Top-down auditory plasticity: Acceptable noise level predicts and reflects the effect of perceptual learning in experience-induced plasticity

Objective: In the auditory system, tinnitus and superior speech perception in noise are examples of negative and positive plasticity that can result from sensory neural hearing loss and life experiences dealing with more complex stimuli and learning, respectively. Positive plasticity occurs as a result of learned skills and sensory stimuli; plasticity involves specific neural pathways and can be observed in auditory ascending or descending pathways.Materials & Methods: In this study, we document a form of plasticity in top-down auditory pathways through the measurement of acceptable noise level in 60 adults (27 females and 33 males) with normal hearing. Individuals were assigned to one of two groups: those with and without occupational experience of speech perception in noise.Result: The results showed that the test group had statistically significant lower acceptable noise level and significantly higher background noise level scores compared with the control group.Conclusion: Using acceptable noise level, we attributed differences in individuals’ abilities to tolerate varying amounts of background noise and speech perception in noise function to the auditory efferent system. We therefore concluded that working in crowded locations due to job nature can influence differences in speech perception in noise function

Nutritional diagnoses of oriental beech trees in damaged Caspian forest sites, using the diagnosis and recommendation integrated system (DRIS)

Oriental beech established in the Hyrcanian forests, is a valuable tree whose habitats are constantly exposed to destructive factors which change the nutritional status of soil and leaves. Analysis of foliar elements is a commonly used method for studying tree nutrient status that indicates site's quality. Foliar analysis of beech (Fagus orientalis Lipsky) was carried out in Kojour (Mazandaran) in order to assess the nutritional balance of trees in a damaged forest site (a direct result of livestock grazing and anthropogenic perturbations). Sunny leaves of dominant trees were taken in August and foliar concentration of macroelements, N, P, Ca, K and Mg were measured. The diagnosis and recommendation integrated system (DRIS) analysis was applied for evaluating the nutritional state. The results showed deficiency with K and P in disturbed stands. Nutrient Balance Index (NBI) indicated imbalance in nutrient status. These results suggest the usefulness of DRIS for foliar tissue analysis as an indicator of nutritional status and elemental stress in natural forests

Plant regeneration through indirect organogenesis of chestnut (Castanea sativa Mill.)

To establish an effective protocol for plant regeneration through indirect organogenesis, effects of explants type, culture media and plant growth regulators on callus induction and shoot regeneration of chestnut (Castanea sativa Mill.) were investigated. Three different explants (root, nodal and internodal segment), two different media [Murashige and Skoog medium (MS) and Gamborg's B5 (B5)] and different plant growth regulators (6-benzylaminopurine (BA), thidiazuron (TDZ), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA)) with different concentration (0.2, 0.5, 1 and 1.5 mgL-1) for shoot and root induction were chosen. The results show that nodal segment was the best explant for callus induction (69.4%) when cultured on MS medium supplemented with 1 mgL-1 TDZ and MS was the best medium to induce callus formation (74.6%). The highest shoot multiplication (66.9%) was observed on MS medium with 0.2 mgL-1 TDZ. Regenerated shoots were rooted in vitro on MS containing 1.5 mgL-1 IBA. Also, plantlets with well developed root and shoot systems were acclimatized inside the green house and 80% of the plantlets survived on transfer to garden soil. This protocol provides a basis for future studies on genetic improvement.Key words: Chestnut, node, internode segment, indirect organogenesis, callus formation, shoot regeneration

Economic importance and GIS mapping of medicinal plants in Iran: A Case study of Darkesh

Iran with a wide diversity of wild medicinal plants (8,000 Medicinal plants) is increasingly becoming a valuable source of household income for many rural people. We showed that economic potential of the wild medicinal plant and their contribution to the local people’s livelihoods. This study identified the economic importance of medicinal plants and evaluated with Geographical Information System (GIS) tool to develop spatial maps covering medicinal plants prevalent in Darkesh area, Northern Khorasan, Iran. Then provide the coordinates of the identified area as your results. 10 medicinal plants belonging to 4 families were collected and its geographical distribution is illustrated in the GIS map. More than 50 species were collected and 10 species being the most frequently collected in this area. Most plants were collected in the form of whole plant. It was estimated that at least 18.000 USD are being annually traded in study area, the 10 species most frequently collected contributing most of the retail value. Results from this study indicate that the collection of certain medicinal plants could be increased livelihood for edge community of natural resources. Also, the geographical location of medicinal plants facilitates easy access of medicinal plant's natural habitat and would help to find out potential of medicinal plants in the study area.Keywords: Medicinal plants, Geographical distribution, GIS Mapping, Darkesh, Ira

Auditory Recognition of Words-in-Noise in Normal Hearing and Mild-to-Severe Sensorineural Hearing Loss with Different Configurations

Background and Aim: Sensorineural Hearing Loss (SNHL) reduces audibility and causes distortion, which result in difficulty with speech processing, especially in noisy environments. One of the new speech-in-noise tests is the Words-in-Noise (WIN) test. This study aimed to further investigate the Signal-to-Noise Ratio 50% (SNR-50) in subjects with mild to severe SNHL and different configurations using the Persian version of the WIN test compared to normal-hearing people. Methods: This cross-sectional study was conducted on 54 patients with SNHL aged 17–75 years and 49 normal-hearing people aged 20–48 years. The auditory recognition in the presence of multi-talker babble noise was evaluated by the Persian version of the WIN test (named ARWIN). Results: The mean SNR-50 in the normal-hearing group was 2.56±1.2 dB, which increased significantly in subgroups with mild (10.13±4.8 dB), moderate (14.51±4.7 dB) and moderate-to-severe (16.61±4.3 dB) SNHL (p<0.001). Conclusion: People with SNHL need more SNR by nearly 4–6 times than the normalhearing group for recognition of monosyllabic Persian words in the presence of multi-talker babble noise

A Study of Opportunities and Threats of Descriptive Assessment from Managers, Teachers and Experts Points of View in Chaharmahal and Bakhteyari Primary Schools

The aim of current study is to determine the strength and weakness of executing descriptive evaluation from the viewpoint of deans, teachers and experts of Chaharmahal and Bakhtiari province. A survey descriptive approach was performed. Statistical population includes 208 deans, 303 teachers, and 100 executive experts of descriptive evaluation scheme in Chaharmahal and Bakhtiari province in educational year 1387-88. Sample’s volume after some statistical estimation calculated to be 175, and members of the sample were selected by random sampling of a category proportional to the selected volume, that contains 100 teachers, 50 deans and 25 experts. To identify the justifiability of the inventory, opinions of twelve persons including advisor professor, consulting professor, designer of the descriptive evaluation scheme, four of educational planning department professors and five of experts holding masters and Ph.D. degrees that are executives of the scheme in Chaharmahal and Bakhtiari, were used. Measurement tools included: 1) documents including reports, regulations and documents related to the running of this plan; 2) interviews conducted to use the opinions of experts in doing descriptive evaluation; 3) a self-administrated questionnaire including 4 items and 74 close–ended questions, and open – ended ones. For analyzing the data produced by inventory, we used SPSS-13 to analyze the data in two levels of descriptive and inferential. We also have used single variable t-test, independent t-test, one-way analysis of variance, and least significant difference (LSD) tests. Results showed that the executives of descriptive evaluation scheme in Chaharmahal and Bakhtiari province evaluate the so called scheme above average regarding to four scales (strength and weakness).Key words: Chaharmahal; Bakhteyari; Opportunities; Threats; Primary schoo