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The Apollo Virtual Microscope Collection: Lunar Mineralogy and Petrology of Apollo 11, 12, 14, 15 and 16 Rocks
We report on the new Virtual Microscopes on Apollo 16 lunar samples in our Apollo Virtual Microscope collection
PEER Testbed Study on a Laboratory Building: Exercising Seismic Performance Assessment
From 2002 to 2004 (years five and six of a ten-year funding cycle), the PEER Center organized
the majority of its research around six testbeds. Two buildings and two bridges, a campus, and a
transportation network were selected as case studies to “exercise” the PEER performance-based
earthquake engineering methodology. All projects involved interdisciplinary teams of
researchers, each producing data to be used by other colleagues in their research. The testbeds
demonstrated that it is possible to create the data necessary to populate the PEER performancebased framing equation, linking the hazard analysis, the structural analysis, the development of
damage measures, loss analysis, and decision variables.
This report describes one of the building testbeds—the UC Science Building. The project
was chosen to focus attention on the consequences of losses of laboratory contents, particularly
downtime. The UC Science testbed evaluated the earthquake hazard and the structural
performance of a well-designed recently built reinforced concrete laboratory building using the
OpenSees platform. Researchers conducted shake table tests on samples of critical laboratory
contents in order to develop fragility curves used to analyze the probability of losses based on
equipment failure. The UC Science testbed undertook an extreme case in performance
assessment—linking performance of contents to operational failure. The research shows the
interdependence of building structure, systems, and contents in performance assessment, and
highlights where further research is needed.
The Executive Summary provides a short description of the overall testbed research
program, while the main body of the report includes summary chapters from individual
researchers. More extensive research reports are cited in the reference section of each chapter
The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)
We report a chip-scale lensless wide-field-of-view microscopy imaging technique, subpixel perspective sweeping microscopy, which can render microscopy images of growing or confluent cell cultures autonomously. We demonstrate that this technology can be used to build smart Petri dish platforms, termed ePetri, for cell culture experiments. This technique leverages the recent broad and cheap availability of high performance image sensor chips to provide a low-cost and automated microscopy solution. Unlike the two major classes of lensless microscopy methods, optofluidic microscopy and digital in-line holography microscopy, this new approach is fully capable of working with cell cultures or any samples in which cells may be contiguously connected. With our prototype, we demonstrate the ability to image samples of area 6 mm Ă— 4 mm at 660-nm resolution. As a further demonstration, we showed that the method can be applied to image color stained cell culture sample and to image and track cell culture growth directly within an incubator. Finally, we showed that this method can track embryonic stem cell differentiations over the entire sensor surface. Smart Petri dish based on this technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks
Chiasma
Newspaper reporting on events at the Boston University School of Medicine in the 1960s
A Step-by-step Guide to the Realisation of Advanced Optical Tweezers
Since the pioneering work of Arthur Ashkin, optical tweezers have become an
indispensable tool for contactless manipulation of micro- and nanoparticles.
Nowadays optical tweezers are employed in a myriad of applications
demonstrating the importance of these tools. While the basic principle of
optical tweezers is the use of a strongly focused laser beam to trap and
manipulate particles, ever more complex experimental set-ups are required in
order to perform novel and challenging experiments. With this article, we
provide a detailed step- by-step guide for the construction of advanced optical
manipulation systems. First, we explain how to build a single-beam optical
tweezers on a home-made microscope and how to calibrate it. Improving on this
design, we realize a holographic optical tweezers, which can manipulate
independently multiple particles and generate more sophisticated wavefronts
such as Laguerre-Gaussian beams. Finally, we explain how to implement a speckle
optical tweezers, which permit one to employ random speckle light fields for
deterministic optical manipulation.Comment: 29 pages, 7 figure
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