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currentsinbiology:

Sperm RNA carries marks of trauma (Nature News)

Trauma’s impact comes partly from social factors, such as its influence on how parents interact with their children. But stress also leaves ‘epigenetic marks’ — chemical changes that affect how DNA is expressed without altering its sequence. A study published this week in Nature Neuroscience finds that stress in early life alters the production of small RNAs, called microRNAs, in the sperm of mice (K. Gapp et al. Nature Neurosci. http://dx.doi.org/10.1038/nn.3695; 2014). The mice show depressive behaviours that persist in their progeny, which also show glitches in metabolism.

 A number of sperm trying to fertilise an egg.

currentsinbiology:

How size splits cells

One of the scientists who revealed how plants “do maths” can now reveal how cells take measurements of size. Size is important to cells as it determines when they divide.

In a paper published in eLife, Professor Martin Howard from the John Innes Centre and colleagues from the US, Germany and Singapore discovered that cells measure their surface area using a particular protein, cdr2p. The finding challenges a previous model suggesting that another protein called pom1p senses a cell’s length.

"Many cell types have been shown to reach a size threshold before they commit to cell division and this requires that they somehow monitor their own size," says Professor Martin Howard from the John Innes Centre.

"For the first time we can show how cells sense size and what aspect of size they measure, such as volume, length, mass or surface area."

The scientists found that as cells grow, the concentration of the cdr2p protein grows. The cells use cdr2p to probe the surface area over the whole cell. Their experimental findings contest a previously suggested model.

Reference

Fluorescence micrograph showing human cells at various stages of cell division, starting with interphase at the top. During interphase the cell gets bigger and duplicates its DNA. The second cell shows prophase, the stage at which the chromosomes form. The third cell is in metaphase, where all the chromosomes are attached and aligned on the spindle. The fourth cell down shows anaphase, the stage at which the chromosomes separate. The final cell is in telophase, and the newly separated genetic material is encased into two new nuclei.
Credit: Matthew Daniels, Wellcome Images.

Evolution happens like a movie, with frames moving by both quickly and gradually, and we often can’t see the change while it’s occurring. Every time we find a fossil, it’s a snapshot back in time, often with thousands of frames missing in between, and we’re forced to reconstruct the whole film. Life is what happens in between the snapshots.
Joe Hanson explores why there was no first human (via we-are-star-stuff)

(Source: explore-blog)

Imagine all the food you have eaten in your life and consider that you are simply some of that food, rearranged.

Max Tegmark - read more about his intriguing musings on Integrated Information Theory (IIT) here (paper) and here (article, elaborating on his books core ideas).

IIT contains many echoes of cybernetics and panpsychism, but Tegmark’s angle on it as a physicist is especially interesting.

(via wetwareontologies)

Consider that you can see less than 1% of the electromagnetic spectrum and hear less than 1% of the acoustic spectrum. As you read this, you are traveling at 220 km/sec across the galaxy. 90% of the cells in your body carry their own microbial DNA and are not ‘you’. The atoms in your body are 99.9999999999999999% empty space and none of them are the ones you were born with, but they all originated in the belly of a star. Human beings have 46 chromosomes, 2 less than the common potato. The existence of the rainbow depends on the conical photoreceptors in your eyes; to animals without cones, the rainbow does not exist. So you don’t just look at a rainbow, you create it. This is pretty amazing, especially considering that all the beautiful colors you see represent less than 1% of the electromagnetic spectrum.
(via we-are-star-stuff)

(Source: wallflower-musings)

freshphotons:

The Hungry Microbiome — Christian Stolte, Christopher Hammang (CSIRO Computational Informatics, Sydney, Australia).

Created for the animation “The Hungry Microbiome”, this study shows resistant starch granules and the bacteria which break them down floating above the surface of the colon. At the bottom, a cut-away view of crypts shows the absorption of butyrate (shown as light blue particles), which is a byproduct of the bacteria and the main energy source of the cells in our colon. A steady supply of butyrate helps to detect mutations and prevent cancer. The main point of this study was to develop an interesting lighting scheme for this scene. 

currentsinbiology:

Scientists reported today the first human recipients of laboratory-grown vaginal organs. A research team led by Anthony Atala, M.D., director of Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine, describes in the Lancet long-term success in four teenage girls who received vaginal organs that were engineered with their own cells.
"This pilot study is the first to demonstrate that vaginal organs can be constructed in the lab and used successfully in humans," said Atala. "This may represent a new option for patients who require vaginal reconstructive surgeries. In addition, this study is one more example of how regenerative medicine strategies can be applied to a variety of tissues and organs."
Atlántida M Raya-Rivera, Diego Esquiliano, Reyna Fierro-Pastrana, Esther López-Bayghen, Pedro Valencia, Ricardo Ordorica-Flores, Shay Soker, James J Yoo, Anthony Atala. Tissue-engineered autologous vaginal organs in patients: a pilot cohort study. The Lancet, 2014; DOI: 10.1016/S0140-6736(14)60542-0

The scaffold is configured into a vaginal shape. Credit: Image courtesy of Wake Forest Baptist Medical Center

discoverynews:

Twisted Threads Make Strong, Supple Robots

The current generation of robots always seem so, well, robotic. Their herky-jerky movements are the result of the stiff wires and pulleys that contract and expand to move their limbs. But what if robo-muscles were more like our own; strong, yet supple, self-sufficient for long periods of time (think of the human battery life versus a robot’s) and able to make complex fine motor movements like writing or sewing. Read more

The polymer muscles are 100 times stronger than human muscles and have the power output of an automobile engine.

futurescope:

We will live again

Fascinating, retrofuturistic, tragic and eerie. Worth a look.

WE WILL LIVE AGAIN looks inside the unusual and extraordinary operations of the Cryonics Institute. The film follows Ben Best and Andy Zawacki, the caretakers of 99 deceased human bodies stored at below freezing temperatures in cryopreservation. The Institute and Cryonics Movement were founded by Robert Ettinger who, in his nineties and long retired from running the facility, still self-publishes books on cryonics, awaiting the end of his life and eagerly anticipating the next.

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Directed by Myles Kane & Josh Koury

Produced by Trisha Barkman

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