Starship Asterisk*

Boomer12k wrote:Our gut is a Universe to 100 trillion bacteria that are beneficial to our health.... Take your probiotics...

:---[===] *

Zuben L. Genubi wrote:As amazing and thought-provoking as the "human as spaceship" thread is to ponder, I am having difficulty seeing it as APOD material. This is closer to gastronomy than astronomy.

https://en.wikipedia.org/wiki/Demodex wrote:

[url=https://www.offthemark.com/image/data/cartoons/2000-04-16C.gif][size=200][color=#0000FF]Demodex[/color][/size][/url]

---

<<Demodex (Greek dēmos fat + dēx, a wood worm) is a genus of tiny parasitic mites that live in or near hair follicles of mammals. Two species living on humans have been identified: Demodex folliculorum and Demodex brevis, both frequently referred to as eyelash mites. Demodex canis lives on the domestic dog. Older people are much more likely to carry the mites; about a third of children and young adults, half of adults, and two-thirds of elderly people carried them. The lower rate in children may be because children produce less sebum. In the vast majority of cases, the mites go unobserved, without any adverse symptoms, but in certain cases (usually related to a suppressed immune system, caused by stress or illness), mite populations can dramatically increase, resulting in a condition known as demodicosis or Demodex mite bite, characterised by itching, inflammation, and other skin disorders. Blepharitis (inflammation of the eyelids) can also be caused by Demodex mites.

D. folliculorum and D. brevis are typically found on humans. D. folliculorum was first described in 1842 by Simon; D. brevis was identified as separate in 1963 by Akbulatova. D. folliculorum is found in hair follicles, while D. brevis lives in sebaceous glands connected to hair follicles. Both species are primarily found in the face, near the nose, the eyelashes, and eyebrows, but also occur elsewhere on the body.

The adult mites are only 0.3–0.4 mm long, with D. brevis slightly shorter than D. folliculorum. Each has a semitransparent, elongated body that consists of two fused segments. Eight short, segmented legs are attached to the first body segment. The body is covered with scales for anchoring itself in the hair follicle, and the mite has pin-like mouthparts for eating skin cells and oils (sebum) which accumulate in the hair follicles. The mites can leave the hair follicles and slowly walk around on the skin, at a speed of 8–16 cm per hour, especially at night, as they try to avoid light. The mites are transferred between hosts through contact with hair, eyebrows, and the sebaceous glands of the face. Females of D. folliculorum are larger and rounder than males. Both male and female Demodex mites have a genital opening, and fertilization is internal. Mating takes place in the follicle opening, and eggs are laid inside the hair follicles or sebaceous glands. The six-legged larvae hatch after three to four days, and the larvae develop into adults in about seven days. The total lifespan of a Demodex mite is several weeks.>>

APOD Robot wrote:You are a spaceship soaring through the universe.

Making tuberculosis. Source:
http://ancient-history-to-1800.blogspot ... -fire.html

http://phys.org/news/2016-07-early-emer ... losis.html wrote:

Tuberculosis, commonly known as TB, has been killing people for thousands of years and still continues to do so today—as the researchers note, it kills more people than any other type of bacterial infection. It is also unique in that scientists believe it is one of the few diseases that started in humans rather than other animals. But how it did so has remained a mystery. In this new effort, the researchers suggest it might have evolved from a simple microbe that lived in the soil to one that could kill people because humans learned how to control fire.

Their idea is that sitting around an open fire meant breathing in a lot of smoke, which is known to weaken the immune response to pathogens in the lungs—any microbe that made its way in—via blowing dust, for example—would find a relatively safe place to live. Controlled fire also allowed early people more social time, as it provided light after the sun went down, which the researchers suggest may well have contributed to more physical contact—and that could have allowed the bacteria to become more transmissible. Taken together, the two factors offer a plausible explanation for the evolution of a harmless, soil-dwelling microbe into Mycobacterium tuberculosis.

http://news.nationalgeographic.com/2016/01/160111-microbiome-estimate-count-ratio-human-health-science/ wrote:
<<In a new study posted ahead of publication on the bioRxiv website, three scientists led by the Weizmann Institute of Science’s Ron Milo find that the average human male is made of 30 trillion cells and contains about 40 trillion bacteria, most of which reside in his digestive tract. In other words, your body’s cell count is regularly poised to overtake the bacteria—and sometimes it does, depending on how recently you rid yourself of a few trillion via a bowel movement.>>