Browsing by Subject "Management"

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Assessing Agricultural Nitrous Oxide Emissions and Hot Moments Using Mesocosm Simulations
(2021-02) Miller, Lee
Nitrous oxide (N2O) is a major greenhouse gas and the leading stratospheric ozone depleting substance emitted today. Effective mitigation strategies from agricultural soils, the largest anthropogenic source of N2O, have remained elusive due to the occurrence of difficult to predict “hot moments,” or brief periods that contribute disproportionately to N2O budgets. Future precipitation patterns may further complicate mitigation efforts by causing more favorable soil conditions that drive N2O emissions. The objectives of this thesis, therefore, were to: 1) Assess the sensitivity of N2O emissions to changes in precipitation; 2) Devise an approach to objectively identify hot moments; and 3) Identify the conditions that drive these hot moments. Six growing season simulations with nearly continuous N2O measurements from an indoor mesocosm facility were used to address each of these objectives.Four seasons comparing historical normal (1984-2014) versus end-of-century (2071-2099) precipitation patterns demonstrated that, for non-limiting soil nitrogen, the greatest N2O emissions occurred when soil water-filled pore space (WFPS) was between 40 and 80% and that cumulative emissions increased with the number of days above ~60% WFPS. Consequently, any future changes in precipitation that contribute to these conditions will likely increase N2O emissions. An assessment of 1350 rain events revealed that N2O emissions consistently increased within 24 hours of rainfall and when soil moisture was near ~60% WFPS and NH4+ was greater than 10 mg N kg-1 soil. However, emissions were suppressed when WFPS was ~60% and soil NH4+ was below 5 mg N kg-1 soil, demonstrating that soil NH4+ availability is an important determinant of the N2O emission response to rain. Finally, a new approach to categorize hot moments from background N2O emissions identified greater soil nitrate (NO3-), air temperature, and 10 cm WFPS among hot moments. Further, short-term pulses (up to 38 hours) of hot moments were sustained when nitrate (NO3-) was greater than 50 mg N kg-1 soil and WFPS was above 50%, and were controlled by short-term changes in WFPS and air temperature. These findings have important implications for the development of N2O emission models, agricultural management and mitigation strategies, and demonstrate the efficacy of conducting mesocosm experiments under controlled conditions.
Concussion Injury In Contact Sports
(2008-11-24) Ferguson, Chad
Concussion in sports has long been a recognized entity and has been managed and evaluated in a number of different ways. This project gives a guide to sideline sport attendants or trainers of acute management of concussion in sport as well as the Prague guidelines for returning athletes to sport in a post concussion. The premise of the algorithm is to assure that long term sequelae are avoided by assuring that the player is asymptomatic and returns to play in a stepwise fashion that allows evaluation at each stage to assure the risk to the player is low.
Crossborder management education alliances:case study of the Sasin Graduate Institute of Business Administration in Bangkok, Thailand.
(2011-06) Pembleton, Deborah Jackson
The Sasin Graduate Institute of Business Administration at Chulalongkorn University in Bangkok has celebrated a twenty-five year partnership with the graduate schools of business at Northwestern University (Kellogg) and the University of Pennsylvania (The Wharton School) in the United States. The research question for this study is: "What factors have contributed to the success and sustainability of the crossborder management education alliance at the Sasin Graduate Institute of Business Administration?" The objective of this study is to understand and describe the intercultural working relationships between U.S. and Thai faculty and staff who work within the alliance. By incorporating the U.S. perspective as well as the Thai perspective, this research demonstrates how the national cultures of Thailand and the U.S. influence organizational effectiveness within the crossborder education alliances among these universities. Methods for data collection have involved major triangulation, including participant observation, in-depth semi-structured interviews, and document analysis. Several months of fieldwork were undertaken in Bangkok interviewing key Thai faculty and staff as well as the U.S. visiting faculty and staff. There are three major implications of this study. First, the case demonstrates that organizations rooted in quite different cultures can collaborate effectively and successfully create a long-term sustainable relationship. A key factor related to this success is the cross-culturally sensitive leadership demonstrated by all parties and their abilities to negotiate significant cultural differences. Second, given the escalating costs of higher education associated with the Baumol Disease, alliances among universities can provide a cost-effective approach to providing high-quality and innovative education. Third, the alliance described in this study is an example of the effective internationalization of higher education in a multicultural transnational context. Abstract – Thai Version: available on-line
Data for divergent responses of butterflies and bees to burning and grazing management in tallgrass prairies, 2016-2017
(2022-12-12) Leone, Julia B; Pennarola, Nora P; Larson, Jennifer L; Oberhauser, Karen; Larson, Diane L; leone050@alumni.umn.edu; Leone, Julia B
We studied the impacts of fire and grazing management on butterfly and bee abundance and species richness in tallgrass prairies. This dataset consists of data collected at 10 burned and 10 grazed Minnesota remnant prairies during the summers of 2016 and 2017. We measured insect data (butterfly and bee species richness and abundance), vegetation data (plant species richness, forb frequency, native and invasive graminoid frequency), site characteristics (proportion of sand in the soils, percent of prairie within 1.5 km of each site, site area), and management characteristics (management type (burned or grazed), cattle stocking rate, time since last fire, number of years each site was managed) at sites owned and managed by the Minnesota DNR, U.S. Fish and Wildlife Service, The Nature Conservancy, and private landowners. These data are associated with Leone et al. (2022). Divergent responses of butterflies and bees to burning and grazing management in tallgrass prairies. Ecology and Evolution. 12(12) e9532. http://dx.doi.org/10.1002/ece3.9532. In association with this paper, we hope these data will assist land managers and conservationists in protecting and managing native grasslands and contribute to our understanding of bee and butterfly responses to fire and grazing management practices.
Denitrification in Agricultural Surface Waters: Quantifying the Effect of Environmental Parameters and Hydrologic Connectivity on Nitrate Uptake and Microbial Communities
(2017-10) Tomasek, Abigail
The development of synthetic fertilizer has led to increases in crop yields and allowed for global population growth over the past century. However, this increase in available nitrogen has greatly altered the global nitrogen cycle, including increased nitrate loading to surface water and groundwater in the Midwestern United States, with negative effects on human health and aquatic ecosystems. Therefore, there is a need for effective management strategies and an understanding of the mechanisms for nitrate transport and uptake. Denitrification, the microbiological reduction of nitrate to nitrogen gas, can be viewed as a net sink for reactive nitrogen in aquatic systems. Small areas, termed hot spots, and short time periods, termed hot moments, frequently account for a large portion of denitrification. This research focuses on identifying the environmental parameters and hydrologic regimes that promote denitrification, along with determining how parameters, denitrification rates, and microbiological communities are related at multiple temporal and spatial scales. At the finest scale, a recirculating laboratory flume was used to determine the effect of turbulence and organic carbon on denitrification rates and the microbial community. An outdoor experimental stream and flow-through basin in the Outdoor StreamLab at the St. Anthony Falls Laboratory (SAFL) were used to determine the effect of short-term inundation and periodic inundation on denitrification. At the largest scale, water and sediment samples were collected over two years from a field site in an agricultural watershed in Southern Minnesota. The objectives of this research were to: (1) determine how turbulence and organic carbon affect denitrification, (2) investigate how inundation and hydrologic connectivity leads to the formation of denitrification hot spots and hot moments, (3) quantify and correlate the driving environmental parameters of microbial denitrification and the differences in these relationships for in-channel and riparian locations in an agricultural watershed, (4) develop and evaluate functional relationships between environmental parameters and denitrification rates, and (5) identify how denitrifying gene abundances, denitrification rates, and environmental parameters are related across a hydrologic gradient from channels to riparian areas.
Development of Scaled Measures of User and Citizen Satisfaction with Mn/DOT Services
(Minnesota Department of Transportation, 1996-02) Hansen, Robert A.
This report investigates the application of customer satisfaction concepts and measures to Minnesota Department of Transportation (Mn/DOT) operations. It defines the terms customer and customer satisfaction, estimates the cost of collecting customer satisfaction information, discusses related research and management activities, and makes recommendations. Specific research findings include the following: * The measurement of customer satisfaction primarily occurs in the private sector. * The straightforward definitions of customer and customer satisfaction can be translated to fit public sector needs. * Specifying customers and measuring their satisfaction are deceptively difficult and require input from top management. * Developing and implementing a customer satisfaction measurement system takes time and requires a significant financial investment. * Initial customer satisfaction projects suffer from a higher than average failure rate, often caused by lack of planning before execution. * Segments of the public may view design and implementation of customer satisfaction measures as wasteful, especially if the project is not successful.
Diagnosis and Management of Diabetes
(2008-11-24) Solheid, Greg
Aggressive use of glucose lowering agents to achieve HbA1c levels within normal (<6.0%) significantly increases risk of mortality in type 2 diabetics.
Ecological, Social, And Educational Dimensions Of Restoration: Insights From Berenty Reserve, Madagascar
(2024) Mondragon, Ariadna
Amidst a global biodiversity crisis, ecological restoration emerges as a critical solution to mitigate the devastating effects of biodiversity loss and climate change. Focusing on Madagascar, a biodiversity hotspot facing significant forest loss, this dissertation explores various aspects of ecological restoration in the Berenty Reserve. It integrates ecological, social, and educational perspectives to provide applied knowledge and practical insights, addressing the unique challenges of restoring the tropical dry forest. The study includes a comprehensive baseline inventory of the forests in Berenty to characterize a reference ecosystem to set restoration goals in the reserve. I found that the spiny and gallery forests were different structurally and compositionally, requiring tailored restoration interventions. Special attention was given to Tamarindus indica, the tamarind tree, a species critical for the forests of the reserve and its lemurs, but facing regeneration challenges. I conducted three experiments to understand the impacts of light and water availability on its early life history stages, showing that light is the most limiting resource for tamarind growth and that water availability impacts tamarind more than water frequency. I also addressed management alternatives of the invasive vine Cissus quadrangularis. Investigating its desiccation thresholds, I found that C. quadrangularis can remain viable after losing 80% of its mass, concluding that management strategies should ensure complete desiccation of Cissus fragments to prevent its regrowth. Leveraging on my experience in the Berenty Reserve, I developed a decision case study for use in undergraduate or graduate student classrooms, where students grapple with the complexities of choosing between native and non-native plant species for restoring a tropical dry forest. This educational tool enhances the understanding of restoration ecology and motivates broader engagement. Finally, I examined the integration of the social sciences and/or local ecological knowledge within restoration research, highlighting the gap between theoretical advocacy and practical application and indicating the need for more inclusive and interdisciplinary approaches. Collectively, this work contributes valuable practical and theoretical insights aimed at improving restoration strategies, not only for the dry forests in Madagascar but also for similar ecosystems globally.
The ecology and evolution of an invasive perennial plant (Lythrum salicaria) in the context of biological control by specialist herbivores (Galerucella spp.)
(2013-09) Quiram, Gina Louise
The introduction of non-native species to novel ranges has provided biologists the opportunity to study organisms experiencing sudden and sustained shifts in community composition and selection pressure. Management programs for invasive species can result in similar shifts. In classical biological control programs, non-native species are introduced to control invasive species. The short-term impacts of these introductions on invaded communities are often well documented, but the long-term impacts on the ecology and evolution of target invasive species are not well understood. Using a combination of field surveys, common garden techniques, and quantitative genetic models, I examined the effect of biological control by specialist herbivores (Galerucella spp.) on purple loosestrife (Lythrum salicaria L.) in southern Minnesota (MN), USA. Chapter 1 describes field surveys completed to determine the extent to which biological control directly reduces plant vigor, competitive performance, and reproduction. In Chapter 2, I quantify the extent to which population level variation in vigor, competitive performance, herbivore defense, and herbivore tolerance of L. salicaria reflects an evolutionary divergence following the introduction of biological agents. Finally, in Chapter 3 I assess the potential for L. salicaria to evolve in response to continued selection pressure. The results of these studies show that Galerucella spp. biocontrol agents remain established and continue to feed on L. salicaria in southern MN, but do not universally reduce the vigor, competitive performance, or reproduction of the plant in field populations as compared to populations lacking established populations of biocontrol agents. When grown in a common environment, an experimental garden, populations of L. salicaria having experienced herbivory by Galerucella spp. for 16 years are more vigorous, marginally more competitive, and marginally more tolerant of herbivory compared to populations lacking a historical association with the herbivore. In MN, L. salicaria is currently under selection pressure for increased vigor, and the plant has the genetic capacity to adapt in response to this selection pressure. Further evolution of L. salicaria could decrease the effectiveness of biological control by Galerucella spp.
Effect of grouping strategy and stocking density on the behavior of prepartum dairy cows and the association between behavior and periparturient cow health
(2014-10) Luchterhand, Karen Marie
The transition dairy cow is one of the highest risk animals for falling ill or dying on the dairy farm. The objectives of this thesis were: Determine whether providing a stable pen management affected displacements from the feed bunk and feeding behavior of prepartum Jersey dairy cows; Examine the effects of prepartum stocking density on social, lying and feeding behavior of prepartum Jersey cows;Investigate the relationship between prepartum feeding times and periparturient health disorders, first test milk yield and milk composition in Jersey cows; Determine whether social dominance, determined by displacements from the feed bunk prepartum and 3 different methods, was associated with health, reproduction, and milk yield of transition Jersey cows; and Determine whether lying behavior was associated with postpartum health events up to 60 days in milk.
Engaging the dialectic: managerial resistance to change and innovation in corporate America.
(2012-07) Chermack, Kelly
This dissertation examines the implementation of FREE, an innovation-based, organization-wide workplace flexibility initiative. Through FREE, the company experienced a massive re-structuring to how, when, and where work was done. From its very inception in the company, the FREE concept critiqued and criticized current norms and assumptions about work in corporate America. During FREE training sessions, managers, in particular, began to oppose and resist the rollout. Evident from fieldwork and ethnographic observations of these training sessions, a dialectic model of change fostered a dialectic model of resistance. Resistance emerged at three levels of abstraction: macro, meso, and micro. Analyses indicate that through the operation of these dialectic processes, managers resisted the very idea of changing work on a grad scale, changes in actual work practices, and/or the change agents. In addition, this resistance prompted changes to the change implementation process and FREE, itself, began to change. This dissertation suggests that resistance to change is rooted in conceptualizations of identity and representations of the self in and out of the organization. This work also proposes that resistance to change bears a significant impact on the implementation of the change, so much so that the implementation adapted over time.
Fusarium and Phytophthora Species associated with root rot of soybean (Glycine max)
(2011-01) Bienapfl, John Christopher
Root diseases of soybean cause substantial yield reduction in the United States. Fusarium and Phytophthora represent groups of fungal pathogens commonly associated with root rot of soybean. Little is known regarding their distribution, etiology, and how they may interact in causing root rot on soybean. Additionally, diagnostic tools that allow for rapid and accurate detection of these pathogens are essential for disease management, but need to be developed and validated. Furthermore, fungicidal compounds that potentially affect root infection by these fungal pathogens are being studied to minimize yield losses due to root diseases of soybean and improve crop productivity.
Improved diagnosis and management of viral hemorrhagic septicemia virus in fish
(2013-02) Phelps, Nicholas
Viral hemorrhagic septicemia virus (VHSV) is a highly contagious and pathogenic virus, affecting more than 70 farm raised and wild fish species worldwide. A new viral strain (VHSV-IVb) has proven both virulent and persistent, spreading throughout the Great Lakes of North America and to inland water bodies in the region. As this new biological hazard continues to grow, so too must our understanding of the disease. The focus of this dissertation is to improve diagnostic capacity and management of VHSV-IVb to rapidly respond to outbreaks, prevent further dissemination, and scientifically justify current prevention strategies. To better understand the geographic distribution of the virus, we used a modified real time reverse transcription-polymerase chain reaction (rRT-PCR) assay for high-throughput testing of fish for VHSV. The assay was shown to be twice as sensitive as the gold standard, virus isolation, and did not cross react with other viruses found in fish. In addition, the diagnostic turnaround time was reduced from 28-30 days for virus isolation to 2-4 days for rRT-PCR. To demonstrate the usefulness of the rRT-PCR assay, 115 high priority water bodies in Minnesota were tested by both methods from April 2010 - June 2011. All survey sites tested negative for VHSV by both methods. The survey results have informed fisheries managers on the absence of VHSV in Minnesota and have better prepared them for the eventual arrival of the disease. In addition, the results demonstrate the value of this rRT-PCR as a surveillance tool to rapidly identify an outbreak so that it can be controlled in a timely manner. The aforementioned rRT-PCR assay (Phelps et al. 2012) along with another (Jonstrup et al. 2012), were evaluated for the potential for sample-induced inhibition from common diagnostic samples, including kidney/spleen, entire viscera, and ovarian fluid. The detection of high, medium, and low VHSV-IVb dilutions in each tissue type was not affected using the assay by Jonstrup et al (2012). However, using the assay by Phelps et al. (2012), the detection of VHSV-IVb was decreased for the kidney/spleen samples spiked with low virus levels and increased for the ovarian fluid spiked with medium virus levels. Entire viscera, the tissue type most likely to inhibit the rRT-PCR reaction, did not affect the sensitivity of virus detection for either assay. The emergence of VHSV-IVb in the Great Lakes region has resulted in unprecedented regulatory response to better manage the disease. In Minnesota, all VHSV-susceptible fish must be inspected annually prior to intra or interstate movement - a significant bottleneck for the aquaculture industry. In 2009, Minnesota enacted legislation requiring fish for regulatory health inspections to be collected by a Minnesota Department of Natural Resources (MNDNR) approved individual. The so-called Fish Health Collector could be 1) an American Fisheries Society - Fish Health Section Fish Health Inspector or Pathologist, 2) an accredited veterinarian with approved training, or 3) an individual (i.e. MNDNR field biologist) with approved training. In response, a fish health collector training workshop was developed for veterinarians and field biologists to fulfill the MNDNR requirements. A manual was developed to supplement a full-day workshop and provide the basic information and references to perform a fish health collection. This training resulted in a sufficient number of fish health collectors, well distributed across Minnesota, now available to rapidly respond to a disease outbreak and better serve the regulatory needs of the aquaculture industry. In the USA, current state and federal fish health regulations target the spread of VHSV-IVb through movement restrictions of live fish but largely ignore the potential for the virus to be spread through the commercial distribution and use of frozen baitfish from VHSV-IVb positive regions. Some state laws do require treatment of frozen baitfish to inactivate VHSV and additional methods have been proposed, but there have been few scientific studies examining the efficacy of these treatments. In an effort to evaluate these treatments, bluegills were challenged with VHSV-IVb, frozen to represent standard industry methods, disinfected by various treatments, and tested for infectious VHSV-IVb using virus isolation. The virus was isolated from 70% of fish subjected to three freeze thaw cycles. All other treatment methods were effective in inactivating the virus, including treatment with isopropyl alcohol, mineral oil, salt with borax, and dehydration. Dehydration followed by rehydration is rapid and effective, and therefore, seems to be the best option for inactivating VHSV-IVb present in frozen baitfish while maintaining their usefulness as bait. Monitoring or regulating all risk factors for the transmission of VHSV is an infeasible task. A semi-quantitative risk assessment model was utilized to focus VHSV management efforts in Minnesota. The risk of VHSV introduction to major watersheds in Minnesota was directly correlated with proximity to Lake Superior, the only VHSV-positive waterbody in the state. Although the current regulations are uniform across Minnesota, the risk varied for specific locations within the watersheds. For example, the introduction of game fish for stock enhancement (a common fisheries management practice) was found to be a significant risk factor for VHSV introduction into public waterbodies and waterbodies frequently used for wild baitfish harvest. Aquaculture facilities with strict biosecurity programs and frequent health inspections received the lowest risk scores and were largely considered protected and of low risk for VHSV introduction. These results suggest the current management strategy, based on political boundaries, should be reevaluated. A risk-based management strategy would better allocate efforts to watersheds or specific waterbodies at higher risk and relax efforts in areas of lower risk of VHSV introduction in Minnesota.
Improving the Use of Key Performance Indicators (KPIs) in Operations Management
(2023-08) Mickelson, Brian
This thesis contributes to the knowledge of Key Performance Indicators (KPIs) with a focus on improvement for operations and maintenance.Through literature research, gaps within the use of KPIs throughout different business areas of a functioning organization were identified. Then by conducting case studies, improvement to the implementation of KPIs are suggested. A gap identified through research and observed through the authors work is how the use and even the definitions of KPIs used in operations and maintenance are not linked together for overall improvement. Conflicting KPIs can have operations and maintenance going in different directions. While working at two different operating taconite facilities, the author observed the following: operations feeds into maintenance and maintenance feeds into operation. One cannot solely dictate to the other because the operation runs better when it is a two way street. This is why there is a need to formally tie these areas of work together. This thesis offers suggestions as contributions to continuous improvement utilizing KPIs. Firstly, know your stakeholders, secondly, identify the “why” an improvement needs to be made, thirdly, describe the importance of KPIs, fourthly measure and communicate your success, and finally plan to make changes throughout your improvement process. Improving these identified factors are critical to the success of KPIs. Five case studies were presented and suggestions were given based on these case studies. The case studies vary from non-profit, volunteer, employee owned, and private company working experiences. Findings from this thesis are important to engineering management practice because the need for operational improvement continues to become more important.
Individual Outcomes of Employee Resource Group Membership
(2018-09) Beaver, Gregory
Organizations increasingly promote the equality and inclusion of minority employees and women through the creation and support of diversity management practices – or formalized techniques and programs designed to improve interactions among diverse employee identity groups. However, these diversity initiatives often make demographic differences more salient, or make majority employees feel excluded, leading to unintended consequences. The primary purpose of my dissertation research is to consider the outcomes associated with membership in a specific type of diversity management initiative, employee resource groups (ERGs) created for minority employees and women. I explore this topic in three separate but related essays from different perspectives, using a mix of qualitative, quantitative, and archival data. In Essay 1, I explore the unique challenges faced by minority employees at work and seek to understand how characteristics of identity affect an employee’s decisions to join an ERG, actively participate in it, and experience outcomes of membership. I utilize a longitudinal qualitative data collection method for this Essay to explore how highlighting a minority identity at work through membership in ERGs could generate problems due to social categorization and other processes related to stigma. In Essay 2, I continue to explore potential positive and negative outcomes of ERG membership, and include an examination of the role non-minority employees, or allies (e.g., men in ERGs for women, heterosexuals in ERGs for LGBT employees), in the outcomes of membership. In this Essay I use an online survey of ERG members from across the United States to investigate the expected social and career outcomes of ERG membership, and the role that allies play in either helping, or hampering, these outcomes. iv Finally, in Essay 3 I consider elements of the environment surrounding ERGs and predict that the variation in legal and social contexts around ERGs could both positively and negatively influence minority employee outcomes from membership. By exploring state-level discrimination laws and community-level resources across contexts, in this Essay I sample from employee members of ERGs from across the country and draw on multiple archival and online databases to understand local labor laws and community-level environment to compile this contextual framework.
Losing our lakes: an assessment of the human dimensions of lakeshore landowner shoreland management
(2012-01) Rudberg, Edgar Atwood
The fragility of shorelines and the impact of residential development on habitat and water quality led to the Minnesota Department of Natural Resource's interest in promoting native vegetative buffers. First, I used the Integrative Model (IM) (Fishbein & Yzer, 2003) to evaluate lakeshore homeowners' attitudes, norms and self-efficacy for restoring a native vegetative buffer. Five belief evaluations (decrease maintenance β = .05, increase water quality β = .058, be attractive β = .103, impede recreation β = .046, and create privacy β = -.028 one self-efficacy evaluation (ability to keep up with maintenance β = .23), and three normative influences (family β = -.097, friends β = .051 and Minnesota DNR β = .065) were significant predictors of intention (R2 = .36). Secondly, I used the Theory of Normative Social Behavior (TNSB) (Rimal and Real, 2005) as an alternate model and compared the results with the IM (Fishbein & Yzer 2003). My findings indicated that the IM (R2 = .241) had a greater explanation of variance, when compared to the TNSB, and that a greater amount of the variance was explained by the inclusion of descriptive norms, group ID and injunctive norms (R2 = .323). Finally, I sought to connect risk theory with behavioral theory and propose a framework for doing so. I used a case study of Minnesota shoreland landowners with native vegetative buffers for integrating risk and behavioral theory to segment audiences. My findings showed that 22.5% of survey respondents reported having a vegetative buffer on their shoreland and 10% of respondents had removed native vegetation in the past. I did not find a significant difference between the attitudes towards buffers of those that have removed vegetation and those that have not. However, the findings showed that having a negative attitude towards buffers increased one's odds of not having a native vegetative buffer by 2 ½ times. The analysis also showed that evaluation of buffers significantly predicted respondents' attitudes towards buffers (R 2 =.22, F[2, 11] = 8.69, p < .001). Compared to respondents without native vegetative buffers, the beliefs that buffers create an attractive shore (β = -.143, p = .019), create habitat (β = .32, p < .001), and create privacy (β = .146, p = .020) were predictive of attitude towards buffers for respondents that have buffers.
Management Practices, Milk Yield, and Feed Cost on Confinement Dairy Farms in Minnesota
(2016-09) Kloeckner, Lee
Eighty-two confinement dairy farms in Minnesota with herd sizes from 142 to 2063 cows were visited between May and December 2015. Management practices were compared between farm sizes with large farms having 425 or greater cows (n=41) and small farms having fewer than 425 cows (n=41). A subset of farms (n=67) using freestalls were used to create linear models to identify herd level management factors associated with energy corrected milk (ECM) yield per cow and feed cost per 45.4 kg of ECM. Some management factors were influenced by herd size. Factors associated with ECM yield per cow were feed mixer type, milking frequency, use of bovine somatotropin, freestall stocking density, and feed cost per cow per day. Factors associated with feed cost per 45.4 kg of ECM were percent target refusals, corn silage hybrid variety, hoof trimming schedule, freestall stocking density, freestall type, and brisket board height.
Simple solutions to complex problems in fisheries
(2014-06) Burgess, Matthew G.
Fisheries science faces a challenging combination of complexity and data limitation that places opposing pressures on theoretical research - which seeks to describe the complexity - and empirical research - which is constrained to simplicity by the limitations of available data. In this volume, I present studies aiming to reconcile theoretical and empirical approaches to assessing the current status of fished populations and designing management plans in two ways: i) by using concise mechanistic theories rooted in measurable parameters to develop new predictive assessment tools; and ii) by using ecological and economic theory to develop insights whose applications are not data-dependent or system specific. My research provides several important insights for assessment and management in fisheries: 1) Combinations of biological and socioeconomic conditions that eventually lead to extinction or overfishing can often be empirically identified decades before high harvest rates and large population declines occur, allowing for preventative management. 2) Though there is concern that harvest value, which rises as a harvested species is depleted, can allow profits to be maintained it is driven extinct, this threat most often also requires catch-rates to be substantially robust to declining abundance. Because range contraction often buffers population densities against abundance declines, habitat destruction may exacerbate threats of overharvesting. 3) Assessments based on single-species population models in multispecies fisheries can often provide reliable estimates of sustainable yields and harvest rates in populations with high vulnerability to overfishing, but often significantly overestimate sustainable yields and harvest rates in populations with lower vulnerability. However, single-species assessment frameworks can nonetheless be used to identify conditions leading to such bias, and estimate bounds on its magnitude. 4) Diversifying technologies and efficiencies within fishing fleets often leads to fewer population collapses in both managed and unmanaged fisheries; and increases the positive impact management can make on fishery yields and profits. The studies in this volume provide new perspectives on theoretical-empirical synergies in fisheries research, and maximizing the information value of fisheries data through theoretical concision and ecological abstraction.
Stable Flies, Winter Bedding, and Summer Dairy Cow Comfort
(2015-12) Hansen, Anna
Producers that graze or drylot cows in summer need to provide housing accommodations in winter. Cow comfort is an important consideration when selecting housing, particularly in areas with harsh winters. Alternative housing options being investigated in Minnesota include outwintering on a straw yard, and deep bedded compost. Stable flies, Stomoxys calcitrans (L.), are economically significant pests of dairy cows. Immature flies are found in decaying organic matter, such as soiled bedding. This research addressed how leftover debris from two winter housing systems, outdoor straw packs and indoor sawdust compost barns, differ in numbers and size of stable flies produced the following summer. Fly activity in summer are irritants that trigger defensive behaviors in cattle. Prolonged stress from flies can lead to significant production losses. This research also addressed the effect of three muscid fly species, stable flies, horn flies and face flies, on behavior and milk production of pastured cows.
Trends in Total Phosphorus Concentrations in Urban and Non-Urban Environments
(2017-01) Halbach, Ann
A study of lake trends was conducted across Minnesota and Wisconsin to determine the effects of actions to improve water quality. A comparison between urban and non-urban environments helped determine drivers of change, as many factors contribute to water quality and they differ between environments. Though evidence of both increasing and decreasing trends in phosphorus were observed, there were more lakes with decreasing trends than increasing trends, especially in the urban environment. Similar trend patterns were not found with nitrogen. Trends in nitrogen were more often positive, and trends in N:P were generally strongly positive. Climatic and morphometric factors were not significantly related to trends, but there was a connection between the amount of lawn at lake edge and phosphorus reduction. The results indicate that phosphorus concentrations in the study lakes are improving more frequently than not. This may be due to the adoption of phosphorus control measures.

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