Sustainable management of non-native thistles on the Western Slope

2017 Spring.Includes bibliographical references.The scope of this research is unique in that it encompasses all phases of the weed management process. From problem identification, to identifying and testing solutions, to implementing the solution in a real world environment. The environmental challenges present on Blue Creek Ranch as well as the necessity to manage the expectations of stakeholders made this a multifaceted and challenging project. Field observations of the invasive thistle problem present on Blue Creek Ranch were confirmed through an extensive GIS survey and subsequent geospatial analysis. From this analysis, the invasive thistle infestation on the ranch could be quantified and presented in easily understood maps. This information helped guide management efforts and provided a tool to help educate stakeholders. Once this information was collected, an experiment was devised to judge the impacts of potential treatments on the ranch. Typical infestations of musk thistle an invasive annual thistle, favor highly disturbed lands. However, encroachment into the otherwise healthy montane range is being observed on Colorado's Western Slope. Within the context of a grass fed cattle operation, such as the one on Blue Creek Ranch, this range loss can result in decreased productivity. With the problem identified, there is now a need to identify herbicide treatments that can eliminate the thistles impacts while preserving the lands high forage value. We hypothesize that using selective herbicides, coupled with minimum dose rates, will not impact the overall forage quality of the range or the overall species abundance. In fall of 2014, four post emergent herbicide treatments (2 rates of aminopyralid, picloram and aminocyclopyrachlor) were applied in a split-plot design. In 2015 cover data and above ground biomass were collected to evaluate any treatment effects. Additionally, the edible forage component of the collected biomass was sent for feed analysis. In 2016 only cover data was collected. Across all treatments musk thistle was significantly reduced compared to control with no significant differences found between herbicide treatments. In evaluating species abundance it was found that no herbicide treatment resulted in any significant reduction. Finally, the feed analysis found that while the aminocyclopyrachor treatment tended to reduce the feed values of forbs there is no significant reduction in the overall feed values when total biomass (grass + forbs) is taken into account. These results indicate that regardless of which of the tested herbicides were used, musk thistle can be effectively controlled while at the same time preserving forage quality and, ultimately, production. Finally, all of this information was compiled into a weed management plan that will be presented to the owner and managers of Blue Creek Ranch to guide future management efforts. A plan was devised to define the scope of the management effort, specific management efforts and future monitoring activities. This management plan represents the culmination of the research conducted on Blue Creek Ranch and will be revised and updated as progress is made and new challenges arise

Four-Pass Coupler for Laser-Diode-Pumped Solid-State Laser

A four-pass optical coupler affords increased (in comparison with related prior two-pass optical couplers) utilization of light generated by a laser diode in side pumping of a solid-state laser slab. The original application for which this coupler was conceived involves a neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal slab, which, when pumped by a row of laser diodes at a wavelength of 809 nm, lases at a wavelength of 1,064 nm. Heretofore, typically, a thin laser slab has been pumped in two passes, the second pass occurring by virtue of reflection of pump light from a highly reflective thin film on the side opposite the side through which the pump light enters. In two-pass pumping, a Nd:YAG slab having a thickness of 2 mm (which is typical) absorbs about 84 percent of the 809-nm pump light power, leaving about 16 percent of the pump light power to travel back toward the laser diodes. This unused power can cause localized heating of the laser diodes, thereby reducing their lifetimes. Moreover, if the slab is thinner than 2 mm, then even more unused power travels back toward the laser diodes. The four-pass optical coupler captures most of this unused pump light and sends it back to the laser slab for two more passes. As a result, the slab absorbs more pump light, as though it were twice as thick. The gain and laser cavity beam quality of a smaller laser slab in conjunction with this optical coupler can thus be made comparable to those of a larger two-pass-pumped laser slab

Injection seeded, diode pumped regenerative ring Nd:YAG amplifier for spaceborne laser ranging technology development

A small, all solid state, regenerative ring amplifier designed as a prototype for space application is discussed. Novel features include dual side pumping of the Nd:YAG crystal and a triangular ring cavity design which minimizes the number of optical components and losses. The amplifier is relatively small (3 ns round trip time) even though standard optical elements are employed. The ring regeneratively amplifies a 100 ps single pulse by approximately 10(exp 5) at a repetition rate of 10 to 100 Hz. The amplifier is designed to be injection seeded with a pulsed, 100 ps laser diode at 1.06 microns, but another Nd:YAG laser system supplying higher pulse energies was employed for laboratory experiment. This system is a prototype laser oscillator for the Geoscience Laser Ranging System (GLRS) platform. Results on measurements of beam quality, astigmatism, and gain are given

High Output Maximum Efficiency Resonator

A diode pumped, solid state laser is provided that can produce over 16 billion, 15 mJ, 10 ns Q-Switched laser pulses with a low measured decay rate. The laser can be integrated into a global biomass measuring instrument, and mounted on the International Space Station (ISS)

Data on the number and frequency of scientific literature citations for established medulloblastoma cell lines

This article collates information about the number of scientific articles mentioning each of the established medulloblastoma cell lines, derived through a systematic search of Web of Science, Scopus and Google Scholar in 2016. The data for each cell line have been presented as raw number of citations, percentage share of the total citations for each search engine and as an average percentage between the three search engines. In order to correct for the time since each cell line has been in use, the raw citation data have also been divided by the number of years since the derivation of each cell line. This is a supporting article for a review of in vitro models of medulloblastoma published in “in vitro models of medulloblastoma: choosing the right tool for the job” (D.P. Ivanov, D.A. Walker, B. Coyle, A.M. Grabowska, 2016) [1]

Efficient Dual Head Nd:YAG 100mJ Oscillator for Remote Sensing

A diode pumped, Nd:YAG laser producing 100 mJ Q-switched pulses and employing a dual-pump head scheme in an unstable resonator configuration is described. Each head contains a side pumped zig-zag slab and four 6-bar QCW 808 nm diodes arrays which are de-rated 23%. Denoting 'z' as the lasing axis, the pump directions were along the x-axis in one head and the y-axis in the other, producing a circularized thermal lens, more typical in laser rod-based cavities. The dual head design's effective thermal lens is now corrected with a proper HR mirror curvature selection. This laser has demonstrated over 100 mJ output with high optical efficiency (24%), good TEM(sub 00) beam quality, and high pointing stability

Tuning localized plasmons in nanostructured substrates for surface-enhanced Raman scattering

Comprehensive reflectivity mapping of the angular dispersion of nanostructured arrays comprising of inverted pyramidal pits is demonstrated. By comparing equivalently structured dielectric and metallic arrays, diffraction and plasmonic features are readily distinguished. While the diffraction features match expected theory, localised plasmons are also observed with severely flattened energy dispersions. Using pit arrays with identical pitch, but graded pit dimensions, energy scaling of the localised plasmon is observed. These localised plasmons are found to match a simple model which confines surface plasmons onto the pit sidewalls thus allowing an intuitive picture of the plasmons to be developed. This model agrees well with a 2D finite-difference time-domain simulation which shows the same dependence on pit dimensions. We believe these tuneable plasmons are responsible for the surface-enhancement of the Raman scattering (SERS) of an attached layer of benzenethiol molecules. Such SERS substrates have a wide range of applications both in security, chemical identification, environmental monitoring and healthcare