2008年9月21日星期日

Writing Tips

²  Write unto others as you would have them write unto you.

²  Trim fat words.

²  Dump awkward phrases.

²  Avoid using comparative or relative words whose meaning depend on your readers’ subjective interpretations of quality or quantity.

²  Avoid using words that imply value judgment without specifying what the value is, compared with what, or who is making the judgment.

²  Use words to express rather than to impress (in other words, use big words only when absolutely necessary).

²  Follow a grammatical subject as soon as possible with its verb.

²  Subjects and verbs even when separated by a word string have to agree.

²  Don’t kill verbs by turning them into nouns.

²  Remove as many abstract nouns (e.g. –ions such as complication, dedication, identification) as you can.

²  Use active verbs.

²  Passive verbs attract abstract noun and awkward constructions, avoid them.

²  Liberate disguised verbs.

²  Use dependent clauses instead of prepositional phrases.

²  Avoid strings of adjectives.

²  In formal scientific writing, do not use contractions or exclamation points.

²  A writer who uses hyperbole will come to grief.











Mantis shrimp not only have the ability to see colors from the ultraviolet through to the infrared, but have optimal polarization vision, which humanity has only achieved in the last decade using fast computer technology.

Humans have ten times more bacteria than human cells

The number of bacteria living within the body of the average healthy adult human are estimated to outnumber human cells 10 to 1. Changes in these microbial communities may be responsible for digestive disorders, skin diseases, gum disease and even obesity. Despite their vital importance in human health and disease, these communities residing within us remain largely unstudied.

2008年9月16日星期二


Van der Waals forces in action

Geckos have millions of setae--microscopic hairs on the bottom of their feet. These tiny setae are only as long as two diameters of a human hair. Each seta ends with 1,000 even tinier pads at the tip. These tips, called spatulae, are only 200 nanometers wide--below the wavelength of visible light. These spatuale increase surface density phenomenally, creating a strong adhesive force through van der Waals interactions. Geckos stick to hydrophilic and hydrophobic surfaces equally well. If a gecko used all of its setae at the same time, it could support over 100 kilograms. 

Many small animals (e.g. insects and spiders) partially exploit van der Waals forces. 

Online Dictionaries

2008年9月15日星期一


Erratum

There is a mistake in the textbook regarding the permeability of the lipid bilayer. A pure phospholipid bilayer is only slightly permeable to water. Water molecules move across the cell membrane through water channels, which only admit water molecules. These channels are so narrow that particles larger than the water molecule cannot squeeze through. Because of the positive charge at the center of the channel, positively charged ions such as H3O+ (the hydrogen ion) are deflected. This prevents proton leakage through the channel.