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Superior, WI, United States

The University of Wisconsin–Superior is a public university located in Superior, Wisconsin. UW–Superior grants bachelor's, master's, and specialist's degrees. The university currently enrolls about 2,450 undergraduates and 150 graduate students. Wikipedia.

Rios Mendoza L.M.,University of Wisconsin-Superior | Jones P.R.,Pacific University in Oregon
Environmental Chemistry | Year: 2015

Environmental context Microplastics are a new source of toxic compounds in marine and freshwater environments. This research documents the discovery of microplastic fibres in the seawater column and the chemical analysis of associated toxic chemicals in microplastic marine debris. Microplastic pollution is pervasive and hazardous. Abstract Initial studies of floating plastic debris in the oceans dealt with macroscopic particles. This research found microscale plastic present as well. Chemical analysis of sorbed materials revealed toxic materials associated with the microparticles. Seawater and plastic fragment samples were collected in September 2007 in the North Pacific Central Gyre. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) were detected by mass spectrometry in extracts from the plastic fragments. Net concentrations of PCBs ranged from 1 to 223ngg-1 plastic. The most common synthetic polymers were found to be polypropylene and polyethylene. Microscopic plastic fibres and particles were also discovered in the seawater samples and examined by scanning electron microscopy. Analysis of filtered seawater samples also revealed toxic materials in concentrations lower than found on the plastic particles. © CSIRO 2015. Source

Danz N.P.,University of Wisconsin-Superior | Reich P.B.,University of Minnesota | Frelich L.E.,University of Minnesota | Niemi G.J.,University of Minnesota
Ecography | Year: 2011

Ecological boundaries are critical landscape regions of transition between adjacent ecological systems. While environmental controls of boundaries may operate in a scale-dependent manner, multiple-scale comparisons of vegetation-environment relationships have been characterized for few boundary systems. We used approximately 250000 point records on the occurrence of woody versus grassland vegetation in conjunction with climatic, topographical, and soils data to evaluate scale effects and spatial heterogeneity in a 650-km section of the historic prairie-forest biome boundary of Minnesota, USA. We chose this as a model system because of the availability of historical vegetation data, a considerable spatial extent, a sharp ecological transition, and the ability to avoid confounding from more recent anthropogenic land use change. We developed modeling techniques using hierarchical variance partitioning in a spatially-structured format that allowed us to simultaneously evaluate vegetation-environment relationships across two-dimensional space (i.e. the prairie-forest boundary) and across spatial scales (i.e. varying extents). Soils variables displayed the least spatial autocorrelation at shortest lag distances and tended to be the least important predictors of woody vegetation at all spatial extents. Topographical variables displayed greater spatial heterogeneity in regions dominated by forest compared with prairie and were more important at fine-intermediate spatial scales, highlighting their likely control on fire regimes. An integrated climatic variable (precipitation minus potential evapotranspiration) displayed a trend of increasing spatial variance across the study region and was unambiguously the strongest biome boundary control, although its joint influence with fire was difficult to characterize. Spatially heterogeneous vegetation-environment relationships were observed at all scales, especially at finer scales. Our results suggest that the importance of environmental controls changes smoothly rather than discretely across scales and demonstrate the need to account for spatial non-stationarity and scale to predict and understand vegetation distribution across ecological boundaries. © 2011 The Authors. Ecography © 2011 Ecography. Source

Cao M.,University of Wisconsin-Superior | Zhang Q.,Arkansas State University
International Journal of Production Economics | Year: 2010

In the past decades, firms have strived to achieve greater collaborative advantages with their supply chain partners. The objective of the study is to uncover the nature and characteristics of supply chain collaborative advantage from a focal firm's perspective. Collaborative advantage is defined as strategic benefits gained over competitors in the marketplace through supply chain partnering and partner enabled knowledge creation, and it relates to the desired synergistic outcome of collaborative activity that could not have been achieved by any firm acting alone. The research conceptualizes supply chain collaborative advantage as the five dimensions: process efficiency, offering flexibility, business synergy, quality, and innovation. Data were collected through a web survey of U.S. manufacturing firms in various industries. Reliable and valid instruments were developed through rigorous empirical analysis including structured interviews, Q-sort, and a large-scale study. Predictive validity is evaluated by demonstrating a strong and positive relationship between supply chain collaborative advantage and firm performance. The construct and measures in this study have provided a rich and structured understanding of collaborative advantage in a supply network. The results of the structural analysis indicate that supply chain collaborative advantage indeed has a bottom-line influence on firm performance. © 2010 Elsevier B.V.All rights reserved. Source

Gu X.,University of Wisconsin-Superior
European Journal of Combinatorics | Year: 2014

In 1985, Bollobás, Saito and Wormald characterized all triples (t, d, k) such that every t-edge-connected d-regular graph has a k-factor. An interesting research question is to ask when a t-edge-connected d-regular graph has a k-factor, if the triple (t, d, k) does not satisfy the characterization. The problem was solved by Niessen and Randerath in 1998 in terms of a condition involving the number of vertices of the graph.In this paper, we continue the investigation of the problem from a spectral perspective. We prove that, for a t-edge-connected d-regular graph G with (t, d, k) violating the characterization of Bollobás et al., if a certain eigenvalue, whichever depends on (t, d, k) , is not too large (also depends on (t, d, k) ), then G still has a k-factor. We also provide sufficient eigenvalue conditions for a t-edge-connected d-regular graph to be k-critical and factor-critical, respectively. Our results extend the characterization of Bollobás, Saito and Wormald, the results of Cioabǎ, Gregory and Haemers, the results of O and Cioabǎ, and the results of Lu. © 2014 Elsevier Ltd. Source

Breckenridge A.,University of Wisconsin-Superior
Quaternary Science Reviews | Year: 2015

Reconstructions of glacial Lake Agassiz paleogeography and drainage have been an important contribution to formulating a hypothesis in which glacial Lake Agassiz drainage to the Atlantic Ocean initiated the Younger Dryas cold interval. This study evaluates the lake level and outlet history of Lake Agassiz as recorded by strandlines visible on lidar digital elevation models from North Dakota and Minnesota. The former lake levels are warped due to glacial isostatic adjustment. Older levels have experienced more uplift and therefore have more curvature. The strandline data establish that the Moorhead lowstand of Lake Agassiz was bracketed by the strongly diverging Campbell and Tintah lake levels, which creates a vertical gap between the former lake levels. This gap exists due to a lake level drop of ~90m when the Laurentide Ice Sheet retreat opened a lower outlet, which must have been a northwest outlet to the Arctic Ocean. By applying an exponential decay rebound model, this event dates to 12,180±480calyrBP, post-dating the beginning of the Younger Dryas at 12,900calyrBP. Eastern drainage outlets to the Atlantic Ocean through the Laurentian Great Lakes that were contemporaneous with the onset of the Younger Dryas cannot be ruled out, but if these outlets existed, their duration of occupation was short-lived and not characterized by significant drawdown events within glacial Lake Agassiz. © 2015 Elsevier Ltd. Source

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