❝ Life has no meaning. Each of us has meaning and we bring it to life. It is a waste to be asking the question when you are the answer.
— Joseph Campbell (via sensationalizm)
(Source: goodreads.com)
The colors of the solar system’s innermost planet are enhanced in this tantalizing view, based on global image data from the Mercury-orbiting MESSENGERspacecraft. Human eyes would not discern the clear color differences but they are real none the less, indicating distinct chemical, mineralogical, and physical regions across the cratered surface. Notable at the upper right, Mercury’s large, circular, tan colored feature known as the Caloris basin was created by an impacting comet or asteroid during the solar system’s early years. The ancient basin was subsequently flooded with lava from volcanic activity, analogous to the formation of the lunar maria. Color contrasts also make the light blue and white young crater rays, material blasted out by recent impacts, easy to follow as they extend across a darker blue, low reflectance terrain.
Thomas Wright, An Original Theory or New Hypothesis of the Universe… Wright’s vision of the infinite number of universes that may exist, which he called “a finite view of Infinity.”
-from Star Struck, One Thousand Years of Art and Science of Astronomy by Brasher and Lewis
Why are these people shooting a powerful laser into the center of our Galaxy? Fortunately, this is not meant to be the first step in a Galactic war. Rather, astronomers at the Very Large Telescope (VLT) site in Chile are trying to measure the distortions of Earth’s ever changing atmosphere. Constant imaging of high-altitude atoms excited by the laser — which appear like an artificial star — allow astronomers to instantly measure atmospheric blurring. This information is fed back to a VLT telescope mirror which is then slightly deformed to minimize this blurring. In this case, a VLT was observing our Galaxy’s center, and so Earth’s atmospheric blurring in that direction was needed. As for inter-galaxy warfare, when viewed from our Galaxy’s center, no casualties are expected. In fact, the light from this powerful laser would combine with light from our Sun to together appear only as bright as a faint and distant star.
Neurons (in blue to yellow) growing on top of astrocytes (in red, helper cells within the nervous system) in a human stem cell embryoid body (a cluster of differentiating human embryonic stem cells).
Image by Juan Carlos Izpisúa, Center of Regenerative Medicine in Barcelona.
An Introduction to Fungi
The first thing to know about fungi is that their taxonomy is kind of a nightmare. Previously, fungi had been categorized by form and habit, which DNA analysis is now suggesting does not accurately represent the relationships between species. So any taxonomy discussed here may be inaccurate, or may change as genetic data becomes available. Please feel let me know if you find a updated classification.
Anyway, let’s get on to some fungal basics. This will just be a summary of some important characteristics of fungi.
Nutrition: Fungi are heterotropic, meaning that they consume other organisms or compounds for energy and nutrients. The excrete exoenzymes to digest their substrate and absorb the useful molecules and components.
Vegetative State: Generally, fungi are found as a thallus growing on a substrate. The thallus (Greek: shoot, twig) is the body of the fungi, made up of hyphal strands, which are non-differentiated, vegetative branches of growth. The thallus is also known as the mycelium. Fungi are filamentous because this increases their surface area for the absorption of nutrients. The hyphae can have crosswalls (ie, be spetate) or have no crosswalls (ie, be aseptate or coenocytic). Most septate hyphae have pores in the septa to allow for the cytoplasm and other molecules to flow between cells.
Some fungi are found in non-filamentous forms. These single-celled organisms are called yeasts, and reproduce through budding or fission. Some species have a yeast and a hyphal form, and can switch between the two depending on their environment.
Cell Wall: The cell wall of the true fungi ALWAYS contains chitin. Glucans and other molecules may also be found. (Chitin is also found in the exoskeleton of arthropods.) The membranes also contain ergosterol, which serves the same function as cholesterol in animal cells by making membranes more fluid and easily permeable.
Domain of Life: Fungi are members of the domain Eucara, like animals and plants. They are actually more closely related to animals than they are to plants.
Life Cycle: Although all are eukaryotic, fungi nuclei vary greatly from one another. Species may be uninucleate or multinucleate, may have haploid, diploid, or dikaryotic (possessing two unfused nuclei from different parents in the same hyphal compartment). The reproduction may be simple or complex, and require one, several, or no hosts. Reproduction may be sexual, asexual, parasexual, or a combination of different strategies in the same species or individual.
Propagules: Fungi are propagated by microscopic spores. Some species produce millions of spores, and fungal spores can be found in the air, the fossil record, water, and food. Spores are generally nonmotile, with the Chitryidomycota being an exception to this rule. Possessing filamentous hyphae allows for the easy production, fragmentation, and dissipation of both sexual and asexual spores.
Sporocarps: Sporocarps are the reproductive structures of fungi. They can be macroscopic (like mushrooms) or microscopic (like conidiophores). Often, especially in the Ascomycetes and Basidiomycetes (the “higher fungi”), the sporocarps may be useful for species identification.
Habitat: Fungi are found pretty much everywhere. If it is an environment on land or in fresh or salt water, fungi can be found there.
Ecological Significance: Fungi play important roles as saprotrophs (consumers of dead material), mutualists (such as through the formation of mycorrhizae with plant roots), and parasites. They have great economic significance for culinary reasons, as food spoiling agents, as pests, and as pest control.
Conclusion: A very limited number of fungal species have been named a described. It is estimated that to date, only 5-10% of all fungi have been discovered. This means that it is very common for even the casual mycologist to find a new species! Fungi are a very diverse and important group of organisms, although not very well understood or appreciated by the general public. I hope this series will be informative.
Facial Orientation and Facial Shape in Extant Great Apes: A Geometric Morphometric Analysis of Covariation
The organization of the bony face is complex, its morphology being influenced in part by the rest of the cranium. Characterizing the facial morphological variation and craniofacial covariation patterns in extant hominids is fundamental to the understanding of their evolutionary history. Numerous studies on hominid facial shape have proposed hypotheses concerning the relationship between the anterior facial shape, facial block orientation and basicranial flexion. In this study we test these hypotheses in a sample of adult specimens belonging to three extant hominid genera (Homo, Pan and Gorilla). Intraspecific variation and covariation patterns are analyzed using geometric morphometric methods and multivariate statistics, such as partial least squared on three-dimensional landmarks coordinates. Our results indicate significant intraspecific covariation between facial shape, facial block orientation and basicranial flexion. Hominids share similar characteristics in the relationship between anterior facial shape and facial block orientation. Modern humans exhibit a specific pattern in the covariation between anterior facial shape and basicranial flexion. This peculiar feature underscores the role of modern humans’ highly-flexed basicranium in the overall integration of the cranium. Furthermore, our results are consistent with the hypothesis of a relationship between the reduction of the value of the cranial base angle and a downward rotation of the facial block in modern humans, and to a lesser extent in chimpanzees” (read more).
(Image and text source: PLoS ONE 8(2): e57026)
Nicko Rubinstein Sculptor
- “Green Dog” Bronze and glass and steel 53 x 10 x 36cm. Year 1994
- ”Load” Bronze and sandblasted glass, 40 x 17 x 12cm. Year 2000
- “Caution Children”: Bronze and sandblasted glass: 25 x 14 x 9cm. Year 1998
- “Combat de toros” Bronze, sandblasted glass and colored, 58 x 19 x15cm. Year 2000
- “Like a grain of sand” Bronze, glass and steel. 32 x 33 x 12cm. 2001
- “Rhino X” and sandblasted glass Bronze, Size: 46 x 24 x 16cm. Year 2000
- “Taurus Olé” Bronze and Frosted glass Size: 16 x 31 x 12cm. Year 1998
This is a closeup of the tentacles of Portuguese Man O’War (Physalia physalis)
Photo by Simon de Glanville
