Advent Calendar 2023
It's that time of the year again! Each day until December 24, you can open a door of our online advent calendar to marvel at stunning images of science and find fascinating research information. Be prepared to be amazed and enjoy browsing!
This year, the background to our Advent calendar is a cut-out from one of the first images that EUCLID, ESAs new space telescope, sent to Earth at the beginning of November. It shows the surroundings of the globular star cluster NGC 6397, which lies 7200 light years away from Earth in the southern sky constellation named Ara (Latin for "the Altar").
©ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi, CC BY-SA 3.0 IGO
©ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi, CC BY-SA 3.0 IGO
5
Liver en miniature
Organoids are miniature versions of organs that are cultured from stem cells in the laboratory. They hold great promise for the future of biomedical research, as they enable scientists to study very different aspects such as organ development, tissue regeneration, diseases and new therapies without the need for complete organisms. The cell clumps, which are only a few millimeters in size, therefore make an important contribution to avoiding animal experiments. Researchers at the Max Planck Institute for Molecular Genetics use such liver models to study various diseases. The image shows human liver organoids that secrete albumin (shown here in green). Albumin is one of the most important proteins produced by the liver and is indispensable in the body for transport processes in the blood. The fact that liver organoids produce this protein in the laboratory is proof of the high functionality of these organ models.
Fluorescence microscopy, animated
Fluorescence microscopy, animated
© MPI for Molecular Genetics / Anja Hess
2
The universe in the mainframe
Take a good portion of gas, add dark matter and refine the mixture with gravity and massive neutrinos. Then feed these ingredients into two supercomputers and wait for the result. Well, it wasn't quite that easy for the researchers to recreate the development of the universe and the galaxies within it.. But the recipe worked and delivered the most comprehensive hydrodynamic simulation model of the universe to date. It examines the behavior of liquids and gases under the influence of forces such as flow, pressure and gravity.
This way, the "MillenniumTNG" project was able to model the formation of around one hundred million galaxies in a region with a diameter of almost two and a half billion light years. The image shows a detail from the simulation with gas (top left), dark matter (top right) and starlight (bottom center). Indicated in the two upper sections are the threads of the cosmic web that runs through the cosmos on a large scale. Among other things, the new calculations are intended to contribute to a precision test of the standard cosmological model.
Read more: Putting the universe to the test
Computer simulation
This way, the "MillenniumTNG" project was able to model the formation of around one hundred million galaxies in a region with a diameter of almost two and a half billion light years. The image shows a detail from the simulation with gas (top left), dark matter (top right) and starlight (bottom center). Indicated in the two upper sections are the threads of the cosmic web that runs through the cosmos on a large scale. Among other things, the new calculations are intended to contribute to a precision test of the standard cosmological model.
Read more: Putting the universe to the test
Computer simulation
© Max Planck Institute for Astrophysics, Garching
22
Floating particle trap
...... a shiny gold ring floats in a vacuum chamber at the MPI for Plasma Physics in Garching. In this state, the superconducting magnetic ring can capture charged particles, both positive and negative. The scientists want to use it to investigate matter-antimatter plasmas. On Earth, we only know of such plasmas in science fiction - but they do exist in the universe: in the vicinity of quasars and perhaps also in the accretion discs of young galaxies. In the early phase of our universe, they probably even formed the predominant state of matter.
The antiparticles of electrons are the positively charged positrons. Apart from their opposite electrical charge, they have exactly the same properties. When they collide, they annihilate each other in a very short time. However, the experimental set-up with the floating ring can delay this and thus enable the investigation of pair plasmas. It already works with electrons, and experiments with positrons are next on the agenda.
The video shows how the 15-centimetre ring slowly detaches itself from the platform and appears to fight for its freedom before it finally floats completely freely and stably - a state that lasted for three and a half hours in the experiment
Read more: Trapping antimatter and matter together
Video (please click into the picture to start)
The antiparticles of electrons are the positively charged positrons. Apart from their opposite electrical charge, they have exactly the same properties. When they collide, they annihilate each other in a very short time. However, the experimental set-up with the floating ring can delay this and thus enable the investigation of pair plasmas. It already works with electrons, and experiments with positrons are next on the agenda.
The video shows how the 15-centimetre ring slowly detaches itself from the platform and appears to fight for its freedom before it finally floats completely freely and stably - a state that lasted for three and a half hours in the experiment
Read more: Trapping antimatter and matter together
Video (please click into the picture to start)
© MPI for Plasmaphysics, Garching
3
Bringing light into the darkness
Quarks, leptons, bosons, gluons - at least 37 different elementary particles exist. In order to study them, scientist must first be able to detect them. This is where scintillators come into play, substances that are excited by interactions with high-energy particles and then emit this excitation energy in the form of measurable radiation. Scintillators can be crystals, liquids or polymer solids.
Shown here is a new scintillator material which has been recently developed at the MPI for Nuclear Physics. Its distinctive feature: it can be transparent or opaque, depending on the temperature. This could greatly simplify the detection of neutrinos and antineutrinos. Because by using the opaque material, their signals can be determined much more precisely and distinguished much better from interference signals. It might even make it possible to operate future neutrino detectors on the Earth's surface instead of building them in deep underground laboratories. Another important advantage of the new material: It is much safer and easier to handle than conventional detectors, which are often highly flammable. Using the new scintillator as a candle demonstrates that this is no problem here.
Photography
Shown here is a new scintillator material which has been recently developed at the MPI for Nuclear Physics. Its distinctive feature: it can be transparent or opaque, depending on the temperature. This could greatly simplify the detection of neutrinos and antineutrinos. Because by using the opaque material, their signals can be determined much more precisely and distinguished much better from interference signals. It might even make it possible to operate future neutrino detectors on the Earth's surface instead of building them in deep underground laboratories. Another important advantage of the new material: It is much safer and easier to handle than conventional detectors, which are often highly flammable. Using the new scintillator as a candle demonstrates that this is no problem here.
Photography
© MPI for Nuclear Physics, Heidelberg / Benjamin Gramlich
16
On the trail of life
What physical mechanisms do cells use to organise themselves? To find out, scientists at the Max Planck Institute for the Science of Light are reconstructing the basic structures and patterns of living systems in the laboratory. They achieve this by utilizing biological building blocks such as proteins and lipid membranes. In a carefully controlled artificial environment, they intentionally manipulate individual parameters, such as substance concentrations, and observe the resulting effects of these changes. Through this approach, they gain insights into the interactions among the inanimate components of a cell. Once they comprehend the subsystems and functional units in detail, the researchers aim to assemble these various parts into a functional, artificial cell. This endeavour raises a central question: what constitutes life, and how did it develop? The image shows fluorescently labelled proteins arranging themselves into snowflake-shaped patterns upon contact with lipid membranes.
Fluorescence microscopy
Fluorescence microscopy
© MPI for the Science of Light, Erlangen / Mergime Hasani
23
Decisions made easy
Whether on land, in water, or soaring through the air, animals continually face the challenge of deciding their next direction. But how do they tackle this dilemma? Scientists at the Max Planck Institute for Animal Behaviour have investigated this question using a computer model. This model takes into consideration how the brain represents spatial options for action.
In their exploration, the researchers discovered an algorithm with broad applications across species. According to this algorithm, animals process the complexity of their environment by deconstructing decisions among multiple options into a sequence of simpler choices between just two options—a scientific phenomenon known as "bifurcation." This strategic approach enables them to efficiently and swiftly choose a goal, irrespective of the initial number of options.
Behavioural experiments with animals as diverse as insects and fish have confirmed the model. The figure illustrates the basic geometric principles that control spatial decision making.
Read more: Deciding where to go
Computer simulation
In their exploration, the researchers discovered an algorithm with broad applications across species. According to this algorithm, animals process the complexity of their environment by deconstructing decisions among multiple options into a sequence of simpler choices between just two options—a scientific phenomenon known as "bifurcation." This strategic approach enables them to efficiently and swiftly choose a goal, irrespective of the initial number of options.
Behavioural experiments with animals as diverse as insects and fish have confirmed the model. The figure illustrates the basic geometric principles that control spatial decision making.
Read more: Deciding where to go
Computer simulation
© MPI of Animal Behavior, Konstanz / Vivek Sridhar
13
Effectively together
Our skin forms a protective barrier against pathogens. However, even the smallest injuries can allow bacteria, parasites or fungi to intrude and cause serious infections. To prevent this, scavenger cells of the innate immune system, the so-called neutrophil granulocytes, constantly patrol our blood vessels. At the first signs of inflammation, they migrate into the tissue. And they release chemical signals that attract more and more of their "colleagues”. Together they then attack the pathogens in order to kill and digest them. Max Planck researchers are investigating how such swarms of immune cells assemble – and also how they break up again when the intruders have been eliminated. The latter is important to ensure that the immune response does not overshoot. Because the same mechanisms that serve to eliminate invading pathogens can also cause collateral damage to healthy tissues. As the researchers were able to show, over time the neutrophil become insensitive to the signaling substances that originally brought them together. This leads to the end of the swarm. The image shows a collective of neutrophil granulocytes (green). The multi-colored tracks show the motion paths of the cells.
Read more: Hunting immune cells
Computer simulation
Read more: Hunting immune cells
Computer simulation
© MPI for Immunobiology and Epigenetics, Freiburg / Tim Lämmermann
4
Cells on the move
Many cells can actively migrate. During embryonic development, wound healing and immune defense, cell migration is vital for the organism's survival. However, the urge of cells to migrate can also have fatal consequences – for example in the formation of tumour metastases. Researchers at the MPI for the Physics of Complex Systems are investigating how cells migrate in groups and how they orient themselves in the process. They focus on a process called durotaxis, in which cells follow differences in stiffness of the surface they move on. The illustration visualizes the principle: cell aggregates are shown on a substrate with a stiffness varying from soft (left, yellow) to stiff (right, dark blue). On the soft region, cells remain in place forming a spherical aggregate — a living droplet. On the stiffer region, cells begin to move and the aggregate spreads into a thin film. The aggregate then performs durotaxis: It moves towards even stiffer regions. In frog embryos, scientists showed that durotaxis takes place in nature: When forming the face, certain cells orient themselves based on the stiffness of the underlying tissue.
Illustration
Illustration
© MPI for the Physics of Complex Systems / Mariona Esquerda Ciutat
9
More than the sum of its parts
When many similar units interact in such a way that something new is created, we call this emergence. Many biological processes are only made possible by emergent behavior on a range of very different scales – from individual molecules to cells to entire organisms. Here, scientists at the Max Planck Institute for Dynamics and Self-Organization in Göttingen have used a computer simulation to investigate the behavior of rods with a diameter of around one micrometer (the thousandth part of a millimeter) that grow in length and divide – an idealized form of bacteria. The rods in this virtual colony are colored in the image according to their orientation. They interact with each other exclusively by taking up more and more space as they grow, thereby pushing neighboring particles away. Despite this simple rule, large-scale domains of rods with almost identical orientation are formed over time (as seen from their uniform color). These microdomains are deformed by growth, break up and form again and again. The dynamics strongly depend on the external environment and also influence the shape of the colony as a whole. Using such minimal models, scientists can determine the essential ingredients which enable certain emergent behaviors.
Computer simulation
Computer simulation
© MPI for Dynamics and Self-Organization / Jonas Isensee, Philip Bittihn
7
Marked by disaster
For centuries, volcanic eruptions and earthquakes have shaped the history of Naples and its surroundings. But unlike other Italian cities (and also unlike other settlements closer to the slopes of Mount Vesuvius), Naples was never completely destroyed by the numerous disasters. However, the events have left deep marks on the city – both physically and culturally. Construction, reconstruction, destruction and rebuilding are a fundamental part of Neapolitan history.
In terms of art history, Naples is a palimpsest, so to speak, a document that is frequently washed away and rewritten. This is reflected in the city's architecture as well as in its art, in historical depictions, famous paintings and modern works. Contemporary artists such as pop art superstar Andy Warhol have explored the history of the city – and expressed this in works of art that are now a vital part of the city, such as the large mosaic by South African artist William Kentridge in the Toledo subway station.
Read more: Marked by disaster (PDF)
Video compilation (please click into the picture to start)
Full version: Palimpsest Naples. Natural Disasters (Video with art-historical commentary by scientist Tanja Michalsky and Elisabetta Scirocco) (vimeo / 20:32 min)
In terms of art history, Naples is a palimpsest, so to speak, a document that is frequently washed away and rewritten. This is reflected in the city's architecture as well as in its art, in historical depictions, famous paintings and modern works. Contemporary artists such as pop art superstar Andy Warhol have explored the history of the city – and expressed this in works of art that are now a vital part of the city, such as the large mosaic by South African artist William Kentridge in the Toledo subway station.
Read more: Marked by disaster (PDF)
Video compilation (please click into the picture to start)
Full version: Palimpsest Naples. Natural Disasters (Video with art-historical commentary by scientist Tanja Michalsky and Elisabetta Scirocco) (vimeo / 20:32 min)
© Bibliotheca Hertziana – MPI für Kunstgeschichte, Rom
1
Not brittle at all
Unlike conventional alloys, compositionally complex alloys (CCAs) consist of almost equal proportions of multiple metals, blending at the atomic level. This makes it possible to produce materials that combine disparate properties such as strength and ductility. The material shown here is CoCrFeNi, a CCA that retains its superior mechanical properties even at very low temperatures of -200°C. This material is produced using an additive manufacturing process, often referred to as 3D printing of metals. The decisive factor in this technique is an easy-flowing metal powder to spread uniform thin layers. Max Planck scientists have therefore added hard ceramic nanoparticles to the metal powder. These increase the flowability of the powder, but also the strength and toughness of the resulting alloy. The image shows a cross-sectional view of such a particle. It consists of a core composed of titanium oxide and a shell of titanium nitride, with a diameter measuring just under 150 nanometres (a nanometre is a millionth of a millimetre).
Electron microscopy, colored
Electron microscopy, colored
© MPI für Eisenforschung, Düsseldorf / Vivek Devulapalli
18
Who owns knowledge
In our modern, globalised world, the concept "knowledge" and "ownership" seem to be distinct. But are they truly independent, or are they intricately interconnected? The kn/own/able project –from "know" and "own" , explores the question of who possesses knowledge – not only in an academic context, but also in a social context. It addresses topics such as colonialism and decolonisation, cultural heritage, law and much more, including the evolution of science. Handweaving and the associated production of simple colours in India are an example of this concept: how do we deal with the "unspeakable" knowledge embedded in the bodies of weavers and the woven objects? What value does this knowledge hold in a society where legal ownership is primarily tied to texts like patents and copyright information? Other examples in the historical context are the production of porcelain or silk in China. In a contemporary context, it tackles questions surrounding the rights to traditional knowledge, particularly in the field of medicine.
Read more: knownable.org (interaktive project site)
The book "Ownership of Knowledge" freely available via Open Access.
Photography
Read more: knownable.org (interaktive project site)
The book "Ownership of Knowledge" freely available via Open Access.
Photography
© MPI for the History of Science, Berlin / Photo: Verena Braun
14
As if by magic
It's almost unbelievable at first glance: a large, flawless crystal seemingly appears out of nowhere in a beaker. However, this phenomenon isn't entirely spontaneous, and in reality, it doesn't happen quite as swiftly as it appears in the time-lapse footage. What seems to unfold in seconds in the video actually takes approximately four weeks in the laboratory. To start with, a supersaturated copper sulphate solution is required. Copper sulphate dissolves very well in water, and at high concentrations, the resulting solution takes on a dark blue hue. Under the right conditions, even more salt can be dissolved than the normal saturation allows. When a seed crystal is introduced into such a supersaturated, metastable solution, the crystal grows around this nucleus until the supersaturation is reduced.
Crystallization holds significant importance in both scientific research and industrial production, for example in the extraction and purification of pharmaceuticals. In most cases, the emphasis is on obtaining not large, but exceptionally pure and uniform crystals. Researchers at the Max Planck Institute in Magdeburg therefore closely monitor the crystallization process of various substances in growth chambers, considering factors such as temperature, pressure, or solvent properties.
Photography and Video (please click into the picture to start)
Crystallization holds significant importance in both scientific research and industrial production, for example in the extraction and purification of pharmaceuticals. In most cases, the emphasis is on obtaining not large, but exceptionally pure and uniform crystals. Researchers at the Max Planck Institute in Magdeburg therefore closely monitor the crystallization process of various substances in growth chambers, considering factors such as temperature, pressure, or solvent properties.
Photography and Video (please click into the picture to start)
© MPI for Dynamics of Complex Technical Systems
10
Galactic nursery
About 45 million light years from Earth lies a galaxy called NGC 1097. It has been the subject of the initial observations by Eris, a special infrared camera mounted on one of the eight-meter telescopes of the European Southern Observatory's Very Large Telescope (VLT) at Cerro Paranal in northern Chile. The new instrument provided an image of the center of the galaxy in unprecedented detail. Clearly visible is a ring of gas and dust measuring around 5500 light years across, in which numerous stars are being born. The bright spots on the outer side of the ring are such stellar nurseries. The brown regions, on the other hand, mark dust trails that show how gas from the outside of the galaxy migrates inwards. This process fuels the birth of stars. Deep in the heart of NGC 1097 lurks a supermassive black hole, which is fed by the spiraling inward flow of gas. Eris, built by a consortium led by the Max Planck Institute for Extraterrestrial Physics, will not only observe galaxies over the next ten years, but also exoplanets orbiting foreign stars and dwarf planets in our own solar system.
Read more: Eris sees “first light”
Telescope image
Read more: Eris sees “first light”
Telescope image
© MPE/ESO/ERIS
15
An ancient partnership
Leaf beetles represent one of the most diverse insect families on earth. A well-known representative of this group is the potato beetle. Both the larvae and adult leaf beetles are avid plant feeders, consuming various parts of plants. Researchers at the Max Planck Institute for Chemical Ecology are investigating the digestive systems of several species to understand how these insects have adapted to their herbivorous lifestyle. Symbiotic bacteria, prevalent in the bodies of many leaf beetles, play a pivotal role in this adaptation. They assist in breaking down the plant cell wall and provide essential nutrients, including amino acids and vitamins, to their hosts. These symbiotic relationships have endured for over 60 million years, enabling beetles to thrive in previously uninhabited, nutrient-poor environments. The image features a rare Australian leaf beetle (Spilopyra sumptuosa) distinguished by its metallic colouring on the head, thoracic shield, and elytra. Comprising nearly 3000 individual images, the picture showcases extraordinary sharpness of detail.
Photography
Photography
© MPI for Chemical Ecology
24
Energy!
In medicine, charged protons or electrons are accelerated and fired at diseased tissue, often with the goal of eliminating malignant tumours. These accelerators operate in large facilities, utilizing a series of interconnected electrical fields to propel particles to high speeds and energies. Looking ahead, a more manageable version of such a particle accelerator could be based on plasma waves. In this envisioned approach, charged particles undergo unidirectional acceleration through a series of electric fields. The artist's impression illustrates this concept: a bundle of free protons, measuring only ten centimetres in length (depicted as diffuse reddish dot clouds), resides within a plasma of free charged particles (comprising electrons and ionised atoms, illustrated as small blue dots). A laser pulse (red) penetrates the plasma and the proton bundle from bottom to top , inducing the plasma to oscillate along the laser. In response to its charge, the proton bundle resonates, and splits into a series of concentrated packets akin to sand on a loudspeaker membrane. Electrons can now ride along the resulting electric field chain, as if on a plasma wave, thus achieving acceleration.
Visualization
Visualization
© superbossa.com/ MPI for Physics
12
The Kingdom in the Sky
The entire national territory of Lesotho lies at an altitude of more than 1000 meters above sea level, the vast majority between 1800 and 3000 meters. Hence the nickname "Kingdom in the Sky". In contrast to the surrounding regions in southern Africa, water is abundant here. In winter, the climate is harsh, snow covers the land and the 192-metre-high Maletsunyane waterfall might be frozen.
Scientists at the MPI of Geoanthropology have investigated in the mountainous regions of Lesotho how our ancestors coped with difficult and changing climatic conditions. Because even in the Pleistocene, the last glacial period, the area was inhabited. The researchers analyzed waxes from plant leaves that preserve well in sediments for hundreds of thousands of years. This enabled them to document the vegetation and precipitation conditions over a period of around 60,000 years. Particularly interesting are the last 20,000 years, as climate conditions changed dramatically with the transition from the Pleistocene to the Holocene. As the results show, people used the high-altitude areas of Lesotho continuously, most likely due to the reliable water supply. At the same time, the work shows the unprecedented extent of climate warming and landscape change in this region over the last 200 years.
Read more: Millennia of Ecological Change
Photographie
Scientists at the MPI of Geoanthropology have investigated in the mountainous regions of Lesotho how our ancestors coped with difficult and changing climatic conditions. Because even in the Pleistocene, the last glacial period, the area was inhabited. The researchers analyzed waxes from plant leaves that preserve well in sediments for hundreds of thousands of years. This enabled them to document the vegetation and precipitation conditions over a period of around 60,000 years. Particularly interesting are the last 20,000 years, as climate conditions changed dramatically with the transition from the Pleistocene to the Holocene. As the results show, people used the high-altitude areas of Lesotho continuously, most likely due to the reliable water supply. At the same time, the work shows the unprecedented extent of climate warming and landscape change in this region over the last 200 years.
Read more: Millennia of Ecological Change
Photographie
© MPI of Geoanthropology, Jena / Patrick Roberts
11
Well equipped for life
Oocytes are among the largest cells in the animal kingdom. They contain plenty of nutrients to give the embryo the best possible start into life. When an egg cell is formed, the progenitor cell divides extremely asymmetrically and undergoes a very particular form of cell division: meiosis. Researchers at the Max Planck Institute for Multidisciplinary Science are investigating how the cell division apparatus has adapted to this special type of segmentation. As one model, they use marine organisms such as starfish, whose eggs are ideal for light microscopy: they are highly transparent, easy to handle and divide fast.
From the fertilized egg cell a new multicellular organism can develop through repeated regular divisions, called mitosis. Here you can see a starfish embryo at the beginning of its life, right in the middle of the second division cycle. The chromosomes are highlighted in magenta, the microtubules in yellow. Microtubules are an essential part of the cytoskeleton. They form the so-called spindle, which during the cell division allocates the chromosomes to the two daughter cells.
Fluorescence microscopy
From the fertilized egg cell a new multicellular organism can develop through repeated regular divisions, called mitosis. Here you can see a starfish embryo at the beginning of its life, right in the middle of the second division cycle. The chromosomes are highlighted in magenta, the microtubules in yellow. Microtubules are an essential part of the cytoskeleton. They form the so-called spindle, which during the cell division allocates the chromosomes to the two daughter cells.
Fluorescence microscopy
© MPI for Multidisciplinary Sciences, Göttingen / Mingfang Cai und Peter Lenart
6
Baking in a vacuum chamber
Anyone designing a new material has to understand it down to the detail. For example, there is the question of which atoms the material is consisting of and how these atoms are positioned and bonded to each other. One crucial thing is to measure how the electrons in the material behave. As part of a solid, electrons take on very specific energy levels that are characteristic of many physical properties – such as the question of whether the material is an electrical conductor or an insulator. By exposing the material to X-rays and measuring the energy of the emitted electrons, scientists can draw conclusions about the energy levels in which the electrons were previously located. To do this, however, they must first thoroughly prepare the sample and clean and smooth its surface at an atomic level. Therefore, the very small sample, which is no more than a few millimeters or even micrometers in size, is heated to 600 degrees Celsius in an ultra-high vacuum chamber. The view through the porthole of the chamber is directed at the approximately two-centimeter-long block-shaped sample holder in the center, which, like the connecting wire, glows purple due to the heat.
Photography
Photography
© MPI for Chemical Physics of Solids, Dresden / Katarina Höfer
17
Guardians of the genome
The cells of all "higher organisms” (which essentially refers to all organisms except bacteria) have a nucleus. This nucleus serves as the repository for genetic material, stored in the form of DNA. Isolated from the rest of the cell, known as the cytoplasm, the genetic material is shielded by a double membrane known as the nuclear envelope. The interaction of substances and information between the nucleus and cytoplasm is facilitated exclusively through pores in the nuclear envelope. In a typical vertebrate cell, there are approximately 2000 of these nuclear pores.
These pores possess the ability to constrict and expand, thereby regulating the transportation of materials between the nucleus and the cytoplasm. From a biochemical perspective, a pore is a sophisticated protein complex composed of more than 30 different proteins. Each individual pore is comprised of approximately 1000 of these building blocks and measures only a few ten-thousandths of a millimetre in size.
A research team at the Max Planck Institute of Biophysics has successfully developed a highly detailed model of a human nuclear pore with the assistance of AI. Such models play a crucial in advancing our understanding of the transport and defence mechanisms of pores, allowing for the identification of defects in their structure and function. This knowledge holds significant medical implications, potentially allowing the prevention of viruses like HIV from entering the cell nucleus undetected.
Structural model, created with cryo-electron tomography and AlphaFold2 / Computer simulation (please click on the image to start the video)
These pores possess the ability to constrict and expand, thereby regulating the transportation of materials between the nucleus and the cytoplasm. From a biochemical perspective, a pore is a sophisticated protein complex composed of more than 30 different proteins. Each individual pore is comprised of approximately 1000 of these building blocks and measures only a few ten-thousandths of a millimetre in size.
A research team at the Max Planck Institute of Biophysics has successfully developed a highly detailed model of a human nuclear pore with the assistance of AI. Such models play a crucial in advancing our understanding of the transport and defence mechanisms of pores, allowing for the identification of defects in their structure and function. This knowledge holds significant medical implications, potentially allowing the prevention of viruses like HIV from entering the cell nucleus undetected.
Structural model, created with cryo-electron tomography and AlphaFold2 / Computer simulation (please click on the image to start the video)
© MPI for Biophysics, Frankfurt / Agnieszka Obarska-Kosinska
20
Close-up of stellar birth
Stars do not come into existence gently. It all begins with diffuse clouds of interstellar matter. Due to gravity and the collision of particles, these clouds undergo contraction, eventually breaking down into highly dense fragments. These prestellar cores, in turn, also become unstable, collapsing again to form protostars. In this image captured by the James Webb Space Telescope, one such baby star, only a few tens of thousands of years old, lies hidden behind dense dust curtains at the centre of two gas streams that it spits out in opposite directions. These jets propel matter into space at speeds of several hundred kilometres per second. Upon colliding with nearby gas and dust, these jets conjure up colourful Herbig-Haro objects in the universe, named after the two astronomers who first recognised these phenomena as part of the star formation process. Behind them are shock waves that cause the gas to glow. This particular newborn star is located in the Perseus constellation, around a thousand light years away from Earth, and has only about eight percent of the mass of our Sun. After its turbulent first phase of life, it will eventually reach a state of equilibrium andevolve into a relatively calm, adult star.
Read more: Supersonic outflow of young star
Telescope image (James Webb Space Telescope / NIRCam)
Read more: Supersonic outflow of young star
Telescope image (James Webb Space Telescope / NIRCam)
© ESA/Webb, NASA, CSA, T. Ray (Dublin Institute for Advanced Studies)
21
Painting with DNA
The crescent-shaped freshwater bacterium Caulobacter crescentus has a unique life cycle: when it divides, two different daughter cells are formed. One of them forms a stalk-like projection with which the cell can attach itself to surfaces. Max Planck Fellow Martin Thanbichler uses this special feature to find out how bacteria control their cell cycle and shape. The image shows a C. crescentus cell shortly before division and a newly formed, non-stalked cell next to it. The chromosomal DNA (blue) and the cell membranes (red) were labelled with fluorescent dyes and visualised by means of high-resolution microscopy using the DNA-PAINT technique. The dye molecules bind only temporarily to the DNA or the membranes and generate a brief "flashing" of the fluorescence signal with each binding process. This enables super-resolution reconstruction. In this way, tiny changes in the fine structure of cells can be detected, for example to analyse the effect of antibiotics on cellular physiology in detail.
Read more: A new Achilles heel of the bacterial cell wall
Fluorescence microscopy (DNA paint technique)
Read more: A new Achilles heel of the bacterial cell wall
Fluorescence microscopy (DNA paint technique)
© MPI for Terrestrial Microbiology, Marburg / Rogelio Hernandez-Tamayo
19
Mysterious droplets
In 2009, researchers led by Anthony Hyman from the Max Planck Institute of Molecular Cell Biology and Genetics discovered a completely new state of biological matter: in the cell fluid of nematode embryos, they came across highly concentrated accumulations of proteins that resemble tiny droplets. Unlike cell organelles, these structures, which the scientists named "condensates", lack a surrounding membrane. They have the ability to form rapidly, sometimes in a matter of seconds, and are typically disassembled shortly afterward. The high protein concentration inside the droplets stimulates biochemical reactions that would not be possible outside.
Condensates are also found in human cells and play a vital role in cell metabolism. If their degradation is disrupted - often due to ageing - toxic substances can be deposited in them, which are associated with degenerative diseases such as ALS or Alzheimer's disease. The discovery of droplets is therefore an important starting point for understanding many diseases and exploring the development of novel drugs. The image shows a water-oil emulsion with fluorescently labelled condensates of a nematode protein.
Read more: Droplets in the cellular soup (PDF)
Fluorescence microscopy
Condensates are also found in human cells and play a vital role in cell metabolism. If their degradation is disrupted - often due to ageing - toxic substances can be deposited in them, which are associated with degenerative diseases such as ALS or Alzheimer's disease. The discovery of droplets is therefore an important starting point for understanding many diseases and exploring the development of novel drugs. The image shows a water-oil emulsion with fluorescently labelled condensates of a nematode protein.
Read more: Droplets in the cellular soup (PDF)
Fluorescence microscopy
© MPI of Molecular Cell Biology and Genetics / Anatol Fritsch
8
Spread out
Plants have developed numerous ingenious strategies to disperse their seeds. In the popping cress Cardamine hirsuta, exploding seed capsules propel the seeds in all directions. Max Planck scientists have investigated the mechanism behind this in detail. As they discovered, the polymer lignin (shown here in red) plays a central role. For the slingshot mechanism to work, the polymer must be embedded in the capsule wall (shown here in blue) in a very specific pattern. The micronutrient copper is required for the formation of this pattern. In addition, the researchers have also identified the genes that control the incorporation of lignin into the wall of the seed pod cells. These findings are particularly interesting for the forestry sector, since lignin is the substance that gives wood its strength and rigidity. However, forest soils often have a low copper content, which leads to poor lignification and a weakening of the trees. Understanding the role of copper in the lignification process is therefore also of economic importance.
Read more: Copper makes seed pods explode
Fluorescence microscopy
Read more: Copper makes seed pods explode
Fluorescence microscopy
© MPI for Plant Breeding Research / Miguel Pérez Antón
5
Liver en miniature
Organoids are miniature versions of organs that are cultured from stem cells in the laboratory. They hold great promise for the future of biomedical research, as they enable scientists to study very different aspects such as organ development, tissue regeneration, diseases and new therapies without the need for complete organisms. The cell clumps, which are only a few millimeters in size, therefore make an important contribution to avoiding animal experiments. Researchers at the Max Planck Institute for Molecular Genetics use such liver models to study various diseases. The image shows human liver organoids that secrete albumin (shown here in green). Albumin is one of the most important proteins produced by the liver and is indispensable in the body for transport processes in the blood. The fact that liver organoids produce this protein in the laboratory is proof of the high functionality of these organ models.
Fluorescence microscopy, animated
Fluorescence microscopy, animated
© MPI for Molecular Genetics / Anja Hess
2
The universe in the mainframe
Take a good portion of gas, add dark matter and refine the mixture with gravity and massive neutrinos. Then feed these ingredients into two supercomputers and wait for the result. Well, it wasn't quite that easy for the researchers to recreate the development of the universe and the galaxies within it.. But the recipe worked and delivered the most comprehensive hydrodynamic simulation model of the universe to date. It examines the behavior of liquids and gases under the influence of forces such as flow, pressure and gravity.
This way, the "MillenniumTNG" project was able to model the formation of around one hundred million galaxies in a region with a diameter of almost two and a half billion light years. The image shows a detail from the simulation with gas (top left), dark matter (top right) and starlight (bottom center). Indicated in the two upper sections are the threads of the cosmic web that runs through the cosmos on a large scale. Among other things, the new calculations are intended to contribute to a precision test of the standard cosmological model.
Read more: Putting the universe to the test
Computer simulation
This way, the "MillenniumTNG" project was able to model the formation of around one hundred million galaxies in a region with a diameter of almost two and a half billion light years. The image shows a detail from the simulation with gas (top left), dark matter (top right) and starlight (bottom center). Indicated in the two upper sections are the threads of the cosmic web that runs through the cosmos on a large scale. Among other things, the new calculations are intended to contribute to a precision test of the standard cosmological model.
Read more: Putting the universe to the test
Computer simulation
© Max Planck Institute for Astrophysics, Garching
22
Floating particle trap
...... a shiny gold ring floats in a vacuum chamber at the MPI for Plasma Physics in Garching. In this state, the superconducting magnetic ring can capture charged particles, both positive and negative. The scientists want to use it to investigate matter-antimatter plasmas. On Earth, we only know of such plasmas in science fiction - but they do exist in the universe: in the vicinity of quasars and perhaps also in the accretion discs of young galaxies. In the early phase of our universe, they probably even formed the predominant state of matter.
The antiparticles of electrons are the positively charged positrons. Apart from their opposite electrical charge, they have exactly the same properties. When they collide, they annihilate each other in a very short time. However, the experimental set-up with the floating ring can delay this and thus enable the investigation of pair plasmas. It already works with electrons, and experiments with positrons are next on the agenda.
The video shows how the 15-centimetre ring slowly detaches itself from the platform and appears to fight for its freedom before it finally floats completely freely and stably - a state that lasted for three and a half hours in the experiment
Read more: Trapping antimatter and matter together
Video (please click into the picture to start)
The antiparticles of electrons are the positively charged positrons. Apart from their opposite electrical charge, they have exactly the same properties. When they collide, they annihilate each other in a very short time. However, the experimental set-up with the floating ring can delay this and thus enable the investigation of pair plasmas. It already works with electrons, and experiments with positrons are next on the agenda.
The video shows how the 15-centimetre ring slowly detaches itself from the platform and appears to fight for its freedom before it finally floats completely freely and stably - a state that lasted for three and a half hours in the experiment
Read more: Trapping antimatter and matter together
Video (please click into the picture to start)
© MPI for Plasmaphysics, Garching
3
Bringing light into the darkness
Quarks, leptons, bosons, gluons - at least 37 different elementary particles exist. In order to study them, scientist must first be able to detect them. This is where scintillators come into play, substances that are excited by interactions with high-energy particles and then emit this excitation energy in the form of measurable radiation. Scintillators can be crystals, liquids or polymer solids.
Shown here is a new scintillator material which has been recently developed at the MPI for Nuclear Physics. Its distinctive feature: it can be transparent or opaque, depending on the temperature. This could greatly simplify the detection of neutrinos and antineutrinos. Because by using the opaque material, their signals can be determined much more precisely and distinguished much better from interference signals. It might even make it possible to operate future neutrino detectors on the Earth's surface instead of building them in deep underground laboratories. Another important advantage of the new material: It is much safer and easier to handle than conventional detectors, which are often highly flammable. Using the new scintillator as a candle demonstrates that this is no problem here.
Photography
Shown here is a new scintillator material which has been recently developed at the MPI for Nuclear Physics. Its distinctive feature: it can be transparent or opaque, depending on the temperature. This could greatly simplify the detection of neutrinos and antineutrinos. Because by using the opaque material, their signals can be determined much more precisely and distinguished much better from interference signals. It might even make it possible to operate future neutrino detectors on the Earth's surface instead of building them in deep underground laboratories. Another important advantage of the new material: It is much safer and easier to handle than conventional detectors, which are often highly flammable. Using the new scintillator as a candle demonstrates that this is no problem here.
Photography
© MPI for Nuclear Physics, Heidelberg / Benjamin Gramlich
16
On the trail of life
What physical mechanisms do cells use to organise themselves? To find out, scientists at the Max Planck Institute for the Science of Light are reconstructing the basic structures and patterns of living systems in the laboratory. They achieve this by utilizing biological building blocks such as proteins and lipid membranes. In a carefully controlled artificial environment, they intentionally manipulate individual parameters, such as substance concentrations, and observe the resulting effects of these changes. Through this approach, they gain insights into the interactions among the inanimate components of a cell. Once they comprehend the subsystems and functional units in detail, the researchers aim to assemble these various parts into a functional, artificial cell. This endeavour raises a central question: what constitutes life, and how did it develop? The image shows fluorescently labelled proteins arranging themselves into snowflake-shaped patterns upon contact with lipid membranes.
Fluorescence microscopy
Fluorescence microscopy
© MPI for the Science of Light, Erlangen / Mergime Hasani
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Decisions made easy
Whether on land, in water, or soaring through the air, animals continually face the challenge of deciding their next direction. But how do they tackle this dilemma? Scientists at the Max Planck Institute for Animal Behaviour have investigated this question using a computer model. This model takes into consideration how the brain represents spatial options for action.
In their exploration, the researchers discovered an algorithm with broad applications across species. According to this algorithm, animals process the complexity of their environment by deconstructing decisions among multiple options into a sequence of simpler choices between just two options—a scientific phenomenon known as "bifurcation." This strategic approach enables them to efficiently and swiftly choose a goal, irrespective of the initial number of options.
Behavioural experiments with animals as diverse as insects and fish have confirmed the model. The figure illustrates the basic geometric principles that control spatial decision making.
Read more: Deciding where to go
Computer simulation
In their exploration, the researchers discovered an algorithm with broad applications across species. According to this algorithm, animals process the complexity of their environment by deconstructing decisions among multiple options into a sequence of simpler choices between just two options—a scientific phenomenon known as "bifurcation." This strategic approach enables them to efficiently and swiftly choose a goal, irrespective of the initial number of options.
Behavioural experiments with animals as diverse as insects and fish have confirmed the model. The figure illustrates the basic geometric principles that control spatial decision making.
Read more: Deciding where to go
Computer simulation
© MPI of Animal Behavior, Konstanz / Vivek Sridhar
13
Effectively together
Our skin forms a protective barrier against pathogens. However, even the smallest injuries can allow bacteria, parasites or fungi to intrude and cause serious infections. To prevent this, scavenger cells of the innate immune system, the so-called neutrophil granulocytes, constantly patrol our blood vessels. At the first signs of inflammation, they migrate into the tissue. And they release chemical signals that attract more and more of their "colleagues”. Together they then attack the pathogens in order to kill and digest them. Max Planck researchers are investigating how such swarms of immune cells assemble – and also how they break up again when the intruders have been eliminated. The latter is important to ensure that the immune response does not overshoot. Because the same mechanisms that serve to eliminate invading pathogens can also cause collateral damage to healthy tissues. As the researchers were able to show, over time the neutrophil become insensitive to the signaling substances that originally brought them together. This leads to the end of the swarm. The image shows a collective of neutrophil granulocytes (green). The multi-colored tracks show the motion paths of the cells.
Read more: Hunting immune cells
Computer simulation
Read more: Hunting immune cells
Computer simulation
© MPI for Immunobiology and Epigenetics, Freiburg / Tim Lämmermann
4
Cells on the move
Many cells can actively migrate. During embryonic development, wound healing and immune defense, cell migration is vital for the organism's survival. However, the urge of cells to migrate can also have fatal consequences – for example in the formation of tumour metastases. Researchers at the MPI for the Physics of Complex Systems are investigating how cells migrate in groups and how they orient themselves in the process. They focus on a process called durotaxis, in which cells follow differences in stiffness of the surface they move on. The illustration visualizes the principle: cell aggregates are shown on a substrate with a stiffness varying from soft (left, yellow) to stiff (right, dark blue). On the soft region, cells remain in place forming a spherical aggregate — a living droplet. On the stiffer region, cells begin to move and the aggregate spreads into a thin film. The aggregate then performs durotaxis: It moves towards even stiffer regions. In frog embryos, scientists showed that durotaxis takes place in nature: When forming the face, certain cells orient themselves based on the stiffness of the underlying tissue.
Illustration
Illustration
© MPI for the Physics of Complex Systems / Mariona Esquerda Ciutat
9
More than the sum of its parts
When many similar units interact in such a way that something new is created, we call this emergence. Many biological processes are only made possible by emergent behavior on a range of very different scales – from individual molecules to cells to entire organisms. Here, scientists at the Max Planck Institute for Dynamics and Self-Organization in Göttingen have used a computer simulation to investigate the behavior of rods with a diameter of around one micrometer (the thousandth part of a millimeter) that grow in length and divide – an idealized form of bacteria. The rods in this virtual colony are colored in the image according to their orientation. They interact with each other exclusively by taking up more and more space as they grow, thereby pushing neighboring particles away. Despite this simple rule, large-scale domains of rods with almost identical orientation are formed over time (as seen from their uniform color). These microdomains are deformed by growth, break up and form again and again. The dynamics strongly depend on the external environment and also influence the shape of the colony as a whole. Using such minimal models, scientists can determine the essential ingredients which enable certain emergent behaviors.
Computer simulation
Computer simulation
© MPI for Dynamics and Self-Organization / Jonas Isensee, Philip Bittihn
7
Marked by disaster
For centuries, volcanic eruptions and earthquakes have shaped the history of Naples and its surroundings. But unlike other Italian cities (and also unlike other settlements closer to the slopes of Mount Vesuvius), Naples was never completely destroyed by the numerous disasters. However, the events have left deep marks on the city – both physically and culturally. Construction, reconstruction, destruction and rebuilding are a fundamental part of Neapolitan history.
In terms of art history, Naples is a palimpsest, so to speak, a document that is frequently washed away and rewritten. This is reflected in the city's architecture as well as in its art, in historical depictions, famous paintings and modern works. Contemporary artists such as pop art superstar Andy Warhol have explored the history of the city – and expressed this in works of art that are now a vital part of the city, such as the large mosaic by South African artist William Kentridge in the Toledo subway station.
Read more: Marked by disaster (PDF)
Video compilation (please click into the picture to start)
Full version: Palimpsest Naples. Natural Disasters (Video with art-historical commentary by scientist Tanja Michalsky and Elisabetta Scirocco) (vimeo / 20:32 min)
In terms of art history, Naples is a palimpsest, so to speak, a document that is frequently washed away and rewritten. This is reflected in the city's architecture as well as in its art, in historical depictions, famous paintings and modern works. Contemporary artists such as pop art superstar Andy Warhol have explored the history of the city – and expressed this in works of art that are now a vital part of the city, such as the large mosaic by South African artist William Kentridge in the Toledo subway station.
Read more: Marked by disaster (PDF)
Video compilation (please click into the picture to start)
Full version: Palimpsest Naples. Natural Disasters (Video with art-historical commentary by scientist Tanja Michalsky and Elisabetta Scirocco) (vimeo / 20:32 min)
© Bibliotheca Hertziana – MPI für Kunstgeschichte, Rom
1
Not brittle at all
Unlike conventional alloys, compositionally complex alloys (CCAs) consist of almost equal proportions of multiple metals, blending at the atomic level. This makes it possible to produce materials that combine disparate properties such as strength and ductility. The material shown here is CoCrFeNi, a CCA that retains its superior mechanical properties even at very low temperatures of -200°C. This material is produced using an additive manufacturing process, often referred to as 3D printing of metals. The decisive factor in this technique is an easy-flowing metal powder to spread uniform thin layers. Max Planck scientists have therefore added hard ceramic nanoparticles to the metal powder. These increase the flowability of the powder, but also the strength and toughness of the resulting alloy. The image shows a cross-sectional view of such a particle. It consists of a core composed of titanium oxide and a shell of titanium nitride, with a diameter measuring just under 150 nanometres (a nanometre is a millionth of a millimetre).
Electron microscopy, colored
Electron microscopy, colored
© MPI für Eisenforschung, Düsseldorf / Vivek Devulapalli
18
Who owns knowledge
In our modern, globalised world, the concept "knowledge" and "ownership" seem to be distinct. But are they truly independent, or are they intricately interconnected? The kn/own/able project –from "know" and "own" , explores the question of who possesses knowledge – not only in an academic context, but also in a social context. It addresses topics such as colonialism and decolonisation, cultural heritage, law and much more, including the evolution of science. Handweaving and the associated production of simple colours in India are an example of this concept: how do we deal with the "unspeakable" knowledge embedded in the bodies of weavers and the woven objects? What value does this knowledge hold in a society where legal ownership is primarily tied to texts like patents and copyright information? Other examples in the historical context are the production of porcelain or silk in China. In a contemporary context, it tackles questions surrounding the rights to traditional knowledge, particularly in the field of medicine.
Read more: knownable.org (interaktive project site)
The book "Ownership of Knowledge" freely available via Open Access.
Photography
Read more: knownable.org (interaktive project site)
The book "Ownership of Knowledge" freely available via Open Access.
Photography
© MPI for the History of Science, Berlin / Photo: Verena Braun
14
As if by magic
It's almost unbelievable at first glance: a large, flawless crystal seemingly appears out of nowhere in a beaker. However, this phenomenon isn't entirely spontaneous, and in reality, it doesn't happen quite as swiftly as it appears in the time-lapse footage. What seems to unfold in seconds in the video actually takes approximately four weeks in the laboratory. To start with, a supersaturated copper sulphate solution is required. Copper sulphate dissolves very well in water, and at high concentrations, the resulting solution takes on a dark blue hue. Under the right conditions, even more salt can be dissolved than the normal saturation allows. When a seed crystal is introduced into such a supersaturated, metastable solution, the crystal grows around this nucleus until the supersaturation is reduced.
Crystallization holds significant importance in both scientific research and industrial production, for example in the extraction and purification of pharmaceuticals. In most cases, the emphasis is on obtaining not large, but exceptionally pure and uniform crystals. Researchers at the Max Planck Institute in Magdeburg therefore closely monitor the crystallization process of various substances in growth chambers, considering factors such as temperature, pressure, or solvent properties.
Photography and Video (please click into the picture to start)
Crystallization holds significant importance in both scientific research and industrial production, for example in the extraction and purification of pharmaceuticals. In most cases, the emphasis is on obtaining not large, but exceptionally pure and uniform crystals. Researchers at the Max Planck Institute in Magdeburg therefore closely monitor the crystallization process of various substances in growth chambers, considering factors such as temperature, pressure, or solvent properties.
Photography and Video (please click into the picture to start)
© MPI for Dynamics of Complex Technical Systems
10
Galactic nursery
About 45 million light years from Earth lies a galaxy called NGC 1097. It has been the subject of the initial observations by Eris, a special infrared camera mounted on one of the eight-meter telescopes of the European Southern Observatory's Very Large Telescope (VLT) at Cerro Paranal in northern Chile. The new instrument provided an image of the center of the galaxy in unprecedented detail. Clearly visible is a ring of gas and dust measuring around 5500 light years across, in which numerous stars are being born. The bright spots on the outer side of the ring are such stellar nurseries. The brown regions, on the other hand, mark dust trails that show how gas from the outside of the galaxy migrates inwards. This process fuels the birth of stars. Deep in the heart of NGC 1097 lurks a supermassive black hole, which is fed by the spiraling inward flow of gas. Eris, built by a consortium led by the Max Planck Institute for Extraterrestrial Physics, will not only observe galaxies over the next ten years, but also exoplanets orbiting foreign stars and dwarf planets in our own solar system.
Read more: Eris sees “first light”
Telescope image
Read more: Eris sees “first light”
Telescope image
© MPE/ESO/ERIS
15
An ancient partnership
Leaf beetles represent one of the most diverse insect families on earth. A well-known representative of this group is the potato beetle. Both the larvae and adult leaf beetles are avid plant feeders, consuming various parts of plants. Researchers at the Max Planck Institute for Chemical Ecology are investigating the digestive systems of several species to understand how these insects have adapted to their herbivorous lifestyle. Symbiotic bacteria, prevalent in the bodies of many leaf beetles, play a pivotal role in this adaptation. They assist in breaking down the plant cell wall and provide essential nutrients, including amino acids and vitamins, to their hosts. These symbiotic relationships have endured for over 60 million years, enabling beetles to thrive in previously uninhabited, nutrient-poor environments. The image features a rare Australian leaf beetle (Spilopyra sumptuosa) distinguished by its metallic colouring on the head, thoracic shield, and elytra. Comprising nearly 3000 individual images, the picture showcases extraordinary sharpness of detail.
Photography
Photography
© MPI for Chemical Ecology
24
Energy!
In medicine, charged protons or electrons are accelerated and fired at diseased tissue, often with the goal of eliminating malignant tumours. These accelerators operate in large facilities, utilizing a series of interconnected electrical fields to propel particles to high speeds and energies. Looking ahead, a more manageable version of such a particle accelerator could be based on plasma waves. In this envisioned approach, charged particles undergo unidirectional acceleration through a series of electric fields. The artist's impression illustrates this concept: a bundle of free protons, measuring only ten centimetres in length (depicted as diffuse reddish dot clouds), resides within a plasma of free charged particles (comprising electrons and ionised atoms, illustrated as small blue dots). A laser pulse (red) penetrates the plasma and the proton bundle from bottom to top , inducing the plasma to oscillate along the laser. In response to its charge, the proton bundle resonates, and splits into a series of concentrated packets akin to sand on a loudspeaker membrane. Electrons can now ride along the resulting electric field chain, as if on a plasma wave, thus achieving acceleration.
Visualization
Visualization
© superbossa.com/ MPI for Physics
12
The Kingdom in the Sky
The entire national territory of Lesotho lies at an altitude of more than 1000 meters above sea level, the vast majority between 1800 and 3000 meters. Hence the nickname "Kingdom in the Sky". In contrast to the surrounding regions in southern Africa, water is abundant here. In winter, the climate is harsh, snow covers the land and the 192-metre-high Maletsunyane waterfall might be frozen.
Scientists at the MPI of Geoanthropology have investigated in the mountainous regions of Lesotho how our ancestors coped with difficult and changing climatic conditions. Because even in the Pleistocene, the last glacial period, the area was inhabited. The researchers analyzed waxes from plant leaves that preserve well in sediments for hundreds of thousands of years. This enabled them to document the vegetation and precipitation conditions over a period of around 60,000 years. Particularly interesting are the last 20,000 years, as climate conditions changed dramatically with the transition from the Pleistocene to the Holocene. As the results show, people used the high-altitude areas of Lesotho continuously, most likely due to the reliable water supply. At the same time, the work shows the unprecedented extent of climate warming and landscape change in this region over the last 200 years.
Read more: Millennia of Ecological Change
Photographie
Scientists at the MPI of Geoanthropology have investigated in the mountainous regions of Lesotho how our ancestors coped with difficult and changing climatic conditions. Because even in the Pleistocene, the last glacial period, the area was inhabited. The researchers analyzed waxes from plant leaves that preserve well in sediments for hundreds of thousands of years. This enabled them to document the vegetation and precipitation conditions over a period of around 60,000 years. Particularly interesting are the last 20,000 years, as climate conditions changed dramatically with the transition from the Pleistocene to the Holocene. As the results show, people used the high-altitude areas of Lesotho continuously, most likely due to the reliable water supply. At the same time, the work shows the unprecedented extent of climate warming and landscape change in this region over the last 200 years.
Read more: Millennia of Ecological Change
Photographie
© MPI of Geoanthropology, Jena / Patrick Roberts
11
Well equipped for life
Oocytes are among the largest cells in the animal kingdom. They contain plenty of nutrients to give the embryo the best possible start into life. When an egg cell is formed, the progenitor cell divides extremely asymmetrically and undergoes a very particular form of cell division: meiosis. Researchers at the Max Planck Institute for Multidisciplinary Science are investigating how the cell division apparatus has adapted to this special type of segmentation. As one model, they use marine organisms such as starfish, whose eggs are ideal for light microscopy: they are highly transparent, easy to handle and divide fast.
From the fertilized egg cell a new multicellular organism can develop through repeated regular divisions, called mitosis. Here you can see a starfish embryo at the beginning of its life, right in the middle of the second division cycle. The chromosomes are highlighted in magenta, the microtubules in yellow. Microtubules are an essential part of the cytoskeleton. They form the so-called spindle, which during the cell division allocates the chromosomes to the two daughter cells.
Fluorescence microscopy
From the fertilized egg cell a new multicellular organism can develop through repeated regular divisions, called mitosis. Here you can see a starfish embryo at the beginning of its life, right in the middle of the second division cycle. The chromosomes are highlighted in magenta, the microtubules in yellow. Microtubules are an essential part of the cytoskeleton. They form the so-called spindle, which during the cell division allocates the chromosomes to the two daughter cells.
Fluorescence microscopy
© MPI for Multidisciplinary Sciences, Göttingen / Mingfang Cai und Peter Lenart
6
Baking in a vacuum chamber
Anyone designing a new material has to understand it down to the detail. For example, there is the question of which atoms the material is consisting of and how these atoms are positioned and bonded to each other. One crucial thing is to measure how the electrons in the material behave. As part of a solid, electrons take on very specific energy levels that are characteristic of many physical properties – such as the question of whether the material is an electrical conductor or an insulator. By exposing the material to X-rays and measuring the energy of the emitted electrons, scientists can draw conclusions about the energy levels in which the electrons were previously located. To do this, however, they must first thoroughly prepare the sample and clean and smooth its surface at an atomic level. Therefore, the very small sample, which is no more than a few millimeters or even micrometers in size, is heated to 600 degrees Celsius in an ultra-high vacuum chamber. The view through the porthole of the chamber is directed at the approximately two-centimeter-long block-shaped sample holder in the center, which, like the connecting wire, glows purple due to the heat.
Photography
Photography
© MPI for Chemical Physics of Solids, Dresden / Katarina Höfer
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Guardians of the genome
The cells of all "higher organisms” (which essentially refers to all organisms except bacteria) have a nucleus. This nucleus serves as the repository for genetic material, stored in the form of DNA. Isolated from the rest of the cell, known as the cytoplasm, the genetic material is shielded by a double membrane known as the nuclear envelope. The interaction of substances and information between the nucleus and cytoplasm is facilitated exclusively through pores in the nuclear envelope. In a typical vertebrate cell, there are approximately 2000 of these nuclear pores.
These pores possess the ability to constrict and expand, thereby regulating the transportation of materials between the nucleus and the cytoplasm. From a biochemical perspective, a pore is a sophisticated protein complex composed of more than 30 different proteins. Each individual pore is comprised of approximately 1000 of these building blocks and measures only a few ten-thousandths of a millimetre in size.
A research team at the Max Planck Institute of Biophysics has successfully developed a highly detailed model of a human nuclear pore with the assistance of AI. Such models play a crucial in advancing our understanding of the transport and defence mechanisms of pores, allowing for the identification of defects in their structure and function. This knowledge holds significant medical implications, potentially allowing the prevention of viruses like HIV from entering the cell nucleus undetected.
Structural model, created with cryo-electron tomography and AlphaFold2 / Computer simulation (please click on the image to start the video)
These pores possess the ability to constrict and expand, thereby regulating the transportation of materials between the nucleus and the cytoplasm. From a biochemical perspective, a pore is a sophisticated protein complex composed of more than 30 different proteins. Each individual pore is comprised of approximately 1000 of these building blocks and measures only a few ten-thousandths of a millimetre in size.
A research team at the Max Planck Institute of Biophysics has successfully developed a highly detailed model of a human nuclear pore with the assistance of AI. Such models play a crucial in advancing our understanding of the transport and defence mechanisms of pores, allowing for the identification of defects in their structure and function. This knowledge holds significant medical implications, potentially allowing the prevention of viruses like HIV from entering the cell nucleus undetected.
Structural model, created with cryo-electron tomography and AlphaFold2 / Computer simulation (please click on the image to start the video)
© MPI for Biophysics, Frankfurt / Agnieszka Obarska-Kosinska
20
Close-up of stellar birth
Stars do not come into existence gently. It all begins with diffuse clouds of interstellar matter. Due to gravity and the collision of particles, these clouds undergo contraction, eventually breaking down into highly dense fragments. These prestellar cores, in turn, also become unstable, collapsing again to form protostars. In this image captured by the James Webb Space Telescope, one such baby star, only a few tens of thousands of years old, lies hidden behind dense dust curtains at the centre of two gas streams that it spits out in opposite directions. These jets propel matter into space at speeds of several hundred kilometres per second. Upon colliding with nearby gas and dust, these jets conjure up colourful Herbig-Haro objects in the universe, named after the two astronomers who first recognised these phenomena as part of the star formation process. Behind them are shock waves that cause the gas to glow. This particular newborn star is located in the Perseus constellation, around a thousand light years away from Earth, and has only about eight percent of the mass of our Sun. After its turbulent first phase of life, it will eventually reach a state of equilibrium andevolve into a relatively calm, adult star.
Read more: Supersonic outflow of young star
Telescope image (James Webb Space Telescope / NIRCam)
Read more: Supersonic outflow of young star
Telescope image (James Webb Space Telescope / NIRCam)
© ESA/Webb, NASA, CSA, T. Ray (Dublin Institute for Advanced Studies)
21
Painting with DNA
The crescent-shaped freshwater bacterium Caulobacter crescentus has a unique life cycle: when it divides, two different daughter cells are formed. One of them forms a stalk-like projection with which the cell can attach itself to surfaces. Max Planck Fellow Martin Thanbichler uses this special feature to find out how bacteria control their cell cycle and shape. The image shows a C. crescentus cell shortly before division and a newly formed, non-stalked cell next to it. The chromosomal DNA (blue) and the cell membranes (red) were labelled with fluorescent dyes and visualised by means of high-resolution microscopy using the DNA-PAINT technique. The dye molecules bind only temporarily to the DNA or the membranes and generate a brief "flashing" of the fluorescence signal with each binding process. This enables super-resolution reconstruction. In this way, tiny changes in the fine structure of cells can be detected, for example to analyse the effect of antibiotics on cellular physiology in detail.
Read more: A new Achilles heel of the bacterial cell wall
Fluorescence microscopy (DNA paint technique)
Read more: A new Achilles heel of the bacterial cell wall
Fluorescence microscopy (DNA paint technique)
© MPI for Terrestrial Microbiology, Marburg / Rogelio Hernandez-Tamayo
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Mysterious droplets
In 2009, researchers led by Anthony Hyman from the Max Planck Institute of Molecular Cell Biology and Genetics discovered a completely new state of biological matter: in the cell fluid of nematode embryos, they came across highly concentrated accumulations of proteins that resemble tiny droplets. Unlike cell organelles, these structures, which the scientists named "condensates", lack a surrounding membrane. They have the ability to form rapidly, sometimes in a matter of seconds, and are typically disassembled shortly afterward. The high protein concentration inside the droplets stimulates biochemical reactions that would not be possible outside.
Condensates are also found in human cells and play a vital role in cell metabolism. If their degradation is disrupted - often due to ageing - toxic substances can be deposited in them, which are associated with degenerative diseases such as ALS or Alzheimer's disease. The discovery of droplets is therefore an important starting point for understanding many diseases and exploring the development of novel drugs. The image shows a water-oil emulsion with fluorescently labelled condensates of a nematode protein.
Read more: Droplets in the cellular soup (PDF)
Fluorescence microscopy
Condensates are also found in human cells and play a vital role in cell metabolism. If their degradation is disrupted - often due to ageing - toxic substances can be deposited in them, which are associated with degenerative diseases such as ALS or Alzheimer's disease. The discovery of droplets is therefore an important starting point for understanding many diseases and exploring the development of novel drugs. The image shows a water-oil emulsion with fluorescently labelled condensates of a nematode protein.
Read more: Droplets in the cellular soup (PDF)
Fluorescence microscopy
© MPI of Molecular Cell Biology and Genetics / Anatol Fritsch
8
Spread out
Plants have developed numerous ingenious strategies to disperse their seeds. In the popping cress Cardamine hirsuta, exploding seed capsules propel the seeds in all directions. Max Planck scientists have investigated the mechanism behind this in detail. As they discovered, the polymer lignin (shown here in red) plays a central role. For the slingshot mechanism to work, the polymer must be embedded in the capsule wall (shown here in blue) in a very specific pattern. The micronutrient copper is required for the formation of this pattern. In addition, the researchers have also identified the genes that control the incorporation of lignin into the wall of the seed pod cells. These findings are particularly interesting for the forestry sector, since lignin is the substance that gives wood its strength and rigidity. However, forest soils often have a low copper content, which leads to poor lignification and a weakening of the trees. Understanding the role of copper in the lignification process is therefore also of economic importance.
Read more: Copper makes seed pods explode
Fluorescence microscopy
Read more: Copper makes seed pods explode
Fluorescence microscopy
© MPI for Plant Breeding Research / Miguel Pérez Antón
5
Liver en miniature
Organoids are miniature versions of organs that are cultured from stem cells in the laboratory. They hold great promise for the future of biomedical research, as they enable scientists to study very different aspects such as organ development, tissue regeneration, diseases and new therapies without the need for complete organisms. The cell clumps, which are only a few millimeters in size, therefore make an important contribution to avoiding animal experiments. Researchers at the Max Planck Institute for Molecular Genetics use such liver models to study various diseases. The image shows human liver organoids that secrete albumin (shown here in green). Albumin is one of the most important proteins produced by the liver and is indispensable in the body for transport processes in the blood. The fact that liver organoids produce this protein in the laboratory is proof of the high functionality of these organ models.
Fluorescence microscopy, animated
Fluorescence microscopy, animated
© MPI for Molecular Genetics / Anja Hess
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8
5