Flow sorting in the study of teratocarcinoma cell differentiation

Flow cytometry is a technique by which particles (cells, subcellular fragments, bacteria) in aqueous suspension are passed one by one through a sensing region where optical (or electrical) signals are generated. These signals for each individual cell are collected and processed, and may be stored to yield the distr1bution of the property measured for the population of cells analyzed. Most often cells are fluorescently labelled (with fluorescent dyes, particles or antibodies) and fluorescence signals are measured. Instruments called flow sorters in addition have a sorting capability which allows physical separation of a desired subpopulation for further analysis. This thesis is concerned with the cell biological application of such an instrument with particular emphasis on the use of the sorting capabilities. The process of cell specialization which occurs when a multicellular organism develops from one cell into the mature organism is called cell differentiation. Mouse teratocarcinoma cells share many properties with early embryonic cells and can be used as an tn vitro cell model system to study the early events of cell differentiation. Some aspects of teratocarcinoma cell differentiation may especially profitable be studied by making use of the sorting capabilities of the cell sorter and this is what the main part of this thesis is about. Teratocarcinoma cells can be induced to differentiate by treatment with chemical inducers. Analysis of properties changing upon differentiation can yield information about their role in the differentiation process. One of these properties is the "fluidity" of the plasma membrane. A part of this thesis describes the flow cytophotometric measurement of this change after induction of differentiation

Особливості правового регулювання ліцензування господарської діяльності у сфері обігу дорогоцінного каміння

Здійснення господарської діяльності, на сьогодні, в нашій державі постійно трансформуються залежно від встановлених і закріплених в нормативно правових актах визначених і регульованих державою процедур, зокрема, шляхом ліцензування господарської діяльності, тому державна галузева політика у сфері діяльності суб’єктів господарювання, пов’язаної з дорогоцінними металами і дорогоцінним камінням має бути відрегульована належним чином не тільки через призму ліцензування, але й з урахуванням забезпечення балансу економіки та національної економічної безпеки країни. Ключові слова: ліцензування, ліцензія, господарська діяльність, процедура, нагляд, контроль, суб’єкти господарювання, дорогоцінні метали і каміння, використання дорогоцінних металів і дорогоцінного каміння.Осуществление хозяйственной деятельности, на сегодня, в нашем государстве постоянно трансформируются в зависимости от установленных и закрепленных в нормативно-правовых актах определенных и регулируемых государством процедур, в частности, путем лицензирования хозяйственной деятельности, поэтому государственная отраслевая политика в сфере деятельности субъектов ведения хозяйства, связанной с драгоценными металлами и драгоценными камнями должена быть отрегулирована должным образом не только через призму лицензирования, но и с учетом обеспечения баланса экономики и национальной экономической безопасности государства. Ключевые слова: лицензирование, лицензия, хозяйственная деятельность, процедура, контроль, субъекты ведения хозяйства, драгоценные металлы и камни, использование драгоценных металлов и драгоценных камней.Realization of enterprising movement, nowadays, in our state constantly transformed depending on position and envisaged in the normatively-legal acts of certain and managed by the state procedures, in particular, by licensing of enterprising, that is why public branch policy in the field of activity of enterprises, related to the precious metals and jewels must be adjusted properly not only through the prism of licensing but also taking into account providing of balance of economy and national economic security of a state. Key words: licensing, license, economic activity, procedure, supervision, control, enterprises, precious metals and stones, apply of precious metals and precious stones

Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study

The VESSEL12 (VESsel SEgmentation in the Lung) challenge objectively compares the performance of different algorithms to identify vessels in thoracic computed tomography (CT) scans. Vessel segmentation is fundamental in computer aided processing of data generated by 3D imaging modalities. As manual vessel segmentation is prohibitively time consuming, any real world application requires some form of automation. Several approaches exist for automated vessel segmentation, but judging their relative merits is difficult due to a lack of standardized evaluation. We present an annotated reference dataset containing 20 CT scans and propose nine categories to perform a comprehensive evaluation of vessel segmentation algorithms from both academia and industry. Twenty algorithms participated in the VESSEL12 challenge, held at International Symposium on Biomedical Imaging (ISBI) 2012. All results have been published at the VESSEL12 website http://vessel12.grand-challenge.org. The challenge remains ongoing and open to new participants. Our three contributions are: (1) an annotated reference dataset available online for evaluation of new algorithms; (2) a quantitative scoring system for objective comparison of algorithms; and (3) performance analysis of the strengths and weaknesses of the various vessel segmentation methods in the presence of various lung diseases.Rudyanto, RD.; Kerkstra, S.; Van Rikxoort, EM.; Fetita, C.; Brillet, P.; Lefevre, C.; Xue, W.... (2014). Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study. Medical Image Analysis. 18(7):1217-1232. doi:10.1016/j.media.2014.07.003S1217123218

Measuring the effect of structural connectivity on the water dynamics in heterogeneous porous media using speedy neutron tomography

The temporal and spatial distribution of water within a porous medium is affected by the medium¿s structure, i.e., the spatial arrangement of its constituents. To analyze structural effects on the fluid dynamics, we measured the 3D water content distribution in a heterogeneous sand column during two drainage-wetting cycles using neutron transmission tomography. The sample with a volume of 105 cm3 contained 101 cubes of fine and 49 cubes of coarse sand with particles ranging from 0.01 to 0.05 and 0.03 to 0.09 cm, respectively. The pressure at the lower boundary was determined by the water reservoir positioned between 7 and 39 cm below the top of the column. The duration of one complete 3D scanning with a spatial resolution of 127 ¿m was 56 s. The signal to noise ratio of the measurements was low due to the short exposure time in the neutron beam, but it was possible to quantify the water content in the individual cubes and hence the effect of structure on macroscopic water distribution. Continuous structures of coarse sand drained faster than coarse sand without connection to the upper boundary. During the initial wetting phase, cubes of coarse sand material completely embedded in the fine material remained water unsaturated due to air entrapment. The effect of the coarse sand connectivity was analyzed in two-dimensional numerical simulations based on Richards equation. In contrast to the measurements, no effect of structure connectivity was found. The coarse sand cubes embedded within the fine matrix drain as quickly as the coarse sand cubes arranged in a continuous channel due to the model assumption of a continuous air phase