BC TECH
Saved by @ThomassRichards

In continuum mechanics, stress is a physical quantity that expresses the internal forces that neighbouring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material.

 For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushes on the particles immediately below it. When a liquid is in a closed container under pressure, each particle gets pushed against by all the surrounding particles.
The container walls and the pressure-inducing surface (such as a piston) push against them in (Newtonian) reaction.
These macroscopic forces are actually the net result of a very large number of intermolecular forces and collisions between the particles in those molecules. Stress is frequently represented by a lowercase Greek letter sigma (σ).
Residual stresses inside a plastic protractor are revealed by the polarized light.
Strain inside a material may arise by various mechanisms, such as stress as applied by external forces to the bulk material (like gravity) or to its surface (like contact forces, external pressure, or friction).
Any strain (deformation) of a solid material generates an internal elastic stress, analogous to the reaction force of a spring, that tends to restore the material to its original non-deformed state.
In liquids and gases, only deformations that change the volume generate persistent elastic stress.
However, if the deformation changes gradually with time, even in fluids there will usually be some viscous stress, opposing that change. Elastic and viscous stresses are usually combined under the name mechanical stress.
Significant stress may exist even when deformation is negligible or non-existent (a common assumption when modeling the flow of water). Stress may exist in the absence of external forces; such built-in stress is important, for example, in prestressed concrete and tempered glass.
Stress may also be imposed on a material without the application of net forces, for example by changes in temperature or chemical composition, or by external electromagnetic fields (as in piezoelectric and magnetostrictive materials).
Virial stress 🧐 is a measure of mechanical stress on an atomic scale for homogeneous systems.

More from NotTheMacAnon

NotTheMacAnon
NotTheMacAnon
@NotTheMacAnon1
During a normal pregnancy, oxidative stress enhances antioxidant mechanisms that are capable of reacting by way of enzyme activity and non-enzyme free radical deactivators. However, pregnancy is also a state in which this adaptation and balance may be easily disrupted.

There is strong evidence that a chronicin flammatory reaction combined with the presence of a local oxidizing environment may play a vital role in the etiology and development of complications during pregnancy.

In late pregnancy, damage to DNA (especially when it is caused by oxidative stress) is associated with pre-eclampsia(PE), intrauterine growth restriction (IUGR), and the death of mothers in developing countries; it largely determines pregnancy – related susceptibility to diseases

The referential values of ROS and NOS and their minimal and safe concentrations or physiologically beneficial concentrations are yet to be determined.

The measurement of oxidative stress in vivo is perceived as controversial,

as the sen-sitivity and specificity of various oxidative stress markers is unknown.. .
HEALTH
NotTheMacAnon
NotTheMacAnon
@NotTheMacAnon1
Transduction is the process by which foreign DNA is introduced into a cell by a virus or viral vector.

Viral vectors are tools commonly used by molecular biologists to deliver genetic material into cells.

Viruses have evolved?

specialized molecular mechanisms

to efficiently

transport their genomes

inside the cells they infect.

Delivery of genes, or other genetic material, by a vector is termed transduction and the infected cells are described as transduced.

A transducer is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.
HEALTH
Advertisement
NotTheMacAnon
NotTheMacAnon
@NotTheMacAnon1
🤫
SCIENCE
NotTheMacAnon
NotTheMacAnon
@NotTheMacAnon1
2020 marks the start of the quantum dot revolution.

Completely ignoring the fact that "photocatalytic generation of reactive oxygen species (ROS) from quantum dots (QDs) has been widely reported."

Results: It was found that whereas singlet oxygen (1O2) was not produced by photoexcited QDs, superoxide anion(O2− )and hydroxyl radicals(OH) were generated by QDs, especially in the presence of a physiological concentration of electron donating agent including NADH.

Using cell metabolic activity assays and various probes of ROS generation, the formation of ROS in cellular environments was demonstrated.

Conclusion: Illumination of QD-treated cells and bacteria with light did affect viability. The above results, together with those of assays in the presence of various scavengers of specific ROS, indicate that the formation of ROS by QDs mainly proceeded via electron transfer.
FOR LATER READ
NotTheMacAnon
NotTheMacAnon
@NotTheMacAnon1
👍🏻


https://t.co/0ywQ1y5NDj

Pott found an association between exposure to soot and a high incidence of scrotal skin cancer in chimney sweeps. This cancer is now known as Pott's or chimney sweep cancer.

Coal contains trace amounts of naturally-occurring radioactive elements. The process of burning coal at coal-fired power plants, called combustion, creates wastes that contain small amounts of naturally-occurring radioactive material (NORM).

Fly ash particles (a major component of coal ash) can become lodged in the deepest part of your lungs, where they trigger asthma, inflammation and immunological reactions.
SONG

More from Tech

Josh Butler
Josh Butler
@JoshButler
Users: hey can you get rid of the Nazis please

Twitter: ok sure, we've changed the stars to hearts for likes

Users: no no, zero Nazis please

Twitter: yep we're getting rid of Vine

Users: nah hey, what about the Nazis

Twitter: ok ok fine, no more likes

Really though, if you had to ask any average user what were the main things leading to a bad "quality of debate" on this bad website, the tiny little heart symbols would not exactly be at the top of most people's lists
TECH
Neil S W Murray
Neil S W Murray
@neilswmurray
1) Looking back on my "career" with @TheNordicWeb over the last 5 years, in retrospect it's easy for me to join up the dots and make sense of the journey:

#cphftw #sthlmtech #helyes 🇩🇰🇫🇮🇮🇸🇳🇴🇸🇪

2)

- Join & start community initiatives to meet people
- Learn from these people about how special the Nordic tech scene is
- Share this with the world through The Nordic Web
- Realise the real value is in the data, particularly in building network
- Use network to raise a fund

3) In fact, it looks all very strategic, but the reality is anything but.

My lack of vision and goals during this 5 year period was _criminal_

Any movement from one step to the next was never pre-planned and was instinctive, or worse, accidental.

4) While I am embarrassed to think of my headless chicken self, there's also part of me that thinks that none of this would have turned out where it did if I had of been deliberate and strategic about this.

5) In fact, I think my genuine love for the Nordics and the ecosystem is the MAIN reason to explain how I raised my fund & managed to move from step to step.

My story is a good example of how passion can be more powerful than strategy in the early stage of an idea/company.
TECH
Advertisement
Biz Stone
Biz Stone
@biz
Originally, tweet length was 160 minus username length. One day, I turned to Jack and pointed out that I got one more character than him. He said, "That's not fair. We should standardize." I agreed. He said, "How about 140?" I said, "Sure." And he updated the code.

Last year, we upgraded tweet length to 280 and guess what? Use of 'please' is up 54% and 'thank you' is up 22%. I love that! Also, people are asking more questions and having more conversations. All this, and the majority of tweets are still under 140. It worked.
TECH
Colby Fayock
Colby Fayock
@colbyfayock
Next.js has taken the web dev world by storm

It’s the @reactjs framework devs rave about praising its power, flexibility, and dev experience

Don't feel like you're missing out!

Here's everything you need to know in 10 tweets

Let’s dive in 🧵


Next.js is a @reactjs framework from @vercel

It couples a great dev experience with an opinionated feature set to make it easy to spin up new performant, dynamic web apps

It's used by many high-profile teams like @hulu, @apple, @Nike, & more

https://t.co/whCdm5ytuk


@vercel @hulu @Apple @Nike The team at @vercel, formerly Zeit, originally and launched v1 of the framework on Oct 26, 2016 in the pursuit of universal JavaScript apps

Since then, the team & community has grown expotentially, including contributions from giants like @Google

https://t.co/xPPTOtHoKW


@vercel @hulu @Apple @Nike @Google In the #jamstack world, Next.js pulled a hefty 58.6% share of framework adoption in 2020

Compared to other popular @reactjs frameworks like Gatsby, which pulled in 12%

*The Next.js stats likely include some SSR, arguably not Jamstack

https://t.co/acNawfcM4z


@vercel @hulu @Apple @Nike @Google The easiest way to get started with a new Next.js app is with Create Next App

Simply run:

yarn create next-app

or

npx create-next-app

You can even start from a git-based template with the -e flag

yarn create next-app -e https://t.co/JMQ87gi1ue

https://t.co/rwKhp7zlys
TECH
Trond Bjor\xf8y
Trond Bjorøy
@trondbjoroy
1/12 @HathorNetwork offers a unique set of features for both builders and users. Some well known ones, others not so much. Let’s look at why you might want to consider Hathor as the layer 1 solution for your project. $HTR @HTRFDT #BuildOnHathor

2/12 Easy tokenization is the obvious one. You create your own token in less than a minute, no coding required.

3/12 As opposed to ERC tokens, your custom Hathor token is a layer 1 token. It inherits the same features and security as the native token, $HTR, effectively giving your token the same level of security as the #Bitcoin $BTC blockchain.

4/12 Hathor Network also passed their security audit by @SlowMist_Team so you can feel safe knowing that your L1 token fulfills the same security requirements as $HTR.

5/12 By configuring built-in nano contracts you will be able to add logic to your token. No coding required. Native nano contracts also mitigate the risk of bugs and security issues that comes with custom smart contracts development on other platforms. $HTR
TECH

You May Also Like

foone
foone
@Foone
I got a Toshiba T1200, which has a bad screen, and a dead CMOS battery, and I thought the hard drive was broken too...


but I rebooted it and heard a KTHUNK and a really loud spin-up noise and holy shit, the hard drive works!


and it still has files on it. the newest date is January 1994.


It's a 21mb hard drive, with ~37k of bad sectors.

This fucker is never going to spin up again, so I better go find some serial cables and copy shit off now.


The backlight is fucked so I'm shining a flashlight on it.
without it, it looks like this.
TECH
John Myles White
John Myles White
@johnmyleswhite
This post is pretty bizarre, but it manages to hit on so many false beliefs that I've seen hurt junior data scientists that it deserves some explicit

(1) The notion that R is well-suited to "building web applications" seems totally out of left field. I don't feel like most R loyalists think this is a good idea, but it's worth calling out that no normal company will be glad you wrote your entire web app in R.

(2) It is true that Python had some issues historically with the 2-to-3 transition, but it's not such a big deal these days. On the flip side, I have found interesting R code that doesn't run in modern R interpreters because of changes in core operations (e.g. assignment syntax).

(3) "Most of the time we only need a latest, working interpreter with the latest packages to run the code" -- this is where things get real and reveal some things that hurt data scientists. If this sentence is true, it's likely because you don't share code with coworkers.

(3) Really is a broader issue in data science: people only think of what they need to do their work if no one else existed and code was never maintained. Junior data scientists almost always operate on projects they start from scratch and don't have to maintain for long.
DATA SCIENCE
Advertisement
Hermann Peterscheck
Hermann Peterscheck
@petershk
For fun I made a Robinhood account. It took me 5 minutes to sign up, get approved and transfer funds for trading...

Here's some details... Read on.

...it took me another 5 minutes to get qualified for options.

If I share a sign up I get "free shares" and I can share as much as I want up to 500$ worth.

The main UI has a prepopulated "list" of stocks/crypto to watch and links to news.


Clicking a stock opens a "trade" button that looks like this.

Notice options is first, buy second.

Options took me to an approval process (which took about a minute) and now away I go trading Baba options.


Buying stock looks like this. It emphasizes fractional shares.
TRADING
Suhail
Suhail
@Suhail
1/ The first 18 months of starting a company is often life or death. I must've made 5 different companies that each failed within 9 mo. 😭 Each time the company failed I figured out what I could do better. Eventually startup #6 got to $40K/mo by month 18. Here’s what I learned...

2/ Stay focused! Ignore things that are a waste of time: meetups & conferences, meetings with no clear agenda, fundraising if you're not fundraising, reading lots of tech media articles, etc. Every week should feel like significant progress in the first year.

3/ Your first 5 hires will be the difference between life or death. Choose carefully. Be picky. Many of the things we do at the company still are a result of those early hires' legacy. Have fun as a tight knit team. It will change & evolve as you get bigger so enjoy this moment.

4/ Growth may be flat for the first 9 months. It's gonna be okay. Almost every company has experienced this: Airbnb had to sell cereal in-between, Slack failed as a gaming company first, Tesla sold only 147 cars after 6 years! You probably won't be an overnight success either.

5/ In the beginning, do customer support yourself. You will learn a lot about why your product sucks. I did 5,000+ support tickets when it was the two of us. Delight customers & fix things fast while you learn. It will help you build an amazing intuition about your customers.
STARTUPS
Brian Cates
Brian Cates
@drawandstrike
Trump is gonna let the Mueller investigation end all on it's own. It's obvious. All the hysteria of the past 2 weeks about his supposed impending firing of Mueller was a distraction. He was never going to fire Mueller and he's not going to


Mueller's officially end his investigation all on his own and he's gonna say he found no evidence of Trump campaign/Russian collusion during the 2016 election.

Democrats & DNC Media are going to LITERALLY have nothing coherent to say in response to that.

Mueller's team was 100% partisan.

That's why it's brilliant. NOBODY will be able to claim this team of partisan Democrats didn't go the EXTRA 20 MILES looking for ANY evidence they could find of Trump campaign/Russian collusion during the 2016 election

They looked high.

They looked low.

They looked underneath every rock, behind every tree, into every bush.

And they found...NOTHING.

Those saying Mueller will file obstruction charges against Trump: laughable.

What documents did Trump tell the Mueller team it couldn't have? What witnesses were withheld and never interviewed?

THERE WEREN'T ANY.

Mueller got full 100% cooperation as the record will show.
POLITICS