内容摘要：For their conclusions to be considered bulletproof, they need to get to what is known as the five-sigma threshold – 99.99994 percent certainty.

For their conclusions to be considered bulletproof, they need to get to what is known as the five-sigma threshold – 99.99994 percent certainty.

Centuries-old manuscripts in Oualata libraries face destruction as desert sands encroach on the ancient Mauritanian town.Oualata forms part of a quartet of fortified towns, or ksour, granted World Heritage status for their historical significance as trading and religious centres. Today, they preserve vestiges of a rich medieval past.

Throughout Oualata, doors fashioned from acacia wood, adorned with traditional designs painted by local women, punctuate the earthen facades. Family libraries safeguard centuries-old manuscripts, invaluable records of cultural and literary heritage passed down through generations.Yet, Oualata’s proximity to the Malian border leaves it acutely vulnerable to the unforgiving environment of the Sahara. Scorching heat and seasonal downpours have left piles of stone and gaping holes in the town’s historical walls, the aftermath of especially severe recent rains.“Many houses have collapsed because of the rains,” said Khady, standing beside her crumbling childhood home, now her inheritance from her grandparents.

Depopulation has only accelerated Oualata’s decline.“The houses became ruins because their owners left them,” explained Sidiya, who is a member of a national foundation dedicated to preserving the country’s ancient towns.

For generations, Oualata’s population has steadily dwindled as residents depart in search of work, leaving the historical buildings neglected. The traditional structures, coated in reddish mud-brick known as banco, were crafted to withstand the desert climate, but require maintenance after each rainy season.

Much of the Old Town now stands abandoned, with only about one-third of its buildings inhabited.“There are those who left and actively try to prevent parallel imports,” Burmistrov told Al Jazeera.

Burmistrov said he is aware of Western companies that have threatened to blacklist Russian partners over their use of parallel imports, although he declined to name any firms.“Then, there are those who turn a blind eye to the issue. Finally, there are those who continue actively trading with Russia through intermediaries, effectively facilitating parallel imports themselves”.

While boycotting Russia was a voluntary decision for most companies, producers of so-called luxury goods have additional legal perils to consider under US and European sanctions.Luxury goods are defined broadly, including cars with a market value of more than 50,000 euros, home appliance hairdryers, washing machines and refrigerators worth more than $750, and smartphones worth more than $300, among other items.