9.19.18. Studycation Day 31/35 - I woke up, did the dishes and laundry, and studied for 6 hours. I read some more of my bio textbook, I did the majority of my pre-lab, and I finished 2/3 of statistics revision posters I’m making. I am super tired today because my partner and I stayed up a bit too late watching Bojack Horseman, oops! 😋
Spores from the parasitic fungi called the cordyceps infects an insects brain and directs the insect upwards towards the forest canopy where it latches onto a plant to eventually die.
After growing for about 3 weeks within the dead insect, the cordyceps unleashes spores into the forest, infecting other insects within the immediate area. There are thousands of different types of cordyceps fungi and each specialise in just one type of insect species.
Patients who survive a brief cardiac arrest and who appear
neurologically intact should nonetheless receive a detailed
neuropsychological assessment before being discharged, suggests a joint
study by researchers at Baycrest’s Rotman Research Institute (RRI) and
Israel’s Rambam Medical Center.
The study, recently published in the journal Resuscitation,
found that patients discharged in “good neurological condition” after a
brief cardiac arrest (when the heart suddenly stops beating normally and
cannot pump blood effectively) had significant memory problems and a 10
to 20 per cent reduction in size of their brain’s memory region, the
hippocampus. Individuals who performed worse on memory tests showed
greater changes to their hippocampus.
In Canada and the U.S., 464,000 people suffer a cardiac arrest outside
of a hospital with an average of 46,400 people (10 per cent) surviving
these incidents annually. It’s estimated that 20 to 50 per cent of these
survivors continue to experience memory and cognitive problems that
impact their quality of life.
Comprehensive neuropsychological testing could provide cardiac arrest
survivors better support for the challenges they may face upon
discharge, says Dr. Vess Stamenova, first author on the study and a
postdoctoral fellow at the Women’s College Hospital, who completed the
research during her time as a fellow at the RRI.
“Identifying patients at risk will allow cardiac arrest survivors to
have appropriate recommendations for rehabilitation before they are
discharged,” says Dr. Stamenova. “These people may go home and think
they are neurologically fine, but then they realize things have changed
and they may not be able to do their job, and it can be difficult for
them to figure out where to seek help.”
Dr. Stamenova adds that a comprehensive neurological consult would be
helpful to patients, since individual cognitive screening measures such
as the Cerebral Performance Category Scale, Mini Mental Status
Examination and the Montreal Cognitive Assessment, cannot detect the
memory problems faced by cardiac arrest survivors.
This joint study conducted neuropsychological assessments and brain
imaging on 18 patients who either had a heart attack or brief cardiac
arrest at the Rambam Medical Center in Haifa, Israel. Patients who had
cardiac arrests lasting for a brief period before receiving CPR (less
than three minutes on average) were tested between two to four years
after the incident.
The hippocampus is known to be sensitive to a lack of oxygen, but the
effect is larger than expected, says Dr. Stamenova. This is the first
study to capture brain imaging of patients who had short cardiac
arrests. Previous research has looked at animals or patients with more
prolonged cardiac arrest.
“Unfortunately cardiac arrest survivors may return home after the
incident without a clear understanding of their memory deficits or
access to rehabilitation programs,” says Dr. Asaf Gilboa, the paper’s
senior author, scientist at the RRI and assistant professor of
psychology at the University of Toronto. “Arming these patients with
appropriate resources will improve their recovery and allow them to
resume their day-to-day activities.”
On Sept. 15, 2017, our Cassini spacecraft ended its epic exploration of Saturn with a planned dive into the planet’s atmosphere–sending back new science to the very last second. The spacecraft is gone, but the science continues!
New research emerging from the final orbits represents a huge leap forward in our understanding of the Saturn system – especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised. How did they form? What holds them in place? What are they made of?
Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini’s Grand Finale. That’s when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.
Knowing Cassini’s days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn’s magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the engineering push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.
Many more Grand Finale science results are to come, but today’s highlights include:
Complex organic compounds embedded in water nanograins rain down from Saturn’s rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of organics is different from that found on moon Enceladus – and also different from those on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.
For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes – a phenomenon known as “ring rain.” But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it’s all falling out of the rings faster than scientists thought – as much as 10,000 kg of material per second.
Scientists were surprised to see what the material looks like in the gap between the rings and Saturn’s atmosphere. They knew that the particles throughout the rings ranged from large to small. They thought material in the gap would look the same. But the sampling showed mostly tiny, nanograin- and micron-sized particles, like smoke, telling us that some yet-unknown process is grinding up particles. What could it be? Future research into the final bits of data sent by Cassini may hold the answer.
Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric current system that connects the rings to the top of Saturn’s atmosphere.
Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn’t block the belt from forming.
Unlike every other planet with a magnetic field in our Solar System, Saturn’s magnetic field is almost completely aligned with its spin axis. Think of the planet and the magnetic field as completely separate things that are both spinning. Both have the same center point, but they each have their own axis about which they spin. But for Saturn the two axes are essentially the same – no other planet does that, and we did not think it was even possible for this to happen. This new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth’s magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It’s a mystery physicists will be working to solve.
Cassini flew above Saturn’s magnetic poles, directly sampling regions where radio emissions are generated. The findings more than doubled the number of reported crossings of radio sources from the planet, one of the few non-terrestrial locations where scientists have been able to study a mechanism believed to operate throughout the universe. How are these signals generated? That’s still a mystery researchers are looking to uncover.
For the Cassini mission, the science rolling out from Grand Finale orbits confirms that the calculated risk of diving into the gap – skimming the upper atmosphere and skirting the edge of the inner rings – was worthwhile.
Almost everything going on in that region turned out to be a surprise, which was the importance of going there, to explore a place we’d never been before. And the expedition really paid off!
Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.
To read the papers published in Science, visit: URL to papers
The human gut is lined with more than 100 million nerve cells, it’s practically a brain unto itself. And indeed, the gut actually talks to the brain, releasing hormones into the bloodstream that, over the course of about 10 minutes, tell us how hungry it is, or that we shouldn’t have eaten an entire pizza. But a new study reveals the gut has a much more direct connection to the brain through a neural circuit that allows it to transmit signals in mere seconds. The findings could lead to new treatments for obesity, eating disorders, and even depression and autism, all of which have been linked to a malfunctioning gut.
The study reveals “a new set of pathways that use gut cells to rapidly communicate with … the brain stem,” says Daniel Drucker, a clinician-scientist who studies gut disorders at the Lunenfeld-Tanenbaum Research Institute in Toronto, Canada, who was not involved with the work. Although many questions remain before the clinical implications become clear, he says, “This is a cool new piece of the puzzle.”
In 2010, neuroscientist Diego Bohórquez of Duke University in Durham, North Carolina, made a startling discovery while looking through his electron microscope. Enteroendocrine cells, which stud the lining of the gut and produce hormones that spur digestion and suppress hunger, had footlike protrusions that resemble the synapses neurons use to communicate with each other.
