Monday, October 21, 2019
Science Breakthroughs (2002-2013) Essays
Science Breakthroughs (2002-2013) Essays Science Breakthroughs (2002-2013) Essay Science Breakthroughs (2002-2013) Essay Nueva EciJa University of Science and Technology Laboratory High School Gen. Tinio St. , Cabanatuan City Science Breakthroughs (2002-2013) Submitted to: Maam Arlene Gonzales Submitted by: Euna Rastyne T. Mejia Ill-Argon In 2002, U. S. scientists at the State University of New York at Stony Brook have created the first synthetic virus. Using directions downloaded from the Internet and chemicals obtained from a mail-order company, they built an apparently identical copy of the poliovirus. When injected into lab mice, the synthetic virus caused paralysis and then death. The scientists, who published their findings in the online journal Science Express in July 2002, said that they undertook the experiment to prove the alarming fact that a functional pathogenic virus could be constructed without access to a natural virus. Is this small step for biochemistry a great leap for bioterrorism? Scientists say that few people now have the skill to build a synthetic virus, much less one that could be an efficient bioweapon. The genome of the highly contagious smallpox virus is about 25 times as long as that of the poliovirus and has a more complex process of replication. But its synthesis may one day be possible. This being so, the experiment raises questions about the wisdom of ceasing vaccination when a natural virus has been eradicated. In 2003, the Hubble telescope has detected the oldest known planetâ⬠and it appears to have been formed billions of years earlier than astronomers thought possible. Nicknamed Methuselah after the aged biblical patriarch, the planet is an astonishing 12. 7 billion years old. In contrast, all other known planets (including our own) were created about 8 billion years later, roughly 4. 5 billion years ago. Methuselahs age is causing stronomers to reevaluate the prevalent theory of planet formation, which argues that the early universe did not contain sufficient heavy elements (e. g. , carbon, silicon, and oxygen) to allow for planets to form. But Methuselah defies this theory, having debuted when the primordial universe had only one-thirtieth of the heavy elements existing when our own solar system was born. In 2004, celebrated physicist black holes. Whats more, his error cost him a long-standing bet, obliging him to present a baseball encyclopedia to John Preskill of the California Institute of Technology. On the bright side, Hawkings black hole recantation had a rather exciting side-effect: l think, he ventured, l have solved a major problem in theoretical physics. Formed from a collapsed star, a black hole is a cosmic vacuum cleaner, whose gravitational pull is so strong that it sucks up everything in its way. In 1976, Hawking theorized that black holes emit random radiation (later named Hawking radiation) and lose mass until they eventually evaporate without a trace. All the matter sucked into a black hole, and all information about it (its quantum mechanical properties), would then be lost forever. But Hawkings theory contradicts an essential principle of quantum physics: no information can ever be truly destroyed. Black holes, if Hawking was right, defy the laws of the universe as we know it. This radical theory, according to Preskill, precipitated a genuine crisis in fundamental physics. Preskill resisted accepting what became known as the black hole information paradox, and in 1997 Hawking (along with another colleague) bet him that information swallowed by a black hole is forever hidden from the outside universe and can never be revealed, even as the black hole evaporates and ompletely disappears. Seven years later, Hawking claims to have solved the very paradox he created. According to his revised theory, black holes eventually open up, revealing information about what went into themâ⬠the information remains firmly in our universe, Hawking asserted. Preskill was pleased enough at having won the bet, but acknowledged, Ill be honest, I didnt understand the talk. Neith er did most others in the audience of the 17th International Conference on General Relativity and Gravitation in Dublin, leaving a stunned group of 800 scientists not sure what had hit hem. Hawkings published proof of his revolutionary findings will follow, but in the meantime, he has paid off his bet to Preskill. The bettors had agreed upon an encyclopedia, which, unlike a black hole, is something from which information can be recovered at will. In 2005, paleontologists discovered the existence of soft tissue in a 68-million-year-old Tyrannosaurus Rex fossil. An unprecedented find in a prehistoric creatureâ⬠scientists had assumed no such tissue could survive more than 100,000 yearsâ⬠the soft tissue included cells and blood vessels. The discovery was a erendipitous one. Because this T. rex fossil was located in a remote part of Montana (the Hell Creek formation, where about two dozen species of dinosaurs have been found) the fossil had to be removed by helicopter. According to paleontologist Jack Horner, who participated in the excavation, we actually had to split the thighbone into two pieces to get it into the helicopter. When his colleague Mary Schweitzer later examined the hollow cavity of the broken bone in her North Carolina State University lab, she discovered the pliable tissue. Scientists predict the soft tissue will rovide a gold mine of information about the physiology of dinosaurs. Examination of the soft tissue has already yielded several exciting revelations. The tissue included medullary bone, a calcium-enriched substance temporarily present when birds are ready to produce eggshells and lay eggs. Not only does the presence of medullary bone reveal that this particular T. rex was female (paleontologists have never before determined the sex of a dinosaur), but the existence of medullary tissue also According to Schweitzer, it links the reproductive physiology of dinosaurs to birds very closely. It indicates that dinosaurs produced and shelled their eggs much more like modern birds than like modern crocodiles. Horner commented that this is another piece to the puzzle and there are a lot of them. Anyone who would argue that birds and dinosaurs are not relatedâ⬠frankly, Id put them in the Flat Earth Society group. In 2006, paleontologists revealed the discovery of a 375-million-year-old transitional species whose anatomical traits bridge the gap between fish and tetrapod (four-legged vertebrate). Nicknamed the fishapod, its formal name is Tiktaalik roseae, from the Inuit name for a large shallow-water fish. Tiktaalik Joins several other significant transitional fossilsâ⬠the most famous of which is Archaeopteryx, the part-bird, part-reptile considered the missing link between birds and dinosaurs, which was discovered in 1860, Just two years after Darwin published The Origin of Species. The transformation of aquatic creatures into land animals took place during the Devonian period, about 410 to 356 million years ago. But before the discovery of the 375-million-year-old Tiktaalik fossils, there had been no actual fossil evidence to illustrate this crucial evolutionary moment. According to paleontologist Neil Shubin of the University of Chicago, We are capturing a very significant transition at a key moment of time. What is significant about the animal is that it is a fossil that blurs the distinction between two forms of lifeâ⬠between an animal that lives in water and an animal that lives on land. Tiktaalik resembles a huge scaly fish with a flat, crocodile snout. What amazed scientists was its pectoral fins, which contain bones forming the beginnings of a shoulder, elbow, wrist, hand, and even nascent fingers. Shubin describes the fin as basically a scale-covered arm, asserting hat heres a creature that has a fin that can do push-ups. Tiktaalik could pull its own weight, dragging itself along in shallow water and onto dry land, much like a seal. Tiktaalik also distinguishes itself from a fish by the existence of a primitive neck and ribs. As Harvard University paleontologist Farish A. Jenkins explains, Out of water, these fish encountered gravitational forces very different from the relative buoyancy they enjoyed in an aquatic setting. Restructuring of the body to withstand these forces is evident in the ribs, which are plate-like and overlap like shingles, orming a rigid supporting mechanism for the trunk. And while a fish has no need of a neckâ⬠in water, its entire torso easily falls into place behind its head when changing directionsâ⬠Tiktaaliks developed neck allowed it to move its head while its body, constrained by the stronger pull of gravity on land, remained stationary. According to Edward Daeschler of the Academy of Natural Sciences, the combination of these radically new anatomical features with classic fishlike traits demonstrates that evolution proceeds slowly in a mosaic pattern with some elements changing hile others stay the same. In 2007, scientists reported that they could use human skin cells to create embryonic stem cells. Stem cells have the remarkable ability to grow indefinitely, serving as a sort of repair system for the body. They can potentially divide without limit into any one of the 220 types of cells in the body to without embryonic destruction, which would eliminate the ethical controversy and limited funds for research. With ethical problems out of the way, more resources will become available for stem cell research. Generating stem cells could lead to new isease treatments by taking skin cells from a person with an illness and generating more stem cells that could be observed from the earliest stages of development. By watching a disease as it develops, scientists could potentially design drugs to not only treat it but also prevent it. With stem cells produced from a patients own skin cells, it is possible to create tissue that would not be rejected by their immune systemâ⬠the same result would require cloning with embryonic stem cells. In 2008, California became the first U. S. state to ban the use of trans fats by restaurants nd food retailers. Trans fats, or hydrogenated oils, are used in processed foods to increase their shelf life. Trans fats are also linked to coronary heart disease. California has 88,000 restaurants that will be affected when this law goes into effect by 2010. California Governor Arnold Schwarzenegger said the new law was a strong step toward creating a healthier future. Any restaurant violating the new law will incur fines from $25 to $1,000. In 2009, the Human Epigenome was decoded. The decoding of the human genome nearly a decade ago fueled expectations that an nderstanding of all human hereditary influences was within sight. But the connections between genes and, say, disease turned out to be far more complicated than imagined. What has since emerged is a new frontier in the study of genetic signaling known as epigenetics, which holds that the behavior of genes can be modified by environmental influences and that those changes can be passed down through generations. So people who smoke cigarettes in their youth, for example, sustain certain epigenetic changes, which may then increase the risk that their childrens children will reach puberty early. In October, a team led by Joseph Ecker at the Salk Institute in La Jolla, Calif. studied human skin and stem cells to produce the first detailed map of the human epigenome. By comparing this with the epigenomes of diseased cells, scientists will be able to work out how glitches in the epigenome may lead to cancers and other diseases. The study, which was published in the journal Nature, is a giant leap in geneticists quest to better understand the strange witches brew of nature and nurture that makes us who we are. In 2010, researchers from the J. Craig Venter Ins titute reported the successful construction of first self-replicating, synthetic bacterial cell. They copied and modified an entire genome of a small bacterial cell, inserted it into a living cell of another species, and by doing so created a new, synthetic life. This is the first self-replicating species that weve had on the planet whose parent is a computer, U. S. scientist Craig Venter who led the team said. It also is the first species to have its own website encoded in its genetic code. This is the first self-replicating species that weve had on the planet whose parent is a computer, U. S. scientist Craig Venter who led the team said. It lso is the first species to have its own website encoded in its genetic code. Scientists hope to patent the organism, called Mycoplasma laboratorium and engineer it to manufacture cheap biofuels, medicines and other useful compounds. In 2011, NASAs Kepler Mission scientists, who are charged with discovering Earth-like planets in the so-called habitable zone of stars in the Milky Way, announced the Tatooine); located the first two known Ea rth-sized exoplanets; quadrupled the number of worlds known to exist beyond our solar system; and spied Kepler-22b â⬠the most Earth-like planet weve encountered yet. And heres the really exciting bit: Kepler is Just getting warmed up. In 2012, for the first time in history, researchers at Kyoto University created a mouse by using eggs derived from stem cells alone. The achievement once again shows the remarkable possibilities presented by regenerative technologies like stem cells, while raising pressing ethical questions about the potential for human births in which parents might not be required. In 2013, the idea of taking someone elses poop and giving it a new home in your own colon may sound repulsive, but the treatment has proven emarkably effective in curing infections of C. ifficileâ⬠a nasty bacteria that kills 15,000 people each year. Take heart: The digested food waste in feces isnt itself the cure. Youre simply gaining some of the helpful bacteria living in the donors gutâ⬠like a farmer choosing the hardiest crops to seed next years fields. The bacteria produce proteins that are involved in a lot more diseases than we realized, says Roizen. Still grossed out? Researchers in Canada have developed a method to deliver Just the bacteriaâ⬠no fecesâ⬠via an oral pill, skipping the need for a poo enema.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.