Saturday, April 16, 2016

New Zika research: It just keeps getting worse

Hawai`i continues to be on the alert for Zika virus, and there are increasing good reasons for concern.

Here are some updates on Zika virus.

The Centers for Disease Control and Prevention have confirmed the link between the mosquito-borne disease and babies born with shrunken heads, a condition called microcephaly.

Here’s the ScienceDaily piece on that. 

 The report from CDC was published in the New England Journal of Medicine under the title,  “Zika Virus and Birth Defects — Reviewing the Evidence for Causality.” The original paper is here.

There’s a caveat here. This isn’t original research, but a review of the original research done by others, and it concludes that, considered as a whole, the connection is inescapable. 

Here is the language they used: “we evaluated available data using criteria that have been proposed for the assessment of potential teratogens. On the basis of this review, we conclude that a causal relationship exists between prenatal Zika virus infection and microcephaly and other serious brain anomalies.”

In adults, Zika has been associated with a neurological disease called Guillain-Barre Syndrome. Now, another new paper suggests that adults with Zika are also at risk for a rare autoimmune disorder, acute disseminated encephalomyelitis.

The connection between Zika and this brain disease is still not entirely locked up. Brazilian researchers found 151 cases of brain disorders among Zika patients. Only a very few came down with acute disseminated encephalomyelitis. 

The paper on this was presented this week to the conference of the the American Academy of Neurology. The ScienceDaily story on it is here. 

It is, once again, not a smoking gun, but there are reasons for concern, and there are worries about why and how Zika attacks the brain. 

“Clinicians should be vigilant for the possible occurrence of (acute disseminated encephalomyelitis) and other immune-mediated illnesses of the central nervous system," said James Sejvar, with the Centers for Disease Control and Prevention.

There have been suggestions that Zika may not only be transmitted by mosquito, but that it might be spread directly between humans through sexual activity. A new French study, reported in the New England Journal of Medicine and here on EurekAlert,  confirms it.

"Their analyses have shown 100% genetic correlation between the form of the virus present in a man who contracted the virus in Brazil and that of a woman who had never travelled in the epidemic area, but who had sexual relations with him," the EurekAlert article said.

Oh, and here's an interesting piece, also in ScienceDaily, about a new mosquito trap, developed by Canadian and Mexican researchers, that may help reduce the populations of the Aedes mosquitoes that carry Zika.

See RaisingIslands’ previous posts on Zika here.

© Jan TenBruggencate 2016

Thursday, April 14, 2016

The Hawaiian extinction bomb: global numbers don't come close

The global extinction crisis is pretty bad, unless you actually include all the extinctions.

Not to do so is a little like arguing that tsunami damage wasn’t bad—as long as you don’t count the coastal areas.
In which case it’s worse than bad. It can be catastrophic. And the Hawaiian Islands are an example of just how bad the global extinction crisis is.

(Image: Laminella sanguinea, one of a handful of remaining amastrid land snail species, this one a tree-dweller in Wai`anae Mountains. Credit:: Kenneth A. Hayes.)

One of the standards of species condition is the International Union for Conservation of Nature Red List, which attempts to document the conservation status of all species of life—animals, plants, even fungi. But it’s way behind, and hasn’t even yet considered a lot of species.

IUCN lists as extinct just a few hundred of the tens of thousands of listed species. A tiny fraction of an understated total.You can visit the IUCN site here.

In some large Hawaiian genera, more than half the species are gone, and sometimes far more than half.

A paper in the journal Conservation Biology last year looked at a genus of Hawaiian land snails, Amastridae.

The paper, “Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction,” was written by Claire Regnier, Philippe Bouchet, Kenneth A. Hayes, Norine W. Yeung, Carl C. Christensen, Daniel J.D.Chung, Benoıt Fontaine, and Robert H. Cowie. They are researchers from France, the Mainland, and the Bishop Museum and University of Hawai`i.

There are 325 known species of Amastridae, many known only from ancient chalky shells found in soil and sediment, only 15 are absolutely known to still survive.Of the total of 325, at the time the paper was written, IUCN listed just 33 as extinct. But the paper’s authors say that’s not nearly the whole story.

In fact, the authors say, 43 are from fossil evidence and almost surely extinct, 88 more are also certainly extinct. Another 179 lack evidence of extinction, but most are probably gone.

Yes, that leaves 15 of 325 that are certainly still surviving. There are probably a few more, but not many more. Rats may be a big cause of extinctions. Indeed, almost all of the extinct Amastridae are ground-dwelling, where they would have been easy prey.

And things don’t look good for the future: “All amastrid populations remain precarious, and all 15 extant species should be considered critically endangered. For example, the only two known populations of A. spirizona, in the Waianae Mountains, have been monitored for some years and are declining continually,” the authors write

The authors argue that the IUCN’s failure to accurately assess the loss, and its understatement of the actual numbers “has been used to downplay the biodiversity crisis.”

They admit that islands are special cases, and don’t necessarily represent the global picture, but the opposite is also true.

“In general, oceanic island biotas are especially susceptible to extinction and global rate generalizations do not reflect this,” the collaborators wrote.

And it’s not just snails that are disappearing from the islands, of course. We have lost most of our forest birds. Two-thirds of the 113 species of birds known to have existed in the Hawaiian Islands are now certainly extinct. Several others haven’t been seen in decades and are probably gone as well.

Researchers talk about our being in the world’s sixth massive wave of extinctions. But the world’s biodiversity loss is nothing compared to that in the Hawaiian Islands.  

The loss globally is not in the hundreds, as IUCN suggests, but in the tens of thousands, said Robert Cowie,  a Hawai`i researcher and one of the authors of the snail study.

“We showed, based on extrapolation from a random sample of land snail species from all over the world, and via two independent approaches, that we may already have lost 7 percent (130,000 extinctions) of all the animal species on Earth,” Cowie said.

© Jan TenBruggencate 2016

Tuesday, April 12, 2016

Circling the globe on the power of the sun: Solar Impulse II ready to leave Honolulu

There’s so much going on in the solar world, but the concept of flying around the world in a plane powered by solar cells is one step beyond.

Hawai`i has some solar flying cred. (Image, the Helios flying wing off Kaua`i. Credit: NASA.)

AeroVironment’s  solar plane Helios flew off Kaua`i’s Pacific Missile Range Facility early in the last decade. Ultimately, the experimental unmanned aircraft crashed in June 2003 in rough weather, but not until it had set some records, including a world record altitude in 2001 for non-rocket-powered flight.

The Helios flying wing reached 96,863 feet on the back of some solar cells and propellers.
Its other mission was to prove that solar planes could fly continuously, using fuel cells to store energy during the day, which could be used to power the plane at night.

(Image: Solar Impulse II over Hawai`i. Credit: Solar Impulse.)

It was Solar Impulse I that accomplished that goal in 2010, staying aloft for 26 hours.

That was then. Today, another solar aircraft, Solar Impulse II is parked in Honolulu, ready for the next leg of its flight around the world. That mission was delayed last year when its flight across the western Pacific damaged some of its batteries.

Solar Impulse II is an idea 15 or more years old, and in some ways it is a descendant of the Helios. While Helios was flying, back in 2002, Solar Impulse pilot Bertrand Piccard consulted with AeroVironment’s late Paul McCready, one of the visionaries in solar-powered flight.

The new Solar Impulse, completed in 2014, is a feather-light but gangly aircraft, with honeycombed wings that stretch 236 feet tip to tip. Its upper surfaces are covered by photovoltaic cells. It has four electric motors powering four propellers, each powered by lithium-ion batteries.

Looks a bit like a giant dragonfly.

SI II launched on its global tour in 2015 from Abu Dhabi. Pilots Piccard and André Borschberg took turns flying the one-seat aircraft. They crossed Asia, hopping to stops in Oman, India, Myanmar, China and finally Japan, and then made their longest flight, from Japan to Hawai`i, last year.

The Japan-Hawai`i leg was the world’s longest-ever solar-powered flight. Pilot Borschberg stayed aloft 8 minutes short of 118 hours. But in doing so, his batteries overheated and were damaged, requiring replacement. That, and weather, kept SI II grounded on O`ahu for most of a year.

But the organizers say they are days from a new liftoff, aimed at crossing the rest of the Pacific and then continuing around the world, back to their Abu Dhabi starting point. The remaining flights are expected to all be shorter than the Japan-Hawai`i marathon of five days aloft.

The eastern Pacific flight's conclusion will be determined by wind or weather.  The plane could land anywhere up or down the West Coast, or as far inland as Arizona.

SI II, in anticipation of taking off in mid-April, performed several takeoffs, extended flights and landings in late March from the runway at Kalaeloa with Piccard at the controls.

In a blog post, Piccard wrote: “It was beautiful to fly #Si2 under the full moon tonight and I really enjoyed it. I even flew with the window open to feel the night breeze. My second
landing was the best: a kiss landing. We call it like that because the plane touches down so smoothly that you can barely feel it.”

Here is a YouTube video on the mission. Here is the Solar Impulse website. The mission is to send the world a message about the potential of clean fuels. Here is their clean fuels website.

You can subscribe to get updates on the voyage here. The most recent information we have is that it should leave within two weeks.

When the Solar Impulse II does take off for its long voyage to the northeast, it will pass over hundreds of Hawaiian rooftops outfitted with the same technology that is keeping this plucky airborne adventurer aloft.

© Jan TenBruggencate 2016

Wednesday, April 6, 2016

Hawaiian bats: new data reveals a more complicated history

The story of Hawai`i’s bat populations just got more complicated.

The Islands have long been assumed to have just a single land mammal, the `ope`ape`a or Hawaiian hoary bat. 

(Image: The bones of a newly reported but extinct Hawaiian bat, which has been named Synemporion keana, discovered in Maui’s Mahiehie Cave. Credit: © American Museum Novitates)

Our marine mammals, the seals and porpoises and whales, pretty clearly got here by swimming. But for a land animal, arriving across a couple of thousands of miles of ocean is more problematic. So, no rats, mice, dogs, cats, wolves, cows, or any other land mammals in pre-contact Hawai`i. 

But bats, particularly migratory bats capable of long-distance flight, could presumably have made the cross-ocean transit.

And new evidence says they did, several different times.

A study by the late Bishop Museum mammologist Alan Ziegler, Bishop Museum entomologist Frank Howarth and Nancy Simmons of the American Museum of Natural History, reveals that the Hawaiian hoary bat is actually two populations, descended from two separate immigration events more than 9,000 years apart. 

Their paper, published in the journal American Museum Novitates, is here, and there’s a press release from the American Museum of Natural History is here

 The first Hawaiian hoary bat arrived in the Islands about 10,000 years ago—long before humans were present. The second immigration was just 800 years ago. Both of those immigrations involved the same species, although there are differences among zoologists whether they have since evolved into new species. 

The parent species was Lasiurus cinereus, and authors take the view that the Hawaiian bat is a subspecies, Lasiurus cinereus semotus.  But they agree that further study could change that designation.

But they also noted something that has been understood for decades: that fossil evidence shows that there was another bat, now extinct, flying Hawaiian skies. 

It is smaller than the `ope`ape`a and different in several ways. It has been given the scientific name Synemporion keana.

Like the hoary bat, it appears to have been an insect eater, and to have been spread throughout the Hawaiian Islands. It is not clear where the parent Synemporion came from, but it evolved into a distinct species in the Hawaiian Islands.

The paper’s co-author, Frank Howarth, first found the bones of this bat in a Maui cave in 1981. 

"The initial specimens included skeletons embedded in crystals on the lava tube wall and thus were likely very old. Ziegler eagerly guided me through the bat collection at the Bishop Museum to identify the bat and show me features to look for in order to find additional material for study," Howarth said.

Since then, fossil bones from the bat have been found on a total of five Hawaiian islands. Ziegler, a noted and respected Hawaiian biologist, died in 2003 before completing his study of the new bat. His work was completed by Simmons.

The fossil record suggests this bat was Hawai`i’s first bat. 

The oldest fossil bones date back 320,000 years, but the authors say the limited fossil record doesn’t allow an accurate arrival date. It could be a few millions of years earlier.  

Synemporion keana appears to have gone extinct about 1,100 years ago—roughly the time when both humans and rats first appeared in the Hawaiian Islands.

The authors suggest that Polynesian rats, Rattus exulans, which arrived with the first Polynesian settlers, may have either directly or indirectly led to the bats’ extinction.

“If Synemporion roost sites were accessible to rats, it is possible that Rattus exulans may have had a direct impact on the bat populations by preying upon roosting bats and/or their young. Alternatively, the effects of rats on the local environment may have indirectly contributed to bat population reductions and extinction,” the paper says.

It’s possible that the bats survived into the historic period, when Europeans brought in roof rats, cats, mongooses and other predators, which would have completed the extinction if the Polynesian rats hadn’t, they write.

© Jan TenBruggencate 2016

Friday, April 1, 2016

Sea level rise could be twice the level expected in this century--look to the big ice sheets.

We have recently seen not one but several papers suggesting that the Intergovernmental Panel on Climate Change has been far too conservative on sea level change.

That it’s likely to rise not just two or three but maybe twice as much in the coming decades.

Think about that in areas where waves are already eating at the foundations of home, are washing over roads, are eroding our beach parks.

(Image: Researchers service a PROMICE automatic weather station on the Greenland ice sheet. PROMICE stands for Programme for Monitoring of the Greenland Ice Sheet. Credit: William Colgan, York University.)

We’ve known for some time that the IPCC estimates left out big sources of ocean rise, simply because it wasn’t clear at the time how to make sense of what was likely to happen. Now new information is beginning to clear that up.

An article in Nature looks at the impacts of melting of the Antarctic ice sheet, both in the past and in the possible future. During the last interglacial period, 115,000 to 130,000 years ago, sea level was six to nine meters higher than now. Yes, in the range of 20 to 30 feet higher.

 “The Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability,” wrote the authors, Robert De Conto of the University of Massachusetts and David Pollard of Pennsylvania State.

They estimate that Antarctic melting ice alone will provide three feet of rise, on top of the rise from other sites and from thermal expansion of warming oceans.

“Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated,” they wrote.

Their work builds on numerous research projects, including one published in 2015 in the journal Science, which predicted that Antarctic and Greenland ice would be the dominant sources of sea level rise in the future—although they haven’t been the major sources until now.

“Although thermal expansion of seawater and melting of mountain glaciers have dominated global mean sea level (GMSL) rise over the last century, mass loss from the Greenland and Antarctic ice sheets is expected to exceed other contributions to GMSL rise under future warming,” these authors wrote.

Both groups looked at past sea level change data to recognize that we are at a turning point, at which the big ice sheets start contributing.

“Present climate is warming to a level associated with significant polar ice-sheet loss in the past,” wrote the authors of the Science article.

What’s been going on in the past is that mostly mountain glaciers and floating ice has been melting, but the melting of floating ice doesn’t cause sea level rise—any more than a melting ice cube causes your drink to overflow.

However, when the world's giant ice sheets begin melting, that adds significant amounts of water to the oceans. Researchers have been able to compare previous warming episodes with ice sheet actions and sea levels.

Still another study, this one in Geophysical Research Letters, looked into two exceptional melt episodes in 2012 in the Greenland ice sheet. It found that the ice melt incidents, which normally are caused directly by the sun, were significantly caused by warm, moist air.

“When we were analysing our weather station data, we were quite surprised, that the exceptional melt rates we observed were primarily caused by warm and moist air, because ice sheet wide melt is usually dominated by radiant energy from sunlight,” said Robert Fausto, of the Geological Survey of Denmark and Greenland. He was the lead author of the report.

“Exceptional melt episodes dominated by non-radiant energy are expected to occur more frequently in the future due to climate change. This makes it critical to better understand the influence of these episodes on ice sheet health,” Faust said.

© Jan TenBruggencate 2016