life outside netflix: fact

fact

Nobel Prize in Chemistry 2015

By Tina - December 09, 2015

0 Comments

fact

Dungeness crab and toxic algae

By Tina - November 12, 2015

I wanted to make a crab cake casserole for Thanksgiving this year, but because of the current toxic algae situation along the California coast, it doesn't look like the crab cakes will happen. Bummer.

The toxic algal bloom (brought on by warm El Nino waters) has caused the commercial crab season to be postponed until further notice (that super sucks for the fishermen). The harmful algal bloom (HAB) is created by the planktonic diatom Psudeoom-nitzchia. These guys are not good because they produce the neuotoxin, domoic acid (DOM), which is responsible for a neurological disorder called amnesic shellfish poisoning (ASP).

DOM ACTION
There are a couple of mechanisms attributed as mediators for the effects of domoic acid (DOM). The mech through glutamate receptors is the biggie for excitatory neurotransmission.

Glutamate is a excitatory neurotransmitter in the brain. Kainic acid (KA) is an excitatory amino acid (EAA) analogue of glutamate that is very structurally similar to DOM. Meaning that DOM can bind to glutamate receptors (GluRs, responsible for memory processing) to act as a potent excitatory neurotransmitter and induce neurotoxic effects.

So a couple of things are going on. DOM activates the ionotropic GluRs (iGluRs). DOM also activates the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/KA receptor (AMPA/KA-R). AMPA/KA-R causes increased levels of intracellular calcium²⁺ions. More calcium ions releases more glutamate. Extra glutamate activates the N-methyl-D-aspartic acid receptor (NMDA-R). All these excess things are bad and can cause apoptotic and necrotic neuronal cell death....so yea. No crab.

IMAGE SOURCE: http://www.trbimg.com/img-563d5eb8/turbine/la-dd-dungeness-crab-season-delayed-toxic-algae-20151105
SOURCE: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2525487/, http://abc7news.com/business/tiburon-researchers-study-this-years-toxic-algae-bloom/1076860/, http://www.medicaldaily.com/warm-waters-pacific-ocean-stoke-algal-bloom-which-releases-neurotoxin-delaying-361096, http://www.latimes.com/food/dailydish/la-dd-dungeness-crab-season-delayed-toxic-algae-20151105-story.html

3 Comments

fact

The common cold and why old people insist you wear extra layers in bad weather

By Tina - October 14, 2015

The body reacts and acclimates to the cold in a number of ways. Our bodies shiver and our teeth chatter. Goosebumps form. All this is done by the little almond in our brains (the hypothalamus- responsible for thermoregulation) to make sure that we keep warm when the weather outside is frightful. Now as the temperature outside gets cooler, the old people in your family are probably telling you to bundle up as a preemptive measure against "getting sick" because of the chilly weather outside.
Well is it true?
The idea that the temperature can make a person more susceptible to getting a cold has always been regarded as an old wives' tale that isn't true and is just told to scare the children. What happens instead of the cold giving you a cold is that people generally stay indoors when the weather outside is bad. They stay inside with recycled air and cough on each other. It's a people behavior thing.
So it's not true?
But actually being lazy and staying inside (and coughing on everybody) might not be the only reason why people get colds more often during chilly weather time. Rhinovirus (aka RV, the germs that cause the common cold) strains replicate way better in colder temperatures. Why?
Researchers at Yale first started out by modifying a strain of the rhinovirus to infect mice ('cause the people rhinovirus doesn't infect rodents). Then they used these strains to infect airway epithelial cells of mice and compared the transcriptional response of the cells at 33 and 37 degrees Celsius. Incubating the cells at a lower temperature showed that the antiviral defense response was not as strong when compared to incubation at a higher temperature. How? Well, the results indicate that during rhinovirus replication, higher temperatures reveal more RLR ligand accumulation (RIG-I-Like receptors that detect viral RNA species by triggering interferon response for antiviral response) which leads to stronger antiviral gene expression... meaning that there is a possible temperature dependence of common cold sickness and you should wear a sweater and not breathe in cold air.

IMAGE SOURCE: http://i.telegraph.co.uk/multimedia/archive/00789/flu-460_789486c.jpg, http://files.mom.me/photos/2014/12/10/6-86303-big-red-jacket-1418253983.jpg, http://files.mom.me/photos/2014/12/10/6-86300-puffy-pink-baby-1418253965.jpg
SOURCE: http://www.pbs.org/wgbh/nova/next/body/scientists-finally-prove-cold-weather-makes-sick/, Foxman, Ellen F., James A. Storer, Megan E. Fitzgerald, Bethany R. Wasik, Lin Hou, Hongyu Zhao, Paul E. Turner, Anna Marie Pyle, and Akiko Iwasaki. "Temperature-dependent Innate Defense against the Common Cold Virus Limits Viral Replication at Warm Temperature in Mouse Airway Cells." Proceedings of the National Academy of Sciences Proc Natl Acad Sci USA 112.3 (2015): 827-32. Web., http://news.yale.edu/2015/01/05/cold-virus-replicates-better-cooler-temperatures

0 Comments

fact

Schrodinger's cat: to be && not to be

By Tina - October 06, 2015

A lot of people have heard of Schrodinger's cat, but not many know the purpose behind the thought experiment.

Schrodinger came up with a thought experiment

A cat is placed in a box with a Geiger counter, a hammer, a radioactive substance, and a vial of poison. Once the radioactive material decays, the Geiger will detect and trigger the hammer to smash the vial of poison. This kills the cat. The decaying of the radioactive material is completely random. → Meaning that the cat status cannot be determined and it's status is considered to be both dead and alive. Key word to know: SUPERPOSITION (pretty much meaning adding multiple quantum states together... in this case the cat having both dead and alive statuses)

Um, why?

The Schrodinger's cat paradox was used to critique the Copenhagen Interpretation saying that the quantum mechanics behind Copenhagen interpretation for everyday big objects (like stuff that's not atoms, classically big stuff) is not very good at describing what's going on.

What is Copenhagen Interpretation of Quantum Mechanics?

The Copenhagen Interpretation basically said that the superposition of a quantum system will only cease once observed, and once observed (just once you know what is going on), the superposition collapses into definite states.

Schrodinger's cat today

New studies are revealing that the weirdness of really small things being able to exist in several states at once may also extend to big things (like cats!!!)... but other new studies are also revealing that this weirdness may not extend to big things (like cats!!!) too..........

Quantum physics: Schrodinger's cat is still alive (challenge of achieving ground state... to show cat object quantum superposition can exist, cat object system need to be at quantum ground state to begin experiment--- hard to do!!!! but possible by coupling between cat oscillator and laser light cooled electron spin)

Schrodinger's cat is now fat (superconducting quantum interference device (SQUID) rings show current decay through quantum mechanical tunnelling... oscillation between two states characterized by clockwise or counterclockwise current flow of SQUID ring dunked in microwaves show coherence gap)

How gravity kills Schrodinger's cat (maybe in space, cats can have quantum coherence, but on Earth it is not possible because gravity)

Fattening up Schrodinger's cat (physicists in Austria made fat Schrodinger cats of up to 430 atoms wide)

Reincarnation can save Schrodinger's cat (people from University of California Santa Barbara un-collapsed an almost collapsed quantum state by shooting microwaves at a phase qubit)

IMAGE SOURCE: https://s-media-cache-ak0.pinimg.com/736x/04/bb/18/04bb1878f1a377f4c5064d3112deba82.jpg
SOURCE: Wrachtrup, Jörg. "Quantum Physics: Schrödinger's Cat Is Still Alive." Nat Phys Nature Physics 5.4 (2009): 248-49. Web., Blatter, Gianni. "Schrödinger's Cat Is Now Fat." Nature 406.6791 (2000): 25-26. Web., Gibney, Elizabeth. "How Gravity Kills Schrödinger's Cat." Nature (2015): n. pag. Print., Ball, Philip. "Fattening up Schrödinger's Cat." Nature (2011): n. pag. Print., Merali, Zeeya. "Reincarnation Can save Schrödinger's Cat." Nature (2008): n. pag. Web.

0 Comments

fact

Ice, ice baby: working with ice cores

By Tina - September 07, 2015

When I was in college, I worked at an ice core vacuum lab interested in the history of trace gases obtained from ice cores (they also researched about oceanic trace gases responsible for atmospheric processes affecting climate change, but during my stay at the ice lab, I only handled ice cores). These trace gases were extracted and then quantified using gas chromatography mass spectroscopy. It was pretty labor intensive work, but I liked it. Not many people have had the experiences I had while working there.

The entire experimental process starts with the ice core. Now what is an ice core? And what makes them so special? Ice cores are samples of ice drilled from ice sheets. These samples offer direct information to past atmospheric and climate conditions. This is because the ice forms from layers of incremental buildup of annual snowfall, trapping atmospheric concentrations of gas bubbles, particles (like dust), and human pollutants.

Some of the trace gases of interest include: halocarbons (methyl chloride and methyl bromide → ozone depleters), carbonyl sulfide (COS → statospheric sulfate precursor), and hydrocarbons (ethane → biomass burning emission tracer).

What the Autospec mass spectrometer looked like

These trace gases are able to be identified and quantified using GC-MS (gas chromatography mass spectroscopy). The mass spec used at the research lab is really cool- it uses a double focusing magnetic sector mass analyzer.

A mass analyzer separates the ionized particles based on charge to mass ratios. In a magnetic sector mass analyzer, a magnetic field separates the charged particles by deflecting the charged ions to a circular motion perpendicular to the magnetic field... basically this means that moving charged ions will have a curved trajectory because of the magnetic field. Ions with distinct m/z values will have the same trajectory paths because their degree of deflection will be the same (degree of deflection proportional to the square root of m/z ratio), and only ions of mass to charge ratio with equal centrifugal and centripetal forces will go through to the detector. All this just means that magnetic sector mass analyzers focus angular dispersions.

A double focusing mass analyzer has a magnetic and an electrostatic sector. The electrostatic sector mass analyzer can be thought of as a kinetic energy selector (focus energies). The ions are separated while in flight by the electric field. The force on the ion (from electric field) is equal to the centripetal force. Passage to detection is only allowed for ions with specific energies. Having both sectors make the resolution loads better, producing some awesome data.

IMAGE SOURCE:Alamy... image taken from http://www.theguardian.com/science/2015/may/03/climate-change-scepticism-denial-lukewarmers, second image from http://www.ess.uci.edu/group/esaltzman/instrumentation

SOURCE: http://chemistry.clemson.edu/ChemDocs/marcusgroup/software/CONCEPT/DFA/DFA.HTM, Skoog et al, Principles of Instrumental Analysis, http://climatechange.umaine.edu/icecores/IceCore/Home.html

1 Comments

fact

Why is the sky blue?

By Tina - August 20, 2015

As a kid I would sit in the backseat and look up out the window and wonder why the sky was blue. But as an incredibly lazy kid, I never bothered to find out the answer until college. And it wasn't even me looking the answer up. We were given the explanation in p-chem lecture.

The skinny

The air molecules in the Earth's atmosphere scatter short wavelengths more strongly so than long wavelengths. Blue light is a short wavelength.

The fat fat fattie

To understand (and appreciate!!) the blue sky phenomenon, we gotta cover a few main ideas....

The atmosphere
Think of the atmosphere as containing many molecules of different gases. Nitrogen and oxygen gas are the big ones, making up about 99% of the atmospheric gases. But carbon dioxide and argon gas are also present. There are trace amounts of other gases as well. (There's also water vapor and tiny particles of dust, etc, etc. present in the Earth's atmosphere too.)

The visible spectrum
Visible light travels in waves. The energy of radiation is dependent on its wavelength and frequency. The longer the wavelength, the shorter the frequency and smaller the energy.
The visible spectrum is the part of the electromagnetic spectrum that we can see. The wavelength range of the visible light corresponds to ~400-700 nanometers. Blue light has a wavelength of about 470 nanometers. And on the other end of the visible spectrum, red light has a wavelength of about 650 nanometers.

Light scattering
Photons can be absorbed or emitted by atoms. And photons can also be scattered. Rayleigh scattering is the elastic scattering of light responsible for the blue skies. Sunlight strikes the air molecules causing the light to be scattered. No energy is lost (elastic... same state) and no frequency changes occur. Lord Rayleigh calculated that the scattered intensity from super small molecules/particles (called dipole scatterers and gotta be much smaller than the wavelengths) to be:

where N is the number of scatterers, α is the polarizability, R is the distance to the particle, and θ is the scattering angle. From the equation you can see that the strength of the scattering is strongly dependent of the wavelength --> blue skies!!!

Now what happens if the scattering from molecules/particles are larger than a wavelength? That is when Mie scattering occurs. Unlike Rayleigh scattering, Mie scattering is not strongly wavelength dependent. Mie scattering is responsible for the white light from fog and the white glare you see around the sun.

IMAGE SOURCE: Abel Leeman's Flower in the Sky from StockImages.com
SOURCE: Peter Atkin's Quanta, Matter, and Change

1 Comments

Nobel Prize in Chemistry 2015

Dungeness crab and toxic algae

The common cold and why old people insist you wear extra layers in bad weather

Schrodinger's cat: to be && not to be

Ice, ice baby: working with ice cores

Why is the sky blue?

About me

Labels

recent posts

Blog Archive

Categories

Press

Follow on instagram