Congratulations to Maryam Mirzakhani for being the first female to win the Fields Medal.
h/t Gnotic Pasta
Originally shared by STEM Women on G+
Maryam Mirzakhani, the first female winner of Fields Medal
Often described as the “mathematician’s Nobel Prize”, the Fields Medal has never been won by a female mathematician since it was established in 1936. Until now.
“A native of Iran, Maryam Mirzakhani is at Stanford University in California. She won for her work on “the dynamics and geometry of Riemann surfaces and their moduli spaces.”
“Perhaps Maryam’s most important achievement is her work on dynamics,” says Curtis McMullen of Harvard University. Many natural problems in dynamics, such as the three-body problem of celestial mechanics (for example, interactions of the Sun, the Moon and Earth), have no exact mathematical solution. Mirzakhani found that in dynamical systems evolving in ways that twist and stretch their shape, the systems’ trajectories “are tightly constrained to follow algebraic laws”, says McMullen
These are RNA viruses causing hemorrhagic fever (http://en.wikipedia.org/wiki/Ebola_virus_disease). Symptoms appear 8-10 days after contracting the disease and include fever, sore throat, muscle pain, and headaches. Typically nausea, vomiting, and diarrhea follow, along with decreased functioning of the liver, kidneys and in some cases with internal and external bleeding.
♦ How does one get infected
As many virus diseases (HIV, for example) this disease too has come to infect humans through primates. However, the reservoir for the viruses are thought to be bats in the African jungles.
Close contact with body fluids (blood, vomit, saliva, etc.) of an infected person/animal is responsible for the spread of this disease.
♦ Debunking some Ebola myths
1. Ebola spreads through air
No. Except the Reston ebolavirus none of the othe species are spread via aerosols (droplets in the air). Reston is shed in the form of droplets only by pigs. If you’re exposed to a pig infected by this strain, the chances of you dying are slim. The disease causing capability of this particular strain is not good enough to kill.
In fact, as Tara C. Smith mentioned in a G+ HOA (see link below) according to Prof Peter Piot (the scientist who discovered ebola) even if you are sitting next to an ebola infected individual on the subway, you might not get infection. Only close contact with infected body fluids leads to an infection.
2. _ This is the Zombie Apocalyspe_
No, it’s not. And though we must all be alert and vigilant, we should not panic! If contained, this disease can be controlled. Please help in spreading awareness in your community about the prevention strategies. Once we understand the science behind it, everything falls into perspective.
3. The ebola patients in the US are being treated by some secret serum
The serum is not a secret panacea developed exclusively for US citizens. And neither is it some devil concoction. The serum is a cocktail of antibodies raised in laboratory animals (in Biosafety level 4 laboratories). Please listen to Vincent Racaniello’s (Earth’s Virology Professor) take on this aspect in the hangout. As he says, scientists are not a part of any conspiracy. They are doing their job. The benefit of the community is the bottomline for all research.
Spread awareness and not rumors!
Following are some very useful links:
This week in virology episode ‘Ebola! Don’t panic’. Listen to Vincent Racaniello and friends discussing Ebola.
This is a timely HOA, that should be interesting as well.
#scienceeveryday
Originally shared by Science on Google+
Join us for a Science on Google+ Hangout on Air as we speak to Professor Vincent Racaniello and Dr Tara C. Smith about the recent Ebola outbreak. We will discuss the basics of Ebola, why the epidemic has spread, how it might be curtailed, and debunk some of the myths surrounding this outbreak. Please leave your questions on the Event page.
Vincent is a professor of virology at the University of Columbia and is a fantastic science communicator. Tara is an epidemiologist at Kent State University who has written numerous articles debunking some of the myths surrounding Ebola. This HOA will be hosted by Dr Buddhini Samarasinghe and Dr Zuleyka Zevallos. You can tune in on Sunday August 10th at 2.30 PM Pacific, 5.30 PM Eastern. The hangout will be available for viewing on our YouTube channel (https://www.youtube.com/ScienceHangouts) after the event.
Besides Richard Green, I would say Joseph Fourier or Johann Radon just because my work wouldn’t exist without them. The Fourier transform is integral to MRI as the data is frequency encoded. For other imaging techniques that use projection data, e.g., CT, the Radon transform is important in image reconstruction using a technique called filter back projection.
I’ve been neglecting my #CHMedicalImagingSeries because I’ve been crazy busy at work. We are getting a new SPECT/CT which, ironically (or maybe not) is the next modality in the series. Because cancer affects so many people, directly and indirectly, I think it’s important to re-share Buddhini Samarasinghe’s stellar work in her series. Even for researchers like us, cancer is personal. When the drudgery of lab work or analysis makes you want to crawl under your desk or when frustration from confounding results makes you want to pull your hair out (if you have hair), we remind ourselves of the loved ones, friends, acquaintances, etc. that have been hurt by cancer. We march on, with your support, with your stories, with your courage.
So if you want to know about cancer without the jargon, read Buddhini’s series. Hopefully my series will resume soon.
W.K. Kellogg Biological Station – Michigan State University
My sister chose the W.K. Kellogg Biological Station (KBS), the manor in particular, to have her wedding ceremony this past Friday. It’s a fantastic venue for a wedding, with wild flowers everywhere, history, and science. W.K. Kellogg was the business-minded, of the two Kellogg brothers. He’s the one who founded the cereal company. John Harvey Kellogg was the brother who started the sanatorium in Battle Creek, MI. There is a lot of information about the brothers, including the documentary The Kellogg Brothers: Corn Flake Kings, so I’m only going to briefly talk about the biological station.
The manor was the home of W.K. Kellogg and was built in 1925 overlooking Gull Lake in what is now called Hickory Corners, MI. In 1928, W.K. Kellogg deeded Kellogg Experimental Farm and the Kellogg Bird Sanctuary to the Michigan State College of Agriculture. The entire 32 acre estate was given to the Michigan State University in 1951.
Bird Sanctuary
W.K. Kellogg was interested in wildlife conservation and KBS is fortunately the intersection of three major bird migration routes. The bird sanctuary opened in 1928 and is a major attraction. Their mission statement: The W.K. Kellogg Bird Sanctuary conserves native habitat for migratory and resident birds and through research, education, and outreach helps people gain environmental awareness about our past, present, and future.
Kellogg Experimental Forest
The Kellogg Experimental Forest is 728 acres, which includes two artificially created ponds. They have developed hybrid spruce and poplar trees. The Spartan Spruce, is a cross between a blue spruce from southern Colorado and the white spruce from Michigan’s upper peninsula. The needles are blue like a blue spruce but soft like a white spruce.
Biofuel
KBS is working on a lot of interesting questions related to biofuels, such as economy (when does it make economic sense for farmers to switch to production of biofuel sources), what effect does growing biofuel sources, such as corn, have on soil or wildlife habitat, and how much cellulose based ethanol can be made produced from various crops. For example Brazil is doing quite well with sugar cane based ethanol, whereas in the USA most of the biofuel ethanol is from corn.
There’s a lot of interesting science going on at KBS. I plan to go back to see the bird sanctuary, especially the birds of prey.
I was interested in learning more about my dog’s tapeworm infection so Google sent me down the worm rabbit hole. She was asymptomatic. We had her stool checked as a requirement for a daycare center. It came back positive for tapeworm and she was given Panacur ™ (Fenbendazole). The handout that the vet gave us talked a lot about Dipylidium caninum, which is a tapeworm that is transmitted by fleas. We didn’t notice any fleas on our dog and she is not scratching excessively. So I talked to the vet and he said she has a different type of tapeworm. It was close to closing time so I didn’t press him for more information. I went down the rabbit hole, I mean wormhole looking for more information. It turns out that Panacur ™ only works for Taenia pisiformis, which is a type of tapeworm with rabbits as an intermediate host.
§ Life cycle
The general life cycle of a tapeworm starts with proglottids or eggs in the feces of the primary host. Proglottids is a segment of the tapeworm that contains a complete set of reproductive organs. The intermediate host gets infected with the eggs or proglottids, for D. caninum that would be fleas and for T. pisiformis it would be rabbits. The primary host gets D. caninum by eating the fleas, not by flea bites. If your dog or cat gets bitten, they would naturally scratch the bite with their teeth and would get the larvae into their mouths. So infants can get D. caninum by putting an infected flea in their mouth. That’s why it’s rare for humans to get D. caninum. For T. pisiformis, it’s a bit more gruesome because the main way to get infected is to bite an infected rabbit because it’s their viscera (internal organs, predominantly in the abdomen) that contains the larvae. The larvae travel from the rabbit’s intestines, into the blood stream, and then to the viscera. I’m still not sure how my dog got infected. I bet Tommy Leung can tell us more about tapeworms.
§ So how does Fenbendazole work?
Fenbendazole is in a class of drugs called anthelmintics, which are drugs that expel worms from the body by killing them or stunning them. In the case of Fenbendazole, it interferes with tubulin polymerization. Microtubules are part of the cytoskeleton. If tubulin polymerization is disrupted, the cells essentially dissolve/collapse.
It might look like a beautiful flower, but this image of the week is more the stuff of nightmares! The picture above shows a dog tapeworm (Taenia pisiformis) taken using a light microscope. The image clearly shows the hooks of the tapeworm on its head (scolex), which it uses (along with four suckers) to attach to the small intestine of canids like dogs and foxes.
The image was taken by Spike Walker. The tapeworm was on a microscope slide, giving it a slightly squashed look. The muscle and other tissue of the tapeworm were stained red, but the hooks (made of chitin) don’t stain. Therefore, Spike used a contrast enhancement technique called Rheinberg illumination, which gives the hooks their bright colours against a blue background. First demonstrated over a hundred years ago by Julius Rheinberg, this involves using coloured filters so a transparent sample can be seen.
I applaud Nickelodeon (Nick News) for taking on such a sensitive topic. I’m looking forward to seeing how both sides are presented and what the audiences reaction is.
Tuesday, July 1 at 8:00 pm ET
I believe it will be available on their website the following day.
I hope team USA does well, especially better than this guy, against Portugal. The image below is from the International Museum of Surgical Science. I was there just before closing so I went through rather hurriedly. So I don’t recall what the placard said about this. I don’t think it is plastination but I don’t remember. I’ll be back and take notes. Here’s more from IMSS
There is a report making the rounds on social media that really needs to be explained, because as usual the media hype is distorting the findings. The article in question was published in the Cell Stem Cell journal, and is #OpenAccess (http://goo.gl/pnoiwa). I will explain the background, what these results mean, and more importantly, what they don’t mean.
✤ Traditional chemotherapy is toxic to cells. The only reason traditional chemotherapy works is because it kills cancer cells faster than it kills normal cells. The side effects from chemo often happen because normal cells are also affected. One such side effect is the suppression of the immune system. This happens because chemo damages adult stem cells too, which impairs tissue repair and regeneration.
✤ Blood stem cells (known as hematopoietic stem cells) are responsible for replacing our blood cells; these reside in the bone marrow. In this study, scientists investigated the effect of prolonged fasting on hematopoietic stem cells.
✤ Mice used in this study were fasted for 48 hours, which the scientists defined as prolonged fasting. These mice received no food, only water. They then treated the mice with cyclophosphamide, a common chemotherapy drug. They found that cycles of prolonged fasting reduced the damage caused to hematopoietic stem cells when the mice were treated with cyclophosphamide. They also found that prolonged fasting cycles promoted the regeneration of blood cells through the protection of hematopoietic stem cells.
✤ Next, the scientists tested whether the effects of prolonged fasting were independent of the toxic side effects of chemotherapy. Could prolonged fasting alone stimulate hematopoietic stem cells to self-renew? Indeed, it could.
✤ What is the molecular mechanism for this process? A growth factor known as Insulin-like Growth Factor-1 (IGF-1) seemed to be involved. Growth factors are proteins that control the multiplication of cells. To examine this mechanism, the scientists used mice that were deficient in IGF-1. If you’re curious about how these ‘knockout mice’ are generated, read http://goo.gl/jdbqbk. When these IGF-1 deficient mice were treated with cyclophosphamide, they showed similar results to the prolonged fasting mice; reduced levels of hematopoietic stem cell damage. So getting rid of IGF-1 induced the same protective effects on hematopoietic stem cells.
✤ How does IGF-1 signalling protect hematopoietic stem cells? They found that the activity of an enzyme known as PKA was also reduced in these prolonged fasting/IGF-1 deficient mice. PKA controls the pathway involved in stem cell regeneration. So inhibiting IGF-1 or PKA signalling mimics the effect of prolonged fasting; it promotes the regeneration of hematopoietic stem cells, thereby reducing the immuno-suppressive side effect of chemotherapy.
✤ This is really interesting data – this research has identified one of the signalling pathways in the intricate network of reactions controlling the behaviour of hematopoietic stem cells. The mechanism involves PKA and IGF-1 signalling.
WHAT THE DATA DOESN’T SHOW
What this doesn’t show is that fasting is magically a cure-all for cancer. There isn’t a single study that shows lowered incidence of cancer in human populations that fast regularly. The fasting that these mice underwent also did not include the feasting that goes on every night as seen with human populations either. The scientists also conducted a small Phase I clinical trial in which patients undergoing chemotherapy fasted for 72h – the results are promising; their hematopoietic stem cells were protected when compared with the non-fasting control group. But obviously more data is needed, and it is highly inadvisable to fast before undergoing chemo, without the explicit guidance of a physician.
To summarise, fasting is not a cure for cancer. If anything, fasting does “cure” everything, eventually; this pathway involves a mechanism known as ‘death’.
Image: fasting causes a major reduction in white blood cells followed by their replenishment after refeeding. These effects of prolonged fasting can result in the reversal of chemotherapy-induced immunosuppression.
