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Mehdi Rahimmalek Babak Bahreininejad Mojtaba Khorrami Badraldin Ebrahim Sayed Tabatabaei 《Biochemical genetics》2009,47(11-12):831-842
Thymus daenensis is an aromatic medicinal plant endemic to Iran. We used inter simple sequence repeat (ISSR) markers to detect genetic polymorphism in this herb using 17 T. daenensis accessions collected from different geographic regions in Iran. The 15 primers chosen for analysis revealed 256 bands, of which 228 (88.9%) were polymorphic. Jaccard’s similarity indices based on ISSR profiles were subjected to UPGMA cluster analysis. The generated dendrogram revealed two major groups. The Tc group included the accessions collected from the center of the Zagros Mountains, and the Te group was collected from the extremes of the Zagros range. A principal coordinate analysis confirmed the results of clustering. The results showed that the divergence of accessions based on the Zagros Mountains is more logical in comparison with classification on the basis of provincial borders. Gene diversity and expected heterozygosity were greater in the Tc group than in the Te group, suggesting that the germplasm collected from the center of the Zagros Mountains is more variable. 相似文献
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Eric A. Zilli Motoharu Yoshida Babak Tahvildari Lisa M. Giocomo Michael E. Hasselmo 《PLoS computational biology》2009,5(11)
Models of the hexagonally arrayed spatial activity pattern of grid cell firing in the literature generally fall into two main categories: continuous attractor models or oscillatory interference models. Burak and Fiete (2009, PLoS Comput Biol) recently examined noise in two continuous attractor models, but did not consider oscillatory interference models in detail. Here we analyze an oscillatory interference model to examine the effects of noise on its stability and spatial firing properties. We show analytically that the square of the drift in encoded position due to noise is proportional to time and inversely proportional to the number of oscillators. We also show there is a relatively fixed breakdown point, independent of many parameters of the model, past which noise overwhelms the spatial signal. Based on this result, we show that a pair of oscillators are expected to maintain a stable grid for approximately t = 5µ
3
/(4πσ)
2 seconds where µ is the mean period of an oscillator in seconds and σ2 its variance in seconds2. We apply this criterion to recordings of individual persistent spiking neurons in postsubiculum (dorsal presubiculum) and layers III and V of entorhinal cortex, to subthreshold membrane potential oscillation recordings in layer II stellate cells of medial entorhinal cortex and to values from the literature regarding medial septum theta bursting cells. All oscillators examined have expected stability times far below those seen in experimental recordings of grid cells, suggesting the examined biological oscillators are unfit as a substrate for current implementations of oscillatory interference models. However, oscillatory interference models can tolerate small amounts of noise, suggesting the utility of circuit level effects which might reduce oscillator variability. Further implications for grid cell models are discussed. 相似文献
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Babak Arjmand Seyed Hamidreza Aghayan Parisa Goodarzi Mohammad Farzanehkhah Seyed Mohamadjavad Mortazavi Mohamad Hossein Niknam Ali Jafarian Farzin Arjmand Soheyla Jebelly far 《Cell and tissue banking》2009,10(3):247-252
Iranian Tissue Bank prepares a wide range of human tissue homografts such as; heart valve, bone, skin, amniotic membrane and
other tissues for different clinical applications. The purpose of this study was to determine the seroprevalence of HTLV in
tissue donors. About 1,548 tissue donors were studied during a 5-years period by ELISA assays. HTLV1,2—antibodies were tested for all of donors with other tests upon American Association of Tissue Banks (AATB) standards. About
25 (1.61%) out of 1,548 tissue donors were HTLV positive that 17 donors were male and 8 were female (female/male ratio was
approximately 47%). Regarding to the prevalence of HTLV among tissue donors and importance of cell and tissue safety and quality
assurance, we recommend that all blood, cell and tissue banks should be involved both routine serological methods and other
complementary tests such as polymerase chain reaction (PCR) for diagnosis of HTLV. 相似文献
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Jeroen van Steenis Babak Gharali Theo Zeegers Hussein Sadeghi Namaghi 《Zoology in the Middle East.》2018,64(4):345-359
The hoverfly Trichopsomyia ochrozona (Stackelberg, 1952) (Diptera: Syrphidae) is recorded for the first time from Iran. An illustrated key to the West Palaearctic species of Trichopsomyia is presented. Illustrations of the puparium of Trichopsomyia joratensis Goeldin, 1997 and the larva and puparium of T. ochrozona are given and their larval and adult habitats are described. A short discussion is given on the known larval habitat of other West Palaearctic Trichopsomyia species. Some of the synonyms have been evaluated and Pipiza melancholica Meigen, 1822 is withdrawn from synonymy of Trichopsomyia flavitarsis (Meigen, 1822) and is considered as a junior synonym of Musca viduata Linnaeus, 1758 syn. nov. 相似文献