760 research outputs found

    Impact of aging on the auditory system and related cognitive functions: A narrative review

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    Age-related hearing loss (ARHL), presbycusis, is a chronic health condition that affects approximately one-third of the world’s population. The peripheral and central hearing alterations associated with age-related hearing loss have a profound impact on perception of verbal and non-verbal auditory stimuli. The high prevalence of hearing loss in the older adults corresponds to the increased frequency of dementia in this population. Therefore, researchers have focused their attention on age-related central effects that occur independent of the peripheral hearing loss as well as central effects of peripheral hearing loss and its association with cognitive decline and dementia. Here we review the current evidence for the age-related changes of the peripheral and central auditory system and the relationship between hearing loss and pathological cognitive decline and dementia. Furthermore, there is a paucity of evidence on the relationship between ARHL and established biomarkers of Alzheimer’s disease, as the most common cause of dementia. Such studies are critical to be able to consider any causal relationship between dementia and ARHL. While this narrative review will examine the pathophysiological alterations in both the peripheral and central auditory system and its clinical implications, the question remains unanswered whether hearing loss causes cognitive impairment or vice versa

    Psychometric properties of Persian version of the multifactor leadership questionnaire (MLQ)

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    Background: Outstanding leadership is one of the important and vital concepts in management and educational leadership debates especially in educational organizations such as universities. Thus, effective educational leadership and adopting an appropriate tool to assess leadership in education are crucial in these institutions. The present study was conducted to develop an instrument for measuring the leadership style in faculty members. Methods: In this descriptive cross-sectional study, content and face validity of Multifactor Leadership Questionnaire (MLQ) was examined using the opinions of 10 experienced faculty members as a panel of experts. For construct validity, 210 questionnaires were administered to faculty members of Tehran University of Medical Sciences. Confirmatory factor analysis was run using principal component analysis and Varimax rotation method. The reliability of the scale was measured through internal consistency using Cronbach's alpha formula. Confirmatory factor analysis was used to examine the construct validity of the questionnaire. Data were analyzed using SPSS v.16 and LISREL software. Results: Factor analysis and expert opinion resulted in a questionnaire with 18 items across six subscales including idealized influence, inspirational motivation, intellectual stimulation, individualized consideration, contingent reward, and management by exception. The reliability coefficient of the questionnaire was acceptable (0.90). Confirmatory factor analysis showed that the scale had appropriate goodness of fit. Conclusion: The 18-item Educational Leadership Questionnaire was found to have acceptable validity and reliability for measuring leadership style in the faculty. It is recommended that the questionnaire be administered to a larger sample

    Mechanical Characteristics of the Fine Roots of Two Broadleaved Tree Species from the Temperate Caspian Hyrcanian Ecoregion

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    In view of the important role played by roots against shallow landslides, root tensile force was evaluated for two widespread temperate tree species within the Caspian Hyrcanian Ecoregion, i.e., Fagus orientalis L. and Carpinus betulus L. Fine roots (0.02 to 7.99 mm) were collected from five trees of each species at three different elevations (400, 950, and 1350 m a.s.l.), across three diameter at breast height (DBH) classes (small = 7.5–32.5 cm, medium = 32.6–57.5 cm, and large =57.6–82.5 cm), and at two slope positions relative to the tree stem (up- and down-slope). In the laboratory, maximum tensile force (N) required to break the root was determined for 2016 roots (56 roots per each of two species x three sites x three DBH classes x two slope positions). ANCOVA was used to test the effects of slope position, DBH, and study site on root tensile force. To obtain the power-law regression coefficients, a nonlinear least square method was used. We found that: 1) root tensile force strongly depends on root size, 2) F. orientalis roots are stronger than C. betulus ones in the large DBH class, although they are weaker in the medium and small DBH classes, 3) root mechanical resistance is higher upslope than downslope, 4) roots of the trees with larger DBH were the most resistant roots in tension in compare with roots of the medium or small DBH classes, and 5) the root tensile force for both species is notably different from one site to another site. Overall, our findings provide a fundamental contribution to the quantification of the protective effects of forests in the temperate region

    Gram - positive and gram - negative subcellular localization using rotation forest and physicochemical-based features

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    The functioning of a protein relies on its location in the cell. Therefore, predicting protein subcellular localization is an important step towards protein function prediction. Recent studies have shown that relying on Gene Ontology (GO) for feature extraction can improve the prediction performance. However, for newly sequenced proteins, the GO is not available. Therefore, for these cases, the prediction performance of GO based methods degrade significantly. Results: In this study, we develop a method to effectively employ physicochemical and evolutionary-based information in the protein sequence. To do this, we propose segmentation based feature extraction method to explore potential discriminatory information based on physicochemical properties of the amino acids to tackle Gram-positive and Gram-negative subcellular localization. We explore our proposed feature extraction techniques using 10 attributes that have been experimentally selected among a wide range of physicochemical attributes. Finally by applying the Rotation Forest classification technique to our extracted features, we enhance Gram-positive and Gram-negative subcellular localization accuracies up to 3.4% better than previous studies which used GO for feature extraction. Conclusion: By proposing segmentation based feature extraction method to explore potential discriminatory information based on physicochemical properties of the amino acids as well as using Rotation Forest classification technique, we are able to enhance the Gram-positive and Gram-negative subcellular localization prediction accuracies, significantly

    Intense physical activity is associated with cognitive performance in the elderly

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    Numerous studies have reported positive impacts of physical activity on cognitive function. However, the majority of these studies have utilised physical activity questionnaires or surveys, thus results may have been influenced by reporting biases. Through the objective measurement of routine levels of physical activity via actigraphy, we report a significant association between intensity, but not volume, of physical activity and cognitive functioning. A cohort of 217 participants (aged 60–89 years) wore an actigraphy unit for 7 consecutive days and underwent comprehensive neuropsychological assessment. The cohort was stratified into tertiles based on physical activity intensity. Compared with individuals in the lowest tertile of physical activity intensity, those in the highest tertile scored 9%, 9%, 6% and 21% higher on the digit span, digit symbol, Rey Complex Figure Test (RCFT) copy and Rey Figure Test 30-min recall test, respectively. Statistically, participants in the highest tertile of physical activity intensity performed significantly better on the following cognitive tasks: digit symbol, RCFT copy and verbal fluency test (all P<0.05). The results indicate that intensity rather than quantity of physical activity may be more important in the association between physical activity and cognitive function

    Preferred reporting of case series in surgery (PROCESS) 2023 guidelines.

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    INTRODUCTION: The PROCESS guidelines were developed in 2016 in order to improve the reporting quality of surgical case series. Since its inception, it has been updated twice, in 2018 and 2020, and has been cited over 1000 times. PROCESS guidelines have enjoyed great acceptance within the surgical research community. Our aim is to update the PROCESS guidelines in order to maintain its applicability in the field of surgical research. METHODS: A PROCESS 2023 steering group was created. By working in collaboration, members of this group came up with proposals to update the PROCESS 2020 guidelines. These proposals were presented to an expert panel of researchers, who in turn scrutinised these proposals and decided whether they should become part of PROCESS 2023 guidelines or not, through a Delphi consensus exercise. RESULTS: A total of 38 people participated in the development of PROCESS 2023 guidelines. The majority of items received a score between 7 and 9 from >70% of the participants, indicating consensus with the proposed changes to those items. However, two items (3c and 6a) received a score between 7 and 9 from <70% of the participants, indicating a lack of consensus with the proposed changes to those items. Those items will remain unchanged. DISCUSSION: The updated PROCESS 2023 guidelines are presented with an aim to continue improving the reporting quality of case series in surgery

    Identifying and ranking the barriers to the effectiveness of E-learning In-Service Training (case study Kurdistan University of medical sciences)

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    Background and Objectives: Organizations have used a variety of educational methods to achieve their goals in terms of in-service training of their employees: such as presentations and lectures, group discussions, field visits, or field trips and case studies and so on. Virtual training or e-learning is one of the newest and most innovative training methods that organizations use to train their employees. Due to the special importance of in-service training of employees on one side and the advancements in technology on the other side, the need to use these technologies in the field of organizational training is called for more than ever. But, besides all these factors, organizations should not use unscrupulous and ineffective uses of technology without adequate analysis. but It is also logical to have a deep and accurate understanding of e-learning, in other words evaluate and analyze the barriers ahead. In this regard, the present research aims to study the Virtual In-Service Training of employees and identify barriers to its effectiveness (case study, Kurdistan University of medical sciences). The research is a descriptive survey and in terms of purpose, it's an applied research Materials and Methods: statistical society consisting of managers, academic professors and specialists in the field of the study. 29 people were selected through deliberate and snowball sampling among the statistical society. In order to answer the research questions, Initially, using library study and interview method, data collection was done which resulted in identifying 32 factors. In the qualitative section, the data obtained from the interview were analyzed using content analysis; In this way, the number of words, and terms used in the sentences and the amount of their repetition were counted and checked so that the patterns in the statements were discovered and the obstacles were extracted in the form of short phrases. The Delphi method was then used to confirm the consensus of experts on identified barriers. During the three stages of the Delphi method finally classified 25 factors (barriers) in the form of six main barriers. After concluding the final consensus with the Kendall coefficient of 78%, the factors were ranked using Friedman test. each of the sub-factors was also ranked. Findings: all in all, 32 factors were identified and ranked as barriers to e-learning and In-Service Training: factors related to the learner were ranked first, infrastructure factors, general factors, educational content, factors related to the teacher and organizational factors were ranked afterwards. Each of the main barriers had other sub-factors which were also evaluated and ranked with the Friedman test. For example, in the section on barriers related to learners: learner resistance to change was ranked first, limited knowledge and skills of learners on information technology was ranked second, lack of trust in cyberspace learning was ranked third and learners limitations in accessing Information technology instruments was ranked forth Conclusion:  Considering the identified obstacles and also determining the importance of each of them, Measures (such as cost allocation & so on) taken to ensure the effectiveness of in-service virtual training are suggested to focus primarily on learners and then on other factors based on the degree of  its importance.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================
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