Scientists have long known that exercise can help stave off cognitive decline. Over the past decade evidence has mounted suggesting that this benefit is even greater for those at higher genetic risk for Alzheimer's. For example, two studies by a team in Finland and Sweden found that exercising at least twice a week in midlife lowers one's chance of getting dementia more than 20 years later, and this protective effect is stronger in people with the APOE e4 gene. Several others reported that frequent exercise—at least three times a week in some studies; up to more than an hour a day in others—can slow cognitive decline only in those carrying the high-risk gene. Furthermore, for those who carry the gene, being sedentary is associated with increased brain accumulation of the toxic protein beta-amyloid, a hallmark of Alzheimer's.
More recent studies, including a 2012 paper published in Alzheimer's & Dementia and a 2011 paper in NeuroImage, found that high-risk individuals who exercise have greater brain activity and glucose uptake during a memory task compared with their less active counterparts or with those at low genetic risk.
This link to metabolism may help explain why exercise protects APOE e4 carriers. According to a theory proposed in May by anthropologist David Raichlen and psychologist Gene Alexander, both at the University of Arizona, the answer lies in our evolutionary past. Two million years ago, when our ancestors were much more physically active—for example, perhaps running long distances to hunt prey—only the high-risk gene variant existed, they argue. The gene allowed for better metabolism during intense activity, and its downside, faster cognitive decline, was counteracted by our ancestors' active way of life. As humans adopted more sedentary habits, other variants of the gene appeared, and in modern times we are now seeing the negative effect of the high-risk gene more often than its benefit.
The world's largest catamaran - the Pieter Schelte - to be used in offshore oil work and pipelaying. $3 billion and a larger version is already being planned.
Length overall (incl. tilting lift beam and stinger): 477 m (1,565 ft)
Length overall (excl. tilting lift beam and stinger): 382 m (1,253 ft)
Length between perpendiculars: 370 m (1,214 ft)
Breadth: 124 m (407 ft)
Depth to main deck: 30 m (98 ft)
Slot length: 122 m (400 ft)
Slot width: 59 m (194 ft)
Topsides lift capacity: 48,000 t (105,820 kips)
Jacket lift capacity: 25,000 t (55,116 kips)
Stinger length (incl. transition frame): 210 m (690 ft)
Operating draught: 10-25 m (32-82 ft)
Maximum speed: 14 knots
Total installed power: 95,000 kW
Accommodation: 571 persons
Dynamic positioning system: LR DP (AAA), fully redundant Kongsberg K-Pos DP-22 and 2 x cJoy system
Deck cranes: 3 x Pipe transfer cranes of 50 t (110 kips) at 33 m (108 ft), 1 x Special purpose crane of
600 t (1,323 kips) at 20 m (66 ft)
Work stations: Double-joint factory with 5 line-up stations and 2 stations for combined external and internal welding; Main firing line with 6 welding stations for double joints, 1 NDT station and 6 coating stations
Potts first came up with the idea as a way to explore the impact of inbreeding. Those studies revealed harmful effects of cousin-level inbreeding that had gone unnoticed for decades of research on mouse genetics. Laboratory mice that are only slightly less healthy may not appear so when given ample food and living space. But if there is a defect in any physiological system, it is likely to stand out during intense competition.
"When they really have to compete directly, males are constantly testing each other and fighting over territories," Potts says. "If they don't win a territory, females won't consider them when it comes time to choose a mate."
In a study published last year, the performance assay revealed that doses of sugar that people regularly consume - and deemed safe by regulators - may in fact be toxic. When mice ate a diet of 25 percent extra sugar (the mouse equivalent of drinking three cans of soda daily) females died at twice the normal rate and males were a quarter less likely to hold territory and reproduce.
In the Paxil study, the researchers gave food laced with the antidepressant to 20 breeding pairs of mice for several weeks, until all had produced up to four litters. Doses were equivalent to about 1.8 times the level typically prescribed for people. The offspring also ate Paxil-laced chow until they reached breeding age. The researchers then released the exposed offspring into the competitive arena with the offspring of a control group of mice never exposed to Paxil. Groups consisted of eight males and 14 to 16 females, creating population densities comparable to those seen in the wild. The researchers started five such populations and kept them going for six months.
Males exposed to Paxil were about half as likely to control a territory. They also lagged behind control males in body weight throughout the weeks of competition and were more likely to die. Exposed males produced 44 percent fewer offspring. Exposed females showed no significant weight or mortality differences, but they produced half as many offspring as control females at the initial assessment. Their fecundity rebounded at later time points.
Annette Kim, a professor at the University of Southern California who researches urbanization, spent last year in China's capital city studying the underground housing market.
"Part of why there's so much underground space is because it's the official building code to continue to build bomb shelters and basements," Kim says. "That's a lot of new, underground space that's increasing in supply all the time. They're everywhere."
She says apartments go one to three stories below ground. Residents have communal bathrooms and shared kitchens. The tiny, windowless rooms have just enough space to fit a bed.
Pedestrians pass a high-rise building being constructed in Beijing
"It's tight," Kim says. "But I also lived in Beijing for a year, and the city, in general, is tight."
With an average rent of $70 per month, she says, this is an affordable option for city-dwellers.
But living underground is illegal, Kim says, since housing laws changed in 2010.
And, in addition, there's a stigma to living in basements and bomb shelters, as Kim found when she interviewed residents above ground about their neighbors directly below.
A candidate for the most beautiful wood framed bicycle - Ken Piper's road bike. Properly done wood framed bikes can have a wonderful ride and are durable. They're usually expensive and heavy. This one certainly would be expensive if ever sold, but it isn't impossibly heavy at under 10 kg.
The major of Paris recently announced an anti-pollution plan (use your favorite translator) that would move a lot of vehicular tracks from Paris by 2020 - with four districts becoming mostly pedestrian zones. She didn't provide many details and it still must be presented to the city council, but it is a dramatic move. Depending on the details and public will it may even be possible.