Tag: sciencesunday

Time for some smelly science

Fresh Air’s Terry Gross interviews Alexandra Horowitz to discuss her new book, Being a Dog. One of the fascinating capabilities that Alexandra mentions in the interview is that dogs can tell time via smell. We know dogs have a tremendously more sensitive sense of smell compared to us. It makes sense that dogs can use smell to tell time, if you think of time in a different way. For example, they can smell just traces of something left behind by another animal. Therefore they know that a faint smell is from the past. They also can detect faint smells in the air, perhaps around the corner. Therefore, they can smell the future. The way Alexandra describes a more traditional sense of time is pretty interesting. As the air heats up in your house, you can imagine air currents change. The smell of the room should change too. Remember we are visual creatures but dogs are more olfactory. Imagine 3D smell instead of sight. It makes sense that the scent profile of a room would change depending on the time a day and therefore a clue to what time it is. It’s very much like how we can use shadows to guess if it’s midday or evening.

Alexandra mentioned the vomernasal organ, sometimes called the Jacobson’s organ and I’m guessing a lot of people have never heard of it. The vomernasal organ (VNO) is the peripheral sensory organ in the olfactory system that involves chemoreception. Pheromones are often mentioned in the definition of VNO but in some non-mammalian species, such as snakes, VNO might be used to track prey using chemoreception. Therefore focusing just on pheromones is not broad enough of a definition. There is some debate as to whether or not humans have a VNO. It seems clear that it exists in the embryonic stage. The debate seems to be whether or not it is functional as adults. The article by Meredith (linked below) focuses not on whether it exists but what its function could be.

The other interesting thing from the Meredith article is the section about pheromones, where he talks about the definition and its use in scientific discourse. So first, the definition.

What is a pheromone and is it a well-defined, scientifically useful concept? The term pheromone was coined to describe a chemical substance which carries a message about the physiological or behavioral state of an insect to members of its own species, resulting in ‘a specific reaction, for example a definite behaviour or a developmental process’ (Karlson and Luscher, 1959).

He goes on to discuss how communication by pheromones needs to be mutually beneficial for sender and receiver. That benefit, is in an evolutionary sense.

The term pheromone is not going to disappear so long as it holds the public fascination. Its use for a class of chemicals that communicate information seems reasonable, but the definition is important if the term is to be useful in scientific discourse. Too rigid a definition can make its applicability to real situations so limited that it is useless. We know that even archetypal insect pheromones are not unique chemicals used by single species, as supposed in some definitions [see discussions in Beauchamp et al. and Albone (Beauchamp et al., 1976; Albone, 1984)]. Similarly, too broad a definition devalues the term and also makes it useless.

Getting back to the interview with Alexandra and dogs’ incredible sense of smell, there are some great illustrations in the PBS, NOVA article below. An eye opening estimate of how much more sensitive dogs’ sense of smell compared to ours is something like 10,000 to 100,000 times ours.

In Alexandra’s previous book, Inside of a Dog, she writes that while we might notice if our coffee has had a teaspoon of sugar added to it, a dog could detect a teaspoon of sugar in a million gallons of water, or two Olympic-sized pools worth.

Hopefully you have a sense of dogs’ great sense of smell now.

Human Vomeronasal Organ Function: A Critical Review of Best and Worst Cases

Michael Meredith

Chem. Senses (2001) 26 (4): 433-445.

http://chemse.oxfordjournals.org/content/26/4/433.full

Dogs’ Dazzling Sense of Smell

On NOVA

http://www.pbs.org/wgbh/nova/nature/dogs-sense-of-smell.html

#ScienceSunday

http://www.npr.org/2016/10/04/496417068/from-fire-hydrants-to-rescue-work-dogs-perceive-the-world-through-smell

How are the scientific method, free market, and natural selection related?

Read Sabine Hossenfelder’s blog post to find out. I particularly like this paragraph:

In science, the most relevant restriction is that we can’t just randomly generate hypotheses because we wouldn’t be able to test and evaluate them all. This is why science heavily relies on education standards, peer review, and requires new hypotheses to tightly fit into existing knowledge. We also need guidelines for good scientific conduct, reproducibility, and a mechanism to give credits to scientists with successful ideas. Take away any of that and the system wouldn’t work.

http://backreaction.blogspot.com/2015/11/the-scientific-method-is-not-myth.html

I write to try to undo the hype in a new scientific findings where a newspaper has lathered on too much hype. I also moderate the Science on Google+ community. So I often get comments about how we should question everything, that science is about challenging everything. If you don’t question everything, e.g., evolution, climate change, etc. then you aren’t doing science. Sadly, these comments often come from climate change deniers, believers in pseudoscience or conspiracies.  So I often have to explain that skepticism is fine, however, when you have an extraordinary claim, you need extraordinary evidence. I’ve written about that before.

Skepticism doesn’t equal question all things

https://plus.google.com/u/0/+Scienceongoogleplus/posts/dTJssSxdALH

I’m not sure many people truly understand the scientific method and IFLS doesn’t help with catchy GIFs with no science or attribution.

Science is not about certainty. Science is about finding the most reliable way of thinking, at the present level of knowledge. Science is extremely reliable; it’s not certain. In fact, not only it’s not certain, but it’s the lack of certainty that grounds it. Scientific ideas are credible not because they are sure, but because they are the ones that have survived all the possible past critiques, and they are the most credible because they were put on the table for everybody’s criticism. […]

http://goo.gl/0e7p7

Image source: https://www.flickr.com/photos/neotsn/4947989561

#ScienceSunday  

h/t Filippo Salustri 

Acanthonus armatus Dumb Ass-fish

I would be willing to do an MRI on this fish to confirm that it’s brain is small. The Ass-fish, Acanthonus armatus, is known for it’s small brain relative to its head size. It’s not clear where the name Ass-fish came from but it’s ugly appearance matches the name.

It’s part of the cusk-eel family. From Wiki:

The cusk-eel family (Ophidiidae) is a group of marine bony fishes in the order Ophidiiformes. The scientific name is from the Greek ophis meaning “snake”, and refers to their eel-like appearance. However, they can be distinguished from true eels of the order Anguilliformes by their ventral fins, which are developed into a forked barbel-like organ below the mouth in the cusk-eels; in the true eels by contrast they are never well-developed and usually missing entirely.

https://en.wikipedia.org/wiki/Cusk-eels

While trying to learn more about cusk-eels, I learned that the deepest known living fish is another cusk-eel. Abyssobrotula galatheae was taken from a depth of 8,370 m (27,460 ft) in Puerto Rico.

https://en.wikipedia.org/wiki/Abyssobrotula_galatheae

Which reminded me of a popular eel like fish that’s supposed to bring good luck in parts of Asia. The Silver Arowana is much better looking than the Ass-fish.

https://en.wikipedia.org/wiki/Silver_arowana

The finding has been published here:

New Records of Seven Cusk-Eels (Ophidiidae) and Brotulas (Bythitidae) in Coastal Waters of British Columbia, Canada

Northwestern Naturalist 96(1):71-80. 2015

http://www.bioone.org/doi/10.1898/NWN14-17.1

Happy #ScienceSunday  

http://www.cbc.ca/news/canada/british-columbia/assfish-royal-bc-museum-display-1.3404806

Moringa oleifera Seeds can clean water

Dr. Stephanie Velegol and colleagues recently published their work on explaining how a protein from the seeds of the Moringa oleifera tree can kill bacteria. It was known for some time that women in Egypt would use the seeds to clean dirty water. Since modern filtration systems are expensive and difficult to get to rural areas, understanding how the Moringa oleifera seeds work is important. Using cryo-TEM and simulations (among other techniques), they were able to demonstrate how the Moringa oleifera cationic protein (MOCP) kills bacteria. It fuses the inner and outer bacteria membranes.

☼ cryogenic electron microscopy (cryo-EM)

Cryo-EM (transmission EM in this case) is a technique where the sample is cryogenically frozen and then sliced for the EM scope. There are two main types of EM: transmission and scanning. In transmission EM, the electrons go through the sample. In scanning EM the electrons go over the sample. Unlike optical (common) microscopes, EM, as you probably guessed, use electrons instead of light. You can read more here:

http://www.explainthatstuff.com/electronmicroscopes.html

☼ Simulations

Using data from multiple techniques, the researchers simulated what was going on with the MOCP and a test bacteria, E. coli. The data suggest that the MOCP cause flocculation and fusion of the inner and outer membranes.  Within 50 seconds the MOCP cause flocculation (like aggregation) of the bacteria. The simulations also suggest how the structure of the MOCP functions during the fusion process.

You can read the news blurb from Penn State here:

http://goo.gl/Bv4UkA

The full article is here (behind a paywall).

The Flocculating Cationic Polypetide from Moringa oleifera Seeds Damages Bacterial Cell Membranes by Causing Membrane Fusion.

Shebek K, Schantz AB, Sines I, Lauser K, Velegol S, Kumar M.

Langmuir. 2015 Apr 21;31(15):4496-502. doi: 10.1021/acs.langmuir.5b00015. Epub 2015 Apr 10.

http://www.ncbi.nlm.nih.gov/pubmed/25845029

#ScienceSunday  

h/t Gnotic Pasta and rasha kamel 

Skepticism doesn’t equal question all teh things

This is a great PSA from the folks who moderate the Science on Google+ community. There is also confusion about love for science and skepticism. As a moderator and someone who writes science posts, I get people who argue that everyone should be a skeptic. However, the list below has no room for skepticism in general. Scientists certainly debate new findings in those areas but the foundations (evolution for example) are not up for debate and skepticism.

Originally shared by Science on Google+

PSA: Evidence-Based Science on Google+

Some scientific facts aren’t up for debate in our science community. As scientists, we follow where the evidence leads, and the overwhelming evidence supports anthropogenic climate change, the efficacy of vaccines, the soundness of evolutionary theory, and the safety of GMO. There is vigorous debate within various scientific disciplines on how these settled areas of science work and what future outcomes of (for example) climate change or evolution will be. However, debate over mechanisms and outcomes should never be considered debate over the basic facts of a subject. A person claiming, for example, that anthropogenic climate change is a hoax is making an extraordinary claim against a huge body of peer-reviewed evidence, and barring extraordinary, credible, peer-reviewed evidence to support that claim, a post making such a claim will be removed from this community. Extraordinary claims require extraordinary proof.

The focus of our community is on research trying to address these issues, and not to rehash or debate the evidence. Unlike politicians, we don’t take positions to win votes or gain popularity. Rather, we ground our positions in the best evidence available to us, recognizing that scientific evidence may be incomplete but is constantly self-correcting. 

What is scientific consensus? :  https://plus.google.com/u/0/+Scienceongoogleplus/posts/5LRg4oTFAFU

Cartoon credit: http://joyreactor.com/post/805720

#ScienceSunday  

You are entitled to your own opinions but not to your own facts

I hope the backlash against anti-vaxxers has a positive outcome, i.e., they stay out of the public or get vaccinated. There is ignorance about how the immune system works and therefore how vaccines work. Some anti-vaxxers claim that the Amish don’t get sick and do not vaccinate but that’s not correct. They suffer from some horrible diseases. Here’s an interesting article from The Atlantic (h/t Mary Mangan) 

https://plus.google.com/u/0/+MaryMangan/posts/X1SkdjrxDgJ

Here’s a two-second primer on the immune system:

Exposure to a foreign body (antigen) causes the immune system to generate antibodies. The antibodies identify the antigens so that your immune system (T cells) can remove the foreign body. In the case of naturally acquired immunity, you are exposed to the live virus, e.g., influenza. In the case of a vaccine, you are given an attenuated virus, i.e., one that cannot replicate. Would you rather go to a so called Chicken Pox party and get real Chicken Pox or get the vaccine where you have milder symptoms if you get Chicken Pox at all? It’s true that not all vaccines are 100%. That’s partly due to biodiversity. It should be easy to understand that we all aren’t identical. However, in the case of measles, the vaccine is 95% effective and measles is one of the most contagious diseases, more than ebola. If you are not vaccinated, you have 90% chance of getting measles.

Herd immunity is essential for those who can’t get vaccinated because they are too young or are allergic. Read more about herd immunity here:

If you have a minute, really just 60 seconds, and you want to learn what herd immunity is

https://www.youtube.com/watch?feature=player_embedded&v=brNscgAG3Nc

More on Herd Immunity if you have more time

http://www.health.harvard.edu/video/herd-immunity/

For those who actually want to be educated, here’s a great article from Liza Gross

Doubt and Denialism: Vaccine Myths Persist in the Face of Science

http://goo.gl/f7Y1f

Regarding thimerosal as a preservative in vaccines:

Furthermore, all new vaccines licensed since 1999 are free of thimerosal as a preservative

http://goo.gl/v0KRe

Yet the rate of autism increases? Where’s the link? There is none.

https://plus.google.com/+livescience/posts/iqzXqH1eHwC

And you are aware of the increase in Pertussis in Washington state due to anti-vaxxer parents? Here’s how science is presented (by Philip Plait) 

http://goo.gl/8xRa7

Here’s a few more links:

Tussle with Pertussis – Whooping cough

http://goo.gl/b8wWHn

It does matter, Alijah should not have been in ICU

http://goo.gl/cvknyY

Finally, I’ll point you to as disturbing story about anti-vaxxers going after a family that lost their infant to whooping cough. http://goo.gl/saspV

#ScienceSunday  

Originally shared by Yonatan Zunger

As a measles outbreak spreads across the US, with 14 states now affected, the advocates of letting deadly epidemics run wild are finding themselves suddenly unpopular:

Members of the anti-vaccine movement said the public backlash had terrified many parents. “People are now afraid they’re going to be jailed,” said Barbara Loe Fisher, the president of the National Vaccine Information Center, a clearinghouse for resisters. “I can’t believe what I’m seeing. It’s gotten so out of hand, and it’s gotten so vicious.”

This is not, to be honest, an unreasonable fear: it turns out that when you recklessly engage in conduct which places another person (or the general public) in danger of death or serious bodily injury, you may well have a reason to fear that people might want you to go to jail. The technical term is “reckless endangerment.” And when people — especially children — start actually dying because of your actions, you may well have reason to fear that your neighbors may suggest that you find some other neighbors, starting right away.

The reaction to this outbreak has, however, offered me some real hope. I suspect that as soon as people remember just why people were so terrified of these diseases, the popularity of the “anti-vaccine” movement is likely to plummet, largely at the hands of people who don’t feel like being put in mortal danger by their neighbors’ fears. Hopefully, this movement will be gone and forgotten before too many people die. (But I want to be honest here: people are going to die. Mostly kids.)

We should recognize that there are real access problems in some parts of the country: the government pays for vaccines but not the doctor’s time, and if you get paid by the hour and don’t have a car, simply the time to go to the doctor is a major factor. But we know how to fix these problems: the mobile vaccination stations that helped end the polio epidemic of the 1950’s are proof of that.

The best proof by far, though, is that some states are doing a great job to this day. It turns out that the winner is Mississippi, which has managed to achieve a 99.7% immunization rate for the most serious diseases! They’ve done this through a combination of a strong public health program and not messing around with their laws. You can read more about what they’ve done, and how they stack up against other states, at http://wpo.st/QKT20 .

I suggest a three-point strategy:

(1) Make sure that the CDC-approved vaccine schedule is available to every person. Task an agency with achieving as close to 100% coverage as possible; the only people who shouldn’t be getting these are people for whom there is a medical reason not to.

(2) Educate the public about what’s going on and why. Don’t be afraid to pull out the old videos and show people of just why measles is not a “thing you just get over.” 

(3) Starting in areas where vaccination is already reliably available, and ultimately spreading to all areas of the country, impose criminal liability for the deliberate failure to vaccinate without medical reason, under existing laws for reckless endangerment and/or child endangerment. 

My parents and their generation got to watch their families and their friends die from these diseases. I don’t want to do the same.

h/t to Kyla Myers for the WaPo article about Mississippi’s success. Another very interesting article to read is http://goo.gl/BYp3iF, from the Journal of the American Academy of Physician Assistants, which goes through the reasons why people aren’t getting vaccinated and proposes several ways to help fix it. Thanks to James Salsman for that one.

Special thanks to Steve Esterly for his thorough critique of a previous version of this post, and in particular catching that I had misinterpreted the JAAPA article in a rather important way. 

http://www.nytimes.com/2015/01/31/us/vaccine-critics-turn-defensive-over-measles.html?_r=1

Skepticism doesn’t equal question all teh things

This is a great PSA from the folks who moderate the Science on Google+ community. There is also confusion about love for science and skepticism. As a moderator and someone who writes science posts, I get people who argue that everyone should be a skeptic. However, the list below has no room for skepticism in general. Scientists certainly debate new findings in those areas but the foundations (evolution for example) are not up for debate and skepticism.

Originally shared by Science on Google+

PSA: Evidence-Based Science on Google+

Some scientific facts aren’t up for debate in our science community. As scientists, we follow where the evidence leads, and the overwhelming evidence supports anthropogenic climate change, the efficacy of vaccines, the soundness of evolutionary theory, and the safety of GMO. There is vigorous debate within various scientific disciplines on how these settled areas of science work and what future outcomes of (for example) climate change or evolution will be. However, debate over mechanisms and outcomes should never be considered debate over the basic facts of a subject. A person claiming, for example, that anthropogenic climate change is a hoax is making an extraordinary claim against a huge body of peer-reviewed evidence, and barring extraordinary, credible, peer-reviewed evidence to support that claim, a post making such a claim will be removed from this community. Extraordinary claims require extraordinary proof.

The focus of our community is on research trying to address these issues, and not to rehash or debate the evidence. Unlike politicians, we don’t take positions to win votes or gain popularity. Rather, we ground our positions in the best evidence available to us, recognizing that scientific evidence may be incomplete but is constantly self-correcting. 

What is scientific consensus? :  https://plus.google.com/u/0/+Scienceongoogleplus/posts/5LRg4oTFAFU

Cartoon credit: http://joyreactor.com/post/805720

#ScienceSunday  

Amazing cephalopod mom

This octopus smashed the record for egg brooding. She spent 4.5 years protecting her eggs in Monterey Bay. You can read more about her here: http://goo.gl/AIBCzN

So of the choices at Science, this is my selection for image of the year, 2014. What’s your? http://goo.gl/oRmJwM

#ScienceSunday