Lake Wisconsin, WI, United States
Lake Wisconsin, WI, United States

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Fons J.,University of Wisconsin Rock County
Physics Teacher | Year: 2010

Students can be seen throughout any campus in America carrying their cell phones, laptop computers, and iPhones. I've seen a tremendous increase in the student use of laptop computers during lectures and students often ask for electronic copies of lectures rather than printed versions. In an attempt to adapt to my students' increasingly technology-driven lifestyle, I issued a tablet computer to all of my students, and for a year all course materials were digital, with no distribution of paper.


Levine T.D.,Murray State University | Levine T.D.,University of Wisconsin Rock County | Hansen H.B.,Nebraska Wesleyan University | Gerald G.W.,Nebraska Wesleyan University
Biological Journal of the Linnean Society | Year: 2014

Because of the sedentary lifestyle of freshwater mussels, studies examining their movement capabilities are scarce. However, the ability to burrow into the substrate and the ability to remain stationary are likely crucial components of their behavioural repertoire. The performance of these different tasks is likely to be affected by the presence of the shell ornamentation characteristic of many mussel species. Previous studies have suggested that shell ornamentation results in a trade-off between burrowing ability and remaining stationary when an extrinsic force attempts to dislodge it from the substrate once buried. We examined the effect of morphology and shell ornamentation on burrowing performance and anchoring ability by artificially creating shell ornamentation on a relatively smooth-shelled species (Potamilus alatus). Burrowing behaviours and performance and the force required to dislodge mussels (anchoring ability) were quantified with and without ornamentation. Interestingly, we found that the artificial shell ornamentation had no significant effect on burrowing behaviours and performance or dislodgement force. Burrowing and dislodgement, however, were both highly influenced by shell size and shape. All of the available information suggests that shell size, shape, and sculpture influence burrowing and anchoring in complex ways that needs further examination. © 2013 The Linnean Society of London.


Klubertanz T.H.,University of Wisconsin Rock County
Entomological News | Year: 2015

Seven new state and sixty-four new county records of mayflies (Insecta: Ephemeroptera) are given for Illinois, Iowa, Michigan, Minnesota, Missouri, and Nebraska based upon review of existing collections as well as newly collected material. New state records are provided for Baetis brunneicolor (Baetidae), Iswaeon anoka (Baetidae), Procloeon fragile (Baetidae), Pseudocentroptiloides usa (Baetidae), Cercobrachys lilliei (Caenidae), and Heptagenia whitingi (Heptageniidae).


Dabrowski J.,University of Wisconsin Rock County | Munson E.V.,University of Wisconsin - Milwaukee
Interacting with Computers | Year: 2011

For over 40 years, system response time has been a topic of interest and controversy in computer science. Since the late 1960s, the field has seen numerous studies conducted and articles written addressing the issue. Many factors were measured in these studies including: users' accuracy and error rates with different levels of system response time, user performance speed and the efficiency of the commands used, how user interactions with the computer changed as a result of changes in system response time, how their bodies reacted physiologically to those same changes and even how happy, satisfied, anxious or annoyed they were as system response times changed. In this paper, we summarize the major issues in system response time research and look at what can be concluded from them. Generally, researchers have suggested specific response-time guidelines based on the complexity of the task or the type of interaction with the computer. We suggest that rather than system response time being task- or expectation-focused, instead interactions with a computer fall into two categories: control tasks and conversational tasks. For control tasks, immediate response times are necessary for optimal user performance whereas for conversational tasks, some delays may be necessary to maintain the optimal pacing of the on-going conversation. The location and duration of these delays will depend on both task complexity and user expectations. Future system response time research is needed to further quantify limits of delay detection, and the location and duration of inter-task delays to optimize user performance and satisfaction with computers. © 2011 British Informatics Society Limited. Published by Elsevier B.V. All rights reserved.


Fleischmann J.A.,University of Wisconsin Rock County | Plesha M.E.,University of Wisconsin - Madison | Drugan W.J.,University of Wisconsin - Madison
Geotechnical and Geological Engineering | Year: 2014

We perform numerical simulations using the discrete element method (DEM) to determine yield surfaces for large samples of randomly packed uniform spheres with constant normal and tangential contact stiffnesses (linear spring model) and uniform inter-particle friction coefficient μ, for a large range of values of the inter-particle friction coefficient μ. The beauty of DEM is that the micromechanical properties of the spheres, especially the inter-particle friction coefficient μ, are known exactly. Further, simulations can be performed with particle rotation either prohibited or unrestrained, which provides an effective means for evaluating analytical models that employ these assumptions. We compare the resulting yield surfaces to the Mohr-Coulomb, Matsuoka-Nakai, Lade-Duncan, and Drucker-Prager yield surfaces, and determine the relationship between the resulting material friction angle φ{symbol} on the macroscale and the inter-particle friction coefficient μ (or the inter-particle friction angle φ{symbol}μ) on the microscale. We find the Lade-Duncan yield surface provides the best agreement, by far, with the simulations in all cases. We also monitor inter-particle friction work and particle rotation within each specimen during the DEM simulations, both globally and on a particle-by-particle basis, and we compare the results obtained from DEM simulations in which the spheres were allowed full three-dimensional translational and rotational freedom of motion and DEM simulations in which particle rotation was prohibited. © 2014 Springer International Publishing Switzerland.


Block J.E.,Murray State University | Gerald G.W.,Nebraska Wesleyan University | Levine T.D.,Murray State University | Levine T.D.,University of Wisconsin Rock County
Journal of Freshwater Ecology | Year: 2013

Despite the limited mobility of freshwater mussels, locomotion, especially burrowing, may be a critical part of their ecology. The effects of temperature on burrowing activities in freshwater mussels have not received much attention. In the laboratory, we studied the effects of three temperatures (ca. 10, 20, and 30°C) on mussel burrowing behaviors and performance. Behaviors assessed include latency to valve opening, latency until the foot becomes extended, and latency until burrowing. We also quantified burrowing performance by measuring burrowing duration. Mussels were significantly more likely to extend their foot and ultimately burrow at the highest experimental temperature. Burrowing performance was not significantly impacted, with burrowing duration being largely unaffected by temperature. This pattern suggests a hypothetical mechanism, whereby if some temperature threshold is reached that allows burrowing, the animal burrows normally. If that threshold is not attained, the mussel will not explore its environment nor burrow. The implications of this work are important to mussel biology and conservation because the thermal regimes of aquatic systems are changing with other global temperatures and smaller-scale effects are common, such as alteration of thermal regimes due to the outflow from dams. If mussels in these systems are affected they are likely, in turn, to affect community and ecosystem ecology in their native habitats. © 2013 Taylor and Francis Group, LLC.


Anderson T.L.,University of Missouri | Anderson T.L.,Murray State University | Mott C.L.,Valdosta State University | Levine T.D.,Murray State University | And 2 more authors.
Copeia | Year: 2013

Predation risk is an important contributor to community structure that varies in response to abiotic and biotic factors In aquatic habitats, predation risk is often linked to hydroperiod as the latter directly influences predator identity within these ecosystems For pond-breeding salamanders, intraguild predation (IGP) and cannibalism are prevalent interactions in larval communities, but the frequency of each type of agonistic interaction, as well as changes in their pervasiveness along hydroperiod gradients are not well understood Size-structured populations of aquatic life stages (paedomorphic adults and overwintered larvae) of mole salamanders (Ambystoma talpoideum) have the potential to be dominant IG predators and cannibals in permanent ponds because of large size advantages over successive cohorts, but the species exists as only a single larval cohort in temporary ponds with reduced predatory abilities on guild members Thus, both the potential for and intensity of predation by this species is linked to hydroperiod; yet, the predatory abilities of aquatic life stages of mole salamanders have not been evaluated This study examined the extent to which larger size classes (paedomorphs and overwintered larvae) of mole salamanders preyed upon conspecifics and a congeneric competitor, the spotted salamander (Ambystoma maculatum) Predation trials occurred in indoor microcosms and were executed under two habitat treatments that included pseudo-natural conditions containing alternate prey and refugia, as well as simplified environments (no alternative food or cover) Embryos or hatchlings of mole and spotted salamanders were exposed either separately or concurrently to paedomorphic and overwintered larval mole salamanders in each habitat treatment Additionally, overwintered larvae were offered as prey to paedomorphic adults No significant differences in mortality were observed between habitat treatments (complex versus simple) for either embryo or hatchling predation experiments Mortality of mole and spotted embryos did not differ when they were offered separately or together, but paedomorphs caused significantly higher mortality among mole embryos compared to spotted embryos Hatchlings of both species were heavily preyed upon (nearly 100% in all trials), but overwintered larvae exhibited 100% survival with paedomorph predators, indicating size-thresholds of predation risk that were not species specific Paedomorphs and overwintered larvae therefore are most likely generalist predators that feed equally and effectively on hatchlings of co-occurring species, but are more likely to consume egg masses that do not incur significant handling costs When present, paedomorphs or overwintered larvae have the potential to alter population dynamics of both guild members and conspecifics by being dominant predators on early life stages As the prevalence of overwintering and paedomorphosis varies along hydroperiod gradients, predation risk from this species is likely to occur discontinuously and thereby may be an important, yet variable, structuring force © 2013 by the American Society of Ichthyologists and Herpetologists.


Fleischmann J.A.,University of Wisconsin Rock County | Drugan W.J.,University of Wisconsin - Madison | Plesha M.E.,University of Wisconsin - Madison
Journal of the Mechanics and Physics of Solids | Year: 2013

In Part I, Fleischmann et al. (2013), we performed theoretical analyses of three cubic packings of uniform spheres (simple, body-centered, and face-centered) assuming no particle rotation, employed these results to derive the effective elastic moduli for a statistically isotropic particulate material, and assessed these results by performing numerical discrete element method (DEM) simulations with particle rotations prohibited. In this second part, we explore the effect that particle rotation has on the overall elastic moduli of a statistically isotropic particulate material. We do this both theoretically, by re-analyzing the elementary cells of the three cubic packings with particle rotation allowed, which leads to the introduction of an internal parameter to measure zero-energy rotations at the local level, and numerically via DEM simulations in which particle rotation is unrestrained. We find that the effects of particle rotation cannot be neglected. For unrestrained particle rotation, we find that the self-consistent homogenization assumption applied to the locally body-centered cubic packing incorporating particle rotation effects most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new self-consistent results and theoretical modeling of particle rotation effects together lead to significantly better theoretical predictions of Poisson's ratio than all prior published results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to prior theoretical analyses based on hypotheses involving overall inter-particle contact distributions. Thus, our results permit a direct assessment of the reasons for the theory-experiment discrepancies noted in the literature with regard to previous theoretical derivations of the macroscopic elastic moduli for particulate materials, and our new theoretical results greatly narrow such discrepancies. © 2013 Elsevier Ltd. All rights reserved.


Fleischmann J.A.,University of Wisconsin Rock County | Drugan W.J.,University of Wisconsin - Madison | Plesha M.E.,University of Wisconsin - Madison
Journal of the Mechanics and Physics of Solids | Year: 2013

We derive the macroscopic elastic moduli of a statistically isotropic particulate aggregate material via the homogenization methods of Voigt (1928) (kinematic hypothesis), Reuss (1929) (static hypothesis), and Hershey (1954) and Kröner (1958) (self-consistent hypothesis), originally developed to treat crystalline materials, from the directionally averaged elastic moduli of three regular cubic packings of uniform spheres. We determine analytical expressions for these macroscopic elastic moduli in terms of the (linearized) elastic inter-particle contact stiffnesses on the microscale under the three homogenization assumptions for the three cubic packings (simple, body-centered, and face-centered), assuming no particle rotation. To test these results and those in the literature, we perform numerical simulations using the discrete element method (DEM) to measure the overall elastic moduli of large samples of randomly packed uniform spheres with constant normal and tangential contact stiffnesses (linear spring model). The beauty of DEM is that simulations can be run with particle rotation either prohibited or unrestrained. In this first part of our two-part series of papers, we perform DEM simulations with particle rotation prohibited, and we compare these results with our theoretical results that assumed no particle rotation. We show that the self-consistent homogenization assumption applied to the locally body-centered cubic (BCC) packing most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new analytical self-consistent results lead to significantly better predictions of Poisson's ratio than all prior published theoretical results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to all prior theoretical analyses, which were based on difficult-to-verify hypotheses involving overall inter-particle contact distributions. We continue the analysis begun in this first part for the case of unrestrained particle rotation in Part II, Fleischmann et al. (2013). © 2013 Elsevier Ltd. All rights reserved.


Klubertanz T.H.,University of Wisconsin Rock County
Entomological News | Year: 2016

Fifteen new district and regional records of mayflies (Ephemeroptera) are given for Kenora District and Northwestern Ontario, Canada, based upon new field work. Records are provided for species of Arthropleidae (1), Baetidae (3), Baetiscidae (1), Caenidae (2), Ephemeridae (3), Ephemerellidae (2), Heptageniidae (1), and Siphlonuridae (2).

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