Search Results: BunsenBwog
BunsenBwog: Genes That Matter
Our favorite kind of Gene

Our favorite kind of Gene

In an attempt to satisfy the 1% of Bwog readers who are science majors, we’re bringing back an old favorite: BunsenBwog—a brief review of some of the science-related findings and contributions done by members of our campus community. This week, we sent mad scientist Mason Amelotte to the CUMC newsroom to find out what’s new.

Find yourself buying too many $3 Rolling Rock’s at 1020 every weekend? Fear not, thirsty undergrad. Neuroscientists at Columbia University Medical Center have identified neurons in the brain that both trigger and suppress our sense of thirst. CAMKII neurons were found to turn thirst on when activated, and VGAT neurons were found to turn thirst “off.” Both neurons were found in the subfornical organ in the hypothalamus through “mind control” experiments on mice.

“But what about controlling my appetite?” you ask. “How am I supposed to say no to JJ’s Place when my heart (and stomach) tell me otherwise?” Well lover of food, researchers at CUMC and at the New York Stem Cell Foundation have found a way to generate hypothalamic cells, generally inaccessible neurons that control appetite. Through genetic reprogramming, researchers converted human skin cells into induced pluripotent stem cells, which they then turned into hypothalamic neurons. This now gives researchers means by which to study diseases like obesity.

“But I’m not worried about eating all the time! I’m so tired that I can barely keep my eyes open” Well, researchers at the Center for Infection and Immunity have you covered there, as well. Are you someone that identifies as having myalgic encephalomyelitis, otherwise known as Chronic Fatigue Syndrome? If so, you must be exhausted from being told all the time that your disease is merely psychologic (double entendre intended)! Scientists have actually discovered distinct immune changes in patients with the disease that may actually make diagnosis easier and more accurate!

“None of these apply to me because I’m perfectly healthy! Do you have any news related to something a little bit more mainstream?” Of course we do, pseudo-science intellectual. Remember that #IceBucketChallenge that clogged newsfeeds everywhere last summer? Well it turns out that researchers have found a new specific gene that’s related to sporadic amyotrophic lateral sclerosis, also known as ALS. This new gene, called TBK1, plays an important part in affecting patients’ inflammation and autophagy. Tell that one to your friends in Mel’s!

Bob’s Burgers is amazing via Wikia

BunsenBwog: Kids These Days

Yeah science, bitch!

Even though it’s March, the “new year, new us” mindset is alive and well. We’re bringing back an element of our past with the revival of BunsenBwog—a brief review of some of the science-related findings and contributions done by members of our campus community. We enlisted the assistance of Bunsen Burner Belle Briana Bursten to enlighten us with her scientific wisdom. 

Everyone knows that a cellphone is the number one item in a millennial’s starter pack, so we think it’s pretty smart that Columbia’s Mailman School of Public Health and College of Physicians and Surgeons decided to capitalize on the usage of this technological necessity for health purposes. Earlier this year, kids were sent text messages reminding them to get their second flu vaccination. The results? Text messages both increased the receipt of the vaccination and also brought children to receive their vaccinations sooner.

A new magnetic technology developed by doctors at Columbia known as MAGEC (MAGnetic Expansion Control) is now being used to treat early-onset Scoliosis in children. While growing rods are effective in correcting the curvature of the spine for children with Scoliosis, the child is also subjected to multiple surgeries throughout their youth in order to adjust the size of the rod. However, the MAGEC permits surgeons to lengthen the rods with a handheld external magnet, thus avoiding surgery and additional costs for parents.

According to a CUMC study, children and adolescents with autism have an excessive amount of synapses in the brain. This excess affects cognitive development, particularly during the “pruning process.” Knowledge of this neurological finding can perhaps lead to a cure, as there are drugs available that may work to restore synaptic pruning.

Outbreaks of Kawasaki disease in Japan, a rare childhood condition that causes inflammation of the blood vessels that later leads to heart disease, may be traced to wind currents coming from northeast China. A study by Mailman School of Public Health reveals that instances of the disease peaked when winds that originated from a region with “vast cereal croplands” swept over specific locations.

Missin Walter White via Shutterstock

BunsenBwog: Medical Science Omnibus

Read about a study correlating sadness and short-term gratification and by extension consumption of Ben and Jerry’s after the jump!

Zach Kagan PhD (Professional hummus Dipper) gives a rundown of what is happening in the medical world.  

Here’s the problem with modern medical science: it’s just too damn productive. In the past medicine was all about leeches, treacle, and the occasional tobacco smoke blown up the rectum. But scientists and doctors seem to think they can improve on proven, albeit antiquated, techniques. Damn their steadfast pursuit of knowledge. Their curiosity cannot be sated!

And so BunsenBwog is left with stacks upon stacks of new papers on medicine each week. And they just keep coming. There’s only one prescription fit to treat this problem, and it involves a concentrated dose of medical science news.


BunsenBwog: Diet of the Stars

Some galaxy somewhere

After a brief hiatus, BunsenBwog is back, bringing you the best science happenings at Columbia. This week, Bwog’s resident stargazer Zach Kagan discovers that when you stare into a black hole, it stares back into you.

While Columbians have been bogged down with hurricanes, blizzards and midterms, NASA’s plucky  NuSTAR X-ray telescope has been enjoying clear skies in orbit 550 km above Earth’s surface. BunsenBwog has been keeping close tabs on NuSTAR because A) it’s awesome and B) Columbia Engineers are responsible for the device that allows the telescope to focus and amplify X-rays as they are collected. Now NuSTAR has been directed at the center of our galaxy, to observe the massive black hole in the center of the Milky Way. To be more accurate, it’s aimed at Sagittarius A*, a very compact radio-source that is thought to be a black hole.

However, Sgr A* doesn’t act like black holes in neighboring galaxies, which have a habit of gobbling up whatever star or gas cloud passes too close to their event horizon. That cosmic consumption results in temperatures of over 100,000 million degrees Celsius and massive emissions of radiation, but scientists haven’t seen the same behavior from Sgr A*. Then again, there’s been no way to directly measure the X-rays created during such events, until now. NuSTAR is already  collecting X-ray data from Sgr A*  which will allow astrophysicists to learn more about the eating habits of black holes. According to Columbia’s Professor Chuck Hailey, “astronomers have long speculated that the black hole’s snacking should produce copious hard X-rays, but NuSTAR is the first telescope with sufficient sensitivity to actually detect them.” Your sleeping and smoking habits after the jump

BunsenBwog: The Price of Sustainability, with a Soda on the Side

Carbon footprint

Bwog’s resident carbon confidant, Zach Kagan, brings us sordid tales of sustainability, statistics, and snacks.

This midterm season, an incalculable number of sodas and assorted caffeinated beverages will be drunk. Scores of candy bar pick-me-ups will be scoffed. Bag after bag of vending machine purchased chips will be opened and consumed. Exams and snacking go hand and hand this time of the semester, but as you cram for your sustainable development midterm, you may pause and wonder about the sustainability of your own increasingly junk food fueled diet. As it happens, PepsiCo wondered the exact same thing and, thanks to engineering professor Christoph Meinrenken, they know quite a bit more about it.

But PepsiCo didn’t just want to analyze one product. It wanted to determine the carbon footprint of each of its 10,000+ products, not an easy task. Determining the footprint of something requires so-called “life-cycle assessment,” following the product on each stage of its development from bare materials to consumption. Each step of production has its own set of emission factors that needs to be accounted for. Each requires a different team of experts to analyze and compute the footprint. That data needs to then be used to create a meaningful description of the carbon footprint of an individual product. To repeat that process for each of PepsiCo’s products would take an exorbitant amount of time, money, and patience. Prof. Meinrenken sensed that this problem could be solved much more efficiently, but to do so he would have to think outside the box.


BunsenBwog: Race for the (Nobel) Prize

This week on BunsenBwog, our double feature puts the Homeric dichotomy of city of peace and city of war to shame. Zach Kagan brings you the stories of how the Nobel prize relates to sweet-toothed Swedes and the legitimacy of North Korean nuclear tests.

Oh the irony

This week Columbia celebrates the addition of CC and College of Physicians and Surgeons alum Robert Lefkowitz to its list of 95+ “Columbia affiliates” who have been awarded a Nobel prize. Lefkowitz won this year’s Chemistry Nobel for his work with Brian K. Kobilka on G-protein coupled receptors (or GPCRs). His original interest was studying the mechanisms that control heart contractions. Knowing that certain hormones such as adrenaline can increase heart rate, Lefkowitz and Kobilka set out to characterize the so-called beta-adrenergic receptors responsible for reacting to such hormones. The researchers were able to clone these receptors and in doing so, they created new avenues to study GPCRs in general. Their result proved influential in pharmaceuticals as well, where it led to the development of groundbreaking cardiovascular medications.

Columbia continues to hold the world record for number of Nobel laureates, that is counting all current and former alumni, faculty, and mathematical geniuses who choose to work as university janitors. What gives Columbia an edge over runner-ups such as University of Chicago or Cambridge? According to Columbia Prof. Franz H. Messerli, the answer might lie in the amount of chocolate consumption. Messerli ranked countries by number of Nobel laureates per capita, and then cross referenced that list with the average amount of chocolate consumption per person in that country.

The result turned out to be a “close, significant linear correlation between chocolate consumption per capita and the number of Nobel laureates per 10 million persons.” Messerli’s regression line suggested that it requires about 0.4 kg of chocolate per capita per year in order to produce an extra Nobel laureate. There was only one major outlier: Sweden. The Scandinavian nation that awards the Nobel prizes also seems to win several of them, without a suitably high level of chocolate consumption to match. Messerli provided the following explanation: “the Swedes are particularly sensitive to chocolate, and even minuscule amounts greatly enhance their cognition.” Read about dangerous explosions, or the lack thereof, after the jump

BunsenBwog: Ego Tripping at the Gates of Columbia

Bill Nye is off this week and filling in is the lesser known Science Guy, Bwog’s very own Zach Kagan who takes a look at some of Columbia’s great intellectuals and their research below:  

Professor Terry A. Plank and Professor Maria Chudnovsky

Columbia Professors are no slouches in the brain department. Still, despite their surplus IQ points, few would likely describe themselves as geniuses. Maybe the Core’s infatuation with Socrates has rubbed off on them, or maybe its just plain bad taste. Who knows?  Regardless, for two professors, it’s about to get a lot harder to prevent ego-tripping. That’s because Prof. Terry A. Plank and Prof. Maria Chudnovsky have both been awarded MacArthur “Genius” Grants!

Well, they’re only informally called the “genius grants”. Each of this years’s 23 MacArthur Fellows were anonymously chosen by their peers and given $500,000 to do as they please with, so long as it furthers the scope and goals of their research. Prof. Plank was selected for her work at the Lamont-Doherty Earth Observatory measuring the CO2 concentration of Pacific Ocean volcanoes, while Prof. Chudnovsky was selected for her research “on the structure of abstract graphs with a focus on graph theory and combinatorial optimization,” which are important mathematical topics often applied by engineers.

more science stuff after the quantum leap

BunsenBwog: A Sunday Morning Chat with W. Ian Lipkin
oooh, you clever alt text checker. Have a cookie

He’s cured three diseases before you even woke up this morning.

Bwog’s avant-garde epidemiologist, Zach Kagan, ventures out on this fine Sunday armed with sleep inertia and a healthy sense of adventure. He discusses recent development in Chronic Fatigue Syndrome (CFS) with our very own Professor Lipkin.

Professor W. Ian Lipkin has been featured in several editions of BunsenBwog, and why wouldn’t he be? As the director of the Center for Infection and Immunity and John Snow Professor of Epidemiology at the Mailman School, Prof. Lipkin has metaphorical fingers in so many metaphorical pies that he ought to get metaphorical carpal tunnel. BunsenBwog has covered his work on the Borna Disease VirusKawasaki Disease, and the film, Contagion, where he acted as a creative consultant (and provided inspiration for one of the characters). But these are but tiny portions of the research Dr. Lipkin contributes to at the CII. That is why I was so excited when Prof. Lipkin agreed to speak with me about the CII’s latest findings on Chronic Fatigue Syndrome.

The first thing you learn about W. Ian Lipkin is that he’s extremely and perpetually busy, making it difficult to find a time to actually sit down and talk. After a week of negotiations with his personal assistant, Prof. Lipkin decided to E-mail me himself. At 6 A.M. on a Sunday. “Best for me would be 9am.”

Had an obnoxious ray of sunlight not accidentally woken me up at 8:30 A.M., I probably would have slept through my only shot at an interview. Well, it was what I wanted, wasn’t it? So I set forth, sleep deprived and slightly hungover, to meet Lipkin in his 105th street townhouse home. When I found his house, Prof. Lipkin was waiting in the kitchen, eating a sandwich and fiddling with an espresso maker. Thankfully, some of that coffee found its way into the miniature mug being handed to me. And, eventually, we started talking about the CII.

Click here if you are tired

BunsenBwog: Eilat the Friendly Virus

What’s more destructive than an alphavirus? A T-Rex loose in NY.

Bwog’s personal plasmid profiler, Zach Kagan, recounts us with the exciting tales of mosquitos, viruses, telescopes and Golden Geese in this week’s Bunsen Bwog. 

We already know what science would do with a 65-million year mosquito sample: make a dinosaur theme park and hire Jeff Golblum to get chased around by velociraptors. But what does science do with a thirty year old mosquito sample? Make a theme park based on hair-rock, Rubik’s cubes, and massive shoulder pads? Unfortunately for the nostalgic among us, science is too socially minded to burden the world with a resurgence of parachute pants and John Hughes movies. Instead they’ve made a key step towards eliminating mosquito-borne viruses, which is marginally cooler than the 80’s, I guess…

The sample in questions was originally found in the Negev Desert of Israel by Hebrew University’s Joseph Peleg. Afterwards, it was shipped around the world, just one in a collection of over 5,000 other mosquito samples, until it was tested by a University of Texas professor named Robert Tesh and his graduate student Farooq Nasar. Nasar discovered that whatever virus the mosquito was carrying, it wouldn’t infect vertebrate cells. From there the virus sample was sent to a lab at Columbia’s Mailman School of Public Health where a team of grad students got to “deep sequencing” the virus’ DNA. In other words, resequencing nucleotides over and over again to eliminate errors.

The Columbia team found that there were actually two viruses present, one that attacked insect cells and another, which they termed the Eilat Virus, that merely infected them. The second one is what the team was interested in, but they never would have detected it if it weren’t for its more careless roommate going around killing cells and, presumably, being a general slob. Eilat cannot infect or reproduce in animal cells, which is curious enough, but it turns out from the deep sequencing results that Eilat is a member of the alphavirus family. Alphaviruses are a bunch of mosquito-borne miscreants that cause all sorts of diseases in domesticated animals and humans such as “chikungunya, Venezuelan equine encephalitis, western equine encephalitis and eastern equine encephalitis.”

That makes Eilat the Casper the Friendly Ghost of viruses. While all of Eilat’s big brothers go out and infect animals, Eilat just stays in mosquito cells and tries not to be too much of a bother. But Eilat is going to show them. Researchers are using the virus to create vaccines for other alphaviruses. All they have to do is to create a modified version of Eilat with an encasing similar to a dangerous alphavirus, but with Eilat’s chill attitude intact. Thanks Eilat, you a bro. *fist bump*
Read more of BunsenBwog here

BunsenBwog: Mayans, Droughts, and the True Price of Corn
Can you avoid the barrels?

Real life Donkey Kong

This week, our aspiring anthropologist, Zach Kagan, trekked down to 112th and Broadway to talk with climate scientist Benjamin Cook about his research on the real Mayan apocalypse, not the one purported to happen on December 21st, 2012.

Climate science tends to obsess with the far future. What will climate patterns be like in five, ten, fifty years from now? Will there be enough clean water for our grandchildren? Can we impede the rate of climate change or should we all just get used to the taste of nutritious Soylent Green?

While these questions are important, others like Columbia/NASA researcher Benjamin Cook and his collaborators are looking for answers from the past. Not the geologic past either, but specifically 1,300 years ago: the collapse of the Mayan civilization. The Classic Maya collapse has troubled generations of historians and archeologists. Why was it that, after centuries of expansion and increasing sophistication from 300 AD to 900 AD, the Mayans declined so rapidly? Cities were abandoned and people fragmented into smaller groups mainly along southern Mexico and Guatemala. There are dozens upon dozens of theories for this collapse, ranging from hostile invasions to revolts to disease. However, the most accepted one has recently been the drought theory.

The idea is that the Mayans suffered from a prolonged period of intense drought lasting for 200 years. Though it might not be as exciting as the climatic battle for Chichén Itzá, but water is crucial for producing food that sustains a society. After all, a society can only function as long as it produces enough food for everyone to eat, even if some people are rulers, priests, or merchants instead of farmers. A structured and heavily stratified society like the Mayans needed a large food surplus to exist. No water means no food surplus, which means no Mayan civilization. Evidence collected from tree rings, cave formations, and lakebeds seems to support this theory.

What’s the catch? Read more after the jump.

BunsenBwog: A Matter Darkly

Each week, amateur astronomer Zach Kagan watches the skies for signs of SCIENCE. We present here this week’s findings—a special offering that highlights the search for dark matter.

Dark Matter is a term that’s thrown around a lot when people talk about unsolved mysteries in astrophysics. You’ve probably heard about the stuff, but you may not know what it is, which is fine because neither do the astrophysicists. The problem is that galaxies don’t rotate the way that they should. We predicted that outer stars should move much slower than inner cluster stars. However, they tend to move at similar velocities on the galaxy’s edge. That isn’t possible according to our understanding of gravity, so an explanation was developed: there must be much more mass in the galaxy than is observed. Much much more. Around 20 times more. And all that mass, which drives the rotation of outer stars, must completely be non-visible.

So what was this stuff? Two theories emerged. The first supposed that all this dark matter was made up of large, dim objects like black holes, rogue planets, and dense neutron stars. These objects were collectively called MACHOs (Massively Compact Halo Objects). The second theory supposed that dark matter was made up of Weakly Interacting Massive Particles, or WIMPs because scientists have a sense of humor too. Over time, as experiments found negative results for MACHOs, WIMPs became the popular theory for the nature of dark matter, even though no one was sure what WIMPs were anyway.

But WIMPs are elusive, as Columbia astrophysics professor Elena Aprile has found. Prof. Aprile led a team of scientists at Italy’s Gran Sasso laboratory on a 13 month search for the most promising WIMP candidates. The Columbia team built a sophisticated device called the XENON100, which uses ultra dense liquid Xenon to sense rare collisions with the faint WIMP particles. The device is brought deep—roughly 5,000 feet—underground in a chamber lined with copper and lead to filter out the hailstorm of particles we normally experience on the surface (such as cosmic and background radiation). However Aprile’s team didn’t find anything, not even after 225 full days of data gathering by XENON100.


BunsenBwog: A Strange Kind of Optimism

See you real soon!

It’s the end of the semester and the end of BunsenBwog for another year. While last week focused on science’s somber stories, today Bwog’s enthusiastic arborist Zach Kagan brings you amazing accounts of nature in a world altered by man.

New York City is an “urban heat island,” a zone of increased temperatures caused by the high heat capacities of artificial structures like buildings and roads. BunsenBwog has previously discussed the costs of living in “urban heat islands.” Thousands die each year due to heat waves and it costs the city millions in electricity. But for trees it turns the city into a giant arboretum. A new study led by Columbia alum Stephanie Y. Searle found that red oak seedlings planted in Central Park grow eight times faster than those outside the city in the Hudson Valley and Catskill Mountains. While Searle (who planted the trees as an undergrad) admits that city pollution can harm trees, or fertilize them with extra airborne nitrogen, heat is the major factor. With temperatures averaging 4 to 8 degrees higher inside the city, urban trees can more quickly perform the chemical reactions necessary for photosynthesis. This agrees with other studies which suggest that certain plants thrive in the “urban heat island,” but others are not as resilient. For now, though, New York in summer is just hot enough for red oaks to shoot up like weeds.

This is good news for the campaign to green NYC. But besides parks and boulevards where can the city squeeze in a bit more plant life? Answer: take to the rooftops! Transforming bare, heat capturing downtown rooftops (a contributing factor to the “urban heat island”) into Greenwich Village gardens not only looks good, but also saves energy. One of the most popular plants used for green roofs is sedum (stonecrop), a low growing plant often used a garden ground cover. The advantage of sedum is its ability to efficiently retain water runoff, but recently a team of Columbia researchers have found that some grass species may do better. But whether it’s sedum, grass, or trees, more vegetation is a good thing. For example, trees can reduce certain types of common urban pollution by 15-20%, which is great for asthma sufferers. A Columbia study found that those living in neighborhoods with more street trees tended to have significantly lower childhood asthma rates, meaning that planting a tree is good for both you and the planet!
BunsenBwog: Somber Science

Not that important after all

Each week Bwog’s resident Cell Scrutinizer, Zach Kagan, takes the top science news and breaks it down for the rest of us. This week, it’s less launching rockets and cloning dinosaurs and more of the heavy stuff. 

Polycyclic aromatic hydrocarbons (PAHs) are common urban pollutants responsible for myriad health issues. Children of mothers exposed to higher levels of PAHs tend to have lower IQs and are more likely to suffer from mental health problems such as anxiety and depression. In addition, Columbia’s Mailman School of Public Health has found that women exposed to these pollutants during pregnancy have twice the likelihood of having obese children. The study focused on 702 non-smoking pregnant women of African American or Dominican decent in Manhattan and the Bronx who wore small backpacks that sampled the air around them. This is the first study to suggest that environmental chemicals may have a role in the increasing rates of childhood obesity in America. There is hope, however: another team of Mailman School researchers found that the US could reach its childhood obesity goals by cutting out just 64 calories a day, on average. This is because the energy gap between calories consumed and calories used by the body often very slight, but overtime can lead to significant weight gain. This means that with subtle tweaks to children’s diets and activities (less juice, more outdoor playtime), parents can overcome the gap and have a healthier child.


BunsenBwog: Everyone Walk The Dinosaur
photoshopped by zach!

Talk about a "Distant Origin"

Back from Bacchanal? Get back in the spirit of science with more far out stories of the hubris of man, brought to you by your paleontologist pal Zach Kagan.

There comes a point in the career of any great scientist where he or she can get away with a lot. Legendary chemistry professor and arbiter of first year orgo, Ronald Breslow, knows exactly what position he’s in, that’s why he concluded his most recent paper with a paragraph describing “
advanced versions of dinosaurs” that may have evolved on other planets. His statements have attracted media attention, to to the point where space dinosaurs are the biggest science story coming out of Columbia this week. See, Breslow’s been interested for years in the origins of life on Earth, with his personal belief being that life was seeded via a meteorite carrying biological material. The paper supported this theory, proposing that the reason most amino acids on Earth have left-chiralities and most sugars have right-chiralities (a term describing a type in asymmetry in molecular structure) is because those were the types present on whatever body seeded the earth millions of years ago. Breslow then speculates what life on other planets that have been seeded with similar molecules would look like, which is where he brings up the alien dinos. Of course evolution doesn’t work that way and life doesn’t inevitably go though a dinosaur phase. In all fairness, ol’ Breslow knew this and probably threw in the dinosaur bit to spice the writing up. Prof. Breslow, here’s a free piece of advice: next time throw in a line about zombies or vampires, then see how much media coverage your paper gets.
BunsenBwog: Science Is A Battlefield

More controversial that you'd think

Grab your lab coats and slap on your safety goggles, because the world of science is in turmoil. Sort of. This week Zealous Xenobiologist Zach Kagan brings you exciting tales of global warming, stem cells, the secrets of the the brain and more.

Last Wednesday Havemeyer Hall became a battleground over the future direction of Neuroscience research. In a public debate, moderated by Robert Kulwhich of Radiolab fame, two top neuroscientists argued over the direction of future research: In one corner we have Sebastian Seung, MIT professor of computational neuroscience and swanky dresser, and in the other corner we have the one-and-only director of the Center for Neural Science at NYU, Tony Movshon. Seung came into the ring swinging, arguing the the ways that neurons interconnect throughout the brain is the most important avenue for research. Movshon fought back, standing firm in his belief that scientists should specialize in which area of the brain they study, getting deeper into how each individual part functions. In the end both combatants went the whole fifteen without a knock out, but it was a hell of a show.

Most people, other than Fox news pundits, will agree that global warming is caused by increased carbon dioxide levels. However, there have been many other warm periods, which begs the question–was CO2 also involved in these instances? The answer is generally yes, according to a sweeping new study analyzing the global mean temperatures and carbon dioxide levels throughout time. When CO2 levels go up, temperature rises not long after. For example, approximately 21,000 years ago variations in the Earth’s orbit caused warmer summer in the norther hemisphere, causing glaciers to melt, the resulting glacial water altered the Atlantic current system, allowing deep sea CO2 to escape into the atmosphere, warming the planet. Columbia post doctorate fellow Jeremy Shakun remarks: “We constructed the first-ever record of global temperature spanning the end of the last ice age based on 80 proxy temperature records from around the world… It’s no small task to get at global mean temperature.”