35 research outputs found

    Laterally Orienting C. elegans Using Geometry at Microscale for High-Throughput Visual Screens in Neurodegeneration and Neuronal Development Studies

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    C. elegans is an excellent model system for studying neuroscience using genetics because of its relatively simple nervous system, sequenced genome, and the availability of a large number of transgenic and mutant strains. Recently, microfluidic devices have been used for high-throughput genetic screens, replacing traditional methods of manually handling C. elegans. However, the orientation of nematodes within microfluidic devices is random and often not conducive to inspection, hindering visual analysis and overall throughput. In addition, while previous studies have utilized methods to bias head and tail orientation, none of the existing techniques allow for orientation along the dorso-ventral body axis. Here, we present the design of a simple and robust method for passively orienting worms into lateral body positions in microfluidic devices to facilitate inspection of morphological features with specific dorso-ventral alignments. Using this technique, we can position animals into lateral orientations with up to 84% efficiency, compared to 21% using existing methods. We isolated six mutants with neuronal development or neurodegenerative defects, showing that our technology can be used for on-chip analysis and high-throughput visual screens

    A Multi-Platform Flow Device for Microbial (Co-) Cultivation and Microscopic Analysis

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    Novel microbial cultivation platforms are of increasing interest to researchers in academia and industry. The development of materials with specialized chemical and geometric properties has opened up new possibilities in the study of previously unculturable microorganisms and has facilitated the design of elegant, high-throughput experimental set-ups. Within the context of the international Genetically Engineered Machine (iGEM) competition, we set out to design, manufacture, and implement a flow device that can accommodate multiple growth platforms, that is, a silicon nitride based microsieve and a porous aluminium oxide based microdish. It provides control over (co-)culturing conditions similar to a chemostat, while allowing organisms to be observed microscopically. The device was designed to be affordable, reusable, and above all, versatile. To test its functionality and general utility, we performed multiple experiments with Escherichia coli cells harboring synthetic gene circuits and were able to quantitatively study emerging expression dynamics in real-time via fluorescence microscopy. Furthermore, we demonstrated that the device provides a unique environment for the cultivation of nematodes, suggesting that the device could also prove useful in microscopy studies of multicellular microorganisms

    Zastosowanie urządzenia do badania natÄ™ĆŒenia haƂasu w warunkach laboratoryjnych

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    Noise and vibration are concomitant work processes, all machinery possibly different production machines or vehicles. Vibration and noise of the working environment can not be completely eliminated, but they can be reduced to an acceptable value. Our goal is to reduce vibration and noise just using pneumatic flexible shaft couplings. To measure use hand-held analyzer type 2250. The article describes a device for measuring noise which is located at our workplace. It's a sound analyzer fourth generation. This device allows different operating modes and can be extended to other work moduls.HaƂas i wibracje są zjawiskami towarzyszącymi procesom pracy we wszystkich urządzeniach oraz maszynach produkcyjnych, czy teĆŒ ƛrodkach transportu. Nie da się caƂkowicie wyeliminować wibracji i haƂasu, ale moĆŒemy je zredukować do dopuszczalnej wartoƛci. Naszym celem jest zmniejszenie wibracji oraz haƂasu wƂaƛnie przez zastosowanie elastycznych sprzęgieƂ pneumatycznych Ƃączących waƂy. Do pomiarĂłw uĆŒyjemy ręcznego analizatora dĆșwięku typu 2250. ArtykuƂ przedstawia urządzenie do pomiaru haƂasu, ktĂłre znajduje się w naszej pracowni. Jest to analizator dĆșwięku czwartej generacji. Urządzenie to ma rĂłĆŒne tryby pracy i moĆŒna je rozbudować, dodając kolejne moduƂy robocze

    On the Correspondence of the Experimental EEL Spectra with the Electron Structure of Tungsten

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    In the previous paper [7] we have directly compared the experimental Electron Energy Loss (EEL) spectra with both the theoretical bulk density-of-states (BDOS) and surface density-of-states (SDOS) functions for tungsten. On the base of the ILEED intensity calculations we have estimated to what extend an EEL spectrum measured at some value of the primary electron energy Ep\text{}_{p}, should correspond either to the SDOS or to the BDOS. Also, the angular acceptance of a CMA has been used to separate the EEL spectra measured as a function of Ep\text{}_{p} which corresponded either to the [001] direction or to the [011] in parallel to the studied (001) surface. In the present paper we propose a procedure which combines the Electron Energy Loss Spectra (EELS) simulation method based on Bauer's theory [1,2] and the inelastic low energy diffraction (ILEED). If the standard simulation procedure is applied for tungsten an ambiguity would arise because the DOS function is very anisotropic and varies as a function of both the direction along the surface and the depth considered within several atomic layers. The application of ILEED has supplemented the simulation procedure with the method which identifies both the correspondence of a reciprocal-lattice vector to a measured EEL spectrum and the localization of a studied electron structure with regard to the distance from the surface

    Mineralogical and oxygen isotope composition of inorganic dust-fall in WrocƂaw (SW Poland) urban area – test of a new monitoring tool

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    We have analysed the mineralogical and oxygen isotope composition of solid inorganic atmospheric particles (SIAP) in WrocƂaw (SW Poland) to determine potential natural and anthropogenic sources of deposited dust. The mineralogical compositions of SIAP and local soils are very similar and quite typical. Dust sources were attributed to high emission sources (two large coal-fired power generation plants, i.e., "WrocƂaw and "Czechnica") and low emission sources (mostly small furnaces for home heating). A mullite phase was confirmed in the non-magnetic fraction of high emission dust. The ή1818181
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