Comment

Comment by Dr. Krishna Kumari Challa on Monday

In theory, oppositely charged micro black holes could then be brought together, one by one, leading them to merge into a single black hole that 'evaporates' very quickly into pure energy. The extracted energy wouldn't come from within the black hole, but just outside it: where gravity concentrates.
This mind-bending suggestion is not beyond the realms of possibility. Tiny, primordial black holes are thought to exist, but have never been detected – perhaps because they have radiated away most of their energy after forming in the primeval plasma that filled the Universe following the Big Bang.
But the prospect of 'micro black hole batteries' will more than likely remain purely hypothetical, saying more about how far trends in battery technology have to go than where we'll actually end up.

"Today's batteries are extremely inefficient compared to their ultimate potential, and we are likely just at the very beginning of a battery revolution," Espen Haug, a theoretical physicist and finance analyst at the Norwegian University of Life Sciences, and Gianfranco Spavieri, a physicist at the University of the Andes Venezuela, write in their published paper.
part 2

Comment by Dr. Krishna Kumari Challa on Monday

Physicists Say The Ultimate Battery Could Harness The Power of Black Holes

The quest to generate more energy from less material while avoiding burning any more fossil fuels than our planet can handle is spawning some, let's say, creative ideas.
Nuclear fusion records are being smashed, even if only by the tiniest of margins and seconds at a time. Meanwhile, solar panels are becoming increasingly efficient as expected and their installation – atop car parks and green roofs – is also more strategic, helping to reap bigger and bigger gains.
But how to store that energy and relinquish it on demand across the electricity grid remains a huge challenge, even if battery storage and manufacturing capacity are trending upwards, making prices plummet.

Theoretical scientists are a particularly imaginative bunch when it comes to projecting how those trends might play out or where innovation could take us, years into the future.

In the latest turn, two physicists have been pondering the ultimate theoretical limits of battery energy density, based on Einstein's general theory of relativity.

Starting with a strict interpretation of equations describing perfectly round masses that don't rotate, the pair describe the behavior of ideal models of microscopic black holes forming in a tight space jam-packed with energy. Thanks to the way these tiny monsters interact, the whole system could act somewhat like a nuclear reactor, freeing energy stored in the bonds of particles to generate enormous amounts of clean energy.

These black holes would need to be charged and tiny, just one Planck mass each, so that when bundled together into cells packed with similarly charged black holes, their electromagnetic repulsion offsets the pull of gravity, creating stable energy storage that doesn't gobble itself up. More massive black holes are also less energy-dense than tiny ones.
Part 1

Comment by Dr. Krishna Kumari Challa on Monday

To deepen their understanding of the impact of epistemic injustice—injustice around the domain of knowledge—the researchers focused on the emotional consequences of feedback. They modeled epistemic injustice in the lab by creating an experiment to safely simulate everyday experiences of invalidation. Participants observed a game, then shared their knowledge about the game—either how it worked or how they felt about it.

The crucial part of the experiment came next; participants received feedback, supposedly from their partner in the game, about what they shared. Some feedback was validating, some was discrediting, and some was mildly insulting.

The participants then rated how positive or negative that feedback made them feel, the key measure of their emotional responses. The researchers combined the experiment with surveys of variables thought to factor into epistemic injustice—race, gender and experiences with race-based discrimination and trauma.

--

The experiment conducted by researchers revealed an important generality about knowledge. People find it more emotionally taxing to have their understanding of facts questioned than to have their feelings questioned.

But more important findings came from the experiment outcomes combined with the surveys, which showed that race and gender factored into the experimental results.

These findings are consistent, with research on prejudice and discrimination showing that Black men experience more racial discrimination in areas where credibility is extremely important—such as employment, educational settings and interactions with law enforcement—but where credibility can be undermined by emotional responses.

Another consistent finding underscored the importance of individual differences. Validation—when participants were told that they were right—was significantly more positive for white women compared with white men, which resonates with studies showing that positive interventions boost women's academic performance.

Insights from this study could benefit managers, educators and people interested in living and working in safer and more just communities. For universities, we think the results highlight the world of emotional coping mechanisms spoken about too rarely, but always under the surface in intellectual spaces.

Laura Niemi et al, The emotional impact of baseless discrediting of knowledge: An empirical investigation of epistemic injustice, Acta Psychologica (2024). DOI: 10.1016/j.actpsy.2024.104157

Part 2

**

Comment by Dr. Krishna Kumari Challa on Monday

Persistent questioning of knowledge takes a toll: New study supports theories that baseless discrediting harms

It can be demoralizing for a person to work in a climate of repetitive skepticism and doubt about what they know, a new study shows.

This is  not about healthy, well-founded skepticism. This is about failures-of-exchange when a person is persistently overlooked, unheard, brushed off and explained to. 

Why? Something about who the person is—their identity—suggests to their interlocuter that they couldn't possibly be right due to the interlocuter's bias. These biases take many forms: race or ethnicity, manner of speaking, weight, attractiveness, age, style and so on.

Researchers have theorized that baseless discrediting of what people with marginalized social identities know is a central driver of prejudice and discrimination.

They conducted experiments that backed up these theories, finding that people are emotionally invested in being treated as credible, even in anonymous games. Further, they found that emotional impact of discreditation varies based on gender, race and experience with racial discrimination. 

The authors think that hostility in intellectual arenas is an ethical issue.

Discrediting of a person as a legitimate knower can be subtle, which makes it difficult to isolate, and, therefore, understudied.

But growing research shows regular exposure to even relatively subtle prejudice and discrimination degrades physical and mental health, leading to outcomes like high blood pressure, chronic stress and depression.

Part 1

Comment by Dr. Krishna Kumari Challa on Monday

(PS: Please take this work with a pinch of salt because we are waiting for reproduction of these results.

This is still under review and the point difference is small.

And, students, this is not an excuse for your laziness. Because this need not be the case every time you write your exams. Most of the time in my practical and viva part of exams I was the last person to submit my results and got interviewed but still got top ranks).

Zhihan (Helen) Wang et al, 30 Million Canvas Grading Records Reveal Widespread Sequential Bias and System-Induced Surname Initial Disparity (2023). On SSRN: ssrn.com/abstract=4603146

Part 4

Comment by Dr. Krishna Kumari Challa on Monday

Their research uncovered a clear pattern of a decline in grading quality as graders evaluate more assignments. According to Wang, students whose surnames start with A, B, C, D or E received a 0.3-point higher grade out of 100 possible points than compared to when they were graded randomly. Likewise, students with later-in-the-alphabet surnames received a 0.3-point lower grade—creating a 0.6-point gap.

A 0.6-point difference might seem small, but such a disparity did affect students' course grade-point averages, which negatively influences opportunities in their respective career paths.

The Researchers suspect that fatigue among the examiners is one of the major factors that is driving this effect, because when you're working on something for a long period of time, you get tired and then you start to lose your attention and your cognitive abilities are dropping.

The researchers note the option exists to grade the assignments in a random order, and some educators do, but alphabetical order is the default mode in Canvas and other online learning management systems. One simple fix would be to make random order the default setting.

They also suggest academic institutions could hire more graders for larger classes, distribute the workload among more people or train them to be aware of and lessen the bias while grading.

The study is under review by the journal Management Science and currently available as a working paper.

Part 3

Comment by Dr. Krishna Kumari Challa on Monday

Researchers find lower grades given to students with surnames that come later in alphabetical order

(This title is somewhat misleading, please read on to know why)

Knowing your ABCs is essential to academic success, but having a last name starting with A, B or C might also help make the grade.

What's in a name? A lot!

An analysis by researchers of more than 30 million grading records from U-M finds students with alphabetically lower-ranked names receive lower grades. This is due to sequential grading biases and the default order of students' submissions in Canvas—the most widely used online learning management system—which is based on the alphabetical rank of their surnames. What's more, they find, those alphabetically disadvantaged students receive comments that are notably more negative and less polite, and exhibit lower grading quality measured by post-grade complaints from students.

Part 2

Comment by Dr. Krishna Kumari Challa on Monday

Researchers find lower grades given to students with surnames that come later in alphabetical order

Knowing your ABCs is essential to academic success, but having a last name starting with A, B or C might also help make the grade.

What's in a name? A lot!

An analysis by  researchers of more than 30 million grading records from U-M finds students with alphabetically lower-ranked names receive lower grades. This is due to sequential grading biases and the default order of students' submissions in Canvas—the most widely used online learning management system—which is based on the alphabetical rank of their surnames. What's more, they find, those alphabetically disadvantaged students receive comments that are notably more negative and less polite, and exhibit lower grading quality measured by post-grade complaints from students.

 Researchers suspect that fatigue is one of the major factors that is driving this effect, because when you're working on something for a long period of time, you get tired and then you start to lose your attention and your cognitive abilities  are dropping.

The researchers note the option exists to grade the assignments in a random order, and some educators do, but alphabetical order is the default mode in Canvas and other online learning management systems. One simple fix would be to make random order the default setting.

They also suggest academic institutions could hire more graders for larger classes, distribute the workload among more people or train them to be aware of and lessen the bias while grading.

The study is under review by the journal Management Science and currently available as a working paper.

Zhihan (Helen) Wang et al, 30 Million Canvas Grading Records Reveal Widespread Sequential Bias and System-Induced Surname Initial Disparity (2023). On SSRN: ssrn.com/abstract=4603146

part 1

Comment by Dr. Krishna Kumari Challa on Saturday

This response doesn't take long at all either. In the experiments run for the study, it took less than a minute for these types of bacteria to realize that blood was nearby and to head towards it.

"We show here that the bacterial attraction response to serum is robust and rapid," write the researchers in their published paper.

The types of bacteria investigated here, from the family Enterobacteriaceae, have already been linked to conditions such as gastrointestinal bleeding and sepsis, particularly where IBD is involved.
The thinking is that these bacteria are latching on to the internal bleeding that often comes with IBD, which is how fatalities can occur.
Knowing more about how bacteria sense the serum in blood, and make use of it, might eventually save lives if treatments are focused on this. By learning how these bacteria are able to detect sources of blood, in the future we could develop new drugs that block this ability.
Bacterial vampirism mediated through taxis to serum:

https://elifesciences.org/reviewed-preprints/93178v2

Comment by Dr. Krishna Kumari Challa on Saturday

Some Microbes Are Tiny 'Vampires' With a Deadly Attraction to Human Blood
Researchers have discovered what they describe as 'bacterial vampirism', identifying particular types of bacteria that are attracted to human blood – an attraction that can lead to fatal infections.
Researchers outline how these deadly bacteria are drawn to serum – the liquid part of our blood – because of the nutrients and energy it provides.

That can be a particular problem for people with irritable bowel disease (IBD), where intestinal bleeding can offer gut bacteria a route into the bloodstream. However, these findings also shed light on potential new treatment routes.
Bacteria infecting the bloodstream can be lethal. Some of the bacteria that most commonly cause bloodstream infections actually sense a chemical in human blood and swim toward it.
The researchers used a customized device for injecting tiny amounts of fluid and a high-powered microscope to analyze the interaction of bacteria and blood.

Strains of three bacteria known to cause fatal infections, belonging to the species Salmonella enterica, Escherichia coli, and Citrobacter koseri, were found to be attracted to the human serum.

What's more, the team identified some of the biological interactions: it looks as though the amino acid serine is one of the chemicals the bacteria can sense, seek out, and consume, via particular protein receptors.
Part 1

• ‹ Previous
• 1
• 2
• 3
• 4
• 5
• 6
• …
• 843
• Next ›
• Page