Has it really been this long since I added to the blog? My apologies to anyone still following. Many things have happened since I last visited. I promise I will add more details soon.
Warning colouration paved the way for louder, more complex calls in certain species of poisonous frogs
Frogs are well-known for being among the loudest amphibians, but new research indicates that the development of this trait followed another: bright colouration. Scientists have found that the tell-tale colours of some poisonous frog species established them as an unappetizing option for would-be predators before the frogs evolved their elaborate songs. As a result, these initial warning signals allowed different species to diversify their calls over time.
Zoologists at the National Evolutionary Synthesis Centre (NESCent), the University of British Columbia, and other research universities assembled an acoustic database to analyse more than 16,000 calls from 172 species within the poison frog family, Dendrobatidae. The paper, which will appear in the December issue of the Proceedings of the Royal Society B, is now available online.
The study included both frogs that display bright colours and others that rely on camouflage for protection. Each call was examined in terms of pitch and duration, and researchers also factored in the size of the frogs and their visibility to predators. They found that because warning colouration protected them from predators, they were better able to attract a mate with low-pitch, pulsing vocalizations in plain sight than their quieter, darker-hued relatives.
“This allows the frog to have a unique type of call—a noisy call,” said lead author Juan C. Santos, formerly of NESCent and now at the University of British Columbia. “These noisy kinds of calls, in general, are what the females really like.”
Scientists already understood that predators shied away from brightly coloured frogs because of visual cues, but Santos and his colleagues hypothesized that some species evolved to include audio signals, as well. Such a warning system is not unprecedented: Tiger moths emit ultrasonic chirps to communicate their unsavoury taste to bats. Without a similar ability, frogs navigate a precarious dilemma in which they must either risk detection by predators or forgo possible courtship.
Initially the researchers expected that audio warnings pre-dated colouration but the results indicate the opposite. Using molecular data and statistical analyses, they were able to infer a phylogenetic tree and pinpoint which trait came first. Their findings indicate that visual traits established the frogs as poisonous and cleared the way for louder, more elaborate calls.
Species relying on camouflage for defence will not invite attention with boisterous calls, while their protected relatives—including non-poisonous frogs that mimic the appearance of their toxic counterparts— can be loud and more nuanced.
“The type of colour they have is in the range of the noisy ones,” Santos said. “When you’re mimicking somebody that’s already protected, you have some freedom to be found by potential mates.”
These calls require high energy expenditures, but the boon of attracting females without predatory threats makes it a rewarding behaviour males. Less is known about the reasons females are attracted to the noisier males and how they appraise the various calls. Santos explained that if the females are being especially picky, it will drive male diversity by pushing them to create even more complex songs.
“What can the females get from this information? Maybe females— by being very picky— increase male diversity,” Santos said. A more diverse pool of potential mates increases the likelihood that their offspring will have more advantageous genes over time.
This work was supported by the National Science Foundation (DEB: 0949899), the National Evolutionary Synthesis Center (NSF EF-0905606 and EF-0423641), and the University of Texas and the Amphibian Tree of Life project (NSF EF-0334952).
Santos, Juan C. et al. (2014). “Aposematism increases acoustic diversification and speciation in poison frogs” Proceedings of the Royal Society B.http://rspb.royalsocietypublishing.org/content/281/1796/20141761.abstract
The National Evolutionary Synthesis Center (NESCent) is a nonprofit science center dedicated to cross-disciplinary research in evolution. Funded by the National Science Foundation, NESCent is jointly operated by Duke University, The University of North Carolina at Chapel Hill, and North Carolina State University. For more information about research and training opportunities at NESCent, visit http://www.nescent.org.
For about a decade, Chinese consumers weren’t getting what they paid for when they purchased Wuchang, a special brand of gourmet rice that has a peculiar scent. The quality was being diluted when less expensive rice was aromatized, added to the packages of the high-quality rice, and sold at the premium price. Researchers at the University of Illinois studied how the tampering scandal affected the public’s perception of risk and their subsequent behavior.
Because public anxiety over the fake rice issue was more pronounced in urban districts, the researchers focused on residents of Xi’an, ultimately analyzing interviews and survey responses of 225 people.
“Over half of the people we interviewed were aware of the product tampering, but only very vaguely,” said U of I agricultural communications professor Lulu Rodriguez. “They rely much more on interpersonal communication with friends and family members for information.”
The study also showed that although people didn’t understand the details or potential health risks that the tainted rice may cause, the public’s perception of risk was considered to be high.
“In this case, their trust of society, such as the government, food-safety regulations, and the mass media was eroded,” Rodriguez said. “This incident came in the wake of other food-safety scandals in China. We hear people say in the interviews, ‘we are left to fend for ourselves.’ They seemed to feel like they need to make use of whatever information sources they have and make do because the government cannot be trusted. And the government tried to place the blame on local agencies.”
Rodriguez explained that rice retailers knew the product tampering was taking place. “Production was not jiving with what was being sold,” she said. About 800,000 tons of Wuchang rice were produced but up to 10 million tons were being sold. Adding 1 pound of fragrance to ten tons of rice allowed the lower-quality rice to pass as the more expensive Wuchang brand rice. The Chinese Central TV finally broke the story, saying that the government was doing its best to punish the culprits and that they would be dealt with accordingly, but that wasn’t good enough to calm the public’s anxiety.
“Fortunately, there wasn’t any real health risk, but that didn’t stop people from thinking about health-related concerns,” Rodriquez said. “It is food, after all, and the public didn’t know exactly what was being added to the rice. It shows that if you have the public perception as a communicator, you have a problem even if the accusations are not correct.”
Although their knowledge level was low, the uncertainty of what was perceived of as involuntary risk was high—high enough that their behavior shifted to not buying the rice.
“More openness is needed,” Rodriguez said. “This incident reminded me of the horrible way that the SARS epidemic was handled, in which the Chinese government delayed notifying the World Health Organization of the outbreak for three months. Keeping quiet just makes people more nervous.”
Rodriguez said that the problem was compounded because no one took ownership of the scandal. “They seemed to think that all they had to do was to assure the public that they were doing their best. But what exactly were they doing? It created high anxiety, particularly in urban districts where rice outlets are concentrated,” she said. “We also noted that although people seemed to know about the incident, they were very reluctant to speak out about it, fearing possible repercussions.”
As an agricultural communications educator, Rodriguez views this incident as a teachable moment.
“There is a window of opportunity for us,” she said. “There are Chinese students who come to the University of Illinois for undergraduate and graduate studies. These younger communicators will have a broader perspective to report on incidents like this. We hope that there can be mechanisms developed that can reestablish trust. Trust is very difficult to build and very easy to destroy.”
“Social trust and risk knowledge, perception and behaviours resulting from a rice tampering scandal” was published in an issue of International Journal of Food Safety, Nutrition and Public Health and written by Lulu Rodriguez, Jing Li, and Sela Sar.
Cheer up, it’s all nonsense.
1. God drowns the whole earth. In Genesis 7:21-23, God drowns the entire population of the earth: men, women, children, fetuses, and perhaps unicorns. Only a single family survives. In Matthew 24:37-42, gentle Jesus approves of this genocide and plans to repeat it when he returns.
2. God kills half a million people. In 2 Chronicles 13:15-18, God helps the men of Judah kill 500,000 of their fellow Israelites.
3. God slaughters all Egyptian firstborn. In Exodus 12:29, God the baby-killer slaughters all Egyptian firstborn children and cattle because their king was stubborn.
4. God kills 14,000 people for complaining that God keeps killing them. In Numbers 16:41-49, the Israelites complain that God is killing too many of them. So, God sends a plague that kills 14,000 more of them.
5. Genocide after genocide after genocide. In Joshua 6:20-21, God helps the Israelites destroy Jericho, killing “men and women, young and old, cattle, sheep and donkeys.” In Deuteronomy 2:32-35, God has the Israelites kill everyone in Heshbon, including children. In Deuteronomy 3:3-7, God has the Israelites do the same to the people of Bashan. In Numbers 31:7-18, the Israelites kill all the Midianites except for the virgins, whom they take as spoils of war. In 1 Samuel 15:1-9, God tells the Israelites to kill all the Amalekites – men, women, children, infants, and their cattle – for something the Amalekites’ ancestors had done 400 years earlier.
6. God kills 50,000 people for curiosity. In 1 Samuel 6:19, God kills 50,000 men for peeking into the ark of the covenant. (Newer cosmetic translations count only 70 deaths, but their text notes admit that the best and earliest manuscripts put the number at 50,070.)
7. 3,000 Israelites killed for inventing a god. In Exodus 32, Moses has climbed Mount Sinai to get the Ten Commandments. The Israelites are bored, so they invent a golden calf god. Moses comes back and God commands him: “Each man strap a sword to his side. Go back and forth through the camp from one end to the other, each killing his brother and friend and neighbor.” About 3,000 people died.
8. The Amorites destroyed by sword and by God’s rocks. In Joshua 10:10-11, God helps the Israelites slaughter the Amorites by sword, then finishes them off with rocks from the sky.
9. God burns two cities to death. In Genesis 19:24, God kills everyone in Sodom and Gomorrah with fire from the sky. Then God kills Lot’s wife for looking back at her burning home.
10. God has 42 children mauled by bears. In 2 Kings 2:23-24, some kids tease the prophet Elisha, and God sends bears to dismember them. (Newer cosmetic translations say the bears “maul” the children, but the original Hebrew, baqa, means “to tear apart.”)
11. A tribe slaughtered and their virgins raped for not showing up at roll call. In Judges 21:1-23, a tribe of Israelites misses roll call, so the other Israelites kill them all except for the virgins, which they take for themselves. Still not happy, they hide in vineyards and pounce on dancing women from Shiloh to take them for themselves.
12. 3,000 crushed to death. In Judges 16:27-30, God gives Samson strength to bring down a building to crush 3,000 members of a rival tribe.
13. A concubine raped and dismembered. In Judges 19:22-29, a mob demands to rape a godly master’s guest. The master offers his daughter and a concubine to them instead. They take the concubine and gang-rape her all night. The master finds her on his doorstep in the morning, cuts her into 12 pieces, and ships the pieces around the country.
14. Child sacrifice. In Judges 11:30-39, Jephthah burns his daughter alive as a sacrificial offering for God’s favor in killing the Ammonites.
15. God helps Samson kill 30 men because he lost a bet. In Judges 14:11-19, Samson loses a bet for 30 sets of clothes. The spirit of God comes upon him and he kills 30 men to steal their clothes and pay off the debt.
16. God demands you kill your wife and children for worshiping other gods. In Deuteronomy 13:6-10, God commands that you must kill your wife, children, brother, and friend if they worship other gods.
17. God incinerates 51 men to make a point. In 2 Kings 1:9-10, Elijah gets God to burn 51 men with fire from heaven to prove he is God.
18. God kills a man for not impregnating his brother’s widow. In Genesis 38:9-10, God kills a man for refusing to impregnate his brother’s widow.
19. God threatens forced cannibalism. In Leviticus 26:27-29 and Jeremiah 19:9, God threatens to punish the Israelites by making them eat their own children.
20. The coming slaughter called Armageddon. According to Revelation 9:7-19, God’s got more evil coming. God will make horse-like locusts with human heads and scorpion tails, who torture people for 5 months. Then some angels will kill a third of the earth’s population. If he came today, that would be 7.2 billion and growing according to this site.
But the abrahamic god of the buy-bull is a loving god right?
What a load of crap Christians are trying to force in to schools.
But as I poured out my thoughts quite by accident it became much more. I wanted to share my reflections with you here, so excuse this indulgence.
Rather happier now I have had the opportunity to say goodbye, as it were, to Nan.
As an Atheist graveyards are strange places for me. I know once we are gone, we are gone. I know there is nothing after, we return to dust and our memory is carried on by our family. Eventually we will return to the stars and become at one at an atomic level with the universe – quite beautiful really.
Life is like energy really, it never really stops it just changes.
When the matriarch of any family passes away a huge whole is left and families can fall in to disarray. I hope my children and grandchildren realise how important family is and make the effort to stay close.To me family has always been important. You realise that when yours is gone and take pains to ensure that your own family treasures their relationship with each other.
I am thankful for my Wife for her loving support, and grateful I have the opportunity to educate my children without the confines, constraints and nonsense that any organized religion imposes. My children question everything, are encouraged to research everything for themselves and are richer for it!
Critical thinking is so lacking in this modern world it is becoming a rarity. Perhaps this is the next form of mental evolution for mankind? Those that have knowledge through research and mental dexterity, and those that choose not to trouble themselves with it and therefore embrace ignorance by blindly believing everything they are told, either from the pulpit or the many forms of filtered media.
It saddens me, which is why I speak out. After a lifetime of controlled blind obedience I feel obligated! I know it is unpleasant for some to hear and see, which is why 5 years ago I had over 600 friends on Facebook and today I have 133!!
For whatever reason, I have very few real friends, but those that I do call close friends I view as my family. They know who they are and know I value their companionship greatly. I confess I am a very lonely person and have a huge whole in my life, not because I have removed ‘God’ from it but because a religion chosen by my family requires them to be totally removed from mine. So all of the friends I ever had and all of the family I was so closely attached to are gone. Their choice killed off a part of me, and left a gaping hole.
Can you even imagine how hard it is to rebuild that?
Can you imagine how hard it is to socialise when you are disabled and wheelchair bound, unable to work any more?
Add in to the equation you have two autistic children who have three siblings. All polite and well behaved children – but looking after 5 kids is daunting.
You also only have a loving and willing father-in-law as the only person you can rely on to look after the children to enable you and your Wife the opportunity to go out and perhaps you begin to see the struggle we have.
BUT, I am not moaning, I don’t think people realise how much Emmajay and I have been through in the relatively short time we have been together, and what we go through on a daily basis.
We almost lost Jacob at 6 weeks. Micah is a very poorly boy with dysfunctional kidneys, he will also face a lifetime of awkwardness from his vitiligo. Autism is an incredibly difficult mental illness and we regularly face meltdowns from both Jacob and Reuben. Imagine a child throwing themselves in to the road or smacking their head on a brick wall because they face a change in routine, a strong smell, a new flavour they haven’t tried etc.
If we were advertising this as a job it would have to come with one hell of a salary and benefits package!
I doubt even then many would cope,
Which makes Emmajay even more amazing.
She does all this AND has to cope with a husband not coping with a recent and permanent disability.
My life is nothing like I envisioned at 18 when I was fed up and bored.
I’d love to have my youth back, and equally I am grateful for the journeys I have taken since then that have shaped me to become the man, husband and father I am today.
There is truth in the saying that life is a journey, just make sure you’re not sat on the bus looking out and watching it pass by! I did that for too long and when I got off at a stop, I found out it was fucking amazing.
Over the last thousand years Christianity has adopted many things from other religions, but it also took from science too.
A Spherical Harmony
The earliest ancient civilizations all shared the same fundamental view of the universe; that our earth lay at the centre. The characteristically inventive Sumerians of what we now call Iraq; the Amorite dynasty that founded the Babylonians; and also the North East African civilisation of the ancient Egyptians; all these ancient civilizations had the Sun, Moon, stars, and planets revolving around us. The specific explanations varied from society to society, but the viewpoint that came to dominate the minds of Europeans was established by successive generations of the ancient Greek philosophers. Though I say “ancient greeks” they were in reality learned philosophers who lived across many centuries with their theories of the cosmos being somewhat refined over a time period scanning more than six hundred years.
Te first known idea of the stars being fixed to a sphere, or hemisphere, rotating around the earth is attributed to Anaximenes of Miletus, who lived in the 6th century BC. Like his predecessors, Anaximenes was preoccupied with cosmology, searching for the world’s origin in which he is most known for his assertion that air is the most basic and originary material and the source of all things. While empirical evidence was essential in Anaximenes’ work, the less evidentiary notions of the divine remained apparent as well. Perhaps in line with early Greek literature that rendered air as the soul, as in the ‘breath of life,’ Anaximenes relates air with god and the divine, according to the accounts of Aetius. The qualities of air, that has similar attributes as the qualities of Anaximander’s aperion, are those of the divine and the eternal. It is posited, by Aetius and later by Cicero, that there is a strong correlation between the notion of air as an originary principle element and the notion of air and breath as the divine and eternal substance of the soul and of god.
In the 6th century, Anaximenes of Miletus, saw the Earth as a kind of flat disc, or a flat-topped cylinder that floated like a cork in the air. Pythagoras of Samos – the same Pythagoras whose theory we use today to calculate the area of a triangle – changed the disc to a globe then placing it at the centre of concentric spheres, one for the Sun, the Moon and each of the planets, with the other stars ‘fixed’ at the furthest distance. For Pythagoras, the physical distances separating the spheres was of great importance, even seeing the seven planetary spheres (Moon and Sun included) and the shpere of the stars being separated in the same seven ratios as those of the musical scale. It was this particular notion that gave us the concept of the “harmony of the spheres” that was to resonate for two milennia.
The model that later became fixed stemmed from a proposition laid down by the philospher and methematician Plato circa. 400 BC. For Plato, the circle was the perfect form and he was totally convinced that the Sun and the Moon revolved around a spherical Earth in circular orbits. Plato’s students were left with the challenge of creating a model that explained his philosophy. Eudoxus of Cnidus offered an ingenious solution of multiple concentric spheres. The orbit of our Moon illustrates this idea; to explain its apparent movement through the heavens the Moon needed three spheres; one rotating every day in order to explain the rising and setting; a second rotating every month in order to explain the movement through the zodiac (movement against the stars); and a third rotating monthly on a slightly different axis in order to explain its variation in latitude. To see Eudoxus solution click here.
The problem that was obvious to the ancient astronomers was that planets behaved in a strange fashion, sometimes they were closer, sometimes farther away from Earth, sometimes speeding up and sometimes slowing down or even appearing to travel backwards. The word “planet” comes from the Ancient Greek word for “wonder”. Our friend Eudoxus required 27 concentric spheres to explain the movements in the heavens, but that was later refined by his contemporary, the great philosopher Aristotle, in to a model of greater perfection. In an attempt to make sense of what was observed, he placed 55 concentric spheres around the Earth, each responsible for a specific movement of the heavenly bodies, always though in the perfect eternal motion of a circle, as they passed through the substance out there that he called the “aether”. At the furthest extremities he placed the “Unmoved Mover”, or the force that centuries later came to represent the all-powerful Christian God.
All this could have, and should have, been rendered irrelevant had the ideas of Aristarchus, also of Samos, caught on some 200 years later! Essentially he had it all worked out. He placed the Sun at the centre of the cosmos, with the Earth and other planets circling it, in the same order as we know them today.
But his theories did not stand up to the withering logic of the time. He was unpicking the established teachings of the great Aristotle and Plato. Yet it didn’t gain kudos because it seemed so self-evidently wrong. If indeed the Earth were moving through space, why would an object thrown upwards come straight back down? Surely it would land at a distance away as the ground the individual were standing on moved through space. So, the common sense of the time indicated that Aristotle had it right.
Disfellowshipping or excommuniation –
Jehovah’s Witnesses practice something they refer to as ‘disfellowshipping’ this is something they use to control their congregations by fear. As someone who was a Jehovah’s Witness and who has been disfellowshipped allow me to please explain what happens to you once you are disfellowshipped.
I was brought up as a Witness* and left when I was in my early thirties. Unlike many ex-JW’s I didn’t walk away from it, despite many seemingly unanswerable questions, I was excommunicated and treated like a criminal. This meant that all of the friends that I had grown up with over the years of being a JW were now no longer permitted to have any contact with me. I couldn’t contact them and explain my side of the story (they wouldn’t take my calls). It meant my immediate family were to no longer have any communication with me (not even via email or text message).
*you can read my story in full here
Now credit to my folks, they allowed me to stay in their house as, due to a divorce I had lost my own along with everything I owned after 6/7 years of marriage to an upright christian sister (yeah right).
Now unless you’ve been through a divorce you cannot understand what it is like, you go through a mourning process as if someone close to you has died. In my case my ex had two kids from a previous marriage who lived with their biological father, but I still loved them as my own.
I mention this as I want you to appreciate how depressed I would have been. I had lost my house and my marriage. I was still working but was obviously not in the best frame of mind. I had a friend and his name was Vodka.
Then I met someone. I could talk and she would listen, we became friends and the rest is history. I was getting on with my life. But this wasn’t what the Jehovah’s Witness plan allowed. Oh hell no, you can’t be happy after you’ve left them! I had had many accusations thrown at me by my ex so they had to act on them, she was of course out for blood. Plus the ‘committee’ were on a witch hunt and I was the target. I never got on with any of them really and none of them knew the real me. I attended the first meeting as I was misled but refused the second one as I knew the outcome already.
(Note; none of the buffoons had any legal or educational qualifications so were never in a position to help – which is surely what Jeebus instructed them to do right?).
So that was that.
My family, my friends, everyone I knew were erased in that moment. Imagine falling from an aircraft a mile up without a parachute that’s kind of how it felt. That inevitable feeling of imminent death.
But it doesn’t come. Well it didn’t for me because I had someone who cared for me. Who encouraged me and helped me to find the answers to those unanswerable queries I mentioned before.
But that isn’t the end of the story. Despite moving on, being social awkward, making a few friends but none I am really close with. I have moments of dark depression and loneliness. These appear at random times and vary in veracity. Sometimes I can mentally kick my ass and get on with it, but when I am low because of illness or whatever, it gets harder. Being disabled doesn’t help much either.
These moments are when you need to speak to a parent, sibling, or mate over the phone or over a pint down the Dock and Duck. But you have no one. I don’t anyhow. I am a social outcast who lacks the skill to befriend. Don’t get me wrong, I have over 100 friends on Facebook! But aside from my wife none I am close to. I’ve put it out there a few times about meeting up for a coffee or a beer. But no one ever responds. I know folks have their own lives and are busy. I know too I am a very vocal Atheist, perhaps too vocal. But I care. Why should anyone have their heart ripped out twice?
So I admit it here (though I doubt anyone reads this blog anymore) I am 42 years old. I am married to a woman whom I love very much. I have five lovely children and……..I am painfully lonely.
I watch those films where a guy meets up with 4 of his buddies who he’s known since school and they go on a road trip and get drunk have a right laugh, gamble, drink, sky dive etc.
I’ve wanted that since I left school! I couldn’t then because of the cult’s restrictions so lost all contact. I couldn’t befriend workmates, because of the cult’s restrictions. Then they took all that away from me (though I am glad to be out trust me).
But they left behind a dysfunctional social outcast. Not that I have a social life.
I get up, I take my medication, some days I can leave the house. Most days I stay in my bed.
I sit and wonder what is the point?
I read to keep my sanity.
There’s that big question mark. What’s the point?
Honestly, if my Wife and kids weren’t here I wouldn’t be.
Even then I have my moments.
Because for all eternity we hold the hand of the person who brought us in to this world, who loved and cared for us, sacrificed much and yet will no longer have any contact with you.
So the wound is an open one, and the pain continues. The anger rises, the frustration takes a grip, but overall that feeling of utter rejection and self loathing permeates your very being.
All because a printing company decided that this control method, never mentioned in their bibles, should be adopted in 1952.
I am thankful for my wife, best friend and soul mate for being there.
Learn more about the Jehovah’s Witness practice of disfellowshipping here:
Researchers at the Université Laval Faculty of Medicine, the Quebec Heart and Lung Institute Research Center, and the Institute of Nutrition and Functional Foods have discovered a natural molecule that could be used to treat insulin resistance and type 2 diabetes. The molecule, a derivative of omega-3 fatty acids, mimics some of the effects of physical exercise on blood glucose regulation. The details of the discovery made by Professor André Marette and his team are published today in Nature Medicine.
It has been known for some time that omega-3 fatty acids can help reduce insulin resistance caused by a diet high in saturated fat. In their earlier work, André Marette and his colleagues had linked these effects to a bioactive lipid called protectin D1. In investigating further, they discovered that another member of the same family named protectin DX (PDX) triggers the production and release of interleukin 6 (IL-6) in muscle cells, a response that also occurs during physical exercise. “Once in the bloodstream, IL-6 controls glucose levels in two ways: it signals to the liver to reduce glucose production and acts directly on the muscles to increase glucose uptake,” explains the researcher who is also Scientific Director of Université Laval’s Institute of Nutrition and Functional Foods.
The researchers used transgenic mice lacking the IL-6 gene to demonstrate the link between PDX and IL-6. PDX had very little effect on the control of blood glucose in these animals. In similar tests conducted on obese diabetic rats, PDX was shown to dramatically improve responsiveness to insulin, the hormone which regulates blood glucose. “The mechanism of action described for PDX represents a new therapeutic strategy for improving glucose control,” proposes the researcher. “Its efficacy may be comparable with that of certain drugs currently prescribed to control glycemia.”
Even though PDX appears to mimic the effect of physical exercise by triggering IL-6 secretion in the muscles, André Marette warns that it is not a substitute for physical activity. “Exercise has cardiovascular and other hormonal benefits that go well beyond its metabolic effects on the muscles,” adds the researcher whose work is supported by the Canadian Institutes of Health Research (CIHR) and the Canadian Diabetes Association.
Professor Marette and Université Laval have filed a patent application for PDX and its therapeutic applications. “For us, the next step is to demonstrate the antidiabetic effects in humans and determine the receptor through which PDX acts.”
In addition to André Marette, the study is authored by Phillip White, Philippe St-Pierre, Alexandre Charbonneau, Patricia Mitchell, Emmanuelle St-Amand, and Bruno Marcotte.
The 2010 Deepwater Horizon blowout discharged roughly five million gallons of oil and up to 500,000 tons of natural gas into Gulf of Mexico offshore waters over a period of 84 days. In the face of a seemingly insurmountable cleanup effort, many were relieved by reports following the disaster that naturally-occurring microbes had consumed much of the gas and oil.
Now, a team of researchers led by University of Georgia marine scientists have published a paper in the journalNature Geoscience that questions this conclusion and provides evidence that microbes may not be capable of removing contaminants as quickly and easily as once thought.
“Most of the gas injected into the Gulf was methane, a potent greenhouse gas that contributes to global climate change, so we were naturally concerned that this potent greenhouse gas could escape into the atmosphere,” said Samantha Joye, senior author of the paper, director of the study and professor of marine science in UGA’s Franklin College of Arts and Sciences. “Many assumed that methane-oxidizing microbes would simply consume the methane efficiently, but our data suggests that this isn’t what happened.”
Joye and colleagues from other universities and government organizations measured methane concentrations and the activity of methane-consuming bacteria for ten months, starting before the blowout with collection of an invaluable set of pre-discharge samples taken in March 2010.
The abundance of methane in the water allowed the bacteria that feed on the gas to flourish in the first two months immediately following the blowout, but their activity levels dropped abruptly despite the fact that methane was still being released from the wellhead.
This new data suggests the sudden drop in bacterial activity was not due to an absence of methane, but a host of environmental, physiological, and physical constraints that made it difficult or impossible for bacteria to consume methane effectively.
“For these bacteria to work efficiently, they need unlimited access to nutrients like inorganic nitrogen and trace metals, but they also need elevated methane levels to persist long enough to support high rates of consumption,” Joye said. “The bacteria in the Gulf were probably able to consume about half of the methane released, but we hypothesize that an absence of essential nutrients and the dispersal of gas throughout the water column prevented complete consumption of the discharged methane.”
Joye insists that while her group’s conclusions differ from those presented in previous studies, there is no serious conflict between their analyses.
“The issue here was short-term sampling versus long-term time series sampling,” she said. “I hope our paper clearly relays the message that long-term sampling is the only way to capture the evolution of a natural system as it responds to large perturbations like oil well blowouts or any other abrupt methane release.”
Ultimately, scientists need to better understand the behavior of these microbes so that they may better gauge the environmental impacts of future accidents and methane releases due to climate change, she said.
“It’s only a matter of time before we face another serious incident like Deepwater Horizon,” Joye said. “The key is understanding the things that regulate how fast bacteria can consume methane, and that will give us insight into the ultimate fate of this potent greenhouse gas in our oceans.”
Carbohydrate-binding proteins fill in gaps in immune defenses
Our bodies produce a family of proteins that recognize and kill bacteria whose carbohydrate coatings resemble those of our own cells too closely, scientists have discovered.
Called galectins, these proteins recognize carbohydrates from a broad range of disease-causing bacteria, and could potentially be deployed as antibiotics to treat certain infections. The results are scheduled for publication in Nature Chemical Biology.
Researchers at Emory University School of Medicine made the discovery with the aid of glass slides coated with an array of over 300 different glycans (carbohydrates found on the surfaces of cells) derived from bacteria, many of which are found in the intestine. One can think of these slides – called microbial glycan microarrays – as wardrobes displaying a variety of clothes worn by gut bacteria.
“Many microbes cover themselves with glycans that somewhat resemble our own cells,” says Richard D. Cummings, PhD, professor and chair of the Department of Biochemistry at Emory University School of Medicine. “That limits how well the immune system can use antibodies to respond to those microbes.”
To prevent auto-immune attack, our bodies usually don’t make antibodies against molecules found on our own cells. That leaves gaps in our defenses that bacteria could exploit. Several of those gaps are filled by galectins, the researchers found.
The discovery expands upon an initial finding, published in Nature Medicine in 2010, describing galectins that recognize and kill bacteria that express the human blood group B antigen.
The Emory researchers collaborated with the laboratory of James C. Paulson, PhD, at the Scripps Research Institute (TSRI). Co-first authors of the paper are Sean Stowell, MD/PhD (a resident in in laboratory and transfusion medicine at Emory), Connie Arthur, PhD (postdoctoral fellow at Emory with Stowell), and research assistant Ryan McBride at TSRI.
In contrast to antibodies, the galectins kill the bacteria directly, without needing other parts of the immune system to pile on. The researchers identified several varieties of bacteria (Pseudomonas aeruginosa, Providencia alcalifaciens, Klebsiella pneumoniae, and Serratia marcescens, for example) targeted for killing by galectins. In some cases, only certain strains of a given bacteria were vulnerable, because only those strains carried the target glycan.
“These studies have opened the way to understanding the ways in which adaptive or antibody-based factors work together with innate or galectin-based factors to give us immunity against a broad range of microbes,” Cummings says.
In addition, the microarray technology provides tools to study glycan-binding antibodies and galectins in populations, he says.
“These studies use tiny amounts of blood – just a few drops – and show how glycan microarrays could supersede previous technology,” he says. “Using these tools, investigators could identify developmental- and age-specific differences in anti-microbial glycan antibodies in humans, which may predict susceptibility to disease.”