51 research outputs found

    Individual differences in auditory brainstem response wave characteristics : relations to different aspects of peripheral hearing loss

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    Little is known about how outer hair cell loss interacts with noise-induced and age-related auditory nerve degradation (i.e., cochlear synaptopathy) to affect auditory brainstem response (ABR) wave characteristics. Given that listeners with impaired audiograms likely suffer from mixtures of these hearing deficits and that ABR amplitudes have successfully been used to isolate synaptopathy in listeners with normal audiograms, an improved understanding of how different hearing pathologies affect the ABR source generators will improve their sensitivity in hearing diagnostics. We employed a functional model for human ABRs in which different combinations of hearing deficits were simulated and show that highfrequency cochlear gain loss steepens the slope of the ABRWave-V latency versus intensity and amplitude versus intensity curves. We propose that grouping listeners according to a ratio of these slope metrics (i.e., the ABR growth ratio) might offer a way to factor out the outer hair cell loss deficit and maximally relate individual differences for constant ratios to other peripheral hearing deficits such as cochlear synaptopathy. We compared the model predictions to recorded click-ABRs from 30 participants with normal or high-frequency sloping audiograms and confirm the predicted relationship between the ABR latency growth curve and audiogram slope. Experimental ABR amplitude growth showed large individual differences and was compared with the Wave-I amplitude, Wave-V/I ratio, or the interwaveI-W latency in the same listeners. The model simulations along with the ABR recordings suggest that a hearing loss profile depicting the ABR growth ratio versus the Wave-I amplitude or Wave-V/I ratio might be able to differentiate outer hair cell deficits from cochlear synaptopathy in listeners with mixed pathologies

    Gastrointestinal Quality of Life in Gastroesophageal Reflux Disease: A Systematic Review

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    Background: The Gastrointestinal Quality of Life Index (GIQLI) is a well-established instrument for the assessment of quality of life (QOL) in gastrointestinal (GI) diseases. The purpose of this literature review was to investigate QOL by means of GIQLI in patients with gastroesophageal reflux disease (GERD) prior to any interventional therapy. There are several reports on GIQLI data; however, comparisons from different countries and/or different GERD cohorts assessing the same disease have to date not been conducted. Methods: The GIQLI uses 36 items around 5 dimensions (GI symptoms [19 items], emotional dimension [5 items], physical dimension [7 items], social dimension [4 items], and therapeutic influences [1 item]). A literature search was conducted on the application of GIQLI in GERD patients prior to interventional therapy using reports in PubMed. Data on the mean GIQLI as well as index data for the 5 dimensions as originally validated were extracted from the published patient cohorts. A comparison with the normal healthy control group from the original publication of the GIQLI validation conducted by Eypasch was performed. Data are presented descriptively as GIQLI points as well as a reduction from 100% maximum possible index points (max 144 index points = highest QOL). Results: In total, 77 abstracts from studies using the GIQLI on patients with GERD were identified. After screening for content, 21 publications were considered for further analysis. Ten studies in GERD patients comprised complete calculations of all dimensions and were included in the analysis. Data from 1,682 study patients were evaluated with sample sizes ranging from 33 to 568 patients (median age of 789 females and 858 males: 51.8 years). The median overall GIQLI for the patient group was 91.7 (range 86–102.4), corresponding to 63.68% of the maximum GIQLI. The dimensions with the largest deviation from the respective maximum score were the physical dimension (55% of maximum) followed by the emotional dimension (60% of maximum). In summary, the GIQLI level in GERD cohorts was reduced to 55–75% of the maximum possible index. Conclusions: Severe GERD causes substantial reductions in the patient’s QOL. The level of GIQLI can carry between different studied GERD cohorts from different departments and countries. GIQLI can be used as an established tool to assess the patient’s condition in various dimensions

    Pubertal maturation and sex effects on the default-mode network connectivity implicated in mood dysregulation

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    This study examines the effects of puberty and sex on the intrinsic functional connectivity (iFC) of brain networks, with a focus on the default-mode network (DMN). Consistently implicated in depressive disorders, the DMN’s function may interact with puberty and sex in the development of these disorders, whose onsets peak in adolescence, and which show strong sex disproportionality (females > males). The main question concerns how the DMN evolves with puberty as a function of sex. These effects are expected to involve within- and between-network iFC, particularly, the salience and the central-executive networks, consistent with the Triple-Network Model. Resting-state scans of an adolescent community sample (n = 304, male/female: 157/147; mean/std age: 14.6/0.41 years), from the IMAGEN database, were analyzed using the AFNI software suite and a data reduction strategy for the effects of puberty and sex. Three midline regions (medial prefrontal, pregenual anterior cingulate, and posterior cingulate), within the DMN and consistently implicated in mood disorders, were selected as seeds. Within- and between-network clusters of the DMN iFC changed with pubertal maturation differently in boys and girls (puberty-X-sex). Specifically, pubertal maturation predicted weaker iFC in girls and stronger iFC in boys. Finally, iFC was stronger in boys than girls independently of puberty. Brain–behavior associations indicated that lower connectivity of the anterior cingulate seed predicted higher internalizing symptoms at 2-year follow-up. In conclusion, weaker iFC of the anterior DMN may signal disconnections among circuits supporting mood regulation, conferring risk for internalizing disorders

    Modelling human choices: MADeM and decision‑making

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    Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

    Business Intelligence in the Database Marketing – A Case Study of a German Insurance Company

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    We perform a case study in order to analyze the BI practices of the database marketing departments of insurance companies and hone in on the challenges they face. More specifically, we take a look at the database marketing department of one of the biggest German insurance companies by executing three guided expert interviews and enhancing the information gathered through a document analysis. Among our findings regarding the department’s BI process are that the department collects customer data solely from internal sources and that the collected data is mainly analyzed through SQL queries. The department’s greatest challenges involve including internal and external data sources that are currently not used in their analyses, gathering and understanding all the data that the company already has — since it is stored in different database tables and in heterogenous formats across the company — and measuring the success of their BI activities

    Hearing-impaired sound perception: What can we learn from a biophysical model of the human auditory periphery?

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    Auditory modelling provides a powerful quantitative framework to study performance in psychoacoustic listening tasks such as signal or modulation detection, and speech perception. Biophysically-inspired auditory models provide the straightforward possibility to account for different aspects of sensorineural hearing loss (e.g., hair cell loss or synaptopathy) and are well suited to study the origin of individual performance differences on behavioural tasks. Here, we simulated how detection thresholds to low- and high-frequency supra-threshold stimuli changed for various profiles of sensorineural hearing loss: (1) normal or high-frequency sloping audio- grams (>1 kHz, 30 dB HL at 8 kHz), and (2) normal or gradual loss of auditory-nerve synapses. The tasks included the detection of amplitude-modulated tones at carrier frequencies of 500 Hz (fmod=5 Hz) and 4 kHz (fmod=100 Hz) presented with or without background noise. The simulations were compared with experimental data collected from listeners with normal or high-frequency sloping audiograms. The simulations accounted for up to 8.6 dB of the experimental variability, where the simulated variability was derived from the maximum shift between simulated thresholds in each condition
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