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Science, nature, history, archaeology, politics, and other topics

[anudibranchaday]

The Dendronotus iris is often called the Giant nudibranch, and for good reason. This nudibranch can grow to a whopping 30cm in length! It lives in muddy subtidal areas from northern Alaska to northern Mexico, at most 200m below the surface. Like many other nudibranchs, the Giant nudibranch has a very specific diet- it feeds solely on the tendrils of the tube-dwelling anemone (as seen in the picture). Funnily enough, the anemones sometimes pull the nudibranch into their tube when they try to hide, although no one seems to be harmed in the process.

[just--space]

Waxing Gibbous Moon Above Earth’s Limb : The waxing gibbous moon is pictured above Earth’s limb as the International Space Station was orbiting 266 miles above the South Atlantic Ocean. (via NASA)

[neurosciencestuff]

Brain pathways of aversion identified

Scientists have long been interested in how the brain creates signals associated with negative emotions in order to better understand how imbalances in the same system can lead to affective disorders such as depression and anxiety.

The amygdala has long been the most commonly studied brain structure for understanding fear, whereas for rewards and positive signals the focus has been on the neurotransmitter dopamine. But when it comes to areas of the brain that control feelings of discomfort and aversion, much less is known.

Brain structure controlling emotions

In the past few years, research has indicated that a brain structure called the habenula controls positive and negative emotions in animal models. Moreover, clinical cases have been conducted with patients suffering from depression where deep brain stimulation of the habenula has been beneficial. The habenula controls both dopamine and the neurotransmitter serotonin, which is thought to play a significant part in the sense of wellbeing. However, it has not been known how the habenula is regulated.

Researchers at Karolinska Institutet have now mapped which networks in the mouse brain control the habenula, and what role they play in aversion.

“We’ve discovered a specific pathway that goes between the hypothalamus and the habenula, and that can be modulated using optogenetics to control the feeling of aversion,” says study leader docent Dinos Meletis at the Department of Neuroscience. “Our hope is that this can lead to the development of new treatments that can rebalance the brain’s networks in for example depression or anxiety disorders.”

Using light to activate neurons

Using optogenetics and other advanced methods, the group were able to identify the identity of the nerve cells and map their interconnections. Optogenetics is a method that uses light to activate specific neurons in order to study how the activation of different networks affects behaviour.

“This methodological revolution in brain research has made it possible to functionally study how different types of nerve cell and pathways actually control different types of behaviour, something that was impossible to do only a decade ago,” says Dr Meletis.

[vugnasmineralblog]

Siegenite Stahlberg Mine (Schwabengrube), Müsen, Siegerland, North Rhine-Westphalia, Germany, Europe

[tangledwing]

Pyromorphite Daoping Mine, Gongcheng Co., Guilin, Guangxi, China.

[drrockclub]

Fossil of the cockle-like mollusc hanging out of the rocky overhang. Preserved as it lived.

Age: Permian (300 - 250 million years)

[drrockclub]

Articulated bivalve fossils

Both shell halves are still closed and intact (articulated), it means that this animal died in this spot exactly (probably buried by a pile of sediment), preserved in its living position. Sedimentary processes or predators have not disturbed it since, and so it has been lying in these sediments for about 250 million years by now.

South Coast, New South Wales, Australia

[thereefuncovered-blog]

This is a tiny, solitary coral know as Cycloseris. By solitary we mean he only has one polyp instead of the colony of polyps that make up most corals. Also, I may say tiny (about 25 mm), but when compared to other polyps he is absolutely massive. 

[thewriterkb]

The World’s Grumpiest Animal: The Black Rain Frog.

[galaxiesoftheuniverse]

NGC 6357

NGC 6357 is a diffuse nebula near NGC 6334 in the constellation Scorpius. The nebula contains many proto-stars shielded by dark disks of gas, and young stars wrapped in expanding “cocoons” or expanding gases surrounding these small stars.

[neurosciencestuff]

Researchers reveal brain connections that disadvantage night owls

Research led by the University of Birmingham in collaboration with researchers at the University of Surrey and the University of Campinas, in Brazil, found that individuals whose internal body clock dictates that they go to bed and wake up very late (with an average bedtime of 2:30am and wake-up time of 10:15am) have lower resting brain connectivity in many of the brain regions that are linked to the maintenance of consciousness.

Importantly, this lower brain connectivity was associated with poorer attention, slower reactions and increased sleepiness throughout the hours of a typical working day.

According to the Office for National Statistics, around 12 per cent of employees work night shifts. We already know that there are huge negative health consequences for night shift workers due to the constant disruption to sleep and body clocks.

However, disruption can also be caused by being forced to fit into a societal 9-5 working day if those timings do not align with your natural biological rhythms. Since around 40-50 per cent of the population identify as having a preference for later bed times and for getting up after 8.20am the researchers say much more needs to be done to explore negative implications for this group.

The lead researcher, Dr Elise Facer-Childs, of the University of Birmingham’s Centre for Human Brain Health, says: “A huge number of people struggle to deliver their best performance during work or school hours they are not naturally suited to. There is a critical need to increase our understanding of these issues in order to minimise health risks in society, as well as maximise productivity.”

The study, published in the journal SLEEP, investigated brain function at rest and linked it to the cognitive abilities of 38 individuals who were identified as either ‘night owls’ or ‘morning larks’ using physiological rhythms (melatonin and cortisol), continuous sleep/wake monitoring and questionnaires. The volunteers underwent MRI scans, followed by a series of tasks, with testing sessions being undertaken at a range of different times during the day from 8am to 8pm. They were also asked to report on their levels of sleepiness.

Volunteers identified as morning larks reported to be least sleepy and had their fastest reaction time during the early morning tests, which was significantly better than night owls. Night owls, however, were least sleepy and had their fastest reaction time at 8pm in the evening, although this was not significantly better than the larks, highlighting that night owls are most disadvantaged in the morning. Interestingly, the brain connectivity in the regions that could predict better performance and lower sleepiness was significantly higher in larks at all time points, suggesting that the resting state brain connectivity of night owls is impaired throughout the whole day (8am-8pm).

Dr Facer-Childs, who is now based at the Monash Institute for Cognitive and Clinical Neurosciences in Melbourne, Australia, says: “This mismatch between a person’s biological time and social time – which most of us have experienced in the form of jet lag – is a common issue for night owls trying to follow a normal working day. Our study is the first to show a potential intrinsic neuronal mechanism behind why ‘night owls’ may face cognitive disadvantages when being forced to fit into these constraints.

“To manage this, we need to get better at taking an individual’s personal body clock into account – particularly in the world of work. A typical day might last from 9am-5pm, but for a night owl, this could result in diminished performance during the morning, lower brain connectivity in regions linked to consciousness and increased daytime sleepiness. If, as a society, we could be more flexible about how we manage time we could go a long way towards maximising productivity and minimising health risks.”

[just--space]

NGC 3324 in Carina : This bright cosmic cloud was sculpted by stellar winds and radiation from the hot young stars of open cluster NGC 3324. With dust clouds in silhouette against its glowing atomic gas, the pocket-shaped star-forming region actually spans about 35 light-years. It lies some 7,500 light-years away toward the nebula rich southern constellation Carina. A composite of narrowband image data, the telescopic view captures the characteristic emission from ionized sulfur, hydrogen, and oxygen atoms mapped to red, green, and blue hues in the popular Hubble Palette. For some, the celestial landscape of bright ridges of emission bordered by cool, obscuring dust along the right side create a recognizable face in profile. The region’s popular name is the Gabriela Mistral Nebula for the Nobel Prize winning Chilean poet. via NASA

[cosmicvastness]

A Cosmic Rose: The Rosette Nebula in Monoceros

The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband and narrowband filters, because sometimes roses aren’t red. Credit: Jean Dean

[cma-korean-art]

Box and Cover with Inlaid Chrysanthemum and Scroll Design, 1200, Cleveland Museum of Art: Korean Art

Size: Body: 2.2 x 7.5 cm (7/8 x 2 15/16 in.); Overall: 3.9 cm (1 9/16 in.) Medium: inlaid celadon ware

https://clevelandart.org/art/1928.167

[slam-african]

Chilkat Blanket, Tlingit, c.1870, Saint Louis Art Museum: Arts of Africa, Oceania, and the Americas

[historyarchaeologyartefacts]

Scaraboid gem with a dolphin, Greek classical period 450–400 BCE[1600x1452]

Source: https://reddit.com/r/ArtefactPorn/comments/csj473/scaraboid_gem_with_a_dolphin_greek_classical/

[mindblowingscience]

Physicists simulate critical 'reheating' period that kickstarted the Big Bang

"This enables us to tell an unbroken story, from inflation to the postinflation period, to the Big Bang and beyond," Kaiser says. "We can trace a continuous set of processes, all with known physics, to say this is one plausible way in which the universe came to look the way we see it today."

As the Big Bang theory goes, somewhere around 13.8 billion years ago the universe exploded into being, as an infinitely small, compact fireball of matter that cooled as it expanded, triggering reactions that cooked up the first stars and galaxies, and all the forms of matter that we see (and are) today.

Just before the Big Bang launched the universe onto its ever-expanding course, physicists believe, there was another, more explosive phase of the early universe at play: cosmic inflation, which lasted less than a trillionth of a second. During this period, matter—a cold, homogeneous goop—inflated exponentially quickly before processes of the Big Bang took over to more slowly expand and diversify the infant universe.

Recent observations have independently supported theories for both the Big Bang and cosmic inflation. But the two processes are so radically different from each other that scientists have struggled to conceive of how one followed the other.

Now physicists at MIT, Kenyon College, and elsewhere have simulated in detail an intermediary phase of the early universe that may have bridged cosmic inflation with the Big Bang. This phase, known as “reheating,” occurred at the end of cosmic inflation and involved processes that wrestled inflation’s cold, uniform matter into the ultrahot, complex soup that was in place at the start of the Big Bang.

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