Some facts: Ginkgo tree

The ginkgo is the oldest living tree species, geological records indicate it has been growing on earth for 250 million years. In the last 30 years, more that 400 studies have given clinical evidence that ginkgo biloba extract prevents and benefits many problems throughout the entire body. Ginkgo is gaining recognition as a brain tonic that enhances memory (particularly in the elderly) because of its positive effects on the vascular system, especially in the cerebellum. It is also used as a treatment for vertigo, tinnitus (ringing in the ears) and a variety of neurological disorders and circulation problems. Ginkgo may help to counteract the effects of ageing, including mental fatigue and lack of energy.

Ginkgo works by increasing blood flow to the brain and throughout the body’s network of blood vessels that supply blood and oxygen to the organ systems. It increases metabolism efficiency, regulates neurotransmitters, and boosts oxygen levels in the brain which uses 20% of the body’s oxygen. The ginkgo tree thrives in full sun and average soil. It is very resistant to infection and pollution. A Ginkgo tree can reach about 30 sometimes 40 metres (100 feet) height and achieve a spread of 9 metres. The trunk can become about 4 metres (13 feet) wide in diameter. Some trees are very wide spreading, others are narrow. The small yellow fruit that falls from the female tree has a strong rancid odour. This is why many cities have bylaws that will say that only the male ginkgo tree can be planted.

Ginkgo nuts are frequently used in Chinese sweet and savory dishes, including soup and porridge. In addition, roasted ginkgo nuts are often served as a digestive aid at formal banquets. You will also see them being given away at Chinese weddings, as they are thought to bring good luck.

Robot blood

Dr Tony Phillips and Patrick L Barry

If you don’t see it for yourself, you might not believe it. A gray blob oozes down the side of a laboratory beaker. It’s heading for the table, but before it gets there a low hum fills the air. Someone just switched on an electromagnet. The goop stiffens, quivers, then carries on oozing only after the hum subsides.

Is it alive?

No, just magnetized.

"We call them magnetorheological fluids - or ‘MR fluids’ for short," says Alice Gast, a professor of chemical engineering at MIT. "They’re liquids that harden or change shape when they feel a magnetic field."

You can make some of this exotic stuff at home. Just mix some powdered iron filings with a thick liquid like corn oil, and presto: a simple MR fluid. Hold a magnet nearby and the bits of iron will line up end-to-end; they form a rigid lattice that stiffens the mixture. Take the magnet away and the fluid will relax again. If you own a sports car or a Cadillac, you might have MR fluids in your shock absorbers. The stiffness of magnetic shocks can be electronically adjusted thousands of times per second, providing a remarkably smooth ride. Similar but more powerful devices have been installed at Japan’s National Museum of Emerging Science and China’s Dong Ting Lake Bridge. They’re there to counteract vibrations caused by earthquakes and gusts of wind.

Motion damping is perhaps the most practical use for MR technology today, but much more is possible. Says Gast: "There are many potential applications that make these fluids very exciting." For example, MR fluids flowing in the veins of robots might one day animate hands and limbs that move as naturally as any humans. Book makers could publish rippling magnetic texts in Braille that blind readers could actually scroll and edit. It might even be possible to train student surgeons using synthetic patients with MR organs that flex and slice like the real thing.

There are many problems to solve before such things are possible. How do you control a magnetic field and deliver it with exquisite precision anywhere inside an MR fluid? Researchers aren’t sure - but that’s another story. Equally important are the inner workings of the MR fluids themselves. "We need to learn much more about their basic physics," says Jack Lekan of NASA’s Glenn Research Center. That’s the goal of an experiment called InSPACE now orbiting Earth onboard the International Space Station. Gast developed InSPACE, short for "Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions," in collaboration with scientists and engineers at the Glenn Research Center. Gast is the principal investigator; Lekan is the project manager.

InSPACE will explore a curious phenomenon: When some low-density MR fluids are exposed to rapidly alternating magnetic fields, their internal particles clump together. Over time they settle into a pattern of shapes that look a bit like fish viewed from the top of a tank. Such clumpy MR fluids don’t stiffen as they should when magnetized.

The fish tank pattern is fragile and takes about an hour to fully develop. It doesn’t occur in MR fluids that are constantly mixed and agitated, as in a car’s suspension, but it could prove troublesome in other situations. The pull of gravity on Earth can distort the pattern - a frustration to scientists trying to study its underlying physics. That’s why Gast and colleagues have sent their MR fluids to orbit. On the space station, astronauts can expose a weightless (freely-falling) fluid to magnetic pulses and record what happens.

"Astronauts are an integral part of our study," notes Lekan. They will reach into the Microgravity Science Glovebox, where the experiment is located, to align and focus cameras on a spot only 0.2 mm wide. If a fluid bubble gets in the way of the shot ... flick! they can remove it.

In early April 2003, ISS Science Officer Don Pettit conducted the first experiments with MR fluids inside the glovebox. His two-hour "run" marked beginning of the InSPACE investigation, which will likely continue off and on throughout the month. Meanwhile, some companies are already forging ahead with new magnetorheological devices. Lord Corporation of North Carolina, for example, is designing an MR washing machine. Magnetic dampers inside the machine will decrease noise and vibration - and save energy. They’re also studying MR technology for seat belts and airbags in cars. Because MR fluids can generate large forces quickly and flexibly, they could be used by automakers to adjust the arresting force of a seatbelt to the size and weight of a passenger. Saving lives and silencing washing machines - and that’s just the beginning. Not bad for a bunch of gray oily goop.

(First Science)

Int’l conference on IT
Prospects and challenges in 21st century

Sudan Jha

Information Technology (IT), one of the best marvels of the 20th Century has changed our everyday lives. The technology is present almost everywhere in human endeavor. But there are still challenges to the development of IT in developing countries like Nepal. One of them is that we do not have a common platform for all the IT graduates, scientists, academicians, students, professionals researchers and others to discuss their ideas. With the aim of bringing all the computer personnel under the same umbrella, Nepal Engineering College in association with the Ministry of Science and Technology (MOST), Royal Nepal Academy of Science and Technology (RONAST), and Nepal College of Information Technology (NCIT) is set to organised an International Conference on IT. The conference is to be held in Kathmandu on May 23rd with the theme "Prospects and challenges in the 21st century". Various eminent personalities from India, USA, UK, and other countries will participate in the conference.

The conference, the first of its kind is being hosted in Nepal in cooperation with Computer Association of Nepal (CAN), Advance Communication Society (ACS) – India and IEEE – India. A total of 246 papers have been received from throughout the world for the conference. Most of the papers are from India including the Indian Institute of Technology, Regional Engineering Colleges, IT companies; however the conference has also received various papers from Australia, Italy, Taiwan, Japan, Bangladesh, Hongkong, Singapore and China.

Various eminent personalities from the National level and International level have an active involvement in the conference. Prof. Dayananda Bajracharya (Vice Chancellor – RONAST), Mr. M.M. Shrestha (Secretary – MoST), Dr. Yuba Raj Khatiwada (Member – National Planning Commission), Mr. Sanjib Rajbhandari (Mercantile Corporation Pvt. Ltd.) are some of the names from National level.

On the other hand, Stephen Olariu (USA), Prof. L.M. Patnaik (Indian Institute of Science and Technology), Dr. Suresh Manandhar (York University, UK), Jay Bagga (Ball State University – USA) are to name a few from International level.

The conference is based on various aspects of the Information Technology like Web Technology, Bio-Informatics and Soft Computing. Similarly, the conference has been sponsored by the University of Technology Sydney Australia, United Nation’s University – International Institute of Software Technology, Macao SAR China, and Advance Communication Society (ACS) – India.

The conference can be taken as an initiation towards the development and generating enthusiasm of IT among the people who are associated towards IT.

Coronavirus cause of SARS

Scientists identify new pathogen in record time

The World Health Organization an nounced that a new pathogen, a member of the coronavirus family never before seen in humans, is the cause of Severe Acute Respiratory Syndrome (SARS). The speed at which this virus was identified is the result of the close international collaboration of 13 laboratories from 10 countries. While many lines of evidence have found strong associations between this virus and the disease over the last weeks, final confirmation came today.

"The pace of SARS research has been astounding," said Dr. David Heymann, Executive Director, WHO Communicable Diseases programmes. "Because of an extraordinary collaboration among laboratories from countries around the world, we now know with certainty what causes SARS."

The successful identification of the coronavirus means that scientists can now confidently turn to other SARS challenges. For example, various laboratories continue to work to unravel the genetic information of the SARS virus and compare the sequences obtained from viruses in different parts of the world. Experts are gathering at WHO this week to map future work on SARS.

"Today, the collaboration continues as top laboratory researchers have come to WHO to design the next steps, a strategy for transforming these basic research discoveries into diagnostic tools which will help us to successfully control this disease," said Heymann.

This collaboration has brought together leading scientific expertise, and was established after WHO issued a global alert on SARS on 12 March 2003. The priority has been to find the cause and to develop diagnostic tests. Two laboratories in China recently joined this network of laboratories from Canada, France, Germany, Hong Kong Special Administrative Region of China, Japan, the Netherlands, Singapore, the United Kingdom, and the United States of America.

"Today, the first part of the mission of our network has been fulfilled, as researchers have both detected a hitherto unknown virus and established it as the cause of SARS. The new coronavirus has been named by WHO and member laboratories as "SARS virus, " said Dr Albert Osterhaus, the Director of Virology at Erasmus Medical Center in Rotterdam. Erasmus completed the work to definitely prove that the new coronavirus causes SARS.

Over the past three weeks, due to the urgency surrounding the worldwide threat to health of SARS and early indications this was a new member of the coronavirus family, research has proceeded under the assumption that SARS was caused by a new coronavirus.

The 13 laboratories have been working on meeting Koch’s postulates, necessary to prove disease causation. These postulates stipulate that to be the causal agent, a pathogen must meet four conditions: it must be found in all cases of the disease, it must be isolated from the host and grown in pure culture, it must reproduce the original disease when introduced into a susceptible host, and it must be found in the experimental host so infected.

Credit for the coronavirus findings, which definitively pinpoints the cause of SARS, is attributed to the 13 laboratories, working in conjunction with WHO.

"The people in this network have put aside profit and prestige to work together to find the cause of this new disease and to find way new ways of fighting it," said Dr Klaus Stöhr, WHO virologist and the coordinator of the collaborative research network. "In this globalized world, such collaboration is the only way forward in tackling emerging diseases."

WHO and the network of laboratories dedicate their detection and characterization of the SARS virus to Dr Carlo Urbani, the WHO scientist who first alerted the world to the existence of SARS in Hanoi, Vietnam, and who died from the disease in Bangkok on 29 March 2003.

(WHO press release)

Composting of organic wastes

Vinod Kumar Sharma

Composting is defined as the bio logical decomposition and stabilisation of organic wastes under conditions that allow development of thermophilic temperatures making a final product without adverse environmental effects. Another definition, recently agreed refers to composting as a controlled aerobic process carried out by successive microbial populations combining both mesophilic and thermophilic activities, leading to the production of carbon dioxide, water, minerals and stabilised organic matter. Generally, composting is applied to solid and semi-solid organic wastes, such as sludge, animal manures, agricultural residues, and municipal solid wastes.

Aerobic composting is the decomposition of organic wastes in the presence of oxygen. The end products are carbon dioxide, ammonia, water and heat. Anaerobic composting is the decomposition of organic wastes in the absence of oxygen; the end-products are methane, carbon dioxide, ammonia, trace amounts of other gases, and other low-molecular –weight organic acids. Ammonia is further oxidised to become nitrate by the nitrifying bacteria during the maturation or curing phase. Aerobic composting has been the preferred process for stabilising large quantities of organic wastes as it releases more heat energy, resulting in a rapid decomposition rate. Anaerobic composting is a slow process and can produce obnoxious odors originating from the intermediate metabolites such as mercaptans and sulfides. Depending on the methods of operation, anaerobic composting can produce temperatures near to or at thermophilic levels. Because of its simplicity, anaerobic composting has found some applications in many rural areas of developing countries in the stabilisation of wastes generated from households and farms.

It should be noted that, in contrast to wastewater treatment, the terms ‘aerobic’ and ‘anaerobic’ for composting have relative meanings. They simply indicate what conditions are predominant in the process. As the compost materials are heterogeneous and bulky in character, in a compost heap there always exists ‘anaerobic’ composting, which is little in ‘aerobic’ composting but abundant in ‘anaerobic’ composting; and vice-versa. Some composting processes, such as composting pits being practiced, are aerobic at first and become anaerobic during the later stages of the composting period.

Using technology as the key, composting can be classified into ‘mechanical’ and ‘non-mechanical’ processes, or ‘on-site’ and ‘off-site’ processes. Composting can also be divided with respect to the modes of operation, i.e. batch operation and continuous or semi-continuous operation. When taking into consideration temperature, composting can be divided into ‘mesophilic’ composting (when temperatures in the compost heap are between 25 and 40 degrees) and ‘thermophilic’ composting (when temperatures are between 50 and 65 degrees).

Benefits and limitations of composting:

The main benefits of composting are classified as follows:

< Waste stabilisation: The biological reactions occurring during composting will convert the putrescible forms of organic wastes into stable, mainly inorganic forms which would cause no pollution effects if discharged on to land or into a water course.

< Pathogen inactivation: The waste heat produced biologically during composting can reach a temperature of about 60 degrees, which is sufficient to inactivate most pathogenic bacteria, viruses, and helminthic ova, provided that this temperature is maintained for at least one day. Therefore the composted products can be safely disposed of on land, or used as fertilisers and soil conditioners.

< Nutrient and land reclamation: The nutrients present in the wastes are usually in complex organic forms, difficult to be taken up by the crops. After composting, these nutrients would be in inorganic forms suitable for crop uptake. The application of composted products as fertilisers to land reduces loss of nutrients through leaching because the inorganic nutrients are mainly in the insoluble forms, which are less likely to leach than the soluble forms of the uncomposted wastes. In addition, the soil fertility is improved, thereby permitting better root growth and consequent ready accessibility to the nutrients. The application of compost to unproductive soils would eventually improve the soil quality and useless lands can be reclaimed.

< Sludge drying: Human excreta, animal manure and sludge contain about 80-95 percent water, which makes the costs of sludge collection, transportation, and disposal expensive. Sludge drying through composting is an alternative in which the waste heat produced biologically will evaporate the water contained in the sludge.

A major drawback of composting concerns the unreliability of the process in providing the expected nutrient concentrations and pathogen die-offs. Since the characteristics of organic wastes can vary greatly from batch to batch, with time, climates and the modes of operation, the properties of the composted products would also vary. The heterogeneous nature of materials in the compost piles causes uneven temperature distribution except in well operated compost reactors, resulting in incomplete inactivation of pathogens present in the composted materials.

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