If Your are looking for the best onlinegames to play then AceOnlineGames.com is the right site. You can play for free, and you dont have to spend any money, except for an internet connection. All popular, and rated games are collected in this site just for you. You can find thousands of games for free. It is one of the best site that gives you more than thousands of online games.

AceOnlineGames.Com gives you more games than you can ever imagine.If you feel bore then visit AceOnlineGames. All you need to do is click on the game and your gaming starts!!

It's been a long time since I have posted or reviewed a site over here so today I would like to present to you all with a funny videos website. The website is called FunnyVideos.Com and it provides some of the best funny videos for you.

If you are bored, or if you have got nothing to do then this website is the right one for you as there seems to be an unlimited amount of funny videos on the website. I watched a few funny videos and they were totally hilarious and they made me laugh a lot. So if you are bored the go to the site funnyvideos2.com and watch online funny videos.

Well today I will provide you an awesome Arcade Games website which you all will definitely love. The site is called www.arcadegames365.com and if you login to the site you will be playing arcade games 365 days a year.

According to wikipedia, "An arcade game is a coin-operated entertainment machine, typically installed in businesses such as restaurants, pubs, video arcades, and Family Entertainment Centers. Most arcade games are redemption games, merchandisers, video games or pinball machines."

The site seems new and fresh with around 100 arcade games added currently. Remember the site focuses only on arcade games. So expect only those games which you used to play as a kid in video game parlors. But all those game are now made in flash and you do not need a coin or pay for one to play the game as they are available for free online.

Today I will review a great looking arcade website called playablefreeonlinegames.com and it's a Free playable online games website. It is a gaming website with an awesome dark template and the gaming site tries to differ from all the other by providing a big preview for all the games.

Apart from the attractive site, the website also has got the best free games available. Currently there are only a few hundreds of games in the site but they are the best ones int the gaming industry. So, when you visit this site be ready to play only awesome flash games.

Today I have another Free games website to share with everyone. The site GamesNepal.Com, just like those which I have reviewed over the past few weeks is a free online flash games website and has a collection of good amount of games.

The site has a clean and light layout so it will not be a pain in the eye for the gamers visiting this site. The site also has only a considerable amount of ads so while playing the games, visitors will not be disturbed. The top 20 games which are the most played games by the visitors of the site are displayed and the newest 20 games are also shown on the left blocks of the site. This site seems to allow an unlimited number of plays but you can register in order to be able to play as a registered user and count the number of games you have played in the site.

Currently the site was more than 1K flash games and more than 700k game plays. There are already 250+ gamers who have joined the site. So the sites stats look pretty amazing and I suggest everyone interested in flash gaming to try out www.GamesNepal.com

We all remember mario as a cute little gaming character who jumps on enemies, eats mushrooms, jumps around, fights dragons so that he can save the princess. We all have played those mario games at least once in our lifetime or atleast we have heard about mario. I believe that there are very few people in the world who does not recognize mario.

These days we can find many free mario games online on the web. The games are a remake of the classic mario games and those games remind us of the original mario games created by nintendo. The games are usually created in flash and have the same sprites of mario created by nintendo(used without the permission of nintendo :P) and also use the same music of the original mario.

Whatever or however the remakes are created I would like to say that they are still fun to play and remind us gamers of our childhood days when we first got to play mario and how we got addicted it and mastered it as well. So be reminded of your childhood memories and play some online mario games.

Fission weapons discussed above are ultimately limited in their destructive capability by the sheer size a subcritical mass can assume -- and be imploded quickly enough by high explosives to form a supercritical assembly. The largest known pure fission weapon tested had a 500 kiloton yield. This is some thirty-eight times the release which destroyed Hiroshima in 1945. Not satisfied that this was powerful enough, designers developed thermonuclear (fusion) weapons.

Fusion exploits the energy released in the fusing of two atoms to form a new element; e.g. deuterium atoms fusing to form helium, ²H + ²H = ⁴He₂ , as occurs on the sun. For atoms to fuse, very high temperatures and pressures are required. Only fusion of the lightest element, hydrogen, has proven practical. And only the heavy isotopes of hydrogen, ²H (deuterium) and ³H (tritium), have a low enough threshold for fusion to have been used in weapons successfully thus far.

The first method tried (boosting) involved simply placing ³H in a void within the center of a fission weapon, where tremendous temperatures and high pressures were attendant to the fission explosion. This worked; contributing energy to the overall explosion, and boosting the efficiency of the Pu fissioning as well (fusion reactions also release neutrons, but with much higher energy).

Because ³H is a gas at room temperature, it can be easily 'bled' into the central cavity from a storage bottle prior to an explosion, and impact the final yield of the device. This is still used today, and allows for what is termed 'dial-a-yield' capability on many stockpiled weapons.

Multistage thermonuclear weapons -- the main component of today's strategic nuclear forces -- are more complex. These employ a 'primary' fission weapon to serve merely as a trigger. As mentioned above, the fission weapon is characterized by a tremendous energy release in a small space over a short period of time. As a result, a very large fraction of the initial energy release is in the form of thermal X-rays.

These X-rays are channeled to a 'secondary' fusion package. The X-rays travel into a cavity within a cylindrical radiation container.

The radiation pressure from these X-rays either directly, or through an intermediate material often cited as a polystyrene foam, ablates a cylindrical enclosure containing thermonuclear fuel (shown in blue at left); this can be Li²H (lithium deuteride).

Running along the central axis of this fuel is a rod of fissile material, termed a 'sparkplug'.

The contracting fuel package becomes denser, the sparkplug begins to fission, neutrons from this transmute the Li²H into ³H that can readily fuse with ²H (the fusion reaction ³H + ²H has a very high cross-section, or probability, in typical secondary designs), heat increases greatly, and fusion continues through the fuel mass.

A final 'tertiary' stage can be added to this in the form of an exterior blanket of ²³⁸U, wrapping the outer surface of the radiation case or the fuel package. ²³⁸U is not fissionable by the slower neutrons which dominate the fission weapon environment, but fusion releases copious high energy neutrons and this can fast fission the ordinary uranium.

This is a cheap (and radiologically very dirty) way to greatly increase yield. The largest weapon ever detonated -- the Soviet Union's 'super bomb', was some 60 MT in yield, and would have been nearer 100MT had this technique been used in its tertiary. Again, to control the yield precisely, ³H may be bled from a separate tank into the core of the primary, as shown in the hypothetical diagram on the left of a modern thermonuclear weapon.

This primary/secondary/tertiary or multistage arrangement can be increased -- unlike the fission weapon -- to provide insane governments with any arbitrarily large yield.

Fusion, or thermonuclear weapons, are not simple to design nor are they likely targets of construction for would-be terrorists today.

Many aspects of the relevant radiation transport, X-ray opacities, and ultra-high T and D equations-of-state (EOS) for relevant materials are still classified to this day (though increasing dissemination of weapons-adaptable information from the inertially-confined fusion (ICF) area may change this in time). Keeping such information classified makes good sense.

Source: Simpelthiniking.com

Nuclear weapons exploit two principle physical, or more specifically nuclear, properties of certain substances: fission and fusion.

Fission is possible in a number of heavy elements, but in weapons it is principally confined to what is termed slow neutron fission in just two particular isotopes: ²³⁵U and ²³⁹Pu. These are termed fissile, and are the source of energy in atomic weapons. An explosive chain reaction can be started with relatively slight energy input (so-called slow neutrons) in such material.

Isotopes are 'varieties' of an element which differ only in their number of neutrons. For example, hydrogen exists as ¹H ²H and ³H -- different isotopes of the same chemical element, with no, one, and two neutrons respectively. All the chemical properties, and most of the physical properties, are the same between isotopes. Nuclear properties may differ significantly, however.

The fission, or 'splitting' of an atom, releases a very large amount of energy per unit volume -- but a single atom is very small indeed. The key to an uncontrolled or explosive release of this energy in a mass of fissile material large enough to constitute a weapon is the establishment of a chain reaction with a short time period and high growth rate. This is surprisingly easy to do.

Fission of ²³⁵U (uranium) or ²³⁹Pu (plutonium) starts in most weapons with an incident source of neutrons. These strike atoms of the fissile material, which (in most cases) fissions, and each atom in so doing releases, on average, somewhat more than 2 neutrons. These then strike other atoms in the mass of material, and so on.

If the mass is too small, or has too large a surface area, too many neutrons escape and a chain reaction is not possible; such a mass is termed subcritical. If the neutrons generated exactly equal the number consumed in subsequent fissions, the mass is said to be critical. If the mass is in excess of this, it is termed supercritical.

Fission (atomic) weapons are simply based on assembling a supercritical mass of fissile material quickly enough to counter disassembly forces.

The majority of the energy release is nearly instantaneous, the mean time from neutron release to fission can be of the order of 10 nanoseconds, and the chain reaction builds exponentially. The result is that greater than 99% of the very considerable energy released in an atomic explosion is generated in the last few (typically 4-5) generations of fission -- less than a tenth of a millisecond.

This tremendous energy release in a small space over fantastically short periods of time creates some unusual phenomena -- physical conditions that have no equal on earth, no matter how much TNT is stacked up.

Plutonium (²³⁹Pu) is the principal fissile material used in today's nuclear weapons. The actual amount of this fissile material required for a nuclear weapon is shockingly small.

In the Fat Man (Nagasaki) weapon design an excess of Pu was provided. Most of the remaining bulk of the weapon was comprised of two concentric shells of high explosives. Each of these was carefully fashioned from two types of explosives with differing burn rates. These, when detonated symmetrically on the outermost layer, caused an implosion or inward-moving explosion.

The two explosive types were shaped to create a roughly spherical convergent shockwave which, when it reached the Pu 'pit' in the center of the device, caused it to collapse.

The Pu pit became denser, underwent a phase change, and became supercritical.

A small neutron source, the initiator, placed in the very center of this Pu pit, provided an initial burst of neutrons -- final generations of which, less than a microsecond later, saw the destruction of an entire city and more than 30,000 people..

Nearly all the design information for weapons such as these is now in the public domain; in fact, considering the fact that fission weapons exploit such a simple and fundamental physical (nuclear) property, it is no surprise that this is so. It is more surprising that so much stayed secret for so long, at least from the general public.

A neutron reflector, often made of beryllium, is placed outside the central pit to reflect neutrons back into the pit. A tamper, often made of depleted uranium or ²³⁸U helps control premature disassembly. Modern fission devices use a technique called 'boosting' , to control and enhance the yield of the device.

Today's nuclear threat lies mostly in preventing this fissile special nuclear material (often referred to as SNM) from falling into the wrong hands: once there, it is a very short step to construct a working weapon.

source : simplethinking

Eating less salt can reduce the risk of cardiovascular disease by 25% and cut the risk of death from all causes by a fifth, according to a new study.

The 15-year study of 2400 people demonstrates for the first time that cutting back on salt can reduce the risk of diseases such as stroke and heart attack, in addition to lowering blood pressure.

Volunteers in the study who were assigned to a low-salt regime had a 20% lower risk of death from all causes over the course of the study than their control counterparts. The findings should compel governments to take more action to reduce the salt content of processed foods, says Nancy Cook at the Brigham and Women's Hospital in Boston, Massachusetts, US, who led the study.

Numerous studies have documented how consuming foods high in salt can lead to high blood pressure. This happens because the salt draws more water into the blood, and the increase in fluid volume exerts more pressure on vessel walls. High blood pressure is known to contribute to heart disease, but few studies have shown a direct link between salty foods and the condition.

Salt snapshot

In the late-1980s and early-1990s Cook and colleagues collected urine samples from more than 3000 people with above-normal blood pressure. Analysing the urine samples collected over the course of a 24-hour-period gave the researchers a snapshot of the subjects' salt intake. On average, they were consuming 10 grams of salt per day.

Cook's team then randomly assigned half of these participants to attend weekly workshops that taught how to cook low-salt meals and read nutrition labels on packaged foods.

After approximately three months of this nutrition counselling, urine sampling revealed that the subjects reduced their daily salt intake by about 3 grams per day on average – the equivalent of about half a teaspoon.

Fifteen years later Cook's team was able to obtain follow-up health information about 2415 of the participants from medical records and telephone interviews.

Healthy choices

Phone interviews indicated that those who had received training on how to reduce their salt intake many years ago continued to consume less of it than their control counterparts. For example, 47% of those who received this intervention said they looked for reduced-salt foods in the supermarket, compared with 29% of the control group.

Of the 200 people who had developed cardiovascular disease – including heart attacks and stroke – in the past 15 years, 112 had received no dietary recommendations and 88 were in the group taught to reduce their salt intake.

After controlling for factors such as weight and age, the researchers calculated that reducing one's salt intake by 30% could decrease the risk of cardiovascular disease by 25%.

Cook says that the results of the study should encourage governments to "work with the food industry to come up with lower sodium foods", and notes that salt content is highest in processed and fast-foods. "People generally consume much more salt than what is biologically needed."

In 2006, the American Medical Association urged the US Food and Drug Administration to revoke the "generally recognised as safe" (GRAS) status of salt and to adopt stricter salt guidelines.

Current US dietary guidelines recommend that people consume less than one teaspoon of salt per day.

Journal reference: BMJ (DOI: 10.1136/bmj.39147.604896.55)

High temperatures can make an Australian lizard that is genetically male develop into a female. The finding throws new light on how sex is determined in reptiles.

For most reptiles, a gene on a sex chromosome triggers an embryo to develop as either a male or a female. In some species, males have an X and a Y chromosome, while females are XX, as in mammals. In other species of lizards, males are ZZ while females are ZW, as in birds.

But for a third group of reptiles, which includes all crocodiles, alligators and marine turtles, temperature, rather than a gene on a sex chromosome, triggers either male or female differentiation. Extreme low or high temperatures generally lead to more females.

Now a team led by Alex Quinn at Canberra University in Australia has found that the central bearded dragon (Pogona vitticeps) is susceptible to both types of sex trigger, and that temperature can override its genetic gender.

Transitional form

When the team incubated eggs at relatively high temperatures – between 34°C and 37°C – the majority of embryos that had ZZ sex chromosomes (genetically male), hatched as females. The team thinks the bearded dragon represents a transitional form, in evolutionary terms, between the two main methods of sexual determination.

The research shows that, for the bearded dragon at least, the W chromosome is not necessary in producing a female. The team suspects that a double dose of a particular gene on the Z chromosome is instead crucial for maleness, and that this gene is inactivated by high temperatures.

“The possibility that there is a male-determining, dosage-dependent gene on the Z chromosome of bearded dragons is an important insight,” says Quinn, “because to date, scientists have discovered the master sex-determining gene only in mammals and a single species of fish.”

The team plans to hunt for that master gene in the bearded dragon. They also want to investigate how widespread the phenomenon of temperature sex reversal really is in reptiles.

If many other reptiles with sex chromosomes are also susceptible to temperature, this would broaden the number of species that could be vulnerable to climate change.

“The concern is that the current rate of climate warming could be too rapid for these species to adapt to, and this could potentially result in heavily skewed sex ratios, and even population crashes in some cases,” Quinn says.

Journal reference: Science (vol 316, p 411)

Regular aspirin use may protect more than just your heart - it could also reduce your risk of getting cancer.

Aditya Bardia and colleagues at the Mayo Clinic College of Medicine in Rochester, Minnesota, analysed the cancer history of more than 22,000 post-menopausal women over 12 years. Those who reported taking aspirin regularly at the start of the study were 16 per cent less likely to develop cancer and 13 per cent less likely to die from it during that time. The only lifestyle factor that influenced the results was smoking, which reduced the protective effect slightly.

Bardia says aspirin's anti-inflammatory action is probably responsible, although a similar effect
was not seen with other anti-inflammatories, such as ibuprofen. The findings were presented at a meeting of the American Association for Cancer Research in Los Angeles this week.