535 research outputs found
The Grizzly, October 31, 1980
Campus Poll Favors Reagan, Anderson • Sorority Pleads Guilty To Alcohol Violations • Board Approves Cost Increases For Next Year • Carter & Reagan Make Final Philly Appearances • Athletic Hall of Fame Slated For Founder\u27s Day • It\u27s Laurie for Holmecoming Queen 1980 • Utility Gym Opens With Exciting Concert • Richter Hosts Town Meeting • APO Charter Reviewed • Halloween Dates Back 2000 Years • Booters Drop Three Straight • Gridders Drowned By Swarthmore • Hockey Suffers Season\u27s Second Defeat • Homecoming Sweet For Cross Countryhttps://digitalcommons.ursinus.edu/grizzlynews/1045/thumbnail.jp
Cheatgrass (Bromus tectorum) distribution in the intermountain Western United States and its relationship to fire frequency, seasonality, and ignitions
Cheatgrass (Bromus tectorum) is an invasive grass pervasive across the Intermountain Western US and linked to major increases in fire frequency. Despite widespread ecological impacts associated with cheatgrass, we lack a spatially extensive model of cheatgrass invasion in the Intermountain West. Here, we leverage satellite phenology predictors and thousands of field surveys of cheatgrass abundance to create regional models of cheatgrass distribution and percent cover. We compare cheatgrass presence to fire probability, fire seasonality and ignition source. Regional models of percent cover had low predictive power (34% of variance explained), but distribution models based on a threshold of 15% cover to differentiate high abundance from low abundance had an overall accuracy of 74%. Cheatgrass achieves ≥ 15% cover over 210,000 km2 (31%) of the Intermountain West. These lands were twice as likely to burn as those with low abundance, and four times more likely to burn multiple times between 2000 and 2015. Fire probability increased rapidly at low cheatgrass cover (1–5%) but remained similar at higher cover, suggesting that even small amounts of cheatgrass in an ecosystem can increase fire risk. Abundant cheatgrass was also associated with a 10 days earlier fire seasonality and interacted strongly with anthropogenic ignitions. Fire in cheatgrass was particularly associated with human activity, suggesting that increased awareness of fire danger in invaded areas could reduce risk. This study suggests that cheatgrass is much more spatially extensive and abundant than previously documented and that invasion greatly increases fire frequency, even at low percent cover
A Synthesis of the Effects of Cheatgrass Invasion on US Great Basin Carbon Storage
Non-native, invasive Bromus tectorum (cheatgrass) is pervasive in sagebrush ecosystems in the Great Basin ecoregion of the western United States, competing with native plants and promoting more frequent fires. As a result, cheatgrass invasion likely alters carbon (C) storage in the region. Many studies have measured C pools in one or more common vegetation types: native sagebrush, invaded sagebrush and cheatgrass-dominated (often burned) sites, but these results have yet to be synthesized. We performed a literature review to identify studies assessing the consequences of invasion on C storage in above-ground biomass (AGB), below-ground biomass (BGB), litter, organic soil and total soil. We identified 41 articles containing 386 unique studies and estimated C storage across pools and vegetation types. We used linear mixed models to identify the main predictors of C storage. We found consistent declines in biomass C with invasion: AGB C was 55% lower in cheatgrass (40 ± 4 g C/m2) than native sagebrush (89 ± 27 g C/m2) and BGB C was 62% lower in cheatgrass (90 ± 17 g C/m2) than native sagebrush (238 ± 60 g C/m2). In contrast, litter C was \u3e4× higher in cheatgrass (154 ± 12 g C/m2) than native sagebrush (32 ± 12 g C/m2). Soil organic C (SOC) in the top 10 cm was significantly higher in cheatgrass than in native or invaded sagebrush. SOC below 20 cm was significantly related to the time since most recent fire and losses were observed in deep SOC in cheatgrass \u3e5 years after a fire. There were no significant changes in total soil C across vegetation types. Synthesis and applications. Cheatgrass invasion decreases biodiversity and rangeland productivity and alters fire regimes. Our findings indicate cheatgrass invasion also results in persistent biomass carbon (C) losses that occur with sagebrush replacement. We estimate that conversion from native sagebrush to cheatgrass leads to a net reduction of C storage in biomass and litter of 76 g C/m2, or 16 Tg C across the Great Basin without management practices like native sagebrush restoration or cheatgrass removal
The Grizzly, March 27, 1981
Parents Day Slated for Early April • Overwhelming Enthusiasm Welcomes Special Olympics • Bomberger Tower Under Construction • SPC Elects New Grizzly Editor-in-Chief • Shakespeare Opens • Departmental Focus: Math Department • Transplanted Texan: NY to Collegeville • Spectrum Tries New Ticket Sales • Values Next Forum Topic • TV Production in Communications • Language Clubs Host Dessert Festival • Final Exam Schedule • Baseball Team Carries Much Potential • Hoopsters Finish 3rd in Nation • Tennis Team Prepares for Tough Season • Women\u27s Lacrosse Start Season 1-1https://digitalcommons.ursinus.edu/grizzlynews/1056/thumbnail.jp
The Grizzly, February 13, 1981
Water Crisis Worsens: TCE Also a Problem • Pett Leaving Economics Department • Mobley Breaks Basketball Record • News Briefs: Meistersingers concert in Oreland; Ursinus professor published • Departmental Focus: English Department; History Department • Orientation Committee Applications Being Taken • 1981 Fraternity Pledge Classes • Music News • Female Artists Topic of Forum • Coffeehouse: A Folk Touch • Candidates for USGA Offices • Women\u27s B-Ball Undefeated 9 Straight • Tight Season Ahead for Intramural B-Ball • Badminton Team Playin\u27 Tough • Hoopsters Claim Two More Victims • Grizzly Grapplers Mark at 7-4-1 • Aquabears Dunk Foes: Swimmers Living Up to .500 Goalhttps://digitalcommons.ursinus.edu/grizzlynews/1052/thumbnail.jp
Recommended from our members
Global Education Handbook: Modules for Teaching Pre-School to Secondary School
This handbook was developed to assist K-12 teachers who wish to introduce a global perspective into their curriculum. The modules were developed by classroom teachers and include such topics as: Anti-bias Curriculum: A Multicultural Perspective,” “The African Influence in Puerto Rican Music,” and “Multicultural Education: An Approach through Beauty, Fashion and Art.” Organized according to grade levels, each module is divided into a series of lessons complete with objectives and a detailed description of materials and activities.
It is the purpose of the Global Education Handbook to contribute to networking within the community of educators, locally and globally. The Handbook provides examples of lesson plans and units with a global perspective for use at the pre-school, elementary, middle, and secondary grade levels. It identifies a global network of resources which is available to educators who want to bring the world into their classrooms. Included is an account of an early childhood educator in a rural elementary school in Western Massachusetts who is attempting to instill a global perspective in her curriculum. Her experiences bring to light many of the challenges which confront new and veteran educators who wish to globalize their classrooms and their schools.
The Handbook is organized into chapters according to grade level: pre-school, elementary, middle, and secondary. The material within each of these chapters was developed by teachers who implemented these global education units in their classrooms. Each unit is comprised of several lessons that have either a geographic, cultural, or issue-based focus. These resources can be used directly from the Handbook and it is hoped that they will inspire the development of other lessons and units particular to the unique needs of each educator
The Grizzly, October 3, 1980
Administration Focuses Attention On Pledging • Ritter Investigation Continues • Strangers Vandalize Beardwood Extinguishers • USGA Sponsors Alcohol Awareness Program • Women Experience the Excitement of Bid Day • College Disciplines Two Fraternities • Prof Appointed in Ec/BA • Photography Course Offered In Evening School • Values Education Examined By Committee • Candidates\u27 Platforms for Campus Elections • Classes of \u2781, \u2783 to Sponsor Gong Show • Album Review: Panorama: New View New Wave • Time Square Is Sheer Inspiration • Rush Returns to Philadelphia After Long Delay • Dingy Room Ideas Vol. II • Field Hockey Ties W&M; Beats Gettysburg • Volleyball Lookin\u27 Good • Awesome Widener Crunches Grizzlies • Sports Profile: Debbie Tweed • Cross Country Streak Alive • Despite 2-0 Loss, Booters Still Showing Promisehttps://digitalcommons.ursinus.edu/grizzlynews/1042/thumbnail.jp
Three-sided pyramid wavefront sensor. II. Preliminary demonstration on the new CACTI testbed
The next generation of giant ground and space telescopes will have the
light-collecting power to detect and characterize potentially habitable
terrestrial exoplanets using high-contrast imaging for the first time. This
will only be achievable if the performance of Giant Segmented Mirror Telescopes
(GSMTs) extreme adaptive optics (ExAO) systems are optimized to their full
potential. A key component of an ExAO system is the wavefront sensor (WFS),
which measures aberrations from atmospheric turbulence. A common choice in
current and next-generation instruments is the pyramid wavefront sensor (PWFS).
ExAO systems require high spatial and temporal sampling of wavefronts to
optimize performance, and as a result, require large detectors for the WFS. We
present a closed-loop testbed demonstration of a three-sided pyramid wavefront
sensor (3PWFS) as an alternative to the conventional four-sided pyramid
wavefront (4PWFS) sensor for GSMT-ExAO applications on the new Comprehensive
Adaptive Optics and Coronagraph Test Instrument (CACTI). The 3PWFS is less
sensitive to read noise than the 4PWFS because it uses fewer detector pixels.
The 3PWFS has further benefits: a high-quality three-sided pyramid optic is
easier to manufacture than a four-sided pyramid. We detail the design of the
two components of the CACTI system, the adaptive optics simulator and the PWFS
testbed that includes both a 3PWFS and 4PWFS. A preliminary experiment was
performed on CACTI to study the performance of the 3PWFS to the 4PWFS in
varying strengths of turbulence using both the Raw Intensity and Slopes Map
signal processing methods. This experiment was repeated for a modulation radius
of 1.6 lambda/D and 3.25 lambda/D. We found that the performance of the two
wavefront sensors is comparable if modal loop gains are tuned.Comment: 28 Pages, 15 Figures, and 4 Table
Defining System Requirements for Simplified Blood Culture to Enable Widespread Use in Resource-Limited Settings
Bacterial blood stream infections (BSI) are a common cause of mortality and morbidity globally. As the causative agents and the resulting treatment decisions vary, near-patient testing and surveillance tools are necessary to monitor bacterial causes and resistance to antimicrobial agents. The gold standard to identify BSIs is blood culture (BC), a methodology not widely available in resource-limited settings. The aim of the study was to map out a target product profile of a simplified BC system (SBCS) to inform product development efforts. To identify the desired characteristics of a SBCS, we enlisted a small group of specialists working in Africa and Asia. Questions were used to understand challenges and how these constraints inform system requirements. The specialists were infectious disease physicians, public health/clinical microbiologists, clinical researchers, and technology experts with different geographical backgrounds. All suggested that BC should ideally be available at the district hospital level. Many of the same operational challenges, such as limited availability of culture bottles, electricity and internet connectivity, profuse dust, the lack of ambient temperature control, and human capacity constraints were identified across the different regions. BCs, although the accepted gold standard for diagnosis of BSIs, are not widely available outside of reference/research centers in Africa and Asia. To extend the reach of this important tool, it is crucial to engage product developers and academic research partners to develop accessible alternatives.</jats:p
Defining System Requirements for Simplified Blood Culture to Enable Widespread Use in Resource-Limited Settings
Bacterial blood stream infections (BSI) are a common cause of mortality and morbidity globally. As the causative agents and the resulting treatment decisions vary, near-patient testing and surveillance tools are necessary to monitor bacterial causes and resistance to antimicrobial agents. The gold standard to identify BSIs is blood culture (BC), a methodology not widely available in resource-limited settings. The aim of the study was to map out a target product profile of a simplified BC system (SBCS) to inform product development efforts. To identify the desired characteristics of a SBCS, we enlisted a small group of specialists working in Africa and Asia. Questions were used to understand challenges and how these constraints inform system requirements. The specialists were infectious disease physicians, public health/clinical microbiologists, clinical researchers, and technology experts with different geographical backgrounds. All suggested that BC should ideally be available at the district hospital level. Many of the same operational challenges, such as limited availability of culture bottles, electricity and internet connectivity, profuse dust, the lack of ambient temperature control, and human capacity constraints were identified across the different regions. BCs, although the accepted gold standard for diagnosis of BSIs, are not widely available outside of reference/research centers in Africa and Asia. To extend the reach of this important tool, it is crucial to engage product developers and academic research partners to develop accessible alternatives.</jats:p
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