### activity | penetration:

Invasion
* Some invasions cause diseases
  - fatal diseases
* also continue to spread infectious diseases and generate violence.
* are entrances
  - penetrations
  - the number-one component of biotic change in the world today
* can have impact
  - negative impact
* can have severe impact
  - increase competition, alter abiotic conditions, and provide refuge for consumers
* cause death
  - loss of biodiversity within species, between species, and of ecosystems
* is the expansion of tumors into neighboring healthy tissue
  - hallmark of the malignant tumor
* may have devastate effects
* offer opportunity.
* probably function of both the infected cell and the bacterial cells.
* results in the development of a diffuse interface between contiguous tissues.

### activity | penetration | invasion:

Bacterial invasion
* All bacterial invasions are due to poor epithelium.
* can also cause a secondary pneumonia.
* causes painful, swollen abscesses under the lower jaw.

Biological invasion
* are a major threat to biodiversity
  - well documented phenomena
* can dramatically alter community composition and ecosystem function
  - strongly influence species interactions such as pollination
* occur when a plant or animal finds itself in a new, favorable environment.

Light penetration
* Some light penetrations prevent photosynthesis.
* has a definite influence on colonisation in the marine environment.
* is especially poor in turbid water with dense surface populations of algae.

### activity | penetration:

Raid
* are embezzlement.
* arrays are highly reliable, high-volume units of storage on a network.
* is an acronym for redundant array of independent disks
  - assembly of disk drives, known as disk array, that operates as one storage unite
  - the organization of multiple disks into a large, high performance logical disk
  - used to virtualize computer storage
* lead to attacks.
* magnetic storage unit similar to a mainframe computer.
* means of providing fault tolerance to a computer or server.
* method of combining several hard drives into one logical unit
  - into one unit
* set of technologies that are used to make more efficient use of disk resources.
* storage system that uses multiple disks to store and distribute data.
* term used in computing.
* way of storing the same data in different places on multiple hard disks.
+ RAID, Basic concepts used by RAID systems, Stripe size and chunk size: spreading the data over several disks
  * RAID works by spreading the data over several disks. Two of the terms often used in this context are 'stripe size' and 'chunk size'
  - Introduction, What is RAID?: Storage devices
  * RAID is done by  using special hardware  or software on the computer. The joined hard disks will then look like one hard disk to the user. Most RAID levels increase the redundancy. This means that they store the data more often, or they store information on how to reconstruct the data. This allows for a number of disks to fail without the data being lost. When the failed disk is replaced, the data it should contain will be copied or rebuilt from the other disks of the system
+ Virtualization: Computing
  * RAID is used to virtualize computer storage. The fact that it is made of several disks that work together is hidden.
  * RAID is a term used in computing. With RAID, several hard disks are made into one logical disk. There are different ways this can be done. Each of the methods that puts the hard disks together has some benefits and drawbacks over using the drives as single disks, independent of each other.