The fluctuations of physicochemical factors and phytoplankton populations of Urmia Lake, Iran

Urmia Lake is one of the two large hypersaline lakes in the world which have Artemia. It is located in northwest of Iran. Due to a decrease in water inflow and volume, the salinity of Urmia Lake has reached to more than 300 g.l-1 since 2001. The increased salinity has greatly influenced biological aspects of the lake, and caused the lake undergoes at critical conduction. The aim of the present study was to investigate the distribution fluctuations of phytoplanktons and selected physicochemical factors in relation to Artemia distribution in Urmia Lake during 8 months. Statistical analysis of mean values of ion concentrations and phytoplankton abundance indicated significant differences among sampling months. The minimum and maximum values for the selected factors were, as Cl- 176.2-201.3 g.l-1 , CO2 95-175mg.l-1 , dissolved oxygen (DO) 0.1-2.8 mg.l-1 , HCO3 - 144-496 mg.l-1 , PO42+ 104-875 mg.l-1, NO3- 330-4104 mg.l-1, NO2- 4-21.5 mg.l-1, SO42- 10490-29840 mg.l-1, Ca2+ 561-1606 mg.l-1, Mg2+ 3649-14587 mg.l-1 while water hardness was 21000- 62000 mg.l-1. Fourteen phytoplankton genera included Bacillariophyceae (10 genera),Chlorophyceae (2 genera) and Cyanophyceae (2 genera) were identified during sampling period. The smallest average density of phytoplankton 97249 L-1 was observed in December 2005 and the greatest average density 481983 L-1 in August 2005. Dunaliella sp. composed 92.1% of the lake's phytoplankton. Statistical analysis of phytoplanktons fluctuations showed a significant difference among different months (p< 0.05)

The growth, survival rate and reproductive characteristics of Artemia urmiana fed by Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. as feeding microalgae

This study was performed to compare the efficiency of six microalgae namely Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. on the growth, survival rate and reproduction efficacy in Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the f/2 culture medium. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. A highly significant difference (p<0.01) were found among three microalgae in terms of length growth, survival rates and reproduction characteristics in A. urmiana. In spite of higher length growth of A.urmiana fed on N. oculata than A. urmiana fed by T. suecica but survival and reproduction in the latter was better than the first treatment. In general, D. tertiolecta was more efficient than other microalgae examined in the present study on A. urmiana concerning not only to growth and survival but also to reproduction mode. So, it is preferred to feed A. urmiana

A case of rhinolithiasis

Rhinolith is an uncommon nasal mass in children and adolescents. We report a 8 years old boy with a history of long standing foul smelling right sided nasal discharge, progressive nasal obstruction and recurrent epistaxis, which was clinically suspected as being due to the presence of a long standing foreign body. Rhinolith in the right nasal cavity was diagnosed on rigid endoscopic examination. Rhinolith was removed by using a 00 rigid nasal endoscope.Key Words: Rhinolith, Endoscop

Wavelet Decomposition-Based Analysis of Mismatch Negativity Elicited by a Multi-Feature Paradigm

In this study, event-related potentials (ERPs) collected from normally hearing subjects and elicited by a multi-feature paradigm were investigated, and mismatch negativity (MMN) was detected. Standard stimuli and five types of deviant stimuli were presented in a specified sequence, while EEG data were recorded digitally at a 1024 sec–1 sampling rate. Two wavelet analyses were compared with a traditional difference-wave (DW) method. The Reverse biorthogonal wavelet with an order of 6.8 and the quadratic B-Spline wavelet were applied for seven-level decomposition. The sixth-level approximation coefficients were appropriate for extracting the MMN from the averaged trace. The results obtained showed that wavelet decomposition (WLD) methods extract MMN as well as a band-pass digital filter (DF). The differences of the MMN peak latency between deviant types elicited by B-Spline WLD were more significant than those extracted by the DW, DF, or Reverse biorthogonal WLD. Also, wavelet coefficients of the delta-theta range indicated good discrimination between some combinations of the deviant types.У суб’єктів із нормальним слухом реєстрували пов’язані з подією потенціали, викликані з використанням множинної парадигми. Стандартні слухові стимули та девіантні стимули п’яти типів пред’являли в специфічній послідовності; ЕЕГ-потенціали відводили з частотою дискретизації 1024 c–1. Результати двох видів вейвлет-аналізу порівнювали з даними, отриманими із застосуванням традиційного методу диференціації хвиль (DW). Зворотний біортогональний вейвлет порядку 6.8 і квадратичний B-сплайновий вейвлет використовували для декомпозиції сьомого порядку. Коефіцієнти наближення шостого порядку виявилися застосовними для виділення негативності розузгодження (MMN) із усереднених записів. Як показали результати, методи вейвлет-декомпозиції (WLD) дозволяють виділити негативність розузгодження так само успішно, як і цифрові фільтри. Відмінності латентних періодів піків негативності розузгодження для девіантних варіантів стимуляції, виявлені в разі застосування В-сплайнової WLD, були більш вірогідними, ніж аналогічні відмінності при використанні методу диференціації хвиль, цифрової фільтрації або зворотної біортогональної WLD. Вейвлет-коефіцієнти для дельта-тета-діапазону також дозволяли отримати найкращу дискримінацію деяких комбінацій девіантних типів