Re-engineering the Milk Value Chain Using Bio-sensors
Colin Kingston, colin.kingston@sensortec.co.nz, Sensortec Ltd.
     Dairy farmers around the world share a common problem of declining farm gate prices for their raw milk. Milk buyers are also putting farmers under pressure to achieve constant improvements in milk quality in order to satisfy consumers’ growing nutritional and health demands. Their dilemma is compounded by their exclusion from those downstream parts of the milk value chain that add most value to their commodity after it has left the farm. A New Zealand-based research and technology company plans to exploit the potential for bio-sensing of milk components, online at the dairy farm, in order to re-engineer the milk value chain. This technology will empower dairy farmers both to lower their production costs and to add more value to their milk before it leaves the farm, thus creating a paradigm shift in the farm income equation.

In-line inspection of milk for abnormalities using a Sensortec sensor.
     Unique in its position at the interface between dairy engineering and biotechnology, Sensortec has invested heavily in forming partnerships with international experts in varying disciplines, including leading dairy scientists and sensor specialists. By leveraging the combined capabilities of these experts, Sensortec aims to become the leading bio-tech solutions provider in the field of adding value to milk on-farm.
     The core approach to Sensortec’s developments is to develop sensors that measure the biological causes of phenomena in animals more than the down-stream behavioral or physiological effects. This approach follows the so-called cause/effect spectrum and is based on the premise that the further away from the true biological cause a measurement system gets, the more likely it is that the effect can be the result of other causes. Thus, Sensortec’s focus is to develop families of sensors to evaluate conditions based on a range of animal health and milk quality spectra.
     Sensortec’s research is concentrated in four main areas: animal health and well-being, milk quality and composition, fertility, and nutrition. Current work is focused on the application areas of mastitis, oestrus detection, pregnancy diagnosis, and monitoring of milk abnormalities.

Constructing Wetlands To Replace Rural Septic Systems
ASAE member Wayne E. Woldt, wwoldt1@unl.edu, University of Nebraska-Lincoln
     Households, businesses, and isolated communities that do not have public sewers must utilize on-site treatment systems to manage their wastewater. The most common on-site wastewater treatment system includes a septic tank and soil drain field. The development and advancement of alternative on-site wastewater treatment systems is becoming more important for a number of reasons. State and local regulations are demanding a greater level of treatment, especially in higher density developments. Traditional leaching field systems are prone to failure due to soils with low, or very high, permeability. Conventional alternatives, such as lagoons, tend to be unpleasant from an aesthetic perspective.
     A constructed wetland utilizing subsurface wastewater flow represents a natural treatment system consisting of one or more lined, or unlined, basins filled with gravel material. The basin(s) may be planted with reeds, bulrush, cattail, or similar hydrophytes. A septic tank is used for pretreatment, and the tank wastewater effluent is piped to the wetland cell where it flows below the wetland surface. The subsurface environment provides treatment that includes physical, chemical, and biological transformation processes. This treatment results in reduced pollutant levels and enhanced water quality, so that effluent may be discharged to the environment.

Natural wastewater treatment systems, such as this constructed wetland, offer an alternative to traditional septic systems and rely extensively on biological processes to treat the waste. They can also be an attractive addition to the landscape and yield small quantities of wetland vegetation, such as cattails, for use in seasonal floral work.
     A full-scale subsurface flow constructed wetland research facility was established at the Rogers Research Farm near Lincoln, Neb. and managed by the Department of Biological Systems Engineering at the University of Nebraska-Lincoln. A research study to evaluate the wetland treatment performance for a single-family dwelling has been underway for more than five years. The wetland was designed and constructed with consideration for the cold climate conditions in Nebraska. The overall system consists of four main components: septic tank, 5,700 liter (1,500 gallon), wetland cell, 14 x 4 x 1 meters (45 x 13 x 2 feet), full retention wildlife habitat and evaporation pond, and connecting pipes and fixtures. The wetland cell was planted with cattails and reeds.
     System monitoring has shown that the subsurface treatment wetland is feasible for a single-family household in a continental climate. The system has performed without hydraulic failure, and the treatment performance in reducing organic pollutants is promising. The temperature in the wetland cell has always remained above freezing at a depth of 15 centimeters (6 inches). While some wetlands report clogging, this system has not experienced failure due to clogging. Additional research has resulted in the development of a new modeling approach, using fuzzy inference methods, to predict the performance of constructed wetland systems. Research is currently underway to develop a multi-scale porous media-based biofilm model to simulate the dynamics of wastewater treatment. The research system has yielded valuable information and continues to provide an attractive, effective, and odor-free wastewater treatment alternative for the residents at the research farm.

Bringing the Sun Underground
Biophamaceutical crops in mines
ASAE member Dennis R. St. George, drstgeorge@hydro.mb.ca, Manitoba Hydro
     Manitoba Hydro’s engineers have designed a lighting system that could benefit world health by lowering the cost of producing and developing drugs that would help millions of people live longer, healthier lives. They have succeeded in bringing the rough equivalent of sunshine into the depths of an unused mine near Flin Flon, Manitoba, Canada, to raise genetically modified plants that produce specialized proteins needed by the pharmaceutical industry.
     Producing the proteins from plants underground instead of traditional processes, such as fermentation in above ground factories, is a secure approach estimated to reduce production costs 10 to 50 times. The process will also speed the development of new drugs critical in the fight against cancer, AIDS, and other diseases.

The underground growth chamber offers many advantages over above-ground growth operations.
     Plant-made pharmaceuticals is a term used to describe growing and harvesting genetically modified crops with the object of producing pharmaceuticals. The crops serve as biological factories that can generate drugs otherwise difficult or expensive to produce.
     The mine offers physical security for the operation. Security is critical because the types of plants grown in the mine are of high value. The setting offers biosecurity for the plants. Because biopharmaceutical plants are plants that have been genetically modified, it is desirable to isolate them from the surface environment to avoid cross-pollination and other potential bio-risks. In addition, the operation takes advantage of an infrastructure that would otherwise remain unused once the mining operations are complete.
     The technology proved itself in January 2002 when one of the first crops was harvested. The crop was grown successfully in a mine drift under a lighting system developed by Manitoba Hydro. For a number of years Manitoba Hydro has been researching innovative lighting systems. Prairie Plant Systems Inc. in Saskatoon offered to help develop a lighting system to provide artificial sunlight in the most cost-effective manner possible.
     Prairie Plant Systems is a plant biotechnology company in Saskatchewan with a focus on research and development. In 1990, the company began the first of several successful joint ventures with Hudson Bay Mining & Smelting to establish a greenhouse several hundred meters below the surface to grow flowers and herbs.
     Growing plants underground in a mine is an energy intensive process. It takes up to 5 megawatts per hectare (2.5 acres), with 80 percent of the energy going to the lights. A combination of metal halide and high pressure sodium lighting proved efficient at producing enough light of the right quality for the plants. The design generates one-third to one-half the photosynthetic energy produced on a clear sunny day in a uniform manner for even plant growth.

Plant Population vs. Plant Average: New Paradigm of Crop Simulation Modeling
E. Jallas, jallas@cirad.fr; P. Martin, pierre.martin@cirad.fr; M. Cretenet, cretenet@cirad.fr, Decision Support Groupe, CIRAD, France; S. Turner, sturner@ra.msstate.edu, and ASAE member J. McKinion, mckinion@csrumsu.ars.ag.gov, USDA-ARS-GPA; and ASAE member R. H. Mohtar, mohtar@purdue.edu, Decision Support Groupe, CIRAD-France, and Purdue University
     Traditional plant architectural models or “visualization models” propose to visually create realistic three-dimensional plants. The visualization is based on field sampling and the application of an algorithm to standardize the 3-D description of a plant. “L-systems” and the “Reference Axis” are two such approaches.
     Mechanistic or physiologically based models, built using mathematical expressions of the interactions between plant components, propose to describe how a plant functions. They simulate physiologically realistic plants based on estimates of physiological development and growth. Their equations are derived from field experiments.

Visualization at three different days of a plant average for a crop with high nitrogen fertilization and good water supply.
     Both modeling paradigms were integrated in this study. Functions and concepts obtained from mechanistic and architectural modeling theories were used to develop an integrated system. The system was derived from an enhanced “mechanistic” model, GOSSYM, with 3-D architectural extensions. This was accomplished by associating growth and development functions with actual locations in 3-D space. The resulting model allows vastly improved model output interpretation, use of the model as a surrogate experimental environment, and allows better integration of knowledge about how plants grow into a unique system.
     The new model, named COTONS®, produces “life-like” plants. Now the farmer deals with simulation results analogous to the ones he deals with in a 3-D world. Importantly, variability is captured and expressed visually. It is the first step for better characterizing production risk in human-based terms. This new model symbolizes crop models for the next century.

Visualization of eight plants growing in parallel.
     The COTONS® Model is a physiologically detailed simulation growth and development cotton model. It includes a plant model and a soil model. Weather information, some cultural practices, and genetic characteristics drive the plant model. Plant development is limited by water and nitrogen supply and also by soil water potential status. When the plant grows, its shade limits soil water evaporation but at the same time the plant uptakes water and nitrogen. The plant sub-model includes two important concepts: “materials balance” and the use of different stresses (N, H2O, C) to regulate plant growth. Each day, the model calculates carbohydrate supply based on external factors (light, temperature, water supply, etc.), plant water status, and leaf area. The system then calculates the carbohydrate demand for growth, respiration, and plant maintenance based on external factors and plant status. Finally, the system partitions the carbohydrate supply to the different organs based on their demand and priority levels with fruit having the highest priority and storage the lowest.
     The use of a crop model by producers and even scientists is difficult due to the input/output interface of this kind of system. Graphical tools now exist and are available on desktop computers. Thus, it is possible to visualize output as “Virtual Plants” resulting from the simulation and making the simulation more understandable to farmer and scientists. The level of detail simulated by the model facilitated the integration of a visualization tool of COTONS®. This visualization is done using an architectural engine which simulates the sizes of each organ (by length, diameter, and width), their spatial position, the shape of each organ, and then displays all of this information. COTONS® calls a “Plant Morphology” sub-model daily which simulates sizes of all organs. It then calls another routine to build the 3Dplant architecture by positioning all the plant organs in 3D space. All the plants are different having varying plant heights, numbers of bolls, boll positions, etc. They did not emerge necessarily on the same day, and they had to compete for light interception. Finally, a routine displays the results. The morphology sub-model calculates volume and area variables (length and diameter) from dry weights simulated by the plant model. The architectural routine builds the 3-D plant architecture from organ lengths and diameters, the phyllotaxy angles, insertion angles, and deviation angles. All these angles are fixed and they are assumed to be variety dependent. An iterative process places each organ, relative to its bearer, in 3D space. Also a shape made from polygons is associated to each organ. The morphology sub-model controls the size of the shape.
Development of Cell-based Biosensors
ASAE member Mark Riley, riley@Ag.arizona.edu, The University of Arizona
     Researchers at the University of Arizona are studying a new way to measure the effects of particulate matter (PM10 and PM2.5) and other inhalation hazards on human health. Asthma, emphysema, lung distress, hospital admissions, and the death rate of people with weakened immune systems correlate with increases in PM emissions. Previous methods have focused on quantifying the mass of particles of certain aerodynamic radii, but this provides limited information on the true impact of inhaling potentially diverse types of materials. For example, the composition of these particles has a tremendous effect on whether they do harm in the lung or are entirely benign. The goal of this research is to develop sensors that can provide information on the true biological damage caused by contact of such materials with cells of the lung.

In this atomic force microscopic image of epithelial cells on a glass surface, cells are strongly attached to the surface and to each through multiple connections. Length of the field is 100 µm; height of cells is 2.72 µm. (Image provided by Christopher Juncker and Joseph Simmons)
     The research employs laboratory cultures of lung cells isolated from rats. Below is an image of nine cells (an epithelial cell line that forms tight junctions and a single monolayer of cells) attached to a glass surface and to each other. Each spherical “lump” is a cell. Suspected hazardous materials are introduced to these cells in a controlled manner and the response of the cells is monitored. These cells can respond in a number of ways, including altering their secretion of proteins, losing their cell membrane integrity, and through initiating of cell death processes. The challenge this group is undertaking is in identifying pathways of cell response that can also be easily quantified using portable and automatable measurement schemes.
     The measurement schemes being investigated range from use of an inexpensive metabolic biosensor to more complex methods using various types of spectroscopy. In the metabolic biosensor, a dye is added to the solution bathing the cells and their rate of metabolism is quantified after exposure to a toxicant. Healthy cells, or those exposed to a non-hazardous material, display a high level of metabolism. Cells that have been exposed to a highly toxic compound have a diminished rate of metabolism either due to direct cell damage or to modulation through compounds secreted by other damaged cells. The spectroscopic approach, being evaluated in collaboration with other researchers at The University of Arizona and at Imperial College, London, employs light in the infrared as a means to monitor changes to a cell’s composition or to direct damage of compounds within the cell due to exposure to toxins. This approach has the capability to distinguish between different causes of cell damage and has the potential to be very sensitive to low levels of many types of compounds.
     Together these biological sensing technologies can provide a means to monitor the true impact of inhaling specific types of particulate matter by people or animals. The method may provide an early warning system as to when airborne environments present significant risk prior to health effects being experienced by people.

Sustained Release of Porcine Somatotropin (pST) Gene
Protein from biocompatible and biodegradable polymeric nanospheres
Dan Luo, dl79@cornell.edu, and ASAE member Norm R. Scott, nrs5@cornell.edu, Cornell University
     Somatotropins are endogenous protein hormones that play important roles in regulating animal growth rate, feed efficiency, and nutrients partitioning. The principal mechanism of somatotropin lies in the partitioning of absorbed nutrients, including lipogenesis and lipolysis, carbohydrate metabolism, protein and mammary gland metabolism.
     Delivery of exogenous pST to swine has resulted in tremendous positive benefits, as shown in Table 1. The safety of somatotropin administration, including the safety for treated farm animals, human consumers, and the environment has been well studied. For animals, no adverse conditions have been linked to somatotropin treatment. For human consumers, animal somatotropins are species specific; they are inactive in humans even when injected. In addition, somatotropins are heat and pH labile; they undergo rapid degradation with heating, as in cooking, or low pH, as in the digestive tract. For the environment, the impact is positive due to the reduction of animal waste products and increase of feed efficiency.
     Although somatotropin and its delivery to agriculturally important animals have created new paradigms in animal agriculture, the delivery of pST has typically relied on hypodermic needles and daily injections, which are inefficient, impractical, and economically ineffective. It is of paramount importance to develop delivery systems that are sustained, biocompatible, efficient, and cost-effective.
     The idea of sustained delivery of growth hormones to farm animals was proposed in 1987 at the ASAE Winter Meeting by co-author Scott:
     “Daily injections of these hormones are likely to be impractical for commercial herds and flocks. Engineers can play an important role in the development of administration systems for the very small amounts of hormones required on a daily basis because injections with hypodermic needles, as now practiced in research, will be time consuming and inefficient in the commercial enterprise … the design of an injectable, slow release formulation lasting for a significant period of time such as a month or more with time release … and other potential approaches offer exciting challenges to the biological engineer.”

Morphology of PLGA-DNA microspheres and their size distributions.
     Sixteen years later, such injectable, slow release, and sustained delivery systems for farm animals are still not available. The combined efforts of Luo and Scott are to design and create a sustained pST gene or protein delivery system based on FDAapproved polymers that are low-cost, biocompatible, biodegradable, and injectable. Research being carried out includes microsphere fabrication and DNA/protein encapsulation; control and optimization of the physical, chemical, and biological properties of the delivery system; control of animal growth and nutrition; and improvement of overall animal production efficiency. The general methodology employed is based on a molecular bioengineering design involving a multidisciplinary approach that includes polymer sciences, pST biology, protein chemistry, nanotechnology, and synthetic DNA delivery technologies. This novel long-term polymeric delivery system is expected to greatly increase animal productivity, effectively improve the control of animal growth, and significantly improve general animal well being.

Autonomous Robotic Vehicles
Useful for agricultural and environmental applications
ASAE members Steven G. Hall, shall5@bae.lsu.edu, and Randy R. Price, rprice@bae.lsu.edu, Louisiana State University
     Aquaculture is a fast growing area worldwide and represents about $200 million per year in Louisiana alone. However, bird depredation can decimate fish yields. It is estimated that one egret can eat .15 kilograms (one-third pound) of fish per day, while a great heron can eat .3 to .35 kilograms (two-thirds to three-fourths pound) per day. This can be especially troublesome in ponds that have been stocked with young fish. It is estimated that wading birds could cause profound losses up to $10,000 per week on some bait fish farms during fall migration, and catfish losses amounted to $3.3 million due to doublecrested cormorants. The need for effective means to reduce bird predation is clear.

The scarebot, a small self-guided boat, patrols a pond to scare birds away.
     Present approaches include sonic cannons, which work well initially, but the birds become accustomed to the loud noises. As well, the loud boom produced by the cannons can be bothersome to surrounding communities. Poisons, scarecrows, and nets are also used but have toxicity or cost constraints.
     An alternate approach, being developed at Louisiana State University (LSU), is to create small self-guided boats that can patrol the pond, using passive and active methods to scare the birds away. These vehicles presently use small shore sensors which close a magnetic switch when the boat touches shore and guide the boat to turn back into the pond. Shore sensors have proven effective and the global positioning system (GPS) can provide guidance, especially in open water. Microprocessors which operate on low power (0.1 ampere at 5 volts) provide guidance while solar panels provide power. Infrared sensors and a non-destructive water cannon have been through initial testing to detect the birds and shoot a water spray at them to actively repel birds.
     Efficacy tests were performed on .4-hectare (1-acre) ponds stocked with catfish fingerlings located at the LSU Agricultural Center Aquaculture Research Station. Testing was performed with either one or two boats on the pond for three days at a time and then removed for three days, and the procedure was repeated over three months.
     A time-lapse VCR was used to record camera shots of the pond throughout the day using a black and white security camera with wide–angle lens. The tapes were analyzed. Statistical analysis showed significant reduction of bird predation on ponds with boats. During this study, cormorants, egrets, and herons were the major predatory birds.
     The scarebot concept has proven the device to be effective at reducing bird predation on selected aquaculture ponds. Licensing for commercial production is underway with the hope that the scarebot will soon be available to farmers, aquaculturalists, recreational pond users, and water reservoir managers for use in appropriate situations.
     Additional developments include motion detection systems using near infrared sensors or machine vision, improvements in energy conservation measures, more effective navigation, and additional environmentally friendly bird hazing mechanisms such as a water cannon, laser lights, or sounds of bird predators. For more information, visit www.bae.lsu.edu/research/scarebot.htm.

Simulation Game for Improving Fresh Produce Retailing
Deepak Aggarwal, aggarwal@griffin .uga.edu; ASAE member Stanley E. Prussia, sprussia@griffin.uga.edu; Wojciech J. Florkowski, wflorko@gaes, University of Georgia; and Don Lynd, Don.Lynd@usda.gov, Agricultural Marketing Services
     Decisions by produce managers determine the quality and availability of fresh produce at retail stores. Quality is lowered when excess product is ordered and held for several days. Empty shelves result from insufficient quantities being ordered. The supply chain originates with produce grown on the farm followed by various links to the retailer. Produce retail managers need proper training tools to understand supply-chain system concepts and to develop ordering skills that enhance the probability of uninterrupted supply, minimum losses, and increased profits.

The play screen of a computer simulation game, developed for learning about fresh produce retailing.
     At the University of Georgia, a computer simulation game was developed as an entertaining approach for learning about fresh produce retailing. The player assumes the role of a retailer striving to minimize inventory without running out of an item. A Windows environment and Stella software (www.hps-inc.com) were used to model the supply chain based on system thinking and dynamics to simulate the flow of orders in the produce delivery chain.
     The player selects a consumer demand from various deterministic and stochastic consumer demand options. Players are challenged by delays in produce delivery (two weeks) and perishability of the produce. Tension is caused from conflicting objectives of running out of produce and avoiding the penalty resulting from excess inventory. If required, the player can reduce his excess inventory by exercising his option of putting produce on sale. The bank balance shows the impact of the decisions made.
     The simulation provides a hands-on, interactive tool to learn about complex concepts encountered in fresh produce chains. Players are surprised by the difficulties encountered for maintaining low inventories while maintaining an uninterrupted supply, even at the easiest level. The simulation game provides an interesting way to help students and managers understand the dynamics of fresh produce marketing systems. The outcome will be fresher produce without risk of empty shelves. To download the game, go to www.griffin.uga.edu/ageng/programs/programs.html.

Designing Bioreactors: Thinking In and Out of a Box
ASAE member Joel L. Cuello, jcuello@ag.arizona.edu, The University of Arizona
     Abioreactor, quite simply, is a vessel or a box. To design a bioreactor is to devise ways to control the physical and biochemical environment inside this box, which involves regulating the flow of energy and materials in and out of it, for the purpose of optimizing the desired biochemical reaction that is taking place inside the box. The biochemical reaction in question may be growth, assimilation, secretion, and even death. The biological agents performing the pertinent biochemical reactions are typically microbial, animal or plant cells, or organs.
     There are numerous types of bioreactors with varied applications, ranging from production of medicinal compounds to beer and wine making. Specific and current examples include a vertical flat-plate bioreactor that is being designed at The University of Arizona to grow photosynthesizing cyanobacteria to assimilate carbon dioxide (CO2), a known greenhouse gas. Its long-term application is to capture CO2 emitted by electric power plants to minimize its release into the atmosphere and to help mitigate global warming. The cyanobacteria, while attached to the plates, are fed with liquid nutrients being re-circulated within the bioreactor. The idea is to keep the cyanobacteria “happy” inside the bioreactor by meeting their needs, such as nutrients, light, etc., and to keep them performing their “job” of sequestering CO2. For the longterm and more energy-efficient application, light will be channeled into the bioreactor through fiberoptic cables from solar concentrators.

An ebb-and-flow bioreactor is intermittently filled and drained with a nutrient solution to allow for repetitive nourishment time and breathing time for the roots that produce economically important chemicals.
     To produce pharmaceutical compounds, an ebb-and-flow bioreactor was designed to grow plant roots that have been genetically modified. The roots are kept nourished by immersion in a liquid nutrient solution. Keeping the roots immersed in the solution, however, will cause them to “drown” due to limitation in oxygen uptake. Hence, the bioreactor is intermittently filled and drained with the nutrient solution to allow for repetitive nourishment time and breathing time for the roots. The intermittent ebbing and flowing of the nutrient solution within the bioreactor is timed based on the oxygen consumption rate of the roots.

A continuous stirred tank reactor is designed for killing pathogenic bacteria and viruses present in recycled water by bombarding them with both gaseous ozone and ultraviolet radiation.
     Another example of a bioreactor type is one that is equipped with a rotating impeller, called a continuous stirred tank reactor, designed to achieve quick and good mixing of the solution it contains. This bioreactor type is also currently being used at The University of Arizona for two applications: one, for growing microbes, and the other, for killing microbes. The first application is for growing the bacterium E. coli, which has been genetically modified so that it manufactures the chemical BST. The second application is for killing pathogenic bacteria and viruses present in recycled water. The idea in the first application is to keep the E. coli cells “happy” by feeding them with the sugar glucose, supplying them with oxygen, and keeping the solution at the appropriate temperature and pH, etc. By contrast, the idea in the second application is to terminate the bacterial cells and viruses by bombarding them with both gaseous ozone and ultraviolet radiation which acts on the microbes by attacking their membranes and coatings and degrading their genetic materials.

Example of solar concentrators that channel light through fiber-optic cables helping to make the flat-plate bioreactor, that grows photosynthesizing cyanobacteria for CO2, capture more energy-efficient.
     Thus, there are many ways to design a box that is meant to serve as incubator for a desired biochemical reaction. Creativity and knowledge of engineering sciences and biology are necessary ingredients in this exciting design process.

Complete Recycling Systems for “Waste”
ASAE member Bill Butterworth, environment@usk.u-net.com, Land Network International Ltd.
     Why is it that natural ecosystems do not appear to “leak” nutrients? With the help of ASAE online Technical Library, Land Network International was able to answer that question and describe how the “closed loop” works (see Resource, April 2001, p. 13). As a result, this company convinced the United Kingdom Environment Agency to use large compost heaps on farms to recycle locally. Farmers are now given shares in a “reverse franchise” network.

Land Network’s rendition of the closed loop giving pollution control and scope to build a global carbon sink.
     The main feedstocks include separated municipal wastes, wood wastes from furniture manufacture, food industry wastes, many washings and sludges, feathers, and biosolids. Such high volume, low-value materials cannot economically be moved long distances for large centralized operations. Repeated applications of up to 250 tons per hectare (100 tons per acre) per annum build up organic matter which helps reduce crop disease. High carbon organics composts hold up to 10 times their own weight of water, so the method also forms “top soil reservoirs,” which reduce irrigation need. Farmers earn cash as a “gate fee” for taking the wastes and reduce their expenditure on bought-in mineral fertilizers.
     According to Environment Agency figures, around 40 to 45 percent of nitrogen in mineral fertilizers goes straight into ground water with rain. This is both a pollution problem and an economic loss. The goal is to procure enough nitrogen for the needs of any individual farm from local wastes. If mineral N is needed, members of the consortium can be trained to eliminate that loss by adding it to the compost process at the right time.
     Land Network works with the existing waste transport operators but builds in integrated logistics. The company normally expects to cut waste truck-miles on the public road by 50 to 80 percent. Waste producers get lower costs, too. They also move in the direction of “going organic.” Indeed, the potential to build a global carbon sink, reduce nitrate pollution, and reduce irrigation need now exists.

Multiple Air Pollutant Removal in a Biological Filter
Engineering parameters and microbial ecology
Y. Ding, njdymmt@hotmail.com; K. C. Das, kdas@engr.uga.edu; ASAE member J. R. Kastner, jkastner@engr.uga.edu; and W. B. Whitman, whitman@arches.uga.edu, The University of Georgia
     Air pollution control is an expensive environmental requirement for many industries. Industry is constantly searching for more effective, lower-cost technologies. Biological filters fit this description, especially for large volume emissions with low pollutant concentrations. Microorganisms growing on the biofilter media metabolize pollutants leaving little residues that have to be further managed. Although biofilters have been in use for over two decades, little is known about the interaction of the microbial biota within the filter and the filter’s engineering operating characteristics. Research at the University of Georgia addressed this limitation while looking at a biofilter treating hydrogen sulfide and methanol, two pollutants commonly seen together in pulp and paper industry emissions.
     Engineers and microbiologists worked together to characterize contaminant removal kinetics in conjunction with changes in the microbial ecology monitored using 16S rRNA gene libraries developed from biofilter samples. New biofilter media possessed high microbial diversity (Shannon Weaver Index H = 3.65), species richness (Richness Index d = 23.94), and evenness. However, after treating H2S for some time, microbial diversity reduced (H = 1.33, d = 2.77), selecting for sulfur-oxidizing bacteria Thiobacillus and Sulfobacillus. Introduction of CH3OH resulted in the appearance of ribotypes related to the CH3OH-oxidizing bacteria Methylosinus and Methylocella within the microbial community. In addition, some of the organisms detected when only H2S was being treated continued to coexist with the new populations increasing community diversity (H = 3.02), species richness (d = 15.10), and evenness.
     Kinetics of H2S degradation improved in the presence of CH3OH, with first order rate constant being significantly higher (á = 0.05) when both gases were present (k = 0.031 sec-1) than when only H2S was being treated (k = 0.021 sec-1). Results confirm increased community diversity and species richness contributes to overall improvement in removal of target compounds. Understanding changes in microbial communities in the presence of multiple contaminant gases can help in better design and management of biofilters.
Managing Aquatic Ecosystem Processes at the Watershed Level
An ecological engineering approach ASAE members Indrajeet Chaubey, chaubey@uark.edu; Marty D. Matlock, Mmatlock@uark.edu, University of Arkansas; and Brian E. Haggard, haggard@uark.edu, USDA-ARS-PPPSRU
     Ecosystem processes are complex and difficult to manage. The ecological engineering group within the Biological and Agricultural Engineering Department at the University of Arkansas applies the principles of ecology and engineering to investigate and restore ecosystems degraded by human activity focusing on the smallest unit of ecosystem management – the watershed. The ecological engineering group’s research includes investigation of the response of aquatic systems to nutrient enrichment from diffuse and point sources, control of biotic and abiotic processes on water quality and in the landscape for enhanced ecological services, and combining these investigations to enhance ecosystem management and develop decision support systems.

University of Arkansas graduate students deploy a passive diffusion periphytometer on the White River, Ark.
     Nutrient dynamics investigations provide insight into watershed/ stream-sediment interactions. The approach is to quantify the processes that control stream nutrient concentrations, rate of nutrient transport within the aquatic ecosystem, and partitioning of nutrients between biotic and abiotic components within streams. The in-stream investigations include measuring wholereach nutrient retention efficiency; algal response in situ to nutrient enrichment; and storage, buffering, and exchange of biologically available nutrients in stream sediments. For example, a passive diffusion periphytometer is used to assess algal nutrient limitation and assimilation capacity in streams; this technology may be used to develop nutrient management thresholds for streams based on comprehensive measures of nutrient assimilative capacity. Periphytometers have also been used to evaluate in situ eco-toxicological effects of anti-microbial agents on stream algae. We integrate aquatic ecosystem process measurements and modeling with geographic information system-based watershed models to assess and restore ecological services at the landscape level, focusing on regional land use change, riparian cover loss, and stream geomorphologic alteration.
     The ecological engineering group’s focus is developing tools and methods for restoring/preserving ecological services and sustainable ecosystem management. Major research projects include assessing biological and chemical responses of drinking water reservoirs to anthropogenic stressors, developing urban greenways with enhanced ecological services, and integrating stakeholder feedback into watershed stakeholder and policy-maker decision support systems.

The Path to Healthier Potato Chips
ASAE member Rosana Moreira, Tmoreira@tamu.edu, Texas A&M University
     The path to healthier potato chips began at an unusual site where abandoned oil reservoirs are located. This is an interesting twist to the decade-old Texas A&M study of engineering mechanics of the deep-frying process for chips.
     Intrigue with oil began during a biopolymer project to recover oil from abandoned reservoirs, studying how oil moves through porous soil. Oil in porous media is the same in the ground or in a chip; although different situations, the principles are the same. The amount of oil absorbed by the chip during frying is what drives fat and calories up. Temperature and oil quality also play key roles.
     “Can healthier potato chips with the same taste, less fat, and more Vitamin C and other nutrients be made?” wondered researchers. One research goal is to produce snack foods that taste more like “real foods” and yet have a beneficial effect on human health. While baked chips may be healthier, the taste is not the same as those that are fried.
     The secret to healthier chips lies in the frying – the process that turns a bit of potato, tortilla, sweet potato, apple, or banana into a crispy chip. Examinations focusing on chip microstructure – to see how this structure changes as it becomes a chip – were fruitful. Research showed that changes in the physical structure of the chip during frying affect the final product. Findings even allowed for creation of computer simulations of the deep-frying process.
     In addition to traditional deep-fat frying, experimentation with vacuum frying and steam drying has been done. Vacuum frying can produce potato chips with about 27-percent oil content, as opposed to up to 38-percent oil content for current chip frying technology. Steam drying is better for the product, resulting in no color change as well as lower oil content. As well, more Vitamin C is retained in steam-dried potato chips.
Automated Monitoring System Tends the Flock
Chris Hoffacker, choffack@engr.uga.edu, University of Georgia
     Poultry production has historically required operators to keep a close watch over the flock since quick action is required when trouble develops. Modern production breeds have been developed to grow quickly but, as a consequence, are very intolerant of extremes in their environment – like high temperature and humidity – and can die quickly if exposed. Efforts to minimize the impact of environmental extremes include automated poultry house controllers that automatically adjust heating and ventilation rates based on the ambient conditions in the house. Although an improvement over manual controls, these systems do not monitor the state of the animals themselves and thus, can miss important details. If physiological information were available to an automated system, early danger signals from the birds would be known long before the chickens showed any outward signs of distress, by which time it is often too late.

A telemetry device surgically implanted in the bird transmits physiological data to a receiver and controller that adjusts the environment to suit the chicken.
     Study of this problem is the purpose of Dr. Takoi Hamrita’s research group at the University of Georgia. Using surgically implanted devices in the body cavity of live chickens, numerous physiological elements can be measured realtime and transmitted to a computer-based control system where the data can be analyzed and appropriate changes to the environment made. Early work was limited to monitoring body temperature and the use of artificial intelligence through trained neural networks to predict animal responses. Current efforts include the monitoring of heart rate and generalized motor activity to better judge those data sources for environmental control. Telemetered body temperature as feedback has been used in a standard industrial closed loop control architecture for maintaining optimal fan speed in a “tunnel ventilation” setup. Tunnel ventilation, a common method of cooling chickens in hot and humid environments, exposes the birds to fixed velocity forced air, sometimes at over 2 meters per second (6.7 feet per minute). In laboratory tests, birds were placed in an excessively warm and humid environment while an implanted telemetry sensor reported their body temperature. Instead of fixed velocity air, the closed loop control used this body temperature to determine an appropriate fan speed to maintain a healthy deep body temperature in the birds.
     The future of implementing this approach in commercial applications is limited by the cost, size, and power requirements of the telemetry implants. However, as technology advances toward smaller and more efficient devices, widespread use of bio-telemetry to monitor and maintain livestock production environments is a logical next step.

Phytoremediation
ASAE member Stacy Lewis Hutchinson, sllhutch@bae.ksu.edu, Kansas State University
     Non-point source (NPS) pollution has been called the nation’s largest water quality problem, and its reduction is a major challenge facing society today. Since the approval of the Clean Water Act of 1972, the United States has made great advances in reducing point source pollution from industrial and municipal wastewater systems. Unfortunately, not enough has been done to control non-point source or diffuse pollution resulting in approximately 40 percent of rivers, lakes, and estuaries being unfit for basic uses.
     The Water Quality Act of 1987 established the Non-point Source Management Program, which calls for states to develop and implement management programs. The establishment and maintenance of vegetated buffer systems for the purpose of phytoremediating NPS pollution is a management practice that needs to be studied and optimized.

Surface runoff sampler located at the edge of an agricultural field in Clay County, Kan. Runoff samples are analyzed for pesticides, nutrients, and sediment. Samples are compared to runoff samples collected at the stream edge of the buffer to determine the impact of the buffer vegetation on pollutant reduction.
     Phytoremediation combines the Greek word phyto, meaning plant, and remedium, the Latin suffix meaning to cure or restore. Phytoremediation is a relatively new technology that uses higher order, “green” plant systems to clean water and soils contaminated with hazardous inorganic and organic compounds. In the last decade, the term has been expanded to cover several plant-induced remediation mechanisms including phytostabilization for heavy metals; phytovolatilization for mercury, selenium, and chlorinated solvents; phytotransformation for munitions, pesticides, and chlorinated solvents; and rhizosphere degradation or plant-assisted bioremediation for organic compounds. Depending on the contaminant of concern, combined phyto-mechanisms may be capable of more rapidly cleaning contaminated sites.
     Current research at Kansas State University is focused on understanding the impact of different vegetation species on the degradation of pesticides, animal waste, petroleum products, and heavy metals. Additionally, researchers are studying the impact of different management practices such as irrigation and fertilization for process optimization. Results from this research will lead to improved designs for riparian buffers and field borders to control pollution in field runoff, a better understanding of bioretention cell function for urban storm water management, and improved site plans for using vegetated treatment systems to clean up hazardous waste sites.

Multi-spectral Vision Technology for Precision Farming
The future of site-specific crop management
ASAE members Yunseop (James) Kim, KimJames@JohnDeere.com, John Deere Worldwide Commercial and Consumer Equipment, and John F. Reid, ReidJohnF@JohnDeere.com, John Deere Technology Center
     Agricultural fields are variable and require site-specific crop management. Nitrogen (N) is an essential nutrient required for plant growth and a major component of the chlorophyll molecule enhancing photosynthesis. However, excessive N fertilizer leaches into the groundwater and creates serious environmental problems. Thus, there is an opportunity for sensors that can assess plant N-deficiency throughout the growing season to enable producers to reach their production goals while maintaining environmental quality.

Figure 1. Ground-based real-time crop remote sensing system (left: hardware layout, right: sensor platform).
     A real-time in-field sensor that predicts plant nitrogen stress and applies only required amount of fertilizer has been developed. The sensor measures leaf reflectance from a nadir view over a crop under natural ambient illumination and feeds back to a sprayer with global positioning satellite (GPS) record as shown in Figure 1.
     The researchers deployed a three-charge-coupled device (CCD) multi-spectral camera to percept the reflectance response of crop canopies. They identified images of three spectral ranges (green with 550±50 nm, red with 650±50nm, and nearinfrared with 800±50 nm) to derive leaf reflectance index. They studied the change of image intensity due to varying ambient illumination and developed a fuzzy logic controller that dynamically adjusts the camera exposure and gain in order to maintain image intensity. Their studies included reflectance compensation of the effect of varying solar zenith angles so that the validation remains under time constraint.

Figure 2. Non-vegetation elimination using image segmentation (left: raw image, right: processed image).

Figure 3. Sensor assessment of nitrogen stress level compared with SPAD measurements.

     The advantage of the vision-based spectral sensor is emphasized by image processing to eliminate effects of non-vegetation components such as soil, shadow, and specular leaf portions that significantly degrade performance of a standard spectroscopy as shown in Figure 2. In experimental study of corn field, the sensor provided reliable performance, at maximum two meters per second (6.7 feet per minute) vehicle speed, superior to soil plant analysis development (SPAD) chlorophyll measurements as as shown in Figure 3. Preliminary study of the sensor-based supplemental N treatment promised economical and environmental benefit in crop N management. The researchers believe that the vision-based multi-spectral technology will be expanded for the future precision farming.
Engineering the Optical Control of Biology Light-activated DNA
W. Todd Monroe, tmonroe@LSU.edu, Louisiana State University,
      DNA participates in a multitude of biological processes that govern who we are and how we feel. The regulation of DNA-dependent processes is central to the proper function of living cells as well as molecular biology assays. The directed control of when and where DNA activity takes place is of interest both in clinical gene therapy trials and at the bench in research or diagnostic assays. While many chemical and biochemical compounds have been used to regulate the activity of DNA, most strategies are limited to the aqueous-based diffusion of the activator to the target DNA or cell itself. Louisiana State University’s (LSU) Biological and Agricultural Engineering Department is “shedding new light on the topic” by attempting to augment DNA control from the traditional reliance on chemical species to a light-based modulation.
     An example of a biological engineering project focused at the cellular and molecular levels, the LSU team chemically blocks DNA by attaching photosensitive cage compounds that can be subsequently activated with light to control DNA function. The attachment of cage compounds to DNA blocks bioactivity until exposed to near-UV light (365 nanometers) that photocleaves the cage, releasing the DNA in its original and bioactive form.

     The idea of “caging DNA” was born in the author’s graduate mentor’s laboratory at Vanderbilt University. Rick Haselton and colleagues noted that, for the past two decades, the caging of smaller molecules (such as adenosine triphosphate and neurotransmitters) had been utilized in biological studies to explore the timing of cell motility, muscle contractility, and kinetics of other intracellular processes. The idea to use cage chemistry to similarly control the timing but also the location of DNAdependent processes initiated this project.
     The author sees potential future application of this lightactivated strategy in assisting the realization of genetic therapies in the clinic. Gene therapy is the production of therapeutic products by the body’s own cellular machinery. DNA containing the code to produce these products must be introduced into the patient’s cells. Successful in vivo gene therapy must both deliver these foreign genes to the specific target cells and restrict this expression to only these target cells.
     One potential strategy for targeting expression of introduced genes is the non-specific delivery of “silent” genes followed by reactivation at selected sites. As seen in the illustration below, silent (caged) DNA transgenes could be injected into a patient followed by pinpointed laser light exposure at sites of pathology to activate the therapeutic DNA. This technique could be used to control the timing and location of expressed genes and reduce side effects by restricting production of the therapeutic products to the intended tissues. Ultimately, this biophotonic strategy may offer a new form of engineered control over DNAdependent processes.