The History of Zika

Zika virus, which is spread through mosquito bites, tends to cause a low fever, skin rash and conjunctivitis (pink eye). 

However, when contracted by pregnant women, the virus may be linked with microcephaly (underdeveloped skull and brain) in affected developing babies. 

The virus was first identified in rhesus monkeys in Uganda in 1947, and in humans in 1952 in Uganda and Tanzania. In 2015, Zika outbreaks were confirmed in Brazil and Colombia.

The virus has also been reported in the U.S. In 2016, officials with the World Health Organization declared the virus and associated birth defects an international public health emergency.

An epidemiology team from the Centers for Disease Control and Prevention (CDC) arrived in Brazil today (Feb. 22) to investigate the link between Zika virus and microcephaly (small head and brain size).

The 16-member group is training its Brazilian counterparts in Joao Pessoa, Brazil, according to National Public Radio (NPR). After that, all of the researchers will collect data on 400 to 500 Brazilian women who have had babies in the past few months.

Using this information, the researchers will set up a case-control study that will help them analyze the various risk factors, be it Zika virus, rubella, malnutrition or environmental toxins, that could account for birth disorders, such as microcephaly.

"Having the data at this point in time are very critically important for understanding the impact Zika might be having in the future and as it spreads in the region," J. Erin Staples, a CDC medical officer leading the CDC team in Brazil, told NPR.

In the meantime, Brazilian researchers sequenced the genome of the Zika virus, according to a report from the Federal University of Rio de Janeiro. The researchers also isolated the virus from the brains of fetuses who had microcephaly and died shortly after birth, according to the news outlet Agência Brasil, providing more evidence that the virus is linked to the disorder.

Zika Identified in North Carolina Resident19 February 2016, 11:08 AM EST

North Carolina has identified its first case of Zika virus, health officials reported today (Feb. 19).

The patient is an adult who got the virus while traveling in a country with ongoing transmission of Zika. However, the person's symptoms have since resolved, according to the North Carolina Department of Health and Human Services.

"As long as the outbreak continues in Central and South America and the Caribbean, we expect to see more travel-related Zika virus infections in our state," Dr. Randall Williams, the state health director, said in a statement. "While travel-related cases don’t present a public health threat to North Carolina, we always actively monitor emerging global situations and adjust resources to meet needs."

Sea level rise in 20th century was fastest in 3,000 years, study finds

Global sea level rose faster in the 20th century than in any of the 27 previous centuries, according to a Rutgers University-led study published today.

Moreover, without global warming, global sea level would have risen by less than half the observed 20th century increase and might even have fallen.

Instead, global sea level rose by about 14 centimeters, or 5.5 inches, from 1900 to 2000. That's a substantial increase, especially for vulnerable, low-lying coastal areas.

"The 20th century rise was extraordinary in the context of the last three millennia - and the rise over the last two decades has been even faster," said Robert Kopp, the lead author and an associate professor in Rutgers' Department of Earth and Planetary Sciences.

The study, published in Proceedings of the National Academy of Sciences, used a new statistical approach developed over the last two and a half years by Kopp, his postdoctoral associates Carling Hay and Eric Morrow, and Jerry Mitrovica, a professor at Harvard University.

"No local record measures global sea level," Kopp said. "Each measures sea level at a particular location, where it is buffeted by a variety of processes that cause it to differ from the global mean. The statistical challenge is to pull out the global signal. That's what our statistical approach allows us to do."

Notably, the study found that global sea level declined by about 8 centimeters [3 inches] from 1000 to 1400, a period when the planet cooled by about 0.2 degrees Celsius [0.4 degrees Fahrenheit].

"It is striking that we see this sea-level change associated with this slight global cooling," Kopp said. By comparison, global average temperature today is about 1 degrees Celsius [1.8 degrees Fahrenheit] higher than it was in the late 19th century.

A statistical analysis can only be as good as the data it's built upon. For this study, a team led by Andrew Kemp, an assistant professor of earth and ocean sciences at Tufts University, and Benjamin Horton, a professor in Rutgers' Department of Marine and Coastal Sciences, compiled a new database of geological sea-level indicators from marshes, coral atolls and archaeological sites that spanned the last 3,000 years.

The database included records from 24 locations around the world. Many of the records came from the field work of Kemp, Horton, or team members Roland Gehrels of the University of York in the United Kingdom and Jeffrey Donnelly of the Woods Hole Oceanographic Institution. The analysis also tapped 66 tide-gauge records from the last 300 years.

"Scenarios of future rise depend upon our understanding of the response of sea level to climate changes," Horton said. "Accurate estimates of sea-level variability during the past 3,000 years provide a context for such projections."

Kemp said, "As geologists, we can reconstruct how sea level changed at a particular site, and progress in the last 10 years has allowed us to do so with ever more detail and resolution. Gathering together and standardizing these reconstructions gave us a chance to look at what they had in common and where they differed, both of which can tell us about the causes of past, present and future sea-level change."

Kopp's collaborators Klaus Bittermann and Stefan Rahmstorf at the Potsdam Institute for Climate Impact Research in Germany used the study's global sea-level reconstruction to calculate how temperatures relate to the rate of sea-level change.

Based on this relationship, the study found that, without global warming, 20th century global sea-level change would very likely have been between a decrease of 3 centimeters [1.2 inches] and a rise of 7 centimeters [2.8 inches].

A companion report finds that, without the global warming-induced component of sea-level rise, more than half of the 8,000 coastal nuisance floods observed at studied U.S. tide gauge sites since 1950 would not have occurred. The Climate Central report, led by Benjamin Strauss and co-authored by Kopp, Bittermann, and William Sweet of NOAA, was also published today.

The Kopp-led study also found that it's very likely that global sea level will rise by 1.7 to 4.3 feet in the 21st century if the world continues to rely heavily upon fossil fuels. Phasing out fossil fuels will reduce the very likely rise to between 0.8 and 2.0 feet.

Scientists at the following institutions contributed to the study: Rutgers, The State University of New Jersey; Tufts University; Potsdam Institute for Climate Impact Research in Germany; Woods Hole Oceanographic Institution; University of York in the United Kingdom; and Harvard University. The research was funded by the National Science Foundation, the National Oceanic and Atmospheric Administration, the New Jersey Sea Grant Consortium, the Strategic Environmental Research and Development Group, the U.K. National Environmental Research Council, the Royal Society, and Harvard University.

Gravitational Waves – Explained

A century after Albert Einstein rewrote our understanding of space and time, physicists have confirmed one of the most elusive predictions of his general theory of relativity. In another galaxy, a billion or so light-years away, two black holes collided, shaking the fabric of spacetime. Here on Earth, two giant detectors on opposite sides of the United States quivered as gravitational waves washed over them. After decades trying to directly detect the waves, the recently upgraded Laser Interferometer Gravitational-Wave Observatory, now known as Advanced LIGO, appears to have succeeded, ushering in a new era of astronomy.

What are gravitational waves?
Colossal cosmic collisions and stellar explosions can rattle spacetime itself. General relativity predicts that ripples in the fabric of spacetime radiate energy away from such catastrophes. The ripples are subtle; by the time they reach Earth, some compress spacetime by as little as one ten-thousandth the width of a proton.

How are they detected?
To spot a signal, LIGO uses a special mirror to split a beam of laser light and sends the beams down two 4-kilometer-long arms, at a 90 degree angle to each other. After ricocheting back and forth 400 times, turning each beam’s journey into a 1,600 kilometer round-trip, the light recombines near its source. But a gravitational wave stretches one tube while squeezing the other, altering the distance the two beams travel relative to each other. Because of this difference in distance, the recombining waves are no longer perfectly aligned and therefore don’t cancel out. The detector picks up a faint glow, signaling a passing wave.

What are other sources of gravitational waves?
By studying computer simulations of astrophysical phenomena, scientists can figure out what type of signals to expect from various gravitational wave sources.

Spinning neutron stars
A single spinning neutron star, the core left behind after a massive star explodes, can whip up spacetime at frequencies similar to those produced by colliding black holes.

Supernovas
Powerful explosions known as supernovas, triggered when a massive star dies, can shake up space and blast the cosmos with a burst of high-frequency gravitational waves.

Supermassive black hole pairs
Pairs of gargantuan black holes, more than a million times as massive as the sun and larger than the ones Advanced LIGO detected, radiate long, undulating waves. Though Advanced LIGO can’t detect waves at this frequency, scientists might spot them by looking for subtle variations in the steady beats of pulsars.

Big Bang
The Big Bang might have triggered universe-sized gravitational waves 13.8 billion years ago. These waves would have left an imprint on the first light released into the cosmos 380,000 years later, and could be seen today in the cosmic microwave background.

How else are we looking for gravitational waves?
LIGO isn’t the only game in town when it comes to hunting for gravitational waves. Here are a few other ongoing and future projects.

Ground-based interferometers
A couple of other detectors similar to LIGO are in Europe. The Virgo detector, near Pisa, Italy, is being upgraded and will team up with LIGO later this year. GEO600, near Hannover, Germany, has been the only interferometer running for the past several years while Virgo and LIGO underwent renovations. A third LIGO detector, this one in India, is scheduled to join the search in 2019.

Space-based interferometers
In space no one can you hear you scream. Neither do you have to deal with pesky Earth-based phenomena like seismic tremors. Researchers have been lobbying the European Space Agency to put a LIGO-like detector in space — the Evolved Laser Interferometer Space Antenna — sometime in the 2030s. In anticipation of eLISA, ESA recently launched the LISA Pathfinder, a mission to test technologies needed for the full-fledged space-based gravitational wave detector.

Pulsar timing arrays To pick up the relatively low-frequency hum of colliding supermassive black holes, researchers are turning to pulsars. These rapidly spinning neutron stars (the cores left behind after a massive star explodes) send out steady pulses of radio waves. As a gravitational wave squeezes and stretches the space between Earth and a pulsar, the beat appears to quicken and diminish. Three projects — the Parkes Pulsar Timing Array in Australia, NANOGrav in North America and the European Pulsar Timing Array in Europe — are monitoring dozens of pulsars for tempo changes that can reveal not only single collisions but the cacophony of gargantuan black holes smashing together throughout the universe.

Cosmic microwave background polarization Gravitational waves released in the wake of the Big Bang would have left a mark on the cosmic microwave background, or CMB. This radiation fills the universe and is a relic from the moment light could first travel freely through the cosmos, about 380,000 years after its birth. The CMB preserved how space stretched and squeezed following a phenomenal expansion a trillionth of a trillionth of a trillionth of a second after the Big Bang. Many telescopes are searching for this signature by looking for specific patterns in how the CMB light waves align with one another. It’s not easy though; the BICEP2 project already mistook dust in the Milky Way for its cosmic quarry.

What can we learn from gravitational waves? LIGO’s success is akin to Galileo turning his telescope toward the sky. Before that moment we knew little about the stars and planets. We didn’t realize there are other galaxies and had no concept of the immensity of the universe. Gravitational waves are a new way of seeing the cosmos. They are a striking confirmation of general relativity and will reveal cataclysmic explosions and collisions throughout the universe. But as with Galileo’s telescope, much of what gravitational waves can teach us is probably yet to be imagined.