On the matrices with constant determinant and permanent over roots of unity

AbstractLet μm be the group of mth roots of unity. In this paper it is shown that if m is a prime power, then the number of all square matrices (of any order) over μm with non-zero constant determinant or permanent is finite. If m is not a prime power, we construct an infinite family of matrices over μm with determinant one. Also we prove that there is no n×n matrix over μp with vanishing permanent, where p is a prime and n=pα−1

Phase diagram of the one dimensional anisotropic Kondo-necklace model

The one dimensional anisotropic Kondo-necklace model has been studied by several methods. It is shown that a mean field approach fails to gain the correct phase diagram for the Ising type anisotropy. We then applied the spin wave theory which is justified for the anisotropic case. We have derived the phase diagram between the antiferromagnetic long range order and the Kondo singlet phases. We have found that the exchange interaction (J) between the itinerant spins and local ones enhances the quantum fluctuations around the classical long range antiferromagnetic order and finally destroy the ordered phase at the critical value, J_c. Moreover, our results show that the onset of anisotropy in the XY term of the itinerant interactions develops the antiferromagnetic order for J<J_c. This is in agreement with the qualitative feature which we expect from the symmetry of the anisotropic XY interaction. We have justified our results by the numerical Lanczos method where the structure factor at the antiferromagnetic wave vector diverges as the size of system goes to infinity.Comment: 9 pages and 9 eps figure

Aberrant Frequency Related Change-Detection Activity in Chronic Tinnitus

Tinnitus is the perception of sound without the occurrence of an acoustic event. The deficit in auditory sensory or echoic memory may be the cause of the perception of tinnitus. This study considered the mismatch negativity (MMN) to investigate the potential difference between and within groups of persons with normal hearing (NH) and tinnitus. Using an auditory multi-feature paradigm to elicit the MMN, this study considered the MMN peak amplitude at two central frequencies for two MMN subcomponents. These central frequencies were 1 and 5 kHz, which the latter was closer to the perceived tinnitus frequency in the group with tinnitus. The deviants were higher frequency, lower frequency, higher intensity, lower intensity, duration, location (left), location (right), and gap. The pure tone audiometry (PTA) test and distortion product otoacoustic emissions (DPOAE) test showed no meaningful difference between the two groups. For the frontal subcomponent, the mean amplitudes of the MMN peak for the two groups illustrated less negative meaningful MMN peak amplitudes in the group of persons with tinnitus. For the supratemporal component at 5 kHz central frequency, amplitudes were lower for the group of persons with tinnitus, whereas for the central frequency of 1 kHz, most deviants exhibited meaningful differences. Additionally, within-group comparisons indicated that mean amplitudes for both groups were more negative at the central frequency of 1 kHz for the frontal MMN subcomponent. In comparison, the supratemporal component illustrated a lower peak amplitude at 5 kHz central frequency in the group of persons with tinnitus and no difference in the NH group, which is a unique observation of this study. Results of the between-groups are in accordance with previous studies and within-group comparisons consider the probability of decreasing the change detection capability of the brain. The results of this study indicate that increasing the frequency of the stimuli close to the tinnitus perceived frequencies decreases the prediction error, including the prediction error of the silence. Such a decrease may cause the prediction error of the spontaneous neural activity in the auditory pathway to exceed the silence prediction error, and as a result, increases the probability of occurrence of tinnitus in higher frequencies according to the predictive coding model. © Copyright © 2020 Asadpour, Jahed and Mahmoudian

The investigation of semantic memory deficit in chronic tinnitus: a behavioral report Investigação do déficit de memória semântica no zumbido crônico: um relato comportamental

Introduction: Tinnitus is a central auditory disorder in which different processing systems are involved as a network. One of these networks is memory. Previous studies have demonstrated some deficits in various types of memory in chronic tinnitus. Objectives: The main purpose of the present study was to investigate the semantic memory, which is not yet investigated in the tinnitus population. Methods: In this case�control study, 15 subjects with chronic tinnitus and 16 matched healthy controls were included. 40 semantically related and 40 semantically unrelated word pairs were presented to the participants in a counter-balanced fashion. They were asked to make decision about their semantic relatedness. Then the participants� reaction times and the accuracy of responses were calculated. Results: Mean of reaction times were significantly longer in the tinnitus group (M = 1034 ms, SD = 0.31) compared to the control group (Mean = 1016 ms, SD = 0.13), p < 0.05. However, no significant difference was found for the mean percentage of correct responses between the two groups. Conclusion: The current study provided behavioral evidence that chronic tinnitus can affect the semantic memory. Such behavioral outcomes may provide new insights into more research activities in the field of electrophysiology and neuroimaging in the tinnitus population. © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facia

The investigation of semantic memory deficit in chronic tinnitus: a behavioral report Investigação do déficit de memória semântica no zumbido crônico: um relato comportamental

Introduction: Tinnitus is a central auditory disorder in which different processing systems are involved as a network. One of these networks is memory. Previous studies have demonstrated some deficits in various types of memory in chronic tinnitus. Objectives: The main purpose of the present study was to investigate the semantic memory, which is not yet investigated in the tinnitus population. Methods: In this case�control study, 15 subjects with chronic tinnitus and 16 matched healthy controls were included. 40 semantically related and 40 semantically unrelated word pairs were presented to the participants in a counter-balanced fashion. They were asked to make decision about their semantic relatedness. Then the participants� reaction times and the accuracy of responses were calculated. Results: Mean of reaction times were significantly longer in the tinnitus group (M = 1034 ms, SD = 0.31) compared to the control group (Mean = 1016 ms, SD = 0.13), p < 0.05. However, no significant difference was found for the mean percentage of correct responses between the two groups. Conclusion: The current study provided behavioral evidence that chronic tinnitus can affect the semantic memory. Such behavioral outcomes may provide new insights into more research activities in the field of electrophysiology and neuroimaging in the tinnitus population. © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facia

Auditory electrical tinnitus suppression in patients with and without implants

The aim of this study was to evaluate the effectiveness of electrical tinnitus suppression in two groups of chronic severe tinnitus sufferers. Through standard tinnitus questionnaires, we compared the effectiveness of extratympanic and intratympanic auditory electrical stimulation (AES) by cochlear implants (CI) for the suppression or abolition of the perception of tinnitus and the decrease of its associated complaints. We made otolaryngological and comprehensive audiological assessment and also tinnitus measurement in each group of patients before and after AES and 50 days later. We investigated the dimensions of psychological complaints due to chronic and disabling tinnitus by means of the tinnitus questionnaire (TQ). The control examination during at least seven sessions (50 days) after AES in the group of patients without implants showed improvement in 20 of 32 patients (62.5); 12 (37.5) did not notice any change. In the comparative group of patients with implants, improvement occurred in 16 of 20 patients (75); during the switch-on of the speech processor, these patients reported significant attenuation or complete suppression of their tinnitus. Complete suppression of the tinnitus after CI was observed for 11 patients (55), and 5 patients (25) demonstrated significant attenuation of tinnitus. Nonsuppression of tinnitus was observed for only 4 patients (25). None of our patients was affected by an increment in the tinnitus owing to CI. The differences of means of scores in the standard TQ were significant in both groups of patients. A comparison of TQ score differences between patients with and without implants showed no significance. We concluded that AES is a useful and effective therapeutic intervention in patients with tinnitus. Extratympanic AES reduces the effects of the tinnitus but presents limitations, mainly owing to the short duration of the electrical residual inhibition of the tinnitus. CI is shown to be more efficient for the treatment of tinnitus, mainly because the electrical stimulation affects a wider area of the cochlea and is presented for longer sessions. Therefore, patients affected by incapacitating tinnitus should be considered for continuous use of electrical stimulation

The effect of noscapine on oxygen-glucose deprivation on primary murine cortical neurons in high glucose condition

In the present work we set out to investigate the neuroprotective effects of noscapine (0.52 µM) in presence of D-glucose on primary murine foetal cortical neurons after oxygen� glucose deprivation/24 h. recovery. Cell viability, nitric oxide production and intracellular calcium ((ca2+)i) levels were evaluated by MTT assay, the modified Griess method and Fura-2 respectively. 25 and 100 mM D-glucose could, in a concentration dependent manner, improve cell viability and decrease NO production and (ca2+)i level in neuronal cells after ischemic insult. Moreover, pre-incubation of cells with noscapine, noticeably enhanced protective effects of 25 and 100 mM D-glucose compared to similar conditions without noscapine pretreatment. In fact, noscapine attenuated NO production in a dose-dependent fashion, after 30 minutes (min) OGD, during high-glucose (HG) condition in cortical neurons. Pretreatment with 2 μM noscapine and 25 or 100 mM D-glucose, was shown to decrease the rise in (ca2+) induced by Sodium azide/glucose deprivation (chemical OGD) model. These effects were morei pronounced than that of 25 or 100 mM D-glucose alone. The present study demonstrated that the neuroprotective effects of HG before an ischemic insult were augmented by pre-treatment with noscapine. Our results also suggested that the neuroprotection offered by both HG and noscapine involve attenuation of NO production and (ca2+)i levels stimulated by the experimental ischemia in cortical neurons. © 2016 by School of Pharmacy

Stable Iterative Variable Selection

Motivation: The emergence of datasets with tens of thousands of features, such as high-throughput omics biomedical data, highlights the importance of reducing the feature space into a distilled subset that can truly capture the signal for research and industry by aiding in finding more effective biomarkers for the question in hand. A good feature set also facilitates building robust predictive models with improved interpretability and convergence of the applied method due to the smaller feature space. Results: Here, we present a robust feature selection method named Stable Iterative Variable Selection (SIVS) and assess its performance over both omics and clinical data types. As a performance assessment metric, we compared the number and goodness of the selected feature using SIVS to those selected by Least Absolute Shrinkage and Selection Operator regression. The results suggested that the feature space selected by SIVS was, on average, 41% smaller, without having a negative effect on the model performance. A similar result was observed for comparison with Boruta and caret RFE. Availability and implementation: The method is implemented as an R package under GNU General Public License v3.0 and is accessible via Comprehensive R Archive Network (CRAN) via https://cran.r-project.org/package¼sivs. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online.</p

The potential role of auditory prediction error in decompensated tinnitus: An auditory mismatch negativity study

Introduction: Some tinnitus subjects habituate to their tinnitus but some others do not and complain of its annoyance tremendously. Normal sensory memory and change detection processes are needed for detecting the tinnitus signal as a prediction error and habituation to tinnitus. The purpose of this study was to compare auditory mismatch negativity as the index of sensory memory and change detection among the studied groups to search for the factors involving in the perception of tinnitus and preventing habituation in decompensated tinnitus subjects. Methods: Electroencephalography was recorded from scalp electrodes in compensated tinnitus, decompensated tinnitus, and no tinnitus control subjects. Mismatch negativity was obtained using the oddball paradigm with frequency, duration, and silent gap deviants. Amplitude, latency, and area under the curve of mismatch negativities were compared among the three studied groups. Results: The results showed lower mismatch negativity amplitude and area under the curve for the higher frequency deviant and for the silent gap deviant in decompensated tinnitus group compared to normal control and compensated tinnitus group. Conclusions: This study revealed a deficit in sensory memory and change detection processing in decompensated tinnitus subjects. This causes persistent prediction errors; tinnitus signal is consistently detected as a new signal and activates the brain salience network and consequently prevents habituation to tinnitus. Mismatch negativity is proposed as an index for monitoring tinnitus rehabilitation. © 2019 The Authors. Brain and Behavior published by Wiley Periodicals, Inc

The relationship between treatment of mental disorder and chronic tinnitus

Introduction: Comorbidity of chronic tinnitus and mental disorders may result in more disability. Objectives: This research provides an evaluation about the effects of medically treated comorbid mental disorder on chronic tinnitus. Materials and Methods: Fifty-five patients diagnosed with chronic tinnitus and mental disorders were randomly requited by producing a before-after design. They underwent three months of drug therapy for comorbid mental disorders by psychiatrists. Study instruments are Tinnitus Handicap Inventory, Tinnitus Questionnaire, Loudness Match Tinnitus, Hamilton Depression Rating Scale, Beck Anxiety Inventory, The Structured Clinical Interview and Symptom Check List-90. Results: Three months medical treatment puts forward the argument that among mental disorders, anxiety and major depressive disorder demonstrate a significant reduction. Pearson Correlation coefficient ostensibly reveals that there is no significant relationship between mental disorders and tinnitus severity. The statistics lend support to profound effect of major depressive disorder as a key factor on tinnitus disability exacerbation. Medical treatment also touches on issue such as tinnitus severity, its disabling effects and TQ subscales that statistics shows significant trends in their reduction. Conclusion: Findings lay emphasis on tinnitus severity reduction and connection might be established between alleviated mental disorders comorbidity and the improvement of quality of life