120 research outputs found

    Neural and computational approaches to auditory scene analysis

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    Our perception of the world is highly dependent on the complex processing of the sensory inputs by the brain. Hearing is one of those seemingly effortless sensory tasks that enables us to perceive the auditory world and integrate acoustic information from the environment into cognitive experiences. The main purpose of studying auditory system is to shed light on the neural mechanisms underlying our hearing ability. Understanding the systematic approach of the brain in performing such complicated tasks is an ultimate goal with numerous clinical and intellectual applications. In this thesis, we take advantage of various experimental and computational approaches to understand the functionality of the brain in analyzing complex auditory scenes. We first focus on investigating the behavioral and neural mechanisms underlying auditory sound segregation, also known as auditory streaming. Employing an informational masking paradigm, we explore the interaction between stimulus-driven and task-driven attentional process in the auditory cortex using magnetoencephalography (MEG) recordings from the human brain. The results demonstrate close links between perceptual and neural consequences of the auditory stream segregation, suggesting the neural activity to be viewed as an indicator of the auditory streaming percept. We examine more realistic auditory scenarios consisted of two speakers simultaneously present in an auditory scene and introduce a novel computational approach for decoding the attentional state of listeners in such environment. The proposed model focuses on an efficient implementation of a decoder for tracking the cognitive state of the brain, inspired from neural representation of auditory objects in the auditory cortex. The structure is based on an state-space model with the recorded MEG signal and individual speech envelopes as the input and the probability of attending to the target speaker as the output of the model. The proposed approach benefits from accurate and highly resolved estimation of attentional state in time as well as the inherent model-based dynamic denoising of the underlying state-space model, which makes it possible to reliably decode the attentional state under very low SNR conditions. As part of this research work, we investigate the neural representation of ambiguous auditory stimuli at the level of the auditory cortex. In perceiving a typical auditory scene, we may receive incomplete or ambiguous auditory information from the environment. This can lead to multiple interpretations of the same acoustic scene and formation of an ambitious perceptual state in the brain. Here, in a series of experimental studies, we focus on a particular example of ambitious stimulus (ambitious Shepard tone pair) and investigate the neural correlates of the contextual effect and perceptual biasing using MEG. The results from psychoacoustic and neural recordings suggest a set of hypothesis about the underlying neural mechanism of short-term memory and expectation modulation in the nervous system

    Oral lichen planus and hepatitis C virus infection; a symbiotic relationship or a mere co-incidence?

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    Background: Lichen planus (LP) is a common idiopathic chronic inflammatory immune mediated mucocutanous disease that effects stratified squamous epithelia and appendices. Hepatitis C virus (HCV) infection is quite common across the world. A couple of reports have suggested positive association of HCV infection and oral lichen planus (OLP) and most of the studies are usually confined to Mediterranean and south European countries. Due to high incidence and suspected alliance between these two diseases in Pakistan, the following study was conducted with the view that it may help clinicians to set guidelines for HCV testing of lichen planus patients.Methods: Approximately 11500 patients from general population coming to dental diagnostics department of Fatima Memorial Hospital, Lahore (from March 2015-February 2016) were screened clinically for OLP and by ELISA for HCV infection. Out of these 11500 patients 103 were selected one of them incidental and the other pre-diagnosed or both incidental and both pre-diagnosed. These patients were unaware but had either one or both OLP and HCV infection which was confirmed clinically and by ELISA respectively.Results: Majority of patients presenting for other dental complaints were unaware of these diseases process going on in them and was mostly an incidental finding by the clinician. Either one or both OLP and HCV infection were more conjoint in females comprising 77.7% of the total subjects. OLP alone was most common finding comprising 66.67% of the cases. HCV infection alone was present in 15.53% whereas 16.50% subjects showed presence of both OLP and HCV infection.Conclusions: The current study could not detect statistically significant relationship between OLP and HCV infection in Pakistani population which could be due to genetic variation or may be geographic relationship

    PENGARUH PEMAHAMAN TENTANG RIBA, KUALITAS PELAYANAN, DAN LOKASI TERHADAP KEPUTUSAN MASYARAKAT MENABUNG PADA BANK SYARIAH (STUDI PADA MASYARAKAT DI KELURAHAN KENALI BESAR)

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    Bank merupakan suatu tempat transaksi yang sangat penting bagi masyarakat, dimana di zaman modern ini kecepatan transakasi sangat dibutuhkan agar perputaran uang semakin cepat dan meningkatkan perekonomian masyarakat. Perbankan syariah merupakan suatu sistem yang dikembangkan berdasarkan syariah (hukum) Islam. Indonesia yang sebagian besar penduduknya adalah muslim memberikan peluang yang besar bagi perkembangan bank syariah. Seperti halnya di Kelurahan Kenali Besar yang berada di Kecamatan Alam Barajo, Kota Jambi. Masyarakat di kelurahan ini mayoritas adalah pemeluk agama Islam, namun jumlah bank syariah yang tersedia cukup minim yaitu hanya satu buah kantor cabang BSI (Bank Syariah Indonesia) yang dimana sebelumnya adalah Bank BNI Syariah. Walaupun jumlah bank syariah yang berada di kelurahan kenali besar hanya sedikit, namun tidak mengurangi minat masyarakat tersebut untuk menabung pada bank sayariah. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pemahaman tentang riba, kualitas pelayanan, dan lokasi terhadap keputusan masyarakat di kelurahan kenali besar menabung pada bank syariah. Adapun menggunakan tiga dimensi untuk mengukur keputusan masyarakat yang memilih menabung pada bank syariah yaitu pemahaman tentang riba, kualitas pelayanan, dan lokasi. Hasil dari analisis uji-F terhadap seluruh variabel indikator menunjukkan bahwa ketiga dimensi secara bersama-sama memiliki pengaruh secara signifikan terhadap keputusan masyarakat menabung pada bank syariah, dapat dilihat dari hasil penelitian fhitung > ftabel 42,361 > 3,94 dengan nilai sig 0,000 < 0,05. Nilai koefisien determinan sebesar 55,6% dan sisanya sebesar 44,4% keputusan menabung pada bank syariah dipengaruhi oleh variabel lainnya yang tidak diteliti dalam penelitian ini. Adapun hasil dari analisis uji-t diperoleh bahwa masing-masing dari dimensi yaitu pemahaman tentang riba memiliki pengaruh yang positif dan signifikan yaitu sebesar 16,9%, kualitas pelayanan memiliki pengaruh yang positif dan signifikan yaitu sebesar 50,8% dan lokasi memiliki pengaruh yang positif dan signifikan yaitu sebesar 28,6%. Dari uji-t diatas dapat dilihat bahwa dari ketiga variabel memiliki pengaruh yang signifikan dan positif terhadap keputusan masyarakat menabung pada bank syariah

    Association of dietary total antioxidant capacity, alternative healthy eating index, and dietary inflammatory index with semen quality in men seeking infertility treatment

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    BackgroundSince the association between dietary quality scores and semen quality remains unclear, we carried out a hospital-based cross-sectional study to investigate the association of Dietary Total Antioxidant Capacity (dTAC), Dietary Inflammatory Index (DII), and Alternative Healthy Eating Index (AHEI) scores with semen quality in men seeking infertility treatment.MethodsThis study enrolled 210 men with unexplained or idiopathic infertility. Semen samples were collected and analyzed according to the WHO 2010 criteria. Dietary data was collected using a 168-item semi-quantitative food frequency questionnaire (FFQ) developed for Tehran Lipid and Glucose Study. Multivariable logistic regression models were used to estimate the relationship between dTAC, AHEI, and DII scores with abnormal semen in crude and adjusted models.ResultsThere were no significant differences across quartile categories of the dTAC, AHEI, and DII scores regarding semen parameters. There was a trend toward a significant direct association between DII and abnormal semen risk (p = 0.01). Infertile men in the highest quartile of DII had a 2.84 times higher risk of abnormal semen in the crude model (OR: 3.84; 95% CI: 1.64–8.95); such that remained after adjusting for several potential confounders. There was no significant association between dTAC or AHEI and the risk of abnormal semen in infertile men, either before or after adjusting for potential confounders. Total energy (p = 0.05), fat (p = 0.02), saturated fat (p = 0.02), mono-saturated fat (p = 0.009), Thiamine (Vitamin B1) (p = 0.02), Niacin (Vitamin B3) (p = 0.03), Calcium (p = 0.01), and Selenium (p = 0.01) were inversely associated with semen normality.DiscussionThe study suggests that certain dietary factors may affect semen quality, and the mechanisms underlying the observed associations are likely multifactorial, involving complex interactions between diet, oxidative stress, inflammation, and hormone levels. Further research is required to confirm the results, fully elucidate the mechanisms underlying the associations, and identify specific dietary interventions that may improve male fertility outcomes

    Manufacturing a modified carbon paste electrode with catalase enzyme-Au nanoparticles for electrochemical sensing of hydrogen peroxide and their electrocatalytic properties

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    To find hydrogen peroxide, different techniques applied, recently. In this practice we decided to produce a modified carbon paste electrode by catalase enzyme-Au nanoparticles for electrochemical sensing hydrogen peroxide and their electroactivity characteristics. Cyclic voltammetry were done electrochemical researches. A three-electrode method including a modified carbon paste electrode with catalase enzyme-Au nanoparticles as the operant electrode, a platinum string electrode as a counter electrode, and saturated calomel electrode as a reference electrode, was applied. Cyclic voltammetric assays were done with different scan speed area from of 50 mV s−1 to 500 mV s−1. Transmission electron microscopy was checked external morphological characteristics of Au nanoparticles. H2O2 in 100 μM to 450 μM area could find out by designed biosensor. By perform assays in two weeks regular interval, the resistance of modified carbon paste electrode with catalase enzyme-Au nanoparticles biosensor has been determine and it has been discovered that after 14 days, modified carbon paste electrode with catalase enzyme-Au nanoparticles keeps its 97% activity. Keywords: electrochemical sensing, hydrogen peroxide, catalase enzyme, Au nanoparticle

    Quantum and classical control of single photon states via a mechanical resonator

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    Optomechanical systems typically use light to control the quantum state of a mechanical resonator. In this paper, we propose a scheme for controlling the quantum state of light using the mechanical degree of freedom as a controlled beam splitter. Preparing the mechanical resonator in non-classical states enables an optomechanical Stern–Gerlach interferometer. When the mechanical resonator has a small coherent amplitude it acts as a quantum control, entangling the optical and mechanical degrees of freedom. As the coherent amplitude of the resonator increases, we recover single photon and two-photon interference via a classically controlled beam splitter. The visibility of the two-photon interference is particularly sensitive to coherent excitations in the mechanical resonator and this could form the basis of an optically transduced weak-force sensor

    Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990-2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

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    Background: The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic. Methods: To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0). Findings: In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1–38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78–0·91) per female living with HIV in 2019, 0·99 male infections (0·91–1·10) for every female infection, and 1·02 male deaths (0·95–1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58–35·43, and a 39·66% decrease in deaths, 36·49–42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05–0·06) and the global incidence-to-mortality ratio was 1·94 (1·76–2·12). No regions met suggested thresholds for progress. Interpretation: Sub-Saharan Africa had both the highest HIV burden and the greatest progress between 1990 and 2019. The number of incident cases and deaths in males and females approached parity in 2019, although there remained more females with HIV than males with HIV. Globally, the HIV epidemic is far from the UNAIDS benchmarks on progress metrics. Funding: The Bill & Melinda Gates Foundation, the National Institute of Mental Health of the US National Institutes of Health (NIH), and the National Institute on Aging of the NIH

    Global, regional, and national burden of stroke and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels. Methods We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level. Findings In 2019, there were 12·2 million (95% UI 11·0–13·6) incident cases of stroke, 101 million (93·2–111) prevalent cases of stroke, 143 million (133–153) DALYs due to stroke, and 6·55 million (6·00–7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8–12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1–6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0–73·0), prevalent strokes increased by 85·0% (83·0–88·0), deaths from stroke increased by 43·0% (31·0–55·0), and DALYs due to stroke increased by 32·0% (22·0–42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0–18·0), mortality decreased by 36·0% (31·0–42·0), prevalence decreased by 6·0% (5·0–7·0), and DALYs decreased by 36·0% (31·0–42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0–24·0) and incidence rates increased by 15·0% (12·0–18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5–3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5–3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57–8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97–3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01–1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7–90·8] DALYs or 55·5% [48·2–62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3–48·6] DALYs or 24·3% [15·7–33·2]), high fasting plasma glucose (28·9 million [19·8–41·5] DALYs or 20·2% [13·8–29·1]), ambient particulate matter pollution (28·7 million [23·4–33·4] DALYs or 20·1% [16·6–23·0]), and smoking (25·3 million [22·6–28·2] DALYs or 17·6% [16·4–19·0]). Interpretation The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries.publishedVersio

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin
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