The vast majority of studies on daily nut consumption and weight have shown no significant weight gain in the short or long term. But doesn't that violate some pesky law of the physical universe? Conservation of energy isn't just a good idea, it's the law. The first law of thermodynamics. Energy can neither be created nor destroyed. It is a law that cannot be broken even by the most hardened nut cases. Calories can't just disappear. One solution offered to the mystery of the missing calories has been dubbed the pistachio principle. Maybe nuts are just such a pain to eat. For example, in-shell pistachio slow the rate of consumption because of increased preparation time and this may permit greater metabolic feedback during the ingestive event that augments the tidy with the potential to reduce the energy content of the eating event.  Yeah, but what about shelled nuts? Well, you still gotta chew them. A study out of Japan suggested that increasing dietary hardness, meaning difficulty of chewing, was associated with lower waste circumference. Now your jaws do burn some calories, but it's not much exercise.  So it may just be the tedium of chewing that leads one to eat less. Then there's the fecal excretion theory. Many of the cell walls of chewed almonds, for example, remain intact in the digestive tract. So even though a nut may technically have a certain number of calories in it, maybe they just go out the other end and you don't absorb many of them. To test both these theories, all scientists would have to do is compare weight gain from nuts to weight gain from nut butters. Stay tuned.


The first kind of hormone we're going to look at is the steroid hormone. Now, steroid hormones usually end in the word sterone, like testosterone, or progesterone, or aldosterone, or cortisol. But you'll remember cortisol is also a steroid hormone just because, check this thing out, they all kind of look very similar just because they're all made from cholesterol. If you remember, cholesterol is a lipid, and as such, it's hydrophobic.  And that, so it's this hydrophobic substance. That actually is going to affect its mechanism of action. So let's go make a list of characteristics about the steroid hormones that are significant to us. First of all, just like any hormone, they get dumped into the blood. That's the first thing that happens. So there's my little bloodstream, and here's my little steroid hormone. Okay? Now, the anatomical structures that produce steroid hormones, usually they're made in the gonads, which in females, ovaries and in the fellas, the testes, and they're also made in the adrenal glands. So this is the anatomical place where they come from. Who are they going to affect? That depends on who has receptors for the specific hormones. So the next question is, how do they act? How do they carry out an action? And what are some key characteristics of the actions that they produce?  Basically, blood is water. So they're sitting inside this bloody water going, this is not cool, and they'll all clump together like oil and water unless they are being carried. They have their own little special carrier boats. I'll even make a little flag there so that you remember that this is a little boat. It's probably made out of a protein which is hydrophilic and so then it can float through the water but it needs, or it can float through the blood, but it needs that carrier in order to be able to do its job. Now, we will have some kind of target cell and here's the interesting thing. I'm going to tell you, of course, you should assume that how is the steroid hormone going to have an effect? It has to come in contact with the receptor. That's the first thing. So if you have an organ that does not have testosterone receptors, then that organ, it doesn't matter how much testosterone is in your system, that organ will not be affected because it doesn't have the receptors for it anyway. But steroid hormones are unique. Most of the time, the receptor is not embedded in the cell membrane like you would expect. What am I drawing right here? Most of the time, the receptor is floating in the nucleus and this is a hint to its action, like what it's going to actually do. Now, think about this. Steroid hormones are hydrophobic so they can easily pass through diffuse through cell membranes and look, in they go. And look through the cell membrane and that's the nuclear envelope. And look, they find these floating cytoplasmic or nuclear receptors. So this is a receptor that's just chilling. It's floating in the nucleus. They can float in the cytoplasm. Sometimes steroid hormones do have receptors that are embedded in the cell membrane. I'm going to put them in all the locations. But most of the time, they're actually found inside the nucleus. This is where they are most of the time. Because they're hydrophilic, I mean phobic, because they're hydrophobic, the steroid hormone just diffuses right in. Now, the action, that's how the hormone gets in. The action happens when the hormone binds to the receptor. So that's stage one. It's in the nucleus. So go ahead and take a wild guess. Like, what do you think is going to happen? Well, what we're actually going to produce, step two, is going to be to produce some kind of what? Some kind of machinery. Does that work for you? Some kind of necessary stuff to increase protein synthesis. What does that make you think of? Well, the whole purpose of DNA is to contain the directions for building proteins. Hopefully, you're getting a sense that these proteins that we're building are actually super important. If we're going to increase protein synthesis, it isn't just like, okay, go, make some proteins. It's like, we need this specific protein. And that's what this receptor plus this hormone stimulates. If protein synthesis increases, and you end up with some sort of product, some sort of protein, what is it? An enzyme? Is it another substance that's going to get dumped out somewhere? Does it have a specific effect on the heart? Does it have a specific effect on the size of the gonads? Who knows what the actual product is going to do, but the product causes the action or the impact. And here's the deal. Steroid hormones are slow. Think about it. I mean, I hope you remember from Bio One, the process of protein synthesis. You have to transcribe the DNA into messenger RNA. You have to translate the messenger RNA into a protein that happens in the ribosome. And while it happens, like, shockingly fast, if you think about, like, the fact that it's happening in my body right now, like a million times, that's really fast. But compared to our other mechanisms, you'll see that, whoa, it's actually kind of slow. That process takes a significant amount of time to end up with a functional viable protein. And here's the other thing that is true. There's a one-to-one hormone-to-product ratio. So essentially, I don't know how to say this, but one-to-one hormone-to-product ratio. And that just means if you want one protein produced to stimulate an action, you have to send in one hormone. And then it'll happen. If you want more protein, then you just have to send in more hormones. The only way to amplify the effect is to increase the amount of hormone that you've produced. So it's slow, and you can't amplify it.  Sorry, if you want the message to get out there, you have to, each hormone has to deliver the message personally. And that just takes a while. That's slow. That's why if you start taking steroids, you're not going to see a result tomorrow. You're going to see a result in a couple weeks because that's how long it takes for those steroid hormones to have an effect. Let's talk about amino acid derivatives. These guys are kind of a set of in-betweener hormones.


A regular expression, abbreviated to RE, REGX, REGX and more, is commonly used in software development and searching algorithms for matching patterns and text. They are particularly important for implementing programming languages. Regular expressions are powerful formula for defining patterns to search for, yet they are also very simple. They can be defined with combinations of just four symbols, the clean star, shown as an asterisk, alternation, a vertical bar, and the open and closed parentheses. Say we want to search these terms and conditions for important dates. For simplicity, we'll only worry about numerical dates. There are only a few different formats we can expect dates to be in, right? We just search for day, day, month, month, year, year. However, it could be day, day, month, month, year, year, year, year, if you're being formal, or maybe just day, day, month, month, if you don't need the year. But the first month digit can only be zero or one, and the first day digit can only be zero to three. Sometimes people ignore the zero if the date is only one digit, so it could just be day, month. But for other people the month comes before the day, so we have to account for that too. My word, it's all so complicated, isn't it? Thankfully, we can use regular expressions to simplify writing rules for the patterns we want to match. This series of videos explores the idea more closely, looking at the meaning of these basic symbols, some common extended syntax, and the close connection between regular expressions and finite state automata.


you know i'm recording right oh wow hi poo bear hello what are you doing i'm standing in front of my new car your new car yes no yeah no uh-huh well let's take a look at it okay back up here get a little video of that check this out what is it poo it's a shabby uh-oh goes the news crew we're filming news crew anyway it's a what it's a shabby shabby what hhr yeah you like it yeah i do like it is that a door there yes it is oh really uh-huh let's take a gander around this side and check this out guys look at this door is that weird or what pretty nice little ride you got there these little work but it is what eight years old almost yeah but give you a quick little tour here there's her little skull air freshener leave it to poo not buick but it's got a couple little scratches and stuff we've got to get out of it huh yeah show them i want to show them that neat thing and it's two towns it's like a charcoal gray down here in a silver color up there and it fades in around the hood so that's really cool it's kind of a customs paint there so get the door into here this is what i like poo bear came up with this idea we can put beers in there nice good thinking poo one on the other side too so it's two-seater it's considered a panel now what's going on with that other door i'm not sure i've never seen one like this so i'm guessing that door was damaged on the other side somehow and they've just you know replaced that door or maybe they was going to make it over i don't know i don't know but how's it run runs good got the 2.2 door overhead cam ecotech engine huh yep and as shabar found out it'll smoke the tires it'll smoke in front tires as long as i want it to huh yeah i mean we're not talking a little chirp i mean it was blowing blue smoke off them tires wasn't it yes it was i couldn't get over how peppy that little son of a gun is but we finally got another Chevy so but yeah that hood see it's dark here and then it kind of fades into silver there pretty neat but yeah it needs clean we haven't washed there anything yet it's too cold so there it is guys uh what is it no way i hit the record button i went to snap picture hit the record button sorry so it's an 08 right yeah get another picture of this right here for you we put them wheel covers on last night it just had those stupid looking ones same ones they put on a cobalt really that's all that thing is got a cobalt engine cobalt transmission cobalt steering wheel cobalt radio cobalt electric system yeah but what i don't like about it is where's the damn battery i don't know is it in the back yes it's right by the spare tire oh son of a bean but anyway it's cool but it's getting cold out poo bears getting cold so we just wanted to share this with you so what do you say poo poo bear out all right she bear i'm gone bye guys