Aquaponics: A Sustainable Food Production System That Provides Research Projects for Undergraduate Engineering Students

Aquaponics is a closed-loop, recirculating water system in which plants and fish grow together mutualistically. Aquaponics resembles a natural river or lake basin in which fish waste serves as nutrients for the plants, which in turn clean the water for the fish. Tilapia and salad greens or herbs are common fish and plants grown in an aquaponics system. The external inputs to an aquaponics system are fish food, minimal amount of water, and energy for lighting and heating the water for the fish and plants. Aquaponics is a sustainable, efficient system to raise fish protein and vegetables for human consumption. Aquaponics systems can be located anywhere in the world where there is adequate energy with a minimal amount of water. Aquaponics is particularly suited to arid climates because it uses much less water to grow plants than soil-based systems. In fact, the only water that is lost is evaporation and transpiration from the plants. Although the field of aquaponics is growing world-wide, the capital and operational costs of producing the plants and fish have not been quantified intensively in the peer-reviewed literature. The relationship between the amount of external energy (fish food plus energy for light and heat) to the output (weight of fish and plants) has not been measured well for aquaponics units in temperate climates. The lack of quantification of the input-output has suppressed aquaponics progress because it is difficult to compare the cost of fish and salad greens grown with aquaponics and conventional methods, such as aquaculture and soil-based methods. The diverse nature of aquaponics and the need to quantify the relationship between input-output presents opportunities for research projects for undergraduate engineering students in Mechanical, Electrical, and Civil Engineering. The following are examples: Sensors: What type of sensors are ideal to measure air and water temperature, water PH, dissolved O2, and nitrates? Thermodynamics: What type of water heating system is most efficient to maintain desirable water and air temperature? Water Quality: What are the optimal methods to filter out the solid fish waste (feces) and introduce necessary bacteria into the system? Hydraulics: What size of pump and diameter of pipe are needed to maintain optimal flow rate? System Design: What are the optimal ratios between fish tank volume and grow area volume? What is the optimal drop in water level between components to utilize the gravity system? Marquette University College of Engineering is building a laboratory to conduct aquaponics research. The design of the system along with the lessons learned will be presented, along with a detailed list of specific projects for engineering students. Lessons learned from this research will aid the development of aquaponics in temperate climates but also possibly in subtropical and tropical region

On the motion of a classical charged particle

We show that the Lorentz-Dirac equation is not an unavoidable consequence of energy-momentum conservation for a point charge. What follows solely from conservation laws is a less restrictive equation already obtained by Honig and Szamosi. The latter is not properly an equation of motion because, as it contains an extra scalar variable, it does not determine the future evolution of the charge. We show that a supplementary constitutive relation can be added so that the motion is determined and free from the troubles that are customary in Lorentz-Dirac equation, i. e. preacceleration and runaways

Cheating In Business Schools, The Millennial Generation, Gender And Racial Diversity: Has The Paradigm Shifted

Cheating in college is not new.  In 1960 over 50 percent of students admitted they cheated.  In the second decade of the 21st century has anything changed?  This research project looked at three possible new variables, the Millennial Generation, Gender, and Diversity.  Results suggest the amount of reported cheating remains the same even with current “Gen Yers” in college.  There was also no measured difference in cheating between men and women students.  Finally, the present study found that Asian-Americans admitted to cheating far more than the average and Latino-Americans reported to have cheated in college far less than the average current students in college.  This paper concludes with the following three implications: 1) Current college undergraduates, “the Millennial Generation,” may actually be more ethical as measured in this study than their Boomer Parents.  2) Women and graduates as measured in this study may be more prone to college cheating than women students in the past—trends of a new post-feminist generation?  3) Finally, diversity and the core values embedded in America’s individual subcultures, such as Asian and Hispanic, appear to significantly influence ethical choices of today’s college students—diversity within the melting pot

How Real Managers In The Real World Build Real Teams: A Call For Relevance

Few places in the management literature is there a greater divide between theory and practice than in Team Building.  Yes, academics have thoroughly researched what this “ideal team” should look like, its various developmental stages, even the proper mix of roles – yet this author would argue we as educators and consultants know little of how to really develop teams and offer even less of this in equipping our students-managers for this central task.  The purpose of this paper is a call for relevance – a challenge to move from speculative theory on team development to actual practice – identifying what works and what doesn’t. Following a literature review which underlines how theoretical our field has become concerning team development, an actual research study will be reported.  Forty-two MBA students participated in a study where near ideal work teams were developed.  Then these same students were asked, “What went right?  Identify four lessons you learned on how to build an energized team.”  The following is a partial list of student observations on what contributed most to an ideal team: listening, clearly defined goals and tasks, respect for each other, urgency of time, strong norms that rejected loafers, lack of formal structure, and allowing natural leaders to lead. The paper ends with a discussion on implications for managers hoping to develop energized work teams: ·                     Ad Hoc Teams are Best.  Standing groups which lack “Sunset Causes” tend to become political over time.·                     Find the Right Mix between Formal and Informal.  Informal gives energy, formal gives needed structure.·                     Leadership Must Emerge Early in the Process and be Accepted by Most.  There is a critical moment where leaderless teams dissolve into political games.·                     Strong Norms of Mutual Respect Must be Present from the Beginning.  The tendency toward competition in early team formation must quickly be moderated and directed toward task completion. In conclusion, our theoretical traditions have led us to a profound understanding of group dynamics, but to remain relevant we owe our students a practical guide as well.  A guide that discussed how Real Managers in the Real World develop Real Teams

The Annual Performance Review As A Positive Source For Employee Motivation?

Few places in management literature offer a greater divide between theory and practice than in the Annual Performance Review. Yes, academics have thoroughly researched what the ideal review should look like, yet these authors would argue, as educators and consultants, that we know little on how to really develop and effectively conduct a performance review that serves as a positive source for employee motivation. The purpose of this paper is to call for relevance—a challenge to move from theory to actual practice. Eighty-one practicing managers representing some 23 companies were asked to both assess their ongoing annual assessment and to evaluate a new model of assessment introduced in the present paper. The findings suggest that in the first decade of the 21st century, considerable skepticism remains over almost any model used in the performance review, and this includes skepticism concerning the newly introduced model.The paper concludes with the following three implications of the present study: 1.       The harsh realities of the new workplace bring new challenges to employee appraisals.2.       The strength of the employee-supervisor relationship is far more important than the ‘correct’ assessment method.3.       Any effective motivating performance review must be conducted in a positive work environment marked by the application of best practices.&nbsp

Lars Hætta’s miniature world: Sámi prison op-art autoethnography

This article examines a collection of miniature objects, now held in museum collections, which were originally made by a Sámi political prisoner in Norway during the mid-19th century as part of an educational programme. The author draws on recent developments in the theory of miniaturization to consider these miniatures as examples of prison op-art autoethnography: communicative devices which seek to address broad and complex social issues through the process of the creation and distribution of semiophorically functionless mimetic objects of reduced scale and complexity, and which reflect the restrictions of incarcerated artistic expression and the questions this raises regarding authenticity and hybridity

Hydrogen Epoch of Reionization Array (HERA)

The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn ($z\sim30$). During these epochs, early stars and black holes heated and ionized the IGM, introducing fluctuations in 21 cm emission. HERA is designed to characterize the evolution of the 21 cm power spectrum to constrain the timing and morphology of reionization, the properties of the first galaxies, the evolution of large-scale structure, and the early sources of heating. The full HERA instrument will be a 350-element interferometer in South Africa consisting of 14-m parabolic dishes observing from 50 to 250 MHz. Currently, 19 dishes have been deployed on site and the next 18 are under construction. HERA has been designated as an SKA Precursor instrument. In this paper, we summarize HERA's scientific context and provide forecasts for its key science results. After reviewing the current state of the art in foreground mitigation, we use the delay-spectrum technique to motivate high-level performance requirements for the HERA instrument. Next, we present the HERA instrument design, along with the subsystem specifications that ensure that HERA meets its performance requirements. Finally, we summarize the schedule and status of the project. We conclude by suggesting that, given the realities of foreground contamination, current-generation 21 cm instruments are approaching their sensitivity limits. HERA is designed to bring both the sensitivity and the precision to deliver its primary science on the basis of proven foreground filtering techniques, while developing new subtraction techniques to unlock new capabilities. The result will be a major step toward realizing the widely recognized scientific potential of 21 cm cosmology.Comment: 26 pages, 24 figures, 2 table

Till Planting of Corn in Eastern South Dakota: Irrigation - Dryland

A growing interest is evident in minimum tillage, or combined tillage, operations for growing corn. In addition to conventional planters, machines are available commercially which will till-plant, wheel-track plant, hardground list, or strip-process plant. Modifications of these machines and machines for new planting systems that appear periodically on the market reflect the interest among today\u27s farm operators in minimum tillage or reduced tillage. Any discussion involving minimum tillage requires a definition or explanation of what is meant by the term. To some people it means reducing the number of trips made across the field by combining individual operations into a once-over operation. In this case the number of tillage operations are not reduced, just the number of trips over the field. To others it implies reducing the number of individual operations done in one or several passes over the field

Membrane-To-Nucleus Signaling Links Insulin-Like Growth Factor-1- and Stem Cell Factor-Activated Pathways

Stem cell factor (mouse: Kitl, human: KITLG) and insulin-like growth factor-1 (IGF1), acting via KIT and IGF1 receptor (IGF1R), respectively, are critical for the development and integrity of several tissues. Autocrine/paracrine KITLG-KIT and IGF1-IGF1R signaling are also activated in several cancers including gastrointestinal stromal tumors (GIST), the most common sarcoma. In murine gastric muscles, IGF1 promotes Kitl-dependent development of interstitial cells of Cajal (ICC), the non-neoplastic counterpart of GIST, suggesting cooperation between these pathways. Here, we report a novel mechanism linking IGF1-IGF1R and KITLG-KIT signaling in both normal and neoplastic cells. In murine gastric muscles, the microenvironment for ICC and GIST, human hepatic stellate cells (LX-2), a model for cancer niches, and GIST cells, IGF1 stimulated Kitl/KITLG protein and mRNA expression and promoter activity by activating several signaling pathways including AKT-mediated glycogen synthase kinase-3β inhibition (GSK3i). GSK3i alone also stimulated Kitl/KITLG expression without activating mitogenic pathways. Both IGF1 and GSK3i induced chromatin-level changes favoring transcriptional activation at the Kitl promoter including increased histone H3/H4 acetylation and H3 lysine (K) 4 methylation, reduced H3K9 and H3K27 methylation and reduced occupancy by the H3K27 methyltransferase EZH2. By pharmacological or RNA interference-mediated inhibition of chromatin modifiers we demonstrated that these changes have the predicted impact on KITLG expression. KITLG knock-down and immunoneutralization inhibited the proliferation of GIST cells expressing wild-type KIT, signifying oncogenic autocrine/paracrine KITLG-KIT signaling. We conclude that membrane-to-nucleus signaling involving GSK3i establishes a previously unrecognized link between the IGF1-IGF1R and KITLG-KIT pathways, which is active in both physiologic and oncogenic contexts and can be exploited for therapeutic purposes