Note: This page contains sample records for the topic canal tympanic membrane from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results. Last update: August 15, 2014.
The intrinsic stength of the tympanicmembrane of a guinea pig was tested by applying static overpressure to the sealed external auditory canal. In nine ears with surgically established middle ear ventilation the mean bursting pressure was 200 mm Hg. In n...
The human tympanicmembrane has reasonably good sound sensing properties. A destroyed tympanicmembrane due to middle ear diseases or traumata may be repaired by different types of grafts. Middle ear surgery mostly uses autologous temporal fascia, cartilage, or cartilage perichondrium transplants. We have investigated the acoustical and mechanical properties of these materials and compared them with human tympanicmembrane by constructing an ear canal model completed by an artificial tympanicmembrane. Circular stretched human fascia, perichondrium, and cartilage preparations were exposed to static pressures up to 4 kPa and white noise sound pressure levels of 70 dB. The vibrational amplitudes and displacements due to static pressure of the graft material were measured by laser Doppler vibrometry and compared. The thin materials temporal fascia and perichondrium show similar amplitude frequency responses compared to the tympanicmembrane for dynamic excitation. The displacement of these materials at static pressures above 4 kPA yields a higher compliance than tympanicmembrane. The acoustical and mechanical properties of cartilage transplants change with the thickness of the slices. However, the thinner the cartilage slice combined with lower stability, the more similar is the frequency response with the intact tympanicmembrane. The vibration amplitudes decrease more and more for layer thicknesses above 500 micrometers. Cartilage acts as an excellent transplant material which provides a better prognosis than different materials in cases of ventilation disorders with long-term middle ear pressure changes. Large cartilage slice transplants should not exceed layer thicknesses of 500 micrometer in order to prevent drawbacks to the transfer characteristics of the tympanicmembrane.
This study aimed to retrospectively evaluate the prognosis and outcome of tympanicmembrane perforations with a particular focus on the fate of the perforation edge flaps.Chart records of 329 patients with a single ear traumatic tympanicmembrane perforation were retrieved and analyzed. Of these patients, 70 were left to heal spontaneously, 93 received gelatin sponge patching treatment and 114 were
Background Traumatic perforation of the tympanicmembrane may be due to direct or indirect source. The aim of the study is to profile the various aetiologies of traumatic tympanicmembrane perforation in Ilorin, north central Nigeria. A retrospective review of 64 patients seen at the University of Ilorin Teaching hospital, Ilorin, Nigeria over a ten year period (January 1998 to Dec 2007) with history of traumatic tympanicmembrane perforation from various causes, these also included multiply injured patients with bleeding from middle ear as part of their presentations. The data retrieved included the biodata, the clinical presentations, source of injury, the clinical findings and the treatment outcome. The data were entered into an SPSS version 11 computer soft ware and analyzed descriptively. Findings Sixty four (64) ears were analysed, Age range 6 months to 50 yrs, mean age of 29.2 yrs 7.9% of them were ?5 years, 29.7% between 21-34 years, and 37.7% were 35 years and above. The male to female ratio was 2.5:1.0. Commonest aetiology was from slaps, then road traffic injury (RTI) in 35.9% and 23.5%, Majority of the slap injury were from fights (30.5%), security agents, senior students and cultists at schools (17.4% each). Sudden hearing loss was a typical presentation (95.3%), majority of the patient defaulted from follow up once the symptoms of bleeding and pain subsided. Only 7.8% had neomembrane formation on follow up Conclusion Traumatic perforation of the tympanicmembrane is an uncommon injury that is under-reported, there is the need to educate on alternative punitive measure among students and security agents, unskilled removal of foreign body, early identification, evaluation and referral of patients reduces the attendant morbidity.
Perforation of the tympanicmembrane occurs frequently as a result of infection, external trauma, and high-level impulsive\\u000a sound pressure, such as that associated with an explosion. Many different surgical techniques can be used to repair the tympanic\\u000a membrane and ossicles. Clinical operations such as tympanoplasty are undertaken to repair the damaged tympanicmembrane and\\u000a ossicles, thus improving hearing and reducing
Fatih Oktem; Murat Toprak; Murat Yener; Ergun Bozdag; Emin Sunbuloglu; Tuncer Toprak
Background During investigation and diagnosis of patients, accurate temperature measurement is of great importance. The advantages of tympanicmembrane thermometry are speed (temperature reading available within seconds), safety, and ease of use. The aim of this study was to compare the accuracy of infrared tympanic thermometers in comparison to mercury thermometers in measurement of body temperature. Methods Axillary and tympanic temperature was measured simultaneously in consecutive patients using mercury glass and infrared tympanic thermometers at Omdurman Hospital, Sudan during October 2012. Results In total, temperature was measured in 174 patients, 95 of whom (54.6%) were male. The mean (SD) patient age and weight was 33.18 (25.07) years and 52.13 (69.85) kg. There was no significant difference in mean (SD) temperature measurement between mercury and infrared tympanicmembrane thermometers, 37.29°C (0.91) versus 37.38°C (0.95), P?=?0.373, respectively. There was a significant positive correlation between axillary and tympanic body temperature measurements (r?=?0.697, P?0.001). The mean difference between the two readings (with limits of agreements) was - 0.093 (?0.20; 0.02) °C. Conclusion In this study, tympanicmembrane thermometry is as reliable and accurate as axillary mercury glass thermometry. Thus, tympanic thermometry can be used in clinical practice, especially in the emergency setting, where ease of use and speed of obtaining the temperature reading are important.
The author reports a recently recognised physical examination finding, otoscope fogging, for perforated tympanicmembrane. Otoscope fogging is defined as condensation forming in the view field of the otoscope while inspecting the ear. In the setting of occult perforation secondary to the inability to visualise the entire tympanicmembrane, otoscope fogging may provide the clinician with valuable information since medical management may differ if perforation is present. PMID:24879720
In this paper a digital holographic interferometry (DHI) system with three object-illumination beams is used for the first time to detect and measure micrometer deformations on the surface of a tympanicmembrane. Using this optical setup allows all three object displacement components x, y, and z, to be independently calculated. The corresponding deformations are registered using a cw laser in stroboscopic mode and a CCD camera synchronized to the excitation acoustic wave that produces a resonant vibration mode on the tympanicmembrane surface. A series of digital holographic interferograms record the displacements undergone by the tympanicmembrane and from them full field deformation phase maps are obtained. From the latter it is possible to observe the displacement of the tympanicmembrane in response to the sound pressure. The study was performed on the tympanicmembrane taken from a post-mortem cat. The results show the feasibility to apply a similar optomechanical arrangement for the study in humans, representing an alternative technique for the study of pathologies in the tympanicmembrane.
Muñoz Solís, S.; Mendoza Santoyo, F.; Del Socorro Hernández-Montes, M.
The study of the tympanicmembrane is fundamental because it is one of the most important components of the middle ear. By finding the membrane's vibration patterns and quantifying the induced displacement, it is possible to characterize and determine its physiological state. Digital Holographic Interferometry (DHI) has proved to be a promising optical non-invasive and quasi-real time method for the investigation of different mechanical parameters of biological tissues. In this paper, we present a digital holographic interferometry setup used to measure the frequency response of the tympanicmembrane in post-mortem cats subject to acoustic stimuli in the range of 485 Hz up to 10 kHz. We show the resonant vibration patterns found for this range of frequencies and the corresponding displacement amplitudes induced by the acoustic waves. The results show the potential that this method has to help improve the understanding of the tympanicmembrane's working mechanisms.
Hernández-Montes, María Del Socorro; Mendoza-Santoyo, Fernando; Muñoz-Solís, Silvino
Recordings of steady state tympanicmembrane and rectal temperature were made on three subjects in ambient environments of 10, 16, 22, 28, 34, 39, and 44 C. Rectal temperature was idependent of ambient temperature over this ambient range. Temperature at t...
Optical coherence tomography (OCT) is an imaging modality that enables micrometer-scale contactless subsurface imaging of biological tissue. Endoscopy, as another imaging method, has the potential of imaging tubular organs and cavities and therefore has opened up several application areas not accessible before. The combination of OCT and endoscopy uses the advantages of both methods and consequently allows additional imaging of structures beneath surfaces inside cavities. Currently, visual investigations on the surface of the human tympanicmembrane are possible but only with expert eyes. up to now, visual imaging of the outer ear up to the tympanicmembrane can be carried out by an otoscope, an operating microscope or an endoscope. In contrast to these devices, endoscopy has the advantage of imaging the whole tympanicmembrane with one view. The intention of this research is the development of an endoscopic optical coherence tomography (EOCT) device for imaging the tympanicmembrane depth-resolved and structures behind it. Detection of fluids in the middle ear, which function as an indicator for otitis media, could help to avoid the application of antibiotics. It is possible to detect a congeries of fluids with the otoscope but the ambition is to the early detection by OCT. The developed scanner head allows imaging in working distances in the range from zero up to 5 mm with a field of view of 2 mm. In the next step, the scanner head should be improved to increase the working distance and the field of view.
Burkhardt, Anke; Walther, Julia; Cimalla, Peter; Bornitz, Matthias; Koch, Edmund
Perforation of the tympanicmembrane occurs frequently as a result of infection, external trauma, and high-level impulsive sound pressure, such as that associated with an explosion. Many different surgical techniques can be used to repair the tympanicmembrane and ossicles. Clinical operations such as tympanoplasty are undertaken to repair the damaged tympanicmembrane and ossicles, thus improving hearing and reducing the chance of infection. The membrane is repaired or replaced with the use of graft materials, either from the patient's body or from artificial sources. The selection of graft material is very important because, as much as possible, it must exhibit the same dynamic behavior as the natural membrane. To compare various allograft materials, investigators developed a model of the ear on which different graft materials can be replaced. Three different membrane materials - irradiated allograft dura (Tutoplast Dura; IOP Inc., Costa Mesa, Calif), irradiated allograft fascia lata (Tutoplast Fascia Lata; IOP Inc.), and irradiated allograft fascia temporalis (Tutoplast Fascia Temporalis; IOP Inc.) - were used. Vibration responses of these membrane materials produced by defined sound signals with different frequencies were recorded by a small strain gauge; the spectra of sound for various corresponding input signals were recorded, and the results were compared with those of the sample graft material. Tutoplast Fascia Lata accomplished the best dynamic performance in vitro. Additional clinical and experimental data are needed, however, to determine which of these materials provides the best audiological and clinical performance. PMID:17526464
A theoretical analysis and a computational simulation of the vibrations of the tympanicmembrane is presented. A new model based in the vibrations of a membrane of two regions with different densities is proposed to model the eardrum. Values of vibration frequencies as also the vibration modes are obtained. It is demonstrated, according to our model, that the (0,1) and (0,2) modes are the most important for the vibration of the tympanum.
We clarified the localization of lymphatic vessels in the tympanicmembrane and proliferation of lymphatic vessels during regeneration after perforation of the tympanicmembrane by using whole-mount imaging of the tympanicmembrane of Prox1 GFP mice. In the pars tensa, lymphatic vessel loops surrounded the malleus handle and annulus tympanicus. Apart from these locations, lymphatic vessel loops were not observed in the pars tensa in the normal tympanicmembrane. Lymphatic vessel loops surrounding the malleus handle were connected to the lymphatic vessel loops in the pars flaccida and around the tensor tympani muscle. Many lymphatic vessel loops were detected in the pars flaccida. After perforation of the tympanicmembrane, abundant lymphatic regeneration was observed in the pars tensa, and these regenerated lymphatic vessels extended from the lymphatic vessels surrounding the malleus at day 7. These results suggest that site-specific lymphatic vessels play an important role in the tympanicmembrane. PMID:24055876
Highlights: •We newly developed the whole-mount imaging method of the tympanicmembrane. •Lymphatic vessel loops were localized around the malleus handle and annulus tympanicus. •In regeneration, abundant lymphatic vessels were observed in the pars tensa. •Site-specific lymphatic vessels may play an important role in the tympanicmembrane. -- Abstract: We clarified the localization of lymphatic vessels in the tympanicmembrane and proliferation of lymphatic vessels during regeneration after perforation of the tympanicmembrane by using whole-mount imaging of the tympanicmembrane of Prox1 GFP mice. In the pars tensa, lymphatic vessel loops surrounded the malleus handle and annulus tympanicus. Apart from these locations, lymphatic vessel loops were not observed in the pars tensa in the normal tympanicmembrane. Lymphatic vessel loops surrounding the malleus handle were connected to the lymphatic vessel loops in the pars flaccida and around the tensor tympani muscle. Many lymphatic vessel loops were detected in the pars flaccida. After perforation of the tympanicmembrane, abundant lymphatic regeneration was observed in the pars tensa, and these regenerated lymphatic vessels extended from the lymphatic vessels surrounding the malleus at day 7. These results suggest that site-specific lymphatic vessels play an important role in the tympanicmembrane.
Miyashita, Takenori, E-mail: email@example.com [Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kagawa 761-0793 (Japan)] [Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kagawa 761-0793 (Japan); Burford, James L. [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)] [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Hong, Young-Kwon [Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)] [Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Gevorgyan, Haykanush; Lam, Lisa [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)] [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Mori, Nozomu [Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kagawa 761-0793 (Japan)] [Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kagawa 761-0793 (Japan); Peti-Peterdi, Janos [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)] [Department of Physiology and Biophysics and Department of Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)
Hypothesis The sound-induced motion of the tympanicmembrane has features that are most consistent with modal responses to a uniform stimulus. Background Conceptual models of the coupling of tympanic-membrane motion to the ossicular chain can be classified as either modal responses to a uniform stimulation of the entire membrane, or traveling wave models in which sound energy is captured at the membrane’s rim and travels along the surface to the umbo. The stroboscopic holography technique we employ can separate strongly modal or traveling-wave dominated motions of the tympanicmembrane surface. Methods We use computer-aided opto-electronic holography with stroboscopic illumination to measure the magnitude and phase of the sound-induced motion of over 40000 points on the surface of the tympanicmembrane in cadaveric human temporal bones. Our techniques are sensitive to motions of the membrane as small as 0.01 microns, and allow determinations of membrane displacement at frequencies as large as 20 kHz. Results We report clear signs of both modal tympanicmembrane responses and traveling waves on the human tympanicmembrane. Modal responses are seen throughout the frequency range, while the traveling waves are most apparent between 2 and 8 kHz. In general, the magnitudes of the traveling waves are small compared to the modal magnitudes. Conclusion Much of the motion of the tympanicmembrane is well approximated by modal motions of the TM surface. This conclusion has implications for ear drum pathology and its treatment.
Rosowski, JJ; Cheng, JT; Merchant, SN; Harrington, E; Furlong, C
It is shown that a pressure change of 30 mm saline in the perilymph fluid can be detected by the tympanicmembrane displacement (TMD) measurement system, as a change in the mean volume displacement and maximum inward volume displacement of the tympanic me...
Our objectives were to review all reported staging systems of tympanicmembrane (TM) retraction pockets (RP) and to report their reliability and utility to our daily clinical practice in terms of follow-up and decision making in the management of RP. We aim to propose a new management algorithm of TMRPs. We conducted a thorough research on Ovid Medline, Pubmed and Cochrane databases for English and French languages studies published between 1963 and 2012 on the retraction pocket. Studies were excluded if it were a short comments, photo clinical cases, experimental studies or round table articles. Cholesteatoma was not included in keywords, since it is considered as an advanced pathological entity with different staging and management approaches. We included 60 of 756 articles that met our inclusion criteria. Sadé and Berco proposed the first staging system of RP in 1976, while the last one was described by Borgstein et al. in 2007. From 1976 to 2007, 12 different staging systems have been described for tympanicmembrane retractions. There are three broad categories of TMRPs: localized retractions of the pars tensa, generalized retractions of the pars tensa (atelectasis) and retraction of the pars flaccida. Most of the described staging systems are useful for following up the evolution of retractions over time. However, no consensus was found concerning the decision making in its management. In conclusion, proper management of TMRPs requires a reproducible, easily applicable staging system with low inter- and intra-observer variability. We propose a management algorithm that considers the functional handicap of the patient rather than the topographic description of the TM. PMID:23892691
To evaluate and analyse the hearing loss in tympanicmembrane perforation based on size, site and duration of perforation. The material for this study was comprised of 100 patients of either sex and of age 15 years and above selected randomly. Size of tympanicmembrane perforation was assessed under microscope using calibrated wire look. Patients were divided into three groups according to size; group I (0-9 mm(2)), Group II (9-30 mm(2)), Group III (? 30 mm(2)); according to site into anterior and posterior group; according to involvement of malleus into malleolar and non malleolar and according to duration into Group A (<1 year), Group B (1-5 years), Group C (? 5 years). Hearing loss was measured in each case with pure tone audiometry. Data was analysed statistically using paired t-test. Hearing loss increased as the perforation size increased [I vs. II (t - 4.23, p < 0.001), II vs. III (t - 8.19, p < 0.001), I vs. III (t - 11.68, p < 0.001)]. Hearing loss was more in posterior quadrant perforation than anterior quadrant perforation but difference was not significant statistically (t - 1.15, p > 0.05). Hearing loss was more in malleolar perforation (t - 5.74, p < 0.001). Hearing loss increased as the duration of disease increased [A vs. B (t - 2.01, p < 0.043), A vs. C (t - 5.49, p < 0.001), B vs. C (t - 4.14, p < 0.001)]. PMID:22754796
Otitis media diagnosis can be assisted by measuring the shape of the tympanicmembrane. We have developed an ear speculum for an otoscope, including spatially distributed source and detector optical fibers, to generate source-detector intensity matrices (SDIMs), representing the curvature of surfaces. The surfaces measured were a model ear with a latex membrane and harvested temporal bones including intact tympanicmembranes. The position of the tympanicmembrane was shifted from retracted to bulging by air pressure and that of the latex membrane by water displacement. The SDIM was normalized utilizing both external (a sheared flat plastic cylinder) and internal references (neutral position of the membrane). Data was fitted to a two-dimensional Gaussian surface representing the shape by its amplitude and offset. Retracted and bulging surfaces were discriminated for the model ear by the sign of the Gaussian amplitude for both internal and external reference normalization. Tympanicmembranes were separated after a two-step normalization: first to an external reference, adjusted for the distance between speculum and the surfaces, and second by comparison with an average normally positioned SDIM from tympanicmembranes. In conclusion, we have shown that the modified otoscope can discriminate between bulging and retracted tympanicmembranes in a single measurement, given a two-step normalization.
Otitis media diagnosis can be assisted by measuring the shape of the tympanicmembrane. We have developed an ear speculum for an otoscope, including spatially distributed source and detector optical fibers, to generate source-detector intensity matrices (SDIMs), representing the curvature of surfaces. The surfaces measured were a model ear with a latex membrane and harvested temporal bones including intact tympanicmembranes. The position of the tympanicmembrane was shifted from retracted to bulging by air pressure and that of the latex membrane by water displacement. The SDIM was normalized utilizing both external (a sheared flat plastic cylinder) and internal references (neutral position of the membrane). Data was fitted to a two-dimensional Gaussian surface representing the shape by its amplitude and offset. Retracted and bulging surfaces were discriminated for the model ear by the sign of the Gaussian amplitude for both internal and external reference normalization. Tympanicmembranes were separated after a two-step normalization: first to an external reference, adjusted for the distance between speculum and the surfaces, and second by comparison with an average normally positioned SDIM from tympanicmembranes. In conclusion, we have shown that the modified otoscope can discriminate between bulging and retracted tympanicmembranes in a single measurement, given a two-step normalization. PMID:21950937
Fibrous layers of the lamina propria influence dynamic behavior of the tympanicmembrane by producing strong anisotropic extensional stiffness, while the mucous and epidermal layers are primarily responsible for curvature dependent structural damping and ...
The objective of this study was to investigate the effects of changes in cochlear perilymphatic fluid pressure on the volume displacement of the tympanicmembrane during acoustically induced reflex contractions of the stapedius muscle. These changes in pe...
A novel infrared (IR) transparent optical fiber coupled to a hand held otoscope and a radiometer was constructed and used to measure the temperatures of the tympanicmembrane (TM) and to distinguish between diseased and healthy middle ears. A greater temperature difference between TM readings was found when Acute Otitis Media (AOM) existed in one of the ears examined. This supports the hypothesis that acute inflammation of the middle ear will result in elevated local temperature when measured in such a way that the reading is taken only from the TM without interference of the external canal. The use of an optical fiber enabled temperature measurements of the TM with high spatial resolution eliminating the external ear canal interference. A small patient population was examined and the initial results were statistically significant. In the hands of the primary care physician, this tool would prevent misdiagnosis of AOM preventing indiscriminate use of antibiotics and avoiding complications by early diagnosis.
The thickness of the tympanicmembrane has to be known for the formulation of mathematical ear models. Using a commercial confocal laser scanning microscope we have found that the tympanicmembrane has parts thinner than 10 micron. In this study we were forced to excise the tympanicmembranes and due the restricted working distance of the microscope objective, we had to flatten the tympanicmembrane onto a glass plate. Although we were able to measure thickness in fresh samples, thickness could still have been altered by the preparation procedure. S. Khanna developed over the years a powerful heterodyne interferometer with confocal pinholes in the illumination and observation arms. Thanks to its sectioning capabilities it can measure vibrations of structures embedded within other tissue without the need to expose the structure. While using this equipment in measuring vibrations in the middle ear, the idea grew that the interferometer could also be used to measure thickness, by tracking the carrier level of the interferometer while the laser focus is driven through the membrane. The method looks full of promises as measurements on animals with the tympanicmembrane still in its original niche are possible without a prior preparation of the membrane.
Decraemer, Willem F. S.; Khanna, Shyam M.; Dirckx, Joris J. J.
Computer-aided, personal computer (PC) based, optoelectronic holography (OEH) was used to obtain preliminary measurements of the sound-induced displacement of the tympanicmembrane (TM) of cadaver cats and chinchillas. Real-time time-averaged holograms, processed at video rates, were used to characterise the frequency dependence of TM displacements as tone frequency was swept from 400 Hz to 20 kHz. Stroboscopic holography was used at selected frequencies to measure, in full-field-of-view, displacements of the TM surface with nanometer resolution. These measurements enable the determination and the characterisation of inward and outward displacements of the TM. The time-averaged holographic data suggest standing wave patterns on the cat’s TM surface, which move from simple uni-modal or bi-modal patterns at low frequencies, through complicated multimodal patterns above 3 kHz, to highly ordered arrangements of displacement waves with tone frequencies above 15 kHz. The frequency boundaries of the different wave patterns are lower in chinchilla (simple patterns below 600 Hz, ordered patterns above 4 kHz) than cat. The stroboscopic holography measurements indicate wave-like motion patterns on the TM surface, where the number of wavelengths captured along sections of the TM increased with stimulus frequency with as many as 11 wavelengths visible on the chinchilla TM at 16 kHz. Counts of the visible number of wavelengths on TM sections with different sound stimulus frequency provided estimates of wave velocity along the TM surface that ranged from 5 m s?1 at frequencies below 8 kHz and increased to 25 m s?1 by 20 kHz.
Furlong, C.; Rosowski, J. J.; Hulli, N.; Ravicz, M. E.
Multiharmonic optical microscopy has been widely applied in biomedical research due to its unique capability to perform noninvasive studies of biomaterials. In this study, virtual biopsy based on back-propagating multiple optical harmonics, combining second and third harmonics, is applied in unfixed rat tympanicmembrane. We show that third harmonic generation can provide morphologic information on the epithelial layers of rat tympanicmembrane as well as radial collagen fibers in middle fibrous layers, and that second harmonic generation can provide information on both radial and circular collagen fibers in middle fibrous layers. Through third harmonic generation, the capillary and red blood cells in the middle fibrous layer are also noted. Additionally, the 3-D relationship to adjacent bony structures and spatial variations in thickness and curvature are obtained. Our study demonstrates the feasibility of using a noninvasive optical imaging system for comprehensive evaluation of the tympanicmembrane.
A three-dimensional finite element (FE) model of human ear with structures of the external ear canal, middle ear, and cochlea has been developed recently. In this paper, the FE model was used to predict the effect of tympanicmembrane (TM) perforations on sound transmission through the middle ear. Two perforations were made in the posterior-inferior quadrant and inferior site of the TM in the model with areas of 1.33 and 0.82 mm2, respectively. These perforations were also created in human temporal bones with the same size and location. The vibrations of the TM (umbo) and stapes footplate were calculated from the model and measured from the temporal bones using laser Doppler vibrometers. The sound pressure in the middle ear cavity was derived from the model and measured from the bones. The results demonstrate that the TM perforations can be simulated in the FE model with geometrical visualization. The FE model provides reasonable predictions on effects of perforation size and location on middle ear transfer function. The middle ear structure-function relationship can be revealed with multi-field coupled FE analysis.
Gan, Rong Z.; Cheng, Tao; Dai, Chenkai; Yang, Fan; Wood, Mark W.
While occupational injury is associated with numerous individual and work-related risk factors, including long working hours and short sleep duration, the complex mechanisms causing such injuries are not yet fully understood. The relationship between the infrasound pressures of the tympanicmembrane [ear canal pressure (ECP)], detected using an earplug embedded with a low-frequency microphone, and the carotid artery [carotid artery pressure (CAP)], detected using a stethoscope fitted with the same microphone, can be quantitatively characterized using systems analysis. The transfer functions of 40 normal workers (19 to 57 years old) were characterized, involving the analysis of 446 data points. The ECP waveform exhibits a pulsatile character with a slow respiratory component, which is superimposed on a biphasic recording that is synchronous with the cardiac cycle. The respiratory ECP waveform correlates with the instantaneous heart rate. The results also revealed that various fatigue-related risk factors may affect the mean magnitudes of the measured pressures and the delay transfer functions between CAP and ECP in the study population; these factors include systolic blood pressure, salivary amylase activity, age, sleep duration, postural changes, chronic fatigue, and pulse rate. PMID:23363133
Quantitative studies of the mechanical properties of tympanicmembrane (TM) are needed for better understanding of its role in detailed clinical evaluation, its research being of extreme importance because it is one of the most important structures of the middle ear. By finding the membrane's vibration patterns and quantifying the induced displacement it is possible to characterize and determine its physiological status. Digital holographic interferometry (DHI) has proved to be a reliable optical non-invasive and full-field-of-view technique for the investigation of different mechanical parameters of biological tissues, i.e., DHI has demonstrated an ability to detect displacement changes in quasi-real time and without the need to contact the sample's surface under study providing relevant information, such as clinical and mechanical sample properties. In this research fresh tympanicmembrane specimens taken from post-mortem cats are subjected to acoustic stimuli in the audible frequency range producing resonant vibration patterns on the membrane, a feature that results in an ideal application for DHI. An important feature of this approach over other techniques previously used to study the tympanicmembrane vibrations is that it only requires two images and less hardware to carry out the measurements, making of DHI a simpler and faster technique as compared to other proposed approaches. The results found show a very good agreement between the present and past measurements from previous research work, showing that DHI is a technique that no doubt will help to improve the understanding of the tympanicmembrane's working mechanisms.
Hernández-Montes, María del Socorro; Mendoza Santoyo, Fernando; Pérez López, Carlos; Muñoz Solís, Silvino; Esquivel, Jesús
Opto-electronic computer holographic measurements were made of the tympanicmembrane (TM) in cadaveric chinchillas. Measurements with two laser wavelengths were used to compute the 3D-shape of the TM. Single laser wavelength measurements locked to eight distinct phases of a tonal stimulus were used to determine the magnitude and the relative phase of the surface displacements. These measurements were made at over 250,000 points on the TM surface. The measured motions contained spatial phase variations consistent with relatively low-order (large spatial frequency) modal motions and smaller magnitude higher-order (smaller spatial frequency) motions that appear to travel, but may also be explained by losses within the membrane. The measurement of shape and thin shell theory allowed us to separate the measured motions into those components orthogonal to the plane of the tympanic ring, and those components within the plane of the tympanic ring based on the 3D-shape. The predicted in-plane motion components are generally smaller than the out-of-plane perpendicular component of motion. Since the derivation of in-plane and out-of plane depended primarily on the membrane shape, the relative sizes of the predicted motion components did not vary with frequency. Summary: A new method for simultaneously measuring the shape and sound-induced motion of the tympanicmembrane is utilized to estimate the 3D motion on the membrane surface. This article is part of a special issue entitled "MEMRO 2012". PMID:23247058
It is important to determine whether a person has been strangulated and the diagnosis is not always straightforward since ligature marks are not always present. In forensic medicine the physical examination recommended is careful inspection of the head and neck region, oral cavity, examination of the eyes including the conjunctiva on both the upper and lower eyelids and photo documentation. Petechial hemorrhages of the conjunctiva are considered marker of life threatening hanging or strangulation. Hemorrhage from ears, perforated tympanicmembrane and haematotympanum are scarcely described in case reports of strangulated patients. To our knowledge we are the first to report petechial hemorrhages of the tympanicmembrane in a patient following attempted suicide by hanging. We believe that the petechial hemorrhages develop from the capillaries located in lamina propria of the epidermal layer above the fibrous layer. This assumption is made on the basis of our assessment of a normal tympanicmembrane with light microscopy. Petechial hemorrhages of the tympanicmembrane might in fact be the only sign of life threatening pressure applied to the neck. This is a very important finding and prospective studies should be conducted for further clarification on the matter. PMID:23357399
Rasmussen, Eva Rye; Larsen, Per Leganger; Andersen, Kjeld; Larsen, Michael; Qvortrup, Klaus; Hougen, Hans Petter
Tympanicmembrane (TM) temperature asymmetry has been proposed as a phenotypic marker of vulnerability to negative emotionality in children. Little is known about the stability of TM temperatures or how readily one can obtain a reliable index of the phenotype. TM temperatures were collected from 3- to 5-year-old children (N=73) over 5 months…
Examined associations between tympanicmembrane (TM) temperature asymmetries and biobehavioral attributes of 4- to 8- year-old children. Found shared patterns of associations that linked TM temperature lateralities to individual differences in behavior and socioaffective difficulties. Found that warmer left TMs were associated with affectively…
Boyce, W. Thomas; Essex, Marilyn J.; Alkon, Abbey; Smider, Nancy A.; Pickrell, Tyler; Kagan, Jerome
Multiharmonic optical microscopy has been widely applied in biomedical research due to its unique capability to perform noninvasive studies of biomaterials. In this study, virtual biopsy based on back-propagating multiple optical harmonics, combining second and third harmonics, is applied in unfixed rat tympanicmembrane. We show that third harmonic generation can provide morphologic information on the epithelial layers of rat
Wen-Jeng Lee; Chia-Fone Lee; Szu-Yu Chen; Yuh-Shyang Chen; Chi-Kuang Sun
The middle ear is too complex a system for its function to be fully understood with simple descriptive models. Realistic mathematical models must be used in which structural elements are represented by geometrically correct three-dimensional (3D) models with correct physical parameters and boundary conditions. In the past, the choice of boundary conditions could not be based on experimental evidence as no clear-cut data were available. We have, therefore, studied the deformation of the tympanicmembrane (TM) at its boundaries using X-ray microscopic computed tomography in human and gerbil while static pressure was applied to the ear canal. The 3D models of the TM and its bony attachments were carefully made and used to measure the deformation of the TM with focus on the periphery and the manubrium attachment. For the pars flaccida of the gerbil, the boundary condition can, for the most part, be described as simply supported. For the human pars flaccida, the situation is more complicated: superiorly, the membrane contacts the underlying bone more and more when pushed further inward, and it gradually detaches from the wall when sucked outward. In gerbil, the attachment of the TM to the manubrium can be described as simply supported. In human, the manubrium is attached underneath the TM via the plica mallearis and the contact of the TM with the bone is indirect. For both human and gerbil, a simple boundary condition for the peripheral edge of the pars tensa is not appropriate due to the intricate structure at the edge: the TM thickens rapidly before continuing into the annulus fibrosis which finally makes contact with the bone.
Gea, Stefan L. R.; Funnell, Robert W. J.; Dirckx, Joris J. J.; Maier, Hannes
The human tympanicmembrane (TM) transfers sound in the ear canal into the mechanical vibration of the ossicles in the middle ear. The dynamic properties of TM directly affect the middle ear transfer function. The static or quasi-static mechanical properties of TM were reported in the literature, but the dynamic properties of TM over the auditory frequency range are very limited. In this paper, a new method was developed to measure the dynamic properties of human TM using the Dynamic-Mechanical Analyzer (DMA). The test was conducted at the frequency range of 1 to 40 Hz at three different temperatures: 5°, 25° and 37°C. The frequency-temperature superposition was applied to extend the testing frequency range to a much higher level (at least 3800 Hz). The generalized linear solid model was employed to describe the constitutive relation of the TM. The storage modulus E’ and the loss modulus E” were obtained from 11 specimens. The mean storage modulus was 15.1 MPa at 1 Hz and 27.6 MPa at 3800 Hz. The mean loss modulus was 0.28 MPa at 1 Hz and 4.1 MPa at 3800 Hz. The results show that the frequency-temperature superposition is a feasible approach to study the dynamic properties of the ear soft tissues. The dynamic properties of human TM obtained in this study provide a better description of the damping behavior of ear tissues. The properties can be transferred into the finite element (FE) model of the human ear to replace the Rayleigh type damping. The data reported here contribute to the biomechanics of the middle ear and improve the accuracy of the FE model for the human ear.
The purpose of the present work is to investigate the spatial vibration pattern of the gerbil tympanicmembrane (TM) as a function of frequency. In vivo vibration measurements were done at several locations on the pars flaccida and pars tensa, and along the manubrium, on surgically exposed gerbil TMs with closed middle ear cavities. A laser Doppler vibrometer was used to measure motions in response to audio frequency sine sweeps in the ear canal. Data are presented for two different pars flaccida conditions: naturally flat and retracted into the middle ear cavity. Resonance of the flat pars flaccida causes a minimum and a shallow maximum in the displacement magnitude of the manubrium and pars tensa at low frequencies. Compared with a flat pars flaccida, a retracted pars flaccida has much lower displacement magnitudes at low frequencies and does not affect the responses of the other points. All manubrial and pars tensa points show a broad resonance in the range of 1.6 to 2 kHz. Above this resonance, the displacement magnitudes of manubrial points, including the umbo, roll off with substantial irregularities. The manubrial points show an increasing displacement magnitude from the lateral process toward the umbo. Above 5 kHz, phase differences between points along the manubrium start to become more evident, which may indicate flexing of the tip of the manubrium or a change in the vibration mode of the malleus. At low frequencies, points on the posterior side of the pars tensa tend to show larger displacements than those on the anterior side. The simple low-frequency vibration pattern of the pars tensa becomes more complex at higher frequencies, with the breakup occurring at between 1.8 and 2.8 kHz. These observations will be important for the development and validation of middle ear finite-element models for the gerbil. PMID:23624883
Maftoon, Nima; Funnell, W Robert J; Daniel, Sam J; Decraemer, Willem F
Patient with a round and soft lesion completely covered with skin without modification in color fulfilling approximately 90% of external ear canal diameter. Patient’s complain was dullness sensations on affected ear. CT scan demonstrated lack of tympanicmembrane commitment and pathological findings were compatible with hemangioma. Conclusion: It is important to define whether there is hemangioma's involvement of tympanicmembrane,
José Faibes Lubianca Neto; Mauricio Schreiner Miura; Catia Saleh; Marina de Andrade; Melina Assmann
We demonstrate the possibility of using a quantum-confined semiconductor structure laser operating in the autodyne regime for the investigation of the amplitude-frequency characteristics of the tympanicmembrane (TM). Using such a laser, it is established that an increase in the acoustic pressure leads to the appearance of subharmonics in the spectrum of TM oscillations at frequencies equal to one-half and one-quarter of the exciting signal frequency, which is evidence for period-doubling bufurcations.
Usanov, D. A.; Mareev, O. V.; Skripal', A. V.; Mareev, G. O.; Kamyshanski?, A. S.
The purpose of this prospective clinical trial was to evaluate the success rate of our newly developed surgical technique for fat graft myringoplasty (FGM). We also aimed to assess the correlations between the size of perforations and closure rates, as well as the results of re-gained hearing in successful cases with respect to sizes of perforations. Thirty consecutive patients with persistent tympanicmembrane perforation were included in this study. All patients underwent fat graft myringoplasty with a newly developed technique. Treatment success was defined as an intact tympanicmembrane (TM) at the 3-month follow-up visit. Bone conduction (BC) and air conduction (AC) thresholds at the frequencies of 0.5, 1, 2, 3, and 4 kHz were recorded preoperatively and at the 3rd month postoperatively. The range of perforation sizes among the 30 patients was 7 mm in 13 of the patients (43 %), 6 mm in 8 of the patients (27 %), and 5 mm in nine of the patients (30 %). Closure of tympanicmembrane perforations with this new technique was achieved in 27 out of the 30 patients, with a success rate of 90 %. The average of the air-bone gap (dB) was similar in preoperative and postoperative periods for 5- and 6-mm sized perforation groups (p = 0.09 and p = 0.49). However, in the 7-mm sized perforation group, the average of the air-bone gap (dB) was higher in the preoperative period than the postoperative period (p = 0.004). The average of the air-bone gap (dB) for all patients was higher in the preoperative period than the postoperative period (p = 0.001). In conclusion, FGM performed with this technique may be used as an alternative for the closure of tympanicmembrane perforations larger than 5 mm. PMID:22983221
Opto-electronic computer holographic measurements were made of the tympanicmembrane (TM) in cadaveric chinchillas. Measurements with two laser wavelengths were used to compute the 3D-shape of the TM. Single laser wavelength measurements locked to eight distinct phases of a tonal stimulus were used to determine the magnitude and the relative phase of the surface displacements. These measurements were made at over 250,000 points on the TM surface. The measured motions contained spatial phase variations consistent with relatively low-order (large spatial frequency) modal motions and smaller magnitude higher-order (smaller spatial frequency) motions that appear to travel, but may also be explained by losses within the membrane. The measurement of shape and thin shell theory allowed us to separate the measured motions into those components orthogonal to the plane of the tympanic ring, and those components within the plane of the tympanic ring based on the 3D-shape. The predicted in-plane motion components are generally smaller than the out-of-plane perpendicular component of motion. Since the derivation of in-plane and out-of plane depended primarily on the membrane shape, the relative sizes of the predicted motion components did not vary with frequency.
Quantitative analyses of the tympanicmembrane mechanical properties are needed for better understanding of its role in detailed clinical evaluation. Optical methods like Digital Holographic Interferometry (DHI), time averaged holography and ESPI are quite promising for the investigation of biological tissues. Their demonstrated ability to detect displacement changes in quasi and real time and without contacting the sample surface under study provides relevant features, such as clinical and mechanical properties. In this research time averaged vibrations patterns are shown for fresh tympanicmembrane specimens taken from post-mortem cats, and subject to acoustic stimuli in the frequency range of 485 Hz up to 10 kHz. The results may provide information about sample mechanical characteristics such as its elasticity coefficient. An important feature of this approach over other techniques previously used to study the vibrations of the tympanicmembrane is that it only requires an image and less equipment to carry out the measurements. Good agreement was found between the present and past measurements from previous research work. Results show the usefulness of the method in the medical field in providing relevant data about key mechanical characteristics of biological samples.
Del Socorro Hernández-Montes, Maria; Muñoz Solís, Silvino; Mendoza Santoyo, Fernando
A new anatomically-accurate Finite Element (FE) model of the tympanicmembrane (TM) and malleus was combined with measurements of the sound-induced motion of the TM surface and the bony manubrium, in an isolated TM-malleus preparation. Using the results, we were able to address two issues related to how sound is coupled to the ossicular chain: (i) Estimate the viscous damping within the tympanicmembrane itself, the presence of which may help smooth the broadband response of a potentially highly resonant TM, and (ii) Investigate the function of a peculiar feature of human middle-ear anatomy, the thin mucosal epithelial fold that couples the mid part of the human manubrium to the TM. Sound induced motions of the surface of ex vivo human eardrums and mallei were measured with stroboscopic holography, which yields maps of the amplitude and phase of the displacement of the entire membrane surface at selected frequencies. The results of these measurements were similar, but not identical to measurements made in intact ears. The holography measurements were complemented by laser-Doppler vibrometer measurements of sound-induced umbo velocity, which were made with fine-frequency resolution. Comparisons of these measurements to predictions from a new anatomically accurate FE model with varied membrane characteristics suggest the TM contains viscous elements, which provide relatively low damping, and that the epithelial fold that connects the central section of the human manubrium to the TM only loosely couples the TM to the manubrium. The laser-Doppler measurements in two preparations also suggested the presence of significant variation in the complex modulus of the TM between specimens. Some animations illustrating the model results are available at our website (www.uantwerp.be/en/rg/bimef/downloads/tympanic-membrane-motion). PMID:24657621
De Greef, Daniel; Aernouts, Jef; Aerts, Johan; Cheng, Jeffrey Tao; Horwitz, Rachelle; Rosowski, John J; Dirckx, Joris J J
Computer-assisted time average holographic interferometry was used to study the vibration of the human tympanicmembrane (TM) in cadaveric temporal bones before and after alterations of the ossicular chain. Simultaneous laser Doppler vibrometer measurements of stapes velocity were performed to estimate the conductive hearing loss caused by ossicular alterations. The quantified TM motion described from holographic images was correlated with stapes velocity to define relations between TM motion and stapes velocity in various ossicular disorders. The results suggest that motions of the TM are relatively uncoupled from stapes motion at frequencies above 1000 Hz.
Cheng, Jeffrey T.; Ravicz, Michael E.; Rosowski, John J.; Hulli, Nesim; Hernandez-Montes, Maria S.; Furlong, Cosme
The tympanicmembrane is a key component of the human auditory apparatus. Good estimates of tympanicmembrane mechanical properties are important to obtain realistic models of middle ear mechanics. Current literature values are almost all derived from direct mechanical tests on cut-out strips. For a biomedical specimen like the tympanicmembrane, it is not always possible to harvest strips of uniform and manageable geometry and well-defined size suitable for such mechanical tests. In this work, elastic and viscoelastic properties of human tympanicmembrane were determined through indentation testing on the tympanicmembrane in situ. Indentation experiments were performed on three specimens with a custom-built apparatus that was also used in previously published works. Two types of indentation tests were performed on each specimen: (i) sinusoidal indentation at 0.2 Hz yielding the quasi-static Young's modulus and (ii) step indentation tests yielding viscoelastic properties in the quasi-static regime (0-20 Hz). In the cyclic indentation experiments (type i), the indentation depth and resulting needle force were recorded. The unloaded shape of the tympanicmembrane and the membrane thickness were measured and used to create a specimen-specific finite element model of the experiment. The Young's modulus was then found through optimization of the error between model and experimental data; the values that were found for the three different samples are 2.1 MPa, 4.4 MPa and 2.3 MPa. A sensitivity analysis showed that these values are very sensitive to the thickness used in the models. In the step indentation tests (type ii), force relaxation was measured during 120 s and the relaxation curves were fitted with a 5 parameter Maxwell viscoelastic model. The relaxation curves in the time domain were transformed to complex moduli in the frequency domain, yielding viscoelastic properties in the quasi-static regime only. PMID:22583920
Aernouts, Jef; Aerts, Johan R M; Dirckx, Joris J J
Investigations of the tympanicmembrane (TM) can have an important impact on understanding the sound conduction in the ear and can therefore support the diagnosis and treatment of diseases in the middle ear. High-speed Doppler optical coherence tomography (OCT) has the potential to describe the oscillatory behaviour of the TM surface in a phase-sensitive manner and additionally allows acquiring a three-dimensional image of the underlying structure. With repeated sound stimuli from 0.4 kHz to 6.4 kHz, the whole TM can be set in vibration and the spatially resolved frequency response functions (FRFs) of the tympanicmembrane can be recorded. Typical points, such as the umbo or the manubrium of malleus, can be studied separately as well as the TM surface with all stationary and wave-like vibrations. Thus, the OCT methodology can be a promising technique to distinguish between normal and pathological TMs and support the differentiation between ossicular and membrane diseases. PMID:23225692
Burkhardt, Anke; Kirsten, Lars; Bornitz, Matthias; Zahnert, Thomas; Koch, Edmund
Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, laser vibrometry requires free visual access to the object under investigation, and acquiring free visual access to the ossicles through the ear canal requires the removal of the tympanicmembrane (TM), with the result that the ossicles can no longer be stimulated acoustically. To overcome this, we devised a new setup in which the ossicles can be driven magnetically. After measuring the response of the TM to an acoustic signal, we then remove it and attach a small magnet to the exposed manubrium (a part of the most lateral auditory ossicle, the malleus, which is normally attached to the TM). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a setup may have uses in research on middle ear mechanics, such as the measurement of nonlinearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis or in chronic otitis media. We describe our setup and discuss the viability of our method and its future clinical potential by presenting some measurements on an artificially fixated ear.
Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, laser vibrometry requires free visual access to the object under investigation, and acquiring free visual access to the ossicles through the ear canal requires the removal of the tympanicmembrane (TM), with the result that the ossicles can no longer be stimulated acoustically. To overcome this, we devised a new setup in which the ossicles can be driven magnetically. After measuring the response of the TM to an acoustic signal, we then remove it and attach a small magnet to the exposed manubrium (a part of the most lateral auditory ossicle, the malleus, which is normally attached to the TM). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a setup may have uses in research on middle ear mechanics, such as the measurement of nonlinearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis or in chronic otitis media. We describe our setup and discuss the viability of our method and its future clinical potential by presenting some measurements on an artificially fixated ear. PMID:24387412
A digital holographic interferometry (DHI) system with three object-illumination beams is used for the first time to measure micro-deformations along the x, y and z axes (3D) on the tympanicmembrane (TM) surface of a post-mortem cat. In order to completely and accurately measure the TM surface displacements its shape is required to map on it the x, y and z micro-deformations. The surface contour is obtained by applying small shifts to the object illumination source position. A cw laser in stroboscopic mode and a CCD camera were used and synchronized to the acoustic excitation wave that produces a resonant vibration mode on the tympanicmembrane surface. This research work reports on the 3D full field of view response of the TM to sound pressure, and has as its main goal the presentation of DHI as an alternative technique to study the TM real displacement behavior when subjected to sound waves, so it can be used as a diagnostic tool to prevent and treat TM diseases. PMID:22418368
Solís, S Muñoz; Santoyo, F Mendoza; Hernández-Montes, M del Socorro
Tympanicmembrane perforations (TMP) are relatively common but are typically not treated in their acute stage, as most will heal spontaneously in 7–10 days. Those cases which fail to heal within 3 months are called chronic TMP which attract surgical intervention (e.g. myringoplasty), typically with a temporalis fascia autograft. New materials for the repair of chronic TMP are being developed to address deficiencies in the performance of autografts by undergoing evaluation in animal models prior to clinical study. However, there is currently a lack of ideal chronic TMP animal models available, hindering the development of new treatments. Various techniques and animal species have been investigated for the creation of chronic TMP with varied success. In the present commentary, we bring to the attention of readers the recent report by Shen et al. in Journal of Translational Medicine. The study reported the creation of a chronic TMP animal model in plasminogen gene deficient mice. However, the short observation time (9, 19 days), lack of success rate and the scarcity of solid evidence (e.g. otoscopic & histologic images) to confirm the chronicity of TMP warrant a more thorough discussion.
Tympanicmembrane perforations (TMP) are relatively common but are typically not treated in their acute stage, as most will heal spontaneously in 7-10 days. Those cases which fail to heal within 3 months are called chronic TMP which attract surgical intervention (e.g. myringoplasty), typically with a temporalis fascia autograft. New materials for the repair of chronic TMP are being developed to address deficiencies in the performance of autografts by undergoing evaluation in animal models prior to clinical study. However, there is currently a lack of ideal chronic TMP animal models available, hindering the development of new treatments. Various techniques and animal species have been investigated for the creation of chronic TMP with varied success. In the present commentary, we bring to the attention of readers the recent report by Shen et al. in Journal of Translational Medicine. The study reported the creation of a chronic TMP animal model in plasminogen gene deficient mice. However, the short observation time (9, 19 days), lack of success rate and the scarcity of solid evidence (e.g. otoscopic & histologic images) to confirm the chronicity of TMP warrant a more thorough discussion. PMID:24669846
Wang, Allen Y; Shen, Yi; Wang, Jeffrey T; Eikelboom, Robert H; Dilley, Rodney J
Sound-induced displacement of the tympanicmembrane (TM) is the first stage in the forward transformation of environmental sound to sound within the inner ear, while displacement of the TM induced by mechanical motions of the ossicular chain is the last stage in the reverse transformation of sound generated within the inner ear to clinically valuable otoacoustic emissions (OAEs). In this study, we use stroboscopic holographic interferometry to study motions of the human cadaveric TM evoked by both forward and reverse stimuli. During forward acoustic stimulation, pure tones from 500 to 10000 Hz are used to stimulate the TM, while reverse stimulation is produced by direct mechanical stimulation of the ossicular chain. The TM surface motions in response to both forward and reverse stimuli show differences and similarities, including the modal motion patterns at specific frequencies as well as the presence and directions of traveling waves on the TM surface.
Cheng, Jeffrey Tao; Harrington, Ellery; Horwitz, Rachelle; Furlong, Cosme; Rosowski, John J.
In this study, the tympanicmembrane (TM) of the guinea pig was exposed to a blast wave generated by micro-explosion of 10mg silver azide, and the time history of TM rupture was recorded using a high-speed video camera. The relationship between the process of TM rupture and the peak pressure of the blast wave was then examined. The critical value which caused the TM rupture was found to be 192dB SPL (79.6kPa), and when this level of pressure was applied to the TM, tears were immediately caused in the radial direction, although they did not subsequently expand. When pressures above 195dB SPL (112kPa) were applied to the TM, it suffered a perforation, and this perforation continued to expand for several milliseconds, even after disappearance of the pressure change caused by the blast wave.
The objective was to compare the outcomes of spontaneous closure and hyaluronic acid (HA) ester patching (Epifilm®) in subjects with traumatic tympanicmembrane (TM) perforation. This was a prospective, controlled study performed at a tertiary teaching and research hospital. During 6-month period, subjects were divided into spontaneous closure (group A) and HA ester patch-Epifilm® (group B) group. Demographic data, presenting symptoms, closure rate, closure time and audiometric data were evaluated and compared between groups. In total, 155 subjects were evaluated. Group A consisted of 62.6 % (n = 97) of the subjects, whereas group B consisted of 37.4 % (n = 58) of the subjects. Group B had significantly shorter closure times when compared with group A (6.61 ± 4.59 vs. 10.60 ± 5.23 weeks, p = 0.001). When the closure time was evaluated according to perforation size both grade 1 and 2 perforations have significantly shorter closure times when compared with group A (6.33 ± 4.54 vs. 10.80 ± 5.69 weeks, for grade 1 and 6.650 ± 2.07 vs. 10.30 ± 4.32 weeks for grade 2 perforations). Closure rates were not significant between groups (85.6 % for group A and 94.8 % for group B). When the closure rate was evaluated according to perforation size no significant difference exists for grade 1, 2 and 3 perforations between groups. Both air conduction and air-bone gap were significantly improved in both groups. HA ester patch (Epifilm®) is a non-toxic material that can be used in traumatic tympanicmembrane perforations. In this study, use of HA ester patching was resulted with earlier closure time but not resulted with higher closure rates. PMID:23292038
Study objective: To delineate the features of superior canal dehiscence syndrome (SCDS) based on four cases and a literature review. Patients and methods: Four cases of SCDS were iden- tified by computed tomography (CT) of the petrous bone in patients with mixed hearing loss and a normal tympanicmembrane. Results: Dehiscence of the superior semicircular canal was bilateral in 2
Sophie Jacquot-Laperrière; Pierre Bertholon; Sandrine Chardon; Jean-Michel Prades; Christian Martin
Recently, we introduced a Digital Optoelectronic Holographic System (DOEHS) for measurement of acoustically induced deformations of the human tympanicmembrane (TM) in order to study and diagnose pathologic conditions of the middle-ear. The DOEHS consists of laser-delivery illumination (IS), optical head (OH), image-processing computer (IP), and positioning arm (PS) subsystems. Holographic information is recorded by a CCD and numerically reconstructed by Fresnel approximation. Our holographic otoscope system is currently deployed in a clinic and is packaged in a custom design. Since digital holography is a high sensitivity measurement technique and the interfering light waves travel along different paths, it makes measurements acquired by DOEHS susceptible to external vibrations. In order to avoid this susceptibility, we are testing a shearography setup as OH. Shearography presents same advantages as holographic interferometry, but it is less susceptible to vibration and external noise, which is a characteristic needed for the use of our techniques in a clinical environment. In this paper we present work in progress in our development of a shearography technique based on a Mach-Zehnder configuration as OH and demonstrate its application by quantifying vibrations modes in thin membranes, including human TM. Results are compared with those obtained with DOEHS.
Flores-Moreno, J. M.; Furlong, Cosme; Cheng, Jeffrey T.; Rosowski, John J.; Merchant, S. N.
There are not many studies on the effect of the site and size of the perforation on the hearing loss. This study is set to investigate the relationship between the size and site of perforation and hearing loss. This study was carried out between September 2011 to September 2013, at a tertiary care centre during which 100 cases of chronic otitis media tubotympanic type having central perforation were selected. All patients underwent, tympanoplasty using temporalis fascia/cartilage graft, underlay technique with or without simple mastoidectomy/modified radical mastoidectomy and followed up for 3 months and evaluated for graft uptake and hearing improvement with respect to size and site of TM perforation. To measure the size of perforation intra-operatively, thin transparency sheet was used, on which a graph paper of 1 × 1 mm(2) size was printed. Significant relationship was observed between size and site of tympanicmembrane perforation with hearing loss. Perforations which were involving all four quadrants (AS + AI + PS + PI) are having maximum residual perforations after the surgery. In relation with size, subtotal perforation were having more residual perforations postoperatively, followed by medium sized perforations. An inherent relationship noted between ossicular involvement and hearing loss, maximum average hearing loss was observed in those cases, where all three ossicles (malleus, incus & stapes) were involved, also more hearing loss was noted in posterior perforations. PMID:25032126
Tympanicmembrane (TM) perforation is still one of the most common otology complications. New designs of biomaterials, and lately tissue-engineered composites and grafts, have thoroughly revolutionized the management of TM perforation. In this study, we examined a biologically modified collagen-immobilized polydimethyl siloxane patch to repair TM perforation. In vitro potential of the aforementioned patch as a scaffold to support fibroblast cell growth and adhesion was assessed. An in vivo assay of the patch for initiating repair of TM perforations also was investigated. In vitro assay showed that the patch has significantly increased cell adhesion and growth in comparison with unmodified ones (p < 0.05). In vivo study also showed an overall closure rate of TM perforation of 70% and an average gain of 15.75 ± 4.29 dB in air-bone gap. This study shows that the preliminary in vivo evaluation of a modified siloxane patch in humans had promising results and is comparable to existing biomaterial patches. PMID:22162221
Greater understanding of tympanicmembrane (TM) biomechanics has the potential to guide future advances in medical technology related to its surgical repair (myringoplasty). The pars tensa of the TM is a composite structure with two collagen fiber layers that provide the main scaffolding for the TM. The external layer is arranged in an approximately radial configuration, and the other is arranged in an approximately circumferential configuration. A more detailed knowledge of collagen fiber orientation and volume fraction could greatly improve existing mechanical simulations of the TM. To address this, we employed multiphoton microscopy (MPM) imaging of the TM in two modalities: second harmonic generation (SHG) and two-photon fluorescence (TPF). The unique spectral signature of SHG allows selective imaging of collagen fibers. TPF also produces images of fibrillar-type collagen but lacks the specificity of SHG. Both the SHG and TPF images show patterns of collagen organization in the TM that match expected results with respect to both orientation and size. Through MPM, we intend to accurately determine the collagen fiber layer thickness, density, and orientation as a function of radial position and quadrant location.
Jackson, R. P.; Chlebicki, C.; Krasieva, T. B.; Puria, S.
Current methodologies for characterizing tympanicmembrane (TM) motion are usually limited to either average acoustic estimates (admittance or reflectance) or single-point mobility measurements, neither of which suffices to characterize the detailed mechanical response of the TM to sound. Furthermore, while acoustic and single-point measurements may aid in diagnosing some middle-ear disorders, they are not always useful. Measurements of the motion of the entire TM surface can provide more information than these other techniques and may be superior for diagnosing pathology. We present advances in our development of a new compact optoelectronic holographic otoscope (OEHO) system for full field-of-view characterization of nanometer-scale sound-induced displacements of the TM surface at video rates. The OEHO system consists of a fiber optic subsystem, a compact otoscope head, and a high-speed image processing computer with advanced software for recording and processing holographic images coupled to a computer-controlled sound-stimulation and recording system. A prototype OEHO system is in use in a medical research environment to address basic science questions regarding TM function. The prototype provides real-time observation of sound-induced TM displacement patterns over a broad frequency range. Representative time-averaged and stroboscopic holographic interferometry results in animals and human cadaver samples are shown, and their potential utility is discussed.
Del Socorro Hernández-Montes, Maria; Furlong, Cosme; Rosowski, John J.; Hulli, Nesim; Harrington, Ellery; Cheng, Jeffrey Tao; Ravicz, Michael E.; Santoyo, Fernando Mendoza
Most of the current optical non-invasive methodologies used to characterize the tympanicmembrane (TM) motion generate data in the z direction only, i.e., employ an out-of-plane sensitive configuration. In this paper, 3-D digital holographic interferometry (3-D DHI), is used to measure micrometer displacements from the TM surface. The proposed optical configuration provides information from three sensitivity vectors that separate the contributions from x, y and z displacement components. In order to achieve high accuracy of the sensitivity vector and to obtain the complete determination of the 3-D TM displacements, its surface contour is obtained by moving only two object illumination sources chosen from any pair within the DHI optical setup. Results are presented from measurements corresponding to individual displacements maps for the three orthogonal displacements components x, y and z combined with the TM shape from an ex-vivo cat. These results will no doubt contribute to enhance the understanding and determinate the mechanical properties of this complex tissue.
del Socorro Hernández-Montes, M.; Muñoz Solis, S.; Mendoza Santoyo, F.
The tympanicmembrane (TM), separating the external and middle ear, consists of fibrous connective tissue sandwiched between epithelial layers. To treat chronic ear infections, tympanostomy drainage tubes are placed in surgically created holes in TMs which can become chronic perforations upon extrusion. Perforations are repaired using a variety of techniques, but are limited by morbidity, unsatisfactory closure rates, or minimal regeneration of the connective tissue. A more effective, minimally-invasive therapy is necessary to enhance the perforation closure rate. Current research utilizing decellularized or alignate materials moderately enhance closure but the native TM architecture is not restored. Poly(glycerol sebacate) (PGS) is a biocompatible elastomer which supports cell migration and enzymatically degrades in contact with vascularized tissue. PGS spool-shaped plugs were manufactured using a novel process. Using minimally invasive procedures, these elastomeric plugs were inserted into chronic chinchilla TM perforations. As previously reported, effective perforation closure occurred as both flange surfaces were covered by confluent cell layers; >90% of perforations were closed at 6-week postimplantation. This unique in vivo environment has little vascularized tissue. Consequently, PGS degradation was minimal over 16-week implantation, hindering regeneration of the TM fibrous connective tissue. PGS degradation must be enhanced to promote complete TM regeneration. PMID:22821822
Sundback, C A; McFadden, J; Hart, A; Kulig, K M; Wieland, A M; Pereira, M J N; Pomerantseva, I; Hartnick, C J; Masiakos, P T
Despite recent technological advances in diagnostic methods including imaging technology, it is often difficult to establish a preoperative diagnosis of conductive hearing loss (CHL) in patients with an intact tympanicmembrane (TM). Especially, in patients with a normal temporal bone computed tomography (TBCT), preoperative diagnosis is more difficult. We investigated middle ear disorders encountered in patients with CHL involving an intact TM and normal TBCT. We also analyzed the surgical results with special reference to the pathology. We reviewed the medical records of 365 patients with intact TM, who underwent exploratory tympanotomy for CHL. Fifty nine patients (67 ears, eight bilateral surgeries) had a normal preoperative TBCT findings reported by neuro-radiologists. Demographic data, otologic history, TM findings, preoperative imaging findings, intraoperative findings, and pre- and postoperative audiologic data were obtained and analyzed. Exploration was performed most frequently in the second and fifth decades. The most common postoperative diagnosis was stapedial fixation with non-progressive hearing loss. The most commonly performed hearing-restoring procedure was stapedotomy with piston wire prosthesis insertion. Various types of hearing-restoring procedures during exploration resulted in effective hearing improvement, especially with better outcome in the ossicular chain fixation group. In patients with CHL who have intact TM and normal TBCT, we should consider an exploratory tympanotomy for exact diagnosis and hearing improvement. Information of the common operative findings from this study may help in preoperative counseling. PMID:23744181
Kim, Se-Hyung; Cho, Yang-Sun; Kim, Hye Jeong; Kim, Hyung-Jin
Doppler vibrometers are used by many research groups to monitor the motion of the tympanicmembrane (TM) and of middle ear ossicles for in vivo and in vitro studies. Power densities in these applications reach 80 W/cm(2). To determine the safe limit of exposure, a cw dye laser at a wavelength of 633 nm was used to investigate the threshold of thermal damage of TM of pigs under exposure times of 60 s. To determine the applied power density accurately, the spot size of the laser beam was monitored by an objective lens and a CCD camera. Twenty-six laser exposed samples of TM were stained by haematoxylin and eosin stain and the semi-thin sections were examined microscopically. In none of the sections was any laser induced damage observed with power densities below 7.1 kW/cm(2), whereas serious damage occurred showing coagulation, carbonisation and perforation in all cases with laser powers above 8.2 kW/cm(2). The threshold for damage and the conical shape of the damage zone is explained by photon propagation and absorption in the tissue especially by the increase of the scattering factor at higher tissue temperature. The thermal damage threshold of 8 kW/cm(2) is compared to the maximum permissible exposure given in laser safety standards for skin. PMID:10748330
Acoustically induced vibrations of the tympanicmembrane (TM) play a primary role in the hearing process, in that these motions are the initial mechanical response of the ear to airborne sound. Characterization of the shape and three-dimensional (3-D) displacement patterns of the TM is a crucial step to a better understanding of the complicated mechanics of sound reception by the ear. Sound-induced 3-D displacements of the TM are estimated from shape and one-dimensional displacements measured in cadaveric chinchillas using a lensless dual-wavelength digital holography system (DWDHS). The DWDHS consists of laser delivery, optical head, and computing platform subsystems. Shape measurements are performed in double-exposure mode with the use of two wavelengths of a tunable laser, while nanometer-scale displacements are measured along a single sensitivity direction with a constant wavelength. Taking into consideration the geometrical and dimensional constrains imposed by the anatomy of the TM, we combine principles of thin-shell theory together with displacement measurements along a single sensitivity vector and TM surface shape to extract the three principal components of displacement in the full-field-of-view. We test, validate, and identify limitations of this approach via the application of finite element method to artificial geometries.
Khaleghi, Morteza; Lu, Weina; Dobrev, Ivo; Cheng, Jeffrey Tao; Furlong, Cosme; Rosowski, John J.
Bacterial cellulose (BC)-based biomaterials on medical device platforms have gained significant interest for tissue-engineered scaffolds or engraftment materials in regenerative medicine. In particular, BC has an ultrafine and highly pure nanofibril network structure and can be used as an efficient wound-healing platform since cell migration into a wound site is strongly meditated by the structural properties of the extracellular matrix. Here, the fabrication of a nanofibrillar patch by using BC and its application as a new wound-healing platform for traumatic tympanicmembrane (TM) perforation is reported. TM perforation is a very common clinical problem worldwide and presents as conductive hearing loss and chronic perforations. The BC nanofibrillar patch can be synthesized from Gluconacetobacter xylinus; it is found that the patch contained a network of nanofibrils and is transparent. The thickness of the BC nanofibrillar patch is found to be approximately 10.33 ± 0.58 ?m, and the tensile strength and Young's modulus of the BC nanofibrillar patch are 11.85 ± 2.43 and 11.90 ± 0.48 MPa, respectively, satisfying the requirements of an ideal wound-healing platform for TM regeneration. In vitro studies involving TM cells show that TM cell proliferation and migration are stimulated under the guidance of the BC nanofibrillar patch. In vivo animal studies demonstrate that the BC nanofibrillar patch promotes the rate of TM healing as well as aids in the recovery of TM function. These data demonstrate that the BC nanofibrillar patch is a useful wound-healing platform for TM perforation. PMID:23554356
Kim, Jangho; Kim, Seung Won; Park, Subeom; Lim, Ki Taek; Seonwoo, Hoon; Kim, Yeonju; Hong, Byung Hee; Choung, Yun-Hoon; Chung, Jong Hoon
Background: To compare two methods of tympanicmembrane (TM) grafting when graft materials medial or lateral to malleus, this study have been done. Materials and Methods: In this clinical trial which was conducted in Alzahra and Kashani hospitals, between June 2010 and February 2012, 56 patients with chronic otitis media and perforated TM entered the study in two groups. The inclusion criteria consisted of patients who were at least 15-years-old without history of smoking, diabetes mellitus or autoimmune disease. Exclusion criteria of the study: No compliance for follow up, post-surgical ear trauma or any infective pathology that directly affects the ear. In Group A patients, the graft material is pierced in near central part of the graft and they lodged so that the malleus handle projects through the graft perforation. Group B had grafting in the lateral side of the malleus. Three month after surgery both groups examined and tested by audiometry. Success of surgery is defined as complete repair of TM, without lateralization, atelectasis, blunting or retraction pocket. Results: This study contained 28 patients in Group A and 28 in Group B. Overall success rate was 94.64% that was 96.42% in Group A, and 92.85% in Group B. Differences of air-bone gap in each group before and after surgery was 16.10 (±4.89) in Group A, and 15.78 (±3.40) in Group B. Improvement of hearing level was not significant between two surgical methods (P = 0.442). Conclusions: Both techniques (medial and lateral to malleus handle) of TM grafting are effective with success rates 96.42% and 92.85% respectively.
The quasi-static elastic properties of the tympanicmembrane system can be described by the areal modulus of elasticity determined by a middle ear model. The response of the tympanicmembrane 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 tympanicmembrane 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 tympanicmembrane 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), 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 tympanicmembrane system. Future model improvements include exact determination of the tympanicmembrane 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.
Many passengers experience discomfort during flight because of the effect of low humidity on the skin, eyes, throat, and nose. In this physiological study, we have investigated whether flight and low humidity also affect the tympanicmembrane. From previous studies, a decrease in admittance of the tympanicmembrane through drying might be expected to affect the buffering capacity of the middle ear and to disrupt automatic pressure regulation. This investigation involved an observational study onboard an aircraft combined with experiments in an environmental chamber, where the humidity could be controlled but could not be made to be as low as during flight. For the flight study, there was a linear relationship between the peak compensated static admittance of the tympanicmembrane and relative humidity with a constant of proportionality of 0.00315 mmho/% relative humidity. The low humidity at cruise altitude (minimum 22.7 %) was associated with a mean decrease in admittance of about 20 % compared with measures in the airport. From the chamber study, we further found that a mean decrease in relative humidity of 23.4 % led to a significant decrease in mean admittance by 0.11 mmho [F(1,8)?=?18.95, P?=?0.002], a decrease of 9.4 %. The order of magnitude for the effect of humidity was similar for the flight and environmental chamber studies. We conclude that admittance changes during flight were likely to have been caused by the low humidity in the aircraft cabin and that these changes may affect the automatic pressure regulation of the middle ear during descent. PMID:23887775
This work shows that confocal microscopy allows a quantitative study of delicate 3D-biotissue in fresh condition, thus avoiding histological preparation processes. The developed procedure results in exact and accurate thickness data for mum-sized objects with a measuring error of less than 1mum. It is, however, necessary to take into account the effect of focal shift in the case of refractive index mismatch to obtain such precise data. The use of the proposed method is advised instead of the use of a paraxial approximation for the axial scale correction because the method improves measurement precision by a factor of four. The axial scaling correction factors obtained in this work show that for most practical situations the correction cannot be ignored when one wants to obtain precise quantitative data. The thickness correction method can also be used to determine with high accuracy the index of refraction of biological tissue. The thickness measurement method was applied to fresh, untreated tympanicmembranes of the gerbil, the cat and the human. Thickness had to be measured at many points as it differs strongly across the membrane. Similar thickness distributions were found in all pars tensas measured even across the species studied: (1) a very thin, central region with a rather constant thickness, curving as a horse shoe upwards around the manubrium (thickness: gerbil: about 7mum, cat: about 10mum, human: large inter-specimen variation: 40mum-120mum), (2) a thinnest zone at the inferior side, (3) a thicker zone at the supero-anterior side, (4) superior to the umbo, an anterior region thicker than the posterior region, (5) maximal thicknesses in a very small region near the entire manubrium and the entire annular periphery. The pars flaccida is found to be thicker than the pars tensa. It shows no central homogeneous zone: the thickness varies irregularly and very rapidly over short distances. Arbitrarily spaced bumps and notches are present over the entire pars flaccida surface. The thickness results advise against the use of single thickness values in mathematical models. The presented thickness and its spatial distribution can be introduced into middle ear computer models to further improve model realism.
The tympanicmembrane model as developed by Parent and Allen [(2007). J. Acoust. Soc. Am. 122(2), 918-931] is shown to have active, lossy, and non-reciprocal properties despite being described as lossless. These properties are traced back to its scattering junction formulations. Some impedance parameters are shown to have ambiguous values which complicate interpreting the physics of the model's internal wave propagation. Certain model parameters omitted from the original paper have been derived from the original computer simulation source code used by Parent and Allen. PMID:24815233
Sound-induced motion of the surface of the human tympanicmembrane (TM) was studied by stroboscopic holographic interferometery, which measures the amplitude and phase of the displacement at each of about 40000 points on the surface of the TM. Measurements were made with tonal stimuli of 0.5, 1, 4 and 8 kHz. The magnitude and phase of the sinusoidal displacement of the TM at each driven frequency were derived from the fundamental Fourier component of the raw displacement data computed from stroboscopic holograms of the TM recorded at eight stimulus phases. The correlation between the Fourier estimates and measured motion data was generally above 0.9 over the entire TM surface. We used three data presentations: (i) Plots of the phasic displacements along a single chord across the surface of the TM, (ii) Phasic surface maps of the displacement of the entire TM surface, and (iii) Plots of the Fourier derived amplitude and phase-angle of the surface displacement along four diameter lines that define and bisect each of the four quadrants of the TM. These displays led to some common conclusions: At 0.5 and 1 kHz, the entire TM moved roughly in-phase with some small phase delay apparent between local areas of maximal displacement in the posterior half of the TM. At 4 and 8 kHz, the motion of the TM became more complicated with multiple local displacement maxima arranged in rings around the manubrium. The displacements at most of these maxima were roughly in-phase, while some moved out-of-phase. Superposed on this in- and out-of-phase behavior were significant cyclic variations in phase with location of less than 0.2 cycles or occasionally rapid half-cycle step-like changes in phase. The high frequency displacement amplitude and phase maps discovered in this study can not be explained by any single wave motion, but are consistent with a combination of low and higher order modal motions plus some small traveling-wave-like components. The observations of the dynamics of TM surface motion from this study will help us better understand the sound-receiving function of the TM and how it couples sound to the ossicular chain and inner ear.
Cheng, Jeffrey Tao; Aarnisalo, Antti A.; Harrington, Ellery; Hernandez-Montes, Maria del Socorro; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.
Two hundred and twenty two children with persistent bilateral otitis media with effusion (OME) were treated with unilateral ventilation tube insertion and no treatment to the contralateral ear. The tympanicmembrane changes in the operated and unoperated ears were compared during a 12 year follow-up. Segmental atrophy resulted from tube insertion whereas minor scarring and thickening of the pars tensa was related to the middle ear condition. Eight three percent of untreated ears and 85% of those treated with tubes did not develop atelectasis. Sixty percent of untreated ears and 64% of treated ears did not develop attic retraction. Very few cases (1.5 and 2%) in untreated and treated ears, respectively developed severe atelectasis. The overall duration of OME was assessed from the pre-operative history of hearing loss, the 3 month period of pre-operative observation and the post-operative time with effusion. There is a relationship between duration of the disease and development of both atelectasis and attic retraction. PMID:7836032
``Time-averaged holography'' and ``holographic interferometry'' enable recording of the complete vibration pattern of a surface within several seconds. The results appear in the form of fringes. Vibration amplitudes smaller than 100 nm are not readily measurable by these techniques, because such small amplitudes produce variations in gray level, but not fringes. In practice, to obtain clear fringes in these measurements, stimulus sound pressures higher than 100 dB SPL must be used. The phase of motion is also not obtainable from such fringe techniques. In this study, a sinusoidal phase modulation technique is described, which allows detection of both small amplitudes of motion and their phase from time-averaged speckle pattern interferometry. In this technique, the laser injection current is modulated and digital image processing is used to analyze the measured patterns. When the sound-pressure level of stimuli is between 70 and 85 dB SPL, this system is applied to measure the vibratory response of the tympanicmembrane (TM) of guinea pig temporal bones at frequencies up to 4 kHz where complicated vibration modes are observed. The effect of the bulla on TM displacements is also quantified. Results indicate that this system is capable of measuring the nanometer displacements of the TM, produced by stimuli of 70 dB SPL.
A procedure for imaging the canine tympanic bulla, external ear canal and adjacent structures using currently available ultrasound equipment was established. Lateral and ventral transducer positions were identified for this purpose and a 6.5 MHz curvilinear transducer was considered to be optimal. The sonographic appearance of these structures in cadavers and live dogs unaffected by ear disease is documented. Fluid
A. M. Dickie; R. Doust; L. Cromarty; V. S. Johnson; M. Sullivan; J. S. Boyd
Eustachian tube function is important in pressure regulation of the middle ear. The efficacy or magnitude of pressure equilibration by tube openings should be determined by the gradient between middle ear and ambient pressure, but in theory also the duration of the tube opening may play a role. This study employed direct measurements of middle ear pressure in patients, who after parotidectomy had a catheter inserted into the mastoid with a pressure transducer connected. Thus, monitoring of the middle ear pressure in response to experimentally induced pressure changes could be performed under physiological conditions with an intact tympanicmembrane. A set of six experiments was performed in four healthy subjects with different pressure deviations, where the counter-regulation was recorded over 10 min's time frames; a total of 75 events of tube openings were recorded. The transducer had a high accuracy of ±0.1 daPa, and data were sampled at 10 Hz, so that detailed parameters for each tube opening event could be obtained: the pressure change, the pressure gradient, and the duration of the opening were determined. The pressure changes in response to Eustachian tube openings showed significant positive correlation to the pressure gradient and ambient pressure (p < 0.001). However, the duration of the opening time was not related to the pressure gradient (p = 0.16), as well as the pressure change was also not related to the duration of the opening time (p = 0.34). This meant that the magnitude of a pressure equilibration during tube openings was only determined by the pressure gradient and not variations in the duration of the opening time. Additional correlations were investigated including the pressure change rate. In conclusion, under physiological conditions the opening of the Eustachian tube behaves similarly to a reflex mechanism with relative constant duration. Therefore, in order to equilibrate higher pressure gradients, series of Eustachian tube openings are needed, rather than the tube will open during a longer period of time. This article is part of a special issue entitled "MEMRO 2012". PMID:23347915
Evaluation of preoperative and postoperative equivalent ear canal volume measures on 334 children (ages 6 weeks to 6.7 years) with chronic otitis media with effusion found that the determination could be made very accurately for children 4 years and older. Criterion values for tympanicmembrane perforation and preoperative and postoperative…
Otoscopic examination and cytology of the equine ear would be beneficial in diseases such as head trauma, headshaking, otitis externa secondary to otitis media, vestibular disease, aural neoplasia and aural pruritus secondary to parasites. In practice, otic examinations of horses are rarely done due to the perceived difficulty in visualizing the equine external ear canal and tympanicmembrane, as well
Sandra J. Sargent; Linda A. Frank; Benjamin R. Buchanan; Robert L. Donnell; Federica Morandi
A technique for measuring in real-time continuous out-of-plane displacements of delicate objects is proposed, and demonstrated on the tympanicmembrane of Mongolian Gerbil. The technique is based on the combination of two methods: the spatial phase shifting (SPS) and the modified temporal phase unwrapping (TPU). The combination allows to obtain, in several steps, the phase values of the points that undergo out-of-plane displacement as the object is deformed. The technique reduces the frame acquisition time of the standard TPU used in moiré interferometry by a factor of 4, which is important to diminish post-mortem artifacts during in-vitro experiments and to reduce motion artifacts in in-vivo tests. The proposed technique is robust against problems associated with the temporal phase-shifting method, such as nonlinear phase shift and noise. The advantages and disadvantages are discussed.
Martínez-Celorio, R. A.; Dirckx, Joris J. J.; Buytaert, Jan A. N.; Martí-López, Luis; Decraemer, Wim
Introduction Incomplete punctal canalization is an uncommon congenital disorder characterized by a dysgenetic punctum with membranes. External membranes, the most common type of incomplete punctal canalization are flat and overlie the punctum as a veil. We describe a newer variant of incomplete punctal canalization, its clinical profile, diagnostic criteria and management. Case presentation A 9-year-old Indian boy presented with watering of his right eye since birth. His right eye lower punctal area showed an avascular translucent elevation that appeared to have a smooth dome shape. An examination at high magnification showed the slopes of the dome gradually merging and contiguous with the tarsal conjunctiva. Based on a very high degree of suspicion, an impression of atypical external membrane variety of incomplete punctal canalization was made. Membranotomy was successful in the management of his condition. Conclusions A high degree of suspicion is the key point in the diagnosis of this variant, keeping in mind the other features described for incomplete punctal canalization- external membrane. It is possible that ballooning of these membranes may represent an evolutionary stage in the process of complete canalization and this could be the starting point for further dacryo-embryologic exploration and correlations.
We have developed a drug delivery system for prolonged trans-tympanic antibiotic delivery from a single dose administration. Increased permeability to ciprofloxacin of the intact tympanicmembrane (TM) was achieved by chemical permeation enhancers (CPEs--bupivacaine, limonene, sodium dodecyl sulfate); this was also seen by CPEs contained within a hydrogel (poloxamer 407) to maintain the formulation at the TM. The CPE-hydrogel formulation had minimal effects on auditory thresholds and tissue response in vivo. CPE-hydrogel formulations have potential for ototopical delivery of ciprofloxacin for the treatment of acute otitis media (AOM) and other middle ear diseases. PMID:23146430
Khoo, Xiaojuan; Simons, Emmanuel J; Chiang, Homer H; Hickey, Julia M; Sabharwal, Vishakha; Pelton, Stephen I; Rosowski, John J; Langer, Robert; Kohane, Daniel S
Otitis media with effusion (OME) occurs when fluid collects in the middle-ear space behind the tympanicmembrane (TM). As a result of this effusion, sounds can become attenuated by as much as 30-40 dB, causing a conductive hearing loss (CHL). However, the exact mechanical cause of the hearing loss remains unclear. Possible causes can include altered compliance of the TM, inefficient movement of the ossicular chain, decreased compliance of the oval window-stapes footplate complex, or altered input to the oval and round window due to conduction of sound energy through middle-ear fluid. Here, we studied the contribution of TM motion and umbo velocity to a CHL caused by middle-ear effusion. Using the chinchilla as an animal model, umbo velocity (V U) and cochlear microphonic (CM) responses were measured simultaneously using sinusoidal tone pip stimuli (125 Hz-12 kHz) before and after filling the middle ear with different volumes (0.5-2.0 mL) of silicone oil (viscosity, 3.5 Poise). Concurrent increases in CM thresholds and decreases in umbo velocity were noted after the middle ear was filled with 1.0 mL or more of fluid. Across animals, completely filling the middle ear with fluid caused 20-40-dB increases in CM thresholds and 15-35-dB attenuations in umbo velocity. Clinic-standard 226-Hz tympanometry was insensitive to fluid-associated changes in CM thresholds until virtually the entire middle-ear cavity had been filled (approximately >1.5 mL). The changes in umbo velocity, CM thresholds, and tympanometry due to experimentally induced OME suggest CHL arises primarily as a result of impaired TM mobility and TM-coupled umbo motion plus additional mechanisms within the middle ear. PMID:23615802
Thornton, Jennifer L; Chevallier, Keely M; Koka, Kanthaiah; Gabbard, Sandra A; Tollin, Daniel J; Tollin, Daniel
Time-averaged holograms describing the sound-induced motion of the tympanicmembrane (TM) in cadaveric preparations from three mammalian species and one live ear were measured using opto-electronic holography. This technique allows rapid measurements of the magnitude of motion of the tympanicmembrane surface at frequencies as high as 25 kHz. The holograms measured in response to low and middle-frequency sound stimuli are similar to previously reported time-averaged holograms. However, at higher frequencies (f>4 kHz), our holograms reveal unique TM surface displacement patterns that consist of highly-ordered arrangements of multiple local displacement magnitude maxima, each of which is surrounded by nodal areas of low displacement magnitude. These patterns are similar to modal patterns (two-dimensional standing waves) produced by either the interaction of surface waves traveling in multiple directions or the uniform stimulation of modes of motion that are determined by the structural properties and boundary conditions of the TM. From the ratio of the displacement magnitude peaks to nodal valleys in these apparent surface waves, we estimate a Standing Wave Ratio of at least 4 that is consistent with energy reflection coefficients at the TM boundaries of at least 0.35. It is also consistent with small losses within the uniformly stimulated modal surface waves. We also estimate possible TM surface wave speeds that vary with frequency and species from 20 to 65 m/s, consistent with other estimates in the literature. The presence of standing wave or modal phenomena has previously been intuited from measurements of TM function, but is ignored in some models of tympanicmembrane function. Whether these standing waves result either from the interactions of multiple surface waves that travel along the membrane, or by uniformly excited modal displacement patterns of the entire TM surface is still to be determined. PMID:19328841
Rosowski, John J; Cheng, Jeffrey Tao; Ravicz, Michael E; Hulli, Nesim; Hernandez-Montes, Maria; Harrington, Ellery; Furlong, Cosme
Otoscopic examination and cytology of the equine ear would be beneficial in diseases such as head trauma, headshaking, otitis externa secondary to otitis media, vestibular disease, aural neoplasia and aural pruritus secondary to parasites. In practice, otic examinations of horses are rarely done due to the perceived difficulty in visualizing the equine external ear canal and tympanicmembrane, as well as the need for chemical restraint. In this study, the proximal external ear canal was examined in live horses using a handheld otoscope and in cadaver heads using video otoscopy. Visualization of the proximal ear canal of the sedated horse could be done with a handheld otoscope, but more sedation or general anaesthesia and a video otoscope would be required to adequately visualize the tympanicmembrane in the live horse. The proximal ear canals of 18 horses were examined cytologically and cultured aerobically. In three horses, both ears were sampled. No cells or organisms were seen on cytological examination of 11/21 ears. Nine of the 21 ears were sterile when cultured. Ten of the 21 ears had mixed growth with low numbers of organisms (Corynebacterium sp. being most common). Two of the 21 ears had heavy growth of a single organism (Corynebacterium sp. and Staphylococcus intermedius, respectively). Equine cadaver heads were examined in cross-section by computed tomography (CT) imaging and histopathology in order to further understand the anatomy of the equine external ear canal. Equine practitioners should be aware that otic examination is possible and may provide important diagnostic information. PMID:16674732
Sargent, Sandra J; Frank, Linda A; Buchanan, Benjamin R; Donnell, Robert L; Morandi, Federica
The use of a miniature microphone probe tube for sound-pressure level measurements in the outer earcanal was studied in four experiments. The main reason was to evaluate this method for clinical applications and for measurements of hearing protector attenuation. All measurements were registered in 1/3-oct bands. The dynamic range, frequency response of the microphone system, the insertion loss of the probe tube walls, and the influence of the probe tube in the ear canal on the sound-pressure level were examined. The first experiment attempted to determine an optimal placement of the probe tube in the earcanal. Sound-pressure levels resulting from a known free-field sound stimulus were measured at 12 different positions in the earcanal of human subjects. The results indicated that the position which is least sensitive for small movements of the probe tube on the measure was within 1 to 3 mm of the tympanicmembrane. In a second experiment the changes in sound transfer function to the tympanicmembrane caused by the microphone itself, when positioned just outside the ear canal entrance, were studied for 72 angles of sound incidences in ten subjects. A few minor but significant changes were observed with the microphone in this position. In a third experiment, sound transfer functions were measured from free sound field to the tympanicmembrane in 19 subjects. The measurements were performed in 1/3-oct frequency bands (0.2 to 20 kHz) with sound incidences from 24 azimuthal positions and for each of these, three different elevations. The inter- and intrasubject-variability are analyzed and discussed. Finally, the reliability of probe tube microphone measurements was evaluated by repeated measurements of the sound transfer function, five times in ten subjects with the sound incidence from one position. The results indicated very small variations between repeated measurements. PMID:8445126
This paper presents the analysis and discussion about different effects of the external auditory canal (EAC) geometry on the response of the human hearing system. Simulation has been made by means of 3D finite element models which included EAC and a model of the ossicular-eardrum system. Different EAC geometries were constructed, coupled to a middle ear model validated in previous works. The EAC geometry is based on anatomical measurements taken from the literature. The relative position and orientation of the tympanicmembrane and section reduction of the canal at the isthmus were studied and analyzed with a harmonic analysis. A sound pressure level of 90 dB was applied at the canal entrance and through fluid-structure coupling, the pressures in the umbo and the displacements of umbo and stapes footplate were measured in a frequency range from 100 Hz to 20000 Hz.
Caminos, Luis; Garcia-Gonzalez, Antonio; Gonzalez-Herrera, Antonio
Patients who present at hearing clinics with a conductive hearing loss (CHL) in the presence of an intact, healthy tympanicmembrane create a unique challenge for otologists. While patient counseling, treatment options, and outcome vary with differing middle-ear pathologies, a non-invasive diagnostic that can differentiate between these pathologies does not currently exist. We evaluated the clinical utility and diagnostic accuracy of two non-invasive measures of middle-ear mechanics: ear-canal reflectance (ECR) and umbo velocity (VU).
Merchant, Gabrielle R.; Nakajima, Hideko H.; Pisano, Dominic V.; Röösli, Christof; Hamade, Mohamad A.; Mafoud, Lorice; Halpin, Christopher F.; Merchant, Saumil N.; Rosowski, John J.
The objective of the present work was to study specific features of the eustachian tube after the insertion of the shunt into the tympanicmembrane and to measure the pressure necessary to ensure passive opening of the tube in the patients presenting with exudative otitis medium (EOM). The study included 87 patients with this pathology who underwent shunting of the tympanic cavity following a course of conservative treatment. Threshold audimetry and acoustic impedancemetry were performed in all the patients to estimate the patency of the eustachian tube with the perforated tympanicmembrane. It is concluded that the shunting of the tympanic cavity resulted in markedly disturbed dynamic function of the Eustachian tube in the majority of the patients (59%) regardless of the severity of hearing impairment. PMID:23715483
Tympanate hearing has evolved in at least 6 different orders of insects, but had not been reported until recently in the Diptera. This study presents a newly discovered tympanal hearing organ, in the parasitoid tachinid fly, Ormia ochracea. The hearing organ is described in terms of external and internal morphology, cellular organization of the sensory organ and preliminary neuroanatomy of the primary auditory afferents. The ear is located on the frontal face of the prothorax, directly behind the head capsule. Conspicuously visible are a pair of thin cuticular membranes specialized for audition, the prosternal tympanalmembranes. Directly attached to these membranes, within the enlarged prosternal chamber, are a pair of auditory sensory organs, the bulbae acusticae. These sensory organs are unique among all auditory organs known so far because both are contained within an unpartitioned acoustic chamber. The prosternal chamber is connected to the outside by a pair of tracheae. The cellular anatomy of the fly's scolopophorous organ was investigated by light and electron microscopy. The bulba acustica is a typical chordotonal organ and it contains approximately 70 receptor cells. It is similar to other insect sensory organs associated with tympanal ears. The similarity of the cellular organization and tympanal morphology of the ormiine ear to the ears of other tympanate insects suggests that there are potent constraints in the design features of tympanal hearing organs, which must function to detect high frequency auditory signals over long distances. Each sensory organ is innervated by a branch of the frontal nerve of the fused thoracic ganglia. The primary auditory afferents project to each of the pro-, meso-, and metathoracic neuropils. The fly's hearing organ is sexually dimorphic, whereby the tympanalmembranes are larger in females and the spiracles larger in males. The dimorphism presumably reflects differences in the acoustic behavior in the two sexes. PMID:8118848
Vibrations of the tympanicmembrane (TM) play a key role for the transmission of sound to the inner ear. Today, there exist still problems in measuring the movement of the TM and there are unresolved issues in understanding the TM and its behavior. A non-invasive and contact-free in vivo investigation of the structure and the functional behavior of the TM would be a big step forward. In the presented study, the suitability of optical coherence tomography (OCT) for measuring the oscillation patterns of the TM in the frequency range covering the range of the human speech perception should be tested. For functional imaging a sound chirp was generated in the frequency range between 0.4 kHz - 6.4 kHz. To obtain the movement within a sufficient resolution, a grid of 25 x 25 measurement points was generated over the whole TM. The information of the oscillatory movement was encoded in the Doppler signal, provided by M-scans at several points of the TM. The frequency response functions of each frequency showed different oscillation patterns on the TM. The acquisition time of one single M-scan was only 8.5 ms and of the entire TM 5.3 s, emphasizing the potential of the method for future in vivo applications. Furthermore, the morphology was acquired with the same OCT-system, showing the feasibility for structural imaging and differentiation between typical regions of the TM. Thus, OCT was shown as a suitable method for the simultaneous measurement of the functional and structural behavior of the TM.
Burkhardt, Anke; Kirsten, Lars; Bornitz, Matthias; Zahnert, Thomas; Koch, Edmund
Summary The anatomy of the facial nerve canal in the adult and the prenatal development of this canal are well described in the literature. It is divided into three segments (the labyrinthine segment, the tympanic segment and the mastoid segment). However, little is known of the facial canal anatomy in the newborn and almost nothing in the child. Postnatal changes
The influence of thermal pressure fluctuations on the tympanicmembrane has been re-examined as a possible contributing determinant of the threshold of human hearing over the range of audible frequencies. The early approximate calculation of Sivian and White  is shown to result in higher values of thermal noise pressure on the tympanium of a model meatus than the result obtained by directly calculating the noise pressure from thermally excited resonant ear canal modes. [4pt]  L.J. Sivian and S.D. White, ``Minimum audible sound fields,'' J. Acoust. Soc. Am. 4, 288-321 (1933).
The records of 60 dogs that had a resection of the lateral wall of the vertical ear canal (Zepp) were examined. The surgical outcomes were evaluated in association with the following variables: breed, sex, age of onset of the otitis externa, duration of the disease before the surgery was performed, treatment received for the otitis externa, the status of the ear and tympanicmembrane at the time of the surgery, the culture results, and concurrent medical problems. The outcome of surgery was acceptable in 45% and unacceptable in 55% of the cases. Breed was the only factor that could be correlated with the outcome. The procedure failed in 86.5% of the cocker spaniels. When surgical outcomes in breeds other than cocker spaniels were evaluated, 63% were acceptable and 37% were unacceptable. Sharpeis were found to have an ear canal of small diameter compared with that of other breeds and a tendency to have better outcomes.
An ultrasonographic approach for the tympanic bulla in calves is described. Ultrasound evaluation was performed through a lateral approach on 7 fetuses, 2 newborn calves, and 4 living calves of various ages. The probe was positioned caudal to the vertical mandibular ramus, ventral to the base of the ear. Three different positions of the probe were used. The tympanic bulla and adjacent structures were successfully identified and their ultrasonographic appearance described. Fluid within the tympanic bulla was visualized in 12 bullae in the cadavers and in 6 bullae in live calves. Ultrasound imaging has been shown to be useful but its diagnostic value remains to be studied in clinical cases of otitis media in calves.
Gosselin, Veronique Bernier; Babkine, Marie; Nichols, Sylvain; Desrochers, Andre
Piezosurgery is a recently developed system for cutting bone with microvibrations. The objectives of the present study were to report our experience with the piezoelectric device in the intact canal mastoidectomy, and to compare the results with traditional method by means of microdrill. A non-randomized controlled trial was undertaken on 60 intact canal wall mastoidectomy performed using the piezoelectric device (30 patients) or the microdrill (30 patients). Before 1 month and 1 year after surgery, all the patients underwent the following instrumental examinations: otomicroscopic evaluation of the tympanicmembrane and external auditory duct, bone conduction threshold audiometry, tympanometry, transient-evoked otoacoustic emissions with linear click emission, distortion product otoacoustic emissions, auditory brainstem response (ABR) by MK 12-ABR screener with natus-ALGO2e (Amplifon, Milan, Italy), and electronystamographic recording. The piezoelectric device is proved to be effective in sclerotic and pneumatic mastoid, with an excellent control and without side effects on the adjacent structures of the middle and inner ear (lateral sinus, facial nerve, and/or dura mater). The operation time has been the same as compared with microdrill, and the average hospital stay was significantly (p < 0.05) shorter. Postoperatively, all patients had uneventful recovery with no evidence of audiovestibular deficit or side effects. Our experience highlights the safety of the piezoelectric device on the anatomic structures of the middle and inner ear, and demonstrates its efficiency in terms of cutting precision and healing process. PMID:20577753
Measurement of rectal (T sub re), auditory canal (T sub ac), positioned 8 to 10 mm from the tympanicmembrane, and mean skin temperature (mean T sub sk) in five men during various exercise regimens at an ambient temperature (T sub a) of 25 C (phase one) and in two men during rest and exercise at 5, 15, 25, and 35 C T sub a (phase two). The purpose was to determine if T sub ac can be used as an accurate estimate of core temperature. Previous observations that T sub ac was highly correlated with T sub re but T sub ac was consistently lower than T sub re are confirmed; the mean difference varied from 0.4 C at rest to 1.1 C at the end of exercise. It is concluded that auditory canal temperature cannot be utilized as an estimate of core temperature, but T sub ac may be used to estimate mean body temperature where very accurate measurements are not required.
Objective. The bacterial examination has been performed during the course of the root canal treatment. In the present pilot study, the new developed method, using fluorescence reagents and a membrane filter, was applied to the detection and quantification of bacteria in infected root canals, in order to evaluate the outcomes of the treatment. Methods. Six infected root canals with periapical lesions from 5 subjects were included. Informed consent was obtained from all subjects (age ranges, 23–79 years). Samples from infected root canals were collected at the beginning of the treatment (termed #25 First), the end of the first day of treatment (termed #55 First), and the next appointment day (termed #55 Second). Then, the bacterial count (CFU) was measured using fluorescence reagents (4?,6?-diamidino-2-phenylindole and propidium iodide) and the polycarbonate membrane filter by Bioplorer. Results. The mean ± SD of CFU in the sample of “#25 First” was (1.0 ± 1.4) × 105. As the root canal treatment progressed, the CFU decreased as 7.9 × 103 (#55 First) and 4.3 × 102 (#55 Second). Conclusion. In the present pilot study, rapid detection and quantification of bacteria in infected root canals were found to be successfully performed using fluorescence reagents and a membrane filter (Bioplorer analysis).
A study was conducted to determine the performance of buried plastic membrane linings, primarily 10-mil PVC, used for seepage control in Bureau irrigation canals. Samples from 10 canal installations ranging in service life from 1 to 19 years were evaluate...
...Tympanostomy tube with semipermeable membrane. (a) Identification. A tympanostomy tube with a semipermeable membrane is a device intended to be...device is inserted through the tympanicmembrane to permit a free exchange...
...Tympanostomy tube with semipermeable membrane. (a) Identification. A tympanostomy tube with a semipermeable membrane is a device intended to be...device is inserted through the tympanicmembrane to permit a free exchange...
Summary \\u000a Mechanical loading of the cervical spine during car accidents often lead to a number of neck injury symptoms with the common\\u000a term Whiplash Associated Disorders (WAD). Several of these symptoms could possibly be explained by injuries to the cervical\\u000a spinal nerve root region.\\u000a \\u000a \\u000a \\u000a It was hypothesised that the changes in the inner volume of the cervical spinal canal during
M. Y. Svensson; B. Aldman; O. Boström; J. Davidsson; H.-A. Hansson; P. Lövsund; A. Suneson; A. Säljö
Summary Drop attacks represent a significant problem during the natural course of Meniere’s disease. They are characterized by a sudden fall to the ground without loss of consciousness. Diagnosis is clinical and based on the typical description of the patient. Involvement of vertical canal is possible during Meniere’s disease and also after gentamicin application. Treatment of drop attacks is still a matter of discussion; most cases have a benign course with spontaneous remission and no treatment is necessary. In severe cases, aggressive treatment (surgical or pharmacological) is necessary. A case of drop attack associated with vertical vertigo is presented. Vestibular tests were performed in order to assess the involvement of inner ear. Caloric test and ice water test reveal no response. Vestibular Evoked Myogenic Potentials are present even after high doses of gentamicin. Drop attacks and vertical vertigo can occur after trans-tympanic gentamicin and can be well managed with high doses of local gentamicin.
Dallan, I; Bruschini, L; Nacci, A; Bignami, M; Casani, AP
Objective. Rapid and accurate core temperature measurement is vitally important in trauma patients, especially in those with\\u000a accidental hypothermia. We tested a new aural thermometer to measure “tympanic” temperatures and assessed its accuracy during\\u000a normothermic and hypothermic cardiopulmonary bypass.Methods. Tympanic, esophageal, and blood temperatures were compared in 10 patients undergoing open-heart surgery. In addition, the\\u000a stability and reaction time of
B. H. Walpoth; J. Galdikas; F. Leupi; W. Muehlemann; P. Schlaepfer; U. Althaus
Compared to auditory brainstem responses (ABRs), cochlear microphonics (CMs) may be more appropriate to serve as a supplement to the test of otoacoustic emissions (OAEs). Researchers have shown that low-frequency CMs from the apical cochlea are measurable at the tympanicmembrane using high-pass masking noise. Our objective is to study the effect of such noise at different intensities on low-frequency CMs recorded at the ear canal, which is not completely known. Six components were involved in this CM measurement including an ear canal electrode (1), a relatively long and low-frequency toneburst (2), and high-pass masking noise at different intensities (3). The rest components include statistical analysis based on multiple human subjects (4), curve modeling based on amplitudes of CM waveforms (CMWs) and noise intensity (5), and a technique based on electrocochleography (ECochG or ECoG) (6). Results show that low-frequency CMWs appeared clearly. The CMW amplitude decreased with an increase in noise level. It decreased first slowly, then faster, and finally slowly again. In conclusion, when masked with high-pass noise, the low-frequency CMs are measurable at the human ear canal. Such noise reduces the low-frequency CM amplitude. The reduction is noise-intensity dependent but not completely linear. The reduction may be caused by the excited basal cochlea which the low-frequency has to travel and pass through. Although not completely clear, six mechanisms related to such reduction are discussed. PMID:24793117
Polarized transport of the hormone auxin plays crucial roles in many processes in plant development. A self-organizing pattern of auxin transport--canalization--is thought to be responsible for vascular patterning and shoot branching regulation in flowering plants. Mathematical modeling has demonstrated that membrane localization of PIN-FORMED (PIN)-family auxin efflux carriers in proportion to net auxin flux can plausibly explain canalization and possibly other auxin transport phenomena. Other plausible models have also been proposed, and there has recently been much interest in producing a unified model of all auxin transport phenomena. However, it is our opinion that lacunae in our understanding of auxin transport biology are now limiting progress in developing the next generation of models. Here we examine several key areas where significant experimental advances are necessary to address both biological and theoretical aspects of auxin transport, including the possibility of a unified transport model. PMID:24296041
The auditory systems of several species of singing and acoustically communicating grasshoppers, as well as of silent grasshoppers, were compared with respect to the external structure of the tympana, thresholds of the tympanal nerve response and projection areas of tympanal nerves within the metathoracic part of the ventral nerve cord. Extracellular recordings from the tympanal nerves, using suction electrodes, revealed
Besides a knowledge of material properties geometric properties are needed to investigate the mechanical behavior of the human eardrum. Although the geometry of the eardrum has been examined methodically, its composition has been described in the literature. The true surface geometry of a cadaver specimen of the human eardrum was examined under a laser-scanning microscope. Forty points (85 parameters) depicted the surface of this cadaver specimen and formed the basis for a finite shell model. Furthermore, the coupling with the malleus and its suspension was simulated. Additional geometric and material parameters were chosen from the available literature. Both static behavior and the influence of a parameter variation to modal behavior of the finite element model were tested. ANSYS 5.1 software was used for this study. PMID:9556711
he medical literature contains an increasing number of reports that establish the safety of cochlear implanta- tion in both adults and children. Complications, however, are not inexistent, with reported rates between 3% and 13% for major complications and 7% to 37% for minor compli- cations.1 Though the exact definitions vary between series, major complications are generally defined as those that
Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanicmembrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold. PMID:21989514
ter Hofstede, Hannah M; Goerlitz, Holger R; Montealegre-Z, Fernando; Robert, Daniel; Holderied, Marc W
Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanicmembrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.
Ter Hofstede, Hannah M.; Goerlitz, Holger R.; Montealegre-Z, Fernando; Robert, Daniel; Holderied, Marc W.
In this study, we have discussed the facial canal dehiscence rates in patients with scutum defect, who had undergone surgery with the diagnosis of chronic otitis media with or without cholesteatoma. The operation records of 154 patients who had undergone tympanomastoidectomy with the diagnosis of chronic otitis media with or without cholesteatoma were retrospectively analyzed. Scutum defect was investigated by inspection under direct high magnification following tympanomeatal flap elevation during the operation. Facial canal dehiscence was evaluated by inspection and through palpation by blunt picking after the pathological tissues had been removed. The rate of scutum defect was determined as 29.22% (45 out of 154 patients), and the rate of facial canal dehiscence was determined as 22.07% (34 out of 154 patients). While facial canal dehiscence was encountered in 55.55% of the patients with scutum defect, this rate was determined as 8.25% in patients without scutum defect. While the tympanic segment was the most commonly affected segment of the facial canal, isolated mastoid segment involvement was encountered in only 1 (2.94%) patient. The presence of scutum defect is a significant finding for the prediction of the extent of the disease and facial canal dehiscence. Thus, the surgeon should pay more attention to avoid facial nerve injury during the operation in the patient in whom a scutum defect is detected. PMID:23553244
The magnet-drive hearing device (MHD) is a small completely-in-the-canal hearing aid prototype that drives the tympanicmembrane (TM) through a magnetic interface. A cadaveric temporal bone was prepared. The MHD was coupled to a nickel-epoxy pellet glued to the umbo. Frequency sweeps between 0.3 and 10 kHz were performed, and the MHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer and compared with sound-induced displacements. The MHD had a linear frequency response and low total harmonic distortion. The pellet placement altered the stapes movements; however, the changes were statistically insignificant. Inputs of 100 and 300 mV produced displacements equivalent to those of the natural sound at 70- and 80-dB sound pressure level, respectively. The coupling of this novel device using a magnetic interface to the umbo had a frequency output wider than air conduction devices, and its actuator was effective in driving the TM. PMID:23264118
Mahboubi, Hossein; Malley, Melinda J D; Paulick, Peyton; Merlo, Mark W; Bachman, Mark; Djalilian, Hamid R
Two infants, 6 months and 4 months of age, presented with bilateral or unilateral external auditory canal polyps and otorrhea, respectively. Additional findings on examination included otitis media and mastoiditis. Tympanicmembrane perforation was noted in one patient and a postauricular abscess in the other. Incisional biopsies of the polyps and abscess were reported as nonspecific mixed inflammation and abscess wall, respectively. There was a limited response to an empirical 5-day course of trimethoprim sulfamethoxazole. The children were referred to the academic hospital, and excision of the polyps and biopsies of the middle ear, mastoid, and postauricular abscess was undertaken. All the biopsies demonstrated donovanosis. Reappraisal of the initial incisional biopsies also confirmed donovanosis. Trimethoprim sulfamethoxazole was administered to both patients for 3 weeks, with resolution of the lesions. Subsequent investigations confirmed genital tract donovanosis, human immunodeficiency virus seropositivity, acquired immunodeficiency syndrome, and pulmonary tuberculosis in both mothers. Heightened awareness of the occurrence of donovanosis at unusual sites and improved recognition of the histomorphological features of the disease, especially in small and superficial biopsies, are pivotal not only for its correct diagnosis in extragenital cutaneous and extracutaneous locations but also for timely and adequate therapy and an improved infant and maternal outcome. PMID:23169417
Tympanal hearing organs of insects emit distortion-product otoacoustic emissions (DPOAEs), which in mammals are used as indicator for nonlinear cochlear amplification, and which are highly vulnerable to manipulations interfering with the animal's physiological state. Although in previous studies, evidence was provided for the involvement of auditory mechanoreceptors, the source of DPOAE generation and possible active mechanisms in tympanal organs remained unknown. Using laser Doppler vibrometry in the locust ear, we show that DPOAEs mechanically emerge at the tympanum region where the auditory mechanoreceptors are attached. Those emission-coupled vibrations differed remarkably from tympanum waves evoked by external pure tones of the same frequency, in terms of wave propagation, energy distribution, and location of amplitude maxima. Selective inactivation of the auditory receptor cells by mechanical lesions did not affect the tympanum's response to external pure tones, but abolished the emission's displacement amplitude peak. These findings provide evidence that tympanal auditory receptors, comparable to the situation in mammals, comprise the required nonlinear response characteristics, which during two-tone stimulation lead to additional, highly localized deflections of the tympanum. PMID:24817310
27. VIEW OF TWIN FALLS MAIN CANAL HEADGATE WITH CANAL BRIDGE IN DISTANCE; LOOKING SOUTHWEST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
2. CANAL BOAT ENTERING THE DELAWARE CANAL FROM OF THE LEHIGH RIVER. BOATS COULD BE FERRIED ACROSS THE DELAWARE RIVER TO THE MORRIS CANAL BY A CABLE SUPPORTED TROLLEY. - Morris Canal, Phillipsburg, Warren County, NJ
In Diptera, tympanal hearing has evolved at least twice in flies that belong to two different families, the tachinids and the sarcophagids. Common to these flies is their parasitoid reproductive strategy, both relying on the acoustic detection and localization of their hosts, singing insects, by means of tympanal hearing organs. In the present study, the external anatomy of the unusual
BACKGROUND: It is now common for parents to measure tympanic temperatures in children. The objective of this study was to assess the diagnostic accuracy of these measurements. METHODS: Parents and then nurses measured the temperature of 60 children with a tympanic thermometer designed for home use (home thermometer). The reference standard was a temperature measured by a nurse with a
This study was designed to assess children's behavioral responses to tympanic thermometry. In addition, parents' and nurses' impressions of this new technology were evaluated. 224 patients were enrolled from three private pediatric practices. Patients were alternately assigned to have their temperature taken with either a tympanic thermometer or with a rectal or oral thermometer. Parents and nurses were then asked
Compelling stories exude from this Country's nearly 400 National Park Service sites. As the NPS nears its Centennial in 2016, parks look to share their untold stories. Along the 184.5 miles of the C&O Canal National Historical Park towpath countless stories sparkle! Tales of the canal boat captains, lock keepers, the construction of the canal. When visiting the C&O Canal
Infrared tympanic thermometers (ITTs) are easy to use and have a quick response time. They are widely used for temperature measurement of the human body. The accuracy and uncertainty of measurement is the importance performance indicator for these meters. The performance of two infrared tympanic thermometers, Braun THT-3020 and OMRON MC-510, were evaluated in this study. The cell of a temperature calibrator was modified to serve as the standard temperature of the blackbody. The errors of measurement for the two meters were reduced by the calibration equation. The predictive values could meet the requirements of the ASTM standard. The sources of uncertainty include the standard deviations of replication at fixed temperature or the predicted values of calibration equation, reference standard values and resolution. The uncertainty analysis shows that the uncertainty of calibration equation is the main source for combined uncertainty. Ambient temperature did not have the significant effects on the measured performance. The calibration equations could improve the accuracy of ITTs. However, these equations did not improve the uncertainty of ITTs.
Background Tympanic thermometry has come as a suitable alternative to traditional thermometry because of its safety and ease of use. However, it is still yet to gain wide acceptance in African settings due to conflicting results on its accuracy, thus rectal thermometry remains the gold standard in the newborn. The aim of this study was to compare tympanic and rectal temperatures in term Nigerian neonates. Methods Rectal and tympanic temperatures were measured simultaneously in 300 consecutive term neonates between the ages of 37 and 42?weeks gestation using mercury-in-glass and the Infrared tympanic thermometers respectively. Paired t test, Pearson correlation coefficient and the Bland-Altman plot were used to compute data. Using rectal thermometry as gold standard, the sensitivity, specificity and predictive values of tympanic thermometry at various rectal temperature cut-offs were determined. Receiver Operating Curves (ROC) were constructed and the Areas Under the Curves (AUC) were compared. Results The mean rectal temperature (37.34?±?0.55°C) was significantly higher than the mean tympanic temperature (37.25?±?0.56°C) (p?0.001) with a mean difference of 0.09?°C?±?0.24?°C (95% CI: 0.06, 0.12). There was a strong positive correlation between the two measurements (r?=?0.9; p?0.001). Tympanic thermometry showed sensitivities ranging from 65% to 86% and specificities of 95% to 99% at rectal temperature cut-offs of 37.5°C to 38°C. The positive and negative predictive values of the tympanic temperatures at the various temperature cut-offs ranged from 82% to 93% and 80% to 98% respectively. Accuracy was noted to increase with higher temperatures as shown by the Receiver Operating Curves with the highest accuracy at the temperature cut-off of 38°C and AUC of 0.91. Conclusions The sensitivity of tympanic thermometry was relatively low in detecting rectal temperatures despite the good correlation and agreement between them. The specificities and predictive values of tympanic temperatures in detecting rectal temperatures were high and accuracy increased with higher temperatures. Though using the tympanic route for measuring temperature in the newborn is relatively safe and non-invasive, its low sensitivity limits its use. Further studies would be required to further assess the accuracy of tympanic temperature measurements in the newborn.
Opinion statement Atrioventricular (AV) canal defects should be diagnosed by means of echocardiography. Infants with complete AV canal defects\\u000a should undergo intracardiac surgical repair before pulmonary vascular obstructive disease develops, preferably before 6 months\\u000a of age. Repair of partial AV canal defects or primum atrial septal defects can be postponed until 18 to 36 months of age if\\u000a the patient does
56. CROSS SECTIONS OF CANAL AND TUNNELS. POWER CANAL, SALT RIVER RESERVOIR Courtesy of U.S.G.S., Reclamation Service - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
Bitter Root Irrigation district canal, looking east, typical section (canal full) - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT
6. O'BRIAN CANAL/DENVER-HUDSON CANAL BIFURCATION POINT The O'Brian Canal is flowing to the left; the Denver-Hudson Canal is flowing to the right - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO
The acoustic parasitoid fly Ormia ochracea locates its host, a singing field cricket, by means of a pair of small tympanal organs which are less than 2?mm in width.\\u000a Nevertheless, laser vibrometric evidence shows that this tympanal system is directionally sensitive to sound through the action\\u000a of a flexible intertympanal bridge that mechanically couples the tympana. Biomechanical data, a mechanical
I NOTICE in your number of 4th inst. an article relating to the Suez Canal (by Mr. Login, C.E., late of the Ganges Canal), and shall be glad if you will allow me to make a few observations with reference to it.
Among all the engineering feats of the 20th century, the Panama Canal was certainly one of the greatest. The Panama Canal Authority (PCA) provides this home page, which contains a vast amount of information regarding the canal's origins and current affairs. Most visitors to the Web site will be mainly interested in the complete history of the canal. This begins with early plans by the Spanish in the 1500s, and documents all progress until the final completion in 1914. An impressive photo gallery includes historical pictures and panoramic views of four main locations, and a live camera shows the boat traffic in the canal at ten second intervals. Other resources such as maritime operations and news articles are also available.
...Otoscope. (a) Identification. An otoscope is a device intended to allow inspection of the external ear canal and tympanicmembrane under magnification. The device provides illumination of the ear canal for observation by using an AC- or...
The labral pilifers and the labial palps form ultrasound-sensitive hearing organs in species of two distantly related hawkmoth subtribes, the Choerocampina and the Acherontiina. Biomechanical examination now reveals that their ears represent different types of hearing organs. In hearing species of both subtribes, the labral pilifer picks up vibrations from specialized sound-receiving structures of the labial palp that are absent in non-hearing species. In Choerocampina, a thin area of cuticle serves as an auditory tympanum, whereas overlapping scales functionally replace a tympanum in Acherontiina that can hear. The tympanum of Choerocampina and the scale-plate of Acherontiina both vibrate maximally in response to ultrasonic, behaviourally relevant sounds, with the vibrations of the tympanum exceeding those of the scale plate by ca. 15 dB. This amplitude difference, however, is not reflected in the vibrations of the pilifers and the neural auditory sensitivity is similar in hearing species of both subtribes. Accordingly, morphologically different - tympanal and atympanal - but functionally equivalent hearing organs evolved independently and in parallel within a single family of moths.
Gopfert, Martin C; Surlykke, Annemarie; Wasserthal, Lutz T
Drosophila kelch has four protein domains, two of which are found in kelch-family proteins and in numerous nonkelch proteins. In Drosophila, kelch is required to maintain ring canal organization during oogenesis. We have performed a structure–function analysis to study the function of Drosophila kelch. The amino-terminal region (NTR) regulates the timing of kelch localization to the ring canals. Without the NTR, the protein localizes precociously and destabilizes the ring canals and the germ cell membranes, leading to dominant sterility. The amino half of the protein including the BTB domain mediates dimerization. Oligomerization through the amino half of kelch might allow cross-linking of ring canal actin filaments, organizing the inner rim cytoskeleton. The kelch repeat domain is necessary and sufficient for ring canal localization and likely mediates an additional interaction, possibly with actin.
In this lesson designed to enhance literacy skills, students look at how the construction of the Erie Canal brought about major changes within United States, particularly in New York City, upstate New York, and the Midwest.
Predicting the transit capacities of the various Panama Canal alternatives required analyzing data on present Canal operations, adapting and extending an existing computer simulation model, performing simulation runs for each of the alternatives, and using the simulation model outputs to develop capacity estimates. These activities are summarized in this paper. A more complete account may be found in the project final report (TAMS 1993). Some of the material in this paper also appeared in a previously published paper (Rosselli, Bronzini, and Weekly 1994).
Bronzini, M.S. [Oak Ridge National Lab., Knoxville, TN (United States). Center for Transportation Analysis
Turtles, like other amphibious animals, face a trade-off between terrestrial and aquatic hearing. We used laser vibrometry and auditory brainstem responses to measure their sensitivity to vibration stimuli and to airborne versus underwater sound. Turtles are most sensitive to sound underwater, and their sensitivity depends on the large middle ear, which has a compliant tympanic disc attached to the columella. Behind the disc, the middle ear is a large air-filled cavity with a volume of approximately 0.5 ml and a resonance frequency of approximately 500 Hz underwater. Laser vibrometry measurements underwater showed peak vibrations at 500-600 Hz with a maximum of 300 µm s(-1) Pa(-1), approximately 100 times more than the surrounding water. In air, the auditory brainstem response audiogram showed a best sensitivity to sound of 300-500 Hz. Audiograms before and after removing the skin covering reveal that the cartilaginous tympanic disc shows unchanged sensitivity, indicating that the tympanic disc, and not the overlying skin, is the key sound receiver. If air and water thresholds are compared in terms of sound intensity, thresholds in water are approximately 20-30 dB lower than in air. Therefore, this tympanic ear is specialized for underwater hearing, most probably because sound-induced pulsations of the air in the middle ear cavity drive the tympanic disc. PMID:22438494
Christensen-Dalsgaard, Jakob; Brandt, Christian; Willis, Katie L; Christensen, Christian Bech; Ketten, Darlene; Edds-Walton, Peggy; Fay, Richard R; Madsen, Peter T; Carr, Catherine E
The objective of this study was to evaluate, over the long-term, the anatomic and functional outcome of canal wall-down mastoidectomy performed for chronic otitis media with cholesteatoma and chronic otomastoiditis resistant to all conservative treatment. The study was made through a retrospective review of 338 cases of consecutive primary canal wall-down mastoidectomies performed between 1974 and 1998. Included were 259 cases with sufficient data. In all cases, functional reconstruction was performed at the same time as the mastoidectomy. Demographic and clinical data were collected from each file. From the clinical data, the surgical techniques, complications, the number of follow-up visits necessary to ensure cavity cleanliness, details of care provided over the period 1 to 24 years (mean, 7 years) after the operation, and audiometric data from admission and from the latest postoperative follow-up were retained. Canal wall-down mastoidectomies were followed up an average of 10 times during the first 6 months after operation, twice a year over the 6-year period following surgery, and less than twice a year beyond the 6-year period. Care was dispensed for meatal stenosis, scars, infections, polyps, and beads of cholesteatoma. Surgical revisions were performed because of residual or recurrent cholesteatoma in 6.1% of the cases, because of perforation of the tympanicmembrane in 7.3% of the cases, and to improve hearing in 12.2% of the cases. At the last consultation, 1 to 24 years after surgery, cavities were found to be dry and self-cleaning in 95% of the cases, and still humid, with otorrhea, in 5% of the cases. Over the long-term, the hearing threshold remained unchanged in 41.3% of the cases. It was improved after surgery by 10 to 19 dB in 15.4% of the cases, by 20 to 29 dB in 11.5% of the cases, and by more than 29 dB in 3.8% of the cases. The hearing threshold was thus improved or at least remained unchanged in 72.0% of cases. Hearing losses occurred in 28% of the cases: by 10 to 19 dB in 11.9%, by 20 to 29 dB in 6.5%, and by more than 29 dB in 9.2% of the cases. A sensorineural hearing loss of more than 60 dB at all frequencies occurred immediately after the operation in 2 cases (0.7%). There was 1 case of facial paralysis (0.3%). Four patients (1.5%) complained of persistent vertigo. Canal wall-down mastoidectomy is an adequate treatment for chronic otitis with cholesteatoma or chronic otomastoiditis. The anatomic and functional results are satisfactory, and the rate of complications is acceptably low. A tympanoplasty can be performed simultaneously. Thus, for the large majority of patients, only a single intervention is required; however, a small minority can benefit from a revision tympanoplasty. In order to obtain these results, both the patient and the surgeon should engage in a long-term follow-up. PMID:15562896
Kos, Maria Izabel; Castrillon, Rodrigo; Montandon, Pierre; Guyot, Jean-Philippe
Present experiments were designed to quantify the alternating current (AC) component of the semicircular canal microphonic for angular motion stimulation as a function of stimulus frequency and amplitude. The oyster toadfish, Opsanus tau, was used as the experimental model. Calibrated mechanical indentation of the horizontal canal duct was used as a stimulus to generate hair-cell and afferent responses reproducing those present during head rotation. Sensitivity to polarization of the endolymph DC voltage re: perilymph was also investigated. Modulation of endolymph voltage was recorded using conventional glass electrodes and lock-in amplification over the frequency range 0.2-80 Hz. Access to the endolymph for inserting voltage recording and current passing electrodes was obtained by sectioning the anterior canal at its apex and isolating the cut ends in air. For sinusoidal stimulation below approx.10 Hz, the horizontal semicircular canal AC microphonic was nearly independent of stimulus frequency and equal to approximately 4 microV per micron indent (equivalent to approx. 1 microV per deg/s). A saturating nonlinearity decreasing the microphonic gain was present for stimuli exceeding approx.3 micron indent (approx. 12 deg/s angular velocity). The phase was not sensitive to the saturating nonlinearity. The microphonic exhibited a resonance near 30Hz consistent with basolateral current hair cell resonance observed previously in voltage-clamp records from semicircular canal hair cells. The magnitude and phase of the microphonic exhibited sensitivity to endolymphatic polarization consistent with electro-chemical reversal of hair cell transduction currents.
Rabbitt, R. D.; Boyle, R.; Highstein, S. M.; Dalton, Bonnie P. (Technical Monitor)
There is great interest in the membrane lipids of archaea (glycerol dialkyl glycerol tetraethers [GDGTs]) as tracers of archaeal biomass because of their utility as paleoproxies and because of the biogeochemical importance of archaea. While core GDGTs (formed by hydrolysis of polar head groups of intact GDGTs after cell death) are appropriate for paleostudies, they have also been used to trace archaeal populations. Also, despite the small size (0.2 by 0.7 ?m) of cultivated marine archaea, 0.7-?m glass-fiber filters (GFFs) are typically used to collect GDGTs from natural waters. We quantified both core and intact GDGTs in free-living (0.2- to 0.7-?m), suspended (0.7- to 60-?m), and aggregate (>60-?m) particle size fractions in Puget Sound (Washington State). On average, the free-living fraction contained 36% of total GDGTs, 90% of which were intact. The intermediate-size fraction contained 62% of GDGTs, and 29% of these were intact. The aggregate fraction contained 2% of the total GDGT pool, and 29% of these were intact. Our results demonstrate that intact GDGTs are largely in the free-living fraction. Because only intact GDGTs are present in living cells, protocols that target this size fraction and analyze the intact GDGT pool are necessary to track living populations in marine waters. Core GDGT enrichment in larger-size fractions indicates that archaeal biomass may quickly become attached or entrained in particles once the archaea are dead or dying. While the concentrations of the two pools were generally not correlated, the similar sizes of the core and intact GDGT pools suggest that core GDGTs are removed from the water column on timescales similar to those of cell replication, on timescales of days to weeks.
The University of Florida's George A. Smathers Libraries and the Panama Canal Museum have worked together to create this engaging digital collection that tells the story of Panama and the Canal Zone. The collection contains 158 items, including newspaper clippings, illustrations, stock shares, and more. The Leonard Carpenter Panama Canal Collection contains a mix of photos of dredging work, military personnel, and a U.S. Navy dirigible. Another smaller collection contains items from the Government Documents Department, such as annual reports, maps, and Congressional hearing transcripts. Visitors can search the entire collection by keyword, and they shouldn't miss the 1754 maps of Panama and the surrounding region by Jacques Nicolas Bellin.
7. 'FLOW IN CANAL NO. 1, A JOINTLY USED CANAL, ON MAY 22 WHEN 210 SECOND FEET OF WATER WAS FLOWING. THIS WAS LATER INCREASED TO 240 SECOND FEET FOR A NUMBER OF DAYS TO SATISFY THE DEMANDS OF THE DRY GULCH COMPANY.' 1925 - Irrigation Canals in the Uinta Basin, Duchesne, Duchesne County, UT
The Environmental Protection Agency (EPA) conducted a 3-month monitoring study of the Love Canal area near Niagara Falls, N.Y., after the federal government pronounced that a potential health risk existed due to chemical waste dumps. In 1982 the Department of Health and Human Services (HHS) decided that the area was habitable, subject to implementation of effective safeguards against leakage from the canal and to cleaning up of the contaminants. Now, the Congressional Office of Technology Assessment (OTA) has announced that, with the information available, it is not possible to demonstrate with certainty that unsafe levels do not exist within the so-called “emergency declaration area” (EDA).
Three experiments were conducted to evaluate the effect of different management strategies on body temperature of feedlot steers finished in the summer months. In Exp. 1, 24 crossbred steers were chosen to assess the effect of altered feed intake and feeding time on tympanic temperature (TT) response. Managed feeding (MF) treatments were applied for 22 d only and provided 1)
M. S. Davis; T. L. Mader; S. M. Holt; A. M. Parkhurst
Certain moths possess tympanic organs (ears) that detect the echolocation signals of hunting, insectivorous bats. The auditory characteristics of these ears are matched to the acoustic features of the echolocation calls emitted by the moths' sympatric bat fauna. The two-celled ears of noctuoid moths from the Hawaiian island of Kauai, a site with only one species of bat (Lasiurus cinereus
BACKGROUND: In this study we sought to determine the usefulness of a novel earphone-type infrared tympanic thermometer (IRT) for core temperature moni- toring during surgery. METHODS: Two groups of patients were studied under different surgical conditions. The first group consisted of 18 adult patients (ASA I or II) who had been scheduled for elective surgery under general anesthesia. Before induction
Summary 1.In recordings from single tympanic receptor fibres inC. biguttulus, the response to synthesized sounds (rectangularly modulated white noise) interrupted by very brief (a few milliseconds) gaps was examined. In behavioral tests, females of the species respond very differently to such ‘model syllables’ at moderate intensities, depending on the gap width. If the gaps (in a moderateintensity syllable) are larger
To guide surgery of nerves that traverse and surround the tympanic cavity in the rat, anatomical illustrations are required that are topographically correct. In this study, maps of this area are presented, extending from the superior cervical ganglion to the otic ganglion. They were derived from observations that were made during dissections using a ventral approach. Major blood vessels, bones, transected muscles of the tongue and neck and supra and infrahyoid muscles serve as landmarks in the illustrations. The course of the mandibular, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves with their branches, and components of the sympathetic system, are shown and discussed with reference to data available in the literature. Discrepancies in this literature can be clarified and new data are presented on the trajectories of several nerves. The course of the tympanic nerve was established. This nerve originates from the glossopharyngeal nerve, enters the tympanic cavity, crosses the promontory, passes the tensor tympani muscle dorsally, and continues its route intracranially to the otic ganglion as the lesser petrosal nerve after intersecting with the greater petrosal nerve. Auricular branches of the glossopharyngeal and of the vagus nerve were noted. We also observed a pterygopalatine branch of the internal carotid nerve, that penetrates the tympanic cavity and courses across the promontory.
WEIJNEN, J. A. W. M.; SURINK, S.; VERSTRALEN, M. J. M.; MOERKERKEN, A.; DE BREE, G. J.; BLEYS, R. L. A. W.
Objective The goal of the present study was to investigate the clinical utility of measurements of ear-canal reflectance (ECR) in a population of patients with conductive hearing loss in the presence of an intact, healthy tympanicmembrane (TM) and an aerated middle ear. We also sought to compare the diagnostic accuracy of umbo velocity (VU) measurements and measurements of ECR in the same group of patients. Design This prospective study comprised 31 adult patients with conductive hearing loss, of which 14 had surgically-confirmed stapes fixation due to otosclerosis, 6 had surgically-confirmed ossicular discontinuity, and 11 had CT- and VEMP-confirmed superior semicircular canal dehiscence (SCD). Measurements on all 31 ears included pure-tone audiometry for 0.25 – 8 kHz, ECR for 0.2 – 6 kHz using the Mimosa Acoustics HearID system, and VU for 0.3 – 6 kHz using the HLV-1000 laser Doppler vibrometer (Polytec Inc). We analyzed power reflectance |ECR|2 as well as the absorbance level = 10×log10(1?|ECR|2). All measurements were made prior to any surgical intervention. The VU and ECR data were plotted against normative data obtained in a companion study of 58 strictly defined normal ears (Rosowski et al. 2011). Results Small increases in |ECR|2 at low-to-mid frequencies (400–1000 Hz) were observed in cases with stapes fixation, while narrow-band decreases were seen for both SCD and ossicular discontinuity. The SCD and ossicular discontinuity differed in that the SCD had smaller decreases at mid-frequency (~1000 Hz), while ossicular discontinuity had larger decreases at lower frequencies (500–800 Hz). SCD tended to have less air-bone gap at high frequencies (1–4 kHz) compared to stapes fixation and ossicular discontinuity. The |ECR|2 measurements, in conjunction with audiometry, could successfully separate 28 of the 31 cases into the three pathologies. By comparison, VU measurements, in conjunction with audiometry, could successfully separate various pathologies in 29 of 31 cases. Conclusions The combination of |ECR|2 with audiometry showed clinical utility in the differential diagnosis of conductive hearing loss in the presence of an intact TM and an aerated middle ear, and appears to be of similar sensitivity and specificity to measurements of VU plus audiometry. Additional research is needed to expand upon these promising preliminary results.
Nakajima, Hideko H.; Pisano, Dominic V.; Roosli, Christof; Hamade, Mohamad A.; Merchant, Gabrielle R.; Mahfoud, Lorice; Halpin, Christopher F.; Rosowski, John J.; Merchant, Saumil N.
The Panama Canal was quite an undertaking of labor and engineering, and by the time it was completed on August 15th, 1914 the project had been underway (in some form) for well over two decades. Along the way, over 55,000 workers had been involved, 5,000 people had died during the project's duration, and over 350 million dollars had been spent. This riveting documentary looks at the history of this project, and visitors can watch the entire program here. The extra features provided here are real treats, and they can be found on the left-hand side of the page. Here visitors will find an interactive map of the Panama Canal region, along with a timeline, and an interview with the program's producer, Amanda Pollak. Also, the site includes articles on yellow fever, the workers, and the chief engineers of the Canal. Primary resources such as part of the canal record of 1907, suggestions for further reading, and teacher resources round out the site.
Local wound debridement in the diseased pulp space is the main step in root canal treatment to prevent the tooth from being a source of infection. In this review article, the specifics of the pulpal microenvironment and the resulting requirements for irrigating solutions are spelled out. Sodium hypochlorite solutions are recommended as the main irrigants. This is because of their
The purpose of this environmental failure case study paper is to provide educational materials for environmental engineering courses dealing with design and operation of landfills for hazardous waste. In 1978, it was discovered that hazardous waste had contaminated homes and schools in the Love Canal area, a former chemical landfill which became a 15 acre neighborhood of the City of
Alicia Saunte? Phillips; Yung-Tse Hung; Paul A. Bosela
One of the normal interesting variations that we may encounter in the mandible is bifid mandibular canal. This condition can lead to difficulties when performing mandibular anesthesia or during extraction of lower third molar, placement of implants, and surgery in the mandible. Therefore diagnosis of this variation is sometimes very important and necessary.
One of the normal interesting variations that we may encounter in the mandible is bifid mandibular canal. This condition can lead to difficulties when performing mandibular anesthesia or during extraction of lower third molar, placement of implants, and surgery in the mandible. Therefore diagnosis of this variation is sometimes very important and necessary. PMID:23814555
The location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, such as extraction of an impacted third molar, dental implant treatment, and sagittal split ramus osteotomy. We report 3 Japanese patients with bifid mandibular canals using panoramic radiograph and multi-slice helical computed tomography (CT) images. In 2 of the 5 sides, the bifid mandibular canal was suggested on panoramic radiograph. The bifid mandibular canal had a short and narrow upper canal toward the distal area of the second molar in 4 sides, and a short and narrow lower canal toward the distal area of second molar in 1 side, as revealed on reconstructed CT images. Since the location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, they should be carefully observed using reconstructed CT images. PMID:17356369
PURPOSE Chemoradiotherapy has replaced radical surgery as the initial treatment of choice for anal canal cancer. The roles of these therapeutic modalities are discussed and recommendations on management of anal canal cancer are made based on currently available evidence. Areas for further studies also are identified.METHODS Literature on management of anal canal cancer from January 1970 to July 2003 obtained via MEDLINE
A dominant theme of acoustic communication is the partitioning of acoustic space into exclusive, species-specific niches to enable efficient information transfer. In insects, acoustic niche partitioning is achieved through auditory frequency filtering, brought about by the mechanical properties of their ears. The tuning of the antennal ears of mosquitoes and flies, however, arises from active amplification, a process similar to that at work in the mammalian cochlea. Yet, the presence of active amplification in the other type of insect ears--tympanal ears--has remained uncertain. Here we demonstrate the presence of active amplification and adaptive tuning in the tympanal ear of a phylogenetically basal insect, a tree cricket. We also show that the tree cricket exploits critical oscillator-like mechanics, enabling high auditory sensitivity and tuning to conspecific songs. These findings imply that sophisticated auditory mechanisms may have appeared even earlier in the evolution of hearing and acoustic communication than currently appreciated. Our findings also raise the possibility that frequency discrimination and directional hearing in tympanal systems may rely on physiological nonlinearities, in addition to mechanical properties, effectively lifting some of the physical constraints placed on insects by their small size  and prompting an extensive reexamination of invertebrate audition. PMID:24076240
One of the most important waterways in the world, the Suez Canal runs north to south across the Isthmus of Suez in northeastern Egypt. This image of the canal covers an area 36 kilometers (22 miles) wide and 60 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. It shows the northern part of the canal, with the Mediterranean Sea just visible in the upper right corner. The Suez Canal connects the Mediterranean Sea with the Gulf of Suez, an arm of the Red Sea. The artificial canal provides an important shortcut for ships operating between both European and American ports and ports located in southern Asia, eastern Africa, and Oceania. With a length of about 195 kilometers (121 miles) and a minimum channel width of 60 meters (197 feet), the Suez Canal is able to accommodate ships as large as 150,000 tons fully loaded. Because no locks interrupt traffic on this sea level waterway, the transit time only averages about 15 hours. ASTER acquired this scene on May 19, 2000.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation; identifying crop stress; determining cloud morphology and physical properties; evaluating wetlands; mapping surface temperature of soils and geology; and measuring surface heat balance.
15. ROUTE OF CANAL NORTHWEST OF THE DILLON CEMETERY. CANAL PASSES BELOW HILLSIDE IN FOREGROUND, THROUGH THE LOWER EDGE OF THE TREES ON LEFT, ON FAR SIDE OF SMALL VALLEY JUST RIGHT OF CENTER, AND AROUND THE PROMINENT POINT ON THE RIGHT. VIEW IS TO THE EAST-SOUTHEAST. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
A diagnosis of inflammatory polyp is based on otoscopic, radiographic, and histologic information. Heavy sedation or anesthesia is necessary in most cases to thoroughly examine the external ear canal, tympanicmembrane, and nasopharynx. Look to see if the tympanicmembrane is perforated, or bulging, cloudy, or discolored if it is intact; these changes are consistent with otitis media. Polyps extending
The ultrastructure of tympanoslerotic tissue, surgically excised from patients, has been studied with particular reference to the morphological changes of the connective tissue components and mineralization. Detailed analysis revealed the combination of degenerative and fibroplastic alterations, especially in the circular fibrous layer of the thickened lamina propria. In the biological material in this study the authors recognized different stages of calcium plaque development with discrete, moderate, and severe degree of mineralization. Extracellular matrix vesicles, with or without calcareous deposits, released by degenerating fibroblasts were prominent. In these biopsies no distinct morphological features of an inflammatory reaction were seen. PMID:24134073
This paper presents in vivo experimental measurements of vibrations on the pars flaccida, along the manubrium and at several points on the pars tensa in the gerbil with open middle-ear cavity. The effects of progressive opening of the middle-ear cavity are presented, with up to five different extents of opening. In all manubrial, pars-tensa and pars-flaccida responses, opening the cavity causes an increase in the low-frequency magnitude and a shift of the main middle-ear resonance to lower frequencies and introduces an antiresonance. However, opening the cavity has little or no effect on either the mode of vibration of the manubrium or the breakup frequency of the pars tensa. When the opening is gradually widened, the antiresonance frequency moves to higher frequencies. When the opening is made as wide as anatomically possible, the antiresonance moves to almost 10 kHz. The main increase in the low-frequency response magnitude happens upon making the smallest hole in the cavity wall, and further progressive enlarging of the opening has little or no effect on the low-frequency magnitude. The antiresonance interferes with the response shapes. An identification method is suggested for eliminating the effect of the antiresonance in order to estimate the ideal open-cavity response. The method is validated and then applied to manubrial and pars-tensa responses. Estimating the ideal open-cavity responses will simplify comparison of the data with numerical models which do not include the air cavity. The data collected at intermediate stages of opening will be useful in validating models that do include the cavity. PMID:24452323
Maftoon, Nima; Funnell, W Robert J; Daniel, Sam J; Decraemer, Willem F
Every vertebrate organism uses fluid-filled semicircular canals (SCCs) to sense rotation -- and thus to balance, navigate and hunt. Whereas the size of most organs typically scales with the size of the organism itself, the SCC are all about the same size -- whether in lizards, mice, humans, or whales. What is so special about these dimensions? We consider fluid flow in the canals and elastic deformations of a sensory membrane, and isolate physical and physiological constraints required for successful SCC function. We demonstrate that the `parameter space' open to evolution is almost completely constrained; furthermore, the most sensitive possible SCC has dimensions that are remarkably close to those common to all vertebrates.
When in 1978, the New York State Department of Health issued the report, `Love Canal---Public Health Time Bomb,' the serious effects of chemical waste contamination in the Love Canal area became an issue of national concern. A few `studies' since then have produced results in concert with those of initial reports that described `conditions of acute health effects' as being
When in 1978, the New York State Department of Health issued the report, ‘Love Canal—Public Health Time Bomb,’ the serious effects of chemical waste contamination in the Love Canal area became an issue of national concern. A few ‘studies’ since then have produced results in concert with those of initial reports that described ‘conditions of acute health effects’ as being linked to hazardous wastes incorporated in landfill in the Love Canal site near Niagara Falls, New York. Now that a ‘blue ribbon’ panel of experts from the medical sciences has reviewed the problems of Love Canal, however, a different view has emerged. The ‘Report of the Governors' Panel to Review Scientific Studies and the Development of Public Policy on Problems Resulting from Hazardous Wastes,’ transmitted in October of this year, identifies the following factors about the health effects at Love Canal:
Objectives The aim of this study was to compare the hearing outcomes between canal wall up mastoidectmy (CWUM) and canal wall down mastoidectmy (CWDM). Methods One hundred seventy one chronic suppurative otitis media (CSOM) patients were enrolled in this retrospective study. The patients who underwent the second staged ossiculoplasty at least 6 months after mastoidectomy and who had an intact, well aerated tympanic cavity as well as intact mobile stapes at the time of operation were selected from the medical record. Based on the type of mastoid surgery, the patients were categorized into two groups: the CWUM (n=38) and CWDM groups (n=133). The hearing results of the CWUM and CWDM groups were compared using the pre- and post-operative air-bone gap (ABG) at 3 months after ossiculoplasty. Results The preoperative ABG in both groups (CWUM and CWDM) were 28.4±15.6 dB and 31.8±14.5 dB, respectively (P=0.18). Both groups didn't show any significant difference (10.9 dB vs. 13.5 dB, respectively) (P=0.21) for the postoperative ABG closure. The proportion of patients with an ABG less than 20 dB was 58.6% of the CWDM patients and 68.4% of the CWUM patients (P=0.25). Conclusion The type of mastoid surgery (CWUM and CWDM) did not affect the hearing results of CSOM patients. When choosing the type of mastoidectomy procedure for CSOM surgery, the hearing outcomes are basically the same for both types of procedure.
Kim, Min-Beom; Choi, Jeesun; Lee, Jae Kwon; Park, Ju-Yeon; Chu, Hosuk; Cho, Yang-Sun; Hong, Sung Hwa
The construction of visual and manipulative aids, clear resin blocks with root-canal-like spaces, for simulation of root canals is explained. Time, materials, and techniques are discussed. The method allows for comparison of canals, creation of any configuration of canals, and easy presentation during instruction. (MSE)
...Canal Fest of the Tonawandas, Erie Canal, Tonawanda, NY AGENCY...temporary safety zone on the Erie Canal, Tonawanda, NY. This...vessels from a portion of the Erie Canal during the Canal Fest...Proposed Rulemaking A. Regulatory History and Information The Coast...
A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.
Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel
... of one’s own voice), hypersensitivity to bone-conducted sounds, and an apparent conductive hearing loss revealed on ... of the bony canal) can be displaced by sound and pressure stimuli. There are normally only two ...
In the first part of this series (ES and T, April 1987, pp. 328-31) it was pointed out that the methods and conclusions of EPA's Love Canal Study were the subject of some controversy in the environmental community. Others defended the agency's approaches and methods. Part 2 makes no attempt to resolve the controversy; its purpose is to present the results and conclusions of the Love Canal.
When driven at sound pressure levels greater than ~110 dB stimulus pressure level, the mammalian middle ear is known to produce subharmonic distortion. In this study, we simultaneously measured subharmonics in the ear canal pressure, intracochlear pressure, and basilar membrane or round window membrane velocity, in gerbil. Our primary objective was to quantify the relationship between the subharmonics measured in the ear canal and their intracochlear counterparts. We had two primary findings: (1) The subharmonics emerged suddenly, with a substantial amplitude in the ear canal and the cochlea; (2) at the stimulus level for which subharmonics emerged, the pressure in scala vestibuli/pressure in the ear canal amplitude relationship was similar for the subharmonic and fundamental components. These findings are important for experiments and clinical conditions in which high sound pressure level stimuli are used and could lead to confounding subharmonic stimulation. PMID:22526734
IntroductionHistologic investigations have demonstrated that root canal sealers can induce mild to severe bone resorption. Alkaline phosphatase (ALP) is a membrane-bound glycoprotein, which is one of the osteogenic differentiation markers considered to indicate the formation of new bone. The aim of this study was to investigate the effects of an epoxy resin-based sealer AH26, a zinc oxide–eugenol–based sealer Canals, and
Angus crossbred yearling steers ( n = 168) were used to evaluate effects on performance and tympanic temperature (TT) of feeding additional potassium and sodium to steers exposed to excessive heat load (maximum daily ambient temperature exceeded 32°C for three consecutive days) during seasonal summer conditions. Steers were assigned one of four treatments: (1) control; (2) potassium supplemented (diet containing 2.10% KHCO3); (3) sodium supplemented (diet containing 1.10% NaCl); or (4) potassium and sodium supplemented (diet containing 2.10% KHCO3 and 1.10% NaCl). Overall, additional KHCO3 at the 2% level or NaCl at the 1% level did not improve performance or heat stress tolerance with these diet formulations. However, the addition of KHCO3 did enhance water intake. Independent of treatment effects, TT of cattle displaying high, moderate, or low levels of stress suggest that cattle that do not adequately cool down at night are prone to achieving greater body temperatures during a subsequent hot day. Cattle that are prone to get hot but can cool at night can keep average tympanic temperatures at or near those of cattle that tend to consistently maintain lower peak and mean body temperatures. In addition, during cooler and moderately hot periods, cattle change TT in a stair-step or incremental pattern, while under hot conditions, average TT of group-fed cattle moves in conjunction with ambient conditions, indicating that thermoregulatory mechanisms are at or near maximum physiological capacity.
Mader, T. L.; Gaughan, J. B.; Johnson, L. J.; Hahn, G. L.
Ciprofloxacin is a synthetic fluoroquinolone antibiotic that has been used for systemic treatment of otitis media in adults. It was approved for topical treatment of otorrhea in children with tympanostomy tubes. The aim of this work was to enhance the local non-invasive delivery of ciprofloxacin to the middle ear across an intact tympanicmembrane (TM) in an attempt to treat acute otitis media (AOM) ototopically. In order to achieve this goal, ciprofloxacin nano-transfersomal vesicles were prepared by thin film hydration (TFH) technique, using several edge activators (EAs) of varying hydrophilic-lipophilic balance (HLB) values. A full factorial design was employed for the optimization of formulation variables using Design-Expert(®) software. The optimal formulation was subjected to stability testing, ex-vivo permeation studies (through ear skin and TM of rabbits), and in-vivo evaluation. Results revealed that the optimal formulation (composed of phospholipid and sodium cholate as an EA at a molar ratio of 5:1) exhibited enhanced ex-vivo drug flux through ear skin and TM when compared with the commercial product (Ciprocin(®) drops). It demonstrated a greater extent of in-vivo drug deposition in the TM of albino rabbits relative to Ciprocin(®). Consequently, transfersomes could be promising for the non-invasive trans-tympanic delivery of ciprofloxacin. PMID:24971692
Al-Mahallawi, Abdulaziz Mohsen; Khowessah, Omneya Mohammed; Shoukri, Raguia Ali
32. VIEW OF TWIN FALLS MAIN CANAL FROM VICINITY OF PROPOSED POWER CANAL, LOOKING UPSTREAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
The Treaty calls for the establishment of the Panama Canal Commission to replace on October 1, 1979, the Canal Zone Government and Panama Canal Company presently responsible for administering Canal operations. The Treaty expires on December 31, 1999, at w...
1. DIVERSION GATE AT SPILLWAY, NORTH CANAL DAM (DIVERSION GATE FEEDING PIPE AT LOWER RIGHT), VIEW TO SOUTHWEST. - North Canal Dam & Diversion Canals, Deschutes Reclamation & Irrigation Company Canal, Empire Boulevard vicinity, Bend, Deschutes County, OR
The Isthmus of Corinth has played a very important role in the history of Greece. It is the only land bridge between the country's north (Attica) and south (Peloponnese). It is a 6 km wide tongue of land separating the Gulf of Corinth from the Saronic Sea. Populations, armies and commodities have got to move through it. In the 6th century BCE, the Greeks built the Diolkos, a 10 meter-wide stone roadway to pull ships across the Isthmus on wooden cylinders and wheeled vehicles. In 1882, a canal was started and completed 11 years later. It is 6343 meters long, 25 meters wide, and 8 meters deep. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: 25.3 by 37.7 kilometers (15.7 by 23.4 miles) Location: 37.9 degrees North latitude, 23 degrees East longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: May 9, 2005
The fine structure and the distribution of an esterase have been studied in the cuticle of Galleria larvae, Tenebrio larvae and pupae, and in the wax-secreting cuticle of the honey bee, and compared with those in the cuticle of the caterpillar of Calpodes. In Galleria and Tenebrio the pore canals are spaces passing through the lamellate endocuticle from the epithelium to the epicuticle. They contain a filament from the cells which may be concerned in their formation. The shape of the pore canal is probably determined by the orientation of the fibres making up the lamellae in the endocuticle and is not a regular helix. The pore canals also contain numerous filaments of another sort which pass on through the epicuticle and are believed to be the origin of the surface wax. They are particularly abundant in the pore canals of the honey bee wax-secreting cuticle and extend into the cell in long pockets surrounded by an envelope of the plasma membrane. The esterase is probably concerned with the final stage of wax synthesis, for its distribution is similar to that of the lipid filaments.
To report a rare case of maxillary canine with two root canals. The case describes the treatment of a maxillary canine with two root canals which was referred from department of prosthodontia for intentional root canal treatment for prosthetic rehabilitation. Clinical examination revealed a maxillary canine with carious lesion and responded within normal limits to electric pulp test. Radiographic examination revealed a distal carious lesion (close proximity to pulp) and also appeared to be an additional canal in this permanent maxillary canine.
The New York State Department of Health has been involved at the Love Canal since 1978. The State has carried out numerous environmental and toxicological studies. The major purposes for these studies were to define how Love Canal contaminants might be escaping into the environment at large, what paths contaminant migration might take, and what toxicological effects Love Canal chemicals
There are three types of the root canal sealers commonly used in clinical applications. They are calcium hydroxide base (Sealapex), zinc oxide–eugenol base (Canals), and epoxy-resin base (AH Plus). Elutable substances and degradation products from root canal sealers may gain access to periodontal tissue in a number of ways. The purpose of the present study was to evaluate the biologic
Tsui-Hsien Huang; Shinn-Jyh Ding; Ting-Zen Hsu; Zen-Dar Lee; Chia-Tze Kao
Background\\/Purpose: Anal canal duplication (ACD) is the most distal and the least frequent digestive duplication. A review of the English-language literature found 15 cases reported in the pediatric age group. Methods: A retrospective chart review was performed for our experience from 1999 to 2001 with 6 patients who presented with a midline postanal opening. Results: All of 6 patients were
Many years ago I saw a picture of a huge set of wheels that was used to remove tree stumps during the construction of the Erie Canal (1817-1825) and was intrigued by its use of leverage, mechanical advantage, and torque. Figure 1 is a scale model of the device based on my memory of the (lost) picture and published accounts.
Transduction in the semicircular canal was studied by focusing an infrared beam on either side of exposed ampullae from the posterior canals of Rana pipiens. The direction of fluid movement resulting from a stimulus was inferred by observing the polarity of the change in afferent impulse mean rate relative to the spontaneous value. On the basis of the accepted functional polarization of this receptor, the results indicate that fluid moved toward the warmer side of the ampulla. Convection and thermal reception were shown to be unlikely explanations for these results. Morover, cupular displacements toward the warmer side would not be expected. Because thermo-osmosis can cause fluid to move toward the warmer side in a gelatin membrane, the results can be interpreted as evidence that thermo-osmosis occurred in the gelatinous cupula and influenced the transduction mechanism. Thermo-osmosis of liquids appears to be due to an electric field that is set up in a charged membrane; hence, the hair cells might have detected an electric field that occurred in the cupula during thermo-osmosis. Electroreception might be an important link in the transduction of physiological stimuli also. Rotational stimuli could result in weak electric fields in the cupula by the mechanoelectric effect. Cupular displacements could be important for large stimuli, but extrapolations to threshold stimuli suggest displacements of angstrom amplitudes. Therefore, electroreception by the hair cells could be an explanation of the great sensitivity that has been observed in the semicircular canal and other labyrinthine receptors.
The mandibular canal transmits the inferior alveolar artery, vein and the inferior alveolar nerve. From an embryological perspective, there might be three inferior dental nerves innervating three groups of mandibular teeth. During rapid prenatal growth and remodeling in the ramus region there is spread of intramembranous ossification that eventually forms the mandibular canal. Occurrence of bifid/trifid mandibular canals in some patients is secondary to incomplete fusion of these three nerves. Various types of bifid mandibular canals have been classified according to anatomical location and configuration. This case report highlights an unusual variant of the mandibular canal. PMID:18197857
Fish use their lateral line system to detect minute water motions. The lateral line consists of superficial neuromasts and canal neuromasts. The response properties of canal neuromasts differ from those of superficial ones. Here, we report the design, fabrication, and characterization of an artificial lateral line canal system. The characterization was done under various fluid conditions, including dipolar excitation and turbulent flow. The experimental results with dipole excitation match well with a mathematical model. Canal sensors also demonstrate significantly better noise immunity compared with superficial ones. Canal-type artificial lateral lines may become important for underwater flow sensing.
Every vertebrate organism uses fluid-filled semi-circular canals (SCC) to sense angular rotation -- and thus to balance, navigate, and hunt. Whereas the size of most organs typically scales with the size of the organism itself, the SCC are all about the same size--whether in lizards, mice, humans or whales. What is so special about these dimensions? We consider fluid flow in the canals and elastic deformations of a sensory membrane, and isolate physical and physiological constraints required for successful SCC function. We demonstrate that the `parameter space' open to evolution is almost completely constrained; furthermore, the most sensitive possible SCC has dimensions that are remarkably close to those common to all vertebrates.
28 samples of tissue from the middle ear obtained at removal of chemodectoma were studied histologically. Investigation of the tympanic cavity mucosa has shown correlation between the severity of fibroatrophic changes in the middle ear mucosa and duration of the disease. Pathomorphological alterations in the middle ear mucosa at early stages of chemodectoma (stage I and II) are similar to those in chronic lingering mucositis. PMID:11510059
Antoniev, V F; Matela, I I; Rogov, K A; Popadiuk, V I
Selective brain cooling in humans, with venous blood returning from the head surface as the relevant heat sink, was proposed\\u000a more than two decades ago as a mechanism protecting the brain against damage in hyperthermic conditions. Brain cooling was\\u000a inferred from decreases of tympanic temperature under the premise that it reflected brain temperature closely, even in conditions\\u000a of external head
The purpose of this Cooperative Research and Development Agreement (CRADA) was to assess and develop control practices for nuisance algae growth in power canal that delivers water to hydro-generation facilities. This growth results in expenditures related not only to lost generation but also labor and materials costs associated with implementing remediation procedures. On an industry-wide basis these costs associated with nuisance algal growth are estimated to be several million dollars per year.
Three experiments were conducted to evaluate the effect of different management strategies on body temperature of feedlot steers finished in the summer months. In Exp. 1, 24 crossbred steers were chosen to assess the effect of altered feed intake and feeding time on tympanic temperature (TT) response. Managed feeding (MF) treatments were applied for 22 d only and provided 1) ad libitum access to feed at 0800 (ADLIB), 2) feed at 1600 with amount adjusted so that no feed was available at 0800 (BKMGT), 3) feed at 1600 at 85% of predicted ad libitum levels (LIMFD). During heat stress conditions on d 20 to 22 of MF, LIMFD and BKMGT had lower (P < 0.05) TT than ADLIB from 2100 through 2400. A carryover effect of limit-feeding was evident during a severe heat episode (d 36 to 38) with LIMFD steers having lower (P < 0.05) TT than ADLIB. In Exp. 2, TT were obtained from 24 crossbred steers assigned to three treatments, consisting of no water application (CON), water applied to feedlot mound surfaces from 1000 to 1200 (AM) or 1400 to 1600 (PM). From 2200 to 0900 and 1200 to 1400, steers assigned to morning sprinkling treatment had lower (P < 0.05) TT than steers assigned to afternoon sprinkling treatment. In Exp. 3, 24 steers were utilized in a 2 x 2 factorial arrangement of treatments with factors of feeding time [0800 (AMF) and 1400 (PMF)] and sprinkling (WET and DRY). Tympanic temperatures were monitored under hot environmental conditions on d 30 to 32 and 61 to 62. A feeding time x sprinkling interaction (P < 0.001) was evident on d 30 to 32, although AMF/DRY steers had the highest (P < 0.05) TT. On d 61 to 62, TT of PMF steers was higher (P < 0.05) than AMF between 1500 to 1800. Use of sprinklers can effectively reduce TT of feedlot cattle, whereas shifting to an afternoon vs morning feeding time was most beneficial when bunks were empty several hours prior to feeding. PMID:12661645
A study of the gains or losses of nine canals near Beaver, Utah, was made to aid in the water allocation of the canal systems. The canals included in this study are Manderfield Ditch, Last Chance Canal, Christiansen Ditch, Mammoth Canal, City Ditch, Owens Ditch, South Field Ditch, Patterson Ditch and Aberdare Canal. Four sets of seepage measurements were made during 1974, but flow was observed in all nine canals only during the set of measurements made in June. Adjustments for fluctuations in flow in the canals were made from information obtained from water-stage recorders operated at selected locations along the canals during the time of each seepage run.
179. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, September, 1912. Photographer unknown. VIEW OF LOW LINE CANAL, TWIN FALLS COUNTY; VIEW OF LOW LINE CANAL IN PETE LINK'S FIELD. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of
Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material 'entombs' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as
The objective of this case report is to help clinicians identify bifid mandibular canals on panoramic radiographs and subsequently use the information in the modification of dental treatment planning. A 45-year old man was referred to the service of Oral Diagnosis and Radiology. Routine panoramic radiography, suggested the presence of bilateral bifid mandibular canals (BMC). Mandibular computed tomography revealed a clear view of bilateral mandibular canals. BMC can be detected on a panoramic radiograph. PMID:19218898
Miloglu, Ozkan; Yilmaz, Ahmet Berhan; Caglayan, Fatma
The New York State Department of Health has been involved at the Love Canal since 1978. The State has carried out numerous environmental and toxicological studies. The major purposes for these studies were to define how Love Canal contaminants might be escaping into the environment at large, what paths contaminant migration might take, and what toxicological effects Love Canal chemicals might have individually and together. Although underground contaminant migration was hypothesized along swales and underground utility bedding, these mechanisms have been proven not to be operative except for some migration along the utility bedding under Frontier Avenue. In general no underground migration has occurred outside the confines of the three city blocks that contain the Love Canal referred to as the ''first ring''. Studies have been confused by apparent burial of waste materials in areas proximate but not directly connected to the Love Canal. Migration of Love Canal leachate has occurred through storm sewers. Love Canal contaminants have reached creeks to the north and the Niagara River to the south through storm sewer transport. In spite of finding 2, 3, 7, 8 tetrachlorodibenzoparadioxin (TCDD), toxicological studies in situ and through exposure to volatile components in Love Canal soils do not indicate unusual toxicity. Animal studies continue in an attempt to determine the teratogenic and fetotoxic potential of Love Canal chemicals under different routes of exposure.
The semicircular canal system of vertebrates helps coordinate body movements, including stabilization of gaze during locomotion. Quantitative phylogenetically informed analysis of the radius of curvature of the three semicircular canals in 91 extant and recently extinct primate species and 119 other mammalian taxa provide support for the hypothesis that canal size varies in relation to the jerkiness of head motion during locomotion. Primate and other mammalian species studied here that are agile and have fast, jerky locomotion have significantly larger canals relative to body mass than those that move more cautiously.
Spoor, Fred; Garland, Theodore; Krovitz, Gail; Ryan, Timothy M.; Silcox, Mary T.; Walker, Alan
...employees of the Canal Zone Merit System or Panama Canal Employment System. 315.601...employees of the Canal Zone Merit System or Panama Canal Employment System. (a) Agency...before March 31, 1982, or under the Panama Canal Employment System, which...
...employees of the Canal Zone Merit System or Panama Canal Employment System. 315.601...employees of the Canal Zone Merit System or Panama Canal Employment System. (a) Agency...before March 31, 1982, or under the Panama Canal Employment System, which...
We demonstrated specific responses from the anterior and the posterior semicircular canal to irrigation of the outer ear canal with cold water in the Rhesus monkey. This required i) three-dimensional analysis of the evoked eye movements in the planes of the semicircular canals (canal plane vectors, CPV); ii) assessing these CPV responses in eight different head positions relative to gravity; iii) comparing the responses in 6 normal animals (12 ears) with responses after selective plugging of pairs of semicircular canals (all, both lateral, and right anterior + left posterior). The results showed: i) Irrigation of the outer ear canal with cold water induces thermoconvection also in the posterior and anterior semicircular canals. This can be inferred from the sinusoidal modulation of eye movement components with changes in position of the corresponding semicircular canal plane relative to gravity; ii) Specific vertical canal responses occur exclusively in the direction of the corresponding semicircular canal, though they are superimposed with response components of other origin, one probably related to endolymph shift in the lateral semicircular canal; iii) before possible clinical application, these different response components of vertical canals will need to be determined in humans. PMID:8831835
Böhmer, A; Straumann, D; Suzuki, J; Hess, B J; Henn, V
10. DETAIL, SOUTHEAST SPAN THROUGH CANAL, VIEW BLOCKED BY STEEL, CLAD COUNTER WEIGHT, WATER SPAN RAISED OUT OF VIEW - Cape Cod Canal Lift Bridge, Spanning Cape Cod Canal, Buzzards Bay, Barnstable County, MA
31. VIEW OF TWIN FALLS MAIN CANAL BRIDGE FROM DOWNSTREAM LOOKING UPSTREAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
24. TWIN FALLS MAIN CANAL HEADWORKS, DOWNSTREAM LOOKING TOWARD THE EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
22. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
26. DETAIL OF HEADGATE HOIST MACHINERY, TWIN FALLS MAIN CANAL. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
29. VIEW OF TWIN FALLS MAIN CANAL BRIDGE FROM UPSTREAM LOOKING DOWNSTREAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
23. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING NORTHEAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
30. VIEW OF TWIN FALLS MAIN CANAL FROM BRIDGE LOOKING WEST DOWNSTREAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
15. VIEW OF GAGE IRRIGATION CANAL NEAR HILLTOP DRIVE AND BARTON ROAD, SHOWING END OF SIPHON. CANAL FOLLOWS CONTOUR OF HILL UNDER DIRT ROAD - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA
63. PLANS FOR PROPOSED HISTORICAL CANAL SECTION AND PUBLIC BOAT LAUNCH RAMP Plan Sheet D-29976, Venice Canals Rehabilitation, Sheet 25 of 26 (delineated by Manuel Bartolome, November 1991) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA
Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ
The region of the optic strut is sometimes traversed by some minor canals whose incidence and general characteristics have never been studied. As such canals could be the route for vessels that could interfere in the surgery of the orbital apex, we undertook a detailed anatomical study on a vast collection of dry skulls. The examination of 943 dry adult skulls and 360 foetal skulls was carried out to precise the anatomy of canals in the optic strut area, their development and relationships with the optic canal. A canal traversing the optic strut was present in 8.54 % of the orbits. Based on diameter, position within the optic strut, and thickness of the bony plate separating it from the optic canal or from the superior orbital fissure, the canals piercing the optic strut were classified into four types, which include the well-known duplication of the optic canal, different aspects of the metoptic canal and a type of canal that to our knowledge has never been reported. Warwick’s foramen was found in 0.74 % of orbits. The area of the optic strut is the frequent site of canals joining the orbit with the middle cranial fossa. Some of them can host the ophthalmic artery; others could be run by minor vessels which, however, could be the source of annoying bleedings in surgical procedures. PMID:23959928
Semicircular canal dehiscence is a congenital syndrome that mainly affects the superior and, less commonly, the posterior semicircular canals. The diagnosis of superior semicircular canal dehiscence syndrome depends on the demonstration of a very small defect in the bony wall of the superior semicircular canal. Any amount of intact bone present excludes the diagnosis. The study will give an approximation of the incidence of semicircular canal dehiscence in Singapore. No specific data regarding the number of such cases exist currently. Retrospective review of CT scans of the temporal bone performed at our institution between January 2005 and July 2007 revealed a total of 10 such cases over this period, comprising 8 males and 2 females, with all cases involving the superior semicircular canal. Almost all of the patients scanned had evidence of previous or existing cholesteatoma. Three patients had bilateral superior semicircular canal dehiscence (all males), with an almost equal number of semicircular canal dehiscence on both sides for both sexes. Our study shows no significant advantage to obtaining reformatted oblique sagittal images for all temporal bone studies, unless the visualized walls show questionable defects. In these cases, reconstructed images are probably advantageous and should be obtained and reviewed. PMID:19098078
Objectives\\/Hypotheses: To determine the symp- toms, signs, and findings on diagnostic tests in pa- tients with clinical manifestations of superior canal dehiscence. To investigate hypotheses about the ef- fects of superior canal dehiscence. To analyze the out- comes in patients who underwent surgical repair of the dehiscence. Study Design: Review and analysis of clinical data obtained as a part of
This paper provides general background information relating to the physical characteristics and operations of the Suez Canal. In connection with the future development of the Canal, the research programme currently being undertaken by a British consortium is outlined, with particular reference to the traffic system presently operating.
Waddington's (1942) notion of canalization has been widely invoked in developmental psychology to conceptualize species-typical regularities in behavioral development as genetically determined. In contrast, a developmental systems view, such as the one described in the present article, sees the genes as only one component in a hierarchy of influences, all of which contribute to canalize behavioral development. A key issue
An unusual and functionally insignificant variant of the internal auditory canal is presented. Marked dilatation of one canal was demonstrated by petrous bone tomography. Pantopaque cisternography revealed a large intracanalicular extension of the subarachnoid space with no evidence of tumor. No patients should undergo exploration of this region without prior Pantopaque studies.
Objective. Periapical periodontitis is an infectious and inflammatory disease of the periapical tissues caused by oral bacteria invading the root canal. In the present study, profiling of the microbiota in infected root canals was performed using anaerobic culture and molecular biological techniques for bacterial identification. Methods. Informed consent was obtained from all subjects (age ranges, 34–71 years). Nine infected root canals with periapical lesions from 7 subjects were included. Samples from infected root canals were collected, followed by anaerobic culture on CDC blood agar plates. After 7 days, colony forming units (CFU) were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Results. The mean bacterial count (CFU) in root canals was (0.5 ± 1.1) × 106 (range 8.0 × 101–3.1 × 106), and anaerobic bacteria were predominant (89.8%). The predominant isolates were Olsenella (25.4%), Mogibacterium (17.7%), Pseudoramibacter (17.7%), Propionibacterium (11.9%) and Parvimonas (5.9%). Conclusion. The combination of anaerobic culture and molecular biological techniques makes it possible to analyze rapidly the microbiota in infected root canals. The overwhelming majority of the isolates from infected root canals were found to be anaerobic bacteria, suggesting that the environment in root canals is anaerobic and therefore support the growth of anaerobes.
...2010-07-01 2010-07-01 false Franklin Canal. 117.445 Section 117...Requirements Louisiana Â§ 117.445 Franklin Canal. The draw of the Chatsworth Bridge, mile 4.8 at Franklin, shall open on signal from...
...2009-07-01 2009-07-01 false Franklin Canal. 117.445 Section 117...Requirements Louisiana Â§ 117.445 Franklin Canal. The draw of the Chatsworth bridge, mile 4.8 at Franklin, shall open on signal from 5...
The Corinth Canal crosses the isthmus of Corinth and is of great importance for Mediterranean navigation as well as the railroad and highway connections between southern and central Greece. In the century-long history of the Canal, the slopes have shown only minor stability problems despite their significant length, very steep inclination and, more importantly, the strong earthquakes that have frequently
A. G. Anagnostopoulos; N. Kalteziotis; G. K. Tsiambaos; M. Kavvadas
...2010-07-01 2010-07-01 false Houma Canal. 117.453 Section 117.453...Requirements Louisiana Â§ 117.453 Houma Canal. The draw of the S3197 bridge, mile 1.7 at Houma, shall open on signal if at least...
...2009-07-01 2009-07-01 false Houma Canal. 117.453 Section 117.453...Requirements Louisiana Â§ 117.453 Houma Canal. The draw of the S3197 bridge, mile 1.7 at Houma, shall open on signal if at least...
During instrumentation of the root canal, it is important to develop a continuously tapered form and to maintain the original shape and position of the apical foramen. However, the presence of curvatures may cause difficulty in root canal instrumentation. The ability to keep the instruments centered is essential to provide a correct enlargement, without excessive weakening of the root structure. Several studies have shown that Ni-Ti instruments remain significantly more centered and demonstrated less canal transportation than stainless steel files. Considerable research has been undertaken to understand the several factors related to an instrument's canal-centering ability. In this article, we have discussed the influence of various parameters such as alloys used in the manufacture of instruments, instrument cross-section, taper, and have given tips on canal-centering ability.
Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu; Porkodi, Ilango; Pradeep, Gali
Procedural accidents leading to complications such as canal transportation have been ascribed to inapt cleaning and shaping concepts. Canal transportation is an undesirable deviation from the natural canal path. Herewith a case of apical transportation of root canal resulting in endodontic retreatment failure and its management is presented. A healthy 21-year-old young male presented discomfort and swelling associated with painful endodontically retreated maxillary incisor. Radiograph revealed periradicular radiolucency involving underfilled 11 and overfilled 12. Insufficiently obturated 11 exhibited apical transportation of canal. This type III transportation was treated by periradicular surgery and repair using white mineral trioxide aggregate (MTA). Comfortable asymptomatic patient presented uneventful healing at third and fourth month recall visits. A decrease in the size of radiolucency in radiograph supported the clinical finding. In the present case, MTA is useful in repairing the transportation defect. The result of these procedures is predictable and successful.
Maxillary first molar with two palatal canals is rare. Clinicians should be aware of the normal anatomy of root canal system and vigilant about the possible existence of canal variation. A patient with acute episode of chronic pulpitis of 26, as presented by the case report, was examined to have four canals, which were the mesial buccal canal, the distal buccal canal, the mesial palatal canal and the distal palatal canal. When suspecting the existence of canal variation, clinicians should carefully explore the pulpal floor, further by changing the X-ray projection angle to confirm the existence of variation and prevent the missed canals, all of which are necessary for a successful root canal therapy. PMID:23852074
Background It has been believed that location of the perforation has a significant impact on hearing loss. However, recent studies have demonstrated that the perforation sites had no impact on hearing loss. We measured the velocity and pattern of the manubrium vibration in guinea pigs with intact and perforated eardrum using a laser Doppler vibrometer in order to determine the effects of different location perforations on the middle ear transfer functions. Methods Two bullas from 2 guinea pigs were used to determine stability of the umbo velocities, and 12 bullas from six guinea pigs to determine the effects of different location perforations on sound transmission. The manubrium velocity was measured at three points on the manubrium in the frequencies of 0.5–8 kHz before and after a perforation was made. The sites of perforations were in anterior-inferior (AI) quadrants of left ears and posterior-inferior (PI) quadrants of right ears. Results The manubrium vibration velocity losses were noticed in the perforated ears only below 1.5 kHz. The maximum velocity loss was about 7 dB at 500 Hz with the PI perforation. No significant difference in the velocity loss was found between AI and PI perforations. The average ratio of short process velocity to the umbo velocity was approximately 0.5 at all frequencies. No significant differences were found before and after perforation at all frequencies (p>0.05) except 7 kHz (p?=?0.004) for both AI and PI perforations. Conclusions The manubrium vibration velocity losses from eardrum perforation were frequency-dependent and the largest losses occur at low frequencies. Manubrium velocity losses caused by small acute inferior perforations in guinea pigs have no significant impact on middle ear sound transmission at any frequency tested. The manubrium vibration axis may be perpendicular to the manubrium below 8 kHz in guinea pigs.
The comprehensive environmental study which describes the results of a monitoring program conducted by EPA at Love Canal is evaluated by EPA's former study director. Attention is focused on the episode's history and the agency's study methods. The aim of the program was to constitute a study team, design a monitoring study, reprogram and reallocate the financial resources needed to conduct the study, and identify and employ contractors who would collect and analyze environmental samples. The agency was directed to ensure the quality of the data acquired from various environmental media and analyzed by numerous laboratories; to integrate, interpret, and report the data; and to assess, from an environmental perspective, the habitability of the area.
Objective: To describe and illustrate three distinct surgical approaches that permit exposure and resection of extradural, intradural, and transdural lesions involving the hypoglossal canal. Study design: Case series. Setting: University medical center. Patients: Four patients with lesions of the hypoglossal canal were reviewed to illustrate our philosophy when selecting a surgical approach to the hypoglossal canal. Interventions: Three separate surgical approaches were used to approach lesions involving various segments of the hypoglossal canal. Main outcome measures: Initial clinical presentation, tumor type, treatment course, complications and functional outcomes of hearing, lower cranial nerves, and great vessels. Results: A modified pre- and postauricular infratemporal fossa approach was used to permit the complete resection of an extradural hypoglossal canal schwannoma. The far lateral approach was used to remove a posterior fossa meningioma that involved the intradural hypoglossal canal. A transjugular craniotomy was used to resect a jugulotympanic paraganglioma with transdural hypoglossal canal involvement. Postoperatively, there were no major complications. However, one patient had cerebrospinal fluid rhinorrhea that resolved with lumbar subarachnoid drainage and another had a pseudomeningocele that resolved spontaneously. Dysphagia was not observed in any patient and all were discharged within 1 week of surgery. All patients are free of recurrence by clinical and radiographic examination with at least 2 years of follow-up. Conclusions: Lesions of the hypoglossal canal can be safely and effectively resected using the appropriate skull base approach. The three skull base approaches described herein provide access to selected portions of the hypoglossal canal and allow for preservation of hearing, the lower cranial nerves, and great vessels.
Calzada, Gabriel; Isaacson, Brandon; Yoshor, Daniel; Oghalai, John S.
Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Department of Endodontics, Tabriz University of Medical Sciences, Iran.
97. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; OVERALL WEST VIEW FROM CANAL SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
158. Photocopy of transit book (taken from Twin Falls Canal Company Transit Book #404T, Page 3, #46, Division One). START OF MAIN CANAL SURVEY, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
28. VIEW FROM IMMEDIATELY DOWNSTREAM OF TWIN FALLS MAIN CANAL HEADWORKS WITH CANAL BRIDGE IN DISTANCE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
131. FORKS DIVERSION, HIGH LINE AND LOW LINE CANALS, TWIN FALLS COUNTY, SOUTH OF HANSEN, IDAHO; INLET SIDE OF LOW LINE CANAL, WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
154. Photocopy of transit book (taken from Twin Falls Canal Company Surveyor's Transit Book #405T, Page 2, #46 Division One). STATEMENT OF SIGHT-SETTING FOR 1903 SURVEY TO ALIGN SOUTH SIDE CANAL, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
177. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, September, 1912. Photographer unknown. COTTONWOOD FLUME, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; SOUTH VIEW FROM UPPER SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
94. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; CLOSE-UP OF GATES FROM THE CANAL SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
91. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; NORTHEAST VIEW OF CANAL AND GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
150. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Book #363, Page 42, entitled, 'Diversion Tunnels', located in Twin Falls Canal Company office, Twin Falls, Idaho). PLAN OF DIVERSION TUNNELS, MILNER DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ROCK CREEK CROSSING, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
89. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; OUTLET SIDE OF CANAL, SOUTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
149. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; CLOSE-UP OF MAIN CANAL GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
88. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; WEST VIEW OF CANAL AND GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
180. Photocopy of Photograph, Twin Falls Canal Company. E. Pettygro, Photographer, date unknown. BLASTING TWIN FALLS CANAL, TWIN FALLS COUNTY; BLASTING COTTONWOOD AREA TO REPLACE FLUME BY RUNNING HIGH LINE THROUGH SOLID ROCK. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
123. MCMULLEN CREEK, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; SOUTH VIEW OF THE CREEK EMPTYING INTO THE HIGH LINE CANAL. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
At the request of the U.S. Department of Agriculture, Soil Conservation Service, and the Menard Irrigation Company, a seepage investigation was made on Noyes Canal (Menard Irrigation Company Canal) in Menard County, Texas, from the headgates of the canal to where the canal empties back into the San Saba River.
3. Dundee Canal looking northwest from north of Dundee Textile Company Mill - Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ
44. CROSS SECTION OF GRAND CANAL (not to scale, but representative of all six canals) Plan Sheet D-29976, Venice Canals Rehabilitation, Sheet No. 7 of 26 (delineated by T. Wu and E. Lee, March 1991) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA
This case report illustrates the nonsurgical endodontic management of a seven-canaled mandibular second molar. The root canal configuration presented as four mesial and three distal canals. Identification of the canal system was made with the aid of magnification, ultrasonics, and multiple angulated radiographs. Postoperative examination at 18 months showed a clinically asymptomatic tooth with resolution of the periapical pathology. PMID:24634902
7. View north at back (canal side) of culvert inlet, with canal bank completely removed. Background to foreground: back of inlet headwall with tops of high inlet barrels exposed; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall at site of former canal edge of canal bank; dewatered canal bed and plank sheathing on top of culvert barrels beneath canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ
During the summer and fall of 1980 the U.S. Environmental Protection Agency (EPA) conducted a comprehensive multimedia environmental monitoring program in the vicinity of the inactive hazardous wastes landfill known as Love Canal, located in Niagara Falls...
During the summer and fall of 1980 the U.S. Environmental Protection Agency (EPA) conducted a comprehensive multimedia environmental monitoring program in the vicinity of the inactive hazardous wastes landfill known as Love Canal, located in Niagara Falls...
The results of computer simulation of both natural and modified cumulus clouds appropriate to the Panama Canal Zone were analyzed to derive tables of the probability of increasing or decreasing rainfall, the expected amounts of rainfall increase or decrea...
We report a 76-year-old man, a retired farmer, presenting with bilateral external auditory canal obstruction. Skin examination revealed multiple pruritic nodules and periorbital purpura. Ear canal opening surgery was performed. Skin and ear canal biopsy revealed extensive amyloid depositions. Immunoelectrophoresis for urinary Bence-Jones protein was positive, and bone marrow examination showed plasma cell dyscrasia. He received chemotherapy for amyloid light-chain amyloidosis secondary to light-chain multiple myeloma but died from myeloma progression. This case demonstrated how infiltrative conditions such as amyloidosis can lead to bilateral auditory canal obstruction and that the diagnosis of amyloidosis can be missed if a clinician focuses solely on a single organ. PMID:24825551
The four volumes in this set comprise the working guideline documents for the Love Canal Study. The documents were developed to direct both the prime contractor and subcontractors while performing for the Environmental Protection Agency. Detailed procedur...
8. VIEW SHOWING THE DEMOSSING OF GRAND CANAL LOCATION UNKNOWN. AT TEAM OF HORSES ON OPPOSITE BANKS OF THE CANAL DRAG A CHAIN BETWEEN THEM ALONG THE BOTTOM OF THE CANAL, WHICH PULLS THE MOSS AND WEEDS LOOSE. THE PLANS THEN FLOAT DOWN THE CANAL AND ARE CAUGHT IN A SCREEN AND REMOVED. Photographer unknown, 1923 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ
Extensive Mayan-built irrigation canals, hidden for more than 1,000 years beneath dense rain forest in Guatemala, have been revealed by a new radar system developed by the Jet Propulsion Laboratory (JPL). The radar's unveiling of the ancient canal systems, dug by the Maya between 250 B.C. and 900 A.D. in Guatemala and the neighboring country of Belize, may answer a
Dr. Becker visited the Canal Zone in 1913 as a geologist of the United States Geological Survey and since that time has given the problem the benefit of his study. His appointment as a member of the committee of the National Academy of Sciences has made it appropriate for his conclusions, based upon his personal observations and already reported in part to the Canal Commission, to be stated for the benefit of his associates and other American scientists and engineers.
Ovular morphology was examined ultrastructurally inPseudotsuga menziesii to determine the effects of the ovule on pollen development. Vesicles containing lipid-like substances traverse cell walls\\u000a of the inner epidemis of the integument and release their contents at the integument surface to form the integumentary membrane.\\u000a A major aqueous secretion from the integument into the micropylar canal is proposed to occur by
Summary Parasitoid wasps produce virulence factors that bear significant resemblance to viruses and have the ability to block host defense responses. The function of these virulence factors, produced predominantly in wasp venom glands, and the ways in which they interfere with host development and physiology remain mysterious. Here, we report the discovery of a specialized system of canals in venom glands of five parasitoid wasps that differ in their infection strategies. This supracellular canal system is made up of individual secretory units, one per secretory cell. Individual units merge into the canal lumen. The membrane surface of the proximal end of each canal within the secretory cell assumes brush border morphology, lined with bundles of F-actin. Systemic administration of cytochalasin D compromises the integrity of the secretory unit. We show a dynamic and continuous association of p40, a protein of virus-like particles from a Drosophila parasitoid, L. heterotoma, with the canal and venom gland lumen. Similar structures in three Leptopilina species and Ganaspis xanthopoda, parasitoids of Drosophila spp., and Campoletis sonorenesis, a parasitoid of Heliothis virescens, suggest that this novel supracellular canal system is likely to be a common trait of parasitoid venom glands that is essential for efficient biogenesis and delivery of virulence factors.
The basilar membrane in gerbil differs from most other mammals, since its width and thickness show little variation from base to apex, and tympanic fiber layer in the pectinate zone forms a pronounced arch. Measurements indicate a quadratically increasing stiffness under point loading, which is contrary to the expected behavior of an arch. The plateau value has been considered to be the physiologically relevant stiffness, but it only occurs after 10-25 ?m of deflection, whereas the normal physiological deflection is in the submicron range. The present work aims to resolve these contradictions by considering the mechanics of the geometric configuration.
Kapuria, Santosh; Steele, Charles R.; Puria, Sunil
Two Macaca (fascicularis) monkeys were used to study the effect of two warm endodontic condensation techniques (Endotec and vertical condensation method) on periodontal tissues. The specimens were histologically evaluated at 3 and 32 days after the endodontic treatments were completed. In this study the periodontium was divided into coronal, middle, and apical thirds. Results indicated that there was no heat-related damage to periodontal tissues from either of the two methods employed. However, some Endotec specimens generated small, reactive inflammatory infiltrates that were restricted to the root canal opening or adjacent periodontal membrane. Similarly, some vertical condensation specimens developed periapical inflammatory processes as well, but they were more extensive and comprised the alveolar bone and marrow spaces. PMID:2011357
Castelli, W A; Caffesse, R G; Pameijer, C H; Diaz-Perez, R; Farquhar, J
The purpose of this in vitro study was to evaluate the ability of a silicon-based root canal sealer, compared to zinc oxide and eugenol and an epoxy resin-based sealers, for filling of simulated lateral canals. Thirty extracted single-rooted human teeth were selected, conventional access was made and the working length was established 1 mm from the apical foramen. Three simulated lateral canals, one in each root third (coronal, middle and apical) were prepared in both the mesial and distal surfaces of each tooth using a size 15 reamer adapted to a low-speed handpiece. Each root canal was instrumented using ProTaper rotary files up to file F3 at the working length, and then irrigated with 2.5% NaOCl followed by EDTA. The teeth were assigned to 3 groups (n=10), according to the root canal sealer: Roeko Seal (Group 1), Sealer 26 (group 2) and Grossman's sealer (Group 3). Gutta-percha cold lateral condensation technique was performed in all groups. Postoperative radiographs were taken and the images were projected for evaluation of the quality of lateral canal filling. Data were submitted to statistical analysis by Kruskal Wallis test at 5% significance level. The results showed that Grossman's sealer filled a larger number of lateral canals than Roeko Seal (p<0.05) and Sealer 26 (p<0.01). It may be concluded that Roeko Seal silicone-based root canal sealer was not as effective as the Grossman's sealer for filling of simulated lateral canals. The lateral canals localized in the apical third of the root were more difficult to be filled. PMID:17639195
Barbizam, João Vicente Baroni; Souza, Matheus; Cecchin, Doglas; Dabbel, Jakob
The use of infrared tympanic thermometers for monitoring patient health is widespread. However, studies into the performance of these thermometers have questioned their accuracy and repeatability. To give users confidence in these devices, and to provide credibility in the measurements, it is necessary for them to be tested using an accredited, standard blackbody source, with a calibration traceable to the International Temperature Scale of 1990 (ITS-90). To address this need the National Physical Laboratory (NPL), UK, has recently set up a primary ear thermometer calibration (PET-C) source for the evaluation and calibration of tympanic (ear) thermometers over the range from 15 °C to 45 °C. The overall uncertainty of the PET-C source is estimated to be +/- 0.04 °C at k = 2. The PET-C source meets the requirements of the European Standard EN 12470-5: 2003 Clinical thermometers. It consists of a high emissivity blackbody cavity immersed in a bath of stirred liquid. The temperature of the blackbody is determined using an ITS-90 calibrated platinum resistance thermometer inserted close to the rear of the cavity. The temperature stability and uniformity of the PET-C source was evaluated and its performance validated. This paper provides a description of the PET-C along with the results of the validation measurements. To further confirm the performance of the PET-C source it was compared to the standard ear thermometer calibration sources of the National Metrology Institute of Japan (NMIJ), Japan and the Physikalisch-Technische Bundesanstalt (PTB), Germany. The results of this comparison will also be briefly discussed. The PET-C source extends the capability for testing ear thermometers offered by the NPL body temperature fixed-point source, described previously. An update on the progress with the commercialisation of the fixed-point source will be given.
One of the most important developments in the existence of human society was the successful shift from a subsistence economy based on foraging to one primarily based on food production derived from cultivated plants and domesticated animals. The shift to plant food production occurred in only a few independent centers around the world and involved a commitment to increased sedentism and social interaction and to permanent agricultural fields and canals. One center was Peru, where early civilization and food production were beginning to develop by at least 4,500 years ago. New archeological evidence points to 5,400- and possible 6,700-year-old small-scale gravity canals in a circumscribed valley of the western Andean foothills in northern Peru that are associated with farming on low terrace benches at the foot of alluvial fans in areas where the canals are drawn from hydraulically manageable small lateral streams. This evidence reveals early environmental manipulation and incipient food production in an artificially created wet agroecosystem rather than simply the intensive harvesting or gardening of plants in moist natural areas. This finding is different from previously conceived notions, which expected early canals in lower-elevated, broad coastal valleys. The evidence also points to communal organization of labor to construct and maintain the canals and to the scheduling of daily activities beyond individual households. The development of early organized irrigation farming was combined with a hunting and gathering economy to support an increase in the local population size.
This clinical article describes 4 different case reports of maxillary first molars with unusual anatomy of 6 root canals and their endodontic management. Treating these additional canals in maxillary first molars might be challenging. Inability to locate and properly treat these extra canals might lead to failures. A thorough knowledge of root canal morphology and the proper use of microscopes increase chances for successful clinical results. Because presence of these extra canals is not unusual and naming these canals still remains elusive, a new nomenclature is suggested for ease of communication. PMID:20478469
...All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules of Navigation, part IV. (c) Panama Canal and Suez Canal tonnage certificates are in...
...All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules of Navigation, part IV. (c) Panama Canal and Suez Canal tonnage certificates are in...
...All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules of Navigation, part IV. (c) Panama Canal and Suez Canal tonnage certificates are in...
2. SECONDARY DIVERSION GATE, NORTH/PILOT BUTTE CANAL, VIEW TO THE SOUTHWEST. - North Canal Dam & Diversion Canals, North Canal, North Division Street & U.S. Highway 97 vicinity, Bend, Deschutes County, OR
Spontaneous cerebrospinal fluid (CSF) leaks from the fallopian canal are extremely rare, as only a few cases have been reported in the world literature. We describe a case of spontaneous CSF otorrhea through an enlarged geniculate fallopian canal. The patient was a 45-year-old woman who presented with a history of CSF rhinorrhea and otorrhea from the right ear. Myringotomy and tube insertion revealed CSF otorrhea. Contrast-enhanced computed tomography revealed that the geniculate fossa was smoothly enlarged (demonstrating remodeling of bone). A middle fossa craniotomy with temporal bone exploration was performed. Intraoperative inspection detected the presence of a fistula secondary to a lateral extension of the subarachnoid space through the labyrinthine segments of the fallopian canal. We discuss the management of this unusual finding, which involves sealing the fistula while preserving facial nerve function. PMID:23532657
During sustained constant velocity and low-frequency off-vertical axis rotations (OVAR), otolith signals contribute significantly to slow-phase eye velocity. The adaptive plasticity of these responses was investigated here after semicircular canal plugging. Inactivation of semicircular canals results in a highly compromised and deficient vestibulo-ocular reflex (VOR). Based on the VOR enhancement hypothesis, one could expect an adaptive increase of otolith-borne angular velocity signals due to combined otolith/canal inputs after inactivation of the semicircular canals. Contrary to expectations, however, the steady-state slow-phase velocity during constant velocity OVAR decreased in amplitude over time. A similar progressive decrease in VOR gain was also observed during low-frequency off-vertical axis oscillations. This response deterioration was present in animals with either lateral or vertical semicircular canals inactivated and was limited to the plane(s) of the plugged canals. The results are consistent with the idea that the low-frequency otolith signals do not simply enhance VOR responses. Rather, the nervous system appears to correlate vestibular sensory information from the otoliths and the semicircular canals to generate an integral response to head motion.
Growing the intracellular bridges that connect nurse cells with each o ther and to the developing oocyte is vital for egg development. These ring canals increase from 0.5 microns in diameter at stage 2 to 10 microns in diameter at stage 11. Thin sections cut horizontally as you would cut a bagel, show that there is a layer of circumferentially oriented actin filaments attached to the plasma membrane at the periphery of each canal. By decoration with subfragment 1 of myosin we find actin filaments of mixed polarities in the ring such as found in the "contractile ring" formed during cytokinesis. In vertical sections through the canal the actin filaments appear as dense dots. At stage 2 there are 82 actin filaments in the ring, by stage 6 there are 717 and by stage 10 there are 726. Taking into account the diameter, this indicates that there is 170 microns of actin filaments/canal at stage 2 (pi x 0.5 microns x 82), 14,000 microns at stage 9 and approximately 23,000 microns at stage 11 or one inch of actin filament! The density of actin filaments remains unchanged throughout development. What is particularly striking is that by stages 4-5, the ring of actin filaments has achieved its maximum thickness, even though the diameter has not yet increased significantly. Thereafter, the diameter increases. Throughout development, stages 2-11, the canal length also increases. Although the density (number of actin filaments/micron2) through a canal remains constant from stage 5 on, the actin filaments appear as a net of interconnected bundles. Further information on this net of bundles comes from studying mutant animals that lack kelch, a protein located in the ring canal that has homology to the actin binding protein, scruin. In this mutant, the actin filaments form normally but individual bundles that comprise the fibers of the net are not bound tightly together. Some bundles enter into the ring canal lumen but do not completely occlude the lumen. all these observations lay the groundwork for our understanding of how a noncontractile ring increases in thickness, diameter, and length during development. PMID:8601614
The success of the endodontic treatment depends on the microbial suppression in the root canal and periapical region. Endodontic instrumentation alone cannot achieve a sterile condition. With the advent of non-instrumentation endodontic treatment and lesion sterilization and tissue repair, local application of antibiotics has been investigated. Triple antibiotic paste (TAP) containing metronidazole, ciprofloxacin, and minocycline has been reported to be a successful regimen in controlling the root canal pathogen and in managing non-vital young permanent tooth. This paper reviews the existing literature on biocompatibility, efficiency, drawbacks of TAP in endodontic therapy and pulp revascularization.
35. VIEW SHOWING THE HEAD OF THE ARIZONA CANAL AT GRANITE REEF DAM, LOOKING WEST. GATEKEEPER'S HOUSE IS IN THE BACKGROUND Photographer: James Eastwood, June 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
9. VIEW SHOWING ARIZONA CANAL WITH CITRUS ORCHARDS, FACING NORTH. CAMELBACK MOUNTAIN IS IN THE BACKGROUND Photographer: unknown. No date - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
33. VIEW SHOWING THE REMAINS OF THE ORIGINAL ARIZONA CANAL HEADING, ARIZONA DAM, LOOKING EAST Photographer: Mark Durben, December 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
5. VIEW SHOWING DREDGING OF ARIZONA CANAL NEAR THE GRANITE REEF DAM. SOUTH INTAKE OF THE DAM IS IN THE BACKGROUND Photographer: Walter J. Lubken. March 1908 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
39. VIEW OF HORSE AND ESCAPE STEPS ON ARIZONA CANAL, LOOKING NORTH ON THE SALT RIVER INDIAN RESERVATION Photographer: James Eastwood, June 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
55. VIEW OF WEST ENTRANCE BRIDGE CROSSING THE ARIZONA CANAL AT THE ARIZONA BILTMORE, LOOKING EAST Photographer: Kevin Kriesel-Coons, May 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
1. VIEW OF ARIZONA FALLS ON THE ARIZONA CANAL, PRIOR TO CONSTRUCTION OF POWER PLANT IN 1901, FACING EAST Photographer: unknown. No date. - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
38. VIEW SHOWING SITE OF THE OLD ARIZONA CANAL POWER HOUSE, LOOKING SOUTH ON THE SALT RIVER INDIAN RESERVATION (NOW SPILLWAY A) Photographer: James Eastwood, June 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
49. VIEW OF ARIZONA CANAL AT SCOTTSDALE ROAD, LOOKING NORTHWEST. DECORATIVE FOOTBRIDGE AND GATES ARE VISIBLE Photographer: James Eastwood, July 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
7. VIEW OF ARIZONA CANAL ABOVE EVERGREEN, SHOWING LACK OF SILT. OLD TOOTH MARKS OF DRAGLINE BUCKET MADE IN 1909 CALICHE BOTTOM WERE STILL VISIBLE Photographer: unknown. February 1938 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
4. VIEW SHOWING EXCAVATION IN ARIZONA CANAL, 8 MILES NORTHEAST OF PHOENIX. NOTE MEN DRILLING AND EXCAVATING IN OPERATION; CAMELBACK MOUNTAIN IN THE DISTANCE Photographer: Walter J. Lubken. No date - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
MAIN CANAL HEADWORKS, FROM DOWNSTREAM (TO RIGHT), NOTE SAND AND SILT SLUICE GATE FOR DIVERSION DAM ON LEFT, VIEW TO NORTHWEST - Salmon Creek Diversion Dam, Main Canal Headworks, Salmon Creek, Okanogan, Okanogan County, WA
53. LAYOUT OF POWER CANAL LINE, LIST OF STRUCTURES Courtesy of Reclamation Service, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
60. ROOSEVELT POWER CANAL, FLUME AT STA. 973 Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
8. A COMPLETED CULVERT ON THE POWER CANAL LOCATED ABOUT FOUR MILES EAST OF ROOSEVELT Photographer: Walter J. Lubken, March 29, 1905 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
76. CONDENSED PROFILE OF ROOSEVELT POWER CANAL Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
54. PLAT OF POWER CANAL NO. 1, SHOWING LOCATION OF STRUCTURES, ETC. Courtesy of the Dept. of the Interior, U. S. Reclamation Service, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
9. LOOKING EAST UP THE POWER CANAL SHOWING A WOODEN FLUME, CUT AND COVER AND TUNNEL NO. 10 Photographer: Walter J. Lubken, February 21, 1906 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
78. POWER CANAL DIVERSION DAM, EXISTING STRUCTURE Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
5. SCRAPERS AT WORK ON THE POWER CANAL, TWO MILES EAST OF LIVINGSTONE, ARIZONA Photographer: Walter J. Lubken, August 1, 1904 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
12. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND BARTON ROAD SHOWING BEGINNING OF SIPHON, DATED '1952' - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA
Bitter Root Irrigation district canal, looking east, typical section and crossing - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT
23. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1917. VIEW OF FLUME NO. 3 OF GAGE IRRIGATION CANAL AND NEW 66' REINFORCED CONCRETE PIPELINE - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
The Deschutes Canal-Lining Demonstration Project is a cooperative effort among the Bureau of Reclamation, several irrigation districts, and several geosynthetic lining manufacturers. The purpose of the study is to develop low-cost canal-lining technologie...
7. VIEW OF MAIN CANAL, LOOKING SOUTH, IMMEDIATELY DOWNSTREAM FROM THE SNAKE RIVER VALLEY IRRIGATION DISTRICT, SECTION 34, T2N, R37E - Woodville Canal Company, West side of Snake River (River Mile 796), Woodville, Bingham County, ID
6. REMAINS OF PLANK WALL NAILED TO POSTS WITHIN CANAL CONSTRUCTED TO PROTECT OUTSIDE CANAL BANK. VIEW IS TO THE WEST. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
7. REMAINS OF PLANK WALL WITHIN CANAL CONSTRUCTED TO PROTECT OUTSIDE CANAL BANK, LOOKING SOUTHWEST. NOTE CROSS SUPPORT POLES EXTENDING TO HILLSIDE. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
122. Jet Lowe, Photographer, July 1978. POWER CANAL LOOKING NORTH. WOODEN LINING OF CANAL STILL VISIBLE NEXT TO ROCKS. - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI
31. Floating original Ship Canal draw (in background) to University Heights location. New Ship Canal draw in foreground. June 1906 photograph. - University Heights Bridge, Spanning Harlem River at 207th Street & West Harlem Road, New York, New York County, NY
1. CONTEXTUAL VIEW OF THE IRRIGATION CANAL BRIDGE, LOOKING NORTHWESTERLY. - Washington Water Power Company Post Falls Power Plant, Irrigation Canal Bridge, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID
79. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME - LONGITUDINAL SECTIONS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
81. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUMES - CENTER BENT DETAILS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
80. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME - FLUME DETAILS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
View north, north wall of canal, hoboken rail yard in background. - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Long Slip Canal, New Jersey Transit Hoboken Rail Yard, Hoboken, Hudson County, NJ
View north, west (back) wall of canal, mu shed in background. - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Long Slip Canal, New Jersey Transit Hoboken Rail Yard, Hoboken, Hudson County, NJ
View east, view of full length of canal, west wall pileheads in foreground. - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Long Slip Canal, New Jersey Transit Hoboken Rail Yard, Hoboken, Hudson County, NJ
13. VIEW OF WESTERN CANAL EAST OF CARRIAGE LANE IN TEMPE, SHOWING DROP STRUCTURE AND GROUNDWATER PUMP. THIS IS THE LAST OF FOUR PUMPS WHICH FEED DIRECTLY INTO THE CANAL BETWEEN ALMA SCHOOL ROAD AND PRICE ROAD. ON THIS DAY, ALL FOUR PUMPS, OPERATING AT FULL OUTPUT, HAVE CONSIDERABLY SWELLED THE FLOW TO THE CANAL. NOTE THE OLD FASHIONED BRICKWORK ON THE NORTH BANK. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ
28. MAIN CANAL - Photographic copy of historic photo, July 18, 1906 (original print located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) J.J. Lubken, photographer 'LOOKING SOUTH FROM STATION 413, ON THE MAIN CANAL, SHOWING THE REMODLING SIC OF THE OLD PECOS VALLEY IRRIGATING CANAL' - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM
14. VIEW OF WESTERN CANAL AT THE SALT RIVER PROJECT'S KYRENE STEAM POWER PLANT, TEMPE. THE WESTERN CANAL BEGINS TO TURN NORTH AT THIS POINT, AND DIVERTS WATER TO THE HIGHLINE PUMP PLANT AND THE KYRENE LATERAL. THE KYRENE PLANT INLET (LEFT-CENTER) ALSO DIVERTS CANAL WATER FOR PLANT OPERATION AND COOLING. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ
6. View southwest, culvert inlet with canal bank completely removed. Left to right: back of headwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall along former edge of canal bank; dewatered canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ
Although the Suez Canal is the most important man-made waterway in the world, rivaled perhaps only by the Panama Canal, little research has been done into forecasting its traffic flows. This paper uses both univariate ARIMA (Autoregressive Integrated Moving Average) and Neural network models to forecast the maritime traffic flows in the Suez Canal which are expressed in tons. One
25. TWIN FALLS MAIN CANAL HEADWORKS FROM UPSTREAM LOOKING TOWARD THE WEST (DAM-TENDER RICHARD CARL ADJUSTING THE GATES TO ALLOW 3400 CFS THROUGH). - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
19. Photocopied August 1978. CANAL SECTION I, LOOKING EAST, 1900, WITH SEVERAL PARTIALLY SUBMERGED STEAM SHOVELS SHOWN IN THE FLOODED CANAL. ONE OF THE TEMPORARY BRIDGES CONSTRUCTED OVER THE CANAL RIGHT -OF-WAY IS VISIBLE IN THE BACKGROUND. (39) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI
...2010-01-01 2010-01-01 false Panama Canal Commission employees. 550.714...GENERAL) Severance Pay Â§ 550.714 Panama Canal Commission employees. (a...employee separated from employment with the Panama Canal Commission as a result of the...
...2009-01-01 2009-01-01 false Panama Canal Commission employees. 550.714...GENERAL) Severance Pay Â§ 550.714 Panama Canal Commission employees. (a...employee separated from employment with the Panama Canal Commission as a result of the...
4. Lower end of the Old Crosscut Canal, aerial overhead view. Old Crosscut runs top right to center, west of sheds and piles; Grand Canal runs lower right to center left. Note control gates on Grand, but no wasteway. Photographer unknown, 1952. Source: Pueblo Grande Museum cultural Park. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ
Summary Spinal canal areas were measured prospectively in 22 consecutive burst fractures of the thoracolumbar junction, preoperatively, within 1 week postoperatively and 1 year after operation. Preoperative canal encroachment averaged 38% (range 10%–70%) of the estimated original area. The 11 patients with neurological impairment had a significantly more severe initial canal encroachment (mean 48%) than those who were neurologically intact
L. Sjiistriim; O. Jacobsson; G. Karlstriim; P. Pech; W. Rauschning
187. Photocopy of drawing, Twin Falls Canal Company, date unknown. TOPOGRAPHICAL MAP OF MILNER DAM LOCATION, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT MAP. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
182. Photocopy of Photograph, Twin Falls Canal Company. Photographer and date unknown. MILNER DAM TUNNELS, TWIN FALLS COUNTY, MILNER, IDAHO; APPROACH TO TUNNELS. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
183. Photocopy of map (Twin Falls Canal Company). TOPOGRAPHICAL MAP OF MILNER DAM SITE, TWIN FALLS COUNTY, MILNER, IDAHO; MAP, LEFT SIDE ONLY. CROSS REFERENCE: ID-15-192. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
141. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, IDAHO; CLOSE-UP OF MAIN HEADGATES, RADIAL GATES INSIDE, SOUTHEAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
90. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; CLOSE-UP OF GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
99. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; CLOSE-UP OF OUTLET SIDE OF GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
137. TWIN FALLS SOUTH SIDE MAIN CANAL DIVERSION HEADGATES, TWIN FALLS COUNTY, MILNER, IDAHO; OVERALL VIEW OF MAIN HEADGATES, DAM IN BACKGROUND. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
151. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Transit Book #363, Page 20). SURVEY PRINT SHOWING POINT SPILLWAY AND FIELD NOTES, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
191. Photocopy of drawing, Twin Falls Canal Company, date unknown. SPILLWAY GATES, MILNER DAM, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
110. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; INLET SIDE WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
93. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF KIMBERLY, IDAHO; OVERALL NORTHEAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
113. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; CLOSE-UP OF INLET SIDE OF SIPHON, NORTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
130. FORKS DIVERSION, HIGH LINE AND LOW LINE CANALS, TWIN FALLS COUNTY, SOUTH OF HANSEN, IDAHO; OUTLET SIDE OF THE HIGH LINE GATES, NORTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
186. Photocopy of drawing, Twin Falls Canal Company, date unknown. DRY CREEK RESERVOIR, CASSIA COUNTY (NOW TWIN FALLS COUNTY); MAP. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
115. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; WEST VIEW OF SIPHON CROSSING ROCK CREEK. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
157. Photocopy of drawing (taken from Twin Falls Canal Company Field Book #360, Page 75, entitled, 'Clay-Seam Cut-Off.' Cross-Reference: ID-15-153). MILNER DAM SURVEY, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
98. SHOESTRING, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; PROFILE VIEW, SOUTH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
109. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; OVERALL VIEW LOOKING WEST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
152. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Transit Book #363, Page 1). 1912 CONDITION REPORT OF MILNER DAM AREA, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
193. Photocopy of Photograph, Twin Falls Canal Company, date unknown. MILNER DAM PROFILE, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
181. Photocopy of Photograph, Twin Falls Canal Company. Photographer and date unknown. POINT SPILL, TWIN FALLS COUNTY; SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
194. Photocopy of drawing, Twin Falls Canal Company, date unknown. PROFILE AND GATE PLAN, NORTH ISLAND CROSS SECTION OF DAM, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
148. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; HEADGATES AT INLET, SOUTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
192. Photocopy of drawing, Twin Falls Canal Company, date unknown. TOPOGRAPHICAL MAP (DAM DRAWN IN), MILNER SITE, TWIN FALLS COUNTY, MILNER, IDAHO; RIGHT SIDE OF MAP (LEFT ON ID-15-183). - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
185. Photocopy of drawing, Twin Falls Canal Company, date unknown. MILNER DAM CROSS SECTION PLAN, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
114. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OVERALL VIEW, WEST OF INLET SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
153. Photocopy of drawing (taken from Twin Falls Canal Company Field Book #360, Page 74, entitled, 'Clay-Seam Cut-Off.' Cross-Reference: ID-15-157). MILNER DAM SURVEY, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
190. Photocopy of drawing, Twin Falls Canal Company, date unknown. GENERAL PLAN OF MILNER DAM TUNNELS, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
147. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, IDAHO; VIEW OF MAIN HEADGATES, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
178. Photocopy of Photograph, Twin Falls Canal Company. C. R. Savage, Photographer, March, 1905. FIRST FULL WATER OVER MILNER DAM, TWIN FALLS COUNTY, MILNER, IDAHO; SOUTHWEST VIEW OF SPILLWAY GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
116. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; CLOSE-UP OF OUTLET, DIVERSION SPILL IN BACKGROUND, WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
112. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OUTLET SIDE, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
111. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OVERALL VIEW OF SIPHON, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
95. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; OVERALL VIEW LOOKING EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
124. MCMULLEN CREEK HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; OVERALL SOUTH VIEW OF DRAW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
155. Photocopy of transit book (taken from Twin Falls Canal Company Surveyor's Transit Book #405T, Page 1, #46 Division One). STATEMENT RE: SURVEY ALIGNMENT 3/03, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
92. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; CLOSE-UP OF OUTLET SIDE OF GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
96. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; OUTLET SIDE OF CEDAR DRAW, WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
195. Photocopy of drawing, Twin Falls Canal Company, date unknown. PLAN OF CONSTRUCTION AREA PLANT, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
14. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND BARTON ROAD, SHOWING OLD ROUTE OF CANAL VIADUCT ACROSS BARTON ROAD. SIPHON NOW GOES UNDER ROAD AND EMERGES AT RIGHT REAR BELOW TWO TELEPHONE POLES (SEE CA-120-15) - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA
16. VIEW OF HIGHLINE CANAL PIPELINE OUTLET, SHOWING THE OUTLET, A GROUNDWATER PUMP (LEFT), AND THE SOUTH BRANCH OF THE CANAL (FOREGROUND), August 1989 - Highline Canal & Pumping Station, South side of Salt River between Tempe, Phoenix & Mesa, Tempe, Maricopa County, AZ
Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.
82. ROOSEVELT POWER CANAL, SUGGESTED ARRANGEMENT FOR ELECTRICAL OPERATION OF SLUICE GATES AND CANAL INTAKE GATES AT DIVERSION DAM Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
47. FEEDER CANAL AT WILL'S BASIN. BOATS IN THE FOREGROUND SHOW THE CONTRAST BETWEEN A FULLY LOADED CANAL BOAT (LEFT) AND AN EMPTY ONE (RIGHT). D, L & W RAILROAD'S DOUBLE INTERSECTION PRATT TRUSS BRIDGE IS VISIBLE IN BACKGROUND. - Morris Canal, Phillipsburg, Warren County, NJ
Primary malignant melanoma rarely occurs in the external auditory canal. In the few reported cases, treatment with lateral temporal bone resection, superficial parotidectomy, and neck dissection were suggested. We describe a 52-year-old man with this disease, managed by sentinel node biopsy with lymphoscintigraphy guidance, lateral temporal bone resection, and postoperative radiotherapy. The patient refused superficial parotidectomy and neck dissection. Although
Chiu-Hung Lin; Tzong-Yang Tu; Pen-Yuan Chu; Yi-Wei Chen; Wing-Yin Li
Superior semicircular canal dehiscence (SCD) syndrome aords a unique oppor- tunity to study a novel pathology in otolaryngology (rst dened in 1998) and the mechanisms by which it aects hearing. Patients with SCD syndrome present with a wide variety of symptoms: some present with vestibular symptoms (vertigo, oscillosp- sia, disequilibrium) others present with auditory symptoms (autophony, hyperacusis, low frequency conductive
During the summer and fall of 1980 the U.S. Environmental Protection Agency (EPA) conducted a comprehensive multimedia environmental monitoring program in the vicinity of the inactive hazardous wastes landfill known as Love Canal, located in Niagara Falls, New York. The studies c...
The four volumes in this set comprise the working guideline documents for the Love Canal Study. The documents were developed to direct both the prime contractor and subcontractors while performing for the Environmental Protection Agency. Detailed procedures for each analysis type...
This report summarizes the prime contractor activities during the monitoring phase of the Love Canal project. Since GCA Corporation was only responsible for data collection, no analytical results appear in this report. The program involved a multifaceted sampling and analytical e...
During the summer and fall of 1980 the U.S. Environmental Protection Agency (EPA) conducted a comprehensive multimedia environmental monitoring program in the vicinity of the inactive hazardous wastes landfill known as Love Canal, located in Niagara Falls, New York. The studies c...
This report provides the documentation of the Suez Canal Clearance Operations NIMBUS STAR, NIMBUS MOON, and NIMROD SPAR undertaken by Task Force 65 during the period 11 April to 15 December 1974. Under the terms of two bilateral agreements between the Gov...
The booklet, designed to explore the issues of international justice in the context of the Gospel, reviews relations between the United States and Panama. It includes background materials and a study guide for parish leaders and other educators. The central question pertaining to the Panama Canal concerns the rights of the United States according…
PREFACE: 'The creation of the Panama Canal was far more than a vast, unprecedented feat of engineering. It was a profoundly important historic event and a sweeping human drama not unlike that of war. Apart from wars, it represented the largest, most costly single effort ever before mounted anywhere on earth. It held the world's attention over a span of
R. Frank Chiappetta; Tom Treleaven; Eduardo Nixon; John Dean Smith
The purpose of this study was to determine the organisms impacting waterhyacinth in the Panama Canal prior to the introduction of biocontrol agents, and to quantify their effects on the plant population. The purpose of this report was to present the proce...
Dental anatomical variations play a significant role in the diagnosis and a successful treatment outcome in endodontics. It is essential for the clinician to have a clear picture and understanding of the pulpal anatomy and its variations. In a mandibular second premolar, it is rare to find extra roots and canals. The aim of the present article is to report a case about the successful diagnosis, and clinical management of a three-rooted mandibular second premolar with three independent roots and canals.
Purpose To delineate three dimensionally the neural canal landmarks—Bruch's membrane opening (BMO), anterior sclera canal opening (ASCO), anterior laminar insertion (ALI), posterior laminar insertion (PLI), and posterior scleral canal opening (PSCO)—and the anterior-most aspect of the subarachnoid space (ASAS), within digital three-dimensional (3-D) reconstructions of the monkey optic nerve head (ONH). Methods The trephinated ONH and peripapillary sclera from both eyes of three early glaucoma (EG) monkeys (one eye normal, one eye with laser-induced EG) were serial sectioned at 3-?m thickness, with the embedded tissue block face stained and imaged after each cut. The images were aligned and stacked in a 3-D volume, within which the BMO, ASCO, ALI, PLI, PSCO, and ASAS were delineated in 40 digital, radial, and sagittal sections. An ellipse was fitted to the 80 BMO points to establish a BMO zero reference plane, on which all other points were projected. The distance from each projected point to the BMO centroid (offset) and BMO zero reference plane (depth) were calculated and compared regionally between normal and EG eyes, both overall and within each monkey, by analysis of variance. Results BMO was the clinically visible optic disc margin in all six eyes. The neural canal architecture was highly variable in the three normal eyes. Radial expansion of the neural canal was greatest posteriorly in the EG eyes. Axial elongation of the canal was less pronounced overall but was regionally present within all three EG eyes. ASAS was regionally radially expanded and anteriorly displaced within two of the three EG eyes. Conclusions Profound deformation of the neural canal and ASAS architecture are present in young adult monkey eyes at the onset of ONH surface change in early experimental glaucoma.
Downs, J. Crawford; Yang, Hongli; Girkin, Christopher; Sakata, Lisandro; Bellezza, Anthony; Thompson, Hilary; Burgoyne, Claude F.
Objectives To describe the histopathologic findings in the temporal bones of a patient with who had been diagnosed during life with superior canal dehiscence (SCD) syndrome. Methods The patient was diagnosed with SCD at the age of 59. She became a temporal bone donor, and died of unrelated causes at the age of 62. Both temporal bones were prepared in celloidin and examined by light microscopy. Results She developed bilateral aural fullness, pulsatile tinnitus and difficulty tolerating loud noises after minor head trauma at age 53. Symptoms were worse on the right. She also had valsalva-induced dizziness and eye movements, as well as sound-induced dizziness (more prominent on the right), consistent with SCD. Audiometry showed a small air bone gap of 10 dB in the right ear. VEMP testing showed an abnormally low threshold of 66 dB on the right, and CT scan showed dehiscence of the superior canal on the right. Histopathology of the right ear showed a 1.4 × 0.6 mm dehiscence of bone covering the superior canal. Dura was in direct contact with the endosteum and the membranous duct at the level of the dehiscence. No osteoclastic process was evident within the otic capsule bone surrounding the dehiscence. The left ear showed thin but intact bone over the superior canal. Both ears showed focal microdehiscences of the tegmen tympani and tegmen mastoideum. The auditory and vestibular sense organs on both sides were normal. No endolymphatic hydrops was observed. Conclusions The findings were consistent with the hypothesis put forth by Carey and colleagues that the SCD may arise from failure of postnasal bone development, and that minor trauma may disrupt thin bone or stable dura over the superior canal.
Teixido, Michael; Kung, Brian; Rosowski, John J.; Merchant, Saumil N.
Objective?Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods?Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results?Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion?Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students. PMID:23730547
Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil
Permanent hearing loss is caused by the irreversible damage of cochlear sensory hair cells and nonsensory supporting cells. In the postnatal cochlea, the sensory epithelium is terminally differentiated, whereas tympanic border cells (TBCs) beneath the sensory epithelium are proliferative. The functions of TBCs are poorly characterized. Using an Axin2(lacZ) Wnt reporter mouse, we found transient but robust Wnt signaling and proliferation in TBCs during the first 3 postnatal weeks, when the number of TBCs decreases. In vivo lineage tracing shows that a subset of hair cells and supporting cells is derived postnatally from Axin2-expressing TBCs. In cochlear explants, Wnt agonists stimulated the proliferation of TBCs, whereas Wnt inhibitors suppressed it. In addition, purified Axin2(lacZ) cells were clonogenic and self-renewing in culture in a Wnt-dependent manner, and were able to differentiate into hair cell-like and supporting cell-like cells. Taken together, our data indicate that Axin2-positive TBCs are Wnt responsive and can act as precursors to sensory epithelial cells in the postnatal cochlea. PMID:23444352
Jan, Taha Adnan; Chai, Renjie; Sayyid, Zahra Nabi; van Amerongen, Renée; Xia, Anping; Wang, Tian; Sinkkonen, Saku Tapani; Zeng, Yi Arial; Levin, Jared Ruben; Heller, Stefan; Nusse, Roel; Cheng, Alan Gi-Lun
Tumors of the anus and perianal skin are rare. Their presentation can vary and often mimics common benign anal pathology, thereby delaying diagnosis and appropriate and timely treatment. The anatomy of this region is complex because it represents the progressive transition from the digestive system to the skin with many different co-existing types of cells and tissues. Squamous cell carcinoma of the anal canal is the most frequent tumor found in the anal and perianal region. Less-frequent lesions include Bowen's and Paget's disease, basal cell carcinoma, melanoma, and adenocarcinoma. This article aims to review the clinical presentation, diagnostic evaluation, and treatment options for neoplasms of the anal canal and perianal skin.
The clinical and laboratory findings in six patients with congenital narrowing of the cervical spinal canal and neurological symptoms are described. A variable age of onset and an entirely male occurrence were found. Signs and symptoms of spinal cord dysfunction predominated in all but one patient. Symptoms were produced in five patients by increased physical activity alone. Congenital narrowing of the cervical spinal canal may result in cord compression without a history of injury and occasionally without evidence of significant bony degenerative changes. The clinical features may be distinguishable from those found in cervical spondylosis without congenital narrowing. Intermittent claudication of the cervical spinal cord appears to be an important feature of this syndrome. Surgery improved four out of five people.
results : SIRs were elevated for cancers of the bladder (SIRNYS = 1.44; 95% confidence interval (CI), 0.91-2.16) and kidney (SIRNYS = 1.48; 95% CI, 0.76-2.58). Although CIs included 1.00, other studies have linked these cancers to chemicals similar to those found at Love Canal. We also found higher rates of bladder cancer among residents exposed as children, based on
Lenore J. Gensburg; Cristian Pantea; Christian Kielb; Edward Fitzgerald; Alice Stark; Nancy Kim
Horizontal eye movements in squirrel monkeys were recorded in response to ice-water caloric stimuli before and after horizontal canal (HC) inactivation, achieved by a plugging procedure. Calorics were presented with the subjects supine and prone, and the maximum slow phase eye velocity (SPEV) of the induced nystagmus was assessed. SPEV responses from normal ears were always directed toward the stimulated side when the monkeys were supine, and toward the opposite side when they were prone. Supine responses were always greater than prone ones. After HC-plug, which abolishes the canal's mechanical response to rotatory or convection current stimulation, small SPEV responses were routinely observed. However, they were always directed toward the stimulated side, regardless of head orientation. The results are consistent with the notion that the normal caloric response is composed of the sum of a convention current component which is dependent upon head orientation, a smaller position-dependent component of unclear origin, and a direct temperature effect on the canal's sensory apparatus which is independent of head orientation. PMID:4082971
A 26-year-old man was suffering from pericoronitis of his mandibular third molars. To determine the position of the mandibular canal in relation to the roots of the third molars, a panoramic radiograph was made. The radiograph revealed at the right side a bifid mandibular canal and the upper part of the canal seemed to be related to the third molar. Additionally, a cone beam CT was made, which revealed a bifid mandibular canal at the left side and a trifid mandibular canal at the right side. Anatomical anomalies of the mandibular canal may have clinical implications, such as an increased risk of injury to the inferior alveolar nerve in case of removing a mandibular third molar and inadequate local anesthetics. PMID:21298889
Mizbah, K; Gerlach, N; Maal, T J; Bergé, S J; Meijer, G J
Superior semicircular canal dehiscence syndrome may have a congenital basis. CT scans of 44 control and 21 dehiscent superior canals were examined to determine if dehiscent canals were more cephalically placed or vertically oriented than control canals. Results showed that neither was the case. Instead, the defect may be in the process of ossification above the superior canal.
Valeria L. Potyagaylo; Charley C. Della Santina; Lloyd B. Minor; John P. Carey
Dental anatomical variations play a significant role in the diagnosis and a successful treatment outcome in endodontics. It is essential for the clinician to have a clear picture and understanding of the pulpal anatomy and its variations. In a mandibular second premolar, it is rare to find extra roots and canals. The aim of the present article is to report a case about the successful diagnosis, and clinical management of a three-rooted mandibular second premolar with three independent roots and canals. PMID:24910669
Three patients with exclusively or predominantly intracanalicular neuromas and 5 with presumably normal internal auditory canals were examined with prototype 1.4- or 1.5-tesla magnetic resonance (MR) scanners. MR images showed the 7th and 8th cranial nerves in the internal auditory canal. The intracanalicular neuromas had larger diameter and slightly greater signal strength than the nerves. Early results suggest that minimal enlargement of the nerves can be detected even in the internal auditory canal.
Background Bifid mandibular canals (BMC) and trifid mandibular canals (TMC) are variations on the normal anatomy with incidences ranging\\u000a from 0.08% to 65.0%. Such aberrations have an important clinical impact. For example, an extra mandibular canal may explain\\u000a inadequate anesthesia, especially when two mandibular foramina are involved. Furthermore, during mandibular surgery, a second,\\u000a or even third, neurovascular bundle may be damaged
K. Mizbah; N. Gerlach; T. J. Maal; S. J. Bergé; Gert J. Meijer
A number of acoustical applications require the transformation of acoustical quantities, such as impedance and pressure that are measured at the entrance of the ear canal, to quantities at the eardrum. This transformation often requires knowledge of the shape of the ear canal. Previous attempts to measure ear-canal area functions were either invasive, non-reproducible, or could only measure the area function up to a point mid-way along the canal. A method to determine the area function of the ear canal from measurements of acoustic impedance at the entrance of the ear canal is described. The method is based on a solution to the inverse problem in which measurements of impedance are used to calculate reflectance, which is then used to determine the area function of the canal. The mean ear-canal area function determined using this method is similar to mean ear-canal area functions measured by other researchers using different techniques. The advantage of the proposed method over previous methods is that it is non- invasive, fast, and reproducible.
21. 1934 aerial of Tempe Canal, Sections 19 and 30 (T1N R5E) and Sections 24 and 25 (T1N R4E) (top of page is north). The main canal enters the picture at upper right and curves out of picture at lower right. The Hayden Branch (thin dark line) runs from top of picture to the southwest, then curves to the west. The Western Branch enters picture running parallel to main canal, then angles off to southwest. Photographer: Unknown, 1934. Source: SRP Cartographic Drafting - Tempe Canal, South Side Salt River in Tempe, Mesa & Phoenix, Tempe, Maricopa County, AZ
20. 1934 aerial of Tempe Canal, Sections 9, 16, and 17 (T1N R5E) (top of page is north). The Tempe Crosscut is seen as the dark line entering from top right, which turns north, then curves around the Chandler Falls powerhouse. The canal then curves slowly around to the southwest. The old Trunk Ditch is visible at the top of the curve, coming in from the northeast. A wasteway (top left) runs west from the canal to the Salt River. Photographer: Unknown, 1934. Source: SRP Cartographic Drafting - Tempe Canal, South Side Salt River in Tempe, Mesa & Phoenix, Tempe, Maricopa County, AZ
The Operating Characteristics and Capacity Evaluation (OCCE) Study was one of the components of a group of studies of future alternatives to the Panama Canal, sponsored by a study commission formed by the governments of Panama, the US and Japan. The basic tool in the conduct of the study was the Waterway Analysis Model (WAM), developed originally by the US Army Corps of Engineers for use on the US inland waterway system and adapted under OCCE for study of Panama Canal alternatives. The study synthesized the many alternative plans for the Canal proposed historically into four basic groups: High-Rise Lock Canal, Low-Rise Lock Canal, Sea-Level Canal and Status Quo Canal. For economy, the sea-level cases were based on, essentially, a single-lane canal, in conjunction with the status quo canal. Hydraulic and navigation studies indicted that to achieve safe navigation, tide gates or locks would be required to control currents that would otherwise be generated by the differences in tides between the two oceans. The alternatives studied in detail are illustrated in the body of the paper.
Rosselli, A.T. [TAMS Consultants, Inc., New York, NY (United States); Bronzini, M.S. [Oak Ridge National Lab., TN (United States). Center for Transportation Analysis; Weekly, D.A. [Army Corps of Engineers, Huntington, WV (United States). Navigation Planning Center
12. VIEW OF WESTERN CANAL AT ALMA SCHOOL ROAD IN MESA, THE LOCATION AT WHICH THE PECK, PINE AND WALLACE FEEDERS FORMERLY JOINED TO FORM THE WESTERN CANAL. THE PECK AND PINE FEEDERS, NOW KNOWN AS LATERAL 9 AND LATERAL 10, AND ALMOST ENTIRELY PIPED, STILL JOIN THE WESTERN CANAL AT THIS POINT, BUT AN EQUALLY IMPORTANT SOURCE OF SUPPLY IS THE NUMEROUS GROUNDWATER PUMPS LOCATED ON THE SYSTEM. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ
The following obturation techniques were compared on their ability to obturate lateral canals in vitro, lateral condensation (LC), continuous wave of condensation (CW), warm vertical condensation (WV), carrier-based thermoplasticized gutta-percha (CB), warm lateral condensation (WL), and vertically condensed high-temperature gutta-percha (HT). A root canal system with lateral canals in the coronal, middle, and apical thirds was prepared in resin blocks. Each block was obturated using each technique (n = 30, 15 each, with and without sealer). The length of gutta-percha and sealer in each of the lateral canals was measured with a measuring microscope and statistically compared. All techniques obturated all three levels of lateral canals with sealer. WV, CB, and CW were able to fill the lateral canals with gutta-percha significantly better when root canal sealer was used. WV, CB, CW, and HT filled the coronal and middle lateral canals significantly better with gutta-percha than LC or WL condensation. CB and CW filled the apical lateral canal significantly better with gutta-percha than HT, WV, WL, or LC. PMID:10530265
DuLac, K A; Nielsen, C J; Tomazic, T J; Ferrillo, P J; Hatton, J F
1. Membrane potential responses of dissociated gerbil type I semicircular canal hair cells to current injections in whole cell current-clamp have been measured. The input resistance of type I cells was 21.4 +/- 14.3 (SD) M omega, (n = 25). Around the zero-current potential (Vz = -66.6 +/- 9.3 mV, n = 25), pulsed current injections (from approximately -200 to 750 pA) produced only small-amplitude, pulse-like changes in membrane potential. 2. Injecting constant current to hyperpolarize the membrane to around -100 mV resulted in a approximately 10-fold increase in membrane resistance. Current pulses superimposed on this constant hyperpolarization produced larger and more complex membrane potential changes. Depolarizing currents > or = 200 pA caused a rapid transient peak voltage before a plateau. 3. Membrane voltage was able to faithfully follow sine-wave current injections around Vz over the range 1-1,000 Hz with < 25% attenuation at 1 kHz. A previously described K conductance, IKI, which is active at Vz, produces the low input resistance and frequency response. This was confirmed by pharmacologically blocking IKI. This conductance, present in type I cells but not type II hair cells, would appear to confer on type I cells a lower gain, but a much broader bandwidth at Vz, than seen in type II cells.
...mobility characteristics of the tympanicmembrane to evaluate the functional...abnormalities in the mobility of the tympanicmembrane due to stiffness, flaccidity...muscle, to monitor healing of tympanicmembrane grafts or...
...mobility characteristics of the tympanicmembrane to evaluate the functional...abnormalities in the mobility of the tympanicmembrane due to stiffness, flaccidity...muscle, to monitor healing of tympanicmembrane grafts or...
The document consists of a role-playing game and related teacher's guide designed to illustrate decision-making processes leading to the building of the Middlesex Canal in Massachusetts in 1793. The primary educational objective is to involve students in the decision-making process through role play. The game is designed to facilitate…
This activity is one of a series of 17 teacher-developed instructional activities for geography at the secondary-grade level described in SO 009 140. This activity investigates environmental quality employing the problem-solving technique. Using a map which shows the proposed route of the cross-Florida barge canal as a focal point, the teacher…
The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (I(geo)) class 4-6), whereas NBC sediments are enriched in Sn, Cu, Zn, and Hg (I(geo) class 4-6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metals found in these sediments. The calculated I(geo), Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai Metropolitan City have negatively influenced on the surrounding aquatic ecosystem. PMID:22231589
Jayaprakash, M; Nagarajan, R; Velmurugan, P M; Sathiyamoorthy, J; Krishnamurthy, R R; Urban, B
Data from the New York Cancer Registry show no evidence for higher cancer rates associated with residence near the Love Canal toxic waste burial site in comparison with the entire state outside of New York City. Rates of liver cancer, lymphoma, and leukemia, which were selected for special attention, were not consistently elevated. Among the other cancers studied, a higher rate was noted only for respiratory cancer, but it was not consistent across age groups and appeared to be related to a high rate for the entire city of Niagara Falls. There was no evidence that the lung cancer rate was associated with the toxic wastes buried at the dump site.
Janerich, D.T.; Burnett, W.S.; Feck, G.; Hoff, M.; Nasca, P.; Polednak, A.P.; Greenwald, P.; Vianna, N.
There are many techniques and materials to fill the root canal system. In this paper a number of the most popular techniques and materials is discussed mainly with the purpose to give an overview, and to understand the advantages and disadvantages of the various types of root fillings. Discussed are sealers based on zinc oxide-eugenol, synthetics and those that adhere to dentine or to which medicaments have been added. Of the various filling techniques the cone cementation techniques like single cone and lateral compaction are discussed, while of the warm techniques the lateral, vertical, and thermomechanical compaction as well as injection and core carrier techniques are described. PMID:16385933
53. VIEW OF ARIZONA CANAL AT 48TH STREET, LOOKING SOUTH, SHOWING CHECK STATION TO OLD CROSSCUT CANAL Photographer: James Eastwood, July 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
...Customs treatment after transiting the Panama Canal. 148.3 Section 148.3 ...Customs treatment after transiting the Panama Canal. Passengers' baggage and...States from vessels which have transited the Panama Canal are subject to Customs...
...Testing Operations, Chicago Sanitary and Ship Canal, Romeoville, IL AGENCY: Coast...safety zone on the Chicago Sanitary and Ship Canal (CSSC) near Romeoville, IL. This...Testing Operations, Chicago Sanitary and Ship Canal, Romeoville, IL. (a)...
...Operation Regulation; Lake Washington Ship Canal at Seattle, WA AGENCY: Coast Guard...3, all crossing the Lake Washington Ship Canal at Seattle, WA. The deviation is...3, all crossing the Lake Washington Ship Canal at Seattle, WA. The requested...
...Drawbridge Operation Regulation; Duluth Ship Canal, Duluth- Superior Harbor, MN AGENCY...Drawbridge Operation Regulation; Duluth Ship Canal, Duluth-Superior Harbor, MN...Light at the lakeward end of the Duluth Ship Canal. It is a vertical lift type...
...Drawbridge Operation Regulations; Duluth Ship Canal (Duluth- Superior Harbor). AGENCY...regulation governing the operation of the Duluth Ship Canal Aerial Bridge at Mile 0.1 over the Duluth Ship Canal, at Duluth, MN, for scheduled...
The China Grand Canal is one of the earliest canals in the world, having lasted for nearly 3000 years. Even its section canals have a rich history, such as the North-South Grand Canal that was established during the Sui Dynasty, whereas the Beijing-Hangzhou Canal was excavated during the Yuan Dynasty and the east line of the South-to-North Water Diversion. As one of the longest in the world, the China Grand Canal's total length is over 3500 kilometers. This length includes the navigable, unnavigable, and underground sections. Making the best use of situations and according to local conditions, the Chinese people harmoniously constructed the Beijing-Hangzhou Canal with nature. Tens of millions of workers took nearly 3000 years to complete the great shipping system. Navigable sections still exist for up to 900 kilometers and the volume of freight traffic is approximately 300 million tons. The canal remains the main logistical channel of the North-to-South Coal Transportation, South-to-North Water Diversion, and resources circulation. To date, China is promoting the success of heritage application. Part of these efforts is the declaration of the China Grand Canal as a World Cultural Heritage by 2014. In addition, the east route of the South-to-North Water Transfer project is planned to be navigable by 2016. The ancient Beijing-Hangzhou Grand Canal will usher in the new ecological civilization and cultural revival along the canal. This paper presents technical methods of water environment evolution research on the river system, river, and water quality along the Beijing-Hangzhou Canal through the integration of historical literature and modern remote sensing image data. The study carried out water environment investigation and analysis along the Beijing-Hangzhou canal by using ETM, SPOT image data, and GPS measurement data. Spatial and temporal evolution characteristics and regulations of the Beijing-Hangzhou Grand Canal regional water environment in the span of 3000 years were obtained. As a key national cultural relic, candidate of the world cultural heritage, and route of the South-to-North Water Diversion, the China Great Canal is a worthy subject of a study. Results presented in this paper therefore have high realistic significance.
Endodontic therapy consists in cleaning and shaping the root canal system, removing organic debris and sealing the intra-canal space with permanent filling materials. The purpose of this study was to evaluate various root canal fillings in order to detect material defects, the marginal adaptation at the root canal walls and to assess the quality of the apical sealing. 21 extracted single-root canal human teeth were selected for this study. We instrumented all roots using NiTi rotary instruments. All canals were enlarged with a 6% taper size 30 GT instrument, 0,5 mm from the anatomical apex. The root canals were irrigated with 5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid (EDTA). After the instrumentation was completed, the root canals were obturated using a thermoplasticizable polymer of polyesters. In order to assess the defects inside the filling material and the marginal fit to the root canal walls, the conebeam micro-computed tomography (CB?CT) was used first. After the CB?CT investigation, time domain optical coherence tomography working in en face mode (TDefOCT) was employed to evaluate the previous samples. The TDefOCT system was working at 1300 nm and was doubled by a confocal channel at 970 nm. The results obtained by CB?CT revealed no visible defects inside the root-canal fillings and at the interfaces with the root-canal walls. TDefOCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region.
This case report presents an unusual root canal system in a maxillary first molar tooth: a single canal in a single root. The endodontic access cavity displayed only 1 canal orifice. This case demonstrated that: 1) clinicians must have adequate knowledge about root canal morphology and its variations; 2) the location and morphology of root canals should be identified radiologically before the root canal treatment; and 3) careful examination of radiographs and the internal anatomy of teeth is essential. PMID:18926738
de la Torre, Francisco; Cisneros-Cabello, Rafael; Aranguren, José Luis; Estévez, Roberto; Velasco-Ortega, Eugenio; Segura-Egea, Juan José
Benjamin Alcock (1801-?) was a prominent anatomist from Ireland who is remembered most for his description of the pudendal canal. He was privileged to train under the great Irish anatomist, Abraham Colles. Following his training and several early teaching engagements, he was appointed as the first Professor of Anatomy and Physiology at Queen's College, Cork. He became a Fellow of the Royal College of Surgeons in Ireland. After several years of teaching at Queen's College, Alcock was forced to resign after a dispute over the Anatomy Act of 1832, during which he conveyed his disapproval of participation in the procurement of corpses for the school. Several years after his resignation, he left for the United States and removed himself from the view of the profession. His anatomical contributions were published in The Cyclopaedia of Anatomy and Physiology. The description he gave of the sheath enclosing the pudendal nerve and internal pudendal vessels is his most famous contribution to the literature. He is remembered eponymously for Alcock's canal. This article's intent is to clearly and concisely depict the life and contribution of Benjamin Alcock. PMID:22488487
Oelhafen, Kim; Shayota, Brian J; Muhleman, Mitchel; Klaassen, Zachary; Tubbs, R Shane; Loukas, Marios
To assess the normal dimensions of the lumbar spinal canal, 100 normal healthy subjects of either sex between 25 and 45 years age were x-rayed for lumber vertebral column in both posteroanterior and lateral views and the canal was measured by Jones and Thomson method. The lumbar spinal canal showed constant dimensions in both sexes in all age groups when studied separately in the male and female subjects. However, no change in relative dimensions was observed between 25 and 45 years. The canal showed gradual decrease in measurement from L1 to L5 vertebral levels in both sexes but relative width of the canal was more in the females than in the males of the same age group. The normal values of the canal to vertebral body ratio (C/B) varies between 1:2.0 and 1:5.0. The ratio 1:2.0 indicates a wider canal whereas any ratio beyond 1:5.0 would be conclusive of stenosis of the lumbar vertebral canal. PMID:2513423
Central disc protrusions are often misdiagnosed as other lesions, particularly those with block of spinal canal. Between October 1970 and February 1978 the author had 15 cases of spinal canal block due to central disc protrusions. Of these, 5 cases were i...
62. VIEW SHOWING END OF THE ARIZONA CANAL AT SKUNK CREEK, LOOKING WEST. DEMOSSING STATION IS LEFT OF CENTER AND DRAIN GATES ARE RIGHT OF CENTER Photographer: James Eastwood, July 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ
The aim of this study was to examine the effect of ozone gas on the remaining bacteria after chemomechanical instrumentation of tooth root canal. The study was carried out at the Department of Endodontics and Restorative dentistry, School of Dental Medicine, University of Zagreb. A total of 37 tooth root canals from 23 teeth (10 incisors, 2 canines, 8 premolars and 3 molars) with a diagnosis of chronic apical periodontitis (17 untreated teeth and 6 retreatments) from 20 adult patients (11 females and 9 male) were selected. Endodontic samples consisted of 74 swabs from 37 canals. The first root canal swab was taken following a completed chemomechanical instrumentation by a sterile paper point after rinsing the root canal with a sterile saline solution. The canal was dried and treated with ozone gas for 40 seconds (HealOzone, Kavo, Germany). After the ozone treatment the canal was rinsed with a sterile saline solution a second swab was taken. The swabs were stored in transport media until cultivation. Microbiological identification was performed by macromorphological, micromorphological, commercial biochemical test microbiological analysis and bacteria count. A significant decrease in the number of bacteria (p < 0.001) was found after the ozone treatment: the total number of bacteria was 82%, 67% of aerobic and 93% of anaerobic bacteria. When analysing individually, a significant decrease was found for Streptococcus mitis and Propionibacterium acnes (p < 0.05). The results of this study shows the efficacy of ozone on the bacterial count reduction in the root canal treatment. PMID:23697257
ObjectivesThe relatively new clinical entity superior canal dehiscence syndrome (SCDS) is diagnosed by clinical symptoms and signs. Coronal computed tomography (CT) has been used to confirm the diagnosis. A consecutive series of temporal bone CT scans was reviewed to define the prevalence of a dehiscent-appearing superior semicircular canal.
Robert A Williamson; Jeffrey T Vrabec; Newton J Coker; Marlin Sandlin
Objectives: Superior semicircular canal dehiscence syndrome (SCD) is a recently described cause of vestibulopathy that results from the absence of bone over the superior semicircular canal. Since the initial description of this syndrome, we have diagnosed 23 patients with SCD. In this article, we discuss the diagnosis and treatment of patients with this syndrome.Methods: Retrospective chart review of the patients
Todd Alan Hillman; Clough Shelton; Thomas R. Kertesz
8. FLUME BOX Y, LOOKING NORTH. CANAL HEADING RIGHT FOLLOWS HILLSIDE INTO DRAINAGE; FLUME HEADING LEFT CROSSED GULCH ON A TRESTLE. NOTE CONCRETE ABUTMENTS NEAR TOP RIGHT INSTALLED IN 1935 TO PREVENT WATER FROM ESCAPING CANAL AT OLD TRESTLE ENTRANCE. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
10. CANAL CUT THROUGH SHALE BEDROCK ON PROMINENT POINT, LOOKING NORTH-NORTHEAST. NOTE CONCRETE ABUTMENTS PROBABLY INSTALLED IN 1935 TO PREVENT WATER FROM ESCAPING THROUGH A CANAL BANK BREACH. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
The water body in the Suez Canal is a combination of waters from differ- ent sources. Hence, its exact hydrographic structure is very difficult to define. Three main water masses are identified along the Canal on account of their salinity values: Levantine water mass I, the Suez Bay water mass II, and the Bitter Lake water mass IV, in addition
This paper considers the determination of the maximum shipping capacity of the Suez canal. Initially, some assumptions are made in order to calculate the ‘theoretical’ maximum capacity in terms of ‘standard ships’. This last term defines ships which transit the Canal at a given speed and at a given time interval from the vessel ahead and astern. Data has been
The concentration of nine heavy metals (Cu, Zn, Cd, Pb, Ni, Cr, Co, Fe and Mn) in waters of the Suez Canal and in the nearby waters was measured seasonally during 1997 - 1998 in their dissolved (D) and particulate (P) forms. The results revealed that the northern part of the canal (at Port Said) recorded higher concentrations for most
Photocopy: Map of canal crossing Schoharie Creek, 1834 from Holmes Hutchinson MS Vol. 9, Plate 39. Manuscript and History Section, New York State Library, Albany, New York. - Erie Canal (Enlarged), Schoharie Creek Aqueduct, Spanning Schoharie Creek, Fort Hunter, Montgomery County, NY
5. Lower end of the Old Crosscut Canal, circa 1977 aerial view. The Old Crosscut runs from bottom right to join the Grand. Note lack of trees, and wasteway to the bed of the Salt River. Photographer unknown. Source: Pueblo Grande Museum Cultural Park. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ
Objective To characterize the physiologic nature of the vestibular dysfunction that occurs with the normative aging process. Study design Cross-sectional study. Setting Tertiary care academic medical center. Patients Fifty individuals age 70 and above. Interventions Head thrust dynamic visual acuity testing (htDVA) and cervical and ocular vestibular-evoked myogenic potential (VEMP) testing. Main Outcome Measures Semicircular canal function measured by htDVA in each of the three semicircular canal planes, and saccular and utricular function measured by cVEMP and oVEMP testing, respectively. Results We observed significant declines in semicircular canal function in each of the canal planes as well as otolith function associated with aging. We found that individuals with impaired horizontal and superior semicircular canal function were likely to also have concomitant deficits in utricular but not saccular function. Overall, we noted that the prevalence of semicircular canal dysfunction was highest followed by saccular then utricular impairment, although we did observe individuals with isolated otolith deficits. Conclusions These data suggest an overall decline in semicircular canal as well as otolith function associated with aging, although the magnitude of impairment was greater for the semicircular canals than the otoliths in this elderly population. A better understanding of the specific vestibular deficits that occur with aging can inform the development of rational screening, vestibular rehabilitation and fall risk reduction strategies in older individuals.
Agrawal, Yuri; Zuniga, M. Geraldine; Davalos-Bichara, Marcela; Schubert, Michael C.; Walston, Jeremy D.; Hughes, Jennifer; Carey, John P.
3. Lower end of the Old Crosscut Canal, aerial view to north. The Old Crosscut runs top left to lower right, west of meat packing plant and stockyards. Photographer unknown, c. 1939. Source: Pueblo Grande Museum Cultural Park. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ
We report a rare anatomical variation of an anomalous supernumerary muscle in a male cadaver. It was crossing Guyon's canal, superficial to the ulnar nerve and ulnar artery, and inserted into the aponeurosis of the little finger. This muscle could potentially cause entrapment of the ulnar nerve in Guyon's canal. PMID:22747362
Paraskevas, Georgios K; Ioannidis, Orestis; Economou, Dimitrios S
14. ANGULAR QUARTZITE ROCK REINFORCEMENT ON INTERIOR OF OUTSIDE CANAL BANK, LOOKING SOUTH-SOUTHEAST. CANAL ROUTE VISIBLE ALONG HILLSIDE NEAR TOP LEFT. NOTE DILLON RESERVOIR, HIGHWAY 6, AND NEW RESIDENTIAL CONSTRUCTION AT RIGHT AND CENTER. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
3. Photocopied August 1978. OLD CANAL RIGHT-OF-WAY WEST OF COUNTRY CLUB SHOWING PARTIALLY EXCAVATED CANAL. THE EMBANKMENTS ARE VISIBLE ON THE FAR RIGHT AND THE FAR LEFT, (903) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI
20. Photocopied August 1978. CANAL SECTION III, LOOKING SOUTH, AUGUST OR SEPTEMBER 1900, FOLLOWING A MAJOR BANK SLIDE. SLIDES LIKE THIS ONE WERE FAIRLY FREQUENT FOLLOWING RAIN STORMS BEFORE THE CANAL WALLS WERE TIMBER LINED IN THE EARTH SECTIONS. (64) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI
18. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT BEFORE 1989 REALIGNMENT, LOOKING NORTH TOWARD RAILROAD CROSSING AND CROSSCUT STEAM PLANT LARGE WHITE BUILDING. THE CROSSCUT HYDRO PLANT IS HIDDEN BY TREES TO RIGHT OF STEAM PLANT. Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ
17. Photocopied August 1978. CANAL SECTION II, NEAR ASHMUN STREET, LOOKING WEST, DECEMBER 7, 1900. ONE OF THE CITY'S NEW BRIDGES OVER THE CANAL IS IN THE BACKGROUND. TEMPORARY DUMP TRACKS, DUMP TRAINS AND DUMP TRAIN LOCOMOTIVES, AND STEAM SHOVELS ARE ALL SHOWN IN OPERATION. (106) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI
67. CANAL TENDER'S HOUSE AT LOCK 2 EAST. DUE TO DETERIORATION OF THE BUILDINGS WALLS AND FOUNDATION, CABLES FROM AN INCLINED PLANE WERE WRAPPED AROUND THE HOUSE AND FASTENED TO PLANE RAILS PLACED ON OPPOSITE ENDS OF THE STRUCTURE. - Morris Canal, Phillipsburg, Warren County, NJ
63. CANAL BOAT IN CRADLE AT TOP OF PLANE. TO PASS OVER THE SUMMIT (THE HUMP OF LAND AT THE TOP OF PLANE TO HOLD BACK THE WATER AT THAT LEVEL), THE BOATS HAVE SEEN HINGED AND TWO CRADLES ARE USED TO CARRY THE BOAT UP THE PLANE. - Morris Canal, Phillipsburg, Warren County, NJ
VIEW LOOKING NORTHEAST, LOCK 35 IS ON THE RIGHT. CANAL WORKERS ARE CLEANING TRASH GRATES TO LOCK 35 WATER INLET. ENTRANCE TO OLD LOCK 71 ON LEFT. NOTE THE SEDIMENT BUILD UP IN THE ENTRANCE CHANNEL TO OLD LOCK 71. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY
MTR CANAL IS FILLED WITH WATER. MAN STANDS ON MOVABLE BRIDGE. NOTE CHAINS AND HOOK AT LEFT. THIS SECTION OF CANAL PROJECTED EAST BEYOND THE SITE OF THE MTR BUILDING. INL NEGATIVE NO. 6003. Unknown Photographer, 6/16/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
REACTIVITY MEASUREMENT FACILITY, UNDER CONSTRUCTION OVER MTR CANAL IN BASEMENT OF MTR BUILDING, TRA-603. WOOD PLANKS REST ON CANAL WALL OBSERVABLE IN FOREGROUND. INL NEGATIVE NO. 11745. Unknown Photographer, 8/20/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
...previously disturbed canal right-of-way. The transmission line would be constructed using approximately 51 wood poles and 25 glue laminate poles which would be placed in augered holes in the spoil piles that border the canal from its construction. The...
61. PAGE THREE OF PLANS FOR GRAND CANAL AT WASHINGTON STREET TIDEGATE SYSTEM REHABILITATION Plan Sheet D-28451, Sheet No. 3 of 3 (delineated by H. V. Nguyen, November 1985) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA
60. PAGE TWO OF PLANS FOR GRAND CANAL AT WASHINGTON STREET TIDEGATE SYSTEM REHABILITATION Plan Sheet D-28451, Sheet No. 2 of 3 (delineated by H. V. Nguyen, November 1985) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA
1. VIEW LOOKING NORTH FROM DEWATERED CANAL; HEADGATES AND INTAKE CHANNEL AT LEFT; GUARDLOCK AT CENTER; SHEET PILING THROUGH SITE OF TOWPATH AT RIGHT - Dundee Canal, Headgates, Guardlock & Uppermost Section, 250 feet northeast of Randolph Avenue, opposite & in line with East Clifton Avenue, Clifton, Passaic County, NJ
From experiments on such membranes as apple skin, parchment paper membrane, and a membrane of completely dry collodion, results have been obtained which could be interpreted by the assumption that these membranes are less permeable for anions than for cations. In parchment paper there is only a relative diminution of the mobility of the anions, in the apple skin and in the dry collodion membrane there is practically no permeability for anions at all. The theory is developed which explains how the decrease or complete lack of mobility of anions influences the electromotive effects of the membrane and the diffusibility of electrolytes across a membrane. The results of the theory are compared with the experimental results. In membranes impermeable for anions the permeability for cations gives the same order of cations as for the mobilities in a free aqueous solution. But the differences of the mobilities are enormously magnified, e.g. the mobilities of H(*) and Li(*), which are in the proportion of about 1:10 in aqueous solution, are in proportion of about 1:900 in the collodion membrane. The general cause for the retardation of ionic mobility within the membrane may be supposed to be the increased friction of the water envelope dragged along by the ion in the capillary canals of the membrane. The difference of the effect on the cations and on the anions may be attributed to the electric charge of the walls of the canals. PMID:19872189
Patients attending a dedicated dental clinic during the previous 24 months were assessed for the success of root canal treatment. Two groups, totalling 48 patients, had root canal treatment to 57 teeth performed by one operator. All treatment was carried out without antibiotic prophylaxis over two or more appointments. Patients with HIV infection had root canal treatment to 40 teeth. Sixteen patients in the control group had root canal treatment to 17 teeth. Short-term success was determined by follow-up appointments 1-3 months following obturation. No complications were experienced in either group, except with one HIV infected patient. The results of this clinical study indicate that root canal treatment can be carried out following standard procedures and without antibiotic prophylaxis. PMID:8144247
A study was conducted during the summer of 2003 on Mapleton Lateral Canal near Mapleton, Utah, to determine gain or loss of flow in the canal from seepage. Measurements were made in May, June, July, and September of 2003. The uppermost reach of the canal had an apparent average loss of 2.6 cubic feet per second. The next reach downstream showed an apparent average gain of 1.4 cubic feet per second. The next three downstream reaches had apparent average losses of 2.4, 2.5, and 2.7 cubic feet per second. The apparent average net loss from the canal was 8.8 cubic feet per second, or a loss of 30 percent of the total discharge measured at the head of the canal.
A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material.
Mingenbach, William A. (P.O. Box 49, Taos, NM 87571)
Introduction: The purpose of this in vitro study was to introduce a new method to describe root canal curvatures and to assess the degree of curvature of human permanent mandibular teeth with curved root canals. Materials and Methods: One hundred and thirty five mesial root canals of mandibular first and second molar teeth were selected. Access cavities were prepared. After inserting a K-file size #10 into each canal, radiographs were taken. Canal curvature was determined by measuring the Schneider angle, canal access angle, as well as the canal radius, length, height and curvature starting distance on scanned radiographs using a computerized image processing system. Data was evaluated statistically using Pearson correlation. Results: The mean canal access angle (CAA) and Schneider angle (S) were 8.04? (3.46) and 19? (6.99), respectively. The Pearson correlation analysis found significant positive correlation between S and CAA (r=0.826, P<0.0001). Negative correlations were found between radius and length (r= –0.4, P<0.0001), radius and Schneider angle (r= –0.4, P<0.0001), radius and CAA (r= –0.24, P=0.004) and CAA and curvature starting distance (r= 0.4, P<0.0001). There was no correlation between height and distance (r=0.013, P=0.789), as well as CAA and height (r=0.654, P=0.001). Conclusion: Under the limitations of this study, the results indicated that the shape of root canal curvature can be more accurately described using two angles, Schneider in combination with Canal access angle. The related parameters included radius, length, distance and height of curvature. [Iranian Endodontic Journal 2009;4(4):131-4
The purpose of this study was to observe the seal obtained in human root canals under different in vitro treatment conditions. Root canals of freshly extracted human maxillary incisors received traditional biomechanical preparation and irrigation with 10% NaClO, followed by a final rinse of distilled water. Teeth were divided into four groups. In group 1, each root canal was dried with one paper point. In group 2, each root canal was dried with four paper points. Group 3 was dried with four paper points, followed by a gentle burst of warm air. Group 4 was dried using four paper points, followed by an internal 200 degrees C heat probe. Twenty canals in each group were filled with a gutta-percha cone and a zinc oxide-eugenol sealer, whereas 20 were filled with a glass ionomer sealer. All teeth were immediately immersed in India ink for 1 or 4 wk. The teeth were cleared, and the dye penetration-leakage measured with an accuracy of +/- 0.01 mm. Optimum sealing conditions were observed when the canal was dried with paper points and a 200 degrees C probe. There were no significant differences between 1 and 4 wk immersion. Glass ionomer sealer appeared more susceptible to the wet condition of the root canal walls than zinc oxide-eugenol sealer. An additional 40 teeth were prepared in the same manner as the dye penetration tests to observe the drying conditions of the root canal walls, and the moisture inside the canals was measured to an accuracy of 0.0001 g. The highest degree of internal canal wall dryness was found in group 4. PMID:11199739
Hosoya, N; Nomura, M; Yoshikubo, A; Arai, T; Nakamura, J; Cox, C F
The present study describes the localization and distribution of putative ecto-nucleoside-triphosphate-diphosphohydrolases in the frog semicircular canals. These enzymes provide the terminating mechanism of adenosine-5'-triphosphate (ATP) signalling. The localization of the ATP hydrolysis was mapped ultracytochemically using a one-step cerium citrate reaction. Electron-dense precipitates, indicating ecto-adenosine-triphosphatase (ecto-ATPase) activity, were found at the outer surface of plasma membranes of crista hair cells and supporting cells of the sensory epithelium, transitional cells and undifferentiated cells of the ampullar wall and dark cells constituting the secretory epithelium. Non-sensory cells of the ampulla usually exhibited reaction deposits at the level of both apical and basolateral membranes coming into contact with the endolymph and the perilymph respectively, while cells constituting the sensory epithelium showed evident differences in relation to their position. Hair cells and supporting cells of the peripheral regions exhibited clear reaction products both at the level of apical and basolateral membranes, while those of the isthmus region showed abundant reactivity only at the level of their apical membranes. Of particular interest was the observation that hair cell stereocilia exhibited an abundant ecto-ATPase activity, thus suggesting a possible colocalization of enzymatic sites with purinergic receptors and mechanotransduction channels. This strategic expression of ecto-ATPase sites could provide a rapid mechanism of ATP removal able to rapidly restore the sensitivity of transduction channels. In conclusion, the widespread distribution of ecto-ATPase sites at the level of sensory and non-sensory cells of the frog semicircular canals suggests that ATP may have a key role in controlling vestibular function. PMID:12583876
Gioglio, Luciana; Russo, Giancarlo; Polimeni, Mariarosa; Prigioni, Ivo
We present a preliminary report on the use of a new technique for measuring the motion of the basilar membrane, high-frequency ultrasound Doppler vibrometry. Using a custom-built, 1 mm diameter probe, we collected ultrasonic reflections from intracochlear structures and applied pulsed-wave Doppler vibrometry to measure the basilar membrane response to pressure applied in the ear canal.
Torbatian, Z.; Garland, P.; Adamson, R. B. A.; Bance, M.; Brown, J. A.
Superior semicircular canal dehiscence (SCD) syndrome exhibits pressure- and/or sound-induced oscillopsia and vertigo due to an absence of bone overlaying the superior semicircular canal. A 33-year-old man with right-ear SCD reported dizziness in a noisy hall three years earlier followed by dizziness during flatulence, straining or coughing, and right-ear autophony. Audiography showed a right-ear low-frequency air-bone gap, with positive Tullio phenomenon and a Valsalva maneuver against closed glottis causing torsional-vertical nystagmus. Temporal-bone computed tomography (CT) led to a diagnosis of right-ear SCD syndrome. Surgical dehiscence plugging with calcium phosphate cement via the middle fossa resolved vestibular and cochlear symptoms in the more than two years since. PMID:21770307
\\u000a The aim of this study was to assess imaging findings of posterior semicircular dehiscence on computed tomography and to evaluate\\u000a incidence of posterior and superior semicircular canal dehiscence in patients presenting with vertigo, sensorineuronal hearing\\u000a loss or in a control group without symptoms related to the inner ear. Computed tomography was performed in 507 patients presenting\\u000a either with vertigo
G. A. Krombach; E. DiMartino; T. Schmitz-Rode; A. Prescher; P. Haage; S. Kinzel; R. W. Günther
The toxic wastes that were dumped in the 1950s at Love Canal in New York and then seeped into groundwater and the basements of local residents in the late 1970s are to be finally incinerated, according to a plan recently announced by the US Environmental Protection Agency (EPA). This last, five-year stage in the cleanup will entail the building of an incinerator for burning 35,000 cubic yards of dioxin-contaminated sediment dredged from creeks and sewers in the area at a cost of up to $31 million. The incinerated residue - which will be purified of detectable levels of dioxin, says EPA - will be returned to the site and spread several feet deep.
We have designed, built and tested an anthropomorphic-scale surrogate spinal canal, for use in preliminary evaluations of the performance characteristics of a novel intradural spinal cord stimulator. The surrogate employs a silicone mock spinal cord with semi-major and semi-minor diameters of 10 and 6 mm, respectively, commensurate with those of actual thoracic-level spinal cord. The axial restoring force provided by the 300 µm thick silicone denticulate ligament constructs on the mock cord is ~ 0.32 N mm(-1) over a 1.5 mm range of displacement, which is within a factor of 2 of that measured by others in human cadaver specimens. Examples of testing protocols of prototype intradural stimulators that employ this device are discussed. PMID:22953718
Wenzel Leopold Gruber and Primo Dorello were great anatomists and researchers during the 19th and 20th centuries. Their contributions to neuroanatomy—namely the Gruber's (petrosphenoidal) ligament and Dorello's canal, respectively—have come to be important structures in various approaches through the middle fossa. These structures have also helped provide us with an understanding of the mechanism of sixth nerve paresis in various pathological conditions, such as raised intracranial pressure and Gradenigo syndrome. Their numerous publications have stood as a reference to anatomical researchers. Gruber's description of internal mesogastric hernia and the Meckel-Gruber anastomosis are also widely known in medical literature. The following article is an attempt to reflect upon the life and works of Gruber and Dorello and the importance of their research.
Determining root canal length is a crucial step in success of root canal treatment. Root canal length is commonly estimated based on pre-operation intraoral radiography. 2D depiction of a 3D object is the primary source of error in this approach. Techniques based on impedance measurement are more accurate than radiographic approaches, but do not offer a method for depicting the shape of canal. In this study, we investigated a stererotactic approach for modeling and measurement of root canal of human dentition. A weakly perspective model approximated the projectional geometry. A series of computer-simulated objects was used to test accuracy of this model as the first step. The, to assess the clinical viability of such an approach, endodontic files inserted in the root canal phantoms were fixed on an adjustable platform between a radiographic cone and an image receptor. Parameters of projection matrix were computed based on the relative positions of image receptors, focal spot, and test objects. Rotating the specimen platform from 0 to 980 degrees at 5-degree intervals set relative angulations for stereo images. Root canal is defined as the intersection of two surfaces defined by each projection. Computation of error for length measurement indicates that for angulations greater than 40 degrees the error is within clinically acceptable ranges.
Complications that arise during endodontic procedures pose serious threats to the long-term integrity and health of the tooth. Potential complexities of root canals include residual pulpal tissue, cracks, mesial-buccal 2 and accessory canals. In the case of a failed root canal, a successful apicoectomy can be jeopardized by isthmuses, accessory canals, and root microfracture. Confirming diagnosis using a small imaging probe would allow proper treatment and prevent retreatment of endodontic procedures. An ultrathin and flexible laser scanning endoscope of 1.2 to 1.6mm outer diameter was used in vitro to image extracted teeth with varied root configurations. Teeth were opened using a conventional bur and high speed drill. Imaging within the opened access cavity clarified the location of the roots where canal filing would initiate. Although radiographs are commonly used to determine the root canal size, position, and shape, the limited 2D image perspective leaves ambiguity that could be clarified if used in conjunction with a direct visual imaging tool. Direct visualization may avoid difficulties in locating the root canal and reduce the number of radiographs needed. A transillumination imaging device with the separated illumination and light collection functions rendered cracks visible in the prepared teeth that were otherwise indiscernible using reflected visible light. Our work demonstrates that a small diameter endoscope with high spatial resolution may significantly increase the efficiency and success of endodontic procedures.
Blank, Molly A. B.; Friedrich, Michal; Hamilton, Jeffrey D.; Lee, Peggy; Berg, Joel; Seibel, Eric J.
Canalplasty for congenital atresia of the external auditory canal is associated with a high postoperative stenosis rate in the literature. The authors describe an original surgical and stenting technique that has been used systematically since 2000 in the paediatric otolaryngology department of Trousseau hospital in Paris. After minimal endaural canalplasty, possibly combined with lining of the external auditory canal by skin graft, a stent is sutured to the opening of the ear canal and left in place for 4 weeks. This stenting technique can be used for a shorter duration after tympanoplasty in children with behavioural disorders. PMID:23755961
Denoyelle, F; Leboulanger, N; Philippon, D; Loundon, N; Garabédian, E N
Cytogenetic analyses were performed on peripheral blood from 46 present or past residents of the area surrounding Love Canal, a former dump site for chemical wastes in Niagara Falls, NY. Participants included 17 persons in whom cytogenetic analyses had been performed in 1980 and 29 persons who had been living in 1978 in seven homes that directly adjoined the canal and in which environmental tests showed elevated levels of chemicals spreading from the canal. Frequencies of chromosomal aberrations and of sister chromatid exchange (SCE) did not differ significantly from control levels. For all participants, cigarette smoking was associated with an increase in sister chromatid exchange frequency. PMID:6700040
Heath, C W; Nadel, M R; Zack, M M; Chen, A T; Bender, M A; Preston, R J
Cytogenetic analyses were performed on peripheral blood from 46 present or past residents of the areas surrounding Love Canal, a former dump site for chemical wastes in Niagara Falls, NY. Participants included 17 persons in whom cytogenetic analyses had been performed in 1980 and 29 persons who had been living in 1978 in seven homes that directly adjoined the canal and in which environmental tests showed elevated levels of chemicals spreading from the canal. Frequencies of chromosomal aberrations and of sister chromatid exchange (SCE) did not differ significantly from control levels. For all participants, cigarette smoking was associated with an increase in sister chromatid exchange frequency.
Negotiation of constricted canals can be a challenge during endodontic treatment. Over the years, several strategies have been presented in order to overcome the difficulties imposed by this anatomical feature. This paper presents three cases using a different protocol from that recommended by the manufacturer of the Protaper System in order to facilitate the negotiation of constricted canals. These cases suggest that the modified protocol shown is able to perform the shaping process with less resistance, reducing the risk of instrument separation and performing an effective process to reach the apical thirds in constricted canals.
Negotiation of constricted canals can be a challenge during endodontic treatment. Over the years, several strategies have been presented in order to overcome the difficulties imposed by this anatomical feature. This paper presents three cases using a different protocol from that recommended by the manufacturer of the Protaper System in order to facilitate the negotiation of constricted canals. These cases suggest that the modified protocol shown is able to perform the shaping process with less resistance, reducing the risk of instrument separation and performing an effective process to reach the apical thirds in constricted canals. PMID:24900926
Machado, Ricardo; Silva, Emmanuel João Nogueira Leal; Vansan, Luiz Pascoal
23. 1988 aerial of Tempe Canal, Sections 30 and 31 (T1N R5E) and Sections 25 and 36 (T1N R4E) (top of page is north). Tempe Canal cuts across top right of picture, then reenters at center right along the north side of the Superstition Freeway before turning south and crossing the freeway on a flume. White lines show the alignment of the Price Freeway. Also visible, upper left, is the Western Branch angling from the northeast toward McClintock Drive. Photographer: Unknown, 1988. Source: SRP Cartographic Drafting. - Tempe Canal, South Side Salt River in Tempe, Mesa & Phoenix, Tempe, Maricopa County, AZ
Taurodontism is a morpho-anatomical abnormality in the shape of a tooth. An enlarged pulp chamber, apical displacement of the pulpal floor and no constriction at the level of the cemento-enamel junction are the characteristic features. Special care is required in all aspects of endodontic treatment of a taurodontal tooth, including identifying the orifice, canal exploration, cleaning, shaping and obturation of the root canal. This case report describes the successful endodontic treatment of a taurodontic mandibular second premolar with five root canals. PMID:23890265
In this paper are determined the principal curvatures and principal curvature lines on canal surfaces which are the envelopes of families of spheres with variable radius and centers moving along a closed regular curve in R3. By means of a connection of the differential equations for these curvature lines and real Riccati equations, it is established that canal surfaces have at most two isolated periodic principal lines. Examples of canal surfaces with two simple and one double periodic principal lines are given. PMID:16936931
The first recorded root canal filling was placed 2,200 years ago. However, a plethora of new types of canal-filling materials and techniques have been introduced very recently, which are described and discussed in this article. Many of these new techniques (thermomechanical compaction and thermoplasticized gutta-percha) are variations of the vertical compaction of warm gutta-percha. Others are combinations of gutta-percha techniques and silver points (Thermafil, Densfil). Apical third and injection-type fillings are also available. This article also discusses the future of canal fillings, including calcium phosphate cements and dentin adhesives. PMID:8935001