turtle carapace.

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    Achrai, Ben; Bar-On, Benny; Wagner, H Daniel

    2014-02-01

    The turtle shell is a natural shield that possesses complex hierarchical structure, giving rise to superior mechanical properties. The keratin-covered boney top (dorsal) part of the shell, termed carapace, is composed of rigid sandwich-like ribs made of a central foam-like interior flanked by two external cortices. The ribs are attached to one another in a 3-D interdigitated manner at soft unmineralized collagenous sutures. This unique structural combination promotes sophisticated mechanical response upon predator attacks. In the present study mechanical bending tests were performed to examine the static behavior of the red-eared slider turtle carapace, in different orientations and from various locations, as well as from whole-rib and sub-layer regions. In addition, the suture properties were evaluated as well and compared with those of the rib. A simplified classical analysis was used here to rationalize the experimental results of the whole rib viewed as a laminated composite. The measured strength (~300MPa) and bending modulus (~7-8.5GPa) of the rib were found to be of the same order of magnitude as the strength and modulus of the cortices. The theoretical prediction of the ribs' moduli, predicted in terms of the individual sub-layers moduli, agreed well with the experimental results. The suture regions were found to be more compliant and weaker than the ribs, but comparatively tough, likely due to the interlocking design of the boney zigzag elements. © 2013 Elsevier Ltd. All rights reserved.

  15. Dissecting the frog inner ear with Gaussian noise .2. Temperature dependence of inner ear function

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    vanDijk, P; Wit, HP; Segenhout, JM

    1997-01-01

    The temperature dependence of the response of single primary auditory nerve fibers (n = 31) was investigated in the European edible frog, Rana esculenta (seven ears). Nerve fiber responses were analyzed with Wiener kernel analysis and polynomial correlation. The responses were described with a casca

  16. Modeling and estimating acoustic transfer functions of external ears with or without headphones.

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    Deng, Huiqun; Yang, Jun

    2015-08-01

    The acoustic transfer functions of external ears with or without headphones affect the features of perceived sounds and vary considerably with listeners and headphones. A method for estimating the frequency responses of external-ear transfer functions from the sound at the entrance of a blocked ear canal (or from the input of a headphone) to the sound at the eardrum for different listeners and headphones is developed based on an acoustic signal model of external ears. The model allows for applying realistic data about individual external ears and headphones and is advantageous over current standard ear simulators with fixed structures limited to simulating average ear canals and eardrum impedances below 10 kHz. Given different eardrum impedances, ear canal shapes, lengths, and headphones, the frequency responses of external-ear transfer functions are estimated and presented. In addition, a method of determining the Norton equivalent volume velocity or Thevenien equivalent sound pressure sources of a headphone from sound pressure signals in an acoustic tube is presented. These methods are validated via direct measurements and expected to have applications in headphone sound reproduction, headphone and hearing aid design, and audiometric and psychoacoustic measurements to produce desired sounds at the eardrums of different listeners.

  17. Assessment of middle ear function in patients with cleft palate treated under "Smile Train Project"

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    Prachi Gautam

    2011-01-01

    Full Text Available Objective: To evaluate the middle ear function in patients of cleft palate treated under "Smile Train Project". Materials and Methods: Sixty patients (120 ears; 32 male and 28 female of cleft palate with or without cleft lip were evaluated in pediatrics and ENT OPD in preoperative period. A general medical check up was performed in pediatrics OPD to evaluate the associated craniofacial anomalies. Middle ear function was evaluated in ENT OPD. Otoscopy was done in all patients. Cases under five years of age were evaluated for middle ear function by tympanometry and cases with more than five years of age were evaluated by tympanometry for middle ear function and pure tone audiometry to establish the type of hearing loss. The results are presented as number of ears. Results: A total of 50% of the patients in the study group were in zero- to two-year age group. Otoscopy findings in 120 ears showed that 66.66% of the patients had dull tympanic membrane suggesting a diagnosis of otitis media with effusion. Tympanometry was done in 110 ears, of which, 72.72% of ears had type B tympanogram suggesting otitis media with effusion. Pure tone audiometry in more than five years age group showed that 81.25% ears had conductive hearing loss. Conclusion: This study suggests the need of preoperative ENT check up and audiological assessment in patients of cleft palate undergoing palatal surgery under "Smile Train Project". The association of otitis media with effusion in patients with cleft palate appears strong and a high degree of suspicion for the disease should be kept in them. The anatomical defect and possible causative pathophysiology also supports the inference. Otitis media with effusion causing hearing loss in these patients causes speech delay and unfavorable outcome despite aggressive speech therapy in postoperative period. A co-ordinate team approach of concerned specialists involved in managing these patients would definitely improve their outcome.

  18. Ear-body lift and a novel thrust generating mechanism revealed by the complex wake of brown long-eared bats (Plecotus auritus).

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    Johansson, L Christoffer; Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders

    2016-04-27

    Large ears enhance perception of echolocation and prey generated sounds in bats. However, external ears likely impair aerodynamic performance of bats compared to birds. But large ears may generate lift on their own, mitigating the negative effects. We studied flying brown long-eared bats, using high resolution, time resolved particle image velocimetry, to determine the aerodynamics of flying with large ears. We show that the ears and body generate lift at medium to cruising speeds (3-5 m/s), but at the cost of an interaction with the wing root vortices, likely reducing inner wing performance. We also propose that the bats use a novel wing pitch mechanism at the end of the upstroke generating thrust at low speeds, which should provide effective pitch and yaw control. In addition, the wing tip vortices show a distinct spiraling pattern. The tip vortex of the previous wingbeat remains into the next wingbeat and rotates together with a newly formed tip vortex. Several smaller vortices, related to changes in circulation around the wing also spiral the tip vortex. Our results thus show a new level of complexity in bat wakes and suggest large eared bats are less aerodynamically limited than previous wake studies have suggested.

  19. Ear Infection (Middle Ear)

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    Ear infection (middle ear) Overview By Mayo Clinic Staff An ear infection (acute otitis media) is most often a bacterial or viral infection that affects the middle ear, the air-filled space behind the eardrum that ...

  20. Of mice, moles and guinea pigs: functional morphology of the middle ear in living mammals.

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    Mason, Matthew J

    2013-07-01

    The middle ear apparatus varies considerably among living mammals. Body size, phylogeny and acoustic environment all play roles in shaping ear structure and function, but experimental studies aimed ultimately at improving our understanding of human hearing can sometimes overlook these important species differences. This review focuses on three groups of mammals, bringing together anatomical, zoological and physiological information in order to highlight unusual features of their middle ears and attempt to interpret their function. "Microtype" ears, found in species such as mice and bats, are associated with high-frequency hearing. The orbicular apophysis, the focus of some recent developmental studies on mouse ears, is characteristic of microtype mallei but is not found in humans or other "freely mobile" species. The apophysis increases ossicular inertia about the anatomical axis of rotation: its adaptive purpose in a high-frequency ear is still not clear. Subterranean mammals have convergently evolved a "freely mobile" ossicular morphology which appears to favour lower-frequency sound transmission. More unusual features found in some of these animals include acoustically coupled middle ear cavities, the loss of middle ear muscles and hypertrophied ossicles which are believed to subserve a form of inertial bone conduction. Middle ears of the rodent group Ctenohystrica (which includes guinea pigs and chinchillas, important models in hearing research) show some striking characteristics which together comprise a unique type of auditory apparatus requiring a classification of its own, referred to here as the "Ctenohystrica type". These characteristics include a distinctive malleus morphology, fusion of the malleus and incus, reduction or loss of the stapedius muscle, a synovial stapedio-vestibular articulation and, in chinchillas, enormously expanded middle ear cavities. These characteristics may be functionally linked and associated with the excellent low

  1. Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: Functional and morphological evaluation in animal model

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    Dong-Kee Kim

    2014-01-01

    Full Text Available The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1, bilaterally plugged group (G2, unilaterally plugged group (G3 and noise control group (G4 and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

  2. Functional Morphology and Symmetry in the Odontocete Ear Complex.

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    Ary, William; Cranford, Ted W; Berta, Annalisa; Krysl, Petr

    2016-01-01

    Odontocete ear complexes or tympanoperiotic complexes (TPCs) were compared for asymmetry. Left and right TPCs were collected from one long-beaked common dolphin (Delphinus capensis) and one Amazon River dolphin (Inia geoffrensis). Asymmetry was assessed by volumetric comparisons of left and right TPCs and by visual comparison of superimposed models of the right TPC to a reflected mirror image of the left TPC. Kolmogorov-Smirnov tests were performed to compare the resonant frequencies of the TPCs as calculated by vibrational analysis. All analyses found slight differences between TPCs from the same specimen in contrast to the directional asymmetry in the nasal region of odontocete skulls.

  3. Effects of polylactic acid film on middle ear mucosa and cochlear function in Guinea pigs.

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    Ensari, Nuray; Tutar, Hakan; Ekinci, Ozgur; Ugur, Mehmet Birol; Bayazıt, Yıldırım A; Gokdogan, Cagil; Goksu, Nebil

    2015-05-01

    Our aim was to assess the effects of polylactic acid (PLA) on middle ear mucosa and cochlea, to be used as a film barrier for postoperative adhesion prevention in the middle ear. Twenty-one albino Guinea pigs were included in the study. A window was opened on both tympanic bulla and on one side PLA material was placed in the middle ear and on the other side only fenestration was performed and used as a control. All Guinea pigs underwent evaluation of tympanic membranes microscopically; functional hearing was analyzed by auditory brainstem responses preoperatively, in the first and the sixth month. All Guinea pigs were killed on the sixth month for histopathologic evaluation of their temporal bones. There was no statistical difference between both groups regarding hearing thresholds, interpeak wave latencies preoperatively and on first and the sixth months postoperatively. Histopathological evaluation revealed no specific changes. There was a mild local inflammation both in the PLA implanted and control ears. PLA film barrier most likely has no toxic effects on Guinea pig middle ear and does not show any ototoxic side effects.

  4. The Carina© middle ear implant: surgical and functional outcomes.

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    Bruschini, Luca; Berrettini, Stefano; Forli, Francesca; Murri, Alessandra; Cuda, Domenico

    2016-11-01

    The Carina© system (Cochlear Ltd, Sydney, Australia) is a totally implantable prosthesis designed to meet the needs of acoustic amplification in adults with moderate-to-severe sensorineural or mixed hearing loss. It mechanically stimulates the ossicles or labyrinthine windows. The object of this study was to update surgical and functional results obtained in a consistent sample of Carina© recipients. The data sheets of 26 patients who underwent Carina© surgery at two ENT units [i.e., ENT Audiology and Phoniatrics Unit of the University Hospital of Pisa (Pisa, Italy) and ENT Unit of "Guglielmo da Saliceto" Hospital of Piacenza (Piacenza, Italy)] were evaluated for the surgical and audiological outcomes. Twenty patients received a unilateral device, whereas six patients were bilaterally implanted (simultaneously in one patient and sequentially in the remaining five patients). The total number of ears implanted in this study was 32. Most implanted patients expressed a high degree of satisfaction with the prosthesis, which highlights the improvement in hearing in different environmental conditions, the cosmetic advantages, and greater freedom in performing common activities in daily living. Audiological examination demonstrated valid functional gain and significant improvement in speech perception in quiet. Based on this experience, the Carina© is a valid alternative to hearing aids. Moreover, a bilateral implantation, even a simultaneous implantation, is a viable option for selected motivated patients because the intervention is generally well tolerated and the surgery time is relatively fast.

  5. The physics of hearing: fluid mechanics and the active process of the inner ear.

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    Reichenbach, Tobias; Hudspeth, A J

    2014-07-01

    Most sounds of interest consist of complex, time-dependent admixtures of tones of diverse frequencies and variable amplitudes. To detect and process these signals, the ear employs a highly nonlinear, adaptive, real-time spectral analyzer: the cochlea. Sound excites vibration of the eardrum and the three miniscule bones of the middle ear, the last of which acts as a piston to initiate oscillatory pressure changes within the liquid-filled chambers of the cochlea. The basilar membrane, an elastic band spiraling along the cochlea between two of these chambers, responds to these pressures by conducting a largely independent traveling wave for each frequency component of the input. Because the basilar membrane is graded in mass and stiffness along its length, however, each traveling wave grows in magnitude and decreases in wavelength until it peaks at a specific, frequency-dependent position: low frequencies propagate to the cochlear apex, whereas high frequencies culminate at the base. The oscillations of the basilar membrane deflect hair bundles, the mechanically sensitive organelles of the ear's sensory receptors, the hair cells. As mechanically sensitive ion channels open and close, each hair cell responds with an electrical signal that is chemically transmitted to an afferent nerve fiber and thence into the brain. In addition to transducing mechanical inputs, hair cells amplify them by two means. Channel gating endows a hair bundle with negative stiffness, an instability that interacts with the motor protein myosin-1c to produce a mechanical amplifier and oscillator. Acting through the piezoelectric membrane protein prestin, electrical responses also cause outer hair cells to elongate and shorten, thus pumping energy into the basilar membrane's movements. The two forms of motility constitute an active process that amplifies mechanical inputs, sharpens frequency discrimination, and confers a compressive nonlinearity on responsiveness. These features arise because the

  6. Cellular Mechanism of Inner Ear Genetic Disease, roles of Kv7.1 (KCNQ1) Channel

    Science.gov (United States)

    Mousavi Nik, Atefeh

    Potassium channels are the most diverse and widely distributed membrane protein in all living organisms. They have various roles in the body such as controlling membrane potential, cell volume, and cell migration. Many studies have shown that mutation in these channels is associated with different diseases for example: Hearing Defect, Cardiac Arrhythmia, Episodic Ataxia, Seizure and Neuromyotonia. One of the most important diseases associated with K+ channel mutations is called Jervell and Lange-Nielsen syndrome (JLNS). This disease causes bilateral congenital deafness and the patients also suffer from Long QT and they usually experience syncopal episodes in their life and eventually die as a result of cardiac arrest. The gene KCNQ1 encodes the Kv7.1 voltage gated potassium channel. This channel expresses in apical membrane of marginal cell in stria vasularis of cochlea and secret K+ ion to endolymp to keep the endocochlear potential stable, which is necessary for the inner ear to function properly. Kv7.1 channel also expresses in cardiac myocytes and mutation in this gene is associated with another syndrome called Romano-Ward syndrome (RWS). Although Romano-Ward patients have mutation in KCNQ1, similar to Jervell and Lange-Nielsen patients, they only suffer from cardiac defect, and their hearing is completely normal. Several studies identified that mutations in Kv7.1 gene is associated with JLNS and RWS, but the biophysical and cellular mechanisms of these mutations are still unknown. To determine the cellular mechanisms of JLNS and RWS, and to provide mechanistic insight on the functional outputs of JLNS versus RWS mutations, we generated several mutant forms of the human Kv7.1 ( KCNQ1) clone, using site-directed mutagenesis to define their sub-cellular localization and examined their electrophysiological properties. We identified JLNS and RWS mutations at the S4-S5-linker, the pore loop (P-loop) and the C-terminus of hKv7.1 which have been found to control

  7. From ear to uncertainty: Vestibular contributions to cognitive function.

    Directory of Open Access Journals (Sweden)

    Paul eSmith

    2013-11-01

    Full Text Available In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and cortex play in spatial orientation. In this review we summarise the evidence that vestibular loss causes cognitive disorders, especially spatial memory deficits, in animals and humans and critically evaluate the evidence that these deficits are not due to hearing loss, problems with motor control, oscillopsia or anxiety and depression. We review the evidence that vestibular lesions affect head direction and place cells as well as the emerging evidence that artificial activation of the vestibular system, using galvanic vestibular stimulation, can modulate cognitive function.

  8. Evidence for a functional subdivision of Premotor Ear-Eye Field (Area 8B.

    Directory of Open Access Journals (Sweden)

    Marco eLanzilotto

    2015-01-01

    Full Text Available The Supplementary Eye Field (SEF and the Frontal Eye Field (FEF have been described as participating in gaze shift control. Recent evidence suggests, however, that other areas of the dorsomedial prefrontal cortex also influence gaze shift. Herein, we have investigated electrically evoked ear- and eye movements from the Premotor Ear-Eye Field, or PEEF (area 8B of macaque monkeys. We stimulated PEEF during spontaneous condition (outside the task performance and during the execution of a visual fixation task (VFT. In the first case, we functionally identified two regions within the PEEF: a core and a belt. In the core region, stimulation elicited forward ear movements; regarding the evoked eye movements, in some penetrations, stimulation elicited contraversive fixed-vectors with a mean amplitude of 5.14°; while in other penetrations, we observed prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position. On the contrary, in the belt region, stimulation elicited backward ear movements; regarding the eye movements, in some penetrations stimulation elicited prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position, while in the lateral edge of the investigated region, stimulation elicited contralateral goal-directed eye movements having end-points that fell beyond 15° in respect to the primary eye position. Stimulation during VFT either did not elicit eye movements or evoked saccades of only a few degrees. Finally, even though no head rotation movements were observed during the stimulation period, we viewed a relationship between the duration of stimulation and the neck forces exerted by the monkey’s head. We propose an updated vision of the PEEF composed of two functional regions, core and belt, which may be involved in integrating auditory and visual information important to the programming of gaze

  9. Age-regulated function of autophagy in the mouse inner ear.

    Science.gov (United States)

    de Iriarte Rodríguez, Rocío; Pulido, Sara; Rodríguez-de la Rosa, Lourdes; Magariños, Marta; Varela-Nieto, Isabel

    2015-12-01

    Autophagy is a highly conserved catabolic process essential for embryonic development and adult homeostasis. The autophagic machinery supplies energy by recycling intracellular components and facilitates the removal of apoptotic cells. In the inner ear, autophagy has been reported to play roles during early development in the chicken embryo and in the response to otic injury in the adult mouse. However, there are no studies on the expression of the autophagy machinery in the postnatal and adult inner ear. Insulin-like growth factor 1 (IGF-1) is one of the factors that regulate both otic development and cochlear postnatal maturation and function. Here, we hypothesised that autophagy could be one of the processes involved in the cochlear development and functional maturation. We report that autophagy-related genes (ATG) Becn1, Atg4g and Atg5 are expressed in the mouse cochlea, vestibular system and brainstem cochlear nuclei from late developmental stages to adulthood. Atg9 was studied in the mouse cochlea and showed a similar pattern. The presence of autophagic flux was confirmed by decreased sequestosome 1 (SQSTM1/p62) and increased relative levels of microtubule-associated protein light chain 3-II (LC3-II). Inner ear autophagy flux is developmentally regulated and is lower at perinatal stages than in the adult mouse, where an expression plateau is reached at the age of two-months, coinciding with the age at which full functional activity is reached. Expression is maintained in adult mice and declines after the age of twelve months. LC3B labelling showed that autophagy was primarily associated with spiral ganglion neurons. Over time, Igf1 wild type mice showed lower expression of genes coding for IGF-1 high affinity receptor and the family factor IGF-2 than null mice. Parallel analysis of autophagy machinery gene expression showed no significant differences between the genotypes over the lifespan of the null mice. Taken together, these results show that the

  10. Ear Tubes

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  11. Ear-body lift and a novel thrust generating mechanism revealed by the complex wake of brown long-eared bats (Plecotus auritus)

    DEFF Research Database (Denmark)

    Johansson, L Christoffer; Håkansson, Jonas; Jakobsen, Lasse;

    2016-01-01

    into the next wingbeat and rotates together with a newly formed tip vortex. Several smaller vortices, related to changes in circulation around the wing also spiral the tip vortex. Our results thus show a new level of complexity in bat wakes and suggest large eared bats are less aerodynamically limited than....... We also propose that the bats use a novel wing pitch mechanism at the end of the upstroke generating thrust at low speeds, which should provide effective pitch and yaw control. In addition, the wing tip vortices show a distinct spiraling pattern. The tip vortex of the previous wingbeat remains...... previous wake studies have suggested....

  12. Finding an analytic description of the resolution function for n_TOF-EAR2 at CERN

    CERN Document Server

    Eriksson, John Benjamin

    2017-01-01

    At CERN's neutron time-of-flight facility n_TOF a high intensity pulsed neutron source is used to measure energy-dependent neutron-induced reaction cross sections of isotopes relevant to various fields of research such as nuclear astrophysics, -technology or -medicine. Neutron kinetic energies are determined using the time-of-flight (ToF) technique. A correct ToF to energy conversion is essential and is influenced by many factors, one of which is the so-called resolution function (RF). The RF is a characteristic unique to each experimental facility and can only be determined through simulations using Monte Carlo codes. The goal of this project is to find an analytic description of the RF for n_TOF-EAR2. Two functions for two different energy ranges were found, each a combination of linear, polynomial and exponential functions. Furthermore, the energy dependence of the function's parameters was investigated.

  13. Development and Integration of the Ear.

    Science.gov (United States)

    Fuchs, Jennifer C; Tucker, Abigail S

    2015-01-01

    The perception of our environment via sensory organs plays a crucial role in survival and evolution. Hearing, one of our most developed senses, depends on the proper function of the auditory system and plays a key role in social communication, integration, and learning ability. The ear is a composite structure, comprised of the external, middle, and inner ear. During development, the ear is formed from the integration of a number of tissues of different embryonic origin, which initiate in distinct areas of the embryo at different time points. Functional connections between the components of the hearing apparatus have to be established and maintained during development and adulthood to allow proper sound submission from the outer to the middle and inner ear. This highly organized and intimate connectivity depends on intricate spatiotemporal signaling between the various tissues that give rise to the structures of the ear. Any alterations in this chain of events can lead to the loss of integration, which can subsequently lead to conductive hearing loss, in case of outer and middle ear defects or sensorineural hearing loss, if inner ear structures are defective. This chapter aims to review the current knowledge concerning the development of the three ear compartments as well as mechanisms and signaling pathways that have been implicated in the coordination and integration process of the ear.

  14. Cauliflower Ear

    Science.gov (United States)

    ... dientes Video: Getting an X-ray What's Cauliflower Ear? KidsHealth > For Kids > What's Cauliflower Ear? Print A A A Have you ever seen someone whose ear looks bumpy and lumpy? The person might have ...

  15. Ear barotrauma

    Science.gov (United States)

    Barotitis media; Barotrauma; Ear popping - barotrauma; Pressure-related ear pain; Eustachian tube dysfunction - barotrauma ... The air pressure in the middle ear is most often the same as the air ... body. The Eustachian tube is a connection between the middle ...

  16. Swimmer's ear

    Science.gov (United States)

    ... worse when you pull on the outer ear Hearing loss Itching of the ear or ear canal ... reduce itching and inflammation Pain medicine, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) Vinegar (acetic acid) ...

  17. Ear wax

    OpenAIRE

    Browning, George GG

    2008-01-01

    Ear wax only becomes a problem if it causes a hearing impairment, or other ear-related symptoms. Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by hearing aids, or by the use of cotton buds to clean the ears.Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes.

  18. Genetic evidence for conserved non-coding element function across species--the ears have it

    Directory of Open Access Journals (Sweden)

    Eric E Turner

    2014-01-01

    Full Text Available Comparison of genomic sequences from diverse vertebrate species has revealed numerous highly conserved regions that do not appear to encode proteins or functional RNAs. Often these conserved non-coding elements, or CNEs, direct gene expression to specific tissues in transgenic models, demonstrating they have regulatory function. CNEs are frequently found near ‘developmental’ genes, particularly transcription factors, implying that these elements have essential regulatory roles in development. However, actual examples demonstrating CNE regulatory functions across species have been few, and recent loss-of-function studies of several CNEs in mice have shown relatively minor effects. In this Perspectives article, we discuss new findings in fancy rats and Highland cattle demonstrating that function of a CNE near the Hmx1 gene is crucial for normal external ear development and resembles loss-of function Hmx1 coding mutations in mice and humans. These findings provide important support for similar developmental roles of CNEs in divergent species, and reinforce the concept that CNEs should be examined systematically in the ongoing search for genetic causes of human developmental disorders in the era of genome-scale sequencing.

  19. The mechanism and site of action of lidocaine hydrochloride in guinea pig inner ear.

    Science.gov (United States)

    Laurikainen, E; Lin, X; Nuttall, A L; Dolan, D F

    1997-07-01

    Lidocaine was applied to the round window (RW) in order to localize its site of action in the cochlea. Cochlear microphonic (CM), summating potential (SP), and compound action potential (CAP) input/output functions were measured to a 16 kHz tone burst to assess the functional changes of the cochlea. In separate experiments, the effect of lidocaine on the whole cell current of isolated outer hair cells (OHC) was studied. A dose of 2 microliters of 40 mM lidocaine in saline solution, when applied to the RW, caused a small change in all measured variables, indicating a passage of the drug through the RW membrane to sites of action. However, 160 mM of lidocaine further decreased CM, SP, and CAP by a total of 40% from the control. A partial recovery occurred for CM during the 30 min follow-up period. CAP and SP continued to decline. In isolated OHCs, lidocaine decreased the whole cell current in a dose-dependent fashion. The KD for lidocaine effect on OHCs was 7 mM. Our in vivo results indicate that lidocaine affects OHCs and reduces CM, causing a subsequent reduction in SP and CAP. The increased effect of lidocaine on CAP and SP, while CM is recovering, suggests an additional specific effect of lidocaine on the cochlear nerve and/or on inner hair cells. Considering that lidocaine alters OHC current (in isolated hair cells) and that lidocaine does not affect endocochlear potential [Laurikainen et al. Acta Otolaryngol (Stockh) 1991: 112: 800-9], the observed CM changes are most likely due to an in vivo effect on OHCs. Thus, the early effect of lidocaine on the cochlea appears to be due to a significant change in organ of Corti function, rather than to direct anesthesia of the cochlear nerve. Later, an independent effect of the drug may occur on neural tissues in the inner ear.

  20. Your Ears

    Science.gov (United States)

    ... gross and useful. continue The Middle Ear: Good Vibrations After sound waves enter the outer ear, they travel through the ... ear's main job is to take those sound waves and turn them into vibrations that are delivered to the inner ear. To ...

  1. Ear Pieces

    Science.gov (United States)

    DiJulio, Betsy

    2011-01-01

    In this article, the author describes an art project wherein students make fanciful connections between art and medicine. This project challenges students to interpret "ear idioms" (e.g. "blow it out your ear," "in one ear and out the other") by relying almost entirely on realistic ear drawings, the placement of them, marks, and values. In that…

  2. A study of middle ear reconstruction, the degree of functional restoration and causes of graft failure following chronic ear disease

    Directory of Open Access Journals (Sweden)

    Vishnu Prasad

    2014-07-01

    Conclusion: Patients with normal Eustachian tube function, large and medium size mastoids, small and medium size perforations of the tympanic membrane would have a good rate of graft uptake with tympano-ossiculoplasties thereby returning to normal hearing postoperatively.

  3. Mouse middle ear ion homeostasis channels and intercellular junctions.

    Directory of Open Access Journals (Sweden)

    Lisa M Morris

    Full Text Available HYPOTHESIS: The middle ear contains homeostatic mechanisms that control the movement of ions and fluids similar to those present in the inner ear, and are altered during inflammation. BACKGROUND: The normal middle ear cavity is fluid-free and air-filled to allow for effective sound transmission. Within the inner ear, the regulation of fluid and ion movement is essential for normal auditory and vestibular function. The same ion and fluid channels active in the inner ear may have similar roles with fluid regulation in the middle ear. METHODS: Middle and inner ears from BALB/c mice were processed for immunohistochemistry of 10 specific ion homeostasis factors to determine if similar transport and barrier mechanisms are present in the tympanic cavity. Examination also was made of BALB/c mice middle ears after transtympanic injection with heat-killed Haemophilus influenza to determine if these channels are impacted by inflammation. RESULTS: The most prominent ion channels in the middle ear included aquaporins 1, 4 and 5, claudin 3, ENaC and Na(+,K(+-ATPase. Moderate staining was found for GJB2, KCNJ10 and KCNQ1. The inflamed middle ear epithelium showed increased staining due to expected cellular hypertrophy. Localization of ion channels was preserved within the inflamed middle ear epithelium. CONCLUSIONS: The middle ear epithelium is a dynamic environment with intrinsic mechanisms for the control of ion and water transport to keep the middle ear clear of fluids. Compromise of these processes during middle ear disease may underlie the accumulation of effusions and suggests they may be a therapeutic target for effusion control.

  4. PorcineLEM domain-containing 3:Molecular cloning, functional characterization, and polymorphism associated with ear size

    Institute of Scientific and Technical Information of China (English)

    LIANG Jing; SHI Hui-bi; ZHANG Qin; WANGLi-xian; LI Na; ZHANG Long-chao; WANGLi-gang; LIU Xin; ZHAO Ke-bin; YAN Hua; PU Lei; ZHANG Yue-bo

    2016-01-01

    Ear size exhibits remarkable diversity in pig breeds.LEM domain-containing 3 (LEMD3) on chromosome 5 is considered as an important candidate for porcine ear size. This is the ifrst study on cloning and characterization ofLEMD3 cDNA. The complete cDNA contains 4843 bp, including a 2736-bp open reading frame (ORF), a 37-bp 5´-untranslated region (UTR) and a 2070-bp 3´-UTR. The completeLEMD3 gene is 126241-bp and contains 13 exons and 12 introns. The ORF encodes a deduced LEMD3 protein of 911 amino acids, which shares 82–94% nucleic acid and 51–96% amino acid identity with other species. A phylogenetic tree constructed based on the amino acid sequences revealed that the porcine LEMD3 protein was closely related with cattle LEMD3. Resequencing of the ORF and promoter ofLEMD3 from Minzhu pig and Large White revealed three single nucleotide polymorphisms (SNPs): L964C>A in the complete coding region, L4625A>G in the 3´ UTR, and L-394T>C in the promoter region. Genome-wide association study (GWAS) revealed that al of SNPs were shown signiifcant association with ear size in Large White×Minzhu pig intercross population. With conditional GWAS, –log10(P-value) decreased by more than 80% when each of three SNPs was included as a ifxed effect. These results suggested direct involvement ofLEMD3 or close linkage to the causative mutation for ear size. The ifndings of this study might form the basis for understanding the genetic mechanism of ear size variation in pigs and provide potential molecular markers for screening ear size diversity in pig breeds.

  5. Choosing which ear to implant in adult candidates with functional residual hearing.

    Science.gov (United States)

    Fielden, Claire A; Mehta, Rajnikant L; Kitterick, Pádraig T

    2016-04-01

    This study examined whether audiologists consider the potential benefits of contralateral hearing aid use following cochlear implantation when recommending which ear to implant in UK adult candidates with residual hearing. Thirty-four audiologists from providers of adult implantation services completed a decision-choice experiment. Clinicians were willing to consider recommending that the poorer ear be implanted, provided it had been aided continuously, suggesting that their decision making seeks to preserve access to residual hearing in the non-implanted ear where possible. Future approaches to determining candidacy should therefore consider that a sub-set of patients may obtain additional benefit from this residual hearing following implantation.

  6. Ear Tumors

    Science.gov (United States)

    ... Japanese Espaniol Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language. * This is ... the Ears, Nose, and Throat Additional Content Medical News Ear Tumors ... NOTE: This is the Consumer Version. DOCTORS: Click ...

  7. Ear Disorders

    Science.gov (United States)

    ... You use all of them in hearing. Sound waves come in through your outer ear. They reach your middle ear, where they make your eardrum vibrate. The vibrations are transmitted through three tiny bones, called ossicles, ...

  8. Elephant ear

    Science.gov (United States)

    ... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Elephant ear URL of this page: //medlineplus.gov/ency/article/002867.htm Elephant ear To use the sharing features on this page, please enable JavaScript. Elephant ear plants are indoor or outdoor plants with very large, ...

  9. Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae).

    Science.gov (United States)

    Woodman, Neal; Gaffney, Sarah A

    2014-07-01

    Small-eared shrews (Mammalia: Soricidae: Cryptotis), exhibit modifications of the forelimb skeleton that have been interpreted as adaptations for semifossoriality. Most species inhabit remote regions, however, and their locomotory and foraging behaviors remain mostly speculative. To better understand the morphological modifications in the absence of direct observations, we quantified variation in these species by measuring 151 individuals representing 18 species and populations of Cryptotis and two species of moles (Talpidae) for comparison. From our measurements, we calculated 22 indices, most of which have been used previously to characterize substrate use among rodents and other taxa. We analyzed the indices using 1) average percentile ranks, 2) principal components analysis, and 3) cluster analysis. From these analyses, we determined that three basic modes of substrate adaptation are present within Cryptotis: 1) a primarily terrestrial mode, with species that are capable of burrowing, but lack adaptations to increase digging efficiency, 2) a semifossorial mode, with species whose forelimbs bones show strong muscle attachment areas and increased mechanical advantage, and 3) an intermediate mode. In addition to identifying new morphological characters and contributing to our understanding of the functional morphology of soricids, these analyses provide additional insight into the ecology of the species of interest.

  10. Numerical study of influence of anisotropy on flanging earing based on Barlat six-component yield function

    Institute of Scientific and Technical Information of China (English)

    李大永; 张少睿; 彭颖红; 胡平

    2003-01-01

    The anisotropy of stamped sheet metal exerts evident effects on the formability. Barlat six-component yield function was introduced into the elastoplastic finite element formulation based on the principle of virtual velocity and the discrete Kirchhoff triangular element model. The flanging earing in cylindrical cup drawing process of circular sheet metal was numerically simulated. The influence of anisotropy on the forming process was studied.

  11. Infliximab has no apparent effect in the inner ear hearing function of patients with rheumatoid arthritis and ankylosing spondylitis.

    Science.gov (United States)

    Toktas, H; Okur, E; Dundar, U; Dikici, A; Kahveci, O K

    2014-01-01

    Animal studies suggest that tumor necrosis factor (TNF) alpha blockers may pass to the inner ear in adequate concentration. In this prospective study, we aimed to evaluate the effect of infliximab on the inner ear hearing function in patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA). The patients with high disease activity, who were planned to begin infliximab for therapy by physical medicine and rehabilitation department, were referred to ear-nose-throat clinic for consultation. After physical and otoscopic examination, audiological tests were performed. Air conduction thresholds between 250 and 8,000 Hz, bone conduction thresholds between 500 and 4,000 Hz, pure tone average, speech discrimination scores, distortion product otoacoustic emission (DPOAE) were used to evaluate the hearing function. The tests were repeated 2 and 6 months after the initiation of the drug "infliximab." A total of 44 ears of 22 patients (17 males and 5 females) were evaluated. Fifteen patients had a diagnosis of AS, and seven patients had RA. After initiation of infliximab therapy, statistically significant improvement was observed in disease activity scores [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for AS, Disease Activity Score 28 (DAS-28) for RA] after 2 and 6 months (p  0.05). Any problem about the balance, vertigo, or dizziness was not reported from the patients during the treatment period. As a result, our study showed that there was no notable change or deterioration in the hearing function of the patients with AS and RA who were treated with infliximab. Further studies with higher number of patients with AS and RA and also with different TNF alpha inhibitors are needed to make more valid conclusion.

  12. Inner Time and Inner Ear

    CERN Document Server

    Rvachov, Michael

    2012-01-01

    Sounds are information sequences that cannot exist outside of a time base and therefore cannot be analyzed inside an animal without an accurate internal clock. It is suggested that the clock may be hidden in the inner ear. It is shown that if a mechanism of counting of the electrical charge passing through the inner ear hair cells exists then the mechanism can be used both for the conversion of acceleration into velocity and as the inner clock, in the presence of a constant current. The causes of vertigo during rotation are discussed. It is shown that if a continuous inner time exists then sleeping is a mathematical necessity. It is indicated that both for visual and hearing inputs the recognition of an input signal is recognition of function(s) of two variables.

  13. Influence factor analysis of mechanical damage on corn ear picking%玉米摘穗收获机械损伤影响因素分析

    Institute of Scientific and Technical Information of China (English)

    耿爱军; 杨建宁; 张姬; 张智龙; 杨启勇; 李汝莘

    2016-01-01

    针对辊式玉米收获机收获损失大、籽粒损伤高的问题,该文通过理论分析与台架试验相结合的方法对摘穗过程中玉米损伤的影响因素及趋势进行了分析,建立了摘穗时果穗受力的数学模型并分析了各作用力随摘穗辊间隙、果穗直径的变化规律及其对收获损失和籽粒损伤的影响:随着摘穗辊间隙和果穗直径增大,摘穗辊凸棱对果穗的作用力、果穗受到摘穗辊的摩擦力以及果穗大端籽粒所受竖直方向的作用力都呈增大趋势,果穗损伤增加;果穗长度超过175 mm时,随果穗长度增加籽粒损伤明显增大,但果穗长度对籽粒损失无显著影响;摘穗辊转速在650~850 r/min变化时,果穗损伤率和籽粒损失随转速增加呈现先减小后增大的趋势;利用高速摄像技术对果穗的运动分析发现:果穗竖直方向运动速度对果穗损伤无明显影响,但果穗与摘穗辊接触时间越长,越容易对果穗造成损伤。该文通过对机械摘穗损伤机理的分析明确了影响摘穗损伤的主要因素,可为玉米摘穗装置的优化设计提供参考。%In order to study the damage and mechanism of corn during corn ear picking, this paper analyzed the force of corn ear when picking corn ear, and then found that there were 3 kinds of forces working on corn ear, which were the reacting force, the frictional forces of stripping roller and the force of stripping roller rib, and caused the corn ear damage with different forms. This paper made the mathematical model of forces, and analyzed their change law and their influence on the damage of corn ear. With the rising of corn ear diameter, the reacting force, the frictional forces of stripping roller and the seed loss increased. The experiments of corn ear picking were carried out on test bed. The results showed that the damage of corn seed increased as the length of corn ear was greater than 175 mm. Because with the

  14. Drugs affecting the inner ear. A review of their clinical efficacy, mechanisms of action, toxicity, and place in therapy.

    Science.gov (United States)

    Norris, C H

    1988-12-01

    Many drugs have a site of action within the inner ear. The list includes therapeutic, diagnostic and ototoxic agents. Therapeutic agents are most useful in cases of infections, endolymphatic hydrops, vascular insufficiency, vertigo of peripheral origin, autoimmune disease, otosclerosis (otospongiosis), sudden hearing loss and tinnitus. For infections, the most widely used anti-microbial agents are the penicillins and cephalosporins. There are no antiviral agents that have been proven useful for inner ear viral infections. However, steroids have been of some value for controlling some of the sequelae. Steroids have also been useful in conjunction with ampicillin in cases of syphilitic hearing loss. In cases of endolymphatic hydrops, the diuretics chlorthalidone, hydrochlorothiazide and acetazolamide have been useful. When diuretic and diet therapy cannot control endolymphatic hydrops, ototoxic drugs such as streptomycin have been used. In cases of vascular insufficiency within the inner ear, vasodilators such as carbon dioxide, papaverine, buphenine (nylidrin), naftidrofuryl (nafronyl) and thymoxamine have been recommended, but their true efficacy is questionable. Some success with betahistine has been achieved but the mechanism of this drug's action may be other than vasodilatation. Vertigo is best controlled with antihistamines and anticholinergics and with certain calcium channel blockers. Autoimmune inner ear disease appears to respond to a combination of steroids and cyclophosphamide. Although controversial, current pharmacotherapy for otosclerosis includes sodium fluoride. Sudden hearing loss is treated with a 'shotgun' combination of drugs and/or bed rest. There are as yet no drugs which can be used to routinely reduce tinnitus although some medications may help the patient tolerate the problem. Lignocaine (lidocaine) is useful in diagnosing, and very evanescently reducing, tinnitus. Glycerin (glycerol) is useful in diagnosing endolymphatic hydrops and may at

  15. A new developmental mechanism for the separation of the mammalian middle ear ossicles from the jaw

    Science.gov (United States)

    Urban, Daniel J.; Anthwal, Neal; Luo, Zhe-Xi; Maier, Jennifer A.; Sadier, Alexa

    2017-01-01

    Multiple mammalian lineages independently evolved a definitive mammalian middle ear (DMME) through breakdown of Meckel's cartilage (MC). However, the cellular and molecular drivers of this evolutionary transition remain unknown for most mammal groups. Here, we identify such drivers in the living marsupial opossum Monodelphis domestica, whose MC transformation during development anatomically mirrors the evolutionary transformation observed in fossils. Specifically, we link increases in cellular apoptosis and TGF-BR2 signalling to MC breakdown in opossums. We demonstrate that a simple change in TGF-β signalling is sufficient to inhibit MC breakdown during opossum development, indicating that changes in TGF-β signalling might be key during mammalian evolution. Furthermore, the apoptosis that we observe during opossum MC breakdown does not seemingly occur in mouse, consistent with homoplastic DMME evolution in the marsupial and placental lineages. PMID:28179517

  16. Integrating function and mechanism.

    Science.gov (United States)

    McNamara, John M; Houston, Alasdair I

    2009-12-01

    Behavioural ecology often makes the assumption that animals can respond flexibly by adopting the optimal behaviour for each circumstance. However, as ethologists have long known, behaviour is determined by mechanisms that are not optimal in every circumstance. As we discuss here, we believe that it is necessary to integrate these separate traditions by considering the evolution of mechanisms, an approach referred to as 'Evo-mecho'. This integration is timely because there is a growing awareness of the importance of environmental complexity in shaping behaviour; there are established and effective computational procedures for simulating evolution and there is rapidly increasing knowledge of the neuronal basis of decision-making. Although behavioural ecologists have built complex models of optimal behaviour in simple environments, we argue that they need to focus on simple mechanisms that perform well in complex environments.

  17. Ear Problems

    Science.gov (United States)

    ... have cold or flu symptoms?YesNoDo you have tooth pain on the same side as the ear pain ... or 2 days, see your doctor.Start OverDiagnosisA tooth problem can radiate pain to the ear on the same side.Self ...

  18. Ear, Nose, Throat, Head and Neck Surgery Department Functioning as a Team in Nigeria: Any Benefit?

    OpenAIRE

    Adobamen, P. R. O. C.; Egbage, E. E.

    2012-01-01

    To call attention to the synergistic benefit of working as a team in a clinical department and to encourage others, to emulate this pattern of patients’ care for better results. Patients that were seen at the Ear, Nose, Throat, Head and Neck Surgery Clinic of the University of Benin Teaching Hospital, Benin City, Nigeria, who had the benefit of their cases reviewed by more than one consultant were included into the study. Parameters retrieved from the case notes included number of consultants...

  19. Mechanics of advanced functional materials

    CERN Document Server

    Wang, Biao

    2013-01-01

    Mechanics of Advanced Functional Materials emphasizes the coupling effect between the electric and mechanical field in the piezoelectric, ferroelectric and other functional materials. It also discusses the size effect on the ferroelectric domain instability and phase transition behaviors using the continuum micro-structural evolution models. Functional materials usually have a very wide application in engineering due to their unique thermal, electric, magnetic, optoelectronic, etc., functions. Almost all the applications demand that the material should have reasonable stiffness, strength, fracture toughness and the other mechanical properties. Furthermore, usually the stress and strain fields on the functional materials and devices have some important coupling effect on the functionality of the materials. Much progress has been made concerning the coupling electric and mechanical behaviors such as the coupled electric and stress field distribution in piezoelectric solids, ferroelectric domain patterns in ferr...

  20. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... to Pneumococcal Vaccine Additional Content Medical News External Otitis (Swimmer's Ear) By Bradley W. Kesser, MD, Associate ... the Outer Ear Ear Blockages Ear Tumors External Otitis (Swimmer's Ear) Malignant External Otitis Perichondritis External otitis ...

  1. Ear Infections in Children

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Ear Infections in Children On this page: What is ... additional information about ear infections? What is an ear infection? An ear infection is an inflammation of ...

  2. Modeling Analysis of Biomechanical Changes of Middle Ear and Cochlea in Otitis Media

    Science.gov (United States)

    Gan, Rong Z.; Zhang, Xiangming; Guan, Xiying

    2011-11-01

    A comprehensive finite element (FE) model of the human ear including the ear canal, middle ear, and spiral cochlea was developed using histological sections of human temporal bone. The cochlea was modeled with three chambers separated by the basilar membrane and Reissner's membrane and filled with perilymphatic fluid. The viscoelastic material behavior was applied to middle ear soft tissues based on dynamic measurements of tissues in our lab. The model was validated using the experimental data obtained in human temporal bones and then used to simulate various stages of otitis media (OM) including the changes of morphology, mechanical properties, pressure, and fluid level in the middle ear. Function alterations of the middle ear and cochlea in OM were derived from the model and compared with the measurements from temporal bones. This study indicates that OM can be simulated in the FE model to predict the hearing loss induced by biomechanical changes of the middle ear and cochlea.

  3. Airplane Ear

    Science.gov (United States)

    ... severe hearing loss Ringing in your ear (tinnitus) Spinning sensation (vertigo) Vomiting resulting from vertigo Bleeding from ... the back of the nasal cavity and the top of the throat meet (nasopharynx). When an airplane ...

  4. The benefit of the reverse transfer function in the fitting process of the Vibrant Soundbridge middle ear implant.

    Science.gov (United States)

    Karkas, Alexandre; Chahine, Karim; Schmerber, Sébastien

    2012-02-01

    Reverse transfer function (RTF) measurement of the Vibrant Soundbridge (VSB) middle ear implant (MEI) is an objective method to evaluate the function of the VSB and can be used to adjust the Connexx value required to reach the optimal VSB gain during fitting sessions. To investigate the sound transfer of the VSB with the RTF in implanted patients and evaluate the role of RTF in the fitting process of the VSB. This was a prospective study including patients undergoing VSB implantation and RTF recording from March 2007 to October 2010. Three parameters were analyzed. 1) RTF: energy transmitted in dB SPL to ear canal by retrograde vibration of malleus and tympanic membrane. 2) Connexx value: level of amplification in dB delivered by the audioprocessor to the floating mass transducer (FMT). 3) VSB gain: difference in dB HL in free field between aided and unaided conditions. Ten patients fitted the criteria. RTF measurements revealed a significant inter-patient disparity. We adjusted the Connexx value according to the RTF value to obtain an optimal VSB gain within comfort levels. The VSB gain and RTF with Connexx value were closely correlated together. The mean VSB gain and RTF value converted to dB HL had comparable values.

  5. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  6. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    2002-01-01

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  7. An Adaptive Neural Mechanism with a Lizard Ear Model for Binaural Acoustic Tracking

    DEFF Research Database (Denmark)

    Shaikh, Danish; Manoonpong, Poramate

    2016-01-01

    mechanism uses to learn the target’s velocity via fast correlation-based unsupervised learning. Simulation results for tracking a pure tone acoustic target moving along a semi-circular trajectory validate our approach. Three different angular velocities in three separate trials were employed...

  8. A functional role of the sky's polarization pattern for orientation in the greater mouse-eared bat.

    Science.gov (United States)

    Greif, Stefan; Borissov, Ivailo; Yovel, Yossi; Holland, Richard A

    2014-07-22

    Animals can call on a multitude of sensory information to orient and navigate. One such cue is the pattern of polarized light in the sky, which for example can be used by birds as a geographical reference to calibrate other cues in the compass mechanism. Here we demonstrate that the female greater mouse-eared bat (Myotis myotis) uses polarization cues at sunset to calibrate a magnetic compass, which is subsequently used for orientation during a homing experiment. This renders bats the only mammal known so far to make use of the polarization pattern in the sky. Although there is currently no clear understanding of how this cue is perceived in this taxon, our observation has general implications for the sensory biology of mammalian vision.

  9. Ear, Hearing and Speech

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2000-01-01

    An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)......An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)...

  10. Ear, nose, throat, head and neck surgery department functioning as a team in Nigeria: any benefit?

    Science.gov (United States)

    Adobamen, P R O C; Egbage, E E

    2014-01-01

    To call attention to the synergistic benefit of working as a team in a clinical department and to encourage others, to emulate this pattern of patients' care for better results. Patients that were seen at the Ear, Nose, Throat, Head and Neck Surgery Clinic of the University of Benin Teaching Hospital, Benin City, Nigeria, who had the benefit of their cases reviewed by more than one consultant were included into the study. Parameters retrieved from the case notes included number of consultants that reviewed each case, age, sex of patients, diagnosis, whether there was controversy, complimentary or synergistic benefit from the team work. 124 patients completed the study. 99 patients (79.84%) were reviewed by two consultants and 25 (20.16%) were reviewed by three of the four consultants available in the department. 79 (63.71%) patients had the benefit of a complimentary management, while 38 (30.65%) had synergistic benefit from the team work. Intradepartmental team work in patient management produces synergistic benefit for patients and more experience among consultant staff.

  11. Listening to the ear

    Science.gov (United States)

    Shera, Christopher A.

    Otoacoustic emissions demonstrate that the ear creates sound while listening to sound, offering a promising acoustic window on the mechanics of hearing in awake, listening human beings. That window is clouded, however, by an incomplete knowledge of wave reflection and transmission, both forth and back within the cochlea and through the middle ear. This thesis "does windows," addressing wave propagation and scattering on both sides of the middle ear. A summary of highlights follows. Measurements of the cochlear input impedance in cat are used to identify a new symmetry in cochlear mechanics-termed "tapering symmetry" after its geometric interpretation in simple models-that guarantees that the wavelength of the traveling wave changes slowly with position near the stapes. Waves therefore propagate without reflection through the basal turns of the cochlea. Analytic methods for solving the cochlear wave equations using a perturbative scattering series are given and used to demonstrate that, contrary to common belief, conventional cochlear models exhibit negligible internal reflection whether or not they accurately represent the tapering symmetries of the inner ear. Frameworks for the systematic "deconstruction" of eardrum and middle-ear transduction characteristics are developed and applied to the analysis of noninvasive measurements of middle-ear and cochlear mechanics. A simple phenomenological model of inner-ear compressibility that correctly predicts hearing thresholds in patients with missing or disarticulated middle-ear ossicles is developed and used to establish an upper bound on cochlear compressibility several orders of magnitude smaller than that provided by direct measurements. Accurate measurements of stimulus frequency evoked otoacoustic emissions are performed and used to determine the form and frequency variation of the cochlear traveling-wave ratio noninvasively. Those measurements are inverted to obtain the spatial distribution of mechanical

  12. Doppler optical coherence microscopy and tomography applied to inner ear mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Page, Scott; Freeman, Dennis M. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Ghaffari, Roozbeh [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States)

    2015-12-31

    While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.

  13. Changes in microvascular permeability of the middle ear mucosa following the occulsion of the eustachian tube of rabbits. The functional investigation using radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Yasutaka

    1988-12-01

    Serial changes in submucosal microvascular permeability of the middle ear and the response to histamine after occlusion of the eustachian tube were functionally investigated using radioisotope in rabbits with experimentally induced otitis media with effusion. Tritium water was administered through intravenous injection and transference of tritium water into the middle ear cavity was measured by radioactivity of the middle ear perfusate. Morphological changes were concurrently examined for comparison. Vascular permeability, as measured one, 7, and 14 days after occlusion of the eustachian tube, increased with time. A histological study showed an edematous hypertrophy of the submucosal tissue of the middle ear, suggesting a noticeable increase in microvascular permeability. The response of the middle ear mucosa to histamine, which was added to the fluid for perfusion, gradually decreased after occlusion of the eustachian tube, although the effect of histamine tended to persist for a long time, irrespective of the amount of administration. The results indicated that the mucosal membrane of the middle ear has a noticeable permeability at least up to 14 days after occlusion, and that histamine may be responsible for the increase of submucosal microvascular permeability not only in the normal middle ear cavity but also in otitis media with effusion which results in the persistance of the disease. The presence of factors permeable to the blood, other than histamine, caused microvascular peameability to increase, probably resulting in chronic or irreversible inflammation. This may be explained by markedly proliferative or parenchymatous connective tissues observed 7 and l0 weeks after occlusion. It should be noted that surgical treatment be performed as early as possible in the case of otitis media with effusion. (Namekawa, K) 80 refs.

  14. Travel Inside the Ear

    Medline Plus

    Full Text Available ... Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach your ear, ... heard a soft sound or a loud sound. The sound passes through the outer ear and is ...

  15. Ear Plastic Surgery

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  16. Autoimmune Inner Ear Disease

    Science.gov (United States)

    ... Find an ENT Doctor Near You Autoimmune Inner Ear Disease Autoimmune Inner Ear Disease Patient Health Information ... with a hearing loss. How Does the Healthy Ear Work? The ear has three main parts: the ...

  17. Better Ear Health

    Science.gov (United States)

    ... Marketplace Find an ENT Doctor Near You Better Ear Health Better Ear Health Patient Health Information News ... often helpful to those with this condition. Swimmer’s Ear An infection of the outer ear structures caused ...

  18. How the Ear Works

    Science.gov (United States)

    ... Find an ENT Doctor Near You How the Ear Works How the Ear Works Patient Health Information News media interested in ... public relations staff at newsroom@entnet.org . The ear has three main parts: the outer ear (including ...

  19. Cosmetic ear surgery

    Science.gov (United States)

    Otoplasty; Ear pinning; Ear surgery - cosmetic; Ear reshaping; Pinnaplasty ... Cosmetic ear surgery may be done in the surgeon's office, an outpatient clinic, or a hospital. It can be performed under ...

  20. Functions and Mechanisms of Sleep

    Directory of Open Access Journals (Sweden)

    Mark R. Zielinski

    2016-04-01

    Full Text Available Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader’s understanding of the functions of sleep.

  1. Benign ear cyst or tumor

    Science.gov (United States)

    Osteomas; Exostoses; Tumor - ear; Cysts - ear; Ear cysts; Ear tumors; Bony tumor of the ear canal ... bony tumors of the ear canal (exostoses and osteomas) are caused by excess growth of bone. Repeated ...

  2. The Anatomy and Function of the Ear of the Bottle-nosed Dolphin Tursiops truncatus

    NARCIS (Netherlands)

    Purves, P.E.; Utrecht, van W.L.

    1963-01-01

    3. An account is given of sound conductivity experiments which were carried out on the auditory structures in a very fresh, dead specimen of Tursiops. 4. The probable function of the external auditory meatus is discussed in relationship to the arrangement of the accessory air sinuses of the middle e

  3. The Anatomy and Function of the Ear of the Bottle-nosed Dolphin Tursiops truncatus

    NARCIS (Netherlands)

    Purves, P.E.; Utrecht, van W.L.

    1963-01-01

    3. An account is given of sound conductivity experiments which were carried out on the auditory structures in a very fresh, dead specimen of Tursiops. 4. The probable function of the external auditory meatus is discussed in relationship to the arrangement of the accessory air sinuses of the middle e

  4. Quantum mechanics without potential function

    Energy Technology Data Exchange (ETDEWEB)

    Alhaidari, A. D., E-mail: haidari@sctp.org.sa [Saudi Center for Theoretical Physics, P.O. Box 32741, Jeddah 21438 (Saudi Arabia); Ismail, M. E. H. [Department of Mathematics, University of Central Florida, Orlando, Florida 32816 (United States)

    2015-07-15

    In the standard formulation of quantum mechanics, one starts by proposing a potential function that models the physical system. The potential is then inserted into the Schrödinger equation, which is solved for the wavefunction, bound states energy spectrum, and/or scattering phase shift. In this work, however, we propose an alternative formulation in which the potential function does not appear. The aim is to obtain a set of analytically realizable systems, which is larger than in the standard formulation and may or may not be associated with any given or previously known potential functions. We start with the wavefunction, which is written as a bounded infinite sum of elements of a complete basis with polynomial coefficients that are orthogonal on an appropriate domain in the energy space. Using the asymptotic properties of these polynomials, we obtain the scattering phase shift, bound states, and resonances. This formulation enables one to handle not only the well-known quantum systems but also previously untreated ones. Illustrative examples are given for two- and three-parameter systems.

  5. Ear infection - chronic

    Science.gov (United States)

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... up. When this happens, infection can occur. A chronic ear infection develops when fluid or an infection ...

  6. Travel Inside the Ear

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach ... are smaller than an orange seed. It then travels into the inner ear, which is filled with ...

  7. Ear tube insertion - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100045.htm Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Review Date 8/ ...

  8. Astrocytic glycogenolysis: mechanisms and functions.

    Science.gov (United States)

    Hertz, Leif; Xu, Junnan; Song, Dan; Du, Ting; Li, Baoman; Yan, Enzhi; Peng, Liang

    2015-02-01

    Until the demonstration little more than 20 years ago that glycogenolysis occurs during normal whisker stimulation glycogenolysis was regarded as a relatively uninteresting emergency procedure. Since then, a series of important astrocytic functions has been shown to be critically dependent on glycogenolytic activity to support the signaling mechanisms necessary for these functions to operate. This applies to glutamate formation and uptake and to release of ATP as a transmitter, stimulated by other transmitters or elevated K(+) concentrations and affecting not only other astrocytes but also most other brain cells. It is also relevant for astrocytic K(+) uptake both during the period when the extracellular K(+) concentration is still elevated after neuronal excitation, and capable of stimulating glycogenolytic activity, and during the subsequent undershoot after intense neuronal activity, when glycogenolysis may be stimulated by noradrenaline. Both elevated K(+) concentrations and several transmitters, including the β-adrenergic agonist isoproterenol and vasopressin increase free cytosolic Ca(2+) concentration in astrocytes, which stimulates phosphorylase kinase so that it activates the transformation of the inactive glycogen phosphorylase a to the active phosphorylase b. Contrary to common belief cyclic AMP plays at most a facilitatory role, and only when free cytosolic Ca(2+) concentration is also increased. Cyclic AMP is not increased during activation of glycogenolysis by either elevated K(+) concentrations or the stimulation of the serotonergic 5-HT(2B) receptor. Not all agents that stimulate glycogenolysis do so by directly activating phophorylase kinase--some do so by activating processes requiring glycogenolysis, e.g. for synthesis of glutamate.

  9. Functional consequences of a novel middle ear adaptation in the central African frog Petropedetes parkeri (Ranidae).

    Science.gov (United States)

    Narins, P M; Lewis, E R; Purgue, A P; Bishop, P J; Minter, L R; Lawson, D P

    2001-04-01

    During the breeding season, each tympanic membrane of males of the Old World treefrog Petropedetes parkeri is decorated with a single, prominent, fleshy tympanic papilla. The tympanic papilla, located dorsally on the tympanic membrane, is covered by an epidermal surface and is composed of non-ossified, spongiform tissue containing a number of globular, fluid-filled vesicles found at highest density near the papillar tip. These vesicles appear to have exit pores and are probably simple alveolar exocrine glands. Injecting sound into the pressurized vocal cavity of the male and measuring the vibration velocity response of the tympanic membrane revealed that from 0.3 to 2.0 kHz the tympanic papilla velocity amplitude is on average 20 dB lower than that of a point diametrically opposite on the ventral half of the tympanic membrane. The close agreement between the dominant frequency of the call and the frequency of the maximum spectral peak of the Fast Fourier Transform of the impulse response of the eardrum is consistent with the use of the eardrum in this species both as a call receiver and as a call radiator, similar to the function suggested for the eardrum of the male bullfrog Rana catesbeiana. Unexpectedly, surgically removing the tympanic papilla lowered the frequency of the peak vibrational amplitude, testifying to the importance of membrane tension as a dominant factor in the vibratory behavior of the eardrum. During normal positive-pressure breathing, the tympanic papillae move conspicuously, suggesting a possible rôle as a visual signal.

  10. Inner ear supporting cells: rethinking the silent majority.

    Science.gov (United States)

    Wan, Guoqiang; Corfas, Gabriel; Stone, Jennifer S

    2013-05-01

    Sensory epithelia of the inner ear contain two major cell types: hair cells and supporting cells. It has been clear for a long time that hair cells play critical roles in mechanoreception and synaptic transmission. In contrast, until recently the more abundant supporting cells were viewed as serving primarily structural and homeostatic functions. In this review, we discuss the growing information about the roles that supporting cells play in the development, function and maintenance of the inner ear, their activities in pathological states, their potential for hair cell regeneration, and the mechanisms underlying these processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Ear-to-Ear On-Body Channel Fading in the ISM-band for Tangentially-Polarized Antennas

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2011-01-01

    The ear-to-ear on-body channel fading has been studied in the ISM-band. The ear-to-ear path gain was measured on six persons in an indoor environment for a duration of 200 s. The channel fading has been characterized in terms of empirical cumulative distribution functions (CDF), average fade...

  12. Investigating Science Student Teachers' Ideas about Function and Anatomical Form of Two Human Sensory Organs, the Eye and the Ear

    Science.gov (United States)

    Kunt, Halil

    2016-01-01

    The purpose of this research was to determine science student teachers' level of knowledge about the anatomical structure of two sensory organs, the eye and the ear, in addition to vision and hearing processes. Conducted with 86 science student teachers, research utilized drawing methods and open-ended questions as data collection instruments. The…

  13. Functional Ear (A)Symmetry in Brainstem Neural Activity Relevant to Encoding of Voice Pitch: A Precursor for Hemispheric Specialization?

    Science.gov (United States)

    Krishnan, Ananthanarayan; Gandour, Jackson T.; Ananthakrishnan, Saradha; Bidelman, Gavin M.; Smalt, Christopher J.

    2011-01-01

    Pitch processing is lateralized to the right hemisphere; linguistic pitch is further mediated by left cortical areas. This experiment investigates whether ear asymmetries vary in brainstem representation of pitch depending on linguistic status. Brainstem frequency-following responses (FFRs) were elicited by monaural stimulation of the left and…

  14. Aminoglycoside-induced hair cell death of inner ear organs causes functional deficits in adult zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Phillip M Uribe

    Full Text Available Aminoglycoside antibiotics, like gentamicin, kill inner ear sensory hair cells in a variety of species including chickens, mice, and humans. The zebrafish (Danio rerio has been used to study hair cell cytotoxicity in the lateral line organs of larval and adult animals. Little is known about whether aminoglycosides kill the hair cells within the inner ear of adult zebrafish. We report here the ototoxic effects of gentamicin on hair cells in the saccule, the putative hearing organ, and utricle of zebrafish. First, adult zebrafish received a single 30 mg/kg intraperitoneal injection of fluorescently-tagged gentamicin (GTTR to determine the distribution of gentamicin within inner ear sensory epithelia. After 4 hours, GTTR was observed in hair cells throughout the saccular and utriclar sensory epithelia. To assess the ototoxic effects of gentamicin, adult zebrafish received a single 250 mg/kg intraperitoneal injection of gentamicin and, 24 hours later, auditory evoked potential recordings (AEPs revealed significant shifts in auditory thresholds compared to untreated controls. Zebrafish were then euthanized, the inner ear fixed, and labeled for apoptotic cells (TUNEL reaction, and the stereociliary bundles of hair cells labeled with fluorescently-tagged phalloidin. Whole mounts of the saccule and utricle were imaged and cells counted. There were significantly more TUNEL-labeled cells found in both organs 4 hours after gentamicin injection compared to vehicle-injected controls. As expected, significantly fewer hair cell bundles were found along the rostral-caudal axis of the saccule and in the extrastriolar and striolar regions of the utricle in gentamicin-treated animals compared to untreated controls. Therefore, as in other species, gentamicin causes significant inner ear sensory hair cell death and auditory dysfunction in zebrafish.

  15. Play it by Ear

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren Helstrup; Thaysen, Jesper

    2014-01-01

    The first antenna for ear-to-ear communication with a standard Bluetooth chip has the potential to improve hearing aid technology.......The first antenna for ear-to-ear communication with a standard Bluetooth chip has the potential to improve hearing aid technology....

  16. 3D Printed Bionic Ears

    Science.gov (United States)

    Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C.

    2013-01-01

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  17. 3D printed bionic ears.

    Science.gov (United States)

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

    2013-06-12

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.

  18. Molecular mechanisms of NCAM function

    DEFF Research Database (Denmark)

    Hinsby, Anders M; Berezin, Vladimir; Bock, Elisabeth

    2004-01-01

    receptor that responds to both homophilic and heterophilic cues, as well as a mediator of cell-cell adhesion. This review describes NCAM function at the molecular level. We discuss recent models for extracellular ligand-interactions of NCAM, and the intracellular signaling cascade that follows to define...

  19. Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear.

    Science.gov (United States)

    Jones, Chonnettia; Qian, Dong; Kim, Sun Myoung; Li, Shuangding; Ren, Dongdong; Knapp, Lindsey; Sprinzak, David; Avraham, Karen B; Matsuzaki, Fumio; Chi, Fanglu; Chen, Ping

    2014-11-01

    The coordinated polarization of neighboring cells within the plane of the tissue, known as planar cell polarity (PCP), is a recurring theme in biology. It is required for numerous developmental processes for the form and function of many tissues and organs across species. The genetic pathway regulating PCP was first discovered in Drosophila, and an analogous but distinct pathway is emerging in vertebrates. It consists of membrane protein complexes known as core PCP proteins that are conserved across species. Here we report that the over-expression of the murine Ankrd6 (mAnkrd6) gene that shares homology with Drosophila core PCP gene diego causes a typical PCP phenotype in Drosophila, and mAnkrd6 can rescue the loss of function of diego in Drosophila. In mice, mAnkrd6 protein is asymmetrically localized in cells of the inner ear sensory organs, characteristic of components of conserved core PCP complexes. The loss of mAnkrd6 causes PCP defects in the inner ear sensory organs. Moreover, canonical Wnt signaling is significantly increased in mouse embryonic fibroblasts from mAnkrd6 knockout mice in comparison to wild type controls. Together, these results indicated that mAnkrd6 is a functional homolog of the Drosophila diego gene for mammalian PCP regulation and act to suppress canonical Wnt signaling.

  20. Ear Infection and Vaccines

    Science.gov (United States)

    ... an ENT Doctor Near You Ear Infection and Vaccines Ear Infection and Vaccines Patient Health Information News ... or may need reinsertion over time. What about vaccines? A vaccine is a preparation administered to stimulate ...

  1. Middle Ear Infections

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Middle Ear Infections Page Content Article Body What are the ... illness. What if a child with a middle ear infection is in great pain and discomfort? The ...

  2. Ear surgery - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100016.htm Ear surgery - series—Normal anatomy To use the sharing ... Overview This image demonstrates normal appearance of the ears in relation to the face. Review Date 10/ ...

  3. Otoplasty (Cosmetic Ear Surgery)

    Science.gov (United States)

    ... By Mayo Clinic Staff Otoplasty — also known as cosmetic ear surgery — is a procedure to change the ... Society of Plastic Surgeons. http://www.plasticsurgery.org/Cosmetic-Procedures/Ear-Surgery.html. Accessed June 16, 2015. ...

  4. Middle Ear Infections (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Middle Ear Infections KidsHealth > For Parents > Middle Ear Infections Print ... 3 years old. A Close Look at the Ear To understand how ear infections develop, let's review ...

  5. The Role of Estrogen and Estrogen Receptors in the Development and Function of Inner Ear%雌激素及其受体在内耳发育和功能上的作用

    Institute of Scientific and Technical Information of China (English)

    杨利平; 吴耀松; 刘辉; 陈玉龙

    2012-01-01

    雌激素在生殖系统、认知记忆系统、骨骼和神经的发育及其功能维持等多种生理功能中扮演了重要的作用.近年来,在内耳发育及其功能研究过程中,许多学者发现在听力和平衡系统功能上的性别差异可能归根因于不同性别的雌激素水平差异.这些研究表明,雌激素及其受体在内耳发育、听力和平衡系统功能维持上也具有重要作用.该文用一个新的视角聚焦于雌激素及其受体在内耳发育和功能上的研究进展.该综述能为进一步研究雌激素在听力和平衡系统中的作用机制及相关疾病的临床治疗提供参考.%The sex hormone estrogen is a hormonal multi-tasker, contributing to roles as diverse as the differentiation and function of the reproductive tract, memory storage, bone growth and nerve system. In recent years, in the investigation on the development and function of inner ear, many authors have shown a gender difference in hearing function and some of them implied that part of this variation was due to the difference in estrogen levels between females and males. These studies suggested that estrogen and estrogen receptors have an effect on the development of inner ear, hearing and vestibular functions. This paper focus on the investigation progress of estrogen and estrogen receptors in the development and function of inner ear from a novel perspective and provides a reference for the further study of estrogen role in the mechanism of hearing and balance systems and clinical therapy of related diseases.

  6. Ear Injuries (For Parents)

    Science.gov (United States)

    ... head, sports injuries, and even listening to loud music can cause ear damage, which can affect hearing and balance. That's because the ear not ... Hearing Loss or Balance Problems Ear injuries can affect kids differently. ... sounds or music notes hearing only certain or muffled sounds ringing ...

  7. Parvoviral left-end hairpin ears are essential during infection for establishing a functional intranuclear transcription template and for efficient progeny genome encapsidation.

    Science.gov (United States)

    Li, Lei; Cotmore, Susan F; Tattersall, Peter

    2013-10-01

    The 121-nucleotide left-end telomere of Minute Virus of Mice (MVM) can be folded into a Y-shaped hairpin with short axial ears that are highly conserved within genus Parvovirus. To explore their potential role(s) during infection, we constructed infectious plasmid clones that lacked one or other ear. Although these were nonviable when transfected into A9 cells, excision of the viral genome and DNA amplification appeared normal, and viral transcripts and proteins were expressed, but progeny virion production was minimal, supporting the idea of a potential role for the ears in genome packaging. To circumvent the absence of progeny that confounded further analysis of these mutants, plasmids were transfected into 293T cells both with and without an adenovirus helper construct, generating single bursts of progeny. These virions bound to A9 cells and were internalized but failed to initiate viral transcription, protein expression, or DNA replication. No defects in mutant virion stability or function could be detected in vitro. Significantly, mutant capsid gene expression and DNA replication could be rescued by coinfection with wild-type virions carrying a replication-competent, capsid-gene-replacement vector. To pinpoint where such complementation occurred, prior transfection of plasmids expressing only MVM nonstructural proteins was explored. NS1 alone, but not NS2, rescued transcription and protein expression from both P4 and P38 promoters, whereas NS1 molecules deleted for their C-terminal transactivation domain did not. These results suggest that the mutant virions reach the nucleus, uncoat, and are converted to duplex DNA but require an intact left-end hairpin structure to form the initiating transcription complex.

  8. Vestibular function disorders and potential mechanisms in irradiation nasopharyngeal carcinoma patients.

    Science.gov (United States)

    Sun, Dianshui; Zhao, Miaoqing; Yin, Jinjun; Xu, Ying; Zhang, Hao; Xia, Ming

    2016-08-01

    Vestibular function disorders were widespread among nasopharyngeal carcinoma (NPC) patients. The radiation doses to the inner ears were associated with the incidence of vestibular function disorders, but the correlations were mild. The inflammatory responses and possible resolution obstacles of inflammation participated in persistent vestibular function disorders after irradiation. To investigate the incidence of vestibular function disorders in NPC patients after irradiation and potential mechanisms. Patients who received radical intensity-modulated radiotherapy for their NPC were recruited. The serum levels of IL-6 and IL-17 were detected by ELISA method. Vestibular evoked myogenic potential (VEMP) tests were used to evaluate vestibular function and correlation analyses were used to analyze the potential mechanisms of vestibular function disorders. Thirty-eight patients were included. The incidences of abnormal ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were 65.79% and 80.26% at the time of completion of radiotherapy, and 61.84% and 71.05% at 3 months after radiotherapy. The mean and maximum radiation doses to the inner ears were both significantly associated with abnormal oVEMP and cVEMP (p < 0.05, all), but the correlations were all mild. The serum levels of IL-6 and IL-17 were both significantly associated with abnormal oVEMP and cVEMP after irradiation (p < 0.05, all).

  9. Analysis of chick (Gallus gallus middle ear columella formation

    Directory of Open Access Journals (Sweden)

    Mercer Kathryn J

    2010-02-01

    Full Text Available Abstract Background The chick middle ear bone, the columella, provides an accessible model in which to study the tissue and molecular interactions necessary for induction and patterning of the columella, as well as associated multiple aspects of endochondral ossification. These include mesenchymal condensation, chondrogenesis, ossification of the medial footplate and shaft, and joint formation between the persistent cartilage of the extracolumella and ossified columella. Middle and external ear defects are responsible for approximately 10% of congenital hearing defects. Thus, understanding the morphogenesis and the molecular mechanisms of the formation of the middle ear is important to understanding normal and abnormal development of this essential component of the hearing apparatus. Results The columella, which arises from proximal ectomesenchyme of the second pharyngeal arch, is induced and patterned in a dynamic multi-step process. From the footplate, which inserts into the inner ear oval window, the shaft spans the pneumatic middle ear cavity, and the extracolumella inserts into the tympanic membrane. Through marker gene and immunolabeling analysis, we have determined the onset of each stage in the columella's development, from condensation to ossification. Significantly, a single condensation with the putative shaft and extracolumella arms already distinguishable is observed shortly before initiation of five separate chondrogenic centers within these structures. Ossification begins later, with periosteum formation in the shaft and, unexpectedly, a separate periosteum in the footplate. Conclusions The data presented in this study document the spatiotemporal events leading to morphogenesis of the columella and middle ear structures and provide the first gene expression data for this region. These data identify candidate genes and facilitate future functional studies and elucidation of the molecular mechanisms of columella formation.

  10. Characteristics of laser-induced shock wave injury to the inner ear of rats

    Science.gov (United States)

    Kurioka, Takaomi; Matsunobu, Takeshi; Niwa, Katsuki; Tamura, Atsushi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro

    2014-12-01

    Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury.

  11. Diverse Roles of Axonemal Dyneins in Drosophila Auditory Neuron Function and Mechanical Amplification in Hearing.

    Science.gov (United States)

    Karak, Somdatta; Jacobs, Julie S; Kittelmann, Maike; Spalthoff, Christian; Katana, Radoslaw; Sivan-Loukianova, Elena; Schon, Michael A; Kernan, Maurice J; Eberl, Daniel F; Göpfert, Martin C

    2015-11-26

    Much like vertebrate hair cells, the chordotonal sensory neurons that mediate hearing in Drosophila are motile and amplify the mechanical input of the ear. Because the neurons bear mechanosensory primary cilia whose microtubule axonemes display dynein arms, we hypothesized that their motility is powered by dyneins. Here, we describe two axonemal dynein proteins that are required for Drosophila auditory neuron function, localize to their primary cilia, and differently contribute to mechanical amplification in hearing. Promoter fusions revealed that the two axonemal dynein genes Dmdnah3 (=CG17150) and Dmdnai2 (=CG6053) are expressed in chordotonal neurons, including the auditory ones in the fly's ear. Null alleles of both dyneins equally abolished electrical auditory neuron responses, yet whereas mutations in Dmdnah3 facilitated mechanical amplification, amplification was abolished by mutations in Dmdnai2. Epistasis analysis revealed that Dmdnah3 acts downstream of Nan-Iav channels in controlling the amplificatory gain. Dmdnai2, in addition to being required for amplification, was essential for outer dynein arms in auditory neuron cilia. This establishes diverse roles of axonemal dyneins in Drosophila auditory neuron function and links auditory neuron motility to primary cilia and axonemal dyneins. Mutant defects in sperm competition suggest that both dyneins also function in sperm motility.

  12. The Role of Immittance Audiometry in Detecting Middle Ear Disease

    OpenAIRE

    Jacobson, John T.

    1981-01-01

    Immittance audiometry is an objective technique which evaluates middle ear function by three procedures: static immittance, tympanometry, and the measurement of acoustic reflex threshold sensitivity. This article discusses the technique's ability to identify middle ear effusion, the single leading ear disease in children.

  13. Why do elephants flap their ears?

    African Journals Online (AJOL)

    the elephant's ears serve as an important heat-regulating mechanism is not ... thermocouples; the cleaned vessel surface temperature was considered adequate .... The pathways for this transfer must be largely convective and evaporative.

  14. Acoustics of the human middle-ear air space.

    Science.gov (United States)

    Stepp, Cara E; Voss, Susan E

    2005-08-01

    The impedance of the middle-ear air space was measured on three human cadaver ears with complete mastoid air-cell systems. Below 500 Hz, the impedance is approximately compliance-like, and at higher frequencies (500-6000 Hz) the impedance magnitude has several (five to nine) extrema. Mechanisms for these extrema are identified and described through circuit models of the middle-ear air space. The measurements demonstrate that the middle-ear air space impedance can affect the middle-ear impedance at the tympanic membrane by as much as 10 dB at frequencies greater than 1000 Hz. Thus, variations in the middle-ear air space impedance that result from variations in anatomy of the middle-ear air space can contribute to inter-ear variations in both impedance measurements and otoacoustic emissions, when measured at the tympanic membrane.

  15. Numerical analysis of ossicular chain lesion of human ear

    Institute of Scientific and Technical Information of China (English)

    Yingxi Liu; Sheng Li; Xiuzhen Sun

    2009-01-01

    Lesion of ossicular chain is a common ear disease impairing the sense of hearing. A comprehensive numerical model of human ear can provide better understanding of sound transmission. In this study, we propose a three-dimensional finite element model of human ear that incorporates the canal, tympanic membrane, ossicular bones,middle ear suspensory ligaments/muscles, middle ear cavity and inner ear fluid. Numerical analysis is conducted and employed to predict the effects of middle ear cavity, malleus handle defect, hypoplasia of the long process of incus,and stapedial crus defect on sound transmission. The present finite element model is shown to be reasonable in predicting the ossicular mechanics of human ear.

  16. 鼻咽癌放疗对耳损伤的临床观察%Effect of Radiotherapy on Ear Function in Nasopharyngeal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    薛英; 彭涛

    2012-01-01

    目的:探讨放疗对鼻咽癌患者耳部结构及功能的影响.方法:选择无耳病及听力正常的163例鼻咽癌患者,于放疗前及放疗后不同时间点检测其耳部的结构及听功能状态.结果:随放疗时间及放疗结束后的时间延长,外耳道炎、分泌性中耳炎及化脓性中耳炎的发生率增加,不同性质的耳聋的发生率及听力损失的程度亦逐渐增加.结论:放疗对鼻咽癌患者的耳部的结构及功能损伤明显,严重影响鼻咽癌患者生存质量.%Objective: To study the changes of ear function and construction after radiotherapy in naso-pharyngeal carcinoma. Methods: Hearing and physical examination were performed in 163 patients with nasopharyngeal carcinoma at different time after radiotherapy. Results: The incidence of the otitis externa,secretory otitis media, suppurative otitis media, different type hearing loss and extent of hearing loss was increased according to radiotherapeutic time and the time after radiation. Conclusion: Injury of structure and function of ear was apparently affected after radio-theray of nasopharyngeal carcinoma and life quality of patients with nasopharyngeal carcinoma was markedly lowered.

  17. Modeling Ear-Canal Acoustics, Incorporating Visco-Thermal Effects and the Influence of the Middle Ear

    Science.gov (United States)

    Gowdy, Lauren E.; Withnell, Robert H.

    2011-11-01

    The ear canal, below about 6 kHz, is well described by a uniform cylinder (sound propagates predominantly as plane waves) with the middle ear being a non-rigid termination. A non-rigid termination can be viewed as altering, as a function of frequency, the acoustic length and radius of the cylinder. It is generally assumed that sound transmission in the ear canal over this frequency range is lossless. This paper presents a method for calculating the influence of visco-thermal losses and the middle ear on ear canal acoustics. The acoustic input impedance was derived from sound pressure measurements in the ear canal and then a nonlinear least-square-fit to the data with a one-dimensional model incorporating visco-thermal losses generated length, radius, and middle ear impedance parameters. It was found that a rigid wall assumption for visco-thermal calculations was insufficient to account for damping in the ear canal. The properties of the ear canal wall (not being a rigid, low-friction surface), incorporated into visco-thermal losses as a scaling factor, provided a better fit to the data. Viscous and thermal losses were both found to affect sound propagation in the ear canal, viscous losses being more significant, altering the acoustic input impedance of the ear primarily in the region of the standing wave frequency. The model data suggests that the middle ear influences ear canal acoustics up to about 3 kHz.

  18. Morphological and mechanical changes in juvenile red-eared slider turtle (Trachemys scripta elegans) shells during ontogeny.

    Science.gov (United States)

    Fish, Jennifer F; Stayton, Charles T

    2014-04-01

    Turtles experience numerous modifications in the morphological, physiological, and mechanical characteristics of their shells through ontogeny. Although a general picture is available of the nature of these modifications, few quantitative studies have been conducted on changes in turtle shell shape through ontogeny, and none on changes in strength or rigidity. This study investigates the morphological and mechanical changes that juvenile Trachemys scripta elegans undergo as they increase in size. Morphology and shell rigidity were quantified in a sample of 36 alcohol-preserved juvenile Trachemys scripta elegans. Morphometric information was used to create finite element models of all specimens. These models were used to assess the mechanical behavior of the shells under various loading conditions. Overall, we find that turtles experience complementary changes in size, shape, deformability, and relative strength as they grow. As turtles age their shells become larger, more elongate, relatively flatter, and more rigid. These changes are associated with decreases in relative (size independent) strength, even though the shells of larger turtles are stronger in an absolute sense. Decreased deformability is primarily due to changes in the size of the animals. Residual variation in deformability cannot be explained by changes in shell shape. This variation is more likely due to changes in the degree of connectedness of the skeletal elements in the turtle's shells, along with changes in the thickness and degree of mineralization of shell bone. We suggest that the mechanical implications of shell size, shape, and deformability may have a large impact on survivorship and development in members of this species as they mature. Copyright © 2013 Wiley Periodicals, Inc.

  19. Comparison of f2/f1 ratio functions in rabbit and gerbil: Ear-canal DPOAEs vs noninvasively inferred intracochlear DPs

    Science.gov (United States)

    Martin, Glen K.; Stagner, Barden B.; Dong, Wei; Lonsbury-Martin, Brenda L.

    2015-12-01

    The properties of distortion product otoacoustic emissions (DPOAEs), i.e., distortion products (DPs) measured in the ear canal, have been thoroughly described. However, considerably less is known about the behavior of intracochlear DPs (iDPs). Detailed comparisons of DPOAEs to iDPs would provide valuable insights on the extent to which ear-canal DPOAEs mirror iDPs. Prior studies described a technique whereby the behavior of iDPs could be inferred by interacting a probe tone (f3) with the iDP of interest to produce a `secondary' DPOAE (DPOAÉ). The behavior of DPOAÉ was then used to deduce the characteristics of the iDP. In the present study, this method was used in rabbits and gerbils to simultaneously compare DPOAE f2/f1-ratio functions to their iDP counterparts. The 2f1-f2 and 2f2-f1 DPOAEs were collected with f1 and f2 primary-tone levels varied from 35-75 dB SPL, and with a 50-dB SPL f3 placed at a DP/f3 ratio of 1.25 to evoke a DPOAÉ at 2f3-(2f1-f2) or 2f3-(2f2-f1). Control experiments demonstrated little effect of the f3-probe tone on DPOAE-ratio functions. Substitution experiments were performed to determine any suppressive effects of the f1 and f2 primaries on the generation of DPOAÉ, as well as to infer the intracochlear level of the iDP once the DPOAÉ was corrected for suppression. Results showed that at low primary-tone levels, 2f1-f2 DPOAE f2/f1-ratio functions peaked around f2/f1=1.25, and exhibited an inverted U-shaped function. In contrast, simultaneously measured 2f1-f2 iDP-ratio functions peaked at f2/f1≈1. Similar growth of the inferred iDP was obtained for higher-level primaries when the ratio functions were corrected for suppressive effects. At these higher levels, DPOAE-ratio functions leveled off and no longer showed the steep reduction at narrow f2/f1 ratios. Overall, noninvasive estimates of 2f1-f2 iDP-ratio functions agreed with reports of similar functions directly measured for 2f1-f2 DPs on the basilar membrane (BM) or in

  20. Proteomics and the Inner Ear

    Directory of Open Access Journals (Sweden)

    Isolde Thalmann

    2001-01-01

    Full Text Available The inner ear, one of the most complex organs, contains within its bony shell three sensory systems, the evolutionary oldest gravity receptor system, the three semicircular canals for the detection of angular acceleration, and the auditory system - unrivaled in sensitivity and frequency discrimination. All three systems are susceptible to a host of afflictions affecting the quality of life for all of us. In the first part of this review we present an introduction to the milestones of inner ear research to pave the way for understanding the complexities of a proteomics approach to the ear. Minute sensory structures, surrounded by large fluid spaces and a hard bony shell, pose extreme challenges to the ear researcher. In spite of these obstacles, a powerful preparatory technique was developed, whereby precisely defined microscopic tissue elements can be isolated and analyzed, while maintaining the biochemical state representative of the in vivo conditions. The second part consists of a discussion of proteomics as a tool in the elucidation of basic and pathologic mechanisms, diagnosis of disease, as well as treatment. Examples are the organ of Corti proteins OCP1 and OCP2, oncomodulin, a highly specific calcium-binding protein, and several disease entities, Meniere's disease, benign paroxysmal positional vertigo, and perilymphatic fistula.

  1. [Brain mechanisms of male sexual function].

    Science.gov (United States)

    Wang, Ying; Dou, Xin; Li, Jun-Fa; Luo, Yan-Lin

    2011-08-01

    In this paper, we reviewed the brain imaging studies of male sexual function in recent years from three aspects: the brain mechanism of normal sexual function, the brain mechanism of sexual dysfunction, and the mechanism of drug therapy for sexual dysfunction. Studies show that the development stages of male sexual activities, such as the excitement phase, plateau phase and orgasm phase, are controlled by different neural networks. The mesodiencephalic transition zone may play an important role in the start up of male ejaculation. There are significant differences between sexual dysfunction males and normal males in activation patterns of the brain in sexual arousal. The medial orbitofrontal cortex and inferior frontal gyrus in the abnormal activation pattern are correlated with sexual dysfunction males in sexual arousal. Serum testosterone and morphine are commonly used drugs for male sexual dysfunction, whose mechanisms are to alter the activating levels of the medial orbitofrontal cortex, insula, claustrum and inferior temporal gyrus.

  2. Functional genomic analysis of constitutive and inducible defense responses to Fusarium verticillioides infection in maize genotypes with contrasting ear rot resistance.

    Science.gov (United States)

    Lanubile, Alessandra; Ferrarini, Alberto; Maschietto, Valentina; Delledonne, Massimo; Marocco, Adriano; Bellin, Diana

    2014-08-25

    Fusarium verticillioides causes ear rot in maize (Zea mays L.) and accumulation of mycotoxins, that affect human and animal health. Currently, chemical and agronomic measures to control Fusarium ear rot are not very effective and selection of more resistant genotypes is a desirable strategy to reduce contaminations. A deeper knowledge of molecular events and genetic basis underlying Fusarium ear rot is necessary to speed up progress in breeding for resistance. A next-generation RNA-sequencing approach was used for the first time to study transcriptional changes associated with F. verticillioides inoculation in resistant CO441 and susceptible CO354 maize genotypes at 72 hours post inoculation. More than 100 million sequence reads were generated for inoculated and uninoculated control plants and analyzed to measure gene expression levels. Comparison of expression levels between inoculated vs. uninoculated and resistant vs. susceptible transcriptomes revealed a total number of 6,951 differentially expressed genes. Differences in basal gene expression were observed in the uninoculated samples. CO441 genotype showed a higher level of expression of genes distributed over all functional classes, in particular those related to secondary metabolism category. After F. verticillioides inoculation, a similar response was observed in both genotypes, although the magnitude of induction was much greater in the resistant genotype. This response included higher activation of genes involved in pathogen perception, signaling and defense, including WRKY transcription factors and jasmonate/ethylene mediated defense responses. Interestingly, strong differences in expression between the two genotypes were observed in secondary metabolism category: pathways related to shikimate, lignin, flavonoid and terpenoid biosynthesis were strongly represented and induced in the CO441 genotype, indicating that selection to enhance these traits is an additional strategy for improving resistance

  3. [Conversion disorder : functional neuroimaging and neurobiological mechanisms].

    Science.gov (United States)

    Lejeune, J; Piette, C; Salmon, E; Scantamburlo, G

    2017-04-01

    Conversion disorder is a psychiatric disorder often encountered in neurology services. This condition without organic lesions was and still is sometimes referred as an imaginary illness or feigning. However, the absence of organic lesions does not exclude the possibility of cerebral dysfunction. The etiologic mechanisms underlying this disorder remain uncertain even today.The advent of cognitive and functional imaging opens up a field of exploration for psychiatry in understanding the neurobiological mechanisms underlying mental disorders and especially the conversion disorder. This article reports several neuroimaging studies of conversion disorder and attempts to generate hypotheses about neurobiological mechanisms.

  4. Plant Stems: Functional Design and Mechanics

    Science.gov (United States)

    Speck, Thomas; Burgert, Ingo

    2011-08-01

    Plant stems are one of nature's most impressive mechanical constructs. Their sophisticated hierarchical structure and multifunctionality allow trees to grow more than 100 m tall. This review highlights the advanced mechanical design of plant stems from the integral level of stem structures down to the fiber-reinforced-composite character of the cell walls. Thereby we intend not only to provide insight into structure-function relationships at the individual levels of hierarchy but to further discuss how growth forms and habits of plant stems are closely interrelated with the peculiarities of their tissue and cell structure and mechanics. This concept is extended to a further key feature of plants, namely, adaptive growth as a reaction to mechanical perturbation and/or changing environmental conditions. These mechanical design principles of plant stems can serve as concept generators for advanced biomimetic materials and may inspire materials and engineering sciences research.

  5. LDV measurement of bird ear vibrations to determine inner ear impedance and middle ear power flow

    Science.gov (United States)

    Muyshondt, Pieter G. G.; Pires, Felipe; Dirckx, Joris J. J.

    2016-06-01

    The mechanical behavior of the middle ear structures in birds and mammals is affected by the fluids in the inner ear (IE) that are present behind the oval window. In this study, the aim was to gather knowledge of the acoustic impedance of the IE in the ostrich, to be able to determine the effect on vibrations and power flow in the single-ossicle bird middle ear for future studies. To determine the IE impedance, vibrations of the ossicle were measured for both the quasi-static and acoustic stimulus frequencies. In the acoustic regime, vibrations were measured with a laser Doppler vibrometer and electromagnetic stimulation of the ossicle. The impedance of the inner ear could be determined by means of a simple RLC model in series, which resulted in a stiffness reactance of KIE = 0.20.1012 Pa/m3, an inertial impedance of MIE = 0.652.106 Pa s2/m3, and a resistance of RIE = 1.57.109 Pa s/m. The measured impedance is found to be considerably smaller than what is found for the human IE.

  6. Travel Inside the Ear

    Medline Plus

    Full Text Available ... Search form Search A–Z Index Español Menu Home Health Info Hearing, Ear Infections, and Deafness Balance ... Committees Contact Us Get Involved You are here Home » Health Info » Hearing, Ear Infections, and Deafness Travel ...

  7. "Swimmer's Ear" (Otitis Externa) Prevention

    Science.gov (United States)

    ... infections, swimmer’s ear, and healthy swimming. "Swimmer's Ear" (Otitis Externa) What are the symptoms of swimmer's ear? ... Healthy page. Reference CDC. Estimated burden of acute otitis externa —United States, 2003–2007 . MMWR Morb Mortal ...

  8. Ear - blocked at high altitudes

    Science.gov (United States)

    High altitudes and blocked ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... eustachian tube is a connection between the middle ear (the space deep to the eardrum) and the ...

  9. Epigenetic regulation in the inner ear and its potential roles in development, protection, and regeneration

    Directory of Open Access Journals (Sweden)

    Jian eZuo

    2015-01-01

    Full Text Available The burgeoning field of epigenetics is beginning to make a significant impact on our understanding of tissue development, maintenance, and function. Epigenetic mechanisms regulate the structure and activity of the genome in response to intracellular and environmental cues that direct cell-type specific gene networks. The inner ear is comprised of highly specialized cell types with identical genomes that originate from a single totipotent zygote. During inner ear development specific combinations of transcription factors and epigenetic modifiers must function in a coordinated manner to establish and maintain cellular identity. These epigenetic regulatory mechanisms contribute to the maintenance of distinct chromatin states and cell-type specific gene expression patterns. In this review, we highlight emerging paradigms for epigenetic modifications related to inner ear development, and how epigenetics may have a significant role in hearing loss, protection, and regeneration.

  10. Microcapsule mechanics: from stability to function.

    Science.gov (United States)

    Neubauer, Martin P; Poehlmann, Melanie; Fery, Andreas

    2014-05-01

    Microcapsules are reviewed with special emphasis on the relevance of controlled mechanical properties for functional aspects. At first, assembly strategies are presented that allow control over the decisive geometrical parameters, diameter and wall thickness, which both influence the capsule's mechanical performance. As one of the most powerful approaches the layer-by-layer technique is identified. Subsequently, ensemble and, in particular, single-capsule deformation techniques are discussed. The latter generally provide more in-depth information and cover the complete range of applicable forces from smaller than pN to N. In a theory chapter, we illustrate the physics of capsule deformation. The main focus is on thin shell theory, which provides a useful approximation for many deformation scenarios. Finally, we give an overview of applications and future perspectives where the specific design of mechanical properties turns microcapsules into (multi-)functional devices, enriching especially life sciences and material sciences.

  11. Mechanical properties of functionalized carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z Q; Liu, B; Chen, Y L; Hwang, K C [FML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Jiang, H [Department of Mechanical and Aerospace Engineering, Arizona State University, Tempe, AZ 85287 (United States); Huang, Y [Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208 (United States)], E-mail: liubin@tsinghua.edu.cn, E-mail: y-huang@northwestern.edu

    2008-10-01

    Carbon nanotubes (CNTs) used to reinforce polymer matrix composites are functionalized to form covalent bonds with the polymer in order to enhance the CNT/polymer interfaces. These bonds destroy the perfect atomic structures of a CNT and degrade its mechanical properties. We use atomistic simulations to study the effect of hydrogenization on the mechanical properties of single-wall carbon nanotubes. The elastic modulus of CNTs gradually decreases with the increasing functionalization (percentage of C-H bonds). However, both the strength and ductility drop sharply at a small percentage of functionalization, reflecting their sensitivity to C-H bonds. The cluster C-H bonds forming two rings leads to a significant reduction in the strength and ductility. The effect of carbonization has essentially the same effect as hydrogenization.

  12. Core collapse supernova remnants with ears

    CERN Document Server

    Grichener, Aldana

    2016-01-01

    We study the morphologies of core collapse supernova remnants (CCSNRs) and find that about third of CCSNRs have two opposite `ears' protruding from their main shell, and that the typical energy that is required to inflate these ears is about 10 percents of the explosion kinetic energy. We argue that these properties are most compatible with the expectation from the explosion jet feedback mechanism (JFM). Based on previous studies of ears in CCSNRs and the similarity of some ears to those found in planetary nebulae, we assume that the ears are inflated by jets that are launched during the explosion, or a short time after it. In the JFM explosion process the last jets' launching episode takes place just after the core has been ejected. These jets expand freely, interact with the exploding gas at some distance from the center, and form the ears. Under simple geometrical assumptions we find that the extra kinetic energy of the ears is in the range of 1 to 10 percents of the explosion energy. As not all of the kin...

  13. Hearables: Multimodal physiological in-ear sensing

    CERN Document Server

    Goverdovsky, Valentin; Nakamura, Takashi; Looney, David; Sharp, David J; Papavassiliou, Christos; Morrell, Mary J; Mandic, Danilo P

    2016-01-01

    Future health systems require the means to assess and track the neural and physiological function of a user over long periods of time and in the community. Human body responses are manifested through multiple modalities, such as the mechanical, electrical and chemical; yet current physiological monitors (actigraphy, heart rate) largely lack in both the desired cross-modal and non-stigmatizing aspects. We address these challenges through an inconspicuous and comfortable earpiece, equipped with miniature multimodal sensors, which benefits from the relatively stable position of the ear canal with respect to vital organs to robustly measure the brain, cardiac and respiratory functions. Comprehensive experiments validate each modality within the proposed earpiece, while its potential in health monitoring is illustrated through case studies. We further demonstrate how combining data from multiple sensors within such an integrated wearable device improves both the accuracy of measurements and the ability to deal wit...

  14. Minimally invasive ear reshaping with a 1450-nm diode laser using cryogen spray cooling in New Zealand white rabbits.

    Science.gov (United States)

    Holden, Paul K; Chlebicki, Cara; Wong, Brian J F

    2009-01-01

    Otoplasty is the current standard of care for treating prominent ears, a psychologically and sometimes functionally disabling disorder. The technically demanding procedure carries many risks such as poor aesthetic outcome, need for revision surgery, and need for general anesthesia. This study investigates the use of laser irradiation combined with cryogen skin cooling and stenting to reshape cartilage in the ears of New Zealand white rabbits. In this prospective, randomized, internally controlled animal study, the right ears of 9 rabbits were mechanically deformed with a jig and then irradiated with a 1450-nm diode laser combined with cryogen skin cooling (14 J/pulse with cryogen spray for 33 milliseconds per cycle and a 6-mm spot size). The left ear served as the control. The ears were splinted for 1, 3, or 4 weeks. The rabbits were then given a lethal dose of intravenous pentobarbital, and the splints were removed and ears examined and photographed. Light and confocal microscopy were performed on the specimens. Shape change was observed in all 9 treated rabbit ears, while none of the control ears (stenting alone) showed significant change. Qualitatively, reshaped ears were stiffer after 4 weeks of splinting than after 1 or 3 weeks. None of the rabbits showed evidence of skin injury nor did they show signs of postprocedural pain. Findings from histologic analysis in the treated areas showed evidence of an expanded chondrocyte population in the region of laser irradiation, along with some perichondrial thickening and some fibrosis of the deep dermis. Confocal microscopy revealed minimal cellular death at 1 week and none thereafter. Cartilage reshaping using laser energy can be performed safely transcutaneously using cryogen spray cooling in rabbits. This animal model has similarity to human ears with regard to skin and cartilage thickness and is a stepping stone toward developing minimally invasive laser auricle reshaping in humans.

  15. Clathrin-independent endocytosis: mechanisms and function

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; Pust, Sascha; Skotland, Tore

    2011-01-01

    a large fraction of the clathrin-independent uptake is dynamin-independent. Today, two decades later, the field has developed considerably. New techniques have enabled a detailed analysis of several clathrin-independent endocytic mechanisms, and caveolae have been found to be mostly stable structures...... having several functions of their own. This article aims at providing a brief update on the importance of clathrin-independent endocytic mechanisms, how the processes are regulated differentially, for instance on the poles of polarized cells, and the challenges in studying them....

  16. Ear Problems in Swimmers

    Directory of Open Access Journals (Sweden)

    Mao-Che Wang

    2005-08-01

    Full Text Available Acute diffuse otitis externa (swimmer's ear, otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  17. Ear problems in swimmers.

    Science.gov (United States)

    Wang, Mao-Che; Liu, Chia-Yu; Shiao, An-Suey; Wang, Tyrone

    2005-08-01

    Acute diffuse otitis externa (swimmer's ear), otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  18. Commissioning of n_TOF EAR2

    CERN Multimedia

    The construction of the second beam line and experiment area (EAR2) of the n_TOF facility is currently ongoing and scheduled to be completed by July 2014. An extensive series of measurements is planned in order to determine the beam characteristics like the neutron flux, the spatial beam profile and the resolution function, as well as the response of several detectors considered for use in future measurements at EAR2. A rigorous study of backgrounds will be undertaken in various conditions.

  19. What middle ear parameters tell about impedance matching and high frequency hearing.

    Science.gov (United States)

    Hemilä, S; Nummela, S; Reuter, T

    1995-05-01

    Acoustic energy enters the mammalian cochlea aided by an anatomical impedance matching performed by the middle ear. The purpose of this paper is to analyse the functional consequences of changes in scale of the middle ear when going from the smallest mammals to the largest. Our anatomical measurements in mammals of different sizes ranging from bats to elephants indicate that middle ear proportions are largely isometric. Thus the calculated transformer ratio is basically independent of animal size, a typical value lying between 30 and 80. Similarly, the calculated specific acoustic input impedance of the inner ear is independent of animal size, the average value being about 140 kPa s/m. We show that if the high frequency hearing limit of isometric ears is limited by ossicle inertia, it should be inversely proportional to the cubic root of the ossicular mass. This prediction is in reasonable agreement with published audiogram data. We then present a three-parameter model of the middle ear where some obvious deviations from perfect isometry are taken into account. The high frequency hearing limits of different species generally agree well with the predictions of this simple model. However, the hearing limits of small rodents clearly deviate from the model calculation. We interpret this observation as indicating that the hearing limit towards very high frequencies may be set by cochlear transduction mechanisms. Further we discuss the exceptional high frequency hearing of the cat and the amphibious hearing of seals.

  20. Signaling regulating inner ear development: cell fate determination, patterning, morphogenesis, and defects.

    Science.gov (United States)

    Nakajima, Yuji

    2015-02-01

    The membranous labyrinth of the inner ear is a highly complex organ that detects sound and balance. Developmental defects in the inner ear cause congenital hearing loss and balance disorders. The membranous labyrinth consists of three semicircular ducts, the utricle, saccule, and endolymphatic ducts, and the cochlear duct. These complex structures develop from the simple otic placode, which is established in the cranial ectoderm adjacent to the neural crest at the level of the hindbrain at the early neurula stage. During development, the otic placode invaginates to form the otic vesicle, which subsequently gives rise to neurons for the vestibulocochlear ganglion, the non-sensory and sensory epithelia of the membranous labyrinth that includes three ampullary crests, two maculae, and the organ of Corti. Combined paracrine and autocrine signals including fibroblast growth factor, Wnt, retinoic acid, hedgehog, and bone morphogenetic protein regulate fate determination, axis formation, and morphogenesis in the developing inner ear. Juxtacrine signals mediated by Notch pathways play a role in establishing the sensory epithelium, which consists of mechanosensory hair cells and supporting cells. The highly differentiated organ of Corti, which consists of uniformly oriented inner/outer hair cells and specific supporting cells, develops during fetal development. Developmental alterations/arrest causes congenital malformations in the inner ear in a spatiotemporal-restricted manner. A clearer understanding of the mechanisms underlying inner ear development is important not only for the management of patients with congenital inner ear malformations, but also for the development of regenerative therapy for impaired function.

  1. A genome-wide linkage and association study of musical aptitude identifies loci containing genes related to inner ear development and neurocognitive functions

    Science.gov (United States)

    Oikkonen, J.; Huang, Y.; Onkamo, P.; Ukkola-Vuoti, L.; Raijas, P.; Karma, K.; Vieland, V. J.; Järvelä, I.

    2014-01-01

    Humans have developed the perception, production and processing of sounds into the art of music. A genetic contribution to these skills of musical aptitude has long been suggested. We performed a genome-wide scan in 76 pedigrees (767 individuals) characterized for the ability to discriminate pitch (SP), duration (ST) and sound patterns (KMT), which are primary capacities for music perception. Using the Bayesian linkage and association approach implemented in program package KELVIN, especially designed for complex pedigrees, several SNPs near genes affecting the functions of the auditory pathway and neurocognitive processes were identified. The strongest association was found at 3q21.3 (rs9854612) with combined SP, ST and KMT test scores (COMB). This region is located a few dozen kilobases upstream of the GATA binding protein 2 (GATA2) gene. GATA2 regulates the development of cochlear hair cells and the inferior colliculus (IC), which are important in tonotopic mapping. The highest probability of linkage was obtained for phenotype SP at 4p14, located next to the region harboring the protocadherin 7 gene, PCDH7. Two SNPs rs13146789 and rs13109270 of PCDH7 showed strong association. PCDH7 has been suggested to play a role in cochlear and amygdaloid complexes. Functional class analysis showed that inner ear and schizophrenia related genes were enriched inside the linked regions. This study is the first to show the importance of auditory pathway genes in musical aptitude. PMID:24614497

  2. Functional Toxicogenomics: Mechanism-Centered Toxicology

    Directory of Open Access Journals (Sweden)

    Chris D. Vulpe

    2010-11-01

    Full Text Available Traditional toxicity testing using animal models is slow, low capacity, expensive and assesses a limited number of endpoints. Such approaches are inadequate to deal with the increasingly large number of compounds found in the environment for which there are no toxicity data. Mechanism-centered high-throughput testing represents an alternative approach to meet this pressing need but is limited by our current understanding of toxicity pathways. Functional toxicogenomics, the global study of the biological function of genes on the modulation of the toxic effect of a compound, can play an important role in identifying the essential cellular components and pathways involved in toxicity response. The combination of the identification of fundamental toxicity pathways and mechanism-centered targeted assays represents an integrated approach to advance molecular toxicology to meet the challenges of toxicity testing in the 21st century.

  3. Swimmer's Ear (For Parents)

    Science.gov (United States)

    ... Child What Kids Say About: Handling Stress Anxiety, Fears, and Phobias Community Service: A Family's Guide to ... can drain into the ear canal through a hole in the eardrum and cause it. What Are ...

  4. Travel Inside the Ear

    Medline Plus

    Full Text Available ... stirrup. These are the smallest bones in your body. Together they are smaller than an orange seed. It then travels into the inner ear, which ... organizations Related Topics ...

  5. Travel Inside the Ear

    Medline Plus

    Full Text Available Skip to main content U.S. Department of Health & Human Services National Institutes of Health Search Search form Search A–Z Index Español Menu Home Health Info Hearing, Ear Infections, and Deafness ...

  6. Ototoxicity (Ear Poisoning) (For Parents)

    Science.gov (United States)

    ... Teaching Kids to Be Smart About Social Media Ototoxicity (Ear Poisoning) KidsHealth > For Parents > Ototoxicity (Ear Poisoning) Print A A A What's in ... result of taking the drugs. This is called ototoxicity or " ear poisoning ." Ototoxicity damages the inner ear — ...

  7. Sports injuries of the ear.

    Science.gov (United States)

    Wagner, G A

    1972-07-01

    The author describes common sports injuries involving the ear. Such injuries include hematoma, lacerations, foreign bodies (tattoo), and thermal injuries. Ear canal injuries include swimmer's ear and penetrating injuries. Tympanum injuries include tympanic membrane perforations, ossicular discontinuity, eustachian tube dysfunction, temporal bone fractures and traumatic facial nerve palsy. Inner ear injuries include traumatic sensorineural deafness. The author emphasizes the management of these injuries.

  8. Flying and Your Child's Ears

    Science.gov (United States)

    ... Media Flying and Your Child's Ears KidsHealth > For Parents > Flying and Your Child's Ears Print A A A What's in this article? Flying's Effects on Ears Tips for Easing Ear Pain en español Como cuidar los oídos de su hijo(a) cuando vuele en avión Flying's Effects on ...

  9. In vivo areal modulus of elasticity estimation of the human tympanic membrane system: modelling of middle ear mechanical function in normal young and aged ears

    DEFF Research Database (Denmark)

    Gaihede, Michael Lyhne; Donghua, Liao; Gregersen, H.

    2007-01-01

    are related to these, but studies are few and mostly not comparable. The elastic properties of membranes can be described by the areal modulus, and these may also be susceptible to age-related changes reflected by changes in the areal modulus. The areal modulus is determined by the relationship between...... a younger (n = 10) and an older (n = 10) group of normal subjects. The areal modulus for lateral and medial displacement of the tympanic membrane system was smaller in the older group (mean = 0.686 and 0.828 kN m(-1), respectively) compared to the younger group (mean = 1.066 and 1.206 kN m(-1), respectively...... finite element analyses. In vivo estimates of Young's modulus in this study were a factor 2-3 smaller than previously found in vitro. No significant age-related differences were found in the elastic properties as expressed by the areal modulus....

  10. Ototoxicidade e otoproteção em orelha interna de cobaias utilizando gentamicina e amicacina: aspectos ultra-estruturais e funcionais Ototoxicity and otoprotection in the inner ear of guinea pigs using gentamicin and amikacin: ultrastructural and functional aspects

    Directory of Open Access Journals (Sweden)

    Thomaz José Marra de Aquino

    2008-12-01

    Full Text Available A ototoxicidade ainda é um desafio para medicina. A descoberta dos mecanismos endógenos autoprotetores das células ciliadas externas associados a métodos de avaliação funcional e ultra-estrutural das mesmas abriu nova perspectiva no entendimento e controle destes mecanismos. OBJETIVO: O trabalho objetivou determinar se subdoses de gentamicina protegia contra ototoxicidade da amicacina baseado nestes mecanismos e determinar se a amplitude das emissões otoacústicas teria correlação com grau de integridade das células ciliadas. MATERIAL E MÉTODO: Estudo experimental. Utilizando 31 cobaias, administrou-se soro fisiológico, gentamicina e amicacina, isoladamente e associadas, via intramuscular, por 12, 30 e 42 dias. Pesquisa de emissões otoacústicas foi realizada no início e final do experimento, comparado com estudo da integridade coclear, por microscopia eletrônica. RESULTADOS: Subdoses de gentamicina não protegeram a orelha interna contra toxicidade da amicacina; diminuições da amplitude das emissões otoacústicas apresentaram forte correlação com aumento de lesões das células ciliadas. CONCLUSÃO: Os achados contribuem para o entendimento dos mecanismos de ototoxicidade e otoproteção da orelha interna. A determinação da correlação entre amplitude de emissões e integridade celular tem grande importância no acompanhamento das lesões de células ciliadas, com possível aplicação no monitoramento de ototoxicidade por drogas em humanos.Ototoxicity is still a challenge to medicine. The discovery of self-protecting endogenous mechanisms of the outer hair cells associated with their functional and ultra-structural assessment methods has opened new horizons in the understanding and controlling of these mechanisms. AIM: this paper aimed at establishing whether or not underdoses of gentamicin could protect the inner ear against the harmful effects of amikacin, based on these protection mechanisms and determine if the

  11. Intercellular Ca2+ Waves: Mechanisms and Function

    Science.gov (United States)

    Sanderson, Michael J.

    2012-01-01

    Intercellular calcium (Ca2+) waves (ICWs) represent the propagation of increases in intracellular Ca2+ through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca2+ from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs. PMID:22811430

  12. Impact of Placement of In-the-Ear Antenna on Ear-to-Ear Path Gain

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper;

    2015-01-01

    An in-the-ear antenna is rotated in the concha. For the different placements the ear-to-ear path gain is simulated and measured. The simulations and measurements show that the ear-to-ear path gain varies with more than 15 dB even though it is the same antenna that occupies the same volume, which...... has only been rotated. This illustrates the importance of the correct placement of the antenna. The variation of the ear-to-ear path gain is compared with the far-field efficiency in order to explain part of the variation. The best and worst placements’ radiation patterns are analyzed....

  13. Inner ear disturbances related to middle ear inflammation

    Science.gov (United States)

    Sone, Michihiko

    2017-01-01

    ABSTRACT The inner and middle ear are connected mainly through round and oval windows, and inflammation in the middle ear cavity can spread into the inner ear, which might induce a disturbance. In cases with intractable otitis media, attention should also be paid to symptoms related to the inner ear. In this paper, middle ear inflammation and related inner ear disturbances are reviewed with a focus on representative middle ear diseases (such as acute otitis media, chronic otitis media, otitis media with anti-neutrophil cytoplasmic antibody-associated vasculitis, eosinophilic otitis media, cholesteatoma with labyrinthine fistula, and reflux-related otitis media). Their clinical concerns are then discussed with reference to experimental studies. In these diseases, early diagnosis and adequate treatment are required to manage not only middle ear but also inner ear conditions.

  14. Loss of MAFB Function in Humans and Mice Causes Duane Syndrome, Aberrant Extraocular Muscle Innervation, and Inner-Ear Defects.

    Science.gov (United States)

    Park, Jong G; Tischfield, Max A; Nugent, Alicia A; Cheng, Long; Di Gioia, Silvio Alessandro; Chan, Wai-Man; Maconachie, Gail; Bosley, Thomas M; Summers, C Gail; Hunter, David G; Robson, Caroline D; Gottlob, Irene; Engle, Elizabeth C

    2016-06-02

    Duane retraction syndrome (DRS) is a congenital eye-movement disorder defined by limited outward gaze and retraction of the eye on attempted inward gaze. Here, we report on three heterozygous loss-of-function MAFB mutations causing DRS and a dominant-negative MAFB mutation causing DRS and deafness. Using genotype-phenotype correlations in humans and Mafb-knockout mice, we propose a threshold model for variable loss of MAFB function. Postmortem studies of DRS have reported abducens nerve hypoplasia and aberrant innervation of the lateral rectus muscle by the oculomotor nerve. Our studies in mice now confirm this human DRS pathology. Moreover, we demonstrate that selectively disrupting abducens nerve development is sufficient to cause secondary innervation of the lateral rectus muscle by aberrant oculomotor nerve branches, which form at developmental decision regions close to target extraocular muscles. Thus, we present evidence that the primary cause of DRS is failure of the abducens nerve to fully innervate the lateral rectus muscle in early development.

  15. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Dirckx, Joris J J; Jacobsen, Henrik

    2010-01-01

    HYPOTHESIS:: Middle ear pressure (MEP) is actively regulated by both the Eustachian tube and the mastoid air cell system. BACKGROUND:: MEP is a highly significant factor involved in many clinical conditions related to otitis media. Basic knowledge on its overall regulation remains insufficient...... of these distinct mechanisms were found. CONCLUSION:: The human mastoid as well as the Eustachian tube was capable of active counter-regulation of the MEP in short-term experimental pressure changes in healthy ears. Thus, these 2 systems seemed to function in a complementary way, where the mastoid was related...

  16. Consequences of early adverse rearing experience (EARE) on development: insights from non-human primate studies

    Science.gov (United States)

    Zhang, Bo

    2017-01-01

    Early rearing experiences are important in one's whole life, whereas early adverse rearing experience (EARE) is usually related to various physical and mental disorders in later life. Although there were many studies on human and animals, regarding the effect of EARE on brain development, neuroendocrine systems, as well as the consequential mental disorders and behavioral abnormalities, the underlying mechanisms remain unclear. Due to the close genetic relationship and similarity in social organizations with humans, non-human primate (NHP) studies were performed for over 60 years. Various EARE models were developed to disrupt the early normal interactions between infants and mothers or peers. Those studies provided important insights of EARE induced effects on the physiological and behavioral systems of NHPs across life span, such as social behaviors (including disturbance behavior, social deficiency, sexual behavior, etc), learning and memory ability, brain structural and functional developments (including influences on neurons and glia cells, neuroendocrine systems, e.g., hypothalamic-pituitary-adrenal (HPA) axis, etc). In this review, the effects of EARE and the underlying epigenetic mechanisms were comprehensively summarized and the possibility of rehabilitation was discussed. PMID:28271667

  17. Design of a dynamic sensor inspired by bat ears

    Science.gov (United States)

    Müller, Rolf; Pannala, Mittu; Reddy, O. Praveen K.; Meymand, Sajjad Z.

    2012-09-01

    In bats, the outer ear shapes act as beamforming baffles that create a spatial sensitivity pattern for the reception of the biosonar signals. Whereas technical receivers for wave-based signals usually have rigid geometries, the outer ears of some bat species, such as horseshoe bats, can undergo non-rigid deformations as a result of muscular actuation. It is hypothesized that these deformations provide the animals with a mechanism to adapt their spatial hearing sensitivity on short, sub-second time scales. This biological approach could be of interest to engineering as an inspiration for the design of beamforming devices that combine flexibility with parsimonious implementation. To explore this possibility, a biomimetic dynamic baffle was designed based on a simple shape overall geometry based on an average bat ear. This shape was augmented with three different biomimetic local shape features, a ridge on its exposed surface as well as a flap and an incision along its rim. Dynamic non-rigid deformations of the shape were accomplished through a simple actuation mechanism based on linear actuation inserted at a single point. Despite its simplicity, the prototype device was able to reproduce the dynamic functional characteristics that have been predicted for its biological paragon in a qualitative fashion.

  18. [Inner Ear Hearing Loss].

    Science.gov (United States)

    Hesse, G

    2016-06-01

    Hearing loss is one of the most dominant handicaps in modern societies, which additionally very often is not realized or not admitted. About one quarter of the general population suffers from inner ear hearing loss and is therefore restricted in communicational skills. Demographic factors like increasing age play an important role as well as environmental influences and an increasing sound and noise exposure especially in leisure activities. Thus borders between a "classical" presbyacusis - if it ever existed - and envirionmentally induced hearing loss disappear. Today restrictions in hearing ability develop earlier in age but at the same time they are detected and diagnosed earlier. This paper can eventually enlighten the wide field of inner ear hearing loss only fragmentarily; therefore mainly new research, findings and developments are reviewed. The first part discusses new aspects of diagnostics of inner ear hearing loss and different etiologies.

  19. Dynamin: characteristics, mechanism of action and function.

    Science.gov (United States)

    Wiejak, Jolanta; Wyroba, Elzbieta

    2002-01-01

    Dynamin - a member of the GTP-ase protein family - is essential for many intracellular membrane trafficking events in multiple endocytic processes. The unique biochemical features of dynamin - especially its propensity to assemble - enable severing the nascent vesicles from the membrane. The mechanism of dynamin's action is still a subject of debate - whether it functions as a mechanochemical enzyme or a regulatory GTPase. The GTPase domain of dynamin contains three GTP-binding motifs. This domain is very conservative across the species, including that recently cloned by us in the unicellular eukaryote Paramecium. Dynamin interacts with a number of partners such as endophilin and proteins involved in coordination of endocytosis with motor molecules. A growing body of evidence indicates that dynamin and dynamin-related proteins are involved both in pathology and protection against human diseases. The most interesting are dynamin-like Mx proteins exhibiting antiviral activity.

  20. Measuring directional characteristics of in-ear recording devices

    DEFF Research Database (Denmark)

    Christensen, Flemming; Hoffmann, Pablo F.; Hammershøi, Dorte

    2013-01-01

    With the availability of small in-ear headphones and miniature microphones it is possible to construct combined in-ear devices for binaural recording and playback. When mounting a microphone on the outside of an insert earphone the microphone position deviates from ideal positions in the ear canal....... The pinna and thereby also the natural sound transmission are altered by the inserted device. This paper presents a methodology for accurately measuring the directional dependent transfer functions of such in-ear devices. Pilot measurements on a commercial available device are presented and possibilities...

  1. The Application of Virtual Reality Technology to Ear Microsurgery

    Institute of Scientific and Technical Information of China (English)

    谢叻; 戴培东; 张天宇; 周印; 魏安顺; 王克强; 金德才; 李树峰; 王正敏

    2004-01-01

    The broad application of virtual reality (VR) to medicine has been of great value. The virtual surgery is one of technically difficult applications. With the expansion of the increasingly fine and complicated ear microsurgery, new methods are required to train the doctors. It is necessary and of practical significance to apply VR to the ear micro-operation, which is a functional operation with high precision and great difficulties. In this article,medical VR applications were reviewed. The application of VR to the ear microsurgery was discussed and the virtual ear microsurgery system was designed.

  2. The Notch ligand JAG1 is required for sensory progenitor development in the mammalian inner ear.

    Directory of Open Access Journals (Sweden)

    Amy E Kiernan

    2006-01-01

    Full Text Available In mammals, six separate sensory regions in the inner ear are essential for hearing and balance function. Each sensory region is made up of hair cells, which are the sensory cells, and their associated supporting cells, both arising from a common progenitor. Little is known about the molecular mechanisms that govern the development of these sensory organs. Notch signaling plays a pivotal role in the differentiation of hair cells and supporting cells by mediating lateral inhibition via the ligands Delta-like 1 and Jagged (JAG 2. However, another Notch ligand, JAG1, is expressed early in the sensory patches prior to cell differentiation, indicating that there may be an earlier role for Notch signaling in sensory development in the ear. Here, using conditional gene targeting, we show that the Jag1 gene is required for the normal development of all six sensory organs within the inner ear. Cristae are completely lacking in Jag1-conditional knockout (cko mutant inner ears, whereas the cochlea and utricle show partial sensory development. The saccular macula is present but malformed. Using SOX2 and p27kip1 as molecular markers of the prosensory domain, we show that JAG1 is initially expressed in all the prosensory regions of the ear, but becomes down-regulated in the nascent organ of Corti by embryonic day 14.5, when the cells exit the cell cycle and differentiate. We also show that both SOX2 and p27kip1 are down-regulated in Jag1-cko inner ears. Taken together, these data demonstrate that JAG1 is expressed early in the prosensory domains of both the cochlear and vestibular regions, and is required to maintain the normal expression levels of both SOX2 and p27kip1. These data demonstrate that JAG1-mediated Notch signaling is essential during early development for establishing the prosensory regions of the inner ear.

  3. A Model for the representation of Speech Signals in Normal and Impaired Ears

    DEFF Research Database (Denmark)

    Christiansen, Thomas Ulrich

    2004-01-01

    A model of human auditory periphery, ranging from the outer ear to the auditory nerve, was developed. The model consists of the following components: outer ear transfer function, middle ear transfer function, basilar membrane velocity, inner hair cell receptor potential, inner hair cell probabili...

  4. From Ear to Brain

    Science.gov (United States)

    Kimura, Doreen

    2011-01-01

    In this paper Doreen Kimura gives a personal history of the "right-ear effect" in dichotic listening. The focus is on the early ground-breaking papers, describing how she did the first dichotic listening studies relating the effects to brain asymmetry. The paper also gives a description of the visual half-field technique for lateralized stimulus…

  5. Seeing With the Ears

    NARCIS (Netherlands)

    Koenderink, Jan

    2015-01-01

    In recent talks, I mentioned how my artist friends often complain that their clients see with their ears. It recently dawned on me that nobody understood what I said, or—worse—got the wrong idea. The audience thinks of bionic devices (Proulx, Stoerig, Ludowig, & Knoll, 2008) or bat echo location (Mo

  6. Fgf19 expression patterns in the developing chick inner ear.

    Science.gov (United States)

    Sánchez-Calderón, Hortensia; Francisco-Morcillo, Javier; Martín-Partido, Gervasio; Hidalgo-Sánchez, Matías

    2007-01-01

    The inner ear is a complex sensorial structure with hearing and balance functions. A key aim of developmental biology is to understand the molecular and cellular mechanisms involved in the induction, patterning and innervation of the vertebrate inner ear. These developmental events could be mediated by the expression of regulating genes, such as the members of the family of Fibroblast Growth Factors (Fgfs). This work reports the detailed spatial and temporal patterns of Fgf19 expression in the developing inner ear from otic cup (stage 14) to 8 embryonic days (stage 34). In the earliest stages, Fgf19 and Fgf8 expressions determine two subdomains within the Fgf10-positive proneural-sensory territory. We show that, from the earliest stages, the Fgf19 expression was detected in the acoustic-vestibular ganglion and the macula utriculi. The Fgf19 gene was also strongly, but transiently, expressed in the macula lagena, whereas the macula neglecta never expressed this gene in the period analysed. The Fgf19 expression was also clearly observed in some borders of various sensory elements. These results could be useful from further investigations into the role of FGF19 in otic patterning.

  7. Low-set ears and pinna abnormalities

    Science.gov (United States)

    Low-set ears; Microtia; "Lop" ear; Pinna abnormalities; Genetic defect-pinna; Congenital defect-pinna ... conditions: Abnormal folds or location of the pinna Low-set ears No opening to the ear canal ...

  8. Ear, Nose & Throat Issues & Down Syndrome

    Science.gov (United States)

    ... Throat Issues & Down Syndrome Ear, Nose & Throat Issues & Down Syndrome Ear, nose, and throat (ENT) problems are common ... What ENT Problems Are Common in Children With Down Syndrome? External Ear Canal Stenosis Stenotic ear canals (narrow ...

  9. The analysis of ear canals

    Science.gov (United States)

    Ou, Gen

    In this thesis complex 3-D ear canal finite element models are simplified using transfer matrices to 1-D models. This simplification allows analysis on the sound propagation in the ear, which results in potentially using a non-invasive probe to determine the acoustical properties of the ear.

  10. Passive and active middle ear implants

    Directory of Open Access Journals (Sweden)

    Beutner, Dirk

    2009-01-01

    Full Text Available Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants.

  11. The plastic ear and perceptual relearning in auditory spatial perception.

    Science.gov (United States)

    Carlile, Simon

    2014-01-01

    The auditory system of adult listeners has been shown to accommodate to altered spectral cues to sound location which presumably provides the basis for recalibration to changes in the shape of the ear over a life time. Here we review the role of auditory and non-auditory inputs to the perception of sound location and consider a range of recent experiments looking at the role of non-auditory inputs in the process of accommodation to these altered spectral cues. A number of studies have used small ear molds to modify the spectral cues that result in significant degradation in localization performance. Following chronic exposure (10-60 days) performance recovers to some extent and recent work has demonstrated that this occurs for both audio-visual and audio-only regions of space. This begs the questions as to the teacher signal for this remarkable functional plasticity in the adult nervous system. Following a brief review of influence of the motor state in auditory localization, we consider the potential role of auditory-motor learning in the perceptual recalibration of the spectral cues. Several recent studies have considered how multi-modal and sensory-motor feedback might influence accommodation to altered spectral cues produced by ear molds or through virtual auditory space stimulation using non-individualized spectral cues. The work with ear molds demonstrates that a relatively short period of training involving audio-motor feedback (5-10 days) significantly improved both the rate and extent of accommodation to altered spectral cues. This has significant implications not only for the mechanisms by which this complex sensory information is encoded to provide spatial cues but also for adaptive training to altered auditory inputs. The review concludes by considering the implications for rehabilitative training with hearing aids and cochlear prosthesis.

  12. The plastic ear and perceptual relearning in auditory spatial perception.

    Directory of Open Access Journals (Sweden)

    Simon eCarlile

    2014-08-01

    Full Text Available The auditory system of adult listeners has been shown to accommodate to altered spectral cues to sound location which presumably provides the basis for recalibration to changes in the shape of the ear over a life time. Here we review the role of auditory and non-auditory inputs to the perception of sound location and consider a range of recent experiments looking at the role of non-auditory inputs in the process of accommodation to these altered spectral cues. A number of studies have used small ear moulds to modify the spectral cues that result in significant degradation in localization performance. Following chronic exposure (10-60 days performance recovers to some extent and recent work has demonstrated that this occurs for both audio-visual and audio-only regions of space. This begs the questions as to the teacher signal for this remarkable functional plasticity in the adult nervous system. Following a brief review of influence of the motor state in auditory localisation, we consider the potential role of auditory-motor learning in the perceptual recalibration of the spectral cues. Several recent studies have considered how multi-modal and sensory-motor feedback might influence accommodation to altered spectral cues produced by ear moulds or through virtual auditory space stimulation using non-individualised spectral cues. The work with ear moulds demonstrates that a relatively short period of training involving sensory-motor feedback (5 – 10 days significantly improved both the rate and extent of accommodation to altered spectral cues. This has significant implications not only for the mechanisms by which this complex sensory information is encoded to provide a spatial code but also for adaptive training to altered auditory inputs. The review concludes by considering the implications for rehabilitative training with hearing aids and cochlear prosthesis.

  13. Genome-Wide Scan Reveals LEMD3 and WIF1 on SSC5 as the Candidates for Porcine Ear Size

    Science.gov (United States)

    Luo, Weizhen; Liu, Xin; Yan, Hua; Zhao, Kebin; Shi, Huibi; Zhang, Yuebo; Wang, Ligang; Wang, Lixian

    2014-01-01

    The quantitative trait loci (QTL) for porcine ear size was previously reported to mainly focus on SSC5 and SSC7. Recently, a missense mutation, G32E, in PPARD in the QTL interval on SSC7 was identified as the causative mutation for ear size. However, on account of the large interval of QTL, the responsible gene on SSC5 has not been identified. In this study, an intercross population was constructed from the large-eared Minzhu, an indigenous Chinese pig breed, and the Western commercial Large White pig to examine the genetic basis of ear size diversity. A GWAS was performed to detect SNPs significantly associated with ear size. Thirty-five significant SNPs defined a 10.78-Mb (30.14–40.92 Mb) region on SSC5. Further, combining linkage disequilibrium and haplotype sharing analysis, a reduced region of 3.07-Mb was obtained. Finally, by using a selective sweep analysis, a critical region of about 450-kb interval containing two annotated genes LEMD3 and WIF1 was refined in this work. Functional analysis indicated that both represent biological candidates for porcine ear size, with potential application in breeding programs. The two genes could also be used as novel references for further study of the mechanism underlying human microtia. PMID:25006967

  14. Genome-wide scan reveals LEMD3 and WIF1 on SSC5 as the candidates for porcine ear size.

    Science.gov (United States)

    Zhang, Longchao; Liang, Jing; Luo, Weizhen; Liu, Xin; Yan, Hua; Zhao, Kebin; Shi, Huibi; Zhang, Yuebo; Wang, Ligang; Wang, Lixian

    2014-01-01

    The quantitative trait loci (QTL) for porcine ear size was previously reported to mainly focus on SSC5 and SSC7. Recently, a missense mutation, G32E, in PPARD in the QTL interval on SSC7 was identified as the causative mutation for ear size. However, on account of the large interval of QTL, the responsible gene on SSC5 has not been identified. In this study, an intercross population was constructed from the large-eared Minzhu, an indigenous Chinese pig breed, and the Western commercial Large White pig to examine the genetic basis of ear size diversity. A GWAS was performed to detect SNPs significantly associated with ear size. Thirty-five significant SNPs defined a 10.78-Mb (30.14-40.92 Mb) region on SSC5. Further, combining linkage disequilibrium and haplotype sharing analysis, a reduced region of 3.07-Mb was obtained. Finally, by using a selective sweep analysis, a critical region of about 450-kb interval containing two annotated genes LEMD3 and WIF1 was refined in this work. Functional analysis indicated that both represent biological candidates for porcine ear size, with potential application in breeding programs. The two genes could also be used as novel references for further study of the mechanism underlying human microtia.

  15. Anteverted concha: A new ear deformational anomaly

    Directory of Open Access Journals (Sweden)

    Fabrizio Schönauer

    2015-09-01

    Full Text Available Most auricular deformities involve the helix and the antihelix (Stahl's bar, lop and prominent ear; an isolated conchal deformity is uncommon in an otherwise normal ear. When a convexity rather than a concavity of the concha is present, it can be defined as “anteverted concha”. The anteverted concha causes not only aesthetic but also functional problems. It may be so severe as to occlude the external auditory meatus. In a newborn ear amenable to moulding, anteverted concha can be treated non-surgically by splinting. If this time window has passed, then surgical excision of the conchal bulge can give good results in the adult. We present two such cases and their treatment.

  16. The contralateral ear in cholesteatoma.

    Science.gov (United States)

    da Costa, Sady Selaimen; Teixeira, Adriane Ribeiro; Rosito, Letícia Petersen Schmidt

    2016-07-01

    Middle ear cholesteatoma has been extensively studied. Theories of cholesteatoma pathogenesis involving previous tympanic membrane retraction are the most widely accepted, but the contralateral ear in patients with cholesteatoma remains unstudied. This study aimed to investigate the contralateral ear in patients with cholesteatoma, and to determine whether the characteristics of it differ according to patient age and cholesteatoma growth patterns. This study was cross sectional. We evaluated 356 patients with middle ear cholesteatoma in at least one ear, and no history of surgery, between August 2000 and March 2013. Otoendoscopy was conducted on both the affected and the contralateral ear. They were classified as normal, tympanic membrane perforation, moderate to severe tympanic membrane retraction and cholesteatoma. The mean age of the patients was 32.77 years, and 53.1 % of the cohort were female. Only 34.8 % of the contralateral ears were normal. The most common abnormality was moderate to severe tympanic membrane retraction (41.6 %). Cholesteatoma was identified in 16 %. Children exhibited a greater frequency of tympanic membrane retractions, whereas adults exhibited a greater frequency of cholesteatoma. All of the contralateral ears in the anterior epitympanic group were normal, but otherwise there were no differences in the contralateral ear when we compared the cholesteatoma growth patterns. We conclude that patients diagnosed with acquired cholesteatoma of one ear are significantly more likely to exhibit abnormalities of the contralateral ear.

  17. nEar 05

    Institute of Scientific and Technical Information of China (English)

    S&C Labs

    2005-01-01

    Ego Systems简称ESI或Ego-Sys,这问韩国公司一向以制造低价格、高性能的专业音频产品闻名于专业音频制作领域。其产品涵盖了专业录音卡、监听音箱和USB声卡等。在大家的印象中,可能还记得MAYA录音卡、nEar 08监听音箱,以及MAYA EX系列USB声卡。其中,nEar08监听音箱曾在本刊2001年第18期报道过,那是它首次在国内媒体上亮相。经过四年多的市场检验,

  18. Darwin's Eclipse Concerned Function versus Mechanism

    Science.gov (United States)

    Tryon, Warren W.

    2009-01-01

    Comments on a article by Dewsbury (February-March 2009) in which he stated, "Darwin provided a viable mechanism for evolutionary change, natural selection" (p. 67). Although this view is consistent with the modern synthesis, the author argues that (a) the natural selection "mechanism" provided by Darwin was not initially accepted by scientists…

  19. Darwin's Eclipse Concerned Function versus Mechanism

    Science.gov (United States)

    Tryon, Warren W.

    2009-01-01

    Comments on a article by Dewsbury (February-March 2009) in which he stated, "Darwin provided a viable mechanism for evolutionary change, natural selection" (p. 67). Although this view is consistent with the modern synthesis, the author argues that (a) the natural selection "mechanism" provided by Darwin was not initially accepted by scientists…

  20. 耳-体穴按压治疗老年功能性便秘临床观察%Clinical Observation of eEar-body Acupoints with Acupressure Treating Senile Functional Constipation

    Institute of Scientific and Technical Information of China (English)

    张海涛; 常雪利; 乔兴国

    2013-01-01

    Objective:To investigate the clinical efficacy of ear-body acupoints with acupressure treating senile functional constipation. Methods:67 patients of senile functional constipation were randomly divided into treatment group and control group, each of 32 cases, respectively treated with ear acupoints by seeds burying combining acupressure of body acupoints and Chinese medicine, the effects of two groups were compared. Results:The total effective rates of treatment group was 94.29%, obviously higher than that of control group by 71.88%(P<0.05). Conclusion:There are bet-ter clinical efficacy of ear-body acupoints with acupressure treating senile functional constipation.%  目的:观察耳-体穴结合按压治疗老年功能性便秘的临床疗效。方法:67例年功能性便秘患者随机分为治疗组35例和对照组32例,分别采用耳穴埋籽结合体穴按压和中成药治疗,对比两组效果。结果:治疗组总有效率为94.29%,明显高于对照组的71.88%(P<0.05)。结论:耳-体穴按压治疗老年功能性便秘有较好的临床疗效。

  1. Classification and diagnosis of ear malformations

    OpenAIRE

    Bartel-Friedrich, Sylva; Wulke, Cornelia

    2008-01-01

    In the ENT region 50% of the malformations affect the ear. Malformations of the outer and middle ear are predominantly unilateral (ca. 70-90%) and mostly involve the right ear. Inner ear malformations can be unilateral or bilateral. The incidence of ear malformations is approximately 1 in 3800 newborns. Ear malformations may be genetic (associated with syndromes or not, with family history, spontaneous mutations) or acquired in nature. Malformations can affect the outer ear (pinna and externa...

  2. Major evolutionary transitions and innovations: the tympanic middle ear

    Science.gov (United States)

    2017-01-01

    One of the most amazing transitions and innovations during the evolution of mammals was the formation of a novel jaw joint and the incorporation of the original jaw joint into the middle ear to create the unique mammalian three bone/ossicle ear. In this review, we look at the key steps that led to this change and other unusual features of the middle ear and how developmental biology has been providing an understanding of the mechanisms involved. This starts with an overview of the tympanic (air-filled) middle ear, and how the ear drum (tympanic membrane) and the cavity itself form during development in amniotes. This is followed by an investigation of how the ear is connected to the pharynx and the relationship of the ear to the bony bulla in which it sits. Finally, the novel mammalian jaw joint and versatile dentary bone will be discussed with respect to evolution of the mammalian middle ear. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’. PMID:27994124

  3. Planar cell polarity in the inner ear: how do hair cells acquire their oriented structure?

    Science.gov (United States)

    Lewis, Julian; Davies, Alex

    2002-11-05

    Sensory hair cells in the ear and lateral line have an asymmetrical hair-bundle structure, essential for their function as directional mechanotransducers. We examine four questions: (1) how does the planar asymmetry of the individual hair cell originate? (2) How are the orientations of neighboring hair cells coordinated? (3) How is the orientation of a group of hair cells controlled in relation to the ear as a whole? (4) How does the initial cell asymmetry lead to creation of the asymmetrical hair bundle? Studies of the development of hairs and bristles in Drosophila, combined with genetic data from vertebrates, suggest that the answer to questions (1) and (2) lies in asymmetries that develop at the cell cortex and at cell-cell junctions, generated by products of a set of primary planar cell polarity genes, including the transmembrane receptor Frizzled. A separate and largely independent mechanism controls asymmmetric allocation of cell fate determinants such as Numb at mitosis, in Drosophila and possibly in the ear also. Little is known about long-range signals that might orient hair cells globally in the ear, but progress has been made in identifying a set of genes responsible for read-out of the primary polarity specification. These genes, in flies and vertebrates, provide a link to assembly of the polarized cytoskeleton; myosin VIIA appears to belong in this group. The mechanism creating the staircase pattern of stereocilium lengths is unknown, but could involve regulation of stereocilium growth by Ca(2+) ions entering via transduction channels.

  4. Surgical and Technical Modalities for Hearing Restoration in Ear Malformations.

    Science.gov (United States)

    Dazert, Stefan; Thomas, Jan Peter; Volkenstein, Stefan

    2015-12-01

    Malformations of the external and middle ear often go along with an aesthetic and functional handicap. Independent of additional aesthetic procedures, a successful functional hearing restoration leads to a tremendous gain in quality of life for affected patients. The introduction of implantable hearing systems (bone conduction and middle ear devices) offers new therapeutic options in this field. We focus on functional rehabilitation of patients with malformations, either by surgical reconstruction or the use of different implantable hearing devices, depending on the disease itself and the severity of malformation as well as hearing impairment. Patients with an open ear canal and minor malformations are good candidates for surgical hearing restoration of middle ear structures with passive titanium or autologous implants. In cases with complete fibrous or bony atresia of the ear canal, the most promising functional outcome and gain in quality of life can be expected with an active middle ear implant or a bone conduction device combined with a surgical aesthetic rehabilitation in a single or multi-step procedure. Although the surgical procedure for bone conduction devices is straightforward and safe, more sophisticated operations for active middle ear implants (e.g., Vibrant Soundbridge, MED-EL, Innsbruck, Austria) provide an improved speech discrimination in noise and the ability of sound localization compared with bone conduction devices where the stimulation reaches both cochleae.

  5. Acoustic impedances of ear canals measured by impedance tube

    DEFF Research Database (Denmark)

    Ciric, Dejan; Hammershøi, Dorte

    2007-01-01

    During hearing sensitivity tests, the sound field is commonly generated by an earphone placed on a subject ear. One of the factors that can affect the sound transmission in the ear is the acoustic impedance of the ear canal. Its importance is related to the contribution of other elements involved...... in the transmission such as the earphone impedance. In order to determine the acoustic impedances of human ear canals, the standardized method for measurement of complex impedances used for the measurement of the audiometric earphone impedances is applied. It is based on the transfer function between two microphone...... locations in an impedance tube. The end of the tube representing the measurement plane is placed at the ear canal entrance. Thus, the impedance seen from the entrance inward is measured on 25 subjects. Most subjects participated in the previous measurement of the ratio between the pressures at the open...

  6. [Intervention of spiral ligament fibrocytes in the metabolic regulation of the inner ear].

    Science.gov (United States)

    García Berrocal, José Ramón; Méndez-Benegassi, Iván; Martí, Cristina; Ramírez Camacho, Rafael

    2008-12-01

    Maintenance of the K(+) gradient between endolymph and perilymph is essential for normal hearing and depends primarily on the activity of the stria vascularis. Abundant Na-K-ATPase in marginal strial cells provides a pumping mechanism for preserving the K(+) level of the endolymph and consequently, the endocochlear potential. Fibrocytes in the lateral wall of the cochlea supply K(+) to the strial pump, via gap junctions, by recycling back into the stria the ions that efflux from the scala media during auditory transduction. The lateral wall of the cochlea encloses five types of fibrocytes, differentiated by their location, structural features and content of enzymes mediating or energizing ion transport. The disruption of the gap junction bonds by connexin mutations and other pathologies leads to an interruption of K(+) recirculation pathways. The expression of cochlin and otoraplin, proteins that participate in structural or regulatory functions in the inner ear, suggests more diversity and complexity of the mesenchymal tissues than envisioned previously. The presence of otospiralin, a novel protein found in fibrocytes of spiral limbus, spiral ligament and subepithelial regions of the vestibule, represent a critical finding since that protein has been shown to be essential for the survival of the hair cells and supporting cells of the inner ear. A more profound knowledge and understanding of the function of inner ear fibrocytes will provide a new and promising aetiopathogenic approach to the treatment of inner ear disorders.

  7. Consequences of early adverse rearing experience(EARE) on development: insights from non-human primate studies.

    Science.gov (United States)

    Zhang, Bo

    2017-01-18

    Early rearing experiences are important in one's whole life, whereas early adverse rearing experience(EARE) is usually related to various physical and mental disorders in later life. Although there were many studies on human and animals, regarding the effect of EARE on brain development, neuroendocrine systems, as well as the consequential mental disorders and behavioral abnormalities, the underlying mechanisms remain unclear. Due to the close genetic relationship and similarity in social organizations with humans, non-human primate(NHP) studies were performed for over 60 years. Various EARE models were developed to disrupt the early normal interactions between infants and mothers or peers. Those studies provided important insights of EARE induced effects on the physiological and behavioral systems of NHPs across life span, such as social behaviors(including disturbance behavior, social deficiency, sexual behavior, etc), learning and memory ability, brain structural and functional developments(including influences on neurons and glia cells, neuroendocrine systems, e.g., hypothalamic-pituitary-adrenal(HPA) axis, etc). In this review, the effects of EARE and the underlying epigenetic mechanisms were comprehensively summarized and the possibility of rehabilitation was discussed.

  8. Ear Recognition Based on Gabor Features and KFDA

    OpenAIRE

    Li Yuan; Zhichun Mu

    2014-01-01

    We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the s...

  9. Pressure difference receiving ears

    DEFF Research Database (Denmark)

    Michelsen, Axel; Larsen, Ole Næsbye

    2007-01-01

    of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound...... waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface...

  10. The ear: Diagnostic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vignaud, J.; Jardin, C.; Rosen, L.

    1986-01-01

    This is an English translation of volume 17-1 of Traite de radiodiagnostic and represents a reasonably complete documentation of the diseases of the temporal bone that have imaging manifestations. The book begins with chapters on embryology, anatomy and radiography anatomy; it continues with blood supply and an overview of temporal bone pathology. Subsequent chapters cover malformations, trauma, infections, tumors, postoperative changes, glomus tumors, vertebasilar insufficiency, and facial nerve canal lesions. A final chapter demonstrates and discusses magnetic resonance images of the ear and cerebellopontine angle.

  11. Mechanisms of T regulatory cell function.

    Science.gov (United States)

    Askenasy, Nadir; Kaminitz, Ayelet; Yarkoni, Shai

    2008-05-01

    Regulatory T cells (Treg) play a pivotal role in tolerance to self-antigens and tissue grafts, and suppression of autoimmune reactions. These cells modulate the intensity and quality of immune reactions through attenuation of the cytolytic activities of reactive immune cells. Treg cells operate primarily at the site of inflammation where they modulate the immune reaction through three major mechanisms: a) direct killing of cytotoxic cells through cell-to-cell contact, b) inhibition of cytokine production by cytotoxic cells, in particular interleukin-2, c) direct secretion of immunomodulatory cytokines, in particular TGF-beta and interleukin-10. In addition to differential contributions of these mechanisms under variable inflammatory conditions, mechanistic complexity and diversity evolves from the diverse tasks performed by various Treg cell subsets in different stages of the immune reaction. Here we attempt to integrate the current experimental evidence to delineate the major suppressive pathways of Treg cells.

  12. Molecular mechanisms of androgen receptor functions

    NARCIS (Netherlands)

    K. Steketee (Karine)

    2007-01-01

    textabstractThe androgens testosterone (T) and dihydrotestosterone (DHT) are steroid hormones, which are necessary for development and maintenance of the functions of the male sex organs, including the prostate. Androgens also play an important role in benign abnormalities of the prostate and in the

  13. Molecular mechanisms of androgen receptor functions

    NARCIS (Netherlands)

    K. Steketee (Karine)

    2007-01-01

    textabstractThe androgens testosterone (T) and dihydrotestosterone (DHT) are steroid hormones, which are necessary for development and maintenance of the functions of the male sex organs, including the prostate. Androgens also play an important role in benign abnormalities of the prostate and in the

  14. MICROBIOLOGY OF ITCHY EARS

    Directory of Open Access Journals (Sweden)

    Vijin Ravindran Nambiar

    2015-04-01

    Full Text Available Objective: To study microbiology of external auditory canal in patients with itchy ears and to also study susceptibility profiles of pathogenic organisms to aid in appropriate management. Materials & Methods: A total of hundred patients were selected. An external ear canal swab was taken. For recovery of bacteria, the samples were emulsified in a solution of BHI broth to study aerobic and anaerobic bacteria. Fungal microbiology was studied by KOH mount and fungal culture. Culture and sensitivity was done for the pathogenic organisms. Results: Of the total hundred patients, 48% patients had no growth. There were no anaerobes isolated. Of the remaining 52% cases, 33% of the growth was aerobic bacteria and 19% of the growth was fungi. Of the aerobic bacteria, coagulase negative staphylococcus was isolated from 22 patients, staphylococcus aureus from 9 patients and pseudomonas aeruginosa from 2 patients. Of the fungal species, candida was isolated from 11 patients and aspergillus niger from 8 patients. Conclusion: Our study concluded that there need not be an underlying bacterial or fungal infection to cause itching as evidenced by a condition called asteatosis. Hence, asteatosis should be considered as one of the differential diagnosis for chronic and persistent itching when all other causes have been ruled out. We also found that topical ciprofloxacin drops is equally effective against the common bacterial pathogens.

  15. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

    Jordan, M J; Aagaard, Per; Herzog, W

    2015-01-01

    Due to a high incidence of anterior cruciate ligament (ACL) re-injury in alpine ski racers, this study aims to assess functional asymmetry in the countermovement jump (CMJ), squat jump (SJ), and leg muscle mass in elite ski racers with and without anterior cruciate ligament reconstruction (ACL......-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs...

  16. Effect on cochlea function of guinea pig after controlled release recombinant human bone morphogenetic protein 2 transplanted into the middle ear

    Institute of Scientific and Technical Information of China (English)

    LI Xue-sheng; SUN Jian-jun; JIANG Wei; LIU Xiao

    2010-01-01

    Background The recombinant human bone morphogenetic protein 2 (rhBMP-2) has been used to induce osteogenesis in animals' middle ear and this technique is possible to be used to reconstruct the defects of ossicles. The side effects of the rhBMP-2 in middle ear should be observed before using in clinic. Thus we prepared the controlled release rhBMP-2 and implanted it into the acoustic bulla of guinea pigs. The effect on the cochlea was observed. Methods We prepared the acellular cancellous bone, accompanied with rhBMP-2. The material accompanied with rhBMP-2 was implanted into one acoustic bulla of the animal and the opposite side of the acoustic bulla was implanted with acellular cancellous bone without rhBMP-2. Totally 20 guinea pigs were undergone this procedure. After the operation, the auditory brainstem response (ABR) of the animals was tested according to the time sequence. Three months after the operation, the animals were sacrificed. The osteogenesis induced by rhBMP-2, the acoustic bulla and cochlea affected by rhBMP-2 were observed. The structures of hair cells were observed after silver nitrate staining. Results The animals were recovered soon after surgery. The hearing thresholds of the animals were declined slightly just after the surgery and come back completely after 3 months. Also, the bulla and cochlea were normal in shape. The osteogenesis occurred in the pore of the acellular cancellous bone with rhBMP-2. There was not any abnormal hyperplasia of bone in the bulla and cochlea. The articulation between the stapes and oval window was not merged. The shapes of the hair cells were normal and there was no obvious deletion of the hair cells compared with control group. Conclusions The controlled release rhBMP-2 transplanted into the middle ear could induce osteogenesis in the bulla of the animals. It did not affect the shape of the bulla and the hearing threshold of the animal, and did not induce the abnormal hyperplasia of bone in the bulla and might

  17. Osteomas of the middle ear

    Directory of Open Access Journals (Sweden)

    Sente Marko

    2004-01-01

    Full Text Available INTRODUCTION Osteomas of the middle ear are small, single, usually unilateral, peduncular growths, off-white in color, with smooth or multilobular surface, asymptomatic or causing functional disorders (progressive hearing loss, pathological appearance of the eardrum, vertigo and otorrhea, of unclear or unknown etiology. Fleury described three types of osteomas: massive, diffuse atticoantral and localized type. The therapy is surgical. Small and asymptomatic ones are followed-up. Cremers suggests surgical intervention in cases of progressive growth and increased hearing loss. Case description Discharge and pain in the left ear started twelve years ago, accompanied by impaired hearing and tinnitus. Four months ago the symptoms aggravated and discharge and pain increased. Otomicroscopic findings revealed: perforation in the posterior attic and a prominent polypous, clustered bright red formation. Schüller X-ray showed total absence of pneumocyte cells, with distinct sclerotic changes. Retroauricular access showed a biventricular bony formation in the cavum and partly in the antrum. A cholesteatoma extended from the cavum into the antrum, above the osteatoma. The bony formation was separated transmeatally from the grip in the posterior attic using a chisel, partially removing the bone wall of the exterior aural tube, removing it completely through the mastoid antrum. The removed bony mass, sized 5 x 8 x 8 mm, included also the incus. DISCUSSION Osteoma was discovered accidentally. Regarding clinical features, it belonged to the second group, due to progressive hearing loss, recurrent episodes of otorrhea, pain, biventricular shape and association with cholesteatoma. It was removed using a combined method. It was not possible to establish when the osteoma exactly started generating. It is possible that the initial complaints twelve years ago were the first signs of illness, and chronic otitis may have occurred as a consequence of the tumor.

  18. Microfluidics as a functional tool for cell mechanics

    OpenAIRE

    Vanapalli, Siva A.; Duits, Michel H.G.; Mugele, Frieder

    2009-01-01

    Living cells are a fascinating demonstration of nature’s most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax—thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remodeling of the cytoskeleton. To understand this intricate coupling between mechanical properties, mechanical function and force-induced biochemical signaling requires tools that are capable of both c...

  19. Current concepts of hair cell differentiation and planar cell polarity in inner ear sensory organs.

    Science.gov (United States)

    Sienknecht, Ulrike J

    2015-07-01

    Phylogenetically and ontogenetically, vertebrate development led to the generation of several inner ear sensory organs. During embryogenesis, cell fate specification determines whether each progenitor cell differentiates into a sensory hair cell or a supporting cell within the common sensory primordium. Finally, all sensory epithelia of the inner ear consist of a hair cell/supporting cell mosaic, albeit with anatomical differences depending on the sensory organ type. Hair cells develop a polarized bundle of stereovilli that is of functional importance for mechanotransduction. After initiating stereovillar development, hair cells align their bundles in a coordinated fashion, generating a characteristic hair cell orientation pattern, a process referred to as planar cell polarity (PCP). The pathway that controls PCP in the inner ear needs both to establish the development of a polarized morphology of the stereovillar bundle of the hair cell and to organize a systematic hair cell alignment. Because the hair cell orientation patterns of the various inner ear organs and vertebrate species differ fundamentally, it becomes apparent that in vertebrates, different aspects of PCP need to be independently controlled. In spite of important progress recently gained in the field of PCP research, we still need to identify the mechanisms (1) that initiate molecular asymmetries in cells, (2) that guide the transmission of polarity information from cell to cell, and (3) that consistently translate such polarity information into morphological asymmetries of hair cells.

  20. Biomarkers and Mechanisms of FANCD2 Function

    Directory of Open Access Journals (Sweden)

    Henning Willers

    2008-01-01

    Full Text Available Genetic or epigenetic inactivation of the pathway formed by the Fanconi anemia (FA and BRCA1 proteins occurs in several cancer types, making the affected tumors potentially hypersensitive to DNA cross-linkers and other chemotherapeutic agents. It has been proposed that the inability of FA/BRCA-defective cells to form subnuclear foci of effector proteins, such as FANCD2, can be used as a biomarker to aid individualization of chemotherapy. We show that FANCD2 inactivation not only renders cells sensitive to cross-links, but also oxidative stress, a common effect of cancer therapeutics. Oxidative stress sensitivity does not correlate with FANCD2 or RAD51 foci formation, but associates with increased γH2AX foci levels and apoptosis. Therefore, FANCD2 may protect cells against cross-links and oxidative stress through distinct mechanisms, consistent with the growing notion that the pathway is not linear. Our data emphasize the need for multiple biomarkers, such as γH2AX, FANCD2, and RAD51, to capture all pathway activities.

  1. Diving injuries to the inner ear.

    Science.gov (United States)

    Farmer, J C

    1977-01-01

    Most of the previous literature concerning otologic problems in compressed gas environments has emphasized middle ear barotrauma. With recent increases in commercial, military, and sport diving to deeper depths, inner ear disturbances during these exposures have been noted more frequently. Studies of inner ear physiology and pathology during diving indicate that the causes and treatment of these problems differ depending upon the phase and type of diving. Humans exposed to simulated depths of up to 305 meters without barotrauma or decompression sickness develop transient, conductive hearing losses with no audiometric evidence of cochlear dysfunction. Transient vertigo and nystagmus during diving have been noted with caloric stimulation, resulting from the unequal entry of cold water into the external auditory canals, and with asymmetric middle ear pressure equilibration during ascent and descent (alternobaric vertigo). Equilibrium disturbances noted with nitrogen narcosis, oxygen toxicity, hypercarbia, or hypoxia appear primarily related to the effects of these conditions upon the central nervous system and not to specific vestibular end-organ dysfunction. Compression of humans in helium-oxygen at depths greater than 152.4 meters results in transient symptoms of tremor, dizziness, and nausea plus decrements in postural equilibrium and psychomotor performance, the high pressure nervous syndrome. Vestibular function studies during these conditions indicate that these problems are due to central dysfunction and not to vestibular end-organ dysfunction. Persistent inner ear injuries have been noted during several phases of diving: 1) Such injuries during compression (inner ear barotrauma) have been related to round window ruptures occurring with straining, or a Valsalva's maneuver during inadequate middle ear pressure equilibration. Divers who develop cochlear and/or vestibular symptoms during shallow diving in which decompression sickness is unlikely or during

  2. Effect of tympanostomy tube insertion on middle ear function in children with secretory otitis media%鼓室置管对儿童分泌性中耳炎中耳功能影响的研究

    Institute of Scientific and Technical Information of China (English)

    毛承刚; 万俐佳; 周小淳; 吴燕; 鲁海涛

    2012-01-01

    目的 探讨鼓室置管治疗儿童分泌性中耳炎对中耳功能的影响.方法 选取47例(58耳)临床诊断为分泌性中耳炎的患儿,分别在鼓室置管术前及术后1个月、6个月进行纯音测听、声导抗、畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)检查和耳镜检查,以评估鼓室置管手术前后中耳功能的变化及术后的并发症.结果 鼓室置管术后1个月、6个月分别行耳镜和声导抗检查,均较术前听力明显提高.术后6个月与术后1个月检查结果比较,听力改变差异无统计学意义.与鼓室置管术前比较,DPOAE引出率及部分频率幅值提高,差异具有统计学意义.鼓室置管术后的并发症主要是中耳感染、分泌性中耳炎复发、鼓膜穿孔和鼓膜内陷.结论 鼓室置管治疗儿童分泌性中耳炎,应用检测纯音测听、声导抗、DPOAE和耳镜检查,了解鼓室置管术后的并发症情况,综合评价对中耳功能的影响,具有临床指导意义.%Objective To investigate the effect of tympanostomy tube insertion on the middle ear function in children with secretory otitis media ( SOM). Methods Pure tone audiometry, acoustic impedance , distortion product otoacoustic emission ( DPOAE) examination and otoscopy were carried out in 47 children (58 ears) with SOM before tube insertion, one month and 6 months after tube insertion respectively to evaluate the changes of middle ear function and surgical complications. Results One month and 6 months after tube insertion, hearing of children with catheter patency was significantly improved. In addition, the detection rate and amplitude of DPOAE were significantly increased. The difference of hearing 1 month and 6 months after tube insertion was statistically insignificant. Surgical and postoperative complications included middle ear infection, recurrent SOM, tympanic perforation and tympanic membrane retraction. Conclusion Pure tone audiometry, acoustic impedance

  3. An in vitro model of murine middle ear epithelium

    Directory of Open Access Journals (Sweden)

    Apoorva Mulay

    2016-11-01

    Full Text Available Otitis media (OM, or middle ear inflammation, is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology it is clear that epithelial abnormalities underpin the disease. There is currently a lack of a well-characterised in vitro model of the middle ear (ME epithelium that replicates the complex cellular composition of the middle ear. Here, we report the development of a novel in vitro model of mouse middle ear epithelial cells (mMECs at an air–liquid interface (ALI that recapitulates the characteristics of the native murine ME epithelium. We demonstrate that mMECs undergo differentiation into the varied cell populations seen within the native middle ear. Proteomic analysis confirmed that the cultures secrete a multitude of innate defence proteins from their apical surface. We showed that the mMECs supported the growth of the otopathogen, nontypeable Haemophilus influenzae (NTHi, suggesting that the model can be successfully utilised to study host–pathogen interactions in the middle ear. Overall, our mMEC culture system can help to better understand the cell biology of the middle ear and improve our understanding of the pathophysiology of OM. The model also has the potential to serve as a platform for validation of treatments designed to reverse aspects of epithelial remodelling that underpin OM development.

  4. Apraxia: neural mechanisms and functional recovery.

    Science.gov (United States)

    Foundas, Anne L

    2013-01-01

    Apraxia is a cognitive-motor disorder that impacts the performance of learned, skilled movements. Limb apraxia, which is the topic of this chapter, is specific to disordered movements of the upper limb that cannot be explained by weakness, sensory loss, abnormalities of posture/tone/movement, or a lack of understanding/cooperation. Patients with limb apraxia have deficits in the control or programming of the spatial-temporal organization and sequencing of goal-directed movements. People with limb apraxia can have difficulty manipulating and using tools including cutting with scissors or making a cup of coffee. Two praxis systems have been identified including a production system (action plan and production) and a conceptual system (action knowledge). Dysfunction of the former produces ideomotor apraxia (e.g., difficulty using scissors), and dysfunction of the latter induces ideational apraxia (e.g., difficulty making a cup of coffee). Neural mechanisms, including how to evaluate apraxia, will be presented in the context of these two praxis systems. Information about these praxis systems, including the nature of the disordered limb movement, is important for rehabilitation clinicians to understand for several reasons. First, limb apraxia is a common disorder. It is common in patients who have had a stroke, in neurodegenerative disorders like Alzheimer disease, in traumatic brain injury, and in developmental disorders. Second, limb apraxia has real world consequences. Patients with limb apraxia have difficulty managing activities of daily living. This factor impacts healthcare costs and contributes to increased caregiver burden. Unfortunately, very few treatments have been systematically studied in large numbers of patients with limb apraxia. This overview of limb apraxia should help rehabilitation clinicians to educate patients and caregivers about this debilitating problem, and should facilitate the development of better treatments that could benefit many people in

  5. Mirror neurons: functions, mechanisms and models.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael A

    2013-04-12

    Mirror neurons for manipulation fire both when the animal manipulates an object in a specific way and when it sees another animal (or the experimenter) perform an action that is more or less similar. Such neurons were originally found in macaque monkeys, in the ventral premotor cortex, area F5 and later also in the inferior parietal lobule. Recent neuroimaging data indicate that the adult human brain is endowed with a "mirror neuron system," putatively containing mirror neurons and other neurons, for matching the observation and execution of actions. Mirror neurons may serve action recognition in monkeys as well as humans, whereas their putative role in imitation and language may be realized in human but not in monkey. This article shows the important role of computational models in providing sufficient and causal explanations for the observed phenomena involving mirror systems and the learning processes which form them, and underlines the need for additional circuitry to lift up the monkey mirror neuron circuit to sustain the posited cognitive functions attributed to the human mirror neuron system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Intra- and interspecific responses to Rafinesque’s big-eared bat (Corynorhinus rafinesquii) social calls.

    Energy Technology Data Exchange (ETDEWEB)

    Loeb, Susan, C.; Britzke, Eric, R.

    2010-07-01

    Bats respond to the calls of conspecifics as well as to calls of other species; however, few studies have attempted to quantify these responses or understand the functions of these calls. We tested the response of Rafinesque’s big-eared bats (Corynorhinus rafinesquii) to social calls as a possible method to increase capture success and to understand the function of social calls. We also tested if calls of bats within the range of the previously designated subspecies differed, if the responses of Rafinesque’s big-eared bats varied with geographic origin of the calls, and if other species responded to the calls of C. rafinesquii. We recorded calls of Rafinesque’s big-eared bats at two colony roost sites in South Carolina, USA. Calls were recorded while bats were in the roosts and as they exited. Playback sequences for each site were created by copying typical pulses into the playback file. Two mist nets were placed approximately 50–500 m from known roost sites; the net with the playback equipment served as the Experimental net and the one without the equipment served as the Control net. Call structures differed significantly between the Mountain and Coastal Plains populations with calls from the Mountains being of higher frequency and longer duration. Ten of 11 Rafinesque’s big-eared bats were caught in the Control nets and, 13 of 19 bats of other species were captured at Experimental nets even though overall bat activity did not differ significantly between Control and Experimental nets. Our results suggest that Rafinesque’s big-eared bats are not attracted to conspecifics’ calls and that these calls may act as an intraspecific spacing mechanism during foraging.

  7. Conceptual modelling approach of mechanical products based on functional surface

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A modelling framework based on functional surface is presented to support conceptual design of mechanical products. The framework organizes product information in an abstract and multilevel manner. It consists of two mapping processes: function decomposition process and form reconstitution process. The steady mapping relationship from function to form (function-functional surface-form) is realized by taking functional surface as the middle layer. It farthest reduces the possibilities of combinatorial explosion that can occur during function decomposition and form reconstitution. Finally, CAD tools are developed and an auto-bender machine is applied to demonstrate the proposed approach.

  8. Protein mechanics: a route from structure to function

    Indian Academy of Sciences (India)

    Richard Lavery; Sophie Sacquin-Mora

    2007-08-01

    In order to better understand the mechanical properties of proteins, we have developed simulation tools which enable these properties to be analysed on a residue-by-residue basis. Although these calculations are relatively expensive with all-atom protein models, good results can be obtained much faster using coarse-grained approaches. The results show that proteins are surprisingly heterogeneous from a mechanical point of view and that functionally important residues often exhibit unusual mechanical behaviour. This finding offers a novel means for detecting functional sites and also potentially provides a route for understanding the links between structure and function in more general terms.

  9. Expression of macrophage migration inhibitory factor and CD74 in the inner ear and middle ear in lipopolysaccharide-induced otitis media.

    Science.gov (United States)

    Ishihara, Hisashi; Kariya, Shin; Okano, Mitsuhiro; Zhao, Pengfei; Maeda, Yukihide; Nishizaki, Kazunori

    2016-10-01

    Significant expression of macrophage migration inhibitory factor and its receptor (CD74) was observed in both the middle ear and inner ear in experimental otitis media in mice. Modulation of macrophage migration inhibitory factor and its signaling pathway might be useful in the management of inner ear inflammation due to otitis media. Inner ear dysfunction secondary to otitis media has been reported. However, the specific mechanisms involved are not clearly understood. The aim of this study is to investigate the expression of macrophage migration inhibitory factor and CD74 in the middle ear and inner ear in lipopolysaccharide-induced otitis media. BALB/c mice received a transtympanic injection of either lipopolysaccharide or phosphate-buffered saline (PBS). The mice were sacrificed 24 h after injection, and temporal bones were processed for polymerase chain reaction (PCR) analysis, histologic examination, and immunohistochemistry. PCR examination revealed that the lipopolysaccharide-injected mice showed a significant up-regulation of macrophage migration inhibitory factor in both the middle ear and inner ear as compared with the PBS-injected control mice. The immunohistochemical study showed positive reactions for macrophage migration inhibitory factor and CD74 in infiltrating inflammatory cells, middle ear mucosa, and inner ear in the lipopolysaccharide-injected mice.

  10. Why Do Elephants Flap Their Ears?

    Science.gov (United States)

    Koffi, Moise; Jiji, Latif; Andreopoulos, Yiannis

    2009-11-01

    It is estimated that a 4200 kg elephant generates as much as 5.12 kW of heat. How the elephant dissipates its metabolic heat and regulates its body temperature has been investigated during the past seven decades. Findings and conclusions differ sharply. The high rate of metabolic heat coupled with low surface area to volume ratio and the absence of sweat glands eliminate surface convection as the primary mechanism for heat removal. Noting that the elephant ears have high surface area to volume ratio and an extensive vascular network, ear flapping is thought to be the principal thermoregulatory mechanism. A computational and experimental program is carried out to examine flow and heat transfer characteristics. The ear is modeled as a uniformly heated oscillating rectangular plate. Our computational work involves a three-dimensional time dependent CFD code with heat transfer capabilities to obtain predictions of the flow field and surface temperature distributions. This information was used to design an experimental setup with a uniformly heated plate of size 0.2m x 0.3m oscillating at 1.6 cycles per second. Results show that surface temperature increases and reaches a steady periodic oscillation after a period of transient oscillation. The role of the vortices shed off the plate in heat transfer enhancement will be discussed.

  11. Investigation of the ear-to-ear radio propagation channel

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Thaysen, J; Jakobsen, Kaj Bjarne

    2011-01-01

    The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head. The investi......The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head...

  12. [Research progress of mechanism of functional dyspepsia treated with acupuncture].

    Science.gov (United States)

    Yan, Kaiwei; Zhao, Ling; Yang, Jie; Lan, Ying; Xu, Jing; Wei, Chenchen; Liang, Fanrong

    2015-09-01

    Literature about functional dyspepsia treated with acupuncture in recent 5 years is retrieved in China National Knowledge Infrastructure (CNKI), Wanfang database and PubMed. The research achievements are arranged and summed up to explore the mechanism of acupuncture for functional dyspepsia. It is found that acupuncture can regulate the secretion of braingut petide, and cause the coordination response of limbic system-brain. Also, it adjusts serum molecule metabolin and the gene expression of the transduction pathway of adjustment signal for rats. It is believed that functional dyspepsia treated with acupuncture is through multiple ways, and adjusting the function of braingut axis is one of the important mechanisms.

  13. Human ear recognition by computer

    CERN Document Server

    Bhanu, Bir; Chen, Hui

    2010-01-01

    Biometrics deals with recognition of individuals based on their physiological or behavioral characteristics. The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. Unlike the fingerprint and iris, it can be easily captured from a distance without a fully cooperative subject, although sometimes it may be hidden with hair, scarf and jewellery. Also, unlike a face, the ear is a relatively stable structure that does not change much with the age and facial expressions. ""Human Ear Recognition by Computer"" is the first book o

  14. Outcomes in Endoscopic Ear Surgery.

    Science.gov (United States)

    Kiringoda, Ruwan; Kozin, Elliott D; Lee, Daniel J

    2016-10-01

    Endoscopic ear surgery (EES) provides several advantages compared with traditional binocular microscopy, including a wide-field view, improved resolution with high magnification, and visual access to hidden corridors of the middle ear. Although binocular microscopic-assisted surgical techniques remain the gold standard for most otologists, EES is slowly emerging as a viable alternative for performing otologic surgery at several centers in the United States and abroad. In this review, we evaluate the current body of literature regarding EES outcomes, summarize our EES outcomes at the Massachusetts Eye and Ear Infirmary, and compare these results with data for microscopic-assisted otologic surgery.

  15. Evidence for a Right-Ear Advantage in Newborn Hearing Screening Results.

    Science.gov (United States)

    Ari-Even Roth, Daphne; Hildesheimer, Minka; Roziner, Ilan; Henkin, Yael

    2016-12-06

    The aim of the present study was to investigate the effect of ear asymmetry, order of testing, and gender on transient-evoked otoacoustic emission (TEOAE) pass rates and response levels in newborn hearing screening. The screening results of 879 newborns, of whom 387 (study group) passed screening successfully in only one ear in the first TEOAE screening, but passed screening successfully in both ears thereafter, and 492 (control group) who passed screening successfully in both ears in the first TEOAE, were retrospectively examined for pass rates and TEOAE characteristics. Results indicated a right-ear advantage, as manifested by significantly higher pass rates in the right ear (61% and 39% for right and left ears, respectively) in the study group, and in 1.75 dB greater TEOAE response amplitudes in the control group. The right-ear advantage was enhanced when the first tested ear was the right ear (76%). When the left ear was tested first, pass rates were comparable in both ears. The right-ear advantage in pass rates was similar in females versus males, but manifested in 1.5 dB higher response amplitudes in females compared with males, regardless of the tested ear and order of testing in both study and control groups. The study provides further evidence for the functional lateralization of the auditory system at the cochlear level already apparent soon after birth in both males and females. While order of testing plays a significant role in the asymmetry in pass rates, the innate right-ear advantage seems to be a more dominant contributor. © The Author(s) 2016.

  16. Lumped parametric model of the human ear for sound transmission.

    Science.gov (United States)

    Feng, Bin; Gan, Rong Z

    2004-09-01

    A lumped parametric model of the human auditoria peripherals consisting of six masses suspended with six springs and ten dashpots was proposed. This model will provide the quantitative basis for the construction of a physical model of the human middle ear. The lumped model parameters were first identified using published anatomical data, and then determined through a parameter optimization process. The transfer function of the middle ear obtained from human temporal bone experiments with laser Doppler interferometers was used for creating the target function during the optimization process. It was found that, among 14 spring and dashpot parameters, there were five parameters which had pronounced effects on the dynamic behaviors of the model. The detailed discussion on the sensitivity of those parameters was provided with appropriate applications for sound transmission in the ear. We expect that the methods for characterizing the lumped model of the human ear and the model parameters will be useful for theoretical modeling of the ear function and construction of the ear physical model.

  17. Speaker Recognition Based on Vocal Mechanism and Human Ear Perceptual Characteristic%基于发声机理与人耳感知特性的说话人识别

    Institute of Scientific and Technical Information of China (English)

    杜晓青; 于凤芹

    2013-01-01

    The fusion algorithm of Mel Frequency Cepstral Coefficient(MFCC) and Linear Prediction Cepstrum Coeficient(LPCC) can only react the static characteristics of the speech and LPCC can not describe the local characteristics of the speech low frequency well. So the fusion of Hilbert-Huang Transform(HHT) cepstrum coefficient and Relative Spectra-Perception Linear Prediction Cepstrum Coefficient(RASTA-PLPCC) is proposed, getting a new speaker recognition algorithm that reflects both vocal mechanism and human ear perceptual characteristics. The HHT cepstrum coefficient reflects the human vocal mechanism, and it can reflect the dynamic characteristics of the speech, as well as better describe the local characteristics of the speech low frequency. PLPCC reflects the human ear perceptual characteristics, whose identification performance is better than the MFCC. Two features are combined with the three fusion algorithms, and the fusion feature is sent into the Gaussian mixture model to do speaker recognition. Simulation results demonstrate that compared with the fusion of LPCC and MFCC, the fusion algorithm gets higher recognition rate, and recognition rate is increased by 8.0%.%Mel频率倒谱系数(MFCC)与线性预测倒谱系数(LPCC)融合算法只能反映语音静态特征,且LPCC对语音低频局部特征描述不足。为此,提出将希尔伯特黄变换(HHT)倒谱系数与相对光谱-感知线性预测倒谱系数(RASTA-PLPCC)融合,得到一种既反映发声机理又体现人耳感知特性的说话人识别算法。HHT倒谱系数体现发声机理,能反映语音动态特性,并更好地描述信号低频局部特征,可改进LPCC的不足。PLPCC体现人耳感知特性,识别性能强于MFCC,用3种融合算法对两者进行融合,将融合特征用于高斯混合模型进行说话人识别。仿真实验结果表明,该融合算法较已有的MFCC与LPCC融合算法识别率提高了8.0%。

  18. The relationship between auditory sensitivity and ear asymmetry on a dichotic listening task.

    Science.gov (United States)

    Emmerich, D S; Harris, J; Brown, W S; Springer, S P

    1988-01-01

    Using an adaptive forced-choice procedure, the average absolute sensitivity of the right ears of a group of right-handed males was found to be slightly greater than that of their left ears. There was no ear difference in performance on a monaural syllable-identification task using easily detectable stimuli, however. The magnitude of the ear difference in absolute sensitivity was significantly correlated with performance on a dichotic-listening task. In a second experiment, the adaptive forced-choice procedure was used to assess differences in absolute sensitivity in a group of left-handed males. The right ears of those left-handers showing a right-ear advantage on the dichotic-listening task were slightly more sensitive than their left ears. The left ears of those left-handers showing a dichotic left-ear advantage were slightly, but not significantly, more sensitive than their right ears. The correlation of the ear differences in absolute sensitivity with performance on the dichotic-listening task for the left-handers was not significantly different from zero. Results of both experiments are discussed in terms of their implications for the nature of hemispheric asymmetry of function, and the interpretation of dichotic and monaural asymmetries.

  19. Finite element modelling of sound transmission from outer to inner ear.

    Science.gov (United States)

    Areias, Bruno; Santos, Carla; Natal Jorge, Renato M; Gentil, Fernanda; Parente, Marco Pl

    2016-11-01

    The ear is one of the most complex organs in the human body. Sound is a sequence of pressure waves, which propagates through a compressible media such as air. The pinna concentrates the sound waves into the external auditory meatus. In this canal, the sound is conducted to the tympanic membrane. The tympanic membrane transforms the pressure variations into mechanical displacements, which are then transmitted to the ossicles. The vibration of the stapes footplate creates pressure waves in the fluid inside the cochlea; these pressure waves stimulate the hair cells, generating electrical signals which are sent to the brain through the cochlear nerve, where they are decoded. In this work, a three-dimensional finite element model of the human ear is developed. The model incorporates the tympanic membrane, ossicular bones, part of temporal bone (external auditory meatus and tympanic cavity), middle ear ligaments and tendons, cochlear fluid, skin, ear cartilage, jaw and the air in external auditory meatus and tympanic cavity. Using the finite element method, the magnitude and the phase angle of the umbo and stapes footplate displacement are calculated. Two slightly different models are used: one model takes into consideration the presence of air in the external auditory meatus while the other does not. The middle ear sound transfer function is determined for a stimulus of 60 dB SPL, applied to the outer surface of the air in the external auditory meatus. The obtained results are compared with previously published data in the literature. This study highlights the importance of external auditory meatus in the sound transmission. The pressure gain is calculated for the external auditory meatus.

  20. Global Ear. Werke 2001 - 2006

    Index Scriptorium Estoniae

    2006-01-01

    Dresdenis muusikafestivalil "Global Ear" 23.3.03 esitusel Eesti heliloojate muusika: Helena Tulve "lumineux/opaque", Jaan Rääts "Meditation", Mirjam Tally "Aura", Mati Kuulberg "Sonate Nr.4", Mari Vihmand "Seitsmele"

  1. Global Ear. Werke 2001 - 2006

    Index Scriptorium Estoniae

    2006-01-01

    Dresdenis muusikafestivalil "Global Ear" 23.3.03 esitusel Eesti heliloojate muusika: Helena Tulve "lumineux/opaque", Jaan Rääts "Meditation", Mirjam Tally "Aura", Mati Kuulberg "Sonate Nr.4", Mari Vihmand "Seitsmele"

  2. Multiple Osteomas in Middle Ear

    Directory of Open Access Journals (Sweden)

    Yongxin Li

    2012-01-01

    Full Text Available Since the first description of middle ear osteomas by Thomas in 1964, only few reports were published within the English literatures (Greinwalid et al., 1998; Shimizu et al., 2003; Cho et al., 2005; and Jang et al., 2009, and only one case of the multiple osteomas in middle ear was described by Kim et al., 2006, which arose from the promontory, lateral semicircular canal, and epitympanum. Here we describe a patient with multiple middle ear osteomas arising from the promontory, incus, Eustachian tube, and bony semicanal of tensor tympani muscle. This patient also contracted the chronic otitis media in the ipsilateral ear. The osteomas were successfully removed by performing type III tympanoplasty in one stage.

  3. 21 CFR 870.2710 - Ear oximeter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear oximeter. 870.2710 Section 870.2710 Food and... CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2710 Ear oximeter. (a) Identification. An ear... ear. The amount of reflected or scattered light as indicated by this device is used to measure...

  4. [Reconstruction of the ear in the burns patient].

    Science.gov (United States)

    Carrillo-Córdova, Jorge Raúl; Jiménez Murat, Yusef; Apellaniz-Campo, Armando; Bracho-Olvera, Hazel; Carrillo Esper, Raúl

    2017-03-06

    Face burns are a singular pathology with great functional and psychological impact in the patients suffering them. The ears play a fundamental role in personal interactions and damage to this organ results in physical and emotional distress. The reconstructive treatment of the burned ear is a challenge. Multiple procedures have been described to achieve success in the reconstruction of the burned ear; immediate reconstruction with autologous rib cartilage, secondary reconstruction, alloplastic material reconstruction, tissue expansion, skin grafts and also microvascular flaps are some of the most common procedures used in this patients. All these techniques focus on giving a natural appearance to the patient. Burns to the ears affect 30% of the patients with facial burns, they require an excellent treatment given by a multidisciplinary team. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  5. Improvement of the Yield Function of Continuum Mechanics of Textured Polycrystals%多晶体织构材料连续介质力学屈服函数的改进

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The calculation procedure of the continuum mechanics of textured polycrystals (CMTP) method is reviewed to estimate calculating time with various yield functions (YFs). A so-called semi-quadratic YF is proposed to eliminate time-consuming numerical calculation and avoid the decrease of prediction precision. The reasonability of the new YF is proved by making the comparisons between predicted R-values and earing behaviour for some materials and the experimental results.

  6. On quantum mechanical phase-space wave functions

    DEFF Research Database (Denmark)

    Wlodarz, Joachim J.

    1994-01-01

    An approach to quantum mechanics based on the notion of a phase-space wave function is proposed within the Weyl-Wigner-Moyal representation. It is shown that the Schrodinger equation for the phase-space wave function is equivalent to the quantum Liouville equation for the Wigner distribution...

  7. Connectivity analysis of suggestive brain areas involved in middle ear pressure regulation in humans

    DEFF Research Database (Denmark)

    SA, Sami; Gaihede, Michael

    2010-01-01

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations......HYPOTHESIS:: Middle ear pressure (MEP) is actively regulated by both the Eustachian tube and the mastoid air cell system. BACKGROUND:: MEP is a highly significant factor involved in many clinical conditions related to otitis media. Basic knowledge on its overall regulation remains insufficient...... of these distinct mechanisms were found. CONCLUSION:: The human mastoid as well as the Eustachian tube was capable of active counter-regulation of the MEP in short-term experimental pressure changes in healthy ears. Thus, these 2 systems seemed to function in a complementary way, where the mastoid was related...

  8. Basic and clinical physiology of the inner ear receptors and their neural pathways in the brain.

    Science.gov (United States)

    Sohmer, H; Freeman, S

    2000-01-01

    The six receptors of the inner ear (cochlea, two otolith organs and three semicircular canals) share a common transduction unit made up of a sensory hair cell, a first order sensory neuron and the synapse between them. Displacement of the stereocilia in a particular direction leads to excitation of the hair cell and activation of the neuron. Electrical and mechanical reflections of these stages of transduction can be recorded non-invasively in humans and in animals. These include cochlear microphonic potentials, otoacoustic emissions, auditory and vestibular evoked potentials. The ability to record these activities can be used to track the development of inner ear function in the fetus and neonate and to study the effects of various ototoxic agents (e.g. noise) and drugs.

  9. Configuration space representation for micro-mechanism function

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, E. [Purdue Univ., Lafayette, IN (United States). Computer Science Dept.; Allen, J. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachine Dept.

    1998-11-01

    This paper describes the configuration space representation of mechanical function and shows how it supports the design of micro-mechanisms. The domain characteristics of curved geometry, joint play, and custom joints render traditional design tools inappropriate, but configuration spaces can model these characteristics. They represent the quantitative and the qualitative aspects of kinematic function in a concise geometric format that helps designers visualize system function under a range of operating conditions, find and correct design flaws, study joint play, and optimize performance. The approach is demonstrated on a surface micromachined counter meshing gear discrimination device developed at Sandia National Laboratories.

  10. Modification of closed tympanoplasty in middle ear cholesteatoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-gang; LIU Xiang; CHEN Sui-jun; CHEN Bin; ZHENG Yi-qing

    2010-01-01

    Background Classic mastoidectomy and modified mastoidectomy are traditional surgical procedures for middle ear cholesteatoma with goals of eradicating diseases, creating dry ears and preventing severe complications. However, the drawback of these procedures is the lack of hearing improvement. Therefore, our study aimed to investigate the effects and safety of a modification of closed tympanoplasty for middle ear cholesteatoma.Methods Eighty-three patients were recruited in this study based on the following two criteria: each patient had middle ear cholesteatoma in one ear; the affected ears had a functional eustachian tube and had neither intracranial nor extracranial complications. All the patients received a modification of closed tympanoplasty which included ossicular reconstruction with total ossicular replacement prosthesis (TORP) or partial ossicular replacement prosthesis (PORP) and membrane repair with conchal cartilage-perichondral complex.Results All the 83 cases had dry ears with membranes healed within 4-6 postoperative weeks. After 6 postoperative months, there were 3 cases with re-perforation at the tympanic membrane center and after 1.5 postoperative years, there were 5 cases with cholesteatoma recurrence (6.02%). Function tests after one postoperative year exhibited an improvement of pure tone audiometry (PTA) in 27 cases that was more than 30 dB, in 33 cases between 20-29 dB, 14 cases with improvement between 10-19 dB, and in 9 cases there was no improvement.Conclusions The modified closed tympanoplasty procedure for middle ear cholesteatoma in the present study has all the advantages of both close-cavity and open-cavity procedures. It has low recurrence rate and good hearing improvement.

  11. Injuries of the external ear.

    Science.gov (United States)

    Templer, J; Renner, G J

    1990-10-01

    Ear injuries occur in people of all ages but predominate in active people such as wrestlers, boxers, and bike riders. The types and extent of injury are a function of the force causing the injury. Shearing forces of moderate intensity cause hematoma formation, whereas greater force causes lacerations or even amputation. Sharp objects cause lacerations determined by the force, direction, and point of impact. The high ratio of surface area to mass makes the auricle vulnerable to extremes of temperature. People participating in high-risk activities should wear protective headgear. The goal of treatment is to restore the normal contours while preventing infection. Hematoma results in disfigurement by organization or chondritis. Evacuation and pressure dressings using sterile technique correct the condition. Second-degree burns are treated by regular cleansing and application of topical antimicrobials. Deeper burns require debridement, biologic dressings, or burying the cartilage subcutaneously for later reconstruction. Simple lacerations are closed under aseptic technique using either skin-to-skin sutures only or sutures of the skin combined with intercartilage sutures. Extensive and complex lacerations require meticulous care to match all fragments and prevent infection or loss of tissue. Bare cartilage must be covered with vascularized tissue. The treatment of total amputation is controversial. Some advocate reattachment as a composite graft using intravenous low molecular weight dextrans and heparin as adjuvants. Mladick dermabrades the amputated pinna, reattaches it with sutures, and then slips it into a pocket of elevated postauricular skin for 2 weeks. Others urge microvascular reanastomosis of the small nutrient vessels. Brent and Byrd separate the cartilage from its overlying skin and envelope it first with vascularized temporoparietal fascia and then a split-thickness skin graft. Chondritis is the most feared complication of injury or surgery of the pinna. It

  12. The wave function essays on the metaphysics of quantum mechanics

    CERN Document Server

    Albert, David Z

    2013-01-01

    This is a new volume of original essays on the metaphysics of quantum mechanics. The essays address questions such as: What fundamental metaphysics is best motivated by quantum mechanics? What is the ontological status of the wave function? Does quantum mechanics support the existence of any other fundamental entities, e.g. particles? What is the nature of the fundamental space (or space-time manifold) of quantum mechanics? What is the relationship between the fundamental ontology of quantum mechanics and ordinary, macroscopic objects like tables, chairs, and persons? This collection includes a comprehensive introduction with a history of quantum mechanics and the debate over its metaphysical interpretation focusing especially on the main realist alternatives.

  13. Multi-frequency tympanometry as a diagnostic test of middle ear function in infants%0-12月龄婴幼儿不同频率声导抗测试研究

    Institute of Scientific and Technical Information of China (English)

    孙婧; 赵正言; 付勇; 吴磊

    2015-01-01

    Objective To report tympanometry results at 226, 678 and 1000 Hz in infants aged from 0 month to 12 months, and to evaluate the value of multiple frequency tympanometry in diagnosing middle ear function in infants. Methods A sample of 200 infants with normal hearing were divided into four groups by age:i.e. Groups 1 (0– 28 days), 2 (1–3 months, ± 3 days), 3 (4–6 months, ± 7 days) and 4 (7–12 months, ±7 days) (n=50 in each group). Tympanograms from different age groups including their frequency characteristics were obtained using a GSI TympStar 2 Middle-Ear analyzer. Results 1) At 226 Hz, tympanom-etry equivalent ear canal volume (Ecv) increased with age, while tympanometric peak pressure (TPP) and peak compensated static acoustic admittance (Ymt) decreased. 2) TPP and Ymt at 678 and 1000 Hz increased with age, although the lowest TPP and Ymt was seen in infants in Group 2. Within each age group, TPP and Ymt at 1000 Hz were greater than those at 678 Hz. Probe tone frequency and age showed a remarkable im-pact on TPP and Ymt. 4) The middle ear resonance frequency was 284 ± 48 Hz for Group1, 293 ± 51 Hz for Group 2, 450±152 Hz for Group 3 and 650±205 Hz for Group 4. Conclusion In evaluating middle ear func-tion in infants younger than 6 months, the 1000 Hz probe tone should be used, while the 678 Hz tone can be a supplementary option in cases when 1000 Hz tympanograms indicate an occlusion effect. For infants between 7 and 12 months, the 226 Hz tone should be used for tympanogram, while the 1000 Hz tone should be used for impedance tests. Probe tones of different frequencies and different reference values should be used for different ages for accurate evaluation of middle ear functions.%目的:分析0~12月龄听力正常婴幼儿226Hz、678Hz和1000Hz探测音声导抗测试的结果,探讨不同频率探测音声导抗鼓室图在评价该年龄段婴幼儿中耳功能中的作用。方法200例0~12月听力正常婴幼儿分成4组,每组50

  14. Introducing Viewpoints of Mechanics into Basic Growth Analysis-(XIII) : Comparing Growth Mechanics between Logistic Functions and Basic Growth Functions-

    OpenAIRE

    Shimojo, Masataka; Shao, Tao; Ishimatsu, Satoshi; Tanoue, Jun; Kakihara, Hidetoshi; Sata, Chiemi; Fukudome, Hayato; Ishiwaka, Reiko; Asano, Yoki; Nakano, Yutaka; Tobisa, Manabu; Masuda, Yasuhisa

    2009-01-01

    This study was conducted to compare growth mechanics between logistic functions and basic growth functions. The results obtained were as follows. Differential equation for basic growth function showed that the square of growth rate was described using the product of weight and growth acceleration. This form was similar to Newton's law of motion where differential of momentum is described using the product of mass of an object and acceleration. However, differential equation for logistic funct...

  15. Microfluidics as a functional tool for cell mechanics.

    Science.gov (United States)

    Vanapalli, Siva A; Duits, Michel H G; Mugele, Frieder

    2009-01-05

    Living cells are a fascinating demonstration of nature's most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax-thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remodeling of the cytoskeleton. To understand this intricate coupling between mechanical properties, mechanical function and force-induced biochemical signaling requires tools that are capable of both controlling and manipulating the cell microenvironment and measuring the resulting mechanical response. In this review, the power of microfluidics as a functional tool for research in cell mechanics is highlighted. In particular, current literature is discussed to show that microfluidics powered by soft lithographic techniques offers the following capabilities that are of significance for understanding the mechanical behavior of cells: (i) Microfluidics enables the creation of in vitro models of physiological environments in which cell mechanics can be probed. (ii) Microfluidics is an excellent means to deliver physical cues that affect cell mechanics, such as cell shape, fluid flow, substrate topography, and stiffness. (iii) Microfluidics can also expose cells to chemical cues, such as growth factors and drugs, which alter their mechanical behavior. Moreover, these chemical cues can be delivered either at the whole cell or subcellular level. (iv) Microfluidic devices offer the possibility of measuring the intrinsic mechanical properties of cells in a high throughput fashion. (v) Finally, microfluidic methods provide exquisite control over drop size, generation, and manipulation. As a result, droplets are being increasingly used to control the physicochemical environment of cells and as biomimetic analogs of living cells. These powerful attributes of microfluidics should further stimulate novel means of investigating the link between physicochemical cues and the biomechanical

  16. Microscopic view of osseointegration and functional mechanisms of implant surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Han, Guang; Shen, Zhijian, E-mail: shen@mmk.su.se

    2015-11-01

    Argon ion beam polishing technique was applied to prepare the cross sections of implants feasible for high resolution scanning electron microscope investigation. The interfacial microstructure between newly formed bone and implants with three modified surfaces retrieved after in vivo test using three different animal models was characterized. By this approach it has become possible to directly observe early bone formation, the increase of bone density, and the evolution of bone structure. The two bone growth mechanisms, distant osteogenesis and contact osteogenesis, can also be distinguished. These direct observations give, at microscopic level, a better view of osseointegration and expound the functional mechanisms of various implant surfaces for osseointegration. - Highlights: • Argon ion beam polishing was used for cross sections of interface. • The interfaces between new bone and implants can be distinguished. • Two bone growth mechanisms were verified. • The functional mechanisms of three modified implants were expounded.

  17. Effect of the middle ear reflex on sound transmission to the inner ear of rat.

    Science.gov (United States)

    Pilz, P K; Ostwald, J; Kreiter, A; Schnitzler, H U

    1997-03-01

    The effect of the acoustic middle ear reflex (MER) was quantified using electrodes chronically implanted in the middle ears of rats. Cochlear microphonics (CM) and middle ear muscle EMG were measured under light Ketamin anesthesia after stimulation with tone pulses of 5-20 kHz ranging between 75 and 120 dB SPL. With increasing intensity, the CM measured before the onset of the MER increased to a maximum amplitude and then decreased with higher SPLs. At 10 kHz this maximum was reached at 95 dB SPL, for other stimulus frequencies at higher SPLs. After a latency of 10-20 ms, CM to 10 kHz stimuli of 80-95 dB SPL were decreased by the attenuating action of the MER. The lowest threshold of the MER was also measured at 10 kHz (77 dB SPL in the mean). To stimuli greater than 100 dB SPL after a latency of 6-10 ms, the CM amplitude was increased. That this CM increase to intense stimuli is caused by the action of the MER was confirmed by control experiments such as cutting the tendons of the middle ear muscles. The CM decrease to stimuli below 100 dB SPL, as well as the increase to very intense stimuli, can be explained by sound attenuation caused by the MER, together with the nonlinear dependence of CM amplitude on stimulus level. The observed shift of the maxima of the CM input-output function by the MER to higher stimulus levels probably indicates an increase of the dynamic range of the ear.

  18. Ear Disorders in Scuba Divers

    Directory of Open Access Journals (Sweden)

    MH Azizi

    2010-12-01

    Full Text Available History of underwater diving dates back to antiquity. Breath-hold technique in diving was known to the ancient nations. However, deep diving progressed only in the early decades of the 19th century as the result of advancements in efficient underwater technologies which subsequently led to invention of sophisticated sets of scuba diving in the 20th century. Currently, diving is performed for various purposes including commercial, recreational, military, underwater construction, oil industry, underwater archeology and scientific assessment of marine life. By increasing popularity of underwater diving, dive-related medical conditions gradually became more evident and created a new challenge for the health care professionals, so that eventually, a specialty the so-called “diving medicine” was established. Most of the diving-associated disorders appear in the head and neck. The most common of all occupational disorders associated with diving are otologic diseases. External otitis has been reported as the most common otolaryngologic problem in underwater divers. Exostosis of the external ear canal may be formed in divers as the result of prolonged diving in cold waters. Other disorders of the ear and paranasal sinuses in underwater divers are caused by barometric pressure change (i.e., barotraumas, and to a lesser extent by decompression sickness. Barotrauma of the middle ear is the most prevalent barotrauma in divers. The inner ear barotraumas, though important, is less common. The present paper is a brief overview of diving-related ear disorders particularly in scuba divers.

  19. Functional methods underlying classical mechanics, relativity and quantum theory

    OpenAIRE

    Kryukov, Alexey A.

    2013-01-01

    The paper investigates the physical content of a recently proposed mathematical framework that unifies the standard formalisms of classical mechanics, relativity and quantum theory. In the framework states of a classical particle are identified with Dirac delta functions. The classical space is "made" of these functions and becomes a submanifold in a Hilbert space of states of the particle. The resulting embedding of the classical space into the space of states is highly non-trivial and accou...

  20. Better-ear glimpsing efficiency with symmetrically-placed interfering talkers.

    Science.gov (United States)

    Brungart, Douglas S; Iyer, Nandini

    2012-10-01

    In listening tasks where a target speech signal is spatially separated from a masking voice, listeners can often gain a substantial advantage in performance by attending to the ear with the better signal-to-noise ratio (SNR). However, this better-ear strategy becomes much more complicated when a target talker located in front of the listener is masked by interfering talkers positioned at symmetric locations to the left and right of the target. When this happens, there are no long-term SNR advantages at either ear and the only binaural SNR advantages available are the result of complicated better-ear glimpses that vary as a function of frequency and rapidly switch back and forth between the two ears according to the natural fluctuations in the relative levels of the two masking voices. In this study, a signal processing technique was used to take the better-ear glimpses that would ordinarily be randomly distributed across the two ears in a binaural speech signal and move them all into the same ear. This resulted in a monaural signal that contained all the information available to an ideal listener using an optimal binaural glimpsing strategy. Speech intelligibility was measured with these optimized monaural stimuli and compared to performance with unprocessed binaural speech stimuli. Performance was similar in these two conditions, suggesting that listeners with normal hearing are able to efficiently extract information from better-ear glimpses that fluctuate rapidly across frequency and across the two ears.

  1. Bandwidth Analysis of Functional Interconnects Used as Test Access Mechanism

    NARCIS (Netherlands)

    Van den Berg, A.; Ren, P.; Marinissen, E.J.; Gaydadjiev, G.; Goossens, K.

    2010-01-01

    Test data travels through a System on Chip (SOC) from the chip pins to the Core-Under-Test (CUT) and vice versa via a Test Access Mechanism (TAM). Conventionally, a TAM is implemented using dedicated communication infrastructure. However, also existing functional interconnect, such as a bus or Netwo

  2. A Primer on Elliptic Functions with Applications in Classical Mechanics

    Science.gov (United States)

    Brizard, Alain J.

    2009-01-01

    The Jacobi and Weierstrass elliptic functions used to be part of the standard mathematical arsenal of physics students. They appear as solutions of many important problems in classical mechanics: the motion of a planar pendulum (Jacobi), the motion of a force-free asymmetric top (Jacobi), the motion of a spherical pendulum (Weierstrass) and the…

  3. Thermodynamic Derivation of the Equilibrium Distribution Functions of Statistical Mechanics.

    Science.gov (United States)

    Stoeckly, Beth

    1979-01-01

    Presents a simplified derivation of the equilibrium distribution functions. The derivation proceeds from the change in the Helmholtz free energy when a particle is added to a system of fixed temperature, volume, and chemical potential. The derivations show the relationship between statistical mechanics and macroscopic thermodynamics. (Author/GA)

  4. Microfluidics as a functional tool for cell mechanics

    NARCIS (Netherlands)

    Vanapalli, Siva A.; Duits, Michel H.G.; Mugele, Frieder

    2009-01-01

    Living cells are a fascinating demonstration of nature’s most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax—thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remod

  5. Stimulus-dependent effects on right ear advantage in schizophrenia

    Directory of Open Access Journals (Sweden)

    Smucny J

    2012-09-01

    Full Text Available Jason Smucny,1,3 Korey Wylie,3 Jason Tregellas1–31Neuroscience Program, University of Colorado Anschutz Medical Campus, 2Research Science, Denver VA Medical, Center, 3Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USABackground: When presented with different sounds in each ear (dichotic listening, healthy subjects typically show a preference for stimuli heard in the right ear, an effect termed "right ear advantage". Previous studies examining right ear advantage in schizophrenia have been inconsistent, showing either decreased or increased advantage relative to comparison subjects. Given evidence for enhanced semantic processing in schizophrenia, some of this inconsistency may be due to the type of stimuli presented (words or syllables. The present study examined right ear advantage in patients and controls using both words and syllables as stimuli.Methods: Right ear advantage was compared between 20 patients with schizophrenia and 17 healthy controls. Two versions of the task were used, ie, a consonant-vowel pairing task and a fused rhymed words task.Results: A significant group × task interaction was observed. Relative to healthy controls, patients showed a greater difference on the syllable-based task compared with the word-based task. The number of distractors marked during the syllable-based task was inversely correlated with score on the Global Assessment of Function Scale.Conclusion: The findings are consistent with a left hemisphere dysfunction in schizophrenia, but also suggest that differences may be stimulus-specific, with a relative sparing of the deficit in the context of word stimuli. Performance may be related to measures of social, occupational, and psychological function.Keywords: schizophrenia, right ear advantage, dichotic, distraction

  6. Investigation of the ear-to-ear radio propagation channel

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Thaysen, J; Jakobsen, Kaj Bjarne

    2011-01-01

    The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head. The investi......The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head....... The investigation is done by SAM head phantom measurements and HFSS simulations. The investigations include setups where some propagation paths are blocked by an absorbing material. It is found that the characteristics of the head may cause constructive or destructive interference that may result in up to 10 d...

  7. Classification and diagnosis of ear malformations

    Directory of Open Access Journals (Sweden)

    Bartel-Friedrich, Sylva

    2007-01-01

    Full Text Available In the ENT region 50% of the malformations affect the ear. Malformations of the outer and middle ear are predominantly unilateral (ca. 70-90% and mostly involve the right ear. Inner ear malformations can be unilateral or bilateral. The incidence of ear malformations is approximately 1 in 3800 newborns. Ear malformations may be genetic (associated with syndromes or not, with family history, spontaneous mutations or acquired in nature. Malformations can affect the outer ear (pinna and external auditory canal, EAC, middle ear and inner ear, not infrequently in combination. Formal classification is advisable in order to be able to predict the prognosis and compare treatment schedules. Various classifications have been proposed: pinna and EAC malformations according to Weerda [1], middle ear malformations according to Kösling [2], and inner ear malformations according to Jackler [3], [4], to Marangos [5] and to Sennaroglu [6]. Additionally, we describe Altmann’s classification of atresia auris congenita [7] and the Siegert-Mayer-Weerda score [8] for EAC and middle ear malformations, systems of great practicability that are in widespread clinical use. The diagnostic steps include clinical examination, audiological testing, genetic analysis and, especially, CT and MRI. These imaging methods are most usefully employed in combination. Precise description of the malformations by means of CT and MRI is indispensable for the planning and successful outcome of operative ear reconstruction and rehabilitation procedures, including cochlear implantation.

  8. Neurofilament localization and phosphorylation in the developing inner ear of the rat.

    NARCIS (Netherlands)

    Tonnaer, E.L.G.M.; Peters, T.A.; Curfs, J.H.A.J.

    2010-01-01

    Detailed understanding of neurofilament protein distribution in the inner ear can shed light on regulatory mechanisms involved in neuronal development of this tissue. We assessed the spatio-temporal changes in the distribution of neurofilaments in the developing rat inner ear between embryonic day

  9. Immune system of the inner ear as a novel therapeutic target for sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Takayuki eOkano

    2014-09-01

    Full Text Available Sensorineural hearing loss (SNHL is a common clinical condition resulting from dysfunction in one or more parts in the auditory pathway between the inner ear and auditory cortex. Despite the prevalence of SNHL, little is known about its etiopathology, although several mechanisms have been postulated including ischemia, viral infection or reactivation, and microtrauma. Immune-mediated inner ear disease has been introduced and accepted as one SNHL pathophysiology; it responds to immunosuppressive therapy and is one of the few reversible forms of bilateral SNHL. The concept of immune-mediated inner ear disease is straightforward and comprehensible, but criteria for clinical diagnosis and the precise mechanism of hearing loss have not been determined. Moreover, the therapeutic mechanisms of corticosteroids are unclear, leading to several misconceptions by both clinicians and investigators concerning corticosteroid therapy. This review addresses our current understanding of the immune system in the inner ear and its involvement in the pathophysiology in SNHL. Treatment of SNHL, including immune-mediated inner ear disorder, will be discussed with a focus on the immune mechanism and immunocompetent cells as therapeutic targets. Finally, possible interventions modulating the immune system in the inner ear to repair the tissue organization and improve hearing in patients with SNHL will be discussed. Tissue macrophages in the inner ear appear to be a potential target for modulating the immune response in the inner ear in the pathophysiology of SNHL.

  10. Laser interferometric vibration measurements of the middle ear in healthy humans

    Science.gov (United States)

    Jorge, J. Rodriguez; Hemmert, Werner; Burkhardt, Claus; Zenner, Hans-Peter; Gummer, Anthony W.

    1996-01-01

    The use of spontaneous and evoked otacoustic emissions is now a standard clinical tool for diagnosis of the function of the inner ear. However, it is not possible to extract this information over the entire, functionally relevant frequency range because of imperfect coupling of: (1) stapedial to ear-drum vibrations through the ossicular chain of the middle ear and (2) ear-drum vibrations to air in the external auditory meatus. The problem could be circumvented if it were possible to measure the vibration of the stapes and ear drum. The ear drum can be visualized non-invasively, whereas the stapes is only accessible intra-operatively. Therefore, we designed a laser-interferometric system to non-invasively measure the vibration of the human ear drum. Vibrations were measured with a laser Doppler velocimeter (Polytec OFV-302) coupled into the side arm of an operating microscope (Zeiss OPMI MDM). The wavelength was 633 nm and emitted power was less than 1 mW. Direct coupling through the optics of the operating microscope, instead of through glass fibers, enabled a larger signal-to- noise ratio (20 - 30 dB) due to collection of more reflected light. This coupling scheme avoids the problems associated with having to place a reflecting material on the ear drum. The developed vibration measurement system allows non-invasive, fast and reproducible characterization of the dynamics of the human ear drum and as such can be used for clinical diagnostics.

  11. Loss of peripheral right-ear advantage in age-related hearing loss.

    Science.gov (United States)

    Tadros, Sherif F; Frisina, Susan T; Mapes, Frances; Kim, SungHee; Frisina, D Robert; Frisina, Robert D

    2005-01-01

    In young adults with normal hearing, the right ear is more sensitive than the left to simple sounds (peripheral right-ear advantage) and to processing complex sounds such as speech (central right-ear advantage). In the present investigation, the effects of hearing loss and aging on this auditory asymmetry were examined at both peripheral and central levels. Audiograms and transient evoked otoacoustic emission (TEOAE) and distortion product otoacoustic emission amplitudes were used to assess cochlear function. The contralateral suppression of TEOAEs was measured to assess the medial olivocochlear efferent system. The Hearing in Noise Test (HINT; binaural speech) was conducted to assess higher central auditory function. A group of aged subjects with normal hearing (flat audiograms) were compared to a group of aged subjects with sloping audiograms (presbycusis). At the cochlear (peripheral) level, the normal hearing group showed significantly higher otoacoustic emission amplitudes for the right ear compared to the left ear, which is consistent with the right-ear dominance normally seen in young adults. However, this finding was reversed in the presbycusic group that showed higher left-ear emission amplitudes. At the brainstem level, the amplitudes of TEOAE contralateral suppression were small and no significant difference was found between the right and left ears in both groups. On the contrary, HINT results showed a continuous dominance of the right ear (left hemisphere) in both groups, which was consistent with previous reports showing that the right hemisphere is more affected by age than the left hemisphere.

  12. Measurement of residual stresses using fracture mechanics weight functions

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Y. [Bettis Atomic Power Laboratory, West Mifflin, PA (United States)

    2001-07-01

    A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed. (author)

  13. Interconnections between the Ears in Nonmammalian Vertebrates

    DEFF Research Database (Denmark)

    Feng, Albert S.; Christensen-Dalsgaard, J.

    2010-01-01

    Many of the nonmammalian vertebrates (anurans, lizards, crocodiles, and some bird species) have large, continuous air spaces connecting the middle ears and acoustically coupling the eardrums. Acoustical coupling leads to strongly enhanced directionality of the ear at frequencies where diffraction...

  14. Middle ear infection (otitis media) (image)

    Science.gov (United States)

    Otitis media is an inflammation or infection of the middle ear. Acute otitis media (acute ear infection) occurs when there is ... which causes production of fluid or pus. Chronic otitis media occurs when the eustachian tube becomes blocked ...

  15. DESING OF CYLINDIRICAL EAR OF POLISH

    Directory of Open Access Journals (Sweden)

    Yaşar KARAGÖZ

    2000-02-01

    Full Text Available Plough is an agricultural tool which is used for preparing land to male it ready for sowing. The funotion of lough is to break the compact land into small pieces and to allow a suitable condition for living of culture plants. The ear is the most important part of active plough surface. The geometrical form of ear determines the form of active surface together with the front iron tip. Ploughs are divided into two categories which are European and American types. There are important differencies betucen the European and American tyges with respect to ?, ß and ? angles. Gorjatschkin described the ear form of European ploughs under four main groups which are: 1. Cylindirical ear type, 2. Culture-form ear type, 3. Semi-curled ear type, 4. Curled ear type. In this work, the designing of cylindirical ear was studied.

  16. COMMON INFECTIONS OF THE EAR

    African Journals Online (AJOL)

    Enrique

    April 2004 Vol.22 No.4 CME. 193. KAREN COHEN. MB ChB ... the ear canal and they are usually in the 40 - 50-year age group. ... Treatment. The treatment of choice is intravenous antibiotics consisting of aminoglyco- side, piperacillin and ...

  17. Cell type-specific transcriptome analysis reveals a major role for Zeb1 and miR-200b in mouse inner ear morphogenesis.

    Directory of Open Access Journals (Sweden)

    Ronna Hertzano

    2011-09-01

    Full Text Available Cellular heterogeneity hinders the extraction of functionally significant results and inference of regulatory networks from wide-scale expression profiles of complex mammalian organs. The mammalian inner ear consists of the auditory and vestibular systems that are each composed of hair cells, supporting cells, neurons, mesenchymal cells, other epithelial cells, and blood vessels. We developed a novel protocol to sort auditory and vestibular tissues of newborn mouse inner ears into their major cellular components. Transcriptome profiling of the sorted cells identified cell type-specific expression clusters. Computational analysis detected transcription factors and microRNAs that play key roles in determining cell identity in the inner ear. Specifically, our analysis revealed the role of the Zeb1/miR-200b pathway in establishing epithelial and mesenchymal identity in the inner ear. Furthermore, we detected a misregulation of the ZEB1 pathway in the inner ear of Twirler mice, which manifest, among other phenotypes, malformations of the auditory and vestibular labyrinth. The association of misregulation of the ZEB1/miR-200b pathway with auditory and vestibular defects in the Twirler mutant mice uncovers a novel mechanism underlying deafness and balance disorders. Our approach can be employed to decipher additional complex regulatory networks underlying other hearing and balance mouse mutants.

  18. Histological Changes of the Middle Ear Ossicles Harvested During Cholesteatoma Surgery

    Directory of Open Access Journals (Sweden)

    Lukáš Školoudík

    2016-03-01

    Full Text Available Background: In the cholesteatoma surgery ossicles can be replaced to reconstruct middle ear function. It is important that these ossicles are free of squamous epithelium, to prevent residual disease. This study focuses on the histological findings of the malleus and incus harvested during cholesteatoma surgery. Materials and Methods: Eighty middle ears ossicles were examined in vivo and histologically to consider the relationship of cholesteatoma to ossicles, grade of bone destruction and invasion of cholesteatoma to deeper layers of bone. Results: Serious ossicular destruction was observed more frequently in incus compared to malleus (p = 0.0065. Difference of ossicles destruction between children and adults was not significant (p = 0.3032. Deep invasion of cholesteatoma into the vascular spaces or inner core of the bone was not observed. Conclusions: Autograft ossicles from cholesteatomatous ears should not necessarily be rejected for reconstruction of the ossicular chain. Regarding the histological finding, the authors suggest mechanical cleaning of the ossicle surface to eliminate residual disease.

  19. Nanomaterial-modulated autophagy: underlying mechanisms and functional consequences.

    Science.gov (United States)

    Zheng, Wei; Wei, Min; Li, Song; Le, Weidong

    2016-06-01

    Autophagy is an essential lysosome-dependent process that controls the quality of the cytoplasm and maintains cellular homeostasis, and dysfunction of this protein degradation system is correlated with various disorders. A growing body of evidence suggests that nanomaterials (NMs) have autophagy-modulating effects, thus predicting a valuable and promising application potential of NMs in the diagnosis and treatment of autophagy-related diseases. NMs exhibit unique physical, chemical and biofunctional properties, which may endow NMs with capabilities to modulate autophagy via various mechanisms. The present review highlights the impacts of various NMs on autophagy and their functional consequences. The possible underlying mechanisms for NM-modulated autophagy are also discussed.

  20. Ear recognition based on Gabor features and KFDA.

    Science.gov (United States)

    Yuan, Li; Mu, Zhichun

    2014-01-01

    We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the same size. For its eminent characteristics in spatial local feature extraction and orientation selection, Gabor filter based ear feature extraction is presented in this paper. Kernel Fisher Discriminant Analysis (KFDA) is then applied for dimension reduction of the high-dimensional Gabor features. Finally distance based classifier is applied for ear recognition. Experimental results of ear recognition on two datasets (USTB and UND datasets) and the performance of the ear authentication system show the feasibility and effectiveness of the proposed approach.

  1. Ear Recognition Based on Gabor Features and KFDA

    Directory of Open Access Journals (Sweden)

    Li Yuan

    2014-01-01

    Full Text Available We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the same size. For its eminent characteristics in spatial local feature extraction and orientation selection, Gabor filter based ear feature extraction is presented in this paper. Kernel Fisher Discriminant Analysis (KFDA is then applied for dimension reduction of the high-dimensional Gabor features. Finally distance based classifier is applied for ear recognition. Experimental results of ear recognition on two datasets (USTB and UND datasets and the performance of the ear authentication system show the feasibility and effectiveness of the proposed approach.

  2. Passive ventricular mechanics modelling using MRI of structure and function.

    Science.gov (United States)

    Wang, V Y; Lam, H I; Ennis, D B; Young, A A; Nash, M P

    2008-01-01

    Patients suffering from dilated cardiomyopathy or myocardial infarction can develop left ventricular (LV) diastolic impairment. The LV remodels its structure and function to adapt to pathophysiological changes in geometry and loading conditions and this remodeling process can alter the passive ventricular mechanics. In order to better understand passive ventricular mechanics, a LV finite element model was developed to incorporate physiological and mechanical information derived from in vivo magnetic resonance imaging (MRI) tissue tagging, in vivo LV cavity pressure recording and ex vivo diffusion tensor MRI (DTMRI) of a canine heart. MRI tissue tagging enables quantitative evaluation of cardiac mechanical function with high spatial and temporal resolution, whilst the direction of maximum water diffusion (the primary eigenvector) in each voxel of a DTMRI directly correlates with the myocardial fibre orientation. This model was customized to the geometry of the canine LV during diastasis by fitting the segmented epicardial and endocardial surface data from tagged MRI using nonlinear finite element fitting techniques. Myofibre orientations, extracted from DTMRI of the same heart, were incorporated into this geometric model using a free form deformation methodology. Pressure recordings, temporally synchronized to the tissue tagging MRI data, were used to simulate the LV deformation during diastole. Simulation of the diastolic LV mechanics allowed us to estimate the stiffness of the passive LV myocardium based on kinematic data obtained from tagged MRI. This integrated physiological model will allow more insight into the regional passive diastolic mechanics of the LV on an individualized basis, thereby improving our understanding of the underlying structural basis of mechanical dysfunction in pathological conditions.

  3. Can Loud Music Hurt My Ears?

    Science.gov (United States)

    ... or Too Short All About Puberty Can Loud Music Hurt My Ears? KidsHealth > For Kids > Can Loud Music Hurt My Ears? Print A A A en ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

  4. 21 CFR 878.3590 - Ear prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear prosthesis. 878.3590 Section 878.3590 Food and... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis is a silicone rubber solid device intended to be implanted to reconstruct the...

  5. Can Loud Music Hurt My Ears?

    Science.gov (United States)

    ... What Happens in the Operating Room? Can Loud Music Hurt My Ears? KidsHealth > For Kids > Can Loud Music Hurt My Ears? A A A en español ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

  6. A Myo6 mutation destroys coordination between the myosin heads, revealing new functions of myosin VI in the stereocilia of mammalian inner ear hair cells.

    Directory of Open Access Journals (Sweden)

    Ronna Hertzano

    2008-10-01

    Full Text Available Myosin VI, found in organisms from Caenorhabditis elegans to humans, is essential for auditory and vestibular function in mammals, since genetic mutations lead to hearing impairment and vestibular dysfunction in both humans and mice. Here, we show that a missense mutation in this molecular motor in an ENU-generated mouse model, Tailchaser, disrupts myosin VI function. Structural changes in the Tailchaser hair bundles include mislocalization of the kinocilia and branching of stereocilia. Transfection of GFP-labeled myosin VI into epithelial cells and delivery of endocytic vesicles to the early endosome revealed that the mutant phenotype displays disrupted motor function. The actin-activated ATPase rates measured for the D179Y mutation are decreased, and indicate loss of coordination of the myosin VI heads or 'gating' in the dimer form. Proper coordination is required for walking processively along, or anchoring to, actin filaments, and is apparently destroyed by the proximity of the mutation to the nucleotide-binding pocket. This loss of myosin VI function may not allow myosin VI to transport its cargoes appropriately at the base and within the stereocilia, or to anchor the membrane of stereocilia to actin filaments via its cargos, both of which lead to structural changes in the stereocilia of myosin VI-impaired hair cells, and ultimately leading to deafness.

  7. Novel mechanisms that regulate clot structure/function.

    Science.gov (United States)

    Ariëns, Robert A S

    2016-05-01

    The structure and function of the blood clot has been associated with altered risk of thrombosis. Dense fibrin structures with small pores increase the risk of thrombosis, and have major functional consequences by increasing the resistance to fibrinolysis and altering the visco-elastic properties of the clot. However, while the structural changes to the overall fibrin network have been extensively characterised, little is known regarding the intrafibrillar structure of fibrin, the way protofibrils are arranged inside the fibrin fibers and the functional consequences of this. This brief paper aims to review recent findings regarding novel mechanisms that regulate fibrin intrafibrillar structure, including the degree of protofibril packing, their functional consequences, and the effects of FXIII activation on clot structure and thrombosis. It is concluded that fibrin intrafibrillar structure represents a major novel mechanism that influences clot structure and stability. Future studies are required to investigate the role of fibrin intrafibrillar structure in the functional characteristics of the blood clot, and in diseases of bleeding and thrombosis.

  8. [Development of Fluorescence Sensing Mechanism for Cell Functional Analysis].

    Science.gov (United States)

    Ojida, Akio; Takashima, Ippei

    2016-01-01

      Fluorescence probes are now widely used as indispensable tools in many cell functional analyses. At present, the design of fluorescent probes largely depends on the limited numbers of established sensing mechanisms such as photo-induced electron transfer (PET), photo-induced charge transfer (PCT), and fluorescence resonance energy transfer (FRET). Although these mechanisms are versatile in metal ion sensing, introduction of a new sensing mechanism is highly desirable not only to design a more sophisticated probe with high selectivity and sensitivity but also to expand the diversity of the sensing targets to unveil biological phenomena. In this article, we report the design of dual emission fluorescent probes for metal ions based on a unique fluorescence-sensing mechanism. The fluorescent probes incorporating this sensing mechanism displayed a large emission red-shift on complexation with metal ions such as Cd(II) and Ag(I). X-ray crystallography and theoretical computational calculations of the Cd(II) and Ag(I) complexes revealed that the emission shift was induced by non-coordination contact between the aromatic ring of fluorophore and the metal ion (arene-metal ion contact; AM-contact), which modulates the energy levels of molecular orbitals. The fluorescent probe was successfully applied to in cell ratiometric bioimaging of bioactive hydrogen sulfide (H2S). These successful applications highlight the usefulness of this sensing mechanism in biological fluorescence analysis.

  9. The Structure, Functions, and Mechanical Properties of Keratin

    Science.gov (United States)

    McKittrick, J.; Chen, P.-Y.; Bodde, S. G.; Yang, W.; Novitskaya, E. E.; Meyers, M. A.

    2012-04-01

    Keratin is one of the most important structural proteins in nature and is widely found in the integument in vertebrates. It is classified into two types: α-helices and β-pleated sheets. Keratinized materials can be considered as fiber-reinforced composites consisting of crystalline intermediate filaments embedded in an amorphous protein matrix. They have a wide variety of morphologies and properties depending on different functions. Here, we review selected keratin-based materials, such as skin, hair, wool, quill, horn, hoof, feather, and beak, focusing on the structure-mechanical property-function relationships and finally give some insights on bioinspired composite design based on keratinized materials.

  10. The forced-response test does not discriminate ears with different otitis media expressions.

    Science.gov (United States)

    Casselbrant, Margaretha L; Mandel, Ellen M; Seroky, James T; Swarts, J Douglas; Doyle, William J

    2014-11-01

    Test the hypothesis that the eustachian tube (ET) function measured using standard manometric test methods is different between groups of ears with tympanostomy tubes inserted for recurrent acute otitis media (RAOM) and for chronic otitis media with effusion (COME). A cross-sectional study of ET function in populations of young children with different otitis media expressions. The results for forced-response testing of ET function were compared using a general linear model between 37 ears of 26 children and 34 ears of 26 children, aged 3 and 4 years, with ventilation tubes inserted for COME and RAOM, respectively. There were no significant between-group differences in either the active measure of ET opening function, dilatory efficiency, or in the passive measures reflecting the magnitude of the forces that tend to hold the ET lumen closed, the opening and closing pressures, and passive trans-ET conductance. The results do not support the hypothesis that ET closing forces are less in ears with RAOM when compared to ears with COME, and from the results of earlier studies, ears without disease. Both groups were characterized by a low ET opening efficiency (referenced to ears of adults with no disease history). Because both disease expressions present the same pattern of ET dysfunction, other factors are required to explain why a subset of ears with that type of dysfunction develop RAOM, as opposed to the default expression of COME. 2b © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Effects of Consecutive Wideband Tympanometry Trials on Energy Absorbance Measures of the Middle Ear

    Science.gov (United States)

    Burdiek, Laina M.; Sun, Xiao-Ming

    2014-01-01

    Purpose: Wideband acoustic immittance (WAI) is a new technique for assessing middle ear transfer function. It includes energy absorbance (EA) measures and can be acquired with the ear canal pressure varied, known as "wideband tympanometry" (WBTymp). The authors of this study aimed to investigate effects of consecutive WBTymp testing on…

  12. On the mechanics of functional asymmetry in bipedal walking.

    Science.gov (United States)

    Gregg, Robert D; Dhaher, Yasin Y; Degani, Amir; Lynch, Kevin M

    2012-05-01

    This paper uses two symmetrical models, the passive compass-gait biped and a five-link 3-D biped, to computationally investigate the cause and function of gait asymmetry. We show that for a range of slope angles during passive 2-D walking and mass distributions during controlled 3-D walking, these models have asymmetric walking patterns between the left and right legs due to the phenomenon of spontaneous symmetry-breaking. In both cases a stable asymmetric family of gaits emerges from a symmetric family of gaits as the total energy increases (e.g., fast speeds). The ground reaction forces of each leg reflect different roles, roughly corresponding to support, propulsion, and motion control as proposed by the hypothesis of functional asymmetry in able-bodied human walking. These results suggest that body mechanics, independent of neurophysiological mechanisms such as leg dominance, may contribute to able-bodied gait asymmetry.

  13. From mechanisms to function: an integrated framework of animal innovation

    Science.gov (United States)

    Tebbich, Sabine; Griffin, Andrea S.; Peschl, Markus F.; Sterelny, Kim

    2016-01-01

    Animal innovations range from the discovery of novel food types to the invention of completely novel behaviours. Innovations can give access to new opportunities, and thus enable innovating agents to invade and create novel niches. This in turn can pave the way for morphological adaptation and adaptive radiation. The mechanisms that make innovations possible are probably as diverse as the innovations themselves. So too are their evolutionary consequences. Perhaps because of this diversity, we lack a unifying framework that links mechanism to function. We propose a framework for animal innovation that describes the interactions between mechanism, fitness benefit and evolutionary significance, and which suggests an expanded range of experimental approaches. In doing so, we split innovation into factors (components and phases) that can be manipulated systematically, and which can be investigated both experimentally and with correlational studies. We apply this framework to a selection of cases, showing how it helps us ask more precise questions and design more revealing experiments. PMID:26926285

  14. From mechanisms to function: an integrated framework of animal innovation.

    Science.gov (United States)

    Tebbich, Sabine; Griffin, Andrea S; Peschl, Markus F; Sterelny, Kim

    2016-03-19

    Animal innovations range from the discovery of novel food types to the invention of completely novel behaviours. Innovations can give access to new opportunities, and thus enable innovating agents to invade and create novel niches. This in turn can pave the way for morphological adaptation and adaptive radiation. The mechanisms that make innovations possible are probably as diverse as the innovations themselves. So too are their evolutionary consequences. Perhaps because of this diversity, we lack a unifying framework that links mechanism to function. We propose a framework for animal innovation that describes the interactions between mechanism, fitness benefit and evolutionary significance, and which suggests an expanded range of experimental approaches. In doing so, we split innovation into factors (components and phases) that can be manipulated systematically, and which can be investigated both experimentally and with correlational studies. We apply this framework to a selection of cases, showing how it helps us ask more precise questions and design more revealing experiments.

  15. On the Correspondence Between Newtonian and Functional Mechanics

    Science.gov (United States)

    Piskovskiy, E. V.; Volovich, I. V.

    2011-01-01

    The world view underlying traditional science is based on reductionism and determinism when there is an empty space (vacuum) and material points which move along the Newtonian trajectories. This approach may be called "mechanistic" or "Newtonian". Quantum mechanics, in its Copenhagen interpretation, also adopts this world view. However this world view is not satisfactory by at least two reasons. First, there is uncertainty in the derivation of the position and velocity of the material point and second, it can not solve the time irreversibility problem. Moreover, the Newtonian approach is not well suited for applications of mathematics and physics to life science. Recently a new approach to classical mechanics was proposed in which the basic notion is not the trajectory but a probability distribution. In this functional mechanics approach one deals with the mean trajectories and one has corrections to the Newtonian equation of motion. In this note we consider correspondence between the Newtonian trajectories for an anharmonic oscillator and the averaged trajectories in the functional mechanics and compute the dependence of the characteristic time from the dispersion.

  16. [The antalgic and antiphiogistic function and mechanism of RGDT plaster].

    Science.gov (United States)

    Liu, Xiao-Xia; Wang, Zhi-wang; Chien, Xiao-pin; Liu, Cai-min; Tuo, Hai-yan

    2015-09-01

    To study the antalgic and antiphlogistic functions and mechanism of ronggudingtong (RGDT) plaster (traditional Chinese medicine). The painful models were established with hot plate test or acetic acid writhing and the inflammatory models were established with daubing dimethylbenzene on auricle or injecting formaldehyde in toe or synovial envelope to study the antalgic and antiphlogistic functions of RGDT Plaster. The total protein and leukotriene B4(LTB4) in inflammatory exudate were detected to investigate the antalgic and antiphlogistic mechanism of RGDT plaster. The mice were randomly divided into different groups (n = 11), on the basis of drug using, the indexes of pain threshold, swelling degree were observed. Sixty-six mice were used to establish gasbag synovitis model and randomly divided into normal control group,model control group, positive control group (Voltaren gel 0.8 mg/d)and low/medium/high dosage RGDT plaster treating groups(30 mg/d, 60 mg/d, 120 mg/d). 30 mg/d, 60 mg/d,120 mg/d RGDT plaster could upgrade the pain thresholds, remit auricular and foot swelling (P plaster has some antalgic and antiphlogistic functions, and one of the mechanisms is depressing synthesis of LTB4.

  17. Comparative analysis on data of ear baric function by hypobaric chamber test between helicopter and fighter pilots%直升机和歼击机飞行员耳气压功能比较

    Institute of Scientific and Technical Information of China (English)

    徐先荣; 汪斌如; 金占国; 张扬

    2016-01-01

    目的 比较直升机和歼击机飞行员的耳气压功能,为直升机飞行员航卫保障提供参考依据. 方法 询问飞行合格的220名飞行员(直升机飞行员130人,歼击机飞行员90人)的病史,并对飞行员进行电耳镜、纯音测听、声导抗及前鼻镜、鼻内镜检查,无低压舱检查禁忌证者进行耳气压功能检查.①直升机飞行员和歼击机飞行员均坐于低压舱内模拟飞行,以15~20 m/s速率上升至4 000 m,停留5 min,再以5 m/s速率下降返回地面,出舱后再次行电耳镜、纯音测听和声导抗检查,与进舱前的检查结果进行对照.②歼击机飞行员坐于低压舱内,以20~30 m/s速率模拟上升至4 000 m,停留5 min,再以20~25 m/s速率模拟下降返回地面,出舱后再次行电耳镜、纯音测听和声导抗检查,与进舱前的检查结果进行对照.比较两组飞行员耳气压功能不良的发生率. 结果 ①1例直升机飞行员患感冒,电耳镜检查鼓膜Ⅱ度充血,纯音测听轻度传导性聋,声导抗示C型曲线,故未安排进舱而终止检查.②低压舱模拟慢速率(5 m/s)下降时,直升机飞行员耳气压功能不良的发生率(6.20%)高于歼击机飞行员(0.00%),两组差异有统计学意义(x2 =4.16,P<0.05).③低压舱模拟快速率(20~25 m/s)下降时,歼击机飞行员耳气压功能不良的发生率为7.78%(7/90),与慢速率下降高度时直升机飞行员耳气压功能不良的发生率相比,差异无统计学意义(x2=0.21,P>0.05).结论 对不同机种飞行员进行低压舱耳气压功能检查和航空医学训练时,应按不同速率的上升/下降方案进行岗位胜任能力评价.%Objective To compare the ear baric function of helicopter pilots and fighter pilots and to investigate the aeromedical support on helicopter pilots' ear baric function.Methods One hundred and thirty helicopter pilots and 90 fighter pilots were inquired about their health history and examined by electric

  18. Regulatory Mechanisms and Physiological Significance of Reelin Function.

    Science.gov (United States)

    Kohno, Takao

    2017-01-01

     Reelin is a large secreted glycoprotein that regulates embryonic neuronal lamination and adult synaptic function. Secreted Reelin binds to lipoprotein receptors expressed on neurons. The Reelin-receptor interaction induces phosphorylation of an intracellular adaptor protein Dab1, which is required for normal embryonic brain development and adult brain functions. It has been suggested that Reelin hypofunction plays a role in the pathogenesis of several neuropsychiatric diseases, such as schizophrenia, autism, and Alzheimer's disease. Thus upregulation of Reelin activity may ameliorate the symptoms of neuropsychiatric diseases. However, the regulatory mechanism underlying the functions of Reelin is largely unknown and there are no good animal models of Reelin malfunction; thus, causal relations between Reelin and neuropsychiatric diseases remain unclear. Recently, our studies have shown that proteolytic cleavage of the Reelin protein regulates its activity. Herein, we will review recent findings about relations between Reelin and Alzheimer's disease, and the mechanism underlying the regulation of Reelin function by proteolytic cleavage. Also, we will discuss the prospect of treating neuropsychiatric diseases by upregulation of Reelin activity.

  19. Carcinoid tumour of the middle ear

    LENUS (Irish Health Repository)

    Baig, Salman

    2012-09-01

    A case of middle ear mass in a young female from Ireland is described, who presented with left ear hearing loss and intermittent bloody discharge from the same ear. Examination under microscope revealed occlusive polyp in the left ear and a biopsy had been taken under general anaesthesia. Histopathology report described an adenoma \\/ carcinoid tumour of the middle ear confirmed by positive immunohistochemical staining. CT temporal bones revealed the extension of the disease. The patient underwent left tympanotomy and excision of the tumour. In general, these tumours are regarded as benign but may be mistaken for adenocarcinomas because of their histological heterogenecity.

  20. A Survey on Human Ear Recognition

    Directory of Open Access Journals (Sweden)

    Suvarnsing Bhable

    2015-11-01

    Full Text Available This paper presents an efficient ear recognition technique which derives benefits from the local features of the ear and attempt to handle the problems due to pose, poor contrast, change in illumination and lack of registration. Recognizing humans by their ear have recently received significant attention in the field of research. Ear is the rich in characteristics. This paper provides a detailed survey of research done in ear detection and recognition. This survey paper is very useful in the current state-of- art for those who are working in this area and also for those who might exploit this new approach.

  1. A simple ear splint for microtia patients

    Directory of Open Access Journals (Sweden)

    C J Venkata Krishnan

    2015-01-01

    Full Text Available Microtia is a congenital anomaly of the ear can occur as an isolated birth defect or as part of a spectrum of anomalies or as a syndrome. Microtia is often associated with impaired hearing and or total loss of hearing. Such patients typically require treatment for surgical ear reconstruction and for hearing impairment. Maintenance of ear projection and post auricular sulcus in staged ear reconstruction in microtia is a trying problem. So also is the maintenance of the patency of the external auditory meatus following recanalization and meatoplasty.This case report describes a simple effective way of fabrication of ear splint prosthesis.

  2. A simple ear splint for microtia patients.

    Science.gov (United States)

    Krishnan, C J Venkata; Balaji, S M; Jain, Ashish R

    2015-01-01

    Microtia is a congenital anomaly of the ear can occur as an isolated birth defect or as part of a spectrum of anomalies or as a syndrome. Microtia is often associated with impaired hearing and or total loss of hearing. Such patients typically require treatment for surgical ear reconstruction and for hearing impairment. Maintenance of ear projection and post auricular sulcus in staged ear reconstruction in microtia is a trying problem. So also is the maintenance of the patency of the external auditory meatus following recanalization and meatoplasty.This case report describes a simple effective way of fabrication of ear splint prosthesis.

  3. Prótese implantável do ouvido médio: ganho funcional em perda auditiva mista Middle ear implants: functional gain in mixed hearing loss

    Directory of Open Access Journals (Sweden)

    Mario Emilio Zernotti

    2012-02-01

    Full Text Available Atresia óssea e otite média crônica são os principais grupos de beneficiários com implantes do ouvido médio. Cirurgia de atresia é tecnicamente complexo, tem muitas complicações e resultados funcionais pobres. Os aparelhos auditivos osseointegrados são uma alternativa. Eles fornecem um ganho funcional muito bom, mas tem muitos problemas de pele e osseointegração. Na otite média crônica, ossiculoplastias resolveram parcialmente o problema de audição. Infelizmente, em alguns casos de otites média e cavidades abertas, equipamentos com aparelhos auditivos convencionais são difíceis e muitas vezes insatisfatórios. OBJETIVO: Determinar a utilidade de um implante do ouvido médio. Desenho de estudo longitudinal. MÉTODOS: Vibrant-Soundbrigde foi implantado em oito pacientes com perda auditiva mista grave. Quatro apresentavam otite média crônica e quatro apresentavam atresia unilateral. A colocação do estimulador (FMT ou Floating Mass Transducer foi em cinco pacientes na janela redonda, dois no estribo e um na janela oval. RESULTADOS: Ganho funcional foi de 35 dB, 40 dB, 48,7 dB e 50 dB para as frequências de 500, 1000, 2000 e 4000 Hz, respectivamente. CONCLUSÃO: Vibrant-Soundbrigde é uma excelente opção no restabelecimento da audição em perda auditiva mista grave e profunda. Ele fornece um excelente ganho funcional em doenças de difícil tratamento com equipamentos convencionais.Osseous atresia and chronic otitis media are diseases benefit with middle ear implants. Surgery for atresia is technically complicated, has significant number of complications and functional results are often poor. The osseointegrated hearing aids are an alternative. They provide a very good functional gain, but have many problems with the skin and osseointegration. In chronic otitis media, the ossiculoplasty solved partially the hearing problem. Unfortunately in some cases of otitis media and in open cavities fitted with conventional hearing

  4. Technique for correction of lop ear.

    Science.gov (United States)

    Elsahy, N I

    1990-04-01

    Various techniques of correction of lop ear have been described. Minor lop ear deformity can easily be corrected with simple excision of the overhanging auricular cartilage. Moderate and severe lop ear deformities, on the other hand, are more difficult to correct because there is actual reduction in size of the upper third of the ear in addition to the overhanging auricular cartilage. The purpose of this paper was to present a new technique used to correct the moderate lop ear deformity. In addition to excising the overhanging cartilage, I rotate a cartilage flap from the anthelix upward where the missing superior crus was supposed to be. This flap increases the vertical height of the ear and creates a new superior crus. I applied this technique on three cases of moderate lop ear deformities with good results.

  5. Structural remodeling and mechanical function in heart failure.

    Science.gov (United States)

    Leonard, Bridget Louise; Smaill, Bruce Henry; LeGrice, Ian John

    2012-02-01

    The cardiac extracellular matrix (ECM) is the three-dimensional scaffold that defines the geometry and muscular architecture of the cardiac chambers and transmits forces produced during the cardiac cycle throughout the heart wall. The cardiac ECM is an active system that responds to the stresses to which it is exposed and in the normal heart is adapted to facilitate efficient mechanical function. There are marked differences in the short- and medium-term changes in ventricular geometry and cardiac ECM that occur as a result of volume overload, hypertension, and ischemic cardiomyopathy. Despite this, there is a widespread view that a common remodeling "phenotype" governs the final progression to end-stage heart failure in different forms of heart disease. In this review article, we make the case that this interpretation is not consistent with the clinical and experimental data on the topic. We argue that there is a need for new theoretical and experimental models that will enable stresses acting on the ECM and resultant deformations to be estimated more accurately and provide better spatial resolution of local signaling mechanisms that are activated as a result. These developments are necessary to link the effects of structural remodeling with altered cardiac mechanical function.

  6. Genetic and Epigenetic Mechanisms That Maintain Hematopoietic Stem Cell Function

    Directory of Open Access Journals (Sweden)

    Christian Kosan

    2016-01-01

    Full Text Available All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem cell niche provides the microenvironment to keep HSC in a quiescent state. Furthermore, several transcription factors and epigenetic modifiers are involved in this process. These create modifications that regulate the cell fate in a more or less reversible and dynamic way and contribute to HSC homeostasis. In addition, HSC respond in a unique way to DNA damage. These mechanisms also contribute to the regulation of HSC function and are essential to ensure viability after DNA damage. How HSC maintain their quiescent stage during the entire life is still matter of ongoing research. Here we will focus on the molecular mechanisms that regulate HSC function.

  7. Dominantly-inherited lop ears.

    Science.gov (United States)

    Leung, Alexander K C; Kong, Albert Y F; Robson, W Lane M; McLeod, D Ross

    2007-10-01

    We describe a four-generation Chinese family that included five members who had an isolated bilateral lop ear anomaly. The presentation suggested a dominant mode of inheritance. The absence of male-to-male transmission does not exclude an X-linked dominant mode of inheritance. Since the phenotypic anomaly of the male proband was no more severe than the affected female members, an autosomal dominant mode of inheritance is most likely. 2007 Wiley-Liss, Inc

  8. On the mechanics of cardiac function of Drosophila embryo.

    Science.gov (United States)

    Wu, Mingming; Sato, Thomas N

    2008-01-01

    The heart is a vital organ that provides essential circulation throughout the body. Malfunction of cardiac pumping, thus, leads to serious and most of the times, to fatal diseases. Mechanics of cardiac pumping is a complex process, and many experimental and theoretical approaches have been undertaken to understand this process. We have taken advantage of the simplicity of the embryonic heart of an invertebrate, Drosophila melanogaster, to understand the fundamental mechanics of the beating heart. We applied a live imaging technique to the beating embryonic heart combined with analytical imaging tools to study the dynamic mechanics of the pumping. Furthermore, we have identified one mutant line that exhibits aberrant pumping mechanics. The Drosophila embryonic heart consists of only 104 cardiac cells forming a simple straight tube that can be easily accessed for real-time imaging. Therefore, combined with the wealth of available genetic tools, the embryonic Drosophila heart may serve as a powerful model system for studies of human heart diseases, such as arrhythmia and congenital heart diseases. We, furthermore, believe our mechanistic data provides important information that is useful for our further understanding of the design of biological structure and function and for engineering the pumps for medical uses.

  9. Roll, adhere, spread and contract: structural mechanics of platelet function.

    Science.gov (United States)

    Sorrentino, Simona; Studt, Jan-Dirk; Medalia, Ohad; Tanuj Sapra, K

    2015-01-01

    Platelets are involved in life-sustaining processes such as hemostasis, wound healing, atherothrombosis and angiogenesis. Mechanical trauma to blood vessels causes platelet activation resulting in their adherence and clot formation at the damaged site, culminating in clot retraction and tissue repair. Two of the major players underlying this process are the cytoskeleton, i.e., actin and microtubules, and the membrane integrin receptors. Rare congenital bleeding disorders such as Glanzmann thrombasthenia and Bernard-Soulier syndrome are associated with genetic alterations of platelet surface receptors, also affecting the platelet cytoskeletal structure. In this review, we summarize the current knowledge about platelet structure and adhesion, and delve into the mechanical aspects of platelet function. Platelets lack a nucleus, and can thus provide a minimal model of a biological cell. New biophysical tools may help to scrutinize platelets anew and to extend the existing knowledge on cell biology.

  10. Extracellular matrix structure and nano-mechanics determine megakaryocyte function.

    Science.gov (United States)

    Malara, Alessandro; Gruppi, Cristian; Pallotta, Isabella; Spedden, Elise; Tenni, Ruggero; Raspanti, Mario; Kaplan, David; Tira, Maria Enrica; Staii, Cristian; Balduini, Alessandra

    2011-10-20

    Cell interactions with matrices via specific receptors control many functions, with chemistry, physics, and membrane elasticity as fundamental elements of the processes involved. Little is known about how biochemical and biophysical processes integrate to generate force and, ultimately, to regulate hemopoiesis into the bone marrow-matrix environment. To address this hypothesis, in this work we focus on the regulation of MK development by type I collagen. By atomic force microscopy analysis, we demonstrate that the tensile strength of fibrils in type I collagen structure is a fundamental requirement to regulate cytoskeleton contractility of human MKs through the activation of integrin-α2β1-dependent Rho-ROCK pathway and MLC-2 phosphorylation. Most importantly, this mechanism seemed to mediate MK migration, fibronectin assembly, and platelet formation. On the contrary, a decrease in mechanical tension caused by N-acetylation of lysine side chains in type I collagen completely reverted these processes by preventing fibrillogenesis.

  11. [Functions and mechanisms of dehydroepiandrosterone in nervous system].

    Science.gov (United States)

    Xie, Li; Sun, Hui-Ying; Gao, Jing; Liao, Hong

    2006-10-01

    Dehydroepiandrosterone is the precursor of sex hormone, and can be synthesized in the brain de novo, which means it is a kind of neurosteroid. Animal experiments and clinical researches have proved that DHEA exhibits a variety of functional activities in the nervous system, including neurotrophic, neuroprotective effects and enhancement' of learning and memory, which suggests that it may be useful in preventing and treating some neural diseases such as neurodegenerative diseases, cerebral ischemia, trauma, psychosis and so on. The mechanisms of the effect of DHEA on protection against oxidative stress, excitotoxicity, apoptosis etc. were found to be through both genomic and nongenomic way. These effects and mechanisms in nervous system were summarized in the present paper.

  12. Groups as units of functional analysis, individuals as proximate mechanisms.

    Science.gov (United States)

    Wilson, David Sloan

    2014-06-01

    Whenever selection operates at a given level of a multitier hierarchy, units at that level should become the object of functional analysis, and units at lower levels should be studied as proximate mechanisms. This intuition already exists for the study of genes in individuals, when individuals are the unit of selection. It is only beginning to be applied for the study of individuals in groups, when groups are the unit of selection. Smaldino's target article is an important step in this direction with an emphasis on human cultural evolution, but the same algorithm applies to all multilevel evolutionary processes.

  13. Modeling behavior: the quest to link mechanisms to function.

    Science.gov (United States)

    Janus, C; Dubnau, J

    2003-02-01

    T. Dobzhansky (1973) has been credited with saying: 'nothing in biology makes sense, except in the light of evolution'. The evolutionary conservation of gene function, as well as remarkable conservation of elemental behavioral mechanisms, guarantees that much of what we learn in one organism will inform our understanding of behavior in all animals, including humans. This insight has permitted behavior-geneticists to choose organisms based on experimental tractability for a given scientific question. IBANGS as a society has clearly embraced this Dobzhanskian worldview. As a result, the intellectual synergy of cross-species behavior-genetic analysis was palpable at the IBANGS meeting in Tours, France.

  14. Functional analysis and quantum mechanics: an introduction for physicists

    Energy Technology Data Exchange (ETDEWEB)

    Ranade, Kedar S. [Ulm Univ. (Germany). Inst. fuer Quantenphysik and Center for Integrated Quantum Science and Technology (IQST)

    2015-09-15

    We give an introduction to certain topics from functional analysis which are relevant for physics in general and in particular for quantum mechanics. Starting from some examples, we discuss the theory of Hilbert spaces, spectral theory of unbounded operators, distributions and their applications and present some facts from operator algebras. We do not give proofs, but present examples and analogies from physics which should be useful to get a feeling for the topics considered. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Functional methods underlying classical mechanics, relativity and quantum theory

    Science.gov (United States)

    Kryukov, A.

    2013-04-01

    The paper investigates the physical content of a recently proposed mathematical framework that unifies the standard formalisms of classical mechanics, relativity and quantum theory. In the framework states of a classical particle are identified with Dirac delta functions. The classical space is "made" of these functions and becomes a submanifold in a Hilbert space of states of the particle. The resulting embedding of the classical space into the space of states is highly non-trivial and accounts for numerous deep relations between classical and quantum physics and relativity. One of the most striking results is the proof that the normal probability distribution of position of a macroscopic particle (equivalently, position of the corresponding delta state within the classical space submanifold) yields the Born rule for transitions between arbitrary quantum states.

  16. The porcine ear skin as a model system for the human integument: influence of storage conditions on basic features of epidermis structure and function--a histological and histochemical study.

    Science.gov (United States)

    Meyer, W; Zschemisch, N H; Godynicki, S

    2003-01-01

    Based on careful tissue processing, detailed structural analysis, and histochemical as well as cytophotometrical evaluation of the epidermis, the study presents data with respect to changes of tissue integrity during two storing modes (room temperature and 4 degrees C) and various storage times of the porcine auricle. Structural degeneration was first noted in the barrier region of the epidermis from where such changes spread, independent of storage conditions, from small horizontal necrotic islands and continuously with increasing storage time. The histochemical results corroborated these observations, emphasizing, however, that the lower epidermal layers seemed intact for a longer time period than the upper layers. Cytophotometrical evaluation of histochemical stainings showed, with regard to the enzyme succinate dehydrogenase, that oxidative metabolism was negatively affected in the early stages of storage, whereas epidermal lipids (neutral fats, glycolipids) remained relatively stable, even during storage at room temperature. In conclusion, it was obvious that the barrier region is the most sensitive element of the porcine ear epidermis. Taking into consideration that this part of the epidermis is most important for permeation studies, it seems reasonable to avoid any storage of porcine auricles at room temperature, and to use only auricles that have been stored at 4 degrees C for not more than 4 to 6 hours, immediately after delivery from the slaughter-house. In this way better tissue preservation can be achieved, whereby the use of shinkage-free water-soluble plastic embedding would generally improve the histological control of structural integrity, and the application of an easy to handle enzyme histochemical procedure (e.g. succinate dehydrogenase demonstration) to unfixed fresh-frozen sections would help to control basic aspects of tissue functions. The results are discussed in relation to the use of porcine integument as a model in human dermatological

  17. Correlation between videogame mechanics and executive functions through EEG analysis.

    Science.gov (United States)

    Mondéjar, Tania; Hervás, Ramón; Johnson, Esperanza; Gutierrez, Carlos; Latorre, José Miguel

    2016-10-01

    This paper addresses a different point of view of videogames, specifically serious games for health. This paper contributes to that area with a multidisciplinary perspective focus on neurosciences and computation. The experiment population has been pre-adolescents between the ages of 8 and 12 without any cognitive issues. The experiment consisted in users playing videogames as well as performing traditional psychological assessments; during these tasks the frontal brain activity was evaluated. The main goal was to analyse how the frontal lobe of the brain (executive function) works in terms of prominent cognitive skills during five types of game mechanics widely used in commercial videogames. The analysis was made by collecting brain signals during the two phases of the experiment, where the signals were analysed with an electroencephalogram neuroheadset. The validated hypotheses were whether videogames can develop executive functioning and if it was possible to identify which kind of cognitive skills are developed during each kind of typical videogame mechanic. The results contribute to the design of serious games for health purposes on a conceptual level, particularly in support of the diagnosis and treatment of cognitive-related pathologies.

  18. Ubiquitination-dependent mechanisms regulate synaptic growth and function.

    Science.gov (United States)

    DiAntonio, A; Haghighi, A P; Portman, S L; Lee, J D; Amaranto, A M; Goodman, C S

    2001-07-26

    The covalent attachment of ubiquitin to cellular proteins is a powerful mechanism for controlling protein activity and localization. Ubiquitination is a reversible modification promoted by ubiquitin ligases and antagonized by deubiquitinating proteases. Ubiquitin-dependent mechanisms regulate many important processes including cell-cycle progression, apoptosis and transcriptional regulation. Here we show that ubiquitin-dependent mechanisms regulate synaptic development at the Drosophila neuromuscular junction (NMJ). Neuronal overexpression of the deubiquitinating protease fat facets leads to a profound disruption of synaptic growth control; there is a large increase in the number of synaptic boutons, an elaboration of the synaptic branching pattern, and a disruption of synaptic function. Antagonizing the ubiquitination pathway in neurons by expression of the yeast deubiquitinating protease UBP2 (ref. 5) also produces synaptic overgrowth and dysfunction. Genetic interactions between fat facets and highwire, a negative regulator of synaptic growth that has structural homology to a family of ubiquitin ligases, suggest that synaptic development may be controlled by the balance between positive and negative regulators of ubiquitination.

  19. Comparison of sound transmission in human ears and coupler loaded by audiometric earphones

    DEFF Research Database (Denmark)

    Ciric, Dejan; Hammershøi, Dorte

    2005-01-01

    earphones, which is related to coupling of these earphones to human ears and to the coupler. This is done by measurements of the transfer functions from input voltage of the earphone terminals to the entrance of the ear canal in two situations: open, and blocked. Similar measurements were carried out......The thresholds of hearing are usually determined using audiometric earphones. They are calibrated by means of a standardized acoustical coupler. In order to have determined thresholds independent of the earphone type, the coupler should approximate the average human ear closely. Nevertheless...... in the coupler, but since the "ear canal entrance" is not well-defined for the coupler, the mentioned measurements were done at different depths in the coupler. The sound transmission and coupling were described in terms of the pressure division at the entrance of the ear canal and the transmissions in human...

  20. Diversity in mechanism and function of tRNA methyltransferases

    Science.gov (United States)

    Swinehart, William E; Jackman, Jane E

    2015-01-01

    tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed. PMID:25626150

  1. Potential Mechanisms and Functions of Intermittent Neural Synchronization

    Directory of Open Access Journals (Sweden)

    Sungwoo Ahn

    2017-05-01

    Full Text Available Neural synchronization is believed to play an important role in different brain functions. Synchrony in cortical and subcortical circuits is frequently variable in time and not perfect. Few long intervals of desynchronized dynamics may be functionally different from many short desynchronized intervals although the average synchrony may be the same. Recent analysis of imperfect synchrony in different neural systems reported one common feature: neural oscillations may go out of synchrony frequently, but primarily for a short time interval. This study explores potential mechanisms and functional advantages of this short desynchronizations dynamics using computational neuroscience techniques. We show that short desynchronizations are exhibited in coupled neurons if their delayed rectifier potassium current has relatively large values of the voltage-dependent activation time-constant. The delayed activation of potassium current is associated with generation of quickly-rising action potential. This “spikiness” is a very general property of neurons. This may explain why very different neural systems exhibit short desynchronization dynamics. We also show how the distribution of desynchronization durations may be independent of the synchronization strength. Finally, we show that short desynchronization dynamics requires weaker synaptic input to reach a pre-set synchrony level. Thus, this dynamics allows for efficient regulation of synchrony and may promote efficient formation of synchronous neural assemblies.

  2. Effects of NSAIDs on the Inner Ear: Possible Involvement in Cochlear Protection

    Directory of Open Access Journals (Sweden)

    Akira Hara

    2010-04-01

    Full Text Available Cyclooxygenase and lipoxygenase, two important enzymes involved in arachidonic acid metabolism, are major targets of non-steroidal anti-inflammatory drugs (NSAIDs. Recent investigations suggest that arachidonic cascades and their metabolites may be involved in maintaining inner ear functions. The excessive use of aspirin may cause tinnitus in humans and impairment of the outer hair cell functions in experimental animals. On the other hand, NSAIDs reportedly exhibit protective effects against various kinds of inner ear disorder. The present review summarizes the effects of NSAIDs on cochlear pathophysiology. NSAIDs are a useful ameliorative adjunct in the management of inner ear disorders.

  3. Hair cell bundles: flexoelectric motors of the inner ear.

    Directory of Open Access Journals (Sweden)

    Kathryn D Breneman

    Full Text Available Microvilli (stereocilia projecting from the apex of hair cells in the inner ear are actively motile structures that feed energy into the vibration of the inner ear and enhance sensitivity to sound. The biophysical mechanism underlying the hair bundle motor is unknown. In this study, we examined a membrane flexoelectric origin for active movements in stereocilia and conclude that it is likely to be an important contributor to mechanical power output by hair bundles. We formulated a realistic biophysical model of stereocilia incorporating stereocilia dimensions, the known flexoelectric coefficient of lipid membranes, mechanical compliance, and fluid drag. Electrical power enters the stereocilia through displacement sensitive ion channels and, due to the small diameter of stereocilia, is converted to useful mechanical power output by flexoelectricity. This motor augments molecular motors associated with the mechanosensitive apparatus itself that have been described previously. The model reveals stereocilia to be highly efficient and fast flexoelectric motors that capture the energy in the extracellular electro-chemical potential of the inner ear to generate mechanical power output. The power analysis provides an explanation for the correlation between stereocilia height and the tonotopic organization of hearing organs. Further, results suggest that flexoelectricity may be essential to the exquisite sensitivity and frequency selectivity of non-mammalian hearing organs at high auditory frequencies, and may contribute to the "cochlear amplifier" in mammals.

  4. Optical assessment of middle ear inflammation

    OpenAIRE

    Jung, David S.

    2016-01-01

    This thesis describes the development of an optical device to assess the inflammatory state of the middle ear mucosa through the ear canal, after ventilation tube insertion in otitis media with effusion in children. An optical phantom of the middle ear was developed in order to allow repeatable experiments. The phantom consists of eardrum and mucosa while all other structures are neglected. The optical properties of the phantom were determined based on literature review and experiments on...

  5. Analysis of Earing in Deep Drawn Cups

    Science.gov (United States)

    Aretz, Holger; Aegerter, Johannes; Engler, Olaf

    2010-06-01

    The cup-drawing of a strongly anisotropic sheet metal is simulated using a commercial finite element software along with a user material subroutine. In order to accurately describe the plastic anisotropy of the material the well-known recent yield function `Yld2004-18p' is extended. Regarding the experimental characterization of the considered material the occurrence of dynamic strain aging lead to an oscillating signal of the width change of the tensile samples, which prevented a reliable determination of plastic strain ratios (r-values). Thus, an improved measurement concept was developed that leads to a very robust and reproducible determination of r-values. Furthermore, a novel plane-strain tensile test sample is presented which is used for the characterization of the plastic anisotropy in biaxial loading states. A quantitative comparison with measured earing profiles of deep drawn cups illustrates the predictive capabilities of the numerical simulation.

  6. An Effective 3D Ear Acquisition System.

    Directory of Open Access Journals (Sweden)

    Yahui Liu

    Full Text Available The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition.

  7. An Effective 3D Ear Acquisition System.

    Science.gov (United States)

    Liu, Yahui; Lu, Guangming; Zhang, David

    2015-01-01

    The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition.

  8. The strange case of the ear and the heart: the auricular vagus nerve and its influence on cardiac control

    OpenAIRE

    Murray, AR; Atkinson, L; Mahadi, MK; Deuchars, SA; Deuchars, J

    2016-01-01

    The human ear seems an unlikely candidate for therapies aimed at improving cardiac function, but the ear and the heart share a common connection: the vagus nerve. In recent years there has been increasing interest in the auricular branch of the vagus nerve (ABVN), a unique cutaneous subdivision of the vagus distributed to the external ear. Non-invasive electrical stimulation of this nerve through the skin may offer a simple, cost-effective alternative to the established method of vagus nerve ...

  9. MD 382: Beam Transfer Function and diffusion mechanisms

    CERN Document Server

    Tambasco, Claudia; Buffat, Xavier; Crouch, Matthew; Pieloni, Tatiana; Boccardi, Andrea; Fuchsberger, Kajetan; Gasior, Marek; Kotzian, Gerd; Lefevre, Thibaut; Pojer, Mirko; Salvachua Ferrando, Belen Maria; Solfaroli Camillocci, Matteo; Giachino, Rossano; CERN. Geneva. ATS Department

    2016-01-01

    The Beam Transfer Function (BTF) measurements have been previously tested in the LHC during MD block 1 and 2. Different machine configurations (i.e. energy, beam intensity, emittance etc...) have been tested to determine a safe set-up (excitation amplitude) of the system to be completely transparent to the beam (no emittance blow-up neither losses). The aim of this experiment in MD block 3 was to characterize the Stability Diagram (SD) in the presence of diffusion mechanisms induced by excited resonances due to beam-beam long range and Landau octupole interplay. During the experiment, BTF measurements have been acquired at flat top for different settings of Landau octupole current, different chromaticity values and transverse feedback gains. In this note the description of the experiment is presented together with some preliminary results.

  10. A Hybrid Imperative and Functional Molecular Mechanics Application

    Directory of Open Access Journals (Sweden)

    Thomas Deboni

    1996-01-01

    Full Text Available Molecular mechanics applications model the interactions among large ensembles of discrete particles. They are used where probabilistic methods are inadequate, such as drug chemistry. This methodology is difficult to parallelize with good performance, due to its poor locality, uneven partitions, and dynamic behavior. Imperative programs have been written that attempt this on shared and distributed memory machines. Given such a program, the computational kernel can be rewritten in Sisal, a functional programming language, and integrated with the rest of the imperative program under the Sisal Foreign Language Interface. This allows minimal effort and maximal return from parallelization work, and leaves the work appropriate to imperative implementation in its original form. We describe such an effort, focusing on the parts of the application that are appropriate for Sisal implementation, the specifics of mixed-language programming, and the complex performance behavior of the resulting hybrid code.

  11. FGF23 deficiency leads to mixed hearing loss and middle ear malformation in mice.

    Directory of Open Access Journals (Sweden)

    Andrew C Lysaght

    Full Text Available Fibroblast growth factor 23 (FGF23 is a circulating hormone important in phosphate homeostasis. Abnormal serum levels of FGF23 result in systemic pathologies in humans and mice, including renal phosphate wasting diseases and hyperphosphatemia. We sought to uncover the role FGF23 plays in the auditory system due to shared molecular mechanisms and genetic pathways between ear and kidney development, the critical roles multiple FGFs play in auditory development and the known hearing phenotype in mice deficient in klotho (KL, a critical co-factor for FGF23 signaling. Using functional assessments of hearing, we demonstrate that Fgf[Formula: see text] mice are profoundly deaf. Fgf[Formula: see text] mice have moderate hearing loss above 20 kHz, consistent with mixed conductive and sensorineural pathology of both middle and inner ear origin. Histology and high-voltage X-ray computed tomography of Fgf[Formula: see text] mice demonstrate dysplastic bulla and ossicles; Fgf[Formula: see text] mice have near-normal morphology. The cochleae of mutant mice appear nearly normal on gross and microscopic inspection. In wild type mice, FGF23 is ubiquitously expressed throughout the cochlea. Measurements from Fgf[Formula: see text] mice do not match the auditory phenotype of Kl-/- mice, suggesting that loss of FGF23 activity impacts the auditory system via mechanisms at least partially independent of KL. Given the extensive middle ear malformations and the overlap of initiation of FGF23 activity and Eustachian tube development, this work suggests a possible role for FGF23 in otitis media.

  12. Hsp100/ClpB Chaperone Function and Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Vierling, Elizabeth [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Biochemistry and Molecular Biology

    2015-01-27

    The supported research investigated the mechanism of action of a unique class of molecular chaperones in higher plants, the Hsp100/ClpB proteins, with the ultimate goal of defining how these chaperones influence plant growth, development, stress tolerance and productivity. Molecular chaperones are essential effectors of cellular “protein quality control”, which comprises processes that ensure the proper folding, localization, activation and turnover of proteins. Hsp100/ClpB proteins are required for temperature acclimation in plants, optimal seed yield, and proper chloroplast development. The model plant Arabidopsis thaliana and genetic and molecular approaches were used to investigate two of the three members of the Hsp100/ClpB proteins in plants, cytosolic AtHsp101 and chloroplast-localized AtClpB-p. Investigating the chaperone activity of the Hsp100/ClpB proteins addresses DOE goals in that this activity impacts how “plants generate and assemble components” as well as “allowing for their self repair”. Additionally, Hsp100/ClpB protein function in plants is directly required for optimal “utilization of biological energy” and is involved in “mechanisms that control the architecture of energy transduction systems”.

  13. Human adipocyte function is impacted by mechanical cues.

    Science.gov (United States)

    Pellegrinelli, V; Heuvingh, J; du Roure, O; Rouault, C; Devulder, A; Klein, C; Lacasa, M; Clément, E; Lacasa, D; Clément, K

    2014-06-01

    Fibrosis is a hallmark of human white adipose tissue (WAT) during obesity-induced chronic inflammation. The functional impact of increased interstitial fibrosis (peri-adipocyte fibrosis) on adjacent adipocytes remains unknown. Here we developed a novel in vitro 3D culture system in which human adipocytes and decellularized material of adipose tissue (dMAT) from obese subjects are embedded in a peptide hydrogel. When cultured with dMAT, adipocytes showed decreased lipolysis and adipokine secretion and increased expression/production of cytokines (IL-6, G-CSF) and fibrotic mediators (LOXL2 and the matricellular proteins THSB2 and CTGF). Moreover, some alterations including lipolytic activity and fibro-inflammation also occurred when the adipocyte/hydrogel culture was mechanically compressed. Notably, CTGF expression levels correlated with the amount of peri-adipocyte fibrosis in WAT from obese individuals. Moreover, dMAT-dependent CTGF promoter activity, which depends on β1-integrin/cytoskeleton pathways, was enhanced in the presence of YAP, a mechanosensitive co-activator of TEAD transcription factors. Mutation of TEAD binding sites abolished the dMAT-induced promoter activity. In conclusion, fibrosis may negatively affect human adipocyte function via mechanosensitive molecules, in part stimulated by cell deformation. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  14. Left Atrial Mechanical Function and Global Strain in Hypertrophic Cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Kyung-Jin Kim

    Full Text Available Atrial fibrillation is the most common arrhythmia and is associated with adverse outcomes in hypertrophic cardiomyopathy (HCM. Although left atrial (LA remodeling and dysfunction are known to associate with the development of atrial fibrillation in HCM, the changes of the LA in HCM patients remain unclear. This study aimed to evaluate the changes in LA size and mechanical function in HCM patients compared to control subjects and to determine the characteristics of HCM associated with LA remodeling and dysfunction.Seventy-nine HCM patients (mean age, 54 ± 11 years; 76% were men were compared to 79 age- and sex-matched controls (mean age, 54 ± 11 years; 76% were men and 20 young healthy controls (mean age, 33 ± 5 years; 45% were men. The LA diameter, volume, and mechanical function, including global strain (ε, were evaluated by 2D-speckle tracking echocardiography. The phenotype of HCM, maximal left ventricular (LV wall thickness, LV mass, and presence and extent of late gadolinium enhancement (LGE were evaluated with cardiac magnetic resonance imaging.HCM patients showed increased LA volume index, impaired reservoir function, and decreased LA ε compared to the control subjects. When we divided the HCM group according to a maximal LA volume index (LAVImax of 38.7 ml/m2 or LA ε of 21%, no significant differences in the HCM phenotype and maximal LV wall thickness were observed for patients with LAVImax >38.7 ml/m2 or LA ε ≤21%. Conversely, the LV mass index was significantly higher both in patients with maximal LA volume index >38.7 ml/m2 and with LA ε ≤21% and was independently associated with LAVImax and LA ε. Although the LGE extent was increased in patients with LA ε ≤21%, it was not independently associated with either LAVImax or LA ε.HCM patients showed progressed LA remodeling and dysfunction; the determinant of LA remodeling and dysfunction was LV mass index rather than LV myocardial fibrosis by LGE-magnetic resonance

  15. Bisphenol A affects androgen receptor function via multiple mechanisms.

    Science.gov (United States)

    Teng, Christina; Goodwin, Bonnie; Shockley, Keith; Xia, Menghang; Huang, Ruili; Norris, John; Merrick, B Alex; Jetten, Anton M; Austin, Christopher P; Tice, Raymond R

    2013-05-25

    Bisphenol A (BPA), is a well-known endocrine disruptor compound (EDC) that affects the normal development and function of the female and male reproductive system, however the mechanisms of action remain unclear. To investigate the molecular mechanisms of how BPA may affect ten different nuclear receptors, stable cell lines containing individual nuclear receptor ligand binding domain (LBD)-linked to the β-Gal reporter were examined by a quantitative high throughput screening (qHTS) format in the Tox21 Screening Program of the NIH. The results showed that two receptors, estrogen receptor alpha (ERα) and androgen receptor (AR), are affected by BPA in opposite direction. To confirm the observed effects of BPA on ERα and AR, we performed transient transfection experiments with full-length receptors and their corresponding response elements linked to luciferase reporters. We also included in this study two BPA analogs, bisphenol AF (BPAF) and bisphenol S (BPS). As seen in African green monkey kidney CV1 cells, the present study confirmed that BPA and BPAF act as ERα agonists (half maximal effective concentration EC50 of 10-100 nM) and as AR antagonists (half maximal inhibitory concentration IC50 of 1-2 μM). Both BPA and BPAF antagonized AR function via competitive inhibition of the action of synthetic androgen R1881. BPS with lower estrogenic activity (EC50 of 2.2 μM), did not compete with R1881 for AR binding, when tested at 30 μM. Finally, the effects of BPA were also evaluated in a nuclear translocation assays using EGPF-tagged receptors. Similar to 17β-estradiol (E2) which was used as control, BPA was able to enhance ERα nuclear foci formation but at a 100-fold higher concentration. Although BPA was able to bind AR, the nuclear translocation was reduced. Furthermore, BPA was unable to induce functional foci in the nuclei and is consistent with the transient transfection study that BPA is unable to activate AR.

  16. Prefrontal cortex and neural mechanisms of executive function.

    Science.gov (United States)

    Funahashi, Shintaro; Andreau, Jorge Mario

    2013-12-01

    Executive function is a product of the coordinated operation of multiple neural systems and an essential prerequisite for a variety of cognitive functions. The prefrontal cortex is known to be a key structure for the performance of executive functions. To accomplish the coordinated operations of multiple neural systems, the prefrontal cortex must monitor the activities in other cortical and subcortical structures and control and supervise their operations by sending command signals, which is called top-down signaling. Although neurophysiological and neuroimaging studies have provided evidence that the prefrontal cortex sends top-down signals to the posterior cortices to control information processing, the neural correlate of these top-down signals is not yet known. Through use of the paired association task, it has been demonstrated that top-down signals are used to retrieve specific information stored in long-term memory. Therefore, we used a paired association task to examine the neural correlates of top-down signals in the prefrontal cortex. The preliminary results indicate that 32% of visual neurons exhibit pair-selectivity, which is similar to the characteristics of pair-coding activities in temporal neurons. The latency of visual responses in prefrontal neurons was longer than bottom-up signals but faster than top-down signals in inferior temporal neurons. These results suggest that pair-selective visual responses may be top-down signals that the prefrontal cortex provides to the temporal cortex, although further studies are needed to elucidate the neural correlates of top-down signals and their characteristics to understand the neural mechanism of executive control by the prefrontal cortex.

  17. Ketamine inhibits human sperm function by Ca(2+)-related mechanism.

    Science.gov (United States)

    He, Yuanqiao; Zou, Qianxing; Li, Bingda; Chen, Houyang; Du, Xiaohong; Weng, Shiqi; Luo, Tao; Zeng, Xuhui

    2016-09-09

    Ketamine, a dissociative anesthetic, which was widely used in human and animal medicine, has become a popular recreational drug, as it can induce hallucinatory effects. Ketamine abuse can cause serious damage to many aspects of the organism, mainly reflected in the nervous system and urinary system. It has also been reported that ketamine can impair the male genital system. However, the detailed effect of ketamine on human spermatozoa remains unclear. Thus, we investigated the in vitro effects of ketamine on human sperm functions, to elucidate the underlying mechanism. Human sperm were treated in vitro with different concentrations of ketamine (0, 0.125, 0.25, 0.5, 1 g/L). The results showed that 0.25-1 g/L ketamine inhibited sperm total motility, progressive motility and linear velocity, in a dose-dependent manner. In addition, the sperm's ability to penetrate viscous medium and the progesterone-induced acrosome reaction were significantly inhibited by ketamine. Ketamine did not affect sperm viability, capacitation and spontaneous acrosome reaction. The intracellular calcium concentration ([Ca(2+)]i), which is a central factor in the regulation of human sperm function, was decreased by ketamine (0.125-1 g/L) in a dose-dependent manner. Furthermore, the currents of the sperm-specific Ca(2+) channel, CatSper, which modulates Ca(2+) influx in sperm, were inhibited by ketamine (0.125-1 g/L) in a dose-dependent manner. Our findings suggest that ketamine induces its toxic effects on human sperm functions by reducing sperm [Ca(2+)]i through inhibition of CatSper channel. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. MicroRNAs in sensorineural diseases of the ear

    Directory of Open Access Journals (Sweden)

    Kathy eUshakov

    2013-12-01

    Full Text Available Non-coding microRNAs have a fundamental role in gene regulation and expression in almost every multicellular organism. Only discovered in the last decade, microRNAs are already known to play a leading role in many aspects of disease. In the vertebrate inner ear, microRNAs are essential for controlling development and survival of hair cells. Moreover, dysregulation of microRNAs has been implicated in sensorineural hearing impairment, as well as in other ear diseases such as cholesteatomas, vestibular schwannomas and otitis media. Due to the inaccessibility of the ear in humans, animal models have provided the optimal tools to study microRNA expression and function, in particular mice and zebrafish. A major focus of current research has been to discover the targets of the microRNAs expressed in the inner ear, in order to determine the regulatory pathways of the auditory and vestibular systems. The potential for microRNA manipulation in development of therapeutic tools for hearing impairment is as yet unexplored, paving the way for future work in the field.

  19. The function of the RNA-binding protein TEL1 in moss reveals ancient regulatory mechanisms of shoot development.

    Science.gov (United States)

    Vivancos, Julien; Spinner, Lara; Mazubert, Christelle; Charlot, Florence; Paquet, Nicolas; Thareau, Vincent; Dron, Michel; Nogué, Fabien; Charon, Céline

    2012-03-01

    The shoot represents the basic body plan in land plants. It consists of a repeated structure composed of stems and leaves. Whereas vascular plants generate a shoot in their diploid phase, non-vascular plants such as mosses form a shoot (called the gametophore) in their haploid generation. The evolution of regulatory mechanisms or genetic networks used in the development of these two kinds of shoots is unclear. TERMINAL EAR1-like genes have been involved in diploid shoot development in vascular plants. Here, we show that disruption of PpTEL1 from the moss Physcomitrella patens, causes reduced protonema growth and gametophore initiation, as well as defects in gametophore development. Leafy shoots formed on ΔTEL1 mutants exhibit shorter stems with more leaves per shoot, suggesting an accelerated leaf initiation (shortened plastochron), a phenotype shared with the Poaceae vascular plants TE1 and PLA2/LHD2 mutants. Moreover, the positive correlation between plastochron length and leaf size observed in ΔTEL1 mutants suggests a conserved compensatory mechanism correlating leaf growth and leaf initiation rate that would minimize overall changes in plant biomass. The RNA-binding protein encoded by PpTEL1 contains two N-terminus RNA-recognition motifs, and a third C-terminus non-canonical RRM, specific to TEL proteins. Removal of the PpTEL1 C-terminus (including this third RRM) or only 16-18 amino acids within it seriously impairs PpTEL1 function, suggesting a critical role for this third RRM. These results show a conserved function of the RNA-binding PpTEL1 protein in the regulation of shoot development, from early ancestors to vascular plants, that depends on the third TEL-specific RRM.

  20. Presbycusis: do we have a third ear?

    Directory of Open Access Journals (Sweden)

    Luis Roque Reis

    Full Text Available Abstract Introduction: Age-related hearing changes are the most frequent cause of sensorineural hearing loss in adults. In the literature no studies exist concerning the importance of speechreading in individuals with presbycusis. Equally, no such studies have been carried out with speakers of the Portuguese (Portugal language. Objectives: To evaluate whether the intelligibility of words in presbycusis is improved by speechreading, in such a way that looking at the interlocutor's face while he is talking functions like a “third ear”, and to determine the statistical relevance of the intelligibility improvement by speechreading. Methods: Eleven individuals (22 ears with bilateral and symmetrical sensorineural hearing loss compatible with presbycusis were evaluated. The subjects were aged between 57 and 82 years, with an average of 70 ± 11.51 years and median of 69.5 years. A complete medical and audiological profile of each patient was created and all patients were submitted to a vocal audiogram, without and with observation of the audiologist's face. A descriptive and analytical statistical analysis was performed (Shapiro-Wilk and t pairs tests adopting the significance level of 0.05 (5%. Results: We noticed better performance in intelligibility with speechreading. The p-value was zero (p < 0.05, so we rejected the null hypothesis, showing that there was statistically significant difference with speechreading; the same conclusion was obtained by analysis of the confidence intervals. Conclusions: Individuals with presbycusis in this study, performed better on spoken word intelligibility when the hearing of those words was associated with speechreading. This phenomenon helps in such a way that observation of the interlocutor's face works like a "third ear".

  1. [Botulinum toxin to treat sweat caused sequelae in patients with hearing aids, active middle ear implants and cochlear implants].

    Science.gov (United States)

    Laskawi, R; Winterhoff, J; Blum, J; Matthias, C

    2012-11-01

    The production of sweat in the temporal skin region may be a serious problem for patients with hearing aids, active middle ear implants or cochlear implants. We report on two patients suffering from a loss of function of their hearing aid and a reduction of the "wear comfort" of an active middle ear implant. The patients underwent intracutaneous botulinum toxin (BTX) treatment of the temporal skin region. In both patients a distinct improvement of their complaints occurred, enabling them to use their hearing aids and active middle ear implants continuously. BTX injections are suited to improve sweat-caused complaints in patients with hearing aids, active middle ear implants and cochlear implants.

  2. Playing by Ear: Foundation or Frill?

    Science.gov (United States)

    Woody, Robert H.

    2012-01-01

    Many people divide musicians into two types: those who can read music and those who play by ear. Formal music education tends to place great emphasis on producing musically literate performers but devotes much less attention to teaching students to make music without notation. Some would suggest that playing by ear is a specialized skill that is…

  3. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    life. Ear-EEG may therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. In this study we investigate the application of ear-EEG in objective audiometry....

  4. INNER EAR EMBRYOGENESIS: GENETIC AND ENVIRONMENTAL DETERMINANTS

    Science.gov (United States)

    The anatomy and developmental molecular genetics of the inner ear from establishment of the otic placode to formation of the definitive cochlea and vestibular apparatus will be reviewed and the complex 3-D structural changes that shape the developing inner ear will be illustrated...

  5. Coupled ears in lizards and crocodilians

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob; Bierman, Hilary

    2016-01-01

    Lizard ears are coupled across the pharynx, and are very directional. In consequence all auditory responses should be directional, without a requirement for computation of sound source location. Crocodilian ears are connected through sinuses, and thus less tightly coupled. Coupling may improve...

  6. Characteristics of wideband acoustic immittance in patients with middle-ear dysfunction.

    Science.gov (United States)

    Sanford, Chris A; Brockett, Jeff E

    2014-05-01

    Wideband acoustic immittance (WAI) measurements are a relatively new class of aural acoustic tests that have shown promise as useful tools for evaluating middle-ear status. A growing body of work has described WAI for infants, children, and adults with normal middle-ear function, but a relatively limited number of studies have investigated the influence of specific middle-ear disorders on WAI. Although emerging WAI research data show promising results, additional measurements from ears of patients with a variety of middle-ear disorders are needed. The aims of the present study were to (1) obtain WAI data from patients with a variety of middle-ear conditions, (2) examine relationships between WAI data relative to standard audiometric tests, and (3) identify patterns or profiles in WAI data within and among patients with different middle-ear conditions. A descriptive study. Participants included 30 children and two adults with a variety of middle-ear disorders who were recruited from clinical audiology settings. Experimental ambient and tympanometric WAI data were gathered along with standard audiometric test data as part of clinical audiology appointments. Single-subject and small-group data sets for ears of patients with suspected otitis media with effusion (sOME), pressure equalization (PE) tubes, negative tympanometric peak pressure (TPP), tympanoplasty, and cerumen impaction were obtained. Qualitative analysis and descriptive statistics (means and percentiles) were used to characterize the data. Group mean absorbance for ears in the sOME group was reduced across the majority of frequencies; absorbance for ears with negative TPP was also reduced, although to a lesser degree. Absorbance patterns for ears with PE tubes show even greater differences because of the effects of the tube and open middle-ear cavity. WAI from ears with a tympanoplasty and cerumen impaction was suggestive of middle-ear dysfunction in the presence of normal single-frequency tympanometry

  7. Mechanical and neural function of triceps surae in elite racewalking.

    Science.gov (United States)

    Cronin, Neil J; Hanley, Brian; Bissas, Athanassios

    2016-07-01

    Racewalking is a unique event combining mechanical elements of walking with speeds associated with running. It is currently unclear how racewalking technique impacts lower limb muscle-tendon function despite the relevance of this to muscle economy and overall performance. The present study examined triceps surae neuromechanics in 11 internationally competitive racewalkers (age 25 ± 11 yr) walking and running on a treadmill at speeds between 4.5 and 13.8 km/h while triceps surae fascicle lengths, electromyography, and kinematic data were recorded. Cumulative muscle activity required to traverse a unit distance (CMAPD) was calculated for each muscle. Medial gastrocnemius (MG) and soleus fascicle lengths/velocities were determined using an automated tracking algorithm, and muscle-tendon unit lengths were determined. Running was associated with net shortening of muscle fascicles during stance, combined with substantial lengthening of the muscle-tendon unit, implying energy storage in the Achilles tendon. When the same participants racewalked at the same speed, the fascicles shortened (soleus) or lengthened (MG), coinciding with rapid shortening followed by a relatively small increase in muscle-tendon length during stance. Consequently, compared with running at the same speed, racewalking decreased the energy-saving role of the Achilles tendon. Moreover, CMAPD was generally highest in racewalking, implying that in individual muscles, the energy cost of racewalking was higher than running. Together these results suggest that racewalking is neurally and mechanically costly relative to running at a given speed. As racewalking events are typically between 10 and 50 km, neuromechanical inefficiencies that occur with each stride likely result in substantial energetic penalties.

  8. Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function.

    Science.gov (United States)

    Martin, Laura A; Kennedy, Barry E; Karten, Barbara

    2016-04-01

    Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology.

  9. Microbiology of discharging ears in Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Getachew Tesfaye; Daniel Asrat; Yimtubezinash Woldeamanuel; Messele Gizaw

    2009-01-01

    Objectives:To isolate and identify the bacterial etiologic agents,including their antibiotic susceptibility pat-tern isolated from patients with discharging ear infections.Methods:Between September 2006 and February 2007,178 patients with discharging ear visiting ENT clinics of St.Paul and Tikur Anbessa University Hospi-tals Addis Ababa,Ethiopia were investigated.Results:Of the patients investigated,52.8% were males and 47.2% were females resulting in an overall male to female ratio of 1.1:1.Ear discharge was the commonest clinical finding followed by hearing problem (91.2%),otalgia (ear pain)(74.7%),fever (17.9%)and itching of external ear (5.1%).S.aureus accounted for 30.2% of the total isolates followed by Proteus ssp. (P.mirabilis,P.vulgaris )(25.4%),and P.aeruginosa (13.4%).Both gram positive and negative bac-teria isolated from ear infections showed low resistance rates to most antimicrobial agents tested.Overall ceftri-axone and ciprofloxacin were the most effective drugs when compared to other drugs tested against the gram-positive and gram-negative bacteria.Conclusion:Otitis media was the most common clinical finding in pa-tients with ear infection.With discharging ear,the gram-negative bacteria were the predominant isolates.The susceptibility pattern of isolates from the study showed that ceftriaxone,ciprofloxacin and gentamicin were the most effective drugs.It is recommended that treatment of ear infections should be based on culture and sensi-tivity at the study sites.Therefore,efforts should be directed towards early diagnosis and treatment of acute ear infection and continued re-evaluation of the resistant patterns of organisms to optimize treatments and reduce complications.

  10. Microbiomes of the normal middle ear and ears with chronic otitis media.

    Science.gov (United States)

    Minami, Shujiro B; Mutai, Hideki; Suzuki, Tomoko; Horii, Arata; Oishi, Naoki; Wasano, Koichiro; Katsura, Motoyasu; Tanaka, Fujinobu; Takiguchi, Tetsuya; Fujii, Masato; Kaga, Kimitaka

    2017-10-01

    The aim of this study was to profile and compare the middle ear microbiomes of human subjects with and without chronic otitis media. Prospective multicenter cohort study. All consecutive patients undergoing tympanoplasty surgery for chronic otitis media or ear surgery for conditions other than otitis media were recruited. Sterile swab samples were collected from the middle ear mucosa during surgery. The variable region 4 of the 16S rRNA gene in each sample were amplified using region-specific primers adapted for the Illumina MiSeq sequencer (Illumina, CA, USA)). The sequences were subjected to local blast and classified using Metagenome@KIN (World Fusion, Tokyo, Japan). In total, 155 participants were recruited from seven medical centers. Of these, 88 and 67 had chronic otitis media and normal middle ears, respectively. The most abundant bacterial phyla on the mucosal surfaces of the normal middle ears were Proteobacteria, followed by Actinobacteria, Firmicutes, and Bacteroidetes. The children and adults with normal middle ears differed significantly in terms of middle ear microbiomes. Subjects with chronic otitis media without active inflammation (dry ear) had similar middle ear microbiomes as the normal middle ears group. Subjects with chronic otitis media with active inflammation (wet ear) had a lower prevalence of Proteobacteria and a higher prevalence of Firmicutes than the normal middle ears. The human middle ear is inhabited by more diverse microbial communities than was previously thought. Alteration of the middle ear microbiome may contribute to the pathogenesis of chronic otitis media with active inflammation. 2b. Laryngoscope, 127:E371-E377, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Subdiffusive dynamics of bump attractors: mechanisms and functional roles.

    Science.gov (United States)

    Qi, Yang; Breakspear, Michael; Gong, Pulin

    2015-02-01

    Bump attractors are localized activity patterns that can self-sustain after stimulus presentation, and they are regarded as the neural substrate for a host of perceptual and cognitive processes. One of the characteristic features of bump attractors is that they are neutrally stable, so that noisy inputs cause them to drift away from their initial locations, severely impairing the accuracy of bump location-dependent neural coding. Previous modeling studies of such noise-induced drifting activity of bump attractors have focused on normal diffusive dynamics, often with an assumption that noisy inputs are uncorrelated. Here we show that long-range temporal correlations and spatial correlations in neural inputs generated by multiple interacting bumps cause them to drift in an anomalous subdiffusive way. This mechanism for generating subdiffusive dynamics of bump attractors is further analyzed based on a generalized Langevin equation. We demonstrate that subdiffusive dynamics can significantly improve the coding accuracy of bump attractors, since the variance of the bump displacement increases sublinearly over time and is much smaller than that of normal diffusion. Furthermore, we reanalyze existing psychophysical data concerning the spread of recalled cue position in spatial working memory tasks and show that its variance increases sublinearly with time, consistent with subdiffusive dynamics of bump attractors. Based on the probability density function of bump position, we also show that the subdiffusive dynamics result in a long-tailed decay of firing rate, greatly extending the duration of persistent activity.

  12. Theory of brain function, quantum mechanics and superstrings

    CERN Document Server

    Nanopoulos, Dimitri V.

    1995-01-01

    Recent developments/efforts to understand aspects of the brain function at the {\\em sub-neural} level are discussed. MicroTubules (MTs) participate in a wide variety of dynamical processes in the cell especially in bioinformation processes such as learning and memory, by possessing a well-known binary error-correcting code with 64 words. In fact, MTs and DNA/RNA are unique cell structures that possess a code system. It seems that the MTs' code system is strongly related to a kind of ``Mental Code" in the following sense. The MTs' periodic paracrystalline structure make them able to support a superposition of coherent quantum states, as it has been recently conjectured by Hameroff and Penrose, representing an external or mental order, for sufficient time needed for efficient quantum computing. Then the quantum superposition collapses spontaneously/dynamically through a new, string-derived mechanism for collapse proposed recently by Ellis, Mavromatos, and myself. At the moment of collapse, organized quantum exo...

  13. Mechanical, Thermal and Functional Properties of Green Lightweight Foamcrete

    Directory of Open Access Journals (Sweden)

    Md Azree Othuman Mydin

    2012-09-01

    Full Text Available In recent times, the construction industry has revealed noteworthy attention in the use of lightweight foamcrete as a building material due to its many favourable characteristics such as lighter weight, easy to fabricate, durable and cost effective. Foamcrete is a material consisting of Portland cement paste or cement filler matrix (mortar with a homogeneous pore structure created by introducing air in the form of small bubbles. With a proper control in dosage of foam and methods of production, a wide range of densities (400 – 1600 kg/m 3 of foamcrete can be produced thus providing flexibility for application such as structural elements, partition, insulating materials and filling grades. Foamcrete has so far been applied primarily as a filler material in civil engineering works. However, its good thermal and acoustic performance indicates its strong potential as a material in building construction. The focus of this paper is to classify literature on foamcrete in terms of its mechanical, thermal and functional properties.

  14. The Yeast Genomes in Three Dimensions: Mechanisms and Functions.

    Science.gov (United States)

    Noma, Ken-Ichi

    2017-08-30

    The three-dimensional (3D) genome structure is highly ordered by a hierarchy of organizing events ranging from enhancer-promoter or gene-gene contacts to chromosomal territorial arrangement. It is becoming clear that the cohesin and condensin complexes are key molecular machines that organize the 3D genome structure. These complexes are highly conserved from simple systems, e.g., yeast cells, to the much more complex human system. Therefore, knowledge from the budding and fission yeast systems illuminates highly conserved molecular mechanisms of how cohesin and condensin establish the functional 3D genome structures. Here I discuss how these complexes are recruited across the yeast genomes, mediate distinct genome-organizing events such as gene contacts and topological domain formation, and participate in important nuclear activities including transcriptional regulation and chromosomal dynamics. Expected final online publication date for the Annual Review of Genetics Volume 51 is November 23, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  15. Signaling mechanisms and functional roles of cofilin phosphorylation and dephosphorylation.

    Science.gov (United States)

    Mizuno, Kensaku

    2013-02-01

    Cofilin and actin-depolymerizing factor (ADF) are actin-binding proteins that play an essential role in regulating actin filament dynamics and reorganization by stimulating the severance and depolymerization of actin filaments. Cofilin/ADF are inactivated by phosphorylation at the serine residue at position 3 by LIM-kinases (LIMKs) and testicular protein kinases (TESKs) and are reactivated by dephosphorylation by the slingshot (SSH) family of protein phosphatases and chronophin. This review describes recent advances in our understanding of the signaling mechanisms regulating LIMKs and SSHs and the functional roles of cofilin phospho-regulation in cell migration, tumor invasion, mitosis, neuronal development, and synaptic plasticity. Accumulating evidence demonstrates that the phospho-regulation of cofilin/ADF is a key convergence point of cell signaling networks that link extracellular stimuli to actin cytoskeletal dynamics and that spatiotemporal control of cofilin/ADF activity by LIMKs and SSHs plays a crucial role in a diverse array of cellular and physiological processes. Perturbations in the normal control of cofilin/ADF activity underlie many pathological conditions, including cancer metastasis and neurological and cardiovascular disorders.

  16. Chemopreventive functions and molecular mechanisms of garlic organosulfur compounds.

    Science.gov (United States)

    Trio, Phoebe Zapanta; You, Sixiang; He, Xi; He, Jianhua; Sakao, Kozue; Hou, De-Xing

    2014-05-01

    Garlic (Allium sativum L.) has long been used both for culinary and medicinal purposes by many cultures. Population and preclinical investigations have suggested that dietary garlic intake has health benefits, such as lowering the risk of esophageal, stomach and prostate cancers. Extensive studies from laboratory and animal models have revealed that garlic has a wide range of biological activities, and garlic organosulfur compounds (OSCs) are responsible for the biological activities. However, the presence and potency of garlic OSCs vary with respect to the mode of garlic preparation and extraction. Cooked or processed garlic products showed different kinds of garlic OSCs, some of which are highly unstable and instantly decomposed. These facts, possibly gave paradoxical results on the garlic effects. In this review, we first summarized the biotransformation processes of garlic alliin into different garlic OSCs as well as the garlic OSCs compositions from different garlic preparations. Next, we reviewed the chemopreventive functions and molecular mechanisms focusing on the anti-inflammation, antioxidation, anti-diabetes and anticancer activity behind different garlic OSCs.

  17. Ear advantage and attention: an ERP study of auditory cued attention.

    Science.gov (United States)

    Ofek, E; Pratt, H

    2004-03-01

    The neurophysiological manifestations of left ear advantage to tonal stimuli and its interaction with attention have rarely been studied. Cued attention is a behavioral paradigm to assess the behavioral benefits and costs of allocating attention. In this task a cue predicts the location of a subsequent target to which the subject responds. In most cases the cue correctly predicts the target (valid cues) but at times it does not (invalid cues). Cued attention is a spatial paradigm with stimuli presented to either side. The objectives of this study were: (1) to find the neurophysiological correlates of the ear advantage phenomenon and (2) to assess the interaction of the stimulated side (right vs. left ear advantage) with attention, in a cued attention task. Significant effects on event-related potentials (ERPs) in the cued attention task indicated left ear and right hemisphere advantage. Effects were mostly confined to the right hemisphere. The results indicate interactions among left ear advantage, attention and dominant hand utilization. Ear advantage and attention may involve the same neural mechanisms. In spite of the left ear advantage effect on ERP components, hand dominance determines the final behavioral results (reaction times).

  18. The connexin 30.3 of zebrafish homologue of human connexin 26 may play similar role in the inner ear.

    Science.gov (United States)

    Chang-Chien, Ju; Yen, Yung-Chang; Chien, Kuo-Hsuan; Li, Shaun-Yow; Hsu, Tsai-Ching; Yang, Jiann-Jou

    2014-07-01

    The intercellular gap junction channels formed by connexins (CXs) are important for recycling potassium ions in the inner ear. CXs are encoded by a family of the CX gene, such as GJB2, and the mechanism leading to mutant connexin-associated diseases, including hearing loss, remains to be elucidated. In this study, using bioinformatics, we found that two zebrafish cx genes, cx27.5 and cx30.3, are likely homologous to human and mouse GJB2. During embryogenesis, zebrafish cx27.5 was rarely expressed at 1.5-3 h post-fertilization (hpf), but a relatively high level of cx27.5 expression was detected from 6 to 96 hpf. However, zebrafish cx30.3 transcripts were hardly detected until 9 hpf. The temporal experiment was conducted in whole larvae. Both cx27.5 and cx30.3 transcripts were revealed significantly in the inner ear by reverse transcription polymerase chain reaction (RT-PCR) and whole-mount in situ hybridization (WISH). In the HeLa cell model, we found that zebrafish Cx27.5 was distributed intracellularly in the cytoplasm, whereas Cx30.3 was localized in the plasma membrane of HeLa cells stably expressing Cx proteins. The expression pattern of zebrafish Cx30.3 in HeLa cells was more similar to that of cells expressing human CX26 than Cx27.5. In addition, we found that Cx30.3 was localized in the cell membrane of hair cells within the inner ear by immunohistochemistry (IHC), suggesting that zebrafish cx30.3 might play an essential role in the development of the inner ear, in the same manner as human GJB2. We then performed morpholino knockdown studies in zebrafish embryos to elucidate the physiological functions of Cx30.3. The zebrafish cx30.3 morphants exhibited wild-type-like and heart edema phenotypes with smaller inner ears at 72 hpf. Based on these results, we suggest that the zebrafish Cx30.3 and mammalian CX26 may play alike roles in the inner ear. Thus, zebrafish can potentially serve as a model for studying hearing loss disorders that result from human CX

  19. Brief report: reconstruction of joint hyaline cartilage by autologous progenitor cells derived from ear elastic cartilage.

    Science.gov (United States)

    Mizuno, Mitsuru; Kobayashi, Shinji; Takebe, Takanori; Kan, Hiroomi; Yabuki, Yuichiro; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Nakabayashi, Seiichiro; Ik, Lee Jeong; Maegawa, Jiro; Taniguchi, Hideki

    2014-03-01

    In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age- and sports-related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long-term tissue maintenance. However, it is unknown whether ear-derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear-derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear-derived cartilage progenitor cells. It also demonstrated that ear-derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies.

  20. Effect of acute inner ear pressure changes on low-level distortion product otoacoustic emissions in the guinea pig

    NARCIS (Netherlands)

    Valk, WL; Wit, HP; Albers, FWJ

    2004-01-01

    Objective - To determine a relation between acute inner ear pressure changes and cochlear function as measured by low-level 2f(1) - f(2) distortion product otoacoustic emissions (DPOAEs). Material and Methods - During and after a change in inner ear pressure induced by injection or aspiration of per

  1. Middle ear cavity morphology is consistent with an aquatic origin for testudines.

    Directory of Open Access Journals (Sweden)

    Katie L Willis

    Full Text Available The position of testudines in vertebrate phylogeny is being re-evaluated. At present, testudine morphological and molecular data conflict when reconstructing phylogenetic relationships. Complicating matters, the ecological niche of stem testudines is ambiguous. To understand how turtles have evolved to hear in different environments, we examined middle ear morphology and scaling in most extant families, as well as some extinct species, using 3-dimensional reconstructions from micro magnetic resonance (MR and submillimeter computed tomography (CT scans. All families of testudines exhibited a similar shape of the bony structure of the middle ear cavity, with the tympanic disk located on the rostrolateral edge of the cavity. Sea Turtles have additional soft tissue that fills the middle ear cavity to varying degrees. When the middle ear cavity is modeled as an air-filled sphere of the same volume resonating in an underwater sound field, the calculated resonances for the volumes of the middle ear cavities largely fell within testudine hearing ranges. Although there were some differences in morphology, there were no statistically significant differences in the scaling of the volume of the bony middle ear cavity with head size among groups when categorized by phylogeny and ecology. Because the cavity is predicted to resonate underwater within the testudine hearing range, the data support the hypothesis of an aquatic origin for testudines, and function of the middle ear cavity in underwater sound detection.

  2. Correlative mRNA and protein expression of middle and inner ear inflammatory cytokines during mouse acute otitis media.

    Science.gov (United States)

    Trune, Dennis R; Kempton, Beth; Hausman, Frances A; Larrain, Barbara E; MacArthur, Carol J

    2015-08-01

    Although the inner ear has long been reported to be susceptible to middle ear disease, little is known of the inflammatory mechanisms that might cause permanent sensorineural hearing loss. Recent studies have shown inner ear tissues are capable of expressing inflammatory cytokines during otitis media. However, little quantitative information is available concerning cytokine gene expression in the inner ear and the protein products that result. Therefore, this study was conducted of mouse middle and inner ear during acute otitis media to measure the relationship between inflammatory cytokine genes and their protein products with quantitative RT-PCR and ELISA, respectively. Balb/c mice were inoculated transtympanically with heat-killed Haemophilus influenzae and middle and inner ear tissues collected for either quantitative RT-PCR microarrays or ELISA multiplex arrays. mRNA for several cytokine genes was significantly increased in both the middle and inner ear at 6 h. In the inner ear, these included MIP-2 (448 fold), IL-6 (126 fold), IL-1β (7.8 fold), IL-10 (10.7 fold), TNFα (1.8 fold), and IL-1α (1.5 fold). The 24 h samples showed a similar pattern of gene expression, although generally at lower levels. In parallel, the ELISA showed the related cytokines were present in the inner ear at concentrations higher by 2-122 fold higher at 18 h, declining slightly from there at 24 h. Immunohistochemistry with antibodies to a number of these cytokines demonstrated they occurred in greater amounts in the inner ear tissues. These findings demonstrate considerable inflammatory gene expression and gene products in the inner ear following acute otitis media. These higher cytokine levels suggest one potential mechanism for the permanent hearing loss seen in some cases of acute and chronic otitis media.

  3. Causes of 279 Cases with Sensation of Ear Fullness%279例耳闷胀感的病因分析

    Institute of Scientific and Technical Information of China (English)

    陈平; 周永; 谭颂华; 唐安洲; 黄东红

    2001-01-01

    Objective To analyze the causes inducing the sensation of ear fullness.Methods 362 ears with sensation of ear fullness were collected.The clinic features,audiogram,tympanogram and Eustachian tube function in these ears were analysed.Results 203 ears with type A,111 ears with type B,33 ears with type C and 15 ears with perforated tympanum membrane were found in 362 ears as tympanograms were done.Among audiograms of 362 ears,conductive deafness,sensorineural deafness,mixed deafness and normal ears were 83、81、105 and 93 ears respectively.Eustachian tube test revealed 208 abnormal ears out of 362 ears,and 67 abnormal ears were found in 203 ears with type A tympanogram.Conclusion The causes inducing sensation of ear fullness covered the outer,middle and inner ear,and face nerve.In these cases with sensation of ear fullness,the diseases resulted in sensation of ear fullness mainly were secretory otitis media,sensorineural deafness induced by vary causes and abnormal eustachian tube function.%目的 探讨产生耳闷胀感的部位和原因。方法 收集耳闷胀感为主诉的279例362耳,对患耳的临床表现、鼓室导抗图、纯音测听和咽鼓管功能进行分析。结果 362耳中鼓室导抗图A型203耳、B型111耳、C型33耳以及鼓膜穿孔15耳。纯音测听表现为传导性聋、感音神经性聋、混合性聋以及正常者分别是83耳、81耳、105耳和93耳。在362耳中,咽鼓管功能异常208耳,在A型鼓室导抗图203耳中,咽鼓管功能异常67耳。结论 产生耳闷胀感的病变部位包括外、中、内耳和面神经的病变,其中以分泌性中耳炎、各种原因引起的感音神经性聋和“咽鼓管狭窄症”为多。

  4. Outer- and middle-ear contributions to presbycusis in the Brown Norway rat.

    Science.gov (United States)

    Gratton, Michael Anne; Bateman, Kristin; Cannuscio, Joseph F; Saunders, James C

    2008-01-01

    This paper examines the contribution of the outer and middle ears to the hearing loss associated with presbycusis in Brown Norway rats. Animals were formed into two groups; young adults (2-3 months old) and aged animals (approximately 34 months old). Auditory brainstem response (ABR) thresholds were obtained with the outer ear intact or surgically removed. Tympanic membrane (TM) velocity transfer functions were measured from the umbo with the outer ear removed. The length of the auditory meatus, TM surface area, and TM thickness were quantified. The ABR thresholds were 17-26 dB less sensitive in the aged animals between 8.0 and 40.0 kHz when the outer ear was intact. A significant and reliable reduction in the aged rat velocity transfer function of 5-8 dB occurred between 10.0 and 32.0 kHz, while the low frequency velocity response was only a few decibels greater in the younger animals. The ABR threshold differences between young adult and aged ears were compensated by removing the outer/middle ear effects of aging to reveal a purely sensorineural component of presbycusis. The outer and middle ear effects were calculated directly when the ABR and TM velocity data were obtained with the outer ear removed. The outer ear intact condition was modeled in order to compare the ABR data obtained with the outer ear intact with the TM velocity data obtained with the outer removed. With either procedure, removal of the age-related contributions of the outer and middle ear to the ABR threshold resulted in similar age-related ABR threshold shifts between the two age groups. The pure sensorineural threshold shift component of the ABR response was restricted to frequencies between 5.0 and 20.0 kHz and reached a maximum of approximately 15 dB. These results support the conclusion that there is an outer- and middle-ear contribution to the threshold loss defining presbycusis.

  5. Imaging of the postoperative middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Marc T. [Department of Medical Imaging, Fondation Ophtalmologique Adolphe de Rothschild, 25 rue Manin, 75940, Paris (France); Ayache, Denis [Department of Otorhinolaryngology, Fondation Ophtalmologique Adolphe de Rothschild, Paris (France)

    2004-03-01

    The aim of this article is twofold: (a) to present the principles and the indications of surgical treatment of middle ear pathologies; and (b) to review the imaging findings after middle ear surgery, including the normal postoperative aspects and imaging findings in patients presenting with unsatisfactory surgical results or with suspicion of postoperative complications. This review is intentionally restricted to the most common diseases involving the middle ear: chronic otitis media and otosclerosis. In these specific fields of interest, CT and MR imaging play a very important role in the postoperative follow-up and in the work-up of surgical failures and complications. (orig.)

  6. [Ear keloid and clinical research progress].

    Science.gov (United States)

    Du, Guangyuan; Zhu, Jiang

    2014-04-01

    Keloid refers to the damaged skin due to excessive fibroblast proliferation. Ear is one predilection site. The pathogenesis of ear keloid is not very clear, and the treatment is also varied. Surgery, postoperative radiotherapy and laser treatment, steroid hormones, pressure therapy are the basic treatment methods. Integrated application of a variety of treatments, classification research and new materials using revealed the prospect for the treatment of the disease. This thesis reviews literature about ear keloid in recent 10 years, and introduces this disease and clinical research progress.

  7. Surgical Management of Ear Diseases in Rabbits.

    Science.gov (United States)

    Csomos, Rebecca; Bosscher, Georgia; Mans, Christoph; Hardie, Robert

    2016-01-01

    Otitis externa and media are frequently diagnosed disorders in rabbits and are particularly common in lop-eared breeds because of the specific anatomy of the ear canal. Medical management for otitis externa and media often provides only a temporary improvement in clinical signs. Surgery by means of partial or total ear canal ablation (PECA or TECA) combined with lateral bulla osteotomy (LBO) represents a feasible approach that is well tolerated and provides a good clinical outcome. Short-term complications associated with PECA/TECA-LBO include facial nerve paralysis and vestibular disease.

  8. Oral Pseudoephedrine Decreases the Rate of Trans-mucosal Nitrous Oxide Exchange for the Middle Ear

    Science.gov (United States)

    Teixeira, Miriam S.; Alper, Cuneyt M.; Martin, Brian S; Cullen Doyle, Brendan M.; Doyle, William J.

    2015-01-01

    Objective Determine if oral pretreatment with a vasoconstrictor decreases the blood to middle-ear exchange-rate of the perfusion-limited gas, Nitrous Oxide (N2O). Study Design Randomized, double-blind, crossover study. Methods Ten adult subjects with and 10 without past middle-ear disease completed paired experimental sessions, identical but for oral pretreatment with either pseudoephedrine HCL or lactose placebo. At each session, subjects were fitted with a non-rebreathing mask and breathed room air for 20 minutes (acclimation period), 50% N2O:50% O2 for 20 minutes (experimental period) and 100% O2 for 10 minutes (recovery period). Throughout, heart-rate, blood-pressure and O2 saturation were monitored and bilateral middle-ear pressures were recorded by tympanometry every minute. The primary outcome was the slope of the middle-ear pressure-time function for the experimental period which estimates the volume N2O exchange-rate. Using repeated measures ANOVA, the effects of Group (disease history), Treatment (active vs. placebo) and Period (1 vs. 2) on the recorded vital signs, and of Group, Treatment and Ear (left/right) on the middle-ear pressure-time slope were evaluated for statistical significance. Results Statistically significant effects of Period on O2 saturation (Period 2>Period 1) and of Treatment on heart-rate (Active>Placebo) were documented. Only Treatment was statistically significant for the middle-ear pressure-time slope with a shallower slope characterizing the active treatment session. Conclusion The volume exchange-rate across the middle-ear mucosa of perfusion-limited gases can be modulated pharmacologically. Theoretically, similar drugs can be used to reduce the requisite Eustachian tube opening efficiency for adequate middle-ear pressure regulation. PMID:26152838

  9. Effect of tympanic membrane thickness in fascia myringoplasty on the middle ear transfer function-a finite element ear model%颞肌筋膜重建鼓膜厚度对中耳传声的影响--有限元模型研究

    Institute of Scientific and Technical Information of China (English)

    王杰; Zhao Fei; 李永新

    2015-01-01

    目的研究颞肌筋膜重建鼓膜厚度对中耳传声的影响。方法依据1名成年男性颞骨标本的Micro-CT扫描数据,利用Mimics软件、ANSYS软件建立正常成人中耳有限元模型后,再依据该模型建立从0.05~2.00 mm共9种厚度鼓膜的有限元模型,分别计算不同厚度鼓膜对鼓膜及镫骨底板振动的影响,从而反应不同厚度重建鼓膜对中耳传声的影响。结果当90 dB SPL刺激鼓膜时,所建模型于鼓膜脐部、镫骨底板中央处振幅在文献报道颞骨实验测量结果的范围之内。依据该正常结构中耳有限元模型,建立9种厚度颞肌筋膜重建鼓膜的有限元模型。计算结果显示:当重建鼓膜厚度>0.4 mm时,鼓膜脐部振幅逐渐减低,尤其是当鼓膜厚度>1.0 mm时,影响最明显;当鼓膜厚度为0.05 mm和0.1 mm时,镫骨底板振幅在0.6 kHz以下轻度增强,提高镫骨底板振幅约2 dB,但0.6~8.0 kHz均降低约2.5 dB;当鼓膜厚度为0.2、0.4与0.6 mm时,于约3.0 kHz以下镫骨底板振幅水平下降,幅度约<5.0 dB;当鼓膜厚度为0.6、0.8与1.0 mm时,于3.0 kHz以下镫骨底板振幅减小明显,于0.8 kHz以下约达-10 dB;而当鼓膜厚度为1.5 mm与2.0 mm时,镫骨底板振幅于1.0 kHz以下降低最明显,于0.8、1.0 kHz处分别达-16 dB和-22 dB。另外,于共振峰约3.2 kHz处,9种厚度重建鼓膜对镫骨底板影响最大约-5 dB。共振峰3.2~8.0 kHz之间,镫骨底板均有明显降低,约于5.0 kHz处最大达约-10 dB。结论颞肌筋膜重建后的鼓膜厚度影响鼓膜本身及镫骨底板的振动,当重建鼓膜厚度超过1.0 mm时对中耳传声影响显著增加。%OBJECTIVE To study the effect of the thickness of tympanic membrane rebuilt from fascia myringoplasty on the acoustic transfer function of the middle ear. METHODS A finite element model(FEM) was developed with Mimics and Ansys based on the data from Micro-CT scanning of a

  10. An elastic element in the protocadherin-15 tip link of the inner ear

    Science.gov (United States)

    Araya-Secchi, Raul; Neel, Brandon L.; Sotomayor, Marcos

    2016-11-01

    Tip link filaments convey force and gate inner-ear hair-cell transduction channels to mediate perception of sound and head movements. Cadherin-23 and protocadherin-15 form tip links through a calcium-dependent interaction of their extracellular domains made of multiple extracellular cadherin (EC) repeats. These repeats are structurally similar, but not identical in sequence, often featuring linkers with conserved calcium-binding sites that confer mechanical strength to them. Here we present the X-ray crystal structures of human protocadherin-15 EC8-EC10 and mouse EC9-EC10, which show an EC8-9 canonical-like calcium-binding linker, and an EC9-10 calcium-free linker that alters the linear arrangement of EC repeats. Molecular dynamics simulations and small-angle X-ray scattering experiments support this non-linear conformation. Simulations also suggest that unbending of EC9-10 confers some elasticity to otherwise rigid tip links. The new structure provides a first view of protocadherin-15's non-canonical EC linkers and suggests how they may function in inner-ear mechanotransduction, with implications for other cadherins.

  11. Big Stimulus, Little Ears: Safety in Administering Vestibular-Evoked Myogenic Potentials in Children.

    Science.gov (United States)

    Thomas, Megan L A; Fitzpatrick, Denis; McCreery, Ryan; Janky, Kristen L

    2017-05-01

    Cervical and ocular vestibular-evoked myogenic potentials (VEMPs) have become common clinical vestibular assessments. However, VEMP testing requires high intensity stimuli, raising concerns regarding safety with children, where sound pressure levels may be higher due to their smaller ear canal volumes. The purpose of this study was to estimate the range of peak-to-peak equivalent sound pressure levels (peSPLs) in child and adult ears in response to high intensity stimuli (i.e., 100 dB normal hearing level [nHL]) commonly used for VEMP testing and make a determination of whether acoustic stimuli levels with VEMP testing are safe for use in children. Prospective experimental. Ten children (4-6 years) and ten young adults (24-35 years) with normal hearing sensitivity and middle ear function participated in the study. Probe microphone peSPL measurements of clicks and 500 Hz tonebursts (TBs) were recorded in tubes of small, medium, and large diameter, and in a Brüel & Kjær Ear Simulator Type 4157 to assess for linearity of the stimulus at high levels. The different diameter tubes were used to approximate the range of cross-sectional areas in infant, child, and adult ears, respectively. Equivalent ear canal volume and peSPL measurements were then recorded in child and adult ears. Lower intensity levels were used in the participant's ears to limit exposure to high intensity sound. The peSPL measurements in participant ears were extrapolated using predictions from linear mixed models to determine if equivalent ear canal volume significantly contributed to overall peSPL and to estimate the mean and 95% confidence intervals of peSPLs in child and adult ears when high intensity stimulus levels (100 dB nHL) are used for VEMP testing without exposing subjects to high-intensity stimuli. Measurements from the coupler and tubes suggested: 1) each stimuli was linear, 2) there were no distortions or nonlinearities at high levels, and 3) peSPL increased with decreased tube diameter

  12. Tick in the outer ear canal: Two case reports

    Directory of Open Access Journals (Sweden)

    Özalkan Özkan

    2013-01-01

    Full Text Available Serious systemic diseases such as Crimean Congo Hemorrhagic Fever, Lyme Disease, tularemia, typhus and Q fever can be transmitted by ticks. An 8-year-old boy and a 34-year-old woman were brought to our clinic with ear pains. No symptoms such as fever, headache or lethargy to suggest CCHF were present. The patients both lived in rural areas and were engaged in farming. Full blood count, liver and kidney function tests and serum electrolytes were within normal limits at laboratory tests. Prothrombin time, partial thromboplastin time and INR were normal. The tick was grasped with alligator forceps and removed from the outer ear in one piece with the help of 0-degree rigid otoendoscopy.

  13. Tick in the outer ear canal:Two case reports

    Institute of Scientific and Technical Information of China (English)

    zalkanzkan; Fatih Bingl; Ali Budak

    2013-01-01

    Serious systemic diseases such asCrimeanCongoHemorrhagicFever,LymeDisease, tularemia, typhus andQ fever can be transmitted by ticks.An8-year-old boy and a34-year-old woman were brought to our clinic with ear pains.No symptoms such as fever, headache or lethargy to suggestCCHF were present.The patients both lived in rural areas and were engaged in farming. Full blood count, liver and kidney function tests and serum electrolytes were within normal limits at laboratory tests.Prothrombin time, partial thromboplastin time andINR were normal.The tick was grasped with alligator forceps and removed from the outer ear in one piece with the help of 0-degree rigid otoendoscopy.

  14. Evolution: Fossil Ears and Underwater Sonar.

    Science.gov (United States)

    Lambert, Olivier

    2016-08-22

    A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability.

  15. Ear Infection Treatment: Do Alternative Therapies Work?

    Science.gov (United States)

    ... in books and magazines. They include chiropractic adjustments, homeopathy, herbal eardrops and others. Perhaps you're seeking ... infection treatments have been studied with mixed results. Homeopathy. A controversial treatment for ear infection, homeopathy involves ...

  16. Superglue accidentally used as ear drops

    National Research Council Canada - National Science Library

    Anusha, Bala; Purushotman, R; Lina, L C; Avatar, S

    2012-01-01

    Superglue in the ear as a foreign body is an uncommon presentation. We report the case of a lady who accidentally instilled superglue directly onto her tympanic membrane and presented five days later...

  17. Inner ear malformations: a practical diagnostic approach.

    Science.gov (United States)

    Mazón, M; Pont, E; Montoya-Filardi, A; Carreres-Polo, J; Más-Estellés, F

    Pediatric sensorineural hearing loss is a major cause of disability; although inner ear malformations account for only 20-40% of all cases, recognition and characterization will be vital for the proper management of these patients. In this article relevant anatomy and development of inner ear are surveyed. The role of neuroimaging in pediatric sensorineural hearing loss and cochlear preimplantation study are assessed. The need for a universal system of classification of inner ear malformations with therapeutic and prognostic implications is highlighted. And finally, the radiological findings of each type of malformation are concisely described and depicted. Computed tomography and magnetic resonance imaging play a crucial role in the characterization of inner ear malformations and allow the assessment of the anatomical structures that enable the selection of appropriate treatment and surgical approach. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Female Climacteric Syndrome Treated by Ear Embedding

    Institute of Scientific and Technical Information of China (English)

    王勤

    2003-01-01

    @@ Female climacteric syndrome is a common disease occurring before and after menopause. The author has treated the disease with ear embedding therapy, and achieved satisfactory therapeutic results. The following is a report of the clinical observation.

  19. Neonatal Ear Molding: Timing and Technique.

    Science.gov (United States)

    Anstadt, Erin Elizabeth; Johns, Dana Nicole; Kwok, Alvin Chi-Ming; Siddiqi, Faizi; Gociman, Barbu

    2016-03-01

    The incidence of auricular deformities is believed to be ∼11.5 per 10,000 births, excluding children with microtia. Although not life-threatening, auricular deformities can cause undue distress for patients and their families. Although surgical procedures have traditionally been used to reconstruct congenital auricular deformities, ear molding has been gaining acceptance as an efficacious, noninvasive alternative for the treatment of newborns with ear deformations. We present the successful correction of bilateral Stahl's ear deformity in a newborn through a straightforward, nonsurgical method implemented on the first day of life. The aim of this report is to make pediatric practitioners aware of an effective and simple molding technique appropriate for correction of congenital auricular anomalies. In addition, it stresses the importance of very early initiation of ear cartilage molding for achieving the desired outcome.

  20. Mozart ear: diagnosis, treatment, and literature review.

    Science.gov (United States)

    Yamashita, Ken; Yotsuyanagi, Takatoshi; Saito, Tamotsu; Isogai, Noritaka; Mori, Hiromasa; Itani, Yoshihito

    2011-11-01

    Mozart ear is a congenital auricular deformity, which is mainly characterized by a bulging appearance of the anterosuperior portion of the auricle, a convexly protruded cavum conchae, and a slit-like narrowing of the orifice of the external auditory meatus. It is said to be uncommon, and because no one has yet fully described neither the disease nor the treatment, the concept of Mozart ear has not been unified. This report describes a case of a 13-year-old girl presented with an unusual congenital deformity which showed the features of Mozart ear. It is an extremely rare deformity that only about 4 clinical cases have been reported in medical literature thereby a treatment method has not been fully discussed. For surgical correction of our cases, we excised deformed conchal cartilage, turned it over, regrafted, and maintained a cosmetically positive result. We also reviewed and described the origin, current concept, and treatment method of Mozart ear.

  1. Environment for Auditory Research Facility (EAR)

    Data.gov (United States)

    Federal Laboratory Consortium — EAR is an auditory perception and communication research center enabling state-of-the-art simulation of various indoor and outdoor acoustic environments. The heart...

  2. 21 CFR 874.3430 - Middle ear mold.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Middle ear mold. 874.3430 Section 874.3430 Food... DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3430 Middle ear mold. (a) Identification. A middle ear mold is a preformed device that is intended to be implanted to reconstruct the middle...

  3. 21 CFR 874.4140 - Ear, nose, and throat bur.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear, nose, and throat bur. 874.4140 Section 874...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4140 Ear, nose, and throat bur. (a) Identification. An ear, nose, and throat bur is a device consisting of an interchangeable drill bit that...

  4. 38 CFR 4.87 - Schedule of ratings-ear.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Schedule of ratings-ear...—ear. Diseases of the Ear Rating 6200Chronic suppurative otitis media, mastoiditis, or cholesteatoma... of the substance 10 6208Malignant neoplasm of the ear (other than skin only) 100 Note: A rating...

  5. Erythropoietin and erythropoietin receptor expression in the guinea pig inner ear

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Wagner, Niels; Lidegaard Frederiksen, Birgitte

    2005-01-01

    The erythropoietin receptor (EPOR) is expressed in the brain and erythropoietin (EPO) has been shown to have neurotrophic and neuroprotective functions in the central nervous system and in the retina. These findings may be applied to the inner ear, pending EPO receptor presence. Accordingly......, this study determines expression of EPO and EPOR in the inner ear of the guinea pig. Normal guinea pig inner ears were processed for immunohistochemistry, using poly-clonal antibodies against EPO and the EPO receptor. EPO expression was exclusively found in most, but not all spiral ganglion neurons...... expressed by several cell types within the guinea pig cochlea. We hypothesize on the existence of a local paracrine system and that EPO treatment may be feasible following inner ear damage....

  6. Healthy Functions and Mechanisms of Bamboo-Charcoal Modified Polyesters

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; HE Shu-cai

    2007-01-01

    In this paper, healthy fuactions and mechanismof bamboo-charcoal modified polyesters arc studied. Theresults show that there are five healthy functionsincorporated effectively in bamboo-charcoal modifiedpolyesters, such as good far-lnfrared radiation, good UVprotection, certain negative ion emission, certain anti-bacteria and good absorption functions. The metal elementsand carburets are mainly responsible for far-infrared,negative ion emission functions. UV prevention functionresults mainly from the carbon elements. The absorbabilityand bacteriostasis functions lie in the porous structures.

  7. Osteoma of the middle ear: case report

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ji Hwa [College of Medicine, Inje University, Dongrae Paik Hospital, Busan (Korea, Republic of)

    2005-07-15

    Osteomas of the middle ear are exceedingly rare benign neoplasms. To date, only 21 cases have been reported in the literature. They arise from the promontory, the pyramidal process and the ossicles, and they are usually asymptomatic or cause some conductive hearing loss. We report here the CT and pathologic findings in a 38-year-old woman with a benign osteoma of the middle ear along with chronic otitis media.

  8. Hearing impairment and ear pathology in Nepal.

    Science.gov (United States)

    Little, P; Bridges, A; Guragain, R; Friedman, D; Prasad, R; Weir, N

    1993-05-01

    A stratified random cluster sample of 15,845 subjects was performed in two regions of Nepal to determine the prevalence and main causes of hearing impairment (the most common disability) and the prevalence of ear disease. Subjects reporting current ear pain, or ear discharge, or hearing impairment on direct questioning by a Nepali health worker (primary screening failed), had otoscopy and audiometry (using the Liverpool Field Audiometer) performed, and a questionnaire administered relating to past history. In every fifth house subjects who passed the primary screening (1,716 subjects) were examined to assess the false negative rate of screening. An estimated 16.6 per cent of the study population have hearing impairment (either ear worse than 30 dB hearing threshold level (HTL) 1.0-4.0 kHz, or 50 dB HTL 0.5 kHz), and 7.4 per cent ear drum pathology, equivalent to respectively 2.71 and 1.48 million people extrapolated to the whole of Nepal. Most hearing impairment in the school age group (55.2 per cent) is associated with otitis media or its sequelae. Probably at least 14 per cent of sensorineural deafness is preventable (7 per cent infectious disease, 3.9 per cent trauma, 0.8 per cent noise exposure, 1 per cent cretinism, and 1 per cent abnormal pregnancy or labour). Most individuals reporting current ear pathology (61 per cent) had never attended a health post, and of those receiving ear drop treatment, 84 per cent still had serious pathology. Of subjects who reported ear drop treatment at any time, 31 per cent still had serious pathology. The use of traditional remedies was prevalent.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. The inner ear produces a natriuretic hormone

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, J; Holstein-Rathlou, N H

    1996-01-01

    Cytoplasmic granules have been demonstrated in epithelial cells from the endolymphatic sac, an extraosseus part of the inner ear located in the posterior cranial fossa. Intravenously infused extracts from endolymphatic sacs in anesthetized rats elicited a potent natriuresis and diuresis without...... be the sensory organ/mediator of "cerebral" natriuresis. Furthermore, this substance, tentatively named saccin, may influence the homeostasis of the inner ear fluids and accordingly play a significant role in the pathogenesis of Mèniére's disease....

  10. Evolution of the mammalian middle ear and jaw: adaptations and novel structures.

    Science.gov (United States)

    Anthwal, Neal; Joshi, Leena; Tucker, Abigail S

    2013-01-01

    Having three ossicles in the middle ear is one of the defining features of mammals. All reptiles and birds have only one middle ear ossicle, the stapes or columella. How these two additional ossicles came to reside and function in the middle ear of mammals has been studied for the last 200 years and represents one of the classic example of how structures can change during evolution to function in new and novel ways. From fossil data, comparative anatomy and developmental biology it is now clear that the two new bones in the mammalian middle ear, the malleus and incus, are homologous to the quadrate and articular, which form the articulation for the upper and lower jaws in non-mammalian jawed vertebrates. The incorporation of the primary jaw joint into the mammalian middle ear was only possible due to the evolution of a new way to articulate the upper and lower jaws, with the formation of the dentary-squamosal joint, or TMJ in humans. The evolution of the three-ossicle ear in mammals is thus intricately connected with the evolution of a novel jaw joint, the two structures evolving together to create the distinctive mammalian skull.

  11. Adenovirus Vectors Target Several Cell Subtypes of Mammalian Inner Ear In Vivo

    Science.gov (United States)

    Li, Wenyan; Shen, Jun

    2016-01-01

    Mammalian inner ear harbors diverse cell types that are essential for hearing and balance. Adenovirus is one of the major vectors to deliver genes into the inner ear for functional studies and hair cell regeneration. To identify adenovirus vectors that target specific cell subtypes in the inner ear, we studied three adenovirus vectors, carrying a reporter gene encoding green fluorescent protein (GFP) from two vendors or with a genome editing gene Cre recombinase (Cre), by injection into postnatal days 0 (P0) and 4 (P4) mouse cochlea through scala media by cochleostomy in vivo. We found three adenovirus vectors transduced mouse inner ear cells with different specificities and expression levels, depending on the type of adenoviral vectors and the age of mice. The most frequently targeted region was the cochlear sensory epithelium, including auditory hair cells and supporting cells. Adenovirus with GFP transduced utricular supporting cells as well. This study shows that adenovirus vectors are capable of efficiently and specifically transducing different cell types in the mammalian inner ear and provides useful tools to study inner ear gene function and to evaluate gene therapy to treat hearing loss and vestibular dysfunction. PMID:28116172

  12. Rifle impulse noise affects middle-ear compliance in soldiers wearing protective earplugs.

    Science.gov (United States)

    Job, A; Hamery, P; De Mezzo, S; Fialaire, J-C; Roux, A; Untereiner, M; Cardinale, F; Michel, H; Klein, C; Belcourt, B

    2016-01-01

    We tested middle-ear functioning in humans following intense exposure to noise. Noise generated by small caliber firearms was thought to have no effect on the middle-ear. A cross-over design. We measured middle-ear impedance, acoustic reflex, distortion product otoacoustic emissions (DPOAEs), and transient evoked otoacoustic emissions (TEOAEs) before and after practice rounds performed twice per day. Fifty-nine soldiers equipped with earplugs undergoing regular training for a special mission. The mean noise exposure (LAeq8h) was estimated to be 106 ±1 dB SPL. Impedancemetry revealed a significant increase in the compliance and gradient of the tympano-ossicular chain after impulse noise exposure in the right and left ears. Acoustic reflex reactivity did not show a significant change. DPOAEs and TEOAEs were slightly decreased at 2 kHz, and showed a marked asymmetry in disfavor of the left ear. In soldiers with initial high reactivity of acoustic reflex, increased compliance was associated with a significant decrease in left TEOAEs at 1.5 and 2 kHz. Our results suggest that the use of small-caliber firearms, even while wearing earplugs, affects middle-ear function and may play a role in the early stage of auditory fatigue encompassing tinnitus.

  13. Probiotic and other functional microbes: from markets to mechanisms

    NARCIS (Netherlands)

    Saxelin, M.; Tynkkynen, S.; Matilla-Sandholm, T.; Vos, de W.M.

    2005-01-01

    Insight into the diversity and function of the human intestinal microbiota has been stimulated by clinical studies with bacteria that exhibit specific functions and which are marketed as probiotics to positively affect our health. Initial efforts concentrated on establishing sound scientific support

  14. Probiotic and other functional microbes: from markets to mechanisms

    NARCIS (Netherlands)

    Saxelin, M.; Tynkkynen, S.; Matilla-Sandholm, T.; Vos, de W.M.

    2005-01-01

    Insight into the diversity and function of the human intestinal microbiota has been stimulated by clinical studies with bacteria that exhibit specific functions and which are marketed as probiotics to positively affect our health. Initial efforts concentrated on establishing sound scientific support

  15. Anatomic Considerations on the Middle Ear in Dog

    Directory of Open Access Journals (Sweden)

    Carmen Berghes

    2010-05-01

    Full Text Available Purpose of this study is to explain some aspects of middle ear anatomy in dog. The study was conducted on five dog skulls (different ages from common, large size dogs. The skulls were processed by maceration and submitted to a treatment of mechanical cleaning with perhydrol. The temporal bone was collected first; the external wall was opened carefully to study the tympanic cavity. The ossicles were collected separately and subsequently described. From research carried promontory appears as an elongated projection that separates the oval window and round window. Vestibular window is oval or slightly ovoid shape of a hole, located dorso-medially to the promontory, which communicates with the middle ear vestibule. Cochlearia window appears as a round or circular hole located caudo-lateral to the promontory . it is blocked by a membrane called the tympanum secondary, cavity separating the ramp of the snail. In the ventro-oral cavity openings ductus faringo tympanicum. The osicules sound represented by hammer, anvil and stirrup are articulated with each other and form a chain as a link between the eardrum and vestibular window. Bones are driven by two muscles: the tensor muscle and muscle stirrup eardrum is very thin. osicules ear are relatively large and resemble those of humans. Lenticular bone is the lenticular process of the long arm of anvile.

  16. Better late than never: effective air-borne hearing of toads delayed by late maturation of the tympanic middle ear structures.

    Science.gov (United States)

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Hoke, Kim L

    2016-10-15

    Most vertebrates have evolved a tympanic middle ear that enables effective hearing of airborne sound on land. Although inner ears develop during the tadpole stages of toads, tympanic middle ear structures are not complete until months after metamorphosis, potentially limiting the sensitivity of post-metamorphic juveniles to sounds in their environment. We tested the hearing of five species of toads to determine how delayed ear development impairs airborne auditory sensitivity. We performed auditory brainstem recordings to test the hearing of the toads and used micro-computed tomography and histology to relate the development of ear structures to hearing ability. We found a large (14-27 dB) increase in hearing sensitivity from 900 to 2500 Hz over the course of ear development. Thickening of the tympanic annulus cartilage and full ossification of the middle ear bone are associated with increased hearing ability in the final stages of ear maturation. Thus, juvenile toads are at a hearing disadvantage, at least in the high-frequency range, throughout much of their development, because late-forming ear elements are critical to middle ear function at these frequencies. We discuss the potential fitness consequences of late hearing development, although research directly addressing selective pressures on hearing sensitivity across ontogeny is lacking. Given that most vertebrate sensory systems function very early in life, toad tympanic hearing may be a sensory development anomaly. © 2016. Published by The Company of Biologists Ltd.

  17. Ear Authentication and Template Protection using Bio-key

    Directory of Open Access Journals (Sweden)

    K. Annapurani

    2014-09-01

    Full Text Available Biometric authentication is gaining popularity in the current scenario. Biometric based authentication is the science of using physical or behavioral characteristic for ensuring that the person is the claimed identity. Biometric authentication system is also vulnerable to attacks in various phases. The biometric data stored in the template has to be protected, since variety of attacks like circumvent, covert acquisition affects the normal functioning of the system. An attacker may create new biometric data or steal the template or modify the template. Once the biometric template is compromised then the entire system is lost. So securing biometric template is an important aspect in biometric authentication system. In this study ear biometric template is secured by a new method of generating bio key from the ear fused template. Here the transformed template is stored in the database. During verification phase, for the new biometric sample a bio key is generated. Using this bio key the person is authenticated if the transformed feature generated is matched with the stored one. Hence the template is protected with the bio key. The authenticated person alone can access the system, since the key to decrypt the encrypted template is obtained from the ear trait of the authenticated person. FAR and FRR are used to evaluate the system performance.

  18. Inner ear morphology in the Atlantic molly Poecilia mexicana--first detailed microanatomical study of the inner ear of a cyprinodontiform species.

    Directory of Open Access Journals (Sweden)

    Tanja Schulz-Mirbach

    Full Text Available BACKGROUND: Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining μ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. RESULTS: The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. CONCLUSIONS: Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis--especially with regard to the application of 3D techniques--for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here.

  19. Gain and maximum output of two electromagnetic middle ear implants: are real ear measurements helpful?

    NARCIS (Netherlands)

    Snik, A.F.M.; Noten, J.F.P.; Cremers, C.W.R.J.

    2004-01-01

    We compared the output of two electronic middle ear implants: the Otologics MET device and the Vibrant Soundbridge device. Both devices were programmed in the linear amplification mode. Aided minus unaided sound pressure levels recorded in the ear canal (objective gain) were compared to unaided minu

  20. Prenatal evaluation of the middle ear and diagnosis of middle ear hypoplasia using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Katorza, Eldad; Nahama-Allouche, Catherine; Ducou le Pointe, Hubert; Garel, Catherine [Hopital d' Enfants Armand-Trousseau, Service de Radiologie, Paris (France); Castaigne, Vanina [Hopital Saint-Antoine, Service de Gynecologie-Obstetrique, Paris (France); Gonzales, Marie; Marlin, Sandrine [Hopital d' Enfants Armand-Trousseau, Service de Genetique et Embryologie medicales, Paris (France); Galliani, Eva [Hopital d' Enfants Armand-Trousseau, Service de Chirurgie maxillo-faciale, Paris (France); Jouannic, Jean-Marie; Rosenblatt, Jonathan [Hopital d' Enfants Armand-Trousseau, Service de Gynecologie-Obstetrique, Centre pluridisciplinaire de diagnostic prenatal, Paris (France)

    2011-05-15

    Analysis of the middle ear with fetal MRI has not been previously reported. To show the contribution of fetal MRI to middle ear imaging. The tympanic cavity was evaluated in 108 fetal cerebral MRI examinations (facial and/or cerebral malformation excluded) and in two cases, one of Treacher Collins syndrome (case 1) and the other of oculo-auriculo-vertebral (OUV) spectrum (case 2) with middle ear hypoplasia identified by MRI at 27 and 36 weeks' gestation, respectively. In all 108 fetuses (mean gestational age 32.5 weeks), the tympanic cavity and T2 hypointensity related to the ossicles were well visualised on both sides. Case 1 had micro/retrognathia and bilateral external ear deformity and case 2 had retrognathism with a left low-set and deformed ear. MRI made it possible to recognize the marked hypoplasia of the tympanic cavity, which was bilateral in case 1 and unilateral in case 2. Both syndromes are characterized by craniofacial abnormalities including middle ear hypoplasia, which cannot be diagnosed with US. The middle ear cavity can be visualized with fetal MRI. We emphasize the use of this imaging modality in the diagnosis of middle ear hypoplasia. (orig.)

  1. Measurement of middle ear pressure changes during balloon eustachian tuboplasty: a pilot study.

    Science.gov (United States)

    Todt, Ingo; Abdel-Aziz, Tarek; Mittmann, Philipp; Lehmann, Martin; Ebmeyer, Jörg; Scholtz, Lars-Uwe; Sudhoff, Holger

    2017-05-01

    The middle ear pressure changes detected during BET can be directly attributed to the balloon inflation and may represent a second, immediate, mechanism of action of BET. BET seems to be safe with respect to the risk of a barotrauma. Further human studies are now necessary to confirm the results and gain more insight into the mechanism of action of BET. Since the introduction of Balloon Eustachian Tuboplasty (BET) as a treatment of chronic Eustachian tube dysfunction, the precise mechanism of action is unknown. Long-term effects of BET may be related to observed microfractures of the Eustachian tube cartilage. However, clinical observations indicate a second, immediate mode of action. Therefore, this study investigated and characterized middle ear pressure changes occurring directly during BET procedure. Using a micro-optical pressure sensor, pressure changes during BET were monitored transtympanically in a cadaveric animal study using heathland sheep. Middle ear pressure amplitudes during BET are dependent on the speed of balloon inflation as well as the maximum inflation pressure. A 10-bar inflation pressure yielded a mean middle ear pressure of 5.34 mmHg (71.0 daPA). Negative pressure amplitudes occurring on withdrawal of the balloon catheter are influenced by the speed of withdrawal. No pressure amplitudes capable of causing barotrauma to membranous ear structures could be detected.

  2. Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

    OpenAIRE

    Stefanie Krysiak; Qiang Wei; Klaus Rischka; Andreas Hartwig; Rainer Haag; Thorsten Hugel

    2016-01-01

    Nature often serves as a model system for developing new adhesives. In aqueous environments, mussel-inspired adhesives are promising candidates. Understanding the mechanism of the extraordinarily strong adhesive bonds of the catechol group will likely aid in the development of adhesives. With this aim, we study the adhesion of catechol-based adhesives to metal oxides on the molecular level using atomic force microscopy (AFM). The comparison of single catechols (dopamine) with multiple catecho...

  3. [Changes in plasma inner ear hormones after endolymphatic sac drainage and steroid-instillation surgery (EDSS)].

    Science.gov (United States)

    Kitahara, Tadashi; Horii, Arata; Mishiro, Yasuo; Fukushima, Munehisa; Kondoh, Kazumasa; Okumura, Shin-ichi; Takeda, Noriaki; Kubo, Takeshi

    2002-05-01

    We treated 33 cases of intractable Meniere's disease with endolymphatic sac drainage and steroid-instillation surgery (EDSS), attaining good long-term results in vertigo and hearing. To elucidate how EDSS affects the diseased inner ear, we examined changes in plasma inner ear hormones after EDSS. Among inner ear hormones, plasma vasopressin was significantly decreased after EDSS compared to after mastoidectomy. In cases with good long-term results in vertigo and hearing, postoperative plasma vasopressin remained lower over the long term than in cases with poor results. In cases with negative glycerol test results one year after surgery, postoperative plasma vasopressin also remained significantly lower over the long term than in cases with positive results. Previous studies reported that vestibular neurons projected into hypothalamic supraoptic and paraventricular nuclei and that changes in the inner ear pressure were related to plasma vasopressin. Taken together with present findings, this suggests that EDSS may reduce plasma vasopressin through modification of the diseased inner ear environment, resulting in improved inner ear function.

  4. The candidate splicing factor Sfswap regulates growth and patterning of inner ear sensory organs.

    Directory of Open Access Journals (Sweden)

    Yalda Moayedi

    2014-01-01

    Full Text Available The Notch signaling pathway is thought to regulate multiple stages of inner ear development. Mutations in the Notch signaling pathway cause disruptions in the number and arrangement of hair cells and supporting cells in sensory regions of the ear. In this study we identify an insertional mutation in the mouse Sfswap gene, a putative splicing factor, that results in mice with vestibular and cochlear defects that are consistent with disrupted Notch signaling. Homozygous Sfswap mutants display hyperactivity and circling behavior consistent with vestibular defects, and significantly impaired hearing. The cochlea of newborn Sfswap mutant mice shows a significant reduction in outer hair cells and supporting cells and ectopic inner hair cells. This phenotype most closely resembles that seen in hypomorphic alleles of the Notch ligand Jagged1 (Jag1. We show that Jag1; Sfswap compound mutants have inner ear defects that are more severe than expected from simple additive effects of the single mutants, indicating a genetic interaction between Sfswap and Jag1. In addition, expression of genes involved in Notch signaling in the inner ear are reduced in Sfswap mutants. There is increased interest in how splicing affects inner ear development and function. Our work is one of the first studies to suggest that a putative splicing factor has specific effects on Notch signaling pathway members and inner ear development.

  5. The candidate splicing factor Sfswap regulates growth and patterning of inner ear sensory organs.

    Science.gov (United States)

    Moayedi, Yalda; Basch, Martin L; Pacheco, Natasha L; Gao, Simon S; Wang, Rosalie; Harrison, Wilbur; Xiao, Ningna; Oghalai, John S; Overbeek, Paul A; Mardon, Graeme; Groves, Andrew K

    2014-01-01

    The Notch signaling pathway is thought to regulate multiple stages of inner ear development. Mutations in the Notch signaling pathway cause disruptions in the number and arrangement of hair cells and supporting cells in sensory regions of the ear. In this study we identify an insertional mutation in the mouse Sfswap gene, a putative splicing factor, that results in mice with vestibular and cochlear defects that are consistent with disrupted Notch signaling. Homozygous Sfswap mutants display hyperactivity and circling behavior consistent with vestibular defects, and significantly impaired hearing. The cochlea of newborn Sfswap mutant mice shows a significant reduction in outer hair cells and supporting cells and ectopic inner hair cells. This phenotype most closely resembles that seen in hypomorphic alleles of the Notch ligand Jagged1 (Jag1). We show that Jag1; Sfswap compound mutants have inner ear defects that are more severe than expected from simple additive effects of the single mutants, indicating a genetic interaction between Sfswap and Jag1. In addition, expression of genes involved in Notch signaling in the inner ear are reduced in Sfswap mutants. There is increased interest in how splicing affects inner ear development and function. Our work is one of the first studies to suggest that a putative splicing factor has specific effects on Notch signaling pathway members and inner ear development.

  6. Developmental evolutionary biology of the vertebrate ear: conserving mechanoelectric transduction and developmental pathways in diverging morphologies

    Science.gov (United States)

    Fritzsch, B.; Beisel, K. W.; Bermingham, N. A.

    2000-01-01

    This brief overview shows that a start has been made to molecularly dissect vertebrate ear development and its evolutionary conservation to the development of the insect hearing organ. However, neither the patterning process of the ear nor the patterning process of insect sensory organs is sufficiently known at the moment to provide more than a first glimpse. Moreover, hardly anything is known about otocyst development of the cephalopod molluscs, another triploblast lineage that evolved complex 'ears'. We hope that the apparent conserved functional and cellular components present in the ciliated sensory neurons/hair cells will also be found in the genes required for vertebrate ear and insect sensory organ morphogenesis (Fig. 3). Likewise, we expect that homologous pre-patterning genes will soon be identified for the non-sensory cell development, which is more than a blocking of neuronal development through the Delta/Notch signaling system. Generation of the apparently unique ear could thus represent a multiplication of non-sensory cells by asymmetric and symmetric divisions as well as modification of existing patterning process by implementing novel developmental modules. In the final analysis, the vertebrate ear may come about by increasing the level of gene interactions in an already existing and highly conserved interactive cascade of bHLH genes. Since this was apparently achieved in all three lineages of triploblasts independently (Fig. 3), we now need to understand how much of the morphogenetic cascades are equally conserved across phyla to generate complex ears. The existing mutations in humans and mice may be able to point the direction of future research to understand the development of specific cell types and morphologies in the formation of complex arthropod, cephalopod, and vertebrate 'ears'.

  7. Update on Pyrin Functions and Mechanisms of Familial Mediterranean Fever

    Science.gov (United States)

    Manukyan, Gayane; Aminov, Rustam

    2016-01-01

    Mutations in the MEFV gene, which encodes the protein named pyrin (also called marenostrin or TRIM20), are associated with the autoinflammatory disease familial Mediterranean fever (FMF). Recent genetic and immunologic studies uncovered novel functions of pyrin and raised several new questions in relation to FMF pathogenesis. The disease is clinically heterogeneous reflecting the complexity and multiplicity of pyrin functions. The main functions uncovered so far include its involvement in innate immune response such as the inflammasome assemblage and, as a part of the inflammasome, sensing intracellular danger signals, activation of mediators of inflammation, and resolution of inflammation by the autophagy of regulators of innate immunity. Based on these functions, the FMF-associated versions of pyrin confer a heightened sensitivity to a variety of intracellular danger signals and postpone the resolution of innate immune responses. It remains to be demonstrated, however, what kind of selective advantage the heterozygous carriage conferred in the past to be positively selected and maintained in populations from the Mediterranean basin. PMID:27066000

  8. Maintaining the balance. Novel molecular mechanisms regulating Foxp3 function

    NARCIS (Netherlands)

    Fleskens, V.

    2014-01-01

    A balanced immune response requires tight control of immune activation at various levels, which crucially involves the establishment of specific gene expression programs by key transcriptional regulators including the transcription factor Foxp3. As the driving factor of both development and function

  9. Mechanisms of LAIR-1 mediated inhibition of immune function

    NARCIS (Netherlands)

    Verbrugge, Annelies

    2005-01-01

    The mammalian immune system has to eliminate pathogens, while preventing damage to the host. An adequate function of the immune system therefore requires the coordinate action of activating and inhibitory signals. Loss of inhibitory signals may lead to chronic inflammation or auto-immune disease. A

  10. Molecular Mechanisms Regulating Human Dendritic Cell Development, Survival and Function

    NARCIS (Netherlands)

    L. van de Laar (Lianne)

    2011-01-01

    textabstractDendritic cells (DC) are professional antigen presenting cells (APC) with a dual function in the immune system. On the one hand, these specialized leukocytes are equipped to alert the immune system to invading pathogens or other danger signals. On the other, DC can promote tolerogenic re

  11. Simulations and Measurements of Human Middle Ear Vibrations Using Multi-Body Systems and Laser-Doppler Vibrometry with the Floating Mass Transducer

    OpenAIRE

    Tobias Strenger; Stefan Lehner; Frank Böhnke; Theodor Bretan

    2013-01-01

    The transfer characteristic of the human middle ear with an applied middle ear implant (floating mass transducer) is examined computationally with a Multi-body System approach and compared with experimental results. For this purpose, the geometry of the middle ear was reconstructed from μ-computer tomography slice data and prepared for a Multi-body System simulation. The transfer function of the floating mass transducer, which is the ratio of the input voltage and the generated force, is deri...

  12. Ear Acupuncture in European Traditional Medicine

    Directory of Open Access Journals (Sweden)

    Luigi Gori

    2007-01-01

    Full Text Available Auricular acupuncture is a diagnostic and treatment system based on normalizing the body's dysfunction through stimulation of definite points on the ear. Rudimentary forms of acupuncture which probably arose during the Stone Age have survived in many parts of the world right down to present day. It was used in the ancient Egypt, Rome, Greece and all the Mediterranean area. It is a microacupuncture technique similar to reflexology, and was first described in France in 1950 by Paul Nogier who is considered the Father of modern ear acupuncture. It was speculated that the technique works because groups of pluripotent cells contain information from the whole organism and create regional organization centers representing different parts of the body. Nevertheless stimulation of a reflex point in the ear seems relieve symptoms of distant pathologies. Modern research is confirming the efficacy of ear acupuncture for analgesia and anxiety related disease, while tobacco dependence and other substance abuse still need confirmation. Actually main methodological problems with auricular acupuncture are that exist too many maps with little agreement regarding point location in the ear, and that the correspondence or reflex systems does not correlated with modern knowledge of anatomy and physiology.

  13. Carcinoid tumor of the middle ear.

    Science.gov (United States)

    Nikanne, Elina; Kantola, Olli; Parviainen, Tapani

    2004-08-01

    Although carcinoid tumors are labeled as neuroendocrine tumors they can also originate in tissue lacking neuroendocrine cells, such as that in the middle ear. Symptoms of a carcinoid tumor in the middle ear are common ear symptoms such as fullness, pain and hearing loss. Carcinoid tumors have also been considered to be slow-growing. Both these aspects can easily lead to a relatively late diagnosis of carcinoid tumor of the middle ear. The diagnosis is made histologically, and the tumor is primarily treated surgically. In the follow-up of patients, octreotide scanning has proved to be a sensitive method in cases of both recurrence and metastasis. Our patient was a 34-year-old, otherwise healthy female with left-sided acute otitis media and facial palsy in her left ear. She had also suffered from the same symptoms 4 years earlier. She was treated with an operation, and the histologic diagnosis was a carcinoid tumor. In the follow-up of the patient we used octreotide scanning.

  14. CT of temporal bone - IV. inner ear

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jae Yoon; Sung, Kyu Bo; Youn, Eun Kyoung; Park, Youn Kyeung; Lee, Young Uk [Koryo general Hospital, Seoul (Korea, Republic of)

    1990-07-15

    Temporal bone CT was done in 697 patients from April 1985 to October 1989. The abnormal findings were seen in 453 patients, which were chronic otitis media in 355 patients, fracture in 49 patients and congenital anomaly in 44 patients, etc. The abnormal findings of inner ear were observed on 46 patients. The results were summarized as follows : 1. The incidence of inner ear involvement by chronic otitis media was 7.3% (26/355 : labyrinthine fistula in 17 patients, labyrinthitis ossificans in 9 patients). Labyrinthine fistula was most commonly located on lateral semicircular canal (15/17, 88.2%). 2. Fusion of vestibule with lateral semicircular canal and formation of common cavity was demonstrated incidentally in 5 patients (0.7% of total number of temporal bone CT), and bilateral in 3 patients. 3. The incidence of inner ear anomaly in congenital ear anomaly was 11.4% (5/44). All cases were bilateral and three patients showed associated middle ear anomaly. 4. The incidence of involvement of bony labyrinth in temporal bone fracture was 10.2% (5/49). Labyrinthine fracture was seen all patients of transverse(3) and mixed fracture(1). In longitudinal fracture, labyrinthine fracture was seen in 2.2% (1/45). 5. Others were traumatic labyrinthitis ossificans(1), intracanalicular acoustic neuroma(3) and facial nerve neuroma(1)

  15. Evolution and development of the vertebrate ear

    Science.gov (United States)

    Fritzsch, B.; Beisel, K. W.

    2001-01-01

    This review outlines major aspects of development and evolution of the ear, specifically addressing issues of cell fate commitment and the emerging molecular governance of these decisions. Available data support the notion of homology of subsets of mechanosensors across phyla (proprioreceptive mechanosensory neurons in insects, hair cells in vertebrates). It is argued that this conservation is primarily related to the specific transducing environment needed to achieve mechanosensation. Achieving this requires highly conserved transcription factors that regulate the expression of the relevant structural genes for mechanosensory transduction. While conserved at the level of some cell fate assignment genes (atonal and its mammalian homologue), the ear has also radically reorganized its development by implementing genes used for cell fate assignment in other parts of the developing nervous systems (e.g., neurogenin 1) and by evolving novel sets of genes specifically associated with the novel formation of sensory neurons that contact hair cells (neurotrophins and their receptors). Numerous genes have been identified that regulate morphogenesis, but there is only one common feature that emerges at the moment: the ear appears to have co-opted genes from a large variety of other parts of the developing body (forebrain, limbs, kidneys) and establishes, in combination with existing transcription factors, an environment in which those genes govern novel, ear-related morphogenetic aspects. The ear thus represents a unique mix of highly conserved developmental elements combined with co-opted and newly evolved developmental elements.

  16. [Imaging and audiology analysis of the congenital inner ear malformations].

    Science.gov (United States)

    Zhou, Bao; Lin, Shaolian; Lin, Youhui; Fang, Zheming; Ye, Shengnan; Zhang, Rong

    2015-11-01

    To investigate imaging and audiology features of temporal bone and analyze the classification and prevalence of inner ear abnormalities in children with sensorineural hearing loss. Children who were diagnosed with sensorineural hearing loss were examined by high resolution CT and the inner ear fluid of MRI. And each chart was retrospectively reviewed to determine the imaging and audiology features. There were 125 patients(232 ears) found with inner ear malformation in 590 children with SNHL. About 21.71% of the inner ear malformation occurred in severe and profound hearing loss ears, and 12.85% occurred in r moderate hearing loss ears. The inner ear malformation rate in normal hearing ears were 13.59%. CT and MRI examinations of temporal bone are important diagnostic tools to indentify inner ear malformations. Inner ear malformations are almost bilateral and hearing loss are profoud. Cochleo-vestibular malformations and large vestibular aqueduct are the 2 most frequent deformities. Among the children with SNHL, deformity rate in the severe and profound hearing loss ears is higher than that in moderate hearing loss ear. Inner ear malformations can exist in people with normal hearing.

  17. New insight into the mechanism of mitochondrial cytochrome c function

    DEFF Research Database (Denmark)

    Chertkova, Rita V; Brazhe, Nadezda A; Bryantseva, Tatiana V

    2017-01-01

    We investigate functional role of the P76GTKMIFA83 fragment of the primary structure of cytochrome c. Based on the data obtained by the analysis of informational structure (ANIS), we propose a model of functioning of cytochrome c. According to this model, conformational rearrangements of the P76......GTKMIFA83 loop fragment have a significant effect on conformational mobility of the heme. It is suggested that the conformational mobility of cytochrome c heme is responsible for its optimal orientation with respect to electron donor and acceptor within ubiquinol-cytochrome c oxidoreductase (complex III......) and cytochrome c oxidase (complex IV), respectively, thus, ensuring electron transfer from complex III to complex IV. To validate the model, we design several mutant variants of horse cytochrome c with multiple substitutions of amino acid residues in the P76GTKMIFA83 sequence that reduce its ability to undergo...

  18. Functional genomics of PCOS: from GWAS to molecular mechanisms.

    Science.gov (United States)

    McAllister, Jan M; Legro, Richard S; Modi, Bhavi P; Strauss, Jerome F

    2015-03-01

    Polycystic ovary syndrome (PCOS) is a common endocrinopathy characterized by increased ovarian androgen biosynthesis, anovulation, and infertility. PCOS has a strong heritable component based on familial clustering and twin studies. Genome-wide association studies (GWAS) identified several PCOS candidate loci including LHCGR, FSHR, ZNF217, YAP1, INSR, RAB5B, and C9orf3. We review the functional roles of strong PCOS candidate loci focusing on FSHR, LHCGR, INSR, and DENND1A. We propose that these candidates comprise a hierarchical signaling network by which DENND1A, LHCGR, INSR, RAB5B, adapter proteins, and associated downstream signaling cascades converge to regulate theca cell androgen biosynthesis. Future elucidation of the functional gene networks predicted by the PCOS GWAS will result in new diagnostic and therapeutic approaches for women with PCOS.

  19. Molecular Mechanism of hTERT Function in Mitochondria

    Science.gov (United States)

    2016-10-20

    DNA metabolism REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO 8. PERFORMING...j.ajpath.2011.10.003 Donna Gordon, Janine Santos. The emerging role of telomerase reverse transcriptase (TERT) in mitochondrial DNA metabolism ...lack of reagents to understand and isolate the mitochondrial versus nuclear function of the protein . Nevertheless, we now know that in the mitochondria

  20. Research on Chemical Mechanical Planarization for Functional Ceramics

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Presently, the products of functional ceramic are widely applied in the light & mechatronics fields such as communication, aeronautic and astronautic engineering, military affairs and home-use electrical appliance etc. It's performance of working is mainly determined by the physical performance of the surface. And therefore the roughness and the affected layer's depth of the final processing surface have a direct influence to the performance of the device. It is obvious that how to guarantee the processing ...

  1. Structure, function, and mechanism of human MIF and parasitic orthologs

    OpenAIRE

    Zierow, Swen

    2008-01-01

    The cytokine macrophage migration inhibitory factor (MIF) is a key mediator of the innate and adaptive immune system and plays a critical role in many inflammatory diseases. MIF is required to combat serious infections; however, high-level production of MIF has been linked to a severe outcome of many diseases including adult respiratory distress syndrome, septic shock, rheumatoid arthritis, atherosclerosis and cancer. Over the last years, MIF has also been ascribed important functions in the ...

  2. Zona pellucida domain-containing protein β-tectorin is crucial for zebrafish proper inner ear development.

    Directory of Open Access Journals (Sweden)

    Chung-Hsiang Yang

    Full Text Available BACKGROUND: The zona pellucida (ZP domain is part of many extracellular proteins with diverse functions from structural components to receptors. The mammalian β-tectorin is a protein of 336 amino acid residues containing a single ZP domain and a putative signal peptide at the N-terminus of the protein. It is 1 component of a gel-like structure called the tectorial membrane which is involved in transforming sound waves into neuronal signals and is important for normal auditory function. β-Tectorin is specifically expressed in the mammalian and avian inner ear. METHODOLOGY/PRINCIPAL FINDINGS: We identified and cloned the gene encoding zebrafish β-tectorin. Through whole-mount in situ hybridization, we demonstrated that β-tectorin messenger RNA was expressed in the otic placode and specialized sensory patch of the inner ear during zebrafish embryonic stages. Morpholino knockdown of zebrafish β-tectorin affected the position and number of otoliths in the ears of morphants. Finally, swimming behaviors of β-tectorin morphants were abnormal since the development of the inner ear was compromised. CONCLUSIONS/SIGNIFICANCE: Our results reveal that zebrafish β-tectorin is specifically expressed in the zebrafish inner ear, and is important for regulating the development of the zebrafish inner ear. Lack of zebrafish β-tectorin caused severe defects in inner ear formation of otoliths and function.

  3. Automaticity of walking: functional significance, mechanisms, measurement and rehabilitation strategies

    Directory of Open Access Journals (Sweden)

    David J Clark

    2015-05-01

    Full Text Available Automaticity is a hallmark feature of walking in adults who are healthy and well-functioning. In the context of walking, ‘automaticity’ refers to the ability of the nervous system to successfully control typical steady state walking with minimal use of attention-demanding executive control resources. Converging lines of evidence indicate that walking deficits and disorders are characterized in part by a shift in the locomotor control strategy from healthy automaticity to compensatory executive control. This is potentially detrimental to walking performance, as an executive control strategy is not optimized for locomotor control. Furthermore, it places excessive demands on a limited pool of executive reserves. The result is compromised ability to perform basic and complex walking tasks and heightened risk for adverse mobility outcomes including falls. Strategies for rehabilitation of automaticity are not well defined, which is due to both a lack of systematic research into the causes of impaired automaticity and to a lack of robust neurophysiological assessments by which to gauge automaticity. These gaps in knowledge are concerning given the serious functional implications of compromised automaticity. Therefore, the objective of this article is to advance the science of automaticity of walking by consolidating evidence and identifying gaps in knowledge regarding: a functional significance of automaticity; b neurophysiology of automaticity; c measurement of automaticity; d mechanistic factors that compromise automaticity; and e strategies for rehabilitation of automaticity.

  4. Micromechanical resonator array for an implantable bionic ear.

    Science.gov (United States)

    Bachman, Mark; Zeng, Fan-Gang; Xu, Tao; Li, G-P

    2006-01-01

    In this paper we report on a multi-resonant transducer that may be used to replace a traditional speech processor in cochlear implant applications. The transducer, made from an array of micro-machined polymer resonators, is capable of passively splitting sound into its frequency sub-bands without the need for analog-to-digital conversion and subsequent digital processing. Since all bands are mechanically filtered in parallel, there is low latency in the output signals. The simplicity of the device, high channel capability, low power requirements, and small form factor (less than 1 cm) make it a good candidate for a completely implantable bionic ear device.

  5. Computer-controlled mechanical lung model for application in pulmonary function studies

    NARCIS (Netherlands)

    A.F.M. Verbraak (Anton); J.E.W. Beneken; J.M. Bogaard (Jan); A. Versprille (Adrian)

    1995-01-01

    textabstractA computer controlled mechanical lung model has been developed for testing lung function equipment, validation of computer programs and simulation of impaired pulmonary mechanics. The construction, function and some applications are described. The physical model is constructed from two

  6. DMPD: Molecular mechanisms of the anti-inflammatory functions of interferons. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18086388 Molecular mechanisms of the anti-inflammatory functions of interferons. Ko...varik P, Sauer I, Schaljo B. Immunobiology. 2007;212(9-10):895-901. Epub 2007 Nov 8. (.png) (.svg) (.html) (.csml) Show Molecular... mechanisms of the anti-inflammatory functions of interferons. PubmedID 18086388 Title Molecular

  7. Postoperative Recovery of Mechanical Muscle Function in Hip Replacement Patients

    DEFF Research Database (Denmark)

    Jensen, Carsten; Aagaard, Per; Overgaard, Søren

    2011-01-01

    INTRODUCTION Muscle function in patients with hip osteoarthritis (OA) is not well-studied. We established a new setup of tests in order to monitor patients before and after surgery. Our novel setup was used to evaluate single- and multi-joint strength (torque) and power in a group of 40 – 65 year...... weeks post surgery for both the affected (AF) as well as the non-affected (NA) side. Protocol: All contractions were performed ad libitum and for each muscle group 3 trails of 4s duration were performed. The trail with highest peak torque was used for further analysis. Statistics: Paired students t...

  8. Phospholipase A2 structure/function, mechanism, and signaling1

    OpenAIRE

    Burke, John E.; Dennis, Edward A.

    2009-01-01

    Tremendous advances in understanding the structure and function of the superfamily of phospholipase A2 (PLA2) enzymes has occurred in the twenty-first century. The superfamily includes 15 groups comprising four main types including the secreted sPLA2, cytosolic cPLA2, calcium-independent iPLA2, and platelet activating factor (PAF) acetyl hydrolase/oxidized lipid lipoprotein associated (Lp)PLA2. We review herein our current understanding of the structure and interaction with substrate phosphol...

  9. Transfer function modeling of damping mechanisms in distributed parameter models

    Science.gov (United States)

    Slater, J. C.; Inman, D. J.

    1994-01-01

    This work formulates a method for the modeling of material damping characteristics in distributed parameter models which may be easily applied to models such as rod, plate, and beam equations. The general linear boundary value vibration equation is modified to incorporate hysteresis effects represented by complex stiffness using the transfer function approach proposed by Golla and Hughes. The governing characteristic equations are decoupled through separation of variables yielding solutions similar to those of undamped classical theory, allowing solution of the steady state as well as transient response. Example problems and solutions are provided demonstrating the similarity of the solutions to those of the classical theories and transient responses of nonviscous systems.

  10. Transfer function modeling of damping mechanisms in viscoelastic plates

    Science.gov (United States)

    Slater, J. C.; Inman, D. J.

    1991-01-01

    This work formulates a method for the modeling of material damping characteristics in plates. The Sophie German equation of classical plate theory is modified to incorporate hysteresis effects represented by complex stiffness using the transfer function approach proposed by Golla and Hughes, (1985). However, this procedure is not limited to this representation. The governing characteristic equation is decoupled through separation of variables, yielding a solution similar to that of undamped classical plate theory, allowing solution of the steady state as well as the transient response problem.

  11. Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

    Directory of Open Access Journals (Sweden)

    Stefanie Krysiak

    2015-05-01

    Full Text Available Nature often serves as a model system for developing new adhesives. In aqueous environments, mussel-inspired adhesives are promising candidates. Understanding the mechanism of the extraordinarily strong adhesive bonds of the catechol group will likely aid in the development of adhesives. With this aim, we study the adhesion of catechol-based adhesives to metal oxides on the molecular level using atomic force microscopy (AFM. The comparison of single catechols (dopamine with multiple catechols on hyperbranched polyglycerols (hPG at various pH and dwell times allowed us to further increase our understanding. In particular, we were able to elucidate how to achieve strong bonds of different valency. It was concluded that hyperbranched polyglycerols with added catechol end groups are promising candidates for durable surface coatings.

  12. Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols.

    Science.gov (United States)

    Krysiak, Stefanie; Wei, Qiang; Rischka, Klaus; Hartwig, Andreas; Haag, Rainer; Hugel, Thorsten

    2015-01-01

    Nature often serves as a model system for developing new adhesives. In aqueous environments, mussel-inspired adhesives are promising candidates. Understanding the mechanism of the extraordinarily strong adhesive bonds of the catechol group will likely aid in the development of adhesives. With this aim, we study the adhesion of catechol-based adhesives to metal oxides on the molecular level using atomic force microscopy (AFM). The comparison of single catechols (dopamine) with multiple catechols on hyperbranched polyglycerols (hPG) at various pH and dwell times allowed us to further increase our understanding. In particular, we were able to elucidate how to achieve strong bonds of different valency. It was concluded that hyperbranched polyglycerols with added catechol end groups are promising candidates for durable surface coatings.

  13. [Bone Conduction and Active Middle Ear Implants].

    Science.gov (United States)

    Volkenstein, S; Thomas, J P; Dazert, S

    2016-05-01

    The majority of patients with moderate to severe hearing loss can be supplied with conventional hearing aids depending on severity and cause for hearing loss in a satisfying way. However, some patients either do not benefit enough from conventional hearing aids or cannot wear them due to inflammatory reactions and chronic infections of the external auditory canal or due to anatomical reasons. For these patients there are fully- and semi-implantable middle ear and bone conduction implants available. These devices either directly stimulate the skull (bone conduction devices), middle ear structures (active middle ear implants) or the cochlea itself (direct acoustic stimulation). Patients who failed surgical hearing rehabilitation or do not benefit from conventional hearing aids may achieve a significant better speech understanding and tremendous improvement in quality of life by implantable hearing devices with careful attention to the audiological and anatomical indication criteria.

  14. Precise individualized armature for ear reconstruction

    Science.gov (United States)

    Evenhouse, Raymond J.; Chen, Xiaoming

    1991-04-01

    The cosmetic result of an ear restored surgically or via prosthetics is dependent on the surgeon''s ability to carve a precise cartilage armature at the time of surgery or the prosthetist''s ability to sculpt in wax an exact duplicate of the patient''s " missing" ear. Introducing CAD/CAM technology into the process benefits the esthetic outcome of these procedures. By utilizing serial section information derived from CAT MRI or moulage techniques a mirrorimage of the patient''s " donor" ear is generated. The resulting earform data is then used for the design of a cartilage armature produced by multi-axis milling or to produce by stereolithography a model which serves as the basis for a prosthesis.

  15. The acoustical significance of age-dependent ear elongation

    DEFF Research Database (Denmark)

    Christensen, Flemming

    2015-01-01

    Elderly people, especially some old men, appear to have very large ears. This paper presents an investigation on the acoustic significance of the age dependent ear elongation. HRTFs and ear lengths were measured for two groups of young and old people. The older groups had larger ears on average......, corresponding to what is reported in the literature. For female ears, virtually no acoustical effect was found. For male ears directional dependent effects in the range up to 5 dB on average was found for certain directions and frequencies. Implications on age dependent hearing loss (presbycusis...

  16. Orofacial complex regional pain syndrome: pathophysiologic mechanisms and functional MRI.

    Science.gov (United States)

    Lee, Yeon-Hee; Lee, Kyung Mi; Kim, Hyug-Gi; Kang, Soo-Kyung; Auh, Q-Schick; Hong, Jyung-Pyo; Chun, Yang-Hyun

    2017-08-01

    Complex regional pain syndrome (CRPS) is one of the most challenging chronic pain conditions and is characterized by burning pain, allodynia, hyperalgesia, autonomic changes, trophic changes, edema, and functional loss involving mainly the extremities. Until recently, very few reports have been published concerning CRPS involving the orofacial area. We report on a 50-year-old female patient who presented with unbearable pain in all of her teeth and hypersensitivity of the facial skin. She also reported intractable pain in both extremities accompanied by temperature changes and orofacial pain that increased when the other pains were aggravated. In the case of CRPS with trigeminal neuropathic pain, protocols for proper diagnosis and prompt treatment have yet to be established in academia or in the clinical field. We performed functional magnetic resonance imaging for a thorough analysis of the cortical representation of the affected orofacial area immediately before and immediately after isolated light stimulus of the affected hand and foot and concluded that CRPS can be correlated with trigeminal neuropathy in the orofacial area. Furthermore, the patient was treated with carbamazepine administration and stellate ganglion block, which can result in a rapid improvement of pain in the trigeminal region. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Physiological Mechanisms in Combined Electric-Acoustic Stimulation.

    Science.gov (United States)

    Sato, Mika; Baumhoff, Peter; Tillein, Jochen; Kral, Andrej

    2017-09-01

    Electrical stimulation is normally performed on ears that have no hearing function, i.e., lack functional hair cells. The properties of electrically-evoked responses in these cochleae were investigated in several previous studies. Recent clinical developments have introduced cochlear implantation (CI) in residually-hearing ears to improve speech understanding in noise. The present study documents the known physiological differences between electrical stimulation of hair cells and of spiral ganglion cells, respectively, and reviews the mechanisms of combined electric and acoustic stimulation in the hearing ears. Literature review from 1971 to 2016. Compared with pure electrical stimulation the combined electroacoustic stimulation provides additional low-frequency information and expands the dynamic range of the input. Physiological studies document a weaker synchronization of the evoked activity in electrically stimulated hearing ears compared with deaf ears that reduces the hypersynchronization of electrically-evoked activity. The findings suggest the possibility of balancing the information provided by acoustic and electric input using stimulus intensity. Absence of distorting acoustic-electric interactions allows exploiting these clinical benefits of electroacoustic stimulation.

  18. Heterosis in early maize ear inflorescence development: a genome-wide transcription analysis for two maize inbred lines and their hybrid.

    Science.gov (United States)

    Ding, Haiping; Qin, Cheng; Luo, Xirong; Li, Lujiang; Chen, Zhe; Liu, Hongjun; Gao, Jian; Lin, Haijian; Shen, Yaou; Zhao, Maojun; Lübberstedt, Thomas; Zhang, Zhiming; Pan, Guangtang

    2014-08-11

    Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17) and their F1 hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs) genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex), five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity), and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization). Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an indication that in

  19. Heterosis in Early Maize Ear Inflorescence Development: A Genome-Wide Transcription Analysis for Two Maize Inbred Lines and Their Hybrid

    Directory of Open Access Journals (Sweden)

    Haiping Ding

    2014-08-01

    Full Text Available Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17 and their F1 hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex, five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity, and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization. Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an

  20. [The tempestuous history of middle ear operation].

    Science.gov (United States)

    Betlejewski, Stanisław; Betlejewski, Andrzej

    2008-01-01

    The paper is a review of primary and secondary historical and scientific literature concerning the surgical treatment of the middle ear diseases. The development of mastoid surgery can be traced through the past 4 centuries. Once used as a means of evacuating a postauricular abscess, it has evolved to become a method for gaining entry into the middle ear to control acute and chronic ear diseases, or for treatment of otogenic complications. Earlier works led the way to the postauricular "Wilde incision", which gave rise to Schwartze mastoidectomy. Oscar Wilde's ultimate demise from an otogenic meningitis appears all the more ironic when one considers the role his father, Sir William Wilde, played as one of the founding fathers of modern otology. The death of baron von Berger after mastoidectomy performed for treatment of tinnitus and hypacusis, stopped the further development of surgical procedures for about hundred years. The Joseph Toynbee's "Diseases of the ear" was the first work about ear diseases on a pathologic anatomical base, and fundamental for otology of the German speaking countries in the nineteenth and early twentieth centuries. Otology was emerging as a specific specialty. Von Tröltsch was the first surgeon, who proposed the antral opening through the external ear canal. When Schwartze and his assistant, Eysell, published their paper: "On the Artificial Opening of the Mastoid Air Cells," a century or so had passed since the few previous attempts to remove the tegmen of the mastoid had been reported. One of the greatest otologists of the 19th century was Adam Politzer, His influence on the 50 years of otology has never been equaled. It is in his honor that the International Society of Otology bears his name.

  1. Application of functional neck dissection for lower collar-shaped incision at hair margin behind ear in the treat-ment of differentiated thyroid cancer%耳后发缘低领口状切口的功能性颈清术在分化型甲状腺癌中的应用

    Institute of Scientific and Technical Information of China (English)

    赵健洁; 张晓华; 高博; 姜燕; 文亚渊

    2015-01-01

    Objective To explore role of functional neck dissection for lower collar-shaped incision at hair margin behind ear in the treatment of differentiated thyroid cancer. Methods The clinical data of 11 patients with thyroid papillary carcinoma who underwent func-tional neck dissection for lower collar-shaped incision at hair margin behind ear were retrospectively analyzed. Results The incisions of all patients were unseen in daily life and patients were satisfied with the postoperative appearances. No case of shoulder syndrome,postoperative local recurrence and distant metastasis was observed. Conclusion Functional neck dissection for lower collar-shaped incision at hair margin behind ear is effective in the treatment of differentiated thyroid cancer. Meanwhile it can obviously improve patients’ postoperative appearance and life quality,therefore it is worth clinical application.%目的:探讨耳后发缘低领口状切口的功能性颈清术在分化型甲状腺癌治疗中的作用。方法回顾性分析我科11例甲状腺乳头状癌患者行耳后发缘切口的功能性颈清术治疗的临床资料。结果11例患者术后切口日常情况隐匿不可见,患者对术后外观满意度高,无肩综合征,术后无局部复发及远处转移。结论耳后发缘低领口状切口的功能性颈清术既能达到治疗目的,相较于传统功能性颈清术,能明显改善术后颈部外形,提高患者术后的生活质量,值得临床推广应用。

  2. A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex

    Science.gov (United States)

    2010-08-01

    to test models that allowed simulations of the functional morphology, and consider possible functional implications. Materials and Methods Ethics ...principles of the mammalian middle ear. Advances in Anatomy Embryology and Cell Biology 55: 1–70. 24. McCormick JG, Wever EG, Ridgway SH, Palin J (1980

  3. The Frog Inner Ear: Picture Perfect?

    OpenAIRE

    Mason, Matthew James; Segenhout, Johannes M.; Cobo-Cuan, Ariadna; Quiñones, Patricia M.; van Dijk, Pim

    2015-01-01

    This is the accepted manuscript of a paper published in the Journal of the Association for Research in Otolaryngology (2015) DOI: 10.1007/s10162-015-0506-z Many recent accounts of the frog peripheral auditory system have reproduced Wever’s (1973) schematic cross-section of the ear of a leopard frog. We sought to investigate to what extent this diagram is an accurate and representative depiction of the anuran inner ear, using three-dimensional reconstructions made from serial sections of Ra...

  4. up to one’s ears

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    up to one’s ears可以解释成"很忙"的意思。如:Half the people in my office are home sick,so I’m up to my ears!我办公室里有一半的人有病请假,所以我简直忙得不得了。I’d like to help you paint the kitchen tonight,but I’m up to my ears in paper work I had to bring home from the office.我很愿意今晚帮你把厨房上油漆。可

  5. A Man With Two Burned Ears

    Institute of Scientific and Technical Information of China (English)

    范图雨

    2001-01-01

    Mr Smith was in troublethose days. He drove a car forMr Black, a rich business-man. He worked hard and theshopkeeper liked him. But hecouldn't work when he dranktoo much. And once he al-most fell into the river whenhe drove along the bridge. MrBlack became angry and wasgoing to send him away. Hehad a big family and wasafraid of that and promisedhe would stop drinking atonce. The man told him towait to be dealt with. OneMonday morning, Mr Smithcame into the office, with twobadly burned ears. “Whathappened to your ears?”asked Mr Black.

  6. Cell size control - a mechanism for maintaining fitness and function.

    Science.gov (United States)

    Miettinen, Teemu P; Caldez, Matias J; Kaldis, Philipp; Björklund, Mikael

    2017-09-01

    The maintenance of cell size homeostasis has been studied for years in different cellular systems. With the focus on 'what regulates cell size', the question 'why cell size needs to be maintained' has been largely overlooked. Recent evidence indicates that animal cells exhibit nonlinear cell size dependent growth rates and mitochondrial metabolism, which are maximal in intermediate sized cells within each cell population. Increases in intracellular distances and changes in the relative cell surface area impose biophysical limitations on cells, which can explain why growth and metabolic rates are maximal in a specific cell size range. Consistently, aberrant increases in cell size, for example through polyploidy, are typically disadvantageous to cellular metabolism, fitness and functionality. Accordingly, cellular hypertrophy can potentially predispose to or worsen metabolic diseases. We propose that cell size control may have emerged as a guardian of cellular fitness and metabolic activity. © 2017 WILEY Periodicals, Inc.

  7. [Basic mechanisms: structure, function and metabolism of plasma lipoproteins].

    Science.gov (United States)

    Errico, Teresa L; Chen, Xiangyu; Martin Campos, Jesús M; Julve, Josep; Escolà-Gil, Joan Carles; Blanco-Vaca, Francisco

    2013-01-01

    The aim of this work is to present basic information on the lipoprotein physiology. The protein fraction of lipoproteins consists of several apolipoproteins and enzymes whose functions are lipid transport and metabolism. Classification of lipoproteins is based on their density. Chylomicrons, VLDL, IDL, LDL and HDL can be isolated by ultracentrifugation. Both chylomicrons- and VLDL-triglycerides are transported from the intestine and liver, respectively, to the peripheral tissues. The metabolism of VLDL originates IDL and LDL. LDL is the main transporter of cholesterol to extrahepatic tissues. HDL mobilizes cholesterol from peripheral tissues to the liver where it is secreted to bile as free cholesterol or bile salts, a process termed reverse cholesterol transport. Lipoprotein metabolism can be regulated by nuclear receptors that regulate the expression of genes involved in triglyceride and apolipoprotein metabolism. Copyright © 2013 Elsevier España, S.L. y SEA. All rights reserved.

  8. MD 1856 - Landau Damping: Beam Transfer Functions and diffusion mechanisms

    CERN Document Server

    Tambasco, Claudia; Boccardi, Andrea; Buffat, Xavier; Gasior, Marek; Lefevre, Thibaut; Levens, Tom; Pojer, Mirko; Salvachua Ferrando, Belen Maria; Solfaroli Camillocci, Matteo; Pieloni, Tatiana; Crouch, Matthew Paul; CERN. Geneva. ATS Department

    2017-01-01

    In the 2012, 2015 and 2016 several instabilities were developing during the betatron squeeze where beam-beam interactions become stronger modifying the tune spread provided by the octupoles magnets. Studies of the stability area computed by evaluating the dispersion integral for different tune spread couldn’t explain the 2012 observed instabilities during the squeeze. The size of the stability area given by the computed dispersion integral depends on the transverse tune spread but its shape is defined by the particle distribution in the beams. Therefore any change of the particle distribution due to for instance a diffusion from excited resonances can lead to a deterioration of the Landau stability area. The Beam Transfer Functions (BTF) measurements are direct measurement of the Stability Diagrams (SD). They are sensitive to the particle distribution and contain information about the transverse tune spread in the beams. In this MD we wanted to verify the findings of MD 1407 and try to explain observed inst...

  9. QTL Mapping of Kernel Number-Related Traits and Validation of One Major QTL for Ear Length in Maize.

    Science.gov (United States)

    Huo, Dongao; Ning, Qiang; Shen, Xiaomeng; Liu, Lei; Zhang, Zuxin

    2016-01-01

    The kernel number is a grain yield component and an important maize breeding goal. Ear length, kernel number per row and ear row number are highly correlated with the kernel number per ear, which eventually determines the ear weight and grain yield. In this study, two sets of F2:3 families developed from two bi-parental crosses sharing one inbred line were used to identify quantitative trait loci (QTL) for four kernel number-related traits: ear length, kernel number per row, ear row number and ear weight. A total of 39 QTLs for the four traits were identified in the two populations. The phenotypic variance explained by a single QTL ranged from 0.4% to 29.5%. Additionally, 14 overlapping QTLs formed 5 QTL clusters on chromosomes 1, 4, 5, 7, and 10. Intriguingly, six QTLs for ear length and kernel number per row overlapped in a region on chromosome 1. This region was designated qEL1.10 and was validated as being simultaneously responsible for ear length, kernel number per row and ear weight in a near isogenic line-derived population, suggesting that qEL1.10 was a pleiotropic QTL with large effects. Furthermore, the performance of hybrids generated by crossing 6 elite inbred lines with two near isogenic lines at qEL1.10 showed the breeding value of qEL1.10 for the improvement of the kernel number and grain yield of maize hybrids. This study provides a basis for further fine mapping, molecular marker-aided breeding and functional studies of kernel number-related traits in maize.

  10. Mechanisms and behavioural functions of structural coloration in cephalopods.

    Science.gov (United States)

    Mäthger, Lydia M; Denton, Eric J; Marshall, N Justin; Hanlon, Roger T

    2009-04-06

    Octopus, squid and cuttlefish are renowned for rapid adaptive coloration that is used for a wide range of communication and camouflage. Structural coloration plays a key role in augmenting the skin patterning that is produced largely by neurally controlled pigmented chromatophore organs. While most iridescence and white scattering is produced by passive reflectance or diffusion, some iridophores in squid are actively controlled via a unique cholinergic, non-synaptic neural system. We review the recent anatomical and experimental evidence regarding the mechanisms of reflection and diffusion of light by the different cell types (iridophores and leucophores) of various cephalopod species. The structures that are responsible for the optical effects of some iridophores and leucophores have recently been shown to be proteins. Optical interactions with the overlying pigmented chromatophores are complex, and the recent measurements are presented and synthesized. Polarized light reflected from iridophores can be passed through the chromatophores, thus enabling the use of a discrete communication channel, because cephalopods are especially sensitive to polarized light. We illustrate how structural coloration contributes to the overall appearance of the cephalopods during intra- and interspecific behavioural interactions including camouflage.

  11. RNA-directed DNA methylation: Mechanisms and functions

    KAUST Repository

    Mahfouz, Magdy M.

    2010-07-01

    Epigenetic RNA based gene silencing mechanisms play a major role in genome stability and control of gene expression. Transcriptional gene silencing via RNA-directed DNA methylation (RdDM) guides the epigenetic regulation of the genome in response to disease states, growth, developmental and stress signals. RdDM machinery is composed of proteins that produce and modify 24-nt- long siRNAs, recruit the RdDM complex to genomic targets, methylate DNA and remodel chromatin. The final DNA methylation pattern is determined by either DNA methyltransferase alone or by the combined action of DNA methyltransferases and demethylases. The dynamic interaction between RdDM and demethylases may render the plant epigenome plastic to growth, developmental, and environmental cues. The epigenome plasticity may allow the plant genome to assume many epigenomes and to have the right epigenome at the right time in response to intracellular or extracellular stimuli. This review discusses recent advances in RdDM research and considers future perspectives.

  12. Expression of a truncated ATHB17 protein in maize increases ear weight at silking.

    Science.gov (United States)

    Rice, Elena A; Khandelwal, Abha; Creelman, Robert A; Griffith, Cara; Ahrens, Jeffrey E; Taylor, J Philip; Murphy, Lesley R; Manjunath, Siva; Thompson, Rebecca L; Lingard, Matthew J; Back, Stephanie L; Larue, Huachun; Brayton, Bonnie R; Burek, Amanda J; Tiwari, Shiv; Adam, Luc; Morrell, James A; Caldo, Rico A; Huai, Qing; Kouadio, Jean-Louis K; Kuehn, Rosemarie; Sant, Anagha M; Wingbermuehle, William J; Sala, Rodrigo; Foster, Matt; Kinser, Josh D; Mohanty, Radha; Jiang, Dongming; Ziegler, Todd E; Huang, Mingya G; Kuriakose, Saritha V; Skottke, Kyle; Repetti, Peter P; Reuber, T Lynne; Ruff, Thomas G; Petracek, Marie E; Loida, Paul J

    2014-01-01

    ATHB17 (AT2G01430) is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II) family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize.

  13. Expression of a truncated ATHB17 protein in maize increases ear weight at silking.

    Directory of Open Access Journals (Sweden)

    Elena A Rice

    Full Text Available ATHB17 (AT2G01430 is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize.

  14. MD 1407 - Landau Damping: Beam Transfer Functions and diffusion mechanisms

    CERN Document Server

    Tambasco, Claudia; Boccardi, Andrea; Buffat, Xavier; Gasior, Marek; Lefevre, Thibaut; Levens, Tom; Pojer, Mirko; Salvachua Ferrando, Belen Maria; Solfaroli Camillocci, Matteo; Pieloni, Tatiana; Crouch, Matthew Paul; CERN. Geneva. ATS Department

    2017-01-01

    In the 2012, 2015 and 2016 run several instabilities were developing at flat-top, during and at the end of the betatron squeeze where beam-beam interactions are present. The tune spread in the beams is therefore modified by the beam-beam long-range interactions and by other sources of spread. Studies of the stability area computed by evaluating the dispersion integral for different tune spreads couldn’t explain the observed instabilities during the squeeze and stable beams. The size of the stability area given by the computed dispersion integral depends on the transverse tune spread but its shape is defined by the particle distribution in the beams. Therefore any change of the particle distribution can lead to a deterioration of the Landau stability area. The Beam Transfer Functions (BTF) are direct measurements of the Stability Diagrams (SD). They are sensitive to particle distributions and contain information about the transverse tune spread in the beams. In this note are summarized the results of the BTF...

  15. Exocytosis and endocytosis: modes, functions, and coupling mechanisms.

    Science.gov (United States)

    Wu, Ling-Gang; Hamid, Edaeni; Shin, Wonchul; Chiang, Hsueh-Cheng

    2014-01-01

    Vesicle exocytosis releases content to mediate many biological events, including synaptic transmission essential for brain functions. Following exocytosis, endocytosis is initiated to retrieve exocytosed vesicles within seconds to minutes. Decades of studies in secretory cells reveal three exocytosis modes coupled to three endocytosis modes: (a) full-collapse fusion, in which vesicles collapse into the plasma membrane, followed by classical endocytosis involving membrane invagination and vesicle reformation; (b) kiss-and-run, in which the fusion pore opens and closes; and (c) compound exocytosis, which involves exocytosis of giant vesicles formed via vesicle-vesicle fusion, followed by bulk endocytosis that retrieves giant vesicles. Here we review these exo- and endocytosis modes and their roles in regulating quantal size and synaptic strength, generating synaptic plasticity, maintaining exocytosis, and clearing release sites for vesicle replenishment. Furthermore, we highlight recent progress in understanding how vesicle endocytosis is initiated and is thus coupled to exocytosis. The emerging model is that calcium influx via voltage-dependent calcium channels at the calcium microdomain triggers endocytosis and controls endocytosis rate; calmodulin and synaptotagmin are the calcium sensors; and the exocytosis machinery, including SNARE proteins (synaptobrevin, SNAP25, and syntaxin), is needed to coinitiate endocytosis, likely to control the amount of endocytosis.

  16. Morphologic,mechanical and functional sonographic parameters of arteries in autosomal dominant polycystic kidney disease

    Institute of Scientific and Technical Information of China (English)

    戎殳

    2006-01-01

    Objective To investigate whether the risk factors of cardiovascular disease exist in early stage of ADPKD patients with normal renal function. Methods Morphologic , mechanical and functional sonographic parameters of arteries were examined by high-frequency ultrasonography in 32 hypertensive and 28 normotensive ADPKD patients with preserved renal function, 25 patients with es-

  17. Analysis and Application of Mechanical System Reliability Model Based on Copula Function

    Directory of Open Access Journals (Sweden)

    An Hai

    2016-10-01

    Full Text Available There is complicated correlations in mechanical system. By using the advantages of copula function to solve the related issues, this paper proposes the mechanical system reliability model based on copula function. And makes a detailed research for the serial and parallel mechanical system model and gets their reliability function respectively. Finally, the application research is carried out for serial mechanical system reliability model to prove its validity by example. Using Copula theory to make mechanical system reliability modeling and its expectation, studying the distribution of the random variables (marginal distribution of the mechanical product’ life and associated structure of variables separately, can reduce the difficulty of multivariate probabilistic modeling and analysis to make the modeling and analysis process more clearly.

  18. Influence of EARLI1-like genes on flowering time and lignin synthesis of Arabidopsis thaliana.

    Science.gov (United States)

    Shi, Y; Zhang, X; Xu, Z-Y; Li, L; Zhang, C; Schläppi, M; Xu, Z-Q

    2011-09-01

    EARLI1 encodes a 14.7 kDa protein in the cell wall, is a member of the PRP (proline-rich protein) family and has multiple functions, including resistance to low temperature and fungal infection. RNA gel blot analyses in the present work indicated that expression of EARLI1-like genes, EARLI1, At4G12470 and At4G12490, was down-regulated in Col-FRI-Sf2 RNAi plants derived from transformation with Agrobacterium strain ABI, which contains a construct encoding a double-strand RNA targeting 8CM of EARLI1. Phenotype analyses revealed that Col-FRI-Sf2 RNAi plants of EARLI1 flowered earlier than Col-FRI-Sf2 wild-type plants. The average bolting time of Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants was 39.7 and 19.4 days, respectively, under a long-day photoperiod. In addition, there were significant differences in main stem length, internode number and rosette leaf number between Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants. RT-PCR showed that EARLI1-like genes might delay flowering time through the autonomous and long-day photoperiod pathways by maintaining the abundance of FLC transcripts. In Col-FRI-Sf2 RNAi plants, transcription of FLC was repressed, while expression of SOC1 and FT was activated. Microscopy observations showed that EARLI1-like genes were also associated with morphogenesis of leaf cells in Arabidopsis. Using histochemical staining, EARLI1-like genes were found to be involved in regulation of lignin synthesis in inflorescence stems, and Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants had 9.67% and 8.76% dry weight lignin, respectively. Expression analysis revealed that cinnamoyl-CoA reductase, a key enzyme in lignin synthesis, was influenced by EARLI1-like genes. These data all suggest that EARLI1-like genes could control the flowering process and lignin synthesis in Arabidopsis.

  19. Sudden sensorineural hearing loss: Is there a connection with inner ear electrolytic disorders? A literature review.

    Science.gov (United States)

    Ciorba, Andrea; Corazzi, Virginia; Bianchini, Chiara; Aimoni, Claudia; Skarzynski, Henryk; Skarzynski, Piotr Henryk; Hatzopoulos, Stavros

    2016-12-01

    Electrolytic disorders of the inner ear represent a model that could be implicated in partially explaining the pathogenesis of sudden sensorineural hearing loss (SSNHL). Different types of electrolytes and different inner-ear loci are involved in cochlear homeostasis physiologically, to ensure the maintenance of an ion-balanced cochlear environment allowing a normal hair cell function. It has been hypothesized that a sudden loss of endocochlear potential, due to a rapid disruption of the inner ear fluid osmolality, could be responsible for a deterioration of the hearing function caused by damaged hair cells. The aim of this paper was to review the current literature and identify sources which might validate/fortify the hypothesis that inner ear electrolytic disorders have a role in the etiopathogenesis of SSNHL. The data in the literature underline the importance of ionic homeostasis in the inner ear, but they do not support a direct link between SSNHL and electrolyte disorders/imbalances. There is marginal evidence from otoacoustic emissions research that an indirect link might be present. © The Author(s) 2016.

  20. Middle Ear Infection (Chronic Otitis Media) and Hearing Loss

    Science.gov (United States)

    ... You Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic Otitis Media) and Hearing ... learning important speech and language skills. Types of hearing loss Conductive hearing loss is a form of hearing ...

  1. Pediatric Obesity and Ear, Nose, and Throat Disorders

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Pediatric Obesity and Ear, Nose, and Throat Disorders Pediatric ... of self-esteem, and isolation from their peers. Pediatric obesity and otolaryngic problems Otolaryngologists, or ear, nose, ...

  2. Speed of bionic breaking corn ear hand and experiment on power consumption%仿生玉米掰穗装置掰穗速度与功耗试验

    Institute of Scientific and Technical Information of China (English)

    张丽萍; 李其昀

    2015-01-01

    目前国内外采用的玉米摘穗装置均存在着籽粒破损率高、含杂率高和功率消耗大等问题,为解决上述问题,该文采用模仿人工收获玉米果穗的方式,设计了仿生玉米掰穗装置。首先进行拉力测试试验,分别在静态与动态2种条件下对传统摘穗方式与仿生掰穗方式收获玉米果穗所需力进行测量,验证仿生掰穗方式可行性;然后设计仿生玉米掰穗装置试验台并进行掰穗速度与功率消耗的综合试验,得到掰穗手速度与纯功率消耗的关系。试验表明:静态传统摘穗方式与仿生掰穗方式收获玉米果穗平均所需力分别为435和41.4 N。动态传统摘穗方式与仿生掰穗方式收获果穗平均所需力分别202.5和20.7 N。仿生掰穗比传统摘穗所需力大大减少。与传统玉米收获装置相比(正常工作速度1.2 m/s),该装置功率消耗低,约为36 W,小于传统一对摘穗辊消耗的纯功率(240 W)。该研究为玉米收获机摘穗部件的改进提供了参考。%Corn has already been the first major grain crop in China and its planting area is growing quickly. Compared to the wheat mechanical harvesting, corn mechanical harvesting level is very low. For traditional corn harvesting machine, snapping device most snaps corn ear. It makes extrusion or nibbling on the corn ear caused by snapping roller, leading to the high loss rate. It hinders the development of mechanization. As the subsidies on agriculture are generous in recent years, corn harvesters have been developed rapidly. But there are also many problems that can’t be solved in current corn harvesters, such as high grain damage rate, high impurity rate and high power consumption. So a new way to pick up corn is needed urgently. In order to solve these current problems, our research team designs the bionic device of breaking corn ears. This design’s inspiration is from artificially picking up corn ears; people pick up

  3. The first neutron beam hits EAR2

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    On 25 July 2014, about a year after construction work began, the Experimental Area 2 (EAR2) of CERN’s neutron facility n_TOF recorded its first beam. Unique in many aspects, EAR2 will start its rich programme of experimental physics this autumn.   The last part of the EAR2 beamline: the neutrons come from the underground target and reach the top of the beamline, where they hit the samples. Built about 20 metres above the neutron production target, EAR2 is in fact a bunker connected to the n_TOF underground facilities via a duct 80 cm in diameter, where the beamline is installed. The feet of the bunker support pillars are located on the concrete structure of the n_TOF tunnel and part of the structure lies above the old ISR building. A beam dump located on the roof of the building completes the structure. Neutrons are used by physicists to study neutron-induced reactions with applications in a number of fields, including nuclear waste transmutation, nuclear technology, nuclear astrop...

  4. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. The objective of this study is to investigate the application of ear-EEG in objective audiometry....

  5. THE DISCHARGING EAR: A PRACTICAL APPROACH

    African Journals Online (AJOL)

    Enrique

    The substances that the ear may discharge include wax, pus, mucus, blood, cere- brospinal fluid (CSF) and ... ed with a history of trauma or skull base surgery, is likely to be CSF. Recurrent ... After assessing the patient's hearing with a tuning ...

  6. DNA isolation from rat tail or ear

    NARCIS (Netherlands)

    Cuppen, E.

    2010-01-01

    This protocol describes a rapid procedure for isolating DNA from rat tail or ear punches. The simplest version of the protocol can be scaled for use in 96-well (deep-well) plates. The quality of the DNA is sufficient for any polymerase chain reaction (PCR)-based genotyping approach.

  7. Infrared tympanic temperature and ear canal morphology

    NARCIS (Netherlands)

    Daanen, H.A.M.

    2006-01-01

    Several publications indicate that the infrared tympanic temperature (IRTT) underestimates the core temperature of the body when the ear canal is long, curvy and narrow. In order to quantify these observations, a study was performed in 10 subjects. The IRTT was determined and compared to the oesopha

  8. Analytical model of internally coupled ears

    DEFF Research Database (Denmark)

    Vossen, Christine; Christensen-Dalsgaard, Jakob; Leo van Hemmen, J

    2010-01-01

    , data demonstrating an asymmetrical spatial pattern of membrane vibration. As the analytical calculations show, the internally coupled ears increase the directional response, appearing in large directional internal amplitude differences (iAD) and in large internal time differences (iTD). Numerical...... simulations of the eigenfunctions in an exemplary, realistically reconstructed mouth cavity further estimate the effects of its complex geometry....

  9. DNA isolation from rat tail or ear

    NARCIS (Netherlands)

    Cuppen, E.

    2010-01-01

    This protocol describes a rapid procedure for isolating DNA from rat tail or ear punches. The simplest version of the protocol can be scaled for use in 96-well (deep-well) plates. The quality of the DNA is sufficient for any polymerase chain reaction (PCR)-based genotyping approach.

  10. Fine-mapping quantitative trait loci affecting murine external ear tissue regeneration in the LG/J by SM/J advanced intercross line.

    Science.gov (United States)

    Cheverud, J M; Lawson, H A; Bouckaert, K; Kossenkov, A V; Showe, L C; Cort, L; Blankenhorn, E P; Bedelbaeva, K; Gourevitch, D; Zhang, Y; Heber-Katz, E

    2014-05-01

    External ear hole closure in LG/J mice represents a model of regenerative response. It is accompanied by the formation of a blastema-like structure and the re-growth of multiple tissues, including cartilage. The ability to regenerate tissue is heritable. An F34 advanced intercross line of mice (Wustl:LG,SM-G34) was generated to identify genomic loci involved in ear hole closure over a 30-day healing period. We mapped 19 quantitative trait loci (QTL) for ear hole closure. Individual gene effects are relatively small (0.08 mm), and most loci have co-dominant effects with phenotypically intermediate heterozygotes. QTL support regions were limited to a median size of 2 Mb containing a median of 19 genes. Positional candidate genes were evaluated using differential transcript expression between LG/J and SM/J healing tissue, function analysis and bioinformatic analysis of single-nucleotide polymorphisms in and around positional candidate genes of interest. Analysis of the set of 34 positional candidate genes and those displaying expression differences revealed over-representation of genes involved in cell cycle regulation/DNA damage, cell migration and adhesion, developmentally related genes and metabolism. This indicates that the healing phenotype in LG/J mice involves multiple physiological mechanisms.

  11. The realization of the wave function collapse in the linguistic interpretation of quantum mechanics

    CERN Document Server

    Ishikawa, Shiro

    2015-01-01

    Recently I proposed the linguistic interpretation of quantum mechanics, which is characterized as the linguistic turn of the Copenhagen interpretation of quantum mechanics. This turn from physics to language does not only extend quantum theory to classical theory but also yield the quantum mechanical world view. Although the wave function collapse is prohibited in the linguistic interpretation, in this paper I show that the phenomenon like wave function collapse can be realized in the linguistic interpretation. And furthermore, I propose the justification of the von Neumann-L\\"uders projection postulate. After all, I conclude that the wave function collapse should not be adopted in the Copenhagen interpretation.

  12. Quantum mechanics/molecular mechanics electrostatic embedding with continuous and discrete functions.

    Science.gov (United States)

    Cisneros, G Andrés; Piquemal, Jean-Philip; Darden, Thomas A

    2006-07-20

    A quantum mechanics/molecular mechanics (QM/MM) implementation that uses the Gaussian electrostatic model (GEM) as the MM force field is presented. GEM relies on the reproduction of electronic density by using auxiliary basis sets to calculate each component of the intermolecular interaction. This hybrid method has been used, along with a conventional QM/MM (point charges) method, to determine the polarization on the QM subsystem by the MM environment in QM/MM calculations on 10 individual H(2)O dimers and a Mg(2+)-H(2)O dimer. We observe that GEM gives the correct polarization response in cases when the MM fragment has a small charge, while the point charges produce significant over-polarization of the QM subsystem and in several cases present an opposite sign for the polarization contribution. In the case when a large charge is located in the MM subsystem, for example, the Mg(2+) ion, the opposite is observed at small distances. However, this is overcome by the use of a damped Hermite charge, which provides the correct polarization response.

  13. 40 CFR 211.206-1 - Real ear method.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Real ear method. 211.206-1 Section 211... PRODUCT NOISE LABELING Hearing Protective Devices § 211.206-1 Real ear method. (a) The value of sound... “Method for the Measurement of Real-Ear Protection of Hearing Protectors and Physical Attenuation...

  14. 15 CFR 734.3 - Items subject to the EAR.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Items subject to the EAR. 734.3... EXPORT ADMINISTRATION REGULATIONS § 734.3 Items subject to the EAR. (a) Except for items excluded in paragraph (b) of this section, the following items are subject to the EAR: (1) All items in the...

  15. Ear tube surgery - what to ask your doctor

    Science.gov (United States)

    What to ask your doctor about ear tube surgery; Tympanostomy - what to ask your doctor; Myringotomy - what to ask your doctor ... Why does my child need ear tubes? Can we try other treatments? What are the risks of the surgery? Is it safe to wait before getting ear ...

  16. The use of a SQUID magnetometer for middle ear research

    NARCIS (Netherlands)

    Rutten, W.L.C.; Peters, M.J.; Brenkman, C.J.; Mol, H.; Grote, J.J.; Marel, van der L.C.

    1982-01-01

    A new technique is described for the measurement of vibrations in the temporal bones of an isolated middle ear. The precise recording of vibrations in the middle ear is of importance for the construction and improvement of a middle ear prosthesis.1 The method of measurement is based on a transformat

  17. Erythema associated with pain and warmth on face and ears: a variant of erythermalgia or red ear syndrome?: Doc 602

    National Research Council Canada - National Science Library

    Ming-Chun Chen; Qing-Fang Xu; Di-Qing Luo; Xiang Li; Ding-Yang He

    2014-01-01

    ..., face, ears and even the scrotum. We reported an 18-year-old woman who presented with 3 years history of sole involvement of attacking erythema, pain and warmth over her face and ears without any other associations...

  18. Erythema associated with pain and warmth on face and ears: a variant of erythermalgia or red ear syndrome?

    National Research Council Canada - National Science Library

    Chen, Ming-Chun; Xu, Qing-Fang; Luo, Di-Qing; Li, Xiang; He, Ding-Yang

    2014-01-01

    ..., face, ears and even the scrotum. We reported an 18-year-old woman who presented with 3 years history of sole involvement of attacking erythema, pain and warmth over her face and ears without any other associations...

  19. Mechanotransduction in mouse inner ear hair cells requires transmembrane channel-like genes

    NARCIS (Netherlands)

    Kawashima, Yoshiyuki; Geleoc, Gwenaelle S. G.; Kurima, Kiyoto; Labay, Valentina; Lelli, Andrea; Asai, Yukako; Makishima, Tomoko; Wu, Doris K.; Della Santina, Charles C.; Holt, Jeffrey R.; Griffith, Andrew J.

    2011-01-01

    Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in

  20. Naturopathic treatment for ear pain in children.

    Science.gov (United States)

    Sarrell, E Michael; Cohen, Herman Avner; Kahan, Ernesto

    2003-05-01

    Otitis media is 1 of the most frequent diseases of early infancy and childhood and 1 of the most common reasons for children to visit a physician. In the past 2 decades, there has been a substantial increase in the diagnosis of otitis media worldwide. In the United States, 93% of all children have had at least 1 episode of acute otitis media (AOM) by 7 years of age. Otalgia is the hallmark of AOM. Most affected children either complain of earache or manifest behavior that the parents interpret as indicating ear pain. Treatment of the ear pain early in the course of AOM decreases both parental anxiety and the child's discomfort and accelerates the healing process. The objective of this study was to determine the efficacy and tolerability of naturopathic versus traditional treatment for the management of otalgia commonly associated with AOM in children. The study was designed as a double-blind trial in an outpatient community clinic. A total of 171 children who were aged 5 to 18 years and had otalgia and clinical findings associated with middle-ear infection were studied. The children were randomly assigned to receive treatment with Naturopathic Herbal Extract Ear Drops (NHED) or anesthetic ear drops, with or without amoxicillin. On enrollment, the children were assigned by computer-numbered randomization to receive NHED (contents: allium sativum, verbascum thapsus, calendula flores, hypericum perfoliatum, lavender, and vitamin E in olive oil) 5 drops 3 times daily, alone (group A) or together with a topical anesthetic (amethocaine and phenazone in glycerin) 5 drops 3 times daily (group B), or oral amoxicillin 80 mg/kg/d (maximum 500 mg/dose) divided into 3 doses with either NHED 5 drops 3 times daily (group C) or topical anesthetic 5 drops 3 times daily (group D). A double-blind design was used, and all ear drops were placed in identical bottles. Treatment was initiated by the nurse in all cases. A single physician (M.S.) evaluated and treated all of the patients

  1. Replication of type 5 adenovirus promotes middle ear infection by Streptococcus pneumoniae in the chinchilla model of otitis media

    Science.gov (United States)

    Murrah, Kyle A.; Turner, Roberta L.; Pang, Bing; Perez, Antonia C.; Reimche, Jennifer L.; King, Lauren B.; Wren, John; Gandhi, Uma; Swords, W. Edward; Ornelles, David A.

    2015-01-01

    Adenoviral infection is a major risk factor for otitis media. We hypothesized that adenovirus promotes bacterial ascension into the middle ear through the disruption of normal function in the Eustachian tubes due to inflammation-induced changes. An intranasal infection model of the chinchilla was used to test the ability of type 5 adenovirus to promote middle ear infection by Streptococcus pneumoniae. The hyperinflammatory adenovirus mutant dl327 and the nonreplicating adenovirus mutant H5wt300ΔpTP were used to test the role of inflammation and viral replication, respectively, in promotion of pneumococcal middle ear infection. Precedent infection with adenovirus resulted in a significantly greater incidence of middle ear disease by S. pneumoniae as compared to nonadenovirus infected animals. Infection with the adenovirus mutant dl327 induced a comparable degree of bacterial ascension into the middle ear as did infection with the wild-type virus. By contrast, infection with the nonreplicating adenovirus mutant H5wt300ΔpTP resulted in less extensive middle ear infection compared to the wild-type adenovirus. We conclude that viral replication is necessary for adenoviral-induced pneumococcal middle ear disease. PMID:25251686

  2. Numerical evaluation of implantable hearing devices using a finite element model of human ear considering viscoelastic properties.

    Science.gov (United States)

    Zhang, Jing; Tian, Jiabin; Ta, Na; Huang, Xinsheng; Rao, Zhushi

    2016-08-01

    Finite element method was employed in this study to analyze the change in performance of implantable hearing devices due to the consideration of soft tissues' viscoelasticity. An integrated finite element model of human ear including the external ear, middle ear and inner ear was first developed via reverse engineering and analyzed by acoustic-structure-fluid coupling. Viscoelastic properties of soft tissues in the middle ear were taken into consideration in this model. The model-derived dynamic responses including middle ear and cochlea functions showed a better agreement with experimental data at high frequencies above 3000 Hz than the Rayleigh-type damping. On this basis, a coupled finite element model consisting of the human ear and a piezoelectric actuator attached to the long process of incus was further constructed. Based on the electromechanical coupling analysis, equivalent sound pressure and power consumption of the actuator corresponding to viscoelasticity and Rayleigh damping were calculated using this model. The analytical results showed that the implant performance of the actuator evaluated using a finite element model considering viscoelastic properties gives a lower output above about 3 kHz than does Rayleigh damping model. Finite element model considering viscoelastic properties was more accurate to numerically evaluate implantable hearing devices.

  3. Mechanical Harvesting of Aquatic Plants. Report 2. Evaluation of Selected Handling Functions of Mechanical Control.

    Science.gov (United States)

    1980-06-01

    Table 3. 22. Pushing tests. The pushing tests were conducted along the 23 / SONNET "LAKE TOWING BOOM LOCATION SCALE 0.5 0.5 MILES Figure 9. Location... 73 . The preceding paragraphs present quantitative data and their implication in regard to improving the ability to accomplish selected functions in the...sufficient power to move the boat and cutter reliably through the plant infestation at a speed of at least 3 mph. 73 ... . . 0 0W. - .00 004. m 0 w0 wv m

  4. Influence of ear acupoint seeds burying and acupressure on intestinal functional rehabilitation of patients after accepting gynecological abdominal operation%耳穴埋籽、穴位按压护理对妇科腹部手术后肠功能恢复的影响

    Institute of Scientific and Technical Information of China (English)

    施丽娟; 方克勤; 周萍; 杜宁娜; 于海燕

    2011-01-01

    Objective :To observe the influence of ear acupoint seeds burying and acupressure on the time of passage of gas by anus and defecation of patients after accepting gynecological abdominal operation.Methods: A total of 180 patients after accepting gynecological abdominal operation were randomly divided into 3 groups and treated as follows: ear acupoint seeds burying group (n=59) , acupressure group (n=60) and usual care group (n= 61).The time of passage of gas and defecation by anus, nausea and vomiting, abdominal distension of patients after accepting gynecological abdominal operation were observed.Results:There were significant differences among all three group patients in terms Of the time of passage of gas and defecation by anus (P<0.05).After 6 -12 h,there were significant differences among the three groups in terms of the occurrence of abdominal distension (P<0.05).Conclusion: The therapy of ear acupoint seeds burying and acupressure nursing may promote the early passage of gas and defecation by anus of patients.It can help to promote intestinal functional rehabilitation of patients.%[目的]观察耳穴埋籽、穴位按压对妇科腹部术后病人肛门排气、排便时间的影响.[方法]将180例妇科手术病人随机分为3组:耳穴埋籽组59例、穴位按压组60例、常规护理组61例.观察病人妇科腹部术后肛门排气、排便时间及恶心呕吐、腹胀等情况.[结果]3组病人术后肛门排气、排便时间比较差异有统计学意义(P<0.05);3组病人返回病房6h~12h,腹胀程度组间比较差异有统计学意义(P<0.05).[结论]耳穴埋籽、穴位按压能使妇科术后病人早日排气、排便,有利于促进病人肠功能恢复.

  5. Comparison of molecular mechanics, semi-empirical quantum mechanical, and density functional theory methods for scoring protein-ligand interactions.

    Science.gov (United States)

    Yilmazer, Nusret Duygu; Korth, Martin

    2013-07-11

    Correctly ranking protein-ligand interactions with respect to overall free energy of binding is a grand challenge for virtual drug design. Here we compare the performance of various quantum chemical approaches for tackling this so-called "scoring" problem. Relying on systematically generated benchmark sets of large protein/ligand model complexes based on the PDBbind database, we show that the performance depends first of all on the general level of theory. Comparing classical molecular mechanics (MM), semiempirical quantum mechanical (SQM), and density functional theory (DFT) based methods, we find that enhanced SQM approaches perform very similar to DFT methods and substantially different from MM potentials.

  6. The complete mitochondrial genome sequence of Diannan small-ear pig (Sus Scrofa).

    Science.gov (United States)

    Wang, Ling-Yu; Xu, Dong; Xiao, Ding-Fu; Ma, Hai-Ming

    2016-01-01

    In this study, the complete mitochondrial genome sequence of Diannan small-ear pig in Yunnan Province was firstly reported, which was determined through polymerase chain reaction (PCR) method. The total length of mitochondrial genome of Diannan small-ear pig was 16720 bp, including 34.77% A, 26.18% C, 25.81% T and 13.24% G, and in the order A > C > T > G. Mitochondrial genome contained a major non-coding control region (D-Loop region), 2 ribosomal RNA genes, 13 protein-coding genes (PCGs) and 22 transfer RNA genes. The mitochondrial genome of Diannan small-ear pig provides an important data set for the study on genetic mechanism.

  7. The meaning of the wave function in search of the ontology of quantum mechanics

    CERN Document Server

    Gao, Shan

    2017-01-01

    At the heart of quantum mechanics lies the wave function, a powerful but mysterious mathematical object which has been a hot topic of debate from its earliest stages. Covering much of the recent debate and providing a comprehensive and critical review of competing approaches, this ambitious text provides new, decisive proof of the reality of the wave function. Aiming to make sense of the wave function in quantum mechanics and to find the ontological content of the theory, this book explores new ontological interpretations of the wave function in terms of random discontinuous motion of particles. Finally, the book investigates whether the suggested quantum ontology is complete in solving the measurement problem and if it should be revised in the relativistic domain. A timely addition to the literature on the foundations of quantum mechanics, this book is of value to students and researchers with an interest in the philosophy of physics. Presents a concise introduction to quantum mechanics, including the c...

  8. Ear-Shaped Stable Auricular Cartilage Engineered from Extensively Expanded Chondrocytes in an Immunocompetent Experimental Animal Model.

    Science.gov (United States)

    Pomerantseva, Irina; Bichara, David A; Tseng, Alan; Cronce, Michael J; Cervantes, Thomas M; Kimura, Anya M; Neville, Craig M; Roscioli, Nick; Vacanti, Joseph P; Randolph, Mark A; Sundback, Cathryn A

    2016-02-01

    Advancement of engineered ear in clinical practice is limited by several challenges. The complex, largely unsupported, three-dimensional auricular neocartilage structure is difficult to maintain. Neocartilage formation is challenging in an immunocompetent host due to active inflammatory and immunological responses. The large number of autologous chondrogenic cells required for engineering an adult human-sized ear presents an additional challenge because primary chondrocytes rapidly dedifferentiate during in vitro culture. The objective of this study was to engineer a stable, human ear-shaped cartilage in an immunocompetent animal model using expanded chondrocytes. The impact of basic fibroblast growth factor (bFGF) supplementation on achieving clinically relevant expansion of primary sheep chondrocytes by in vitro culture was determined. Chondrocytes expanded in standard medium were either combined with cryopreserved, primary passage 0 chondrocytes at the time of scaffold seeding or used alone as control. Disk and human ear-shaped scaffolds were made from porous collagen; ear scaffolds had an embedded, supporting titanium wire framework. Autologous chondrocyte-seeded scaffolds were implanted subcutaneously in sheep after 2 weeks of in vitro incubation. The quality of the resulting neocartilage and its stability and retention of the original ear size and shape were evaluated at 6, 12, and 20 weeks postimplantation. Neocartilage produced from chondrocytes that were expanded in the presence of bFGF was superior, and its quality improved with increased implantation time. In addition to characteristic morphological cartilage features, its glycosaminoglycan content was high and marked elastin fiber formation was present. The overall shape of engineered ears was preserved at 20 weeks postimplantation, and the dimensional changes did not exceed 10%. The wire frame within the engineered ear was able to withstand mechanical forces during wound healing and neocartilage

  9. Inner ear dysfunction in caspase-3 deficient mice

    Directory of Open Access Journals (Sweden)

    Woo Minna

    2011-10-01

    Full Text Available Abstract Background Caspase-3 is one of the most downstream enzymes activated in the apoptotic pathway. In caspase-3 deficient mice, loss of cochlear hair cells and spiral ganglion cells coincide closely with hearing loss. In contrast with the auditory system, details of the vestibular phenotype have not been characterized. Here we report the vestibular phenotype and inner ear anatomy in the caspase-3 deficient (Casp3-/- mouse strain. Results Average ABR thresholds of Casp3-/- mice were significantly elevated (P Casp3+/- mice and Casp3+/+ mice at 3 months of age. In DPOAE testing, distortion product 2F1-F2 was significantly decreased (P Casp3-/- mice, whereas Casp3+/- and Casp3+/+ mice showed normal and comparable values to each other. Casp3-/- mice were hyperactive and exhibited circling behavior when excited. In lateral canal VOR testing, Casp3-/- mice had minimal response to any of the stimuli tested, whereas Casp3+/- mice had an intermediate response compared to Casp3+/+ mice. Inner ear anatomical and histological analysis revealed gross hypomorphism of the vestibular organs, in which the main site was the anterior semicircular canal. Hair cell numbers in the anterior- and lateral crista, and utricle were significantly smaller in Casp3-/- mice whereas the Casp3+/- and Casp3+/+ mice had normal hair cell numbers. Conclusions These results indicate that caspase-3 is essential for correct functioning of the cochlea as well as normal development and function of the vestibule.

  10. Molecular mechanisms regulating expression and function of transcription regulator "inhibitor of differentiation 3"

    Institute of Scientific and Technical Information of China (English)

    Robert Wai-sui LIM; Jin-mei WU

    2005-01-01

    The transcription factor antagonist inhibitor of differentiation 3 (Id3) has been implicated in many diverse developmental, physiological and pathophysiological processes. Its expression and function is subjected to many levels of complex regulation. This review summarizes the current understanding of these mechanisms and describes how they might be related to the diverse functions that have been attributed to the Id3 protein. Detailed understanding of these mechanisms should provide insights towards the development of therapeutic approaches to various diseases, including cancer and atherogenesis.

  11. Inner ear pressure changes following square wave intracranial or ear canal pressure manipulation in the same guinea pig

    NARCIS (Netherlands)

    Thalen, E; Wit, H; Segenhout, H; Albers, F

    Inner ear pressure was measured in scala tympani with a micropipette during square wave pressure manipulation of the intracranial compartment and, subsequently, of the external ear canal (EEC) in the same guinea pig. As expected, the combination of the cochlear aqueduct and the inner ear behaves as

  12. Human acoustics: From vocal chords to inner ear

    Science.gov (United States)

    Lamar, Michael Drew

    2005-11-01

    Part I covers the vocal chords, more accurately known as the vocal folds (VF). Modeling efforts are split into two areas: the VF tissue and the airflow. There are multiple existing models of the VF, with varying ranges of complexity for both the tissue and the airflow. In our model, the tissue is based on a recent two-mass model of Bogaert's [5], while the airflow is quasi-one-dimensional and is derived from the two-dimensional compressible Navier-Stokes equations. Our model is more accurate than Bernoulli's law (quasi-steady approximation), yet less complex than the full Navier-Stokes system. The model is shown to reproduce important transient behaviour intrinsic in vocal fold motion, such as pressure peaks before and after vocal fold closure. Part II concerns the inner ear, or cochlea. Again the modeling effort is split into two areas: the cochlear tissue and the cochlear fluid. We model the cochlear fluid with the well known two-dimensional box model of the cochlea, derived from the three-dimensional compressible Navier-Stokes equations. The cochlear tissue structure is where the complexity takes place. We start with Neely and Kim's [25] linear active model for the cochlear structure and modify their active gain parameter into a nonlinear nonlocal functional. The nonlinearity forces us to work in the time domain, which is prone to dispersive instabilities if one uses a frequency domain middle ear model. The middle ear's role as a transient absorber is discussed and its time domain formulation is shown to reduce the dispersive instability. We perform simulations on the full system and show that the model recovers many important nonlinear phenomena, such as suppression and difference tones. A spectrogram based on the cochlear response is created and compared with the spectrogram of the input waveform. In both Part I and Part II, the emphasis is on time dependent modeling and numerical implementation.

  13. Institutional priorities of formation and functioning of the motivational mechanisms in the labor market

    Directory of Open Access Journals (Sweden)

    Strelchenko Elena, A.

    2015-09-01

    Full Text Available In the paper the authors consider institutional features of formation and functioning of motivational mechanisms in the labor market, as well as major trends of Russian modern system of labor motivation. Special attention is paid to the role of salary as an institutional component of the mechanism of labor motivation in conditions of decreasing the lag in the economic development.

  14. Study Hankel Transforms and Properties of Bessel Function via Entangled State Representation Transformation in Quantum Mechanics

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; WANG Yong

    2006-01-01

    In Phys. Lett. A 313 (2003) 343 we have found that the self-reciprocal Hankel transformation (HT) is embodied in quantum mechanics by a transform between two entangled state representations of continuum variables. In this work we study Hankel transforms and properties of Bessel function via entangled state representations' transformation in quantum mechanics.

  15. Melanoma of the ear: results of a cartilage-sparing approach to resection.

    Science.gov (United States)

    McCarty, Melissa A; Lentsch, Eric J; Cerrati, Eric W; Stadelmann, Wayne K

    2013-11-01

    Melanoma of the ear is often treated by composite resection of the skin and cartilage and, occasionally, by total auriculectomy. This review analyzes the oncologic, functional, and esthetic results of cartilage-sparing wide local excision for melanoma of the ear. This retrospective study reviewed patients with ear melanoma treated between 1997 and 2002. All patients were treated with cartilage-sparing wide local excision, and ears were reconstructed with skin grafts and/or local flaps. The majority of patients were men (16/18 patients) who ranged in age from 42 to 82 years. The most common sites of occurrence were the helical rim (7/18 patients) and the earlobe (6/18 patients). The average depth of invasion was 2.02 mm (range 0.4-6.0 mm). Sentinel lymph node biopsy was performed in 13 cases, of which only one was positive. The local control rate was 100 %, overall survival was 72 % (13/18 patients), and disease-specific survival was 89 % (16/18 patients). Average follow-up was 30.5 months (range 1-61). The rates for local control, overall survival, and disease-specific survival were excellent. These data indicate that for the majority of ear melanomas, cartilage-sparing wide local excision is an acceptable means of treatment.

  16. Middle ear impedance studies in elderly patients implications on age-related hearing loss

    Directory of Open Access Journals (Sweden)

    Olusola Ayodele Sogebi

    2015-04-01

    Full Text Available INTRODUCTION: Controversies arise with respect to functioning of the middle ear over time.OBJECTIVE: To assess changes in middle ear impedance that may be related to aging, and/or if there was an association of these changes with those of the inner ear in the elderly patients.METHODS: Cross-sectional, comparative study of elderly patients managed in ear, nose and throat clinics. A structured questionnaire was administered to obtain clinical information. Pure tone audiometry, tympanometry, and acoustic reflexes were performed. Comparative analyses were performed to detect intergroup differences between clinico-audiometric findings and middle ear measures, viz. tympanograms and acoustic reflexes.RESULTS: One hundred and three elderly patients participated in the study; 52.4% were male, averagely 70.0 ± 6.3 years old, age-related hearing loss in 59.2%, abnormal tympanograms in 39.3%, absent acoustic reflex in 37.9%. There was no association between age and gender in patients with abnormal tympanograms and absent acoustic reflex. Significantly more patients with different forms and grades of age-related hearing loss had abnormal tympanometry and absent acoustic reflex.CONCLUSION: Some abnormalities were observed in the impedance audiometric measures of elderly patients, which were significantly associated with parameters connected to age-related hearing loss.

  17. Diversity of Inner Ears in Fishes: Possible Contribution Towards Hearing Improvements and Evolutionary Considerations.

    Science.gov (United States)

    Schulz-Mirbach, Tanja; Ladich, Friedrich

    2016-01-01

    Fishes have evolved the largest diversity of inner ears among vertebrates. While G. Retzius introduced us to the diversity of the gross morphology of fish ears in the late nineteenth century, it was A. N. Popper who unraveled the large variety of the fine structure during the last four decades. Modifications of the basic inner ear structure-consisting of three semicircular canals and their sensory epithelia, the cristae and three otolithic end organs (utricle, saccule, lagena) including the maculae-mainly relate to the saccule and lagena and the respective sensory epithelia, the macula sacculi and macula lagenae. Despite the profound morphological knowledge of inner ears and the morphological variability, the functional significance of this diversity is still largely unknown. The aims of this review are therefore twofold. First it provides an update of the state of the art of inner ear diversity in bony fishes. Second it summarizes and discusses hypotheses on the evolution of this diversity as well as formulates open questions and promising approaches to tackle these issues.

  18. Deletion of a conserved regulatory element required for Hmx1 expression in craniofacial mesenchyme in the dumbo rat: a newly identified cause of congenital ear malformation

    Directory of Open Access Journals (Sweden)

    Lely A. Quina

    2012-11-01

    Hmx1 is a homeodomain transcription factor expressed in the developing eye, peripheral ganglia, and branchial arches of avian and mammalian embryos. Recent studies have identified a loss-of-function allele at the HMX1 locus as the causative mutation in the oculo-auricular syndrome (OAS in humans, characterized by ear and eye malformations. The mouse dumbo (dmbo mutation, with similar effects on ear and eye development, also results from a loss-of-function mutation in the Hmx1 gene. A recessive dmbo mutation causing ear malformation in rats has been mapped to the chromosomal region containing the Hmx1 gene, but the nature of the causative allele is unknown. Here we show that dumbo rats and mice exhibit similar neonatal ear and eye phenotypes. In midgestation embryos, dumbo rats show a specific loss of Hmx1 expression in neural-crest-derived craniofacial mesenchyme (CM, whereas Hmx1 is expressed normally in retinal progenitors, sensory ganglia and in CM, which is derived from mesoderm. High-throughput resequencing of 1 Mb of rat chromosome 14 from dmbo/dmbo rats, encompassing the Hmx1 locus, reveals numerous divergences from the rat genomic reference sequence, but no coding changes in Hmx1. Fine genetic mapping narrows the dmbo critical region to an interval of ∼410 kb immediately downstream of the Hmx1 transcription unit. Further sequence analysis of this region reveals a 5777-bp deletion located ∼80 kb downstream in dmbo/dmbo rats that is not apparent in 137 other rat strains. The dmbo deletion region contains a highly conserved domain of ∼500 bp, which is a candidate distal enhancer and which exhibits a similar relationship to Hmx genes in all vertebrate species for which data are available. We conclude that the rat dumbo phenotype is likely to result from loss of function of an ultraconserved enhancer specifically regulating Hmx1 expression in neural-crest-derived CM. Dysregulation of Hmx1 expression is thus a candidate mechanism for congenital ear

  19. Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals.

    Science.gov (United States)

    Gawriluk, Thomas R; Simkin, Jennifer; Thompson, Katherine L; Biswas, Shishir K; Clare-Salzler, Zak; Kimani, John M; Kiama, Stephen G; Smith, Jeramiah J; Ezenwa, Vanessa O; Seifert, Ashley W

    2016-04-25

    Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury.

  20. Current strategies for drug delivery to the inner ear

    Directory of Open Access Journals (Sweden)

    Hongzhuo Liu

    2013-04-01

    Full Text Available For many years, drug delivery to the inner ear has been a challenge to physicians in the treatment of inner ear disorders. In the past decade, the field of inner ear drug delivery has emerged with the development of new biomaterials and drug delivery technologies to improve the effectiveness of inner ear drug therapy. This paper reviews a number of inner ear drug delivery strategies including systemic, intratympanic, and intracochlear delivery. A focus of this review is the recent advances in intratympanic delivery of medications; approaches utilizing novel biomaterials as well as other recent developments are also discussed. Biotechnology-based approaches, such as gene and stem cell therapy methods are also reviewed. Among the various strategies, local drug delivery approaches including intratympanic and intracochlear drug delivery methods that limit systemic exposure are particularly promising. These inner ear drug delivery systems provide a new opportunity to improve the treatment of inner ear disorders.

  1. Potential psychosocial mechanisms linking depression to immune function in elderly subjects

    NARCIS (Netherlands)

    Bouhuys, AL; Flentge, F; Oldehinkel, AJ; van den Berg, MD

    2004-01-01

    Although depression and immune changes in elderly subjects constitute a considerable health risk, mechanisms underlying the association between depression and immune function are unclear. The question of whether personality and social support can explain the variation in immune function during depre

  2. Diseases of the middle ear in childhood

    Directory of Open Access Journals (Sweden)

    Minovi, Amir

    2014-12-01

    Full Text Available [english] Middle ear diseases in childhood play an important role in daily ENT practice due to their high incidence. Some of these like acute otitis media or otitis media with effusion have been studied extensively within the last decades. In this article, we present a selection of important childhood middle ear diseases and discuss the actual literature concerning their treatment, management of complications and outcome. Another main topic of this paper deals with the possibilities of surgical hearing rehabilitation in childhood. The bone-anchored hearing aid BAHA and the active partially implantable device Vibrant Soundbridge could successfully be applied for children. In this manuscript, we discuss the actual literature concerning clinical outcomes of these implantable hearing aids.

  3. A Rare Case of Petrified Ear

    Directory of Open Access Journals (Sweden)

    Kathryn E. Buikema

    2012-01-01

    Full Text Available Calcification or ossification of the auricle, also referred to as petrified ear, is a rare diagnosis in dermatology. In medical literature, it has most often been attributed to trauma, hypothermia and frostbite, or hypercalcemia secondary to a metabolic or endocrine disorder, such as Addison's disease. Here, we report the clinical and radiologic findings of a 79-year-old African American male whose unilateral petrified auricle was an incidental finding. He had a preceding history of hyperparathyroidism and subsequent hypercalcemia treated with a subtotal parathyroidectomy three years prior to presentation. In addition to laboratory analysis, a history and physical examination was performed which revealed no other signs of hypercalcemia. Radiologic studies demonstrated partial ossification of the external auricular cartilage on the left side. The patient was diagnosed with the rare occurrence of a petrified ear. In light of this case, we provide a discussion concerning the possible etiologies of this diagnosis including appropriate patient evaluation and possible treatment recommendations.

  4. Adhesion functions in cell sorting by mechanically coupling the cortices of adhering cells.

    Science.gov (United States)

    Maître, Jean-Léon; Berthoumieux, Hélène; Krens, Simon Frederik Gabriel; Salbreux, Guillaume; Jülicher, Frank; Paluch, Ewa; Heisenberg, Carl-Philipp

    2012-10-12

    Differential cell adhesion and cortex tension are thought to drive cell sorting by controlling cell-cell contact formation. Here, we show that cell adhesion and cortex tension have different mechanical functions in controlling progenitor cell-cell contact formation and sorting during zebrafish gastrulation. Cortex tension controls cell-cell contact expansion by modulating interfacial tension at the contact. By contrast, adhesion has little direct function in contact expansion, but instead is needed to mechanically couple the cortices of adhering cells at their contacts, allowing cortex tension to control contact expansion. The coupling function of adhesion is mediated by E-cadherin and limited by the mechanical anchoring of E-cadherin to the cortex. Thus, cell adhesion provides the mechanical scaffold for cell cortex tension to drive cell sorting during gastrulation.

  5. Effects of Ultrasonic on the Dehydration Function of Sludge and Discussion on Internal Mechanism

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the effects of ultrasonic on the dehydration function of sludge and internal mechanism.[Method] Taking the residual sludge from a municipal domestic sewage treatment plant as an object,the effects of ultrasonic time and sound energy density on the dehydration function of sludge were studied firstly,then the internal mechanism of improvement of sludge dehydration function by ultrasonic was discussed.[Result] As the increase of ultrasonic time,sludge particles became smaller,a...

  6. Crystallization and mechanical properties of functionalized single-walled carbon nanotubes/polyvinylidene fluoride composites

    DEFF Research Database (Denmark)

    Ma, Jing; Iftekharul Haque, Rubaiyet; Larsen, Mikael

    2012-01-01

    Single-walled carbon nanotubes were purified and functionalized by nitric acid and octadecylamine. Raman and Fourier transform infrared spectroscopy were used to characterize the functionalization of the single-walled carbon nanotubes. Polyvinylidene flouride nanocomposites containing 1 wt......% purified or functionalized single-walled carbon nanotubes were prepared by solution blending and injection molding. The dispersion of different carbon nanotubes in dimethylformamide and in polyvinylidene flouride has been investigated. Mechanical properties show that adding single-walled carbon nanotubes...

  7. Not All Inner Ears are the Same: Otolith Matrix Proteins in the Inner Ear of Sub-Adult Cichlid Fish, Oreochromis Mossambicus, Reveal Insights Into the Biomineralization Process.

    Science.gov (United States)

    Weigele, Jochen; Franz-Odendaal, Tamara A; Hilbig, Reinhard

    2016-02-01

    The fish ear stones (otoliths) consist mainly of calcium carbonate and have lower amounts of a proteinous matrix. This matrix consists of macromolecules, which directly control the biomineralization process. We analyzed the composition of this proteinous matrix by mass spectrometry in a shotgun approach. For this purpose, an enhanced protein purification technique was developed that excludes any potential contamination of proteins from body fluids. Using this method we identified eight proteins in the inner ear of Oreochromis mossambicus. These include the common otolith matrix proteins (OMP-1, otolin-1, neuroserpin, SPARC and otoconin), and three proteins (alpha tectorin, otogelin and transferrin) not previously localized to the otoliths. Moreover, we were able to exclude the occurrence of two matrix proteins (starmaker and pre-cerebellin-like protein) known from other fish species. In further analyses, we show that the absence of the OMP starmaker corresponds to calcitic otoliths and that pre-cerebellin-like protein is not present at any stage during the development of the otoliths of the inner ear. This study shows O. mossambicus does not have all of the known otolith proteins indicating that the matrix proteins in the inner ear of fish are not the same across species. Further functional studies of the novel proteins we identified during otolith development are required.

  8. Characterization of spontaneous otoacoustic emissions in 2-4 day old neonates with respect to gender and ear

    Institute of Scientific and Technical Information of China (English)

    Jinfeng Liu; Baoyu Shi; Ningyu Wang; Jinlan Li

    2009-01-01

    BACKGROUND: Spontaneous otoacoustic emissions (SOAEs) are regarded as a valuable audiometric parameter that objectively reflects the function of outer hair cells (OHCs). Many studies have reported that the incidence of SOAEs in adults is less than 50%. Therefore, measurement of SOAEs may be of little value to clinical examinations. However, the incidence of SOAEs in infants and neonates is higher than in adults.OBJECTIVE: To analyze the basic characteristics of SOAEs in 2-4 day old neonates, and to demonstrate the difference in OHC function between sexes and ears.DESIGN, TIME AND SETTING: Neurophysiological contrast study, performed in the Department of Neonates, Beijing Chaoyang Hospital, Capital Medical University, between December 2007 and August 2008.PARTICIPANTS: A total of 112 newborns (224 ears) consisting of 59 females and 53 males were included in this study.METHODS: The probe was adapted and embedded in the neonate external auditory canal with a foam rubber earplug after checking and clearing up the outer ear canal. The presence of SOAEs was determined when the signal amplitude had a clear peak exceeding -30 dB, or was 3 dB above the noise floor.MAIN OUTCOME MEASURES: The incidence of SOAEs, the number of SOAE signal peaks, and the maximal tension of SOAEs.RESULTS: The incidence in females (79.7%) was higher than males (76.4%) (P> 0.05), and the incidence in right ears (86.6%) was higher than in left ears (69.6%) (P 0.05). The mean maximum SOAE level per ear in females (-3.29 ± 9.28) dB sound pressure level (SPL) was slightly higher than that in males (-3.91 ±9.14) dB SPL(P>0.05). Also, the mean maximum SOAE level in right ears (-2.03 ±9.11) dB SPL was higher than in left ears (-5.50 ± 9.65) dB SPL (P < 0.05). The maximum SOAE level showed a positive correlation with maximum SOAE number in emitting ears (r= 0.55, P< 0.01).CONCLUSION: The incidence of SOAEs in neonates is high (78.1%) within 4 days of birth. The incidence of SOAEs and the maximum SOAE

  9. Paclitaxel reduces formation of hypertrophic scars in the rabbit ear model

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    Huang LP

    2015-07-01

    Full Text Available Li-ping Huang,1* Guo-qi Wang,2* Zi-shan Jia,1 Jing-wen Chen,1 Gang Wang,1 Xing-lin Wang1   1Department of Physical Therapy, 2Department of Orthopedics, Chinese PLA General Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Background and objective: The onset and progression of pathological scarring involves multiple cytokines and complex mechanisms. However, hyperplasia of fibroblasts and neovascularization plays important roles, which can be inhibited by paclitaxel. The aim of this study was to investigate the efficacy of paclitaxel in the treatment of hypertrophic scars on rabbit ears. Methods: Rabbit ear models of hypertrophic scars were established to observe the therapeutic effects of paclitaxel at different concentrations (12 mg/L, 24 mg/L, 48 mg/L, 96 mg/L, 18 mg/L, 54 mg/L, 162 mg/L, 486 mg/L, 30 mg/L, 150 mg/L, 750 mg/L, 3,750 mg/L. The outcome measures included hypertrophic index (HI, density of fibroblasts, density of collagenous fibers, and microvessel density. Results: In comparison with the control group, the concentrations of 96 mg/L, 150 mg/L, and 162 mg/L significantly reduce the formation of hypertrophic scars in the rabbit ear models. However, local necrosis was found in the rabbit ear models treated with paclitaxel solution >400 mg/L. Conclusion: Paclitaxel has strong inhibitory effects on the hyperplasia of fibroblasts, deposition of collagen, and microangiogenesis in hypertrophic scars on rabbit ears within the concentration range from 48 mg/L to 162 mg/L, without causing local necrosis. Keywords: hypertrophic scar, paclitaxel, rabbit ear model

  10. Effects of UMTS cellular phones on human hearing: results of the European project EMFnEAR.

    Science.gov (United States)

    Parazzini, Marta; Sibella, Federica; Lutman, Mark E; Mishra, Srikanta; Moulin, Annie; Sliwinska-Kowalska, Mariola; Woznicka, Ewelina; Politanski, Piotr; Zmyslony, Marek; Thuroczy, Gyorgy; Molnár, Ferenc; Kubinyi, Györgyi; Tavartkiladze, George; Bronyakin, Stanislav; Uloziene, Ingrida; Uloza, Virgijlius; Gradauskiene, Egle; Ravazzani, Paolo

    2009-08-01

    Abstract The European project EMFnEAR was undertaken to assess potential changes in human auditory function after a short-term exposure to radiofrequency (RF) radiation produced by UMTS (Universal Mobile Telecommunication System) mobile phones. Participants were healthy young adults with no hearing or ear disorders. Auditory function was assessed immediately before and after exposure to radiofrequency radiation, and only the exposed ear was tested. Tests for the assessment of auditory function were hearing threshold level (HTL), distortion product otoacoustic emissions (DPOAE), contralateral suppression of transiently evoked otoacoustic emission (CAS effect on TEOAE), and auditory evoked potentials (AEP). The exposure consisted of speech at a typical conversational level delivered via an earphone to one ear, plus genuine or sham RF-radiation exposure produced by a commercial phone controlled by a personal computer. Results from 134 participants did not show any consistent pattern of effects on the auditory system after a 20-min UMTS exposure at the maximum output of the phone with 69 mW/kg SAR in the cochlea region in a double blind comparison of genuine and sham exposure. An isolated effect on the hearing threshold at high frequencies was identified, but this was statistically nonsignificant after correction for multiple comparisons. It is concluded that UMTS short-term exposure at the maximum output of consumer mobile phones does not cause measurable immediate effects on the human auditory system.

  11. Atrial conduction times and left atrium mechanical functions in patients with active acromegaly.

    Science.gov (United States)

    Ilter, A; Kırış, A; Kaplan, Ş; Kutlu, M; Şahin, M; Erem, C; Civan, N; Kangül, F

    2015-03-01

    The aim of this study was to evaluate atrial electromechanical delay (EMD), P wave dispersion (Pwd), and left atrial (LA) mechanical functions in patients with active acromegaly. Twenty-three patients with active acromegaly and 27 age- and sex-matched controls were included in this study. All atrial electromechanical interval parameters (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) were measured from mitral lateral annulus, mitral septal annulus, and right ventricular tricuspid annulus by tissue Doppler imaging. LA volumes were measured by the disk method in the apical four-chamber view and were indexed to the body surface area. Mechanical function parameters of LA were calculated. Pwd was performed by 12-lead electrocardiograms. Atrial electromechanical intervals (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) and Pwd were similar between patients with acromegaly and control subjects (all p > 0.05). LA volumes (maximum, minimum, and presystolic) and LA mechanical functions were not significantly different between the groups (all p > 0.05). Additionally, serum levels of growth hormone and insulin-like growth factor-1 were not correlated with atrial electromechanical parameters and LA mechanical functions. Atrial electrical conduction times were not prolonged and LA mechanical functions were not impaired in patients with active acromegaly compared with controls. And the prevalence of supraventricular arrhythmia risk may not increase in this population.

  12. TOTAL EAR RECONSTRUCTION WITH MONOBLOCK CARTILAGE AND TEMPOROPARIETAL FASCIA

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad

    2015-09-01

    Full Text Available BACKGROUND : Microtia is a congenital ear deformity with incidence of 1:6000. Anotia can be of traumatic origin also. It is one of the greatest challenges to the plastic surgeon to the reconstruct the ear from autologus material . Various developments have occurred in the ear reconstruction from the era of Tanzer. It can be done in a single stage or multiple stages. Single stage ear reconstruction require technical precision, avoids multiple admission of the patient. MATERIAL AND M ETHOD : Between 2007 to 2013 six cases of total ear reconstruction was done in two stage method using autologus coastal cartilage in the department of M.K.C.G medical college by a single surgeon. In the first stage lobule rotation, fabrication of the cartil aginous framework and its implantation were performed. In the second stage elevation of the auricle and formation of tragus was done. All of them underwent stage 1 procedure among them 2 had not turned up for staged 2 procedure. RESULT S: 4 were females and 2 were male. 4 had congenital microtia and two were traumatic amputation of the ear. All had unilateral microtia. The follow up was done for up to 1 year. CONCLUSION: One patient had lost follow up.5 patient had unacceptable ear. Though it is impossible t o reconstruct ear that appear exactly the same as opposite ear , the new ears which were made of correct size and in normal position

  13. Alterations in the Contra lateral Ear in Chronic Otitis Media

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    Mohammad Ali Damghani

    2013-03-01

    Full Text Available Introduction: Chronic otitis media (COM, a persistent and durable inflammation and infection of the middle ear, is a common disorder. Alterations in the contralateral ear in sufferers have been observed in recent years. Because only a few studies have been reported in this area, we performed this study in order to assess alterations in the contralateral ear of patients with COM.   Materials and Methods: Cross-sectional and descriptive methods were used in 100 patients with COM who were selected for surgical treatment and admitted to hospital. An information form was completed for all patients including demographic data, medical history of otoscopy and paraclinical examinations such as pure tone audiometry (PTA, tympanometry, Schuller radiography, and high resolution computed tomography (HRCT. All data were processed using SPSS (version 18 software and descriptive statistical tests.   Results: According to otoscopy, PTA, tympanometry and graphical analysis, 60% of patients experienced disorders of the contralateral ear. Otoscopy analysis showed 54% of patients had a disorder of the contralateral ear, with the most common disorder being perforation of the ear drum. PTA showed a 48% incidence of contralateral ear problems (85% conductive hearing impairment; 12.5% sensorineural hearing impairment; 1.2% mixed. A total of 73.2% of patients with conductive hearing loss had a problem across all frequencies, while half of the patients with sensorineural hearing impairment had problems at frequencies greater than 1000 Hz. According to tympanometry, 38% of patients had problem in the contralateral ear. HRCT and Schuller graphical analyses indicated 31.5% and 36% occurrence of contralateral ear disorders, respectively.   Conclusion:  More than 50% of patients with COM in one ear have a chance of also presenting with the disease in the other ear. Outcomes of this study and previous studies have shown that COM should not be perceived as a disease limited

  14. A mechanical design principle for tissue structure and function in the airway tree.

    Science.gov (United States)

    LaPrad, Adam S; Lutchen, Kenneth R; Suki, Béla

    2013-01-01

    With every breath, the dynamically changing mechanical pressures must work in unison with the cells and soft tissue structures of the lung to permit air to efficiently traverse the airway tree and undergo gas exchange in the alveoli. The influence of mechanics on cell and tissue function is becoming apparent, raising the question: how does the airway tree co-exist within its mechanical environment to maintain normal cell function throughout its branching structure of diminishing dimensions? We introduce a new mechanical design principle for the conducting airway tree in which mechanotransduction at the level of cells is driven to orchestrate airway wall structural changes that can best maintain a preferred mechanical microenvironment. To support this principle, we report in vitro radius-transmural pressure relations for a range of airway radii obtained from healthy bovine lungs and model the data using a strain energy function together with a thick-walled cylinder description. From this framework, we estimate circumferential stresses and incremental Young's moduli throughout the airway tree. Our results indicate that the conducting airways consistently operate within a preferred mechanical homeostatic state, termed mechanical homeostasis, that is characterized by a narrow range of circumferential stresses and Young's moduli. This mechanical homeostatic state is maintained for all airways throughout the tree via airway wall dimensional and mechanical relationships. As a consequence, cells within the airway walls throughout the airway tree experience similar oscillatory strains during breathing that are much smaller than previously thought. Finally, we discuss the potential implications of how the maintenance of mechanical homeostasis, while facilitating healthy tissue-level alterations necessary for maturation, may lead to airway wall structural changes capable of chronic asthma.

  15. The character and consequences of disturbing sound sensations in retraction type middle ear disease.

    Science.gov (United States)

    Bunne, M; Falk, B; Hellström, S; Magnuson, B

    1999-11-15

    Transient sound disturbances are common but neglected symptoms in retraction type middle ear disease (R-MED). The aim of this study was to explore and describe their character, their individual consequences, and their role in the development of tympanic membrane retractions. Fifty-three subjects with manifest retractions and experiences of disturbing sound and ear sensations were interviewed. A qualitative method was used for analysis of the transcribed interviews. Two different patterns emerged from the interviews. 1. Too weak sound was the least common and most tolerable disturbance. It occurred in 45% and was eliminated by Valsalva's inflation. 2. Sudden and transient sensations of too loud and piercing sound, and intermittent autophony frequently caused intense and intolerable discomfort, which might in turn cause loss of control of speech and conversation. These types occurred in 74% and 60%, respectively, and were eliminated by evacuating the middle ear, for example by sniffing. Subjects who described too loud sound or intermittent autophony commonly preferred a retracted tympanic membrane position. This may explain why pressure equalization by swallowing, and inflation by Valsalva's manoeuvre often elicited discomfort. Transient experiences of too loud sound or intermittent autophony may indicate a shift of sound preference towards the sound experienced at negative middle ear pressure, and an unreliable tubal function in the sense that it fails to stay closed to protect the ear from sounds and pressure variations in the nasopharynx. Such experiences of altered sound may trigger evacuation of the middle ear, which eliminates the sound disturbance. It is crucial to identify, interpret, and explain the disturbances correctly in the therapy and prevention of retractions, since habitual evacuation exposes the tympanic membrane to strong negative pressure loads and a subsequent risk of developing retraction.

  16. Searching for Electrical Properties, Phenomena and Mechanisms in the Construction and Function of Chromosomes

    Directory of Open Access Journals (Sweden)

    Ivan Kanev

    2013-03-01

    Full Text Available Our studies reveal previously unidentified electrical properties of chromosomes: (1 chromosomes are amazingly similar in construction and function to electrical transformers; (2 chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3 chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c mechanisms demonstrating heterochromatin to be electrically active and genetically important.

  17. SEARCHING FOR ELECTRICAL PROPERTIES, PHENOMENA AND MECHANISMS IN THE CONSTRUCTION AND FUNCTION OF CHROMOSOMES

    Directory of Open Access Journals (Sweden)

    Ivan Kanev

    2013-03-01

    Full Text Available Our studies reveal previously unidentified electrical properties of chromosomes: (1 chromosomes are amazingly similar in construction and function to electrical transformers; (2 chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3 chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c mechanisms demonstrating heterochromatin to be electrically active and genetically important.

  18. Mechanical system reliability analysis using a combination of graph theory and Boolean function

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J

    2001-04-01

    A new method based on graph theory and Boolean function for assessing reliability of mechanical systems is proposed. The procedure for this approach consists of two parts. By using the graph theory, the formula for the reliability of a mechanical system that considers the interrelations of subsystems or components is generated. Use of the Boolean function to examine the failure interactions of two particular elements of the system, followed with demonstrations of how to incorporate such failure dependencies into the analysis of larger systems, a constructive algorithm for quantifying the genuine interconnections between the subsystems or components is provided. The combination of graph theory and Boolean function provides an effective way to evaluate the reliability of a large, complex mechanical system. A numerical example demonstrates that this method an effective approaches in system reliability analysis.

  19. Barrier Lyapunov function-based model-free constraint position control for mechanical systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seong Ik; Ha, Hyun Uk; Lee, Jang Myung [Pusan National University, Busan (Korea, Republic of)

    2016-07-15

    In this article, a motion constraint control scheme is presented for mechanical systems without a modeling process by introducing a barrier Lyapunov function technique and adaptive estimation laws. The transformed error and filtered error surfaces are defined to constrain the motion tracking error in the prescribed boundary layers. Unknown parameters of mechanical systems are estimated using adaptive laws derived from the Lyapunov function. Then, robust control used the conventional sliding mode control, which give rise to excessive chattering, is changed to finite time-based control to alleviate undesirable chattering in the control action and to ensure finite-time error convergence. Finally, the constraint controller from the barrier Lyapunov function is designed and applied to the constraint of the position tracking error of the mechanical system. Two experimental examples for the XY table and articulated manipulator are shown to evaluate the proposed control scheme.

  20. Ear manipulations reveal a critical period for survival and dendritic development at the single-cell level in Mauthner neurons.

    Science.gov (United States)

    Elliott, Karen L; Houston, Douglas W; DeCook, Rhonda; Fritzsch, Bernd

    2015-12-01

    Second-order sensory neurons are dependent on afferents from the sense organs during a critical period in development for their survival and differentiation. Past research has mostly focused on whole populations of neurons, hampering progress in understanding the mechanisms underlying these critical phases. To move toward a better understanding of the molecular and cellular basis of afferent-dependent neuronal development, we developed a new model to study the effects of ear removal on a single identifiable cell in the hindbrain of a frog, the Mauthner cell. Ear extirpation at various stages of Xenopus laevis development defines a critical period of progressively-reduced dependency of Mauthner cell survival/differentiation on the ear afferents. Furthermore, ear removal results in a progressively decreased reduction in the number of dendritic branches. Conversely, addition of an ear results in an increase in the number of dendritic branches. These results suggest that the duration of innervation and the number of inner ear afferents play a quantitative role in Mauthner cell survival/differentiation, including dendritic development.