Two scientists from the University of Copenhagen have demonstrated that the spinal cord use network mechanisms similar to those used in the brain. The discovery is featured in the current issue of Science.

The research group behind the surprising results consists of Professor Jørn Hounsgaard and Post.doc Rune W. Berg from the University of Copenhagen, and Assistant Professor and PhD Aidas Alaburda from the University of Vilnius. The group has shown that spinal neurons, during network activity underlying movements, show the similar irregular firing patterns as seen in the cerebral cortex.

“Our findings contradict conventional wisdom about spinal cord functions”, says Rune W. Berg from Department of Neuroscience and Pharmacology at the Faculty of Health Sciences.

Until now, the general belief was that the spinal networks functioned mechanically and completely without random impulses. The new discovery enables researchers to use the theory on cortical networks to explore how spinal cords generate movements.

How humans are able to move at all remains a puzzle. Our muscles are controlled by thousands of nerve cells in the spinal cord. This entire, complex system must work as a whole in order to successfully create a single motion. The new research shows that even if we repeat a certain motion with high accuracy, the involved nerve cells never repeat their activity patterns. This particular observation reflects the organisation of the nerve cells of the cerebral cortex.

January 24th, 2007 | Health | 2 comments

A litre of gasoline can be obtained from a kilogram of old plastic sachets by appying a technology being developed by the specialists of the D.I. Mendeleev Russian Chemical-Engineering University. This is one of unique examples how the scientists can use a material initially made of petroleum to get if not oil per se again but the product of petroleum refining – engine fuel.

“The idea of carbonic waste processing into carbohydrates is certainly no new news, says project manager Valery Shvets, Doctor of Chemistry, Professor. For example, two plants – a pilot one and an industrial-scale plant – have recently started operating in the US to process turkey factory wastes, mainly skin, feather and grease, into engine fuel. We, for our part, decided to focus our efforts on obtaining gasoline mainly from man-caused carbonic wastes – such as polyethylene, polypropylene, polystyrene and polyethylene terephthalate wastes. And we have achieved a lot of progress in this direction.”

The technology suggested by V.F. Shvets and his colleagues is based on catalytic thermal treatment of polymeric materials. Its basic stages are as follows. First, the wastes should be grinded (it is not necessary to wash them) and melted down. Them they should be mixed with the catalyst powder and exposed to thermal destruction, simply speaking –kept for some time in the reactor at a definite temperature and pressure.

The catalyst composition is not discussed by the researchers in public press – it is being patented now. It is only known that these are grinded wastes of a single production. Further, the liquid hydrocarbon fraction, which is practically gasoline, is topped and collected from the obtained mass. The authors suggest that gaseous decomposition products should be used as fuel: partly in the same production to ensure the required treatment process temperature, and the remainder – in any other process where fuel gases are needed.

The plant’s working model, or more precisely – a prototype model, is installed on the laboratory desk and functions duly. The plant allows to produce a liter of gasoline and a little fuel gas from a kilogram of polyethylene garbage (the petrol fraction content in the products of treatment reaches 90 percent). The waste represents black viscous substance resembling tar, saturated by the catalyst powder. There remains about a table-spoon amount of it per liter of gasoline. In principle, this product can also be used or burned down – then catalyst can be returned into the process.

Now the researchers continue the work in several directions at once. On the one hand, the reactor for the industry should be large, so scaling is to be performed, however, the authors will not be able to cope with this task independently – they will need to work jointly with production workers. On the other hand, the researchers are striving to make the process continuous, and they have made a lot of progress in this direction. And finally, one of the tasks is to develop a similar technology for processing animal and phytogenic wastes – meat-processing and poultry factory wastes.

Source: InformNauka

January 22nd, 2007 | Earth Sciences and Geomatics, Environment | 1 comment