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wamiller24 — Tue, 18 Nov 2008 14:32:08 +0000

I have decide to research the country of Australia. I hope to learn about the way of life i would like to learn the way/method of those as students in Australia. here is wat i know:

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the mainland of the world’s smallest continent, the major island of Tasmania, and numerous other islands in the Indian and Pacific Oceans.N4 Neighboring countries include Indonesia, East Timor and Papua New Guinea to the north, the Solomon Islands, Vanuatu and New Caledonia to the north-east, and New Zealand to the south-east. Australia is the only country to occupy an entire continent.

Before European settlement in the late 1700s and early 1800s, the Australian mainland was inhabited by around 250 individual nations [7] of indigenous Australians who lived sustainably on the land for around 40,000 years.[8] After sporadic visits by fishermen from the immediate north and European discovery by Dutch explorers in 1606,[9] the eastern half of Australia was claimed by the British in 1770 and initially settled through penal transportation to the colony of New South Wales, commencing on 26 January 1788. As the population grew and new areas were explored, another five largely self-governing Crown Colonies were established during the 19th century.

On 1 January 1901, the six colonies became a federation, and the Commonwealth of Australia was formed. Since Federation, Australia has maintained a stable liberal democratic political system and remains a Commonwealth realm. The capital city is Canberra, located in the Australian Capital Territory (ACT). The population is just over 21.3 million, with approximately 60% of the population concentrated in and around the mainland state capitals of Sydney, Melbourne, Brisbane, Perth, and Adelaide.

Metallic Bonding

wamiller24 — Fri, 18 Jan 2008 14:33:40 +0000

Metallic bonding is the electrostatic attraction between delocalized electrons, called conduction electrons, and the metallic ions within metals. Because it involves the sharing of free electrons among a lattice of positively-charged metal ions, metallic bonding may be compared to that within molten salts. The metallic bond accounts for many physical characteristics of metals, such as strength, malleability, ductility, conduction of heat and electricity, and luster. Metallic bonds are non-polar, because in alloys there is little difference among the electro negativities of the atoms participating in the bonding interaction (and in pure elemental metals, none at all), and the electrons involved in the interaction are delocalized throughout the crystalline structure of the metal. Metal atoms contain few electrons in their valence shells relative to their periods or energy levels. Such electrons can stray easily from the atoms and become delocalized, forming a sea of electrons permeating a giant lattice of positive ions. The freedom of conduction electrons to migrate gives metal atoms, or layers of them, the capacity to slide past each other, giving rise to metals’ typical characteristic phenomena of malleability and ductility. The electrons and positive ions in metals have a strong attractive force between them. Much energy is required to overcome it. Therefore, metals often have high melting and boiling points. The principle is similar to that of ionic bonds. Because metals’ conduction electrons move independently in a sea of negative charge, metals exhibit electrical conductivity, allowing charge to pass quickly through them, manifested as current. A few non-metals conduct electricity, notably graphite (which, like metals, has free electrons) and molten and aqueous ionic compounds, which have free ions. Heat conduction works on the same principle; free electrons can transfer energy at a faster rate than the fixed electrons of other substances, such as those which are covalently bonded.

‘Death Star’ Black Hole Fires At Neighboring Galaxy

wamiller24 — Wed, 19 Dec 2007 15:30:54 +0000

Each wavelength shows a different aspect of this system, known as 3C321. The Chandra X-ray image provides evidence that each galaxy contains a rapidly growing supermassive black hole at its center. The glow from the stars in each galaxy can be detected from Hubble’s optical light images (not shown). A bright spot in the VLA and MERLIN radio image shows where the jet has struck the side of the galaxy – about 20,000 light years from the main galaxy – dissipating some of its energy. An even larger “hotspot” of radio emission detected by VLA reveals that the jet terminates much farther away from the galaxy, at a distance of about 850,000 light years away. Large quantities of warm and hot gas could be detected in the vicinity of the galaxies, indicating the supermassive black holes in both galaxies have had a violent past. Faint emission from Chandra, Hubble and Spitzer, not shown in this image, indicate that the galaxies are orbiting in a clockwise direction, implying that the companion galaxy is swinging into the path of the jet.Since the Chandra data shows that particle acceleration is still occurring in this hotspot, the jet must have struck the companion galaxy relatively recently, less than about a million years ago (i.e. less than the light travel time to the hotspot). This relatively short cosmic time frame makes this event a very rare phenomenon. This “death star galaxy” will produce large amounts of high-energy radiation, which may cause severe damage to the atmospheres of any planets in the companion galaxy that lie in the path of the jet.

Ancient Fish Bones Reveal Impacts Of Global Warming Beneath The Sea

wamiller24 — Wed, 19 Dec 2007 15:29:17 +0000

Through the study of archaeological material, tax accounts, church registers and account books of monasteries, an international group of fisheries ecologists and fisheries/maritime historians have drawn a picture of marine life in the northern European seas (North Sea, Wadden Sea, Baltic Sea, and White Sea) as it looked in the past.New historical documentation is increasingly becoming available. Its interpretation is providing a broader basis for understanding processes and mechanisms that lead to variations in marine populations and ecosystems. The studies in this special issue are important contributions to the establishment of new baselines for management of marine ecosystems including conservation strategies for overexploited living resources. They were conducted under the auspices (or as part of) the History of Marine Animal Populations, a project of the international collaboration, the Census of Marine Life. 108,000 fish bones from 7000 BC predict the futureGlobal and regional climate models predict that air and sea temperatures will rise by approximately 3°C during the next 70–100 years. In order to understand some of the processes by which global warming might affect marine fish species near Denmark, researchers have investigated the fish fauna during one of the warmest prehistoric periods (the warm Atlantic period: ca. 7000–3900 BC). A total of 108,000 fish bones were identified, and amongst them were bones of many species, for example, anchovy and black sea bream, which we usually consider to be typical of waters much farther south and warmer like the Bay of Biscay and the Mediterranean Sea. When temperatures cooled after the warm period ended, most of these species disappeared from the archaeological record, suggesting that local abundances declined. However, many of those same warm-water species have recently reappeared in waters around Denmark as temperatures have risen in the last 10–15 years. The archaeological information can be an indicator of which species may become common as climate change progresses and warms.There were also thousands of cod bones present together with the warm-water species. That result was surprising because investigators knew that the increase in sea temperatures since the late 1980s to the early 1990s has reduced the survival of young cod in the North Sea. How can these two findings be reconciled? The researchers believe that the difference is due to the much lower fishing pressure in the archaeological period. The message from their work is that sustainable cod populations can be maintained in the North Sea even during the climate change expected in the 21st century, but the fish mortality needs to be lowered.The climate influence the Gulf of Riga fisheries in during the 17th centuryThe exploited fish population in the Gulf of Riga was very different in the beginning of the 17th century from what is seen today. Archival evidence reveal that the timing of the fishing season, and species composition and, to an extent, the amounts of fish catches in the Gulf of Riga are strongly linked to climate dynamics.The time-period 1675-1696 belongs to the coldest period of the Little Ice Age. During that time, fishing in the Gulf of Riga took place at more than 20 localities along the whole coast of the basin and was therefore an important livelihood at these times. Herring, flounder and eelpout (considered to be cold-tolerant species) formed the majority of the catch while the importance of species such as perch, pikeperch and various cyprinids, which prefer warm-water and are nowadays relatively widespread, was less than 1% of the catches. Herring were in the coastal areas from the end of March to November. The highest catch was in today’s terms taken during the warm season – June and July. This should be considered as a direct effect of severe winters, due to which the ice-cover melted relatively late and therefore, massive herring migration to spawning areas near the coast was shifted later in the season. During the period studied, two sub-periods were identified: 1675-1683 and 1685-1696. Winters were more severe during the second period, and as a result, herring fishing seasons started later due to a shift in the timing of herring spawning in the summer months. As a result, the window where fish were available for fisheries was a shorter period of time. This led to substantially lower herring catches, and this is direct evidence of a climatic impact.Why did the fishery collapse in the Limfjord in 1830?The Limfjord in northern Denmark is a shallow sound which has supported commercial fisheries for centuries. In the beginning of the 19th century, the fishery declined by 90%, and fishermen went bankrupt when all the fish disappeared. What happened to all the fish?By reconstruction of historical data series for herring, eel and whitefish the question has now been answered. We now know that both nature and humans played a significant role in the collapse. In 1825 a winter storm broke the narrow Agger Tange isthmus, which used to separate the Limfjord from the North Sea. That led to an increase of salinity in the western part of the Limfjord. The eel population declined due to the salt water intrusion, and resulted in a 15-year long crisis for the eel fisheries before it had fully recovered. The whitefish did not survive the salinity obstacle and has never returned to the area. The commercially most important fishery was for herring. The collapse of the herring fishery was most likely due to unsustainable fishing practices, such as fishing on top of spawning areas, eventually destroying the production rate of new young herring. Today the herring have returned to the area, but not nearly in the same numbers as they were in the early 19th century.The study of the Limfjord fisheries provides an example of how historical ecology may help ‘shift the baseline’ by revealing the previous existence of a marine ecosystem very different from that which is known from contemporary ecological research.These findings are presented in a special issue of Fisheries Research “History of Marine Animal Populations and their Exploitation in Northern Europe,” 14 papers starting from ca. 7000 BC to present. The volume is edited by Henn Ojaveer and Brian R. MacKenzie.Reference: Fisheries Research “History of Marine Animal Populations and their Exploitation in Northern Europe Volume 87, Issues 2-3, Pages 101-262 (November 2007)

Wild Chimpanzees Appear Not To Regularly Experience Menopause

wamiller24 — Wed, 19 Dec 2007 15:28:00 +0000

“We find no evidence that menopause is common among wild chimpanzee populations,” says lead author Melissa Emery Thompson, a postdoctoral researcher in anthropology at Harvard University. “While some female chimpanzees do technically outlive their fertility, it’s not at all uncommon for individuals in their 40s and 50s — quite elderly for wild chimpanzees — to remain reproductively active.”While wild chimpanzees and humans both experience fertility declines starting in the fourth decade of life, most other human organ systems can remain healthy and functional for many years longer, far outstripping the longevity of the reproductive system and giving many women several decades of post-reproductive life.By contrast, in chimpanzees reproductive declines occur in tandem with overall mortality. A chimpanzee’s life expectancy at birth is only 15 years, and just 7 percent of individuals live to age 40. But females who do reach such advanced ages tend to remain fertile to the end, Emery Thompson and her colleagues found, with 47 percent giving birth once after age 40, including 12 percent observed to give birth twice after age 40.“Fertility in chimpanzees declines at a similar pace to the decline in survival probability, whereas human reproduction nearly ceases at a time when mortality is still very low,” the researchers write in Current Biology. “This suggests that reproductive senescence in chimpanzees, unlike in humans, is consistent with the somatic aging process.”In other words, human evolution has resulted in an extended life span without complementary extended reproduction.“Why hasn’t reproduction kept pace with the general increase in human longevity? It may be because there hasn’t been anything for natural selection to act on, though there is heritable variation in age of menopause,” Emery Thompson says. “However, it may be that the advantage older females gain by assisting their grandchildren outstrips any advantage they might get by reproducing themselves.”The oldest known wild chimpanzee, who died earlier this year at approximately age 63, gave birth to her last offspring just eight years ago, at about 55. Female chimpanzees only give birth every 6 to 8 years, on average, and they generally begin reproducing at age 13 to 15. This makes the chimpanzee reproductive profile much longer and flatter than that of humans, whose procreation is concentrated from age 25 to 35.Emery Thompson and her colleagues gathered data from six wild chimpanzee populations in Tanzania, Uganda, Guinea, and Gambia. They compared these chimpanzees’ fertility patterns to those seen among two well-studied human foraging populations, in Botswana and Paraguay.This research was described recently in the journal Current Biology.Emery Thompson’s co-authors are Richard W. Wrangham of Harvard; James H. Jones of Stanford University; Anne E. Pusey and Jane Goodall of the Jane Goodall Institute; Stella Brewer-Marsden and David Marsden of the Chimpanzee Rehabilitation Trust; Tetsuro Matsuzawa, Toshisada Nishida, and Yukimaru Sugiyama of Kyoto University; and Vernon Reynolds of Oxford University. Their work was supported by numerous organizations, with primary funding coming from the National Science Foundation, MEXT Japan, the Jane Goodall Institute, and the Louis Leakey Foundation.

Engineering Blood Vessels That Could Be Used In Human Body

wamiller24 — Wed, 19 Dec 2007 15:26:41 +0000

The work focuses on vascular tissue, which includes capillaries, the tiniest blood vessels, and is an important part of the circulatory system. The team has created a surface that can serve as a template to grow capillary tubes aligned in a specific direction. The researchers built their template using microfabrication machinery at Draper Laboratory in Cambridge. Normally such technology is used to build micro-scale devices, but the researchers adapted it to create nano-scale patterns on a silicone elastomer substrate. The surface is patterned with ridges and grooves that guide the cells’ growth.“The cells can sense (the patterns), and they end up elongated in the direction of those grooves,” said Christopher Bettinger, MIT graduate student in materials science and engineering and lead author of the paper.The cells, known as endothelial progenitor cells (EPCs), not only elongate in the direction of the grooves, but also align themselves along the grooves. That results in a multicellular structure with defined edges, also called a band structure.Once the band structures form, the researchers apply a commonly used gel that induces cells to form three-dimensional tubes. Unlike cells grown on a flat surface, which form a network of capillary tubes extending in random directions, cells grown on the nano-patterned surface form capillaries aligned in the direction chosen by the researchers. The researchers believe the technique works best with EPCs because they are relatively immature cells. Earlier attempts with other types of cells, including mature epithelial cells, did not produce band structures. Growing tissue on a patterned surface allows researchers a much greater degree of control over the results than the classic tissue engineering technique of mixing cell types with different growth factors and hoping that a useful type of tissue is produced, said Bettinger.

Cells Discarded From Womb Lining During A Woman’s Period Are New Type Of Stem Cell

wamiller24 — Fri, 16 Nov 2007 14:49:10 +0000

Dr Xiaolong Meng of the Bio-Communications Research Institute in Wichita, Kansas, led the research team consisting of scientists from the University of Alberta, University of Western Ontario and Medistem Laboratories. The team identified a new type of stem cell that can be reproducibly isolated from menstrual blood collected from healthy female subjects.

“We have many problems with our current methods of stem cell therapy, like those taken from bone marrow,” commented Dr Meng, “They may be rejected by the recipient and/or have limited potential to generate new tissue. Now we’ve found a possible new way to overcome these difficulties by using cells from menstrual blood.”

The growth of new blood vessels from pre-existing blood vessels is an essential part of the uterine or womb phase of the menstrual cycle. Cells collected from the menstrual blood of women include types which can be cultured in the laboratory, which replicate almost 70 times in a very rapid time span. This replication rate is far faster than cells which are currently used, taken from umbilical cord blood and bone marrow.

The cells are so unique in their ability to develop into at least 9 different cells including heart, liver and lung, that researchers called the cells Endometrial Regenerative Cells (ERC). Not only do ERC replicate at a phenomenal rate of almost every 20 hours, but they produce unique growth factors at a rate of almost 100,000 greater than cells from umbilical cord blood.

A mere 5ml of menstrual blood collected from a healthy woman provided enough cells which after two weeks of culture provided beating heart cells. The results of this breakthrough research indicate that these cells could be cultured at a large scale, thereby providing an alternative to the current methods of using bone marrow and umbilical cord blood, which itself poses threats of rejection.

Life Without the Atom Bomb!!!!

wamiller24 — Fri, 16 Nov 2007 13:24:40 +0000

How well can you speak an Asian language or German? With out the mighty atomic bomb which helped to end WWII. After the use of the atom bomb on Hiroshima, the atom bomb as been a great intimidation weapon. Like a strong secret weapon that everyone fears, only everyone knows about it. Without the Manhattan project; America could have lost WWII, thus falling under the control of nations such as Japan or Germany. Without the atom bomb other nations would have the courage to challenge the Super Power Nations causing massive chaos and more World Wars. Just imagine what would have come of the Cold War without the threat of the ATOMIC BOMB!!!!

wamiller24 — Fri, 09 Nov 2007 14:46:11 +0000

In 2004, the remains of ancient, Hobbit-like people were found on the island of Flores in Indonesia. The discovery was made by Australian archaeologists who claimed that these people represented a new branch in the human family tree and called them Homo floresiensis. Some hailed this as the most significant fossil discovery in a century, but a few scientists disagreed – claiming that they weren’t a new species but merely modern humans with microencephaly, a congenital disorder that stunts brain growth.Recently, a team of researchers from Australian National University lead by Adam Brumm published a paper in Nature supporting the view that the Hobbit is a new species. They have linked flint tools found on the island to the Hobbit species, showing that they were not humans with a brain disease but people with a unique culture and the ability to make tools despite their small brain.This skill may have been passed down to the Hobbit from its ancestors. Homo floresiensis (who existed 70,000 to 12,000 years ago) appears to be the descendant of an unknown species that became isolated in Flores over 800,000 years ago and made stone tools. The large number of flints found directly associated with the hobbit are the same as those found at the 850,000 year old Mata Menge site in central Flores where their ancestors lived. “This suggests that hominids on Flores were making the same kinds of tools on the island for hundreds of thousands of years,” Brumm says.But there is some debate as to whether the tools are really the work of the Hobbit. Some scientists claim that the Hobbit and modern humans (Homo sapiens) could have co-existed on the island for over 30,000 years – and hence that the tools could have been crafted by our own species.

Florida Red Tides Linked To Mississippi River Nutrient Outflow

wamiller24 — Fri, 09 Nov 2007 14:45:14 +0000

According to the model, algal blooms form on the Florida coast because of weather and gulf currents. The algae grows offshore, supplied with additional nutrients that appear to have originated from the Mississippi River, in a process driven by normal seasonal wind patterns.

“We found that the concentrations of nutrients needed to start the Florida red tides is much lower than previously suspected,” said NOAA oceanographer and lead author of the paper, Richard Stumpf, Ph.D. “The hypothesis means that offshore areas should be examined for both small increases in nutrients and modest concentrations of the algae at the start of the bloom season.”

Harmful algal blooms occur in the waters of almost every U.S. coastal state, caused by numerous different species. Their direct economic effects in the United States are estimated to average $75 million annually, including public health costs, commercial fishing closures, recreation and tourism losses, and in management and monitoring costs.

While outflow from the Mississippi River travels westward most of the year, early summer prevailing winds carry it eastward, bringing nutrients, especially nitrogen, toward Florida. The nutrients then settle into deeper water, where they are taken up by the algae. The blooms, of the red tide species Karenia brevis, start on the shelf, and are brought onshore and concentrated by the prevailing wind patterns of late summer and fall. The study has implications for predictions and for monitoring of these blooms, including potential variations in intensity between years and regions. It also finds that even relatively small increases in nitrogen can account for the initiation of the blooms offshore.

NOAA, working in partnership with scientists at Mote Marine Laboratory in Sarasota, Fla., is already beginning to test the hypothesis through the use of autonomous underwater vehicles carrying instruments called “BreveBusters.” The vehicles are checking for the presence of Karenia brevis blooms further off the coast in deeper Gulf of Mexico waters.

The new hypothesis links results from several extensive research programs conducted in the Gulf of Mexico over the last decade including the NOAA-funded Florida Ecology and Oceanography of Harmful Algal Bloom program. Understanding initiation of red tide should lead to improved monitoring, modeling, and research strategies for these blooms.

Since 2004, NOAA has been providing operational forecasts of harmful algal bloom impacts in the eastern Gulf of Mexico. The new results offer the potential of providing better forecasts of when the blooms start, allowing for more effective monitoring.