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The human temporal bone preparation is an acknowledged model for research of the physical processes affecting the outer ear canal and eardrum. Changes affecting the oscillation and resonance behavior of the tympanicmembrane and ear canal between death and temporal bone preparation presently exist in only a few studies. Since the influence of age and physique, as well as the width of ear canal on the ear canal resonance may be important, we prepared two separate studies to analyze these questions. The goal of our first test series involved children and was devised to determine if changes in the outer auditory canal resonances differed according to age. In so doing, canal resonance was recorded with a real ear measurement system. Further, we recorded middle ear pressure, impedance of the tympanicmembrane, ear canal volume, height, weight and surface of the body, head and ear size. We found a significant decrease in the resonance frequency of the outer ear which was age-dependent and was 2.75 kHz in the 7-year-old child. In a separate study we wanted to know if results found in the postmortem temporal bone reflected in vivo relationships. A tympanometer and real ear measurement system was used to test the resonance behavior of the auditory canal as well as the vibration of the eardrum in dependence on temperature and the time after death for 9 h. We then proved the absence of significant changes in the auditory canal and eardrum oscillation in this time period before possible postmortem changes occurred. Our findings show that the method of bone preservation after its preparation is decisive for the validity of measurements in the isolated human temporal bone. PMID:9486378
Vitzthum, H G; Weimann, S; Scheinpflug, L; Vorwerk, U; Begall, K
The tympanicmembrane is a key component of the human auditory apparatus which is a complex biomechanical system, devoted to sound reception and perception. Over the past 30 years, various bioengineering approaches have been applied to the ear modeling and particularly to the middle part. The tympanicmembrane, included in the middle ear, transfers sound waves into mechanical vibration from the ear canal into the middle ear. Changes in structure and mechanical properties of the tympanicmembrane due to middle ear diseases or damages can deteriorate sound transmission. An accurate model of the tympanicmembrane, which simulates the acoustic-mechanical transmission, could improve clinical surgical intervention. In this paper a detailed survey of the biomechanics and the modeling of the tympanicmembrane focusing on the finite element method is conduced. Eight selected models are evaluated and compared deducing the main features and most design parameters from published models, mainly focusing on geometric, constraint and material aspects. Non-specified parameters are replaced with the most commonly employed values. Our simulation results (in terms of modal frequencies and umbo displacement), compared with published numerical and experimental results, show a good agreement even if some scattering appears to indicate the need of further investigation and experimental validation. PMID:21376326
Volandri, G; Di Puccio, F; Forte, P; Carmignani, C
The tympanicmembrane or eardrum of human ear transfers sound waves into mechanical vibration from the external ear canal\\u000a into the middle ear and cochlea. Mechanical properties of the tympanicmembrane (TM) play an important role in sound transmission\\u000a through the ear. Although limited resources about linear elastic properties of the TM are available in literature, there is\\u000a a lack
The tympanicmembrane is a key component of the human auditory apparatus which is a complex biomechanical system, devoted to sound reception and perception. Over the past 30 years, various bioengineering approaches have been applied to the ear modeling and particularly to the middle part. The tympanicmembrane, included in the middle ear, transfers sound waves into mechanical vibration from
G. Volandri; F. Di Puccio; P. Forte; C. Carmignani
This paper presents the authors' experiences with one method of reconstruction of the tympanicmembrane when it is totally absent or when there is a fixed, retracted, defective, or absent malleus. Ten patients undergoing surgery for chronic suppurative otitis media between April, 1971, and January, 1973, had homograft tympanicmembranes and/or ossicles used to reconstruct the defect in the tympanicmembrane or ossicular mechanism. The patients had certain clinical and surgical characteristics in common: 1. all had either an absent tympanicmembrane or almost total perforation of it; 2. all were operated upon in the absence of acute infection or active drainage; cholesteatoma, if present, was totally removed; 3. all had patent eustachian tubes; 4. all had intact middle ear mucosa at the time of utilization of the homograft; 5. all patients were operated upon by the same surgeon; 6. all of the homografts were obtained within 24 hours and were used within one month after the death of the donor; 7. all of the homografts used had been preserved in 70 percent ethyl alcohol; 8. all of the homograft materials came from donors who were under 40 years of age at the time of death and who died of accidental causes. (None of the donors was known to have any pre-existing disease); 9. all homografts, after being placed in proper position in the recipient, were covered with ear canal skin; 10. all patients received homografts that were from the corresponding ear of the donor. (In other words, right ear homografts were used in the patient's right ear, etc.); 11. whenever the tympanic ring was greater than the size of the homograft, the patient's temporalis fascia was used in conjunction with the homograft tympanicmembrane to bridge the defect; 12. all patients had the middle ear packed with gelfoam prior to inserting the homograft (compressed gelfoam was used also for the outer packing); 13. none of the patients had tissue-typing procedures carried out in an effort to match the donor and the recipient, nor was any attempt made to match the sex of the donor and the recipient; and 14. all patients received antibiotics postoperatively; however, none received immunosuppressive therapy postoperatively. In 3 of 10 patients receiving homografts, the malleus was normal, and only the tympanicmembrane was reconstructed. In seven others there was a fixed, retracted, defective or absent malleus in addition to the tympanicmembrane defect.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1053359
Hemangiomas of the external auditory canal, involving the posterior bony canal and the adjacent tympanicmembrane, although rare, are considered a specific disease entity of the human external auditory canal. Hemangiomas of the tympanicmembrane and/or external auditory canal are rare entities; there are 16 previous case reports in the literature. It is a benign vascular tumor. It generally occurs in males in the sixth decade of life. Total surgical excision with or without tympanicmembrane grafting appears to be effective in the removal of this benign neoplasm. The authors present a case and a review of the literature discussing diagnostic and surgical approaches.
The objective of this article is to introduce portable devices capable of providing video images of the tympanicmembrane and tympanic cavity of the ear. Specifically, digital video otoscopy is introduced as an effective platform for tympanicmembrane characterization. In addition, we show how digital image enhancement and segmentation processing techniques can be applied to the acquired images, which could provide more visual detail and objective clinical interpretation. PMID:22255217
Cheng, Lin; Liu, Jinfeng; Roehm, Corrie E; Valdez, Tulio A
The tympanicmembrane or eardrum of human ear transfers sound waves into mechanical vibration from the external ear canal into the middle ear and cochlea. Mechanical properties of the tympanicmembrane (TM) play an important role in sound transmission through the ear. Although limited resources about linear elastic properties of the TM are available in literature, there is a lack of measurement or modeling of viscoelastic properties of the TM at low stress levels. In this study, the uniaxial tensile, stress relaxation, and failure tests were conducted on fresh human cadaver TM specimens to explore mechanical properties of the TM. The experimental results were analyzed using the hyperelastic Ogden model and digital image correlation method. The constitutive equation and non-linear elastic properties of the TM were presented by functions of the stress and strain at the stress range from 0 to 1 MPa. Viscoelastic properties of the TM were described by the stress relaxation function and hysteresis. The results show that the uniaxial tensile test with the aid of digital image correlation analysis is a reliable and useful approach for measuring mechanical properties of ear tissues. The data presented in this paper contribute to ear biomechanics in both experimental measurement and theoretical analysis of ear tissues. PMID:17160465
The migration of squamous epithelium of external ear through a tympanicmembrane perforation into the middle ear forms a cholesteatoma. But it is extremely a rare condition to observe extensive cholesteatoma on the medial surface of tympanicmembrane with perforation. This condition is termed tympanicmembrane cholesteatoma (TMC). We herein present an exceptional case of extensive TMC with marginal perforation.
Sakalli, Erdal; Kaya, Deniz; Celikyurt, Cengiz; Erdurak, Selcuk Cem
Casts and crusts of the tympanicmembrane were removed from patients with previous otitis media. Casts are formed of adherent keratinocytes in a matrix of dried exudate. Detachment from the drumhead leaves the underlying epidermis intact. Casts are defined as those crusts that have detached spontaneously from the surface of the drum. A mechanism based on epithelial proliferation induced by inflammation within the middle ear, with subsequent keratinocyte retention and thickening, is proposed. PMID:2426916
This study investigates guinea-pig and horse tympanicmembranes, sheep dura and chicken eggshell membranes in terms of thickness, histology and tissue interaction with the carbon-dioxide and the erbium:YAG laser. Comparison with formalin-fixed human tympanicmembranes as reference structure has provided a suitable model for further research in laser myringotomy. The horse tympanicmembrane seems to meet our demands regarding the three parameters mentioned above.
Purpose To compare measurements made with four infrared tympanic thermometers (Genius®, Thermopit®, Quickthermo®, and Thermoscan®)\\u000a with those recorded from thermocouples positioned in the contralateral ear.\\u000a \\u000a \\u000a \\u000a Methods Four tympanic thermometers were evaluated in 50 healthy volunteers (12 female and 38 male). Temperatures were measured, in\\u000a random order, at the right tympanicmembrane four times and the highest temperature was considered to be the
Background. Tympanicmembrane perforation may occur when ear pressures are excessive, including valsalva maneuver associated with active labor and vaginal delivery. A pressure differential across the eardrum of about 5 psi can cause rupture; the increased intraabdominal pressure spikes repeatedly manifested by "pushing" during second-stage labor easily approach (and may exceed) this level. Material and Method. We describe a healthy 21-year old nulliparous patient admitted in active labor at 39-weeks' gestational age. Results. Blood appeared asymptomatically in the left ear canal at delivery during active, closed-glottis pushing. Otoscopic examination confirmed perforation of the left tympanicmembrane. Complete resolution of the eardrum rupture was noted at postpartum check-up six weeks later. Conclusion. While the precise incidence of intrapartum tympanicmembrane rupture is not known, it may be unrecognized without gross blood in the ear canal or subjective hearing loss following delivery. Only one prior published report on tympanicmembrane perforation during delivery currently appears in the medical literature; this is the first English language description of the event. Since a vigorous and repetitive valsalva effort is common in normal vaginal delivery, clinicians should be aware of the potential for otic complications associated with the increased intraabdominal pressure characteristic of this technique. PMID:20204134
Baum, Jonathan D; Rattigan, Meghan I; Sills, Eric Scott; Walsh, Anthony P H
Experimental total ear canal ablation with lateral tympanic bulla osteotomy (TECA-LBO) was performed in 13 normal dogs to evaluate healing and retention of brain stem auditory evoked potentials (BSAEP) after surgery. Healing was evaluated by gross and microscopic examination of the surgery sites after 1 (n = 2), 4 (n = 8), 5 (n = 1), and 6 (n = 1) weeks. One dog was eliminated from the study. Brain stem auditory evoked potentials were measured using an air-conducted sound stimulus before and after surgery and before killing. Two dogs had nearly complete obliteration of the tympanic cavity by immature fibrous connective tissue. Eight dogs responded to surgery by either complete or partial re-formation of the tympanic cavity. Retention of the tympanicmembrane in three dogs promoted re-formation of the tympanic cavity and blind epithelialized pockets in the surgery site with accumulation of keratinized debris. Granulation tissue formation and extensive proliferation of new bone on the internal surface of the tympanic bulla was seen in 10 dogs. Proliferative bone completely obliterated the tympanic cavity in two of these dogs. Eleven of 13 dogs had no detectable air-conducted BSAEP after surgery. There was no change in BSAEP measurements before killing compared with postoperative measurements in any dog. Two dogs with retained tympanicmembranes had measurable BSAEP after surgery. This study shows that healing after TECA-LBO may be highly variable. Retention of the tympanicmembrane and small osteotomies appeared to promote reformation of tympanic cavities and prevent ingrowth of granulation tissue.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7701765
The shape of the tympanicmembrane is fairly complicated and seems to be of significant importance in the coupling of the acoustic sound pressure in the external ear canal to the motion of the middle ear ossicles. Precise measurements of the tympanicmembrane shape are not available in literature. To measure the shape of a very thin, curved biological membrane a technique is required which does not deform the surface during the measurement. Casting techniques are therefore not well suited. A noncontacting measurement technique based on moire interferometry proved to be a better tool. A moire shift interferometer was used to measure with great precision the shape of the external surface of human and cat tympanicmembrane. The dense matrix of z(x,y) values thus obtained does not only describe the shape with high spatial resolution but may also be used to calculate different geometrical parameters. As an example of direct application the authors have calculated the area of the curved surface to the pars tensa and pars flaccida for a human and a cat tympanicmembrane.
Background Although tympanicmembrane perforations are common, there have been few systematic studies of the structural features determining the magnitude of the resulting conductive hearing loss. Our recent experimental and modeling studies predicted that the conductive hearing loss will increase with increasing perforation size, be independent of perforation location (contrary to popular otologic belief), and increase with decreasing size of the middle-ear and mastoid air space (an idea new to otology). Objective To test our predictions regarding determinants of conductive hearing loss in tympanicmembrane perforations against clinical data gathered from patients. Study Design Prospective clinical study. Setting Tertiary referral center. Inclusion Criteria Patients with tympanicmembrane perforations without other middle-ear disease. Main Outcome Measures Size and location of perforation; air-bone gap at 250, 500, 1,000, 2,000, and 4,000 Hz; and tympanometric estimate of volume of the middle-ear air spaces. Results Isolated tympanicmembrane perforations in 62 ears from 56 patients met inclusion criteria. Air-bone gaps were largest at the lower frequencies and decreased as frequency increased. Air-bone gaps increased with perforation size at each frequency. Ears with small middle-ear volumes, ?4.3 ml (n = 23), had significantly larger air-bone gaps than ears with large middle-ear volumes, >4.3 ml (n = 39), except at 2,000 Hz. The mean air-bone gaps in ears with small volumes were 10 to 20 dB larger than in ears with large volumes. Perforations in anterior versus posterior quadrants showed no significant differences in air-bone gaps at any frequency, although anterior perforations had, on average, air-bone gaps that were smaller by 1 to 8 dB at lower frequencies. Conclusion The conductive hearing loss resulting from a tympanicmembrane perforation is frequency-dependent, with the largest losses occurring at the lowest sound frequencies; increases as size of the perforation increases; varies inversely with volume of the middle-ear and mastoid air space (losses are larger in ears with small volumes); and does not vary appreciably with location of the perforation. Effects of location, if any, are small.
Mehta, Ritvik P.; Rosowski, John J.; Voss, Susan E.; O'Neil, Ellen; Merchant, Saumil N.
The probe TTS-400 for the tympanicmembrane temperature monitoring of non-tactile type Bi-Temp TM-200D for adult patients is big enough to cause bleeding sometimes in the external acoustic canal because it is easy to bend its tip against the wall of the canal, inducing a wrong measurement. Therefore, we developed a new medium sized probe and compared the efficacy of the probe to the ordinary adult type probe. In six patients under general anesthesia, 54 measurements of tympanicmembrane temperature were performed using both probes and simultaneous monitoring of rectal temperature was performed. The bending of the tip of the probe was seen in 20/54 measurements of the adult type probe, which was with more than 9/54 measurements of the medium sized probe. The bleeding was seen in two patients of the adult type probe and only one patient of the medium sized probe. There were good correlations in the measured temperatures between the adult type probe and the medium sized probe. These two measured temperatures correlated well with the rectal temperature. In conclusion, a new medium sized probe is useful in clinical settings. PMID:8905957
In Novenuber 1992, 45 desert bighorn sheep (Ovis canadensis nelsoni) were captured at Old Dad Peak and the Kelso Mountains of southern California (USA) using a netgun fired from a helicopter. Tympanicmembrane temperature was compared to rectal temperature for 22 sheep to deternuine uf tympanicmembrane temperature was a reliable indicator of hyperthermia and capture stress. All animals captured
During stridulation in the gomphocerine grasshopper Omocestus viridulus the leg movements, sound pattern and either summed auditory nerve activity or single interneuron activity were recorded. Simultaneous laser interferometric and vibrometric measurements of the displacement and velocity of the tympanicmembrane were performed at the pyriform vesicle (d-receptor group). Slow displacements of the tympanicmembrane occur in phase with the ventilatory
The ears of stridulating crickets are exposed to loud self- generated sounds that might desensitise the auditory system and reduce its responsiveness to environmental sounds. We examined whether crickets prevent self- induced auditory desensitisation, and measured the responsiveness of the peripheral auditory system of the cricket (acoustic spiracle, tympanicmembrane and tympanic nerve) during pharmacologically induced sonorous (two-winged) and silent
Crickets have two tympanalmembranes on the tibiae of each foreleg. Among several field cricket species of the genus Gryllus (Gryllinae), the posterior tympanalmembrane (PTM) is significantly larger than the anterior membrane (ATM). Laser Doppler\\u000a vibrometric measurements have shown that the smaller ATM does not respond as much as the PTM to sound. Hence the PTM has been\\u000a suggested
Natasha Mhatre; Fernando Montealegre-Z; Rohini Balakrishnan; Daniel Robert
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.
Objectives/Hypothesis To test urinary bladder matrix (UBM) as a potential treatment for tympanicmembrane (TM) healing and regeneration. Study Design This prospective pilot study was designed to provide both qualitative and semiquantitative assessment of temporal and spatial healing events in the chinchilla model of chronic TM perforations with and without UBM patching. Methods Bilateral myringotomies were performed and repeated as necessary to create subtotal perforations over an 8-week period. Myringoplasty was then performed, with left TMs serving as controls and right TMs receiving UBM patches. TMs were excised at 4 weeks, 8 weeks, and 12 weeks. Fixed tissue samples were characterized for gross morphology, then processed for microscopic evaluation. Results Chronic perforations were maintained with one or more repeated myringotomies. Although both control and patched TMs were thicker than native tissue, patched TMs were transparent and uniform in thickness without any inclusions. UBM patches were readily degraded and replaced by newly deposited and organized host tissue that recapitulated the native TM layers. Conclusions UBM scaffolds were an effective biological scaffold for TM closure and tissue remodeling, leading to thicker than normal anatomy but otherwise normal morphology. Future studies are required to determine functional and temporal outcomes as well as alternative patch orientations. The results show particular promise as a superior alternative means of reconstructing not only chronic TM perforations but also dimeric TMs associated with retraction pockets and atelectasis.
Parekh, Aron; Mantle, Belinda; Banks, Juliane; Swarts, J. Douglas; Badylak, Stephen F.; Dohar, Joseph E.; Hebda, Patricia A.
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.
The ears of stridulating crickets are exposed to loud self-generated sounds that might desensitise the auditory system and reduce its responsiveness to environmental sounds. We examined whether crickets prevent self-induced auditory desensitisation, and measured the responsiveness of the peripheral auditory system of the cricket (acoustic spiracle, tympanicmembrane and tympanic nerve) during pharmacologically induced sonorous (two-winged) and silent (one-winged) stridulation. The acoustic spiracles remained open during stridulation, so the self-generated auditory signal had full access to both the external side and the internal side of the tympanicmembrane. When the spiracles shut in resting crickets, the responsiveness of the tympanicmembrane to acoustic stimuli varied according to the phase of ventilation and was minimal during expiration. The tympanicmembrane oscillated in phase with the self-generated sounds during sonorous chirps and did not oscillate during silent chirps. In both sonorously and silently singing crickets, the responses of the tympanicmembrane to acoustic stimuli were identical during the chirps and the chirp intervals. Bursts of activity were recorded in the tympanic nerve during sonorous chirps; however, activity was minor during silent chirps. In sonorously and in silently singing crickets, the summed nerve response to acoustic stimuli in the chirp intervals was the same as in resting crickets. The response to stimuli presented during the syllable intervals of sonorous chirps was slightly reduced compared with the response in the chirp intervals as a consequence of receptor habituation. In silently singing crickets, acoustic stimuli elicited the same summed nerve response during chirps and chirp intervals. These data indicate that in the cricket no specific mechanism acts to reduce the responsiveness of the peripheral auditory pathway during stridulation. PMID:11249838
The purpose of this study is to evaluate the blood volume and blood flow in human tympanicmembrane. Hemoglobin concentration (IHb) and oxygen saturation of hemoglobin (ISO2) were measured in 71 ears by using a tissue spectrum analyzer. Blood flow (Flow level) was measured in 40 ears by using a laser speckle flow meter. By using two fiber optic probes, these three parameters were measured in the tense part of the tympanicmembrane. A comparison was made between the measurements made with fiber probe touching the tympanicmembrane and the measurements not touching it. Between two measuring patterns, there was no significant differentiation in three parameters, so we took non-touching technique. IHb and Flow level had reproducibility between the first and second recordings. But ISO2 did not have clear reproducibility. In normal tympanicmembrane, IHb and Flow level were not significantly correlated (r = 0.52). IHb was 16 +/- 1.3 (Mean +/- SEM) in normal cases, 17 +/- 4.6 in otitis media with effusion and 104 +/- 22.8 in acute otitis media. Flow level was 0.7 +/- 0.07 in normal cases, 0.6 +/- 0.07 in otitis media with effusion and 2.2 +/- 0.37 in acute otitis media. It is considered that the measurement of hemoglobin concentration by using tissue spectrum analyzer and the measurement of blood flow by using laser speckle flow meter are useful in the studies of the pathophysiology of human tympanicmembrane. PMID:2147717
Yamaguchi, M; Agawa, K; Kanetake, H; Koike, Y; Kashima, K
We compared three types of tympanicmembrane thermometer, Bi-Temp TM-200D (RSP), Mona-Therm (MT), and Quick Thermo (QT). RSP uses a thermister method, MT a thermo-couple method, and QT detects an infrared energy. The tympanicmembrane temperature measured with RSP correlated significantly with those measured with MT or QT. RSP showed temperatures 0.5 to 0.6 degree C lower than MT and 0.3 degree C lower than QT. At the initial phase of monitoring the temperature, RSP showed a gradual increase to a stable temperature. However, MT indicated a transient increase followed by a decrease to a stable temperature. Both reached to stable temperatures in 100 to 120 seconds. These characteristics of thermometers should be considered when we compare the tympanicmembrane temperature measured with various thermometers. PMID:8741485
Central nervous system (CNS) involvement by chronic lymphocytic leukemia (CLL) can present with dramatic neurologic findings or can be quite subtle, discovered only at the time of autopsy. We describe a case of CLL in a patient who presented initially with hearing loss and was ultimately found to have involvement of the tympanicmembrane. She noted improvement of her hearing after induction therapy but was not aware at the time of the involvement of her CNS with CLL. Upon worsening of hearing at the time of relapse, she was evaluated by imaging and CSF analysis as well as biopsy of the tympanicmembrane, and involvement of the CNS was confirmed. She has received CNS-directed therapy with intrathecal liposomal cytarabine and intravenous CNS-directed therapy and has noted improved hearing and resolution of her imaging and CSF findings. This is the first reported case of tympanicmembrane involvement with CLL and describes potentially effective methods for managing this challenging complication.
Cohen, Jonathon B.; Cavaliere, Robert; Byrd, John C.; Andritsos, Leslie A.
This study was performed to determine the historical development of the techniques used to represent the pathologic conditions of the tympanicmembrane. The first coloured attempts were the drawings of Adam Politzer in 1865. Over the following 50 years other otologists produced their own atlases of drawings. At the beginning of the 20th century some otologists tried to photograph the tympanicmembrane but without success. This method was progressively improved and by 1960 two techniques were used: through a speculum or with a microscope. The quality was not optimal, and for this reason, atlases produced during this period were with retouched or water-coloured photographs. It was with the discovery of new endoscopic fibres at the beginning of the 1960s that endoscopic photography progressively replaced all other methods. The precision of these pictures is very important for improving the quality of teaching of the different tympanicmembrane pathology. PMID:12080986
Acute otitis media (AOM) is a rapid infection of middle ear due to bacterial or viral invasion. The infection commonly leads to negative pressure and purulent effusion in the middle ear. To identify how these changes affect tympanicmembrane (TM) mobility or sound transmission through the middle ear, we hypothesize that pressure, effusion, and structural changes of the middle ear are the main mechanisms of conductive hearing loss in AOM. To test the hypothesis, a guinea pig AOM model was created by injection of Streptococcus pneumoniae. Three days post inoculation, vibration of the TM at umbo in response to input sound in the ear canal was measured at three experimental stages: intact, pressure-released, and effusion-drained AOM ears. The vibration of the incus tip was also measured after the effusion was removed. Results demonstrate that displacement of the TM increased mainly at low frequencies when pressure was released. As the effusion was removed, the TM mobility increased further but did not reach the level of the normal ear at low frequencies. This was caused by middle ear structural changes or adhesions on ossicles in AOM. The structural changes also affected movement of the incus at low and high frequencies. The results provide new evidence for understanding the mechanism of conductive hearing loss in AOM. PMID:23483330
Sound transmission through ears with tympanic-membrane (TM) perforations is not well understood. Here, measurements on human-cadaver ears are reported that describe sound transmission through the middle ear with experimentally produced perforations, which range from 0.5 to 5.0 mm in diameter. Three response variables were measured with acoustic stimulation at the TM: stapes velocity, middle-ear cavity sound pressure, and acoustic impedance at the TM. The stapes-velocity measurements show that perforations cause frequency-dependent losses; at low frequencies losses are largest and increase as perforation size increases. Measurements of middle-ear cavity pressure coupled with the stapes-velocity measurements indicate that the dominant mechanism for loss with TM perforations is reduction in pressure difference across the TM; changes in TM-to-ossicular coupling generally contribute less than 5 dB to the loss. Measurements of middle-ear input impedance indicate that for low frequencies, the input impedance with a perforation approximates the impedance of the middle-ear cavity; as the perforation size increases, the similarity to the cavity's impedance extends to higher frequencies. The collection of results suggests that the effects of perforations can be represented by the path for air-volume flow from the ear canal to the middle-ear cavity. The quantitative description of perforation-induced losses may help clinicians determine, in an ear with a perforation, whether poor hearing results only from the perforation or whether other pathology should be expected. PMID:11572354
Voss, S E; Rosowski, J J; Merchant, S N; Peake, W T
A quantitative model of the human middle ear with a tympanic-membrane (TM) perforation is developed. The model is constrained by several types of acoustic measurements made on human cadaver ears, which indicate that perforation-induced changes in transmission result primarily from changes in driving pressure across the TM and that perforation-induced change in the structure of the TM and its coupling to the ossicles contributes a substantially smaller component. The model represents the effect of a perforation on the pressure difference across the TM by inclusion of a path for sound coupling through the perforation from the ear canal to the middle-ear cavity. The model implies that hearing loss with perforations depends primarily on three quantities: the perforation diameter, sound frequency, and the volume of air in the middle-ear cavity. For the conditions that produce the largest hearing loss (low frequency and large perforation), the model yields a simple dependence of loss on frequency, perforation diameter, and middle-ear cavity volume. Predictions from this model may be useful to clinicians in determining whether, in particular cases, hearing losses are explainable by the observed perforations or if additional pathology must be involved. PMID:11572355
Voss, S E; Rosowski, J J; Merchant, S N; Peake, W T
The function of the middle ear is to resolve the acoustic impedance mismatch between the air in the ear canal and the fluid of the inner ear. Without this impedance matching, very little acoustic energy would be absorbed into the cochlea. The first step in this process is the tympanicmembrane (TM) converting sound in the ear canal into vibrations of the middle ear bones. Understanding how the TM manages its task so successfully over such a broad frequency range should lead to more satisfactory and less variable TM repairs (myringoplasty). In addition, understanding the mechanics of the TM is necessary to improve the coupling between ossicular prostheses and the TM. Mathematical models have played a central role in helping the research community understand the mechanics of the eardrum. However, all models require parameters as inputs. Unfortunately, most of the parameters needed for modeling the TM are not well known. In this work, several approaches for inferring the material properties of the TM are explored. First, constitutive modeling is used to estimate an elastic modulus based on the elastic modulus of collagen and experimentally observed fiber densities. Second, experimental tension and bending test results from the literature are re-interpreted using composite laminate theory. Lastly, dynamic measurements of the cat TM are used in conjunction with a composite shell model to bound the material parameters. Values from the literature, both measurement and modeling efforts, and from the present analysis are brought together to form a coherent picture of the TM's material properties. In the human, the data bound the elastic modulus between 0.1 and 0.3 GPa. In the cat, the data suggest a range of 0.1-0.4 GPa. These values are significantly higher than previous estimates. PMID:16023467
Fay, Jonathan; Puria, Sunil; Decraemer, Willem F; Steele, Charles
Background Gas exchange between the middle ear and adjacent compartments determines the trajectory of middle ear pressure change. Little information is available regarding the permeability of the tympanicmembrane (TM) to physiological gases. Objective Determine in vivo if the human TM is permeable to O2 and CO2 at physiologic transTM pressure gradients. Methods An ear canal (EC) probe (ECP) constructed from a custom-fitted acrylic body, a glass capillary tube enclosing an oil meniscus to maintain ambient ECP+EC pressure and a silica glass microtube linked to a mass spectrometer (MS) for measuring gas composition was hermetically sealed within one ear canal of 15 adults. ECP+EC volume was measured and gas samples taken at 10 minute intervals for 1 hour. 1:100,000 epinephrine was applied topically to the ipsilateral TM to decrease blood flow and the experiment repeated. The MS recorded ECP+EC pressures of O2 (32 AMU) and CO2 (44 AMU) were regressed on time and the slope divided by the predicted transTM partial-pressure gradients to yield estimates of transTM O2 and CO2 conductance. Results Consistent with expectation for transTM gas exchange, ECP+EC O2 decreased and CO2 increased during the experiments. TransTM CO2 exchange was faster after application of the epinephrine suggesting an effect of perfusion on that estimate. The ratio of O2/CO2 conductances was approximately 5 which is not consistent with the TM acting primarily as a water or lipid barrier to diffusion. Conclusion The human TM is permeable to CO2 and O2 at physiologic pressure gradients.
Yuksel, Sansak; Swarts, J. Douglas; Banks, Julianne; Seroky, James T.; Doyle, William J.
Background Past in vivo studies in humans showed that the tympanicmembrane (TM) is permeable to physiological gases. Animal studies show that transTM CO2 conductance is increased by TM pathology. Objective Determine if transTM CO2 exchange in humans is affected by atrophic and sclerotic pathologies. Methods An ear canal (EC) probe (ECP) constructed from a custom-fitted acrylic body, a glass capillary tube enclosing an oil meniscus to maintain ambient ECP+EC pressure and a silica glass microtube linked to a mass spectrometer (MS) for measuring gas composition was hermetically sealed within the ear canal of the test ear. ECP+EC volume was measured and gas samples taken at 10 minute intervals for 1 hour. The fractional CO2 pressure measured in the ECP+EC for each sample was regressed on time and the slope of the function multiplied by the ECP+EC volume and divided by the estimated transTM CO2 gradient at the start of the experiment to yield transTM CO2 conductance (uL/min/Pa). Data were complete for 15 normal, 13 sclerotic and 9 atrophic TMs. Results The average (±std) transTM CO2 conductances were 1.76×10?4 ± 7.27×10?5, 2.26×10?4 ± 1.5×10?4 and 2.36×10?4 ± 1.14×10?4 uL/min/Pa/TM for the normal, sclerotic and atrophic TMs, respectively. A pairwise comparison of data for the normal and atrophic TMs under the directional hypothesis of a greater CO2 exchange rate for thinner TMs approached statistical significance (P=.07). A similar pairwise comparison for the sclerotic and normal TMs did not approach statistical significance (P=.28) Conclusion The effect of TM pathologies on CO2 conductance is limited.
Yuksel, Sancak; Swarts, J. Douglas; Banks, Julianne; Doyle, William J.
The full-field thickness distribution, three-dimensional surface model and general morphological data of six human tympanicmembranes are presented. Cross-sectional images were taken perpendicular through the membranes using a high-resolution optical coherence tomography setup. Five normal membranes and one membrane containing a pathological site are included in this study. The thickness varies strongly across each membrane, and a great deal of inter-specimen variability can be seen in the measurement results, though all membranes show similar features in their respective relative thickness distributions. Mean thickness values across the pars tensa ranged between 79 and 97 ?m; all membranes were thinnest in the central region between umbo and annular ring (50-70 ?m), and thickness increased steeply over a small distance to approximately 100-120 ?m when moving from the central region either towards the peripheral rim of the pars tensa or towards the manubrium. Furthermore, a local thickening was noticed in the antero-inferior quadrant of the membranes, and a strong linear correlation was observed between inferior-posterior length and mean thickness of the membrane. These features were combined into a single three-dimensional model to form an averaged representation of the human tympanicmembrane. 3D reconstruction of the pathological tympanicmembrane shows a structural atrophy with retraction pocket in the inferior portion of the pars tensa. The change of form at the pathological site of the membrane corresponds well with the decreased thickness values that can be measured there. PMID:23673509
Van der Jeught, Sam; Dirckx, Joris J J; Aerts, Johan R M; Bradu, Adrian; Podoleanu, Adrian G H; Buytaert, Jan A N
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
|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…
Objective: To describe the patient, disease and clinical characteristics that optimize the effectiveness of laser tympanicmembrane fenestration (LTMF) to treat chronic otitis media with effusion (OME). Setting: Four pediatric otolaryngology tertiary referral centers. IRB approved; participation by informed consent. Methods: An observational clinical effectiveness trial was conducted in 164 ears (94 children), who had chronic OME. All patients were
Linda Brodsky; Steve Cook; Ellen Deutsch; Patrick Brookhouser; Charles Bower; Milton Waner; James Reilly; David Chait; Christopher Poje; Steve Shaha
|Hemispheric activation during cognitive tasks using functional magnetic resonance imaging (fMRI) can be difficult to interpret, uncomfortable, and is not widely available. This study investigated whether tympanicmembrane thermometry could be used as a broad measure of hemispheric activation. Infrared probes measured ear temperature continuously…
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
Jeffrey Tao Cheng; Ellery Harrington; Rachelle Horwitz; Cosme Furlong; John J. Rosowski
Hemispheric activation during cognitive tasks using functional magnetic resonance imaging (fMRI) can be difficult to interpret, uncomfortable, and is not widely available. This study investigated whether tympanicmembrane thermometry could be used as a broad measure of hemispheric activation. Infrared probes measured ear temperature continuously…
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
Large tympanicmembrane perforations usually require a surgical tympanoplasty for closure. Reducing surgical costs and risks has encouraged investigators to examine nonsurgical office procedures for healing these perforations. Growth accelerators are the most promising agents. We study here the closure of large acute perforations using weekly applications of 1 mg of 1% hyaluronic acid (HA), 0.4 ?g basic fibroblast growth
The authors conclude that workers with tympanicmembrane defects (perforated eardrums) should not be excluded from working in atmospheres containing concentrations of hydrogen sulfide (HâS). Several existing requirements and recommendations exclude workers with perforated eardrums from working in or around HâS. Such protective measures stem from the belief that HâS can enter the body through the perforation in sufficient measure
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
Tympanicmembrane temperature (TMT) offers a methodologically simple and noninvasive means to provide a physiological measure of hemispheric activation, although the mechanisms by which it may be related to hemispheric activity are not completely known. Here, the authors examined TMT at baseline and after a mood-induction protocol. They replicate baseline associations between increased absolute difference between left and right TMT and increased anger, and found evidence for a link between increased TMT and increased ipsilateral hemispheric activation after mood-induction. They also found tentative evidence for the existence of right-lateralized emotional hyperthermia after mood-induction. PMID:23695535
Propper, Ruth E; Januszewski, Ashley; Brunyé, Tad T; Christman, Stephen D
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
We examined the effect of moderate ambient temperature variance on the relationship between oral (OT), rectal (RT), and tympanicmembrane (TMT) temperature in 21 healthy adults. Calibrated digital electronic thermometers were used to assess OT and RT, while TMT was measured using an infrared detection device and microprocessor. Recordings were made at baseline and after 15 and 20 minutes of
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.
Tympanicmembrane (TM) velocities of vocalizing male frogs, Eleutherodactylus coqui, were measured in the field using laser vibrometry. The animal's call produced levels of 114-120 dB SPL measured at distances of 12-20 mm from the eardrum and mean TM displacements in response to the two notes of the male's own advertisement call were 1.84 and 2.08 nm, respectively. These values are close to the TM displacements obtained in response to playback of the two-note call at much lower sound levels. Thus TM vibrations are attenuated during phonation in the frog, and several candidate mechanisms for auditory sensitivity reduction are discussed. PMID:1619130
Tympanicmembrane pathological findings such as perforations and tympanosclerotic plaques (along with conductive hearing loss and purulent drainage) are the most typical trademarks of either active or burned-out chronic otitis media. These findings are normally evaluated by an expert using visual subjective analysis. In this work, we present a computational semi-automated method to quantify these pathologies. We also present a validation study of the method using a subset of 39 cases randomly extracted from a set of more than 2000 cases (perforations and tympanosclerosis) of the Hospital de Clínicas de Porto Alegre. The validation was performed using Ground Truth images, generated by experts, and has shown promising results. PMID:19643399
An infrared tympanicmembrane thermometer (FIRST temp) said to approximate core temperature accurately is being marketed as a noninvasive, quick, and easy-to-use clinical instrument. The determination of tympanicmembrane temperatures by this device was compared with the determination of oral, rectal, or axillary temperatures by a conventional glass thermometer. Subjects were patients of a pediatric group practice in Houston, Texas. FIRST temp and conventional temperature determinations on individual patients were completed within 5 minutes of each other. The presence or absence of otitis media was noted by the examining physician. Agreement between the two methods of temperature determination was assessed by calculating limits of agreement within which 95% (+/- 2 standard deviations) of individual differences would fall. The location of conventional thermometer (oral, rectal, axillary), time interval between the two separate measures, and the presence or absence of otitis media were entered into a multiple regression analysis to determine whether these factors influenced the observed differences between the two methods. A total of 144 patients were enrolled in the study; oral comparisons were obtained in 92 (57%) patients, rectal in 35 (24%), and axillary in 29 (19%). The upper and lower limits of agreement between temperature methods were 1.12 degrees C and 0.89 degrees C and the mean difference was -0.12 degrees C. Regression analysis revealed that only the site of conventional thermometer location (oral, rectal, axillary) was a significant predictor of FIRST temp/conventional differences. Each site had a range of agreement greater than 1.65% degrees C; axillary temperatures had the greatest range (-0.94 degree C to +1.30 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1741208
Hypothesis It was hypothesized that laser-Doppler vibrometry measurements of umbo velocity in aerated middle ears with conductive loss can differentiate ossicular interruptions, stapes fixations, and mallear fixations. More generally, we hypothesize that laser-Doppler vibrometry measurements of umbo velocity can give information about how differences in the impedance that the ossicles work against affect middle-ear function. Background Laser-Doppler vibrometry is a well-established research tool for exploring middle-ear function. The authors wished to investigate its potential as a clinical tool for differential diagnosis of the cause of conductive hearing loss. Methods Laser-Doppler vibrometry was used to investigate the relationship between the sound-induced velocity of the tympanicmembrane at the umbo and the cause of conductive hearing loss when the tympanicmembrane was normal and the middle ear was aerated. The results of measurements in 17 adult ears before exploratory tympanotomy were compared with the surgically determined cause of the hearing loss. The authors also measured the motion of the umbo in 10 patients who had undergone successful small-fenestra stapedectomy procedures. In all the studied ears, pure-tone audiograms were measured at the time of laser-Doppler vibrometry testing. Results There were clear statistical differences between the umbo velocity in normal ears and in ears with different ossicular pathologic conditions. There was also a clear separation of the results between ears with ossicular interruptions and ossicular fixation. The pattern of laser-Doppler vibrometry measurements in poststapedectomy ears approximated the pattern in ears with ossicular interruptions. Conclusion Comparison of laser-Doppler vibrometry results and audiometry may be a sensitive and selective indicator of ossicular pathologic conditions as well as a useful tool for investigating middle ear function.
Rosowski, John J.; Mehta, Ritvik P.; Merchant, Saumil N.
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
Stroboscopic holography was used to quantify dynamic deformations of the tympanicmembrane (TM) of the entire surface of the TM before and after cartilage tympanoplasty of the posterior or posterior-superior part of the TM. Cartilage is widely used in tympanoplasties to provide mechanical stability for the TM. Three human cadaveric temporal bones were used. A 6 mm × 3 mm oval cartilage graft was placed through the widely opened facial recess onto the medial surface of the posterior or posterior-superior part of the TM. The graft was either in contact with the bony tympanic rim and manubrium or not. Graft thickness was either 0.5 or 1.0 mm. Stroboscopic holography produced displacement amplitude and phase maps of the TM surface in response to stimulus sound. Sound stimuli were 0.5, 1, 4 and 7 (or 8) kHz tones. Middle ear impedance was measured from the motion of the entire TM. Cartilage placement generally produced reductions in the motion of the TM apposed to the cartilage, especially at 4 kHz and 7 or 8 kHz. Some parts of the TM showed altered motion compared to the control in all three cases. In general, middle ear impedance was either unchanged or increased somewhat after cartilage reconstruction both at low (0.5 and 1 kHz) and high (4 and 7 kHz) frequencies. At 4 kHz, with the 1.0 mm thick graft that was in contact with the bony tympanic rim, the impedance slightly decreased. While our earlier work with time-averaged holography allowed us to observe differences in the pattern of TM motion caused by application of cartilage to the TM, stroboscopic holography is more sensitive to TM motions and allowed us to quantify the magnitude and phase of motion of each point on the TM surface. Nonetheless, our results are similar to those of our earlier work: The placement of cartilage on the medial surface of TM reduces the motion of the TM that apposes the cartilage. These obvious local changes occur even though the cartilage had little effect on the sound-induced motion of the stapes.
Aarnisalo, Antti A.; Cheng, Jeffrey T.; Ravicz, Michael E.; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.
Introduction Identifying fever can influence management of the emergency department (ED) patient, including diagnostic testing, treatment, and disposition. We set out to determine how well oral and tympanicmembrane (TM) temperatures compared with rectal measurements. Methods A convenience sample of consecutively adult ED patients had oral, TM, and rectal temperatures performed within several minutes of each other. Descriptive statistics, Bland–Altman agreement matrices with 95% confidence interval (CI), and measures of test performance, including sensitivity, specificity, predictive values, and interval likelihood ratios were performed. Results A total of 457 patients were enrolled with an average age of 64 years (standard deviation: 19 years). Mean temperatures were: oral (98.3°F), TM (99.6°F), and rectal (99.4°F). The mean difference in rectal and oral temperatures was 1.1°F, although there was considerable lack of agreement between oral and rectal temperatures, with the oral temperature as much as 2.91°F lower or 0.74°F higher than the rectal measurement (95% CI). Although the difference in mean temperature between right TM and rectal temperature was only 0.22°F, the right TM was lower than rectal by up to 1.61°F or greater by up to 2.05°F (95% CI). Test performance varied as the positive predictive value of the oral temperature was 97% and for tympanic temperature was 55% (relative to a rectal temperature of 100.4°F or higher). Comparative findings differed even at temperatures considered in the normal range; among patients with an oral temperature of 98.0 to 98.9, 38% (25/65) were found to have a rectal temperature of 100.4 or higher, while among patients with a TM of 98.0 to 98.9, only 7% (10/134) were found to have a rectal temperature of 100.4 or higher. Conclusion The oral and tympanic temperature readings are not equivalent to rectal thermometry readings. Oral thermometry frequently underestimates the temperature relative to rectal readings, and TM values can either under- or overestimate the rectal temperature. The clinician needs to be aware of the varying relationship between oral, TM, and rectal temperatures when interpreting readings.
Barnett, Barbara J; Nunberg, Stacy; Tai, Julia; Lesser, Martin L; Fridman, Vladmir; Nichols, Patricia; Powell, Richard; Silverman, Robert
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.
Background: Considering the presence of squamous epithelial cells and fibroblasts in the tympanicmembrane (TM), topical estrogen application may influence the repair of TM perforations. Therefore, this study was designed to investigate the healing effect of topical estrogen on chronic TM perforations and improvement in hearing threshold. Materials and Methods: Sixty patients were enrolled in a randomized clinical trial. Thirty patients were treated with paper patch and 30 with estrogen-impinged paper patch. Complete closure of the TM perforation and hearing threshold were evaluated in both groups. Chronic unilateral perforations of the TM involving less than 40% of the total area of the TM without active disease in the middle ear were selected. The margin of the perforation was chemically trimmed using 15% trichloroacetic acid and patching performed under an operating microscope. Microscopic examination was performed after 14 days and repeated after 30 days. Complete closure of the TM perforation was considered as successful repair. Hearing threshold was determined before the start of the trial and 30 days after treatment. Results: No significant difference was found between the two groups after 14 days in complete closure of the perforation (P = 0.310). After 30 days, patients treated with estrogen-impinged paper patch showed a significantly higher rate of closure of the perforation (63.4%) and improvement in hearing threshold (P = 0.017). Conclusion: Topical estrogen may have a healing effect on chronic TM perforations and improvement in hearing threshold.
Barati, Behrouz; Abtahi, Seyyed Hamid Reza; Hashemi, Seyyed Mostafa; Okhovat, Seyyed Ahmad Reza; Poorqasemian, Mehdi; Tabrizi, Ali Goljanian
Abstract Conclusion: The pathogenesis of secondary acquired cholesteatoma with a tympanicmembrane (TM) perforation is very different from that of other types of cholesteatoma. This disease should be clearly categorized as a different type of cholesteatoma. Objective: Primary cholesteatoma generally arises from retraction of the squamous epithelium of the TM. However, in rare cases, epithelial invasion occurs from the edge of the TM perforation and migrates to the medial surface of the TM and middle ear cavity. The aim of this study was to evaluate the clinical features of secondary acquired cholesteatoma with a TM perforation. Methods: We investigated 13 ears that underwent surgical treatment after the diagnosis of secondary acquired cholesteatoma with a TM perforation. Patient backgrounds, the preoperative appearances of TM, intraoperative findings, and histopathological findings were investigated. Results: The average age was much higher than that of patients with other types of cholesteatoma, suggesting that it must require long periods of time to establish the disease. The common area of the epithelial invasion was on the superior part of the TM perforation around the tip of the malleus handle. The tendon of the tensor tympani muscle plays an important role as an extension route for this disease. PMID:23848236
Twelve cases of neonates admitted to the neonatal unit of our hospital, between January 1, 2000, and December 31, 2005, because of otorrhea due to spontaneous perforation of the tympanicmembrane within the first 10 days of life are presented. Data were collected retrospectively from medical records. Cultures of the middle ear exudate grew PSEUDOMONAS AERUGINOSA in 10, SERRATIA MARCENSCENS in 1, and STAPHYLOCOCCUS AUREUS in 1 neonate. Cultures of nasopharyngeal secretions grew P. AERUGINOSA in nine, S. MARCENSCENS in one, S. AUREUS in one, and STREPTOCOCCUS VIRIDANS in one neonate. Middle ear versus nasopharyngeal secretions cultures grew the same organism in 11 neonates. A 10-day course of parenteral antibiotics was administered (ampicillin-ceftazidime for all neonates except for the one neonate with the S. AUREUS otitis who received netilmicin-cloxacillin). All neonates had uneventful course and were discharged home in good clinical condition. Our findings suggest that neonates with eardrum perforation should receive antibiotics parenterally, as the most common pathogens is P. AERUGINOSA, for which there are no satisfactory antibiotics for oral use. PMID:20225173
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
We evaluated the usefulness of a novel earphone-type infrared tympanic thermometer (IRT) during cardiac surgery with cardiopulmonary\\u000a bypass. Tympanicmembrane temperature (T\\u000a Tym) was monitored using the IRT inserted into the right ear canal of 12 adult patients (ASA III) who had been scheduled for\\u000a elective cardiac surgery with cardiopulmonary bypass under general anesthesia. Rectum (T\\u000a Rec) and nasopharyngeal temperatures
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, we report the fabrication of a nanofibrillar patch by using BC and its application as a new wound-healing platform for traumatic tympanicmembrane (TM) perforation. 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 was found that the patch contained a network of nanofibrils and was transparent. The thickness of the BC nanofibrillar patch was found to be approximately 10.33 ± 0.58 ?m, and the tensile strength and Young's modulus of the BC nanofibrillar patch were 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 showed that TM cell proliferation and migration were stimulated under the guidance of the BC nanofibrillar patch. In vivo animal studies demonstrated that the BC nanofibrillar patch promotes the rate of TM healing as well as aids in the recovery of TM function. Our 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
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.
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
Clinical diagnosis of acute otitis media (AOM) in children is not easy. It was assumed that there is a difference (Delta) T between the TympanicMembrane (TM) temperatures in the two ears in unilateral AOM and that an accurate measurement of (Delta) T may improve the diagnosis accuracy. An IR transmitting fiber, made of AgClBr, was coupled into a hand held otoscope and wa used for the non-contact measurements of TT, the TM temperature. Experiments were carried out, first, on a laboratory model that simulated the human ear, including an artificial tympanicmembrane and an artificial ear canal. Measurements carried out using commercially available tympanic thermometers shown that the temperature Tc of the ear canal affected the results. Tc did not affect the fiberoptic radiometer, and this device accurately measured the true temperature, TT of the tympanicmembrane.
Recent studies using a satellite-linked dive recorder have shown that the hooded seal (Cystophora cristata), a common Arctic pinniped, can dive to a depth of > 1000 m and stay submerged for close to 1 h. At these depths the water pressure reaches 100 atm, entailing obvious risk of serious damage to the hearing apparatus, mainly the tympanicmembrane (TM) and middle ear (ME). We dissected and photodocumented the temporal bones of five newborn and three adult hooded seals in order to study the temporal bone structure and reveal its protective mechanisms for extreme pressure changes. Specimens were sectioned and stained for light microscopy. The thicknesses of the pars tensa and pars flaccida were found to average 60 and 180 microm, respectively. The ME cavity hosts a cavernous tissue of thin-walled vessels beneath the modified respiratory epithelium. The ME and external ear canal (EAC) volumes can be altered appreciably by filling/emptying the cavernous tissue with blood. The ossicles were fixed by contracting the tensor tympani and stapedius muscles simultaneously with complete occlusion of the EAC. According to Boyle's law, the volume of the gas-filled ME cavity at a depth of 1000 m is only 1% of its volume at the surface of the sea. Ascent from such a depth allows the gas in the ME cavity to expand, causing the TM to bulge laterally. This movement is counteracted by a reduction in the blood volume inside the cavernous sinuses, action in the tensor tympani and stapedius muscles and discharge of gas through the Eustachian tube. The presence of a firm, broad-based exostosis in the floor of the EAC lateral to the TM helps to obstruct the EAC. PMID:11678167
The pars flaccida of the Meriones unguiculatus (Mongolian gerbil) was in previous studies shown to bulge almost spherically when pressurized, a behavior suggesting that it is suspended by a fixed circular boundary. The question arises whether this "functional" boundary is based on an underlying circular anatomical boundary, an important issue for modeling the middle-ear mechanics. In this article, the boundaries of the Mongolian gerbil pars flaccida were visualized in situ with otomicroscopy and in slides with light microscopy and by micro-CT radiology. For the major part of its circumference, the pars flaccida was found to be suspended by rigid bone, that is, the tympanic legs. The remaining boundary is made up of the terminal portion of the handle of the malleus and the soft tissue of the terminal arches. The attachment to these structures is simple and uncomplicated, and the geometry is regular and symmetric: deviating by only 3.5% from a perfect circular shape. The findings justify the use of a fixed circular boundary as a good approximation for the modeling of pars flaccida deformation in the Mongolian gerbil. PMID:21538927
Von Unge, Magnus; Buytaert, Jan A N; Dirckx, Joris J J
The healing rate of subacute tympanicmembrane perforations over a 30-day period showed significant difference between the groups (ANOVA; p < 0.001) and was 30.3% for the epidermal growth factor group, 3.6% for the pentoxifylline group, 16.5% for ears treated with epidermal growth factor and pentoxifylline and 8.7% for untreated controls. Conclusions: Epidermal growth factor helps in the healing of
The external auditory canal is an S- shaped osseo-cartilaginous structure that extends from the auricle to the tympanicmembrane. Congenital, inflammatory, neoplastic, and traumatic lesions can affect the EAC. High-resolution CT is well suited for the evaluation of the temporal bone, which has a complex anatomy with multiple small structures. In this study, we describe the various lesions affecting the EAC. PMID:22223939
|In the mid-1800's, the canal system in the U.S. was thriving. But, by the end of that century, roads and railways had replaced these commercial thoroughfares. Renewed interest in the abandoned canals is now resulting in renovation and ecological site development in Pennsylvania and New Jersey. (MA)|
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
In this study, we examined the relationship between a measure of cerebral lateralization--differences in tympanic temperature (T(Ty))--and questionnaire measures of inattentiveness and hyperactivity in both people and dogs. Theories of cerebral lateralization indicate that cerebral asymmetry may improve attentive behaviour. In people, greater left than right T(Ty) was related to increased self-reports of inattentiveness. There was no relationship between lateralized T(Ty) and hyperactivity. In dogs, there was quadratic relationship between lateralized T(Ty) and handler reports of inattentiveness. Increased T(Ty) asymmetry, regardless of direction, was related to more attentiveness. There was no discernable relationship between hyperactivity and lateralized T(Ty). Differences in T(Ty) may be an useful tool for investigating species comparisons of cerebral lateralization. PMID:22488130
The accuracy of tympanometric estimates of ear canal volume was evaluated by testing the following two assumptions on which the procedure is based: (a) ear canal volume does not change when ear canal pressure is varied, and (b) an ear canal pressure of 200 daPa drives the impedance of the middle ear transmission system to infinity so the immittance measured at 200 daPa can be attributed to the ear canal volume alone. The first assumption was tested by measuring the changes in ear canal volume in eight normal subjects for ear canal pressures between +/- 400 daPa using a manometric procedure based on Boyle's gas law. The data did not support the first assumption. Ear canal volume changed by a mean of .113 ml over the +/- 400 daPa pressure range with slightly larger volume changes occurring for negative ear canal pressures than for positive ear canal pressures. Most of the volume change was attributed to movement of the probe and to movement of the cartilaginous walls of the ear canal. The second assumption was tested by comparing estimates of ear canal volume from susceptance tympanograms with a direct measurement of ear canal volume adjusted for changes in volume due to changes in ear canal pressure between +/- 400 daPa. These data failed to support the second assumption. All tympanometric estimates of ear canal volume were larger than the measured volumes. The largest error (39%) occurred for an ear canal pressure of 200 daPa at 220 Hz, whereas the smallest error (10%) occurred for an ear canal pressure of -400 daPa at 660 Hz. This latter susceptance value (-400 daPa at 660 Hz) divided by three is suggested to correct the 220-Hz tympanogram to the plane of the tympanicmembrane. Finally, the effects of errors in estimating ear canal volume on static immittance and on tympanometry are discussed. PMID:7329051
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
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
The ligaments and folds of the middle ear are compared with the mesentery of the abdominal cavity. From a philogenetic point of view, these structures first appear in the cynodonts. These ligaments maintain the malleus and the incus in the tympanic cavity, increasing the transmission of the auditory system. Some of these ligaments and folds are different in some mammals.
Salvador de Lara Galindo; Maria Elena Cuspinera de Galindo
The contribution of the middle ear air spaces to sound transmission through the middle ear in canal wall-up and canal wall-down mastoidectomy was studied in human temporal bones by measurements of middle ear input impedance and sound pressure difference across the tympanicmembrane for the frequency range 50 Hz to 5 kHz. These measurements indicate that, relative to canal wall-up procedures, canal wall-down mastoidectomy results in a 1 to 5 dB decrease in middle ear sound transmission below 1 kHz, a 0 to 10 dB increase between 1 and 3 kHz, and no change above 3 kHz. These results are consistent with those reported by Gyo et al. (Arch Otolaryngol Head Neck Surg 1986;112:1262-8), in which umbo displacement was used as a measure of sound transmission. A model analysis suggests that the reduction in sound transmission below 1 kHz can be explained by the smaller middle ear air space volume associated with the canal wall-down procedure. We conclude that as long as the middle ear air space is aerated and has a volume greater than 0.7 ml, canal wall-down mastoidectomy should generally cause less than 10 dB changes in middle ear sound transmission relative to the canal wall-up procedure. PMID:9627232
A comparison of parallel measurements of body temperature with infrared tympanic thermometry (First Temp 2000A) in both ears and with rectal mercury thermometer were performed in 100 patients with stroke (n = 60) or spinal cord injury (n = 40). Agreement between the two methods of temperature determination was assessed by calculating limits of agreement within which 95% (+/- 2 SD) of the individual differences would fall. Ear temperature was on average 0.3 +/- 1.0 (2 SD) degrees C above rectal temperature (p < 0.01). The upper and lower limits of agreement between the two methods were -0.7 degrees C and +1.3 degrees C, respectively. Mean difference between ear temperature in right and left ear was 0.0 +/- 0.7 (2 SD) degrees C. According to these results tympanicmembrane temperature measured with First Temp 2000A appears to give clinical significant erroneous readings, and should be used with caution. PMID:8266296
Fremstad, M L; Holden, G M; Anke, A G; Stanghelle, J K
A salient characteristic of most auditory systems is their capacity to analyse the frequency of sound. Little is known about how such analysis is performed across the diversity of auditory systems found in animals, and especially in insects. In locusts, frequency analysis is primarily mechanical, based on vibrational waves travelling across the tympanalmembrane. Different acoustic frequencies generate travelling waves that direct vibrations to distinct tympanal locations, where distinct groups of correspondingly tuned mechanosensory neurons attach. Measuring the mechanical tympanal response, for the first time, to acoustic impulses in the time domain, nanometre-range vibrational waves are characterized with high spatial and temporal resolutions. Conventional Fourier analysis is also used to characterize the response in the frequency domain. Altogether these results show that travelling waves originate from a particular tympanal location and travel across the membrane to generate oscillations in the exact region where mechanosensory neurons attach. Notably, travelling waves are unidirectional; no strong back reflection or wave resonance could be observed across the membrane. These results constitute a key step in understanding tympanal mechanics in general, and in insects in particular, but also in our knowledge of the vibrational behaviour of anisotropic media. PMID:18522928
INTRODUCTION: Temperature measurement is important during routine neurocritical care especially as differences between brain and systemic temperatures have been observed. The purpose of the study was to determine if infra-red temporal artery thermometry provides a better estimate of brain temperature than tympanicmembrane temperature for patients with severe traumatic brain injury. METHODS: Brain parenchyma, tympanicmembrane and temporal artery temperatures
Danielle Kirk; Timothy Rainey; Andy Vail; Charmaine Childs
This article provides an experimental assessment of three commercially available clinical thermometers, using different thermal infrared sensors. This kind of thermometer measures body temperature by detecting infrared radiation from the tympanicmembrane. These thermometers are growing in popularity thanks to their simplicity of use, rapid response and minimal distress to the patient. The purpose of the laboratory tests presented here
This study examined relationships among rectal (Tr), esophageal (T.), and tympanic (Ty) membrane (left and right) responses during exercise in high ambient temperatures. Tr, Te, Tty, and skin (Tsk) temperatures were recorded on 11 subjects Under the follo...
1.The oscillations of the tympanalmembrane of Locusta migratoria were analysed by combined laser vibrometry and interferometry. Simultaneously the activity in the tympanal nerve was recorded extracellularly. The animal was stimulated by sound pulses and one of the hindlegs was passively moved in a sinusoidal manner simulating stridulation. These stimuli were applied separately and in combination.2.Sound stimulation elicited high-frequency membrane
The accuracy of ear-canal admittance and reflectance as measures of the ear's properties depends on the acoustic effects of the canal. Here, measurements of acoustic admittance at different canal locations in domestic cats are used to test three common assumptions. (1) Can a uniform-tube model of the canal represent spatial variations in admittance? Data from cats support this assumption for frequencies below 3 kHz, where the admittance inferred at the tympanicmembrane (TM) based on a uniform-tube model differs by less than 3 dB in magnitude and 0.07 periods in angle from the admittance measured at the TM; for higher frequencies greater differences occur. (2) Do large static air pressures in the canal make the middle ear rigid without affecting the properties of the canal space? The measurements reported indicate that large negative static pressures reduce the low-frequency compliance of the cat middle ear to about 10% of the compliance of the canal air volume. Static displacements of the acoustic probe, TM, and canal walls with static pressure may affect estimates of the canal volume and middle-ear compliance by as much as 15% to 20%. (3) Is the acoustic-reflectance magnitude constant with position along the canal? Reflectance data from cat ear canals generally support this idea, except within a frequency region near 0.5 kHz for which there is evidence of energy loss. These results demonstrate that noninvasive measurements in the canal describe middle-ear acoustic properties to within tolerances that depend on the effects of the canal. PMID:11008816
Trans-tympanic injection into the middle ear has long been the standard for local delivery of compounds in experimental studies. Here we demonstrate the advantages of the novel method of intra-tympanic injection through the otic bone for the delivery of compounds or siRNA into the adult mouse cochlea. First, a fluorescently-conjugated scrambled siRNA probe was applied via intra-tympanic injection into the middle ear cavity and was detected in sensory hair cells and nerve fibers as early as 6 h after the injection. The fluorescent probe was also detected in other cells of the organ of Corti, the lateral wall, and in spiral ganglion cells 48 h after the injection. Furthermore, intra-tympanic delivery of Nox3 siRNA successfully reduced immunofluorescence associated with Nox3 in outer hair cells 72 h after injection by 20%. Drug or siRNA delivery via intra-tympanic injection does not compromise the tympanicmembrane or interfere with noise-induced hearing loss, while trans-tympanic injections significantly altered the cochlear response to noise exposure. In summary, intra-tympanic injection through the otic bone into the middle ear cavity provides a promising approach for delivery of compounds or siRNA to cochlear hair cells of adult mice, relevant for the study of mechanisms underlying inner ear insults and, specifically, noise-induced hearing loss. PMID:23183031
The feasibility of virtual otoscopy (VO) imaging was evaluated in five dogs with experimentally induced otitis media, two control dogs, and two canine patients with otitis media. VO images of the tympanic cavity and ossicles were generated with commercially available software using raw computed tomography (CT) data. Eight out of 10 ears inoculated with pathogen exhibited obvious clinical signs associated with otitis externa. CT images revealed soft tissue density material occupying the tympanic bulla compatible with otitis media in three dogs with experimentally induced otitis media and two patients. No remarkable features were observed on the radiographs. Four different VO views (ear canal, tympanic bulla, eustachian tube, and ossicular chain) were created. Promontory, cochlea window, tympanic, and septum bulla as well as ossicles were easily and clearly distinguished except for the incus and stapes of the clinical patients. VO images were not more suitable than images created with conventional CT for accurately diagnosing otitis media in this study. However, it appears that VO could be more feasible for assessing the complex structure of the inner ear in dogs with fluid-filled tympanic cavities since fluid accumulation within the tympanic bulla did not affect the evaluation of bony tissue in the middle ear on VO images.
Cho, Youngkwon; Jeong, Jimo; Lee, Haebeom; Kim, Minsu; Kim, Namsoo
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
We evaluated the usefulness of a novel earphone-type infrared tympanic thermometer (IRT) during cardiac surgery with cardiopulmonary bypass. Tympanicmembrane temperature (T(Tym)) was monitored using the IRT inserted into the right ear canal of 12 adult patients (ASA III) who had been scheduled for elective cardiac surgery with cardiopulmonary bypass under general anesthesia. Rectum (T(Rec)) and nasopharyngeal temperatures (T(Naso)) were also monitored, and all temperatures were recorded at 5-min intervals during cardiopulmonary bypass. Operating room temperature was kept at 20°-27°C; a conductive warming/cooling system was used to control the patient's body temperature. Of 265 measurements obtained, body temperature range was 31.6°-37.6°C. No complications were related to site of insertion of the monitoring probe. Significant correlations were seen between T(Tym) and T(Naso) (r = 0.971, P < 0.001), and T(Tym) and T(Rec) (r = 0.759, P < 0.001). A Bland-Altman plot showed that average temperature of T (Tym) was 0.06°C above T(Naso) (±0.66°C, 2 SD) and 0.12°C below T(Rec) (±1.78°C, 2 SD). We conclude that an earphone-type IRT is noninvasive and hygienic and could continuously evaluate selective cerebral temperature during cardiopulmonary bypass in adults. PMID:21519927
A chordotonal organ occurring in the posterior metathorax of an atympanate moth, Actias luna (L.) (Bombycoidea: Saturniidae), appears to be homologous to the tympanal organ of the noctuoid moth. The peripheral anatomy of the metathoracic nerve branch, IIIN1b1 was examined in Actias luna with cobalt-lysine and Janus Green B, and compared to its counterpart, IIIN1b (the tympanal branch), in Feltia heralis (Grt.) (Noctuoidea: Noctuidae). The peripheral projections of IIIN1b1 were found to be similar in both species, dividing into three branches, the second (IIIN1b1b) ending as a chordotonal organ. The atympanate organ possesses three sensory cell bodies and three scolopales, and is anchored peripherally via an attachment strand to the undifferentiated membranous region underlying the hindwing alula, which corresponds to the tympanal region of the noctuoid metathorax. Extracellular recordings of the IIIN1b1 nerve in Actias luna revealed a large spontaneously active unit which fired in a regular pattern (corresponding to the noctuoid B cell) and smaller units (corresponding to the noctuoid acoustic A cells) which responded phasically to low frequency sounds (2 kHz) played at high intensities (83-96 dB, SPL) and also responded phasically to raising and lowering movements of the hindwing. We suggest that the chordotonal organ in Actias luna represents the evolutionary prototype to the noctuoid tympanal organ, and that it acts as a proprioceptor monitoring hindwing movements. This system, in its simplicity (consisting of only a few neurons) could be a useful model for examining the changes to the nervous system (both central and peripheral) that accompanied the evolutionary development of insect tympanal organs. PMID:2273092
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.
In clinical measurements of hearing sensitivity, a given earphone is assumed to produce essentially the same sound-pressure level in all ears. However, recent measurements [Voss et al., Ear and Hearing (in press)] show that with some middle-ear pathologies, ear-canal sound pressures can deviate by as much as 35 dB from the normal-ear value; the deviations depend on the earphone, the middle-ear pathology, and frequency. These pressure variations cause errors in the results of hearing tests. Models developed here identify acoustic mechanisms that cause pressure variations in certain pathological conditions. The models combine measurement-based Thévenin equivalents for insert and supra-aural earphones with lumped-element models for both the normal ear and ears with pathologies that alter the ear's impedance (mastoid bowl, tympanostomy tube, tympanic-membrane perforation, and a "high-impedance" ear). Comparison of the earphones' Thévenin impedances to the ear's input impedance with these middle-ear conditions shows that neither class of earphone acts as an ideal pressure source; with some middle-ear pathologies, the ear's input impedance deviates substantially from normal and thereby causes abnormal ear-canal pressure levels. In general, for the three conditions that make the ear's impedance magnitude lower than normal, the model predicts a reduced ear-canal pressure (as much as 35 dB), with a greater pressure reduction with an insert earphone than with a supra-aural earphone. In contrast, the model predicts that ear-canal pressure levels increase only a few dB when the ear has an increased impedance magnitude; the compliance of the air-space between the tympanicmembrane and the earphone determines an upper limit on the effect of the middle-ear's impedance increase. Acoustic leaks at the earphone-to-ear connection can also cause uncontrolled pressure variations during hearing tests. From measurements at the supra-aural earphone-to-ear connection, we conclude that it is unusual for the connection between the earphone cushion and the pinna to seal effectively for frequencies below 250 Hz. The models developed here explain the measured pressure variations with several pathologic ears. Understanding these mechanisms should inform the design of more accurate audiometric systems which might include a microphone that monitors the ear-canal pressure and corrects deviations from normal. PMID:10738809
Objective Reflectance measured in the ear canal offers a noninvasive method to monitor the acoustic properties of the middle ear, and few systematic measurements exist on the effects of various middle-ear disorders on the reflectance. This work utilizes a human cadaver-ear preparation and a mathematical middle-ear model to both measure and predict how power reflectance ? is affected by the middle-ear disorders of static middle-ear pressures, middle-ear fluid, fixed stapes, disarticulated incudo-stapedial joint, and tympanic-membrane perforations. Design ? was calculated from ear-canal pressure measurements made on human-cadaver ears in the normal condition and five states: (1) positive and negative pressure in the middle-ear cavity, (2) fluid-filled middle ear, (3) stapes fixed with dental cement, (4) incudo-stapedial joint disarticulated, and (5) tympanic-membrane perforations. The middle-ear model of Kringlebotn (1988) was modified to represent the middle-ear disorders. Model predictions are compared to measurements. Results For a given disorder, the general trends of the measurements and model were similar. The changes from normal in ?, induced by the simulated disorder, generally depend on frequency and the extent of the disorder (except for the disarticulation). Systematic changes in middle-ear static pressure (up to ± 300 daPa) resulted in systematic increases in ?. These affects were most pronounced for frequencies up to 1000 to 2000 Hz. Above about 2000 Hz there were some asymmetries in behavior between negative and positive pressures. Results with fluid in the middle-ear air space were highly dependent on the percentage of the air space that was filled. Changes in ? were minimal when a smaller fraction of the air space was filled with fluid, and as the air space was filled with more saline, ? increased at most frequencies. Fixation of the stapes generally resulted in a relatively small low-frequency increase in ?. Disarticulation of the incus with the stapes led to a consistent low-frequency decreases in ? with a distinctive minimum below 1000 Hz. Perforations of the tympanicmembrane resulted in a decrease in ? for frequencies up to about 2000 Hz; at these lower frequencies, smaller perforations led to larger changes from normal as compared to larger perforations. Conclusions These preliminary measurements help assess the utility of power reflectance as a diagnostic tool for middle-ear disorders. In particular, the measurements document (1) the frequency ranges for which the changes are largest and (2) the extent of the changes from normal for a spectrum of middle-ear disorders.
It is very important to make a safe, dry, trouble-free ear for the canal wall down mastoidectomy. Although fascia graft is the most common material used for the repair of the perforated tympanicmembrane, it is usually too small to cover the whole mastoid cavity in canal wall down mastoidectomy. The presence of exposed bone delays the epithelialization and results in prolonged otorrhea. We present a new simple technique that uses a postauricular, inferiorly based pedicled flap. Although our deep temporalis fascial-periosteal flap is not bulky, it is large enough to obliterate a sclerotic mastoid cavity without the need for additional flaps. It shrinks much less than a muscular flap during the healing period. In addition to reducing the cavity volume, this flap promotes the epithelialization over the bone and the shortening of the healing time. Although only a small number of patients were included in this study, coverage of a canal wall down mastoid cavity by a deep temporalis fascial-periosteal flap is expected to be a reliable and effective technique that results in a dry, trouble-free mastoid cavity. PMID:17146402
Introduction Temperature measurement is important during routine neurocritical care especially as differences between brain and systemic temperatures have been observed. The purpose of the study was to determine if infra-red temporal artery thermometry provides a better estimate of brain temperature than tympanicmembrane temperature for patients with severe traumatic brain injury. Methods Brain parenchyma, tympanicmembrane and temporal artery temperatures were recorded every 15–30 min for five hours during the first seven days after admission. Results Twenty patients aged 17–76 years were recruited. Brain and tympanicmembrane temperature differences ranged from -0.8 °C to 2.5 °C (mean 0.9 °C). Brain and temporal artery temperature differences ranged from -0.7 °C to 1.5 °C (mean 0.3 °C). Tympanicmembrane temperature differed from brain temperature by an average of 0.58 °C more than temporal artery temperature measurements (95% CI 0.31 °C to 0.85 °C, P < 0.0001). Conclusions At temperatures within the normal to febrile range, temporal artery temperature is closer to brain temperature than is tympanicmembrane temperature.
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...
This study describes time course and ultrastructural changes during axonal degeneration of different neurones within the tympanal nerve of the locust Schistocerca gregaria. The tympanal nerve innervates the tergit and pleurit of the first abdominal segment and contains the axons of both sensory and motor neurones. The majority of axons (approx. 97%) belong to several types of sensory neurones: mechano-
Canals have been used to distribute water for irrigation for several millennia. The practices gradually evolved from a shovel to open gaps in a berm to fixed structures to movable structures such as gates. Regulation of water in canals is still by manual labor in most parts of the world. A few hydra...
In a prospective, unblinded, controlled study, 303 children underwent comparison of rectal (RT) and right-sided tympanicmembrane (TMT) temperatures. Digital electronic thermometers were used for RT, while two different infrared detection devices assessed TMT. The performance of TMT devices were compared using correlation with RT, fever detection, and ease of use. Correlation between RT and the two devices was good, r = 0.70 and r = 0.69, with little influence of patient age on performance. Using receiver operating characteristics curves to assess fever screening. Thermoscan performed somewhat better than First Temp. Staff rated the Thermoscan as significantly easier to use. PMID:2029813
Clinical diagnosis of acute otitis media (AOM) in children is not easy. It was assumed that there is a difference (Delta) T between the TympanicMembrane (TM) temperatures in the two ears in unilateral AOM and that an accurate measurement of (Delta) T may improve the diagnosis accuracy. An IR transmitting fiber, made of AgClBr, was coupled into a hand
Gadi Fishman; Ari Derowe; Eyal Ophir; Vered Scharf; Abraham Shabtai; Dov Ophir; Abraham Katzir
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.
3. ELEVATION. FROM SOUTH WITH CANAL PRISM. - Canal Road Bridge, Canal Road spanning Delaware Canal Diversion, Locks 22 & 23 in Delaware Canal State Park in Williams Township, Raubsville, Northampton County, PA
Foramen of Huschke, which is also known as the foramen tympanicum, is an anatomical variation of the tympanic portion of the temporal bone. This foramen is located on the anteroinferior aspect of the external auditory canal, posteromedial to the temporomandibular joint. Herein, a rare case of foramen Huschke with a herniation of the soft tissues around the temporomandibular joint that result in severe otalgia and its treatment are presented. PMID:21316883
The mechanical tuning of the ear in the moth Empyreuma pugione was investigated by distortion-product otoacoustic emissions (DPOAE) and laser Doppler vibrometry (LDV). DPOAE audiograms were assessed using a novel protocol that may be advantageous for non-invasive auditory studies in insects. To evoke DPOAE, two-tone stimuli within frequency and level ranges that generated a large matrix of values (960 frequency-level combinations) were used to examine the acoustic space in which the moth tympanum shows its best mechanical and acoustical responses. The DPOAE tuning curve derived from the response matrix resembles that obtained previously by electrophysiology, and is V-shaped and tuned to frequencies between 25 and 45 kHz with low Q10dB values of 1.21±0.26. In addition, while using a comparable stimulation regime, mechanical distortion in the displacement of the moth's tympanalmembrane at the stigma was recorded with a laser Doppler vibrometer. The corresponding mechanical vibration audiograms were compared with DPOAE audiograms. Both types of audiograms have comparable shape, but most of the mechanical response fields are shifted towards lower frequencies. We showed for the first time in moths that DPOAE have a pronounced analogy in the vibration of the tympanicmembrane where they may originate. Our work supports previous studies that point to the stigma (and the internally associated transduction machinery) as an important place of sound amplification in the moth ear, but also suggests a complex mechanical role for the rest of the transparent zone. PMID:23868848
This study was designed to determine if temperature readings using a new tympanic thermometer are affected by otitis media. These readings were also compared to a rectal or oral temperature. Eighty-four children with unilateral suppurative or non-suppurative otitis media diagnosed clinically by their pediatricians were enrolled in the study. Temperatures were measured in both ears using the Thermoscan PRO-1 Instant
A newly designed infrared radiation sensor for a clinical tympanic thermometer has been developed. A very small packaging size (2.2 mm × 2.3 mm × 0.8 mm) is achieved so that the sensor can be used in the human auricle. To realize high sensitivity, infrared sensing regions in the shape of a pair of micro-air-bridges are encapsulated in a vacuum
Reported methods which have been used to measure tympanic temperatures on cadavers up to now are quite invasive. They involve the use of a probe which can perforate the tympanicmembrane and frequently causes bleeding from the ear. For this reason a non traumatic method for estimating tympanic temperature should be applied. Infrared tympanic thermometry seems to be a plausible option. Reliability of infrared tympanic thermometry (ITT) has been largely assessed on living individuals but only one author up to now has assessed its applicability for post-mortem interval determination. Thus the authors set out to test the difference between ear temperatures taken with a probe vs. ITT, differences between left and right ear and reproducibility of measurements of ITT. The aim of the study was to verify whether ITT could be a plausible option for measuring ear temperature for PMI estimation. Ear temperatures were taken on 25 cadavers (15 males, 10 females). Temperatures were taken alternately by similarly trained personnel by two technical methods (Checktemp 1 thermocouple probe and First Temp Genius infrared thermometer) for a total of 93 measurements. Statistical analysis of the data was performed using SAS statistical software. The range of temperature measured was from 20 to 28 degrees C, statistical analysis revealed no differences within the two technical methods, both for right and left ear (ITT: 22.33+/-0.35 vs. probe: 23.08+/-0.25; P=0.087). The study shows the ITT method can be considered as a possible alternative to the probe for measuring ear temperative and further studies should be considered. PMID:19329079
Cattaneo, C; Di Giancamillo, A; Campari, O; Orthmann, N; Martrille, L; Domeneghini, C; Jouineau, C; Baccino, E
Background: The ring canals in the ovary of the fruit fly Drosophila provide a versatile system in which to study the assembly and regulation of membrane-associated actin structures. Derived from arrested cleavage furrows, ring canals allow direct communication between cells. The robust inner rim of filamentous actin that attaches to the ring-canal plasma membrane contains cytoskeletal proteins encoded by the
Perineal canal (PC) is a rare anomaly constituting 4% of all anorectal malformations. Sixty patients (56 females and 4 males) with PC managed over the past 27 years are reported. The ages ranged from 2 days to 13 years. The chief symptom was passage of fecal matter through both the anus and the fistula. One girl had undergone previous, unsuccessful surgery. All our patients were treated by anterior sagittal anorectoplasty (ASARP), which allowed anatomic exposure and accurate repair of the anomaly. In 49 patients without any perineal inflammation primary ASARP was undertaken. Surgery was delayed in 11 patients with perineal excoriations and/or active inflammation. One patient died post-operatively due to unrelated causes and 1 developed a recurrence. Anal dilation was required in 7 cases. Fifty patients were seen at first follow-up 12 weeks after surgery. All were continent and had normal defecation without the use of laxatives. Thirty-four could be followed up to the age of 3 years; they were continent with normal bowel habits. There was no shift in the position of the anus and no instance of rectal dilation. Individualization of the management and operation by the anterior sagittal approach thus offers good results in this uncommon anorectal anomaly. PMID:9099646
Wakhlu, A; Pandey, A; Prasad, A; Kureel, S N; Tandon, R K; Wakhlu, A K
The frequency of occurrence of tympanic cranial spines in the kelp rockfish (Sebastes atrovirens), an eastern Pacific scorpaenid, was examined over much of the species' geographic range. Tympanic spines occur significantly more often in individuals from t...
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
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.
A comparative study of the semicircular canal section versus the Bureau's typical trapezoidal canal section was made to define the potential efficiencies to be gained through the use of this more hydraulically efficient open channel shape. Associated fact...
Background Body temperature can be measured in seconds with tympanic thermometers as opposed to minutes with mercury ones. The aim of this study was to compare tympanic and oral mercury thermometer measurements under high ambient field temperatures. Results Tympanic temperature (measured thrice by 3 operators) was compared to oral temperature measured once with a mercury-in-glass thermometer in 201 patients (aged ?5?years), on the Thai-Myanmar border. Ambient temperature was measured with an electronic thermo-hygrometer. Participants had a mean [min-max] age of 27 [5–60] years and 42% (84) were febrile by oral thermometer. The mean difference in the mercury and tympanic temperature measurement for all observers/devices was 0.09 (95%CI 0.07-0.12)°C and intra-class correlation for repeat tympanic measurements was high (?0.97) for each observer. Deviations in tympanic temperatures were not related to ambient temperature. Conclusion Clinically significant differences were not observed between oral and tympanic temperature measurements at high ambient temperatures in a rural tropical setting.
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.
Otitis media in the rabbit commonly results in fluid accumulation in the tympanic bulla. Radiographic detection of fluid in the tympanic bulla is only moderately sensitive in the dog and cat. The purpose of this study was to investigate the accuracy of radiographic detection of fluid in the rabbit tympanic bulla for three different radiographic projections. Forty rabbit cadavers were used. Half of the tympanic bullae were randomly allocated to be filled with soft tissue material. Following this procedure, each specimen was radiographed in three projections: dorsoventral (DV), rostro 40 degrees ventral-caudodorsal (R40 degrees V-CdDO), and left and right latero 40 degrees ventral-laterodorsal (Lat40 degrees V-LatDO). After imaging, each specimen was frozen and sectioned to determine the content of the tympanic bullae. Images were interpreted and scored independently by two board-certified radiologists. There was no significant difference in sensitivity or specificity between the three projections when compared with the gross findings following sectioning, but observer confidence was highest for the DV projection. Accuracy of radiographic fluid detection was similar to that reported in the dog and cat. The DV and R40 degrees V-CdDO allow comparison of both tympanic bullae on a single radiograph, but the DV was subjectively easier to position, while the Lat40 degrees V-LatDO requires two radiographs for comparison. PMID:20166393
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.
Tympanic hearing is a true evolutionary novelty that appears to have developed independently in at least five major tetrapod groups-the anurans, turtles, lepidosaurs, archosaurs and mammals. The emergence of a tympanic ear would have increased the frequency range and sensitivity of hearing. Furthermore, tympana were acoustically coupled through the mouth cavity and therefore inherently directional in a certain frequency range, acting as pressure difference receivers. In some lizard species, this acoustical coupling generates a 50-fold directional difference, usually at relatively high frequencies (2-4kHz). In ancestral atympanate tetrapods, we hypothesize that low-frequency sound may have been processed by non-tympanic mechanisms like those in extant amphibians. The subsequent emergence of tympanic hearing would have led to changes in the central auditory processing of both high-frequency sound and directional hearing. These changes should reflect the independent origin of the tympanic ears in the major tetrapod groups. The processing of low-frequency sound, however, may have been more conserved, since the acoustical coupling of the ancestral tympanate ear probably produced little sensitivity and directionality at low frequencies. Therefore, tetrapod auditory processing may originally have been organized into low- and high-frequency streams, where only the high-frequency processing was mediated by tympanic input. The closure of the middle ear cavity in mammals and some birds is a derived condition, and may have profoundly changed the operation of the ear by decoupling the tympana, improving the low-frequency response of the tympanum, and leading to a requirement for additional neural computation of directionality in the central nervous system. We propose that these specializations transformed the low- and high-frequency streams into time and intensity pathways, respectively. PMID:18331899
Tympanic hearing is a true evolutionary novelty that appears to have developed independently in at least five major tetrapod groups—the anurans, turtles, lepidosaurs, archosaurs and mammals. The emergence of a tympanic ear would have increased the frequency range and sensitivity of hearing. Furthermore, tympana were acoustically coupled through the mouth cavity and therefore inherently directional in a certain frequency range, acting as pressure difference receivers. In some lizard species, this acoustical coupling generates a 50-fold directional difference, usually at relatively high frequencies (2–4 kHz). In ancestral atympanate tetrapods, we hypothesize that low-frequency sound may have been processed by non-tympanic mechanisms like those in extant amphibians. The subsequent emergence of tympanic hearing would have led to changes in the central auditory processing of both high-frequency sound and directional hearing. These changes should reflect the independent origin of the tympanic ears in the major tetrapod groups. The processing of low-frequency sound, however, may have been more conserved, since the acoustical coupling of the ancestral tympanate ear probably produced little sensitivity and directionality at low frequencies. Therefore, tetrapod auditory processing may originally have been organized into low- and high-frequency streams, where only the high-frequency processing was mediated by tympanic input. The closure of the middle ear cavity in mammals and some birds is a derived condition, and may have profoundly changed the operation of the ear by decoupling the tympana, improving the low-frequency response of the tympanum, and leading to a requirement for additional neural computation of directionality in the central nervous system. We propose that these specializations transformed the low- and high-frequency streams into time and intensity pathways, respectively.
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
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.
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.
...SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices...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...
... positions "open" the lumbar canal and take the pressure off the nerves that go to the legs. In severe cases, stenosis can cause partial or complete bowel or bladder incontinence Diagnosis & Tests ...
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.
Objective To show that traumatic neuroma of the tympanic (Jacobson’s) nerve may be a cause of recurrent intractable otalgia in patients following radical mastoidectomies Study Design Histologic evaluation of four temporal bones from three patients with a history of recurrent otalgia following radical mastoidectomy. Subjects and Methods The medical records of three patients with multiple middle ear surgeries in four ears because of recurrent otalgia were reviewed. Histopathologic studies of the four temporal bones were performed. Results All four of the temporal bones that underwent multiple surgeries were found to have traumatic neuromas of the tympanic (Jacobson’s) nerve. Conclusion Recurrent otalgia in patients after radical middle ear surgery may be caused by a traumatic neuroma of the tympanic (Jacobson’s) nerve.
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.
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.
3 The present study compared between Japanese and Vietnamese subjects living in Hanoi, the local evaporation rate by sweating and the tympanic temperature during legs immersion in warm water. Seven Vietnamese and seven Japanese (who had lived in Hanoi for 1-2 years) participated in the experiments, which were performed in April, 2001 in Hanoi (Vietnam). It was found that the
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
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 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).
Evolutionary genetics has recently made enormous progress in understanding how genetic variation maps into phenotypic variation. However why some traits are phenotypically invariant despite apparent genetic and environmental changes has remained a major puzzle. In the 1940s, Conrad Hal Waddington coined the concept and term "canalization" to describe the robustness of phenotypes to perturbation; a similar concept was proposed by Waddington's contemporary Ivan Ivanovich Schmalhausen. This paper reviews what has been learned about canalization since Waddington. Canalization implies that a genotype's phenotype remains relatively invariant when individuals of a particular genotype are exposed to different environments (environmental canalization) or when individuals of the same single- or multilocus genotype differ in their genetic background (genetic canalization). Consequently, genetic canalization can be viewed as a particular kind of epistasis, and environmental canalization and phenotypic plasticity are two aspects of the same phenomenon. Canalization results in the accumulation of phenotypically cryptic genetic variation, which can be released after a "decanalizing" event. Thus, canalized genotypes maintain a cryptic potential for expressing particular phenotypes, which are only uncovered under particular decanalizing environmental or genetic conditions. Selection may then act on this newly released genetic variation. The accumulation of cryptic genetic variation by canalization may therefore increase evolvability at the population level by leading to phenotypic diversification under decanalizing conditions. On the other hand, under canalizing conditions, a major part of the segregating genetic variation may remain phenotypically cryptic; canalization may therefore, at least temporarily, constrain phenotypic evolution. Mechanistically, canalization can be understood in terms of transmission patterns, such as epistasis, pleiotropy, and genotype by environment interactions, and in terms of genetic redundancy, modularity, and emergent properties of gene networks and biochemical pathways. While different forms of selection can favor canalization, the requirements for its evolution are typically rather restrictive. Although there are several methods to detect canalization, there are still serious problems with unambiguously demonstrating canalization, particularly its adaptive value. PMID:16250465
Love Canal is known worldwide as the site of one of the worst non-nuclear environmental disasters in modern history. For 12 years, a Niagara Falls, New York chemical company used the canal bed as a chemical dump. This article discusses the computerized control of equipment used to remove the toxic materials from the ground under Love Canal, and how the
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
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.
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 ultimate goals of endodontic treatment are complete removal of bacteria, their byproducts and pulpal remnants from infected root canals and the complete seal of disinfected root canals. Intracanal medicaments have been thought an essential step in killing the bacteria in root canals; however, in modern endodontics, shaping and cleaning may be assuming greater importance than intracanal medicaments as a means of disinfecting root canals. Until recently, formocresol and its relatives were frequently used as intracanal medicaments, but it was pointed out that such bactericidal chemicals dressed in the canal distributed to the whole body from the root apex and so might induce various harmful effects including allergies. Furthermore, as these medicaments are potent carcinogenic agents, there is no indication for these chemicals in modern endodontic treatment. Today, biocompatibility and stability are essential properties for intracanal medicaments. The more modern meaning of intracanal dressing is for a blockade against coronal leakage from the gap between filling materials and cavity wall. Calcium hydroxide has been determined as suitable for use as an intracanal medicament as it is stable for long periods, harmless to the body, and bactericidal in a limited area. It also induces hard tissue formation and is effective for stopping inflammatory exudates. Single-visit endodontics, where intracanal medicaments are not used, is generally not now contraindicated and various reports have shown that the clinical outcomes between single- and multiple- visit endodontics are similar. There is no reason to counsel against single-visit endodontics: however, if multiple-visit endodontics is chosen, calcium hydroxide is recommended to be used as an intracanal medicament. PMID:19323305
Kawashima, Nobuyuki; Wadachi, Reiko; Suda, Hideaki; Yeng, Thai; Parashos, Peter
Objective This study compares measurements of ear-canal reflectance (ECR) to other objective measurements of middle-ear function including, audiometry, umbo velocity (VU), and tympanometry in a population of strictly defined normal hearing ears. Design Data were prospectively gathered from 58 ears of 29 normal hearing subjects, 16 female and 13 male, aged 22–64 years. Subjects met all of the following criteria to be considered as having normal hearing. (1) No history of significant middle-ear disease. (2) No history of otologic surgery. (3) Normal tympanicmembrane (TM) on otoscopy. (4) Pure-tone audiometric thresholds of 20 dB HL or better for 0.25 – 8 kHz. (5) Air-bone gaps no greater than 15 dB at 0.25 kHz and 10 dB for 0.5 – 4 kHz. (6) Normal, type-A peaked tympanograms. (7) All subjects had two “normal” ears (as defined by these criteria). Measurements included pure-tone audiometry for 0.25 – 8 kHz, standard 226 Hz tympanometry, Ear canal reflectance(ECR) for 0.2 – 6 kHz at 60 dB SPL using the Mimosa Acoustics HearID system, and Umbo Velocity (VU ) for 0.3 – 6 kHz at 70–90 dB SPL using the HLV-1000 laser Doppler vibrometer (Polytec Inc). Results Mean power reflectance (|ECR|2) was near 1.0 at 0.2– 0.3 kHz, decreased to a broad minimum of 0.3 to 0.4 between 1 and 4 kHz, and then sharply increased to almost 0.8 by 6 kHz. The mean pressure reflectance phase angle (?ECR) plotted on a linear frequency scale showed a group delay of approximately 0.1 ms for 0.2 – 6 kHz. Small significant differences were observed in |ECR|2 at the lowest frequencies between right and left ears, and between males and females at 4 kHz. |ECR|2 decreased with age, but reached significance only at 1 kHz. Our ECR measurements were generally similar to previous published reports. Highly significant negative correlations were found between |ECR|2 and VU for frequencies below 1 kHz. Significant correlations were also found between the tympanometrically determined peak total compliance and |ECR|2 and The results suggest that middle-ear compliance VU at frequencies below 1 kHz. contributes significantly to the measured power reflectance and umbo velocity at frequencies below 1 kHz, but not at higher frequencies. Conclusions This study has established a database of objective measurements of middle ear function (ear-canal reflectance, umbo velocity, tympanometry) in a population of strictly defined normal hearing ears. The data will promote our understanding of normal middle ear function, and will serve as a control for comparison to similar measurements made in pathological ears.
Rosowski, John J; Nakajima, Hideko H.; Hamade, Mohamad A.; Mafoud, Lorice; Merchant, Gabrielle R.; Halpin, Christopher F.; Merchant, Saumil N.
This study examined the relationship between three instruments used in measuring tympanic, axillary, and rectal temperatures in infants less than 1 year of age. Temperatures were measured by Oto-temp Pedi Q tympanic thermometers, Becton Dickinson axillary thermometer, and rectal thermometers. A convenience sample of 5 infants less than 90 day and 54 greater than 90 days with fever, as well as 34 infants less than 90 days and 27 infants greater than 90 days without fever were studied. Correlations of infants less than 90 days and greater 90 days of age, as well as differences between infant temperature with and without fevers as variables, were examined. Results indicated a strong statistical relationship between Oto-Temp Pedi Q, Becton Dickinson axillary temperatures, and rectal temperatures, but not strong enough to base critical clinical decisions. Age and presence or absence of fever significantly affected the relationships between thermometers. PMID:10337119
Angus crossbred yearling steers (n?=?168) were used to evaluate effects on performance and tympanic temperature (TT) of feeding additional potassium and sodium\\u000a to steers exposed to excessive heat load (maximum daily ambient temperature exceeded 32°C for three consecutive days) during\\u000a seasonal summer conditions. Steers were assigned one of four treatments: (1) control; (2) potassium supplemented (diet containing\\u000a 2.10% KHCO3); (3)
T. L. Mader; J. B. Gaughan; L. J. Johnson; G. L. Hahn
Acoustic signals (10–100 msec, 5kHz, 70 or 80 dB) have an inhibitory effect on chirping in the cricketGryllus campestris L. After a reaction time of approximately 50 msec there is a period of about 150 msec (at 27 °C) during which it is very unlikely that a chirp will begin. The effect is not abolished by removal of the tympanal
Two independent methods of comparison, serial homology and phylogenetic character mapping, are employed to investigate the\\u000a evolutionary origin of the noctuoid moth (Noctuoidea) ear sensory organ. First, neurobiotin and Janus green B staining techniques\\u000a are used to describe a novel mesothoracic chordotonal organ in the hawkmoth, Manduca sexta, which is shown to be serially homologous to the noctuoid metathoracic tympanal
Jayne E. Yack; Geoff G. E. Scudder; James H. Fullard
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
Summary 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.
Love Canal is known worldwide as the site of one of the worst non-nuclear environmental disasters in modern history. For 12 years, a Niagara Falls, New York chemical company used the canal bed as a chemical dump. This article discusses the computerized control of equipment used to remove the toxic materials from the ground under Love Canal, and how the minimization of maintenance is reducing maintenance costs and increasing operator safety.
McPherson, G.; Rider, G.J.; Sadowski, B.; Moore, M.
The report contains the following meteorological data collected at sites within Fort Sherman, Panama Canal Zone during March 1971: Atmospheric precipitation; Atmospheric temperature; Barometric pressure; Humidity; Wind.
|Vision researchers have investigated the differences between global and local feature perception. No one has, however, examined the role of global and local feature discrimination in sustained attention tasks. In this experiment participants performed a sustained attention task requiring either global or local letter target discriminations or…
Helton, William S.; Hayrynen, Lauren; Schaeffer, David
Vision researchers have investigated the differences between global and local feature perception. No one has, however, examined the role of global and local feature discrimination in sustained attention tasks. In this experiment participants performed a sustained attention task requiring either global or local letter target discriminations or…
Helton, William S.; Hayrynen, Lauren; Schaeffer, David
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
REACTOR CANAL AFTER IT HAS BEEN TILED. WATER FILLS CANAL PART WAY TO TOP. CAMERA FACES WEST. INL NEGATIVE NO. 3993-A. Unknown Photographer, 12/28/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
A cancer researcher reviews the events surrounding the toxic waste contamination at Love Canal with emphasis on the political nature of the controversy about its health impact. Antagonism between the community and the New York State Department of Health was fueled by several factors: the state's awareness that it gained from delay in investigation, disagreement on health problems to be studied, control over the information gathering process, silencing of opposition opinion, and the violation of norms of scientific behavior. The author calls for the establishment of standards of ethical behavior for scientists in such situations, standards for conflict resolution, and means of appeal for those injured. PMID:7107238
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:
38. James River and Kanawha Canal Locks. The canal, which operated between 1835 to 1880, serves as the focal point of the area's interpretation. The Battery Creek Lock was reconstructed between 1961 and 1965. Severe flooding in 1985 damaged the lock gates which were reconstructed in 1987-88. The view is to the south. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC
Accidental injury to the facial nerve where the bony canal defects are present may result with facial nerve dysfunction during otological surgery. Therefore, it is critical to know the incidence and the type of facial nerve dehiscences in the presence of normal development of the facial canal. The aim of this study is to review the site and the type of such bony defects in 144 patients operated for facial paralysis, myringoplasty, stapedotomy, middle ear exploration for sudden hearing loss, and so forth, other than chronic suppurative otitis media with or without cholesteatoma, middle ear tumors, and anomaly. Correlation of intraoperative findings with preoperative computerized tomography was also analyzed in 35 patients. Conclusively, one out of every 10 surgical cases may have dehiscence of the facial canal which has to be always borne in mind during surgical manipulation of the middle ear. Computerized tomography has some limitations to evaluate the dehiscent facial canal due to high false negative and positive rates.
The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and technically challenging. This case report presents the treatment of a mandibular first molar with five root canals, of which three were located in the mesial root. A third canal was found between the mesiobuccal and mesiolingual root canals. The morphological pattern of separate apical terminations of three mesial root canals with separate orifices, as manifested in this case, is a rare one.
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.
IntroductionThe aim of this study was to compare the canal transportation and changes in canal curvature after canal preparation with 2 nickel-titanium (NiTi) rotary instruments, Twisted (TF) and K3 file systems.
The high resistance to field aging displayed by buried phosphorous pentoxide catalytically blown asphalt membranecanal lining indicated that a method for distinguishing this type material from other catalyst-prepared asphalt cements would be beneficial. ...
Diverticula of the tympanic pneumatic system were present lateral to the basicranium in Allosaurus, as evidenced by depressions on the basicranium and the presence of pneumatic foramina. An examination of an ontogenetic series of basicrania of A. fragilis shows this system to exhibit both ontogenetic and individual variation. Anteriorly, diverticula initially invade the basipterygoid process and withdraw with age (ontogenetic
With the increasing number of reports of aberrant root canal morphology, the clinician needs to be aware of the variable anatomy. Various case reports have been published with the finding of middle mesial canal in mandibular first molar, however finding of middle distal canal in distal root of mandibular first molar is rare. This case report describes root canal treatment of two rooted mandibular first molar with five root canals (three in distal and two in mesial root), and Sert and Bayirli Type XVIII canal configuration in distal root.
Infrared tympanic thermometers (ITT) are used to determine core body temperature in human subjects. Current models are unreliable in non-clinical and non-laboratory situations. A new ITT device is being developed to correct this problem. To ensure that th...
Lock No. 1- St. Lucie Canal. Sector gates, horizontal struts-canal side. - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL
INTRODUCTION The condition superior semi-circular canal dehiscence was first described by Minor et al. in 1998. PRESENTATION Of Case We describe a novel surgical approach to the management of superior semicircular canal dehiscence. Our surgical technique involves a transmastoid rather than middle cranial fossa approach to the superior semicircular canal. CONCLUSION We conclude that the transmastoid approach, if anatomically feasible, carries significant advantages compared to middle cranial fossa craniotomy approach for the management of superior semicircular canal dehiscence.
The root canal anatomy of 19 mandibular second molars with C-shaped canals was investigated by rendering the roots transparent and allowing the canal system to be observed by black ink infiltration. The presence of three root canals was most frequent, and lateral canals were found in all roots. Transverse anastomoses were found in 15 of the 19 roots. The apical foramen was most commonly situated away from the apex, and apical deltas were found in 16 of the 19 roots. The C-shaped canals were found more frequently in Asians than in other racial groups (P less than 0.02). The formation of C-shaped roots and their racial predilection is discussed. A case report of the root canal treatment of a C-shaped canal is included and suggestions are made concerning suitable procedures for use in root canal treatment of these complex canal systems. PMID:2391180
Summary The radicular canal is defined as the lateral part of the spinal canal containing the spinal nerve root from its point of emergence through the dural envelope up to and including the intervertebral foramen. The radicular canal, resembling a hollow hemicylinder opened towards the midline, can be divided into three parts, i.e. retrodiscal, parapedicular (the lateral recess per se)
J. M. Vital; B. Lavignolle; N. Grenier; F. Rouais; R. Malgat; J. Senegas
The controversy regarding removal of the posterior external canal wall during mastoid surgery spans many decades. There are inherent advantages and disadvantages to either removing or not removing the canal wall. The operation must be tailored to the patient and his or her unique situation. We describe our experience with external canal wall reconstruction and mastoid obliteration with hydroxyapatite in
Canalization is the suppression of phenotypic variation. Depending on thecauses of phenotypic variation one speaks either of genetic or environmentalcanalization. Genetic canalization describes insensitivity of a character to mutations,and the insensitivity to environmental factors is called environmentalcanalization. Genetic canalization is of interest because it influences the availabilityof heritable phenotypic variation to natural selection and is thus potentiallyimportant in...
Conclusions 1.Deformation of the canal cross section occurs where Frov.2.A stable canal section can be obtained by two methods: take cross-sectional shapes and a velocity regime such that the inequality Fro?Frv is fulfilled at all points of the wetted perimeter; partially reinforce the canal side slopes in the region where Froiv.
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.1
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
In Drosophila oogenesis, the development of a mature oocyte depends on having properly developed ring canals that allow cytoplasm transport from the nurse cells to the oocyte. Ring canal assembly is a step-wise process that transforms an arrested cleavage furrow into a stable intercellular bridge by the addition of several proteins. Here we describe a new gene we named cheerio that provides a critical function for ring canal assembly. Mutants in cheerio fail to localize ring canal inner rim proteins including filamentous actin, the ring canal-associated products from the hu-li tai shao (hts) gene, and kelch. Since hts and kelch are present but unlocalized in cheerio mutant cells, cheerio is likely to function upstream from each of them. Examination of mutants in cheerio places it in the pathway of ring canal assembly between cleavage furrow arrest and localization of hts and actin filaments. Furthermore, this mutant reveals that the inner rim cytoskeleton is required for expansion of the ring canal opening and for plasma membrane stabilization.
Robinson, D. N.; Smith-Leiker, T. A.; Sokol, N. S.; Hudson, A. M.; Cooley, L.
A case of endodontic treatment of a mandibular first premolar exhibiting a total of four distinct root canals and four apical foramina is described. This occurrence in mandibular first premolar has rarely been reported in the endodontic literature. Endodontic treatment that considers the anatomic variation of root canal morphology is important to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation with ethylenediaminetetraacetic acid might allow the flow of sealer into the narrowed but unprepared part of the canal. This offers valuable adjuncts for the successful negotiation of calcified main canals, thereby facilitating optimum chemo-mechanical debridement of the root canal system. PMID:23382063
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
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
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.
A method of reducing canal seepage by injecting an asphalt emulsion under the soil surface was investigated. This technique is intended for use in unlined canals with water delivery commitments which would not allow dewatering for conventional lining cons...
Cleaning and shaping are important steps in the root canal treatment. Despite the technological advances in endodontics, K and Hedstroen files are still widely used. In an attempt to be more effective in preparing the root canals, faster and more cutting efficient kinematic, alloys and design alternatives utilizing mechanically oscillating or rotary files are proposed. Even with all these technological innovating alternatives, the preparation of root canals remains a challenge. PMID:23579914
Leonardo, Renato de Toledo; Puente, Carlos Garcia; Jaime, Alejandro; Jent, Carol
This article reviews a case involving endodontic treatment of a mandibular second molar with C-shaped canal morphology and five separate canals. The C-shaped canal variation of morphology is unusual and can lead to difficulties during treatment. Preoperative radiographs are limited in their ability to detect this entity; for a favorable treatment outcome, knowledge of the C-shaped canal's existence and morphology is essential. PMID:15206259
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...
...the Tonawandas, Erie Canal, Tonawanda, NY AGENCY: Coast Guard, DHS. ACTION: Temporary...safety zone on the Erie Canal, Tonawanda, NY. This safety zone is intended to restrict...held on the Erie Canal near Tonawanda, NY. The Captain of the Port Buffalo has...
This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory
Mateus Silveira Martins Hartmann; Fernando Branco Barletta; Vânia Regina Camargo Fontanella; José Roberto Vanni
SECTION OF CANAL AT PROPOSED McLELLAN DRIVE INTERCHANGE, SHOWING CANAL (RIGHT), BRIDAL TRAIL (CENTER) AND PEDESTRIAN/BICYCLE TRAIL (RIGHT). VIEW TO NORTH - High Line Canal, Mouth of South Platte River to confluence with Second Creek, Denver, Denver County, CO
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
Lock No. 1- St. Lucie Canal. Guide & connecting walls, timber guide walls - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL
Lock No. 1- St. Lucie Canal. Guide & connecting walls, connecting walls - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL
AFT DETAIL VIEW OF THE CANAL INSPECTION BOAT LOCKPORT ON DISPLAY OUTSIDE THE ERIE CANAL MUSEUM, WHICH WAS ORIGINALLY THE LOCK-COMPLEX POWER PLANT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY
Lock No. 1- St. Lucie Canal. Sector gates, vertical struts- lower gate - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL
5. Division Gates of the Consolidated Canal, looking northeast. The Tempe Canal heads here (left). Photographer: Mark Durben, February 1989. Source: SRPA - Tempe Canal, South Side Salt River in Tempe, Mesa & Phoenix, Tempe, Maricopa County, AZ
|Illustrates the relationship between the technology of canal building and the development of national unity prior to the Revolutionary War. Examines George Washington's efforts to build the Potomac canal. Encourages students to consider the interrelationships among technology, resources, politics, and leadership. Includes two student handouts and…
The Panama Canal connects the Atlantic and Pacific Oceans for purposes of navigation. On its way it crosses Miraflores Lake and Gatun Lake. Three navigation locks at each end of the Canal lift ships from the ocean to Gatun Lake through a height of 26 m (8...
T. M. Parchure S. C. Wilhelms S. Sarruff W. H. McAnally
...2013-07-01 2013-07-01 false Company Canal. 117.438 Section 117.438 Navigation and Navigable Waters COAST GUARD, DEPARTMENT...REGULATIONS Specific Requirements Louisiana Â§ 117.438 Company Canal. (a) The draw of the...
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
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.
Illustrates the relationship between the technology of canal building and the development of national unity prior to the Revolutionary War. Examines George Washington's efforts to build the Potomac canal. Encourages students to consider the interrelationships among technology, resources, politics, and leadership. Includes two student handouts and…
Though the minimum area section is generally adopted for canals,it is not the least earthwork cost section as it does not involve the cost of earthwork which varies with the excavationdepth. On account of complexities of analysis, explicit designequations for minimum earthwork cost canal sections has not available yet. In this investigation explicit equations and section shape coefficients for the
Prabhata K. Swamee; Govinda C. Mishra; Bhagu R. Chahar
...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...
Under the two-year Love Canal Remedial Action Project, funded by the New York State Department of Environmental Conservation (DEC) and engineered by Conestoga-Rovers and Associates, the construction of a unique system for the containment, collection, and treatment of contaminated leachate is under way at Love Canal, the abandoned chemical dump of Hooker Chemical Corp. By the end of the project,
C-shaped canal configurations present special clinical problems including relief of pain, copious bleeding, and difficulty in cleaning, shaping, and filling. A review of the literature, radiographic characteristics that make diagnosis possible before the canal is accessed, and suggestions for instrumentation and filling are provided here. PMID:23087935
Linear, anionic polyacrylamide (PAM) is being considered in the western United States as a technology to reduce seepage in unlined water delivery canals. A broad laboratory and field testing program has been undertaken to understand the benefits and potential environmental impacts of PAM use. The ability to predict the fate and transport of PAM in water delivery canals could prove
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
Conclusions 1.The morphometric method of estimating the geometry of stable canal channels, as based on a deeper physical nature and using the fluvial process theory principle, has become most popular in solving the problem of designing canals in alluvial soil. It can be considered that sufficiently reliable relations have presently been obtained which can be used in practice with consideration
IT has been suggested from time to time that the pore canals of the insect cuticle offer an important channel for the entry of contact insecticides, and Wigglesworth1, working on the bug Rhodnius, in which the canals contain protoplasmic filaments, or perhaps fluid, has recently given additional evidence in favour of this view. But Richards and Anderson2, as a result
Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required. PMID:9242125
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. PMID:22557916
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.
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.
Fifty-seven adults with apical periodontitis were examined for the presence of nonpigmented Bacteroides species in 62 infected root canals. Nonpigmented Bacteroides species were found in 35 canals. In four cases two nonpigmented Bacteroides species and in one case three nonpigmented Bacteroides species were found. Species belonging to the B. fragilis group were not isolated. The most frequently isolated species were B. buccae (15 strains), B. oris (12 strains), and B. oralis (7 strains). alpha-Fucosidase, beta-N-acetylglucosaminidase, and beta-xylosidase appeared to be useful in the identification of B. buccae and B. oris. Corroding Bacteroides species were not found; all corroding strains were identified as Wolinella recta. The occurrence of nonpigmented Bacteroides species was compared with the severity of the periapical infection. A total of 13 B. buccae strains were found in acute infections and only 2 strains were found in asymptomatic infections, whereas other nonpigmented Bacteroides species were present in acutely infected and asymptomatic teeth with nearly equal frequency. Ultrastructural study of 13 B. buccae strains showed that 8 strains had a crystalline proteinaceous surface layer (S-layer) outside the outer membrane, but all 13 strains had areas of crystalline protein throughout in the outer membrane. The results suggest that B. buccae may have a specific role in the development of an acute opportunistic infection. Images
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.
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. PMID:23862051
103. CANAL AT THE ENTRANCE TO THE POMPTON FEEDER NEAR MOUNTAIN VIEW, NEW JERSEY. THE POMPTON FEEDER BOATS TO TRAVEL NORTH 4.26 MILES TO TO POMPTON AS WELL AS PROVIDING THE MAIN CANAL WITH WATER FROM GREENWOOD LAKE. A MODIFIED QUEEN POST TRUSS BRIDGE SPANS THE CANAL IN THE FOREGROUND. - Morris Canal, Phillipsburg, Warren 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
We report a clinical case of maxillary right second molar with two palatal root canals. The morphology is atypical because it is characterized by two palatal roots with two canals with widely separated orifices and canals. Modifications to the normal access opening and examination of the pulpal floor for additional canals are stressed.
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
Meda L. Negrutiu; Cosmin Sinescu; Florin Topala; Luminita Nica; Ciprian Ionita; Corina Marcauteanu; Luciana Goguta; Adrian Bradu; George Dobre; Mihai Rominu; Adrian Gh. Podoleanu
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
The aim of this study was to evaluate the effects of argon laser irradiation of the semicircular canals using computed tomography (CT) images and to examine the basis for laser treatment for benign paroxysmal positional vertigo (BPPV). CT images of the posterior canal were evaluated postoperatively in a patient with intractable BPPV, in whom the unilateral posterior and lateral semicircular canals were irradiated with an argon laser. In addition, bootstrap analysis of 20 patients with normal CT findings of the temporal bone was performed and previous experimentally obtained histologic findings were compared. Cross-sections of the posterior canals of 20 patients were found to show no difference in size between the right and left sides. The laser-irradiated posterior canal became narrower than that on the non-irradiated healthy side in our patient. There was a discrepancy between the CT images and experimentally obtained histologic findings that showed complete occlusion of the canal. CT images of a patient with severe vertigo demonstrated that argon laser irradiation to the blue-lined semicircular canals did not occlude the canal of the corresponding areas, while the canal of the guinea pig histologically showed complete obstruction with new bone after irradiation with the same energy (1.5 W, 0.5 s, spot size: around 200 ?m in diameter). The patient has been free from vertigo for 16 years. Marked constriction of the semicircular duct corresponding to the irradiated area appeared to be effective in treating intractable BPPV. PMID:22053860
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...
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...
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
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.
Perioperative Guyon's canal and carpal canal pressure in one-forearm portal endoscopic carpal tunnel release surgery were measured in resting position and during active power gripping in 66 hands. This was done using the continuous infusion technique with a local anaesthetic and without pneumatic tourniquet. Immediate mean postoperative Guyon's canal and carpal canal pressure decreased in both measurements. During active power gripping, postoperative Guyon's canal pressure was less than 40 mmHg in 61 hands, however, this increased to over 40 mmHg in five hands. In these five hands, Guyon's canal syndrome did not develop. Guyon's canal and carpal canal pressures were only correlated during postoperative active power gripping. It remains unclear whether immediate postoperative Guyon's canal pressure correlates with higher pressures a few days later as reported in cases of transient postoperative Guyon's canal syndrome. PMID:19282410
Attempts to explain abducens vulnerability have centered around the petroclival segment of its pathway in the skull base, in particular, its relations to the Dorello's canal and the petrosphenoidal ligament of Grüber. This study aims to contribute to the definition of the Dorello's canal and to the understanding of abducens vulnerability from an evolutionary perspective. The petroclival region and the Dorello's canal in particular were examined in a sample of 86 primate skulls. The sample contains 20 Pan troglodytes (common chimpanzee), 35 Gorilla gorilla, 20 Pongo pygmaeus (orangoutan), and 11 Hylobates moloch (gibbon) skulls. Distance between the petrous apex and tip of the posterior clinoid process was measured using a 10-mm scale that was inserted into the endocranium. Complete absence of the Grüber ligament and an uninterrupted osseous circumference of the Dorello's canal (foramen) was demonstrated in all nonhuman primate species. Whatever the reason for the morphological difference between the human and ape Dorello's canal, it is without a doubt suggestive of the source of vulnerability of the abducens nerve, as the ligament of Grüber, unique to the human configuration, renders the contents of the Dorello's canal susceptible to compression against the cranial base. PMID:22451800
The abundance and phylogenetic composition of antibiotic resistant bacteria in canals of metropolitan Bangkok, Thailand, were investigated using a microcolony method and fluorescence in situ hybridization (FISH). Cells were directly trapped from aquatic samples onto polycarbonate membranes and incubated for 24 hr on selective agar containing antibiotics. Individual antibiotic resistant bacterial microcolonies samples were classified on the filter using FISH
Simulation studies have demonstrated that automatic control of canals is more effective when feedforward scheduling, or routing of know demand changes, is combined with centralized, automatic, distant, downstream-water-level control. In practice, few canals use this approach. To help further develop...
Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182
Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep
\\u000a The sacral hiatus is used for access to the spinal canal in many neurosurgical and anesthesiologic procedures. The aim of\\u000a the present paper is to give a review of its anatomical characteristics relevant to permit correct and uncomplicated accesses.\\u000a The sacral hiatus is posteriorly closed by the superficial dorsal sacrococcygeal ligament (also called sacrococcygeal membrane)\\u000a which has to be pierced
Andrea Porzionato; Veronica Macchi; Anna Parenti; Raffaele De Caro
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
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.
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
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.
2. VIEW NORTHWEST, GENERAL VIEW SHOWING RAILWAY CANAL TRUSS IN CENTER, RAILWAY RIVER TRUSS ON LEFT, HIGHWAY TRUSSES IN BACKGROUND - White Rock Bridge, Spanning Pawcatuck River & White Rock Canal, Westerly, Washington County, RI
22. Photocopy of photograph (original print at Gage Canal Company Office), photographer and date unknown. 'FLUME NO. 9, 'GAGE CANAL SYSTEM,' RIVERSIDE, CAL.' VIEW OF FLUME OVER TEQUESQUITE ARROYO. - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
24. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1939. VIEW OF SAND PUMP HOUSE AT THE HEAD OF THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
26. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1931. VIEW OF CONSTRUCTION OF GUNITE INVERT SIPHON REPLACING FLUME NO. 10 ON GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
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
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
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
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
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
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
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
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
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
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
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
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
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 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
28. Site Plan, Arizona Canal at Old Crosscut, September 1972. See photograph AZ-21-8 for view of the completed structure. Source: Salt River Project. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ
33. Grand Canal at Old Crosscut, Site Plan for Conduit and Supervisory Control Equipment, October 1973. Source: Salt River Project. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa 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
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
29. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1926. CENTRIFUGAL PUMPS AT OLIVEWOOD PUMPING STATION ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
27. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1913. TIGHTENING JOINTS AND ADJUSTING PLATES ON STEEL FLUME AT MOCKINGBIRD DAM ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
28. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1913. CONSTRUCTION OF CORE WALL AT MOCKINGBIRD DAM ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
This booklet contains many aspects of a drainage program. Topics discussed include principal causes for the failure of open drainage canals, recent research on the mechanics of open drainage canal maintenance, and the Ahmed Davis shovel. Included in the b...
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
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
NORTHERLY STRETCH OF MILLBURY PORTION; GENERAL VIEW ACROSS CANAL PRISM TO TOWPATH BERM (LATER FILL ENCROACHING LEFT) NEAR CENTER OF THIS STRETCH; VIEW TO SOUTHWEST - Blackstone Canal Worcester-Millbury Segment, Eastern bank of Blackstone River, Millbury, Worcester County, MA
47. PLANS FOR EXISTING THREE-SPAN PEDESTRIAN BRIDGE OVER GRAND CANAL AT 25TH AVENUE Plan Sheet D-5117 (delineated by R. H. Bacon, April 1939) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA
2. LOOKING ACROSS THE CANAL AT CASSEDY'S STORE. STRUCTURE WAS BUILT SO THAT LOADING AND UNLOADING OF GOODS DIRECTLY FROM THE BOATS COULD BE ACCOMPLISHED. - Morris Canal, Cassedy's Store, Waterloo, Sussex County, NJ
5. VIEW SOUTHWEST, INTERIOR CANAL WALL (Original Fabric) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA
...Navigable Waters 1 2013-07-01 2013-07-01 false Lake Washington Ship Canal. 117.1051 Section 117.1051 ...REGULATIONS Specific Requirements Washington Â§ 117.1051 Lake Washington Ship Canal. (a) When fog prevails by...
4. VIEW LOOKING NORTH OF SAN TAN INDIAN CANAL WITH NEWER CHECK AND TURNOUT STRUCTURE IN FOREGROUND - San Carlos Irrigation Project, San Tan Indian Canal, North of Gila River, Coolidge, Pinal County, AZ
2. LOOKING DOWN THE LINED POWER CANAL AS IT WINDS ITS WAY TOWARD THE CEMENT MILL Photographer: Walter J. Lubken, November 19, 1907 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ
9. LOOKING EAST NORTHEAST, CANAL STREET BRIDGE IN FOREGROUND, PENNSYLVANIA RAILROAD BRIDGE IN MIDGROUND. - Pennsylvania Railroad, South Branch Chicago River Bridge, Spanning South Branch of Chicago River Bridge east of Canal Street, Chicago, Cook County, IL
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
OVERALL VIEW OF CASCADE CANAL COMPANY CRIB DAM, LOOKING UPSTREAM FROM DIRECTION OF KACHESS DAM. VIEW TO NORTH - Kachess Dam, 1904 Cascade Canal Company Crib Dam, Kachess River, 1.5 miles north of Interstate 90 , Easton, Kittitas County, WA
... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices Â§ 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a...
...2013-07-01 2013-07-01 false Chesapeake and Delaware Canal. 117.235 Section 117.235 ...OPERATION REGULATIONS Specific Requirements Delaware Â§ 117.235 Chesapeake and Delaware Canal. The draw of the Conrail...
...2010-07-01 2010-07-01 false Chesapeake and Delaware Canal. 117.235 Section 117.235 ...OPERATION REGULATIONS Specific Requirements Delaware Â§ 117.235 Chesapeake and Delaware Canal. The draw of the Conrail...
...2009-07-01 2009-07-01 false Chesapeake and Delaware Canal. 117.235 Section 117.235 ...OPERATION REGULATIONS Specific Requirements Delaware Â§ 117.235 Chesapeake and Delaware Canal. The draw of the Conrail...
...Navigable Waters 1 2009-07-01 2009-07-01 false Muskingum River (Zanesville Canal). 117.849 Section 117.849...REGULATIONS Specific Requirements Ohio Â§ 117.849 Muskingum River (Zanesville Canal). The draw of the Conrail...
...Navigable Waters 1 2010-07-01 2010-07-01 false Muskingum River (Zanesville Canal). 117.849 Section 117.849...REGULATIONS Specific Requirements Ohio Â§ 117.849 Muskingum River (Zanesville Canal). The draw of the Conrail...
1. Photocopy of photograph. ORIGINAL CANAL COAL POCKETS Source: Delaware and Hudson Railroad and Canal, by Wayne County Historical Society. - Honesdale Coal Pockets, Main & Commercial Streets, between 700 & 800 blocks, Honesdale, Wayne County, PA
In this paper, an analytical model of the tympanicmembrane is introduced where the two-dimensional tympanicmembrane is reduced to a one-dimensional string. It is intended to bridge the gap between lumped-element models and finite-element models. In contrast to known lumped-element models, the model takes the distributed effect of the sound field on the tympanicmembrane into account. Compared to finite-element models, it retains the advantage of a low number of parameters. The model is adjusted to forward and reverse transfer functions of the guinea-pig middle ear. Although the fitting to experimental data is not perfect, important conclusions can be drawn. For instance, the model shows that the delay of surface waves on the tympanicmembrane can be different from the signal transmission delay of the tympanicmembrane. In a similar vein, the standing wave ratio on the tympanicmembrane and within the ear canal can considerably differ. Further, the model shows that even in a low-loss tympanicmembrane the effective area, which commonly is associated with the transformer ratio in a lumped-element and some hybrid circuit models, not only is frequency-dependent, but also different for forward and reverse transduction. PMID:21895086
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
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
A comparison of two methods for restoring dredged canals to wetlands was examined at the Jean Lafitte National Historical\\u000a Park and Preserve’s Barataria Preserve Unit near New Orleans, LA. Both northern and southern canals had the remnant dredged\\u000a spoil material returned to the canal, but the southern canal had additional sediment pumped in from a nearby lake. The water\\u000a depth
Joseph J. Baustian; R. Eugene Turner; Nancy F. Walters; David P. Muth
The prevalence of "C" shaped root canals in the second mandibular molars is relatively low, but diagnosis and treatment of these canals are sometimes difficult. Through clinical cases, the authors emphasize on the importance of preoperative X-rays and describe convenient preparation techniques. Some "C" shaped canals are difficult to interpretate because of the thickness of bone trabeculae, and a "C" shaped canal must be suspected when the roots are fuse and/or very close each other. PMID:2633231
Summary The radicular canal is the lateral portion of the spinal canal when it is trefoil. It is a bony and ligamentary, monovertebral and indeformable space, the measurements of which are reproducible. The anatomy of this radicular canal has been studied in the whole of the lumbar vertebrae of 50 anatomical subjects. Its radiological anatomy has been defined by sagittal
Looking east at canal and R. Paul Smith Power Station. The dark trestle at right center carried the spur track to coal unloading facilities located in the space now occupied by the coal pile. - Potomac Edison Company, Chesapeake & Ohio Canal Bridge, Spanning C & O Canal South of U.S. 11, Williamsport, Washington County, MD
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
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
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
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
48. SUMMIT OF THE MORRIS CANAL, 914 FEET ABOVE MEAN HIGH TIDE AT NEWARK, NEW JERSEY. TRACKS OF THE D, L & W RAILROAD CAN BE SEEN AT LEFT. EDGE OF THE LAKE HOPATCONG STATION IS ALSO VISIBLE AT LEFT. PASSENGERS AND FREIGHT COULD BE TRANSFERRED TO SMALL BOATS FOR TRANSPORT THROUGH THE FEEDER CANAL TO LAKE HOPATCONG. - Morris Canal, Phillipsburg, Warren County, NJ
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
Fitting hearing aids to open ear canals, in spite of its many benefits and increased popularity, is particularly prone to feedback problems. The present study examined the system responses of the feedback path and how effective the feedback signals can be cancelled under the open-canal condition. Compared to a traditional fitting method with earmolds, the open-canal fitting has a smaller
The operation of main irrigation canals is complicated in situations where the operator does not have full control over the canal inflow, or where there are very long transmission distances from the point of supply, or both. Experienced operators are able to control the canal, but often supply error...
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
VIEW LOOKING SOUTHWEST AT THE DOWNSTREAM ENTRANCE INTO BARGE CANAL LOCK 34. THE ERIE CANAL MUSEUM (FORMER POWER PLANT) IS IN THE CENTER OF THE VIEW, NOTE THE TURBINE DISCHARGE PORTS VISIBLE IN THIS LOW WATER VIEW. THE PINE STREET BRIDGE IS IN THE BACKGROUND. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY
...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...
...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...
197. Photocopy of drawing, Twin Falls, Canal Company, date unknown. GATE STEMS AND LIFTING DEVICES, NO COUNTY; BLUEPRINT SKETCHES. - 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 aim of this study was to register the root canal number, root canal position, and root canal cross-section in human two-rooted, permanent maxillary second molars. One hundred and fifty-nine such teeth extracted in Denmark were cross-sectioned at the mid-root level and apically in accordance with precise guidelines. The observations were made in a stereomicroscope, corresponding to the above-mentioned section levels. At mid-root there were two canals present in 11% of the teeth examined; the canals were located mesially and distofacially, mesiofacially and distally, or facially and lingually. Three canals positioned mesiofacially, distofacially, and lingually were observed in 89% of the teeth. At the same level 62% of the canal cross-sections were noncircular, some being, for instance, C-shaped, whereas 38% of the cross-sections were circular. Apically, two canals were found, representing 19% of the teeth, with the canal position as at mid-root; 81% of the teeth were three-canaled with the same canal position as at mid-root. At the apical level 60% of the canal cross-sections were noncircular, whereas 40% of the cross-sections were circular. PMID:9477024
Recognition of unusual variations in the canal configuration is critical because it has been established that the root with a single tapering canal and apical foramen is the exception rather than the rule. The early recognition of these configurations facilitates cleaning, shaping, and obturation of the root canal system. “C” configuration, which is an important anatomic variation, presents a thin
1. MAP OF THE OHIO CANAL, INCLUDING LOCK #37 (14 MILE LOCK). MADE UNDER THE DIRECTION OF THE BOARD OF PUBLIC WORKS, DECEMBER 1912. SCALE 80'=1'. PROPERTY OF AMERICAN STEEL AND WIRE COMPANY, CLEVELAND, OHIO. - Ohio & Erie Canal, Lock No. 37, At Canal & Fitzwater Roads, Valley View, Cuyahoga County, OH
4. MAP OF THE OHIO CANAL, INCLUDING LOCK #38 (12 MILE LOCK) AND TINKERS CREEK. MADE UNDER THE DIRECTION OF THE BOARD OF PUBLIC WORKS, DECEMBER 1912. SCALE: 80'=1'. PROPERTY OF THE AMERICAN STEEL & WIRE COMPANY, CLEVELAND, OHIO. - Ohio & Erie Canal, Lock No. 38, Canal & Hillside Roads, Valley View, Cuyahoga County, OH
6. MAP OF THE OHIO CANAL INCLUDING LOCK #39. MADE UNDER THE DIRECTION OF THE BOARD OF PUBLIC WORKS, DECEMBER 1912. SCALE:80'=l'. PROPERTY OF AMERICAN STEEL AND WIRE COMPANY, CLEVELAND, OHIO. - Ohio & Erie Canal, Lock No. 39, West side of Canal Road, 3400 feet north of Stone Road, Valley View, Cuyahoga County, OH
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
31. MAIN CANAL - Photographic copy of historic photo, December 13, 1939 (original print in '1939 Annual Report of the Carlsbad Project,' located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'LINING MAIN CANAL AROUND GYP BEND' - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM
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
Hearing results were studied in pediatric patients after canal-wall-up and canal-wall-down mastoid surgery in a private practice setting. A retrospective chart review was performed on 69 patients who underwent surgery from 1991-1995. Twenty-six patients underwent canal-wall-up mastoidectomies, and 43 patients underwent canal-wall-down mastoidectomies. Various types of ossicular reconstruction were performed in patients in both groups. Hearing was evaluated for preoperative
The study examines whether or not, in the foreseeable future, the United States will bow to pressure, both internal and external, to give up it's exclusive jurisdiction and sovereignty rights over the Panama Canal and the Zone and allow it to be controlle...
The issues listed herein concern the relevancy of the U.S.-Panama Treaty of 1903, the effect of U.S. control of the Canal on relations with Latin America, and alternatives open to the U.S. in solving the Panama Problem. (Modified author abstract)
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...
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...
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
Dwight T. Janerich; William S. Burnett; Gerald Feck; Margaret Hoff; Philip Nasca; Anthony P. Polednak; Peter Greenwald; Nicholas Vianna
The main objective of this paper is to set up an adequate system to operate Bahr Wahba Canal. This well leads to an efficient use of irrigation water that leading to higher crop yields, reduce of operation costs in particular the cost of energy needed for pumping and sustainable management of salinity to prevent loss of agricultural land. Bahr wahba
Since construction in the late 1940's, the Friant-Kern Canal has experienced cracking, sliding, and sloughing of the side slopes in areas of expansive clays in both the concrete-lined and earth-lined portions. In the early 1970's, Bureau of Reclamation de...
Canal automation promises to improve water control and accounting in irrigation delivery systems and also to increase delivery flexibility to users. Despite many recent advances, theoretical and practical issues remain to be resolved for wide application. Past automation efforts have been complicate...
Most species maintain abundant genetic variation and experience a range of environmental conditions, yet phenotypic variation is low. That is, development is robust to changes in genotype and environment. It has been claimed that this robustness, termed canalization, evolves because of long-term natural selection for optimal phenotypes. We show that the developmental process, here modeled as a network of interacting
Objectives: This study was designed to evaluate the authors' experience with canal wall reconstruc- tion (CWR) tympanomastoidectomy with mastoid obliteration in the treatment of chronic otitis media with cholesteatoma. Study Design: Institutional re- view board approved retrospective case review. Meth- ods: Retrospective review was performed of all pa- tients undergoing CWR tympanomastoidectomy with mastoid obliteration from 1997 to 2004. Data
Bruce J. Gantz; Eric P. Wilkinson; Marlan R. Hansen
The authors examine the standard insurance exclusionary clause developed by the Insurance Services Office in 1970 regarding injury and property damage from pollution, specifically, its genesis, its incorporation into New York state statutes, a brief history of Love Canal and its legacy of litigation, recent interpretations by US courts, and current developments. They conclude that, in every state where the
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...
Simulation models for unsteady open channel flows have been commercially available for more than two decades. Most of these models are now available for personal computers and can be used to study the control of irrigation canals. Studies on automatic control methods and algorithms have been perform...
|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…
Data were obtained from 63 in-depth interviews with a primarily random sample of homeowners both relocated from and remaining in the Love Canal area of Niagara Falls, New York. Data analysis centers on the relevance of family health experience and of demo...
In the Western part of the United States of America, more and more irrigation canal networks are being modernized, which often includes some form of real-time automatic water level control. This real-time control consists of water level measurements that are communicated to a controller. The control...
The Royal Dental College, Copenhagen, houses an extensive collection of human teeth extracted in Denmark. The collection currently contains 104 one-rooted, permanent maxillary second molars. The root complex on these teeth was sectioned at the junction between the coronal and the apical halves, i.e. mid-root, and at the junction between the middle and the apical thirds, i.e. apically. Using a stereomicroscope we then registered, mid-root and apically, the following variables: canal number, canal position, and canal cross-section. Mid-root there was 1 centrally located root canal in 25.96% of the teeth examined; 2 canals were observed either mesially and distofacially, mesiofacially and distally, or facially and lingually in 34.62%; 3 canals positioned mesiofacially, distofacially, and lingually were found in 39.42%. At the same level 63.51% of the canal cross-sections were non-circular, whereas 36.49% of the canals had a circular cross-section image. The non-circular canal cross-sections could more specifically be characterized as C-shaped, Y-shaped, hourglass-shaped or the root canal had a greater faciolingual than mesiodistal extension or, respectively, a greater mesiodistal than faciolingual extension. Apically there was 1 centrally located root canal in 35.58%; 2 canals were observed with a position either mesially and distofacially, mesiofacially and distally, or facially and lingually in 37.49%; 3 canals located mesiofacially, distofacially, and lingually were found in 26.92%. At the apical level, 64.32% of the root canal cross-sections were non-circular, whereas 35.68% of the canals showed a circular cross-section. The results presented here are aimed at: clinical dentists, endodontists, and dental morphologists. PMID:1411268
Carlsen, O; Alexandersen, V; Heitmann, T; Jakobsen, P
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.
The root canal anatomy of 149 mandibular second molars was studied using a technique in which the pulp was removed, the canal space filled with black ink and the roots demineralized and made transparent. Of the 149 teeth, 22 per cent had single roots, 76 per cent had two roots and 2 per cent had three roots. In the single-rooted teeth, three canals were most common, while in the mesial root of the two-rooted teeth, two canals that joined near the apex and one canal in the distal root were most frequent. Round canals were most common in two-rooted teeth and C-shaped canals in single-rooted teeth. Transverse anastomoses were found in 33 per cent of roots, most commonly in the middle third of the root. Lateral canals were found in 72 per cent of roots, most commonly in the apical third of the root. The apical foramen was positioned at the apex in only 33 per cent of roots, and apical deltas were found in 35 per cent. The patient's age and race affected canal shape, with more round canals present in patients over 35 years of age, and more C-shaped canals in Asians. The sex of the patient and the side of the mouth affected the presence of apical deltas, with more being found in males and on the left side. Single-rooted teeth had more complex root canal systems than two-rooted teeth, with more lateral canals, transverse anastomoses, apical deltas and C-shaped canals. PMID:2391179
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.
The purpose of this study was to investigate various properties of citric acid and EDTA solution as decalcifying and cleansing agents in root canal irrigation, and antibacterial effects of citric acid and EDTA solution. Powdered dentin-resin mixtures were used for evaluating the decalcifying effect of citric acid and EDTA solution. Twelve bacterial strains isolated from infected root canals, were used to evaluate the antibacterial effects of citric acid and EDTA solution. Powdered dentin-resin mixture was found to be more soluble in a 0.5, 1, and 2 M citric acid solutions than in a 0.5 M EDTA solution. Citric acid solution showed antibacterial effects on all the bacteria used. PMID:8618082
Glass-ionomer root canal sealer is commonly used because of its chemical bonding and favorable physical characteristics when bonding to dentin. This study was designed to determine the tensile bond strength of a glass-ionomer sealer (Ketac Endo, Espe, Seefeld, Germany) on root canal walls after pretreatment with different conditioners. Flat inner surfaces of root canal specimens were prepared. The specimens were divided into five groups of 10 teeth, and the groups were conditioned with one of the following smear layer removal solutions: 15% EDTA/NaOCl, 10% polyacrylic acid, 35% phosphoric acid, 6% citric acid, and 5.25% NaOCl as a control. Then the exposed root canal areas were coated with Ketac-Endo. Tensile bonding was measured using a universal testing machine until ultimate failure was obtained. The groups that were treated with phosphoric acid and citric acid showed significantly higher bond strengths than the groups that were treated with 15% EDTA and polyacrylic acid (p < 0.05). Bonding to dentin without smear layer removal (NaOCl group) was too low to be measured in the testing apparatus. Scanning electron microscopy confirmed that phosphoric and citric acids were more effective in removing smear layer than EDTA or polyacrylic acid. The result supported the view that pretreatment with phosphoric acid or citric acid should be used in association with glass-ionomer root canal sealer to achieve the most effective removal of the smear layer and to provide better adhesion. PMID:11487144
. Atrazine, ametryn, bromacil, simazine and norflurazon were the most frequently detected pesticides in surface water samples\\u000a and DDE, DDD and ametryn were the most frequently detected pesticides in sediment samples collected over the period November\\u000a 1991 to June 1995 in a monitoring network that includes 27 stations in south Florida canals. The 744 pesticide detections\\u000a during this time period
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
The purpose of this study was to compare canal transportation in moderately curved canals using mechanical instrumentation systems. Mesial roots of mandibular first or second molars were mounted in resin using a modified Bramante muffle system and divided into four groups. The roots were cross-sectioned 2 mm from the working length and at the height of root curvature. Tracings of the canal were made from preinstrumentation slides of the cross-sections. The canals were prepared using ProFile Series 29 rotary instruments, Quantec 2000 rotary instruments, Flex-R files in the Endo Gripper contra-angle handpiece, and Shaping Hedstrom files in the M4 contra-angle handpiece. Tracings of the prepared canals were made onto the originals from postinstrumentation slides. A canal centering ratio was calculated along the line of maximum transportation. Quantec 2000 rotary instruments yielded significantly greater transportation at the apical level when compared with the Profile Series 29 system. There were no other significant differences in transportation at either level. There were no differences in the direction of canal transportation between instrument systems, and the direction of canal transportation was not related to the direction of canal curvature. Canal preparation time was shortest with Profile Series 29 system followed by Flex-R files in the Endo Gripper, Quantec 2000, and Shaping Hedstrom files in the M4. PMID:10530247
This report on the Chesapeake and Ohio Canal recounts the history of 22 years of its construction, 74 of its use and maintenance, and 4 of rehabilitation. All three processes for this canal which ran from Georgetown to Cumberland, Maryland, required enorm...
The aim of this study was to provide anatomic data for optic canal decompression. One hundred twenty people (55 males and 65 females) were involved in this study anonymously. Twelve parameters are measured in computed tomography: P1 is the nasal bone tip; P2 is the middle point of tuberculum sellae; P3 is the root of columella nasi; P4 is the cranium end of the optic canal; P5 is the orbit end of the optic canal; P1' is P1's projection on L2; L1 is the line that links P1 and P2; L2 goes through P3 and parallel to L1; L3 is the bisector of right and left and goes through P1. The distance between LI and L2 was 30.47 ± 3.71 mm. The distance between P3 and P1' was 11.66 ± 2.82 mm. The medial canal wall length was 10.64 ± 1.10 mm on the right and 10.51 ± 1.07 mm on the left (P = 0.001). The distance between P1 and P4 was 66.74 ± 5.97 mm. The distance between P1 and P5 was 73.04 ± 6.33 mm on the right and 72.82 ± 6.33 mm on the left (P = 0.004). The distance between P5 and L3 was 6.62 ± 1.33 mm. The distance between P4 and L3 was 12.26 ± 1.63 mm. The distance between P3 and P4 was 75.82 ± 4.63 mm. The distance between P3 and P5 was 82.87 ± 4.60 mm on the right and 82.25 ± 4.86 mm on the left (P = 0.003). The angle between P1P4 and L3 was 12.26 ± 1.63 degrees. The angle between P1P5 and L3 was 5.28 ± 1.13 degrees. The angle between P3P5 and P3P4 was 5.80 ± 0.97 degrees. These results provide a precise location of the optic canal. PMID:23348301
One hundred six human mandibular left and right first premolars, previously extracted due to nonrestorable caries, periodontal disease, or orthodontic reasons, were sectioned perpendicular to the long axis of the root starting at the cementoenamel junction. Three-millimeter sections were made with an ultrathin separating disc to the level of the anatomical apex. After 1 day in 5.25% NaOCl, each section was rinsed in phosphate-buffered saline, evaluated with a stereomicroscope, and photographed. The slides were projected and the shape of the canal, incidence of multiple canals, level of bifurcation, and any other variant anatomy were recorded. Seventy-six percent of the premolars demonstrated Type I canals and 24% contained Type IV. The shape of the canals was predominantly oval or round. An interesting finding was the number of C-shaped canals which were associated predominantly with Type IV canal systems. This occurred in 14% of the roots. PMID:1289476
Returning canal spoil banks into canals, or backfilling, is used in Louisiana marshes to mitigate damage caused by dredging for oil and gas extraction. We evaluated 33 canals backfilled through July 1984 to assess the success of habitat restoration. We determined restoration success by examining canal depth, vegetation recolonization, and regraded spoil bank soils after backfilling. Restoration success depended on: marsh type, canal location, canal age, marsh soil characteristics, the presence or absence of a plug at the canal mouth, whether mitigation was on- or off-site, and dredge operator performance. Backfilling reduced median canal depth from 2.4 to 1.1 m, restored marsh vegetation on the backfilled spoil bank, but did not restore emergent marsh vegetation in the canal because of the lack of sufficient spoil material to fill the canal and time. Median percentage of cover of marsh vegetation on the canal spoil banks was 51.6%. Median percentage of cover in the canal was 0.7%. The organic matter and water content of spoil bank soils were restored to values intermediate between spoil bank levels and predredging marsh conditions. The average percentage of cover of marsh vegetation on backfilled spoil banks was highest in intermediate marshes (68.6%) and lowest in fresh (34.7%) and salt marshes (33.9%). Average canal depth was greatest in intermediate marshes (1.50 m) and least in fresh marshes (0.85 m). Canals backfilled in the Chenier Plain of western Louisiana were shallower (average depth = 0.61 m) than in the eastern Deltaic Plain (mean depth range = 1.08 to 1.30 m), probably because of differences in sediment type, lower subsidence rate, and lower tidal exchange in the Chenier Plain. Canals backfilled in marshes with more organic soils were deeper, probably as a result of greater loss of spoil volume caused by oxidation of soil organic matter. Canals ten or more years old at the time of backfilling had shallower depths after backfilling. Depths varied widely among canals backfilled within ten years of dredging. Canal size showed no relationship to canal depth or amount of vegetation reestablished. Plugged canals contained more marsh reestablished in the canal and much greater chance of colonization by submerged aquatic vegetation compared with unplugged canals. Dredge operator skill was important in leveling spoil banks to allow vegetation reestablishment. Wide variation in dredge performance led to differing success of vegetation restoration. Complete reestablishment of the vegetation was not a necessary condition for successful restoration. In addition to providing vegetation reestablishment, backfilling canals resulted in shallow water areas with higher habitat value for benthos, fish, and waterfowl than unfilled canals. Spoil bank removal also may help restore water flow patterns over the marsh surface. Increased backfilling for wetland mitigation and restoration is recommended.
Previous research on canal automation has dealt with the control of single, in-line canals, while canal operators typically have to control a network of canals. Because the branches in a network are hydraulically coupled with each other, control of a branching canal network based on separate contro...
Complex and unusual root canal morphology is an often occurring phenomenon. Understanding the unusual root canal morphology contributes to success in endodontic treatment. One such variant root canal morphology is the ‘S’ shaped or bayonet shaped root canal. This case report discusses endodontic treatment of a maxillary second premolar with an ‘S’ shaped root canal.
Complex and unusual root canal morphology is an often occurring phenomenon. Understanding the unusual root canal morphology contributes to success in endodontic treatment. One such variant root canal morphology is the 'S' shaped or bayonet shaped root canal. This case report discusses endodontic treatment of a maxillary second premolar with an 'S' shaped root canal. PMID:20351976
82. CANAL WEST OF LOCK 12 EAST NEAR BOONTON. STORAGE BUILDING AND CHUTE ON LEFT SIDE OF CANAL MAY BE A COAL FACILITY. COAL WOULD BE UNLOADED FROM THE BOAT AND PASSED UP THE CHUTE INTO THE COAL STORAGE BIN. COAL COULD THEN BE LOADED INTO WAGONS FROM THE BOTTOM OF THE BIN ON THE OPPOSITE SIDE OF THE STRUCTURE WHEN NECESSARY. - Morris Canal, Phillipsburg, Warren County, NJ
Conventional cleaning and shaping of root canal systems employs hand and\\/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into
Harold E. Goodis; Joel M. White; Sally J. Marshall; Grayson W. Marshall; Emrey Moskowitz
9. EAST SIDE CANAL - Photographic copy of historic photo, September 17, 1940 (original print in '1940 Annual Report of the Carlsbad Project,' located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'CCC ENROLLEES STARTING EXCAVATION FOR ROCK LINING DOWNSTREAM FROM STA. 22. EAST CANAL, LAT. #8' - Carlsbad Irrigation District, East Side Canal, 1 mile North to 2 miles East of Carlsbad, Carlsbad, Eddy County, NM
10. EAST SIDE CANAL - Photographic copy of historic photo, December 3, 1940 (original print in '1940 Annual Report of the Carlsbad Project,' located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'LOOKING DOWN FROM STA. #22 LATERAL #8, EAST CANAL. AFTER CCC ENROLLEES FINISHED ROCK LINING' - Carlsbad Irrigation District, East Side Canal, 1 mile North to 2 miles East of Carlsbad, Carlsbad, Eddy County, NM
The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model\\u000a was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport, and cooling canal geometry\\u000a on aquifer salinization and movement of
Joseph D. Hughes; Christian D. Langevin; Linzy Brakefield-Goswami
The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport, and cooling canal geometry on aquifer salinization and movement
Joseph D. Hughes; Christian D. Langevin; Linzy Brakefield-Goswami
PLANS AND SECTIONS. WEIR SPILLWAY. TEXAS HILL CANAL - STA. 132+82.15. TEXAS HILL CANAL AND DISTRIBUTION SYSTEM. United States Department of Interior, Bureau of Reclamation; Gila Project, Arizona, Wellton-Mohawk Division. Drawing No. 50-D-3200, dated February 7, 1955, Denver, Colorado - Wellton-Mohawk Irrigation System, Relift Station, Texas Hill Canal 2.5, Northern Terminus of Avenue 51 East, approximately .5 mile south of Union Pacific Railroad, Wellton, Yuma County, AZ
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
Recognition of unusual variations in the canal configuration is critical because it has been established that the root with a single tapering canal and apical foramen is the exception rather than the rule. The early recognition of these configurations facilitates cleaning, shaping, and obturation of the root canal system. "C" configuration, which is an important anatomic variation, presents a thin fin connecting the root canals. Because of the importance of its true diagnosis and treatment, a comprehensive review of published information and investigations about it in addition to approaches for its treatment is necessary. PMID:17437864
The critical step for successful treatment of an infected root canal system is to treat the root canal in such a way as to remove as many microbes as possible (in the case of a necrotic tooth) or to maintain the sterility of the canal (in the case of a vital tooth); this is called the microbial control phase of root canal treatment. This article describes the steps required for adequate microbial control. The rationale for minimal apical file sizes and irrigation and antimicrobial medicaments required are described in detail. PMID:19906610
This study analyzed the progressive changes in canal shape after the use of different instruments by hand in simulated S-shaped canals.Forty simulated canals with double curvatures, 30° coronally and 20° apically, were randomly divided into four groups and prepared with stainless steel K-files, the ProTaper for hand use (PHU) system, NiTi K-files, and the combination of PHU and NiTi K-files,
Huang Ding-ming; Luo Hong-xia; Gary S.-P. Cheung; Zhang Lan; Tan Hong; Zhou Xue-dong
PaqueF, Barbakow F, Peters OA. Root canal preparation with Endo-Eze AET: changes in root canal shape assessed by micro-computed tomography. International Endodontic Journal, 38, 456-464, 2005. Aim To evaluate the relative performance of Endo-Eze Anatomic Endodontic Technology (AET) stainless steel instruments when shaping maxillary molar root canals in vitro. Methodology Extracted human maxillary molars were scanned, before and after root
Peters OA, Peters CI, Scho « nenberger K, Barbakow, F. ProTaper rotary root canal preparation: effects of canal anatomy on final shape analysed by micro CT. International Endodontic Journal, 36, 86^92, 2003. Aim To evaluate the relative performance of ProTaper nickel^titanium (Ni^Ti) instruments shaping root can- als of varying preoperative canal geometry. Methodology Extracted human maxillary molars were scanned, before
O. A. Peters; C. I. Peters; K. Schonenberger; F. Barbakow
Background The Love Canal was a rectangular 16-acre, 10-ft-deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site came to public attention in 1978. Only one prior study examined cancer incidence in former residents of the Love Canal neighborhood (LC). Objective In this study we aimed to describe cancer incidence in former LC residents from 1979 to 1996 and to investigate whether it differs from that of New York State (NYS) and Niagara County (NC). Methods From 1978 to 1982, we interviewed 6,181 former residents, and 5,052 were eligible to be included in this study. In 1996, we identified 304 cancer diagnoses in this cohort using the NYS Cancer Registry. We compared LC cancer incidence with that of NYS and NC using standardized incidence ratios (SIRs), and we compared risks within the LC group by potential exposure to the landfill using survival analysis. 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 two cases. Conclusions In explaining these excess risks, the role of exposure to the landfill is unclear given such limitations as a relatively small and incomplete study cohort, imprecise exposure measurements, and the exclusion of cancers diagnosed before 1979. Given the relatively young age of the cohort, further surveillance is warranted.
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.
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
Approximately 30 people drown in Bureau-constructed canals annually. An undetermined number of animals (mostly deer) also drown in these canals. Losses could be eliminated at considerable expense by covering existing canals or by placing them in buried co...
...Menomonee, and Kinnickinnic Rivers and South Menomonee and Burnham Canals. 117...Menomonee, and Kinnickinnic Rivers and South Menomonee and Burnham Canals. ...bridges across the Menomonee River and South Menomonee Canal operate as...
...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...
...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...
...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)...
...Navigation Area; Chicago Sanitary and Ship Canal, Romeoville, IL AGENCY: Coast...Navigation Area in the Chicago Sanitary and Ship Canal, Romeoville, IL. These omissions...of Engineers CSSC Chicago Sanitary and Ship Canal CFR Code of Federal Regulations...
...Navigation Area, Chicago Sanitary and Ship Canal, Romeoville, IL AGENCY: Coast...Navigation Area on the Chicago Sanitary and Ship Canal near Romeoville, IL. This final...electrical barriers in the Chicago Sanitary and Ship Canal (CSSC). These barriers are...
...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...
...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...
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.
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. PMID:8734607
Membranous nephropathy is a kidney disorder that leads to changes and inflammation of the structures inside the kidney ... Membranous nephropathy is caused by the thickening of part of the glomerular basement membrane. The glomerular basement membrane ...
The evolution of the cetacean skeleton followed a path that differentiated this group from other terrestrial mammals about 50 million years ago , and debate is still going on about the relationships between Cetacea and Artiodactyla , , . Some skeletal traits of the basilosaurids (the more advanced forms of Archaeocetes), such as the expansion of the peribullary air sinuses, dental modification and vertebral size uniformity  are maintained and further emphasized also in contemporary odontocetes and mysticetes. Using Dual-Energy X-Ray Absorptiometry here we report that the deposition of bone mineral in fetal and newborn specimens of the fin whale Balaenoptera physalus is remarkably higher in the bulla tympanica than in the adjacent basal skull or in the rest of the skeleton. Ossification of the tympanic bulla in fetal Artiodactyla (bovine, hippopotamus) is minimal, becomes sensible after birth and then progresses during growth, contrarily to the precocious mineralization that we observed in fin whales. Given the importance of the ear bones for the precise identification of phylogenetic relationship in therian evolution , this feature may indicate a specific evolutionary trait of fin whales and possibly other cetacean species or families. Early mineralization of the tympanic bulla allows immediate sound conduction in the aquatic medium and consequently holds potential importance for mother-calf relationship and postnatal survival. PMID:22615912
The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and clinically challenging. This case report presents the treatment of a mandibular first molar with six root canals, of which three canals were located in the mesial root and three in distal root. Third canals were found between the two main root canals. This case presents a rare anatomic configuration and points to the importance of expecting and searching for additional canals. PMID:22629055
Successful root canal treatment depends on adequate cleaning, shaping, and filling of the root canal system. The presence of middle mesial (MM) root canal of mandibular molars has been reported by various authors. But incidence of four canals in mesial root of mandibular molar is very rare. The aim of this case report is to present and describe the identification and management of a mandibular first molar with four canals in the mesial root and single canal in the distal root. PMID:24082581
Successful root canal treatment depends on adequate cleaning, shaping, and filling of the root canal system. The presence of middle mesial (MM) root canal of mandibular molars has been reported by various authors. But incidence of four canals in mesial root of mandibular molar is very rare. The aim of this case report is to present and describe the identification and management of a mandibular first molar with four canals in the mesial root and single canal in the distal root.
This case report presents the endodontic management of a maxillary second molar with clinical and radiographic presentation of 2 palatal canals. The canal morphology was confirmed with the aid of spiral computerized tomography, which revealed a C-shaped canal configuration of palatal canal with 2 separate apical foramens. The article presents the unusual canal morphology alterations and the importance of using diagnostic adjuncts in their accurate diagnosis. PMID:20451838
We investigated spatial responses of the aVOR to small and large accelerations in six canal-plugged and lateral canal nerve-sectioned monkeys. The aim was to determine whether there was spatial adaptation after partial and complete loss of all inputs in a canal plane. Impulses of torques generated head thrusts of ?3,000°/s2. Smaller accelerations of ?300°/s2 initiated the steps of velocity (60°/s). Animals were rotated about a spatial vertical axis while upright (0°) or statically tilted fore-aft up to ±90°. Temporal aVOR yaw and roll gains were computed at every head orientation and were fit with a sinusoid to obtain the spatial gains and phases. Spatial gains peaked at ?0° for yaw and ?90° for roll in normal animals. After bilateral lateral canal nerve section, the spatial yaw and roll gains peaked when animals were tilted back ?50°, to bring the intact vertical canals in the plane of rotation. Yaw and roll gains were identical in the lateral canal nerve-sectioned monkeys tested with both low- and high-acceleration stimuli. The responses were close to normal for high-acceleration thrusts in canal-plugged animals, but were significantly reduced when these animals were given step stimuli. Thus, high accelerations adequately activated the plugged canals, whereas yaw and roll spatial aVOR gains were produced only by the intact vertical canals after total loss of lateral canal input. We conclude that there is no spatial adaptation of the aVOR even after complete loss of specific semicircular canal input.
Dai, Mingjia; Raphan, Theodore; Suzuki, Jun-Ichi; Arai, Yasuko; Cohen, Bernard
External auditory canal (EAC) carcinomas are frequently misdiagnosed. The aim of this study was to conduct a review of misdiagnosed cases and analyze the factors involved. This study was a retrospective assessment. Eighteen of 44 EAC carcinoma cases seen at the Eye and ENT Hospital were misdiagnosed. All medical records were retrospectively analyzed for the age, sex, presenting symptoms, type of misdiagnosis, computed tomographic (CT) or magnetic resonance imaging (MRI) findings, stage of the cancer, surgical approach, histopathological examination, adjunctive therapy (postoperative radiotherapy) and outcomes of treatment. Six cases were misdiagnosed as otitis media, five cases were misdiagnosed as otitis externa, and two cases were misdiagnosed as external auditory canal cholesteatomas. Other misdiagnoses were stenosis of the EAC, ear neuralgia, furuncle of the EAC, benign neoplasm of the EAC and pre-auricular fistula. Our analyses suggest that a biopsy should be conducted to obtain a histopathological diagnosis if an EAC carcinoma is suspected, in case otitis media or otitis externa does not respond to routine anti-bacterials. Head and neck MRI should be used to explore the involvement of soft tissues. Patients with bloody ear discharge and otalgia, particularly with temporal bone erosion seen in a CT scan, are highly likely to have a malignant carcinoma of the temporal bone. PMID:22926989
Many irrigation districts currently operate their main canals, pumping plants, etc. remotely with Supervisory Control and Data Acquisition (SCADA) software. This is usually manual operation with perhaps a few local automatic control features. SacMan (software for automated canal management) is a sof...
The success of endodontic therapy requires a knowledge of the internal and external dental anatomy and its variations in presentation. The internal anatomy of the maxillary central incisor is well known and usually presents with one root and one radicular canal system. This case report describes an endodontic treatment of a maxillary central incisor with two roots and two canal
Emílio Carlos Sponchiado; Hanan Awwad Abdel Qader Ismail; Márcia Raquel Lima Braga; Fabrício Kitazono de Carvalho; Cláudia Andréa Correa Garcia Simões
A correct working length (WL) determination is crucial for the success of the tooth root canal treatment. For this, Electronic Foramen Locators (EFL) are replacing the well established radiographic images technique. Although modern EFLs are based on the relative changes in the root canal impedance measured with a set of frequency, not much studies about this impedance changes was published
M. V. H. Rambo; H. R. Gamba; G. B. Borba; C. A. S. Ramos
25. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, March 1954. VIEW OF THE GAGE IRRIGATION CANAL, CONCRETE 'COVERING COMPLETED & BACKFILLED TO WATERMAN AVENUE...CURVING TOWARD NO. 1 TUNNEL' - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
1. General oblique view from south side of Canal Street showing Paper Machine Building at southwest corner of site; view to northeast. - Champion-International Paper Company, Paper Machine Building, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA
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
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
C. W. Jr. Heath; M. R. Nadel; M. M. Jr. Zack; A. T. L. Chen; M. A. Bender; R. J. Preston
3. GENERAL VIEW ACROSS CANAL PRISM TO TOWPATH BERM NORTH OF THE SPILLWAY; VIEW TO WEST FROM ROUTE 146 EMBANKMENT. - Blackstone Canal Millbury Segment, Beginning northwest of State Route 146 & McCracken Road, running along west side of Route 146, Millbury, Worcester County, MA
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
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
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
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
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
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
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
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
1. GENERAL VIEW, TOWPATH BERM (CENTER) AND CANAL PRISM (LEFT) SOUTH OF THE SPILLWAY; VIEW TO SOUTH. - Blackstone Canal Millbury Segment, Beginning northwest of State Route 146 & McCracken Road, running along west side of Route 146, Millbury, Worcester County, MA
With climatic change, many western states in the United States are experiencing drought conditions. Numerous irrigation districts are losing significant amount of water from their canal systems due to leakage. Every year, on the average 2 million acres of prime cropland in the US is lost to soil erosion, waterlogging and salinity. Lining of canals could save enormous amount of
The Chesapeake and Ohio Canal National Historical Park is one of 358 units of the national park system at the writing. The historic C and O Canal is its primary feature, justifying its designation as a historical park. But hikers and bicyclists along the ...
2. GENERAL VIEW ACROSS CANAL PRISM TO TOWPATH BERM SOUTH OF THE SPILLWAY; VIEW TO SOUTHWEST FROM ROUTE 146 EMBANKMENT. - Blackstone Canal Millbury Segment, Beginning northwest of State Route 146 & McCracken Road, running along west side of Route 146, Millbury, Worcester County, MA
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
6. VIEW WEST, INTERIOR CANAL WALL, FLOOR FULLY EXCAVATED (Original Fabric) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA
3. VIEW EAST, DETAIL OF INTERIOR CANAL WALL (Original Fabric) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA
29. VIEW OF GRAND CANAL, LOOKING WEST TOWARD BROPHY PREP AND ST. FRANCIS CHURCH (compare this photograph with AZ-17-15, taken at the same spot in 1937). Photographer: Kevin Kreisel-Coons, May 1990 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ
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
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 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
Personnel from Armstrong Laboratory Water Quality Function conducted a drainage canal survey at Hickam AFB HI from 16 to 27 Mar 92. The scope of the survey was to indicate if current water quality in the canals is within Hawaii Water Quality Standards. Si...
One Key problem for canal system control is how to select appropriate performance indicators and how to tune the controller with these indicators. A canal system is a multi-input and multi-output (MIMO) system. The judging of control performance can be extremely complicated. In this paper, frequentl...
21. Photocopy of photograph (original print at Gage Canal Company Office), H. B. Wesner, photographer, date unknown. 'VIEWS OF SOUTHERN CALIFORNIA SCENERY. ARTESIAN WELLS, SAN BERNARDINO, CALIFORNIA. SUPPLYING THE GAGE CANAL OF RIVERSIDE.' - California Citrus Heritage Recording Project, Riverside, Riverside County, CA
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
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
The Study of Engineering Feasibility was made pursuant to a request by the Atlantic-Pacific Interoceanic Canal Study Commission that the Chief of Engineers determine the engineering feasibility of constructing a sea-level canal between the Atlantic and Pa...
1. Drop Structure on the Arizona Crosscut Canal. Photographer unknown, no date. Note that caption is incorrect: in relation to Camelback Mountain (rear), this can only be the Old Crosscut. Source: reprinted from the 13th Annual Report of the U.S. Geological Survey, 1893. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ
19. VIEW LOOKING NORTHWEST FROM WITHIN THE ARMORY CANAL WALLS AT THE DOWNSREAM SIDE OF THE CONTROL GATES AND LOCK FOR THE CANAL. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV
A total of 46 extracted maxillary and mandibular molars were examined to determine the incidence of accessory canals in the coronal and middle third of the root surface. A radiopaque dye was drawn through the root canal system under a vacuum of 5 p.s.i., ...
...governing the operation of the State Route 56 swing bridge across Boudreaux Canal, mile 0...deviation from the operating schedule for the swing span bridge across Boudreaux Canal, mile...Chauvin, Terrebonne Parish, Louisiana. The swing span bridge has a vertical clearance...
Summary form only given. The ears are paired sense organs, which collect, transmit, and detect acoustic impulses. Each of them is comprised of three main parts: the outer ear, middle ear, and inner ear. Traveling sound is focused into the external auditory canal by the pinna, causing vibration of the tympanicmembrane and motion of the three ossicles in the
ObjectivesThe study goal was to evaluate the stability of hearing results from short- to long-term follow-up in patients who underwent surgery for congenital aural atresia. We also reviewed complications such as external auditory canal stenosis, lateralization and perforation of the tympanicmembrane, sensorineural hearing loss, and facial palsy.
The author describes common sports injuries involving the ear. Such injuries include hematoma, lacerations, foreign bodies (tattoo), and thermal injuries. Ear canal injuries include swimmer's ear and penetrating injuries. Tympanum injuries include tympanicmembrane perforations, ossicular discontinuity, eustachian tube dysfunction, temporal bone fractures and traumatic facial nerve palsy. Inner ear injuries include traumatic sensorineural deafness. The author emphasizes the management of these injuries.
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.
Objective: Pudendal canal syndrome (PCS) which is comprised of pudendal nerve compression in the pudendal canal occurs commonly in females and presents with pelvic, pubic, suprapubic, anal, and perianal pain, as well as dysuria and dyspareunia. These manifestations are similar to those of interstitial cystitis (IC). We investigated the hypothesis that IC is a manifestation of PCS and may thus
Ahmed Shafik; Olfat El-Sibai; Ali A. Shafik; Ismail A. Shafik
The angular accelerometer of vertebrates, the semi circular canal, is a pressure gage. The transformation, acceleration to pressure, is due to the inertia of the endolymph. In the 0 to 1 Hz frequency interval, the endolymph-cupula system can be described by a second order, localised parameter model with two real time constants. This mechanical model explains the occurr]nces of the vestibular-ocular reflex during rotatory stimulations. However, some features of the response to caloric stimulations cannot be explained from this unique point of view. To correspond to these features, the SCC has to be considered as an inflatable structure, sensitive to weak pressure variations between the endolymph and perilymph. Different parameters of the mechanical model, the internal radius of the membranouscanal, the dimension of the cupula and its elasticity coefficient depend on the inflating pressure. Ménière's disease is caracterised by hydrops, i.e. an increase of the pressure in the membranous SCC. The different mechanisms related to this hydrops, in particular introducing the inflating pressure as a second input to the ampular system, associated to a new concept of the mechanoneural transduction can explain the classical vestibular symptoms of Ménière's disease. Therefore, this overall mechanical model of the SCC indicates that hydrops is the mechanical cause of Ménière's disease and the primary cause is more likely to be a defect in the regulation loop of the inflating pressure. PMID:1896676
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.
Background The Love Canal is a rectangular 16-acre, 10-ft deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site first came to public attention in 1978. No studies have examined mortality in the former residents of the Love Canal neighborhood (LC). Objective The aim of this study was to describe the mortality experience of the former LC residents from the years 1979–1996. Methods From 1978 to 1982, 6,181 former LC residents were interviewed. In 1996, 725 deaths from 1979–1996 were identified in this cohort, using state and national registries. We compared mortality rates with those of New York State (NYS) and Niagara County. Survival analysis examined risks by potential exposure to the landfill. Results We were unable to demonstrate differences in all-cause mortality for either comparison population for 1979 1996. Relative to NYS, the standardized mortality ratio (SMR) was elevated [SMR = 1.39; 95% confidence interval (CI), 1.16–1.66] for death from acute myocardial infarction (AMI), but not relative to Niagara County. Death from external causes of injury was also elevated relative to both NYS and Niagara County, especially among women (SMR = 1.95; 95% CI, 1.25 2.90). Conclusions The role of exposure to the landfill in explaining these excess risks is not clear given limitations such as multiple comparisons, a qualitative exposure assessment, an incomplete cohort, and no data on deaths prior to 1978. Lack of elevation for AMI when compared with Niagara County but not NYS suggests possible regional differences. However, direct cardiotoxic or neurotoxic effects from landfill chemicals or indirect effects mediated by psychological stress cannot be ruled out. Revisiting the cohort in the future could reveal patterns that are not yet apparent.
The primary objective of endodontic therapy is to achieve a three-dimensional obturation of the root canal space after adequate preparation of the canal space to remove the tissue debris, microorganisms, and their byproducts. Anatomical variations have frequently been encountered in endodontic practice and have to be adequately managed by the clinician. Missed roots and canals are a major reason for failure of therapy. Technological advances have given the clinician ample opportunity to identify and treat these aberrations successfully. The present report describes a left mandibular second permanent molar requiring root canal treatment, found to have three separate canals in the mesial root. This case demonstrates a rare anatomical configuration and emphasizes the need for the clinician to be aware of and look out for such variations and use adequate diagnostic methodologies prior to and during therapy to detect such variations. The possibility of additional canals, whenever in doubt, should be explored with the assistance of technologies such as those of magnification and illumination and various diagnostic aids. Operator experience has also shown to be a key factor in negotiation and management of these aberrant canal configurations.
Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1) sound intensity level, (2) forward pressure level, (3) time-domain ear-canal reflectance, and (4) cochlear reflectance. These four related measures are similar to absorbance in their utilization of wideband stimuli and their focus on recording ear-canal sound pressure. The related measures differ from absorbance in how the ear-canal pressure is analyzed and in the type of information that is extracted from the recorded response. Sound intensity level and forward pressure level have both been shown to be better as measures of sound level in the ear canal compared with sound pressure level because they reduced calibration errors due to standing waves in studies of behavioral thresholds and otoacoustic emissions. Time-domain ear-canal reflectance may be used to estimate ear-canal geometry and may have the potential to assess middle ear pathology. Cochlear reflectance reveals information about the inner ear that is similar to what is provided by other types of otoacoustic emissions, and may have theoretical advantages that strengthen its interpretation. PMID:23900185
Neely, Stephen T; Stenfelt, Stefan; Schairer, Kim S
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.
Tympanometric evaluation is routinely used as part of the complete otological examination. During tympanometric examination, evaluation of middle ear pressure and ear canal volume is undertaken. Little is reported in relation to the accuracy and precision tympanometry evaluates external ear canal volume. This study examines the capability of the tympanometer to accurately evaluate external auditory canal volume in both simple and partially obstructed ear canal models and assesses its capability to be used in studies examining the effectiveness of cerumolytics. An ear canal model was designed using simple laboratory equipment, including a 5 ml calibrated clinical syringe (Becton Dickinson, Spain). The ear canal model was attached to the sensing probe of a Kamplex tympanometer (Interacoustics, Denmark). Three basic trials were undertaken: evaluation of the tympanometer in simple canal volume measurement, evaluation of the tympanometer in assessing canal volume with partial canal occlusion at different positions within the model, and evaluation of the tympanometer in assessing canal volume with varying degrees of canal occlusion. 1,290 individual test scenarios were completed over the three arms of the study. At volumes of 1.4 cm(3) or below, a perfect relationship was noted between the actual and tympanometric volumes in the simple model (Spearman's ? = 1) with weakening degrees of agreement with increasing volume of the canal. Bland-Altman plotting confirmed the accuracy of this agreement. In the wax substitute models, tympanometry was observed to have a close relationship (Spearman's ? > 0.99) with the actual volume present with worsening error above a volume of 1.4 cm(3). Bland-Altman plotting and precision calculations provided evidence of accuracy. Size and position of the wax substitute had no statistical effect on results [Wilcoxon rank-sum test (WRST) p > 0.99], nor did degree of partial obstruction (WRST p > 0.99). The Kamplex tympanometer accurately and precisely assesses ear canal volume in the scientific model in both simple and partially occluded wax substitute scenarios up to a volume of 1.4 cm(3). These findings suggest that the Kamplex tympanometer could be used as an effective objective tool in evaluating the efficacy of topical cerumolytics in both laboratory and human models. PMID:21387187
Hydrocele of the canal of Nuck (cyst of the canal of Nuck) is the female homologue of hydrocele of the spermatic cord in males and is a rarely encountered entity, mostly diagnosed on the operating table at the time of suspected inguinal hernia surgery, as the clinical presentation usually is subtle and inconclusive. Diagnosis is mainly by ultrasound and has shown varied presentation of the same over the years. We discuss the sonographic findings of a case of hydrocele of the canal of Nuck.
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.
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
FLOAT OPERATED RADIAL GATE INSTALLATION. WASTEWAY NO. 1. WELLTON-MOHAWK CANAL - STA. 99+23.50. United States Department of the Interior, Bureau of Reclamation; Gila Project, Arizona, Wellton-Mohawk Division. Drawing No. 50-D-2497, dated March 8, 1949, Denver Colorado. Sheet 1 of 7 - Wellton-Mohawk Irrigation System, Wasteway No. 1, Wellton-Mohawk Canal, North side of Wellton-Mohawk Canal, bounded by Gila River to North & the Union Pacific Railroad & Gila Mountains to south, Wellton, Yuma County, AZ
Most canals have either long travel times or insufficient in-canal storage to operate on-demand. Thus, most flow changes must be routed through the canal. Volume compensation has been proposed as a method for easily applying feedforward control to irrigation canals. SacMan (Software for Automated Ca...
The complex configuration of C-shaped canals in mandibular second molars make root canal treatment unusually difficult. The present case highlights their unpredictable canal anatomy and describes the use of two pluggers simultaneously to downpack the main canals. The effect of such a modification on the high-flow characteristics of thermosoftened gutta-percha in vertical condensation is discussed. PMID:11199771
ITRODUCTION: Knowledge of the internal dental morphology is a complex and extremely important point for planning and performing of endodontic treatment. CASE REPORT: The subject of this study was a clinical case of a second maxillary molar with five root canals - one canal in the palatal root, one canal in the distobuccal root and three canals in mesiobuccal root.
Dehiscences of the bony horizontal segment of the facial canal are rather common in human adults. These facial canal dehiscences occur most offen in the region of the oval window. This study presents the observations of the facial canal in the oval window region in 427 operations for otosclerosis. The incidence of dehiscences in the facial canal to the middle
Short-time sound effects such as the boom generated by supersonic aircraft or the burst emanating from weapons cause the tympanum to deform. In the case of too strong sound intensities, lesions of the tympanum may appear. In order to gain insight into the phenomena leading to lesions, the deformations of the tympanum were investigated at different instants after the arrival
P. Smigielski; F. Albe; H. Fagot; A. Dancer; R. Franke
Evaluation of the tympanic bulla (TB) in cases of otitis media in the rabbit can be a diagnostic challenge, although a feature often associated with the condition is the accumulation of fluid or material within the TB. Randomly selected TB from 40 rabbit cadavers were filled with a water-based, water-soluble jelly lubricant. A dorsoventral radiograph and single computed tomography (CT) slice were taken followed by an ultrasound (US) examination. Image interpretation was performed by blinded operators. The content of each TB was determined (fluid or gas) using each technique and the cadavers were frozen and sectioned for confirmation. CT was the most accurate diagnostic method, but US produced better results than radiography. Given the advantages of US over the other imaging techniques, the results suggest that further work is warranted to determine US applications in the evaluation of the rabbit TB and clinical cases of otitis media in this species. PMID:22425310
Different methods and automated devices have been developed to accomplish the enlarging and debriding of root canals. The occurrence of undesired effects on the root canal walls was compared in vitro between a theoretically ideally shaped canal and the Canal Leader, Canal Finder, 3000 Endo Sonic Air, Cavi Endo 25, Enac System, Piezon Master 400 and the Canal Master. Clear casting resin models were used for this purpose. A photographic double exposure was used to superimpose the images of the original canals on the enlarged canals, thus enabling measurement of the material removed. Measurements were made at six different points. Significance was defined at the 5% level (P = 0.05). All instruments and/or devices, with the exception of the Cavi Endo 25, enlarged the convex side of the canals significantly greater at level 1 in comparison to the ideal. On the concave side, significantly smaller differences were found between the ideal and the results of all the enlarging devices, with the exception of the Canal Master. On the convex side at level 2, the Canal Leader, Canal Finder, Cavi Endo, Enac System and Endo Sonic Air showed no statistical differences between ideal and effective material removal. The Piezon Master showed significantly lower material removal in comparison to the ideal. The Canal Master demonstrated statistically higher differences when compared with the ideal.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8406968
Briseño Marroquin, B; Sobarzo-Navarro, V; Devens, S
150. Credit ER. Building reinforced concrete portion of Coleman Canal inverted siphon #2. Longitudinal steel reinforcing rods are visible at bottom. (ER, v. 64 1911 p. 702). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA
A persistent external carotid-vertebrobasilar anastomosis, associated with intracranial aneurysms, was identified. The anomalous\\u000a vessel passed through the hypoglossal canal, and was possibly a variant of the persistent primitive hypoglossal artery.
M. Nakamura; S. Kobayashi; T. Yoshida; M. Kamagata; T. Sasaki
49. View of unlined canal near in-line stream gaging station, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA
32. Moving draw span from Ship Canal to University Heights Bridge. June 14, 1906 artist rendering - University Heights Bridge, Spanning Harlem River at 207th Street & West Harlem Road, New York, New York County, NY
9. FLUME BOX Y, LOOKING SOUTH. CANAL IN FOREGROUND FOLLOWS HILLSIDE INTO DRAINAGE; FLUME HEADING TO RIGHT CROSSED GULCH ON A TRESTLE. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO
Boolean networks are discrete dynamical systems in which the state (0 or 1) of each node is updated at each time t to a state determined by the states at time t-1 of those nodes that have links to it. When these systems are used to model genetic control, the case of canalizing update rules is of particular interest. A canalizing rule is one for which a node state at time t is determined by the state at time t-1 of a single one of its inputs when that inputting node is in its canalizing state. Previous work on the order-disorder transition in Boolean networks considered complex, nonrandom network topology. In the current paper we extend this previous work to account for canalizing behavior.
ObjectivesTo evaluate the efficacy of modifications to the standard canalith repositioning procedure (CRP) in the treatment of benign positional vertigo (BPV) of the horizontal semicircular canal (HSC).
...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Ohio Â§ 117.849 Muskingum River (Zanesville Canal). The draw of the Conrail bridge, mile 77.1 at Zanesville, shall...
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...
73. View of canal, gunite lined, with turnout gates. Photographer Mark Durben. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ
44. DETAIL OF WALL SHOWING 1914 CALENDAR (DEPICTING PANAMA CANAL), PATTERN FOR NARROW GAUGE RR WHEEL, AND AD-LOOKING SOUTHEAST. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA
Conclusions The use of walking excavators when excavating canals through swamped soils and weak supporting soils with the conduction of\\u000a preparatory work for the passage of the excavator is effective and economically advantageous.
Roots of the second mandibular molar often fuse so the purpose of this investigation was to examine the appearance of "C"-shaped root canals and to classify different root canal types. A hundred and twelve randomly chosen second lower permanent molars-after extraction due to periodontal disease-were prepared and then analysed. Contrast liquid (methylene blue) was injected into prepared teeth. Each tooth was cut into slices to view the root canal morphology. Results of the analysis revealed fusion, either total or partial in 14 cases (12.5%). As a conclusion various appearances were classified into 5 types according to the fused canal shapes and the frequency of different types varied from 0.89%-6.25%. PMID:10097434
...REGULATIONS Specific Requirements New York Â§ 117.769 Black Rock Canal...in advance of a vessel's intended time of passage through the draws...four hours in advance of a vessel's time of intended passage through the...
West Branch Pennsylvania Canal, Lock No. 34 Lock Keeper's House, South of State Route 664 along North bank of West Branch of Susquehanna River, 2,000 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA
12. CANAL SLUICE GATE LOCATED 150' WEST OF POWER PLANT. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV
6. VIEW OF POWER PLANT BUILDING LOOKING NORTHWEST. DRY CANAL BED TO THE LEFT. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV
33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01...Section 117.159 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...REGULATIONS Specific Requirements California Â§ 117.159 Grant Line Canal....
3. General view, looking west towards lined canal. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA
The basic question presented is the future military presence in the Panama Canal Zone. Data was gathered from numerous sources. Background material was obtained from current publications as well as reference books. Due to the current nature of the questio...
The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.
Moreira Junior, Gil; Ribeiro Sobrinho, Antonio Paulino; Bambirra, Bernardo Henrique Silva; Bambirra, Felipe Henrique Silva; Carvalho, Maria Auxiliadora Roque; Farias, Luiz Macedo; Nicoli, Jacques Robert; Moreira, Elizabeth Spangler
35. FUEL HANDLING BUILDING, INTERIOR LOOKING SOUTHEAST SHOWING TRANSFER CANAL AREA, DEEP STORAGE AREA, FUEL STORAGE PIT (LOCATION BB) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA
1. WEST FRONT OF HYDROELECTRIC POWERHOUSE WITH INTAKE STRUCTURE, CANAL SPILLWAY AT LEFT CENTER, VIEW EAST - Dayville Mills Hydroelectric Facility, Powerhouse, North side of Route 101, .5 mile west of Route 395, Killingly Center, Windham County, CT
Context view, looking southwest along the Wellton-Mohawk Canal. The wasteway is marked by the white posts on either side of the access road. The pipe across the canal safely carries storm runoff over the canal and is not part of Wasteway No. 1 - Wellton-Mohawk Irrigation System, Wasteway No. 1, Wellton-Mohawk Canal, North side of Wellton-Mohawk Canal, bounded by Gila River to North & the Union Pacific Railroad & Gila Mountains to south, Wellton, Yuma County, AZ
Purpose There is scant and conflicting literature regarding bony canals of the clivus. To date, only osteological observations of\\u000a dry skulls have been made of such structures and multiple hypotheses exist regarding the etiology of these entities and whether\\u000a or not they represent normal variations or pathology. The present study was performed to elucidate, specifically, clival canals\\u000a of the occipital portion
R. Shane Tubbs; Christoph J. Griessenauer; Marios Loukas; Anna Zurada; Mohammadali M. Shoja; Aaron A. Cohen-Gadol
20. VIEW OF NORTH AND EAST ELEVATIONS. HERE, THE CANAL HAS BEEN DRAINED, ALLOWING A RARE VIEW OF THE HEADGATES. THE MILL'S NORTH BASEMENT WALL WAS CLOSED UP WITH CINDER BLOCK AFTER A STORM BROUGHT WATER POWER TO AN END IN 1970. Photographer: Louise Taft Cawood, July 1986 - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH
18. Photo copy of historic photograph, December, 1925. Canal Bridge - Shannock Mill, Photograph No. 60010. View southeast on Main Street towards Shannock Mill Canal Bridge, Carpenter's Shop, 1707 Main Street on the east(left), Clark's Hall, Main Street, to the west (right), and Commercial-Tenement Block, 1660 Main Street, to the west (right). Hussey Photograph Collection. Rhode Island State Archives, Providence, Rhode Island - Shannock Village, Main Street, North Shannock Road, & West Shannock Road, Richmond (historical), Providence County, RI
The hydrocele of the canal of Nuck is quite a rare condition and results from the failure of obliteration of the distal portion of evaginated parietal peritoneum within the inguinal canal which forms a sac containing fluid. It generally presents with painless inguinal swelling. Ultrasonography and MRI is plays an important role to differentiate from the other conditions presenting with inguinal swelling. We present the imaging findings of a case in 5-year-old girl.
Mucoepidermoid carcinoma in the external auditory canal is extremely rare. Strategies used for treatment of mucoepidermoid carcinoma remain controversial. We present a case of mucoepidermoid carcinoma of the external auditory canal. The patient underwent lateral temporal bone resection and the surgical defect was obliterated with temporal muscle. He is currently disease-free, four years after surgery. Proper diagnostic measures and strategy for treatment of mucoepidermoid carcinoma are discussed. PMID:23341793
Mucoepidermoid carcinoma in the external auditory canal is extremely rare. Strategies used for treatment of mucoepidermoid carcinoma remain controversial. We present a case of mucoepidermoid carcinoma of the external auditory canal. The patient underwent lateral temporal bone resection and the surgical defect was obliterated with temporal muscle. He is currently disease-free, four years after surgery. Proper diagnostic measures and strategy for treatment of mucoepidermoid carcinoma are discussed.
Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO
Childbirth is complicated in humans relative to other primates. Unlike the situation in great apes, human neonates are about the same size as the birth canal, making passage difficult. The birth mechanism (the series of rotations that the neonate must undergo to successfully negotiate its mother's birth canal) distinguishes humans not only from great apes, but also from lesser apes and monkeys. Tracing the evolution of human childbirth is difficult, because the pelvic skeleton, which forms the margins of the birth canal, tends to survive poorly in the fossil record. Only 3 female individuals preserve fairly complete birth canals, and they all date to earlier phases of human evolution. Here we present a virtual reconstruction of a female Neandertal pelvis from Tabun, Israel. The size of Tabun's reconstructed birth canal indicates that childbirth was about as difficult in Neandertals as in present-day humans, but the canal's shape indicates that Neandertals had a more primitive birth mechanism. A significant shift in childbirth apparently occurred quite late in human evolution, during the last few hundred thousand years. Such a late shift underscores the uniqueness of human childbirth and the divergent evolutionary trajectories of Neandertals and the lineage leading to present-day humans.
In this study, a comparison of the sealing properties of three different resin-based sealers, AH26, Diaket, and EndoREZ with those of the root canal sealer zinc oxide-eugenol-based U/P Root Canal Sealer was performed. Eighty extracted single-rooted human mandibular first premolar teeth were used. The coronal part of each tooth was removed at the apical 17-mm of roots. The root canals were prepared to a size 7 with ProFile 0.06 taper Series 29 rotary instruments in a crown-down manner before lateral condensation of gutta-percha with the tested sealers (n = 20). A fluid filtration method was used for quantitative evaluation of apical leakage. Statistical analysis revealed that there were no significant differences between the resin-based sealers groups (AH26, Diaket, and EndoREZ) (p > 0.05). U/P Root Canal Sealer, zinc oxide-eugenol-based sealer, leaked significantly more than other tested groups (p < 0.05). Under the limitations of this study, resin-based root canal sealers were found more effective in sealing root canals than the zinc oxide-eugenol-based sealer. PMID:16206202
Horizontal-canal paroxysmal positional vertigo (HC-PPV) is a vestibular syndrome due to canalolithiasis of the horizontal canal. The more common posterior-canal paroxysmal positional vertigo has a well defined and effective therapy, while there have been few reports on physical therapy for HC-PPV, and these have been tried in relatively few patients. We report the results of two different types of treatment of HC-PPV in 92 patients. A group of 21 untreated patients acted as a control group. One method, known as forced prolonged position (FPP), proposes liberating the affected canal by gravitation, and involves having the patient lie on the healthy side for many hours. The other method (the barbecue rotation) is a liberatory manoeuvre which proposes to expel the otoconia from the canal by rotating the patient 270 degrees around the longitudinal axis of the body in rapid steps of 90 degrees. FPP was successful in more than 70% of our patients; the barbecue rotation had slightly less successful but more immediate results. Both methods enable otoconial debris to migrate into the posterior canal. We suggest treating all patients with the two methods in succession. PMID:9726666
Destructive tsunamis in the eastern Mediterranean and Red seas, induced by earthquakes and/or volcanic activity, pose potential hazards to docked seaport shipping and fixed harbor infrastructure as well as to in-transit international shipping within the Suez Canal. Potential vulnerabilities of the Suez Canal to possible tsunami impacts are reviewed by reference to geological, historical, archaeoseismological, and anecdotal data. Tsunami catalogues and databases compiled by earlier researchers are perused to estimate potential return periods for tsunami events that could affect directly the Suez Canal and its closely associated operational infrastructures. Analysis of these various records indicates a centurial return period, or multiples thereof, for long-wave repetition that could generally affect the Nile Delta. It is estimated that tsunami waves 2 m high would have a breaking length about 5 km down Canal whereas a 10 m wave break would occur about 1 km into the Canal. Should a tsunami strike the eastern flanks of the Nile Delta, it would damage Egypt's maritime infrastructure and multi-national commercial vessels and military ships then using the Canal.
The anatomy of third molars has been described as unpredictable. However restorative, prosthetic, and orthodontic considerations often require endodontic treatment of third molars in order for them to be retained as functional components of the dental arch. The purpose of this study was to investigate and characterize the anatomy of maxillary and mandibular third molars. One hundred fifty maxillary and 150 mandibular extracted third molars were vacuum-injected with dye, decalcified, and made transparent. The anatomy of the root canal system was then recorded. Seventeen percent of mandibular molars had one root (40% of which contained two canals), 77% had two roots, 5% had three roots, and 1% had four roots. Teeth with two roots exhibited highly variable canal morphology, containing from one to six canals, including 2.2% that were "C-shaped." Fifteen percent of maxillary molars had one root, 32% had two roots, 45% had three roots, and 7% had four roots. Teeth with one root demonstrated the most unusual morphology, with the number of canals varying from one to six. An in vivo study of the canal morphology of treated third molars is suggested to provide the practitioner with an understanding of the clinical implications of third molar root anatomy. PMID:11469300
Sidow, S J; West, L A; Liewehr, F R; Loushine, R J
Background The knowledge of the root canal morphology and the possible anatomical variations of mandibular premolars are important for the successful endodontic treatment of such cases. The aim of this study was to investigate the presence of two or three root canals in extracted first and second mandibular premolars which were collected from health centers in Syria. Materials and Methods: One hundred and ten human mandibular premolars (70 first premolars and 40 second premolars) with fully developed roots were investigated. After access the cavity of the teeth, the root canals were explored and radiographs were taken. Results: Premolars with one canal were found in 87% of cases (53% first premolar and 34% second premolar) and premolars with two canals were found in 12% of cases (10% first premolar and 2% second premolar). There was just one case (1%) where a first premolar had three canals. These differences were statistically significant with P<0.05. Conclusion: Clinicians should be aware of the anatomical variation in the mandibular premolars and be able to apply this knowledge in radiographical and clinical interpretation.
Objective?The pharyngeal or palatovaginal canal (PC) is a small tunnel that lies between the sphenoid process of the palatine bone and the vaginal process of the sphenoid bone. Currently, little endoscopic information is available about this region. Design and Setting?Endoscopic endonasal cadaveric study. Subjects and Methods?Twenty sides in 10 adult cadaver heads were studied endoscopically. The sphenopalatine foramen (SPF) and the adjacent pterygopalatine fossa were exposed. Dissection medial to the vidian canal demonstrated a tunnel that runs posteromedially in the sphenoid floor. Endoscopic data were documented. Additionally, canal measurements were obtained on 20 sides from coronal CT scans of paranasal sinuses. Results?The PC was identifiable in 85% of the sides, although thickness of its bony wall was variable. The endoscopic relationship of the canal and its artery with other landmarks is described. Radiologically, the diameter of the PC averaged 1.7?mm, and the mean distance from the PC to the vidian canal was 3.78 mm. Conclusion?The current study provides a novel endoscopic identification of an overlooked canal. The pharyngeal artery can be a source of bleeding during extended endoscopic procedures. The PC itself could be a place for finger-like projections of anatomically related neoplasms.
Herzallah, Islam R.; Amin, Sameh; El-Hariri, Mona A.; Casiano, Roy R.
Cleaning and shaping of the root canal system is the most important aspect of successful endodontic therapy. The goal of endodontic cleaning procedures is to eliminate all pulp tissue, microorganisms, and irritating debris. Inadequate cleaning allows bact...
Objective/Hypothesis?Superior semicircular canal (Sup SC) dehiscence syndrome is a rare condition, causing a variety of auditory and vestibular symptoms. The traditional surgical management is a middle cranial fossa, extradural approach to resurface the Sup SC. Recently, a transmastoid approach for plugging of the Sup SC has been developed. We present further data supporting the use of the transmastoid approach in preference to the middle fossa approach. Design?This is a retrospective multi-institutional case series. Method?We included 10 patients in this case series from two tertiary otology institutions. Sup SC dehiscence was confirmed by correlation of clinical symptoms with positive audiometric, vestibular evoked myogenic potential, and computed tomography findings. A transmastoid approach was used for plugging of the Sup SC. Either a single fenestration was created at the site of dehiscence or separate fenestrations sited ampullopetal and ampullofugal to the dehiscence. Results?All patients who underwent this procedure had good symptom control and hearing preservation postoperatively. Conclusion?In patients with adequate temporal bone pneumatization, the transmastoid approach provides a safe and effective alternative to the middle cranial fossa approach. This series has demonstrated excellent symptom control and preservation of hearing with the transmastoid approach. PMID:23904997
Zhao, Yi Chen; Somers, Thomas; van Dinther, Joost; Vanspauwen, Robby; Husseman, Jacob; Briggs, Robert
A large portion of the seismic noise spectrum is dominated by water wave energy coupled into the solid Earth. Distinct mechanisms of water wave induced ground motions are distinguished by their spectral content. For example, cultural noise is generally <1 s period, microseisms dominate the seismic spectrum from periods of 2 to 20 s, and the Earth's "hum" is in the range of 50 to 600 s. We show that in a large lake in the Panama Canal there is an additional source of long-period noise generated by standing water waves, seiches, induced by disturbances such as passing ships and wind pressure. We compare seismic waveforms to water level records and relate these observations to changes in local tilt and gravity due to an oscillating seiche. The methods and observations discussed in this paper provide a first step toward quantifying the impact of water inundation as recorded by seismometers. This type of quantified understanding of water inundation will help in future estimates of similar phenomena such as the seismic observations of tsunami impact. Copyright 2011 by the American Geophysical Union.
McNamara, D. E.; Ringler, A. T.; Hutt, C. R.; Gee, L. S.
OBJECTIVES: The identification and definition of the radiological patterns of the posterior semicircular canal (PSC), with a view to obtain readily applicable conclusions. DESIGN: The parietal morphology of the PSC has been studied by multi-slice helical computed tomography (Philips Brilliance 6). We have determined the distribution of the different types of bone cover of the PSC, taking some previously notified, standardised measurements of normality as reference. RESULTS: 318 patients have been analysed (604 petrous bone) by CT and we have distinguished five different radiological patterns: type or normal, thick, thin, pneumatised and dehiscent. The first three patterns, normal, thick and thin, have in common the existence of a compact bone interposed between PSC and posterior fossa, being in the normal pattern has a thickness of between 0.9 and 2.5 mm (327 cases, 54.13 %), in the thick pattern is ?2.6 mm (99 cases, 16.39 %) and in the thin pattern is ?1.2 mm (158 cases, 26.15 %). The fourth pattern, pneumatised, is characterised by having retro labyrinthine cells between PSC and media fossa (19 cases, 3.14 %). Finally, a dehiscent pattern was observed in 2 cases (0.3 %). CONCLUSION: We describe five different radiological patterns: type or normal, thick, thin, pneumatised and dehiscent. The thin type (<0.5 mm or papyraceous type) and the dehiscent type would be subject to producing pathology, and in some cases the latter could be a consequence of the former. PMID:23783370
Cisneros, Ana Isabel; Whyte, Jaime; Martínez, Claudio; Gracia-Tello, Borja; Whyte, Ana; Obón, Jesús; Crovetto, Rafael; Crovetto, Miguel Angel
The effect of pollution on the phytoplankton in the Ashar Canal was studied during March and June 1976. Higher temperatures were recorded in June. The canal water was more turbid than that of the adjoining Shatt al-Arab estuary due to high algal populations and sewage disposal. The chlorosity values were remarkably high in the canal, due to sewage disposal. The
A total of 139 extracted mandibular second molars were injected with India ink and demineralized. They were made clear and transparent with methyl salicylate, and the anatomy of their canals was studied. It was found that 86.3% of mandibular second molars had two roots, 9.3% had one root, and 4.3% had three roots. Ninety percent of the mesial roots of the mandibular second molars with two roots had two canals (predominantly with a type II or III configuration), and 77.5% of the distal roots of these teeth had one canal (predominantly with a type I configuration). Among the mandibular second molars, 7.2% had C-shaped canals and these configurations were seen mostly in single-rooted mandibular second molars. The results of this study indicate that mandibular second molar teeth have many variations in the number of roots and the morphology of their canals. Therefore it should not be assumed that all mandibular second molar teeth have two roots and three canals. PMID:18403877
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. 10 figs.
6. The cross section of the canal m can be apprDximated by a generalized parabolic relation ~ = Ah x, where m = 1.0 for a rectangular canal, m = 1.5 for a parabolic canal, and m = 2 for a triangular canal . For a trapezoidal canal m = 1.0 + [~'\\/(m + m')], where m, m' is the
In 2003, studies revealed that the waters in the lower reaches of Hood Canal in Washington State had very low dissolved-oxygen concentrations, low enough to cause some fish kills between June and October of that year. In order to determine the transport patterns and the persistence of the low oxygen level in this portion of the canal, the U. S. Geological Survey deployed two instrumented platforms on the seabed near the head of the canal that measured currents over the whole water column, water level, near-bed temperature, salinity and oxygen for 2 months in the fall of 2004. Tidal currents, the dominant current component in the canal, flowed primarily along the canal axis and had speeds of 15-20 cm/s. There was also a persistent internal seiche that caused currents to flow along the canal axis with speeds of a few cm/s. The seiche, which had a period of a few days, caused currents in the surface layer to flow in an opposite direction to currents in water depths deeper than 15 m. A pool of warmer, saltier and more oxygenated water moved past the measurement sites toward the head of the canal with a speed of 1 cm/s. CTD measurements taken near the 2 measurement sites during the deployment indicated that this more oxygenated layer of water extended from the bed to the thermocline. Oxygen data from the tripods showed that this water remained in the region until at least the end of October 2004, when the tripods were recovered.
Noble, Marlene A.; Gartner, Anne L.; Paulson, Anthony J.; Xu, Jingping; Josberger, Edward G.; Curran, Christopher
This project involved the conversion of a British Waterways maintenance craft to a canal boat, powered by a combination of a solid-state hydrogen store, Proton Exchange Membrane (PEM) fuel cell, lead-acid battery pack and a high-efficiency, permanent magnet (NdFeB) electric motor. These replaced the conventional diesel engine thus eliminating water, noise, local and general atmospheric pollution. The "Protium" project applies modern technologies to a traditional mode of transportation. The TiMn2-based metal hydride store exhibited excellent performance as an effective means of storing 4 kg of hydrogen with a suitable desorption flow rate and temperature adequate for the operation of a 1 kW PEM fuel cell in a water-based environment. PMID:22455080
The dynamic concept of the root canal system, which describes a variable morphology of the multiple root canals which are inter-connected by anastomoses, has been established as the prevailing state in the mandibular molars. The aim of this case report was to describe the unusual root canal anatomy that was detected in the mandibular first molar during the routine endodontic treatment. The clinical and the radiographic examinations allowed the detection of the middle mesial root canal between the mesiobuccal and the mesiolingual root canals. This report highlights the importance of such examinations and the need to find and treat the additional canals, to