In this chapter, we review the imaging techniques and methods of molecular interrogation made possible by integrating laser light sources with microscopy. We discuss the advantages of exciting fluorescence by laser illumination and review commonly used laser-based imaging techniques such as confocal, multiphoton, and total internal reflection microcopy. We also discuss emerging imaging modaliti...

Gap junctions have diverse roles in a wide variety of tissues and have recently become a subject of intense investigation in neural circuits where synchrony and oscillations may play an important part. In circuits where gap junctions are present, the possibility arises of identifying intercommunicating cells via introduction of tracer into one cell and observing its spread into its coupled neig...

BACKGROUND Isotopic labeling is an analytic technique that is used to track the movement of isotopes through reaction networks. In general, the applicability of isotopic labeling techniques is limited to the investigation of reaction networks that consider homonuclear moieties, whose atoms are of one tracer element with two isotopes, distinguished by the presence of one additional neutron. RE...

Ray-tracing and UTD (Uniform Theory of Diffraction) techniques are already widely applied to site-specific radio propagation modeling for wireless applications. This paper briefly presents the software tool Radio-Tracer that uses efficient algorithms to calculate dynamically the exact visibility graph of an environment taking into account the position of both transmitter and receivers and the m...

A large-scale, natural-gradient tracer test in a heterogeneous aquifer at a site near Columbus, Miss. is simulated using three-dimensional (3D) hydraulic conductivity distributions derived from the borehole flowmeter test data. The simulated plume is more sensitive to the way the hydraulic conductivity field is interpolated from the measured data than it is to the dispersivity value. The transp...

In part one of this series, Moore (2004a) introduced the general principles of stream gauging by salt dilution. In subsequent articles, Moore (2004b, 2005) described techniques of constant-rate injection and slug injection using salt in solution. This is the final article in the series and details the “mass balance method.” Originally described by Elder et al. (1990), the mass balance method di...

Biosafety Level 3 (BL-3) laboratories are designed to prevent the escape of pathogenic microorganisms by operating at negative pressure so that if microorganisms become airborne, they remain within the laboratory. However, the authors are not aware of any published evidence or international guidance on the level of pressure differential required for BL-3 laboratories. This uncertainty was refle...

Anthropogenic 236U (t½=23.4 My) is an emerging isotopic ocean tracer with interesting oceanographic properties, but only with recent advances in accelerator mass spectrometry techniques is it now possible to detect the levels from global fall-out of nuclear weapons testing across the water column. To make full use of this tracer, an assessment of its input into the ocean over the past decades i...