the present study reports the chromosome number and meiotic behaviour of 14 populationsbelonging to four taxa of anchusa subgenus buglossum gusul. from iran. all populationsshowed the chromosome number 2n= 4x= 32. it is the first meiotic study for a. subg.buglossum. we discuss some habit form and evolutionary aspect in the light of cytogeneticdata. the origin of polyploidy (auto-allopolyploidy)...

Background: Aberrant chromosomes can cause azoospermia but little is known about its molecular mechanism. Our aim is to explore any possible genetic defective to explain a given male infertility. Materials and Methods: An azoopsermic male was identified in a 23 years old male. G-banding and FISH confirmed the karyotype as chromosome insertion (18:7) (q22.1; q36.2q21.11). NGS was performed to an...

Among 17786 karyotyres performed in our center,during 18 years (1357-1375),1300(7.3%) cases of chromosome 21 aberration,including 1284(98.77%) of Down syndrome have been detected.1191 of cases (92.76%) born free trisomy 21:61 cases (4.75%) revealed translocation and 32 cases (2.4%) showed mosaic pattern.among the pateints,59 had robertsonian translocation,2 had translocation between chromosome ...

This paper describes methods that use digital elevation models (DEMs) in hydrology, implemented as an ArcGIS toolbar using Visual Basic and the ESRI object library. I describe generalized channel network delineation to objectively estimate drainage density and by using terrain curvature accommodate spatially variable drainage density. The multiple flow direction field determined from a DEM also...

Background: The maternal age effect for trisomy is well known. However what is less established is whether certain women are more (or less) prone to segregation errors, independent of age. Trisomy arises primarily through maternal meiosis I chromosome segregation errors however the precise mechanism by which these errors occur is unclear. Current dogma attributes the origin of trisomy to malseg...

We describe the structure and operation of a micro/nanofluidic device in which individual metaphase chromosomes can be isolated and processed without being displaced during exchange of reagents. The change in chromosome morphology as a result of introducing protease into the device was observed by time-lapse imaging; pressure-driven flow was then used to shunt the chromosomal DNA package into a...

“There’s plenty of room at the bottom,” as Richard Feynman famously formulated it in 1959 (1). He considered the problem of manipulating and controlling things “at the bottom” of the length scale, from Ångströms to micrometers. The fame came retroactively with the rise of nanotechnology (2). By then, the advantage of studying small objects in small laboratories was clear: in a microscopic labor...

A genome and fatty acid analysis of 16 Pseudomonas stutzeri reference strains having DNA compositions ranging from 62.2 to 65.5 mol% G+C was performed by pulsed-field gel electrophoresis of XbaI and SpeI macrorestriction fragments and gas chromatography of total cellular fatty acids. Macrorestriction fragment patterns were evaluated by using previously described algorithms (D. Grothues and B. T...