On the relaxed maximum-likelihood blind MIMO channel estimation for orthogonal space-time block codes

This paper concerns the maximum-likelihood channel estimation for MIMO systems with orthogonal space-time block codes when the finite alphabet constraint of the signal constellation is relaxed. We study the channel coefficients estimation subspace generated by this method. We provide an algebraic characterisation of this subspace which turns the optimization problem into a purely algebraic one and more importantly, leads to several interesting analytical proofs. We prove that with probability one, the dimension of the estimation subspace for the channel coefficients is deterministic and it decreases by increasing the number of receive antennas up to a certain critical number of receive antennas, after which the dimension remains constant. In fact, we show that beyond this critical number of receive antennas, the estimation subspace for the channel coefficients is isometric to a fixed deterministic invariant space which can be easily computed for every specific OSTB code

Effects of Post-harvest Pre-cooling Processes and Cyclical Heat Treatment on the Physico-chemical Properties of "Red Haven Peaches" and "Shahmiveh Pears" During Cold Storage

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 6 (2004): A. Kalbasi-Ashtari. Effects of Post-harvest Pre-cooling Processes and Cyclical Heat Treatment on the Physico-chemical Properties of "Red Haven Peaches" and "Shahmiveh Pears" During Cold Storage. (July 2004)

Purification and partial characterization of serum immunoglobulin from Persian sturgeon (Acipenser persicus)

In this study, immunoglobulins from serum of Persian sturgeon (Acipenser persicus) were purified and partially characterized. Immunoglobulins were purified from the pooled sera by a combination of salt precipitation, Ion-exchange chromatography and gel filtration methods. DEAE sepharosefast flow and sepharose CL-6B columns were used for Ion exchange-chromatography, and gel filtration, respectively. The purity, molecular weight and molecular distribution of the immunoglobulin preparations was determined by gel electrophoresis (SDS-P AGE) in reducing and non-reducing situations. In gel filtrated immunoglobulins two distinct peaks, high molecular weight (HMW Ig) and low molecular weight (LMW Ig) were obtained. Both HMW Ig and LMW Ig had identical heavy and light chains of 72-75 KDa and 27-29 KDa, respectively, in reducing SDS-P AGE. HMW Ig contained a group of bands, including two major bands in non-reducing SDS-PAGE, In contrast LMW Ig contain more than half of the total immunoglobulin, was 190 KDa. In ion exchange chromatography, immunoglobulins were eluted in three peaks. The first was exclusively monomer and others were mixture of monomer and polymers. This is the first report on persian sturgeon immunoglobulins. Results of this investigation showed that persian sturgeon immunoglobulins was not homogenous in respect of molecular distribution, PI and the type of light chain. The presence of more than one genes for light and\or heavy chains or post transcriptional and\or post modifications may be responsible for these variations

Induction of tetraploidy in rainbow trout (Oncorhynchus mykiss) by heat shock

This study has been conducted for determination of optimum time and duration of thermal shock on tetraploidy induction in Rainbow trout. This study was carried out by induction of 28°C thermal shock in different times after fertilization (49.5, 54.0, 58.5, 63.0, 67.5, 72.0, 76.5 and 81,0°C/hour and different duration (8, 10 and 12 min). Nuclear erythrocytes, cellular area and volume measurement were determined among blood smears of fingerling and statistic analysis showed that, induction of tetraploidy was conducted between 0-75% on various treatment, but highest tetraploidy yield (8.4%) was achieved by thermal shock on 28°C within 12 minutes, 74 degree-hour after fertilization. Moreover, tetra ploidy diagnostic was also approved by determination of nucleolus number in fishes. In this respect tetraploid and diploid fishes have 3-4 and 1-2 nucleolus, respectively

An investigation on the micropyle number in the ova of the strugeon species in Caspian Sea

The micropyle number in the ova of sturgeon species from the South Caspian Sea was investigated. The study was conducted on female broodfishes of three species of sturgeon (Persian sturgeon Acipenser persicus, Stetates sturgeon A. stellatus and great sturgeon Huso huso) included 44 Persian sturgeon, 13 stellate sturgeon and 8 great sturgeon specimens. Fifty eggs were randomly collected from each broodfish and the micropyle number of totally 3250 eggs was determined. Out of 44 Persian sturgeon used, 14 specimens were collected from the south-east Caspian region (Golestan Province, Shaid Marjani Center) and 30 were from the south-west Caspian region (Guilan Province, Shahid Dr. Beheshti Center). The stellate sturgeon specimens were taken from the south-west and the great sturgeon specimens from the south-east Caspian region. The obtained result showed that the mean micropyle number in Persian sturgeon caught from the south-east Caspian region was 8 whereas in those caught from the south-west region was 9. There was no significant difference (p>0.95) in the micropyle number of Persian sturgeon collected from the south-east and south-west regions. The mean micropyle number determined for stellate and great sturgeon was 5. The outer diameter of the micropyle in the Persian, stellate, and great sturgeon were 22 μm, 17 μm and 19 μm respectively

Effect of male age in rainbow trout (Oncorhynchus mykiss) on duration of sperm motility, spermatocrite and eyed egg rate production

Effects of three levels of Rainbow Trout male age (2+, 3+ and 4+ years old), on duration of sperm motility, spermatocrite and eyed egg rate in rainbow trout were studied in Kelardasht Fish Breeding Center. The sperm from 2+ year old males activated by water showed the shortest motility (24.86 sec) (P= 0.007), while those of the 3+ and 4+ years old revealed the longest sperm motility. No significant difference was found between sperm motility of the 3+ and 4+ males. The average spermatocrite in different age groups of male fish was significantly different. This was showed to be 32.66% in 2+ years and 2126 % in 3+ year's male age groups respectively. Eyed egg rate was highest in 2+ years age (86/82%), and was significantly different with the 3+ age group (P=0.02). The eyed egg rate of the 4+ age group was not significantly different with those of the 2+ and 3+ age groups

The role of exopolysaccharides from a chromate reducing Pseudomonas aeruginosa in resistance to hexavalent chromium and antibiotics

زمینه و هدف: کروم شش ظرفیتی (VI) یکی از اکسید کننده های بسیار قوی و جز عناصر سرطان زای گروه A است که در پساب صنایع مختلف وجود دارد. اگزو پلی ساکاریدهای (EPS) ترشح شده توسط باکتری های موجود در این پساب ها می تواند نقش موثری در افزایش مقاومت باکتری ها به این عامل نامساعد ایفا نماید. این تحقیق با هدف بررسی نقش EPS باکتری های مقاوم به کرومات در احیای کروم VI و مقاومت آنتی بیوتیکی آن ها صورت گرفته است. روش بررسی: این مطالعه مقطعی- آزمایشگاهی بر روی باکتری های مقاوم به کرومات موجود در انواع مختلف پساب صورت گرفت. حداکثر غلظت قابل تحمل کرومات (MTC)، مقدار ترشح EPS، احیای کرومات توسط EPS و مقاومت آنتی بیوتیکی جدایه انتخابی به روش کیربی- بائر تعیین گردید. یافته ها: جدایه موثر که واجد بالاترین MTC ( mM128) و حداکثر توان ترشح EPS ( mg.ml-1117/0) بود، بر اساس نتایج تست های بیوشیمیایی گونه ای از سودوموناس آئروژینوزا تشخیص داده شد. مقایسه راندمان 61 درصدی احیای کرومات توسط EPS با راندمان 78 درصدی احیای سلولی کرومات حاکی از نقش قابل توجه EPS در احیای کرومات بود. این باکتری به طیف وسیعی از آنتی بیوتیک ها نیز مقاومت نشان داد. نتیجه گیری: افزایش کروم VI در محیط منجر به افزایش مقاومت باکتری ها با به کارگیری انواع مکانیسم های سازشی چون افزایش ترشح EPS می گردد و به موازات آن مقاومت آنتی بیوتیکی نیز افزایش می یابد. این مقاومت توام از لحاظ پزشکی بسیار مهم بوده و می تواند اطلاعات ارزشمندی در ارتباط با مکانیسم مقاومت آنتی بیوتیکی، ژنتیک پلاسمید و اکولوژی جدایه مورد نظر در اختیار ما قرار دهد