Pláticas en el gringo

En el gringo nunca falta el comentario atinado, erudito, ácido, ridículo, inclemente, mordaz, útil, políticamente incorrecto, informativo o qué se yo qué, después de comer.

¿Por qué no dejar un registro de todos ellos?

8.20.2007

complementando lo del huevo de Enrique (jaja)


.....The egg, says Professor
           Hosick, is the largest cell there is. Properly speaking, the chicken
           "egg" is not the whole shell-covered egg, but rather the
           ovum, which you can see sometimes as a tiny spot (NOT a blood spot)
           on the yoke of the egg. But tiny as it seems, it's huge compared with
           most cells. That ovum is what develops into the chick. The rest is
           just life support......

from http://www.wsu.edu/DrUniverse/eggs4.html

posted by Ana Gutiérrez # 7:19 p.m. 0 comments

La estructura del Huevo

Despues del choro sobre si el huevo es o no es una célula, decidí poner una imagen e interpretarselas.

El óvulo es la celulita marcada como bastodisco, tambien cuando esta fertilizado se le llama blastodermo o disco germinal. Eso es lo que construye un pollo. La yema, se forma una vez que el óvulo madura y la gallina ovula, se va depositando conforme el huevo baja por el oviducto y por eso tiene capas. La membrana vitelina rodea a la yema. no lo encontre en ningun lugar de manera explícita pero sospecho que es un epitelio formado por muchas células. La clara se forma despues, también en capas. al final queda todo cubierto por otras dos membranas y despues por el cascarón, cada membrana debe de ser otro epitelio, así mismo, las chalazas son amortiguadores que estabilizan a la yema, muy probablememente estan hechas de células epiteliales. En resumen, un huevo tiene muchas células saludos.

posted by Enrique # 6:39 p.m. 0 comments

peso de células (pequeñas!)

Sprezzatura in the Lab

Sprezzatura is a term from the Italian Renaissance that denotes the art of making the difficult look easy, a kind of non-chalance. Examples are the Mona Lisa or Michael Jordan at work. In science, some extraordinarily difficult experiments are made to look easy when described in a paper. But we are not so easily fooled; we know what went into them.

I have two recent examples in mind. One is the report that the genome sequence of single bacterial cells can be determined, at least in part. This is being attempted by several other labs, as well, and it is likely that several approaches will become available soon. The one in this report makes use of microfluidics, a fancy way to make test tubes smaller and smaller, each with its own ports for the addition and removal of reactants. The possible uses of such a methodology are open to everyone's imagination.

Device

The Ultraminute Device. Source:
Liesbeth Venema (2007) Applied
Physics: Weight Inside. Nature
446: 994

The second example deals with the fabrication of an ultrasensitive balance capable of measuring the mass of an object in the femtogram range. That's a couple of orders of magnitude smaller than the weight of one E. coli. Their trick is to use an ultraminute cantilever-shaped chamber through which they pump fluids. The chamber with the item to be measured is suspended within a vacuum chamber, a trick which permits measurement of extremely small displacements. How small is extremely small? Single bacteria are no problem, and neither are tiny monolayers of proteins. Again, sit back and let your imagination roam freely─all the questions you could answer with such a device! For a commentary, click here. To offer your own suggestions, post a comment.

Earlier in my life, such feats were in the province of science fiction tales, and even there would have stretched the credulity of the reader.

Tomado de: http://schaechter.asmblog.org/schaechter/

posted by Ana Gutiérrez # 4:11 p.m. 0 comments

8.07.2007

De vuelta a la cotideanidad

La típica conversación de futbol no podía faltar:

- ¿viste el partido del domingo?
- si, quedaron 1-1. Horrible.

...y mucho menos el comentario de un tercero que pesca la platica a la mitad:

- ¿y quien ganó?

... parece que hemos vuelto a la vida cotidiana.

posted by aubin # 4:59 p.m. 0 comments