An Inventions that changed history,,The microwave

 

The Microwave Oven

The microwave oven, aka the "Popcorn and Hot Pockets Warmer," was a happy accident that came from, of all things, a weapons program.

Percy LeBaron Spencer was a self-educated engineer working on radar technology in the years following WWII. The technology in question was the sci-fi sounding magnetron, a piece of machinery capable of firing high intensity beams of radiation.

Above: a scientist, with robot.

Apparently, P.L.S., as some have called him, had a bit of a sweet tooth. Or a strange fetish. Either way, he had a candy bar in his pants while he was in the lab one day. The self-proclaimed engineer noticed that the chocolate bar had melted when he was working with the magnetron.

Spencer disregarded the simple idea that his body heat had melted the chocolate in favor of the less logical and therefore more scientific conclusion that invisible rays of radiation had "cooked it" somehow.

A sane man would stop at this point and realize these magical heat rays were landing just inches from his tender scrotum. Indeed, most of the military experts on hand probably dreamed of the battlefield applications of their new Dick-Melting Ray. But like all men of science, Spencer was fascinated and treated his discovery like a novelty. He used it to make eggs explode and pop kernels of corn ("Imagine, a future where a building full of workers in cubicles eat this all day!")

I proclaim myself to be awesome.

Spencer continued to experiment with the magnetron until he boxed it in and marketed it as a new way to cook food. The initial version of the microwave was roughly six feet tall, weighed in around 750 pounds and had to be cooled with water. But they got it down to size, and today we use it mostly to destroy random objects on YouTube.

Read more: 5 Accidental Inventions That Changed The World | Cracked.com http://www.cracked.com/article_17134_5-accidental-inventions-that-changed-world.html#ixzz1nuRNw5p1

2000..Nobel Prize in Medicine and Physiology.

Arvid Carlsson

Paul Greengard

Eric R. Kandel

The Nobel Prize in Physiology or Medicine 2000 was awarded jointly to Arvid Carlsson, Paul Greengard and Eric R. Kandel "for their discoveries concerning signal transduction in the nervous system".

A signal transduction in biology, is a cellular mechanism. It converts a stimulus into a specific cellular response.^[1] Signal transduction starts with a chemical or physical signal to a receptor, and ends with a change in cell function.

Receptors are in the cell membrane, with part of the receptor outside and part inside the cell.  The chemical signal binds to the outer portion of the receptor, changing its shape. This causes another signal inside the cell.  Some chemical messengers, such as testosterone, can pass through the cell membrane, and bind directly to receptors in the cytoplasm or nucleus.

Sometimes there is a cascade of signals within the cell. With each step of the cascade, the signal can be amplified, so a small signal can result in a large response.^[1] Eventually, the signal creates a change in the cell, either in the expression of the DNA in the nucleus or in the activity of enzymes in the cytoplasm.

Most often, ordered sequences of biochemical reactions inside the cell are involved. These are carried out by enzymes and linked through second messengers. So a "second messenger pathway" is produced. These things usually happen quickly, sometimes very quickly. They may last from milliseconds (in the case ofion flux) to days for gene expression.

The number of proteins and other molecules that take part increases during the process. So a 'signal cascade' develops and a relatively small stimulus may cause a large response.

In bacteria and other single-cell organisms, the transduction processes a cell has limits the number of ways it can respond to its environment. In multicellular organisms, lots of different signal transduction processes are used to coordinate the behavior of individual cells. By this means the function of the organism as a whole is organized. The more complex the organism, the more complex the repertoire of signal transduction processes the organism must possess.

Thus, sensing of both the external and internal environment at the cellular level, relies on signal transduction. Many disease processes such as diabetes, heart disease, autoimmunity and cancer arise from defects in signal transduction pathways. This highlights the critical importance of signal transduction to biology and medicine.^[2]

Four great discoveries.

Here’s a look at some discoveries that have changed the world. It’s nearly impossible to rank their importance though.

10. Australopithecus

Discovered by: An unknown South African

This is known to be the very fist human to exist. The skull was actually discovered by an unknown South African but further investigations were made by Raymond Dart. The fossil was recorded to be 3.7 million years ago. The brains of most species of Australopithecus were roughly 35% of the size of that of a modern human brain. Most species of Australopithecus were diminutive and gracile, usually standing no more than 1.2 and 1.4 m (approx. 4 to 4.5 feet) tall. Actually, the skull found by the South African native was thought be the skull of an ape, but after seeing that the spinal column was connected below the skull and not at the back, it was later concluded that it should be a skull of a man and not of an ape.

9. Penicillin

Discovered by: Alexander Fleming

Everybody knows the story – or at least, should – the brilliant yet notoriously absent-minded biologist Sir Alexander Fleming was researching a strain of bacteria called staphylococci. Upon returning from holiday one time in 1928, he noticed that one of the glass culture dishes he had accidentally left out had become contaminated with a fungus, and so threw it away. It wasn’t until later that he noticed that the staphylococcus bacteria seemed unable to grow in the area surrounding the fungal mould. Fleming didn’t even hold out much hope for his discovery: it wasn’t given much attention when he published his findings the following year, it was difficult to cultivate, and it was slow-acting – it wasn’t until 1945 after further research by several other scientists that penicillin was able to be produced on an industrial scale, changing the way doctors treated bacterial infections forever. Penicillin antibiotics are historically significant because they are the first drugs that were effective against many previously serious diseases such as syphilis and Staphylococcus infections.

8. Oxygen

Discovered by: Carl Wilhelm Scheele

Oxygen was first discovered by Swedish pharmacist Carl Wilhelm Scheele. He had discovered it by about 1772. Scheele called the gas “fire air” because it was the only known supporter of combustion, and wrote an account of this discovery in a manuscript he titled Treatise on Air and Fire, which he sent to his publisher in 1775. However, that document was not published until 1777. Meanwhille, oxygen was also identified by Joseph Priestly in 1774. Priestly discovered a colourless gas from heated red mercuric oxide. He found this gas was highly combustible. He called it dephlogisticated air. Priestly shared his discovery with the French scientist Antoine Lavoiser. Lavoiser was able to show oxygen supported animal life respiration.

7.Gravity

Discovered by: Isaac Newton

Isaac Newton, an English mathematician and physicist, is considered the greatest scientist of all time. Among his many discoveries, the most important is probably his law of universal gravitation. In 1664, Newton figured out that gravity is the force that draws objects toward each other. It explained why things fall down and why the planets orbit around the Sun.

6. Fingerprints

Discovered by: Evangelista Purkinje

The discovery that fingerprints are unique to each individual, are left behind on objects a person touches and can be lifted off those items is nothing short of miraculous. This discovery completely changed the way that law enforcement conducted investigations. In today’s modern age, Jack the Ripper would eventually be caught. Even though it was 1823 when Jan Evangelista Purkinje noticed how unique our fingerprints are, it took some time for law enforcement to figure out ways to use this knowledge. Today, this discovery is used in everyday police work.

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Nobel Prize in Medicine and Physiology..2001.

Leland H. Hartwell

Tim Hunt

Sir Paul M. Nurse

The Nobel Prize in Physiology or Medicine 2001 was awarded jointly to Leland H. Hartwell, Tim Hunt and Sir Paul M. Nurse "for their discoveries of key regulators of the cell cycle".

During that time, scientists and researchers all know that the cells in our bodies divide via cellular division but the mechanisms by which cellular division takes place was still unknown. They had no idea of specific proteins and signaling pathways responsible for the control and regulation of the cell cycle.

BASICS OF THE CELL CYCLE

Scientists estimate that for every gram of tissue in our body, there are one billion cells in it. Can you imagine how many cells compose a single human adult?

All the cells in our body came from a single cell, the fertilized egg cell. During our physical growth, the single fertilized egg cell divides continuously until groups of cells finally make up a tissue, until groups of tissues finally make up an organ, and until a group of organs finally make up a living human. All these cannot be done if our cells are not capable of cellular division.

Cell cycle or cell division cycle is the series of events that happens within the cell leading to its division. The cell cycle consists of several phases.

First is the G1 phase wherein the cell grows bigger until it finally reaches a critical size to enter the next phase, the S phase. During this phase, the genetic materials are duplicated and a copy of the chromosomes is formed. Next is the G2 phase wherein the cell checks if the duplication of the chromosomes is complete and there is further growth in the size of the cell. Next comes the M phase or mitosis phase wherein the cell divides to produce two identical daughter cells. Not all cells in the G1 phase automatically proceeds to the S phase, most of the cells exit the cell cycle and enters a resting phase or G0.

THE MEN BEHIND THE DISCOVERY

Leland Hartwell was born on the 30th of October 1939. During his childhood, he was an avid collector of bugs, butterflies, lizards, snakes and spiders. His major break was when he took the entrance exam on California Institute of Technology and he fell in love with the environment of real sciences. He graduated in 1961 and went to MIT for graduate school and he decided to work on gene regulation. He then became a professor in University of California and in the University of Washington.

Timothy Hunt was born on the 19th of February 1943 at Neston near Liverpool. He earned his B.A. in the University of Cambridge in 1964 and his Ph.D. also in the University of Cambridge.

Sir Paul Nurse was born on the 25 of January 1949. He earned his B.sc. in the University of Birmingham in 1970 and his Ph.D. in the University of East Anglia three years after. He became the Director-General of the Imperial Cancer Research Fund in London and became the head of the cell cycle laboratory.

THE SEMINAL DISCOVERY

Leland Hartwell was the pioneer of studying cell cycle using genetic methods. He made use of the yeast Saccharomyces cerevisiae as the subject of his experiments. In the year 1970, he tried to isolate individual gene that he thought were vital in the control of cell cycle. Successfully, he was able to isolate cells wherein the cell cycle regulator genes were dysfunctional. By the use of this same method, he was able to isolate more than a hundred genes that were directly involved in the control of cell cycle. He called these genes CDC gene which stands for cell division cycle genes. Among the hundreds of CDC genes that he was able to isolate, he noted CDC28 gene for it was observed to control the first step of the cell cycle, progression from the G1 phase. For this function he named the gene, “start.” He also introduced the concept of “checkpoints” wherein the cell cycle stops to check whether the DNA was perfectly duplicated.

The primary focus of the research of Sir Paul Nurse was to identify rate controlling steps in the cell cycle. He used a different type of yeast, Schizosaccharomyces pombe, as the subject of his experiments. In the 1970s, he discovered the CDC2 gene. With the help of his friend Pierre Thuriaux, they were able to prove that CDC2 gene was a rate limiting step controlling the onset of M phase.

On another study, he was trying to find a gene that also controls the transition from G1 to S phase similar to what Hartwell found. As a negative control for this experiment he used CDC2 mutants which he thought would block cell cycle progression from G2 to M phase. Surprisingly, his negative control always gave significant positive responses. He thought that his experiment was flawed and hypothesized that CDC2 was required twice in the cell cycle, first in the transition from G1 to S phase and from G2 to M phase. What he thought to be a faulty experiment turned out to be completely accurate.

Serendipitously, he found that CDC2 gene was also a rate limiting factor for the onset of S phase and M phase. In 1987, he also isolated the corresponding gene in humans which he called CDK1. This gene encodes for a protein that is a member of the cyclin dependent kinase CDK family.

In the early 1980s, Tim Hunt discovered the first cyclin molecule. He made use of another organism in his experiments, Arbacia, a sea urchin. In his experiments, he found strange bands with a basic behavior of strange disappearance which turned out to occur about 10 minutes before each cellular division. He called these bands cyclins because the levels of these proteins vary periodically during the cell cycle. Cyclins are proteins that are formed and then degraded during each cell cycle. This explains their varying levels.

The cyclins bind to the CDK molecules, thereby regulating the CDK activity and selecting the proteins to be phosphorylated. Cyclins have no catalytic activity and CDKs are inactive in the absence of its partner cyclin. When a CDK is activated by its partner cyclin, it activates or deactivates proteins that in turn control the entry of cells into the next phase of the cell cycle.

CLINICAL IMPLICATIONS

This discovery has great impact in cancer research. Chromosome alterations can be caused by faulty cell cycle control, defective S phase or uncontrolled cyclin-CDK activation. These chromosomal abnormalities are directly related to the development of cancer cells. Developments in the field of cancer diagnosis via this discovery include the fact that detecting increased levels of CDK-molecules and cyclins are sometimes found in human tumors like breast cancer and brain tumor. In the field of cancer therapy, inhibitors of CDK-molecules are now being tested for its effects in cancer treatment.

Neolithic Revolution..Formation of the AGRICULTURAL ERA

Neolithic Revolution

The Neolithic Revolution was the first agricultural revolution. It was the wide-scale transition of many human cultures from a lifestyle of hunting and gathering toagriculture and settlement. Archaeological data indicates that various forms of plants and animal domestication evolved independently in six separate locations worldwide circa 10,000–7000 years BP (8,000–5,000 BC). The earliest known evidence exists in the tropical and subtropical areas of southwestern/southern Asia.^[1]

However, the Neolithic Revolution involved far more than the adoption of a limited set of food-producing techniques. During the next millennia it would transform the small and mobile groups of hunter-gatherers that had hitherto dominated human history into sedentary societies based in built-up villages and towns, which radically modified their natural environment by means of specialized food-crop cultivation (e.g., irrigation and food storage technologies) that allowed extensive surplus food production. These developments provided the basis for high population density settlements, specialized and complex labor diversification, trading economies, the development of non-portable art, architecture, and culture, centralized administrations and political structures, hierarchical ideologies, and depersonalized systems of knowledge (e.g., property regimes and writing). The first full-blown manifestation of the entire Neolithic complex is seen in the Middle Eastern Sumerian cities (ca.3,500 BC), whose emergence also inaugurates the end of the prehistoric Neolithic period.

The relationship of the above-mentioned Neolithic characteristics to the onset of agriculture, their sequence of emergence, and empirical relation to each other at various Neolithic sites remains the subject of academic debate, and seems to vary from place to place, rather than being the outcome of universal laws of social evolution.^[2][3]

2002..Nobel Prize in Medicine and Physiooggy

Sydney Brenner

H. Robert Horvitz

John E. Sulston

The Nobel Prize in Physiology or Medicine 2002 was awarded jointly to Sydney Brenner, H. Robert Horvitz and John E. Sulston "for their discoveries concerning 'genetic regulation of organ development and programmed cell death'"

Genetic regulation of programmed cell death

Sir John Sulston of the Wellcome Trust Sanger Institute developed techniques to study cell divisions in the nematode, from the fertilized egg to the 959 cells in the adult organism

SYDNEY BRENNER, H. Robert Howvitz and John . E. Sulston have been jointly awarded the Nobel prize in physiology or medicine. The prize has been awarded by the Nobel assembly at karolinksa Institute for 2002 for their discoveries concerning genetic regulation of organ development and programmed cell death.

The human body consists of hundreds of cell types, all originating from the fertilized egg. During the embryonic and foetal periods, the number of cells increase dramatically. The cells mature and become specialised to form the various tissues and organs of the body. Large numbers of cells are formed also in the adult body. In parallel with this generation of new cells, cell death is a normal process, both in the foetus and adult, to maintain the appropriate number of cells in the tissues. This delicate, controlled elimination of cells is called programmed cell death.

Developmental biologists first described programmed cell death. They noted that cell death was necessary for embryonic development, for example when tadpoles undergo metamorphosis to become adult frogs. In the human foetus, the interdigital mesoderm initially formed between fingers and toes is removed by programmed cell death. The vast excess of neuronal cells present during the early stages of brain development is also eliminated by the same mechanism.

H. Robert Horvitz used C. elegans to investigate whether there was as a genetic program controlling cell death.

Sydney Brenner realized, in the early 1960's, that fundamental questions regarding cell differentiation and organ development were hard to tackle in higher animals. Therefore, a genetically amenable and multicellular model organism simpler than mammals, was required. The ideal solution proved to be the nematodeCaenorhabditis elegans. This worm, approximately 1 mm long, has a short generation time and is transparent, which made it possible to follow cell division directly under the microscope. Brenner provided the basis in a publication from 1974, in which he broke new ground by demonstrating that specific gene mutations could be induced in the genome of C. elegans by the chemical compound EMS (ethyl methane sulphonate).

Different mutations could be linked to specific genes and to specific effects on organ development. Detailed studies in this simple model organism demonstrated that 131 of totally 1090 cells die reproducibly during development, and that this natural cell death is controlled by a unique set of genes.

John Sulston extended Brenner's work with C. elegans and developed techniques to study all cell divisions in the nematode, from the fertilized egg to the 959 cells in the adult organism. In a publication from 1976, Sulston described the cell lineage for a part of the developing nervous system. He showed that the cell lineage is invariant, i.e. every nematode underwent exactly the same program of cell division and differentiation. As a result of these findings Sulston made the seminal discovery that specific cells in the cell lineage always die through programmed cell death and that this could be monitored in the living organism. He described the visible steps in the cellular death process and demonstrated the first mutations of genes participating in programmed cell death, including the nuc-1 gene.

Sulston also showed that the protein encoded by the nuc-1 gene is required for degradation of the DNA of the dead cell. Robert Horvitz continued Brenner's and Sulston's work on the genetics and cell lineage of C. elegans. In a series of elegant experiments that started during the 1970's, Horvitz used C. elegans to investigate whether there was a genetic program controlling cell death. In a pioneering publication from 1986, he identified the first two bona fide "death genes", ced-3 and ced-4. He showed that functional ced-3 and ced-4 genes were a prerequisite for cell death to be executed. Later, Horvitz showed that another gene, ced-9, protects against cell death by interacting with ced-4 and ced-3. He also identified a number of genes that direct how the dead cell is eliminated. Horvitz showed that the human genome contains a ced-3-like gene. We now know that most genes that are involved in controlling cell death in C. elegans, have counterparts in humans.

Salk Institute professor Sydney Brenner demonstrated that specific gene mutations could be induced in genome of C. elegans by the chemical compound EMS (ethyl methane sulphonate).

Knowledge of programmed cell death has helped us to understand the mechanisms by which some viruses and bacteria invade our cells. We also know that in AIDS, neurodegenerative diseases, stroke and myocardial infarction, cells are lost as a result of excessive cell death. Other diseases, like autoimmune conditions and cancer, are characterized by a reduction in cell death, leading to the survival of cells normally destined to die.

Research on programmed cell death is intense, including in the field of cancer. Many treatment strategies are based on stimulation of the cellular "suicide program". This is, for the future, a most interesting and challenging task to further explore in order to reach a more refined manner to induce cell death in cancer cells.

This year's Nobel Laureates in Physiology or Medicine have made seminal discoveries concerning the genetic regulation of organ development and programmed cell death. By establishing and using the nematode Caenorhabditis elegans as an experimental model system, possibilities were opened to follow cell division and differentiation from the fertilized egg to the adult.

The Laureates have identified key genes regulating organ development and programmed cell death and have shown that corresponding genes exist in higher species, including man. The discoveries are important for medical research and have shed new light on the pathogenesis of many diseases.