Japan has executed three death row inmates convicted of murder - the country's first hangings in six months.
One killed two women; another used the internet to find victims considering suicide; the third was from China and killed three Chinese people.
The executions are the first under a new system that combines citizens and professional judges to together decide on serious criminal cases.
Japan's previous executions were carried out in January.
The latest convicts to be executed were Japanese nationals Hiroshi Maeue, 40, and Yukio Yamaji, 25, and 41-year-old Chinese national Chen Detong.
Maeue, executed in Osaka, killed three people in 2005 after he met them through an internet website for people planning to commit suicide.
Yamaji, also executed in Osaka, raped and then stabbed to death two sisters in 2005.
Chen was executed in Tokyo for killing three of his compatriots and injuring three more in Kawasaki, southwest of Tokyo, in 1999.
The death penalty receives widespread support in Japan, but the executions are regularly criticised by the European Union and anti-death penalty campaign groups.
The violence in Xinjiang has not occurred completely out of the blue.
Its root cause is ethnic tension between the Turkic Muslim Uighurs and the Han Chinese. It can be traced back for decades, and even to the conquest of what is now called Xinjiang by the Manchu Qing dynasty in the 18th Century.
In the 1940s there was an independent Eastern Turkestan Republic in part of Xinjiang, and many Uighurs feel that this is their birthright.
Instead, they became part of the People's Republic of China in 1949, and Xinjiang was declared one of China's autonomous regions, in deference to the fact that the majority of the population at the time was Uighur.
This autonomy is not genuine, and - although Xinjiang today has a Uighur governor - the person who wields real power is the regional secretary general of the Chinese Communist Party, Wang Lequan, who is a Han Chinese.
Inward migration
Under the rule of the Communist Party, there has been considerable economic development, but life has been made more difficult for the Uighurs over the past 20-30 years by the migration of many young and technically-qualified Han Chinese from the eastern provinces.
These new migrants are far more proficient in the Chinese language than all but a few Uighurs, and tend to be appointed to the best jobs.
Not surprisingly, this has created deep-seated resentment among the Uighurs, who view the migration of Han into Xinjiang as a plot by the government to dilute them, undermine their culture and prevent any serious resistance to Beijing's control.
More recently, young Uighurs have been encouraged to leave Xinjiang to find work in the rest of China, a process that had already been under way informally for some years.
There was particular concern at government pressure to encourage young Uighur women to move to other parts of China in search of employment - stoking fears they might end up working in bars or nightclubs or even in prostitution, without the protection of family or community.
Islam is an integral part of the life and the identity of the Uighurs of Xinjiang, and one of their major grievances against the Chinese government is the level of restriction imposed on their religious practices.
There are far fewer mosques in Xinjiang than there were before 1949, and they are subject to severe restrictions.
Children under the age of 18 are not permitted to worship in the mosques, and neither are officials of the Communist Party or the government.
Madrasas - religious schools - are also strictly controlled.
UIGHURS AND XINJIANG
Uighurs are ethnically Turkic Muslims
They make up about 45% of the region's population. 40% are Han Chinese
China re-established control in 1949 after crushing short-lived state of East Turkestan
Since then, large-scale immigration of Han Chinese
Uighurs fear erosion of traditional culture
Sporadic violence since 1991
Attack on 4 Aug 2008 near Kashgar kills 16 Chinese policemen
Other Islamic institutions that were once a central part of religious life in Xinjiang have been banned, including many of the Sufi brotherhoods, which are based at the tombs of their founders and provided many welfare and other services to their members.
All religions in China are subject to control by the State Administration for Religious Affairs, but the restrictions on Islam among the Uighurs are far harsher than against most other groups, including the Hui who are also Muslims but are Chinese speakers.
This severity is a result of the association between Muslim groups and the independence movement in Xinjiang, a movement that is absolute anathema to Beijing.
There are groups within Xinjiang that support the idea of independence, but they are not allowed to do so openly because "splitting the motherland" is viewed as treason.
During the 1990s - after the collapse of the Soviet Union and the emergence of independent Muslim states in Central Asia - there was an upsurge in open support for these "separatist" groups, culminating in huge demonstrations in the city of Ghulja in 1995 and 1997.
Beijing suppressed those demonstrations with considerable force, and activists were either forced out of Xinjiang into Central Asia and as far away as Pakistan or were obliged to go underground.
'Climate of fear'
Severe repression since the launch of a "Strike Hard" campaign in 1996 has included harsher controls on religious activity, restrictions on movement, the denial of passports and the detention of individuals suspected of support for separatists and members of their families.
This has created a climate of fear and a great deal of resentment towards the authorities and the Han Chinese.
It is surprising that this resentment has not erupted into public anger and demonstrations before now, but that is a measure of the tightness of control that Beijing has been able to exercise over Xinjiang.
There are a number of emigre Uighur organisations in Europe and the United States; in most cases they advocate genuine autonomy for the region.
In the past, Beijing has also blamed an Eastern Turkestan Islamic Movement for causing unrest, although there is no evidence that this ever existed in Xinjiang.
The authorities in Beijing are unable to accept that their own policies in Xinjiang might be the cause of the conflict, and seek to blame outsiders for inciting the violence - as they do in the case of the Dalai Lama and Tibet.
Even if Uighur emigre organisations wished to provoke unrest, it would be difficult for them to do so and there are, in any case, sufficient local reasons for unrest without the need for external intervention.
Michael Dillon is the former director of the Centre for Contemporary Chinese Studies at the University of Durham. He is also the author of a book entitled Xinjiang: China's Muslim Far Northwest.
The Chinese Gov prohibits the use of this flag - afraid of something?
Clearly Chinese, as you can see.
Q&A: China and the Uighurs
The latest unrest in China's western Xinjiang region follows a long history of discord between China's authorities and the Uighur minority.
Who are the Uighurs?
The Uighurs are Muslims. Their language is related to Turkish and they regard themselves as culturally and ethnically close to other Central Asian nations.
The region's economy has for centuries revolved around agriculture and trade, with towns such as Kashgar thriving as hubs along the Silk Road.
In the early part of the 20th Century, the Uighurs briefly declared independence. The region was brought under the complete control of communist China in 1949.
Officially, Xinjiang is now described by China as an autonomous region, like Tibet to its south.
What are China's concerns about the Uighurs?
Beijing says Uighur militants have been waging a violent campaign for an independent state by plotting bombings, sabotage and civic unrest.
Since the 9/11 attacks in the US, China has increasingly portrayed its Uighur separatists as auxiliaries of al-Qaeda.
It has accused them of receiving training and indoctrination from Islamist militants in neighbouring Afghanistan.
However, little public evidence has been produced in support of these claims.
More than 20 Uighurs were captured by the US military after its invasion of Afghanistan. Though imprisoned at Guantanamo Bay for six years, they were not charged with any offence. Albania accepted five in 2006, four were allowed to resettle in Bermuda in June, 2009, while the Pacific island nation of Palau has agreed to take the others.
What complaints have been made against the Chinese in Xinjiang?
Activists say the Uighurs' religious, commercial and cultural activities have been gradually curtailed by the Chinese state.
China is accused of intensifying its crackdown on the Uighurs after street protests in the 1990s - and again, in the run-up to the Beijing Olympics.
Over the past decade, many prominent Uighurs have been imprisoned or have sought asylum abroad after being accused of terrorism.
China is said to have exaggerated the threat from Uighur separatists in order to justify repression in the region.
Beijing has also been accused of seeking to dilute Uighur influence by arranging the mass immigration of Han Chinese, the country's majority ethnic group, to Xinjiang.
Han Chinese currently account for roughly 40% of Xinjiang's population, while about 45% are Uighurs.
What is the current situation in Xinjiang?
Over the past decade, major development projects have brought prosperity to Xinjiang's big cities.
The activities of local and foreign journalists in the region are closely monitored by the Chinese state and there are few independent sources of news from the region.
China has been keen to highlight improvements made to the region's economy while Uighurs interviewed by the press have avoided criticising Beijing.
However, occasional attacks on Chinese targets suggest Uighur separatism remains a potent - and potentially violent - force.
A protest in July in Urumqi, the region's capital, turned violent, with about 140 people killed and hundreds injured.
Authorities blamed Xinjiang separatists based outside China for the unrest, while Uighur exiles said police had fired indiscriminately on a peaceful protest calling for an investigation into the deaths of two Uighurs in clashes with Han Chinese at a factory in southern China.
In the mid-60s, a golden generation of highly trained whizz kids was pouring out of American universities with PhDs in maths, engineering and chemistry. "It was the generation that went on to drive the development of silicon valley in the 1970s," says Dave Parker, director of the British National Space Centre. "And those people made the moon landing happen."
Wernher von Braun, spirited from postwar Germany in Operation Paperclip, designed the mighty Saturn V rocket, as high as St Paul's Cathedral, which was to carry Nasa astronauts to the moon. "The Saturn V was 365ft tall and made from millions of separate parts, and every single time they pressed the go button it worked," Parker says. "Every single time."
Getting off Earth was difficult, but even tougher tasks lay ahead. Colin Pillinger, who led the doomed UK efforts to land the Beagle 2 probe on Mars in 2003, says: "For Kennedy to stand up and say they were going to the moon and then to put a time limit on it was foolhardy. They just didn't have the technology."
Nasa originally intended to send a giant rocket to the moon, where it would land and then return. Instead, it settled on a more complicated plan involving multistage spacecraft, mid-space docking manoeuvres and a heartstopping final descent in a clumsy lunar lander.
"Everything in it was a step further than they had been before, and they had to do them all one after the other," Pillinger says. "There were single points of failures everywhere you looked." A single point of failure is a critical step that will bring the whole system crashing down if something goes wrong. In space, one single point of failure is the difference between life and death.
Getting off Earth was only the beginning. Parker says: "Getting to the moon is twice as hard as getting into orbit, and landing on the moon is twice as hard as getting there. And coming home is twice as hard again." A speech for President Nixon in the event of failure was written before the astronauts even left Earth.
As the Apollo 11 astronauts headed for the moon, their course trajectory was crucial. The moon is a big target, but the rest of the universe is even bigger. Of the dozen or so robot probes sent to explore the moon by the US and the Soviet Union before Apollo 11 took off, enough had missed the moon for Nasa to be concerned. The course could be tracked and corrected mid-flight, but that needed precisely timed firing of the engines.
"That's why the guidance computers were developed, to make sure they got the timing just right," says Doug Millard, senior curator of space technology at the Science Museum in London. But the term "computer" only barely applies to Nasa's primitive processing technology. Pillinger says: "The only calculator available to scientists at the time was the size of a cash register. You put the levers in the right place and wound the handle." Forget Twitter. While Nasa was at the bleeding edge, the 60s was a time when chemists still relied on logarithm tables, and engineers carried slide rules.
Forty years on, Tim Stevenson, chief engineer at Leicester University's Space Research Centre, says the real achievement of Apollo was less tangible than the programme's whizz-bang technology: fuel cells, inertial guidance systems, freeze-dried food, fire retardants and cordless power tools.
"Apollo was the combination of technologies, none of which was particularly dramatic. Combining it was the achievement. This was a bunch of people who didn't know how to fail. Apollo was a triumph of management, not engineering."
