Using Expert Knowledge to Satisfy Data Needs:Mapping Invasive Plant Distributions in the Western United States

Lack of knowledge about the distributions of plant and animal species can severely hamper management efforts. For invasive plants, distribution and abundance data can inform early detection and rapid response (EDRR) programs aimed at treating initial infestations. These data can be used to create invasion risk models at landscape and regional scales. Further, regional maps of invasive plant abundance are useful for communicating the scope of the invasive species problem to the public and policymakers. Here, we present a set of regional distribution maps for 10 problematic invasive plants in the western United States, created from the expert knowledge of weed managers in over 300 counties. Invasive plant experts identified infestations on paper, and the results were digitized into a regional GIS. Over 40% of requests were returned, resulting in maps with good spatial coverage and distribution data suitable for assessing invasive plant abundance across the western United States. Cheatgrass (Bromus tectorum) and Canada thistle (Cirsium arvense) were the most abundant and widespread of the surveyed species; however, the high concentrations and broad spatial extents of other invasive plants, such as hounds tongue (Cynoglossum officinale), white top (Lepidium draba), and Dalmatian toadflax (Linaria dalmatica), highlight the ongoing problems invasive species pose for western ecosystems, rangelands, and croplands. These results reinforce the critical role that regional mapping efforts can play in assessing and communicating invasion risk. This study suggests that knowledge about plant invasions exists locally and that experts are willing to participate in regional efforts to compile that information

Spatial variations of the fine-structure constant in symmetron models

We investigate the variation of the fine-structure constant, {\alpha}, in symmetron models using N-body simulations in which the full spatial distribution of {\alpha} at different redshifts has been calculated. In particular, we obtain simulated sky maps for this variation, and determine its power spectrum. We find that in high-density regions of space (such as deep inside dark matter halos) the value of {\alpha} approaches the value measured on Earth. In the low-density outskirts of halos the scalar field value can approach the symmetry breaking value and leads to significantly different values of {\alpha}. If the scalar-photon coupling strength {\beta}{\gamma} is of order unity we find that the variation of {\alpha} inside dark matter halos can be of the same magnitude as the recent claims by Webb et al. of a dipole variation. Importantly, our results also show that with low-redshift symmetry breaking these models exhibit some dependence of {\alpha} on lookback time (as opposed to a pure spatial dipole) which could in principle be detected by sufficiently accurate spectroscopic measurements, such as those of ALMA and the ELT-HIRES.Comment: 11 pages, 9 figure

Assessment of Buffet Forcing Function Development Process Using Unsteady Pressure Sensitive Paint

A wind tunnel test was conducted at the Ames Unitary Plan Wind Tunnel to characterize the transonic buffet environment of a generic launch vehicle forebody. The test examined a highly instrumented version of the Coe and Nute Model 11 test article first tested in the 1960s. One of the measurement techniques used during this test was unsteady pressure sensitive paint (uPSP) developed at the Arnold Engineering Development Complex. This optical measurement technique measured fluctuating pressures at over 300,000 locations on the surface of the model. The high spatial density of these measurements provided an opportunity to examine in depth the assumptions underpinning the development of buffet forcing functions (BFFs) used in the development of the Space Launch System vehicle. The comparison of discrete-measurement-based BFFs to BFFs developed by continuous surface pressure integration indicates that the current BFF development approach under predicts low frequency content of the BFFs while over predicting high frequency content. Coherence-based adjustments employed to reduce over prediction in the surface integration of discrete pressure measurements contribute to the inaccuracy of the BFFs and their implementation should be reevaluated

Liana canopy cover mapped throughout a tropical forest with high-fidelity imaging spectroscopy

Increasing size and abundance of lianas relative to trees are pervasive changes in Neotropical forests that may lead to reduced forest carbon stocks. Yet the liana growth form is chronically understudied in large-scale tropical forest censuses, resulting in few data on the scale, cause, and impact of increasing lianas. Satellite and airborne remote sensing provide potential tools to map and monitor lianas at much larger spatial and rapid temporal scales than are possible with plot-based forest censuses. We combined high-resolution airborne imaging spectroscopy and a ground-based tree canopy census to investigate whether tree canopies supporting lianas could be discriminated from tree canopies with no liana coverage. Using support vector machine algorithms, we achieved accuracies of nearly 90% in discriminating the presence–absence of lianas, and low error (15.7% RMSE) when predicting liana percent canopy cover. When applied to the full image of the study site, our model had a 4.1% false-positive error rate as validated against an independent plot-level dataset of liana canopy cover. Using the derived liana cover classification map, we show that 6.1%–10.2% of the 1823 ha study site has high-to-severe (50–100%) liana canopy cover. Given that levels of liana infestation are increasing in Neotropical forests and can result in high tree mortality, the extent of high-to-severe liana canopy cover across the landscape may have broad implications for ecosystem function and forest carbon storage. The ability to accurately map landscape-scale liana infestation is crucial to quantifying their effects on forest function and uncovering the mechanisms underlying their increase

Disentangling the mechanisms and uncovering the scale of increasing liana size and abundance in neotropical forests.

Humans are altering tropical ecosystems and their biotic and biogeochemical processes with unprecedented scale and severity. The increasing size and abundance of tropical lianas (woody climbing plants) relative to trees may be the result of global anthropogenic change, and may further alter forest function. Yet the mechanisms responsible for this reported phenomenon are unclear, and the scale at which it occurs has been unexamined. In this dissertation, I use a combination of empirical experimentation, ground-based forest censuses, and advanced airborne remote sensing imagery and analysis to investigate the question of why lianas are increasing and at what spatial scale. First, I tested the hypothesis that elevated CO2 gives species of lianas a growth advantage relative to trees, especially during periods of seasonal drought. In the first experiments to directly compare the relative response of tropical liana and tree species to elevated CO2, I found no significant differences between the two growth forms. Both lianas and trees responded equally well to elevated CO2, even when soil water was limited by seasonal drought. Second, I extended the tests of liana-tree response to CO2 to include the effects of soil nutrient availability. No interactions between elevated CO2 and either soil nitrogen or phosphorus availability were found for lianas. Instead, changes to soil nutrient availability or CO2 alone had strong and significant effects on lianas. Finally, I used data collected from my field censuses to train machine learning algorithms to detect severe liana coverage in tree canopies using high-resolution hyperspectral imagery. This method proved to be very accurate at distinguishing severe liana cover from liana-free cover in tree canopies, and quantified severe liana infestation as 11.9%-18.0% of the total canopy cover over a 600-ha tropical forest. The results of the experiments and the development of landscape-scale liana detection methods are key steps toward a full understanding of the mechanisms and scope of the liana increase.PHDEcology and Evolutionary BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107049/1/marvs_1.pd

A rectangular waveguide cell for measurement of the shielding effectiveness of anisotropic materials

A method for measuring the shielding effectiveness of planar anisotropic materials using a rectangular waveguide cell is proposed. Computational models are used to verify the behaviour of the cell and validate its ability to measure shielding effectiveness. Results of measurements on a control sample and three carbon-fibre composite laminates in a GTEM cell are presented. A dynamic range of 70 dB with a capability to discriminate 20 dB of anisotropy is achieved in the frequency range 400-1600 MHz using cubic cells of side length 200 mm and 300 mm

No evidence that elevated CO\u3csub\u3e2\u3c/sub\u3e gives tropical lianas an advantage over tropical trees

Recent studies indicate that lianas are increasing in size and abundance relative to trees in neotropical forests. As a result, forest dynamics and carbon balance may be altered through liana‐induced suppression of tree growth and increases in tree mortality. Increasing atmospheric CO2 is hypothesized to be responsible for the increase in neotropical lianas, yet no study has directly compared the relative response of tropical lianas and trees to elevated CO2. We explicitly tested whether tropical lianas had a larger response to elevated CO2 than co‐occurring tropical trees and whether seasonal drought alters the response of either growth form. In two experiments conducted in central Panama, one spanning both wet and dry seasons and one restricted to the dry season, we grew liana (n = 12) and tree (n = 10) species in open‐top growth chambers maintained at ambient or twice‐ambient CO2 levels. Seedlings of eight individuals (four lianas, four trees) were grown in the ground in each chamber for at least 3 months during each season. We found that both liana and tree seedlings had a significant and positive response to elevated CO2 (in biomass, leaf area, leaf mass per area, and photosynthesis), but that the relative response to elevated CO2 for all variables was not significantly greater for lianas than trees regardless of the season. The lack of differences in the relative response between growth forms does not support the hypothesis that elevated CO2 is responsible for increasing liana size and abundance across the neotropics

Taking Development Seriously: Critique of the 2008 \u3ci\u3eJME\u3c/i\u3e Special Issue on Moral Functioning

This essay comments on articles that composed a Journal of Moral Education Special Issue (September, 2008, 37[3]). The issue was intended to honor the 50th anniversary of Lawrence Kohlberg’s doctoral dissertation and his subsequent impact on the field of moral development and education. The articles were characterized by the issue editor (Don Collins Reed) as providing a “look forward” from Kohlberg’s work toward a more comprehensive or integrated model of moral functioning. Prominent were culturally pluralist and biologically based themes, such as cultural learning; expert skill; culturally shaped and neurobiologically based predispositions or intuitions; and moral self-relevance or centrality. Inadequately represented, however, was Kohlberg’s (and Piaget’s) key concept of development as the construction of a deeper or more adequate understanding not reducible to particular socialization practices or cultural contexts. Also neglected were related cognitive-developmental themes, along with supportive evidence. Robert Coles’s account of a sudden rescue is used as a heuristic to depict Piaget’s/Kohlberg’s approach to the development of moral functioning. We conclude that, insofar as the Special Issue does not take development seriously, it moves us not forward but, instead, back to the problems of moral relativism and moral paralysis that Kohlberg sought to redress from the start of his work more than 50 years ago

Etiology of Experimental Osteoarthritis: Early Events and Potential Clinical Implications

Introduction Osteoarthritis (OA) is the most common form of arthritis and accounts for 50% of all chronic conditions in the elderly. One in two adults reported a chronic musculoskeletal condition in 2005, twice the rate of reported chronic heart or respiratory conditions(2). In addition, persons aged 45 to 64 account for an increasingly greater proportion of total musculoskeletal disease treatment costs and lost wages, a trend that will continue for the next several decades(3). Surgical treatment culminating in total joint replacement (TJR) remains the most effective therapy for late stage OA. Current treatment of pre-surgical OA consists of pain relieving medications (i.e. NSAIDs), physical therapy, and mechanical supports (i.e. braces, canes, and walkers). Despite the wealth of clinical data on OA, there is currently no cure for the disease. Our previous work in developing potential disease-modifying osteoarthritis drugs (DMOADs) had yielded promising results, showing a decrease in OA cartilage lesion areas and histological grades (Figure 1). Interestingly, we noted that animals treated for only the first 3 weeks demonstrated near 6-week levels of OA reduction. These differences in treatment responsiveness necessitate a better characterization of the specific cellular phases of OA throughout the natural disease progression. The current study was undertaken to clarify this progression of early OA events. Methods OA was induced in the right knees of 10-week-old male 129 S6/SvEv (Taconic) mice via DMM surgery. Mice receiving sham surgery with no destabilization were used as negative controls. Both groups were sacrificed at 4, 8, 12, 16, and 20-day intervals in order to evaluate OA progression. Knees were harvested, processed, and sectioned at 6um intervals. Sections were stained for cartilage composition (Safranin-O) and scored for progression and severity of OA by 3 blinded observers using a 0-5 scale (modified Mankin System)(4). Both ‘mean maximal’ scores (highest scores per knee), and ‘mean summed scores (sum of scores per knee) were generated using this scale. All scores were averaged across observers. Cartilage lesion area, subchondral bone area (sclerosis), and apoptosis (TUNEL method) were measured using a histomorphometric analysis package (ImageJ)(5). Conclusions Measurable osteoarthritic changes in articular cartilage and underlying bone following meniscal injury occur far earlier than previously described. Some changes are clearly degenerative (OA grade, stage & lesion area), however, some changes (subchondral bone thickening) could be regarded as compensatory supportive mechanisms. Cell death (apoptosis) is an acute event following relatively minor changes to knee biomechanics. Our results suggest an opportunity for intervention early on in OA before the resulting articular changes become irreversible. Specifically, consideration of anti-apoptosis based therapies could prevent much of the subsequent structural changes in articular cartilage. Future Directions Apoptosis data suggests pursuing an anti-apoptotic therapy strategy in the DMM model of OA Early bone sclerotic events suggest bone tissue as a target for anti-OA therapy. Translationally, preventing or delaying OA due to soft tissue injuries (e.g., sports injuries) may be possible with early medical treatment of OA proximal to the time of injury. References (1) International Bone and Joint Decade 2000-2010 Organization, 1999. (2) National Center for Health Statistics, National Health Interview Survey, 2005. (3) Kurtz, SM, Lau, E, et al. Future Young Patient Demand for Primary and Revision Joint Replacement: National Projections from 2010 to 2030. Clinical Orthopaedics and Related Research, April 2009. (4) Kurtz, SM, Ong, K, et. al. Projections of Primary and Revision Hip and Knee Arthroplasty in the United States from 2005 to 2030. The Journal of Bone and Joint Surgery, 2007;89:780-5. (5) http://rsbweb.nih.gov/ij