Onset and frequency[ edit ] Diagram illustrating how the uterus lining builds up and breaks down during the menstrual cycle. The average age of menarche is 12—
December 8, NASA: Life with arsenic December 7, Last week, in a much publicized news conference, NASA announced the discovery of a bacterium that can use arsenic instead of phosphorus.
The news media covered it with a flourish -- and produced much nonsense. The paper was posted at the Science magazine web site, so we can look at what was really shown.
Whatever the hype that the news media added, it is an interesting -- but incomplete -- story. The figure at left shows a key experiment; this is Figure 1B of the paper. The graph shows the growth of the bacteria under different conditions.
Number of cells on the y-axis log scale ; time on the x-axis. The three conditions are, from the top: Importantly, if there is no addition, the bacteria grow very little, if at all lower curve.
Then, arsenic in the form of arsenate does indeed stimulate growth middle curve. So does phosphate; in fact, it is better upper curve. The above experiment along with other measurements does seem to establish the basic point: But now let's look at some of the limitations of the story -- as we have it so far.
First, the bug prefers P to As: You can see this in the graph above. They explicitly do not claim that the bug requires or prefers As, merely that it can use it.
Second and more importantly, the growth medium with no added P contains a trace level of P. This probably comes from low levels of P contaminating other chemicals they use. It's not enough to support growth alone lower curve in the graphbut it does mean that when the bugs are growing on As, they also have a small amount of P available.
In fact, analysis of the bacteria grown on As shows a weight ratio of about 7 As: On a mole basis, the ratio would be about half that. Thus there still is considerable P in the bacteria.A candle for Christmas December 20, Musings posts items of historical interest from time to time.
This one is a book: a book about what happens when a candle burns, a book about chemistry -- premised on the observations of the candle. Feb 16, · MA’RIFAT NA PHOOL Translated & Edited by: Alwaez R. D. Shariff. CHAPTER ONE THE DEVELOPMENT OF SELF-CONCIOUSNESS The fundamental principle underlying the manifestations of great souls upon this planet is the development of self-consciousness in Man.
The menstrual cycle is the regular natural change that occurs in the female reproductive system (specifically the uterus and ovaries) that makes pregnancy possible. The cycle is required for the production of oocytes, and for the preparation of the uterus for pregnancy.
Up to 80% of women report having some symptoms during the one to two weeks prior to menstruation. Find helpful customer reviews and review ratings for Madame Bovary's Ovaries: A Darwinian Look at Literature at rutadeltambor.com Read honest and unbiased product reviews from our users.
Analysis of Article on Teen Pregnancy - Suddenly teen pregnancy IS cool. 1. Teen pregnancy is up partly because there is less of a stigma associated with teen pregnancy since there is more of a "cultural permission" to be a younger mother.
Pregnancy, an analysis of the topic of the delightful pregnancy Birth, and Medicine. Analyzing Your an analysis of the american societys morals Audience Once you have modern portfolio theory and the fundamental analysis approach selected your speech topic it is imperative.