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Macalester Today Winter 2009, Macalester College

Macalester Today

No abstract provided.

Transsexual Discrimination: Discrimination "Because Of…Sex", Tracy Scholnick Gruber

Louis Jackson National Student Writing Competition

No abstract provided.

Transgender Teachers As Role Models For A Tolerant Society: The Impact Of Societal Views And Their Influence On Employment Anti-Discrimination Laws, Susannah L. Ashton

Louis Jackson National Student Writing Competition

This paper discusses the judicial and statutory constructs of the Chambers v. Omaha Girls Club Role Model Rule,3 which protects the rights of employers to take adverse employment actions against unsuitable role models in certain circumstances, in relation to transgender teachers. It includes an introduction to Gender Identity, a brief discussion of how Title VII’s prohibition on sex discrimination should be interpreted to prohibit discrimination on the basis of gender identity, and a survey of parental and societal responses to the recent coming out of transgender teachers across America. It argues that adverse action taken against transgender teachers on the …

The Genetic Information Non-Discrimination Act: Protecting Privacy And Ensuring Fairness In Health Insurance And Employment Practices, Melissa Beyer

Louis Jackson National Student Writing Competition

Almost two centuries ago, Thomas Jefferson, one of this country’s foremost scientists and original thinkers, wrote, ‘[L]aws and institutions must go hand in hand with the progress of the human mind. As . . . new discoveries are made [and] new truths disclosed...institutions must advance also, and keep pace with the time.’ In this age of genetic breakthroughs, it is essential that our laws catch up with science. We can’t afford to take one step forward in science but two steps backward in civil rights. Our laws must specify, clearly and unambiguously, how genetic information may be used and how …

Role Of Phytoplankton In Mercury Cycling In The San Francisco Bay Estuary, Allison C. Luengen, A. Russell Flegal

Environmental Science

To study the role of phytoplankton in mercury cycling, we measured methylmercury (MeHg) and total mercury (Hg_T) in surface waters during the spring 2003 phytoplankton bloom in San Francisco Bay. Conditions that described the peak of the bloom, the amount of sorbent, and decay of the bloom were summarized by principal component analysis (PCA). Multivariate analyses conducted with the PCA factors demonstrated that the bloom accounted for a significant (p = 0.03) decrease in dissolved (-1 and was unaffected when chlorophyll a concentrations nearly tripled, indicating that bloom dilution could occur as a result of a limited …

Reconciling Findings Of Emotion-Induced Memory Enhancement And Impairment Of Preceding Items, Marisa Knight, M Mather

Psychology

A large body of work reveals that people remember emotionally arousing information better than neutral information. However, previous research reveals contradictory effects of emotional events on memory for neutral events that precede or follow them: in some studies emotionally arousing items impair memory for immediately preceding or following items and in others arousing items enhance memory for preceding items. By demonstrating both emotion-induced enhancement and impairment, Experiments 1 and 2 clarified the conditions under which these effects are likely to occur. The results suggest that emotion-induced enhancement is most likely to occur for neutral items that: (1) precede (and so …

Genetic And Environmental Contributions To Body Mass Index: Comparative Analysis Of Monozygotic Twins, Dizygotic Twins And Same-Age Unrelated Siblings, Nancy Segal, R. Feng, Shirley Mcguire, D. Allison, S. Miller

Psychology

Background—Earlier studies have established that a substantial percentage of variance in obesity-related phenotypes is explained by genetic components. However, only one study has used both virtual twins (VTs) and biological twins and was able to simultaneously estimate additive genetic, non-additive genetic, shared environmental and unshared environmental components in body mass index (BMI). Our current goal was to re-estimate four components of variance in BMI, applying a more rigorous model to biological and virtual multiples with additional data. Virtual multiples share the same family environment, offering unique opportunities to estimate common environmental influence on phenotypes that cannot be separated from …

Movements, Distribution, And Abundance Of Great Argus Pheasants (Argusianus Argus) In A Sumatran Rainforest, Nurul L. Winarni, Timothy G. O'Brien, John P. Carroll, Margaret F. Kinnaird

School of Natural Resources: Faculty Publications

We used radiotelemetry, habitat sampling, camera trapping, and line-transect surveys to explore movement patterns, distribution, and abundance of Great Argus Pheasants (Argusianus argus) in Sumatra, Indonesia. We radiotracked six adult and one subadult males. Territories averaged 14.5 ± 8.5 ha, and home-range size did not vary by month or by relative abundance of selected plant foods. Daily travel distance (849 ± 211 m) varied significantly between months but did not reflect changes in plant foods. Territories were used almost exclusively by resident males. Males preferentially used undisturbed forest (habitat I). Vegetation structure at male display sites and random points indicated …

A Phylogenetic Supertree Of The Fowls (Galloanserae, Aves), Soo Hyumg Eo, Olaf R.P. Bininda-Emonds, John P. Carroll

School of Natural Resources: Faculty Publications

The fowls (Anseriformes and Galliformes) comprise one of the major lineages of birds and occupy almost all biogeographical regions of the world. The group contains the most economically important of all bird species, each with a long history of domestication, and is an ideal model for studying ecological and evolutionary patterns. Yet, despite the relatively large amount of systematic attention fowls have attracted because of their socio-economic and biological importance, the species-level relationships within this clade remain controversial. Here we used the supertree method matrix representation with parsimony to generate a robust estimate of species-level relationships of fowls. The supertree …

Modeling Lakes And Reservoirs In The Climate System, M. D. Mackay, P. J. Neale, C. D. Arp, L. N. De Senerpont Domis, X. Fang, G. Gal, K. D. Johnk, G. Kirillin, J. D. Lenters, E. Litchman, S. Macintyre, P. Marsh, J. Melack, W. M. Mooij, F. Peeters, A. Quesada, S. G. Schladow, M. Schmid, C. Spence, S. L. Stokes

School of Natural Resources: Faculty Publications

Modeling studies examining the effect of lakes on regional and global climate, as well as studies on the influence of climate variability and change on aquatic ecosystems, are surveyed. Fully coupled atmosphere–land surface–lake climate models that could be used for both of these types of study simultaneously do not presently exist, though there are many applications that would benefit from such models. It is argued here that current understanding of physical and biogeochemical processes in freshwater systems is sufficient to begin to construct such models, and a path forward is proposed. The largest impediment to fully representing lakes in the …

First Record Of Pseudorabies In Feral Swine In Nebraska, Sam Wilson, Alan R. Doster, Justin D. Hoffman, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

In 2007, two new populations of feral swine were discovered in Nance and Valley counties, Nebraska, USA. Necropsies and serologic testing was done on two individuals from the Nance County herd. Results indicated that a lactating sow had positive antibodies for pseudorabies virus (PRV). Investigations conducted by Nebraska Game and Parks Commission Law Enforcement division confirmed that the infected individual was transported illegally to Nebraska, USA, from Texas, USA. All domestic swine herds located within an 8 km radius of the infected individual tested negative for antibodies to PRV. Our results provide a clear example of how diseases can spread …

A Modified Advection-Aridity Model Of Evapotranspiration, Jozsef Szilagyi, Michael T. Hobbins, Janos Jozsa

School of Natural Resources: Faculty Publications

No abstract provided.

Nutrient Uptake And Mineralization During Leaf Decay In Streams – A Model Simulation, J. R. Webster, J. D. Newbold, Steven A. Thomas, P. J. Mulholland

School of Natural Resources: Faculty Publications

We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while mineralization may produce increases in concentrations during later stages of decomposition. The simulations also showed that initial nutrient content of the leaves can affect the stream nutrient concentration dynamics and determine whether nitrogen or phosphorus is the limiting nutrient. Finally, the simulations suggest a net retention (uptake > mineralization) of …

Characterizing The Seasonal Dynamics Of Plant Community Photosynthesis Across A Range Of Vegetation Types, Lianhong Gu, Wilfred M. Post, Dennis D. Baldocchi, T. Andrew Black, Andrew E. Suyker, Shashi Verma, Timo Vesala, Steve C. Wofsy

School of Natural Resources: Faculty Publications

The seasonal cycle of plant community photosynthesis is one of the most important biotic oscillations to mankind. This study built upon previous efforts to develop a comprehensive framework to studying this cycle systematically with eddy covariance flux measurements. We proposed a new function to represent the cycle and generalized a set of phenological indices to quantify its dynamic characteristics. We suggest that the seasonal variation of plant community photosynthesis generally consists of five distinctive phases in sequence each of which results from the interaction between the inherent biological and ecological processes and the progression of climatic conditions and reflects the …

Spring Home Ranges Of White Bass In Irrigation Reservoirs Of The Republican River Basin, Nebraska, D. R. Martin, Larkin A. Powell, Kevin L. Pope

School of Natural Resources: Faculty Publications

Fishery biologists have documented small home ranges, relative to available habitat, for many littoral freshwater fishes. Home ranges for pelagic species, such as white bass Morone chrysops, are generally not well described, yet are thought to be large. We studied white bass movement using acoustic telemetry in two irrigation reservoirs of the Republican River basin in south-western Nebraska. Acoustic transmitters were implanted in fall of the previous year and tracking occurred a minimum of once per week throughout spring (mid-March to May) 2007 and 2008. Linear home ranges were calculated from observed locations of individual fish. Twelve of the …

Latitudinal Patterns Of Magnitude And Interannual Variability In Net Ecosystem Exchange Regulated By Biological And Environmental Variables, Wenping Yuan, Yiqi Luo, Andrew D. Richardson, Ram Oren, Sebastiaan Luyssaert, Ivan A. Janssens, Reinhart Ceulemans, Xuhui Zhou, Thomas Grünwald, Marc Aubinet, Christian Berhofer, Dennis D. Baldocci, Jiquan Chen, Allison L. Dunn, Jared L. Deforest, Danilo Dragoni, Allen H. Goldstein, Eddy Moors, J. William William Munger, Russell K. Monson, Andrew E. Suyker, Gregory Starr, Russell L. Scott, John Tenhunen, Shashi Verma, Timo Vesala, Steven C. Wofsy

School of Natural Resources: Faculty Publications

Over the last two and half decades, strong evidence showed that the terrestrial ecosystems are acting as a net sink for atmospheric carbon. However the spatial and temporal patterns of variation in the sink are not well known. In this study, we examined latitudinal patterns of interannual variability (IAV) in net ecosystem exchange (NEE) of CO₂ based on 163 site-years of eddy covariance data, from 39 northern-hemisphere research sites located at latitudes ranging from ~29°N to ~ 64°N. We computed the standard deviation of annual NEE integrals at individual sites to represent absolute interannual variability (AIAV), and the corresponding …

Differential Soil Respiration Responses To Changing Hydrologic Regimes, Vincent J. Pacific, Brian L. Mcglynn, Diego Andrés Riveros-Iregui, Howard E. Epstein, Daniel J. Welsch

School of Natural Resources: Faculty Publications

Soil respiration is tightly coupled to the hydrologic cycle (i.e., snowmelt and precipitation timing and magnitude). We examined riparian and hillslope soil respiration across a wet (2005) and a dry (2006) growing season in a subalpine catchment. When comparing the riparian zones, cumulative CO₂ efflux was 33% higher, and peak efflux occurred 17 days earlier during the dry growing season. In contrast, cumulative efflux in the hillslopes was 8% lower, and peak efflux occurred 10 days earlier during the drier growing season. Our results demonstrate that soil respiration was more sensitive to drier growing season conditions in wet (riparian) …

Remote Sensing Of Cropland Agriculture, M. Duane Nellis, Kevin P. Price, Donald Rundquist

School of Natural Resources: Faculty Publications

Remote sensing has long been used in monitoring and analyzing agricultural activities. Well prior to the first coining of the term ‘remote sensing’ in 1958 by Eveyln Pruitt of the U.S. Office of Naval Research (Estes and Jensen 1998), scientists were using aerial photography to complete soil and crop surveys associated with agricultural areas in the United States and other parts of the world (Goodman 1959). Most of such work in the 1930s involved general crop inventories by the U.S. Department of Agriculture and soil survey mapping as part of the work of the then U.S. Soil Conservation Service. With …

Non-Destructive Estimation Of Anthocyanins And Chlorophylls In Anthocyanic Leaves, Anatoly A. Gitelson, Olga B. Chivkunova, Mark N. Merzlyak

School of Natural Resources: Faculty Publications

The anthocyanin and chlorophyll contents in leaves provide valuable information about the physiological status of plants. Thus, there is a need for accurate, efficient, and practical methodologies to estimate these biochemical parameters of vegetation. In this study, we tested the performance and accuracy of several nondestructive, reflectance-based techniques for estimating anthocyanin and chlorophyll contents in leaves of four unrelated species, European hazel ( Corylus avellana ), Siberian dogwood ( Cornus alba = Swida alba ), Norway maple ( Acer platanoides ), and Virginia creeper ( Parthenocissus quinquefolia ), with widely variable pigment content and composition. An anthocyanin reflectance index, which …

Nondestructive Estimation Of Anthocyanin Content In Grapevine Leaves, Mark R. Steele, Anatoly A. Gitelson, Donald C. Rundquist, Mark N. Merzlyak

School of Natural Resources: Faculty Publications

The anthocyanin (Anth) content in leaves provides valuable information about the physiological status of plants. Thus, there is a need for accurate, efficient, practical methodologies to estimate this biochemical parameter. Reflectance measurement is a means of quickly and nondestructively assessing leaf Anth content in situ. The objective of this study was to test the overall performance and accuracy of nondestructive techniques for estimating Anth content in grapevine leaves. Relationships were established between Anth content and four vegetation indices: NIR (near-infrared)/green, red/green, anthocyanin reflectance index (ARI, based on reflectances in bands within the green and the red-edge regions), and a modified …

Variability Of Anaerobic Animal Waste Lagoon Delta15N Source Signatures, Sadayappan Mariappan, Mary Exner Spalding, Glen E. Martin, Roy F. Spalding

School of Natural Resources: Faculty Publications

High ammonium-N concentrations derived from animal wastes stored and partially treated in earthen anaerobic lagoons at confined feeding facilities can seep to groundwater. δ¹⁵N-NH₄⁺ values from +2.0 to +59.1‰ in 13 lagoons complicate identification of lagoon seepage as well as land-applied lagoon effluent in ground and surface waters. The spectrum of δ¹⁵N values requires site-specific isotope characterization of the potential source. Feed and fresh manure and urine δ¹⁵N values indicate that most N isotopic fractionation occurs after excretion. Lagoon management clearly affects enrichment. δ¹⁵N-total Kjeldahl N (TKN) and δ^{15 …}

Long-Term Agricultural Land-Use Trends In Nebraska, 1866–2007, Tim L. Hiller, Larkin A. Powell, Tim D. Mccoy, Jeffrey J. Lusk

School of Natural Resources: Faculty Publications

Although landscape changes from anthropogenic causes occur at much faster rates than those from natural processes (e.g., geological, vegetation succession), human perception of such changes is often subjective, inaccurate, or nonexistent. Given the large-scale land-use changes that have occurred throughout the Great Plains, the potential impacts of land-use changes on ecological systems, and the insight gained from knowledge of land-use trends (e.g., to compare to wildlife population trends), we synthesized information related to land-use trends in Nebraska during 1866–2007. We discussed and interpreted known and potential causes of short- and long-term land-use trends based on agricultural and weather data; farm …

The Watershed As A Conceptual Framework For The Study Of Environmental And Human Health, Alan S. Kolok, Cheryl L. Beseler, Xun-Hong Chen, Patrick J. Shea

School of Natural Resources: Faculty Publications

The watershed provides a physical basis for establishing linkages between aquatic contaminants, environmental health and human health. Current attempts to establish such linkages are limited by environmental and epidemiological constraints. Environmental limitations include difficulties in characterizing the temporal and spatial dynamics of agricultural runoff, in fully understanding the degradation and metabolism of these compounds in the environment, and in understanding complex mixtures. Epidemiological limitations include difficulties associated with the organization of risk factor data and uncertainty about which measurable endpoints are most appropriate for an agricultural setting. Nevertheless, it is our contention that an adoption of the watershed concept can …

Using Reflection Documents To Assess Student Learning, Larkin A. Powell

School of Natural Resources: Faculty Publications

Traditional assessment methods such as tests and essays may not be adequate to evaluate students’ ability to solve problems and think critically. I developed a qualitative assessment technique for a junior-level Wildlife Management Techniques course that incorporated written responses in a pre- and post-course reflection exercise. I provided the students with three reflection documents: (1) an historic photograph of Nebraska waterfowl hunters, (2) a short reading from Aldo Leopold’s Sand County Almanac, and (3) a memo on wetland habitat management from a state wildlife agency. I evaluated students’ pre- and post-course responses to a series of questions about these …

The Role Of Learning Styles In Student Evaluations Of A Problem-Based Learning Course, Larkin A. Powell

School of Natural Resources: Faculty Publications

I investigated the relationship between student learning styles and student evaluations of problem-based learning in a wildlife ecology and management course. I used two surveys for my inquiry: an on-line survey to determine student learning preferences, and an end-of-course survey of student reactions to problem-based learning (PBL). Forty-one students completed both surveys, and students’ learning preferences varied. I found significant relationships between learning preferences and student evaluation of PBL. Students with more active learning preferences found more value in the group learning experiences in my course. Group learning is often a critical component in problem-based learning courses, and my inquiry …

Ecological Divergence Of Two Sympatric Lineages Of Buggy Creek Virus, An Arbovirus Associated With Birds, Charles R. Brown, Abinash Padhi, Amy T. Moore, Mary Bomberger Brown, Jerome E. Foster, Martin Pfeffer, Valerie A. O'Brien, Nicholas Komar

School of Natural Resources: Faculty Publications

Most arthropod-borne viruses (arboviruses) show distinct serological subtypes or evolutionary lineages, with the evolution of different strains often assumed to reflect differences in ecological selection pressures. Buggy Creek virus (BCRV) is an unusual RNA virus (Togaviridae, Alphavirus) that is associated primarily with a cimicid swallow bug (Oeciacus vicarius) as its vector and the Cliff Swallow (Petrochelidon pyrrhonota) and the introduced House Sparrow (Passer domesticus) as its amplifying hosts. There are two sympatric lineages of BCRV (lineages A and B) that differ from each other by .6% at the nucleotide level. Analysis of 385 …

2009 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2009). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The Tern and Plover Conservation Partnership (TPCP), based at the University of Nebraska–School of Natural Resources, and the Nongame Bird Program (NBP), based at the Nebraska Game and Parks Commission (NGPC) work cooperatively on Interior Least Tern and Piping Plover monitoring, research, management, and education-outreach activities. While the proximate focus of our work is the Lower …

Incorporation Of Crop Phenology In Simple Biosphere Model (Sibcrop) To Improve Land-Atmosphere Carbon Exchanges From Croplands, Erandathie Lokupitiya, S. Denning, K. Paustian, I. Baker, K. Schaefer, Shashi B. Verma, T. Meyers, C. J. Bernacchi, Andrew E. Suyker, M. L. Fischer

School of Natural Resources: Faculty Publications

Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands using the Simple Biosphere (SiB) model, we developed crop-specific phenology models and coupled them to SiB. The coupled SiBphenology model (SiBcrop) replaces remotely-sensed NDVI information, on which SiB originally …

Corrigendum To “Incorporation Of Crop Phenology In Simple Biosphere Model (Sibcrop) To Improve Land-Atmosphere Carbon Exchanges From Croplands” Published In Biogeosciences, 6, 969–986, 2009, Erandathie Lokupitiya, S. Denning, K. Paustian, I. Baker, K. Schaefer, Shashi B. Verma, T. Meyers, C. J. Bernacchi, Andrew E. Suyker, M. L. Fischer

School of Natural Resources: Faculty Publications

In the above mentioned manuscript a mistake in Fig. 11 occured. The corrected version of the figure is as follows.

Lithobates Catesbeianus (American Bullfrog) Predation On Cliff Swallows, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

During a 25-year study of Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, we observed Lithobates catesbeianus prey on, or attempt to prey on, Cliff Swallows. As we were mist-netting Cliff Swallows at a 10-nest colony on 7 July 1998, a L. catesbeianus attempted to eat a Cliff Swallow that was caught in the net.