Constantine Alexander's blog

Toads can 'predict earthquakes' and seismic activity

However, biologist Dr Rachel Grant of the Open University, in Milton Keynes, UK, was routinely studying the behaviour of various colonies of common toads on a daily basis in Italy around the time a massive earthquake struck.

via news.bbc.co.uk

Our Oceans

The world's oceans are in trouble. They've become a dumping ground for pollutants; acidity levels are on the rise. 90 percent of the big fish have disappeared. Destructive fishing practices are killing countless numbers of marine mammals each year. Although environmental groups have done impressive work toward making the world greener, up until now the blue part of our planet -- 71 percent of the Earth's surface -- has been largely ignored.

via www.huffingtonpost.com

‘Darth Vader of dolphins’ to release 17 bottlenose

Chris Porter, known internationally as a dolphin slave-trader for his lucrative business capturing dolphins in the Solomon Islands and selling them to aquariums in such locations as Dubai and Mexico, says he has had a change of heart and is planning to release his last 17 bottlenose dolphins.

via www.timescolonist.com

Professor James Lovelock: 'We can't save the planet'

The man who achieved global fame for his theory that the whole earth is a single organism now believes that we can only hope that the earth will take care of itself in the face of completely unpredictable climate change.

via news.bbc.co.uk

With some species rebounding, commission weighs loosening of ban - washingtonpost.com

International policymakers and environmentalists are assessing whaling restrictions at a time when some whale populations have rebounded, but the affects of climate change, and the rise in ocean noise and offshore energy development continue to threaten the giant ocean mammals.

via www.washingtonpost.com

Casting a wide net for an ocean rescue

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via www.sfgate.com

Researchers equip robot sub with sensory system inspired by blind fish.

Clever as a blind fish, the underwater robot "Snookie" can orient itself in murky waters with an artificial sensory organ inspired by the so-called lateral-line system, found in fish and some amphibians. The experimental vehicle was developed by researchers at the Technische Universitaet Muenchen within the framework of the CoTeSys (Cognition for Technical Systems) excellence cluster. In the future, the researchers expect such capabilities to enable underwater robots to work autonomously in operations ranging from deep sea exploration to inspection of sewer pipes.

Conventional robots are tough. Hostile environments, toxic and corrosive gases, low light levels, moisture, dirt and disease mean nothing to them -- unlike humans, for whom such conditions are generally unbearable. However, these robots the ones typically in use today can only do their job provided that they are precisely programmed to take each step.

Autonomous robots, on the other hand, will in the future be able to react intelligently to their surroundings and perform their tasks largely independently. Rather than being rigidly programmed, they rely on their own sensory perceptions. This is after all the only way in which they can recognize the situation they are in and still fulfill their tasks. However, in harsh environments their senses often fail them, laid low by fumes, dust, water, or high temperatures. New senses are called for -- perhaps even sensory organs of a kind that humans lack.

A new research project undertaken by the CoTeSys (Cognition for Technical Systems) excellence cluster in Munich aims to develop the technology to master such new senses. Biophysicist Prof. Leo van Hemmen of the Technische Universitaet Muenchen (TUM) has high hopes that the animal kingdom will provide the means to allow robots to perceive their environment. Fish, scorpions, even frogs, for example, perceive things that remain hidden to human organs. Not only are they able to detect minute pressure differences and vibrations and recognize threats, they use these senses to form an exact picture of their surroundings, enabling them at any moment to decide, for example, how best to seize their prey or how to conceal themselves behind a defensive obstacle. Prof. van Hemmen and his colleagues are studying just how animals do this, researching the algorithms with which their brains record their environment and developing hardware and computer programs to allow robots to imitate them.

Fish and amphibians for example possess an organ, the lateral line, which is non-existent in land animals. With this sensory organ, which extends along the both sides of the body, they are able to perceive minute variations in pressure and current flow. As a result they are able, even in murky water, to form a very detailed picture of their immediate surroundings at a range of about the length of their body. They know where obstacles lie, where dangers lurk, and where their prey are to be found. Lateral lines are composed of hundreds or even thousands of fine sensory hairs that are located in tiny ducts beneath the skin and that register even tiny changes in flow velocity. The African clawed frog Xenopus laevis for example distinguishes between edible and inedible insects on the basis of water-borne vibrations. In terms of precision, these sensors are comparable with the human inner ear, where hundreds of thousands of fine sensory hairs enable us to distinguish between sounds -- from the sigh of the wind to a symphony.

However, the complicated part is not the sensor itself, but how the signals it sends are processed to create a complete picture of the surrounding area. Differences in pressure are much more difficult to accurately pin down than waves of light. We humans perceive the problem when a sound catches our attention and our eyes automatically seek out the source of the sound to confirm the location. Scorpions, on the other hand, use tiny vibrations transmitted through the ground to find their prey, even in the dark of night: These arachnids have sensory hairs on their eight legs, and their brains analyze the tiniest differences in the timing of vibration waves in the sand to detect where their prey is located. Similar algorithms can be used to analyze the lateral line perceptions of fish.

A favorite example studied by the researchers in Munich is the blind Mexican cave fish Astyanax. As a cave-dweller it has no need of sight in the darkness, and as the fish matures its eyes degenerate. Nevertheless, it has no difficulty in navigating its pitch-black habitat, reacting flexibly to changes and adapting quickly to new environments. The fact that robots can learn to do so too is demonstrated by "Snookie," an underwater robot built by an interdisciplinary team of scientists and technical specialists headed by Prof. van Hemmen. "Snookie" named after a species of perch with a distinctive lateral line is a robot fish made of Plexiglas and aluminum, about 80 centimeters long and 30 centimeters in diameter, stuffed to the gills with an electronic control system and a power supply. Among its striking external features are six propeller gondolas that drive and position the robot, and a yellow hemispherical nose to which the sensors that guide the underwater vehicle are secured.

The TUM scientists intentionally chose an underwater vehicle to test their technology, as such vehicles face a very particular set of challenges not experienced by autonomous robots on land:

* Visibility under water is often limited to just a few centimeters.
* The infrared detectors commonly used by land robots alongside cameras to identify their surroundings do not work under water.
* Wireless communication is restricted under water due to poor propagation.
* Energy supplies are limited to the capacity of the batteries, so all systems must operate with extreme efficiency.
* Maximum reliability is also essential, because if something goes wrong, an underwater robot can quickly be lost for ever.

"An underwater robot is as much on its own as a vehicle on Mars," says electrical engineer Stefan Sosnowski. He works in the Department of Robotics headed by Professor Sandra Hirche and is responsible for the design of the underwater craft. His colleague, biophysicist Dr. Jan-Moritz Franosch, aided by a group of students, has developed an artificial lateral line for the robot, enabling "Snookie" to detect obstacles and movements in the water a hand's breadth in front of its nose and on either side. This artificial organ measures changes in pressure and flow around the robot not with conventional dynamic indicators, which would be far too large and imprecise, but with thermistors. When a change in flow velocity occurs, this immediately causes a change in the heat dispersed through a heated wire. This in turn can be measured electronically by the sensor elements with great speed, and in a minimum of space. At intervals of a tenth of a second and using only a tiny amount of electrical energy, the sensors register pressure fluctuations of less than one percent over an area of just a few square millimeters.

The two young scientists look on "Snookie" as more than just an experiment. They expect autonomous underwater robots to find a broad range of applications -- from investigating shipwrecks to carrying out deep-sea search missions, for example to locate the flight recorder after air disasters. More mundanely, they could also be used to inspect tanks and sewer pipes. Prof. van Hemmen also expects that robots with even more sensitive lateral line systems will have considerable potential uses on land, as it is of course equally possible to detect variations in pressure and flow in air, as well as water. Another external project is working on this subject. Man-made lateral lines might for example offer a cheaper alternative to the laser scanners currently used by robots to feel their way about their immediate surroundings with the advantage that, unlike laser scanners, lateral lines won't be blinded by other robots. This would allow autonomous robots to be deployed in swarms, opening the way for entirely new applications.

Biophysicist Prof. van Hemmen has more on his mind than just autonomous underwater robots. His goal is to develop and combine new forms of technological sensory perception, as he is convinced that in this way machines can perceive their environment with much greater accuracy. "The key here is 'multimodal sensing,'" he explains. "Humans, too, don't rely on a single sense. Our brains combine the input from a variety of senses to create an overall image of our surroundings. It is not until one of our senses fails us that we appreciate how important this combination is." Prof. van Hemmen graphically demonstrates this using the following example: "It normally takes maybe ten seconds to strike a match. But if you put on thin gloves to take away the sense of touch, it becomes much harder. Often the task then takes more than a minute."

Van Hemmen is also convinced that robot intelligence benefits little from installing even more cameras to supply even more images. He believes that it is more important for robots to perceive different aspects of their environment with a variety of sensors. However, when it comes to combining these different perceptions, he has to delve deep into the secrets of brain research: How do animals sift through a mass of data to filter out what is really relevant? How do humans manage this? The CoTeSys excellence cluster, he believes, presents an opportunity not just to answer these questions, but, through interdisciplinary cooperation among physiologists, information technologists and engineers, to transfer the new-found principles to the world of technology: "To be alert means reducing data to its essentials. Robots must learn to do this too, even when faced with a wide variety of sensor information."

In fact, CoTeSys specializes in just this kind of interdisciplinary cooperation. The research cluster brings together around 100 scientists working in widely differing fields at five universities and research institutes in the Munich area, in the interest of developing better cognitive capabilities for technical systems. The goal is to make robots more self-sufficient, able to analyze for themselves and flexibly respond to the situations in which they find themselves -- from recognizing their surroundings through to independently performing their allotted tasks. As part of the Excellence Initiative, the Federal and state governments have set aside a total of 28 million euros in funding for the joint project coordinated by the Technische Universitt Mnchen (TUM).

Contact: Markus Bernards
bernards@zv.tum.de
49-892-892-2562
Technische Universitaet Muenchen

Urine sprays during courtship send mixed messages.

Walking through urine drives crayfish into an aggressive sexual frenzy. Researchers writing in the open access journal BMC Biology suggest that a urine-mediated combination of aggressive and reproductive behaviour ensures that only the strongest males get to mate.

Fiona Berry and Thomas Breithaupt from the University of Hull, UK, investigated the effects of urine-based chemical signaling on sexually active crayfish. Breithaupt said, "Our results confirm that females initiate courtship behavior; males will only attempt to mate if they receive urinary signals from the female. Females, however, send a mixed message by releasing an aphrodisiac while also acting very aggressively towards the males".

Females could profit in different ways from displaying such conflicting signals. By stimulating aggressive behaviour in males, females can gauge male size and strength and thereby ensure that only the fittest males get to fertilise their eggs. According to the researchers, "Timing seems to be key to this interaction as urine induces aggression in both sexes. Males will discontinue urine release early in the sexual encounter, which may mitigate the female's antagonism and enhance mating success".

Contact: Graeme Baldwin
graeme.baldwin@biomedcentral.com
44-203-192-2165
BioMed Central

New mathematical model helps biologists understand how coral dies in warming waters.

Cornell University researchers have found a new tool to help marine biologists better grasp the processes under the sea: They have created mathematical models to unveil the bacterial community dynamics behind afflictions that bleach and kill coral. (Public Library of Science Biology, March 30, 2010.)

Warming waters are triggering coral bleaching and disease in the Caribbean, Indian Ocean and Great Barrier Reef off the Australian coast. Now new mathematical models explain for the first time how beneficial bacteria on coral suddenly give way to pathogens when waters warm.

"Before this study, we just had observations but little understanding of the mechanism" for what causes coral disease and bleaching, said Laura Jones, Cornell senior research associate in ecology and evolutionary biology. Justin Mao-Jones '08, conducted the research as an undergraduate in the School of Operations Research and Information Engineering, is the paper's lead author.

The model reveals how a healthy normal microbial community in the coral surface mucus layer protects corals from disease by preventing invasion and overgrowth by pathogenic bacteria. But when corals are stressed, for example by elevated temperatures (a heat spell), the community of microbes suddenly switches. Species associated with a healthy coral organism "resident species" - decline as pathogens associated with coral disease take their place.

The researchers used models to simulate bacterial community dynamics within the surface coral mucus, under normal conditions, and under the warming conditions that lead to a sudden shift from beneficial bacteria to pathogens on the coral's surface.

"There's a critical threshold where the system jumps to a pathogen-dominated state," said Jones.

They also found that the models replicated a pattern others have observed: once the disease-causing microbes establish themselves, they persist even if the water cools down enough to favor the beneficial bacteria. The coral is then often too damaged to recover, and the reefs begin to die.

Preventing oceans from warming will require people to curb climate change, and may be unavoidable in the short term, said Jones. But reducing poor water quality, which stresses the coral and makes the oceans more hospitable to pathogens, could perhaps ward off the sudden shift to pathogens dominating the coral surface, she added.

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University

Bacterial 'food supplements' for small algae.

To boost their diet of mineral nutrients and sunlight, small algae also feast on bacteria in order to grow and fix carbon dioxide (CO2). Understanding more about the lifestyle of small algae - which are major players in CO2 fixation in the ocean - could help to improve ecological models of oceanic and global changes.

Professor Mike Zubkov from the National Oceanography Centre in Southampton presents his study on bacterioplankton consumption at the Society for General Microbiology's spring meeting in Edinburgh today.

The research, conducted on board the Royal Research Ship Discovery in the North Atlantic Ocean in the summer of 2007, found that the smallest algae consume more bacteria than specialised predators such as certain protozoa. This conclusion was supported by further evidence gathered on subsequent research trips to the tropical Atlantic.

It was previously thought that the algae are purely phototrophic organisms, using only sunlight and mineral nutrients dissolved in seawater to fix CO2 into biomass. The researchers think that the ability to also feed on bacteria may well confer an evolutionary advantage to small algae. "Feeding on bacteria provides the smallest algae with biologically concentrated nutrients, giving them a competitive survival edge in the open ocean," said Professor Zubkov.

The findings are being incorporated into ecological models to assess scenarios of oceanic and global changes. "These algae are one of the dominant groups of oceanic CO2 fixers - up to 40% of the gas could be fixed by these microbes in the open ocean. Knowing how they acquire nutrients and build biomass is essential if we are to understand the biological capacity of the ocean to absorb and to retain CO2," said Professor Zubkov.

Contact: Laura Udakis
l.udakis@sgm.ac.uk
44-118-988-1843
Society for General Microbiology