How Do Our Bodies Fight Off Dangerous Chemicals?

We’re all subjects in a massive experiment. Humans have created about 80,000 synthetic industrial compounds — including plastics, the flame retardants that cover our sofas, and pesticides. These compounds have structures that are not commonly seen in nature and present a risk to our health. Everybody on the planet is exposed.

It’s important to understand what these substances are doing to our bodies so that scientists can create a rule book for making these chemicals safer.

The challenge to understanding how dangerous compounds get into our body is complex. The way we have been doing this in the past is to test if a synthetic compound dissolves in fat. If it does then theres a high likelihood that it can easily enter our body’s cells where it can cause harm.

The problem with this method is that it doesn’t always accurately predict how much a compound accumulates in organisms. A historic example of this is DDT which was used on crops to get rid of pests, but ultimately found its way through the food chain. It’s now considered a risk factor for breast cancer in humans.

At UC San Diego’s Scripps Institution of Oceanography, Amro Hamdoun is looking at the biological properties of how these compounds interact with cells. The focus is on how the cell decides which compounds to let in and which ones to eliminate.

 

A New Species of Hummingbird?

UC Riverside researchers have discovered what could be a new species of hummingbird in the Bahamas.

The Bahama Woodstar comprises of two subspecies: Calliphlox evelynae evelynae, found throughout the islands of the Bahamas and Calliphlox evelynae lyrura (“lyrura” for lyre-tailed, refers to the forked tail of males that resembles a classical lyre harp). This lovely creature is only found among the southern Inaguan islands of the Bahama Archipelago.

Based on data from morphology, behavior, genetics and geology, UCR biologist Christopher J. Clark says the two subspecies should be recognized as two distinct species.

“The two subspecies were originally described as separate species, partly on the basis of small differences in the tail feathers between them, but were then classified in 1945 as subspecies of the Bahama Woodstar. It’s time now to call these two distinct species of hummingbirds.”

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Chemists fabricate novel rewritable paper

According to some surveys, 90 percent of all information in businesses today is retained on paper, even though the bulk of this printed paper is discarded after just one use.

First developed in China in about the year A.D. 150, paper has many uses, the most common being for writing and printing upon. Indeed, the development and spread of civilization owe much to paper’s use as writing material.

Such waste of paper (and ink cartridges) — not to mention the accompanying environmental problems such as deforestation and chemical pollution to air, water and land — could be curtailed if the paper were “rewritable,” that is, capable of being written on and erased multiple times.

Chemists at the University of California, Riverside have now fabricated in the lab just such a rewritable paper, one that is based on the color switching property of commercial chemicals called redox dyes. The dye forms the imaging layer of the paper.  Printing is achieved by using ultraviolet light to photobleach the dye, except the portions that constitute the text on the paper.  The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.

Read more about it here →

Small volcanic eruptions explain warming hiatus

Scientists have long known that volcanoes cool the atmosphere because of the sulfur dioxide that is expelled during eruptions. Droplets of sulfuric acid that form when the gas combines with oxygen in the upper atmosphere can persist for many months, reflecting sunlight away from Earth and lowering temperatures at the surface and in the lower atmosphere.

Previous research suggested that early 21st-century eruptions might explain up to a third of the recent warming hiatus.

New research available online in the journal Geophysical Research Letters (GRL) further identifies observational climate signals caused by recent volcanic activity. This new research complements an earlier GRL paper published in November, which relied on a combination of ground, air and satellite measurements, indicating that a series of small 21st-century volcanic eruptions deflected substantially more solar radiation than previously estimated.

“This new work shows that the climate signals of late 20th- and early 21st-century volcanic activity can be detected in a variety of different observational data sets,” said Benjamin Santer, a Lawrence Livermore National Laboratory scientist and lead author of the study.

The warmest year on record is 1998. After that, the steep climb in global surface temperatures observed over the 20th century appeared to level off. This “hiatus” received considerable attention, despite the fact that the full observational surface temperature record shows many instances of slowing and acceleration in warming rates. Scientists had previously suggested that factors such as weak solar activity and increased heat uptake by the oceans could be responsible for the recent lull in temperature increases. After publication of a 2011 paper in the journal Science by Susan Solomon of the Massachusetts Institute of Technology, it was recognized that an uptick in volcanic activity might also be implicated in the warming hiatus.

Prior to the 2011 Science paper, the prevailing scientific thinking was that only very large eruptions — on the scale of the cataclysmic 1991 Mount Pinatubo eruption in the Philippines, which ejected an estimated 20 million metric tons (44 billion pounds) of sulfur — were capable of impacting global climate. This conventional wisdom was largely based on climate model simulations. But according to David Ridley, an atmospheric scientist at MIT and lead author of the November GRL paper, these simulations were missing an important component of volcanic activity.

Ridley and colleagues found the missing piece of the puzzle at the intersection of two atmospheric layers, the stratosphere and the troposphere — the lowest layer of the atmosphere, where all weather takes place. Those layers meet between 10 and 15 kilometers (6 to 9 miles) above the Earth.

Satellite measurements of the sulfuric acid droplets and aerosols produced by erupting volcanoes are generally restricted to above 15 km. Below 15 km, cirrus clouds can interfere with satellite aerosol measurements. This means that toward the poles, where the lower stratosphere can reach down to 10 km, the satellite measurements miss a significant chunk of the total volcanic aerosol loading.

To get around this problem, the study by Ridley and colleagues combined observations from ground-, air- and space-based instruments to better observe aerosols in the lower portion of the stratosphere. They used these improved estimates of total volcanic aerosols in a simple climate model, and estimated that volcanoes may have caused cooling of 0.05 degrees to 0.12 degrees Celsius since 2000.

The second Livermore-led study shows that the signals of these late 20th and early 21st eruptions can be positively identified in atmospheric temperature, moisture and the reflected solar radiation at the top of the atmosphere. A vital step in detecting these volcanic signals is the removal of the “climate noise” caused by El Niños and La Niñas.

“The fact that these volcanic signatures are apparent in multiple independently measured climate variables really supports the idea that they are influencing climate in spite of their moderate size,” said Mark Zelinka, another Livermore author. “If we wish to accurately simulate recent climate change in models, we cannot neglect the ability of these smaller eruptions to reflect sunlight away from Earth.”

To see the full research, go to Geophysical Research Letters and the Wiley Online Library.

The Livermore-led research involved a large interdisciplinary team of researchers with expertise in climate modeling, satellite data, stratospheric dynamics, volcanic effects on climate, model evaluation, statistics and computer science. Other Livermore contributors include Céline Bonfils, Jeff Painter, Francisco Beltran and Gardar Johannesson. Other collaborators include Solomon and Ridley of MIT, John Fyfe at the Canadian Centre for Climate Modeling and Analysis, Carl Mears and Frank Wentz at Remote Sensing Systems and Jean-Paul Vernier at the NASA/Goddard Space Flight Center.

Is The Secret To A Happy Marriage In Your DNA?

Are some people genetically predisposed to stay happily married? Researchers at UC Berkeley have found a major clue in our DNA.

Robert Levenson and his team have found a link between relationship fulfillment and a gene variant — known as the “short allele” — of the serotonin transporter gene. The gene is involved in the regulation of serotonin in the brain and can predict whether a person is attuned or oblivious to the emotional climate of their marriage.

In the study, Levenson found that participants with the short alleles were most unhappy in their marriages when there was a lot of negative emotion —like contempt— but were also happiest when positive emotions like humor were present. (About 30% of the population has this gene variation.)

On the other end of the spectrum, participants with long alleles were satisfied with their marriages regardless of the emotional atmosphere.

Why carrots taste sweeter in winter

UCLA’s Liz Roth-Johnson explains why carrots have more sugar when it’s cold outside.

Because plants are immobile, they must develop defense techniques against predators and the severe cold in winter. For example, carrots have developed the physiological response of increasing their sugar content when it’s cold outside. This helps stop ice crystal formations and prevents damage to the carrot’s cells.

Frost can do a lot of damage to a plant cell. It can squeeze and rupture the cells until they are completely demolished. But in some cases, the plant’s defense mechanism means a tastier vegetable for us to eat. When a carrot defends itself from frost, we get the benefit of enjoying sweeter carrots all winter long.

FEATURING: Liz Roth-Johnson, Ph.D. in Molecular Biology, UCLA

For more information: https://scienceandfooducla.wordpress.com/

Fruit and Liquid Sugar

Liquid sugar, such as in sodas, energy drinks and sports drinks, is the leading single source of added sugar in the American diet, representing 36% of the added sugar we consume.

Research suggests that our bodies process liquid sugar differently than sugar in foods, especially those containing fiber.

Scientists argue that when you eat an apple (for example), you may be getting as many as 18 grams of sugar, but the sugar is “packaged” with about one-fifth of our daily requirement of fiber. Because it takes our bodies a long time to digest that fiber, the apple’s sugar is slowly released into our blood stream, giving us a sustained source of energy.

But when we drink the same amount of sugar in sugary drinks, it doesn’t include that fiber. As a result, the journey from liquid sugar to blood sugar happens quickly, delivering more sugar to the body’s vital organs than they can handle. Over time, that can overload the pancreas and liver, leading to serious diseases like diabetes, heart disease and liver disease.

Watch the full video with UC Davis nutritional biologist, Dr. Kimber Stanhope:

10 Questions with Nobel winner Randy Schekman

The UC Berkeley Nobel laureate who identified how cells transport and secrete proteins answers a few questions.

What is the most exciting field of science at the moment?
Neuroscience. There is so much that we don’t know about the brain.

Do you believe in God?
No, I don’t. But I respect others who do, in particular if they don’t impose their views. I believe strongly in the separation of church and state.

What book about science should everyone read?
People who are interested in the life sciences will enjoy The Double Helix by James Watson; The Eighth Day of Creation by Horace Judson (it covers the history of molecular biology), and The Statue Within, the autobiography of Nobel laureate François Jacob (right), which is beautifully written.

Has Cern been worth the money?
Yes. Just the idea that you can probe the structure of atoms to that degree… Look at all the money we waste on the military, on the prison system.

What words of advice would you give to a teenager who wants a career in science?
I think having a mentor from an early age is very important.

Do you have a fantasy experiment or study that you have been unable to do for logistical/ethical/ cost reasons?
No. I like the simple experiments and my ideas tend to be very practical. Our very first experiments involved petri dishes, incubators, toothpicks and simple chemicals.

What scientific advance would make the most difference to your daily life?
My wife has dementia, so breakthroughs in understanding Parkinson’s disease would change my daily life measurably. With a disease like Parkinson’s or Alzheimer’s, if you had a way of arresting the process – even if you couldn’t prevent it – it would not be a disease at all.

Are you worried about population increase?
Yes. Having effective birth control is crucial. And our agricultural productivity will not keep up unless people lose their irrational fear of GM foods.

Would you like to go on the first one-way journey to Mars?
No. I like it here on Earth, and besides, the trip itself would almost inevitably kill you, because of all the exposure to cosmic radiation.

If I called you a geek would you hold it against me?
No. When I was in high school I got called a nerd. But after I won the Nobel prize they invited me back. I rode up in a limousine and was greeted by a marching band and pompom girls. Kids wanted to take selfies with me. I had replaced Tiger Woods as their most famous graduate… for a day!

Randy Schekman: first, a breakthrough in cell research. Now for one in publishing

 

How dense is a neutron star?

These celestial bodies have some peculiar statistics. For example if you were able to take Mount Everest and cram it into your morning cup of coffee you’d achieve the same density as a neutron star.

The reason why these stars are so dense is because they form from the collapse of a star. The way a star keeps its shape is through chemical reactions such as the conversion of hydrogen atoms bonding to create helium. When these bonds occur they produce an outward force in the form of heat. This force is stronger than gravity and keeps the star from caving in.

One of the outcomes when a star runs out of its energy is that it explodes into a supernova and leaves behind a highly dense remnant the size of the San Francisco Bay which becomes a neutron star.

Watch the full video with Enrico Ramirez-Ruiz at UC Santa Cruz: