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Wednesday, 25 September 2013

New Genus Discovered In The Halmahera Island Of Indonesia

A team of biologists has discovered a new genus of mammal in the Halmahera island, it is a type of rat! The endemic rodent is rather surprisingly close to the locality of Boki Mekot, a mountainous area under immense ecological threat due to mining and deforestation. The species was previously known to the people of that region only! It is a terrestrial spiny rat with brownish grey fur on its back and a greyish white belly, it also possesses a white tail tip. The leader of this successful project, Pierre Henry Fabre, affiliated to the "Centre for Macroecology, Evolution and Climate", states:
 “This new rodent highlights the large amount of unknown biodiversity in this Wallacean region and the importance of its conservation. It constitutes a valuable addition to our knowledge of the Wallacean biodiversity and much remains to be learned about mammalian biodiversity across this region. Zoologists must continue to explore this area in order to discover and describe new species in this highly diverse, but also threatened region.”

Apparently, this discovery massively supports Wallace's idea of faunal backup. Most of the species reflect their eastern originality, but this rat stands out for its western originality, as confirmed by the team of Pierre Henry Fabre.  This study also found that Wallace's zoogeographical boundaries are remarkably accurate! Pierre Henry Fabre expresses his thoughts:
 “Such a remarkable island setting inspired one of the greatest biologists of all time, and if Sir Alfred Russell Wallace were alive today he would surely be excited by the prospect of further conservation and biodiversity study within the Moluccas....”

This region had clearly inspired Sir Alfred Russell Wallace as he wrote his letter of evolution theory to Charles Darwin, back in 1858. The specifications of the fauna and flora and the biodiversity of this region made him to think deeper and he defined the zoogeographical boundaries using the concept of a "Wallace Line."

Friday, 13 September 2013

The Mpemba Efffect: Warmer Water Freezes Faster Than Colder Water

Tanzanian student Erasto Mpemba first encountered the situation while he was studying in Magamba Secondary School, in 1963. During a cookery class, he surprisingly found that a hot ice-cream mix freezes faster than a comparatively colder ice-cream mix! He and Dr. Denis Osborne investigated the matter and the phenomenon was confirmed by Dr. Osborne later. They produced a paper on the topic in 1969. Historically, it was first noted by Aristotle who explained it with a property called antiperistasis, modern science has dismissed this property of matter as an erroneous conception. Medieval scientist Francis Bacon wrote, "aqua parum tepida facilius conglacietur quam omnino frigida." It means that slightly tepid water freezes faster than very cold water. The pioneer of modern co-ordinate geometry Rene Descartes also noted this phenomenon and explained it with his theory of vortices. This theory expounds the nature of empty spaces and how it can be filled up with matter.

However, modern scientists have come up with a good number of explanations, which are dependant upon the experimental setup, dissolved air content in water, its purity, electrolytes dissolved in it and other relatable factors. Some of the most common explanations include:

1. Evaporation: Warmer water evaporates faster thus leaving a relatively smaller mass to be frozen. The endothermic nature of evaporation draws heat from the rest of the content. But this explanation is insufficient and unsatisfactory.

2. Supercooling: This hypothesis states that colder water in a low temperature environment supercools more than hot water and therefore it takes more time to solidify. But this theory does not explain the phenomenon wholly. Experiments that have utilized this theory have drawn significant differences in the conclusions. Scientist Auerbach noted supercooling near the wall in all cases during his experiment but Thomas reported no supercooling in the middle portion of the sample! The main problem is not exactly how supercooling can affect the freezing time but how supercooling is dependant upon the initial temperature. According to Dorsey's theory of phase transition, the temperature of supercooling can be affected by pre-heating. It may also vary by freezing and melting. This theory allows different portions of a bulk sample of liquid to vastly vary its supercooling properties. However, this theory allows no simple explanation to the understanding of the effect.

3. Effect of the Dissolved Solutes: This theory takes into account the effect of sodium, magnesium and other carbonate compounds and explains how these can affect the freezing properties of water.

4. Thermal Conductivity: The container of the hotter water may "melt" through a layer of frost which is an insulator. This allows the container to come in contact of a much colder layer. So, a faster process of cooling occurs. The lower temperature water will tend to freeze from the top but the hotter water will tend to freeze from the bottom.

5. Latent Heat of Condensation: The cooler container draws more condensation than the warmer container during the cooling cycle. This effectively reduces the rate of cooling. Mpemba effect is poorly understood from this theory!

According to J. D. Brownridge, "Hot water will freeze before cooler water only when the cooler water supercools, and then, only if the nucleation temperature of the cooler water is several degrees lower than that of the hot water. Heating water may lower, raise or not change the spontaneous freezing temperature." The fact that this phenomenon is not fully understood is an indication that fundamental problems lie beneath it. According to Monwhea Jeng, "Analysis of the situation is now quite complex, since we are no longer considering a single parameter, but a scalar function, and computational fluid dynamics (CFD) is notoriously difficult."

So, there is always a scope to do this experiment and come up with a theory that would explain this phenomenon fully and be accepted universally. Research work on this field is going on and it is expected that new theories will arise from the current concepts and would possibly include a precise mathematical modelling to account for the discrepancies in the results that have come up over the decades. Will warmer water freeze faster than colder water in the near future? Surely yes!

 

Maintaining A Positive Water Balance: What It Means In A Broader Perspective

These phrases are now being heard in the media regularly: "global warming", "melting of polar ice", "unavailability of drinking water", "drought occurred at a large scale" etc. Worldwide, various organizations and Governments are addressing the intense situations. Droughts essentially weakens the production of various commodities, from vegetables to inks to soft drinks to papers and more. The farmers often suffer the worst alongside the economy and common people. Very recent events include:

1. Drought in the central United States expanded its range as a heatwave dried the last bit of moisture left in the soils and threatening the corn and soybean plants. Iowa of Minnesota, one of the largest grain production regions, is now experiencing a very hot summer, a record in the past 60 years! This drought is expanding towards Kansas & Texas.

2. Namibian drought has hit the country's livestock export badly and this year on two-thirds of the normal livestock export. The agricultural production to decline to by at least 6% as a result of this drought, which is the most intense one in the last 30 years. The authorities roughly predict that it will take around 5 years for the farmers to recoup their losses and this drought may worsen over the course of the next 5 years or so.

3. The increasing harsh climate combined with drought has worsened the scene in Iran. People in the northern provinces of the country are experiencing a hard time in coping up with this as the tea industry, the industry which offers them the most reliable income and job security, is badly suffering from it. Reports from the Iranian Association of Tea Farmers clearly state that the third harvest is stopped due to poverty and drought and the competitive international market is posing a big obstacle.

So, it is very necessary to maintain a positive water balance, both in homes and organizations, to mark a change which would be amplified in the near future as the world's freshwater resource is quickly depleting, global warming doing its part and polar ice melting to engulf the earth's rancour eyesores.

Therefore, a positive water balance should start from the grassroot level to expand into a broader perspective and millions of litres of freshwater can be saved and utilized worldwide over a due course of time. Rainwater harvesting, community water sheds alongside collection of surplus water from agricultural fields are the principal entities in having a positive water balance in a society/region. Also, minimizing the wastage of water in daily life is equally important in the context of this.
Rainwater harvesting can be broadly categorized into surface runoff water harvesting and roof water harvesting. In the roof water harvesting system, the "catchment" or the roof that is intended to receive the rainwater is selected and associated with the system, the other components of the system include a set of drainage pipes, a flushing device, filter, recharge unit and storage unit. Filtration is mainly done by sand-gravel filters, charcoal filters and sponge filters, the latter of which is very suitable for residential units. Percolation tanks are the most effective recharge units and are suitable for a large scale water harvesting system. In the surface runoff water harvesting system, similar procedures are followed but the filtration is more important as surface water is generally more contaminated than roof top water. This system is applicable to agricultural land surplus water, fresh water flooded forests and other places. Implementation of this system is very important as it would lower the risk of creating impervious surfaces, erosion and siltation. Increased runoff worsens groundwater recharge thus making droughts worse. Hortonian overland flow and Hewlettian runoff can also be minimized to a great extent and the collected water would be put into a number of industries, improving the efficiency of the production and promoting a steady water balance. Soil contaminants would not be able to get into various water bodies, thus minimizing the threat posed to aquatic organisms.

So, the initiation of the system is more important. Various NGOs and Governments are promoting rainwater harvesting and positive water balance. It would prevent floods, droughts, save aquatic organisms, help groundwater recharge and production of crops. It is the time for the common people to try this and make the world a better and healthier place in the future for the next generations of us.

Sunday, 8 September 2013

A Certain Type Of Immune Cells Aids Cancer Growth: An Open Question

Recently, rigorous research work in the U.S. has suggested that a certain type of immune cells can actually aid cancer growth! These cells are known as "Myeloid Derived Suppressor" cells that probably provide a niche where the cancer stem cells just might survive and operate after a certain interval of time! Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells that are defined by their myeloid origin, immature state and ability to potently suppress T cell responses. They regulate immune responses and tissue repair in healthy individuals and the population rapidly expands during inflammation, infection and cancer.

  This study was published in the Immunity journal. A review was done by Yazan S Khaled, Basil J Ammori and Eyad Elkord. Cancer stem cells are currently known as resilient to modern chemotherapy and radiation treatments. Researchers firmly believe that only by the elimination of cancer stem cells, cancer can be prevented worldwide. Research work involved the studying of the cells collected from the most common and fatal type of ovarian cancer in which the patients virtually become resistant to chemotherapy and it causes the cancer to grow again. The researchers also said that if a therapy to combat the function of these cells could be identified, it would be possible to eliminate the immune suppression that helps support the cancer.

Vatican Initiative For Peace In Syria Got A Great Response

War always marks the failure of peace, it is always a defeat for humanity.

Pope Francis led a four hour long vigil in St. Peter's Square to protest the socio-political unrest in Syria. More than 70000 people responded to his call to join the rally. People denounced the proposed U.S. led military action following the 21st August chemical weapons attack near Damascus.
 "This evening, I ask the Lord that we Christians, and our brothers and sisters of other religions and every man and woman of good will, cry out forcefully: Violence and war are never the way to peace!"

 A handful number of Christians in Damascus attended a service in a church, joining the Pope's invitation to firmly oppose outside military intervention in this great conflict. Pope Paul VI famously uttered "War never again, never again war" at the United Nations in 1965 before the U.S.-Vietnam conflict grew, sadly his wish did not get fulfilled in the future. Other church officials including the common people have criticized the U.S.-France involvement in the conflict as it would exacerbate the situation for the minority Christians and also for the common people.

But by the time the vigil got underway, the posters and flags had mainly disappeared with leaders from Christians and non-Christians spoke up. Bishops around the world responded to the Pope's call including Italy, Argentina & Cuba. The grand Mufti of Damascus had also invited Muslims to join the fast in solidarity. Long live humanity, long live our immortal consciousness.