The authors demonstrate the generation of multicycle narrow-bandwidth terahertz pulses in periodically inverted GaAs structures using optical rectification of 2 μm, 100 fs pump pulses. Three different types of orientation-inverted samples are employed: optically contacted multilayer, orientation-patterned, and diffusion-bonded GaAs. The terahertz pulses are characterized by two-color (pump at 2...
Background: Mangroves are ecologically important and highly threatened forest communities. Observational and genetic evidence has confirmed the long distance dispersal capacity of water-dispersed mangrove seeds, but less is known about the relative importance of pollen vs. seed gene flow in connecting populations. We analyzed 980 Avicennia germinans for 11 microsatellite...
We constructed an experimental apparatus that used lasers to provide the probe beams for measuring the transient absorption kinetics of bacterioplankton that contain proteorhodopsin, a microbial protein that binds retinal and is analogous to animal rhodopsin. With this approach we were able to observe photocycles characteristic of functioning retinylidene ion...
Most of the research on wave energy conversion
has been focused on the characterization of the
dynamic behavior of arrays of uncontrolled WECs in
specific configurations, in order to quantify changes
in the wave fields and absorbed power without active
control. To maximize wave energy conversion, however,
it is necessary...
This is the fourth in a series of studies to evaluate perceptions of U.S. Department of Agriculture Forest Service law enforcement personnel of the roles, responsibilities, and issues related to their jobs. An e-mail survey was administered to the 89 Forest Service special agents, assistant special agents in charge, senior...
Dynamic bipedal robots, which are capable of versatile behaviour, are rare. Most bipedal robots are either versatile and static or dynamic and limited to specific gaits. Over the last twenty years the bio-inspired spring mass model became a versatile template for bipedal walking and running gaits with many studies motivated...
Swiss needle cast, a foliar disease caused by the Ascomycete Phaeocryptopus gaeumannii (T. Rohde) Petr., continues to afflict Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in north coastal Oregon. Permanent plots were installed in 1998 to assess growth impacts and monitor disease severity. Gross periodic annual increment was measured for three 2-year...
The significance of the various carbon cycling pathways in driving the sharp sulfate methane transition (SMTZ) observed at many locations on continental margins is still a topic of debate. Unraveling these processes is important to our understanding of the carbon cycle in general and to evaluate whether the location of...
African rue is a poisonous, perennial forb that readily invades salt-desert shrub and sagebrush-steppe rangelands. Information detailing options for integrated management of African rue is lacking. To date, a few studies have researched the efficacy of different herbicides for controlling African rue, but none have investigated integrated approaches to its...
We combine large observed data sets and dynamically downscaled climate data to explore historic and future (2050-2069) stream temperature changes over the topographically diverse Greater Yellowstone Ecosystem (elevation range=824-4017m). We link future stream temperatures with fish growth models to investigate how changing thermal regimes could influence the future distribution and...