Virulence

Virulence is, by MeSH definition, the degree of pathogenicity within a group or species of parasites as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenicity of an organism - its ability to cause disease - is determined by its virulence factors. The noun virulence derives from the adjective virulent. Virulent can describe either disease severity or a pathogen's infectivity. The word virulent derives from the Latin word virulentus, meaning "a poisoned wound" or "full of poison."

In an ecological context, virulence can be defined as the host's parasite-induced loss of fitness. Virulence can be understood in terms of proximate causes—those specific traits of the pathogen that help make the host ill—and ultimate causes—the evolutionary pressures that lead to virulent traits occurring in a pathogen strain.

Virulent bacteria

The ability of bacteria to cause disease is described in terms of the number of infecting bacteria, the route of entry into the body, the effects of host defense mechanisms, and intrinsic characteristics of the bacteria called virulence factors. Many virulence factors are so-called effector proteins that are injected into the host cells by special secretion machines such as the type 3 secretion system. Host-mediated pathogenesis is often important because the host can respond aggressively to infection with the result that host defense mechanisms do damage to host tissues while the infection is being countered.

Sleep (system call)

A computer program (process, task, or thread) may sleep, which places it into an inactive state for a period of time. Eventually the expiration of an interval timer, or the receipt of a signal or interrupt causes the program to resume execution.

Usage

A typical sleep system call takes a time value as a parameter, specifying the minimum amount of time that the process is to sleep before resuming execution. The parameter typically specifies seconds, although some operating systems provide finer resolution, such as milliseconds or microseconds.

Windows

On Windows, the Sleep() function takes a single parameter of the number of milliseconds to sleep. The Sleep() function is included in kernel32.dll, but no sleep command (executable) is natively available for scripts (batch files). It can be found in collections of Windows utilities like Windows 2003 Resource Kit.

Unix

On Unix-like operating systems, the sleep() function is called providing a single parameter of type unsigned integer of the number of seconds to sleep. (For more precise sleep times one can use the usleep() function.)

Conjure One (album)

Conjure One is the self-titled debut album by Canadian electronic music project Conjure One, headed by Rhys Fulber. The album was released in September 2002 (see 2002 in music).

Track listing

All tracks written by Rhys Fulber, except where noted.

Sleep (OS X)

Sleep on Macintoshes running on OS X consist of the traditional sleep, Safe Sleep, and Power Nap. In System Preferences, Safe Sleep is referred to as sleep. Since Safe Sleep also allowed state to be restored in an event of a power outage, unlike other operating systems, hibernate was never offered as an option.

In 2005, some versions of Macs running Mac OS X v10.4 began to support Safe Sleep. The feature saves the contents of volatile memory to the system hard disk each time the Mac enters Sleep mode. The Mac can instantaneously wake from sleep mode if power to the RAM has not been lost. However, if the power supply was interrupted, such as when removing batteries without an AC power connection, the Mac would wake from Safe Sleep instead, restoring memory contents from the hard drive.

Safe Sleep capability is found in Mac models starting with the October 2005 revision of the PowerBook G4 (Double-Layer SD). Mac OS X v10.4 or higher is also required. A hack enabled the feature as well on older Macs running Mac OS X v10.4.