Serotonin antagonist

A serotonin antagonist is a drug used to inhibit the action at serotonin receptors.
Many of the most important medications of this class selectively act at the 5-HT3 receptor, and thus are known as 5-HT3 antagonists. However, other drugs such as ketanserin act upon other types of serotonin receptors.
Antagonists of the 5-HT_2A receptor are sometimes used as atypical antipsychotics, with the typical antipsychotics being purely dopamine antagonists.
'Ketanserine' blocks 5 HT2A,5 HT2C and alpha 1 receptors. 'Ondansetron,Dolansetron,Granisetron' are 5 HT3 receptor antagonist.they are efficacious in treating chemotherapy induced emesis. 'Clozapine' blocks 5 HT2A,5 HT2C,D4 receptors. 'Quetiapine' blocks 5 HT2A,5 HT1A,D1-2,HI,alpha 1 receptors. 'Methsergide' is 5 HT2A-2C antagonist and nonselective 5 HT 1 receptor blocker.it causes retrperitoneal fibrosis and mediastinal fibrosis. 'Cyproheptadine' blocks 5 HT2A, HI and it is a mild anticholinergic. 'Pizotifen' is a 5 HT2A-2C , H1 blocker and anticholinergic used for migraine prophylaxis

Crocker Land and Crocker Mountain:The illusions which haunted the geologists

We live in a satellite age; for the most part, we can look at any part of the world’s surface at any time and find what we’re looking for. While the slow-but-constant process of time changes our landscape and always requires changes to maps, the general outline of the world’s landmasses are fairly well-mapped at this point. For the last century or so, we’ve known the outline of the land masses of the world (the most recent significant discovery of land was in 1948 in northern Canada when Prince Charles and Air Force islands were finally mapped by air, and it’s frankly amazing it took that long to find islands that large). The trade-off of having completed the general mapping of the planet (above water, anyway) is that we’ve lost the opportunity to fantasise about what new lands we may discover next. For countless centuries, maps of all kinds displayed hypothetical lands and phantom islands that may or may not have actually existed (almost always not). As you may guess, the polar regions were the last blanks to be filled in, being the most inhospitable locations for human travel. The race to be the first to reach the poles is one of the great modern-day adventure stories, and polar exploration today constantly opens our eyes to new and wonderful places. This entry looks at what may have been the last great mythological land on the planet.

Many phantom lands denoted through the years were the results of mirages and optical illusions; for example, New South Greenland off the Antarctic Peninsula, or Thompson Island in the South Atlantic whose sighting was later found to be an optical refraction of Bouvet Island. Some of these illusions are known as Fata Morgana, in which layers of light are bent passing through temperature layers in an atmospheric duct formed during a thermal inversion. This distorts, compresses and inverts the image the viewer sees. If the angle of light refraction is greater than that of the curvature of the earth, the images refract down toward the viewer, appearing as a band above the horizon (a superior mirage). This may appear to the viewer as though something is rising out of the ocean: an island, a plateau, a set of mountains. Fata Morgana occurs most often in polar regions, where there are large expanses of flat polar ice with uniform temperatures (other flat surfaces such as water and sand can produce them as well). Fata Morgana can even refract images that are dozens or hundreds of kilometres away that would not be normally visible over the horizon, making landmarks appears much closer than they actually are.

Sir John Ross

In 1818, Sir John Ross was on a voyage which was an attempt to discover the long-sought-after Northwest Passage. Ross's ship reached Lancaster Sound in Canada. The Northwest Passage was straight ahead, but John Ross did not go in that direction because he saw, or thought he saw, in the distance, a land mass with mountains, which he believed made going any further simply impossible. He named the mountain range of this supposed land mass "Crocker Mountains". He gave up and returned to England, despite the protests of several of his officers, including First Mate William Edward Parry and Edward Sabine. The account of his voyage, published a year later, brought to light their disagreement, and the ensuing controversy over the existence of Crocker Mountains ruined his reputation. Just a year later William Edward Parry was able to sail further west, through those non-existent mountains.

A 1906 map of the Arctic Ocean (click on the image to expand to 1600x2243). Note the large swath of ocean marked as ‘Unexplored’. As well, note the undefined coastlines on the northeast shore of Greenland and on many of the Canadian Arctic islands. Source: Probert Encyclopaedia, http://www.probertencyclopaedia.com/photolib/maps/Map%20of%20Arctic%20Regions%201906.htm.

Sir John Ross made two errors. His first mistake was when he was sure he saw a land mass and mountains that were not actually there despite the objections of his officers, who must have been more familiar with mirages than he was. Ross's second mistake was to name the apparent mountain range after the First Secretary of the Admiralty. Naming what was in fact a mirage after such a high official cost Sir John Ross dearly: he was refused ship and money for his subsequent expeditions, and was forced to use private funding instead.
In the first decade of the 20^th century, a rush was on to become the first expedition to reach the North Pole. During the course of these expeditions, much new information was gathered on the Arctic. Coastlines became increasingly defined as explorers rushed to fill in the final blanks on the map. One of the more famous (or infamous) expedition leaders was the American Robert Peary, who had been exploring in the North American Arctic since the mid-1880s. Over the past century, both Peary’s personal and professional reputations have taken beatings in scientific circles (rightfully so to some extent; Crocker Land wasn’t the only fictitious entry he attempted to contribute to the world map), but he is responsible for introducing important concepts to extreme travel such as support teams and supply caches (which he naturally called the ‘Peary System’), and he is responsible for mapping much of extreme northern Canada and Greenland. His most famous claim is to being the leader of first expedition to reach the North Pole with Matthew Henson in 1909, a claim generally accepted by most sources but constantly debated over, as Peary had a habit of aggrandising his team’s accomplishments in his journals, and his team had no one along who was actually trained in navigation, making independent confirmation of their position impossible.

This 1912 map shows Crocker Land (and Frederick Cook’s equally fraudulent Bradley Land) in their assumed locations, northwest of Grant Land (the northern lobe of Ellesmere Island). The supposed route to the North Pole of Cook and Peary are shown.

Peary’s previous Arctic expedition of 1905-1906 is the one responsible for Crocker Land . During this expedition, while camping at Cape Thomas Hubbard on Axel Heiberg Island, Peary believed he saw in the distance a landmass that he believed to be about 200 kilometres away. He named the landmass ‘Crocker Land’ after George Crocker (son of railway magnate Charles Crocker), who had funded the expedition. Peary made no actual mention of his supposed discovery for another six months afterward. Most believe that he had actually laid his eyes on a Fata Morgana (assuming he did at all; some claim he simply made it up to get more funding for his next expedition, or to placate his financial backer). There was nothing to go on except for his single claim. Regardless, Crocker Land found itself on maps for the next few years.

In 1913, the explorer/lecturer/ethnologist Donald Baxter MacMillan put together an Arctic expedition that intended to make landing on Crocker Land and map it as one of its goals, along with its other task of documenting Inuit people and natural habitat along the way (one of the crew members was Minik Wallace, one of six Inuit brought to New York by Peary from Greenland in 1897 to be studied and exhibited at the American Museum of Natural History. In a rather sick and sordid tale, Minik’s father’s body soon died of tuberculosis upon arrival; instead of being buried, the body was stripped of all flesh and put on public display at the museum). In the second task, the Crocker Land Expedition succeeded, resulting in the preservation of a large collection of journals and artefacts that helped the Western world gain insight into traditional Inuit lifestyles. On the first task, of course, the expedition failed miserably. At one point, MacMillan believed he had found Crocker Land, laying eyes on what appeared to be a vast land of snowcapped peaks spanning 120 degrees of the horizon. Over the objections of one of his Inuk crewmembers, Piugaattoq, who believed it was a mirage, MacMillan ordered the crew to set course for the supposed land on the recommendation of Fitzhugh Green, the team’s engineer and physicist. As they went ahead, the image distorted and eventually disappeared. The expedition was confronted with the reality that Peary’s Crocker Land did not exist.

The return home for the expedition was even more tragic: back on land, MacMillan sent Green and Piugaattoq to explore a route to the west. The two became trapped, and a dog team died in the snow. An argument ensued, and Green shot Piugaattoq; the murder was covered up by MacMillan so as not to embarrass the expedition. (Interestingly, Green has also entered a relationship with Piugaattoq’s wife, who also happened to be the former mistress of Robert Peary and bore him two children.)
The expedition attempted to return, but the weather turned against them and they were stranded in the region for the next four years.
In December 1914, MacMillan and Tanquary set off for Etah with the intention of sending a message to the outside world that a rescue was needed the following summer. They quickly ran into trouble with the weather and MacMillan turned back. Tanquary pressed on and eventually reached Etah in mid-March 1915.
Word reached the American Museum of Natural History and the George H. Cluett, a three-masted schooner completely unsuitable for Arctic waters, was sent that summer, captained by George Comer. The vessel never reached them. It ended up trapped in ice and did not return for two years.
In 1916, a second relief ship was sent and ran into similar problems. By this time Tanquary, Green and Allen had already made their own way back to the US by dog-sled.

The rest of the expedition was eventually rescued in 1917 by the ship Neptune, commanded by Captain Robert Bartlett.
Although the expedition failed to map the non-existent Crocker Land, much important research was done. A considerable number of photographs and artifacts were returned, documenting the indigenous peoples and natural habitat of the region. Hundreds of photos of the expedition and over 200 artifacts are displayed in the University of Illinois Spurlock Museum.

The existence of Crocker Land still hung on as a remote possibility until the area was traversed by air during the 1937-38 MacGregor Arctic Expedition, finally and thoroughly disproving the notion of an island in the middle of this part of the Arctic.

Source:

1. http://basementgeographer.blogspot.com/2010/12/crocker-land-last-of-phantom-islands.html

2. http://en.wikipedia.org/wiki/Crocker_Land_Expedition

3.  http://en.wikipedia.org/wiki/Crocker_Land

4. http://en.wikipedia.org/wiki/Fata_Morgana_%28mirage%29#Crocker_Mountains_and_Crocker_Land

5. http://nsidc.org/arcticmet/quickfacts/mirage_mistakes.html

6. http://www.trivia-library.com/b/geography-features-the-crocker-lands-mirage.htm

Somalian Warlords

October 3^rd, 1993.
Mid afternoon, Somalia.
Task Force Ranger—which consisted of an assault force made up of US Army Delta Force, Ranger teams, an air element provided by the 160th Special Operations Aviation Regiment, four Navy SEAL operators from SEAL Team Six and members of the Air Force Pararescue/Air Force Combat Controllers--under the command of Major General William F. Garrison executed an operation that involved traveling from their compound on the outskirts of the city to the center with the aim of capturing the leaders of the Habr Gidr clan, headed by warlord Mohamed Farrah Aidid. The assault force consisted of nineteen aircraft, twelve vehicles, including nine Humvees and 160 men.

3 minutes later they are over the target. Then  two two U.S. Black Hawk helicopters were shot down by RPG's and three others were damaged. For the next 17 hours the soldiers found themselves fighting in a deadly battle.

Somalia, formerly known as the Somali Democratic Republic under communist rule, is a country located in the Horn of Africa. Somalia covers the eastern-most portion of Africa. It is bordered by Djibouti to the northwest, Kenya to the southwest, the Gulf of Aden with Yemen to the north, the Indian Ocean to the east, and Ethiopia to the west. With the longest coastline on the continent, its terrain consists mainly of plateaus, plains and highlands. Hot conditions prevail year-round, along with period.

It was colonised by Britain and Italy. Italy acquired full control of their parts of the region in 1927. This occupation lasted until 1941, when it was replaced by a British military administration. Northern Somalia would remain a protectorate, while southern Somalia became a trusteeship. 1960 saw the union of the two regions into the independent Somali Republic under a civilian government.

Mohamed Siad Barre seized power in 1969. He banned political parties, and dismantled the national assembly. Over the next 20 years Barre concentrated much of Somalia’s economic activity and political control in Mogadishu, ignoring the rest of the country. This imbalance gave rise to fighting over increasingly scarce resources and to the creation of militias accountable to faction leaders.

During the cold war both the U.S. and Soviet Union vied for influence and control over Somalia because of its strategic location along oil routes from the Persian Gulf. In the 1970s the USSR armed and aided Somalia. On 13 July 1977 Somalian army invaded Ethoipia. By the end of the month 60% of the Ogaden had been taken by the SNA-WSLF force, including Gode, on the Shabelle River. The attacking forces did suffer some early setbacks; Ethiopian defenders at Dire Dawa and Jijiga inflicted heavy casualties on assaulting forces. The Ethiopian Air Force (EAF) also began to establish air superiority using its Northrop F-5s, despite being initially outnumbered by Somali MiG-21s. However, Somalia was easily overpowering Ethiopian military hardware and technology capability due to massive American military support to Somalia government, which amounted to hundreds of millions of dollars of arms.

Not all communist states sided with Ethiopia. Because of the Sino-Soviet rivalry, China supported Somalia diplomatically and with token military aid. Romania under Nicolae Ceauşescu had a habit of breaking with Soviet policies and maintained good diplomatic relations with Siad Barre.
By 17 August elements of the Somali army had reached the outskirts of the strategic city of Dire Dawa. Not only was the country's second largest military airbase located here, as well as Ethiopia's crossroads into the Ogaden, but Ethiopia's rail lifeline to the Red Sea ran through this city, and if the Somalis held Dire Dawa, Ethiopia would be unable to export its crops or bring in equipment needed to continue the fight. Gebre Tareke estimates the Somalis advanced with two motorized brigades, one tank battalion and one BM battery upon the city; against them were the Ethiopian Second Militia Division, the 201 Nebelbal battalion, 781 battalion of the 78th Brigade, the 4th Mechanized Company, and a tank platoon possessing two tanks. The fighting was vicious as both sides knew what the stakes were, but after two days, despite that the Somalis had gained possession of the airport at one point, the Ethiopians had repulsed the assault, forcing the Somalis to withdraw. Henceforth, Dire Dawa was never at risk of attack.

From October 1977 until January 1978, the SNA-WSLF forces attempted to capture Harar, where 40,000 Ethiopians had regrouped and re-armed with Soviet-supplied artillery and armor; backed by 1500 Soviet "advisors" and 11,000 Cuban soldiers, they engaged the attackers in vicious fighting. Though the Somali forces reached the city outskirts by November, they were too exhausted to take the city and eventually had to withdraw to await the Ethiopian counterattack.
The expected Ethiopian-Cuban attack occurred in early February; however, it was accompanied by a second attack that the Somalis did not expect. A column of Ethiopian and Cuban troops crossed northeast into the highlands between Jijiga and the border with Somalia, bypassing the SNA-WSLF force defending the Marda Pass. The attackers were thus able to assault from two directions in a "pincer" action, allowing the re-capture of Jijiga in only two days while killing 3,000 defenders. The Somali defense collapsed and every major Ethiopian town was recaptured in the following weeks. Recognizing that his position was untenable, Siad Barre ordered the SNA to retreat back into Somalia on 9 March 1978, although Rene LaFort claims that the Somalis, having foreseen the inevitable, had already withdrawn its heavy weapons. The last significant Somali unit left Ethiopia on 15 March 1978, marking the end of the war.

Following the withdrawal of the SNA, the WSLF continued their insurgency. By May 1980, the rebels, with the assistance of a small number of SNA soldiers who continued to help the guerilla war, controlled a substantial region of the Ogaden. However by 1981 the insurgents were reduced to sporadic hit-and-run attacks and were finally defeated.
The Ogaden War weakened the Somali military. Almost one-third of the regular SNA soldiers, three-eighths of the armored units and half of the Somali Air Force (SAF) were lost. The weakness of the Barre regime led it to effectively abandon the dream of a unified Greater Somalia. The failure of the war aggravated discontent with the Barre regime; the first organized opposition group, the Somali Salvation Democratic Front (SSDF), was formed by army officers in 1979.
The United States adopted Somalia as a Cold War client state from the late 1970s to 1988 in exchange for use of Somali bases, and a way to exert influence upon the region. A second armed clash in 1988 was resolved when the two countries agreed to withdraw their militaries from the border.

Somalia became divided into different clans leaded by Warlords. Most notorious of them were Mohamed Farah Aidid.

Following the eruption and escalation of the civil war in Somalia in 1991, the UN and the Organization of African Unity (OAU) strived to abate the suffering that was caused as a result of the high-intensity conflict. Of the Somali population of 4.5 million people, over half were in severe danger of starvation and malnutrition-related disease, mostly in the drought-stricken rural areas.
Another 1.5 million were judged at moderate risk of malnutrition. Three hundred thousand people died outright in the early months of 1992 and another million fled the country as refugees. The UN was engaged in Somalia from early in 1991 when the civil strife began. UN personnel were withdrawn on several occasions during sporadic flare-ups of violence. A series of Security Council resolutions (733, 746) and diplomatic visits eventually helped impose a ceasefire between the two key factions, signed at the end of March 1992. These efforts were aided by other international bodies, such as the Organisation for African Unity, the League of Arab States and the Organisation of the Islamic Conference.

The UN, with the active support of all rebel faction leaders, felt that some sort of peackeeping force would be required to uphold the ceasefire and assist the humanitarian relief effort, in conjunction with other relief agencies and NGOs. By the end of April 1992, the Security Council adopted Resolution 751.
This provided for the establishment of a security force of 50 UN troops in Somalia to monitor the ceasefire. This detachment would be known as the United Nations Operation in Somalia (UNOSOM) and it existed at the consent of those parties who had been represented in the ceasefire.

 aidid

The resolution also allowed for an expansion of the security force, with a number of around 500 troops initially discussed. The first group of ceasefire observers arrived in Mogadishu in early July 1992.

Despite the UN's efforts, all over Somalia the ceasefire was ignored, fighting continued, and continued to increase, putting the relief operations at great risk. The main parties to the ceasefire, General Mohamed Farrah Aidid and "President" Ali Mahdi Muhammad, once again showing the difficult and troubled relations between the warlords, proved to be difficult negotiating partners and continually frustrated attempts to move the peacekeepers and supplies.
In August 1992 the Security Council endorsed sending of another 3,000 troops to the region to protect relief efforts. However, most of these troops were never sent.
Over the final quarter of 1992, the situation in Somalia continued to get worse. Factions in Somalia were splintering into smaller factions and splintering again. Agreements for food distribution with one party were worthless when the stores had to be shipped through the territory of another.
Some elements were actively opposing the UNOSOM intervention. Troops were shot at, aid ships attacked and prevented from docking, cargo aircraft were fired upon and aid agencies, public and private, were subject to threats, robbery and extortion. Meanwhile, hundreds, if not thousands of poverty stricken refugees were starving to death every day.
By November 1992, General Mohamed Farrah Aidid had grown confident enough to formally defy the Security Council and demand the withdrawal of peace keepers, as well as declaring hostile intent against any further UN deployments.

In November 1992, the United States of America offered to establish a multinational force under its own leadership to secure the humanitarian operation. This offer was accepted by the Security Council, and what became known as the Unified Task Force (UNITAF) was authorized to utilize "all necessary means" to ensure the protection of the relief efforts.
Accordingly, the Security Council suspended any further significant strengthening of UNOSOM as UN affairs in Somalia were subsumed by UNITAF (also known to Americans as Operation Restore Hope). With only a handful of the 3,000 plus troops envisaged for UNOSOM ever put in place, the Security Council left it to “the discretion of the Secretary General” as to what should be done with the abortive mission.
UNITAF was composed of forces from 24 different countries, with the vast bulk contributed by the United States. UNITAF soon secured the relief operations which were being coordinated and carried out by UNOSOM, which was also attempting to negotiate a political end to the conflict. Indeed, although UNOSOM had been replaced by UNITAF, it was technically still in operation and would remain ready to resume its function when UNITAF had met its goals of creating a secure environment for humanitarian relief.

The Secretary-General convened a meeting in early 1993 in which 14 important Somalia political and rebel factions agreed to hand over all of their weapons to UNITAF and UNOSOM, and over $130 million was pledged by donors at an aid conference that year to assist in reconstruction. However, Somalia continued the stumble, and in March the UN decided to transform the UNITAF mission into what came to be known as UNOSOM II. The mandate of UNOSOM II stipulated that the operation was to secure continued relief efforts and, more significantly, to restore peace and rebuild the Somali state and economy.

 

The U.N. asked its member nations for assistance.  In December 1992, in one of his last acts as President, George Bush proposed to the U.N. that United States combat troops lead the intervention force.  The U.N. accepted this offer and 25,000 U.S. troops were deployed to Somalia.  President Bush stated that this would not be an “open-ended commitment.”  The objective of Operation Restore Hope was to rapidly secure the trade routes in Somalia so that food could get to the people.  President Bush stated that U.S. troops would be home in time for Bill Clinton’s inauguration in January.

Once President Clinton was inaugurated he stated his desire to scale down the U.S. presence in Somalia, and to let the U.N. forces take over.  In March 1993 the U.N. officially took over the operation, naming this mission UNOSOM – II.  The objective of this mission was to promote “nation building” within Somalia.  One main target was to disarm the Somali people.  UNOSOM – II stressed restoring law and order, improving the infrastructure, and assisting the people with setting up a representative government.

President Clinton supported the U.N. mandate and ordered the number of U.S. troops in Somalia reduced, to be replaced by U.N. troops.  By June 1993, only 1200 U.S. troops remained in Somalia, but on June 5, 1993 24 Pakistani soldiers were ambushed and killed during the inspection of a Somali arms weapons storage site by Aidid`s fanatical followers.  The U.N. responded with an emergency resolution to apprehend those responsible.  While it was not specifically stated, Aidid and his followers were believed to be responsible.  On June 19, 1993 Admiral Howe ordered Aidid’s arrest and offered a $25,000 reward for information leading to this.  He also requested a counterterrorist rescue force after the massacre of the Pakistani troops.

From June 12 through June 16 U.S. and U.N. troops attacked targets in Mogadishu related to Aidid.  On July 12 U.S. Cobra helicopters attacked a house in Mogadishu where clan leaders were meeting.  They destroyed several buildings and many Somalis were killed.  When four Western journalists went to investigate the scene they were beaten to death by a mob of Somalis.  On August 8 four U.S. military police were killed when a land mine was remote-detonated by Somalis.  Two weeks later, six more U.S. soldiers were wounded.  It was at this point that Task Force Ranger was deployed to Somalia.

On August 29 Task Force Ranger flew into Mogadishu.  They were led by General William Garrison and consisted of 440 elite troops from Delta Force.  Their mission was to capture Aidid.  But, at the same time, in September 1993 the Clinton Administration began a secret plan to negotiate with Aidid.  U.S. military commanders within Somalia were not apprised of this.  U.S. Defense Secretary Les Aspin denied a request for armored reinforcements made by General Montgomery.

On October 3, 1993 Task Force Ranger raided the Olympic Hotel in Mogadishu to search for Aidid.  This led to a seventeen-hour battle in which eighteen U.S. soldiers were killed and eighty-four were wounded.  Bodies of dead American soldiers were dragged through the streets of Mogadishu, shown on international news reports. Hundreds of Somalis also died, although the official number has never been released.  This was the longest, most bloody battle for U.S troops since the Vietnam War.  On October 7 President Clinton responded by withdrawing U.S. troops from Somalia.  The hunt for Aidid was abandoned, although U.S. representatives were sent to resume negotiations with clan leaders.

Two weeks after the Battle of Mogadishu General Garrison officially accepted responsibility. In a handwritten letter to President Clinton, Garrison took full responsibility for the outcome of the battle. He wrote that the Task Force Ranger had adequate intelligence for the mission and that their objective (capturing targets from the Olympic Hotel) was met.

What began as a peacekeeping mission to provide relief to the starving people of Somalia essentially ended with a firefight during the Battle of Mogadishu. After all of the U.S. troops were withdrawn in March 1994, 20,000 U.N. troops were still in Somalia. By the late Spring of 1994 all of the remaining U.N. troops were withdrawn, ending UNOSOM-II.

Aidid then declared himself President of Somalia in June 1995, but his government was not internationally recognized. Indeed, within Somalia and even within Mogadishu, his control was fiercely fought over, especially by Ali Mahdi Muhammad. In September 1995, militia forces loyal to Aidid attacked the city of Baidoa, killing 10 Somalis and capturing at least 20 foreign aid workers.

ethiopian army in somalia

On July 24, 1996 Aidid and his militia engaged in battle with the forces of warlords and former Aidid allies Ali Mahdi Muhammad and Osman Ali Atto. Wounded by gunfire during the fight, Aidid suffered a fatal heart attack on August 1, either during or after surgery to treat his wounds.

In the mid ninethies a group of religious extrimists rose in Somalia. They were like talibans of Afganistan. They were against Alliance for the Restoration of Peace and Counter-Terrorism (ARPCT0, the united clans of of the warlords. In this batle the religious extrimists got the upper hand. By June 4 the they had taken Balca and seized the primary ARPCT base in Mogadishu<sup>.

Then</sup> Ethiopian troops invaded Somalian territory on July 20, 2006. Ethiopia maintained it was providing military assistance to the transitional government. They were backed by the US. This time the US prefered warlords than the religious group. On December 27, Ethiopian and Somali government forces were reported en route to Somalia's capital, Mogadishu after capturing the strategic town of Jowhar, 90 km from the capital. After the Fall of Mogadishu to the Ethiopian and government forces on December 28, fighting continued in the Juba River valley, where the UIC retreated, establishing a new headquarters in the city of Kismayo. Then on 9^th January,2007 US air force attacked somalia. They bombed the religious grouop`s position.

On 2008 Somalia was declared a number 1 failed state by the United States think-tank Fund for Peace and the magazine Foreign Policy, publishes an annual index called the Failed States Index. It is clear the political goodwill of the leaders will help this poor nation to build its backbone again.

Incredible energy and perfect health

Tiredness has become an epidemic. Most people feel exhausted every few hours. And thus the billion-dollar industry of stimulants runs to give us the fuel we feel deprived of. Be it tea, coffee, Red-bull, sports drinks, etc etc, they all are required not for taste or health, but to keep us charged.
Just think about the fact that tea or coffee is hardly a century or two old for most parts of the world. Humans had a much tougher life before that and yet never felt need of these stimulants. Please understand that these addictions are merely marketing gimmicks. The commercial mafia thrives and grows only if we are dumb, sick and addicted to them. The marketing frauds will want us to believe in all the rubbish that they produce and would use every moment of our attention to hoodwink us – TV, Newspaper, ads, billboards, music, radio etc etc.
However, here are some excellent tips for you to stay charged throughout the day without taking recourse to these stimulants which only make to addicted and race you faster to old age. They include both do’s and don’ts. Try them at least for 2 weeks and see the change. Use whatever tips you feel is feasible for you right now and share your feedback with us all.
If you find these effective, share the good word around and help others get rid of marketing trap as well.
Some of these tips may sound too simple or insignificant But proof of taste is in its eating. Test out yourself.
Water

1. Drink lots and lots of plain water (unless you have a medical condition that prohibits you from it). Make sure water is not chilled and near body temperature. Drink at least 2 liters of water in the day. Avoid water for an hour before and after meals.
2. Do not drink water during meals. If you feel dry in throat, you can sip in not more than a quarter glass of water in total.
3. Drink one liter of water the first thing in morning. This is separate from the 2 liters you should drink during the day. Drink it before doing for toilet. Resist the urge till you are done with a liter of water.For better results, you can make water slightly lukewarm. Add a pinch of lemon or honey if it suits you.
4. Do not drink lots of water in the last hour of your going to bed.

TV

1. Just stop watching the idiot box. Its not only idiot but dangerous as well. The less TV you watch more energetic and smarter you would feel. Optimize accordingly.
2. Make a rule not to watch TV for at least 2 hours before sleep and 4 hour after waking up. This is worst-case scenario. More you watch TV nearer to your time to bed, closer you approach your agedness. Go to sleep while watching TV only if you hate yourself!
3. Even if you have to watch TV, avoid shifting channels. The flicker dumbs mind and increases tiredness.
4. Ensure you take frequent breaks from gazing the screen. Do not be glued to the screen.

Sleep

1. Take sufficient sleep
2. Do not change sleep timings frequently.
3. Do not sleep under high-speed fan. Lower the fan speed
4. Avoid sleeping in chilled environment. Fresh air is best. But in case you need to sleep in air-conditioner, set the temperature not below 27-28 degree Celsius.
5. Meditate for 10 minutes before sleep. First sit in lotus position and take few deep breaths. Then give yourself positive vibes. Make positive resolutions. Thank God and meditate for a while. We shall discuss the art of meditation in a subsequent post. Then go to sleep.
6. Do not sleep straight on back or stomach. Always sleep on one side.
7. Do not fold your legs tightly while sleeping. Keep body relaxed and straight.
8. Avoid sleeping in the daytime. If you are drowsy or tired, a 20-minute nap after an hour of lunch is sufficient.
9. Make a habit of thanking God for another opportunity to make good efforts, the first thing when you wake up.

Food

1. Say no to spicy, oily, rotten, dirty food.
2. Avoid meat and egg. They are not food for those who seek bliss in life.
3. Do not drink cold drinks, packaged drinks, packaged food, bakery products, chocolates and any artificial food, unless its for prevention of death.
4. Eat non-spicy, simple, natural nutritious food.
5. Make habit of taking few grams of trifala powder daily once with water, either in night or morning
6. Eat sprouts every morning in breakfast
7. Try sucking a piece of ‘Baal Harad’ (Small Harad) after food. It is a great digestive and reverses ageing process
8. Say no to tea, coffee, tobacco, alcohol, narcotics etc. Your body simply does not need it. In few days, you will realize how much more energetic you actually deserve to be, when you replace these unnecessary stuff with tips listed here and in subsequent postings.

Food is a deep subject. Would write more on it in subsequent posts.
Miscellaneous

1. There is no parallel to Brahmacharya. Put simply, it means avoiding even the thought of lust or sex in any form –subtle or coarse. For the western society, it may seem that this would rob away all happiness from life.The truth is completely opposite. Only when you stop feeding yourself with junk, can nectar be served to you. The mere practice of trying to control the mind from various attacks of sensuality is an energizing process. There is a saying that its easy to show valour in one-off war. But one who controls his senses for 24 hours, 365 days relentlessly is the true warrior.

Practice Brahmacharya and get following benefits:
-       inexhaustible source of energy
-       warrior like attitude
-       long disease free life
-       sense of purpose and direction
-       ultimate happiness and bliss
Each of these claims can be tested within merely a month of disciplined practice in this direction. The marketing fraudsters may try to tell you that sex and wine is good. They are not wrong. Its good for them if you are dumb and diseased!

1. Keep your spine straight throughout. A stooping posture makes you lose energy
2. Do exercise regularly. There are various forms of exercise, and you can choose, mix and match most. We will discuss it in further details in subsequent articles.
3. Avoid use of mobile phones, earphones and ipods to extent possible. They are worst drainers of energy these days.
4. Avoid listening to noisy music. Spend time listening to music within. More on this later.
5. Dream big, plan big and put big efforts. Seek knowledge of life, its purpose, mission, desperately. Nothing is more energizing.
6. Smile a lot
7. Understand that death is not the end. It’s the beginning. This life is an opportunity to prepare for that beginning.

Do provide feedback after you test these out. Will keep writing more on these aspects in subsequent posts.
Enjoy inexhaustible source of energy every moment of life!

The Serine Proteases

Rajat Das Gupta

Chymotrypsin, trypsin, and elastase are three enzymes that cleave protein chains.

• Each has its own selectivity: that is, they cleave proteins at different structure points
• They have very strong structural similarity
• They use the same mechanism for the cleavage, a mechanism that very much resembles the mechanism we would write for the acid-catalyzed hydrolysis of an amide

First, the structural similarity:

Superposition of Trypsin (yellow), Elastase (green), and Chymotrypsin (blue) Backbones

The three amino acids picked out in red are the three that actually do the catalysis.
Here are sequence alignments for chymotrypsin (5cha) and trysin (5ptp), and elastase (1est) and trypsin (1tld) produced by the Swiss PDB Viewer:

Chymotrypsin vs Trypsin	Elastase vs Trypsin

• The asterisks mark identical residues, and the dots mark very similar side chains, such as Leu and Ile, or Phe and Tyr
• Deep View calculates an RMS difference between chymotrypsin and trypsin of only 0.94 A, and 1.14 A for the elastase-trypsin pair, reflecting the obvious matches in the graphics above

What we see here is a clear example of divergent evolution. All are derived from a common ancestral serine protease, and are described as homologous. Taking a step further back, one finds that some non-mammalian serine proteases have 20-50% sequence identity with mammalian ones, suggesting a common ancestral protease an evolutionary step further back.
Evolution can converge on functionality also. The first crystal structure of a bacterial serine protease, subtilisin, from B. amyloliquefaciens, shows a thoroughly different construction from the mammalian ones, and essentially no sequence homology:

Subtilisin (B. amyloliquefaciens)
The orange balls are Ca++, providing thermal stability

But the enzymes are functionally identical; subtilisin uses the same three catalytic residues, shown in red: Asp32, His64, and Ser221. The mechanism of catalysis is the same, including the positioning of substrate by hydrogen bonding. This appears to be a case of convergent evolution: Mother Nature found a good idea a second time.
As we have seen in several pictures now, the catalytic work of the proteases is done by the so-called catalytic triad, Asp102, His57, and Ser195:



Here is the triad picked out from the crystal structure of chymotrypsin (the extra fine black lines are artifacts of my effort to hide the rest of the enzyme). Remember that X-rays can't see hydrogen atoms; we have to infer their positions.



The mechanism outlined below applies to all of the serine proteases, with small variations. We start with the binding, in cartoon form.



The next step appears to be His57 removing a proton from the the Ser105 OH, while the O does a nucleophilic attack on the peptide carbonyl:

• The shift of negative charge onto the carbonyl oxygen of the peptide is facilitated by hydrogen bonding of the oxygen to the backbone NH groups of Ser195 and Gly193
• These form what is called "the oxyanion hole"
• We now have a structure equivalent to the tetrahedral intermediate in the non-enzymatic mechanism
• The biggest difference is that the two protons that are part of the OH groups are merely hydrogen-bonded in the enzyme

Whether a tetrahedral intermediate is formed was a point of considerable contention in the early investigations of protease mechanisms; biochemists tended to draw nucleophilic acyl substitutions as if they were S_N2 reactions - all one step.
This ignored a fundamental difference between the two kinds of reaction.

• Nucleophilic substitution, in frontier orbital terms, involves an interaction between the HOMO of the nucleophile and the LUMO of the electrophile (substrate)
• Alkyl substrates, which undergo S_N2 reactions have much different LUMOs than acyl substrates, which form tetrahedral intermediates.

To illustrate, here's the LUMO of ethyl chloride, CH₃CH₂Cl:

LUMO of Ethyl Chloride

You can see that it involves chiefly the C-Cl bond, and has a considerable back lobe where the nucleophile interacts. Now here is the LUMO of acetyl chloride, CH₃(C=O)Cl:

LUMO of Acetyl Chloride

This LUMO is almost exclusively on the C=O, and hence there is no way an attacking nucleophile can break the C-Cl bond directly. In short, a tetrahedral intermediate MUST form because the orbital construction of the substrate won't permit any other pathway. End of story.
OK, so we've got the tetrahedral intermediate. Where next? Here's the tetrahedral intermediate, bound to Ser195 with the former carbonyl oxygen in the "oxyanion hole".



The next step is the reconstruction of the carbonyl double bond, with expulsion of the leaving group - in this case, the rest of the protein. This is the stage at which the protein chain actually is cleaved, and it produces an "acyl enzyme": the acyl part of the peptide that was cleaved, bound as an ester to Ser195.



OK, now we've got to cleave the acyl enzyme; enzyme are catalysts, and are not permanently altered in the reaction. To do this, we need a molecule of water.
From here on out, we're writing the mechanism for hydrolysis of an ester:



Restore the carbonyl double bond:



This releases the other end of the original protein, and restores the catalytic triad to its beginning state:



Dissociation of the second protein fragment leaves the enzyme ready to go again.

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