Selling Morel Mushrooms -- Laws

This is a little off topic of my typical education blog, but I think this is biological information that is sort of a current event in my section of the world.
I recently discovered that the FDA has begun regulating the sell of "mushroom species picked in the wild." Many states have their own laws regulating the sell of mushrooms, but I have not been able to find anything specific for Missouri (my residence).

This issue became important to me because a friend of mine has been warned by a concerned individual that they could be breaking the law by selling the Morel mushrooms that they have harvested in the wild. I did some research and figured out that they aren't joking. The FDA is really trying to regulate wild mushrooms.

In chapter 3, subsection 201.16 of the FDA Food code (latest publishing is 2009 at the time of this blog) it states:

3-201.16 Wild Mushrooms.

1. (A) Except as specified in ¶ (B) of this section, mushroom species picked in the wild shall be obtained from sources where each mushroom is individually inspected and found to be safe by an approvedmushroom identification expert. ^P
2. (B) This section does not apply to:
1. (1) Cultivated wild mushroom species that are grown, harvested, and processed in an operation that is regulated by the food regulatory agency that has jurisdiction over the operation; or
2. (2) Wild mushroom species if they are in packaged form and are the product of a food processing plantthat is regulated by the food regulatory agency that has jurisdiction over the plant.

The conference for food protection points out the loop hole in this law, "There are currently no standards by which a Regulatory Authority can certify that individuals who collect, inspect and sell wild harvested mushrooms are competent in mushroom identification."
I think this means, that if you're certain you know what kind of mushroom you have collected and if you are certain that it's safe, then quite possibly, you are an expert and have some degree of freedom concerning this particular subsection of the FDA food code.
Why would the FDA be so concerned? Well, there are several kinds of mushrooms and some of them are great tasting and nutritious, but others can be poisonous. For example, in the spring time in Missouri, several locals will go out and collect morel mushrooms. This tradition goes back several generations, but what you might not know is that there is a species of mushrooms that look like morels, but are very poisonous.

With that said, it is important to note a few things. I don't know very much about mushrooms, but I do know what a morel is. I can identify a morel, cook a morel, and eat a morel. Does that make me an "identification expert"? Well, I don't know. But I know the difference between good morels and mushrooms that only look like morels, but are actually poisonous. These "False Morels" have a few identifying characteristics. First, while morels have hollow stems, false morels have a very dense stem.

Picture obtained from http://morelmushroomhunting.com/redmorel.htm is representative of a "False morel" and dangerous to eat.

False Morels come from a family called, "Gyromitra" They produce a toxin that do not affect some people, but can cause death in others.

A "True" Morel has a hollow middle as shown in the picture below.

There is a great article on this at The Great Morel if you are interested in learning to identify false morels.

Physics Homework Chapter 14

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LMK what classes you're taking over the summer and next fall. If I can help, I will.
Videos will be posted on Friday and Saturday.

1. Earthquakes at fault lines in Earth's crust create seismic waves, which are longitudinal (P-waves) or transverse (S-waves). The P-waves have a speed of about 5 km/s. Estimate the average bulk modulus of Earth's crust given that the density of rock is about 2,700 kg/m³.
_____ Pa






2. On a hot summer day, the temperature of air in Arizona reaches 101°F. What is the speed of sound in air at this temperature? (Enter your answer to four significant figures. The speed of sound at 0°C is 331 m/s. use the conversion 0°C = 273 K as necessary.)
_____ m/s






3. A group of hikers hears an echo 2.10 s after shouting. how far away is the mountain that reflected the sound wave? (Assume the speed of sound is 340.6 m/s.)
_____ m







4. The range of human hearing extends from approximately 20 Hz to 20,000 Hz. Find the wavelengths of these extremes at a temperature of 11°C.
20 Hz        _____ m
20,000 Hz _____ m







5. When at res, two trains have sirens that emit a frequency of 300 Hz. The trains travel toward one another and toward an observer stationed between them. One of the trains moves at 32.5 m/s, and the observer hears a beat frequency of 2.9 beats per second. What is the speed of the second train, which travels faster than 32.5 m/s?
_____ m/s






6. Two trains on separate tracks move toward each other. Train 1 has a speed of 137 km/h; train 2 a speed of 77.0 km/h. Train 2 blows its horn, emitting a frequency of 500 Hz. What is the frequency heard by the engineer on train 1?
_____ Hz






7. At rest, a car's horn sounds the note A (440 Hz). The horn is sounded while the car is moving down the street. A bicyclist moving in the same direction with one-third the car's speed hears a frequency of 413 Hz.

a) Is the cyclist ahead of or behind the car?
_____

b) What is the speed of the car?
_____ m/s








8. An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 490 hz when the train is approaching him and 471 Hz when the train is receding form him. Using these frequencies, he calculates the speed of the train. What value does he find?
_____ m/s






9. A steel wire in a piano has a length of 0.7000 m and a mass of 3.900 x 10^-3 kg. To what tension must this wire be stretched so that the fundamental vibration corresponds to middle C (ƒ_c = 261.6 Hz on the chromatic musical scale)?
_____ N






10. A stretched string of length L is observed to vibrate in six equal segments when driven by a 637-Hz oscillator. What oscillator frequency will set up a standing wave so that the string vibrates in three segments?
_____ Hz






11. A steel wire with mass 27 g and length 1.15 m is strung on a bass so that the distance from the nut to the bridge is 1.10 m.

a) Compute the linear density of the string.
_____ kg/m

b) What velocity wave on the string will produce the desired fundamental frequency of the E₁ string, 45.23 Hz?
_____ m/s

c) Calculate the tension required to obtain the proper frequency.
_____ N

d) Calculate the wavelength of the string's vibration.
_____ m

e) What is the wavelength of the sound produced in air? (Assume the speed of sound in air is 343 m/s.)
_____ m






12. The windpipe of a typical whooping crane is about 5.1 ft long. What is the lowest resonant frequency of this pipe, assuming that it is closed at one end? Assume a temperature of 35°C.
_____ Hz






13. The human ear canal is about 2.4 cm long. If it is regarded as a tube open at one end and closed at the eardrum, what is the fundamental frequency around which we would expect hearing to be most sensitive?
_____ kHz






14. A pipe open at both ends has a fundamental frequency of 320 Hz when the temperature is 0°C.
a) What is the length of the pipe?
_____ m

b) What is the fundamental frequency at a temperature of 30°C?
_____ Hz






15. Two train whistles have identical frequencies of 1.47 x 10² Hz. When one train is at rest in the station and the other is moving nearby, a commuter standing on the station platform hears beats with a frequency of 8.00 beats/s when the whistles operate together. What are the two possible speeds that the moving train can have?
_____ m/s moving towards the station
_____ m/s moving away from the station

Physics Homework Ch 13

1. A block of mass m = 0.55 kg is attached to a spring with a force constant 109 N/m is free to move on a frictionless, horizontal surface as in the figure below. The block is released from rest after the spring is stretched at distance A = 0.13 m. (Indicate the direction with the sign of your answer. Assume that the positive direction is to the right).

a) At that instant, find the force on the block.
______ N

b) At that instant, find its acceleration
______ m/s²





2.The force constant of a spring is 165 N/m.

a) Find the magnitude of the force required to compress the spring by 4.20 cm from its unstretched length.
______ N

b) Find the magnitude of the force required to stretch the spring by 7.96 cm from its unstretched length.
______ N





3. A slingshot consists of a light leather cup containing a stone. The cup is pulled back against two parallel rubber bands. It takes a force of 15 N to stretch either one of these bands 1.0 cm.

a) What is the potential energy stored in the two bands together when a 44-g stone is placed in the cup and pulled back 0.11-m from the equilibrium position?
______ J

b) With what speed does the stone leave the slingshot?
______ m/s






4. A 10.0-g bullet is fired into, and embeds itself in, a 1.95-kg block attached to a spring with a force constant of 16.2 N/m and whose mass is negligible. How far is the spring compressed if the bullet has a speed of 300 m/s just before it strikes the block and the block slides on a frictionless surface? Note: You must use conservation of momentum in this problem because of the inelastic collision between the bullet and block.
______ m





5. A man enters a tall tower, needing to know its height. He notes that a long pendulum extends from the ceiling almost to the floor and that its period is 10.5 s.

a) How tall is the tower?
______ m

b) If this pendulum is taken to the moon, where the free-fall acceleration is 1.67 m/s², what is the period there?
______ s






6. 10.03 A simple pendulum has a lenght of 52.1 cm and makes 83.8 complete oscillations in 2.00 min.

a) Find the period of the pendulum.
______ s

b) Find the value of g at the location of the pendulum.
______ m/s²






7. The sunusoidal wave shown in the figure below is traveling in the positive x-direction and has a frequency of 14.5 Hz.

a) Find the amplitude.
_____ cm

b) Find the wavelength.
______ cm

c) Find the period
______ s

d) Find the speed of the wave
______ m/s





8. Light waves are electromagnetic waves that travel at 3.00 x 10⁸ m/s. The eye is most sensitive to light having a wavelength of 5.50 x 10⁷ m.

a) Find the frequency of this light wave.
_______ Hz

b) Find its period
_______ s

9. A circus performer stretches a tightrope between two towers. He strikes one end of the rope and sends a wave along it toward the other tower. He notes that it takes the wave 0.885 s to reach the opposite tower, 20.0 m away. If a 1.00-m length of rope has a mass of 0.360 kg, find the tension in the tightrope.
______ N

10. A piano string having a mass per unit length equal to 4.80 x 10^-3 kg/m is under a tension of 1,450 N. Find the speed with which a wave travelson this spring.
______ m/s

ExplainEverything App better than the competition

About two months ago I switched from using educreations to using ExlpainEverything to create the videos found on this blog. Recently, Mike's Online Biology blog was featured on the Explain Everything Website.

I wanted to take a few minutes to explain why I switched from Educreation (a very easy to use and simple App) to using ExplainEverything.

I first started tinkering with the thought of using a whiteboard screencasting app when I saw what Sal Khan was doing with Khan Academy. Khan Academy boasts the most comprehensive (free) online college-level education and even has math tutorials starting from counting and going up through Calculus. I found out about Khan academy while finishing the last semester of my Associates Degree. I was only a little perturbed because I had tried in vain to find a great way to learn biology while I was in Iraq and not once did a Google search return Khan Academy in my search results.

While in Iraq, I had decided to get out of the military and go back to school, with the hope of becoming a doctor. I had a year to get a jump start on my education, but I had no educators or books to learn from. I watched as much as I could find on YouTube  which was a scant few videos covering topics in the central dogma (DNA - RNA - Protein).

After seeing the Khan videos, I thought that this exact same process should be done for every class a college offers. At that point, I thought I would do my part. I sought out an app that would record me while I taught. I found educreations. It's a great app, but I'd like to list the pros and cons

Educreation Pros:
-Very easy to use (start making videos within minutes of downloading)
-Fast processing and uploading of videos to an online server (literally within 2 minutes most of the time)
-Image search feature which allows images to be imported directly from a bing search (I prefer google images).
-an undo button that always works exactly as expected

Educreation Cons:
-Cannot edit the timeline when a mistake is made
-Cannot save template set-ups (if you want to start over you retype everything and redownload all images, and rework EVERYTHING)
- Very poor sound quality (I had to yell in order to record at normal conversational volume)
- CANNOT manage your videos post production

The last one is the most important to me. I cannot download my videos from educreation. They are stuck on the very unheard-of educreation server. I cannot upload them to youtube, I cannot edit them, and I cannot post advertisement overlays on them.

I have petitioned Educreations several times to enable downloading and they have always promised that it "might" be available in the future. Well, that promise is about a year old and nothing has changed. Now, I'm going through the long process of screen-capturing all of the videos I've uploaded and then formatting them to youtube format (A very tedious process).

Explain everything reverses the list:
ExplainEverything Pros:
- Edit the timeline and cut out mistakes
- Save templates for later use
- Better sound quality (no more yelling)
- insert, not only images, but also videos, Audio files, etc
- Allows upload to several different servers (youtube, dropbox, google drive, or even to your ipad photo library)

ExplainEverything Cons:
- the conversion time is about 15 minutes long and
- you can't do anything on your ipad during conversion or it starts over.
      NOTE: if you have a mac or macbook
                 then the mac will do the compression on the computer and free up your ipad
                  No compressor is available for standard PC.
- Takes about an hour or two to get a good understanding of all of the features and how to best use them
- Still haven't figured out the "undo" button. It certainly doesn't work while I'm recording.

Overall, though, the Cons of ExplainEverything are far outweighed by the Pros. I recommend ExplainEverything, not because I was featured on their site, but because they have a great app that I enjoy using.