Pig hearts could be transplanted into humans after baboon success.


A genetically engineered pig heart which was transplanted into a baboon has survived more than a year without being rejected, leading scientists to hope that animal parts could one day provide a limitless sources of organs.

Researchers successfully grafted a pig heart into a baboon more than a year ago and it is still functioning

The hearts of genetically modified pigs could be transplanted into humans to solve the shortage of organ donors, scientists believe.

Researchers successfully grafted a pig heart into a baboon more than a year ago and it is still functioning, they report today.

Until now, organs transplanted into primates have only lasted for a maximum of six months before being rejected.

But scientists have tweaked the DNA of pigs so that their hearts are more compatible with primates and humans.

“The developments may instil a new ray of hope for thousands of patients waiting for human donor organs,” said Muhammad Mohiuddin of the Cardiothoracic Surgery Research Programme at the National Heart, Lung, and Blood Institute in the US.

“If successful, this method could change the current transplant paradigm, eliminating the shortage of donor organs including hearts, livers, kidneys, intestine, as well as insulin producing cells for treatment of diabetes.”

At present people needing a heart transplant must wait until a suitable donor heart becomes available. Last year 145 operations were carried out at seven hospitals in Britain.

However, only eight out of 10 people in the UK receive the transplant they needed because of a lack of suitable donors. Many adults and children are forced to wait more than a year for a new heart.

Those on waiting lists have to use an artificial heart but these are not perfect and have issues with power supplies, infection, and both clotting and haemolysis, the break down of red blood cells.

Transplantation using an animal organ, or xenotransplantation, has been proposed as an option to save human lives, but the challenge has been to stop hosts rejecting donor hearts.

However researchers found that the pig hearts were alive and functioning well more than year after being grafted in place.

Pigs were chosen because their anatomy is compatible with humans and they have a rapid breeding cycle. Pig valves are already swapped for human heart valves.

Critics claim that because the life cycle of pigs is shorter than humans they will need to be replaced. They could also pass on diseases.

But through genetic changes, the scientists have added several human genes to the pig genome as well as removing genes which trigger a dangerous immune response in humans.

Grafts from these genetically engineered pigs are less likely to be seen as foreign, thus reducing the immune reaction against them.

Chris Mason, professor of regenerative medicine at University College London, said: “The fact is you have got lots of people waiting for heart transplants and if you could have a supply of hearts off the shelf then that is clearly beneficial.

“Heart failure is a really horrible condition so anything that could improve quality of life is of great value.

“I think we are a long way off from being able to genetically engineer a whole heart though stem cells so this could provide a good stop-gap.”

The genetic modifications also mean that fewer immunosuppressive drugs are needed which are often responsible for complications. When Christiaan Barnard attempted the first heart transplant in 1967 it was the drugs which killed his patient as his immune system was so weak he died from pneumonia.

The experiments involved using these genetically engineered pig hearts, transplanted in the abdomen of baboons alongside their actual hearts.

The next step is to use hearts from the same pigs to test their ability to provide full life support by replacing the original baboon heart.

Dr Mohiuddin said; “Based on the data from long-term surviving grafts, we are hopeful that we will be able to repeat our results in the life-supporting model.”

Prof Peter Weissberg, the medical director of the British Heart Foundation said: “I think this stands a high chance of happening but it is still a very long way off.

“There were similar projects happening in the 1990s but they ground to a halt because they struggled to deal with the problems of rejection.

“There is a shortage of organs so this could be potentially promising and we already use pig valves in heart surgery.

“But there is a long way to go. They still have to prove this would work in humans.”

The study was presented at the 94th American Association for Thoracic Surgery annual meeting in Toronto.

Scientists Discover A Potential Anti-HIV Protein In Corals.


Whilst screening the National Cancer Institute’s extract repository, scientists discovered a new class of proteins from a feathery coral found in Australian waters. It transpires that these proteins, called cnidarins, are in fact potent inhibitors of HIV entry into T-cells in laboratory tests.

At a time when over 35 million people worldwide are infected with HIV and current treatments are not curative, focusing on the prevention of new infections is paramount in confronting this global problem. HIV has also presented significant challenges in the development of vaccines and none are so far available.

Although condoms are effective at preventing transmission, the fact is: not everybody uses them, and often this is out of the control of some individuals. The development of other methods that can curb sexual transmission are therefore an attractive solution to the problem, and scientists believe that these cnidarins may eventually be used to do just that.

After discovering these proteins, scientists purified them and tested them for inhibitory effects against laboratory HIV strains. They found that they prevented HIV from being able to enter T-cells at impressively low concentrations. T-cells are one of the main cells that HIV targets for replication. The proteins achieved this block by binding to the virus and preventing fusion with the host cell, which is a pre-requisite to viral entry.

Before the scientists can proceed with preclinical tests to find out more about the safety and efficacy of these proteins, they first need to find a way to mass produce these proteins without having to harvest vast quantities of corals.

Although it is certainly very early days, the scientists are optimistic that these proteins may present an ideal candidate for the development of topical gels or lubricants that could prevent sexual HIV transmission without encouraging resistance, which is a problem that current antivirals face.

This study also serves as an exciting reminder for the fact that many natural substances with surprising medicinal properties may await discovery. “The natural products extract repository is a national treasure,” said Barry O’Keefe, senior investigator of this study. “You never know what you might find. Hopefully, discoveries like this will encourage more investigators to use this resource to identify extracts with activity against infectious disease.”

Make Your Own Droplet Microscope Lens for a Penny .


Clear liquid droplets can bend light, acting like a lens. By exploiting this well-known phenomenon, scientists have devised a cheap and simple way to turn a smartphone into a high-resolution microscope. The high-powered lenses cost less than a cent apiece to make, and all you need is a cover slip or glass slide, some common polymer, and an oven. The method would be immensely helpful for diagnosing medical conditions in remote areas and developing countries.

Conventional lenses are usually made in one of two ways. You can grind and polish a flat disk of glass into a particular curved shape, or you can pour gel into molds. These new lentil-sized lenses simply retain the natural shape of liquid droplets. They’re made of a gel-like silicon polymer called polydimethylsiloxane (PDMS) — the same unbreakable, scratch-free stuff used for contact lenses.

And it really sounds quite simple to make. “We put a droplet of polymer onto a microscope cover slip and then invert it. Then we let gravity do the work, to pull it into the perfect curvature,” study author Steve Lee from Australia National University explains in a news release.

By adding small amounts of fluid to the droplet successively after baking the base drop, they managed to reach a (surprisingly high) magnifying power of 160 times with an imaging resolution of four micrometers. They varied the focal lengths by letting the drop hang and then curing (or hardening) them further in the oven.

“What I did was to systematically fine-tune the curvature that’s formed by a simple droplet with the help of gravity, and without any molds,” Lee explains. No complicated machinery needed. Here’s the step-by-step easy-bake recipe:

 

  • 1. Drop a small amount of PDMS onto the slide.
  • 2. Bake at 70 degrees Celsius to harden it and create a base.
  • 3. Afterwards, drop another dollop of PDMS onto the base and flip the slide over.
  • 4. Watch as gravity pulls the new droplet down into a parabolic shape.
  • 5. Bake the droplet again to solidify the lens.
  • 6. Add more drops as needed to hone the lens shape and enhance the imaging quality of the lens.

 

The whole lens was only a few millimeters thick and just over a centimeter in diameter. The team then designed a lightweight 3D-printable frame to hold the lens, along with a couple mini LEDs and a coin battery for watches. The attachment turns a smartphone camera into a dermascope to diagnose skin diseases like melanoma. Dermascopes can cost $500; this new prototype dermascope add-on comes to about $2. You can check out this comparison of the magnified images.

The new dermascope could be commercially available in just a few months, according to Lee. With a different app, a similar tool can help farmers identify pests in the field. And to think, the first droplet lens was made by accident. Serendipitous.
 

 

Yet Another Disease That Responds Better to Marijuana Than Prescription Drugs .


For the estimated five million Americans suffering from  Fibromyalgia (FM), a chronic pain condition of unknown etiology, pain, fatigue, and depression are often a way of life. Though the US Food and Drug Administration has approved a small number of drugs to treat symptoms of FM, many patients report that these prescription pills provide little relief. By contrast, more and more patients with FM are finding effective relief from medical cannabis.

So say the results of a  recent online survey of over 1,300 subjects conducted by  The National Pain Foundation and NationalPainReport.com. Among those surveyed, 379 subjects said that they had used cannabis therapeutically. Sixty-two percent of them rated the substance to be “very effective” in the treatment of their condition. Only five percent of said that cannabis did “not work at all.”

By comparison, among those FM patients who had used Cymbalta (Duloxene), only eight percent rated the drug as “very effective,” and 60 percent said it did “not work at all.” Among those who had used Lyrica (Pregabalin), ten percent said that drug was “very effective,” versus 61 percent who reported no relief. Among those who had used Savella (Milnacipran), ten percent rated the drug as effective, and 68 percent said it was ineffective.

Commenting on the survey results, Dr. Mark Ware — associate professor in family medicine and anesthesia at McGill University in Montreal — told the National Pain Report, “We desperately need someone to step up and explore this potential for the efficacy of cannabis.”

Ware, whose own clinical research  has demonstrated inhaled pot’s efficacy in subjects with hard-to-treat refractory pain, added: “The scientific rationale is there. There are some early preliminary, proof-of-concept clinical trials that demonstrate cannabis may be effective. Now your study adds additional weight that patients are reporting that cannabis may be better than the existing therapies. I think that this really should provide incentives for researchers to take a hard look at clinical trials to really explore that in much more detail.”

Some investigators already have. In 2006,  German scientists reported that the administration of oral THC significantly reduced both chronic and experimentally induced pain in patients with fibromyalgia. Subjects in the trial were administered daily doses of 2.5 to 15 mg of THC, but received no other pain medication during the study. Among those participants who completed the trial, all reported significant reductions in daily pain and electronically induced pain.

More recently, Spanish researchers assessed the use of cannabis treatment of Fibromyalgia. A cursory review of the results indicates why so many FM patients are preferring pot over pills.

Investigators reported, “The use of cannabis was associated with beneficial effects on some FM symptoms. … After two hours of cannabis use, VAS (visual analogue scales) scores showed a statistically significant reduction of pain and stiffness, enhancement of relaxation, and an increase in somnolence and feeling of well being.”

They concluded, “We observe significant improvement of symptoms of FM in patients using cannabis in this study although there was a variability of patterns. This information, together with evidence of clinical trials and emerging knowledge of the endocannabinoid system and the role of the stress system in the pathophysiology of FM suggest a new approach to the suffering of these patients.”

Top Children’s Vitamins are Full of Aspartame , GMO’s and Chemicals .


Are you aware of the ingredients contained in the multivitamin that you feed your children? Some of the most popular childrens vitamins contain genetically-modified organisms (GMOs), aspartame, artificial colours, even aluminum and more besides.

If as an example we look at the Flintstones vitamin, (currently one of the top selling multivitamins in the United States) it contains a number of ingredients such as GMOS’s, aspartame, aluminum, petroleum-derived artificial colours and much more. Such ingredients are known not to be good for our health and infact can have very toxic effects.Lets take a closer look at some of these ingredients.

Aspartame
Aspartame is known to cause damage to the brain at any doseage by leaving Methanol traces in the blood. It is questionable why Aspartame has ever been approved as “safe” especially as it is found in thousands of our everyday food products; not to mention children’s vitamins. It has been linked to Lymphoma and Leukaemia. It is formed using a synthetic combination of the amino acids known as aspartic acid and I-phenylalanine and once it is in our bodies it converts itself into toxic methanol and formaldehyde.

Sorbitol
Sorbitol is a synthetic sugar substitute. It is actually classified as a sugar alcohol. There are links between the ingestion of higher amounts to gastrointestinal problems, ranging from abdominal pain to far more serious conditions such as irritable bowel syndrome.

Hydrogenated Soybean Oil
It is unbelievable that any products containing hydrogenated soybean oil is being marketed for children. They are in fact semi-synthetic fatty acids that then incorporate themselves into our body tissues. They have previously been linked to dozens of harmful health effects, ranging from coronary artery disease to cancer and fatty liver disease to name a few issues.

Ferrous Fumarate
This is possibly even more shocking that Ferrous Fumarate is an ingredient here. Even on the Flintstone’s own website you will find a warning regarding this chemical. In this case it is being used as an iron supplement . However it is important to realize that when consuming iron that comes naturally in food, it is actually impossible to inject toxic amounts that can cause death. But when taking Ferrous Fumarate, fatal levels of toxicity can be reached. What is just as astonishing is that studies have been conducted that show ferrous fumarate doesn’t even affect iron status in children, so not only is it dangerous, but also serves no purpose.

Cupric Oxide
Under the European Union’s Dangerous Substance Directive, Cupric Oxide is actually listed as a hazardous substance! It has been classified as both harmful and dangerous to the environment. It’s usual use is as a pigment in ceramics and also as a chemical in the production of rayon fabric and dry cell batteries. It may be technically correct to call it a mineral, but should it be listed as a nutrient in a children’s vitamin?

Surely it is time for us to examine far more closely what we choose to feed our children. All it takes is a little time spent on investigating and changing our own awareness of what is going on around us. It is so easy to get stuck in a robotic life style, believing what various companies want us to believe without question. All we have to do is notice, after that we can begin making better choices in our own lives. Slowly the world is waking up, and more and more people feel that it’s time to move on, grow and explore our infinite potentiality.Can there be a more important topic to start with then what we feed our children, after all they are the future –.

please sharethis around so others have a chance to see it..

 

Depression detectable in the blood: Platelet serotonin transporter function .


The possibility of using a blood test to detect depression has been demonstrated by researchers. While blood tests for mental illnesses have until recently been regarded as impossible, a recent study clearly indicates that, in principle, depression can in fact be diagnosed in this way and this could become reality in the not too distant future.

Researchers at the MedUni Vienna have demonstrated the possibility of using a blood test to detect depression.
Credit: © ??? / Fotolia

Researchers at the MedUni Vienna have demonstrated the possibility of using a blood test to detect depression. While blood tests for mental illnesses have until recently been regarded as impossible, a recent study clearly indicates that, in principle, depression can in fact be diagnosed in this way and this could become reality in the not too distant future.

Serotonin transporter (SERT) is a protein in the cell membrane that facilitates the transport of the neurotransmitter serotonin (popularly known as the “happiness hormone”) into the cell. In the brain, serotonin transporter regulates neural depression networks. Depressive conditions can frequently be caused by a lack of serotonin. As a result, the serotonin transporter is also the point of action for the major antidepressant drugs.

The serotonin transporter, however, also occurs in large quantities in numerous other organs such as the intestines or blood. Recent studies have shown that the serotonin transporter in the blood works in exactly the same way as in the brain. In the blood, it ensures that blood platelets maintain the appropriate concentration of serotonin in the blood plasma.

Researchers at the MedUni Vienna have now used functional magnetic resonance imaging of the brain and pharmacological investigations to demonstrate that there is a close relationship between the speed of the serotonin uptake in blood platelets and the function of a depression network in the brain.

This network is termed the “default mode network” because it is primarily active at rest and processes content with strong self-reference. Findings from recent years have also demonstrated that it is actively suppressed during complex thought processes, which is essential for adequate levels of concentration. Interestingly, patients with depression find it difficult to suppress this network during thought processes, leading to negative thoughts and ruminations as well as poor concentration.

“This is the first study that has been able to predict the activity of a major depression network in the brain using a blood test. While blood tests for mental illnesses have until recently been regarded as impossible, this study clearly shows that a blood test is possible in principle for diagnosing depression and could become reality in the not too distant future,” explains study leader Lukas Pezawas from the Department of Biological Psychiatry at the University Department of Psychiatry and Psychotherapy within the MedUni Vienna. This result means that the diagnosis of depression through blood tests could become reality in the not too distant future.

The study was carried out by Christian Scharinger and Ulrich Rabl, under the supervision of Lukas Pezawas at the Department of Biological Psychiatry, University Department of Psychiatry and Psychotherapy at the MedUni Vienna, in collaboration with groups from the special research division SFB-35 and other institutions at the MedUni Vienna, as well as international cooperation partners (Technical University of Dresden, Central Institute for Mental Health, Mannheim). Alongside other colleagues from the University Department of Psychiatry and Psychotherapy, the MedUni Vienna’s Centre of Excellence for High Field MR, Clinical Institute of Laboratory Medicine and Institute of Pharmacology were also involved in the study.


Story Source:

The above story is based on materials provided by Medical University of Vienna. Note: Materials may be edited for content and length.


Journal Reference:

  1. Christian Scharinger, Ulrich Rabl, Christian H. Kasess, Bernhard M. Meyer, Tina Hofmaier, Kersten Diers, Lucie Bartova, Gerald Pail, Wolfgang Huf, Zeljko Uzelac, Beate Hartinger, Klaudius Kalcher, Thomas Perkmann, Helmuth Haslacher, Andreas Meyer-Lindenberg, Siegfried Kasper, Michael Freissmuth, Christian Windischberger, Matthäus Willeit, Rupert Lanzenberger, Harald Esterbauer, Burkhard Brocke, Ewald Moser, Harald H. Sitte, Lukas Pezawas. Platelet Serotonin Transporter Function Predicts Default-Mode Network Activity. PLoS ONE, 2014; 9 (3): e92543 DOI: 10.1371/journal.pone.0092543

Mother’s diet affects the ‘silencing’ of her child’s genes.


A unique ‘experiment of nature’ that took place in The Gambia has now revealed that a mother’s diet before she conceives has a permanent effect on her offspring’s genetics. This is the first time the effect has been seen in humans, and is regarded as a major contribution to the field of ‘epigenetics.’

An infant from the Gambia.
 

Mother’s diet before conception can permanently affect how her child’s genes function, according to a study published in Nature Communications.

The first such evidence of the effect in humans opens up the possibility that a mother’s diet before pregnancy could permanently affect many aspects of her children’s lifelong health.

Researchers from the MRC International Nutrition Group, based at the London School of Hygiene & Tropical Medicine and MRC Unit, The Gambia, utilized a unique ‘experiment of nature’ in rural Gambia, where the population’s dependence on own grown foods and a markedly seasonal climate impose a large difference in people’s dietary patterns between rainy and dry seasons.

Through a selection process involving over 2,000 women, the researchers enrolled pregnant women who conceived at the peak of the rainy season (84 women) and the peak of the dry season (83 women). By measuring the concentrations of nutrients in their blood, and later analysing blood and hair follicle samples from their 2-8 month old infants, they found that a mother’s diet before conception had a significant effect on the properties of her child’s DNA.

While a child’s genes are inherited directly from their parents, how these genes are expressed is controlled through ‘epigenetic’ modifications to the DNA. One such modification involves tagging gene regions with chemical compounds called methyl groups and results in silencing the genes. The addition of these compounds requires key nutrients including folate, vitamins B2, B6 and B12, choline and methionine.

Experiments in animals have already shown that environmental influences before conception can lead to epigenetic changes that affect the offspring. A 2003 study found that a female mouse’s diet can change her offspring’s coat colour by permanently modifying DNA methylation.1 But until this latest research, funded by the Wellcome Trust and the MRC, it was unknown whether such effects also occur in humans.

Senior author Dr Branwen Hennig, Senior Investigator Scientist at the MRC Gambia Unit and the London School of Hygiene & Tropical Medicine, said: “Our results represent the first demonstration in humans that a mother’s nutritional well-being at the time of conception can change how her child’s genes will be interpreted, with a life-long impact.”

The researchers found that infants from rainy season conceptions had consistently higher rates of methyl groups present in all six genes they studied, and that these were linked to various nutrient levels in the mother’s blood. Strong associations were found with two compounds in particular (homocysteine and cysteine), and the mothers’ body mass index (BMI) had an additional influence. However, although these epigenetic effects were observed, their functional consequences remain unknown.

Professor Andrew Prentice, Professor of International Nutrition at the London School of Hygiene & Tropical Medicine, and head of the Nutrition Theme at the MRC Unit, The Gambia, said: “Our on-going research is yielding strong indications that the methylation machinery can be disrupted by nutrient deficiencies and that this can lead to disease. Our ultimate goal is to define an optimal diet for mothers-to-be that would prevent defects in the methylation process. Pre-conceptional folic acid is already used to prevent defects in embryos. Now our research is pointing towards the need for a cocktail of nutrients, which could come from the diet or from supplements.”

Dr Rob Waterland of Baylor College of Medicine in Houston, who conducted the epigenetic analyses said: “We selected these gene regions because our earlier studies in mice had shown that establishment of DNA methylation at metastable epialleles is particularly sensitive to maternal nutrition in early pregnancy.”

The authors note that their study was limited by including only one blood sampling point during early pregnancy, but estimates of pre-conception nutrient concentrations were calculated using results from non-pregnant women sampled throughout a whole calendar year. The authors also plan to increase the sample size in further studies.


Story Source:

The above story is based on materials provided by London School of Hygiene & Tropical Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Paula Dominguez-Salas, Sophie E. Moore, Maria S. Baker, Andrew W. Bergen, Sharon E. Cox, Roger A. Dyer, Anthony J. Fulford, Yongtao Guan, Eleonora Laritsky, Matt J. Silver, Gary E. Swan, Steven H. Zeisel, Sheila M. Innis, Robert A. Waterland, Andrew M. Prentice, Branwen J. Hennig. Maternal nutrition at conception modulates DNA methylation of human metastable epialleles. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4746

Inflammation Inhibitor Fails to Affect CV Outcomes.


A novel agent that targets the inflammation process believed involved in cardiovascular events failed to reduce heart attack, stroke, or cardiovascular death in at-risk individuals when compared with placebo, researchers reported here and online in the New England Journal of Medicine.

The composite endpoint was experienced by 9.7% of the patients with chronic coronary heart disease who were treated with the new agent, darapladib, while that endpoint was experienced by 10.4% of patients assigned to placebo (P=0.199), said Harvey D. White, MD, director of the coronary care unit at Auckland City Hospital in Auckland, New Zealand, and a co-chair of the study.

However, secondary endpoints offered promise that darapladib might be helpful in subsets of people in the study, White suggested during his presentation of the at the annual scientific sessions of the American College of Cardiology. For example, he noted that the relative risk reduction for time to first occurrence of major coronary events, which also included urgent coronary revascularization, was decreased by 10% with darapladib when compared with placebo (P=0.045).

However, Howard Bauchner, MD, editor in chief of the Journal of the American Medical Association, who discussed the study at a press conference, told MedPage Today, “This was the finding of a secondary endpoint and when you have a number of secondary endpoints, if you look hard enough there is usually something that meets statistical significance.

“I think they are going to have to go back to ground zero to design a new trial that may work for certain individuals for this drug,” he said.

In the “Stabilization of Atherosclerotic Plaque by Initiation of Darapladib Therapy (STABILITY)” trial, White and colleagues in nine countries enrolled 15,828 individuals who had experienced a prior myocardial infarction, had undergone prior coronary revascularization or had documented multivessel coronary artery disease. He said 7,904 patients in the study were assigned to placebo and 7,924 patients received darapladib 160 mg once daily.

The patients were all being treated with aspirin therapy, statin and anti-hypertensive medication as indicated, and then were randomly assigned to either darapladib or placebo on top of their optimized medical treatment.

After 48 months, researchers observed 819 events in the placebo arm of the study and 769 events in the patients on darapladib.

White said the goal of the study was to determine if treatment with darapladib which inhibits Lp-PLA2, a biomarker of inflammation in blood vessels, could prevent intra-bloodstream events that lead to cardiovascular events. In the bloodstream, Lp-PLA2 is generally found on LDL cholesterol. High Lp-PLA2 levels are a risk factor for coronary heart disease. In animal models, Lp-PLA2 is linked with vulnerable plaque.

He said that the treatment was well tolerated over the median follow-up of 3.7 years in the international, phase III double-blind trial.

“These events are clinically important, with substantial consequences for patients,” said White. “The effects on these endpoints could support the hypothesis that inhibition of Lp-PLA2 with darapladib may alter the composition of atherosclerotic plaques to a less vulnerable state and reduce ischemic events related to coronary artery plaque progression and rupture.”

White said that patients in the study were under good care by their physicians. At baseline, 93% of patients were taking aspirin, 97% were on statins, 79% were taking beta-blockers, and 77% were on antihypertensive ACE-inhibitors. “We set out to test the incremental effect of darapladib on top of optimal treatment,” he said.

STABILITY is the first study to test this inflammation-prevention mechanism for reducing the likelihood that plaque will become an artery-blocking clot. Ongoing analysis of biomarkers, including Lp-PLA2 levels, and genetic sub-studies of STABILITY may help provide insight about darapladib’s potential effects on the prevention of coronary events in patients with stable coronary heart disease.

Females prefer lovers not fighters, horned beetle study finds.


It’s official (in the horned beetle world at least), females prefer courtship over competitiveness – and it doesn’t matter about the size of your mandibles either.

An international study by scientists at the University of Exeter and the Universities of Okayama and Tsukuba in Japan investigated the complicated sexual conflict over mating in Gnatocerus cornutus, the horned flour-beetle.

https://i1.wp.com/cdn.physorg.com/newman/gfx/news/2014/femalesprefe.jpg

Female mate choice and male-male competition are the typical mechanisms of sexual selection. However, these two mechanisms do not always favour the same males.

Male horned beetles have enlarged lower jaws – or mandibles – used to fight rivals, and those with larger mandibles do have a mating advantage when there is direct male-male competition. But until now, it has not been clear whether the actually prefer these highly competitive males.

After conducting experiments with hundreds of the insects, the researchers show that female choice targets male courtship rather than mandible size, and that the two traits are not physically or genetically correlated.

Professor Dave Hosken, of the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus, said: “A major finding of this study was that the most attractive males, those most preferred by females, were not the highly competitive males with large mandibles. This is despite the fact these fighter males enjoy significant mating advantages when in direct competition for females. Instead, females prefer to mate with males that court more. This shows that choice and competition favour different traits.”

The most attractive males, those most preferred by females, were not the highly competitive males with large mandibles. This is despite the fact these fighter males enjoy significant mating advantages when in direct competition for females. Instead, females prefer to mate with males that court more. Credit: Dave Hosken

The scientists also investigated whether females benefit from their choice of mate, both in terms of the effects on their own fitness and on the fitness of their sons and daughters.

Mating with more attractive and competitive males was not found to provide direct benefits to females, but it did lead to them producing more attractive and competitive sons.

For daughters, those whose mothers mated with attractive males (lovers) rather than competitive males (fighters) did not suffer from the masculization costs sometimes observed. These occur because when the body shape changes associated with developing large mandibles in males are transmitted to daughters it means a reduction in egg space.

Radiation level in tuna off Oregon coast tripled after Fukushima disaster


While the state of Oregon gears up to test its shores for radioactive contamination from Japan’s Fukushima nuclear disaster, university scientists have found that radiation levels in some albacore tuna caught off its coast have tripled.

According to researchers at the University of Oregon, the results came after tests analyzed the cesium levels in 26 tuna caught prior to the 2011 nuclear calamity – as far back as 2008 – and those caught after the accident.

AFP Photo / Yoshikazu Tsuno

Although the levels of radioactive isotopes in some of the tuna tripled after the disaster, the researchers found they are still “a thousand times lower” than the safety standards outlined by the US Department of Agriculture.

“A year of eating albacore with these cesium traces is about the same dose of radiation as you get from spending 23 seconds in a stuffy basement from radon gas,” the study’s lead author, Delvan Neville said to Oregon’s Statesman Journal.

Still, Neville added that the discovery of any amount of radiation is significant.

“You can’t say there is absolutely zero risk because any radiation is assumed to carry at least some small risk,” he said. “But these trace levels are too small to be a realistic concern.”

Researchers stated that the migration paths of the tuna could also affect the levels of radiation going forward. Most of the 3-year-old tuna tested had no traces of Fukushima radiation, but 4-year-old tuna – which likely traveled through the radioactive plume a couple of times – had higher cesium levels. Continued migration could increase cesium levels further, but the researchers said it would still fall well below maximum safety levels.

Since the results did reveal a spike in radiation, though, the researchers will be expanding their study beyond Oregon to test a larger number of tuna across the West Coast.

“The presence of these radioactive isotopes is actually helping us in an odd way – giving us information that will allow us to estimate how albacore tuna migrate between our West Coast and Japan,” Neville told the Journal.

Meanwhile, Oregon state itself plans to hold its next quarterly radiation test on May 13. Back in February, Ken Buesseler of the Woods Hole Oceanographic Institution stated that a plume of radioactive water from Fukushima would likely hit the US West Coast by April 2014. Buesseler said the plume is likely too diluted to pose a health concern to Americans or the habitat, but added that only testing will be able to confirm his belief.