Physical Sciences and Mathematics Commons^™

Corn And Soybean Response To Sulfur Application On Iowa Soils, J. E. Sawyer, D. W. Barker

John E. Sawyer

Historically sulfur (S) application has not been recommended on Iowa soils for com and soybean production. Prior research has not determined a consistent need for S fertilization in Iowa, with field research indicating no com or soybean yield response to applied S at virtually every site studied (Thorup and Leitch 1975; Webb, 1978; Alesii 1982; Killorn, 1984; Sexton et al., 1998; Mallarino et al., 2000). The soil supply, in combination with sources such as manure and atmospheric deposition has apparently met com and soybean S needs. Sulfur deficiencies have been reported over the years in various areas of the Midwestern …

What Literacy Means In Math Class: Teacher Team Explores Ways To Remake Instruction To Develop Students' Skills, Jacy Ippolito, Christina L. Dobbs, Megin Charner-Laird

Jacy Ippolito

Using Metastable-State Photoacid For Fluorescence And Ph Modulation, Renan S. Gongora, Juan Arias, Parth K. Patel, Karin Y. Chumbimuni-Torres

Juan Arias

Temperature Of The Plasmasphere From Van Allen Probes Hope, Kevin J. Genestreti, Jerry Goldstein, Grace D. Corley, William Farner, Lynn M. Kistler, Brian A. Larsen, Christopher G. Mouikis, Chae Ramnarace, Ruth M. Skoug, Niescja E. Turner

Niescja E. Turner

We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one-dimensional E→×B→ drifting Maxwellian and that the potential field and motion of the spacecraft may be accounted for in the simplest possible manner, i.e., by a linear shift of coordinates. The first technique …

7Β-Hydroxy­Artemisinin, Paulo B. Carvalho, Bo Liu, Yunshan Wu, John S. Williamson, Mitchell A. Avery

John S. Williamson

Crystals of the title compound [systematic name: (3R,6R,7S,8aR,9R,12aR)-7-hydr­oxy-3,6,9-trimethyl­octa­hydro-3,12-ep­oxy[1,2]dioxepino[4,3-i]isochromen-10(3H)-one], C15H22O6, were obtained from microbial transformation of artemisinin by a culture of Cunninghamella elegans. The stereochemistry of the compound is consistent with the spectroscopic findings in previously published works. A weak O—H⋯O hydrogen bond occurs in the crystal structure, together with intermolecular C—H⋯O hydrogen bonds.

A Few Notes On Nabokov's Childhood Entomology, Victor Fet

Victor Fet

Nabokov's lepidoptery long posed a question: Was he an amateur or a professional entomologist? Today, it has been amply demonstrated that he was a professional. Kurt Johnson says, "For Nabokov, as with many, fascination with the big picture books of butterflies as a young child grew to concerted collecting as a youngster. As with many scientists, these impressions of youth become a driving life force."³ Nabokov started collecting butterflies in 1906, at age seven, and never ceased; he published his first book of poems ten years later, at age seventeen; his first research paper on butterflies, at age twenty; …

The Big Crunch: A Hybrid Solution To Earth And Space Science Instruction For Elementary Education Majors, Cinzia Cervato, Charles Kerton, Andrea Peer, Lesya M. Hassall, Allan Schmidt

Lesya Hassall

We describe the rationale and process for the development of a new hybrid Earth and Space Science course for elementary education majors. A five-step course design model, applicable to both online and traditional courses, is presented. Assessment of the course outcomes after two semesters indicates that the intensive time invested in the development of the course results in a manageable workload during the semester for faculty with an already full teaching load. We also found that average scores in proctored online exams for this cohort of students are identical to the average scores of students from the same major enrolled …

Implementing Propensity Score Matching With Network Data: The Effect Of Gatt On Bilateral Trade, Luca De Benedictis, Bruno Arpino, Alessandra Mattei

Luca De Benedictis

Determination Of Optical Properties Of Secondary Organic Aerosols Using Uv-Vis Spectroscopy, Vanessa Selimovic, Matthew E. Wise, John Shilling

Matthew E. Wise

• Aerosols interact differently with the atmosphere depending on:
• Composition
• Size
• Phase
• Reactivity
• Optical Properties
• Reactivity with atmosphere determines impact on Earth’s radiative budget

[excerpt]

Digital Fabrication Of An Atmospheric Aerosol Impactor, Stefan J. Vincent, Shawn Daley, Matthew E. Wise

Matthew E. Wise

Atmospheric aerosol (AA) particles are defined as solid or liquid particles suspended in the air. AA particles smaller than 10 μm (1x10^-5 meters) in diameter are small enough to bypass the upper respiratory system which functions as a filter for harmful substances entering the lungs. AA particles can be collected using a device called an aerosol impactor. After collection, the particles can be analyzed offline for chemical composition using a variety of analytical techniques. The weight of a commercially manufactured AA particle impactor poses an issue if it is attached to a mobile AA particle sampling platform such as …

The Wrecks Of Lake Champlain, Gary C. Kessler

Gary C. Kessler

Despite the dozens of historically significant wrecks in the lake, only nine are open for diving as part of the Lake Champlain Underwater Historic Preserve. For visitors to the area, five of the wrecks are easily accessible from Burlington, with four being in the immediate vicinity of Burlington Bay. This article will focus on these five wrecks.

On The Redshift Distribution And Physical Properties Of Act-Selected Dsfgs, T. Su, T. A. Marriage, V. Asboth, A. J. Baker, J. R. Bond, D. Crichton, M. J. Devlin, R. Dünner, D. Farrah, D. T. Frayer, M. B. Gralla, K. Hall, M. Halpern, A. I. Harris, M. Hilton, A. D. Hincks, J. P. Hughes, M. D. Niemack, L. A. Page, B. Partridge, J. Rivera, D. Scott, J. L. Sievers, Robert J. Thornton, M. P. Viero, L. Wang, E. J. Wollack, M. Zemcov

Robert Thornton

No abstract provided.

An Overview Of Cryptography (Updated Version 26 February 2017), Gary C. Kessler

Gary C. Kessler

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting health care information. One essential aspect for secure communications is that of cryptography. But it is important to note that while cryptography is necessary for secure communications, it is not by itself sufficient. The reader is advised, then, that the topics covered here only describe the first of many steps necessary for better security in any number of situations.

Discovery Of Thienoquinolone Derivatives As Selective And Atp Non-Competitive Cdk5/P25 Inhibitors By Structure-Based Virtual Screening, Arindam Chatterjee, Stephen J. Cutler, Robert J. Doerksen, Ikhlas A. Khan, John S. Williamson

John S. Williamson

Calpain mediated cleavage of CDK5 natural precursor p35 causes a stable complex formation of CDK5/p25, which leads to hyperphosphorylation of tau. Thus inhibition of this complex is a viable target for numerous acute and chronic neurodegenerative diseases involving tau protein, including Alzheimer’s disease. Since CDK5 has the highest sequence homology with its mitotic counterpart CDK2, our primary goal was to design selective CDK5/p25 inhibitors targeting neurodegeneration. A novel structure-based virtual screening protocol comprised of e-pharmacophore models and virtual screening workflow was used to identify nine compounds from a commercial database containing 2.84 million compounds. An ATP non-competitive and selective thieno[3,2- …

Modeling Out-Of-Plane Actuation In Thin-Film Nematic Polymer Networks: From Chiral Ribbons To Auto-Origami Boxes Via Twist And Topology, Vianney Gimenez-Pinto, Fangfu Ye, Badel Mbanga, Jonathan Selinger, Robin Selinger

Jonathan Selinger

Shining A Light On A University Special Collection With Data Visualization, Lisa Deluca, Katie M. Wissel

Kathryn Wissel, MBA, MI

Sources To Seafood: Mercury Pollution In The Marine Environment, Celia Y. Chen, Charles T. Driscoll, Kathleen F. Lambert, Robert P. Mason, Laurie R. Rardin, Catherine V. Schmitt, N. S. Serrell, Elsie M. Sunderland

Catherine Schmitt

In 2010, the Toxic Metals Superfund Research Program at Dartmouth College brought together a group of 50 scientists and policy stakeholders to form C-MERC, the Coastal and Marine Mercury Ecosystem Research Collaborative. The goal was to review current knowledge—and knowledge gaps—relating to a global environmental health problem, mercury contamination of the world’s marine fish. C-MERC participants attended two workshops over a two-year period, and in 2012 C-MERC authors published a series of peer-reviewed papers in the journals Environmental Health Perspectives and Environmental Research that elucidated key processes related to the inputs, cycling, and uptake of mercury in marine ecosystems, effects …

Adrift In A Sea Of Information About Sustainable Seafood: The Maine Consumer Perspective, Catherine V. Schmitt

Catherine Schmitt

The desire for a sustainable seafood industry that protects the environment and the future of fishing is certainly of interest to consumers, but even here there are conflicting standards, as Catherine Schmitt explores in this article.

How Changing Climate Created Mount Desert Island, Catherine Schmitt

Catherine Schmitt

Acadia is a national park, the first place in eastern U.S. to receive such designation, because of its scenery. Diverse and exposed geology forms the foundation for Acadia’s beauty, but the landscape of today is the result of climate changes over millennia. Climate influences include a land surface worked by glaciers, and diverse flora and fauna as a result of the island’s position on the coast, within a transition zone between temperate ecosystems to the south and the boreal north.

Chemistry 100-051w Online Introduction To Chemistry Fall 2015, Christina Beatty

Christina Beatty

No abstract provided.

The Composition Of Comet C/2012 K1 (Panstarrs) And The Distribution Of Primary Volatile Abundances Among Comets, Nathan X. Roth, Erika L. Gibb, Boncho P. Bonev, Michael A. Disanti, Michael J. Mumma, Geronimo L. Villanueva, Lucas Paganini

Erika Gibb

Detection System For Neutron Β Decay Correlations In The Ucnb And Nab Experiments, Leah J. Broussard, B. A. Zeck, Edith R. Adamek, Stephan Baeßler, Noah Birge, Marie Blatnik, J. David Bowman, Astrid E. Brandt, A. E. Brandt, Matthew Brown, John F. Burkhart, Nathan B. Callahan, Steven M. Clayton, Christopher B. Crawford, Chris Cude-Woods, Scott Currie, Eric B. Dees, Xinjian Ding, Nadia Fomin, Emil Frlez, Jason Fry, Frederick E. Gray, Said Hasan, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Takeyasu M. Ito, Andreas Klein, Hengne Li, Chenyu Liu, Mark F. Makela, P. L. Mcgaughey, J. Mirabal-Martinez, Charles L. Morris, Jose D. Ortiz, Robert W. Pattie Jr., Seppo I. Penttilä, Brad Plaster, Dinko Počanić, John C. Ramsey, A. Salas-Bacci, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, Sky Sjue, Aron Sprow, Z. Tang, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, W. S. Wilburn, T. L. Womack, A. R. Young

Robert W. Pattie Jr.

Building Data And Information Literacy In The Undergraduate Chemistry Curriculum, Yasmeen Shorish, Barbara A. Reisner

Yasmeen Shorish

The Literature and Seminar sequence at James Madison University has been used to develop the chemistry information literacy skills of chemistry majors for over four decades. These courses have been continually updated to emphasize information literacy skills for the twenty-first century. This chapter describes the methods that have been developed to improve chemical, data and general information literacy at a large, public, primarily undergraduate institution. The focus of the first semester course, described in this chapter, is on skill building rather than teaching specific resources. It is a model of integration and collaboration between chemistry faculty and chemistry librarians. Changes …

The Opacity Of Spiral Galaxy Disks. V. Dust Opacity, Hi Distributions And Sub-Mm Emission., Benne W. Holwerda, R. A. Gonzalez, Ronald J. Allen, P. C. Van Der Kruit

Benne Holwerda

The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the “Synthetic Field Method” from González et al. (1998, ApJ, 506, 152), Holwerda et al. (2005a, AJ, 129, 1381). When compared for individual disks, the HI column density and dust opacity do not seem to be correlated as HI and opacity follow different radial profiles. To improve statistics, an average radial opacity profile is compared to an average HI profile. Compared to dust-to-HI estimates from the literature, more extinction is found in this profile. This difference may …

The Opacity Of Spiral Galaxy Disks. Iii. Automating The Synthetic Field Method., Benne W. Holwerda, R. A. Gonzalez, Ronald J. Allen, P. C. Van Der Kruit

Benne Holwerda

Dust extinction in spiral disks can be estimated from the counts of background field galaxies, provided the deleterious effects of confusion introduced by structure in the image of the foreground spiral disk can be calibrated. Gonzalez et al. developed a method for this calibration, the Synthetic Field Method (SFM), and applied this concept to a Hubble Space Telescope (HST )/Wide Field Planetary Camera 2 image of NGC 4536. The SFM estimates the total extinction through the disk without requiring assumptions about the distribution of absorbers or disk light. The poor statistics, however, result in large errors in individual measurements. We …

The Opacity Of Spiral Galaxy Disks. Vi. Extinction, Stellar Light And Color., Benne W. Holwerda, R. A. Gonzalez, P. C. Van Der Kruit, R. J. Allen

Benne Holwerda

In this paper we explore the relation between dust extinction and stellar light distribution in disks of spiral galaxies. Extinction influences our dynamical and photometric perception of disks, since it can distort our measurement of the contribution of the stellar component. To characterize the total extinction by a foreground disk, González et al. (1998, ApJ, 506, 152) proposed the "Synthetic Field Method" (SFM), which uses the calibrated number of distant galaxies seen through the foreground disk as a direct indication of extinction. The method is described in González et al. (1998, ApJ, 506, 152) and Holwerda et al. (2005a, AJ, …

The Opacity Of Spiral Galaxy Disks. Iv. Radial Extinction Profiles From Counts Of Distant Galaxies Seen Through Foreground Disks., Benne W. Holwerda, R. A. Gonzalez, Ronald J. Allen, P. C. Van Der Kruit

Benne Holwerda

Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, Gonzalez et al. and Holwerda et al. developed the Synthetic Field Method (SFM ), which analyzes synthetic fields constructed by adding various deep exposures of unobstructed background fields to the candidate foreground galaxy field. The advantage of the SFM is that it gives the average opacity for the area of a galaxy disk without making assumptions about either the distribution of absorbers or of the disk starlight. However, it …

The Opacity Of Spiral Galaxy Disks Vii. The Accuracy Of Galaxy Counts As An Extinction Probe., Benne W. Holwerda, R. A. Gonzalez, Ronald J. Allen, P. C. Van Der Kruit

Benne Holwerda

The "Synthetic Field Method" (SFM) was introduced by González et al. (1998, ApJ, 506, 152) to calibrate numbers of distant galaxies as a probe of extinction in a foreground spiral disk. González et al. (2003, AJ, 125, 1182) studied the effect of the foreground disk on these numbers using simulations of current and future instruments for fields in the LMC, M 31 and NGC 4536, a galaxy in Virgo. They concluded that: (1) the brighter centers of disks were unsuitable; (2) the granularity of the disk at a fixed surface brightness is the limiting factor in the detection of distant …

Pliocene Record Of Antarctic Sedimentation, Melissa Luna

Melissa Luna

No abstract provided.

Gaps In The Cloud Cover? : Comparing Extinction Measures In Spiral Disks., Benne W. Holwerda, M. Meyer, M. W. Regan, D. Calzetti, K. D. Gordon, J. D. Smith, D. Dale, C. W. Engelbracht, T. Jarrett, M. Thornley, C. Bot, B. Buckalew, R. C. Kennicutt, R. A. Gonzalez

Benne Holwerda

Dust in galaxies can be mapped either by the FIR/submillimeter emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of 15 sections in 13 nearby galaxies to determine the scale of the dusty interstellar medium ( ISM ) responsible for disk opacity: one using stellar reddening and the other a known background source. In our earlier papers, we presented extinction measurements of 29 galaxies, based on calibrated counts of distant background objects identified though foreground disks in Hubble Space Telescope WFPC2 images. For the …