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22,706 full-text articles. Page 5 of 503.

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. McChesney, J. E. Hertzberg, J. F. McManus 2018 Old Dominion University

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus

OEAS Faculty Publications

The mean state and variability of the tropical Pacificis influenced by the depth of the thermocline. During the Last Glacial Maximum (~21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth’s role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean δ18O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical δ18O gradient throughout the eastern equatorial Pacific. We find ...


Microbial Community Structure And Functions Differ Between Native And Novel (Exotic-Dominated) Grassland Ecosystems In An 8-Year Experiment, Aleksandra Checinska Sielaff, Racheal N. Upton, Kirsten S. Hofmockel, Xia Xu, H. Wayne Polley, Brian J. Wilsey 2018 Iowa State University

Microbial Community Structure And Functions Differ Between Native And Novel (Exotic-Dominated) Grassland Ecosystems In An 8-Year Experiment, Aleksandra Checinska Sielaff, Racheal N. Upton, Kirsten S. Hofmockel, Xia Xu, H. Wayne Polley, Brian J. Wilsey

Ecology, Evolution and Organismal Biology Publications

A Grasslands dominated by non-native (exotic) spe- cies have replaced purely native-dominated areas in many parts of the world forming ‘novel’ ecosystems. Altered precipitation patterns are predicted to exacerbate this trend. It is still poorly understood how soil microbial communities and their functions differ between high diversity native- and low diversity exotic-dominated sites and how altered precipitation will impact this difference.

Methods We sampled 64 experimental grassland plots in central Texas with plant species mixtures of either all native or all exotic species; half with summer irrigation. We tested how native vs. exotic plant species mixtures and summer irrigation affected ...


Postseismic Restoration Of The Ecological Environment In The Wenchuan Region Using Satellite Data, Zhibin Huang, Min Xu, Wei Chen, Xiaojuan Lin, Chunxiang Cao, Ramesh Singh 2018 Chinese Academy of Sciences

Postseismic Restoration Of The Ecological Environment In The Wenchuan Region Using Satellite Data, Zhibin Huang, Min Xu, Wei Chen, Xiaojuan Lin, Chunxiang Cao, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Using Landsat remote-sensing data combined with geological information extracted from ALOS and Sentinel-1A radar data, the ecological environment was evaluated in the years 2007, 2008, 2013, and 2017 through gray correlation analysis on the basis of the construction of the pressure-state-response model. The main objective of this research was to assess the ecological environment changes in Wenchuan County before and after the earthquake, and to provide reference for future social development and policy implementation. The grading map of the ecological environment was obtained for every year, and the ecological restoration status of Wenchuan County after the earthquake was evaluated. The ...


Perennial Biomass Crop Establishment, Community Characteristics, And Productivity In The Upper Us Midwest: Effects Of Cropping Systems Seed Mixtures And Biochar Applications, Catherine L. Bonin, Rivka B. Fidel, Chumki Banik, David A. Laird, Robert Mitchell, Emily A. Heaton 2018 Iowa State University

Perennial Biomass Crop Establishment, Community Characteristics, And Productivity In The Upper Us Midwest: Effects Of Cropping Systems Seed Mixtures And Biochar Applications, Catherine L. Bonin, Rivka B. Fidel, Chumki Banik, David A. Laird, Robert Mitchell, Emily A. Heaton

Agronomy Publications

Native perennial plants have potential as bioenergy feedstocks, but their use is currently limited by relatively long establishment times and low biomass yields. Some research suggests that incorporating plant species diversity and applying biochar as a soil amendment might alleviate these limitations by creating a more resilient crop and soil system. The objective of this research was to investigate how 1) seeded plant diversity and 2) biochar soil amendments interact to affect the establishment, yield, and plant species composition of biomass cropping systems during the first four years of growth on productive soils. We measured species emergence, cover, peak and ...


Managing Risk In Grazing Operations, Christopher D. Teutsch, Kenneth H. Burdine 2018 University of Kentucky

Managing Risk In Grazing Operations, Christopher D. Teutsch, Kenneth H. Burdine

Kentucky Grazing Conference

Risk is an inherent part of agricultural production systems. Crane and coworkers (2013) identified five primary areas of risk in grazing operations: 1) MARKETING risk, 2) PRODUCTION risk, 3) LEGAL risk, 4) HUMAN risk, and FINANCIAL risk. These types of risk are described in the accompanying publication entitled “Controlling Risk in Grazing-Based Production Systems” by J. Parsons. This article will discuss the risk associated with “production” in grazing systems, focusing specifically on managing drought in grass based production operations.


Keys To Optimizing Profitability In Cow-Calf Production -- Rooster's Beef, 3 Generations Of Farming & Beef, William Slaton, Becky Slaton 2018 Rooster's Beef

Keys To Optimizing Profitability In Cow-Calf Production -- Rooster's Beef, 3 Generations Of Farming & Beef, William Slaton, Becky Slaton

Kentucky Grazing Conference

Rooster's Beef ultimately began with our family farm -Rocky Bluff Farm - now owned by William and Becky Slaton. It is the cattle producer for our beef sold. The farm is named after two Natural Rock Formations on our property. We have several acres of pasture and including some wooded acres. With rotational grazing and intense management, we are able to have 65 cows in a spring calving group, 15 cows in a fall calving group, 3 bulls, 13 replacement heifers, unweaned calves and 12 calves on finisher feed. We also rent ground to raise and put up our own ...


Grass Finished Beef: Melding Production And Marketing [1], Michael Palmer, Stacie Palmer 2018 Palmer Farms Beef

Grass Finished Beef: Melding Production And Marketing [1], Michael Palmer, Stacie Palmer

Kentucky Grazing Conference

Palmer Farms Beef is a family farm near Murray KY, owned by Michael and Stacie Palmer. We produce, and retail around 40 beef per year.


Grass Finished Beef: Melding Production And Marketing [2], Todd Clark 2018 Clark Family Farms

Grass Finished Beef: Melding Production And Marketing [2], Todd Clark

Kentucky Grazing Conference

No abstract provided.


Turning Grass Into Cash With Small Ruminants, Kenneth Andries 2018 Kentucky State University

Turning Grass Into Cash With Small Ruminants, Kenneth Andries

Kentucky Grazing Conference

As agriculture continues to change, it is important to consider sustainability before starting or expanding any enterprise. One critical factor in any animal agriculture enterprise is controlling feeding costs. Most research indicates feeding is the largest expenses in any livestock enterprise. However, nutrition is critical to overall productivity and the income of the enterprise. Because of this, producers need to find ways to improve nutrient availability while minimizing costs to optimize production and profitability for their livestock enterprise.


Grazing Dairies: Challenges And Opportunities, Howard Straub III 2018 Michigan State University

Grazing Dairies: Challenges And Opportunities, Howard Straub Iii

Kentucky Grazing Conference

No abstract provided.


Considerations For Making A Profit With Stocker Cattle, Jeff Lehmkuhler 2018 University of Kentucky

Considerations For Making A Profit With Stocker Cattle, Jeff Lehmkuhler

Kentucky Grazing Conference

The southeast is home to more than 7.3 million beef cows (USDA 2018). At an estimated 80% weaning rate and 20% heifer retention, the southeast region would be expected to produce more than 4.6 million feeder calves that would go to market in 2018. The cow-calf industry in the region provides an opportunity for the stocker and backgrounding operations to co-exist. Much of the land in the region is best suited for forage and pasture production, which at the current moment, provides a low cost feed for adding pounds to light weight feeder cattle. Yet, the stocker and ...


Measuring Profitability In Grazing Operations, Kenneth H. Burdine 2018 University of Kentucky

Measuring Profitability In Grazing Operations, Kenneth H. Burdine

Kentucky Grazing Conference

When producers make investments in extending their grazing season, they do so in order to obtain an economic benefit. These benefits usually include a reduction in the number of days that stored feed (typically hay) is fed, an increase in carry capacity or stocking rate, or an increase in production level (rates of gain, weaning weights, etc). While all of these are potential benefits of improved grazing systems, a reduction in winter feeding days is often the simplest way to start. When the grazing season is extended, winter feeding days are reduced, and this cost savings can be weighed against ...


Foreword And Conference Information [2018], S. Ray Smith, Christopher D. Teutsch 2018 University of Kentucky

Foreword And Conference Information [2018], S. Ray Smith, Christopher D. Teutsch

Kentucky Grazing Conference

No abstract provided.


The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta 2018 University of Ostrava

The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta

International Journal of Speleology

The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif ...


Modern And Paleoecological Perspectives On A Terrestrial-Marine Linkage In The Falkland Islands, Dulcinea V. Groff 2018 University of Maine

Modern And Paleoecological Perspectives On A Terrestrial-Marine Linkage In The Falkland Islands, Dulcinea V. Groff

Electronic Theses and Dissertations

The Falkland Islands are a biodiversity hotspot in the South Atlantic Ocean, with some of the world’s most important populations of seabirds and seals. The impact of climate change on these marine populations and their coastal breeding habitat in the Falklands is unknown. Coastal grasslands of Poa flabellata (tussac grass) form critical breeding habitat for wildlife, but have been heavily degraded by the introduction of livestock in the 17th century. This dissertation investigates the impacts of global change (climate change, grazing) on P. flabellata and its sensitivity to the fecal nutrient subsidies provided by marine wildlife. Chapter 1 ...


A Sub-Millennial Sediment Record Of Ice-Stream Retreat And Meltwater Storage In The Baltic Ice Lake During The Bølling-Allerød Interstadial, April Lynn Kelly, Sandra Passchier 2018 Montclair State University

A Sub-Millennial Sediment Record Of Ice-Stream Retreat And Meltwater Storage In The Baltic Ice Lake During The Bølling-Allerød Interstadial, April Lynn Kelly, Sandra Passchier

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The rapid retreat of the Baltic Ice Stream and the development of the Baltic Ice Lake is assessed using data from sediment cores retrieved from three sub-basins in the southern Baltic Sea. Hydraulic piston coring by the International Ocean Discovery Program (IODP) recovered for the first time intact glacial lake sequences overlying diamictons and other ice-contact deposits at Sites M0063, M0064 and M0065. Based on the particle size and bulk sediment chemical composition the glacial lake sediments were subdivided into a proximal and a distal varve sequence. The origin of a dark, lithologically distinct horizon between the proximal and distal ...


Theory On Thermodynamic Constraints To Biogeochemical And Metabolic Diversity, Jordan Okie, Everett Shock 2018 Arizona State University

Theory On Thermodynamic Constraints To Biogeochemical And Metabolic Diversity, Jordan Okie, Everett Shock

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


P-T-X Constraints On Ilmenite Unit Cell And Relationship To Kimberlitic And Non-Kimberlitic Sources, Mitchell R. Galarneau 2018 The University of Western Ontario

P-T-X Constraints On Ilmenite Unit Cell And Relationship To Kimberlitic And Non-Kimberlitic Sources, Mitchell R. Galarneau

Electronic Thesis and Dissertation Repository

This research investigates the mineral ilmenite, focusing on the relationship between crystal structure and geochemical and/or pressure data. Ilmenites were obtained from diamond-rich and diamond-poor kimberlites and non-kimberlitic localities, to discriminate between these populations. Crystallographic results showed a delineation between kimberlitic and non-kimberlitic ilmenites at a c-axis value of 14.02 (±0.01) Å. Adding geochemistry and pressure enhances the separation of kimberlitic and non-kimberlitic samples; however, this isn’t the case for diamond-rich versus diamond-poor kimberlites, even with three-dimensional and cluster analyses. A subset of kimberlitic ilmenites (manganese rich) were found with c-axis values and geochemical concentrations similar ...


Characterizing Ice-Wedge Polygon Geomorphology In The Haughton Impact Structure, Devon Island, Jordan Hawkswell 2018 The University of Western Ontario

Characterizing Ice-Wedge Polygon Geomorphology In The Haughton Impact Structure, Devon Island, Jordan Hawkswell

Electronic Thesis and Dissertation Repository

Ice-wedge polygon networks are a common feature in periglacial environments formed through thermal contraction cracking and snowmelt infiltration. Polygons of similar morphology are ubiquitous throughout the mid-latitudes of Mars and are believed to have formed through thermal contraction processes. This study aims to characterize the polygons on Devon Island in the Canadian Arctic and the significant variations in geomorphology they display. The study uses LiDAR data to map, analyse, and compare three sites of polygonal terrain. Variations in polygon morphology such as size and orthogonality are observed in the relatively small study area. The results show that polygon morphologic variations ...


On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. McFarlane 2018 Carleton University

On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. Mcfarlane

International Journal of Speleology

Seven silica biospeleothems from Cueva Charles Brewer, Chimantá Plateau, Venezuela have been successfully U-Th dated despite very low U and high detrital Th concentrations. Growth rates are low, between ~100 to ~800 µm/ka, and are greater closer to water level. Dates in unaltered material are in good stratigraphic order, but secondary silicification may compromise the U-Th system, yielding unreliable sequences of ages. Detritally-enriched layers correlate with global climate cycles of the Late Quaternary, in particular the cooler, drier phases of MIS 5d, 5a, and 4. SEM studies indicate that the peloidal material is made up of silica nano-particles assembled ...


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