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Wednesday, November 30, 2011

Picture of the Week: The Fairy Wasp

Photo Credit: A. Polilov

There has been a lot of buzz about this miniscule insect this week after a publication by Alexey Polilov demonstrated that the fairy wasp's nervous system operates with only 5% of the nucleated neurons of similar species. As you can see from the picture, which is on a 200 micron scale, the wasp is as tiny as some unicellular organisms such as the paramecium and the amoeba. The study showed that in order to exist as such a tiny multicellular creature, some structural sacrifices must be made. Thus, the loss of the nuclei from the nerve cells. This aquatic wasp is so incredibly tiny that it lays its eggs inside the eggs of other insects that also live in ponds. For more on this tiny creature, read Ed Yong's overview of this paper at Discover Blogs.

Monday, November 28, 2011

Can the Black Friday Phenomenon Be Explained by Science? What you missed this holiday break.


Today, as we've come to know it, is Cyber Monday: a day when all the stress and bad behavior exemplified last Friday gets channeled into people's Amazon accounts. This may leave you pounding your keyboard in frustration over that $10 you could have saved on an indestructible iPhone case. However, when you lay it out as simply money saved to time wasted online shopping, you may come out ahead. But what drives us into this craze in the first place? What about Black Friday, where hours in the cold and sometimes violent madness minimally pay off? Scientists have been working on this question for some time now. What is known is that the Black Friday sales mentality plays off of our psyche.

Consumer researchers have shown that perception is key when it comes to influencing purchases. A penny might be negligible when calculating our budgets, but marking a price down just one cent makes it a more desirable purchase, especially when it ends on a nine, such at $9.99 instead of $10. Some businesses even price their items oddly ($6.23) because data shows that consumers will purchase more if they think the store is giving them every tiny bit of value. As long as you convince the customer that they are saving by spending, your purchases will increase. This is the basic science of the deal.

However, in extreme cases like Black Friday, there must be more to it. Although consumer scientists can prove the reasoning for marketing techniques based on statistical data, explaining why we make those choices is harder to do scientifically. Other factors such as emotional involvement, tradition, fear, and competition have been recorded as reasons for shopping insanity. One team of researchers this year is teasing this apart by measuring physiological changes in the heat of the action.

Fifty consumers in large cities braved the crowds on Friday wearing special bracelets that detect microscopic changes in sweat.  These changes, along with movement and body temperature, correlate to various emotional responses. The bracelets, developed by the MIT media lab, will collect data on excitement and relaxation for a company called Shopper Sciences which hopes to improve sales for clients such as Coca-Cola and Hasbro. This study will also look at online shopping, which will allow scientists to monitor facial expressions through web cameras as well.

Even heightened levels of excitement cannot explain the bad behavior we witnessed on this and past Black Fridays, or can it? Some of the same emotional responses that create that shopper's high might be the ones that account for the escalating violence we have seen over the years. In 2010, a woman was arrested here in Madison, Wisconsin for threatening to shoot anyone who would not let her cut in line at Toys R Us. It was also the tragic year an employee was trampled to death by Walmart crowds. This year, nearly 30 people were injured around the country due to fights, crowd control, robberies, and one horrific incident where a woman protected her shopping cart by spraying those around her with pepper spray.

Stores designed to lengthen distance to exits, control for theft, and promote as much merchandise as possible are partially responsible for the problems we have observed. Although consumer research shows that these are smart choices for marketing, when mixed with a sense of competition, fear that you might miss out, and pushing and shoving, instincts kick in. These incidences are not distinct from what is seen when crowds at concerts or rallies get out of hand. Predicting how crowds behave and might react could be key to preventing future problems.

Crowd behavior is poorly understood and difficult to study. Scientists today are making headway using high tech gear and computer modeling. The well known Fruin model shows that when crowd density equals personal space, individual control is lost and the crowd behaves as a single entity. This was supported by a team at Arizona State University who developed a computer model populated with thousands of individual thinkers. What they saw was that even the smallest decisions of an individual, such as changing directions affected the entire crowd as a whole in waves. Another team led by Professor Keith Still also use other non-virtual techniques, such as pressure sensing jackets, to monitor crowd behavior.  Using this information to train employees and law enforcement may allow them to recognize patterns and speed up reaction times.

Although scientists might not have definitive answers for the chaos seen every year after Thanksgiving, new studies may improve how stores operate and how they keep the peace, a win-win for the shops and shoppers. So if you plan on jumping in on the sales madness this year, remember to go in with a plan, consider the real value of the product, and most importantly, keep calm.

References:
1.http://online.wsj.com/article/SB10001424052970203710704577054470345255202.html
2.THE CAUSES AND PREVENTION OF CROWD DISASTERS John J. Fruin, Ph.D., P.E. United States of America
3.http://www.science20.com/news_releases/syn_city_crowd_behavior_and_violence_tipping_points_get_numerical_model
4.http://crowdmodelling.com/

In case you missed it:

The Curiosity launched this week. How they land it may be the most exciting part.

Dr. Deborah Blum continued the analysis of pepper spray on Rachel Maddow's show.

Nature breaks down what the US Budget stalemate means for science

Robojelly mimics real sea jelly


Here's to a steady food coma recovery!

Thursday, November 24, 2011

Picture of the Week: Thanksgiving edition

Public Domain Photo
In honor of the holiday, here is a picture of the fall cranberry harvest.  Made famous by the cheeky Ocean Spray commercials, cranberries are harvested in these large bogs.  Grown in lowlands, the cranberries float off of their vines when the fields are flooded for harvest thanks to large air pockets in the berry.  These beautiful scarlet berries have been a big crop up here in Wisconsin since the 1860s, where they are now grown in 20 counties.  They are considered one of the healthiest fruits around for their high antioxidant concentrations, but beware the trap of the dried cranberry. Until a few years ago, these snacks were more than 50% added sugar....now they are 51% cranberry and 49% sugar.  If you would like more information about cranberries, don't miss the Thanksgiving time lectures by Dr. Robert Skirvin at U of Illinois. He taught me everything I know about these little bouncing berries.

Wednesday, November 23, 2011

Be back soon

Sorry Dear Readers for the delay in content recently. There have been some major changes in my life this past week (more on that later) and I'm running a little behind on content writing.  Stay tuned for the Picture of the Week and a great story about a 13 year old boy making waves in the science community.

Until then, check out my twitter for some fun Turkey Day related trivia!

Friday, November 18, 2011

Venom Goes From Deadly to Life Saving. What you missed this week.

Snake venom is a complicated potion of proteins and other compounds that produce deadly results. Scientists are breaking it down substance by substance, revealing potential drugs for human disease treatments. This week marks one month into one such study on CB24, a crotoxin derived drug from the venom of an American diamondback rattlesnake.

Photo Credit: Doug Hotle cabq.gov
The Phase 1b Clinical trial, headed by Celtic Biotech and oncologist Jacques Medioni, addresses the safety and therapeutic potential of the drug for cancer sufferers. The compound enters cancer cells and causes them to commit cell suicide, known as apoptosis. One previous study on the crotoxin evaluated tolerable doses of the drug and resulted in not only tumor size reduction but also reduced pain for the patients. Rigourously tested on mice and human cancer cell lines, this compound shows promise, especially regarding solid lung and breast tumors.

Last week, four rattlesnakes were transported from the Albuquerque Biopark to the premier venom laboratory at the Kentucky Reptile Zoo to be used in the study. These snakes will be humanely milked for their venom, which will be shipped to France for processing before use in the study. Snake venom is produced by glands under the eye and is injected into prey through large hollow fangs. The collected venom could prove useful in these cancer treatments and has potential for the treatment of other diseases as well. These villians of American Western films could very well be the heroes of the day.


In case you missed it:

The second report on faster than light neutrinos

Nature alienates women scientists with a tired misogynist story, plays "no harm in a joke" card

Cows may...or may not be able to sense magenetic fields

Malaria takes two hits: Genetic protection in sickle cell patients and new vaccine targets

Wednesday, November 16, 2011

Picture of the Week: Diatoms

Photo Credit: Wikimedia commons
No, these little beauties aren't crystals in a kaleidoscope. These unicellular organisms are diatoms, a diverse group of algae that normally reside in fresh and salt water, and one of my personal favorites to look at.  The rigid shapes you see are created by an outer wall made of silica, which can remain in sediment and has contributed greatly to the study of algae evolution. Currently these little guys are being studied in the nanotechnology field due to their itty bitty valve structures that could be useful for medical technologies and solar energy cells.

Monday, November 14, 2011

Tears of Joy for Diabetes Sufferers

The concept of glucose detection from human tears is nothing new. As far back as the 1950s, scientists have looked to tear fluid for the possibility of less invasive glucose monitoring. However, until now this seemed an impossibility.

According to the CDC, diabetes affects over eight percent of Americans. Those who suffer from this disease must constantly monitor their blood glucose levels at least once and sometimes multiple times a day. Currently the most reliable way to do this is to measure the levels directly by drawing blood. Using a lancet, the patient must prick his finger and place a drop of blood on a test strip to be inserted into the monitor. Pricking the finger or other parts of the hand can be very painful and can discourage patients from taking care of themselves, and it is cumbersome to carry all the necessary supplies. A tear based system would provide a less painful and more convenient alternative for diabetes sufferers. 

Although other types of monitors have been developed, none have proved reliable when compared to the invasive blood testing systems. The levels of glucose in tears, however, correlate closely to those measured in blood directly. Unfortunately, this presents a host of new challenges in device development. Because tears contain 30-50 times lower glucose concentrations, a tear glucose sensor must be able to detect very small amounts of glucose even in the presence of higher concentrations of other substances. It also must be able to accomplish this with a very small sample size, only a few microliters. This is just what scientists at the University of Michigan are attempting to create.


Capillary Tear Glucose Monitor Yan et al. Analytical Chemistry

In a study published in the November issue of Analytical Chemistry, Mark Meyerhoff and team described and tested a glucose monitor that required only four or five microliters of tear fluid. Using 12 rabbits, they compared the tear samples to blood samples collected at precisely the same time. Their results indicate that the device is not only selective for glucose in the sample, but also shows strong correlation to glucose levels of individual rabbit blood samples. Their work shows progress in the field, but several questions about marketable monitors remain. Luckily, they are not alone in this endeavor.

Since March of 2010, Jeffrey La Belle and his team at Arizona State University have published sequential studies regarding the development of another tear glucose monitor they call the TOUCH system. Their work takes into account ease of use and affordability in addition to the other requirements previously mentioned. With this work, the team wishes to develop a quick use device you could touch to the white of your eye for only five seconds and then insert into a detector. In the future, they look to improve the reproducibility of device above FDA standards and create a more user friendly version of the device.
TOUCH Glucose Sensor Lan et al. Journal of Diabetes and Technology

Tear glucose monitors could benefit the lives of millions of people.  Although they may never replace blood glucose monitors completely, they could serve as useful tools for day to day monitoring of glucose levels in a normal range. Some hurdles still remain in the road ahead. Cost of device manufacturing is crucial to success. Also, the devices will have to be able to function for those who use eye drops or wear contact lenses. Thanks to these two teams of scientists, the answers to those problems might not be far away.

Ref:

1.  Measurement of Tear Glucose Levels with Amperometric Glucose Biosensor/Capillary Tube  Configuration Qinyi Yan, Bo Peng, Gang Su, Bruce E. Cohan, Terry C. Major, and Mark E. Meyerhoff Analytical Chemistry 2011 83 (21), 8341-8346

2. Kenneth Lan, Kenyon McAferty, Pankti Shah, Erica Lieberman, Dharmendra R. Patel, Curtiss B. Cook, Jeffrey T. La Belle. (2011). A Disposable Tear Glucose Sensor- Part 3: Assessment of Enzymatic Specificity. Journal of Diabetes Science and Technology. 5(5). 1108-1115.

3. Daniel K. Bishop, Jeffrey T. La Belle, Stephen R. Vossler, Dharmendra R. Patel, and Curtiss B. Cook. (2010). A disposable tear glucose biosensor – part 1: design and concept testing. Journal Diabetes Science and Technology. 2:6, 299-306.

4. Jeffrey T. La Belle, Daniel K. Bishop, Stephen R. Vossler, Dharmendra R. Patel, and Curtiss B. Cook. (2010). A disposable tear glucose biosensor – part 2: system integration and model validation. Journal Diabetes Science and Technology. 2:6, 307-11.

Friday, November 11, 2011

Mars500 "lands," Crew pale but healthy. What you missed this week.

The fake mission to Mars at the Institute of Biomedical Problems in Moscow, Mars500, ended a week ago.  After 520 days in isolation, the six-member crew emerged from the first successful full length simulation of the journey to Mars. Family and friends waited in the wings as the hatch opened and the healthy but pale crew members were quickly whisked away for medical examinations. All were reported in peak physical and psychological shape, which bodes well for future trials.

This mission was the first of its kind to examine the possibility of a manned Martian flight. This simulation not only served to investigate the effects of long isolation periods on human health, but also served as a means to test ground-based control center operations. The facility consisted of four hermetically sealed habitat modules and a connected external module for the Mars excursion portion of the trip. The crew worked five day work weeks as astronauts, busying themselves with maintenance, science experiments, and exercises. The crew spent all but thirty days of the mission in transit to Mars or back home, stopping to explore the "Martian" surface for only a short while.

Although communications were available, emails, videos, and messages from loved ones were brought to the men on delay to mimick the real delay experienced in space. One crew member admitted that the video game Counter Strike played a hefty role in staving off boredom. However, crews on the ground kept them on their toes with malfunctions and power outages, fabrications created to look at their performance under pressure. Of course, this study leaves out many factors at play in a real mission to Mars, such as weightlessness, but plans are already in the works for future missions in orbit around the Earth. Though we may be decades away from a real Mars mission, this week we are one step closer to the Red Planet.


In case you missed it:

Rhinos are airlifted to safety, one glimmer of hope after the loss of two rhino species this week

Toxoplasmosa just got more terrifying

We got buzzed by a very large chunk of rock

Sickle-cell protection from Malaria solved


Keep on keepin' on science lovers!

Wednesday, November 9, 2011

Picture of the Week Part 2: Visual Science

Photo Credit: Carl Zimmer from the book Science Ink
I know I've already shown a picture this week, but I thought this was too beautiful to not share. At first glance you see a butterfly, but take a second look and see Darwin's finches.  Stunning.  This photo appears in a new compilation by Carl Zimmer called Science Ink, a book full of beautiful and personal dedications to science in the form of tattoo.  I recommend everyone pick up a copy! 

Tuesday, November 8, 2011

Picture of the week: Sun Spot

Photo credit: Solar Dynamics Observatory/NASA 

This sun spot, discovered by NASA's Solar Dynamics Observatory measures nearly eight times the size of Earth. Magnetic activity around sun spots cause solar flares, and X-class flares can be expected as the spot turns toward Earth.

Monday, November 7, 2011

How do bacteria rally the troops? Quorum sensing unites them with a verbose chemical language.


'E. coli GFP' photo (c) 2011, Ryan Kitko - license: http://creativecommons.org/licenses/by/2.0/
There are many languages spoken that humans are just beginning to understand. The speakers of these languages are thousands of bacteria that use tiny molecules to communicate with their brothers and their competition. Alone, a tiny bacterium can inflict little damage on its host and make little change on its environment, but with a coordinated effort they can have huge effects on their surroundings. In years past, scientists believed the simplicity of bacteria meant that they could only act randomly, with little control, but in more recent times it has become clear that microbial communication known as quorum sensing is a complicated, highly controlled process originating from early evolution.

Quorum sensing was first discovered in Vibrio fischeri, a bacterium that exists in a mutual, or symbiotic, relationship with the Hawaiian Bobtail Squid. This particular bacterium creates a luminescent compound, which the squid uses to hunt at night by hosting the bacterial colony in a specialized organ. What scientists found unusual about this relationship is that the bacteria somehow knew when to light up, just in time for the nightly hunting sessions. What they discovered was that the squid released most of the bacteria each day to allow the colony to grow anew while it slept. The bacteria only glowed when enough of them were present and by nightfall, they made light.

That is when researcher Dr. Bonnie Bassler realized they were on to something interesting. She and her team have carried this work to where it is today. Now it is known that the bacteria use small chemical compounds to notify neighbors that they exist. The system of specific chemicals to specific receptors acts like a lock and key. These types of signals are used by many types of bacteria, including those that hurt humans. Dangerous bacteria use these signals to form a coordinated attack only when enough bacteria are present that our body cannot easily destroy them.

In an April 22, 2011 publication of Molecular Cell, Bassler and collaborators altered forms of the small signaling molecule, known as an autoinducer to see how small changes affected the ability of the receptor to receive the chemical message. They found that molecules with small changes, such as having a longer tail or different chemical group at the head of the molecule, fail to create the stability needed for proper interaction with the receptor. In turn this prevents the receptor from binding DNA and making virulence factors. The researchers then reversed their thinking and created mutations on the receptor to alter binding of the autoinducer. Again, disruption of this interaction prevented the message from reaching the DNA.

In more recent work published in Bioorganic and Medicinal Chemistry, Bassler and collaborators looked at the bacteria that cause cholera. In this case, high numbers of bacteria actually turn off virulence factor creation and cause the bacteria to leave the host in unison. This exodus is responsible for the deadly symptoms of diarrhea and dehydration that make cholera such a horrible illness for humans. By creating a library of analogous small molecules to the autoinducer specific to this bacterium, the team was able to look at which structures increased or decreased the signaling potential. They were then able to map exactly which sites on the receptor were essential.

Manipulating this line of communication could improve the way we treat infection. Currently we treat bacterial infections with general antibiotics. These often work by disrupting essential functions for bacterial survival, interfering with the cell’s ability to make a solid cell wall or reproduce for instance. These antibiotics force a great amount of evolutionary pressure on the bacteria, causing the bacteria to invent ways to get around that for survival. This creates antibiotic resistance. By using a more targeted approach that prevents the bacteria from communicating, scientists could create more focused and gentle methods to treat infection without leading to resistance. Now they are speaking my language.

Ref:
 1. Megan E. Bolitho, Lark J. Perez, Matthew J. Koch, Wai-Leung Ng, Bonnie L. Bassler, Martin F. Semmelhack, Small molecule probes of the receptor binding site in the Vibrio cholerae CAI-1 quorum sensing circuit, Bioorganic & Medicinal Chemistry, Volume 19, Issue 22, 15 November 2011, Pages 6906-6918, ISSN 0968-0896, 10.1016/j.bmc.2011.09.021.

2. Guozhou Chen, Lee R. Swem, Danielle L. Swem, Devin L. Stauff, Colleen T. O'Loughlin, Philip D. Jeffrey, Bonnie L. Bassler, Frederick M. Hughson, A Strategy for Antagonizing Quorum Sensing, Molecular Cell, Volume 42, Issue 2, 22 April 2011, Pages 199-209, ISSN 1097-2765, 10.1016/j.molcel.2011.04.003.