2,175 research outputs found
Failing States or Failing Models?: Accounting for the Incidence of State Collapse
In recent years the notion and phenomenon of .failingÿ states - states deemed incapable to fulfil the basic tasks of providing security for their populace -, has been rapidly drawing attention. I will start off with a closer look at the inci- dence of fragile states and state failure, more specifically of state collapse. Connected with this, I will raise the question of differential degrees of propensity to failure and collapse among contemporary state systems, and to point to apparent regional variations in this regard. Yet, to better understand and respond to sit- uations of state collapse, I shall argue, it will be important to differentiate between different trajectories put into motion after the lifting of hegemon- ic frameworks
Simple delay monitor for droplet sorters
We have constructed a simple device by which the optimal delay time between optical measurement of a cell and the application of the droplet charging pulse can be determined directly in a flow sorter. The device consists of a stainless steel chamber in which the sorted droplets are collected. In the collection chamber the collected droplets run through a capillary where a continuous fluorescence measurement is made. With a sample of fluorescent particles, the delay time is optimal when the measured fluorescence is maximal. The measuring volume is always filled with the last droplets sorted (about 3,000). With this device, the setting of the delay time can be done in a few seconds without the need for microscopical verification. \ud
The fluorescence in the collection chamber is excited and detected via optical fibers using about 10% of the light of the existing laser from the flow cytometer and an extra photomultiplier
Visible diode lasers can be used for flow cytometric immunofluorescence and DNA analysis
This report describes a feasibility study concerning the use of a visible diode laser for two important fluorescence applications in a flow cytometer. With a 3 mW 635 nm. diode laser, we performed immunofluorescence measurements using the fluorophore allophycocyanin (APC). We have measured CD8 positive lymphocytes with a two-step labeling procedure and the resulting histograms showed good separation between the negative cells and the dim and the bright fluorescent subpopulations. As a second fluorescence application, we chose DNA analysis with the recently developed DNA/ RNA stains TOTO-3 and TO-PRO-3. In our setup TO-PRO-3 yielded the best results with a CV of 3.4%. Our results indicate that a few milliwatts of 635 nm light from a visible diode laser is sufficient to do single color immunofluorescence measurements with allophycocyanin and DNA analysis with TO-PRO-3. The major advantages of using a diode laser in a flow cytometer are the small size, the low price, the high efficiency, and the long lifetime
Another face of Lorenz-Mie scattering: monodisperse distributions of spheres produce Lissajous-like patterns
The complete scattering matrix S of spheres was measured with a flow cytometer. The experimental equipment allows simultaneous detection of two scattering-matrix elements for every sphere in the distribution. Two-parameter scatterplots withx andy coordinates determined by the Sll + Sij and S11 - Sij values are measured. Samples of spheres with very narrow size distributions (< 1%) were analyzed with a FlowCytometer, and they produced unexpected two-parameter scatterplots. Instead of compact distributions we observed Lissajous-like loops. Simulation of the scatterplots, using Lorenz-Mie theory, shows that these loops are due not to experimental errors but to true Lorenz-Mie scattering. It is shown that the loops originate from the sensitivity of the scattered field on the radius of the spheres. This paper demonstrates that the interpretation of rare events and hidden features in flow cytometry needs reconsideration
A sub-1-V Bandgap Voltage Reference in 32nm FinFET Technology
The bulk CMOS technology is expected to scale down to about 32nm node and likely the successor would be the FinFET. The FinFET is an ultra-thin body multi-gate MOS transistor with among other characteristics a much higher voltage gain compared to a conventional bulk MOS transistor [1]. Bandgap reference circuits cannot be directly ported from bulk CMOS technologies to SOI FinFET technologies, because both conventional diodes cannot be realized in thin SOI layers and also, area-efficient resistors are not readily available in processes with only metal(lic) gates. In this paper, a sub-1V bandgap reference circuit is implemented in a 32nm SOI FinFET technology, with an architecture that significantly reduces the required total resistance value
Character, Charisma, Hope, and Healing: Reflections on The Rise and Fall of Mars Hill
In the face of giftedness, we can lose sight that the way of Christ is the way of the cross, of self-giving love.
Posting about the podcast The Rise and Fall of Mars Hill from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.
https://inallthings.org/character-charisma-hope-and-healing-reflections-on-the-rise-and-fall-of-mars-hill
A first implementation of an efficient combustion strategy in a multi cylinder two stage turbo CI-engine producing low emissions while consuming a gasoline/EHN blend
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