Breakthrough For Vaccine Research: Mucosa Forms Special Immunological Memory

Complement Pathways

Components of complement pathways of the immune system. 

Classical Pathway: binds to the pathogen surface

C1 binds to phosphocholine on bacteria, which activates C1r to cleave C1s.

Activated C1s cleaves C4 to C4a and C4b.

C4b binds to the microbial surface and also binds C2.

C2 is cleaved to C2a and C2b by C1s, forming the C4bC2a complex.

The C4bC2a complex cleaves C3 to C3a and C3b.

C3b binds to the surface and causes opsonization.

MB-Lectin Pathway: uses mannin-binding lectin to bind to mannose-containing carbohydrates on the pathogen surface

Mannin-binding lectin (MBL) binds to the pathogen surface and activates MASP-2.

MASP-2 cleaves C4 to C4a and C4b.

C4b binds to the microbial surface and also binds C2.

C2 is cleaved to C2a and C2b by MASP-2, forming the C4bC2a complex.

The C4bC2a complex cleaves C3 to C3a and C3b.

C3b binds to the surface and causes opsonization.

Alternative Pathway: binds to the pathogen surface with spontaneously activated complement, amplifies C3b

C3b deposited by the C3 convertase binds to factor B.

Factor B is cleaved by factor D into Ba and Bb, forming the C3bBb complex.

The C3bBb complex cleaves C3 into C3a and C3b.

C3 spontaneously hydrolyzes to C3(H2O).

C3(H2O) binds to factor B, and factor D cleaves factor B.

Upon factor B cleavage, the C3(H2O)Bb complex is formed.

The C3(H2O)Bb complex cleaves C3 into C3a and C3b.

Factor B binds to C3b on the surface and is cleaved to Bb.

Why scientists are rooting for mushrooms

Mushrooms are the organisms that keep on giving. They grow and feed the soil by breaking down organic matter. For centuries, they’ve also been a staple in our diet. 

Recently, people have started taking a closer look at mushrooms, and more specifically, mycelium — the hidden root of mushrooms — as an engineering material to produce goods like surfboards, packaging materials, furniture and even architecture.

As far as natural materials go, there’s never been anything as versatile and cost-effective as fungi, says Sonia Travaglini, a doctoral candidate in mechanical engineering at UC Berkeley, who is collaborating with artist and mycologist Philip Ross to unlock the seemingly infinite potential of fungi.

Mycelium can grow into any shape or size (the largest in the world blankets an entire forest in Oregon). They can be engineered to be as hard and strong as wood or brick, as soft and squishy as foam, or even smooth and flexible, like fabric. 

Unlike other natural materials, mushrooms can rely on their recycling properties to break down organic matter so you can grow a lot of it very quickly and cheaply just by feeding it biodegradable waste. In as little as two weeks, you can cultivate a hunk of mushroom that’s brick-sized.

That mycelium actually takes in waste and carbon dioxide as it grows (one species of fungi even eats plastic trash) instead of expelling byproducts makes it far superior to other forms of production.

Plus, when you’re done with mushroom, you can compost it or break up the material to grow more mycelium from it.

“And, unlike forming synthetic materials, which have to be made while very hot or under pressure, all of which takes a lot of energy to create those conditions, mycology materials grow from mushrooms which grow in our normal habitat, so it’s much less energy-intensive,” said Travaglini.

In the lab, Travaglini and other researchers crush, compress, stretch, pull and bend mycelium to test the amount of force the material can tolerate.   

They found that mycelium is incredibly strong and can withstand a lot of compression and tension.

Most materials are only strong from one direction. But mycology materials are tough from all directions and can absorb a lot force without breaking. So it can withstand as much weight as a brick, but won’t shatter when you drop it or when it experiences a hard impact, said Travaglini. 

As one of the newer organisms receiving an application in biomimetics, a field of science that looks to imitate nature’s instinctive designs to find sustainable solutions and innovation, we might be getting merely a glimpse of what fungi is capable of.

“Mycology is still a whole new field of research, we’re still finding more questions and still really don’t know where it’s going to go, which makes it really exciting,” said Travaglini.

Image sources: Vice UK/Mazda & Pearson Prentice Hall

The 2016 Nobel Prize in Chemistry is awarded to Jean-Pierre Sauvage, Sir Fraser Stoddart, and Bernard Feringa for the design and production of molecular machines with controllable movements: bit.ly/NobelSci2016

(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.

4 new elements added to the periodic table

The seventh row of the Periodic Table of Elements is now complete, rendering all textbooks out of date. The discovered elements don’t have permanent names yet, but their atomic numbers are 113, 115, 117 and 118.

Livermore Lab scientists and international collaborators have officially discovered three of the four new elements: 115, 117 and 118. The illustration above is of 117, tentatively named ununseptium or Uus.

The new elements’ existence was confirmed by further experiments that reproduced them — however briefly. Element 113, for instance, exists for less than a thousandth of a second.

Learn more about the new elements

Crystals of the female hormone oxytocin

In women this hormone is secreted naturally by the pituitary gland. Oxytocin causes contractions of the uterus during labour, and it also stimulates the flow of milk in women who are breast-feeding.

- Carl Sagan, Cosmos.

(Giphy)

Today is the International Day of Women and Girls in Science, so let’s write women back into science history. Check out the gallery here.

A Brand-New Human Organ Has Been Identified

Your body now has an extra organ — meet the mesentery.

A mighty membrane that twists and turns through the gut is starting the new year with a new classification: the structure, called the mesentery, has been upgraded to an organ.

Scientists have known about the structure, which connects a person’s small and large intestines to the abdominal wall and anchors them in place, according to the Mayo Clinic. However, until now, it was thought of as a number of distinct membranes by most scientists. Interestingly, in one of its earliest descriptions, none other than Leonardo da Vinci identified the membranes as a single structure, according to a recent review.

Steve Gentleman, a neuropathologist, demonstrates the process of brain dissection and preservation for research.