Contradictiontonature - Sapere Aude

 Poison in the Brain: Toxic Structures in Neuronal Nuclei of Alzheimer’s Patients 

Spherical structures in the nucleus of nerve cells, so-called nuclear spheres, are suspected to trigger Alzheimer’s disease. A team headed by Dr Thorsten Müller from the research group Cell Signaling in Neurodegeneration has for the very first time demonstrated the presence of the presumably toxic protein aggregates in the human brain. The researchers from Ruhr-Universität Bochum have published their article in the journal Neurobiology of Aging.

The team compared brain samples from Alzheimer’s patients with those of the healthy individuals in the same age group. The result: in the samples taken from Alzheimer’s patients, the number of nuclear spheres was much higher than in those taken from healthy study participants.

Moreover, the group from Bochum analysed in what way nuclear spheres are generated. It was demonstrated in experiments with cell cultures that the amyloid precursor protein (APP) plays a crucial role in this process. APP has long been associated with Alzheimer’s disease. The researchers observed that nuclear sphere generation preferably takes place, if the amyloid precursor protein carries no phosphate group in a specific amino acid. An APP cleavage product, moreover, is contained in the nuclear spheres.

“Extensive nuclear sphere generation in the human Alzheimer’s brain” by Katharina Kolbe, Hassan Bukhari, Christina Loosse, Gregor Leonhardt, Annika Glotzbach, Magdalena Pawlas, Katharina Hess, Carsten Theiss, and Thorsten Müller in Neurobiology of Aging. Published online August 18 2016 doi:10.1016/j.neurobiolaging.2016.08.016

After the four new additions, here’s a look at the origins of all the element names in the periodic table! High-res image/PDF: http://wp.me/p4aPLT-1Ru

Also featured in The Conversation UK alongside an article from Professor Mark Lorch here: https://goo.gl/g60pGU

Meet 5 of the most remarkable humans known to science

Would you rather have 10% of your brain, or no heart?

We might think we know the human body pretty well by now, but scientists are still discovering incredible individuals who are defying all odds by living out their lives with crucial parts missing, added, or tweaked in the most extraordinary ways.

From those with almost superhuman abilities, to others living without the organs we hold most dear, here are five of the most remarkable humans known to medicine.

Read more… 

DNA from the deep? Antikythera shipwreck yields ancient human bones

Death, when it came, was sudden and cruel. The individual, either a crew member or passenger, was trapped on board when the huge ship foundered. Dashed on the rocks, the vessel slid beneath the waves, tumbled down an undersea cliff, and swiftly became buried in sediment on the seabed.

Now, more than 2,000 years later, archaeologists have recovered the bones of the individual they now call Pamphilos. Thought to be a man in his late teens to early 20s, he was on the ship sailing from Asia Minor to Rome when disaster struck off the tiny Greek island of Antikythera between Crete and the Peloponnese.

Got a chemistry-themed watch for Christmas - good for checking the time periodically 😃

(Image caption: Brandeis University professor Ricardo Godoy conducts the experiment in a village in the Bolivian rainforest. The participants were asked to rate the pleasantness of various sounds, and Godoy recorded their response. Credit: Alan Schultz)

Why we like the music we do

In Western styles of music, from classical to pop, some combinations of notes are generally considered more pleasant than others. To most of our ears, a chord of C and G, for example, sounds much more agreeable than the grating combination of C and F# (which has historically been known as the “devil in music”).

For decades, neuroscientists have pondered whether this preference is somehow hardwired into our brains. A new study from MIT and Brandeis University suggests that the answer is no.

In a study of more than 100 people belonging to a remote Amazonian tribe with little or no exposure to Western music, the researchers found that dissonant chords such as the combination of C and F# were rated just as likeable as “consonant” chords, which feature simple integer ratios between the acoustical frequencies of the two notes.

“This study suggests that preferences for consonance over dissonance depend on exposure to Western musical culture, and that the preference is not innate,” says Josh McDermott, the Frederick A. and Carole J. Middleton Assistant Professor of Neuroscience in the Department of Brain and Cognitive Sciences at MIT.

McDermott and Ricardo Godoy, a professor at Brandeis University, led the study, which appeared in Nature on July 13. Alan Schultz, an assistant professor of medical anthropology at Baylor University, and Eduardo Undurraga, a senior research associate at Brandeis’ Heller School for Social Policy and Management, are also authors of the paper.

Consonance and dissonance

For centuries, some scientists have hypothesized that the brain is wired to respond favorably to consonant chords such as the fifth (so-called because one of the notes is five notes higher than the other). Musicians in societies dating at least as far back as the ancient Greeks noticed that in the fifth and other consonant chords, the ratio of frequencies of the two notes is usually based on integers — in the case of the fifth, a ratio of 3:2. The combination of C and G is often called “the perfect fifth.”

Others believe that these preferences are culturally determined, as a result of exposure to music featuring consonant chords. This debate has been difficult to resolve, in large part because nowadays there are very few people in the world who are not familiar with Western music and its consonant chords.

“It’s pretty hard to find people who don’t have a lot of exposure to Western pop music due to its diffusion around the world,” McDermott says. “Most people hear a lot of Western music, and Western music has a lot of consonant chords in it. It’s thus been hard to rule out the possibility that we like consonance because that’s what we’re used to, but also hard to provide a definitive test.”

In 2010, Godoy, an anthropologist who has been studying an Amazonian tribe known as the Tsimane for many years, asked McDermott to collaborate on a study of how the Tsimane respond to music. Most of the Tsimane, a farming and foraging society of about 12,000 people, have very limited exposure to Western music.

“They vary a lot in how close they live to towns and urban centers,” Godoy says. “Among the folks who live very far, several days away, they don’t have too much contact with Western music.”

The Tsimane’s own music features both singing and instrumental performance, but usually by only one person at a time.

Dramatic differences

The researchers did two sets of studies, one in 2011 and one in 2015. In each study, they asked participants to rate how much they liked dissonant and consonant chords. The researchers also performed experiments to make sure that the participants could tell the difference between dissonant and consonant sounds, and found that they could.

The team performed the same tests with a group of Spanish-speaking Bolivians who live in a small town near the Tsimane, and residents of the Bolivian capital, La Paz. They also tested groups of American musicians and nonmusicians.

“What we found is the preference for consonance over dissonance varies dramatically across those five groups,” McDermott says. “In the Tsimane it’s undetectable, and in the two groups in Bolivia, there’s a statistically significant but small preference. In the American groups it’s quite a bit larger, and it’s bigger in the musicians than in the nonmusicians.”

When asked to rate nonmusical sounds such as laughter and gasps, the Tsimane showed similar responses to the other groups. They also showed the same dislike for a musical quality known as acoustic roughness.

The findings suggest that it is likely culture, and not a biological factor, that determines the common preference for consonant musical chords, says Brian Moore, a professor of psychology at Cambridge University, who was not involved in the study.

“Overall, the results of this exciting and well-designed study clearly suggest that the preference for certain musical intervals of those familiar with Western music depends on exposure to that music and not on an innate preference for certain frequency ratios,” Moore says.

R.I.P. Dr. Vera Rubin

As I write this, reports are spreading rapidly through the astronomy community of the death of Dr. Vera Rubin on December 25, 2016. If you don’t know who she was, or what she worked on, come sit by me and let me tell you a story about this lady.

It was at one of the first meetings of the American Astronomical Society I attended. I was a graduate student and giving a talk about outreach and amateur astronomy. I was scared to death because, hey, it was me, a lowly student giving a talk to all these exalted astronomers. A woman sat in the front row and smiled at me as I shuffled the papers on the podium. The room filled and then the session chair gave me the signal that my 10 minutes had started. I plunged into my talk.

At the end, a few people asked questions, everyone clapped politely, and the next person stepped up to the podium. I fled the room to catch my breath. The woman followed me out and asked if I’d like to get a cup of coffee. At the same moment my advisor came out and said, “Oh, I see you’ve met Vera Rubin”, and he proceeded to introduce me to her before being collared by someone else for a chat. Dr. Rubin and I went to get coffee, and for the next 30 minutes or so she asked me all about my work and what I hoped to do when I graduated. It was a wonderful experience.

Over the years we met here and there, and I learned more about her work with galaxy rotation studies and the existence of dark matter. I found it fascinating, as so many people do, and followed her research with interest. When I was asked to write a book about astronomy, one of the directions I got from the editors was to include some bios of “seminal” astronomers. Dr. Rubin was one of those I chose. In retrospect, I wish could have done a book on her work instead of simply a chapter.

I know that Vera Rubin didn’t work in a vacuum on dark matter — that, like Newton and every other astronomer has done — she stood on the shoulders of giants. Her work forged a new path in understanding dark matter and its affect on the universe. Now, she is a giant in her own right. Now, others will stand on her shoulders. Her insights and drive to understand the difficult “galaxy rotation problem” led directly to the theory of dark matter, and more recently to the confirming observations of its existence. It was a monumental achievement.

For her work, Dr. Rubin should have received a Nobel Prize. That didn’t happen and the Nobel physics committee should be thinking hard about why she was overlooked. She has been honored with many other prizes and awards for her insights, and she will be long remembered for her seminal contributions to astronomy.

RIP Dr. Vera Rubin, and deepest condolences to her extended family.

C.C. PETERSEN is a science writer and media producer specializing in astronomy and space science content. 

Source: The Spacewriter

Liver Circulation - Flashcard

The liver is supplied with blood by the hepatic artery and the hepatic portal vein

branches of the hepatic artery and the hepatic portal vein distribute blood to the periphery of the liver lobules.

Blood passes along sinusoids, which are lined by hepatocytes, which perform numerous metabolic and synthetic functions. 

The processed blood passes into branches of the hepatic vein in the centre of each lobule, and eventually drains into the hepatic vein. 

The biliary system is independent of the vascular system and bile moves in the opposite direction to the blood. 

Initially it is collected in bile ductules which are surrounded by collagenous tissue, which forms part of the collagenous trabecular septum. 

The bile is collected by increasingly large trabecular ducts, which fuse to form intrahepatic ducts which finally drain into the main hepatic ducts.

This new drug is as strong as morphine, but without the side effects

Incredible pain relief – without the addiction.

Scientists have developed a new drug that could be a safer alternative to morphine for medical use. The researchers found that engineered variants of endomorphin, a naturally occurring chemical in the body, are as strong as morphine when it comes to killing pain.

On top of that, the medication doesn’t produce any of the unwanted side effects that come with opium-based drugs – such as being extremely addictive. At this point, the findings only relate to tests in rats, but it’s a promising start to what could be a powerful and less problematic painkiller.

Opioid pain medications are commonly used to treat severe and chronic pain, but in addition to their habit-forming qualities, patients also build up a tolerance to them over time. Hand in hand with their addictiveness, this can makes higher doses – and overdoses in drug abuse situations – dangerous. Overdoses can cause motor impairment and potentially fatal respiratory depression, resulting in thousands of deaths in the US every year.