Laser images hint at archaeological discoveries
Alexandra Witze reports in the News Blog, by bombarding a patch of the Honduran rainforest with laser pulses, archaeologists have discovered structures that could be a part of a lost city — or even two:
Images: UTL Scientific, LLC
In spring 2012, scientists from the National Center for Airborne Laser Mapping (NCALM), based at the University of Houston, loaded a plane with a state-of-the-art lidar system and took it down to Honduras. Lidar bounces billions of laser pulses off of the forest and measures the time they take to return. Though most of the pulses reflect off vegetation, some small fraction reaches the ground. Researchers can thus build up a map of the surface by mathematically stripping away the canopy of tree leaves (shown at right).
Lidar has been used to calculate biomass in the Amazon and to hunt for extra structures at Stonehenge. In the dense forests of Central America, though, lidar “is like rewriting history,” says Christopher Fisher, an archaeologist at Colorado State University in Fort Collins. “We have just huge black holes on the map about which we know very little.”
Will lidar surveys become a common tool for archaeologists? Hear more in Alexandra’s post.
Neon behind the signs
Should neon be at the top of the noble gases group? Anne Pichon elaborates in the Sceptical Chymist Blog:
© PHOTO JAPAN / ALAMY
A few different versions of the periodic table do exist — as Michelle Francl wrote about here a while ago in a certain chemistry journal — but we’re all attached to the one that adorned our science class rooms at school: Mendeleev’s version. We generally think that each position is firmly set, but in this issue’s ‘in your element’ article (subscription required) Felice Grandinetti ponders on whether neon should really be at the top of the noble gases group — this would involve helium moving next to hydrogen, at the top of group 2.
An argument in favour of this change is the fact that neon is less reactive than helium. ‘Less reactive’ is perhaps a bit of a stretch when it comes to the noble gases, let me rephrase this to “neon is more inert than helium”. We know that, moving down the periodic table (that is, when moving from helium to neon, then argon, krypton and finally xenon) an increase in polarizability accompanied with a decrease in ionization potential makes elements more prone to form bonds.
Do you agree? More details can be found in Anne’s post.
Science Communication at a Tipping Point
On April 30, COMPASS published a paper at PLOS Biology that shared experiences in science communication over the past decade. This week’s Soapbox Science guest post by Liz Neeley, is a reflection on public and private responses to the ideas they presented, and an attempt to answer, “Where do we go from here?”
I will never forget watching Jon Foley emphatically interrupt a discussion among young faculty with, “Your job is NOT to get tenure! Your job is to change the world.” I tweeted that quip not so long ago, to which @Dreadnought1906 replied, “Yeah, I tried that; they kicked me out of the academy. Junior academics don’t have the power to change the system.”
Yet things are changing. From jobs and funding to publications and politics, this thing we call Science is bigger, messier, and more public than ever before. How do we respond? Over beers, in our blogs, after seminars, uneasy and excited conversations churn. A steady drumbeat pulses: Outreach Training Needed; Escape from the Ivory Tower; Stand Up For Science; (But do try to do so without being such a scientist?).
Feel free to share your thoughts in the comments and join in the online discussions using the #reachingoutsci hashtag.
Four main culprits found for serious childhood diarrhoea
Rotavirus particles
FLICKR/AJC1
Beth Mole explains in the News Blog, just four pathogens underpin most cases of serious diarrhoea in children — the second leading killer of young children worldwide — according to a study published this week in The Lancet:
Out of nearly 40 diarrhoea-causing microbes, the researchers identified four primary culprits: rotavirus, Cryptosporidium, a toxic type of Escherichia coli, and Shigella. The winnowing of the list could allow health experts to design targeted health campaigns.
“I think what we have done is allow doctors and public health experts to prioritize and potentially save thousands of lives,” says Karen Kotloff, a paediatrician at the University of Maryland, Baltimore, and first author of the study. Diarrhoeal diseases kill an estimated 800,000 young children each year, second only to pneumonia, which kills around 1.2 million.
Find out more about the 3-year study in Beth’s post.
Male Black Widows Sniff Out Femme Fatales
In this week’s guest post on Scitable’s Student Voices blog, Sarah Jane Alger discusses a new study demonstrating that spider copulation isn’t simply about the female making a meal out of the male:
Female western black widow by Davefoc (from Wikimedia Commons).
These males may be more picky than once thought, using ordors to determine who to mate with. Evolutionarily, the spiders have to be discerning when their life is on the line.
Sexual reproduction is a costly affair, but the costs are not usually equal for males and females. Among animals, females generally produce larger gametes (eggs are way bigger than sperm), spend more energy gestating or incubating the young before they are born, and spend more effort caring for the young after they are born. It’s no wonder then that across animal species, females are typically more choosy of who they mate with than males are.
But what if the tables are turned and sex is more costly for males than it is for females? Such is often the case for black widow spiders, named for the females’ infamous reputation for making a post-coital snack of their mates. In such a situation where every sexual encounter is potentially the last, who would blame males for being more choosy of their mating partners? But are they?
These answers are revealed in Sarah’s post.
The Joy of Stats
SciLogs blogger Tania Browne, explains in her latest post, you may claim to know nothing about maths, but maths knows a lot about you:
africa, via freedigitalphotos.net
Consider what you did even when you woke up this morning. After you brushed your teeth, you might have put on some face cream that you bought because the TV advert told you 87% of people who used it reported an improvement in the appearance of fine lines and wrinkles. But did you also read the small print at the bottom which said it was 87% of 93 people, tested for a week?
And this doesn’t just go for your every day life. Healthcare workers face an onslaught of medical statistics, and they have to make decisions based on them every day. And what’s more, those Decision Makers are as human as you or I. Statistics are everywhere in health care systems, from the percentage of nurses in a hospital who work part time, through the ethnic groups of the babies born there, to the incidence rate of MRSA in an administrative area, to the systolic and diastolic readings from a 24 hour ambulatory blood pressure check on a single outpatient.
Continue to Tania’s post to find out more.
Data interpretation
Finally, Viktor Poór’s latest cartoon reveals there are several ways you interpret your negative results: