Science Corner

Use of cannabis as a teenager is associated with poorer memory and reasoning

Patricia Conrad from Montreal University was leading a study about the effects of cannabis for teenagers. In puberty, those areas in brain that are most exposed to the effects of cannabis are still developing, it’s effecting to the memory and ability to reason. The study lasted 4 years with 3826 youngsters who were on 7 grades at the beginning of the study and their cognitive skills were assessed by computer tests four times. At the same time, students responded to a questionnaire about alcohol and cannabis use; from there it was shown that the alcohol didn’t effect as much to the memory of the youngsters or to the ability to reason as cannabis. These abilities were weakened when one started to use more cannabis. Also the use of cannabis was associated with more lasting neurotoxic changes in working memory and in regulating one’s own behavior and reactions.


“Alcohol use was not associated with a reduction in these cognitive skills. It suggests that cannabis may have longer lasting effects than alcohol”, the Canadian Neuroscience Association Bulletin summarizes in the results of the study. Cannabis was legalized last year in Canada, being second country in the world to do so, and about fifth of young people aged 15-19 use it. Previous studies show, that also alcohol have role on effecting to the learning, decision-making and cognitive performance such as academic success but now there is more information also how cannabis is harming especially at young age, when you’re brain is still growing.

Combating climate change with billions of trees

photo-1553755322-56baa43a31d7Scientist have calculated for the first time how many trees could be planted outside existing forests, while still avoiding food production areas or cities. By planting billions of trees around the world would be the most important and easiest way to combat climate change, comes as a result from a study published in the science journal “Science”. The new analysis discovered 1.7 billion hectares of land (about 11% of the whole area of Earth; about the size of US and China together) from which 1.2 billion hectares the trees would grew naturally. In this way we would get 25% more forest areas which mean over 500 billion trees. After growing into adulthood, the trees would absorb about 200 gigatons of carbon dioxide released into the atmosphere. This change in the number of forests would cut about 25% of the carbon dioxide in the atmosphere.

“The fact that blows my mind is the scale. I thought that forestation would be the top 10 in the fight against climate change, but it is by far more effective than any other means of combating climate change” says Tom Crowther, professor at the Swiss ETH Zürich University, who led the research. However, if trees were to be planted on the proposed scale, it would take 50 to 100 years to reach their full emission potential. That is why Crowther emphasizes that it is still very important to turn the current emission trend towards zero emissions. But we can still start planting trees, like many countries and individuals have joined the movement, which doesn’t cost you a lot.

Octopuses have exceptional intelligence

photo-1545671913-b89ac1b4ac10According to scientists, the octopus intelligence works in such an exceptional way that it may be worth learning if humankind can ever make acquaintance with the extraterrestrial intelligence; new study shows that octopus tentacles can make independent decisions and cooperate with each other without connection its brain knowing about it. This makes the intelligence of an octopus quite different from other species. They do not have the same central nervous system as the vertebrates; their nerve cells are spread across the animal. The research was presented at the Astrobiology Congress in Seattle, and it was studying giant cods and red cods (octopuses with 8 tentacles) living in the Pacific Ocean. These cods have about 500 million nerve cells, of which about 350 million are in their tentacles, what makes them able to react independently.

Oumuamua object in space left without explanation

Lots of theories in the international media and in the research community were discussed in October 2017, when astronomers discovered something very strange in our solar system: an object described as a cigar, with features of both asteroid and comet, but which didn’t seem to come from our near space. Unfortunately, the object floated away in few weeks; therefore scientist didn’t have enough time to study it.

Artist’s impression of the interstellar asteroid `Oumuamua

“We’ve never seen anything like Oumuamua in our solar system. It’s still a mystery” says Matthew Knight, the second head of the research team at the University of Maryland that started to study Oumuamua. It might be interesting to think that this object was a foreign spaceship of some other intelligent species, since it stayed as a mystery; it didn’t spread gases like comets do, and its trajectory cannot be explained only with gravity. Also its unfamiliar shape and rounding movement was arousing wonder in the whole world. But according to the study, Oumuamua is most likely natural object wandering in space, even we haven’t seen anything like it before; it again doesn’t mean, that it can’t have a natural explanation. In the near future scientists will have more powerful telescopes to study more objects: “We may start seeing new items every year. Then we can know if Oumuamua is weird or ordinary. If you find 10-20 and Oumuamua still seems unusual, we have to reconsider our explanations” Knight explains. For now this object remains bit as a mystery, but we can still let our minds wonder and consider that someone from the outer space passed by us.

Selina Niemi


Picture of Oumuamua: Publisher – European Southern Observatory

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