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Diabetic Retinopathy is a medical disorder in which diabetes mellitus causes damage to the retina. Diabetic Retinopathy is diagnosed using coloured fundus pictures, which requires trained clinicians to recognise the presence and importance of several tiny characteristics, making it a time-consuming task. We present a CNN-based technique to detect Diabetic Retinopathy in fundus pictures in this research. A new segmentation strategy using Gabor filters is employed to prepare the data used to train the model. Data augmentation is used to gather enough data to train the model due to the short dataset. Intricate characteristics in fundus images are detected by our segmentation model, which also detects the presence of DR. The model is efficiently trained using a high-end Graphics Processor Unit (GPU). Keywords: Augmentation, Segmentation, CNN

Aims: In this study we are evaluating the outcome in management of distal radius fracture by closed reduction and percutaneous 5 k-wire fixation in both young and elderly patients in most types of distal radius fracture types where closed reduction is possible and where ulna is intact or reconstruct able.Material and Methods: A total of 50 patients with distal end radius fractures associated with or without other fracture were treated in in the department of Orthopaedics at all hospitals attached to SMS Medical College & Hospital, Jaipur. The patients were treated with closed reduction and 5 k-wire (1.8mm) fixation under anaesthesia. Clinical scoring system of green and o’brein modified by Cooney and Sarmiento’s modification of Lindstorm criteria was recorded.Results: The most commonly encountered complications were superficial pin tract infection (25.5%) and extensor tendon tethering (6.4%) which were less serious complications and resolved completely on removal of k –wires. Cooney modification of Green and O‘ Brien‘s score was showed higher excellent case (84%) than good (10%) and fair (6%)Conclusion: According to our study perfect closed reduction and five k-wire fixation technique is a versatile tool which provides functional outcomes better than conventional k-wire fixation and volar plating in distal end radius fractures.

Cyber-crimes are growing rapidly and to prevent these crimes one should share all the knowledge he/she has to make people aware of these attacks. In the field of Application Security there is a very well-known vulnerability ―SQL INJECTION‖. In this paper, we have focused on what are the type of SQL Injection attacks and where it can be found in any application.

Background: The fracture of distal femur are often unstable and comminuted and as difficult to treat. The incidence of complications in these fracture are relatively high .The purpose of our study was aimed to compare functional outcome between both column fixations by using distal femoral locking compression pate on lateral side and then using TENS nail on medial side to obtain support of medial column versus lateral distal femoral plate.Methods: We have included 80 patients with distal femur fracture with intercondylar extension in our study. We have treated 40 patients with distal femoral locking compression plate and support of medial wall with TENS nail and 40 patients with distal femoral locking compression plate. There were sixty six males and fourteen females. The average age of the patients was 39.08 ± 11.95 years. All the patients were operated between 3 to 9 days. All patients were followed up at 2th, 6th, 10th weeks, 3 month and 6 month regularly and evaluated for fracture healing, Clinical union was defined as a painless fracture site during full weight bearing. Radiological union was defined as bridging trabeculation across the fracture site on three of four cortices. The final outcome was assessed according to schatzker and Lambert scoring system.Results: The result was excellent in twelve, good in fifteen, fair in ten and poor in one in DFLCP with TENS nail group according to schatzker and Lambert scoring system. The result was excellent in eight, good in twelve, fair in twelve and poor in five in DFLCP group according to schatzker and Lambert scoring system. The average time to Union was 17.7 weeks in DFLCP with TENS nail group and 19.9 weeks in DFLCP group. Complications include superficial wound infection in three patients, secondary osteoarthritis in 17 patients and varus angulation in three patients in DFLCP with TENS nail group. In DFLCP group varus angulation was in eleven patients.Conclusions: The use of TENS nail for medial femoral defect along with distal femoral locking compression plate may eliminate the need of plate on medial side. The varus angulation that occurs with defect is decreased and additional long incision and operative time is avoided.

Objective: The purpose of our study is to describe our experience with the non-vascularised fibular autogenous grafts that was used for the treatment of nonunion of long bones including tibia, femur & humerus and to analyse and compare the results in terms of postoperative wound infection, radiographic evidence of union, postoperative pain and functional disability, success rate of procedure etc. with conventional iliac crest bone grafting and plating, at a tertiary care centre.Methods: The study was conducted in department of Orthopedics SMSMC, Jaipur from September 2017 to June 2019 and included 80 cases of nonunion of long bone. Amongst these, 40 cases were treated with fibular strut grafting and 40 cases were treated with iliac crest bone grafting, and all cases were followed postoperatively to compare the results in terms of demographic parameters, union time, postop complications.Result: Amongst 32 cases of nonunion of long bones treated with fibular strut 31 cases (96.9%) showed complete union in mean time interval of 17.77 weeks while only 29 (85.3 %) amongst 34 cases treated with iliac crest bone graft showed union in mean time of 18.41 weeks.Graft site pain was noted in 20.6% cases of iliac crest graft while no cases of fibular strut graft had this problem; EHL weakness was noted in 34.4% of cases and all of them recovered fully at the end of follow up.Conclusion: According to our study fibular strut is a better option in treatment of nonunion long bones as maximum cases showed complete union in less time interval and with very few postoperative complications than iliac crest bone grafting.

Background: To analyse the effect of endometrial scratching on pregnancy rates in previously failed IUI cycles Methods: Randomized control study conducted on Couples attending the Infertility Clinic, Obstetrics & Gynaecology Department, SMS Medical College, Jaipur and requiring repeat IUI were recruited for the study from Feb 2019 to November 2020. Results: women in which IUI failed two times positive results after scratching was present in 16.15% cases followed by 6.92% positive results in women who had three times IUI failed and women who had only one-time IUI failed positive results was present in 4.62% cases. In controls we found positive results with 5.38% in women having one-time IUI failed followed by 3.85% in women where two time IUI failed and only in 2.31% women positive results found having three time IUI failed. Conclusion: In conclusion this study demonstrates 2.5-3 fold increase in pregnancy rates after scratch, endometrial scratching can be a preferred option in patients with previous failed IUI cycles before opting for expensive IVF treatment. Keywords: IUI, IVF, Inferetility

Background: Methods: The present study is a single arm interventional study done at a tertiary care hospital in a metropolitan city. The study participants were the females who had infertility due to PCOS and resistant to clomiphene citrate, and participants were given HMG in a sequential manner with Clomiphene citrate and ovulation was observed using the TVS. Results: 79% of the study participants ovulated at the end of the study as a final outcome and only 25 participants who constitute 21% of the total had not ovulated. No cases of ovarian hyperstimulation and multiple gestation was reported. Conclusion: The study thus concludes that CC with low dose HMG is an efficient and safe method for induction of ovulation in females with CC resistant PCOS related infertility without the dangers of OHSS and other adverse events, also the presence of normal BMI can help in a better rate of ovulation Keywords: HMG, TVS, Infertility

The auditory system uses interaural time- and level differences (ITD and ILD) as cues to localize and lateralize sounds. The availability of ITDs and ILDs in the auditory system is limited by neural phase-locking and by the head size, respectively. Although the frequency-specific limitations are well known, the relative contribution of ITDs and ILDs in individual frequency bands in broad-band stimuli are unknown. To determine these relative contributions, or spectral weights, listeners were asked to judge the lateralization of stimuli consisting of eleven simultaneously presented 1-ERB-wide noise bands centered between 442 Hz and 5544 Hz and separated by 1-ERB-wide gaps. Interaural disparities were applied to each noise band and were roved independently on every trial. The weights were obtained using a multiple linear regression analysis. In a second experiment the effect of temporal context on the spectral weights was investigated. Ten of the noise bands were used as pre- and postcursors and listeners were asked to lateralize the stimuli. Results show that only the lowest- or highest frequency band received highest weight for ITD and ILD, respectively. Temporal context led to significantly enhanced weights given to the band without the pre- and postcursor. The weight enhancement could only be observed at low frequencies, when determined with ITD cues and for low and high frequencies for ILDs. Hence, the auditory system seems to be able to change the spectral weighting of binaural information depending on the information content.PACS43.64.-q · 43.64.+r · 87.19.lt · 43.66.-x · 43.66.+y · 43.64.Bt

Background: Untreated Perthes disease can lead to osteoarthritis by the fourth decade. The treatment is conservative for children 10 years of age at presentation. All patients had limitation of abduction and internal rotation. Eight patients (53.33%) had pain at the hip and 12 patients (80%) had limp. Mean time between diagnosis and corrective surgery was 3 weeks. Results: The evaluation was done using caput index (CI) and epiphyseal quotient (EQ) and articulotrochanteric distance radiologically, range of motion and Harris Hip Score for clinical outcome. All the measurements were carried out on pre- and postoperative X-rays after 3 years followup and compared with the contralateral normal hip. After a mean followup period of 3.4 years, we noted the statistically significant difference between pre- and postoperative values. We noted that all (100%) children in Stage IB, IIA and 50% children in Stage IIB achieved satisfactory results. There was a significant change (P = 0.000) in CI among all the patients after surgery. The final EQ after 3 years of VDRO was 0.606 and was significant (P = 0.0000). Conclusion: In our opinion, based on the encouraging short term radiological and clinical outcomes, VDRO may be regarded as a treatment procedure for late presenting Perthes disease in stage IB, IIA, IIB.

BACKGROUND: Simultaneous traumatic dislocation of both the hips in an individual is an uncommon injury. It accounts for only 1–2% of all traumatic hip dislocations. Simultaneous traumatic dislocation of both the hips in opposite directions i.e., anterior dislocation of one hip and posterior of the other is even rarer. These asymmetric dislocations need prompt identification for appropriate management. While their management should proceed in a manner commensurate with the accepted management of isolated dislocations to avoid complications, it is the timely identification which is essential. STUDY DETAILS: Retrospectively the details of three patients with asymmetric bilateral hip dislocations were collected. The article describes the clinical presentation of each patient and the management offered to them. The follow up duration ranged from 15 months to 24 months. RESULTS: In the short term, the outcomes in terms of hip pain, movements at the hips and radiological parameters like absence of arthritic or avascular changes were found to be satisfactory in each patient. CONCLUSION: Early diagnosis and prompt reduction is the essential first step in the appropriate management of these patients to prevent the possible complications. The associated fractures must be managed as per the established principles of trauma care. Long term follow up is essential for identifying if complications like avascular necrosis and secondary osteoarthritis develop after this uncommon injury.

Purpose Tibial fracture is the most common long bone fracture. Distal third tibial fractures are challenging though open reduction and plating can result in anatomical reduction and rigid fixation. This paper aimed to evaluate and compare the results of medial and lateral locking compression plates for distal third tibial fractures. Methods This prospective clinical study involved 36 patients with distal tibial fractures admitted in Department of Orthopaedics, Sawai Mansingh Medical College & Affiliated Hospital, Jaipur, India, from June 2011 to May 2012, including 29 closed fractures and 7 open fractures at the mean age of 38.9 years. Thirty-six patients were divided equally into two groups based on treatment method, including medial plating group (18 patients) and lateral plating group (18 patients). They were followed up for at least 5 months after discharge. The functional outcomes were evaluated using Tenny and Wiss clinical assessment criteria. Results Malunion was found in 3 cases of medial plating group and in 1 case of lateral plating group. In the medial plating group, there were 5 cases of superficial infections, 1 deep infection, 1 nonunion and 3 wound dehiscence. In the lateral plating group, there was 1 case of superficial infections, 1 deep infection and 1 nonunion. In the lateral plating group, 4 patients reported feeling the plates and screws but none of them asked to remove the hardware. In the medial plating group, 9 patients reported symptomatic hardware problems and 7 asked to remove the hardware. The number of cases graded as excellent/good/fair was 1/8/7 in the medial plating group and 3/7/7 in the lateral plating group respectively. In the medial plating group, the final range of motion was 17.2° in ankle dorsiflexion and 30.7° in ankle plantar flexion. In the lateral plating group, the final range of motion was 19° in ankle dorsiflexion and 34.2° in ankle plantar flexion. Conclusion Lateral plating of distal tibia is safe and feasible, which can provide biological fixation and prevent the soft tissue complications associated with medial plating.

Background Tibia fracture is the most common long bone fracture. The fractures of tibia are commonly open fractures due to subcutaneous position of the tibia. The choice of technique for stabilization of open tibia fractures includes - External fixation, unreamed intra-medullary nails [URTN], Reamed intra-medullary nails, ORIF with Plating. Objectives To evaluate & compare the results of Unreamed Intra-Medullary Nail Versus Half Pin External Fixator in Grade III [A & B] Open tibia fractures. Methods This prospective clinical study [Randomized chit box] was done on 50 patients presenting to our institute within 24 h of injury. Only those who were skeletally mature with open tibia fracture Grade IIIA & IIIB [Gustilo-Anderson] were included in this study. After initial management, radiological assessment was done. Following this adequate wound debridement, skeletal stabilization with either primary URTN or external fixator was done. Inspection and debridement were repeated at 48-h intervals until the wound was considered clean. Results 50 cases [25 each group] were compared in terms of - Final Alignment of the Fracture, Presence of Infection/Non-union/Mal-union, Hardware failure, Time to Bone Union, Number of Operative Procedures after index admission. Mean time to full weight bearing was 20.96 weeks in URTN group versus 24.8 weeks in Ex-fix group. 5 in URTN group required further surgery for non-union versus 11 patients in Ex-fix group. There were 6 significant pin track infection. Removal of nail was required in 1 case of deep infection. Conclusion This study supports the use of the URTN over External fixator in the treatment of severe open tibia fractures.

The loudness of broadband sound is often modeled as a linear sum of specific loudness across frequency bands. In contrast, recent studies using molecular psychophysical methods suggest that low and high frequency components contribute more to the overall loudness than mid frequencies. In a series of experiments, the contribution of individual components to the overall loudness of a tone complex was assessed using the molecular psychophysical method as well as a loudness matching task. The stimuli were two spectrally overlapping ten-tone complexes with two equivalent rectangular bandwidth spacing between the tones, making it possible to separate effects of relative and absolute frequency. The lowest frequency components of the “low-frequency” and the “high-frequency” complexes were 208 and 808 Hz, respectively. Perceptual-weights data showed emphasis on lowest and highest frequencies of both the complexes, suggesting spectral-edge related effects. Loudness matching data in the same listeners confirmed the greater contribution of low and high frequency components to the overall loudness of the ten-tone complexes. Masked detection thresholds of the individual components within the tone complex were not correlated with perceptual weights. The results show that perceptual weights provide reliable behavioral correlates of relative contributions of the individual frequency components to overall loudness of broadband sounds.

Different computational models have been developed to study the interaural time difference (ITD) perception. However, only few have used a physiologically inspired architecture to study ITD discrimination. Furthermore, they do not include aspects of hearing impairment. In this work, a framework was developed to predict ITD thresholds in listeners with normal and impaired hearing. It combines the physiologically inspired model of the auditory periphery proposed by Zilany, Bruce, Nelson, and Carney [(2009). J. Acoust. Soc. Am. 126(5), 2390–2412] as a front end with a coincidence detection stage and a neurometric decision device as a back end. It was validated by comparing its predictions against behavioral data for narrowband stimuli from literature. The framework is able to model ITD discrimination of normal-hearing and hearing-impaired listeners at a group level. Additionally, it was used to explore the effect of different proportions of outer- and inner-hair cell impairment on ITD discrimination. ispartof: JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA vol:144 issue:2 pages:940-954 ispartof: location:United States status: Published online

The sense of taste allows animals to sample chemicals in the environment prior to ingestion. Of the five basic tastes, sour, the taste of acids, had remained among the most mysterious. Acids are detected by Type III taste receptor cells (TRCs), located in taste buds across the tongue and palate epithelium. The first step in sour taste transduction is believed to be entry of protons into the cell cytosol, which leads to cytosolic acidification and the generation of action potentials. The proton-selective ion channel Otop1 is expressed in Type III TRCs and is a candidate sour receptor. Here, we tested the contribution of Otop1 to taste cell and gustatory nerve responses to acids in mice in which Otop1 was genetically inactivated (Otop1-KO). We first show that Otop1 is required for the inward proton current in Type III TRCs from different parts of the tongue that are otherwise molecularly heterogeneous. We next show that in Type III TRCs from Otop1-KO mice, intracellular pH does not track with extracellular pH and moderately acidic stimuli do not elicit trains of action potentials, as they do in Type III TRCs from wildtype mice. Moreover, gustatory nerve responses in Otop1-KO mice were severely and selectively attenuated for acidic stimuli, including citric acid and HCl. These results establish that the Otop1 proton channel plays an important role in acid detection in the context of the mouse gustatory system, evidence that it is a bona fide sour taste receptor.

A computational model of cat auditory nerve fiber (ANF) responses to electrical stimulation is presented. The model assumes that (1) there exist at least two sites of spike generation along the ANF and (2) both an anodic (positive) and a cathodic (negative) charge in isolation can evoke a spike. A single ANF is modeled as a network of two exponential integrate-and-fire point-neuron models, referred to as peripheral and central axons of the ANF. The peripheral axon is excited by the cathodic charge, inhibited by the anodic charge, and exhibits longer spike latencies than the central axon; the central axon is excited by the anodic charge, inhibited by the cathodic charge, and exhibits shorter spike latencies than the peripheral axon. The model also includes subthreshold and suprathreshold adaptive feedback loops which continuously modify the membrane potential and can account for effects of facilitation, accommodation, refractoriness, and spike-rate adaptation in ANF. Although the model is parameterized using data for either single or paired pulse stimulation with monophasic rectangular pulses, it correctly predicts effects of various stimulus pulse shapes, stimulation pulse rates, and level on the neural response statistics. The model may serve as a framework to explore the effects of different stimulus parameters on psychophysical performance measured in cochlear implant listeners.

Acetic acid was used as a model compound for pyrolysis oil in a hydrodeoxygenation (HDO) study. HDO of acetic acid was performed in a packed bed microreactor. The catalyst was reduced sulfided NiMo/Al2O3. The effects of state of aggregation of acetic acid, temperature, hydrogen partial pressure, liquid flow rate, reactor diameter, and residence time on conversion, yield, space-time consumption, and space-time yield were investigated. External and internal mass transfer and heat transfer resistances were also examined in the microreactor. Temperature was a major factor in HDO of acetic acid. Many consider hydrodeoxygenation as an unattractive process due to high pressure requirements (1050–3000 psig). In this work, attempt has been made to show that HDO of acetic acid can be conducted at atmospheric pressure with a significant conversion achieved. More acetic acid was converted during HDO as temperature was increased at constant pressure of 300 psig. Conversion was much higher for vapor phase acetic acid at atmospheric pressure than liquid phase acetic acid. HDO of gas phase acetic acid in a blank reactor compared to a catalytic HDO showed that thermal decomposition of acetic acid did not occur appreciably. Partial pressure of hydrogen above 240 psig had no effect on the conversion of liquid phase acetic acid. Conversion of vapor phase acetic acid increased as the partial pressure of hydrogen increased from 3 psig to 15 psig. Residence time was 0.06 s for a maximum conversion of liquid phase acetic acid, whereas it was 0.03 s for a maximum conversion of vapor phase acetic acid. The conversion of acetic acid for both liquid and vapor phases decreases significantly as the flow rate of acetic acid increases. As reactor diameter increases beyond 0.8 mm, the conversion reduces significantly. Mass transfer resistance was negligible at the superficial velocity of 2.54 m/s and at an average catalyst particle size of 113 μm. Radial temperature difference in the microreactor was less than 5%.

At least two sites of spike generation are observed in the electrically stimulated auditory nerve, namely, the peripheral axon and the central axon. The peripheral axon responds to the cathodic charge and the central axon to the anodic charge with an approximate spike-latency difference of 200 μs. The peripheral axon also shows longer refractory periods than the central axon. In this study, a phenomenological model of the electrically stimulated auditory nerve described in Joshi et al. [JARO 18(2), pp. 323–342] was used to understand the effect of spike generation sites on the temporal coding. Modulation detection thresholds for different carrier pulse rates were predicted from simulated responses of the auditory nerve, and refractoriness of both the axons was varied to test its effect on temporal coding. The results show that an increase in pulse rate increased the number of spikes generated at the central axon, hence decreasing the modulation detection thresholds. Refractoriness also played a crucial ro...

Open fractures with bone loss are a common occurrence following high energy trauma. But usually the bone fragments are lost on the roadside and are not usable. We report a patient who was involved in a head-on collision between two wheelers and presented with a bone fragment embedded in his thigh. Radiological survey revealed no bony injury in that patient. Another patient, who presented at the same time, sustained a segmental fracture of shaft femur and was found to have lost a bone fragment that was similar to the one found in previous patient. CT scan with 3D reconstruction revealed this missing fragment to be the same as that found in previous patient. Both patients had a history of head-on collision while travelling on a two-wheeler. Present case report throws some highlights on the probable mechanism of injury.

Several studies have shown that normal hearing (NH) listeners place greater weight on the edge frequencies of broadband sounds when they are asked to pick the louder of two intervals in a sample discrimination task. However, little is known about the effects of hearing loss on spectral weighting for broadband sounds. In a classic study of sample discrimination, Doherty and Lutfi (1996) found that listeners with hearing loss (HL) placed greater weight on frequencies in the region of the HL and proposed that components that were less audible were weighted higher. The current study investigated the effect of audibility and hearing loss on spectral weighting for loudness judgments using two spectrally overlapping 18-tone complexes (from 208- to 8708-Hz). Four NH and nine HL listeners judged the loudness of tone complexes in two conditions where the mean level of each tone in the complex was set to either 10-dB SL or 75-dB SPL. The results show that listeners placed greater weight on the high-frequency edges o...

An important ability of the auditory system is to localize sound sources in complex acoustical environments. Two important cues for localization are interaural time- and level differences (ITD, ILD). The sensitivity to these cues differs across frequency and has previously been estimated through frequency-specific detection thresholds. Detection thresholds of ITDs/ILDs are, however, affected by stimulus energy in remote spectral regions, referred to as binaural interference. In this study, the spectral weights of ITD- and ILD cues in the lateralization of a broadband signal was investigated using regression analysis. The stimuli consisted of eleven 1-ERB-wide noise bands (442 Hz-5544 Hz) containing ITD or ILD cues. In experiment 1, ITDs or ILDs were applied to the noise bands and roved independently on every trial. In experiment 2, the noise bands centred at 442 Hz and 5544 Hz were removed to investigate the effect of stimulus bandwidth. In experiment 3, the same two noise bands were present, but containe...

The temporal order discrimination of target tone pairs is hindered by the presence of flanker tones but is improved when the flanker tones are captured by a separate stream of tones that match the flankers in frequency [Bregman and Rudnicky (1975). J. Exp. Psychol. 1, 263–267]. In an event-related potential (ERP) study with these stimuli, listeners' mismatch negativity (MMN) responses were temporally linked to the position of the changing target tones, irrespective of streaming. In contrast, N1 response latency varied as a function of the perceived grouping of flanker tones established by previous behavioral studies, providing a neurophysiological index of auditory stream segregation.

Subjects with normal hearing (NH) and with sensorineural hearing loss (SNHL) judged the overall loudness of six-tone complexes comprised of octave frequencies from 0.25 to 8 kHz. The level of each tone was selected from a normal distribution with a standard deviation of 5 dB, and subjects judged which of two complexes was louder. Overall level varied across conditions. In the “loudness” task, there was no difference in mean level across the two stimuli. In the “sample discrimination” task, the two complexes differed by an average of 5 dB. For both tasks, perceptual weights were derived by correlating the differences in level between matched-frequency tones in the complexes and the loudness decision on each trial. Weights obtained in the two tasks showed similar shifts from low to high frequency components with increasing overall level. Simulation of these experiments using a model of loudness perception [Moore and Glasberg (2004), Hear Res. 188, 70–88] yielded predicted weights for these stimuli that were highly correlated with predicted specific loudness, but not with the observed weights.

The current study measured the additional masking obtained for combinations of forward and simultaneous maskers as a function of forward masker bandwidth, signal delay, and simultaneous masker level. The effects of the two individual maskers were equated in all conditions. Additional masking increased with increasing masker level, increasing signal delay, and decreasing masker bandwidth. The portion of the simultaneous masker that made the greater contribution to additional masking was the part that overlapped with the signal, not with the forward masker. The changes in additional masking observed as a function of forward masker bandwidth and the interaction between the effects of forward and simultaneous maskers call into question the use of additional masking as a measure of basilar membrane compression and present problems for the use of simultaneous noise to simulate hearing loss.

CIs stimulate the auditory nerve fibers (ANF) with a train of amplitude modulated current pulses. Depending on polarity, the pulses can generate spikes at different sites along the ANF. The latency difference between spikes generated at the central and the peripheral axons was found to be up to 200 μs in cats and up to 450 μs in humans. These timing differences could be the reason underlying the poor performance of CI listeners in ITD perception. A model of ANF responses to electrical stimulation (Joshi et al., 2016), which includes two sites of spike generation along the ANF was used to simulate the ANF responses to constant-amplitude and modulated pulse trains for different pulse-rates. The fidelity of the temporal coding was quantified by calculating the phase-locking value. The results show that an increase in pulse-rate leads to higher uncertainty in the site of spike generation, reduction in phase-locking, and increase in variance of its distribution. This may account for impaired ITD thresholds obs...

Chronic relapsing-remitting experimental allergic encephalomyelitis (EAE) was induced in cynomolgus monkeys by a single immunization with a homogenate of human brain white matter (BH) in adjuvant. Proliferative T lymphocyte responses to BH, to myelin basic protein (MBP), but not to proteolipid protein, were detected in peripheral blood mononuclear cells (PBMC) of all animals and persisted until their death or, in surviving animals, for greater than 10 mo postimmunization. Responses of higher magnitude tended to be associated with fatal, compared with nonfatal, episodes of clinical EAE. The frequency of MBP-reactive T cells in PBMC of animals with acute EAE was quantitated with a soft agar colony system; the ratio of T cells that proliferated specifically to MBP was estimated at between 5 and 20 per 10(6) PBMC. A similar frequency of peptide-specific T cells was estimated from PBMC of monkeys immunized with a synthetic 14-mer peptide corresponding to a region near the carboxy terminus of MBP. Thus, autoantigen-reactive T cells can be detected in the circulation throughout the course of chronic EAE, are predictive of disease severity, and occur at a frequency similar to that estimated to be present in humans with multiple sclerosis.

Weighting patterns for loudness obtained using the reverse correlation method are thought to reveal the relative contributions of different frequency regions to total loudness, the equivalent of specific loudness. Current models of loudness assume that specific loudness is determined by peripheral processes such as compression and masking. Here we test this hypothesis using 20-tone harmonic complexes (200Hz f0, 200 to 4000Hz, 250 ms, 65 dB/Component) added in opposite phase relationships (Schroeder positive and negative). Due to the varying degree of envelope modulations, these time-reversed harmonic complexes have been shown to produce different outputs at the basilar membrane and different amounts of forward and simultaneous masking. The perceptual weights for loudness did not differ for these two complexes. To determine whether the level rove introduced to obtain weights had changed the fundamental differences in the stimuli, a similar level rove (±8 dB) was introduced on each component of Schroeder positive and negative forward maskers. The Schroder negative maskers continued to be more effective. These results suggest that perceptual weights for loudness are not completely determined by peripheral processes and reflect a central frequency weighting template. [Work supported by NIH R01 DC011806 and P30 DC004662.]

Background: Ununited fracture neck of femur in young adults has been tackled in various ways. Methods: Twenty five patients of ununited fracture neck of femur in age group 21-55 years were treated by closed reduction, cancellous screw fixation and fibular strut graft and followed up for 2-6 years. Time gap between injury and operation was 6 weeks to 58 weeks. Five cases were previously fixed with various fixation devices. Results: Osseous union was achieved in 24 cases with average time of 18.16 weeks. Main complication encountered in follow-up was avascular necrosis of femoral head, others were joint stiffness and shortening. Functional end results were good to excellent in 24 cases. Conclusion: Closed reduction with internal fixation by cancellous screw and fibular strut grafting is easy and useful procedure.

Cochlear implants (CI) stimulate the auditory nerve (AN) with a train of symmetric biphasic current pulses comprising of a cathodic and an anodic phase. The cathodic phase is intended to depolarize the membrane of the neuron and to initiate an action potential (AP) and the anodic phase to neutralize the charge induced during the cathodic phase. Single-neuron recordings in cat auditory nerve using monophasic electrical stimulation show, however, that both phases in isolation can generate an AP. The site of AP generation differs for both phases, being more central for the anodic phase and more peripheral for the cathodic phase. This results in an average difference of 200 μs in spike latency for AP generated by anodic vs cathodic pulses. It is hypothesized here that this difference is large enough to corrupt the temporal coding in the AN. To quantify effects of pulse polarity on auditory perception of CI listeners, a model needs to incorporate the correct responsiveness of the AN to anodic and cathodic polarity. Previous models of electrical stimulation have been developed based on AN responses to symmetric biphasic stimulation or to monophasic cathodic stimulation. These models, however, fail to correctly predict responses to anodic stimulation. This study presents a model that simulates AN responses to anodic and cathodic stimulation. The main goal was to account for the data obtained with monophasic electrical stimulation in cat AN. The model is based on an exponential integrate-and-fire neuron with two partitions responding individually to anodic and cathodic stimulation. Membrane noise was parameterized based on reported relative spread of AN neurons. Firing efficiency curves and spike-latency distributions were simulated for monophasic and symmetric biphasic stimulation. The simulations were in line with the average data for firing thresholds and spike latencies for both, monophasic anodic and monophasic cathodic stimulation. The model also correctly predicted the shift in latency as a function of stimulation level. With the ability to account for the responsiveness to cathodic and anodic phases of electrical stimulation, this model can be applied to account for the response to arbitrary pulse shapes. The evaluation of the neural response to symmetric biphasic pulses helps to estimate the mutual interaction between the two pulse phases. A successful model can be generalized as a framework to test various stimulation strategies and to quantify their effect on the performance of CI listeners in psychophysical tasks.

Performance in pitch discrimination tasks is limited by variability intrinsic to listeners which may arise from peripheral auditory coding limitations or more central noise sources. The present study aimed at quantifying such “internal noise” by estimating the amount of harmonic roving required to impair pitch discrimination performance. Fundamental-frequency difference limens (F0DLs) were obtained in normal-hearing listeners with and without musical training for complex tones filtered between 1.5 and 3.5 kHz with F0s of 300 Hz (resolved harmonics) and 75 Hz (unresolved harmonics). The harmonicity of the tone complexes was varied by systematically roving the frequency of individual harmonics, which was taken from a Gaussian distribution centered on the nominal frequency in every stimulus presentation. The amount of roving was determined by the standard deviation of this distribution, which varied between 0% and 16% of the tested F0. F0DLs for resolved harmonics remained unaffected for up to 6% roving, and increased thereafter. For unresolved harmonics, performance remained stable up to larger roving values. The results demonstrate a systematic relationship between F0DLs and stimulus variability that could be used to quantify the internal noise and provide strong constraints for physiologically inspired models of pitch perception.

In a series of studies, 6 subjects with normal hearing (NH) and 3 with sensorineural hearing loss (SNHL) judged the overall loudness of 6-tone complexes comprised of octave frequencies from 0.25 to 8 kHz. In two tasks, tones were equated in level in dB SPL or in sensation level (SL) and a range of SPL or SL values was tested. Both tasks used two-interval forced-choice trials, with level “jitter” introduced by selecting the level of each tone from a normal distribution with specified mean level and standard deviation of 5 dB. Subjects were instructed to indicate which complex was louder. In the “loudness” task there was no difference in mean level across the two intervals. In the “sample discrimination” task, the two complexes differed by an average of 5 dB. For both tasks,perceptual weights were derived by correlating the differences in level between matched-frequency tones in the complexes and the loudness decision on each trial. Weights derived from the loudness task (no mean level difference) were highly correlated with weights derived from the sample discrimination task (5-dB difference). For SPL conditions, both NH and SNHL subjects placed less weight on the lowest frequency and greater weight on higher frequencies with increasing intensity of the complexes, with larger effects for NH subjects. This effect was not observed in conditions where levels were equated in SL. Weights derived from a single-interval categorical loudness scaling task, where subjects judged the overall loudness of 6-tone complexes, were highly correlated with those from the other tasks. Simulation of these experiments using a model of loudness perception [Moore and Glasberg, J. Hear Res. 188 (70-88)] yielded weights for these stimuli that were highly correlated withspecific loudness, but the observed weights did not agree with predicted weights. This suggests that model assumptions regarding specific loudness are not correct.