The Hadean eon is the earliest geographic eon to exist (unless you count the unofficial Chaotian). It is the time from 4600 million years ago, when the Earth formed, to 4000 million years ago. The name is taken from Hades, god of the underworld in Greek mythology, and probably a fitting choice considering the hellish conditions that existed on Earth at the time. Although we are generally sure that will have been hot, perhaps up to 250°C, and that the atmospheric pressure may have been up to 30 times its current level, the exact atmospheric conditions are still mostly unknown. This mostly because there are very few rocks that even date back this far and so our avenues of study are limited.
Most readers will probably be aware of how important stem cells are when it comes to medical research. As they have yet to differentiate they have the possibility of becoming any cell in the body if required, but this great variability comes with an inherent instability. The hematopoietic stem cells in the bone marrow, the cells from which the blood cells can be formed, have the potential to produce leukaemia and other blood cancers. There is also the risk of local tumours spreading their cells into the bone marrow which can result in cancer stem cells and rapid bone metastasis as the skeleton is invaded by the cancer. It is important to understand how the standard and malevolent stem cells interact with each other in the bone marrow so that these conditions can be counteracted and prevented.
A few months ago I wrote this post about using two photon fluorescence to study the capillary system. The basic idea being to use infrared light, which passes through flesh easily, to excite the fluorescent dye but to use the process of two photon absorption so that the remitted photon can be of greater frequency than infrared. Now although this can be done with a chemical dye, there is another option.
Animals in nature have an uncanny ability to operate as a single unit with collective movement when they group together. Flocks of birds have been found to fit statistical models, people walking together naturally match each others step, bacteria can form groups that then move as one, with each individual responding to the same chemical stimuli.
When people talk about organs the instant thoughts probably go to the heart, liver, stomach and kidneys. The liver is the largest of these internal organs but when it comes to largest organ overall it us outstripped by the skin which is often not thought of as an organ but does contribute to about 15% of a human’s body weight. The skin is, like almost everything else in the human body, made of a lot of water. 64% of the skin is in fact made of water.
The reader may be aware that it is possible for blind individuals to use echolocation to visualise their surroundings. In a very similar way to a bat or dolphin these people can use the reflected sound waves off objects to determine there size and location. Of course, this seems like such an amazing ability, that certainly some people would want to try it out. However people who can see will find such a feat, not just difficult, but impossible. To be able to transform information from your ears into an image in the head requires the use of section of the brain normally reserved for manipulating data from the eyes. Blind people don’t need this part of the brain to gather data from their eyes and so with enough practice it can be adapted into the necessary network to visualise sounds.
In recent years there have been various papers published on the topic of cell and biological tissue stiffness. When in comes to blood pressure, hypertension, asthma and ageing the mechanical elastic properties of the cells involved often change as these diseases develop. For instance if a person is genetically predisposed towards having thicker and stiffer vascular wall tissue it is no surprise that this person has a greater chance of developing a cardiovascular illness.