Iowa Wetlands: Perceptions And Values, 2017 Iowa State University

#### Iowa Wetlands: Perceptions And Values, Christopher D. Azevedo, Joseph A. Herriges Sr., Catherine Kling

*Catherine Kling*

Understanding how Iowans view the benefits and costs of wetlands preservation is key to making decisions about the future of wetlands in Iowa. To that end, the authors created "The Iowa Wetlands Survey." How the survey was designed and administered is described and the results are summarized. The survey reveals important information about how Iowans use wetlands, what they know about wetlands, and how much they value preserving them.

A Tale Of Three Watersheds: Nonpoint Source Pollution And Conservation Practices Across Iowa, 2017 Iowa Geological Survey

#### A Tale Of Three Watersheds: Nonpoint Source Pollution And Conservation Practices Across Iowa, Keith E. Schilling, Mark D. Tomer, Philip W. Gassman, Catherine Kling, Thomas M. Isenhart, Thomas B. Moorman, William W. Simpkins, Calvin F. Wolter

*Catherine Kling*

Many conservation practices and implementation programs exist to address nonpoint source (NPS) pollution losses from agricultural landscapes (Helmers et al., this issue). In order to select the most appropriate practices and programs for reducing NPS pollution in a specific region while maintaining economic return for the landowner, the interacting processes of agricultural management and watershed hydrology need to be understood across broad spatial scales. On a nationwide basis, it is easy to see how NPS pollution in one part of the country might be different than those in another region of the country. For example, cotton growers in the South ...

Global Solutions To Regional Problems: Collecting Global Expertise To Address The Problem Of Harmful Cyanobacterial Blooms. A Lake Erie Case Study, 2017 Bowling Green State University

#### Global Solutions To Regional Problems: Collecting Global Expertise To Address The Problem Of Harmful Cyanobacterial Blooms. A Lake Erie Case Study, George S. Bullerjahn, Robert M. Mckay, Timothy W. Davis, David B. Baker, Gregory L. Boyer, Leslie V. D'Anglada, Gregory J. Doucette, Jeff C. Ho, Elena G. Irwin, Catherine L. Kling, Raphael M. Kudela, Rainer Kurmayer, Anna M. Michalak, Joseph D. Ortiz, Timothy G. Otten, Hans W. Paerl, Boqiang Qin, Brent L. Sohngen, Richard P. Stumpf, Petra M. Visser, Steven W. Wilhelm

*Catherine Kling*

In early August 2014, the municipality of Toledo, OH (USA) issued a ‘do not drink’ advisory on their water supply directly affecting over 400,000 residential customers and hundreds of businesses (Wilson, 2014). This order was attributable to levels of microcystin, a potent liver toxin, which rose to 2.5 mg L1 in finished drinking water. The Toledo crisis afforded an opportunity to bring together scientists from around the world to share ideas regarding factors that contribute to bloom formation and toxigenicity, bloom and toxin detection as well as prevention and remediation of bloom events. These discussions took place at ...

Degraded Water Quality In Lakes: Consequences For Use, 2017 Iowa State University

#### Degraded Water Quality In Lakes: Consequences For Use, Hocheol Jeon, Catherine L. Kling, Yongjie Ji

*Catherine Kling*

Iowa, like many states in the Midwest, suffers from poor water quality. Excess nutrients in the state’s lakes and streams contribute to odor, limited clarity, excess algae and plant growth, and can contribute to a number of other undesirable changes to habitat and water quality. These changes, in turn, can reduce the usage and enjoyment of lakes and streams. Likewise, improvements in water quality brought about by reduced nutrient pollution or lake improvement projects can increase the number of visitors and their enjoyment of natural environments. To better understand what Iowans value about their natural environment and how changes ...

Economic Valuation Of Ecosystem Benefits From Conservation Practices Targeted In Iowa Nutrient Reduction Strategy 2013: A Non Market Valuation Approach, 2017 Iowa State University

#### Economic Valuation Of Ecosystem Benefits From Conservation Practices Targeted In Iowa Nutrient Reduction Strategy 2013: A Non Market Valuation Approach, Mainul Hoque, Catherine L. Kling

*Catherine Kling*

With the aim of improving water quality, the Iowa Nutrient Reduction Strategy 2014 sets a goal of reducing agricultural non-point-source generated nitrogen load by 41 percent and phosphorus load by 29 percent in Iowa’s waterways. The “strategy” describes several land use that could achieve those reductions, such as widespread adoption of conservation practices in farming, land retirement, and wetland restoration that can meet the specified target reduction. The goal of the current study is to identify the range of ecosystem benefits resulting from the conservation practices associated with each of these scenarios and apply a nonmarket valuation method to ...

Another Friday Test, 2017 Selected Works

#### Another Friday Test, Sid Marchseventeen

*Sid Marchseventeen*

Test Demo Search - Two, 2017 Selected Works

#### Test Demo Search - Two, Sid Threemarchsixteen

*Sid Threemarchsixteen*

The Enhanced Principal Rank Characteristic Sequence, 2017 Iowa State University

#### The Enhanced Principal Rank Characteristic Sequence, Steve Butler, Minerva Catral, Shaun M. Fallat, H. Tracy Hall, Leslie Hogben, P. Van Den Driessche, Michael Young

*Leslie Hogben*

The enhanced principal rank characteristic sequence (epr-sequence) of a symmetric n×n matrix is a sequence ℓ_{1}ℓ_{2}⋯ℓ_{n} where ℓ_{k} is A, S, or N according as all, some, or none of its principal minors of order *k* are nonzero. Such sequences give more information than the (0,1) pr-sequences previously studied (where basically the *k*th entry is 0 or 1 according as none or at least one of its principal minors of order *k* is nonzero). Various techniques including the Schur complement are introduced to establish that certain subsequences such as NAN are ...

On Crossing Numbers Of Complete Tripartite And Balanced Complete Multipartite Graphs, 2017 University of Colorado, Denver

#### On Crossing Numbers Of Complete Tripartite And Balanced Complete Multipartite Graphs, Ellen Gethner, Leslie Hogben, Bernard Lidicky, Florian Pfender, Amanda Ruiz, Michael Young

*Leslie Hogben*

The crossing number cr(*G*) of a graph *G* is the minimum number of crossings in a drawing of *G* in the plane with no more than two edges intersecting at any point that is not a vertex. The rectilinear crossing number of *G* is the minimum number of crossings in a such drawing of *G*with edges as straight line segments. Zarankiewicz proved in 1952 that . We generalize the upper bound . to . and prove . We also show that for *n* large enough, and , with the tighter rectilinear lower bound established through the use of flag algebras. A complete multipartite ...

Zero Forcing Propagation Time On Oriented Graphs, 2017 Saint Olaf College

#### Zero Forcing Propagation Time On Oriented Graphs, Adam Berliner, Chassidy Bozeman, Steve Butler, Minerva Catral, Leslie Hogben, Brenda Kroschel, Jephian C.H. Lin, Nathan Warnberg, Michael Young

*Leslie Hogben*

Zero forcing is an iterative coloring procedure on a graph that starts by initially coloring vertices white and blue and then repeatedly applies the following rule: if any blue vertex has a unique (out-)neighbor that is colored white, then that neighbor is forced to change color from white to blue. An initial set of blue vertices that can force the entire graph to blue is called a zero forcing set. In this paper we consider the minimum number of iterations needed for this color change rule to color all of the vertices blue, also known as the propagation time ...

On The Distance Spectra Of Graphs, 2017 Kharazmi University

#### On The Distance Spectra Of Graphs, Ghodratollah Aalipour, Aida Abiad, Zhanar Berikkyzy, Jay Cummings, Jessica De Silva, Wei Gao, Kristin Heysse, Leslie Hogben, Franklin H.J. Kenter, Jephian C.H. Lin, Michael Tait

*Leslie Hogben*

The distance matrix of a graph *G* is the matrix containing the pairwise distances between vertices. The distance eigenvalues of *G* are the eigenvalues of its distance matrix and they form the distance spectrum of *G*. We determine the distance spectra of double odd graphs and Doob graphs, completing the determination of distance spectra of distance regular graphs having exactly one positive distance eigenvalue. We characterize strongly regular graphs having more positive than negative distance eigenvalues. We give examples of graphs with few distinct distance eigenvalues but lacking regularity properties. We also determine the determinant and inertia of the distance ...

Recursive Robust Pca Or Recursive Sparse Recovery In Large But Structured Noise, 2017 Iowa State University

#### Recursive Robust Pca Or Recursive Sparse Recovery In Large But Structured Noise, Chenlu Qiu, Namrata Vaswani, Brian Lois, Leslie Hogben

*Leslie Hogben*

This paper studies the recursive robust principal components analysis problem. If the outlier is the signal-of-interest, this problem can be interpreted as one of recursively recovering a time sequence of sparse vectors, St, in the presence of large but structured noise, Lt. The structure that we assume on Lt is that Lt is dense and lies in a low-dimensional subspace that is either fixed or changes slowly enough. A key application where this problem occurs is in video surveillance where the goal is to separate a slowly changing background (Lt) from moving foreground objects (St) on-the-fly. To solve the above ...

Fractional Zero Forcing Via Three-Color Forcing Games, 2017 Iowa State University

#### Fractional Zero Forcing Via Three-Color Forcing Games, Leslie Hogben, Kevin F. Palmowski, David E. Roberson, Michael Young

*Leslie Hogben*

An r-fold analogue of the positive semidefinite zero forcing process that is carried out on the r-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup when colored with a fractional positive semidefinite forcing set are examined and used to define a three-color forcing game that directly computes the fractional positive semidefinite forcing number of a graph. We develop a fractional parameter based on the standard zero forcing process and it is shown that this parameter is exactly the skew zero forcing number with a three-color approach. This approach ...

Note On Power Propagation Time And Lower Bounds For The Power Domination Number, 2017 Texas State University

#### Note On Power Propagation Time And Lower Bounds For The Power Domination Number, Daniela Ferrero, Leslie Hogben, Franklin H. J. Kenter, Michael Young

*Leslie Hogben*

We present a counterexample to a lower bound for the power domination number given in Liao (J Comb Optim 31:725–742, 2016). We also define the power propagation time, using the power domination propagation ideas in Liao and the (zero forcing) propagation time in Hogben et al. (Discrete Appl Math 160:1994–2005, 2012).

Rainbow Arithmetic Progressions, 2017 Iowa State University

#### Rainbow Arithmetic Progressions, Steve Butler, Craig Erickson, Leslie Hogben, Kirsten Hogenson, Lucas Kramer, Richard Kramer, Jephian C. H. Lin, Ryan R. Martin, Derrick Stolee, Nathan Warnberg, Michael Young

*Leslie Hogben*

In this paper, we investigate the anti-Ramsey (more precisely, anti-van der Waerden) properties of arithmetic progressions. For positive integers n and k, the expression aw([n]; k) denotes the smallest number of colors with which the integers f1; : : : ; ng can be colored and still guarantee there is a rainbow arithmetic progression of length k. We establish that aw([n]; 3) = (log n) and aw([n]; k) = n1o(1) for k 4. For positive integers n and k, the expression aw(Zn; k) denotes the smallest number of colors with which elements of the cyclic group of order n can be ...

Influence Of Condition On Maintenance Requirements Of Dairy Cattle, 2017 Iowa State College

#### Influence Of Condition On Maintenance Requirements Of Dairy Cattle, A. C. Mccandlish, W. G. Gaessler

*Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)*

The ration of the dairy cow is used for maintenance, growth, the formation of body fat, the building up of the foetus and milk production, so the problem of feed utilizaton is a complicated one. 'rhe maintenance ration is more easily studied than are the requirements for growth and productive purposes and yet many of the factors controlling it are not thoroly understood.

Condition in dairy cattle has received little attention in investigational work and its influence on the maintenance requirements of animals has not been studied. In fact, the influence of condition on the maintenance requirements of all classe ...

Nitrification In Acid Soils, 2017 Iowa State College

#### Nitrification In Acid Soils, R. E. Stepheson

*Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)*

It is quite generally believed now that nitrification may occur in acid soils, at least to some extent. The addition of lime, however, results in practically all cases in an increased activity of the nitrifying flora. This is especially true when soils are strongly acid in reaction and low in organic matter and when ammonium sulfate is used to measure nitrification.

Probably it is not merely because lime neutralizes acid soil conditions that it increases nitrification. There may be very important indirect effects of liming which are responsible for greater nitrifying action. Lime makes the soil conditions more favorable for ...

Effect Of Seasonal Conditions And Soil Treatment On Bacteria And Molds In Soil, 2017 Iowa State College

#### Effect Of Seasonal Conditions And Soil Treatment On Bacteria And Molds In Soil, P. E. Brown, W. V. Halversen

*Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)*

The study of the microorganic population of the soil has revealed many interesting facts but none more significant nor of more far-reaching importance than the discovery that molds occur in soils and perform various functions which directly or indirectly exert considerable influence on soil fertility.

The occurrence and activities of bacteria in the soil has been the subject of extensive inquiry and much knowledge along this line has been accumulated. These organisms have been found to occur in large numbers in practically all soils and to play a prominent part in the reactions which must necessarily take place in soils ...

Composition And Digestibility Of Sudan Grass Hay, 2017 Iowa State College

#### Composition And Digestibility Of Sudan Grass Hay, W. G. Gaessler, A. C. Mccandlish

*Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)*

ThE.J introduction of Sudan grass (Andropogon sorglwrn var.) into the United States took place less than nine years ago, but since then this .crop has become widely known and its popularity is rapidly increasing. Sudan grass, being an annual, does not make a good pasture plant, but gives excellent results as a hay or soiling crop; it might also be successfully made into silage if mixed with a legume.

Effects Of Certain Alkali Salts On Ammonification, 2017 Iowa State College

#### Effects Of Certain Alkali Salts On Ammonification, P. E. Brown, D. R. Johnson

*Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)*

The occurrence of so-called" alkali spots" in certain Iowa soils has been nnted in recent publications, these spots are found only in the Wisconsin drift soil area, in association with peat deposits, and are the result of course of peculiarly poor drainage conditions. It is unnecessary here to consider further the causes of these formations or the methods which should be followed in reclaiming the areas affected as these points have been discussed in the publications referred to. It will be sufficient to call attention to the results of the chemical studies of the spots and to consider briefly some ...