Profile

• Telephone

  1-513-887-9360

  
  
• Time Zone

  Eastern

  
  
• Gender

  Male

  
  
• Organization

  Miami University

  
  
• Employment Status

  Retired / Unemployed

  
  
• Role

  Scientist Mentor: I will mentor teams of students online

  
  
• Research Interests (300 words)

  My research focuses on the effects of environmental factors on the development of root systems and stress-induced programed cell death in plants.
  
  Recently my collaborators and I have been experimenting with using computers to produce virtual 3D reconstructions of root tip structure from microscope slides.

  
  
• Do you have previous experience in mentorship or educational outreach? Please list here (200 words)

  I have been an advisor of college botany majors at the undergraduate and graduate level for 29 yr. I have participated in Planting Science since 2008. I created a children's anti-plant blindness outreach program for the entire Hamilton Ohio City School district involving in classroom activities and field trips to the Miami University Conservatory that ran for a decade and served ca. 8000 children.

  
  
• Which of the following best describes your career stage?

  Emeritus/Retired

  
  
• Profile Question 1

  What was the first science experiment you ever designed? How did it turn out?

  
  
• Answer the question you selected for profile question 1 here (300 words):

  As an undergraduate I had a lab job assisting a doctoral student who needed to isolate DNA from the root apical meristems of pea plants. We did not have polymerase chain reaction (PCR) technology to amplify small amounts of DNA in those days, so he needed very large numbers of root tips to get sufficient DNA for an experiment. Based on my classwork and some experiments some other students in our lab had done, I thought I could use elevated temperature to significantly increase the number of cells in these meristems, and therefore reduce the number of root tips we would need to collect to get enough meristem DNA. The experiment was pretty much a failure with respect to its hypothesis and objective, but it serenipitously revealed a lot of surprising effects that elevated temperature had on the development of pea roots. This ultimately led to my own doctoral dissertation research project and subsequent life's work.

  
  
• Profile Question 2

  When and why did you decide to go into a science career?

  
  
• Answer the question you selected for profile question 2 here (300 words):

  When I was contemplating going back to college after 18 yr in other occupations, I discovered it was not necessarily required that one live and work in a city to do science. I wanted my children to grow up in a non-urban environment, so I decided to study agronomy and botany.

  
  
• Profile Question 3

  What is best about being a scientist?

  
  
• Answer the question you selected for profile question 3 here (300 words):

  Being able to make a living discovering new things about the world and sharing those discoveries with colleagues and students.

  
  
• Help represent the outreach efforts of your societies. Please click all those organizations you are a member of:

  Botanical Society of America
  Japanese Society of Plant Physiologists

  
  
• How did you hear about PlantingScience?

  Partner Organization E-mail

  
  
• Preferred Student Level(s)

  Middle School Students (Grades 6,7,8)
  High School Students (Grades 9,10,11,12)
  Undergraduate Students

  
  
• Preferred Investigation Themes

  The Wonder of Seeds (seed germination and growth)
  The Power of Sunlight (photosynthesis and respiration)
  What about Pollen? (pollen and pollination)
  Celery Challenge (plant anatomy, osmosis and diffusion)
  C-Fern in the Open (sexual reproduction, alternation of generations)
  Agronomy Feeds the World (where does food come from?)

  
  
• Challenge, ELL, Honors

  Academically Challenged
  ELL - English language learners
  Honors or AP - Advanced Placement

  
  
• In addition to English, I am comfortable communicating with students in the following languages:

  None of the Above

  
  
• Videoconference Ability

  Yes

  
  
• Capacity: How many teams at a time are you comfortable working with?

  3

  
  

Recent Posts

24fshawhanhcrhspos project 9 Daniel K. Gladish Nov 21 at 10:44pm

Dear Team #9:

Based on your data table, disks did not sink only at the highest salt concentration.  This contradicts part of what you wrote in your Conclusion.  Your data table reports that in 3g of salt in your solution no disks were…

more

Dear Team #9:

Based on your data table, disks did not sink only at the highest salt concentration.  This contradicts part of what you wrote in your Conclusion.  Your data table reports that in 3g of salt in your solution no disks were floating at the beginning of the trial and it took the whole 10min before any disks (3 of 10) began to float.  Your written report should match your data table.

DKG

24fshawhanhcrhspos project 9 Daniel K. Gladish Nov 21 at 10:25pm

Dear Team #9:

Thanks for asking about the reunion.  I graduated from high school in 1967, and this was the first time I've been free to attend a reunion (I recently retired).  Thankfully, one of the organizers thought to make name…

more

Dear Team #9:

Thanks for asking about the reunion.  I graduated from high school in 1967, and this was the first time I've been free to attend a reunion (I recently retired).  Thankfully, one of the organizers thought to make name tags for everyone, or I wouldn't have recognized most of them.

Dish detergent is a surfactant ("surface-active-agent").  It causes water to relax its "surface tension," the property that causes water drops to "bead up" on a waxy surface. Some folks have described this as making water wetter.  Water makes a somewhat tough, film-like surface when it is facing air.  In your experiment, a little bit of dish soap will cause the water at the edges of the leaf disks to relax its surface and make it easier for water to penetrate into the cut edge and into the small air spaces between the leaf cells and replace the air when you generate the low pressure vacuum with the syringe.  That allows the disks to sink.  The dish soap does not prevent the oxygen gas from pushing the water back out of those spaces when photosynthesis is going on.  I think that is sooo cool.

Cheers,  Dr. Dan

 

24fshawhanhcrhspos project 9 Daniel K. Gladish Nov 20 at 09:40pm

Dear Team #9:

I've been a mentor for Planting Science for almost two decades.  With that in mind, I want you to know that you have been one of the most thoughtful and perceptive teams I've mentored.  So, I think it is worth…

more

Dear Team #9:

I've been a mentor for Planting Science for almost two decades.  With that in mind, I want you to know that you have been one of the most thoughtful and perceptive teams I've mentored.  So, I think it is worth mentioning that the experimental system you used is very good for evaluating several different kinds of factors that can affect photosynthesis, and you used it well to evaluate effects of salinity.

In the Info Section you wrote, "We came up with this question through the discussion of how plants live in ocean ecosystems."  I saw your experiment before you made those entries, so I thought you were interested in the effects of salt pollution in human-occupied landscapes.  So, I should tell you that there are very few plants living in ocean ecosystems.  Plants evolved on dry land in freshwater ecosystems, and only a few species have colonized marine environments later, sort of like the way whales evolved from land animals.  The autotrophs that dominate ocean ecosystems are not plants, they are algae and photosynthetic marine bacteria - very important because they are the base of the marine food chain.

You used leaves from a land plant (that you never identified), and land plants generally suffer from exposure to salt for several reasons.  One is that sodium (Na⁺), which is half of sodium chloride, is toxic to most plants.  But there are also effects caused by osmosis (which is very much worth your looking into).  The more "stuff" dissolved in the water outside of living plant cells, the harder it is for them to maintain their internal pressure, obtain water, and  sustain cellular functions of all kinds.

Other things I thought you'd like to know is that water exposed to air naturally contains some dissolved CO₂ and O₂, which explains why algae can do photosynthesis and fish can "breathe" in water.  However, in your experiment, the CO₂ that was already dissolved in the water, plus that which was added by baking soda, should not have affected the solution (and buoyancy) very much.  On the other hand O₂ produced by photosynthesis usually is released as a gas, which will begin to fill spaces between cells in the leaf disks and cause them to float.

Sincerely, Dr. Dan Gladish

P.S.:  Let me know if you want to know what the small amount of dish soap was for.