#Horticulture: Sensor-based irrigation systems show potential to increase greenhouse profitability Wireless sensor-based irrigation systems can offer significant benefits to greenhouse operators.
Advances in sensor technology and increased understanding of plant physiology have made it possible for greenhouse growers to use water content sensors to accurately determine irrigation timing and application rates in soilless substrates.
The wireless sensor systems provide more accurate measurements of substrate moisture than qualitative methods and can save irrigation water labor energy and fertilizer.
The authors of a report published in Horttechnology said that the use of sensor-based irrigation technology can also accelerate container and greenhouse plant production time.
Erik Lichtenberg John Majsztrik and Monica Saavoss reported on a study they designed to determine an optimal formula for ascertaining the true profitability of precision irrigation systems.
Sensor-based irrigation systems substitute capital for water and associated inputs such as energy labor and fertilizer the authors explained.
When benefits and costs accrue at different points in time calculating profit --or indeed comparing them in any way--requires putting benefits and costs on a common time footing.
The researchers designed a methodology for calculating profitability taking differences in timing into account and then applied the methodology to data from gardenia production in a Georgia nursery.
The most convenient method (of calculating profitability) is converting all revenues and costs to constant periodic payments;
e g. annualizing them they explained. We began by discounting all revenues and costs to convert them to their present values.
We then calculated the present value of profit which we converted to a constant annual payment (or loss).
Finally we calculated profit (or loss) per unit area to permit scaling up or down.
The scientists found that controlling irrigation using data from moisture sensors led to substantial reductions in both production time and crop losses.
The weighted average time from planting to sale was over one-third lower while crop losses were reduced by 50%the authors noted.
Calculations showed that annualized profit under the wireless sensor system was over 1. 5 times more than under the nursery's standard practice
and that most of the increase in profit was attributed to a reduction in production time.
Lichtenberg Majsztrik and Saavoss concluded that even if efficiency gains are not as high as those in the study controlling irrigation using wireless sensor systems is likely to increase profitability substantially.
They added that wireless sensor systems can have environmental benefits as well as the economic benefits shown in the study.
The design and conduct of the experiments used in our analysis prevented us from estimating potential environmental benefits
but this technology clearly has promise as a win-win combination of economic and environmental improvements they said.
#Painting robot lends surgeons a hand in the operating room Would you let an artist perform lifesaving surgery on you?
and shapes a surgeon makes with a scalpel using a paintbrush and canvas. His invention a creative blend of art and science could one day lend doctors a hand in practicing complex robot-assisted surgeries without having to step foot in an operating room.
Rethinking roboticslee a sophomore who plans to major in chemistry spent his high school years building everything from a robot that can balance on a beam to a robotic arm that can throw a ball.
During his first year at Wake Forest he heard about a percussion-playing robot designed by Georgia Tech researchers
and started thinking about new ways to apply his hobby. I never really thought you could do music with robots he said.
and that prompted the idea of robotic surgery. Lee said painting and surgery have more in common than initially meets the eye.
A painter has to be nimble and precise with his brushstrokes much like a surgeon must be nimble and precise with a scalpel.
When you are dissecting a part of the human body you have to be one hundred percent perfect he said.
With the support of a grant from the Undergraduate Research and Creative Activities (URECA) Center Lee teamed up with Craig Hamilton an associate professor of biomedical engineering at Wake Forest Baptist Medical center
After weeks of programming I eventually got to the point where the robot could paint shapes and lines in a particular color.
or a house without any input from a human operator Lee next began to teach the robot to paint lines
and shapes a surgeon makes with a scalpel all on its own he said. You can think of a painting canvas as a body and the brush as a surgeon's knife.
Practicing in a surgeon's studiocurrently surgical robots are controlled by a human operator and do not perform procedures autonomously.
While Lee's robot may never be put to work in an operating room it and other robots like it could one day help researchers to design fully autonomous robotic surgeons.
In addition to teaching the robot to paint autonomously Lee also explored the idea of using his robot as a training tool for surgeons who need practice operating a Da vinci surgical arm.
At the Wake Forest Medical center doctors use replica bodies to help train surgeons to use the Da vinci system Lee said.
These replicas are compared pretty expensive to my robotic arm which cost around $1500. This April Lee will represent Wake Forest at the ACC Meeting of the Minds an event where outstanding undergraduate researchers from each ACC university gather at one member university to present their research either verbally or as a poster.
This year the event will take place at the University of Pittsburgh where Lee will demonstrate his robot's painting abilities.
Working with Dr. Hamilton on my robot has been a great opportunity and there are definitely still a lot of things we can still learn from it Lee said.
The above story is provided based on materials by Wake Forest University. Note: Materials may be edited for content and length h
#Laser scientists create portable sensor for nitrous oxide, methane Rice university scientists have created a highly sensitive portable sensor to test the air for the most damaging greenhouse gases.
The device created by Rice engineer and laser pioneer Frank Tittel and his group uses a thumbnail-sized quantum cascade laser (QCL) as well as tuning forks that cost no more than a dime to detect very small amounts of nitrous oxide and methane.
The technique called quartz-enhanced photoacoustic absorption spectroscopy (QEPAS invented at Rice by Tittel, Professor Robert Curl and their collaborators in 2002,
offers the possibility that such devices may soon be as small as a typical smartphone.
The Rice team's device was detailed this month in the Royal Society of Chemistry journal Analyst.
and human activities, such as leakage from natural gas systems and the raising of livestock.""Human activities such as agriculture, fossil fuel combustion, wastewater management and industrial processes are increasing the amount of nitrous oxide in the atmosphere.
The warming impact of methane and nitrous oxide is more than 20 and 300 times, respectively, greater compared to the most prevalent greenhouse gas, carbon dioxide over a 100-year period.
For these reasons, methane and nitrous oxide detection is crucial to environmental considerations.""The small QCL has only become available in recent years,
What makes the technique possible is the small quartz tuning fork, which vibrates at a specific frequency when stimulated."
"The laser beam is focused between the two prongs of the quartz tuning fork. When light at a specific wavelength is absorbed by the gas of interest,
and that excites the quartz tuning fork.""The tuning fork is a piezoelectric element, so when the wave causes it to vibrate,
the Rice team installed it on a mobile laboratory used during NASA's DISCOVER-AQ campaign, which analyzed pollution on the ground and from the air last September.
and the QEPAS sensor's findings compared favorably to the lab's much larger instrument,
"Tittel said smaller QEPAS device will be added this year to the mobile monitoring van currently carrying out a Rice university of Houston survey of pollutants in the city.
Co-authors include Rice graduate student Wenzhe Jiang and former Rice Laser Science Group members Przemystaw Stefanski, Rafat Lewicki, Jiawei Zhang and Jan Tarka.
Tittel is the J. S. Abercrombie Professor in Electrical and Computer engineering and a professor of bioengineering.
#Cell-Squeezing Device Opens New Possibilities for Cell-Based Vaccines A newly published study details how researchers from MIT developed a new microfluidic cell-squeezing device, opening new possibilities for cell
-based vaccines. MIT researchers have shown that they can use a microfluidic cell-squeezing device to introduce specific antigens inside the immune system B cells,
providing a new approach to developing and implementing antigen-presenting cell vaccines. Such vaccines, created by reprogramming a patient own immune cells to fight invaders,
hold great promise for treating cancer and other diseases. However, several inefficiencies have limited their translation to the clinic
and only one therapy has been approved by the Food and Drug Administration. While most of these vaccines are created with dendritic cells,
a class of antigen-presenting cells with broad functionality in the immune system, the researchers demonstrate in a study published in Scientific Reports that B cells can be engineered to serve as an alternative. e wanted to remove an important barrier in using B cells as an antigen-presenting cell population,
helping them complement or replace dendritic cells, says Gregory Szeto, a postdoc at MIT Koch Institute for Integrative Cancer Research and the paper lead author.
Darrell Irvine a member of the Koch Institute and a professor of biological engineering and of materials sciences and engineering, is the paper senior author.
A new vaccine-preparation approachdendritic cells are the most naturally versatile antigen-presenting cells. In the body, they continuously sample antigens from potential invaders,
which they process and present on their cell surface. The cells then migrate to the spleen or the lymph nodes,
where they prime T cells to mount an attack against cells that are infected cancerous or, targeting the specific antigens that are ingested and presented.
Despite their critical role in the immune system dendritic cells have used drawbacks when for cell-based vaccines:
They have a short lifespan, they do not divide when activated, and they are relatively sparse in the bloodstream.
B cells are also antigen-presenting cells, but in contrast to dendritic cells, they can proliferate
when activated and are abundant in the bloodstream. However, their functionality is limited more: Whereas dendritic cells constantly sample antigens they encounter,
A b cell is programmed genetically only to bind to a specific antigen that matches the receptor on its surface.
As such, A b cell generally will not ingest and display an antigen if it does not match its receptor.
Using a microfluidic device, MIT researchers were able to overcome this genetically programmed barrier to antigen uptake by squeezing the B cells.
Through ellsqueeze, the device platform originally developed at MIT, the researchers pass a suspension of B cells and target antigen through tiny, parallel channels etched on a chip.
A positive-pressure system moves the suspension through these channels which gradually narrow, applying a gentle pressure to the B cells.
This queezeopens small, temporary holes in their membranes, allowing the target antigen to enter by diffusion.
This process effectively loads the cells with antigens to prime a response of CD8 or illert cells,
which can then kill cancer cells or other target cells. The researchers studied the squeezed B cells in culture
and found that they could expand antigen-specific T cells at least as well as existing methods using antibody-coated beads.
As proof of concept, the researchers then transferred squeezed B cells and antigen-specific T cells into mice
observing that the squeezed B cells could expand T cells in the spleen and in lymph nodes. The researchers also say that this is the first method that decouples antigen delivery from B-cell activation.
A b cell becomes activated when ingesting its antigen or when encountering a foreign stimulus that forces it to ingest nearby antigen.
This activation causes B cells to carry out very specific functions, which has limited options for B-cell-based vaccine programming.
Using Cellsqueeze circumvents this problem, and by being able to separately configure delivery and activation,
researchers have greater control over vaccine design. Gail Bishop a professor of microbiology at the University of Iowa Carver School of medicine and director of the school Center for Immunology and Immune-Based Diseases, says that this paper presents a reative new approach with considerable potential in the development
of antigen-presenting cell vaccines.?The antigen-presenting capabilities of B cells have often been underestimated, but they are being appreciated increasingly for their practical advantages in therapies,
says Bishop, who was involved not in this research. his new technical approach permits loading B cells effectively with virtually any antigen
and has the additional benefit of targeting the antigens to the CD8 T-cell presentation pathway, thus facilitating the activation of the killer T cells desired in many clinical applications. ain squeezearmon Sharei, now a visiting scientist at the Koch Institute,
developed Cellsqueeze while he was a graduate student in the laboratories of Klavs Jensen, the Warren K. Lewis Professor of Chemical engineering and a professor of materials science and engineering,
and Robert Langer, the David H. Koch Institute Professor and a member of the Koch Institute.
Sharei, Jensen, and Langer are also authors of this paper. In a separate study published last month in the journal PLOS ONE, Sharei and his colleagues first demonstrated that Cellsqueeze can deliver functional macromolecules into immune cells.
The platform has benefits over existing delivery methods, including electroporation and genetically engineered viruses, which are limited to delivering nucleic acids.
While nucleic acids can code a cell for a target antigen these indirect methods have drawbacks:
They have limited ability in coding for difficult-to-identify antigens, and using nucleic acids bears a risk for accidental genome editing.
These methods are also toxic, and can cause cell damage and death. By delivering proteins directly into cells with minimal toxicity,
Cellsqueeze avoids these shortcomings and, in this new study, demonstrates promise as a versatile platform for creating more effective cell-based vaccines. ur dream is to spawn out a whole class of therapies
which involve taking out your own cells, telling them what to do, and putting them back into your body to fight your disease,
whatever that may be, Sharei says. After developing Cellsqueeze at MIT, Sharei co-founded SQZ Biotech in 2013 to further develop
and commercialize the platform. Just as the company has grown since then now up to 13 employees the device has evolved also.
Sharei, now the company CEO, says that by improving the design and increasing the number of channels,
the current generation has a throughput of 1 million cells per second. Future stepsthe researchers say they now plan to refine their B-cell-based vaccine to optimize distribution and function of the immune cells in the body.
A b-cell-based approach could also reduce the amount of patient blood required to prepare a vaccine.
At present patients receiving cell-based vaccines must have drawn blood over several hours each time a new dose must be prepared.
Meanwhile, SQZ Biotech aims to reduce the footprint of its device, which could potentially lower the time
and cost required to engineer cell-based vaccines. e envision a future system, if we can take advantage of its microfluidic nature,
as a bedside or field-deployable device, Sharei says. nstead of shipping your cells off to this big, centralized facility,
you could do it in your hospital or your doctor office. s the biology and technology become further refined,
the authors say that their approach could potentially be a more efficient, more effective, and less expensive method for developing cell-based therapies for patients. own the road,
you could potentially get enough cells from just a normal syringe-based blood draw, run it through a bedside device that has the antigen you want to vaccinate against,
and then you have the vaccine, Szeto says. This research was funded by the Kathy and Curt Marble Cancer Research Fund through the Koch Institute Frontier Research Program, the National Cancer Institute, the National Institute of General medicine Sciences
and the Howard hughes medical institute. Publication: Armon Sharei, et al. x Vivo Cytosolic Delivery of Functional Macromolecules to Immune Cells, PLOS One, 2015;
DOI: 10.1371/journal. pone. 0118803source: Kevin Leonardi, Koch Instituteimage: SQZ Biotec 8
#CCNE1 Gene Turns Back Cellular Clock Yale researchers have discovered a gene that turns back the cellular clock,
greatly aiding the reprogramming of mature cells. An exhaustive analysis of factors that allow mature cells to become like embryonic stem cells again has revealed a spliced form of a gene found only in primates that greatly aids the reprogramming of mature cells.
The discovery of a human-specific gene involved in such a fundamental process as the creation of a pluripotent cell,
one that can become a variety of tissue types, surprised Yale researchers. The gene called CCNE1 is involved normally in cell cycling
but the variant CCNE1 does not appear to play that role and instead appears critical for reprogramming.
It is also unclear why the gene is found only in in primate cells. The Yale team, led by geneticist In-Hyun Park,
is studying how mature cells can be reprogrammed back to their embryonic state. The goal of the research is to better understand the processes of cell fate change
and one day develop customized cell therapies for individual patients. The Yale team used a new form of transciptome analysis that allowed them to more fully explore impact of all types of RNA on cell reprogramming.
The work will be published in June 6 issue of Stem Cell Reports. Publication: Yoshiaki Tanaka, et al. ranscriptome Signature and Regulation in Human Somatic cell Reprogramming, Stem Cell Reports, 2015;
doi: 10.1016/j. stemcr. 2015.04. 009source: Bill Hathaway, Yale Universityimage: Yale Universit e
#New Algorithm Lets Robots Autonomously Plan for Tasks Researchers from MIT have developed a new algorithm that lets autonomous robots divvy up assembly tasks on the fly,
an important step forward in multirobot cooperation. Today industrial robots are remarkably efficient as long as theye in a controlled environment where everything is exactly where they expect it to be.
But put them in an unfamiliar setting, where they have to think for themselves, and their efficiency plummets.
And the difficulty of on the fly-fly motion planning increases exponentially with the number of robots involved.
For even a simple collaborative task a team of, say, three autonomous robots might have to think for several hours to come up with a plan of attack.
This week, at the Institute for Electrical and Electronics Engineersinternational Conference on Robotics and Automation, a group of MIT researchers were nominated for two best-paper awards for a new algorithm that can significantly reduce robot teamsplanning time.
The plan the algorithm produces may not be perfectly efficient, but in many cases, the savings in planning time will more than offset the added execution time.
Watch the MIT researchersteam of robots collaborating to build a chair. The robots autonomously plan how to grasp the parts
Courtesy of the researchersthe researchers also tested the viability of their algorithm by using it to guide a crew of three robots in the assembly of a chair. ee really excited about the idea of using robots in more extensive ways in manufacturing,
says Daniela Rus, the Andrew and Erna Viterbi Professor in MIT Department of Electrical engineering and Computer science,
whose group developed the new algorithm. or this, we need robots that can figure things out for themselves more than current robots do.
We see this algorithm as a step in that direction. us is joined on the paper by three researchers in her lab first author Mehmet Dogar
and Andrew Spielberg and Stuart Baker, both graduate students in electrical engineering and computer science. Grasping consequencesthe problem the researchers address is one in
but problematic for the next step because another robot or sensor is needed, Rus says. he current grasping formation may not allow room for a new robot
or sensor to join the team. So our solution considers a multiple-step assembly operation
and optimizes how the robots place themselves in a way that takes into account the entire process,
Principled procrastinationthe algorithm begins by devising a plan that completely ignores the grasping problem. This is the equivalent of a plan in
Then the algorithm considers the transition from one stage of the operation to the next from the perspective of a single robot
and that part that will work in both stages of the operation, but which won require any modification of any of the other robotsbehavior,
If the algorithm were permitted to run to completion its last few grasp decisions might require the modification of every robot behavior at every step of the assembly process,
In some, they found that their algorithm could, in minutes, produce a workable plan that involved just a few drops,
But their algorithm could still produce a workable plan. ith an elegant heuristic approach to a complex planning problem,
Rus group has shown an important step forward in multirobot cooperation by demonstrating how three mobile arms can figure out how to assemble a chair,
the Professor of Robotics and Intelligent Systems at Swiss Federal Institute of technology in Zurich. y biggest concern about their work is that it will ruin one of the things
#New Technique Increases Nanofiber Production Rate Fourfold Nanofibers polymer filaments only a couple of hundred nanometers in diameter have a huge range of potential applications, from solar cells
to water filtration to fuel cells. But so far, their high cost of manufacture has relegated them to just a few niche industries.
In the latest issue of the journal Nanotechnology, MIT researchers describe a new technique for producing nanofibers that increases the rate of production fourfold
while reducing energy consumption by more than 90 percent, holding out the prospect of cheap, efficient nanofiber production. e have demonstrated a systematic way to produce nanofibers through electrospinning that surpasses the state of the art,
says Luis Fernando Velásquez-García, a principal research scientist in MIT Microsystems Technology Laboratories, who led the new work. ut the way that it done opens a very interesting possibility.
Our group and many other groups are working to push 3-D printing further, to make it possible to print components that transduce,
that actuate, that exchange energy between different domains, like solar to electrical or mechanical. We have something that naturally fits into that picture.
We have an array of emitters that can be thought of as a dot matrix-printer printer, where you would be able to individually control each emitter to print deposits of nanofibers.
Tangled tale Nanofibers are useful for any application that benefits from a high ratio of surface area to volume solar cells, for instance,
which try to maximize exposure to sunlight, or fuel cell electrodes, which catalyze reactions at their surfaces.
Nanofibers can also yield materials that are permeable only at very small scales, like water filters,
or that are remarkably tough for their weight, like body armor. The standard technique for manufacturing nanofibers is called electrospinning,
and it comes in two varieties. In the first, a polymer solution is pumped through a small nozzle,
and then a strong electric field stretches it out. The process is slow, however, and the number of nozzles per unit area is limited by the size of the pump hydraulics. The other approach is to apply a voltage between a rotating drum covered by metal cones and a collector electrode.
The cones are dipped in a polymer solution, and the electric field causes the solution to travel to the top of the cones,
where it emitted toward the electrode as a fiber. That approach is erratic, however, and produces fibers of uneven lengths;
it also requires voltages as high as 100,000 volts. Thinking small Velásquez-García and his co-authors Philip Ponce de Leon, a former master student in mechanical engineering;
Frances Hill, a former postdoc in Velásquez-García group who now at KLA-Tencor; and Eric Heubel, a current postdoc adapt the second approach,
but on a much smaller scale, using techniques common in the manufacture of microelectromechanical systems to produce dense arrays of tiny emitters.
The emitterssmall size reduces the voltage necessary to drive them and allows more of them to be packed together, increasing production rate.
At the same time, a nubbly texture etched into the emitterssides regulates the rate at which fluid flows toward their tips,
yielding uniform fibers even at high manufacturing rates. e did all kinds of experiments, and all of them show that the emission is uniform,
Velásquez-García says. To build their emitters, Velásquez-García and his colleagues use a technique called deep reactive-ion etching.
and a dissolved polymer. When an electrode is mounted opposite the sawteeth and a voltage applied between them,
the water-ethanol mixture streams upward, dragging chains of polymer with it. The water and ethanol quickly dissolve, leaving a tangle of polymer filaments opposite each emitter, on the electrode.
The researchers were able to pack 225 emitters, several millimeters long, on a square chip about 35 millimeters on a side.
At the relatively low voltage of 8, 000 volts, that device yielded four times as much fiber per unit area as the best commercial electrospinning devices.
The work is n elegant and creative way of demonstrating the strong capability of traditional MEMS microelectromechanical systems fabrication processes toward parallel nanomanufacturing
says Reza Ghodssi, a professor of electrical engineering at the University of Maryland. Relative to other approaches, he adds,
there is n increased potential to scale it up while maintaining the integrity and accuracy by
which the processing method is applied. Publication: Philip J Ponce de Leon, et al. arallel nanomanufacturing via electrohydrodynamic jetting from microfabricated externally-fed emitter arrays, Nanotechnology, 2015,26, 225301;
doi: 10.1088/0957-4484/26/22/22530
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