Fecal Matters: A Stepping Stool to Understanding Indigenous Cultures

Humans differ by opinions, traits, and baseball team preferences. But one constant factor unifies all humans–we excrete feces, and scientists have recognized that number 2 is number 1 in terms of material for ancient population studies. Humans expel hundreds of grams of feces each day, and prehistory versions of this abundant matter may provide insight into the lives of ancient humans.

Human feces contain DNA from bacteria, fungi, parasites, and even from the human herself. Suspecting that this excrement is rich in biological clues, a group of researchers conducted experiments to investigate fecal microbiomes and published a study in PLOS ONE detailing insights into the diets and lifestyles of two ancient indigenous cultures of Puerto Rico: the Saladoid and Huecoid.

The Huecoid and the Saladoid populations originated from the East Andes and present-day Venezeula, respectively. However, it is believed that they coexisted on the Puerto Rican Island of Vieques for a thousand years, beginning in 5 AD. Although previous studies and artifacts have shown religious and cultural differences between the two populations, notable biological differences had yet to be discovered until now.


The authors of this study gathered ancient fossilized poop samples, called coprolites, from Vieques and Guayanilla, Puerto Rico, as shown in the image above. Using the excavated samples, the researchers performed DNA sequencing and parasite egg and larva extractions to evaluate the differences in the microbial communities between the two ancient cultures. Contrary to prior belief that a coprolite could not preserve ancient DNA, scientists successfully sequenced the fossil microbes contained in the coprolite core. They found that the bacterial distribution varied significantly between the two cores (as seen in the image above) but most notably, sequencing indicated that the Saladoid population had a 10% higher relative abundance of the bacteria, Bacteroidetes, overall, which may mean that the Saladoid people had a higher protein diet.


Using the remaining coprolite core, the researchers identified parasites based on the shape and presence of dehydrated eggs or larva. According to the authors, the rates of parasite abundance may be double in Saladoid feces as compared to Huecoid. Additionally, the Saladoid core consistently contained hookworms, fish parasites, and dog parasites, providing evidence that the Saladoid people may have eaten raw fish regularly, and may have had dogs as pets. Perhaps sushi and puppies have long been staples in human life?

Researchers also found quite a different diet in the fecal remains of the Huecoid people. The presence of freshwater parasites and evidence of maize may suggest that the Huecoid ate aquatic plants or freshwater invertebrates, and that they may have helped introduce a grain diet to the island.


As the first image shows, the Saladoid and Huecoid populations lived quite close to each other, making these biological differences in the feces appear even more noteworthy. The authors attribute the distinct microbiotas and parasitism composition to diet and cultural differences such as living arrangements, the way food was handled, and human contact with pets.

Although this is a relatively new field of research, analyzing ancient fossilized fecal matter may be useful for scientists trying to characterize indigenous diets and lifestyles. What was previously disregarded as waste may now be considered a trove of historical and scientific data; the clue is in the poo.

Related Content: 


Citation: Cano RJ, Rivera-Perez J, Toranzos GA, Santiago-Rodriguez TM, Narganes-Storde YM, et al. (2014) Paleomicrobiology: Revealing Fecal Microbiomes of Ancient Indigenous Cultures. PLoS ONE 9(9): e106833. doi:10.1371/journal.pone.0106833

Images: Images are from Figure 1, Figure 4, and Table 5 of the published paper.

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PLOS ONE’s Spookiest Images of 2014


As we take a look back at research articles published so far in PLOS ONE in 2014, we realize we have no shortage of images to terrify our readers, or at least sufficiently creep them out long enough to last through Halloween and possibly the whole weekend. Without further ado, we present our staff picks for figures in PLOS ONE articles that we felt were eerie, ghostly, spine-chilling, corpselike, gross, nightmarish, or just plain weird!

If you enjoy these, we encourage you to comment down below with any of your other favorite, spooky PLOS ONE images from this year.

Click on any one image to see a larger version.


Where else would we begin? Those with phobias, look away!




We started off easy and only slightly creepy. The above is actually just a neat 3D model of a bug, specifically a granary weevil.




Okay, this one is definitely creepier than the last image. This is a female (top) and male (bottom) leafcutter bee at the pupal stage…just waiting to come out and say hello.




Eek. This is a fossil millipede embedded in amber, with a close dorsal view of the first segments and mid-body rings. For an overload of creepiness, check out the other figures in the paper.




What’s this?! If spiders can catch fish—they can, as this paper describes, on all continents except Antarctica—what can’t they do? Also, if spiders don’t need webs, are they all set to take over the world?




Here we have more insects in amber. In this image, an ant and a termite hang out together in the same piece of Mexican amber.




This image might look slightly unbelievable, but it shows a new species of spider wasp that may sometimes use dead ants to protect its nest. Obviously…dead ants always add a certain something to the décor, in addition to being excellent home protection!


Other species that give us the creeps




Okay, not so bad, a creepy mushroom-lookalike. What’s slightly freaky about it is that it may be a multicellular organism that does not fit into our current phylogenetic tree, which means that it may be part of a new branch of life.




Yuck. Unlike other baby animals, baby coral? Not as adorable.




Slimey goodness in the form of a vocalizing Indian purple frog.




What on Earth is happening in panel D? Lucky for him, the bioluminescent viper dogfish shark has protruding jaws it uses to capture his prey.




This is an Eurasian brown bear breaking the bones of a deer in different ways—such talent! If she could just focus all her efforts on deer and not other species (cough, cough) that would be fantastic.


Carcasses under the sea




Above is a set of carcasses, including a whale shark in the panel on the top left, is being devoured by fish in the deep sea.




What we see here, for as long as we can bear to look, are dead pigs in the deep sea, showing carcass decomposition assisted by shrimp and crab that eat them and drag them around. Yum.


Let’s put the past behind us




The first eerie image above compares the footprint of an early limbed vertebrate, a temnospondyl (right), with that of a salamander (left). Researchers showed that his walk, shown as a hypothetical in the second image, was probably a lot different from that of a salamander, with a forelimb-driven gait as opposed to the hindlimb-driven one of the latter species.




Yikes. The “ripper” behavioral model is illustrated above for a non-avian theropod dinosaur, known for having a “killing claw” used for slashing and eating prey that are still alive!




Behold a rare “bone bed” containing remnants from a newly discovered species of pterosaur. This mess of bones may indicate that the species was fairly social, outgoing, and lived in groups.


Mummies and the like


Saving the best for last, no scary image list is complete without some totally stomach-wrenching mummy pics. Enjoy!




This South American mummy was likely suffering from a disease, hit in the head, and murdered.




While not a mummy, this young individual may have suffered traumatic brain injury and was buried with two red deer antlers on its chest, a possibly unique funerary practice.




A clothes-wrapped body was found inside this coffin, which is a possible case of cherubism in a 17th-century Korean mummy.




And lastly, the above depicts three plastered skulls dating to a pre-pottery period, with the plastering process a possible representation of the shift from hunter-gathering to food-producing strategies. Scary stuff!

Happy Halloween from PLOS ONE!



Image 1: Slon V, Sarig R, Hershkovitz I, Khalaily H, Milevski I (2014) The Plastered Skulls from the Pre-Pottery Neolithic B Site of Yiftahel (Israel) – A Computed Tomography-Based Analysis. PLoS ONE 9(2): e89242. doi:10.1371/journal.pone.0089242

Image 2: Nguyen CV, Lovell DR, Adcock M, La Salle J (2014) Capturing Natural-Colour 3D Models of Insects for Species Discovery and Diagnostics. PLoS ONE 9(4): e94346. doi:10.1371/journal.pone.0094346

Image 3: Holden AR, Koch JB, Griswold T, Erwin DM, Hall J (2014) Leafcutter Bee Nests and Pupae from the Rancho La Brea Tar Pits of Southern California: Implications for Understanding the Paleoenvironment of the Late Pleistocene. PLoS ONE 9(4): e94724. doi:10.1371/journal.pone.0094724

Image 4: Riquelme F, Hernández-Patricio M, Martínez-Dávalos A, Rodríguez-Villafuerte M, Montejo-Cruz M, et al. (2014) Two Flat-Backed Polydesmidan Millipedes from the Miocene Chiapas-Amber Lagerstätte, Mexico. PLoS ONE 9(8): e105877. doi:10.1371/journal.pone.0105877

Image 5: Nyffeler M, Pusey BJ (2014) Fish Predation by Semi-Aquatic Spiders: A Global Pattern. PLoS ONE 9(6): e99459. doi:10.1371/journal.pone.0099459

Image 6: Coty D, Aria C, Garrouste R, Wils P, Legendre F, et al. (2014) The First Ant-Termite Syninclusion in Amber with CT-Scan Analysis of Taphonomy. PLoS ONE 9(8): e104410. doi:10.1371/journal.pone.0104410

Image 7:  Staab M, Ohl M, Zhu C-D, Klein A-M (2014) A Unique Nest-Protection Strategy in a New Species of Spider Wasp. PLoS ONE 9(7): e101592. doi:10.1371/journal.pone.0101592

Image 8:  Just J, Kristensen RM, Olesen J (2014) Dendrogramma, New Genus, with Two New Non-Bilaterian Species from the Marine Bathyal of Southeastern Australia (Animalia, Metazoa incertae sedis) – with Similarities to Some Medusoids from the Precambrian Ediacara. PLoS ONE 9(9): e102976. doi:10.1371/journal.pone.0102976

Image 9: Toh TC, Ng CSL, Peh JWK, Toh KB, Chou LM (2014) Augmenting the Post-Transplantation Growth and Survivorship of Juvenile Scleractinian Corals via Nutritional Enhancement. PLoS ONE 9(6): e98529. doi:10.1371/journal.pone.0098529

Image 10: Thomas A, Suyesh R, Biju SD, Bee MA (2014) Vocal Behavior of the Elusive Purple Frog of India (Nasikabatrachus sahyadrensis), a Fossorial Species Endemic to the Western Ghats. PLoS ONE 9(2): e84809. doi:10.1371/journal.pone.0084809

Image 11: Claes JM, Partridge JC, Hart NS, Garza-Gisholt E, Ho H-C, et al. (2014) Photon Hunting in the Twilight Zone: Visual Features of Mesopelagic Bioluminescent Sharks. PLoS ONE 9(8): e104213. doi:10.1371/journal.pone.0104213

Image 12: Arilla M, Rosell J, Blasco R, Domínguez-Rodrigo M, Pickering TR (2014) The “Bear” Essentials: Actualistic Research on Ursus arctos arctos in the Spanish Pyrenees and Its Implications for Paleontology and Archaeology. PLoS ONE 9(7): e102457. doi:10.1371/journal.pone.0102457

Image 13: Higgs ND, Gates AR, Jones DOB (2014) Fish Food in the Deep Sea: Revisiting the Role of Large Food-Falls. PLoS ONE 9(5): e96016. doi:10.1371/journal.pone.0096016

Image 14: Anderson GS, Bell LS (2014) Deep Coastal Marine Taphonomy: Investigation into Carcass Decomposition in the Saanich Inlet, British Columbia Using a Baited Camera. PLoS ONE 9(10): e110710. doi:10.1371/journal.pone.0110710

Image 15: Marsicano CA, Wilson JA, Smith RMH (2014) A Temnospondyl Trackway from the Early Mesozoic of Western Gondwana and Its Implications for Basal Tetrapod Locomotion. PLoS ONE 9(8): e103255. doi:10.1371/journal.pone.0103255

Image 16: Fowler DW, Freedman EA, Scannella JB, Kambic RE (2011) The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds. PLoS ONE 6(12): e28964. doi:10.1371/journal.pone.0028964

Image 17: Manzig PC, Kellner AWA, Weinschütz LC, Fragoso CE, Vega CS, et al. (2014) Discovery of a Rare Pterosaur Bone Bed in a Cretaceous Desert with Insights on Ontogeny and Behavior of Flying Reptiles. PLoS ONE 9(8): e100005. doi:10.1371/journal.pone.0100005

Image 18: Panzer S, Peschel O, Haas-Gebhard B, Bachmeier BE, Pusch CM, et al. (2014) Reconstructing the Life of an Unknown (ca. 500 Years-Old South American Inca) Mummy – Multidisciplinary Study of a Peruvian Inca Mummy Suggests Severe Chagas Disease and Ritual Homicide. PLoS ONE 9(2): e89528. doi:10.1371/journal.pone.0089528

Image 19: Coqueugniot H, Dutour O, Arensburg B, Duday H, Vandermeersch B, et al. (2014) Earliest Cranio-Encephalic Trauma from the Levantine Middle Palaeolithic: 3D Reappraisal of the Qafzeh 11 Skull, Consequences of Pediatric Brain Damage on Individual Life Condition and Social Care. PLoS ONE 9(7): e102822. doi:10.1371/journal.pone.0102822

Image 20: Hershkovitz I, Spigelman M, Sarig R, Lim D-S, Lee IS, et al. (2014) A Possible Case of Cherubism in a 17th-Century Korean Mummy. PLoS ONE 9(8): e102441. doi:10.1371/journal.pone.0102441

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You Live in What Kind of Home? A-nem-mo-ne-men… me-ne-mo-nee!

Clownfish Find Refuge among the Toxic Tentacles of Sea Anemones

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As we’ve seen in the movies, the world is a dangerous place for a clownfish far away from home. This is all the more reason to ensure that their homes provide adequate protection. What makes a good home for a clownfish, you might ask? Sea anemones. The toxic venom that anemones produce to kill intruders and prey alike provides clownfish with a safe haven. It’s fairly effective too. Clownfish can live for 35 years or more, which is more than three times the lifespan of their similarly sized fish counterparts! That said, not all anemones are created equal, and there are a number of different species that clownfish colonize. So how does a clownfish choose?

In a recent PLOS ONE study, “Searching for a Toxic Key to Unlock the Mystery of Anemonefish and Anemone Symbiosis,” the authors hypothesized that clownfish might choose a home based on the differing levels of toxicity between anemone species. To investigate further, the authors collected nine of the ten anemone species known to host 26 species of clownfish in the genera Amphiprion and Premnas. Next, they retrieved venom samples from the anemones to analyze their levels of toxicity.

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By observing the effects of the various venoms on mammalian cells, brine shrimp, and shore crabs, the authors were able to calculate the relative toxicity of each anemone species. They then compared these findings to the already existing knowledge of how many species of clownfish colonize each anemone species.

They found that anemones that produce an intermediately toxic venom were the ones that hosted the most species of clownfish. Moreover, the least and most toxic anemones hosted the fewest clownfish. The below graph (Figure 4 in the published article) shows the toxicity ranking for each species of anemone that the authors investigated, in relation to how many species of clownfish they host.

pone.0098449 Third Image

The authors believe these results can likely be explained by a balancing act for the clownfish, between the benefits of protection and the costs of withstanding the venom themselves. Living in a highly toxic environment provides protection from predators, though scientists aren’t certain how the clownfish defend themselves against these toxins. Some think that it may have something to do with a protective layer of mucus on their skin. Regardless of the mechanism, few defenses are “free”, meaning that the clownfish likely has to spend energy defending themselves from the same toxins that protect them from predators.

The fish aren’t the only ones with something to gain from this relationship. Anemones with clownfish associates also benefit from increased protection against other species of fish, which may be potential predators. Such relationships are known as symbiotic.

pone.0098449 Fourth Image

The authors hope their study will spark an interest in anemone toxicity and potentially lead to further research. Additionally, they note the conservation benefits of studying the toxicity of debilitated anemones to gain a better understanding of how human actions impact anemone health. Some concerns for anemones include over-collection and bleaching, a condition that occurs when an anemone’s symbiotic zooxanthellae leave or die.

In the paper, the authors also discuss how the disappearance of host anemone species may either force clownfish to find new host species, or send them into decline. Further research could help us determine whether clownfish are capable of using different species as hosts. Until then, we might remember that “no matter what obstacles you face in life, just keep swimming.”


Nedosyko AM, Young JE, Edwards JW, Burke da Silva K (2014) Searching for a Toxic Key to Unlock the Mystery of Anemonefish and Anemone Symbiosis. PLoS ONE 9(5): e98449. doi:10.1371/journal.pone.0098449

Mebs D (2009) Chemical biology of the mutualistic relationships of sea anemones with fish and crustaceans. Toxicon 54(8): 1071–1074. doi: 10.1016/j.toxicon.2009.02.027

Images: Images are from Figure 4 of the published article, like NEMO – Daita Saru, Anemonemonemone – Matt Clark, 058 – Anemone, Anemonefish & Divers – Neville Wootton.

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Does Urbanization Always Drive Economic Growth? Not Exactly…


We often think of cities as major drivers of economic development and growth. Big cities expand our access to infrastructure like public transit and public education. They allow for more efficient distribution of social services such as government assistance and health care. Cities create large markets for business, and can attract international investment and tourism from around the world. They are hubs of non-agricultural, high-paying professional jobs like banking, law, and engineering. Diversity and face-to-face interactions can lead to new ideas and cross-cultural collaborations. Conventional wisdom holds that cities are good for the economy.

Indeed, the link between a country’s level of urbanization and the size of its gross domestic product (GDP) is well established. The below graph of 2011 data illustrates the strong positive correlation: developed countries with high GDPs have relatively high proportions of their population living in urban areas, and vice versa.

Correlation graphLooking at this graph, it is small wonder, then, that urbanization has become a widely adopted global development strategy. National governments and international development agencies have embarked upon aggressive programs of accelerated urbanization designed to spur economic growth. Simply attract people into the cities, the thinking goes, and then cash in on the forthcoming economic benefits of a largely urban population. Well, it may be more complex than that, according to new research published in PLOS ONE.

Researchers in China examined global economic data on urbanization and per capita GDP levels spanning three decades (1980-2011). During this time, the proportion of the world’s population living in cities grew from just 39% in 1980 to 52% in 2011. And while urbanization and per capita GDP may be strongly correlated, the authors found no correlation between the rates of urbanization and economic growth. In other words, fast urban growth doesn’t always translate into fast GDP growth, as witnessed by the graph below. In stark contrast to the first graph, there is no easily discernible pattern connecting the speed of urbanization and the speed of GDP growth.

Graph with no correlation

The authors also point out that over three decades, many countries—for example, Gabon—had rapidly growing urban populations but low and even negative economic growth (top graph in green below). Conversely, many countries, such as Sri Lanka and Uzbekistan, saw negative rates of urbanization— people leaving cities for rural areas—but still had positive overall economic growth (bottom graph in white). These cases do not support the hypothesis that fast urbanization speeds economic growth.


The authors of the study argue that GDP growth may create conditions that organically drive migration from rural to urban areas, but the assumption that urbanization will necessarily drive strong economic growth may be false. Pointing to the numerous examples of accelerated urbanization without strong economic growth (again, the green graph above), they caution that “urbanization is not an automatic panacea” for economic difficulties. Citing other work, the authors suggest that instead of trying to move people into cities, governments and development agencies should focus on creating a mobile workforce, ensuring broad access to goods and markets, implementing government policies that support commerce, and investing in infrastructure. These efforts could make a bigger difference for short- and medium-term economic growth than arbitrary urbanization targets. While economic growth is an incredibly complex process and much work remains, this study serves as a good reminder not to confuse causation and correlation: just because two variables are closely related doesn’t necessarily mean that one directly causes the other.

Related Content:

Does Human Migration Affect International Trade? A Complex-Network Perspective

Welcome to The World’s Largest Ghost City: Ordos, China

Citation: Chen M, Zhang H, Liu W, Zhang W (2014) The Global Pattern of Urbanization and Economic Growth: Evidence from the Last Three Decades. PLoS ONE 9(8): e103799. doi:10.1371/journal.pone.0103799

Images: Images are from Figures 4 and 5 of the published paper, and from Chi King via Flickr.

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Meet PLOS at the Society of Vertebrate Paleontology 2014

SVP Blog ImageWe are excited to announce that PLOS will be exhibiting at the Society of Vertebrate Paleontology 2014 Annual Meeting from 5-8th November in Berlin.

This is only the second time that the meeting takes place outside North America, and the first time it will be held in continental Europe. To celebrate our attendance PLOS ONE Section Editor, Dr Andy Farke, has specially curated some articles recently published by PLOS. Featured articles range from a description of the oldest Caseid Synapsid to the discovery of a new Ankylosaurid dinosaur, plus many more themed selections. We’ll be giving away some PLOS memorabilia and USB drives featuring this specially curated content, so do visit us early before supplies run out!

We’ll be on the Exhibit Floor, at Booth #14 where you can meet Jenni Horsley, PLOS Collections Editorial Project Coordinator and Alejandra Clark, PLOS ONE Associate Editor. We look forward to meeting you in Berlin and hearing your thoughts about PLOS, open access, open data, and open science.

Image: Godoy PL et al., 2014 (CC-BY)

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Going PRO – clinical trials must plan to capture patient-reported outcomes

14425819028_5021bbcb74_zPost authored by David Moher

All participants in research are important. What patients in clinical trials tell us about treatments – patient-reported outcomes (PROs) such as quality of life and symptoms – is being used more and more to improve decisions about patient-centered care and health policy, but poor reporting of these outcomes risks research effort being wasted. Today, PLOS ONE publishes two important papers concerning patient-reported outcomes.[1,2] Professor Melanie Calvert at the University of Birmingham and her colleagues across the UK, Canada and Australia found that not enough attention has been devoted to PROs in clinical trial protocols, the blueprints for how a trial is run and reported.

Patient-reported outcomes are now getting the focused attention they deserve. In the United States the Patient-Centered Outcome Research Institute was set up in 2010 to conduct “research that answers patients’ questions”, spending nearly $700 million USD on 360 projects. The Canadian Institutes of Health Research recently established the Strategy for Patient-Oriented Research. However, PROs must be collected rigorously from the beginning to minimise loss of research information. CONSORT, the Consolidated Standards of Reporting Trials, has long been the gold standard for trial reporting. In 2013 the CONSORT-PRO Extension was introduced, promoting the transparent reporting of PRO data from trials. However, this guidance is aimed at the end of the research process and may be too late to make researchers think more about patients earlier on – at the protocol stage. Guidance on preparing trial protocols themselves has been developed – the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist was also published in 2013. However, this does not offer PRO-specific guidance.

In the first paper, Calvert and colleagues review the existing guidance for protocol writers on PROs.[1] They found that guidance was hard to access, lacked consistency and may be challenging to put into practice.  In total they uncovered a confusing mix of 162 recommendations across 54 publications.

In the second paper, Kyte and colleagues studied 75 protocols funded by the UK National Institutes of Health Research’s Health Technology Assessment program in 2012-3.[2] About two-thirds of the protocols complied with reporting SPIRIT items. Most troubling was that two of items about randomization – the unique characteristic of randomized trials – were missing in about a fifth of the protocols. Anything less than 100% is avoidable waste and the funder is not getting value for money. More than a third of the sample selected was from 2012, prior to the introduction of SPIRIT, however the NIHR website’s guidance for prospective protocol developers still only suggests using SPIRIT (in section 4.4). This is in contrast to a stronger endorsement of PROSPERO, a registry for systematic review protocols. Clearly there is an opportunity to more strongly recommend using SPIRIT, incorporating PRO issues at the same time.

These papers point to a clear need for more attention to PROs when developing trial protocols, and Prof. Calvert and colleagues used rigorous evidence-based methods that were explicitly reported in sufficient detail to allow interested readers to replicate them.

One suggestion to improve reporting is the development of a SPIRIT PRO extension. The EQUATOR Network already has a library of more than 200 reporting guidelines, with lots more in development. Reporting guideline developers have worked hard to help authors more completely report their research, but the marketplace is getting full. The SPIRIT-PRO extension would need to be both accessible and acceptable to researchers who wish to incorporate PROs in their trials and we need to ensure we don’t make using guidelines, such as a SPIRIT PRO extension, so complicated that it becomes a barrier to using them. We need to consider how to best ease using reporting guidelines: technology might be helpful here.

Another way to increase the use of SPIRIT and PRO guidance would be to build them into teaching about trials in university graduate programs, such as epidemiology and biostatistics. However this is done, researchers need to improve the reporting of patient-reported outcomes for the sake of both the trial participants and the patients who rely on this evidence to improve their health.

Citations: [1] Calvert M et al. (2014) Patient-Reported Outcome (PRO) Assessment in Clinical Trials: A Systematic Review of Guidance for Trial Protocol Writers. PLOS ONE  9(10): e110216 doi:10.1371/journal.pone.0110216

[2] Kyte D et al. (2014) Systematic evaluation of the patient-reported outcome (PRO) content of clinical trial protocols. PLOS ONE  9(10): e110299. doi:10.1371/journal.pone.0110229

Image: Hands_II – Oleg Afonin

david_moherDavid Moher is a senior scientist in the Clinical Epidemiology Program, Ottawa Hospital Research Institute, and Associate Professor, Department of Epidemiology and Community Medicine, University of Ottawa, where he holds a University Research Chair. He has a special interest in journalology (publication science), including ways to improve the quality of reporting health research. He spearheaded the development of the CONSORT Statement for reporting randomized trials, the PRISMA Statement for reporting systematic reviews and meta-analyses, and has been involved in many other reporting guideline initiatives, including SPIRIT and CONSORT PRO. Dr. Moher is associated with many journals: an editor-in-chief of Systematic Reviews; an editorial board member of several journals, including PLOS Medicine, a member of PLOS ONE’s Human Research Advisory Group, the advisory board for the International Congress on Peer Review and Biomedical Publication, and a member of the EQUATOR Network’s steering group.

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Hey, Excuse Me… Is This Guy Boring You?

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Imagine that you’re sitting on a Cretan beach. The sun’s shining and waves are lapping on shore, when suddenly a set of jaws dripping copious amounts of saliva appear above you like some sort of CGI horror masterpiece, wanting to bore a hole in you big enough to crawl through. While this is hopefully not something you need to worry about, it is in fact a concern for the Albinaria land snails that inhabit the Greek islands. Who are the boorish culprits? No other than small beetle larvae of the genus Drilus (shown above), a land snail predator.

In a study recently published in PLOS ONE, researchers aimed to gain a better understanding of the predator-prey interactions between Drilus beetle larvae and Albinaria land snails. They predicted that land snail species with a greater number of ribs on their shell were better protected from invasion; if correct, this would mean the type of predation may affect shell evolution in this species.

The authors surveyed over 1,000 groups of land snail shell samples from a museum and mapped, by region, the frequency of land snail deaths by beetle larvae. Then, using DNA sequencing, they found that while some species of beetle larvae only prey on Albinaria, others take a more generalist approach and feed on a variety of land snail species.

The authors also found that beetle larvae can kill without ever actually having to bore a hole in the snail’s shell. In fact, of the ~170 Albinaria shells the authors collected that showed evidence of a beetle larvae attack, 60 shells had no holes. The researchers suggest that despite the potential challenges of entering through the main opening, such as encountering the clausilium—essentially a front door that the snail can shut (as drawn above)—boring into the shell is still a more rigorous task.

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The scientists’ also directly observed the beetle larvae preying on the land snails, which reinforced that it was not necessary to bore a hole for entry; however, they found that the beetle larvae almost always exited by boring. While there does not seem to be an obvious explanation for why this variation in entry/exit method exists, each choice has its own advantages and disadvantages. The observation period further revealed that the beetle larvae took its time leaving the shell, often living inside it for 22-32 days after each kill before molting and moving on.

Though we still do not have a clear understanding of how these interactions directly impact shell evolution, the authors hope this research provides a basis for future work to build upon. Regardless, I think it’s safe to say that this ‘boring’ research yielded some rather informing results.

Citation: Baalbergen E, Helwerda R, Schelfhorst R, Castillo Cajas RF, van Moorsel CHM, et al. (2014) Predator-Prey Interactions between Shell-Boring Beetle Larvae and Rock-Dwelling Land Snails. PLoS ONE 9(6): e100366. doi:10.1371/journal.pone.0100366

Images: All images are from the article.

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Worms in the Big Apple: Identifying Patterns of Toxocariasis Infection in New York City

For thousands of Americans, roundworm infection may pose a serious threat to their health. Toxocariasis, an illness caused by a parasitic roundworm, can potentially cause chronic health problems, including ocular infections, diminished lung function, and poor cognitive development. It is estimated to be one of the most prevalent neglected infections of poverty (NIP) in the United States, a group of “under the radar” infections that cause major problems for those living in poverty.

Public health officials know that toxocariasis is highly prevalent in urban areas and inner city neighborhoods, but beyond that, this disease isn’t tracked or treated like other illnesses where extensive background research is more accessible. The authors of a paper published in PLOS ONE in June of this year attempted to take a step closer to addressing this issue by looking at how data like ethnicity, education level, or neighborhood size in New York City can provide clues to the likelihood of toxocariasis occurrence.

Figure 1

The researchers in this study used the only source of population-based and location-specific information about toxocariasis that was available: a 1988-1994 National Health and Nutrition Examination Survey (NHANES) that contains a collection of data used to estimate the prevalence of this infection around the United States. By applying these statistics to highly detailed census data from urban areas of New York City, the authors could estimate the probability of toxocariasis in different demographics or neighborhoods. The results of this are shown in the map above.

Figure 2

As this second map indicates (click to enlarge), several different ethnicities in inner cities are at a higher risk for this infection. For instance, African Americans in New York City show a 64% greater risk of infection, and immigrants had a 92% greater chance of infection in comparison to those born in the US. Not only that, New Yorkers’ education levels also correlated with infection: the risk of toxocariasis was about 6% among US-born Latino women with a university education, and up to 57% among immigrant men with less than a high school education. These populations appear to be at particularly high risk for infection, and might be among the first groups surveyed in targeted sampling.

The results of this study are particularly telling for the US’ largest city, which holds almost 8.4 million people in all of its diverse neighborhoods. Wandering the streets of New York at any moment, you might hear one of 800 spoken languages. The dense populations of this city are key to understanding where and why these neglected infections of poverty can develop. More specifically, the colorful areas of these maps can be used to guide testing in inner city neighborhoods.

A few limitations of the study might be that the nationwide (NHANES) survey was conducted 15 years earlier, and it captured far fewer details than the New York City census data. Still, the vivid depictions of these statistics can provide us with much-needed maps for further research and potential surveillance. With more surveillance of this illness, we can gather more data, track, and study this disease. Once we have improved sampling methods, we can better address the public health needs of our urban areas.

Citation: Walsh MG, Haseeb MA (2014) Small-Area Estimation of the Probability of Toxocariasis in New York City Based on Sociodemographic Neighborhood Composition. PLoS ONE 9(6): e99303. doi:10.1371/journal.pone.0099303

Images: All images are from the article.

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Catch the Katydid if You Can


Katydid pic 1

It’s too fast to catch, spears smaller insects with spiny legs, and sings a song that mirrors the syllables of its name, “Ka-ty-did, Ka-ty-didn’t.­ Its music is so catchy, it has even been used as the chorus of popular songs.

Listroscelidinae are a group of insectivorous katydid hunters from South America whose fast and aggressive behavior makes them difficult to capture, let alone identify. According to the authors of a recent PLOS ONE study, these Neotropical katydids have been understudied, partly because we haven’t been able to get our hands on them. However, the authors of this study managed to collect more than 100 specimens from one of the world’s most threatened ecosystems, the Brazilian Atlantic Forest.

They compared these new specimens to existing samples from museums by collecting DNA samples and creating simplified illustrations to document the differences between the physical characteristics in each species. In addition to measuring the phalluses and abdomens, they traced the placement of stridulatory files on their wings, shown in the image below, which katydids rub together to make noise. The different placement of these bands allowed the researchers to distinguish between related species.

After examining the physical characteristics and DNA samples, researchers were able to identify and name eight new species of Neotropical katydids, which have been very difficult to classify and have been re-categorized several times in the last century.

The most distinctive feature of these Neotropical katydids is their spiked legs, which they use to skewer and ensnare insect prey. A close relative of the Listroscelidinae, the Red-eyed Devil, has been documented performing the katydid hunt.

Katydids blogpost

The authors caution that these species may be seriously endangered as they are found only in highly-preserved sections of this threatened forest. Identifying these species has helped reshape how researchers think about them, but there is still much research to be done on this group of Neotropical katydids, as long as researchers can catch up with them!

Citation: Fialho VS, Chamorro-Rengifo J, Lopes-Andrade C, Yotoko KSC (2014) Systematics of Spiny Predatory Katydids (Tettigoniidae: Listroscelidinae) from the Brazilian Atlantic Forest Based on Morphology and Molecular Data. PLoS ONE 9(8): e103758. doi:10.1371/journal.pone.0103758

Images: All images are from the article.

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Detection by Dung: Don’t Eat the Brown Snow


Researchers in Antarctica on a mission to locate penguin colonies found two groups of seabirds, thanks to a little help from satellites, helicopters, and the detection of more “primitive” evidence: penguin poop.

Our favorite tuxedo-clad Emperor penguin is native to Antarctica, but harsh winter conditions and the remoteness of some colonies can make it difficult for biologists to gain a comprehensive population assessment of this “hiding” bird. The first breeding penguin colony was discovered in Antarctica in 1902, and in 1999 thousands of birds were sighted near the Mertz glacier in Antarctica, but for the last century, suspected colonies of Emperor Penguins in the area had yet to be confirmed.

In this recently published PLOS ONE study, the authors used both survey- and satellite-based methods to locate the presence of Emperor penguin colonies on the Mertz glacier, where a previous sighting of thousands of birds had occurred 15 years ago, but a drastic habitat change—the glacier’s “tongue” broke off in February 2010—may have disrupted.


Aerial surveys captured two new potential breeding grounds for colonies, the Eastern and Western (~7,400 breeding pairs total).  Satellite images from a thousand feet in the sky helped the authors detect the Eastern colony by the presence of fecal marks—or in bird specialist speak, “guano”—in the snow.

The red arrow in the image above points out the lovely brown streak of guano strewn across the ice shelf, which indicates the Eastern colony’s previous breeding ground. The authors used this streak as an indication that the Eastern colony was likely close by. Below the guano-streaked, snow-packed shelf, the presence of the Eastern colony was confirmed by researchers trekking across treacherous terrain to visually confirm the presence of the birds.

Unlike the Eastern colony, who mobilized to a fresh home post-breeding, the Western colony seemingly didn’t mind remaining in their breeding muck. This colony was discovered not by satellite but by chance during helicopter flight operations in Antarctica. Although the authors had difficulties finding the Western colony by aerial footage, as pictured in the below image, these social gatherers appeared to differ from the Eastern colony in that they inhabited a large flat surface, and the colony appeared to be much larger.


In the cases of both colonies, aerial surveys appeared to be very effective for locating them. So, until humans evolve warmer winter coats, scientists conducting surveys by foot are still limited by frigid conditions and isolated locations in future South Pole endeavors. To obtain a more accurate picture of total penguin counts, the authors suggest taking multiple aerial images during the breeding season and conducting several-year surveys to confirm numbers in suspected Antarctic penguin colonies. But for now, the game of Hide and Go Poop will continue.

Citation: Ancel A, Cristofari R, Fretwell PT, Trathan PN, Wienecke B, et al. (2014) Emperors in Hiding: When Ice-Breakers and Satellites Complement Each Other in Antarctic Exploration. PLoS ONE 9(6): e100404. doi:10.1371/journal.pone.0100404

Image 1: Emperor Penguins by Lin Padgham

Image 2-3: Figures 1 and 2 from article

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