Chinese scientists have developed a hypothesis that poisonous gas from the deep ocean may have driven one of the severest mass extinctions on the planet.

Sulfureted hydrogen in the depths of the sea may have contributed to the end-Permian extinction that wiped out more than 80 percent of marine life about 250 million years ago, according to the University of Science and Technology of China.

Scientists have posited many hypotheses explaining the mass extinction, including a possible celestial impact and volcano activity.

Through the study of samples of deep-sea sediment, the Chinese team believe they have found evidence indicating the presence of rich sulfureted hydrogen, a poisonous gas, said Shen Yan’an, head of the research.

The interaction between the gas in the deep water with oxygen-rich water on the surface is a deadly mixture, Shen said.

“Today, sulfureted hydrogen exists in some waters in Gulf of Mexico, California and India”, said Shen, adding that the findings could also give insight into climate and environmental changes and inform policies.

The findings have been published in the Proceedings of the National Academy of Sciences of the United States of America.

Fifteen suspects have been arrested in east China’s Zhejiang Province for producing and selling fake and substandard cosmetics, Zhejiang Police said Wednesday.

Police in Taizhou City dismantled seven underground dens during a raid earlier this month and seized over 1,200 boxes of counterfeit cosmetic products and commodities labeled as high-end brands such as Chanel, Lancome, Dior and Estee Lauder.

The goods had a street value of over 827 million yuan (120 million U.S. dollars) at market prices.

A total of 15 suspects were detained, of which 13 have been charged by procurators.

The case surfaced in February last year after a complaint about an Amway-branded toothpaste bought online that was found to be fake.

Investigation into the online store shone a light on a chain that manufacture and distribute counterfeit top brand cosmetics in Henan, Heilongjiang, Guangdong and Zhejiang provinces.

Southwest China’s Yunnan Province has reported another death from the H7N9 strain of bird flu.

The female patient, 23, was mother of the three-year old infant girl who died of H7N9 earlier this month, according to the Health and Family Planning Commission of Yunnan Province Wednesday.

The family of three went to east China’s Jiangxi Province for the Spring Festival holiday on Jan. 21, and had contact with live poultry there.

The patient, who has only been identified by her surname Yang, developed symptoms on Feb. 4. She was hospitalized four days later as she had close contact with her daughter, who tested positive for H7N9 virus and died on Feb. 7.

Her condition deteriorated rapidly and she died in hospital Tuesday night.

Other people who had been in close contact have all tested negative for the virus so far.

H7N9 bird flu has been reported in several provinces in China so far this year, with 79 people died in January from the virus nationwide, according to the National Health and Family Planning Commission.

The live poultry trade has been suspended in cities across the provinces of Sichuan, Hunan and Zhejiang.

H7N9 is a bird flu strain first reported to have infected humans in China in March 2013. Infections usually occur in winter and spring.

China reported 79 fatalities from H7N9 avian flu in January, health authorities said Wednesday.

Since the beginning of the year, 16 provincial regions have reported human H7N9 avian flu cases, with 192 cases in January, according to the National Health and Family Planning Commission.

From Feb. 6 to 12, 69 such cases were reported across the country, including eight fatalities.

In China, most cases were around the Yangtze River Delta and Pearl River Delta areas, said Shu Yuelong, director of the Chinese National Influenza Center.

Contact with infected poultry and exposure to live poultry markets pose risks of infection, Shu said, adding that evidence rules out sustained human-to-human transmission of avian flu.

Health authorities are implementing a raft of measures to address the situation, including improving surveillance and risk assessment, more training for medical staff, and allocating medical resources more effectively.

China plans to accelerate the development of afloating nuclear power platform in the 13th Five-Year Plan (2016-2020) period, according to Wang Yiren, vice director of State Administration of Science, Technology and Industry for National Defense.

Wang told Science and Technology Daily that Chinese authorities have already included the building of a marine nuclear power station into the government’s 13th Five-Year Plan, in an effort to promote ocean oil and gas exploitation and other offshore projects.

Wang said that to become a strong maritime power, exploitation of ocean resources is very significant. However, as the main power source for China’s current offshore operation, diesel generators are both inefficient and harmful to the ocean environment; developing a maritime nuclear power station may solve such problems.

After a range of research and evidence, experts on atomic energy decided to modify the related building schemes based on proven technologies. Wang informed that the small reactors used on land would be applied at sea after necessary improvements have been made.

Currently, China has carried out standard research and begun to tackle key technical problems of building afloating nuclear power platform, including overall design, safety techniques, key equipment tests, and maintenance technology.

The country is doing its own research on the project, as well as seeking cooperation with Russia to hasten the process, Wang said.