Tubular Beads and the Secrets of Offing

Unearthing Ancient Treasures: Tubular Beads and the Secrets of Offing 

Hidden within the annals of history, there are treasures that offer a glimpse into the past, providing us with invaluable insights into the lives of our ancestors. One such treasure, discovered in the hunter-gatherer site of Offing, nestled on the islet bearing its name in the magnificent Magellan Strait of Patagonia, Chile, is a testament to the ingenuity and craftsmanship of those who once called this place home. 

The remarkable discovery in Offing takes the form of tubular beads meticulously crafted from bird bone, specifically the ulna epiphysis. These intricate archaeological artifacts offer a tantalizing connection to a bygone era, where every piece tells a story, and every artifact unveils a mystery. 

To fully appreciate the intricate details and craftsmanship of these ancient beads, modern technology has played a vital role. A detailed stereo-microscope image, captured using a Moticam S6 with a magnification of 10x, offers an up-close and personal look at these delicate remains. This image, a testament to the harmonious marriage of technology and archaeology, was made possible by the skilled eye of José-Miguel Tejero. The specimen, a gracious contribution from Marianne Christensen and Dominique Legoupil, has provided a rare opportunity to explore the past with remarkable clarity. 

Fig .- Tubular Beads on bird bone | Moticam S6 10X

Image Credit: Dr. José Miguel Tejero

The hunter-gatherer site of Offing has long been a site of fascination for archaeologists and historians. The islet's remarkable location, surrounded by the captivating beauty of the Magellan Strait, is a fitting backdrop for the secrets it holds. The tubular beads found here, created with precision and care, are not only a testament to the skills of the individuals who once resided in this region but also a bridge connecting us to their daily lives and traditions.  

In a world that is ever-evolving, where technology continues to shape our future, it is humbling to see how the past and present can converge. The detailed stereo-microscope image of these ancient tubular beads serves as a reminder that even the smallest fragments of history can offer profound insights into the human experience. Thanks to the dedication of archaeologists, historians, and the power of modern technology, we can embark on a journey through time and connect with our ancestors in a way that was once unimaginable. As we gaze upon the carefully crafted beads, we are reminded of the enduring legacy of Offing and the countless stories yet to be discovered in the folds of time. It is through such discoveries that we continue to enrich our understanding of the past and, in doing so, pay homage to the ingenuity of those who came before us.

Department of Evolutionary Anthropology

University of Vienna

© Dr. José Miguel Tejero

Steam Bubble Cavitation

Understanding Corrosion: Cavitation

Cavitation is a fascinating yet destructive phenomenon that can have a profound impact on the integrity of materials, particularly in steam systems. This article delves into the world of cavitation and its role in pitting corrosion, shedding light on how it can lead to significant damage to steam heater tubes and piping systems. 

 

Cavitation occurs when steam bubbles rapidly collapse, generating an extraordinary amount of pressure on the adjacent material. This can result in the formation of pin-sized to larger holes, which can ultimately lead to the leaking of steam heater tubes. The process is driven by the collapse of steam bubbles, creating a highly localized and intense pressure that causes damage to the material's surface. 

Fig 1.- Tube Inside Cavitation | Motic Panthera SMZ171, Moticam 10 Stack

Image Credit: Willem Cramer

Cavitation erosion is closely linked to the behavior of flash steam in the system. Flash steam occupies a relatively large volume but rapidly condenses when it loses heat, which is transferred through the tube wall into the surrounding fluid. This sudden condensation of flash steam results in a significant change in volume. 

The specific volume differences between steam and condensate are key to understanding cavitation's destructive potential. When flash steam condenses, it creates a large void that is swiftly and often violently filled by adjacent condensate. This rapid filling of the void generates shock waves known as water hammer. 

Fig 2.- Tube Outside Cavitation | Motic Panthera SMZ171, Moticam 10 Stack

Image Credit: Willem Cramer

The rapid collapse of the flash volume and the associated shock, caused by high-velocity condensate filling the void, can have severe consequences. The force generated by water hammer and the erosion caused by the swift filling of voids can result in significant damage to piping systems. In conclusion, cavitation is a complex phenomenon with the potential for significant damage in steam systems. The rapid implosion of steam bubbles, driven by specific volume differences between steam and condensate, can lead to the formation of holes and result in pitting corrosion. Understanding the mechanics of cavitation is crucial for preventing and mitigating the destructive consequences it can have on steam heater tubes and piping systems.

© willemsmicroscope.com

What’s in a rat?

The role of rodents in biomedical research is invaluable. Rodents, such as mice and rats, are the most commonly used mammals in biomedical research because of their anatomical, physiological and genetic similarities to humans. 

Scientists are able to genetically adapt mice to study a disease, for example by removing certain genes or by inserting (human) genes that are at the basis of certain disorders. For example, breast cancer can be simulated in mice to study the mechanisms of cancer and to test treatments. Mice and rats are also often used in behavioral studies to test, for example, treatments for memory loss in dementia.

Rodents are used in countless research areas, from cancer to immune diseases, heart disease, hypertension, metabolic and hormonal disorders, diabetes, obesity, osteoporosis, glaucoma, blindness, deafness, psychiatric disorders such as depression and schizophrenia, and neurodegenerative disorders such as Alzheimer's disease, Parkinson's and ALS.

The images taken with the new Moticam S6 camera show a cross-section with details through the upper body of the rat, just above the splice of the trachea into the two bronchi. The beautiful coup shows the various body parts in this cross section, some of which are indicated below.

With thanks to Cees Koopman, veterinarian.

© willemsmicroscope.com

Artery from another perspective

The preparation of the artery shown in both images is of unknown origin and the staining method is unknown as well.

A fluorescence image of an artery tissue as shown here is not usual. The preparation is more or less evenly green fluorescent colored, because the dye used has attached itself to the structural parts of the preparation. We see a fluorescence color image with details as you might encounter in bright field microscopy with dyes such as e.g. toluidine blue. Such dyes show more or less the same details in the preparation with ordinary bright field microscopy as is shown in the first image.

As mentioned before, visualizing a histological specimen completely by using a fluorescent substance is unusual, because here you apply only one color that shows no specific adhesion, except for proteins, because e.g. fat is uncolored in this preparation. With a normal hematoxylin and eosin staining you have more differentiation, namely in the cell core (DNA, dark blue) and proteins, cytoplasm (pink)

In histology, fluorescence is mainly used after a fluorescent substance has been chemically attached to a specific component present in the tissue.

On the fluorescent image of the preparation the parts of an artery can also be seen. The lumen is filled with green colored red blood cells, then there is a very thin (barely visible) layer of endothelium, the meandering lamina elastica interna (clearly visible) a layer of smooth muscle, the thinner lamina elastica externa (clearly visible), the adventitia (connective  tissue) that turns into adipose (fat) tissue. 

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Thousands of small lenses work together

Seen from the front, the head of the honeybee has a triangular shape, the head of the drone it is more round. On the head are the eyes, antennae and mouth parts. Important glands are located in the head and the main center of the nervous system: a nerve bud that serves as a brain.

A switching station

Ganglia are part of the peripheral nervous system. The peripheral nervous system includes all nerves outside the central nervous system (bundles of long nerve shoots with supporting cells) and small centers of nerve cells the ganglia.

A ganglion is a combination of mainly cell bodies (ganglion cells) with the nucleus of the nerve cell surrounded by cytoplasm without further shoots. This cell body with the nucleus as its center forms the metabolic center of the cell and is sensitive to stimuli. Ganglia function as switching stations for nerve impulses.

A pest from Africa

The southern green stinkbug (Nezara viridula) is a relatively new pest that originates from Ethiopia. The pest has a large number of host plants, but in horticulture this bug is mainly found in bell pepper cultivation. In the first instance, in The Netherlands, the southern green stink bug was only spotted at the end of the summer, but the bug has also shown itself earlier in the season in recent years.

Females lay around 30 to 130 eggs at a time. They do this in "glued together", yellow and white clusters at the bottom of the leaf. If they are just laid, they look like little pearls. Depending on the temperature, the eggs hatch after 4 days to 3 weeks and the empty eggs remain on the leaf. The nymphs initially stay together and do not yet affect the plant. They then go through different stages, each time shedding their skin, with each stage having a different appearance. In the fifth stage, the bugs begin to spread over the plant and eat it.

Ficus carica petiole and Wacker 3A staining

Vascular bundles can be seen very well in these cross-sectional views of a leaf stem of the fig tree, thanks to the Wacker 3A triple staining. This coloring is done with a mixture containing Astra blue, Acriflavin and Acridine red.

We see the vascular bundles that lie in an outer circle, characteristic of (eu)dicotyledonous plants. In monocotyledonous plants, the bundles are irregularly distributed over the cross section. The Xylem vessels lie on the inward side and the Phloem vessels on the outside of the outer circle. Between Xylem and Phloem we see the intravascular Cambium. Vascular bundles are also present in the inner basic Parenchyma.

Due to the good uniform thickness of the coupe and the fine quality of the Moticam S12 camera, the photos could be taken without stacking.

Sundew

Sundew or Drosera forms perfect rosettes to the ground and has red tentacles with a sticky, glittering droplet which is secreted by a gland. The flower owes its name to this. Small animals get stuck in the drop and are pushed by the moving tentacles to the leaf surface where they are digested.

Prepared slide by Lieder

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Kahler's disease

The disease owes its name to the Austrian doctor Otto Kahler, who described the disease as one of the first. Kahler's disease, also called multiple myeloma, is a disease of the bone marrow caused by an uncontrolled proliferation of a certain type of white blood cells: plasma cells (also called plasmocytes). Plasma cells are responsible for the formation of antibodies under normal conditions.

The bone marrow is a spongy substance located in the interior of bones, especially the pelvis, sternum, ribs and vertebrae. Bone marrow plays a role in forming bones, but also in forming the cells of the blood: white blood cells (leucocytes), red blood cells (erythrocytes) and platelets (thrombocytes). The disease develops in one abnormal plasma cell, which divides uncontrollably and whose offspring also divides uncontrollably. Since they are all related, they only synthesize one specific type of antibody (or part of it). Since antibodies are proteins, the antibody produced is referred to as the "M protein" (from Myeloma protein). The name paraprotein is also commonly used for the M protein. When a specific piece (called “light chain”) of a paraprotein is found in the urine (or blood serum), it is called the Bence-Jones protein.

It grows on tree trunks

Dilated scalewort or Frullania dilatata grows mainly as a pioneer on trees with a moderately nutrient-rich bark. The species is somewhat drought-tolerant and can be found on free-standing trees, except in forests. Especially in full sun, the plants have their characteristic rust brown color. This moss experienced a decline in the last century due to air pollution, but is now common in almost all parts of The Netherlands. It is an attractive species, which is not easily overlooked in inventories. As a result, the distribution picture does suggest a greater number of occurrences than is actually the case: regularly there is only a single find per square section of land of 1 x 1 km.

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Tempskya, growing millions of years ago

Tempskya is an extinct genus of tree-shaped ferns, the fossils of which have so far only been found in Cretaceous layers. The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic period 145 million years ago to the beginning of the Paleogene period 66 million years ago.

The stem-shaped structure of Tempskya is called "false stem" because it is formed by an entanglement of large numbers of stems and roots. The upward growing stems, which have a diameter of 2.5-10 mm, gave large numbers of roots (diameter about 1 mm) that grew downwards. They formed a felt-like mass around the stems. Because the stems branched regularly, a very solid whole was created. On a cross section of a trunk (see the images) the relatively large stems and the small roots can be seen.

 

Which freshwater algae do we see?

In the video you will find some algae found in fens in the ‘Wortel Kolonie’ located in Belgium. The ‘Wortel Kolonie’ is a beautiful protected nature reserve with a complex of buildings that served as an asylum for vagrants long time ago. (Here you will find the information in Dutch, English, French and German).

This nature reserve contains a few shallow fens. On a summer day in July, some water samples were taken from two fens using a trawl net with a mesh size of 30 microns. Without examining these samples in depth, more than fifty different organisms, phyto- and zooplankton, were found. Only a few of them are shown in the video. In one of the algae we see a oogonium.

The names of the organisms in the video are deliberately omitted here, to give hydrobiology enthusiasts the opportunity to identify the organisms themselves.

Drill a hole before you can eat

The whelk or Buccinum undatum (Linnaeus, 1758) belongs to the snails (Gastropoda).

The whelk is a large, thick predatory snail with 7 or 8 turns. A deep seam runs between the turns. The mouth opening takes up almost half of the shell and ends in a sipho. On the surface there are horizontal ribs and clear vertical growth lines. Often there are also vertical ribs at the top of the shell. It grows up to 11 cm high and 7 cm wide. The whelk has yellowish-white with dark spots. Whelks washed ashore are often dark blue, because they have been lying on the bottom of the sea for a long time.

Vorticella - The fastest bell in the world?

Vorticella is a genus of single celled organisms living in both marine- and freshwater habitats. The members of the vorticella genus are commonly referred to as bell animalcules because of their shape. The thing that makes bell animalcules unique are their long stalks which they use to attach themselves to a substrate, which could be things like rocks, twigs and even small animals. The stalks of vorticella resemble our muscle fibers but are able to contract a lot faster than our muscles are. If the cell gets disturbed, it’s able to contract the stalk with an impressive speed of up to 6 meters per second as a defence mechanism to get away from danger or possibly scare predators away.

Built for speed

The peregrine falcon is one of the fastest birds in the sky. During level flight, with motion generated by wing-beats alone, they can reach speeds between 60-100 km/h. This is one of the fastest known speeds for level flight.

Mint

Mentha spicata (Green Mint) is a low, creeping and rather invasive plant that is indispensable in a fragrant border. Mentha spicata blooms with small pale purple or pink flowers. It easily grows widely on all soil types and will certainly have to be kept under control. It is an herb with numerous uses, both kitchen use and medicinal. On the photo you can see covering hairs and glandular trichomes from which the typical aromatic substances are excreted.

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One Coleps makes two, cell division

• Alga: Coleps
• Order: Prorodontida Corliss, 1974
• Family:  Colepidae Ehrenberg, 1838
• Genus: Coleps Nitzsch, 1827

Coleps is a barrel-shaped ciliate, notable for its regularly arranged ectoplasmic shields, or platelets, of calcium carbonate. The covering with the scales is sometimes completely or partly absent immediately after an amitotic division (direct cleavage of the nucleus without the formation of mitoses). This is clearly visible in the accompanying video. Cell division took approximately 45 minutes. The color of the cell is usually brown and is less determined by the color of the food consumed than with other ciliates.

Giant chromosomes

Giant chromosomes (or polytene chromosomes) are found in the cells of larvae of flies and mosquitoes, in springtails and in some other invertebrates. In mosquitoes we find them, for example, in the cells of the bug Chironomus and in the cells of flies like Drosophila (fruit fly). The growth of these larvae occurs because the cells grow in size, not in number. The chromosomes also grow in size because the DNA multiplies many times without the cell or nucleus dividing. A giant chromosome therefore consists of hundreds to thousands of undivided chromatides. The chromatids have a sequence of light and dark bands, the so-called chromomers. Due to the dimensions of the giant chromosomes, these bands are very noticeable. On the basis of these bands it is easy to indicate where the genes are located on the giant chromosome (called ‘gene mapping’)

On the image, swellings, so called puffs, can be seen at particular sites along the length of the polytene chromosome. These are diffuse uncoiled regions where transcription is actively taking place.

Polytene = composed of many chromatides

Chromatides = the two identical parts of a chromosome
Gene = a piece of DNA containing certain hereditary characteristics

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New Zealand flax

Phormium tenax or New Zaeland flax are evergreen perennials, making a large clump of leathery, strap-shaped leaves coming to a decided point, with tall panicles of small, tubular flowers in summer.

New Zealand flax is an excellent fiber plant, hence the association with real flax (Linum usitatissimum) that is grown in Europe. The fibers of the leaves, up to 2 m long, were used by the Maori to make clothes, bags and shoes, and later the Europeans made rope and sails. All parts of the plant were used: for medicine made from roots, face powder from flower pollen and old blooming stems roped together as rafts.