Malaria, tuberculosis caused death on the ancient Nile



Southwest of Cairo, the Nile branches into a network of canals that feed Fayum, a fertile agricultural basin that was a center of civilization and royal pyramid-building for several centuries. The unusual geology responsible for Fayum’s rich terrain may have also led to the prevalence of malaria and tuberculosis in the region during these ancient times.

Ancient DNA (aDNA) from sixteen mummified heads recovered from the region reveals that at least four of these individuals suffered both these infections simultaneously. Many of the others showed signs of infection with either malaria or tuberculosis, as scientists report in a recent PLOS ONE study.

DNA extracted from muscle tissue samples was tested for the presence of two genes specific to Plasmodium falciparum, the malarial parasite, and another gene specific to Mycobacteria, which cause tuberculosis. Two samples tested positive for DNA specific to Plasmodium, one tested positive for the mycobacterial gene, and four individuals tested positive for DNA from both infectious agents, suggesting they suffered both infections together while alive. A previous study suggests that both malaria and tuberculosis were rampant in the Fayum region in the early 19th century, but the age of these mummified samples extends evidence of these diseases in Lower Egypt as far back as approximately 800 B.C.

The World Health Organization estimates that malaria is almost non-existent in the Fayum basin and the rest of Egypt now, but before its eradication, high levels of infection were seen in certain parts of the country, and were strongly linked to certain geological features. The lakes and canals that made the Fayum region so fertile also served as breeding grounds for the mosquito that carries the malarial parasite.

The heads tested here (all were missing bodies) were recovered from a village cemetery on the west bank of the lower Nile, and date from about 1064 BC to 300 AD, a period marked by an agricultural boom and dense crowding in the region, especially under the rule of the Ptolemies. These conditions may have increased the chances of tuberculosis incidence and spread of the disease. As the aDNA from these mummified heads attests, these living conditions and the unique irrigation of the Fayum basin likely created a harbor for both malaria and tuberculosis in ancient populations of this region.

Citation: Lalremruata A, Ball M, Bianucci R, Welte B, Nerlich AG, et al. (2013) Molecular Identification of Falciparum Malaria and Human Tuberculosis Co-Infections in Mummies from the Fayum Depression (Lower Egypt). PLoS ONE 8(4): e60307. doi:10.1371/journal.pone.0060307

Image: Sailing on the Nile by David Corcoran

Moms and babies respond to childbirth with different stress hormones


A quick internet search reveals that many women rank giving birth as one of the most painful human experiences. Though pain can be hard to quantify objectively, the physiological stress of childbirth is clinically assessed by measuring blood levels of the stress hormone cortisol.

Cortisol is currently used to estimate the stress experienced by both mother and child during the process of giving birth, but recently published PLOS ONE research suggests that a different stress hormone, corticosterone, may be a more accurate way to measure the stress experienced by healthy, full-term babies.

For their study, researchers tested fetal levels of cortisol and corticosterone in 265 samples of umbilical cord blood from healthy deliveries. Though the total levels of cortisol detected were higher than corticosterone levels, fetuses produced the latter at a greater rate in response to the stress of labor and delivery. Newborns secreted more corticosterone when a Caesarian section was performed due to complications during labor than they did after a normal C-section. Fetal corticosterone levels were also higher after passage through the birth canal. These differences were not seen in levels of cortisol production. Based on these data, the authors suggest that the full-term fetus is more likely to secrete corticosterone than cortisol in response to stress and hence, corticosterone may be a more accurate clinical biomarker to assess fetal stress.

Corticosterone isn’t unheard of in the adult world, as adults continue to make the hormone throughout our lives, though in a much smaller proportion relative to cortisol. When babies switch to producing more cortisol rather than corticosterone isn’t yet clear, but the developmental changes involved may help track or diagnose adrenal gland functions in newborns.

Citation: Wynne-Edwards KE, Edwards HE, Hancock TM (2013) The Human Fetus Preferentially Secretes Corticosterone, Rather than Cortisol, in Response to Intra-Partum Stressors. PLoS ONE 8(6): e63684. doi:10.1371/journal.pone.0063684

Image: stress by topgold

Pristine Fossil Reveals Unlikely Pair

Fernandez_Fig1 mediumThe small but sharp-toothed Thrinaxodon probably spent much of its time dining on its Triassic cohabitants, but a study published today reports a pristine fossil of the meat-eater apparently peacefully sharing its burrow with a small amphibian – until they were both buried in a flood.

The researchers uncovered the odd couple through non-destructive imaging 0f a burrow cast from South Africa, where the animals appeared to have died together. In the image of the cast itself, along with the ghostly outlinescast of the animal skeletons you can see that layer 1 is the original bed of the burrow, and layers 2 and 3 correspond to subsequent “pulses” of the flooding event.

The two skeletons are remarkably complete and well-preserved (in the image above Thrinaxodon is shown in brown, and the amphibian in grey), and the artifact provides an excellent opportunity to study the interactions between two different species. Given Thrinaxodon‘s carnivorous ways, it may at first seem most likely that the amphibian was about to be eaten for lunch, but its undisturbed skeleton and lack of expected bite marks rule out this possibility, the authors write. They also conclude that the flood responsible for burying the animals couldn’t have randomly washed the amphibian into the burrow once the animals were already dead because the burrow’s opening was too small.

To find the most likely answer, the researchers turned to modern creatures for insight. They note that animals today will live in a burrow built by another species if it is abandoned, if they can chase away the host, or if the host tolerates their presence. The Thrinaxodon was still in the den, so neither of the first two possibilities seem to apply in this case, leaving the last option as the most likely. As strange as it may seem, it appears that for whatever reason the Thrinaxodon graciously tolerated its amphibian partner’s presence.

If you want to see more, this video shows how the authors virtually dissected the burrow using synchrotron scanning to create an exquisitely detailed reconstruction of the burrow’s contents without cracking it open.

Citation: Fernandez V, Abdala F, Carlson KJ, Cook DC, Rubidge BS, et al. (2013) Synchrotron Reveals Early Triassic Odd Couple: Injured Amphibian and Aestivating Therapsid Share Burrow. PLoS ONE 8(6): e64978. doi:10.1371/journal.pone.0064978 

Exploring multiple facets of modern men’s health

2695540485_7fed1903e5_zJune is Men’s Health Month! This is a time to bring awareness to preventable health issues and encourage early detection of diseases affecting men. As we wind down from celebrating Father’s Day this past weekend, here are a few articles focusing on some important men’s health issues.

Lowering salt intake helps alleviate a number of health concerns, such as decreasing the risk of heart disease, stroke and stomach cancer. However, how easy is it to reduce your sodium intake without compromising taste, or your wallet?  In a recent study, researchers sought to determine how feasible a low-sodium, inexpensive and nutritious meal for men could be. The authors used cost and nutritional data to model and optimize familiar diets. In this analysis, they showed that it is possible to decrease sodium levels to well below the recommended maximum, proving that nutrition does not need to be compromised when preparing an enjoyable low-cost meal.

So what should men be consuming to help with disease prevention? Olive plant leaves (Olea europaea L.) have been used in traditional medicine to treat diabetes for centuries. In a PLOS ONE clinical trial published this year, researchers investigated the effects of olive polyphenols on insulin balance.  In this study, 46 male participants received either capsules of olive leaf extract or a placebo for 12 weeks.  Through their observations, the researchers found that olive leaf extract significantly improved two factors related to Type 2 Diabetes (insulin sensitivity and pancreatic ?-cell secretory capacity) in overweight, middle-aged men.

What about prostate health, you might ask? The Prostate Specific Antigen test, along with digital rectal examination is widely used for prostate cancer screening. PSA, which stands for Prostate Specific Antigen, is a glycoprotein secreted by epithelial cells of the prostate gland, and individuals with prostate cancer have a higher than normal amount of this compound in their systems. PSA levels can also change in response to external factors like surgery, though, so understanding these other forces is crucial for the test to be effective.  In a recent study, authors investigated whether bike riding affects PSA concentration in men. The researchers took blood samples from 129 male participants 60 minutes before a bike ride and 5 minutes after completion. They found that cycling caused their PSA to increase an average of 9.5% when measured within 5 minutes after completing the ride. Based on these findings, the authors suggest a 24–48 hour period of abstinence from cycling before a PSA test to avoid any false positive results.

These articles are just a taste of the published articles touching on men’s health; for more research visit PLOS ONE here.



Wilson N, Nghiem N, Foster RH (2013) The Feasibility of Achieving Low-Sodium Intake in Diets That Are Also Nutritious, Low-Cost, and Have Familiar Meal Components. PLoS ONE 8(3): e58539. doi:10.1371/journal.pone.0058539

de Bock M, Derraik JGB, Brennan CM, Biggs JB, Morgan PE, et al. (2013) Olive (Olea europaea L.) Leaf Polyphenols Improve Insulin Sensitivity in Middle-Aged Overweight Men: A Randomized, Placebo-Controlled, Crossover Trial. PLoS ONE 8(3): e57622. doi:10.1371/journal.pone.0057622

Mejak SL, Bayliss J, Hanks SD (2013) Long Distance Bicycle Riding Causes Prostate-Specific Antigen to Increase in Men Aged 50 Years and Over. PLoS ONE 8(2): e56030. doi:10.1371/journal.pone.0056030

 Image Credit: on Flickr by Lindz Graham

Hairy, Sticky Leg Pads are In: How Different Spiders Hunt


Spiders are everywhere (Arachnophobes, stop reading now). They’re among the most successful predators on earth today and colonize nearly every terrestrial habitat (that is, not just ceiling corners and under beds), and occasionally do so in numbers large enough to take over small islands. Spider silk may be strong enough to stop a speeding train and some webs, ten times stronger than Kevlar, can be large enough to cross rivers in tropical rainforests.

But more than half of today’s spider species don’t rely on webs or silk to capture their prey. Instead, these hunting spiders have evolved hairy adhesive pads on their legs to grab and hold struggling prey down, according to the results of a recently published PLOS ONE study. The adhesive pads, called scopulae, were commonly seen in many spider species but what wasn’t clear until now was whether they were found in all species, or more likely to occur in hunting spiders.

scopulaeIn this study, researchers used a phylogenetic analysis of spider family trees to correlate different species’ prey capture strategies with the presence or absence of adhesive pads on their legs. They found that the majority of spiders were either web builders or free-ranging hunters, and the latter were most often found to have adhesive hairs on their legs (Apart from these two, at least one rare variety may be mostly vegetarian). Nearly 83% of hunting spiders had adhesive bristles on their legs (compared with 1.1% of web-building varieties). Most of these hunters had either not developed silk-dependent strategies to capture prey, or abandoned web-building for hunting.

Spider Web on PlantWhy would so many spiders abandon an obviously successful way to catch prey? Web-building is a useful way to trap insects and some small mammals, but even to a spider, silk is expensive. Creating a web requires work, damages caused by prey or people need frequent repairs, and certain kinds of webs can require large amounts of silk to be effective. The classic orb-web (seen in the picture here) radically reduced these costs, which may be why the spiders that make these are particularly common. However, this new study reveals that hunting has proved at least as successful a strategy as web-building to more than half of today’s spiders.

Bristly scopulae on hunting spiders’ legs have played a big part in this, enabling spiders to grasp and hold on to struggling prey. The thin bristles on scopulae come in many shapes and forms, and also contribute to these spiders’ mad climbing skills. Read more about which spiders evolved these bristles or learn about other arachnid research published in PLOS ONE here.


Citations: Gregori? M, Agnarsson I, Blackledge TA, Kuntner M (2011) How Did the Spider Cross the River? Behavioral Adaptations for River-Bridging Webs in Caerostris darwini (Araneae: Araneidae). PLoS ONE 6(10): e26847. doi:10.1371/journal.pone.0026847

Rogers H, Hille Ris Lambers J, Miller R, Tewksbury JJ (2012) ‘Natural experiment’ Demonstrates Top-Down Control of Spiders by Birds on a Landscape Level. PLoS ONE 7(9): e43446. doi:10.1371/journal.pone.0043446

Wolff JO, Nentwig W, Gorb SN (2013) The Great Silk Alternative: Multiple Co-Evolution of Web Loss and Sticky Hairs in Spiders. PLoS ONE 8(5): e62682. doi:10.1371/journal.pone.0062682

Nyffeler M, Knörnschild M (2013) Bat Predation by Spiders. PLoS ONE 8(3): e58120. doi:10.1371/journal.pone.0058120

Images: Foot of the little jumping spider Euophrys frontalis, credit Jonas Wolffvaried shapes and sizes of bristles on scopulae from pone.0062682spider web on plant by mikebaird

Opportunistic pathogens evolve mostly harmlessly in healthy humans


Humans interact with bacteria almost every minute of our lives. Of the millions of these interactions, only a handful result in disease, and some bacteria only cause infections under certain conditions. In a recent PLOS ONE study, researchers probe these healthy human-bacterial relations  in one particularly notorious pathogen as it spends the majority of its time in our bodies, doing no harm.

Staphylococcus aureus can cause endocarditis, toxic shock syndrome and other diseases, killing approximately 1 in 100,000 infected people in the US each year. Strains like MRSA have also evolved to carry multiple antibiotic resistance genes, making infections extremely difficult to treat. If human-bacterial interactions are to be described as a ‘genetic arms race’, it may be tempting to cast S. aureus as an enemy that carries every available genetic weapon.

Yet despite a few sporadic skirmishes, the majority of our interactions remain peaceful, as these bacteria thrive in healthy human hosts.  In fact, about a third of healthy adults carry S. aureus in our noses at some point in our lives.  In the article, researchers analyzed the genetic changes in S. aureus carried in such hosts by sequencing the genomes of 130 strains of S. aureus from the nasal passages of 13 healthy adults, five of whom carried strains of MRSA (which is often harmless when carried nasally). Despite the arms race metaphors, they found that S. aureus strains in healthy hosts are not incessantly beefing up their genetic arsenal of antibiotic resistance or pathogenesis genes.

They found bacterial genomes were changed by processes of ‘micro-mutation’, i.e.: small bits of genetic material being added or removed, or changes in a single letter in the genetic code. Large insertions and deletions (macro-mutation) were also common, as were changes caused by bacteria-infecting viruses or small, independently moving rings of DNA called plasmids. Overall, the constant changes in S. aureus genomes were geared toward keeping bacterial genomes healthy by clearing erroneous or harmful mutations. Only on rare occasions did these bacteria acquire distinctive surface proteins or an enterotoxin that could alter their pathogenic potential. In addition, their research also analyzed changes in specific genes used to assess bacterial diversity and relatedness, and developed a new method to detect transmission of bacterial strains among human carriers. Read the full study to learn more about these interesting results.

Many of the changes identified in this study may not directly increase the virulence of disease-causing S. aureus. However, previous work by these researchers demonstrated that mutations arising in bacteria carried by healthy hosts may play an important role in tipping the balance between human health and disease. Here, the authors begin to paint a picture of what these mutations are and how they may occur.

Citation: Golubchik T, Batty EM, Miller RR, Farr H, Young BC, et al. (2013) Within-Host Evolution of Staphylococcus aureus during Asymptomatic Carriage. PLoS ONE 8(5): e61319. doi:10.1371/journal.pone.0061319

Image: Scanning electron micrograph of S.aureus with increased resistance to vancomycin. Credit CDC/ Matthew J. Arduino, DRPH


Color and Iridescence in the Stinkbug

fabricant figure 1 pone.0064082

“Beautiful” may not be the first word to describe the stinkbug, but Tectocoris diopthalamus sure are pretty. Pictured above are six specimens, three females (first row) and three males (second row). Do you notice a difference? Hint: it’s all in the colors.

Like mallards, narwhals, and peacocks, T. diopthalamus are sexually dimorphic, meaning that the females and males of the species look physically different. In a new study published last week in PLOS ONE, researchers state that male stinkbugs of this species are more likely than their female counterparts to have large, iridescent patches and to be a deeper shade of red. These eye-catching characteristics may help males attract females and even scare off predators. The colors are variable, however, and subject to a number of environmental factors.

In the study, the researchers used electron microscopy and pigment analysis to study how this stinkbug produces the colors you see above. They identified a type of melanin, which partly make up the blue-green iridescent patches. They also identified a nitrogen-heavy pigment called erythopterin, which produces the orange-red color.  High temperatures and a shortage of nitrogen-rich foods have the potential to affect these respective pigments and lead to a wide range of colorful variations. Neat!


Citation: Fabricant SA, Kemp DJ, Krají?ek J, Bosáková Z, Herberstein ME (2013) Mechanisms of Color Production in a Highly Variable Shield-Back Stinkbug, Tectocoris diopthalmus (Heteroptera: Scutelleridae), and Why It Matters. PLoS ONE 8(5): e64082. doi:10.1371/journal.pone.0064082

Image: Image comes from Figure 1 of the research paper.

Tracing Our Footsteps: Archaeology in the Digital Age

pone.0060755 Geocon Bennett et al Figure 6

Human ancestors that walked the earth left few traces of their passage. Some of their footprints have lithified, or turned to stone, but some survive to this day, unlithified, in soft sediment such as silt. These fragile records of ancient footprints pose a sizable challenge to archaeologists today: how do you preserve the ephemeral? According to new research published in PLOS ONE, the answer may be to “record and digitally rescue” these footprint sites.

The authors explored two methods in this study: digital photogrammetry, where researchers strategically photograph an object in order to derive measurements; and optical laser scanning, where light is used to measure the object’s physical properties. To begin, the authors filled trays with mixtures of sand, cement, and plaster and instructed a participant to walk through these samples. Four wooden 1 cm cubes were then placed beside a select number of footprints and photographs were taken. A laser scanner was then used to measure the same footprints. This simple procedure was also replicated outside of the lab, at a beach in North West England.

In their results, they found that both methods offered similar levels of precision (though, the laser scanner was “slightly more accurate”) and that differences between the two were not statistically significant. These two methods are not, however, without their respective strengths and challenges. Photogrammetry can be an advantage in situations where records need to be taken quickly and inexpensively, as field work can be completing using a camera, tripod, and measuring equipment. This practice is, however, especially subject to human error. Additionally, the accuracy of the images – and consequently the measurements derived from the images – may be compromised by extreme lighting conditions and the depth of the footprint or impression. Alternately, laser scanning is more appropriate in conditions where a high degree of precision is required and footprints are more fragile (and thus unlikely to remain in an “optimal” condition). Laser scanners are, however, more expensive and require a large energy source. The authors advocate that both methods can, and should, be used in tandem to supplement each other.

These digital tools provide an innovative solution to preserving footprint records, especially in cases where traditional on-site, or off-site, preservation is impractical and costly. To learn more about this research and the merits and challenges of digital rescue archaeology, read the full text of the study here.


Image is Figure 6 of the manuscript.

Citation: Bennett MR, Falkingham P, Morse SA, Bates K, Crompton RH (2013) Preserving the Impossible: Conservation of Soft-Sediment Hominin Footprint Sites and Strategies for Three-Dimensional Digital Data Capture. PLoS ONE 8(4): e60755. doi:10.1371/journal.pone.0060755

Science for Marathon Monday

Update: On Monday afternoon at 2:56pm, two explosions occurred near the finish line of the Boston Marathon. In light of these events, PLOS ONE would like to express our deepest sympathies for the victims and families affected by this tragedy.


Still procrastinating on those tax returns? If you have finally filed and are looking to blow off some steam, maybe a 26.2 mile run will do the trick! Today on April 15th, over 27 thousand people will lace up their sneakers, warm up their muscles and prepare for one of the world’s oldest races, the Boston Marathon.

Vasque Mindbenders after a muddy trail run in the hills of Griffith Park.  (c) 2011 Geoff CordnerThe very first Boston Marathon was held in 1897 and was then known as the B.A.A. Road Race. Originally 24.5 miles in length, the race was extended to 26.2 miles in 1924 to conform to the Olympic standard. Since that first race day which featured 15 runners, the marathon has grown immensely, with 26 thousand people participating last year.

In honor of the 117th marathon or whatever race you may be running today, here are some recently published articles featuring the sport:

In a paper published this February, researchers have determined the cause of runners fatigue during a marathon in warm weather. These authors recruited 40 amateur runners to test their fatigue and measure their pace during the race. Through their analysis, the authors found that participants who felt the greatest fatigue had elevated levels of blood markers of muscle breakdown. There is still further research to be done to find if this muscle damage is due to mechanistic or metabolic factors.

But what effect does warm weather have on a marathon? In another recent article, authors investigated whether climate change has affected the winning times of the Boston Marathon.  The authors found the temperatures between 1933 and 2004 did not consistently slow winning times on race day. However, the analysis also indicated that if temperatures warmed by 0.058°C a year, we would have a 95% chance of detecting a slowing of winning marathon times by 2100. And if average race day temperatures had warmed by 0.028°C a year (a mid-range estimate) we would have a 64% chance of detecting a decline in winning timings by 2100.

This analysis gives us some insight on how running may change in the future, but have you ever wondered what the sport was like 30,000 years ago? Unlike current shoe wearing athletes, our ancestors were barefoot runners and so are other modern human populations, including the Daasanach. In an article published this year, researchers have investigated the foot strike patterns among barefoot runners in northern Kenya. Data was collected from 38 adults, who ran at their own speed and distance. The authors found that not all the barefoot runners landed on their fore- or mid foot, but the majority landed on their heels first. This observation dismisses the original hypothesis that the barefoot runners would land on the fore-or mid foot, and suggests that there may be a number of other factors which influence foot strike patterns.

Whether you are ready to take your mark, or getting set to file those taxes, visit our site here for more papers on the topic.



Citation: Del Coso J, Fernández D, Abián-Vicen J, Salinero JJ, González-Millán C, et al. (2013) Running Pace Decrease during a Marathon Is Positively Related to Blood Markers of Muscle Damage. PLoS ONE 8(2): e57602. doi:10.1371/journal.pone.0057602

Citation: Miller-Rushing AJ, Primack RB, Phillips N, Kaufmann RK (2012) Effects of Warming Temperatures on Winning Times in the Boston Marathon. PLoS ONE 7(9): e43579. doi:10.1371/journal.pone.0043579

Citation: Hatala KG, Dingwall HL, Wunderlich RE, Richmond BG (2013) Variation in Foot Strike Patterns during Running among Habitually Barefoot Populations. PLoS ONE 8(1): e52548. doi:10.1371/journal.pone.0052548

Image: on Flickr by geoff cordner

Attention All Procrastinators: There’s Research to Help!


It’s the twelfth of April and the clock is ticking on your tax return. For those of you who haven’t filed, we’ve assembled a few PLOS ONE papers to help get you back on track.

If you’ve pulled up your W-2s, but are tempted to stray why not read this study?  Aptly titled “Lead Me Not into Temptation: Using Cognitive Reappraisal to Reduce Goal Inconsistent Behavior”, this PLOS ONE paper suggests that simply thinking about a task in a different way can improve performance. The researchers instructed study participants to complete a set of simple tasks on the computer. Unbeknownst to the participants, a set of tempting, or distracting, obstacles were embedded in the task. The control group followed the same instructions for the first and second set of tasks. Meanwhile, the test group was told that the second task “aim[ed] to assess your willpower”.

Researchers found that reinterpreting the given task in a different way affected the participants’ performance. Reappraisal helped participants increase the importance of the goal (e.g., proving they had willpower) and decrease the importance of the temptation. Consequently, members of the test group spent less time distracted and derived less pleasure from the temptation than their counterparts in the control group.

In another PLOS ONE study, researchers examined the relationship between physical fitness, as measured by heart rate variability and cognitive performance. Individuals who were recruited underwent physical testing and were divided into high-fit and low-fit groups.  The researchers asked both groups to perform three cognitive tests that measured response time and various types of attention. They found that participants in the high-fit group performed distinctly better than their low-fit counterparts in the first cognitive task, which measured sustained attention.

For those of you who have tried going to the gym and reappraising the taxing task at hand, we’ve found another study that may help you beat procrastination. All you need to do is focus on this:

According to research published last year, viewing kawaii (a Japanese word for cute) images may affect behavior and increase focus. Participants in this study were asked to look at images of baby animals, adult animals, or neutral objects (e.g., food). Researchers then gave participants tasks to complete, such as use tweezers to remove small objects from holes or search for a specific number in a number grid, and assessed their performance. Their results indicate that individuals who looked at cute images prior to the task tended to perform better in tasks that require carefulness.

Procrastinators everywhere, there’s hope – and time – yet! If this science hasn’t convinced you to get back to the task at hand, read more PLOS ONE research about motivation, goals, and reward here.


Leroy V, Grégoire J, Magen E, Gross JJ, Mikolajczak M (2012) Lead Me Not into Temptation: Using Cognitive Reappraisal to Reduce Goal Inconsistent Behavior. PLoS ONE 7(7): e39493. doi:10.1371/journal.pone.0039493

Luque-Casado A, Zabala M, Morales E, Mateo-March M, Sanabria D (2013) Cognitive Performance and Heart Rate Variability: The Influence of Fitness Level. PLoS ONE 8(2): e56935. doi:10.1371/journal.pone.0056935

Nittono H, Fukushima M, Yano A, Moriya H (2012) The Power of Kawaii: Viewing Cute Images Promotes a Careful Behavior and Narrows Attentional Focus. PLoS ONE 7(9): e46362. doi:10.1371/journal.pone.0046362


Procrastination – A1, by LadyDayDream.

Make Room for Me!, by Kimberly Tamkun / USFWS Mountain Prairie.

PLOS ONE goes to Washington D.C. for AACR. Come visit us!

PONE-D-12-27359R1Next week PLOS ONE will join PLOS Biology at the American Association for Cancer Research Annual Meeting.  This meeting will highlight the latest findings in all major areas of cancer research and as a journal that has published thousands of papers on cancer research – the PLOS ONE team is very excited to attend the event.

If you are an author, reviewer, editor, or just curious about PLOS ONE; we encourage you to stop by the PLOS booth (booth #544) between April 7th – April 10th.

Academic Editors: On April 9th, we will be hosting a Meet & Greet from 12:00-1:30 pm at the PLOS booth #544. Please stop by to say hi and to meet your fellow editors, as well as, ONE staff.

Authors:   Find out who has cited your work, how many people are using it in their Mendeley library, and the number of times your pdf has been downloaded (among many other things). Let us demonstrate our article level metrics in exchange for a free t-shirt.

For more information: Check out PLOS Biology’s post on Biologue: PLOS Biology – open for cancer research.  In addition, the PLOS Bio team has assembled a special AACR Collection. These articles cover various aspects of cancer biology published by the journal over the last few years.

Interested in reading cancer research published by PLOS ONE before the conference?  Click here for a list of over 5,000 research articles on the topic.

We hope to see you there!

Image Credit: Figure from Chang H-Y, Shih M-H, Huang H-C, Tsai S-R, Juan H-F, et al. (2013) Middle Infrared Radiation Induces G2/M Cell Cycle Arrest in A549 Lung Cancer Cells. PLoS ONE 8(1): e54117. doi:10.1371/journal.pone.0054117

March Madness: PLOS ONE News and Blog Round-Up

1660014877_10c78dd1a9For the month of March, a variety of papers caught the media’s attention, from distracting cell phone conversations, to the devastating decline in forest elephants.  Here are some of the media highlights for this month:

Have you ever wondered where your hound originated from? In a paper featured this March, researchers have identified the fossil remains of the oldest domestic canine ancestor. In this study, researchers analyzed the DNA of a 33,000 year old tooth belonging to a Pleistocene dog from central Asia. In their evaluation of the fossil, they assessed its relationship to modern dogs and wolves’, concluding the tooth was more closely related to the domestic canine.

In another study, researchers at the Cleveland Clinic have found that football players might sustain long-term brain injuries without ever having a concussion. 67 players who had never suffered a concussion underwent testing over the course of a season.  The testing, which included blood sampling, brain scans, cognitive and functional assessments, screened for potential brain damage among the participants. The researchers searched for S100B in the blood, an antibody linked to brain damage. This antibody was found in many of the participants, with the highest levels belonging to the players with the most hits.

Have you ever found yourself distracted when a co-worker is on a phone call? In an eye-catching paper published this month, PLOS ONE authors examined the effects on attention and memory when listening to cell phone conversations, versus two-sided conversations. The participants were assigned a task while two conversations were in progress, one on a cell phone, and another between two individuals.  After the task was completed, the participants were assigned a recognition memory task and questionnaire measuring the distracting nature of the conversation. The participants who overhead the cell phone conversation measured it as much more distracting compared to the two-sided conversation.

And in a fourth study capturing the attention of many, researchers have examined the decline of forest elephants in Central Africa. The study concludes that forest elephants are being poached at increasing rates. Poaching, in addition to the human population rise and the absence of anti-poaching law enforcement, is contributing to the elephant’s population decline. The analysis revealed that 62 percent of the African forest elephants have been eliminated in the last decade due to poaching.

These four papers are just a taste of the variety of papers published this month. For more research headlines, visit our site here.



Druzhkova AS, Thalmann O, Trifonov VA, Leonard JA, Vorobieva NV, et al. (2013) Ancient DNA Analysis Affirms the Canid from Altai as a Primitive Dog. PLoS ONE 8(3): e57754. doi:10.1371/journal.pone.0057754

Marchi N, Bazarian JJ, Puvenna V, Janigro M, Ghosh C, et al. (2013) Consequences of Repeated Blood-Brain Barrier Disruption in Football Players. PLoS ONE 8(3): e56805. doi:10.1371/journal.pone.0056805

Galván VV, Vessal RS, Golley MT (2013) The Effects of Cell Phone Conversations on the Attention and Memory of Bystanders. PLoS ONE 8(3): e58579. doi:10.1371/journal.pone.0058579

Maisels F, Strindberg S, Blake S, Wittemyer G, Hart J, et al. (2013) Devastating Decline of Forest Elephants in Central Africa. PLoS ONE 8(3): e59469. doi:10.1371/journal.pone.0059469

Image: by digitalART2 on Flickr

What are you in the mood for?: Emotional trends in 20th century books

Literary trends come and go; one year’s vampire is another year’s zombie. According to new research published today in PLOS ONE, certain moods also experience trends in literature. Which moods, or emotions, do you think were popular in the literature of the 20th century?

To find out, researchers created six categories of words to express anger, disgust, fear, joy, sadness and surprise. These terms were pared down to word stems and then entered into Google’s Ngram Viewer, an immense and interactive database of over 5 million books. The researchers looked at all English language books in Google’s database that were published between 1900 and 2000. Three additional datasets were created to analyze the use of mood words in English fiction (i.e., all books written in British and American English, excluding all works of non-fiction), British English books, and American English books.

Their data indicates that the use of mood words generally decreased in books published in the 20th century. Curiously, the use of words relating to disgust declined the most. The use of fear-related words similarly decreased until the 1970s, when the trend took a sharp turn upwards (and continued to climb for the next three decades). When they plotted the frequency of words relating to joy and sadness, the trend of happy and sad words correlated to major historical events such as World War II and the Great Depression.

In their comparison of books written in British and American English, researchers noted that the frequency of mood words in American English books increased relative to British English books beginning in the 1960s. This trend continued throughout the latter portion of the century, even as the use of mood words generally decreased.

For students of cultural and linguistic evolution, these massive, text-based datasets may present a new way of analyzing trends over a great period of time. For others, they can simply provide a fresh perspective on the previous century!

To learn more and share your thoughts about the study, click here to read the full article. If you are interested in similar studies, click here to read the authors’ research on word usage in climate change science and and here for the accompanying New York Times op-ed.



Acerbi A, Lampos V, Garnett P, Bentley RA (2013) The Expression of Emotions in 20th Century Books. PLoS ONE 8(3): e59030. doi:10.1371/journal.pone.0059030


books is power, by the second fiddle

The graph comes from Figure 2 of the manuscript.

Meet Vectidraco, a European pterosaur the size of a crow

Fossil records show that pterosaurs of all sizes and shapes flew through the skies of China and Central Asia about 145 to 66 million years ago. A new species of small pterosaurs described in a PLOS ONE paper reveals that western Europe may have had a similar diversity of these ancient animals. Author Darren Naish discusses the importance of the new species, named Vectidraco.

How did you begin studying dinosaurs (or pterosaurs in particular)?

Most of my research is and has been based on the Lower Cretaceous fossils that come from the Isle of Wight and elsewhere  in southern England. The rocks here are famous for their dinosaurs, but fossil crocodilians, marine reptiles like plesiosaurs and rare pterosaurs are found here too. I’ve always been interested in pterosaurs and for several years have had a special research interest in a highly peculiar pterosaur group called the azhdarchoids – I’ve been working continuously on this group since 2007 or so and have been especially interested in their ecology, functional anatomy and evolutionary relationships. The finding of a new azhdarchoid in the Lower Cretaceous rocks of the Isle of Wight thus combined several of my special interests.

Where and how did you find the new fossil described in your study?

Most Cretaceous Isle of Wight fossils come from a rock unit termed the Wealden Supergroup. The new specimen – we’ve called it Vectidraco – is from a different, younger unit called the Atherfield Clay Formation, and as such it’s (so far as we know) only the second pterosaur reported from this unit.

I should say that the discovery of Vectidraco itself is interesting in that the find was made by a young girl, Daisy Morris (aged just 5 at the time!), while she was on holiday with her family. Daisy’s family wanted this fossil to be studied and cared for properly, so they did what I and many of my colleagues would say is “the right thing” and donated it to The Natural History Museum in London. So, we only know of Vectidraco thanks to Daisy: for this reason we named it in her honour. It’s full name is Vectidraco daisymorrisae.

What was previously known about this group of flying reptiles, the azhdarchoid pterosaurs?

So far as we know right now, azhdarchoids are unique to the Cretaceous period (that is, they were alive between about 145 and 66 million years ago) and all were toothless. They’re actually a pretty diverse group of pterosaurs, with some – like the tapejarids – being relatively small, withwingspans of about 3 feet or slightly less and others – namely the azhdarchids – being gigantic, withwingspans of more than 32 feet.

Tapejarids have short, deep snouts while azhdarchids have incredibly long, pointed jaws, and other kinds of azhdarchoid were intermediate between these two groups. Particularly good azhdarchoid fossils are known from South and North America and China, but their remains have been found right across Europe, Asia and Africa too.

Working out what azhdarchoids did when they were alive has been one of the great questions about the group, but it seems that they were mostly omnivores or carnivores that lived in terrestrial environments.

The paper describes the new fossil as “small-bodied”. How much larger are other known pterosaurs of this kind usually?

Azhdarchoids span a diversity of species that range from ‘small-bodied’ all the way up to gigantic. The biggest kinds –  like the famous Quetzalcoatlus from Texas – were something like 10 feettall at the shoulder and over 450 pounds heavy while small ones, and Vectidraco is one of them, had wingspans of just 30 inches or so and would have been similar in size to crows or gulls. I would say that Vectidraco belonged to an azhdarchoid group where small size was normal and widespread, with large and even giant size evolving in other azhdarchoid lineages.

How did you determine that the new fossil belonged to the same group as these other specimens?

Vectidraco is known only from its pelvis, but even with only a pelvis to go on, we could see several features of the new specimen that made it especially azhdarchoid-like, mostly to do with the weird anatomy of the big, T-shaped bony structure that projects upwards and backwards from the rear part of the pelvis. In an effort to better test the idea that Vectidraco is an azhdarchoid, we included it in a few different phylogenetic analyses and it came out as an azhdarchoid in these too. It also has several unique features, not seen in any other pterosaurs, and for these reasons we were able to name it as a new species.

How does this discovery change what we know about this group of pterosaurs?

We’ve known for a while that small-bodied azhdarchoids lived in western Europe during the Early Cretaceous: a new species called Europejara olcadesorum was described in PLOS ONE last year. Now we’ve found that Vectidraco lived in the same region during the same period, so we’re seeing a pattern: small-bodied azhdarchoids were living alongside longer-snouted, small-bodied pterosaurs and also alongside large, toothy kinds called ornithocheiroids.

This is essentially the same kind of pterosaur community that we  see in Chinese rocks of the same age – the great difference is that the Chinese fossils are relatively numerous, and frequently preserved as complete or near-complete skeletons. In fact, one of the things that we comment on in our paper is the fact that western Europe’s pterosaur assemblage looks far less rich than that of China due to differences in the way these fossils were preserved. Chinese pterosaur and small dinosaur fossils were buried rapidly by volcanic ash and hence preserved whole, while those of western Europe were usually broken apart on floodplains, extensively scavenged, and eventually preserved in fragmentary form.

The western European and Chinese assemblages might actually have contained similar sorts of species, but the conditions local to both places meant that their fossil records ended up being very different.

Read more about this exciting new fossil at Darren Naish’s own blog, Tetrapod Zoology.

Citation: Naish D, Simpson M, Dyke G (2013) A New Small-Bodied Azhdarchoid Pterosaur from the Lower Cretaceous of England and Its Implications for
Pterosaur Anatomy, Diversity and Phylogeny. PLoS ONE 8(3): e58451. doi:10.1371/journal.pone.0058451

Vullo R, Marugán-Lobón J, Kellner AWA, Buscalioni AD, Gomez B, et al. (2012) A New Crested Pterosaur from the Early Cretaceous of Spain: The First European Tapejarid (Pterodactyloidea: Azhdarchoidea). PLoS ONE 7(7): e38900. doi:10.1371/journal.pone.0038900

Images: Specimen and speculative reconstruction of Vectidraco from 10.1371/journal.pone.0058451, Life restoration of the head of Europejara from 10.1371/journal.pone.0038900

Marine microbes make musical waves

Music may be the newest addition to a science communicator’s toolbox. A PLOS ONE paper published today describes an algorithm that represents terabytes of microbial and environmental data in tunes that sound remarkably like modern jazz.

Microbial bebop”, as the authors describe it, is created using five years’ worth of consecutive measurements of ocean microbial life and environmental factors like temperature, dissolved salts and chlorophyll concentrations. These diverse, extensive data are only a subset of what scientists have been recording at the Western Channel Observatory since 1903.

As first author Larsen explained to the Wired blogs, “It’s my job to take complex data sets and find ways to represent that data in a way that makes the patterns accessible to human observations. There’s no way to look at 10,000 rows and hundreds of columns and intuit what’s going on.”

Each of the four compositions in the paper is derived from the same set of data, but highlights different relationships between the environmental conditions of the ocean and the microbes that live in these waters.

“There are certain parameters like sunlight, temperature or the concentration of phosphorus in the water that give a kind of structure to the data and determine the microbial populations. This structure provides us with an intuitive way to use music to describe a wide range of natural phenomena,” explains Larsen in an Argonne National Laboratories article.

Speaking to Living on Earth, Larsen describes how their music highlights the relationship between different kinds of data. “In most of the pieces that we have posted, the melody is derived from a numerical measurement, such that the lowest measure is the lowest note and the highest measure is the highest note. The other component is the chords. And the chords map to a different component of the data.”

As a result, the music generated from microbial abundance data played to chords generated from phosphorus concentration data will sound quite different from the same microbial data played to chords derived from temperature data.

“Songs themselves probably are never going to actively replace, you know, the bar graph for data analysis, but I think that this kind of translation of complex data into a very accessible format is an opportunity to lead people who probably aren’t highly aware of the importance of microbial ecology in the ocean, and give them a very appealing entry into this kind of data”, explained Larsen in the same interview with Living on Earth.

Though their primary intent was to create novel way to symbolize the interactions of microbes in the ocean, the study also suggests that microbial bebop may eventually have applications in crowd-sourcing solutions to complex environmental issues.

For further reading, a PLOS ONE paper in 2010 demonstrated that the metaphors used to explain a problem could have a powerful impact on people’s thoughts and decisions when designing solutions. Could re-phrasing complex environmental data in music lead to solutions we haven’t heard yet? As you ponder the question, listen to some microbial bebop!

Other media sources that also covered this research include LiveScience, gizmag and the PLOS blog Tooth and Claw

Citations:  Larsen P, Gilbert J (2013) Microbial Bebop: Creating Music from Complex Dynamics in Microbial Ecology. PLoS ONE 8(3): e58119. doi:10.1371/journal.pone.0058119

Thibodeau PH, Boroditsky L (2011) Metaphors We Think With: The Role of Metaphor in Reasoning. PLoS ONE 6(2): e16782. doi:10.1371/journal.pone.0016782

Image: sheet music by jamuraa on Flickr