An extremophile is an organism, usually unicellular but not always so, which thrives in or requires extreme conditions. The definition of extreme is anthropocentric, and this is because to the organism itself, its environment, not matter how extreme it may seem to be, is completely normal to itself. Thus, strictly, extremophilic labels should be used to describe the environment that an organism thrives in, regardless of how normal or extreme they may seem to human beings. For example, human beings are classified as a mesophilic aerobe.
When used in the context of describing organisms that thrive in environments that are extreme from human perspectives, most extremophiles are members of the Archaea family, although the terms are occasionally used interchangeably to describe the many extremophilic bacteria and eukarya. The Archaea are a major group of prokaryotes, which are unicellular (in rare cases, multicellular) organisms without a nucleus. This is in contrast to eukaryotes, organisms that have cell nuclei and may be variously unicellular or multicellular. Most prokaryotes are bacteria, and the two terms are often treated as synonyms. However, Carl Woese, originator of the RNA world hypothesis in 1967, has proposed dividing prokaryotes into the Bacteria and Archaea in 1977 because of the significant genetic differences between the two.
It is also important to note that not all extremophiles are unicellular. Examples of extremophilic metazoa are the psychrophilic Grylloblattodea (insects) and antarctic krill (crustaceans).
Different types of extremophiles
There are many different classes of extremophiles, each corresponding to the way its chosen environment differs from what is considered normal by other organisms. These classifications are not exclusive. Many extremophiles fall under multiple categories. For example, organisms living inside hot rocks deep under Earth's surface are both thermophilic and barophilic.
1. Acidophile: An organism which thrives under an environment with an optimum pH level at or below pH 3.
2. Aerobe: An organism which requires O2 to survive. There are 2 sub-categories of aerobes and they are the obligate aerobes and the facultative aerobes. Obligate aerobes require oxygen, while facultative aerobes can use oxygen, but also have other options. Almost all animals, most fungi and several bacteria are obligate aerobes. Being an obligate aerobe, although being advantageous from the energetical point of view, means also obligatory facing high levels of oxidative stress. Yeast, on the other hand, is an example of a facultative aerobe. Individual human cells are also facultative aerobes, as in they can switch to lactic acid fermentation if oxygen is not available. However, for the whole organism this cannot be sustained for long, and humans are therefore obligate aerobes.
3. Alkaliphile: An organism which thrives under an environment with an optimal pH levels of 9 or above, such as soda lakes and carbonate-rich soils.
4. Anaerobe: An organism which does not need O2 to survive. There are several sub-categories of anaerobes in existence. Aerotolerant organisms do not require oxygen, but are not affected by exposure to air. Microaerophiles are organisms that may use oxygen, but only at low concentrations (low micromolar range) and their growth is inhibited by normal oxygen concentrations (approximately 200 micromolar). Nanaerobes are organisms that cannot grow in the presence of micromolar concentrations of oxygen, but can grow with and benefit from nanomolar concentrations of oxygen. Certain anaerobic bacteria produce toxins, such as the tetanus or botulinum toxins, that are highly dangerous to higher organisms, including humans.
5. Endolith: An organism that lives inside rocks down to a depth of up to about 3 km, though it is unknown if that is their limit, or in the pores between mineral grains. Judging from the hyperthermophiles as discussed below, the temperature limit is at about 110°C, which limits the possible depth to 4 km below the continental crust, and 7 km below the ocean floor. Endolithic organisms have also been found in regions of low humidity.
6. Halophile: An organism which thrives in environments with very high concentrations of salt (NaCl) and requires at least 0.2 molar of salt for growth. Of particular note are the extreme halophiles or halobacteria, which require at least 2 molar of salt and are usually found in saturated solutions. These are the primary inhabitants of salt lakes and inland seas, such as the Dead Sea, where they tint the sediments bright colors.
7. Hypolith: An photosynthetic organism that lives inside or underneath rocks in climatically extreme in cold deserts. The rocks are generally translucent to allow for the penetration of light, such as quartz, which is one of the most common translucent rocks.
8. Mesophile: An organism that grows best in moderate temperature, neither too hot nor too cold, typically between 20 and 45 °C with an optimal temperature near 37 °C, which is the normal temperature of the human body. Most organisms that are pathogenic to humans are mesophiles. Organisms that prefer cold environments are termed psychrophilic and those preferring hot temperatures are termed thermophilic. A psychrophile is an organism which thrives at relatively cold temperatures. There are generally considered to be two groups of psychrophiles and they are name the classic psychrophiles and the psychrotrophs by food microbiologists. Classic psychrophiles are those organisms having a optimum growth temperature of 15°C or lower and do not grow in a climate beyond a maximum temperature of 20°C. They are largely found in icy places (such as in Antarctica) or at the freezing bottom of the ocean floor. Psychrotrophs, on the other hand, can grow at 0°C and up through approximately 40°C, and exist in much larger numbers than classic psychrophiles. They are of particular significance to food microbiologists as they can grow in refrigerated environments and cause food spoilage. A thermophile is an organism which thrives at relatively high temperatures, up to about 60 °C. Thermophiles have been found in various geothermally heated regions of the Earth such as hot springs like those in Yellowstone National Park and deep sea hydrothermal vents, and they are primarily responsible for producing the bright colors of the said waters. A hyperthermophile is an organism that thrives in extremely hot environments which are above 60°C. The optimal temperatures are between 80°C and 110°C. In fact, the recently-discovered Strain 121 has been able to double its population within 24 hours in an autoclave at 121°C, hence it was named as such. Many hyperthermophiles are also able to withstand other environmental extremes, such as high acidity or radiation levels. Hyperthermophiles were first discovered in the 1960s in hot springs in Yellowstone National Park, Wyoming. The most hardy hyperthermophiles are known live on the superheated walls of deep-sea hydrothermal vents, requiring temperatures of at least 90°C for survival.
9. Metalotolerant organism: An organism which is capable of tolerating high levels of heavy metals, such as copper, cadmium, arsenic, and zinc.
10. Oligotroph: An organism which is capable of growth in nutritionally limited environments.
11. Piezophile (also known as Barophile): An organism that lives optimally at high hydrostatic pressure, such as in high-pressure deep-sea environments, where pressure is well above atmospheric pressure. A pressure of 1 atmosphere is aproximately equivalent to 0.1 MPa. For every every km below ocean, the pressure increases approximately 10 MPa. For every km below earth’s crust, the pressure increases about 30 MPa. One strain of barophilic bacteria, Hirondellea gigas, was isolated from a sample of the world's deepest sediment, collected from the Mariana Trench, Challenger Deep, at a depth of 10,898 m. The Mariana Trench, Challenger Deep (11°22'N, 142°25'E) is the deepest ocean bottom in the world. Apparently, the Hirondellea gigas could grow only under pressure conditions of greater than 518 bars, that is approximately 50 MPa or more.
12. Radioresistant organism: An organism which is are capable of resisting very high levels of ionizing radiation, such as nuclear power plants. Please kindly refer to previous posting "Deinococcus radiodurans - The most radioresistant organism known to mankind".
13. Xerotolerant organism: An organism which can survive in environments where there is very little water. Water activity is a measure of the amount of water within a substrate that an organism can use to support growth. Xerotolerant organisms can survive in environments with water activity below 0.8. Endoliths and halophiles are xerotolerant.
N.B. Anthropocentrism is the practice, conscious or otherwise, of regarding the existence or concerns of human beings as the central fact of the universe.
Friday, May 27, 2005
Deinococcus radiodurans - The most radioresistant organism known to mankind
Deinococcus radiodurans is an extremophilic bacterium (a category of baterium which we will further discuss in the next posting) and it is the most radioresistant organism known to mankind. Radioresistant organisms is defined as organisms which are capable of living in enviroments with very high levels of ionizing radiation. A dose of 10 Gray or Gy, which is the SI unit of energy for the absorbed dose of radiation and one gray is the absorption of one joule of radiation energy by one kilogram of matter, is sufficient to kill a human. A dose of 60 Gy is sufficient to kill all cells in a culture of E. coli. However, Deinococcus radiodurans is capable of withstanding an instantaneous dose of up to 5,000 Gy with no loss of viability, and an instantaneous dose of up to 15,000 Gy with 37% viability.
It is not entirely clear as to how Deinococcus radiodurans could have developed naturally such a high degree of radioresistance. Naturally, background radiation levels are very low. In most places, background radiation is on the order of 0.4 mGy per year, and the highest known background radiation, which is near Guarapari, Brazil, is only 175 mGy per year. With naturally-occurring background radiation levels so low, mechanisms specifically to ward off the effects of high radiation cannot have been selected for during evolution.
Using genetic engineering, Deinococcus radiodurans has been given the abilities to consume and digest solvents and heavy metals, even in highly radioactive sites. It is now known that Deinococcus radiodurans accomplishes its resistance to radiation by having multiple copies of its genome and rapid DNA repair mechanisms.
When a creature gets hit by a high dose of radiation, the intense energy causes the large DNA molecule in each cell to fall apart. No creature can survive without its genes in working order. Most microbes have tools they can use to repair occasional damage to their DNA. The Deinococcus radiodurans, unlike other bacteria, has lots of extra copies of its genes. Deinococcus radiodurans cells have four to ten copies of their DNA molecule. Most bacteria have only one copy. These copies serve as back-ups, and when radiation hits and the Deinococcus radiodurans’ DNA becomes damaged, the bacterium has a lot more chances of finding an intact copy of each gene to use as it stitches its DNA back together.
In addition to the above, it also appears that Deinococcus radiodurans may have more of the cell repair tools that most bacteria have. Other microbes have many of the same kind of tools, although not in as high numbers and variety as Deinococcus radiodurans does. Michael Daly of the Uniformed Services University of the Health Sciences also suggested that the bacterium uses manganese to protect itself against radiation damage.
As a consequence of its hardiness, Deinococcus radiodurans has been nicknamed "Conan the Bacterium" (after Conan the Barbarian) and its official latin name literally means "strange berry that withstands radiation".
In addition to high levels of ionizing and ultraviolet radiation, it can also survive, and acid genotoxic chemicals, oxidative damage, extreme temperatures and vacuum. It also turns out that Deinococcus radiodurans is also able to live through extensive periods with absolutely no water. It was hypothesized that the bacterium’s radiation resistance could be a lucky side effect of the ability the bacterium evolved to withstand long periods without water, which is a more common natural occurrence than being exposed naturally to incredibly high radiation blasts. This is because dehydration causes the same kinds of breaks in DNA as radiation does and requires the same stitching process to fix these breaks.
Deinococcus radiodurans was discovered in 1956 by A.W. Anderson at the Oregon Agricultural Experiment Station in Corvallis, Oregon. Experiments were being performed to determine if canned food could be sterilized using high doses of gamma radiation. A tin of meat was exposed to a dose of radiation that was thought to kill all known forms of life, but the meat subsequently spoiled and Deinococcus radiodurans was isolated from the meat.
It is not entirely clear as to how Deinococcus radiodurans could have developed naturally such a high degree of radioresistance. Naturally, background radiation levels are very low. In most places, background radiation is on the order of 0.4 mGy per year, and the highest known background radiation, which is near Guarapari, Brazil, is only 175 mGy per year. With naturally-occurring background radiation levels so low, mechanisms specifically to ward off the effects of high radiation cannot have been selected for during evolution.
Using genetic engineering, Deinococcus radiodurans has been given the abilities to consume and digest solvents and heavy metals, even in highly radioactive sites. It is now known that Deinococcus radiodurans accomplishes its resistance to radiation by having multiple copies of its genome and rapid DNA repair mechanisms.
When a creature gets hit by a high dose of radiation, the intense energy causes the large DNA molecule in each cell to fall apart. No creature can survive without its genes in working order. Most microbes have tools they can use to repair occasional damage to their DNA. The Deinococcus radiodurans, unlike other bacteria, has lots of extra copies of its genes. Deinococcus radiodurans cells have four to ten copies of their DNA molecule. Most bacteria have only one copy. These copies serve as back-ups, and when radiation hits and the Deinococcus radiodurans’ DNA becomes damaged, the bacterium has a lot more chances of finding an intact copy of each gene to use as it stitches its DNA back together.
In addition to the above, it also appears that Deinococcus radiodurans may have more of the cell repair tools that most bacteria have. Other microbes have many of the same kind of tools, although not in as high numbers and variety as Deinococcus radiodurans does. Michael Daly of the Uniformed Services University of the Health Sciences also suggested that the bacterium uses manganese to protect itself against radiation damage.
As a consequence of its hardiness, Deinococcus radiodurans has been nicknamed "Conan the Bacterium" (after Conan the Barbarian) and its official latin name literally means "strange berry that withstands radiation".
In addition to high levels of ionizing and ultraviolet radiation, it can also survive, and acid genotoxic chemicals, oxidative damage, extreme temperatures and vacuum. It also turns out that Deinococcus radiodurans is also able to live through extensive periods with absolutely no water. It was hypothesized that the bacterium’s radiation resistance could be a lucky side effect of the ability the bacterium evolved to withstand long periods without water, which is a more common natural occurrence than being exposed naturally to incredibly high radiation blasts. This is because dehydration causes the same kinds of breaks in DNA as radiation does and requires the same stitching process to fix these breaks.
Deinococcus radiodurans was discovered in 1956 by A.W. Anderson at the Oregon Agricultural Experiment Station in Corvallis, Oregon. Experiments were being performed to determine if canned food could be sterilized using high doses of gamma radiation. A tin of meat was exposed to a dose of radiation that was thought to kill all known forms of life, but the meat subsequently spoiled and Deinococcus radiodurans was isolated from the meat.
Thursday, May 26, 2005
Bristlecone Pines - The oldest known living species on earth
The bristlecone pines are a small group of pine trees under the Pinaceae family (genus Pinus, subsection Balfourianae) that can live up to nearly 5,000 years, an age which far exceeds any other living thing known.
There are three closely related bristlecone pines species and they are:
1. Rocky Mountains Bristlecone Pine (Pinus aristata) species which can be found in Colorado, New Mexico and Arizona;
2. Great Basin Bristlecone Pine (Pinus longaeva) species which can be found in in Utah, Nevada and eastern California; and
3. Foxtail Pine (Pinus balfouriana) species which can be found in California.
The oldest living specimen of bristlecone pines that is currently known is an individual of Great Basin Bristlecone Pine nicknamed "Methuselah" after the reportedly longest-lived Biblical patriarch. Methuselah is located between 10,000 and 11,000 feet in the lnyo National Forest within the White Mountains, east of the Sierra Nevada. The core samples of Methuselah indicted the age of the bristlecone pine to be in excess of 4,700 years old, which is 1,500 years more than the age of their nearest competitor, being the Giant Sequoia. And quite possibly, there may be even older specimens may exist elsewhere in the White Mountains and in other remote parts of Nevada.
A bristlecone pine older than "Methuselah" was cut down in 1964 by a geography graduate student performing research in an area now protected by Great Basin National Park in Nevada. The tree, posthumously named "Prometheus", was found to be about 4,900 years old by ring counting.
The other two species, being the Rocky Mountains Bristlecone Pine and the Foxtail Pine, are also long-lived, though not to the extreme extent of Great Basin Bristlecone Pine. Specimens of both types of bristlecone pine have been measured or estimated to be up to 3,000 years old.
Bristlecone pines grow in isolated groves at and just below tree-line. Young bristlecone pines are densely clad with glistening needle-covered branches that sway like foxtails in the wind. With their bristled cones dripping pine scented resin on a warm afternoon, the bristlecone pines exude all the freshness of youth. As centuries pass and the bristlecone pines are battered by the elements, they become sculpted into astonishingly beautiful shapes and forms.
The trees manage to survive in the poorly nourished, alkaline soil with a minimum of moisture and a forty-five day growing season. In fact, the trees longevity is linked to these inhospitable conditions. Between cold temperatures, high winds, and short growing seasons, the bristlecone pines grow very slowly, adding as little as an inch in girth in a hundred years. Those bristlecone pines that grow the slowest produce very dense, highly resinous wood, and it is the dense and resinous wood that enables the bristlecone pines to be highly resistant to invasion by insects, fungi, and other potential pests.
As the tree ages, much of its bark may die. However, while most of its wood is dead, growth barely continues through a narrow strip of living tissue to connect the roots to the handful of live branches. When all life finally ceases, the snags of the bristlecone pines stand for a thousand years or more. The bristlecone pines then continue to be polished by wind driven ice and sand and the dense wood becomes slowly eroded away rather than decayed.
There are three closely related bristlecone pines species and they are:
1. Rocky Mountains Bristlecone Pine (Pinus aristata) species which can be found in Colorado, New Mexico and Arizona;
2. Great Basin Bristlecone Pine (Pinus longaeva) species which can be found in in Utah, Nevada and eastern California; and
3. Foxtail Pine (Pinus balfouriana) species which can be found in California.
The oldest living specimen of bristlecone pines that is currently known is an individual of Great Basin Bristlecone Pine nicknamed "Methuselah" after the reportedly longest-lived Biblical patriarch. Methuselah is located between 10,000 and 11,000 feet in the lnyo National Forest within the White Mountains, east of the Sierra Nevada. The core samples of Methuselah indicted the age of the bristlecone pine to be in excess of 4,700 years old, which is 1,500 years more than the age of their nearest competitor, being the Giant Sequoia. And quite possibly, there may be even older specimens may exist elsewhere in the White Mountains and in other remote parts of Nevada.
A bristlecone pine older than "Methuselah" was cut down in 1964 by a geography graduate student performing research in an area now protected by Great Basin National Park in Nevada. The tree, posthumously named "Prometheus", was found to be about 4,900 years old by ring counting.
The other two species, being the Rocky Mountains Bristlecone Pine and the Foxtail Pine, are also long-lived, though not to the extreme extent of Great Basin Bristlecone Pine. Specimens of both types of bristlecone pine have been measured or estimated to be up to 3,000 years old.
Bristlecone pines grow in isolated groves at and just below tree-line. Young bristlecone pines are densely clad with glistening needle-covered branches that sway like foxtails in the wind. With their bristled cones dripping pine scented resin on a warm afternoon, the bristlecone pines exude all the freshness of youth. As centuries pass and the bristlecone pines are battered by the elements, they become sculpted into astonishingly beautiful shapes and forms.
The trees manage to survive in the poorly nourished, alkaline soil with a minimum of moisture and a forty-five day growing season. In fact, the trees longevity is linked to these inhospitable conditions. Between cold temperatures, high winds, and short growing seasons, the bristlecone pines grow very slowly, adding as little as an inch in girth in a hundred years. Those bristlecone pines that grow the slowest produce very dense, highly resinous wood, and it is the dense and resinous wood that enables the bristlecone pines to be highly resistant to invasion by insects, fungi, and other potential pests.
As the tree ages, much of its bark may die. However, while most of its wood is dead, growth barely continues through a narrow strip of living tissue to connect the roots to the handful of live branches. When all life finally ceases, the snags of the bristlecone pines stand for a thousand years or more. The bristlecone pines then continue to be polished by wind driven ice and sand and the dense wood becomes slowly eroded away rather than decayed.
Tuesday, May 24, 2005
Saffron - The most expensive spice in the world
Saffron is a commercial spice that comes from the bright red stigmas of the saffron flower, or Crocus sativus, which flowers in the fall in many different countries, including Greece, India, Iran and Spain. The Crocus sativus stigmas are the female part of the flower. During a good year, each saffron crocus plant might produce several flowers. Each saffron flower contains three stigmas, which are the only part of the saffron crocus that when dried properly, become commercial saffron. Each red stigma is like a little capsule that encloses the complex chemicals that make up saffron's aroma, flavor, and yellow dye. In order to release these chemicals, you must steep the saffron filaments or threads, which are actually the dried stigmas of the saffron flower. Powdered saffron is more efficient because it does not need to be steeped.
Since each saffron flower contains only three stigmas and the stigmas must be picked from each flower by hand. As such, more than 75,000 blossoms or 225,000 hand-picked stigmas of these saffron flowers are required to produce just about one pound of Saffron filaments, thereby making saffron the most precious and most expensive spice in the world.
Soil and weather conditions naturally vary in the saffron cultivating countries and so do the methods of drying the fresh saffron stigmas. The international measuring stick for determining the quality of saffron is called a photospectometry report, the result of a laboratory analysis of the three chemicals in the saffron stigma which relate to aroma, flavor and color. Even though saffron stigmas are red, their dye is the color of egg yolks which gives the appealing yellow to culinary dishes. The chemicals that are being analyzed in a photospectometry report are crocin (the source of saffron’s strong orange-yellow coloring property), picrocrocin (source of its flavor) and safranal (source of its aroma). The higher the saffron’s coloring strength, the higher its value, as the saffron's coloring strength determines its flavor and aroma. If saffron has the right coloring strength, it will have the right color and general appearance, whether it is in the thread or powder form.
The saffron powder, with a high coloring strength, offers many advantages over the threads. When saffron threads are ground into powder, the chemicals corresponding to aroma, flavor and color are immediately released. The powder is then stored carefully, away from moisture and light, just as the threads need to be in order to maintain their potency. When the saffron powder reaches the chef, it is ready to be added directly to any recipe. When the chef adds the saffron powder to a recipe, immediately the deep yellow dye, delicate aroma and unique flavor are released.
As for saffron in the thread form, in order to release the potent chemicals in the saffron threads, they must be inmersed in an alcoholic, acidic or hot liquid for longer than just a few minutes. This allows aroma, flavor and color to be generously extracted. Saffron threads can release aroma, flavor and color for 24 hours or more, depending on their quality.
N.B. According to Greek myth, handsome mortal Crocos fell deeply in love with the beautiful nymph Smilax. But his overtures were rebuffed by Smilax, and he was turned into a beautiful purple crocus flower.
Since each saffron flower contains only three stigmas and the stigmas must be picked from each flower by hand. As such, more than 75,000 blossoms or 225,000 hand-picked stigmas of these saffron flowers are required to produce just about one pound of Saffron filaments, thereby making saffron the most precious and most expensive spice in the world.
Soil and weather conditions naturally vary in the saffron cultivating countries and so do the methods of drying the fresh saffron stigmas. The international measuring stick for determining the quality of saffron is called a photospectometry report, the result of a laboratory analysis of the three chemicals in the saffron stigma which relate to aroma, flavor and color. Even though saffron stigmas are red, their dye is the color of egg yolks which gives the appealing yellow to culinary dishes. The chemicals that are being analyzed in a photospectometry report are crocin (the source of saffron’s strong orange-yellow coloring property), picrocrocin (source of its flavor) and safranal (source of its aroma). The higher the saffron’s coloring strength, the higher its value, as the saffron's coloring strength determines its flavor and aroma. If saffron has the right coloring strength, it will have the right color and general appearance, whether it is in the thread or powder form.
The saffron powder, with a high coloring strength, offers many advantages over the threads. When saffron threads are ground into powder, the chemicals corresponding to aroma, flavor and color are immediately released. The powder is then stored carefully, away from moisture and light, just as the threads need to be in order to maintain their potency. When the saffron powder reaches the chef, it is ready to be added directly to any recipe. When the chef adds the saffron powder to a recipe, immediately the deep yellow dye, delicate aroma and unique flavor are released.
As for saffron in the thread form, in order to release the potent chemicals in the saffron threads, they must be inmersed in an alcoholic, acidic or hot liquid for longer than just a few minutes. This allows aroma, flavor and color to be generously extracted. Saffron threads can release aroma, flavor and color for 24 hours or more, depending on their quality.
N.B. According to Greek myth, handsome mortal Crocos fell deeply in love with the beautiful nymph Smilax. But his overtures were rebuffed by Smilax, and he was turned into a beautiful purple crocus flower.
Friday, May 20, 2005
Recipe for cooking Dry Abalones
There are mainly 2 different types of Dry Abalones. They are:
Green Abalones: these species of abalone is characterized by their relatively thicker and heavier body and the quality of their meat is firm and fleshy; and
Yellow Abalones: these species of abalone is characterized by their relatively thinner and lighter body and the quality of their meat is generally poorer and tougher.
Recipe for cooking Dry Abalones:
Green Abalones: these species of abalone is characterized by their relatively thicker and heavier body and the quality of their meat is firm and fleshy; and
Yellow Abalones: these species of abalone is characterized by their relatively thinner and lighter body and the quality of their meat is generally poorer and tougher.
Recipe for cooking Dry Abalones:
- Immerse and soak the Dry Abalones in clear water for 2 full days and nights. In the midst of the soaking, change the clear water every 4 to 5 hours.
- After soaking for the above duration, if the cores of the Dry Abalones are still hard, continue to immerse the Dry Abalones in clear water and raise the temperature the clear water to boiling point, after which turn off the fire and allow the clear water to cool to room temperature. If the cores of the Dry Abalones are still hard after the boiling process, repeat the boiling process until the cores of the Dry Abalones are become soft.
- Clean the Dry Abalones again in clear water, while taking special care to clean out the intestines and the chrysanthemums shaped lip edges for sand particles.
- Prepare and clean the required other ingredients, being old hen, chicken feet, lean meat laced with fatty meat, pig ligaments, pork ribs etc.
- Prepare iron pot or clay pot by placing bamboo mat at the bottom of the pot to prevent charring the pot’s bottom. Place the required other ingredients, being old hen, chicken feet, lean meat laced with fatty meat, pig ligaments, pork ribs etc into the pot. Then, place the Dry Abalones into the pot followed by clear water until the water level covers all the Dry Abalones and ingredients. After that, place a little rock sugar into the pot. Take note that when cooking Dry Abalones, salt and soy sauce must never be used to prevent the Dry Abalones from hardening.
- Use big fire to cook the pot of Dry Abalones and ingredients to boiling point before changing to small fire to achieve a consistent small boil or simmer. Maintain this simmering for 18 hours before switching off the fire. After another 12 hours, extract the cooled Dry Abalones from the pot and cut up the Dry Abalones when cold so as to ensure that the sweetness of the Dry Abalones is released from the flesh.
- Use the resultant soup and gravy from the pot to heat up the cut Dry Abalones, at the same time, add the necessary flavoring. After that, the Dry Abalones can be served from consumption.
Venomous Mammals
There are only 2 main species of mammals which are venomous by nature. These mammals include the shrew and the platypus.
Shrews are small, superficially mouse-like mammals of the family Soricidae. Although their external appearance is generally that of a mouse with a long nose, the shrews are not rodents and not closely related and the shrew family is part of the order Eulipotyphla. Shrews have feet with five clawed toes, unlike rodents, which have four. Shrews are also not to be confused with tree shrews, which are also unrelated, and belong to their own order, Scandentia. Shrews are distributed almost worldwide and of the major temperate land masses, only New Guinea, Australia, and New Zealand do not have native shrews at all; South America has shrews only in the far-northern tropical part.
Certain species of shrew are venomous, as in these species produce a toxic secretion which are channeled via little grooves in their teeth on the outside that the venom follows into a bite wound, which probably helps to immobilise especially large prey, such as other small mammals, reptiles, amphibians, fish and larger invertebrates, by its effects on the nervous system. This poisonous bite has been reported from North American Blarina and European Neomys. The bite can be quite painful to a human hand for, although shrew's teeth rarely puncture the skin, the toxin in the saliva of some species seems to produce a slight inflammation and reddening of the skin which can persist for several days.
The platypus (Ornithorhynchus anatinus) is a small, semi-aquatic mammal endemic to the eastern part of Australia, and one of the four extant monotremes, the only mammals that lay eggs instead of giving birth to live young. Please kindly note that the other three are from the echidna family. The scientific name Ornithorhynchus is derived from "ornithorhynkhos", which literally means "bird nose" in Greek, and anatinus means "duck". The name platypus is often prefixed with the adjective "duck-billed" to form duck-billed platypus, despite there being only one species of platypus.
All platypuses are born with spurs on their hind feet to inject venom. The spurs on the female fall off after the first year. The spurs on males become venomous during the breeding season.
N.B. Apparently, there is a slight difference between being vemonous and being poisonous. The definition hinges on how the toxin gets into the prey. A poison is something that has to be eaten or breathed in for it to take effect, that is ingested or inhaled. A venom is usually harmless if eaten. In order for it to do harm, it must come into contact with tissue underneath the skin, that is injected.
Shrews are small, superficially mouse-like mammals of the family Soricidae. Although their external appearance is generally that of a mouse with a long nose, the shrews are not rodents and not closely related and the shrew family is part of the order Eulipotyphla. Shrews have feet with five clawed toes, unlike rodents, which have four. Shrews are also not to be confused with tree shrews, which are also unrelated, and belong to their own order, Scandentia. Shrews are distributed almost worldwide and of the major temperate land masses, only New Guinea, Australia, and New Zealand do not have native shrews at all; South America has shrews only in the far-northern tropical part.
Certain species of shrew are venomous, as in these species produce a toxic secretion which are channeled via little grooves in their teeth on the outside that the venom follows into a bite wound, which probably helps to immobilise especially large prey, such as other small mammals, reptiles, amphibians, fish and larger invertebrates, by its effects on the nervous system. This poisonous bite has been reported from North American Blarina and European Neomys. The bite can be quite painful to a human hand for, although shrew's teeth rarely puncture the skin, the toxin in the saliva of some species seems to produce a slight inflammation and reddening of the skin which can persist for several days.
The platypus (Ornithorhynchus anatinus) is a small, semi-aquatic mammal endemic to the eastern part of Australia, and one of the four extant monotremes, the only mammals that lay eggs instead of giving birth to live young. Please kindly note that the other three are from the echidna family. The scientific name Ornithorhynchus is derived from "ornithorhynkhos", which literally means "bird nose" in Greek, and anatinus means "duck". The name platypus is often prefixed with the adjective "duck-billed" to form duck-billed platypus, despite there being only one species of platypus.
All platypuses are born with spurs on their hind feet to inject venom. The spurs on the female fall off after the first year. The spurs on males become venomous during the breeding season.
N.B. Apparently, there is a slight difference between being vemonous and being poisonous. The definition hinges on how the toxin gets into the prey. A poison is something that has to be eaten or breathed in for it to take effect, that is ingested or inhaled. A venom is usually harmless if eaten. In order for it to do harm, it must come into contact with tissue underneath the skin, that is injected.
Wednesday, May 18, 2005
Antimatter - The most expensive material on earth
Antimatter is essentially substance composed of elementary particles having the mass and electric charge of ordinary matter (such as electrons and protons) but for which the charge and related magnetic properties are opposite in sign.
The existence of antimatter was posited by the electron theory of Paul A.M. Dirac in 1929, where he suggested that the building blocks of atoms, being electrons (negatively charged particles) and protons (positively charged particles), all have antimatter counterparts, being antielectrons and antiprotons. One fundamental difference between matter and antimatter is that their subatomic building blocks carry opposite electric charges. Thus, while an ordinary electron is negatively charged, an antielectron is positively charged (hence the term positrons, which means "positive electrons") and while an ordinary proton is positively charged, an antiproton is negative.
In 1932, the positron (antielectron) was detected in cosmic rays by Caltech scientist Carl Anderson when a positron flew through a detector in his laboratory. This was followed by the discovery of the antiproton and the antineutron which was detected through the use of particle accelerators by Berkeley scientists in the 1950s. Positrons, antiprotons, and antineutrons, collectively called antiparticles, are the antiparticles of electrons, protons, and neutrons, respectively. When matter and antimatter are in close proximity, annihilation occurs within a fraction of a second, and large amounts of energy would be produced as a result.
With the presently known techniques of production, the prevailing market price of one gram of antimatter is approximately US$62,500,000,000,000, thereby making it currently the most expensive material on earth. And if, given the annihilative properties of matter and anti matter in close proximity, antimatter were to be used today for the purpose of producing electricity, the cost from man made antimatter would be approximately US$720,000,000 per kilowatt hour.
According to the “Antimatter Energy” website’s press release number 4 on Coal Power Plants Waste Products dated 14 February 2003, which can be found at the following website:
http://www.antimatterenergy.com/release04.htm,
it says that in accordance with the U.S. Department of Energy, the United States of America generated 1,968 billion kilowatt hours of electricity in 2000 by burning 900 million metric tons of coal, thereby creating 2 billion metric tons of carbon dioxide plus another 360 million metric tons of coal combustion residues of waste in the process. By comparison, an antimatter power plant would use 45 kilograms of antimatter to generate the same 1,968 billion kilowatt hours of electricity. The mass ratio between plants is 25 billion to 1 (2,223 million metric tons/45*2 kilograms).
The existence of antimatter was posited by the electron theory of Paul A.M. Dirac in 1929, where he suggested that the building blocks of atoms, being electrons (negatively charged particles) and protons (positively charged particles), all have antimatter counterparts, being antielectrons and antiprotons. One fundamental difference between matter and antimatter is that their subatomic building blocks carry opposite electric charges. Thus, while an ordinary electron is negatively charged, an antielectron is positively charged (hence the term positrons, which means "positive electrons") and while an ordinary proton is positively charged, an antiproton is negative.
In 1932, the positron (antielectron) was detected in cosmic rays by Caltech scientist Carl Anderson when a positron flew through a detector in his laboratory. This was followed by the discovery of the antiproton and the antineutron which was detected through the use of particle accelerators by Berkeley scientists in the 1950s. Positrons, antiprotons, and antineutrons, collectively called antiparticles, are the antiparticles of electrons, protons, and neutrons, respectively. When matter and antimatter are in close proximity, annihilation occurs within a fraction of a second, and large amounts of energy would be produced as a result.
With the presently known techniques of production, the prevailing market price of one gram of antimatter is approximately US$62,500,000,000,000, thereby making it currently the most expensive material on earth. And if, given the annihilative properties of matter and anti matter in close proximity, antimatter were to be used today for the purpose of producing electricity, the cost from man made antimatter would be approximately US$720,000,000 per kilowatt hour.
According to the “Antimatter Energy” website’s press release number 4 on Coal Power Plants Waste Products dated 14 February 2003, which can be found at the following website:
http://www.antimatterenergy.com/release04.htm,
it says that in accordance with the U.S. Department of Energy, the United States of America generated 1,968 billion kilowatt hours of electricity in 2000 by burning 900 million metric tons of coal, thereby creating 2 billion metric tons of carbon dioxide plus another 360 million metric tons of coal combustion residues of waste in the process. By comparison, an antimatter power plant would use 45 kilograms of antimatter to generate the same 1,968 billion kilowatt hours of electricity. The mass ratio between plants is 25 billion to 1 (2,223 million metric tons/45*2 kilograms).
Friday, May 06, 2005
Medical Journals - Prosopagnosia
Prosopagnosia, or face blindness in layman terms, is a rare disorder of face perception where the ability to perceive and understand faces is impaired, although other basic perceptual skills, such as recognising and discriminating objects, may be relatively intact.
Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face. The face is an important site for the identification of others and conveys significant social information. In view of the importance of its role in social interaction, psychological processes involved in face perception are known to be present from birth, complex, involve large and widely distributed areas in the brain.
Most cases have been reported following focal or localized brain injury, such as physical trauma (head injury), stroke, aneurysm or neurological illness, such as disorders of the central nervous system (brain, brainstem and cerebellum), the peripheral nervous system (neuropathy, including cranial nerves), or the autonomic nervous system (parts of which are located in both central and peripheral nervous system). More recently, cases of congenital or developmental prosopagnosia have also been reported.
Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face. The face is an important site for the identification of others and conveys significant social information. In view of the importance of its role in social interaction, psychological processes involved in face perception are known to be present from birth, complex, involve large and widely distributed areas in the brain.
Most cases have been reported following focal or localized brain injury, such as physical trauma (head injury), stroke, aneurysm or neurological illness, such as disorders of the central nervous system (brain, brainstem and cerebellum), the peripheral nervous system (neuropathy, including cranial nerves), or the autonomic nervous system (parts of which are located in both central and peripheral nervous system). More recently, cases of congenital or developmental prosopagnosia have also been reported.
Thursday, May 05, 2005
Spear of Destiny - The spear that pierced Christ's side
The Spear of Destiny, sometimes known as the Lance, Spear Luin or Spear of Longinus, is claimed to be the spear that pierced the side of Jesus when he was on the cross. It is described in John 19:31-37 as being used by a Roman soldier. Later Christian tradition would give the soldier's name as Gaius Cassius, and he is later called Longinus.
It is superstitiously believed that whosoever might hold the spear would have the power to conquer the world but losing it would mean instant death. The legend states that since the Spear had pierced the body of God, that would be Jesus Christ, it became imbued with some kind of magical power and therefore was a weapon capable of defeating any opponent. It is rumoured that the spear even has the power to kill an angel.
According to its legend, it has passed through the hands of influential world leaders throughout the ages including Constantine, Justinian, Charlemagne, Otto the Great, Kaiser Wilhelm II of Germany, the Habsburg Emperors, and Adolf Hitler.
The earliest reports of the Spear were circa A.D. 570, described as having been on display in the basilica of Mount Zion in Jerusalem adjacent to the Crown of Thorns, which was wore by Jesus Christ on the day he was cruxified on the cross. The point of the spearhead was alleged to have been snapped following the Persian conquest of Jerusalem in A.D. 615. The point was set into an icon, and found its way to the church of Hagia Sophia in Constantinople. It was later transported to France, where it remained in the Sainte Chapelle until the 18th century. The icon was briefly moved to the Bibliotheque Nationale in Paris during the French Revolution, but it subsequently disappeared. The lower section of the spearhead was allegedly conveyed from Jerusalem to Constantinople sometime in the 8th century. It was sent by Sultan Beyazid II as a gift to Pope Innocent VIII in 1492; Innocent had the relic placed in St. Peter's Basilica in Rome. It still resides there. The Catholic Church makes no claim as to its authenticity.
The holy spear that was used by the Holy Roman Emperors (cited from Otto I, Holy Roman Emperor on, the spear described above) as a part of their imperial insignia found its way to Vienna, Austria, where they are kept in a museum.
Hitler's interest in the relic probably originated with his interest in the 1882 opera named “Parsifal”, which was in turn written by Hitler’s favorite composer, Richard Wagner. The opera’s plot revolves around a group of knights and their guardianship of the Holy Grail, as well as the recovery of the Spear.
On March 12, 1938, the day Hitler annexed Austria, he arrived in Vienna a conquering hero. He made his way to the Schatzkammer in the Hofmuseum where he took possession of the Spear which he immediately sent to St. Katherine’s Church in Nuremberg, the spiritual capital of Nazi Germany.
One legend maintains that the spear came into the possession of the United States of America on April 30, 1945; specifically, under the control of the 3rd Army led by General George Patton. Later that day, supposedly in fulfilment of the legend, Hitler committed suicide. Patton became fascinated by the ancient weapon and had its authenticity verified. Patton did not go on to use the spear, as orders came down from General Dwight Eisenhower that the complete Habsburg regalia including the Spear of Longinus were to be returned to the Hofburg Palace , where it remains today. This legend has recently been shown to be quite false. The spear was not recovered until roughly six months after Hitler's suicide, and Patton never had possession of it.
N.B. It should be noted that there is a historical figure named Gaius Cassius Longinus, one of the conspirators responsible for the murder of Gaius Julius Caesar which occurred on the Ides of March, being March 15, in 44 BC.
It is superstitiously believed that whosoever might hold the spear would have the power to conquer the world but losing it would mean instant death. The legend states that since the Spear had pierced the body of God, that would be Jesus Christ, it became imbued with some kind of magical power and therefore was a weapon capable of defeating any opponent. It is rumoured that the spear even has the power to kill an angel.
According to its legend, it has passed through the hands of influential world leaders throughout the ages including Constantine, Justinian, Charlemagne, Otto the Great, Kaiser Wilhelm II of Germany, the Habsburg Emperors, and Adolf Hitler.
The earliest reports of the Spear were circa A.D. 570, described as having been on display in the basilica of Mount Zion in Jerusalem adjacent to the Crown of Thorns, which was wore by Jesus Christ on the day he was cruxified on the cross. The point of the spearhead was alleged to have been snapped following the Persian conquest of Jerusalem in A.D. 615. The point was set into an icon, and found its way to the church of Hagia Sophia in Constantinople. It was later transported to France, where it remained in the Sainte Chapelle until the 18th century. The icon was briefly moved to the Bibliotheque Nationale in Paris during the French Revolution, but it subsequently disappeared. The lower section of the spearhead was allegedly conveyed from Jerusalem to Constantinople sometime in the 8th century. It was sent by Sultan Beyazid II as a gift to Pope Innocent VIII in 1492; Innocent had the relic placed in St. Peter's Basilica in Rome. It still resides there. The Catholic Church makes no claim as to its authenticity.
The holy spear that was used by the Holy Roman Emperors (cited from Otto I, Holy Roman Emperor on, the spear described above) as a part of their imperial insignia found its way to Vienna, Austria, where they are kept in a museum.
Hitler's interest in the relic probably originated with his interest in the 1882 opera named “Parsifal”, which was in turn written by Hitler’s favorite composer, Richard Wagner. The opera’s plot revolves around a group of knights and their guardianship of the Holy Grail, as well as the recovery of the Spear.
On March 12, 1938, the day Hitler annexed Austria, he arrived in Vienna a conquering hero. He made his way to the Schatzkammer in the Hofmuseum where he took possession of the Spear which he immediately sent to St. Katherine’s Church in Nuremberg, the spiritual capital of Nazi Germany.
One legend maintains that the spear came into the possession of the United States of America on April 30, 1945; specifically, under the control of the 3rd Army led by General George Patton. Later that day, supposedly in fulfilment of the legend, Hitler committed suicide. Patton became fascinated by the ancient weapon and had its authenticity verified. Patton did not go on to use the spear, as orders came down from General Dwight Eisenhower that the complete Habsburg regalia including the Spear of Longinus were to be returned to the Hofburg Palace , where it remains today. This legend has recently been shown to be quite false. The spear was not recovered until roughly six months after Hitler's suicide, and Patton never had possession of it.
N.B. It should be noted that there is a historical figure named Gaius Cassius Longinus, one of the conspirators responsible for the murder of Gaius Julius Caesar which occurred on the Ides of March, being March 15, in 44 BC.
Wednesday, May 04, 2005
Natural Nuclear Reactors in Oklo
(Reproduced in full from the fact sheet as published by the U.S. Department of Energy - Office of Civilian Radioactive Waste Management under the following website: http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml)
Creating a nuclear reaction is not simple. In power plants, it involves splitting uranium atoms, and that process releases energy as heat and neutrons that go on to cause other atoms to split. This splitting process is called nuclear fission. In a power plant, sustaining the process of splitting atoms requires the involvement of many scientists and technicians.
It came as a great surprise to most, therefore, when, in 1972, French physicist Francis Perrin declared that nature had beaten humans to the punch by creating the world’s first nuclear reactors. Indeed, he argued, nature had a two-billion-year head start. Fifteen natural fission reactors have been found in three different ore deposits at the Oklo mine in Gabon, West Africa. These are collectively known as the Oklo Fossil Reactors.
And when these deep underground natural nuclear chain reactions were over, nature showed that it could effectively contain the radioactive wastes created by the reactions.
No nuclear chain reactions will ever happen in a repository for high-level nuclear wastes. But if a repository were to be built at Yucca Mountain, scientists would count on the geology of the area to contain radionuclides generated by these wastes with similar effectiveness.
Nature’s reactors
In the early 1970s, French scientists noticed something odd about samples of uranium recovered from the Oklo mine in Gabon, West Africa. All atoms of a specific chemical element have the same chemical properties, but may differ in weight; these different weights of an element are known as isotopes. Some uranium samples from Gabon had an abnormally low amount of the isotope U-235, which can sustain a chain reaction. This isotope is rare in nature, but in some places, the uranium found at Oklo contained only half the amount of the isotope that should have been there.
Scientists from other countries were skeptical when first hearing of these natural nuclear reactors. Some argued that the missing amounts of U-235 had been displaced over time, not split in nuclear fission reactions. "How," they asked, "could fission reactions happen in nature, when such a high degree of engineering, physics, and acute, detailed attention went into building a nuclear reactor?"
Perrin and the other French scientists concluded that the only other uranium samples with similar levels of the isotopes found at Oklo could be found in the used nuclear fuel produced by modern reactors. They found that the percentages of many isotopes at Oklo strongly resembled those in the spent fuel generated by nuclear power plants, and, therefore, reasoned that a similar natural process had occurred.
Uranium isotopes decay at different levels
The uranium in the Earth contains dominantly two uranium isotopes, U-238 and U-235, but also a very small percentage of U-234, and perhaps small, undetectable amounts of others. All of these isotopes undergo radioactive decay, but they do so at different rates. In particular, U-235 decays about six-and-a-third times faster than U-238. Thus, over time the proportion of U-235 to U-238 decreases. But this change is slow because of the small rates of decay.
Generally, uranium isotope ratios are the same in all uranium ores contained in nature, whether found in meteorites or in moon rocks. Therefore, scientists believe that the original proportions of these isotopes were the same throughout the solar system. At present, U-238 comprises about 99.3 percent of the total, and U-235 comprises about 0.7 percent. Any change in this ratio indicates some process other than simple radioactive decay.
Calculating back to 1.7 billion years ago—the age of the deposits in Gabon—scientists realized that the U-235 there comprised about three percent of the total uranium. This is high enough to permit nuclear fissions to occur, providing other conditions are right.
So how did nuclear reactions occur in nature?
Deep under African soil, about 1.7 billion years ago, natural conditions prompted underground nuclear reactions. Scientists from around the world, including American scientists have studied the rocks at Oklo. These scientists believe that water filtering down through crevices in the rock played a key role. Without water, it would have been nearly impossible for natural reactors to sustain chain reactions.
The water slowed the subatomic particles or neutrons that were cast out from the uranium so that they could hit-and split-other atoms. Without the water, the neutrons would move so fast that they would just bounce off, like skipping a rock across the water, and not produce nuclear chain reactions. When the heat from the reactions became too great, the water turned to steam and stopped slowing the neutrons. The reactions then slowed until the water cooled. Then the process could begin again.
Scientists think these natural reactors could have functioned intermittently for a million years or more. Natural chain reactions stopped when the uranium isotopes became too sparse to keep the reactions going.
What happened to the nuclear waste left at Oklo?
Once the natural reactors burned themselves out, the highly radioactive waste they generated was held in place deep under Oklo by the granite, sandstone, and clays surrounding the reactors’ areas. Plutonium has moved less than 10 feet from where it was formed almost two billion years ago.
Today, manmade reactors also create radioactive elements and by-products. Scientists involved in the disposal of nuclear waste are very interested in Oklo because long-lived wastes created there remain close to their place of origin.
The Oklo phenomenon gives scientists an opportunity to examine the results of a nearly natural two billion-year experiment, one that cannot be duplicated in the lab. By analyzing the remnants of these ancient nuclear reactors and understanding how underground rock formations contained the waste, scientists studying Oklo can apply their findings to containing nuclear waste today. The rock types and other aspects of the geology at Oklo differ from those at Yucca Mountain. But this information is useful in the design of a repository at Yucca Mountain. Were the Oklo reactors a unique event in natural history? Probably not. Scientists have found uranium ore deposits in other geological formations of approximately the same age, not only in Africa but also in other parts of the world, particularly in Canada and northern Australia. But to date, no other natural nuclear reactors have been identified.
Scientists believe that similar spontaneous nuclear reactions could not happen today because too high a proportion of the U-235 has decayed. But nearly two billion years ago, nature not only appears to have created her first nuclear reactors, she also found a way to successfully contain the waste they produced deep underground.
The radioactive remains of natural nuclear fission chain reactions that happened 1.7 billion years ago in Gabon, West Africa, never moved far beyond their place of origin. They remain contained in the sedimentary rocks that kept them from being dissolved or spread by groundwater. Scientists have studied Yucca Mountain to see if the geology there might play a similar role in containing high-level nuclear waste.
Creating a nuclear reaction is not simple. In power plants, it involves splitting uranium atoms, and that process releases energy as heat and neutrons that go on to cause other atoms to split. This splitting process is called nuclear fission. In a power plant, sustaining the process of splitting atoms requires the involvement of many scientists and technicians.
It came as a great surprise to most, therefore, when, in 1972, French physicist Francis Perrin declared that nature had beaten humans to the punch by creating the world’s first nuclear reactors. Indeed, he argued, nature had a two-billion-year head start. Fifteen natural fission reactors have been found in three different ore deposits at the Oklo mine in Gabon, West Africa. These are collectively known as the Oklo Fossil Reactors.
And when these deep underground natural nuclear chain reactions were over, nature showed that it could effectively contain the radioactive wastes created by the reactions.
No nuclear chain reactions will ever happen in a repository for high-level nuclear wastes. But if a repository were to be built at Yucca Mountain, scientists would count on the geology of the area to contain radionuclides generated by these wastes with similar effectiveness.
Nature’s reactors
In the early 1970s, French scientists noticed something odd about samples of uranium recovered from the Oklo mine in Gabon, West Africa. All atoms of a specific chemical element have the same chemical properties, but may differ in weight; these different weights of an element are known as isotopes. Some uranium samples from Gabon had an abnormally low amount of the isotope U-235, which can sustain a chain reaction. This isotope is rare in nature, but in some places, the uranium found at Oklo contained only half the amount of the isotope that should have been there.
Scientists from other countries were skeptical when first hearing of these natural nuclear reactors. Some argued that the missing amounts of U-235 had been displaced over time, not split in nuclear fission reactions. "How," they asked, "could fission reactions happen in nature, when such a high degree of engineering, physics, and acute, detailed attention went into building a nuclear reactor?"
Perrin and the other French scientists concluded that the only other uranium samples with similar levels of the isotopes found at Oklo could be found in the used nuclear fuel produced by modern reactors. They found that the percentages of many isotopes at Oklo strongly resembled those in the spent fuel generated by nuclear power plants, and, therefore, reasoned that a similar natural process had occurred.
Uranium isotopes decay at different levels
The uranium in the Earth contains dominantly two uranium isotopes, U-238 and U-235, but also a very small percentage of U-234, and perhaps small, undetectable amounts of others. All of these isotopes undergo radioactive decay, but they do so at different rates. In particular, U-235 decays about six-and-a-third times faster than U-238. Thus, over time the proportion of U-235 to U-238 decreases. But this change is slow because of the small rates of decay.
Generally, uranium isotope ratios are the same in all uranium ores contained in nature, whether found in meteorites or in moon rocks. Therefore, scientists believe that the original proportions of these isotopes were the same throughout the solar system. At present, U-238 comprises about 99.3 percent of the total, and U-235 comprises about 0.7 percent. Any change in this ratio indicates some process other than simple radioactive decay.
Calculating back to 1.7 billion years ago—the age of the deposits in Gabon—scientists realized that the U-235 there comprised about three percent of the total uranium. This is high enough to permit nuclear fissions to occur, providing other conditions are right.
So how did nuclear reactions occur in nature?
Deep under African soil, about 1.7 billion years ago, natural conditions prompted underground nuclear reactions. Scientists from around the world, including American scientists have studied the rocks at Oklo. These scientists believe that water filtering down through crevices in the rock played a key role. Without water, it would have been nearly impossible for natural reactors to sustain chain reactions.
The water slowed the subatomic particles or neutrons that were cast out from the uranium so that they could hit-and split-other atoms. Without the water, the neutrons would move so fast that they would just bounce off, like skipping a rock across the water, and not produce nuclear chain reactions. When the heat from the reactions became too great, the water turned to steam and stopped slowing the neutrons. The reactions then slowed until the water cooled. Then the process could begin again.
Scientists think these natural reactors could have functioned intermittently for a million years or more. Natural chain reactions stopped when the uranium isotopes became too sparse to keep the reactions going.
What happened to the nuclear waste left at Oklo?
Once the natural reactors burned themselves out, the highly radioactive waste they generated was held in place deep under Oklo by the granite, sandstone, and clays surrounding the reactors’ areas. Plutonium has moved less than 10 feet from where it was formed almost two billion years ago.
Today, manmade reactors also create radioactive elements and by-products. Scientists involved in the disposal of nuclear waste are very interested in Oklo because long-lived wastes created there remain close to their place of origin.
The Oklo phenomenon gives scientists an opportunity to examine the results of a nearly natural two billion-year experiment, one that cannot be duplicated in the lab. By analyzing the remnants of these ancient nuclear reactors and understanding how underground rock formations contained the waste, scientists studying Oklo can apply their findings to containing nuclear waste today. The rock types and other aspects of the geology at Oklo differ from those at Yucca Mountain. But this information is useful in the design of a repository at Yucca Mountain. Were the Oklo reactors a unique event in natural history? Probably not. Scientists have found uranium ore deposits in other geological formations of approximately the same age, not only in Africa but also in other parts of the world, particularly in Canada and northern Australia. But to date, no other natural nuclear reactors have been identified.
Scientists believe that similar spontaneous nuclear reactions could not happen today because too high a proportion of the U-235 has decayed. But nearly two billion years ago, nature not only appears to have created her first nuclear reactors, she also found a way to successfully contain the waste they produced deep underground.
The radioactive remains of natural nuclear fission chain reactions that happened 1.7 billion years ago in Gabon, West Africa, never moved far beyond their place of origin. They remain contained in the sedimentary rocks that kept them from being dissolved or spread by groundwater. Scientists have studied Yucca Mountain to see if the geology there might play a similar role in containing high-level nuclear waste.
221b Baker Street, London, England - The residence of Sherlock Holmes
Between 1881-1904, the above address was occupied by Mr. Sherlock Holmes and his colleague, Dr. John H. Watson, M.D., in accordance with the stories written by Sir Arthur Conan Doyle.
Sherlock Holmes and Doctor Watson spent many years at this address in London, England, under the rent of Mrs. Hudson. Characters of every type have frequented the rooms of this place, calling on Holmes for help and assistance on mysteries only the finest criminal detective could unravel. The house was last used as a lodging house in 1936 and the famous first floor study overlooking Baker Street is still faithfully maintained as it was kept in Victorian Times.
Sherlock Holmes, the amateur detective, chemist, violin player, boxer, and swordsman (among other talents), first appeared in Sir Arthur Conan Doyle's "A Study in Scarlet" in the Beeton's Christmas Annual in 1887. A brief description of the house at 221b Baker Street could be found from "The Adventure of the Mazarin Stone" as follows:
“It was pleasant to Dr. Watson to find himself once more in the untidy room of the first floor in Baker Street which had been the starting-point of so many remarkable adventures. He looked round him at the scientific charts upon the wall, the acid-charred bench of chemicals, the violin-case leaning in the corner, the coal scuttle, which contained of old the pipes and tobacco.”
Sherlock Holmes and Doctor Watson spent many years at this address in London, England, under the rent of Mrs. Hudson. Characters of every type have frequented the rooms of this place, calling on Holmes for help and assistance on mysteries only the finest criminal detective could unravel. The house was last used as a lodging house in 1936 and the famous first floor study overlooking Baker Street is still faithfully maintained as it was kept in Victorian Times.
Sherlock Holmes, the amateur detective, chemist, violin player, boxer, and swordsman (among other talents), first appeared in Sir Arthur Conan Doyle's "A Study in Scarlet" in the Beeton's Christmas Annual in 1887. A brief description of the house at 221b Baker Street could be found from "The Adventure of the Mazarin Stone" as follows:
“It was pleasant to Dr. Watson to find himself once more in the untidy room of the first floor in Baker Street which had been the starting-point of so many remarkable adventures. He looked round him at the scientific charts upon the wall, the acid-charred bench of chemicals, the violin-case leaning in the corner, the coal scuttle, which contained of old the pipes and tobacco.”
History of the Marine's Mameluke Sword
(Reproduced from the Marine Corps Historical Center, HQM)
Marine Officers were initially allowed swords of any style as long as they were yellow-mounted.
In 1805, the Marines assembled a fleet to Derna, Tripoli to put down Barbary Coast pirates taking a toll on American merchant ships in the Mediterranean. Lieutenant Presley O'Bannon and his Marines marched across 600 miles of North Africa's Libyan desert to successfully storm the fortified Tripolitan city of Derna.
Hamet Karamanli, a desert chieftain who took as ruler of Tripoli after the war, presented Marine Lieutenant O'Bannon with his personal scimitar to show his appreciation. The scimitar was used by Mameluke warriors of North Africa. By 1825, all Marine officers were mandated to wear the Mameluke sword.
Except for the period from 1859 to 1875, commissioned Marine officers have carried the Mameluke sword.Regulations adopted in 1859 outlined the specifications for the sword still carried by today's noncommissioned officers. The design is based on the 1850 Army foot officers' sword, which Marine officers carried from 1859 to 1875.
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The story of Lieutenant Presley Neville O'Bannon begins in 1805. For several years American ships plying the waters along the coast of North Africa had been endangered by bands of Barbary pirates who grabbed what loot they wanted, killed many of the seamen or shackled them to lives of slavery. Annual payments in tribute to the area's many rulers were demanded for "protection" of American lives and shipping.
Although the U.S. was tired of a Naval war which had dragged on for several years, it decided to carry the fight to Derne, the inland stronghold of the enemy and chief fortress at Tripoli. To do this, General William Eaton, U.S. Navy agent in charge of the region, asked for 100 Marines from a nearby U.S. squadron. In answer to his request, a young Virginian, Lieutenant Presley Neville O'Bannon and seven enlisted Marines were placed at Eaton's disposal.
O'Bannon was given an odd assortment of men to form a task force formidable enough to seek the surrender of Jussup - the reigning Bey of Tripoli. His handful of Marines, a few Greek mercenaries, and a motley crew of cut-throats and sheiks loyal to Hamet Karamanli, the disgruntled brother of the Tripolitan ruler, started from Egypt on the 600-mile trek across the desert of Barca.
Along the way, every obstacle known to the East beset Eaton and O'Bannon. Instead of the usual two weeks, the trip covered 45 days. O'Bannon was called upon to prevent the Moslem's plundering of the Christians. It was he who brought the numerous revolts of the camel drivers to a halt. He constantly prodded the Arab chiefs who repeatedly refused to proceed. And all these delays prolonged the journey, stretched food rations, and at times, exhausted water supplies.
On the 25th day of April, the forces under Eaton and O'Bannon reached Derne and terms of surrender were offered to the enemy. The flag of truce was immediately returned. "My head or yours," came the reply from the Government's stronghold.
O'Bannon then swung into action. With the support of naval gunfire from American ships in the harbor and accompanied by his seven Marines, he spearheaded a bayonet charge which resulted in the capture of the fort on 27 April, 1805. O'Bannon personally lowered the Tripolitian flag and hoisted the Stars and Stripes for the first time on foreign soil, securing the War with Tripoli.
Hamet Karamanli promptly took as ruler of Tripoli and presented the Marine lieutenant with his personal jeweled sword, the same type used by his Mameluke tribesmen. Today, Marine officers still carry this type of sword, commemorating the Corps' service during the Tripolitian War, 1801 - 05.
Appropriately, the actions of O'Bannon and his small group of Marines are commemorated in the second line of the Marines' Hymn with the words, "To the Shores of Tripoli". These same words were also inscribed across the top of the Marine Corps' first standard, adopted around 1800.
Upon his return to this country O'Bannon was given a welcome by the people of Philadelphia and was acclaimed "The Hero of Derne." After his separation from service, O'Bannon went to Kentucky, where his brother, Major John O'Bannon, a Revolutionary War figure, was living. Shortly after his arrival he was elected by the people of Logan County to represent them in the state legislature. He served from 1812 through 1820.
Presley O'Bannon died on September 12, 1850, and was buried in Henry County, Kentucky. In 1919, through the efforts of the Susannah Hart Chapter of the Daughters of the American Revolution, O'Bannon's body was moved to the Frankfort Cemetery at Frankfurt, Kentucky. On a lonely knoll in the cemetery stands a simple stone marking the grave of the "Hero of Derne". It is among the final resting places of vice-presidents, senators, governors, artists, and scores of local patriots who fell in action against the wilderness and foreign aggressors. Even today, many people still stop by to pay their respects to the man who, by his gallant actions, helped to "set the best traditions of the Corps".
Marine Officers were initially allowed swords of any style as long as they were yellow-mounted.
In 1805, the Marines assembled a fleet to Derna, Tripoli to put down Barbary Coast pirates taking a toll on American merchant ships in the Mediterranean. Lieutenant Presley O'Bannon and his Marines marched across 600 miles of North Africa's Libyan desert to successfully storm the fortified Tripolitan city of Derna.
Hamet Karamanli, a desert chieftain who took as ruler of Tripoli after the war, presented Marine Lieutenant O'Bannon with his personal scimitar to show his appreciation. The scimitar was used by Mameluke warriors of North Africa. By 1825, all Marine officers were mandated to wear the Mameluke sword.
Except for the period from 1859 to 1875, commissioned Marine officers have carried the Mameluke sword.Regulations adopted in 1859 outlined the specifications for the sword still carried by today's noncommissioned officers. The design is based on the 1850 Army foot officers' sword, which Marine officers carried from 1859 to 1875.
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The story of Lieutenant Presley Neville O'Bannon begins in 1805. For several years American ships plying the waters along the coast of North Africa had been endangered by bands of Barbary pirates who grabbed what loot they wanted, killed many of the seamen or shackled them to lives of slavery. Annual payments in tribute to the area's many rulers were demanded for "protection" of American lives and shipping.
Although the U.S. was tired of a Naval war which had dragged on for several years, it decided to carry the fight to Derne, the inland stronghold of the enemy and chief fortress at Tripoli. To do this, General William Eaton, U.S. Navy agent in charge of the region, asked for 100 Marines from a nearby U.S. squadron. In answer to his request, a young Virginian, Lieutenant Presley Neville O'Bannon and seven enlisted Marines were placed at Eaton's disposal.
O'Bannon was given an odd assortment of men to form a task force formidable enough to seek the surrender of Jussup - the reigning Bey of Tripoli. His handful of Marines, a few Greek mercenaries, and a motley crew of cut-throats and sheiks loyal to Hamet Karamanli, the disgruntled brother of the Tripolitan ruler, started from Egypt on the 600-mile trek across the desert of Barca.
Along the way, every obstacle known to the East beset Eaton and O'Bannon. Instead of the usual two weeks, the trip covered 45 days. O'Bannon was called upon to prevent the Moslem's plundering of the Christians. It was he who brought the numerous revolts of the camel drivers to a halt. He constantly prodded the Arab chiefs who repeatedly refused to proceed. And all these delays prolonged the journey, stretched food rations, and at times, exhausted water supplies.
On the 25th day of April, the forces under Eaton and O'Bannon reached Derne and terms of surrender were offered to the enemy. The flag of truce was immediately returned. "My head or yours," came the reply from the Government's stronghold.
O'Bannon then swung into action. With the support of naval gunfire from American ships in the harbor and accompanied by his seven Marines, he spearheaded a bayonet charge which resulted in the capture of the fort on 27 April, 1805. O'Bannon personally lowered the Tripolitian flag and hoisted the Stars and Stripes for the first time on foreign soil, securing the War with Tripoli.
Hamet Karamanli promptly took as ruler of Tripoli and presented the Marine lieutenant with his personal jeweled sword, the same type used by his Mameluke tribesmen. Today, Marine officers still carry this type of sword, commemorating the Corps' service during the Tripolitian War, 1801 - 05.
Appropriately, the actions of O'Bannon and his small group of Marines are commemorated in the second line of the Marines' Hymn with the words, "To the Shores of Tripoli". These same words were also inscribed across the top of the Marine Corps' first standard, adopted around 1800.
Upon his return to this country O'Bannon was given a welcome by the people of Philadelphia and was acclaimed "The Hero of Derne." After his separation from service, O'Bannon went to Kentucky, where his brother, Major John O'Bannon, a Revolutionary War figure, was living. Shortly after his arrival he was elected by the people of Logan County to represent them in the state legislature. He served from 1812 through 1820.
Presley O'Bannon died on September 12, 1850, and was buried in Henry County, Kentucky. In 1919, through the efforts of the Susannah Hart Chapter of the Daughters of the American Revolution, O'Bannon's body was moved to the Frankfort Cemetery at Frankfurt, Kentucky. On a lonely knoll in the cemetery stands a simple stone marking the grave of the "Hero of Derne". It is among the final resting places of vice-presidents, senators, governors, artists, and scores of local patriots who fell in action against the wilderness and foreign aggressors. Even today, many people still stop by to pay their respects to the man who, by his gallant actions, helped to "set the best traditions of the Corps".
Sunday, May 01, 2005
Reichenbach Falls - The place of Sherlock Holmes's death
The Reichenbach Falls in Meiringen, Switzerland, has a total drop of 250 metres. At 90 metres, the Upper Reichenbach Falls is one of the highest cataracts in the Alps. This is the place where Sherlock Holmes apparently died at the end of Sir Arthur Conan Doyle’s Sherlock Holmes series "The Adventure of the Final Problem".
Accordingly, to the storyline of "The Adventure of the Final Problem", Watson was tricked by Holmes's greatest opponent, the criminal mastermind Professor Moriarty, to return back to the hotel where he was then staying with Holmes. After Watson realised at last what had happened, Watson rushed back to Reichenbach Falls only to find no-one there, although he did see two sets of footprints going out onto the muddy dead-end path, but none coming back. Towards the end of the path, there were also signs that a violent struggle had taken place. Apparently, it seemed that Holmes and Moriarty have both died, falling to their deaths down the gorge whilst locked in mortal combat.
Accordingly, to the storyline of "The Adventure of the Final Problem", Watson was tricked by Holmes's greatest opponent, the criminal mastermind Professor Moriarty, to return back to the hotel where he was then staying with Holmes. After Watson realised at last what had happened, Watson rushed back to Reichenbach Falls only to find no-one there, although he did see two sets of footprints going out onto the muddy dead-end path, but none coming back. Towards the end of the path, there were also signs that a violent struggle had taken place. Apparently, it seemed that Holmes and Moriarty have both died, falling to their deaths down the gorge whilst locked in mortal combat.
Medical Journals - Hemostasis
The ability of the body to control the flow of blood following any vascular injury is of paramount importance to continued survival. The process of blood clotting and then the subsequent dissolution of the clot, following repair of the injured tissue, is termed hemostasis.
There is a total of 4 major events that occur during hemostasis in a set order following the loss of vascular integrity.
During the initial phase called vascular constriction, the affected vascular tissues limits the flow of blood to the area of injury.
During the second phase, platelets become activated by thrombin and aggregate at the site of injury, forming a temporary, loose platelet plug. The protein fibrinogen is primarily responsible for stimulating platelet clumping. Platelets clump by binding to collagen that becomes exposed following rupture of the endothelial lining of vessels. Upon activation, platelets release ADP and TXA2 (which activate additional platelets), serotonin, phospholipids, lipoproteins, and other proteins important for the coagulation cascade. In addition to induced secretion, activated platelets change their shape to accommodate the formation of the plug.
During the third phase, to insure stability of the initially loose platelet plug, a fibrin mesh (also called the clot) forms and entraps the plug. If the plug contains only platelets it is termed a white thrombus; if red blood cells are present it is called a red thrombus.
During the last phase, the clot must be dissolved in order for normal blood flow to resume following tissue repair. The dissolution of the clot occurs through the action of plasmin.
Two pathways lead to the formation of a fibrin clot: the intrinsic and extrinsic pathway. Although they are initiated by distinct mechanisms, the two converge on a common pathway that leads to clot formation. The formation of a red thrombus or a clot in response to an abnormal vessel wall in the absence of tissue injury is the result of the intrinsic pathway. Fibrin clot formation in response to tissue injury is the result of the extrinsic pathway. Both pathways are complex and involve numerous different proteins termed clotting factors.
N.B. For purposes of laboratory tests, plasma is obtained from whole blood. To prevent clotting, an anticoagulant such as citrate or heparin is added to the blood specimen immediately after it is obtained. (Usually the anticoagulant is already in the evacuated blood collection tube (e.g. Vacutainer or Vacuette when the patient is bled.) The specimen is then centrifuged to separate plasma from blood cells. Plasma can be frozen below negative 80 degree celcius nearly indefinitely for subsequent analysis.
For many biochemical laboratory tests, plasma and blood serum can be used interchangeably. Serum resembles plasma in composition but lacks the coagulation factors. It is obtained by letting a blood specimen clot prior to centrifugation. For this purpose, a serum-separating tube can be used which contains an inert catalyst (such as glass beads or powder) to facilitate clotting as well as a portion of gel with a density designed to sit between the liquid and cellular layers in the tube after centrifugation, making separation more convenient.
Barring the use of the inert catalyst and the centrifugation, if the blood cells and the blood serum were to be allowed to separate naturally, it would take at least 20 minutes and above to occur. As such, if blood that were found on evidence taken from the crime scene were confirmed forensically to have the blood cells to be separated from the blood serum, then it would be extremely likely that the blood were actually planted onto the evidence after the crime was committed rather than transferred onto the evidence during the occurance of the crime.
On a separate note, it is interesting to note that the approximate distribution of blood types in the United States of America population is as follows. The distribution may be differ for specific racial and ethnic groups.
O Rh-positive: 38 percent
O Rh-negative: 7 percent
A Rh-positive: 34 percent
A Rh-negative: 6 percent
B Rh-positive: 9 percent
B Rh-negative: 2 percent
AB Rh-positive: 3 percent
AB Rh-negative: 1 percent
There is a total of 4 major events that occur during hemostasis in a set order following the loss of vascular integrity.
During the initial phase called vascular constriction, the affected vascular tissues limits the flow of blood to the area of injury.
During the second phase, platelets become activated by thrombin and aggregate at the site of injury, forming a temporary, loose platelet plug. The protein fibrinogen is primarily responsible for stimulating platelet clumping. Platelets clump by binding to collagen that becomes exposed following rupture of the endothelial lining of vessels. Upon activation, platelets release ADP and TXA2 (which activate additional platelets), serotonin, phospholipids, lipoproteins, and other proteins important for the coagulation cascade. In addition to induced secretion, activated platelets change their shape to accommodate the formation of the plug.
During the third phase, to insure stability of the initially loose platelet plug, a fibrin mesh (also called the clot) forms and entraps the plug. If the plug contains only platelets it is termed a white thrombus; if red blood cells are present it is called a red thrombus.
During the last phase, the clot must be dissolved in order for normal blood flow to resume following tissue repair. The dissolution of the clot occurs through the action of plasmin.
Two pathways lead to the formation of a fibrin clot: the intrinsic and extrinsic pathway. Although they are initiated by distinct mechanisms, the two converge on a common pathway that leads to clot formation. The formation of a red thrombus or a clot in response to an abnormal vessel wall in the absence of tissue injury is the result of the intrinsic pathway. Fibrin clot formation in response to tissue injury is the result of the extrinsic pathway. Both pathways are complex and involve numerous different proteins termed clotting factors.
N.B. For purposes of laboratory tests, plasma is obtained from whole blood. To prevent clotting, an anticoagulant such as citrate or heparin is added to the blood specimen immediately after it is obtained. (Usually the anticoagulant is already in the evacuated blood collection tube (e.g. Vacutainer or Vacuette when the patient is bled.) The specimen is then centrifuged to separate plasma from blood cells. Plasma can be frozen below negative 80 degree celcius nearly indefinitely for subsequent analysis.
For many biochemical laboratory tests, plasma and blood serum can be used interchangeably. Serum resembles plasma in composition but lacks the coagulation factors. It is obtained by letting a blood specimen clot prior to centrifugation. For this purpose, a serum-separating tube can be used which contains an inert catalyst (such as glass beads or powder) to facilitate clotting as well as a portion of gel with a density designed to sit between the liquid and cellular layers in the tube after centrifugation, making separation more convenient.
Barring the use of the inert catalyst and the centrifugation, if the blood cells and the blood serum were to be allowed to separate naturally, it would take at least 20 minutes and above to occur. As such, if blood that were found on evidence taken from the crime scene were confirmed forensically to have the blood cells to be separated from the blood serum, then it would be extremely likely that the blood were actually planted onto the evidence after the crime was committed rather than transferred onto the evidence during the occurance of the crime.
On a separate note, it is interesting to note that the approximate distribution of blood types in the United States of America population is as follows. The distribution may be differ for specific racial and ethnic groups.
O Rh-positive: 38 percent
O Rh-negative: 7 percent
A Rh-positive: 34 percent
A Rh-negative: 6 percent
B Rh-positive: 9 percent
B Rh-negative: 2 percent
AB Rh-positive: 3 percent
AB Rh-negative: 1 percent
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