They base their findings on 800 Swedish women whose mental health and well-being was formally tracked over a period of almost 40 years as part of the larger Prospective Population Study of Women in Gothenburg, Sweden, which started in 1968.

The women, who were all born in 1914, 1918, 1922 and 1930, underwent a battery of neuropsychiatric tests and examinations in 1968, when they were in their late 30s, mid 40s, and 50s, and then again in 1974, 1980, 1992, 2000 and 2005.

At their initial assessment, the women were quizzed about the psychological impact on them of 18 common stressors, such as divorce, widowhood, serious illness or death of a child, mental illness or alcoholism in a close family member, personal or partner's unemployment, and poor social support.

How many symptoms of distress, such as irritability, fear, andsleep disturbances, and how often they had experienced these in the preceding five years, were noted at every assessment.

In 1968 one in four of the women had experienced at least one stressful event; a similar proportion (23%) had experienced at least two, while one in five had experienced at least three, and 16% four or more. The most commonly reported stressor was mental illness in a close family member.

During the monitoring period, 425 of the women died (at the average age of 79). Between 1968 and 2006, around one in five (19%, 153) developed dementia, 104 of whom developed Alzheimer's disease.

On average, it took 29 years for dementia to develop, with 78 the average age at which the condition was diagnosed.

The number of stressors reported by the women was associated with longstanding symptoms of distress at all of the time points assessed, irrespective of the year of birth.

And the number of stressors reported in 1968 was associated with a 21% heightened risk of developing Alzheimer's disease and a 15% heightened risk of developing any type of dementia, the analysis showed.

The findings held true even after taking account of factors likely to influence the results, including a family history of mental health problems.

The authors emphasize that further research is needed to confirm the results of their study, and to look at whether stress management and behavioural therapy might help.

But they suggest that "stress may cause a number of physiological reactions in the central nervous, endocrine, immune and cardiovascular systems, " and point to other studies showing that stress can cause structural and functional damage to the brain and promote inflammation.

Furthermore, research has also shown that stress hormones can remain at high levels many years after experiencing a traumatic event.

Hot molecular clouds around new-born stars are called "Hot Cores" and have temperature of -- 160 degrees Celsius, 100 degrees hotter than normal molecular clouds. The large size of the hot core discovered by ALMA shows that much more energy is emitted from the central baby star than typical solar-mass young stars. This may be due to the higher mass infall rate, or multiplicity of the central baby star. This result indicates a large diversity in the star formation process.

The research findings are presented in the article "ALMA Observations of the IRDC Clump G34.43+00.24 MM3: Hot Core and Molecular Outflows," published in the Astrophysical Journal, Vol. 775, of September 20, 2013.

A large hot molecular cloud around a very young star was discovered by ALMA. This hot cloud is about ten times larger than those found around typical solar-mass baby stars, which indicates that the star formation process has more diversity than ever thought. This result was published in the Astrophysical Journal on September 20th, 2013.

Stars are formed in very cold (-260 degrees Celsius) gas and dust clouds. Infrared Dark Clouds (IRDC) are dense regions of such clouds, and thought that in which clusters of stars are formed. Since most of stars are born as members of star clusters, investigating IRDCs has a crucial role in comprehensive understanding the star formation process.

A baby star is surrounded by the natal gas and dust cloud, and the cloud is warmed up from its center. Temperature of the central part of some, but not all, of such clouds reaches as high as -160 degrees Celsius. Astronomers call those clouds as "hot core" -- it may not be hot on Earth, but is hot enough for a cosmic cloud. Inside hot cores, various molecules, originally trapped in the ice mantle around dust particles, are sublimated. Organic molecules such as methanol (CH3OH), ethyl cyanide (CH3CH2CN), and methyl formate (HCOOCH3) are abundant in hot cores.

International research team, led by Takeshi Sakai at the University of Electro-Communication, Japan, used ALMA to observe an IRDC named G34.43+00.24 MM3 (hereafter MM3) in the constellation Aquila (the Eagle). They discovered a young object from which the methanol molecular line is strongly emitted. A detailed investigation tells them that the temperature of the methanol gas is -140 degrees Celsius. This shows that MM3 harbors a baby star surrounded by a hot core. The size of the hot core is as large as 800 times 300 astronomical units (au, 1 au equals to the mean distance of the Sun and Earth; 150 million km). Typical size of hot cores around low-mass young stars is several tens to hundred of au, therefore the hot core in MM3 is exceptionally large. Sakai says "Thanks to the high sensitivity and spatial resolution, we need only a few hours to discover a previously unknown baby star. This is an important step to understand the star formation process in a cluster forming region."

The team also observed radio emission from carbon sulfide (CS) and silicon monoxide (SiO) to reveal the detailed structure of the molecular outflow from the baby star. The speed of the emanated gas is 28 km/s and the extent is 4,400 au. Based on these values, the team calculates the age of the outflow of only 740 years. Although molecular outflows are common features around protostars, the outflow as young as the one in MM3 is quite rare. In summary, ALMA finds that the protostar in MM3 is very young but has a giant hot core.

Why the hot core in MM3 is so large? In order to warm up the large volume of gas, the baby star should emit much more energy than typical ones. Protostars produce emission by converting the gravitational energy of infalling material to the thermal energy. The large size of the hot core in MM3 is possibly due to the high mass infalling rate than ever thought. The other possibility is that two or more protostars are embedded in the hot core. The research team has not reached the reason with this observation yet. "ALMA's spatial resolution improves much more in the near future," Sakai says, "Then much detail of the infalling material toward the protostar can be revealed, and it helps us answer to the mystery behind the diversity in star formation."

The show's popular game "One of these things is not like the others" helps young viewers learn to differentiate things that are similar -- a process known as "pattern separation."

A new Brigham Young University study concludes that this same skill fades in adults in proportion to the severity of their symptoms of depression. The more depressed someone feels, the harder it is for them to distinguish similar experiences they've had.

If you've ever forgotten where you parked the car, you know the feeling (though it doesn't mean you have depression).

"That's really the novel aspect of this study -- that we are looking at a very specific aspect of memory," said Brock Kirwan, a psychology and neuroscience professor at BYU.

Depression has been generally linked to poor memory for a long time. To find out why, Kirwan and his former grad student D.J. Shelton put people through a computer-aided memory test. The participants viewed a series of objects on the screen. For each one, they responded whether they had seen the object before on the test (old), seen something like it (similar), or not seen anything like it (new).

With old and new items, participants with depression did just fine. They often got it wrong, however, when looking at objects that were similar to something they had seen previously. The most common incorrect answer was that they had seen the object before.

"They don't have amnesia," Kirwan said. "They are just missing the details."

This can be a challenge in a number of everyday situations, such as trying to remember which friends and family members you've told about something personal -- and which ones are still in the dark.

The findings also give an important clue about what is happening in the brain that might explain this.

"There are two areas in your brain where you grow new brain cells," Kirwan said. "One is the hippocampus, which is involved in memory. It turns out that this growth is decreased in cases of depression."

Because of this study, we know a little more about what these new brain cells are for: helping us see and remember new experiences. The study appears in the journal Behavioral Brain Research.

"By showing that African elephants spontaneously understand human pointing, without any training to do so, we have shown that the ability to understand pointing is not uniquely human but has also evolved in a lineage of animal very remote from the primates," says Richard Byrne of the University of St Andrews, noting that elephants are part of an ancient African radiation of animals, including the hyrax, golden mole, aardvark, and manatee. "What elephants share with humans is that they live in an elaborate and complex network in which support, empathy, and help for others are critical for survival. It may be only in such a society that the ability to follow pointing has adaptive value, or, more generally, elephant society may have selected for an ability to understand when others are trying to communicate with them, and they are thus able to work out what pointing is about when they see it."

Byrne and study first author Anna Smet were studying elephants whose "day job" is taking tourists on elephant-back rides near Victoria Falls, in southern Africa. The animals were trained to follow certain vocal commands, but they weren't accustomed to pointing.

"Of course, we always hoped that our elephants would be able to learn to follow human pointing, or we'd not have carried out the experiments," Smet says. "What really surprised us is that they did not apparently need to learn anything. Their understanding was as good on the first trial as the last, and we could find no sign of learning over the experiment."

Elephants that were more experienced with humans, or those born in captivity, were no better than less-experienced, wild-born individuals when it came to following pointing gestures. Byrne and Smet say it is possible that elephants may do something akin to pointing as a means of communicating with each other, using their long trunk. Elephants do regularly make prominent trunk gestures, but it remains to be seen whether those motions act in elephant society as "points."

The findings help to explain how it is that humans have been able to rely on wild-caught elephants as work animals, for logging, transport, or war, for thousands of years. Elephants have a natural capacity to interact with humans even though -- unlike horses, dogs, and camels -- they have never been bred or domesticated for that role. Elephants seem to understand us humans in a way most other animals don't.

"Elephants are cognitively much more like us than has been realized, making them able to understand our characteristic way of indicating things in the environment by pointing," Byrne says. "This means that pointing is not a uniquely human part of the language system."