Monday, July 17, 2017

The Longest Living Animal May Be a Tubeworm

Large tubeworms living in the cold depths of the Gulf of Mexico may be among the longest living animals in the world. This is revealed in a study in Springer's journal The Science of Nature. According to lead author Alanna Durkin of Temple University in the US, members of the tubeworm species Escarpia laminata live around 100 to 200 years, while the longevity of some even stretches to the three century mark.

Escarpia laminata is a type of tubeworm that lives in cold seeps found between 1000 meters and 3300 meters deep on the ocean floor of the Gulf of Mexico. Hydrogen sulphide, methane and other hydrocarbon-rich fluids seep out of these vents.

Because so little is known about this species and its life history, Durkin and her colleagues set out to estimate its lifespan. The team also wanted to find out if it is as long-lived as other types of tubeworms living in cold seeps in shallower waters, such as Lamellibrachia luymesiand Seepiophila jonesi.

The tubeworm species Escarpia laminata.

Image courtesy of the Chemo III project, BOEM and NOAA OER

They collected and marked 356 tubeworms at different locations in the Gulf of Mexico and measured how much these grew over the course of one year. This method for modelling annual growth was first developed to calculate the age of Lamellibrachia luymesi, which is estimated to live up to 250 years. The average individual growth model was then extended to also include death rates and recruitment rates to construct a population-wide simulation. In the process, the age and growth rates of the individual tubeworms collected could be estimated.

The individual and population level approaches indicate that larger Escarpia laminata individuals live longer than 250 years. An Escarpia laminata tubeworm fifty centimeters in length is predicted to be 202 years old. This species therefore lives much longer than its relatives, Lamellibrachia luymesi and Seepiophila jonesi. This lifespan is also far beyond estimates based on universal scaling laws for Escarpia laminata's body size and ambient temperature.

According to Durkin, Escarpia laminata's extremely low death rate has helped it evolve a very long lifespan. The results support longevity theory, which states that in the absence of any external threats natural selection will select for individuals that show signs of ageing more slowly and can reproduce continually into their old age.

"At more than 250 years old, Escarpia laminata achieves a lifespan that exceeds other longevity records," says Durkin. "Given the uncertainty associated with estimating the ages of the longest individuals, there may be large Escarpia laminata tubeworms alive in nature that live even longer."

The longest-lived land vertebrate ever recorded was a 177-year-old Galapagos giant tortoise, while bowhead whales of 211 years old have been recorded as the longest-lived mammal. Durkin says the marine clam Arctica islandica remains the oldest non-colonial animal known, with an inferred age of 507 years.



Contacts and sources: 
Melanie Lehnert
Springer

Citation: Durkin, A. et al (2017). Extreme longevity in a deep-sea vestimentiferan tubeworm and its implications for the evolution of life-history strategies, The Science of Nature. DOI 10.1007/s00114-017-1479-z

10 Billion Years Light Years Away and a Thousand Times Brighter than the Milky Way

Thanks to gravitational lensing an amplified image of one of the brightest galaxies known from the epoch when the universe was only 20% of its present age has been produced by Gran Telescopio Canarias (GTC),  a team of scientists from the Polytechnic University of Cartagena and the Instituto de Astrofísica de Canarias (IAC) have discovered

The multiple images of the discovered galaxy are indicated by white arrows (bottom right shows the scale of the image in seconds of arc).
Credit: Hubble Space Telescope

According to Einstein’s theory of General Relativity when a ray of light passes close to a very massive object, the gravity of the object attracts the photons and deviates them from their initial path. This phenomenon, known as gravitational lensing, is comparable to that produced by lenses on light rays, and acts as a sort of magnifier, changing the size and intensity of the apparent image of the original object.

Using the gravitational lens effect, a team of scientists from the Instituto de Astrofisica de Canarias (IAC) led by researcher Anastasio Díaz-Sánches of the Polytechnic University of Cartagena (UPT) has discovered a very distant galaxy, some 10 thousand million light years away, about a thousand times brighter than the Milky Way. It is the brightest of the submillimetre galaxies, called this because of their very strong emission in the far infrared. To measure it they used the Gran Telescopio Canarias (GTC) at the Roque de los Muchachos Observatory (Garafía, La Palma).

“Thanks to the gravitational lens” notes Anastasio Díaz Sánchez, a researcher at the UPCT and first author of the article “ produced by a cluster of galaxies between ourselves and the source, which acts as if it was a telescope, the galaxy appears 11 times bigger and brighter than it really is, and appears as several images on an arc centred on the densest part of the cluster, which is known as an “Einstein Ring”. The advantage of this kind of amplification is that it does not distort the spectral properties of the light, which can be studied for these very distant objects as if they were much nearer”.

To find this galaxies, whose discovery was recently published in an article in the Astrophysical Journal Letters, a search of the whole sky was carried out, combining the data bases of the satellites WISE (NASA) and Planck (ESA) in order to identify the brightest submillimetre galaxies. Its light, amplified by a much nearer galaxy cluster acting as a lens, forms an image which appears much bigger than it should, and thanks to this effect they could characterize its nature and properties spectroscopically using the GTC.

Forming stars at high velocity

The galaxy is notable for having a high rate of star formation. It is forming stars at a rate of 1000 solar masses per year, compared to the Milky Way which is forming stars at a rate of some twice a solar mass per year. Susana Iglesias-Groth, an IAC astrophysicist and a co-author of the article, adds. “This type of objects harbour the most powerful star forming regions known in the universe. The next step will be to study their molecular content”.

The fact that the galaxy is so bright, its light is gravitationally amplified, and has multiple images allows us to look into its internal properties, which would otherwise not be possible with such distant galaxies.

“In the future we will be able to make more detailed studies of its star formation using interferometers such as the Northern Extended Millimeter Array (NOEMA/IRAM),in France, and the Atacama Large Millimeter Array (ALMA), in Chile” concludes IAC researcher Helmut Dannerbauer, who is another contributor to this discovery.


Contact:
Susana Iglesias-Groth
Anastasio Díaz Sánchez
Instituto de Astrofísica de Canarias (IAC)


Article: “Discovery of a Lensed Ultrabright Submillimeter Galaxy at z = 2.0439” by Anastasio Díaz Sanchez, Susana Iglesias Groth, Rafael Rebolo and Helmut Dannerbauer, 2017, ApJ Letter.  https://doi.org/10.3847/2041-8213/aa79ef

Sunday, July 16, 2017

Are You Afraid of Crime? It's Contagious Even in Low Crime Neighborhoods

Fear of crime is perpetuated by the opinion of others, and often doesn’t correlate to the actual likelihood of experiencing crime, according to new UCL research.

The findings of the study, published in Proceedings of the Royal Society A, help to explain how a generalised fear of crime exists in cities and countries in which crime rates are low.

“The fear of crime can be considered contagious, because social interaction is the mechanism through which fear is shared and chronically worried populations are created. Even those that have never been a victim of crime can be seriously worried about it,” said study lead Rafael Prieto Curiel (UCL Mathematics).

Image result for crime prevention

Credit: Wikimedia Commons
“Most studies about the fear of crime and perception of security are static observations of the current situation in a particular region or country. We wanted to find out how collective perception of insecurity emerges and changes over time, and how it compares among victims and non-victims of crime,” added Rafael, a former crime analysis mathematician who worked for the police in Mexico City.

The study on the dynamics of the perception of security was developed through a mathematical model that draws heavily on concepts similar to those used for opinion dynamics. A similar technique could be used to understand the dynamics of fear caused by terrorism or public opinion of international migration.

The model simulated the perception of security among a population of 10,000 individuals, who update their perception of security each week. To understand how fear of crime varies across populations three different groups were established to mimic the distribution observed in a city: a large majority statistically immune to crime; a group that experiences a small amount of crime; and a small population that experiences the majority of crimes.

They found that when individuals that never suffer crime only interact with people from their own group, they feel secure. However, only a small amount of interactions between groups is enough to change their perceptions of security. For instance, when 5% of the interactions occur with people from another group, the model predicts that more than 50% of the individuals who never suffer crime will fear it.

Less change is seen among the other two groups, where it is predicted that roughly 60% of those that rarely suffer any crime and 80% of those that suffer higher rates will be concerned about crime whether they interact within or outside their group.

The findings also suggest that a decrease in crime rates might have almost no effect on the perception of security. For example, with low crime levels (5% of its regular level) the simulations predict that between 30 to 40% of the population from all three groups will fear crime.

The researchers say that significant changes to the perception of security among those that are immune to crime is particularly interesting as it highlights that the perception that a region is secure is very unstable. It takes only a small amount of crime to create a generalised fear in the population, and crime rates need to decrease considerably to improve the average perception that a region is secure.

“Fear of crime is not a negative feeling, in fact it creates healthy precautions, like locking the door of our house, but it becomes an issue if it is disproportionate and unmanageable. From a policy perspective, we hope the findings of this study can be used to improve communication and knowledge of crime at regional levels,” concluded Rafael.

The research was funded by CONACYT Mexico and the European Union’s Horizon 2020 research and innovation programme via the FET-Proactive CIMPLEX project.



 

Contacts and sources:
Natasha Downes
University College London

9/11 Survivors Have Increased Risk Of Heart and Lung Diseases from Toxic Dust

"The World Trade Center attack of September 11, 2001 in New York City (9/11) exposed thousands of people to intense concentrations of hazardous materials that have resulted in reports of increased levels of asthma, heart disease, diabetes, and other chronic diseases along with psychological illnesses such as post-traumatic stress disorder (PTSD)," according to a new report on harm caused by the 9/11 tragedy.

People who were exposed to the dust cloud or sustained physical injuries during the terrorist attacks on the World Trade Centre on September 11, 2001 may be at increased long-term risk of asthma, other respiratory diseases and heart attack, according to a study published in the open access journal Injury Epidemiology.

Credit: Wikimedia Commons

Researchers at the New York City Department of Health and Mental Hygiene examined the association between physical injury or acute exposure to the dust cloud on the morning of September 11, 2001, and chronic disease up to ten to eleven years later (2010-2012).

Dr Robert Brackbill, the corresponding author said: "Our findings indicate that intense exposure on a single day -- the first day of the disaster -- contributes substantially to the risk of developing chronic conditions. Continued monitoring of people who were present in the vicinity of the World Trade Center on 11th September by medical providers is warranted for the foreseeable future."

The researchers found that the number of types of injuries, such as fractures, head injuries, or sprains, a person sustained on 11th September 2001 was associated with an increased risk of angina or heart attack in a dose-dependent manner, which means that the risk of having angina or a heart attack increased with every additional injury type. Dust exposure, PTSD and being a rescue worker, as well as current smoking were associated with a higher risk of non-neoplastic lung disease (lung conditions not involving tumors) other than asthma, while dust exposure on its own was associated with an increased risk of asthma. None of these risk factors were associated with a higher risk of diabetes.

Out of the total number of 8,701 people enrolled in this study, 41% had intense exposure to the dust cloud, 10% has a single injury, 2% had two types of injury and 1% had three or more. The researchers found 92 incident cases of heart disease, 327 new cases of diabetes, 308 cases of asthma, and 297 cases of non-neoplastic lung disease among 7,503 area workers, 249 rescue workers, 131 residents and 818 passersby -- the most heavily exposed groups.

To examine the long term health effects of acute exposure to the dust cloud, or physical injury caused by the terrorist attack, the authors used data from the WTC Health Registry cohort. The WTC Health Registry monitors the physical and mental health of 71,431 persons exposed to the attacks on 9/11. It contains data collected during three waves in 2003-2004, 2006-2007 and 2011-2012. A fourth wave of data has been collected but not included in this study.

A lack of specific information on the severity, location and treatment of injuries, as well as on the circumstances in which they were sustained meant that the number of types of injuries was used as a proxy measure for injury severity. However, previous research has shown that more than one type of injury is associated with increased risk of death and longer stays in hospital, according to the authors.



Contacts and sources:
Anne Korn
BioMed Central


Citation: Injury, intense dust exposure, and chronic disease among survivors of the World Trade Center terrorist attacks of September 11, 2001.
Alper et al Injury Epidemiology 2017
DOI: 10.1186/s40621-017-0115-x

The Longest Living Animal May Be a Tubeworm

Large tubeworms living in the cold depths of the Gulf of Mexico may be among the longest living animals in the world. This is revealed in a...