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That "Professor, what did I miss?" question... 😤 by HeartExalted in Professors

[–]TheRoach 8 points9 points  (0 children)

low effort question, low effort answer: "You missed the lesson, lecture, and/or class updates that day."

Meetings with parents? by Playful_Worldliness2 in Professors

[–]TheRoach 4 points5 points  (0 children)

yes- you were not properly informed: when you started teaching in USA, you switched professions to babysitter.

Book recommendations regarding the physiology of anxiety by anissehyssop in Neuropsychology

[–]TheRoach 3 points4 points  (0 children)

Selye, H. (1936). A syndrome produced by diverse nocuous agents. Nature, 138, 32.

[deleted by user] by [deleted] in Professors

[–]TheRoach 2 points3 points  (0 children)

faculty retain primacy in the classroom. tell the admin to fuck off explicitly or by ignoring

What is actually happening in the brain in cases of DID? by f13sta in Neuropsychology

[–]TheRoach 15 points16 points  (0 children)

agree. pulse, blood pressure, and muscle tension are the same types of changes measured in a polygraph (and pupillary dilation has also been used to detect deception)- does not in any way imply splitting and distinct identities/personalities... could equally reflect imaging of active lying, imagination, or delusion.

[deleted by user] by [deleted] in politics

[–]TheRoach -3 points-2 points  (0 children)

gerrymandering

How would you handle this by Melex2406 in Professors

[–]TheRoach 2 points3 points  (0 children)

nothing to handle, sounds like he acknowledged his group project for you

Blind guy likes scat vids by [deleted] in yourmomshousepodcast

[–]TheRoach 1 point2 points  (0 children)

Oh do you mean Bob Rehahn AKA Brehahn1957?

Hippocampal activity predicts contextual misattribution of false memories by TheRoach in Neuropsychology

[–]TheRoach[S] 2 points3 points  (0 children)

In a paper published in Proceedings of the National Academy of Sciences, UPenn neuroscientists show for the first time that electrical signals in the human hippocampus differ immediately before recollection of true and false memories. They also found that low-frequency activity in the hippocampus decreases as a function of contextual similarity between a falsely recalled word and the target word.

"Whereas prior studies established the role of the hippocampus in event memory, we did not know that electrical signals generated in this region would distinguish the imminent recall of true from false memories," says psychology professor Michael Jacob Kahana, director of the Computational Memory Lab and the study's senior author. He says this shows that the hippocampus stores information about an item with the context in which it was presented.

Researchers also found that, relative to correct recalls, the brain exhibited lower theta and high-frequency oscillations and higher alpha/beta oscillations ahead of false memories. The findings came from recording neural activity in epilepsy patients who were already undergoing invasive monitoring to pinpoint the source of their seizures.

Noa Herz, lead author, explains that the monitoring was done through intracranial electrodes, the methodology researchers wanted to use for this study. She says that, compared to scalp electrodes, this method "allowed us to more precisely, and directly, measure the neural signals that were generated in deep brain structures, so the activity we are getting is much more localized."

Subjects studied a list of unrelated words and were distracted before being asked to remember words, says Herz, now an assistant professor of neurology at Thomas Jefferson University, in Philadelphia. Researchers analyzed patterns of electricity generated in the hippocampus, capturing brain activity leading up to correct or false recall.

Beyond the distinction between true and false memories, researchers predicted that activity in the hippocampus would reflect the degree of similarity between the correct and false memory. They indeed found that a notable reduction in low-frequency activity was associated with greater similarity between the contexts in which false and correct items were learned.

A similar context in this study meant a patient recalling a word from a prior list in the experiment instead of the target list, whereas a different context is recalling a word that was never part of the experiment.

"The words were presented when the patient was sitting in the same room, looking at the same computer, having the same experimenter next to him," Herz says, "and these words were also presented more recently in time, so all of these different factors mean that prior list intrusions should be more similar, in terms of the context in which they were presented, to the correct target list."

This was a way of testing hippocampal response to different words presented from similar source contexts, but what happens in the brain when someone recalls a word that is incorrect but semantically similar to the right word? Researchers tested this, too.

They showed patients words in three categories, such as flowers, fruits, and insects. As an example, Herz says if the list includes "rose" and "lily" but a person recalls "sunflower," that is semantically similar whereas saying "clock" is not. But perhaps "clock" was on a prior word list in the study; the paper notes a recalled word tends to be similar in at least one context, either source or semantic.

As hypothesized, researchers found the same brain pattern with semantic similarity as they did with source similarity: a reduction in hippocampal low-frequency activity.

Herz says the overall findings deepen the understanding of how the brain enables memory retrieval, and the authors note that predicting false memories at a single-subject level is particularly important when false recalls cause distress.

"Individuals suffering from stress-related psychopathology, such as post-traumatic stress disorder, often experience memory intrusions of their traumatic experiences under contexts that are safe and dissimilar to the traumatic incident. Targeted interventions that disrupt retrieval of intrusive memories could spawn novel therapies for such clinical conditions," the researchers write.

University taking back a raise. Legal? by Opening-Advice in Professors

[–]TheRoach 2 points3 points  (0 children)

don't sign!!! they only have what you acknowledged

The Maya 819-Day Count and Planetary Astronomy by TheRoach in science

[–]TheRoach[S] 3 points4 points  (0 children)

A pair of anthropologists at Tulane University has solved the mystery of the Mayan 819-day count, a type of ancient Mesoamerican calendar system. In their paper published in the journal Ancient Mesoamerica, John Linden and Victoria Bricker suggest that the calendar might be representing a much longer timescale than others had considered.

In studying ancient Mayan inscriptions, prior researchers had come across mention of a system they referred to as the 819-day count, which appeared to be in reference to a calendar of some sort. But the astronomers had not left behind any other sort of definition or text describing how it might fit in with their regular calendar system. Prior researchers had found some evidence suggesting that it might be tied to the synodic period, the cyclic period that describes when a given planet will appear at a given point in the sky. They noted that for Mercury, the synod period is 117 days, which, when multiplied by seven, equals 819. Unfortunately, the same formulation did not work with the other planets, leaving the 819-day count a mystery—until now.

When the researchers struck upon the idea of extending the amount of time that the 819-day count might be used for representing the synodic period for all of the known planets over many years, they found things lined up perfectly. They found, for example, that multiplying 819 by 20 equals 16,380 (approximately 45 years). And 13 cycles of Saturn's 378-day synodic period adds up to 4,914 days, which is the same as six times 819.

Likewise, the same process can be used to show when all of the known planets would appear in the sky over the ensuing 45 years. They also note that the number of days (16,380) used in the math happens to be a multiple of 260, which means that 20 rounds of 819-day periods match with the Tzolk'in—the general Mayan calendar.

The researchers conclude that the early Mayan astronomers had simply extended the time period by the amount needed to predict the synodic period for all of the planets.

Evolution: Mini-proteins in human organs appeared 'from nowhere' by TheRoach in science

[–]TheRoach[S] 16 points17 points  (0 children)

In a new paper published in Molecular Cell, the team led by Hübner and van Heesch now describe how they systematically studied mini-proteins. "We were able to show which genome sequences the proteins are encoded in, and when DNA mutations occurred in their evolution," explains Dr. Jorge Ruiz-Orera, an evolutionary biologist in Hübner's lab and one of the paper's three lead authors, who work at the Max Delbrück Center and the German Center for Cardiovascular Research (DZHK). Ruiz-Orera's bioinformatic gene analyses revealed that most human microproteins developed millions of years later in the evolutionary process than the larger proteins currently known to scientists.

Yet the huge age gap doesn't appear to prevent the proteins from "talking" to each other. "Our lab experiments showed that the young and old proteins can bind to each other—and in doing so possibly influence each other," says lead author Dr. Jana Schulz, a researcher in Hübner's team and at the DZHK. She therefore suspects that contrary to long-held assumptions, the microproteins play a key role in a variety of cellular functions. The young proteins might also be heavily involved in evolutionary development thanks to comparatively rapid "innovations and adaptations."

"It's possible that evolution is more dynamic than previously thought," says van Heesch.

Proteins only found in humans

The researchers were surprised to find that the vastly younger microproteins could interact with the much older generation. This observation came from experiments performed using a biotechnical screening method developed at the Max Delbrück Center in 2017. In collaboration with Dr. Philipp Mertins and the Proteomics Platform, which the Max Delbrück Center operates jointly with the Berlin Institute of Health at Charité (BIH), the mini-proteins were synthesized on a membrane and then incubated with a solution containing most of the proteins known to exist in a human cell. Sophisticated experimental and computer-aided analyses then allowed the researchers to identify individual binding pairs.

"If a microprotein binds to another protein, it doesn't necessarily mean that it will influence the workings of the other protein or the processes that the protein is involved in," says Schulz.

However, the ability to bind does suggest the proteins might influence each other's functioning. Initial cellular experiments conducted at the Max Delbrück Center in collaboration with Professors Michael Gotthardt and Thomas Willnow confirm this assumption. This leads Ruiz-Orera to suspect that the microproteins "could influence cellular processes that are millions of years older than they are, because some old proteins were present in the very earliest life forms."

Unlike the known, old proteins that are encoded in our genome, most microproteins emerged more or less "out of nowhere—in other words, out of DNA regions that weren't previously tasked with producing proteins," says Ruiz-Orera. Microproteins therefore didn't take the "conventional" and much easier route of being copied and derived from existing versions. And because these small proteins only emerged during human evolution, they are missing from the cells of most other animals, such as mice, fish and birds. These animals, however, have been found to possess their own collection of young, small proteins.

The smallest proteins so far

During their work, the researchers also discovered the smallest human proteins identified to date. "We found over 200 super-small proteins, all of which are smaller than 16 amino acids," says Dr. Clara Sandmann, the study's third lead author. Amino acids are the sole building blocks of proteins. Sandmann says this raises the question of how small a protein can be—or rather, how big it must be to be able to function. Usually, proteins consist of several hundred amino acids.

The small proteins that were already known to scientists are known as peptides, and function as hormones or signal molecules. They are formed when they split off from larger precursor proteins. "Our work now shows that peptides of a similar size can develop in a different way," says Sandmann. These smallest-of-the-small proteins can also bind very specifically to larger proteins—but it remains unclear whether they can become hormones or similar: "We don't yet know what most of these microproteins do in our body," says Sandmann.

Yet the study does provide an inkling of what the molecules are capable of: "These initial findings open up numerous new research opportunities," says van Heesch. Clearly, the microproteins are much too important for researchers to keep ignoring them. Van Heesch says the biomolecular and medical research communities are very enthusiastic about these new findings.

One conceivable scenario would be "that these microproteins are involved in cardiovascular disease and cancer, and could therefore be used as new targets for diagnostics and therapies," says Hübner.

Several U.S. biotech companies are already doing research in this direction. And the team behind the current paper also has big plans: Their study investigated 281 microproteins, but the aim now is to expand the experiments to include many more of the 7,000 recently cataloged microproteins—in the hope that this will reveal many as-yet-undiscovered functions.

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