четверг, 16 февраля 2017 г.

Miasma theory

Have you heart anything about Miasma theory ?

miasma /maɪˈæzmə/ (usually singular) means a heavy cloud of something unpleasant or unhealthy:
A miasma of smog settled over the city.
The origin of the word miasma is New Latin, from Greek, defilement, from miainein to pollute, the first known use was in 1665.
This word (plural miasmas also miasmata \-mə-tə\) can be used for a vaporous exhalation formerly believed to cause disease.

In miasma theory, diseases were caused by the presence in the air of a miasma, a poisonous vapour in which were suspended particles of decaying matter that was characterised by its foul smell. The theory originated in the Middle Ages and endured for several centuries. That a killer disease like malaria is so named - from the Italian mala‘bad’ and aria ‘air’ - is evidence of its suspected miasmic origins.

In notes taken during a voyage to South America on HMS Beagle in the 1830s, Charles Darwin described an illness that he believed was caused by "miasma" emanating from stagnant pools of water. For him, "miasma" had the same meaning that it did when it first appeared in English in the 1600s: an emanation of a vaporous disease-causing substance. But while Darwin was at sea, broader applications of "miasma" were starting to spread. Nowadays, we know germs are the source of infection, so we're more likely to use the newer, more figurative sense of "miasma," which refers to something destructive or demoralizing that surrounds or permeates.

miasmal 

\-məl\ adjective

miasmatic 

\ˌmī-əz-ˈma-tik\ adjective

miasmic 

\mī-ˈaz-mik, mē-\ adjective

miasmically 

\-mi-k(ə-)lē\ adverb

вторник, 14 февраля 2017 г.

Hermann J. Muller




Hermann Joseph Muller was born in New York City on December 21, 1890. His grandparents on his father's side were of artisan and professional background and, though at first Catholics, had emigrated from the Rhineland during the wave of reaction of 1848 to seek the greater freedom of America.

He first discovered that genetic mutations can be induced through the use of X-rays, and he demonstrated that mutations are the result of breakages in chromosomes and of changes in individual genes. The Nobel Prize he got in 1946 for this discovery increased his opportunities to publicize the dangers posed by accumulating spontaneous mutations in the human gene as a result of industrial processes and radiation. He also promoted an idea of sperm banks of gifted men in order to preserve the quality of man’s life for the future.

вторник, 31 января 2017 г.

What happens when your DNA is damaged?

The DNA in just one of your cells gets damaged tens of thousands of times per day. Because DNA provides the blueprint for the proteins your cells need to function, this damage can cause serious issues—including cancer. Fortunately, your cells have ways of fixing most of these problems, most of the time. Monica Menesini details the processes of DNA damage and repair.

пятница, 20 января 2017 г.

History through the eyes of the potato

Baked or fried, boiled or roasted, as chips or fries; at some point in your life you’ve probably eaten a potato. But potatoes have played a much more significant role in our history than just that of the dietary staple we have come to know and love today. Leo Bear-McGuinness shares how without the potato, our modern civilization might not exist at all.

пятница, 13 января 2017 г.

Antibiotic resistance

Right now, you are inhabited by trillions of microorganisms. Many of these bacteria are harmless (or even helpful!), but there are a few strains of ‘super bacteria’ that are pretty nasty -- and they’re growing resistant to our antibiotics. Why is this happening? Kevin Wu details the evolution of this problem that presents a big challenge for the future of medicine.
Watch the video

What causes antibiotic resistance?


The Father of Microbiology

  1. Do you know who invented the first compound microscope?  2. Can you say who discovered bacteria, free-living and parasitic microscopic ...