Texas researchers tease out correlation between DDT exposure and late-onset Alzheimer’s

February 12, 2014

Press release from the University of Texas-Southwestern Medical Center in Dallas:

Research finds elevated levels of DDT metabolite in Alzheimer’s patients

Dr. Dwight German, Professor of Psychiatry

Dr. Dwight German, Professor of Psychiatry – UT-Southwestern photo

DALLAS – January 29, 2014 – Exposure to DDT may increase the likelihood of developing Alzheimer’s disease later in life, a study with researchers at UT Southwestern Medical Center suggests. While previous studies have linked chronic diseases such as cancer and diabetes to DDT, this is the first clinical study to link the U.S.-banned pesticide to Alzheimer’s disease.

The study, published online in JAMA Neurology, found elevated levels of the DDT metabolite, DDE, that were 3.8 times higher in patients diagnosed with Alzheimer’s disease in comparison to control subjects. The studies were conducted in partnership with researchers at Emory University School of Medicine and Rutgers Robert Wood Johnson Medical School.

“We have additional studies underway that will seek to directly link DDT exposure to Alzheimer’s disease,” said co-author Dr. Dwight German, Professor of Psychiatry at UT Southwestern. “If a direct link is made, our hope is to then identify the presence of DDE in blood samples from people at an early age and administer treatments to remove it.”

The study found elevated levels of DDE in blood samples of 86 patients with Alzheimer’s disease as compared to 79 control patients from the UT Southwestern Alzheimer’s Disease Center and the Emory University Alzheimer’s Disease Center.

Researchers made the link between DDE and Alzheimer’s by measuring three components – blood serum levels, severity of the patient’s Alzheimer’s disease as measured by the Mini-Mental State Examination (MMSE) and its relation to serum DDE levels, and the reaction of isolated nerve cells to DDE. Treatment of human nerve cells with DDE caused them to increase the production of the amyloid precursor protein that is directly linked to Alzheimer’s disease.

Participants in the study underwent preliminary testing to ensure that they didn’t have symptoms of other dementia-related diseases, and were an average age of 74, while the control subjects were on average 70 years old. These findings may help lead to the development of early biomarkers that can determine whether a person will develop Alzheimer’s disease later in life due to DDT exposure.

Alzheimer’s disease is the most common neurodegenerative disease worldwide and is expected to increase three-fold over the next 40 years, according to the researchers.

DDT (dichloro-diphenyl-trichloroethane) was used extensively as an insecticide in the 1940s, but has been banned in the United States since 1972 after scientists linked the compound to wildlife health and environmental concerns. DDT is still used in other countries to combat the spread of malaria.

About UT Southwestern Medical Center
UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty includes many distinguished members, including five who have been awarded Nobel Prizes since 1985. Numbering more than 2,700, the faculty is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in 40 specialties to nearly 91,000 hospitalized patients and oversee more than 2 million outpatient visits a year.

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Once again, research seems to demonstrates the wisdom of Rachel Carson, who warned us that we could not know the long-term damage done by untested pesticides applied with abandon in great abundance as if it were a solution to everything.

Carson’s book indicting pesticides regulation, Silent Spring, was published in 1962, with more than 50 pages of footnotes and citations to scientific studies.  In the 52 years since, none of that research has been rebutted by any further research.  Instead, more harms have been discovered, greater questions raised about the damage done by pesticides applied indiscriminantly.


Voyager I becomes Earth’s first interstellar object

September 14, 2013

Can you recall what you were doing on September 5, 1977?

The Voyager 1 aboard the Titan III/Centaur lif...

The Voyager 1 aboard the Titan III/Centaur lifted off on September 5, 1977, joining its sister spacecraft, the Voyager 2, on a mission to the outer planets. Wikipedia image, from NASA

That’s the day NASA launched Voyager I, on a trip to photograph planets in our solar system more close up than we can get with Earth-bound telescopes.  The Hubble Space Telescope was not even on the drawing board then.

After completing its mission, Voyager I continued on its path.  Scientists thought it would survive to leave the solar systems, and a few forward-looking thinkers hoped to learn more about just how far the influence of our Sun really extends.  At some point, Voyager I would leave space where the chief gravitational and wind influence is the Sun, and move into truly inter-stellar (“between the stars”) space, where gravity and particle emissions are dominated by other objects in our galaxy.

Last week NASA announced that time came in August of 2012, confirmed by data transmitted back to earth by Voyager’s primitive capabilities, over the last year.

Space.com explains it well:

Interesting to think of the investment in thought, money, effort and patience by scientists and policy-makers to wait more than 35 years for such a research result.

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Voyager I, artist's interpretation.  NASA image

Voyager I, artist’s interpretation. NASA image


For the birds, scientists at work

July 2, 2013

A scientist at work:

Amanda Holland with one of her research subjects, in South Carolina

Amanda Holland with one of her research subjects, in South Carolina

Kathryn’s cousin, Amanda Holland, moved from researching condors in California, to buzzards in Georgia and South Carolina (for the University of Georgia, I think).

Here she is with one of her research subjects.  Much lore is out there about handling carrion-eating birds for research — they vomit on you only if they like you, for example — but wholly apart from that, how great is this photo of a scientist at work?

I told her to copyright the photo (it is), and to hand on to the meme.  Can’t you see a character in Game of Thrones, or some other fantasy, who carries her own vultures to clean up after she devastates some other army in battle?

Eagles and falcons and owls are okay, but what other bird could conceal the results of the battle, so the warrior princess could move on in stealth?

Science field work looks like great stuff.  My experience is that it’s tiring, and sometimes lonely (though in very beautiful locations) — but the psychic rewards of actually increasing knowledge keep a lot of scientists going.  There’s not a lot of money in it.

Look at the friends you could make!


Annals of global warming: No, polar bears are not “fine” — suffer from loss of sea ice

March 20, 2013

Press release from The Journal of Animal Ecology (links added here):

For polar bears, it’s survival of the fattest

One of the most southerly populations of polar bears in the world – and the best studied – is struggling to cope with climate-induced changes to sea ice, new research reveals. Based on over 10 years’ data the study, published in the British Ecological Society‘s Journal of Animal Ecology, sheds new light on how sea ice conditions drive polar bears’ annual migration on and off the ice.

Led by Dr. Seth Cherry of the University of Alberta, the team studied polar bears in western Hudson Bay, where sea ice melts completely each summer and typically re-freezes from late November to early December. “This poses an interesting challenge for a species that has evolved as a highly efficient predator of ice-associated seals,” he explains. “Because although polar bears are excellent swimmers compared with other bear species, they use the sea ice to travel, hunt, mate and rest.”

Polar bear and two cubs wait for ice to reform

Caption from EurekAlert: An adult female polar bear wearing a GPS-satellite linked collar with her two 10-month-old cubs waits for the sea ice to re-form onshore in western Hudson Bay, Manitoba, Canada. Photo Copyright Andrew Derocher, Univeristy of Alberta.

Polar bears have adapted to the annual loss of sea ice by migrating onto land each summer. While there, they cannot hunt seals and must rely on fat reserves to see them through until the ice returns.

Dr. Cherry and colleagues wanted to discover how earlier thawing and later freezing of sea ice affects the bears’ migration. “At first glance, sea ice may look like a barren, uniform environment, but in reality, it’s remarkably complex and polar bears manage to cope, and even thrive, in a habitat that moves beneath their feet and even disappears for part of the year. This is an extraordinary biological feat and biologist still don’t fully understand it,” he says.

From 1991-97 and 2004-09, they monitored movements of 109 female polar bears fitted with satellite tracking collars. They tagged only females because males’ necks are wider than their heads, so they cannot wear a collar. During the same period, the team also monitored the position and concentration of sea ice using satellite images.

“Defining precisely what aspects of sea ice break-up and freeze-up affect polar bear migration, and when these conditions occur, is a vital part of monitoring how potential climate-induced changes to sea ice freeze-thaw cycles may affect the bears,” he says.

The results reveal the timing of polar bears’ migration can be predicted by how fast the sea ice melts and freezes, and by when specific sea ice concentrations occur within a given area of Hudson Bay.

According to Dr. Cherry: “The data suggest that in recent years, polar bears are arriving on shore earlier in the summer and leaving later in the autumn. These are precisely the kind of changes one would expect to see as a result of a warming climate and may help explain some other studies that are showing declines in body condition and cub production.”

Recent estimates put the western Hudson Bay polar bear population at around 900 individuals. The population has declined since the 1990s, as has the bears’ body condition and the number of cubs surviving to adulthood.

Young polar bear challenged by lack of sea ice, Andrew Derocher photo

Caption from EurekAlert: This is a subadult polar bear on a lake on the shores of Hudson Bay in Manitoba, Canada in November waiting for the sea ice to re-form. Copyright Andrew Derocher, Univeristy of Alberta.

Because polar bears’ main food source is seals, and these are hunted almost exclusively on sea ice, the longer bears spend on land, the longer they must go without energy-rich seals. “Climate-induced changes that cause sea ice to melt earlier, form later, or both, likely affect the overall health of polar bears in the area. Ultimately, for polar bears, it’s survival of the fattest,” says Dr. Cherry.

He hopes the results will enable other scientists and wildlife managers to predict how potential climate-induced changes to sea ice freeze-thaw cycles will affect the ecology, particularly the migration patterns, of this iconic species.

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Seth Cherry et al (2013). ‘Migration phenology and seasonal fidelity of an Arctic marine predator in relation to sea ice dynamics’, doi: 10.1111/1365-2656.12050, is published in the Journal of Animal Ecology on Wednesday 20 March 2013.

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The Presidential Library that isn’t a Presidential Library

March 9, 2013

Campaign poster showing William McKinley holdi...

Campaign poster showing William McKinley holding U.S. flag and standing on gold coin “sound money”, held up by group of men, in front of ships “commerce” and factories “civilization”. (Photo credit: Wikipedia)

Things you learn looking for documents:  The U.S. National Archives now manages the presidential libraries and museums — except for one:  The William McKinley Memorial Library and Museum.

President William McKinley Memorial Library and Museum, in Niles, Ohio.

President William McKinley Memorial Library and Museum, in Niles, Ohio. McKinley was born in Niles. Photo from the LIbrary’s website.

To be more accurate and fair, National Archives manages the documents for the presidential libraries starting with Herbert Hoover, though there are usually special arrangements with each of the libraries.

Separately, the Ladies of Mount Vernon Association manages the research facilities at Mount Vernon, Virginia,  (and the rest of the grounds) associated with George Washington, and the Abraham Lincoln Presidential Library and Museum in Springfield, Illinois, is operated by a separate foundation, too.  The Teddy Roosevelt Center at Dickinson State University in North Dakota stands apart from the National Archives system, too (much TR material can be found at Harvard, too).

The idea of a specific library to hold papers from a president’s term is a mid-20th century idea.  Franklin Roosevelt and Herbert Hoover were the first, with the idea coming about the same time.  Private foundations built and operated them until after the Nixon library, and since then Congress authorized the National Archives to get into the act and coordinate the work, and then made the links official, for libraries from here on out.

For presidents prior to Hoover, papers generally became the property of the outgoing president.  Collection was spotty.  The idea of library dedicated to one president is such a good one, though, that private groups have gone back to set them up for Washington and Lincoln.

And McKinley.

Modern texts don’t show well the high regard McKinley had from Americans before he was assassinated.  Within a few years after his death, the people of Ohio and his birthplace, in Niles, got Congress to approve a memorial.  Eventually the local library moved into the memorial building.

The National McKinley Birthplace Memorial Association was incorporated by a special Act of Congress on March 4, 1911.  The purpose of the Association was to erect a suitable structure marking the birthplace of President William McKinley, the 25th President of the United States. The result was the National McKinley Birthplace Memorial.

McKinley was born in the city of Niles, Ohio on January 29, 1843. The city donated the site for the Memorial which consisted of an entire city square. The architects were McKim, Mead & White of New York and the erection of the Memorial was done by John H. Parker Company, also of New York. Groundbreaking began in 1915 with the corner stone being laid on November 20, 1915.

The building was dedicated on October 5, 1917.

The cost was more than half a million dollars, all of which was donated by the American public.

The 232 foot by 136 foot by 38 foot monument is constructed of Georgian marble with two lateral wings–
one wing houses the public library called the McKinley Memorial Library, and the other wing houses the
McKinley Museum and an auditorium. The Museum contains artifacts of the life and presidency of McKinley.

In the center of the Memorial is a Court of   Honor supported by 28 imposing columns. It features a heroic statue of McKinley sculptured by John Massey-Rhind. Surrounding the statue are busts and tablets dedicated to the members of    McKinley’s cabinet and other prominent men who were closely associated with him.  These bronze busts, mounted on marble pedestals, weigh between 800 and 1100 pounds each.

As a presidential library, the McKinley Memorial Library in Niles is unique.  While it does not offer the vast research resources of the National Archives, it does offer a memorial from the people of Ohio and the U.S., a more down-home look at  reverence for presidents and the keeping of the history of our heroes.

Memorial to President William McKinley in Niles, Ohio

The memorial to President McKinley in Niles. Photo from the McKinley Memorial Library and Museum.

The “official” list of other presidential libraries and museums in the National Archives’ network, listed at the American Presidency Project at the University of California – Santa Barbara:

Herbert Hoover Presidential Library and Museum
Herbert Hoover Presidential Library Association
Franklin D. Roosevelt Library and Digital Archives
Harry S. Truman Library and Museum
The Dwight D. Eisenhower Library
John F. Kennedy Library and Museum
Lyndon Baines Johnson Library and Museum
Richard Nixon Library and Museum
Richard Nixon Library Foundation
Gerald R. Ford Library and Museum
Jimmy Carter Library
Ronald Reagan Presidential Foundation and Library
George Bush Presidential Library and Museum
William J. Clinton Presidential Library and Museum
Clinton Presidential Center
George W. Bush Presidential Library
George W. Bush Presidential Center

More:


CERN press conference: Discovery of the Higgs boson

July 4, 2012

Here is the complete press conference held today, July 4, 2012, at the CERN offices in Geneva, Switzerland.  (Alas, the press conference was not held in Cedar Hill, Texas, making it a monument to the dangers of saying “we can’t be great in America any more” and refusing to appropriate money for science, or anything else good.)

This may be the biggest discovery of the decade for particle physics; it’s incredibly exciting, despite the appearance of calm.  It may be the biggest discovery of the century.  (We have 88 years left in the century, too.)

Description from the poster:

Published on Jul 4, 2012 by

This is the full press conference update on the search for the Higgs boson at CERN in Geneva Switzerland. This press conference followed the 2-hour Seminar that you can see here: http://www.youtube.com/watch?v=JAlgX4FNiyM

This original CERN webcast recording was officially published at https://cdsweb.cern.ch/record/1459604 but I re-uploaded it here because YouTube is best. The CERN Copyright notice seems to say doing something like this may be ok http://copyright.web.cern.ch/ but if they release this video on the official http://youtube.com/cerntv YouTube channel, I may remove this copy from my YouTube account.

So, if the video above goes dark, check the official CERN YouTube site.

Especially for middle school and high school teachers, More:


One more time: Recognizing bogus history

May 14, 2012

2012 is an election year, a time when we make history together as a nation.  Potential turning points in history often get tarred with false interpretations of history to sway an election, or worse, a completely false recounting of history.  Especially in campaigns, we need to beware false claims of history, lest we be like the ignorants George Santayana warned about, doomed to repeat errors of history they do not know or understand.  How to tell that a purported piece of history is bogus?  This is mostly a repeat of a post that first appeared at Millard Fillmore’s Bathtub six years ago.

Recognizing bogus history, 1

Robert Park provides a short e-mail newsletter every Friday, covering news in the world of physics. It’s called “What’s New.” Park makes an art of smoking out bogus science and frauds people try to perpetrate in the name of science, or for money. He wrote an opinion column for the Chronicle of Higher Education [now from Quack Watch; CHE put it behind a paywall] published January 31, 2003, in which he listed the “7 warning signs of bogus science.”

Please go read Park’s entire essay, it’s good.

And it got me thinking about whether there are similar warning signs for bogus history? Are there clues that a biography of Howard Hughes is false that should pop out at any disinterested observer? Are there clues that the claimed quote from James Madison saying the U.S. government is founded on the Ten Commandments is pure buncombe? Should Oliver Stone have been able to to more readily separate fact from fantasy about the Kennedy assassination (assuming he wasn’t just going for the dramatic elements)? Can we generalize for such hoaxes, to inoculate ourselves and our history texts against error?

Bogus science section of Thinkquest logo

Perhaps some of the detection methods Park suggests would work for history. He wrote his opinion piece after the Supreme Court’s decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., in which the Court laid out some rules lower courts should use to smoke out and eliminate false science. As Park described it, “The case involved Bendectin, the only morning-sickness medication ever approved by the Food and Drug Administration. It had been used by millions of women, and more than 30 published studies had found no evidence that it caused birth defects. Yet eight so-called experts were willing to testify, in exchange for a fee from the Daubert family, that Bendectin might indeed cause birth defects.” The Court said lower courts must act as gatekeepers against science buncombe — a difficult task for some judges who, in their training as attorneys, often spent little time studying science.

Some of the Daubert reasoning surfaced in another case recently, the opinion in Pennsylvania district federal court in which Federal District Judge John Jones struck down a school board’s order that intelligent design be introduced to high school biology students, Kitzmiller v. Dover Area School District.

Can we generalize to history, too? I’m going to try, below the fold.

Here are Park’s seven warning signs, boiled down:

Park wrote:

Justice Stephen G. Breyer encouraged trial judges to appoint independent experts to help them. He noted that courts can turn to scientific organizations, like the National Academy of Sciences and the American Association for the Advancement of Science, to identify neutral experts who could preview questionable scientific testimony and advise a judge on whether a jury should be exposed to it. Judges are still concerned about meeting their responsibilities under the Daubert decision, and a group of them asked me how to recognize questionable scientific claims. What are the warning signs?

I have identified seven indicators that a scientific claim lies well outside the bounds of rational scientific discourse. Of course, they are only warning signs — even a claim with several of the signs could be legitimate. [I have cut out the explanations. — E.D.]

  1. The discoverer pitches the claim directly to the media.
  2. The discoverer says that a powerful establishment is trying to suppress his or her work.
  3. The scientific effect involved is always at the very limit of detection.
  4. Evidence for a discovery is anecdotal.
  5. The discoverer says a belief is credible because it has endured for centuries.
  6. The discoverer has worked in isolation.
  7. The discoverer must propose new laws of nature to explain an observation.

Voodoo history

Here, with thanks to Robert Park, is what I propose for the warning signs for bogus history, for voodoo history:

  1. The author pitches the claim directly to the media or to organizations of non-historians, sometimes for pay.
  2. The author says that a powerful establishment is trying to suppress his or her work.  Bogus history relies more on invective than investigation; anyone with an opposing view is an “idiot,” or evil.
  3. The sources that verify the new interpretation of history are obscure, or unavailable; if they involve a famous person, the sources are not those usually relied on by historians.
  4. Evidence for the history is anecdotal.
  5. The author says a belief is credible because it has endured for some time, or because many people believe it to be true.
  6. The author has worked in isolation, and fails to incorporate or explain other, mainstream versions of the history of the incident, and especially the author fails to explain why they are in error.
  7. The author must propose a new interpretation of history to explain an observation.

Any history account that shows one or more of those warning signs should be viewed skeptically.

In another post, I’ll flesh out the reasoning behind why they are warning signs.

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