Analysis of acoustic parameters in normal adults who speak Farsi at Zahedan City

Background and aim: Acoustic measurements have become substantial aspects of voice assessment during the last few decades and studies have established that normative data is necessary for acoustic analysis. Voice acoustic analysis including fundamental frequency (F0), jitter, shimmer, harmonics-to-noise ratio (HNR), and maximum phonation time (MPT) can now be easily recorded and analyzed using a computer. This study was designed to establish the normal acoustic analysis parameters in normal Iranian adults. Methods: This descriptive - analytical study was performed on 45 Iranian women and 45 Iranian men. We made use of Dr. Speech 4.0 software (Vocal Assessment subgroup) for recording and analyzing the acoustic samples under comfortable phonation. Each gender was divided equally into 3 age subgroups. We used the Kruskal-Wallis test to assess the differences between the 3 age groups for each gender. Student’s t-test was used to compare the overall mean value between genders. We used Mann-Whitney U test to analyze gender difference for each age range. Results: Fundamental frequency (F0) of vowel/a/ was calculated in both genders and it was higher in females (213.4±25.4 Hz) than in males (121.3±16.4 Hz) (P<0.05). Conversely, the value of MPT was greater in males (28.0±9.4 sec) than in females (22.6±7.6 sec) (P<0.05). No significant difference was found in average of SPL between females (77.8±5.5 dB (and male (77.5±5.5 dB). We found a significant difference in shimmer and Harmonics-to-noise ratio (H/N ratio) in male subgroup and other acoustic variables were not significantly different. Conclusions: It seems that the majority of voice characteristics of adults was relatively stable and would not change with aging up to 50. More caution should be considered for the usage of shimmer and HNR parameters to compare the voice quality

Aboundance, diversity and distribution of ichthyoplanktons in creeks and coastal waters of Khouzestan Province

This study was carried out on Iranian coastal waters of Khouzestan province during 1995-98. Ichthyoplankton sampling was performed in order to determine its abundance, distribution and diversity. Monthly sampling was carried out from 12 fixed stations in Mahshar-Abadan creeks and 4 stations in west coasts of Khouzestan province waters, by a paired 500 micron Bongo net in oblique hauls from the bottom to the surface. Larvae of 21 families were identified in coastal waters. 16 families of fish larvae were also found in creeks. Most frequent larval families in the creeks were found to be Gobiidae (86%), Engraulidae (9.13%), Clupeidae (2.5%), and in west coasts, they were Gobiidae (49%), Engraulidae (14.5%) and Sciaenidae (7.8%). Other families were found to have a lower frequency and occured only in limited samples. There were distinct differences in fish families occured in two studied areas, although no significant differences were found in diversity of fish families there. The highest frequency of the larvae among most of the families was in March-August period. In the west coastal area, more than 50% of the total identified larvae occured in May, while in creeks, it was in April and June. Presence of larvae from different families showed significant differences. Grouping based on diversity and distribution by one way ANOVA showed the presence of two major spawning seasons in spring and autumn, plus two minor ones in summer and winter. Most of identified specimens were exclusive to neritic and intertidal zones, which live in soft clay substrate

Unexpectedly diverse forest dung beetle communities in degraded rain forest landscapes in Madagascar

Tropical forests, which harbor high levels of biodiversity, are being lost at an alarming speed. Madagascar, a biodiversity hotspot, has lost more than half of its original forest cover. Most of the remaining forests are small fragments of primary and secondary forest with differing degrees of human impact. These forests, as well as coffee and fruit plantations, may be important in supporting the forest-dependent biodiversity in Madagascar but this has been little studied. In Madagascar, dung beetles, which offer important ecosystem services, are largely restricted to forests. We examined the ability of fragmented and degraded forests to support dung beetle diversity, compared to the large areas of primary forest in eastern Madagascar. We found a general trend of a reduction of species with a loss of forest connectivity. In contrast, a higher level of forest disturbance was associated with higher species diversity. In several sites of low-quality forest as many or more species were found as in less disturbed and primary forests. The average size of dung beetles was smaller in the lower quality localities than in the primary forests. These findings suggest that many forest dung beetles in Madagascar are better adapted to forest disturbance than earlier expected, although they require some level of connectivity to surrounding forest. in Malagasy is available with online material.Peer reviewe