Reduction of echolocation call source levels in bats has previously been studied using set-ups with one microphone. By using a 16 microphone array, sound pressure level (SPL) variations, possibly caused by the scanning movements of the bat, can be excluded and the sonar beam aiming can be studied. During the last two meters of approach flights to a landing platform in a large flight room, five big brown bats aimed sonar beams at the landing site and reduced the source level on average by 7 dB per halving of distance. Considerable variation was found among the five individuals in the amount of source level reduction ranging from 4 to 9 dB per halving of distance. These results are discussed with respect to automatic gain control and intensity compensation and the combination of the two effects. It is argued that the two effects together do not lead to a stable echo level at the cochlea. This excludes a tightly coupled closed loop feed back control system as an explanation for the observed reduction of signal SPL in landing big brown bats.
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http://dx.doi.org/10.1121/1.3628345 | DOI Listing |
J Infect Dev Ctries
December 2024
Chest Dpt., Ahmed Maher Teaching Hospital, GOTHI, Cairo, Egypt.
Introduction: The present study aimed to explore the epidemiologic threats and factors associated with the coronavirus disease 2019 (COVID-19)-associated mucormycosis (CAM) epidemic that emerged in Egypt during the second COVID-19 wave. The study also aimed to explore the diagnostic features and the role of surgical interventions of CAM on the outcome of the disease in a central referral hospital.
Methodology: The study included 64 CAM patients from a referral hospital for CAM and a similar number of matched controls from COVID-19 patients who did not develop CAM.
BMC Public Health
January 2025
Research Institute for Healthcare Policy, Korean Medical Association, Yongsan-gu, Seoul, South Korea.
Background: In 2024, the Korean Ministry of Health and Welfare enforced a policy to increase the number of medical school students by 2,000 over the next 5 years, despite opposition from doctors. This study aims to predict the trend of excess or shortage of medical personnel in Korea due to the policy of increasing the number of medical school students by 2035.
Methods: Data from multiple sources, including the Ministry of Health and Welfare, National Health Insurance Corporation, and the Korean Medical Association, were used to estimate supply and demand.
BMC Pulm Med
January 2025
Universal Scientific Education and Research Network (USERN), Tehran, Iran.
Objective: Lung cancer (LC), the primary cause for cancer-related death globally is a diverse illness with various characteristics. Saliva is a readily available biofluid and a rich source of miRNA. It can be collected non-invasively as well as transported and stored easily.
View Article and Find Full Text PDFBiol Res
January 2025
Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
Fluoride (F), as a natural element found in a wide range of sources such as water and certain foods, has been proven to be beneficial in preventing dental caries, but concerns have been raised regarding its potential deleterious effects on overall health. Sodium fluoride (NaF), another form of F, has the ability to accumulate in reproductive organs and interfere with hormonal regulation and oxidative stress pathways, contributing to reproductive toxicity. While the exact mechanisms of F-induced reproductive toxicity are not fully understood, this review aims to elucidate the mechanisms involved in testicular and ovarian injury.
View Article and Find Full Text PDFAm J Orthod Dentofacial Orthop
February 2025
Department of Orthodontics, Faculty of Dentistry, Çanakkale Onsekiz Mart University, Çanakkale, Turkey.
Introduction: This study aimed to assess the precision of an open-source, clinician-trained, and user-friendly convolutional neural network-based model for automatically segmenting the mandible.
Methods: A total of 55 cone-beam computed tomography scans that met the inclusion criteria were collected and divided into test and training groups. The MONAI (Medical Open Network for Artificial Intelligence) Label active learning tool extension was used to train the automatic model.
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