19 Sunday Apr 2020
Posted in Happiness, Uncategorized
“The COVID-19 pandemic has affected almost every facet of human life. Negative emotions like fear, stress, anxiety and depression are inevitable and can overwhelm even the most optimistic of people. What can we do to nurture our happiness during these unprecedented times?”
05 Tuesday Nov 2019
Plants are able to “remember” and “react” to information contained in light, according to researchers.
Plants, scientists say, transmit information about light intensity and quality from leaf to leaf in a very similar way to our own nervous systems.
These “electro-chemical signals” are carried by cells that act as “nerves” of the plants.
In their experiment, the scientists showed that light shone on to one leaf caused the whole plant to respond.
And the response, which took the form of light-induced chemical reactions in the leaves, continued in the dark.
This showed, they said, that the plant “remembered” the information encoded in light.
“We shone the light only on the bottom of the plant and we observed changes in the upper part,” explained Professor Stanislaw Karpinski from the Warsaw University of Life Sciences in Poland, who led this research.
He presented the findings at the Society for Experimental Biology’s annual meeting in Prague, Czech Republic.
“And the changes proceeded when the light was off… This was a complete surprise.”
In previous work, Professor Karpinski found that chemical signals could be passed throughout whole plants – allowing them to respond to and survive changes and stresses in their environment.
But in this new study, he and his colleagues discovered that when light stimulated a chemical reaction in one leaf cell, this caused a “cascade” of events and that this was immediately signalled to the rest of the plant via a specific type of cell called a “bundle sheath cell”.
The scientists measured the electrical signals from these cells, which are present in every leaf. They likened the discovery to finding the plants’ “nervous system”.
What was even more peculiar, Professor Karpinski said, was that the plants’ responses changed depending on the colour of the light that was being shone on them.
“There were characteristic [changes] for red, blue and white light,” he explained.
He suspected that the plants might use the information encoded in the light to stimulate protective chemical reactions. He and his colleagues examined this more closely by looking at the effect of different colours of light on the plants’ immunity to disease.
“When we shone the light for on the plant for one hour and then infected it [with a virus or with bacteria] 24 hours after that light exposure, it resisted the infection,” he explained.
“But when we infected the plant before shining the light, it could not build up resistance.
“[So the plant] has a specific memory for the light which builds its immunity against pathogens, and it can adjust to varying light conditions.”
He said that plants used information encrypted in the light to immunise themselves against seasonal pathogens.
“Every day or week of the season has… a characteristic light quality,” Professor Karpinski explained.
“So the plants perform a sort of biological light computation, using information contained in the light to immunise themselves against diseases that are prevalent during that season.”
Professor Christine Foyer, a plant scientist from the University of Leeds, said the study “took our thinking one step forward”.
“Plants have to survive stresses, such as drought or cold, and live through it and keep growing,” she told BBC News.
“This requires an appraisal of the situation and an appropriate response – that’s a form of intelligence.
“What this study has done is link two signalling pathways together… and the electrical signalling pathway is incredibly rapid, so the whole plant could respond immediately to high [levels of] light.
26 Friday Jul 2019
Posted in Social Science
16 Saturday Mar 2019
I read this article a few years ago and it keeps popping up. From the SMU News, Southern Methodist University in Dallas Texas, USA.
DALLAS (SMUNews) — Researchers from Southern Methodist University have described two seismic events that they believe may offer the first evidence of a previously undetected form of matter passing through the earth.
This form of matter — known as “strange quark matter” — is so dense that a ton-sized nugget would be about the size of a red blood cell. Physicists have suspected since 1984 that this very heavy form of matter might exist, but no one has yet found evidence of it.
In 1984, Harvard physicist and Nobel Laureate Sheldon L. Glashow suggested that one way such matter might be found would be if a physicist teamed up with a seismologist to search for traces of the matter that might have passed through the earth at supersonic speed. In 1993, SMU physicist Vidgor Teplitz asked Eugene Herrin, a seismologist in the Department of Geological Sciences in SMU’s Dedman College, to collaborate with him on the project. The two were assisted by David Anderson, a senior systems analyst in the Department of Geological Sciences, and Ileana Tibuleac, then a Ph.D. student in the Department of Geological Sciences.
In a paper submitted to the Bulletin of the Seismological Society of America and published online at http://xxx.lanl.gov/ (subject area: astrophysics), the SMU researchers describe how they found evidence of strange quark matter by searching through more than a million records of seismic events collected by the U.S. Geological Survey from 1990 to 1993 that were not associated with traditional seismic events such as earthquakes. These records of so-called “unassociated events” were collected from seismic stations set up around the world to monitor earthquakes and nuclear testing.
In a paper previously published in 1995 (available online at http://cornell.mirror.aps.org/abstract/PRD/v53/i12/p6762_1), Herrin and Teplitz had determined that it would be feasible to search for seismic events that might indicate passage of strange quark matter (also known as nuclearites) through the earth because such events would have a distinct seismic signal — a straight line. This would be caused by the large ratio of speed to the speed of sound in the earth. Herrin estimates that strange quark matter might pass through the earth at 250 miles per second, 40 times the speed of seismic waves. The team also determined that the minimum requirement for detection of a nuclearite would be detection of its signal by seven monitoring stations.
In their new paper, the SMU researchers describe two seismic events with the linear pattern they were looking for. One event occurred on Oct. 22, 1993, when something entered the Earth off Antarctica and left it south of India .73 of a second later. The other occurred on Nov. 24, 1993, when an object entered south of Australia and exited the Earth near Antarctica .15 of a second later. The first event was recorded at seven monitoring stations in India, Australia, Bolivia and Turkey, and the second event was recorded at nine monitoring stations in Australia and Bolivia.
“We can’t prove that this was strange quark matter, but that is the only explanation that has been offered so far,” Herrin said.
The SMU team is now trying to determine where the heavy quark matter may have come from. In April 2002, two different teams of scientists reported that they had identified collapsed stars that might be composed of ultradense strange quark matter. Scientists believe that chunks of strange quark matter might be created when stars made of strange quark matter collide.
Unfortunately, Herrin notes, seismologists may not be able to find any more events that suggest the passage of strange quark matter through the Earth. In 1993 the U.S. Geological Survey stopped collecting data from “unassociated events” such as those that the SMU team used in its research.
Related materials:
08 Friday Mar 2019
Interesting article about pets and how humans react/respond to them. From the abstract:
Neural substrates underlying the human-pet relationship are largely unknown. We examined fMRI brain activation patterns as mothers viewed images of their own child and dog and an unfamiliar child and dog. There was a common network of brain regions involved in emotion, reward, affiliation, visual processing and social cognition when mothers viewed images of both their child and dog. Viewing images of their child resulted in brain
activity in the midbrain (ventral tegmental area/substantia nigra involved in reward/affiliation), while a more posterior cortical brain activation pattern involving fusiform gyrus (visual processing of faces and social cognition) characterized a mother’s response to her dog. Mothers also rated images of their child and dog as eliciting similar levels of excitement (arousal) and pleasantness (valence), although the difference in the own vs. unfamiliar child comparison was larger than the own vs. unfamiliar dog comparison for arousal. Valence ratings of their dog were also positively correlated with ratings of the attachment to their dog. Although there are similarities in the perceived emotional experience and brain function associated with the mother-child and mother-dog bond, there are also key differences that may reflect variance in the evolutionary course and function of these relationships.
Stoeckel LE, Palley LS, Gollub RL, Niemi SM, Evins AE (2014) Patterns of Brain Activation when Mothers View Their Own Child and Dog: An fMRI Study. PLoS ONE 9(10): e107205. doi:10.1371/journal.pone.0107205
http://www.plosone.org/article/info%253Adoi%252F10.1371%252Fjournal.pone.0107205
