Tuesday 25 February 2014

Mass strandings of marine mammals blamed on toxic algae: Clues unearthed in ancient whale graveyard

Summary:
Modern whale strandings can be investigated and their causes identified. Events that happened millions of years ago, however, are far harder to analyze -- frequently leaving their cause a mystery. Scientists examined a large fossil site in the Atacama Desert of Northern Chile -- the first definitive example of repeated mass strandings of marine mammals in the fossil record. It reflected four distinct strandings over time, indicating a repeated and similar cause: toxic algae.

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Mass strandings of marine mammals blamed on toxic algae: Clues unearthed in ancient whale graveyard

Date:
February 25, 2014
Source:
Smithsonian
Summary:
Modern whale strandings can be investigated and their causes identified. Events that happened millions of years ago, however, are far harder to analyze -- frequently leaving their cause a mystery. Scientists examined a large fossil site in the Atacama Desert of Northern Chile -- the first definitive example of repeated mass strandings of marine mammals in the fossil record. It reflected four distinct strandings over time, indicating a repeated and similar cause: toxic algae.

In this photo, Chilean and Smithsonian paleontologists study several fossil whale skeletons at Cerro Ballena next to the Pan-American Highway in the Atacama Region of Chile in 2011.
Credit: Adam Metallo/Smithsonian Institution
Mass strandings of whales have puzzled people since Aristotle. Modern-day strandings can be investigated and their causes, often human-related, identified. Events that happened millions of years ago, however, are far harder to analyze -- frequently leaving their cause a mystery. A team of Smithsonian and Chilean scientists examined a large fossil site of ancient marine mammal skeletons in the Atacama Desert of Northern Chile -- the first definitive example of repeated mass strandings of marine mammals in the fossil record. The site reflected four distinct strandings over time, indicating a repeated and similar cause: toxic algae. The team's findings will be published Feb. 26 in the Proceedings of the Royal Society B.



The site was first discovered during an expansion project of the Pan-American Highway in 2010. The following year, paleontologists from the Smithsonian and Chile examined the fossils, dating 6-9 million years ago, and recorded what remained before the site was paved over.
The team documented the remains of 10 kinds of marine vertebrates from the site, named Cerro Ballena -- Spanish for "whale hill." In addition to the skeletons of the more than 40 large baleen whales that dominated the site, the team documented the remains of a species of sperm whale and a walrus-like whale, both of which are now extinct. They also found skeletons of billfishes, seals and aquatic sloths.
What intrigued the team most, however, was how the skeletons were arranged. The skeletons were preserved in four separate levels, pointing to a repeated and similar underlying cause. The skeletons' orientation and condition indicated that the animals died at sea, prior to burial on a tidal flat.
Effects of Toxic Algae
Today, toxins from harmful algal blooms, such as red tides, are one of the prevalent causes for repeated mass strandings that include a wide variety of large marine animals.
"There are a few compelling modern examples that provide excellent analogs for the patterns we observed at Cerro Ballena -- in particular, one case from the late 1980s when more than a dozen humpback whales washed ashore near Cape Cod, with no signs of trauma, but sickened by mackerel loaded with toxins from red tides," said Nicholas Pyenson, paleontologist at the Smithsonian's National Museum of Natural History and lead author of the research. "Harmful algal blooms in the modern world can strike a variety of marine mammals and large predatory fish. The key for us was its repetitive nature at Cerro Ballena: no other plausible explanation in the modern world would be recurring, except for toxic algae, which can recur if the conditions are right."
Harmful algal blooms are common along the coasts of continents; they are enhanced by vital nutrients, such as iron, released during erosion and carried by rivers flowing into the ocean. Because the Andes of South America are iron-rich, the runoff that has occurred along the west coast of South America for more than 20 million years has long provided the ideal conditions for harmful algal blooms to form.
From their research, the scientists conclude that toxins generated by harmful algal blooms most likely poisoned many ocean-going vertebrates near Cerro Ballena in the late Miocene (5-11 million years ago) through ingestion of contaminated prey or inhalation, causing relatively rapid death at sea. Their carcasses then floated toward the coast, where they were washed into a tidal flat by waves. Once stranded on the tidal flat, the dead or dying animals were protected from marine scavengers, and there were no large-land scavengers in South America at this time. Eventually, the carcasses were buried by sand. Because there are four layers at Cerro Ballena, this pathway from sea to land occurred four different times during a period of 10,000 to 16,000 years in the same area.
"Cerro Ballena is the densest site for individual fossil whales and other extinct marine mammals in entire world, putting it on par with the La Brea Tar Pits or Dinosaur National Monument in the U.S.," Pyenson said. "The site preserves marine predators that are familiar to modern eyes, like large whales and seals. However, it also preserves extinct and bizarre marine mammals, including walrus-like whales and aquatic sloths. In this way, the site is an amazing and rare snapshot of ancient marine ecosystems along the coast of South America."
3-D Technology at Cerro Ballena
Because the site was soon to be covered by the Pan-American Highway, time was very limited for the researchers. A major solution came in the form of 3-D technology. Pyenson brought a team of Smithsonian 3-D imaging experts to Chile, who spent a week scanning the entire dig site.
Although all the fossils found from 2010 to 2013 have been moved to museums in the Chilean cities of Caldera and Santiago, the Smithsonian has archived the digital data, including the 3-D scans, from the site at cerroballena.si.edu. There, anyone can download or interact with 3-D models of the fossil whale skeletons, scan Google Earth maps of the excavation quarries, look at a vast collection of high-resolution field photos and videos or take 360-degree tours of the site.
The enormous wealth of fossils that the team examined represents only a fraction of the potential at Cerro Ballena, which remains unexcavated. The scientists conservatively estimate that the entire area preserves several hundred fossil marine mammal skeletons, awaiting discovery. Pyenson's colleagues at the Universidad de Chile in Santiago are actively working to create a research station near the fossils of Cerro Ballena so that those that have been collected and those still covered by sediments can be protected for posterity.



Thursday 20 February 2014

X-Ray: Discovery by Wilhelm Rontgen, 1895


 fACT:

In 1901 Rontgon won the first Nobel prize for Physics for the discoveries of X- rays.

SUMMARY

The German physicist, Wilhelm Röntgen is credited as the discoverer of x-rays in 1895, because he was the first person to systematically produce and detect electromagnetic radiation in a wavelength known as x-rays or Röntgen rays. His discovery was a great revolution in the fields of physics and medicine.
X-Ray: A type of electromagnetic radiation, just like visible light
An x-ray machine sends individual x-ray particles through the body or structure. The images are recorded on a computer or film.
1. Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white.
2. Metal and contrast media (dyes used to highlight areas) will also appear white.
3. Structures containing air will be black and muscle, fat, and fluid will appear as shades of gray.

Tuesday 18 February 2014

Salk Produces Polio Vaccine, 1952

quick facts:

  1. Jonas Salk was born in 1914 in New York City, New York
  2. Polio affected hundreds of thousands of people worldwide before the vaccine
  3. The vaccine's clinical success was made public in 1955
  4. The number of polio cases worldwide is now approaching zero.
Jonas Salk on the cover of Wisdom Magazine
Salk in the Virus Research Lab at the University of Pittsburg
Salk administering the polio vaccine during its clinical trial
Newspaper headlines after the vaccine's release in 1955

Fleming Discovers Penicillin, 1928 - 1945

quick facts:

  1. "Penicillus" is the Latin word for paintbrush
  2. The research and production of penicillin was moved from England to the United States in 1941, to protect it during World War II
  3. The first human patient to use penicillin was a police officer who had cut himself shaving.
  4. The first successful treatment of a patient with penicillin occurred in New Haven, Conn., in 1942
A statute of Alexander Fleming in Madrid, Spain.
A stamp from the Faroe Islands of Alexander Fleming.

Bell Invents the Telephone, 1876

quick facts:

  1. The first message spoken over the phone was "Mr. Watson--come here--I want to see you."
  2. Mr. Watson and Mr. Bell were the first people to make a transcontinental call on January 15, 1915
  3. When a person speaks into the mouthpiece of a phone, the acoustic vibrations from his speech push the metallic coating closer to the electrode, creating variations in voltage and a conversion.
A photo of Alexander Graham Bell.
A drawing on how the telephone works.

Alessandro Volta invents the battery, 1800

quick facts:

  1. Napoleon made Alessandro Volta a count in honor of his work in electricity.
  2. A museum in Como, the Voltain Temple, has been erected in his honor and exhibits some of the original instruments he used to conduct experiments.
  3. In honor of Volta’s work in the field of electricity the electrical unit known as the volt was named in his honor.
Volta Battery
How Batteries Work

Steam Engine, 1781

quick facts:

  1. Since the late 1700s steam engines have become a major source of mechanical power.
  2. In 1781 James Watt patented a steam engine that produced continuous rotative motion.
  3. At the turn of the 19th century, steam-powered transport on both sea and land began to make its appearance becoming ever more dominant as the century progressed.



Frederick William Herschel – Discoverer of Uranus, 1781

quick facts:

  1. Born Friedrich Wilhelm Herschel on November 15, 1738 in Hannover Germany (then under the rule of George I of Great Britain)
  2. In April 1761 he wrote his Symphony,#8 in C Minor
  3. In March 1781 He discovered Uranus.
  4. Died in August 25, 1822 in Obervatory House, Windsor Road, Slough, Royal Berkshire, England

PHOTOS

Van Leeuwenhoek Discovers Microorganisms, 1683

quick facts:

  1. Van Leeuwenhoek was born in 1632 in Delft, Netherlands.
  2. Van Leeuwenhoek is considered the first microbiologist, and is thus known as "the Father of Microbiology."
  3. Although he never published any books, Van Leeuwenhoek sent letters with pictures of his discoveries. His earliest observations were published in a scientific journal of the Royal Society of London,
  4. Van Leeuwenhoek was very interested in microscopes. Extensive tinkering with glass processing led to creation of thin, high-quality glass lenses for his microscopes. He kept his secret to himself.

PHOTOS

A bacteria illustration.
A illustration of bacteria cloud.

Jansen and the 1st Telescope, 1590


The 1st compound microscope designed by Sacharias Jansen.
Picture of a telescope.
Picture of the Hubble telescope.

Quick facts:

  1. Jansen was born 1580 in The Hague, Netherlands.
  2. Two other people are usually associated with the invention of the telescope: Hans Lippershey and Jacob Metius
  3. There was some controversy over who actually invented the first telescope due to conflicting claims about the dates when inventions were made.
  4. Jansen is also associated with the invention of a simple-lens microscope, as well as the compound-lens microscope.

Bruno's Infinite Universe, 1583

quick facts:

  1. Bruno was born 1548 in Nola in the Kingdom of Naples, in modern-day Italy.
  2. The universe was believed to be a finite sphere by ancient philosophers like Plato and Aristotle.
  3. Bruno believed Copernicus's heliocentric model and felt that the universe was infinite because God is infinite.
  4. Bruno was burned at the stake when the Roman Inquisition declared him guilty of heresy for his pantheism.

PHOTOS

A portrait of Giordano Bruno.
A reference map of the Universe.

Copernicus Puts the Sun at the Center of the Universe, 1512

quick facts:

  1. Copernicus was born in 1473 in Torun, Poland
  2. The idea of geocentrism was standardized by Ptolemy circa 150 CE with his book, the Almagest
  3. Copernicus's book, On the Revolution of Heavenly Spheres, details decades of his astronomical work
  4. Heliocentrism didn't find religious opposition until after Copernicus's death
Former Polish coin with the likeness of Copernicus
A portrait of Copernicus drawn in 1580
Supposed childhood home of Copernicus
Monument of Copernicus in Krakow by Cyprian Godebski
College that Copernicus attended, Collegium Maius in Krakow
Heliocentric model in Revolution of the Heavenly Spheres
Mid-16th century portrait of Copernicus by an unknown artist
A digital representation of our solar system

Facts

A portrait of Eratosthenes.

quick facts:

  1. Archimedes was born circa 287 BC in Syracuse, Sicily.
  2. His calculation is flawed because measurements of distance over land were inaccurate at the time; he had to estimate using the amount of time it took to travel between the two cities by camel.
  3. Despite the experimental error, his estimate of the Earth's size was widely accepted for hundreds of years afterwards.
  4. Eratosthenes is known as the first person to prove that the Earth is round, although previous astronomers had simply assumed that it was spherical.

Facts

quick facts:

  1. Socrates never wrote anything down, his students' notes on dialogs and lectures that he gave provide us with insight to his teachings
  2. Plato was a student of Socrates
  3. German philsopher Friedrich Nietzsche said, "I admire the courage and wisdom of Socrates in all he did, said - and did not say."
  4. Socrates was charged with irreverence towards the Athenian gods and was executed by being given poisonous hemlock to drink

PHOTOS

A bust of Socrates.
A statute of Socrates.

History

quick facts:

  1. Thales was one of the 'Seven Sages,' seven semi-legendary wise men who lived in the 6th ad 7th centuries and were credited with creating Greek philosophy
  2. Thales's Theorem states that the diameter of circle always subtends a right angle to any point on the circle. This is very useful in basic geometry when trying to easily find the center of a circle.
  3. Thales believed that the Earth was a flat disc floating on an endless expanse of water, and that water was the primal element from which all things came
  4. Thales became famous in his time for predicting the solar eclipse of 585 BC
Thales of Miletus, from Diogenes Laertius' Lives, 1761, France.
A bust of Thales.

Tuesday 11 February 2014

Scientists Sequence the Genome of the World’s Oldest Continuously Surviving Cancer


Scientists Sequence the Genome of the World’s Oldest Continuously Surviving Cancer

January 24, 2014
Genome of Oldest Cancer Reveals Its Origin and Evolution
Researchers have sequenced the genome of an 11,000-year-old dog cancer, revealing its secrets and origin.
Scientists have sequenced the genome of the world’s oldest continuously surviving cancer, a transmissible genital cancer that affects dogs. This cancer, which causes grotesque genital tumors in dogs around the world, first arose in a single dog that lived about 11,000 years ago. The cancer survived after the death of this dog by the transfer of its cancer cells to other dogs during mating.
The genome of this 11,000-year-old cancer carries about two million mutations – many more mutations than are found in most human cancers, the majority of which have between 1,000 and 5,000 mutations. The team used one type of mutation, known to accumulate steadily over time as a ‘molecular clock’, to estimate that the cancer first arose 11,000 years ago.“The genome of this remarkable long-lived cancer has demonstrated that, given the right conditions, cancers can continue to survive for more than 10,000 years despite the accumulation of millions of mutations”, says Dr Elizabeth Murchison, first author from the Wellcome Trust Sanger Institute and the University of Cambridge.
The genome of the transmissible dog cancer still harbors the genetic variants of the individual dog that first gave rise to the cancer 11,000 years ago. Analysis of these genetic variants revealed that this dog may have resembled an Alaskan Malamute or Husky. It probably had a short, straight coat that was colored either grey/brown or black. Its genetic sequence could not determine if this dog was a male or a female, but did indicate that it was a relatively inbred individual.
“We do not know why this particular individual gave rise to a transmissible cancer,” says Dr Murchison, “But it is fascinating to look back in time and reconstruct the identity of this ancient dog whose genome is still alive today in the cells of the cancer that it spawned.”
Transmissible dog cancer is a common disease found in dogs around the world today. The genome sequence has helped scientists to further understand how this disease has spread.
“The patterns of genetic variants in tumors from different continents suggested that the cancer existed in one isolated population of dogs for most of its history,” says Dr Murchison. “It spread around the world within the last 500 years, possibly carried by dogs accompanying seafarers on their global explorations during the dawn of the age of exploration.”
Transmissible cancers are extremely rare in nature. Cancers, in humans and animals, arise when a single cell in the body acquires mutations that cause it to produce more copies of itself. Cancer cells often spread to different parts of the body in a process known as metastasis. However, it is very rare for cancer cells to leave the bodies of their original hosts and to spread to other individuals. Apart from the dog transmissible cancer, the only other known naturally occurring transmissible cancer is an aggressive transmissible facial cancer in Tasmanian devils that is spread by biting.
“The genome of the transmissible dog cancer will help us to understand the processes that allow cancers to become transmissible,” says Professor Sir Mike Stratton, senior author and Director of the Sanger Institute. “Although transmissible cancers are very rare, we should be prepared in case such a disease emerged in humans or other animals. Furthermore, studying the evolution of this ancient cancer can help us to understand factors driving cancer evolution more generally.”
This work was supported by the Wellcome Trust, the Kadoorie Charitable Foundation, and a L’Oreal-United Nations Educational, Scientific, and Cultural Organization for Women in Science Fellowship.

Study Reveals Why Life in Earth’s Early Oceans Increased in Size


Study Reveals Why Life in Earth’s Early Oceans Increased in Size

January 24, 2014
Biologists Reveal Why Early Life Began to Get Larger in Earths Oceans
Canopy flow and rangeomorph communities. A: Bedding plane, at Mistaken Point, Newfoundland, showing the preservation of rangeomorph taxa. B: Schematic of the reconstructed community showing the velocity gradient (blue arrows) and large Kelvin-Helmholtz vortices. C: Kelvin- Helmholtz vortices visualised at the boundary between parallel flows of different velocity. D: The waving of a vegetated canopy produced by Kelvin-Helmholtz vortices. E: Kelvin-Helmholtz Vortices produced in a cloud layer. Arrows in C-E indicate the relative velocity of flow. F: ‘The Fields’ by Vincdent van Gogh was among a number of his paintings inspired by Kelvin-Helholtz behavior of fields and clouds. Credit: Current Biology
A newly published study examined the earliest communities of large multicellular organisms in the fossil record, revealing why life in Earth’s early oceans increased in size.
Why did life forms first begin to get larger and what advantage did this increase in size provide? UCLA biologists working with an international team of scientists examined the earliest communities of large multicellular organisms in the fossil record to help answer this question.
The life scientists used a novel application of modeling techniques at a variety of scales to understand the scientific processes operating in the deep sea 580 million years ago. The research reveals that an increase in size provided access to nutrient-carrying ocean flow, giving an advantage to multicellular eukaryotes that existed prior to the Cambrian explosion of animal life, said David Jacobs, a professor of ecology and evolutionary biology in the UCLA College of Letters and Science and senior author of the research.
A multidisciplinary research team reconstructed ocean flow in the fossil community using “canopy flow models,” a particular class of flow models consistent with the dense spacing of organisms on the ancient seabed.
The research was inspired by the NASA Astrobiology Institute’s “Foundations of Complex Life” meeting in Newfoundland, Canada, where the oldest known fossil communities of large, multicellular organisms — collectively called rangeomorphs — are found on rock surfaces exposed along the coast. These feather- or brush-shaped creatures ranged in size from several millimeters to tens of centimeters in height.
The scientists addressed the absorption properties of the rangeomorphs’ surfaces based on the model’s results. These rangeomorphs could not photosynthesize because they lived in the extreme depths, where light did not penetrate, Jacobs said. Their complex surfaces suggest that they absorbed dissolved nutrients directly from the water — which raises the question of how rangeomorphs competed with bacteria, which also specialize in absorbing nutrients from seawater.
Understanding what advantages rangeomorphs gained over bacteria by growing tall would provide scientists with insights into what drove the evolution of the first communities of large life forms in the fossil record, Jacobs said.
The scientists discovered that rangeomorphs had an advantage when they grew off the sea floor, as they were exposed to higher flow, generating much greater “nutrient uptake.”
The inducement to “grow upwards is a function of the canopy, which controls the velocity of ocean water as it moves through the rangeomorph community,” Jacobs said. “As individuals grow upwards, the properties of water flow change, which promotes further upward growth.”
Both the canopy-flow and surface-uptake models represent significant advances in scientists’ ability to understand the ecology of fossil and modern communities, Jacobs said. Such modeling may prove critical to understanding processes that affect ocean life today, such as coral bleaching, he said.
Co-authors of the research include David Gold, a UCLA graduate student in Jacobs’ laboratory; Roger Summons (MIT) and David Johnston (Harvard), who helped reconstruct the paleoceanography of this time; and Guy Narbonne (Queens University), Marc LaFlamme (University of Toronto) and Matthew Clapham (UC Santa Cruz), who contributed the paleontological data necessary to populate the model. Marco Ghisalberti of the University of Western Australia in Perth developed and conducted the modeling in collaboration with Jacobs and Gold, who developed the paleo-biomechanical conceptual models to be tested, assembled the research team and directed the research. The research is funded by the NASA Astrobiology Institute.

Researchers Discover New Link between Processes Associated with a Parkinson’s Related Gene Defect



January 30, 2014
Researchers Discover New Link between Processes Associated with a Parkinsons Related Gene Defect
The PINK1 gene plays a role in Parkinson’s disease. If the gene is switched off in the fly, the mitochondria (green) are damaged and the animal’s muscle fibers (red) disintegrate. The activation of the Ret receptor, which binds the growth factor GNDF in humans, counteracts this degeneration. Credit: MPI of Neurobiology / Klein
Researchers from the Max Planck Institute have discovered a new link between processes associated with a Parkinson’s-related gene defect, paving the way to the development of more refined GDNF therapies in the future.
Neurodegenerative diseases like Parkinson’s disease involve the death of thousands of neurons in the brain. Nerve growth factors produced by the body, such as GDNF, promote the survival of the neurons; however, clinical tests with GDNF have not yielded in any clear improvements. Scientists from the Max Planck Institute of Neurobiology in Martinsried and their colleagues have now succeeded in demonstrating that GDNF and its receptor Ret also promote the survival of mitochondria, the power plants of the cell. By activating the Ret receptor, the scientists were able to prevent in flies and human cell cultures the degeneration of mitochondria, which is caused by a gene defect related to Parkinson’s disease. This important new link could lead to the development of more refined GDNF therapies in the future.
In his “Essay on the Shaking Palsy” of 1817, James Parkinson provided the first description of a disease that today affects almost 280,000 people in Germany. The most conspicuous symptom of Parkinson’s disease is a slow tremor, which is usually accompanied by an increasing lack of mobility and movement in the entire body. These symptoms are visible manifestations of a dramatic change that takes place in the brain: the death of large numbers of neurons in the Substantia nigra of the midbrain.
Despite almost 200 years of research into Parkinson’s, its causes have not yet been fully explained. It appears to be certain that, in addition to environmental factors, genetic mutations also play a role in the emergence of the disease. A series of genes is now associated with Parkinson’s disease. One of these is PINK1, whose mutation causes mitochondrial dysfunction. Mitochondria are a cell’s power plants and without them, a cell cannot function properly or regenerate. Scientists from the Max Planck Institute of Neurobiology and their colleagues from Munich and Martinsried have now discovered a hitherto unknown link that counteracts mitochondrial dysfunction in the case of a PINK1 mutation.
The PINK1 gene emerged at a very early stage in evolutionary history and exists in a similar form for example in humans, mice and flies. In the fruit fly Drosophila, a mitochondrial defect triggered by a PINK1 mutation manifests in the fraying of the muscles. Less visible, the flies’ neurons also die. The scientists studied the molecular processes involved in these changes and discovered that the activation of the Ret receptor counteracts the muscle degeneration. “This is a really interesting finding which links the mitochondrial degeneration in Parkinson’s disease with nerve growth factors,” reports Rüdiger Klein, the head of the research study. Ret is not an unknown factor for the Martinsried-based neurobiologists: “We already succeeded in demonstrating a few years ago in mice that neurons without the Ret receptor die prematurely and in greater numbers with increasing age,” says Klein.
The Ret receptor is the cells’ docking site for the growth factor GDNF, which is produced by the body. Various studies carried out in previous years showed that the binding of GDNF to its Ret receptor can prevent the early death of neurons in the Substantia nigra. However, clinical studies on the influence of GDNF on the progression of Parkinson’s in patients did not lead to any clear improvement in their condition.
The new findings from basic research suggest that the mitochondrial metabolism is boosted or re-established through Ret/GNDF. “Based on this finding, existing therapies could be refined or tailored to specific patient groups,” hopes Pontus Klein, who conducted the study within the framework of his doctoral thesis. This hope does not appear to be completely unfounded: The scientists have already discovered a Ret/GDNF effect in human cells with a PINK1 defect similar to that observed in the fruit fly. It may therefore be possible to search for metabolic defects in the mitochondria of Parkinson’s patients in future. A specially tailored GDNF therapy could then provide a new therapeutic approach for patients who test positively.

Study Reveals Shivering and Exercise Equally Convert White Fat to Brown