title: Time series

text: Non-linear dependence of the level of a series on previous data points is of interest, partly because of the possibility of producing a chaotic time series. However, more importantly, empirical investigations can indicate the advantage of using predictions derived from non-linear models, over those from linear models, as for example in nonlinear autoregressive exogenous models. Further references on nonlinear time series analysis: (Kantz and Schreiber), and (Abarbanel)


title: Time series

text: Among other types of non-linear time series models, there are models to represent the changes of variance over time (heteroskedasticity). These models represent autoregressive conditional heteroskedasticity (ARCH) and the collection comprises a wide variety of representation (GARCH, TARCH, EGARCH, FIGARCH, CGARCH, etc.). Here changes in variability are related to, or predicted by, recent past values of the observed series. This is in contrast to other possible representations of locally varying variability, where the variability might be modelled as being driven by a separate time-varying process, as in a doubly stochastic model.


title: Time series

text: In recent work on model-free analyses, wavelet transform based methods (for example locally stationary wavelets and wavelet decomposed neural networks) have gained favor. Multiscale (often referred to as multiresolution) techniques decompose a given time series, attempting to illustrate time dependence at multiple scales. See also Markov switching multifractal (MSMF) techniques for modeling volatility evolution.


title: Time series

text: A Hidden Markov model (HMM) is a statistical Markov model in which the system being modeled is assumed to be a Markov process with unobserved (hidden) states. An HMM can be considered as the simplest dynamic Bayesian network. HMM models are widely used in speech recognition, for translating a time series of spoken words into text.


title: Time series

text: A number of different notations are in use for time-series analysis. A common notation specifying a time series "X" that is indexed by the natural numbers is written


title: Time series

text: Ergodicity implies stationarity, but the converse is not necessarily the case. Stationarity is usually classified into strict stationarity and wide-sense or second-order stationarity. Both models and applications can be developed under each of these conditions, although the models in the latter case might be considered as only partly specified.


title: Time series

text: In addition, time-series analysis can be applied where the series are seasonally stationary or non-stationary. Situations where the amplitudes of frequency components change with time can be dealt with in time-frequency analysis which makes use of a time–frequency representation of a time-series or signal.


title: Time series

text: Time series metrics or features that can be used for time series classification or regression analysis:


title: Time series

text: Time series can be visualized with two categories of chart: Overlapping Charts and Separated Charts. Overlapping Charts display all-time series on the same layout while Separated Charts presents them on different layouts (but aligned for comparison purpose)


title: File system

text: In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file". The structure and logic rules used to manage the groups of data and their names is called a "file system."


title: File system

text: There are many kinds of file systems, each with unique structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is designed specifically for optical discs.


title: File system

text: File systems can be used on many types of storage devices using various media. As of 2019, hard disk drives have been key storage devices and are projected to remain so for the foreseeable future. Other kinds of media that are used include SSDs, magnetic tapes, and optical discs. In some cases, such as with tmpfs, the computer's main memory (random-access memory, RAM) is used to create a temporary file system for short-term use.


title: File system

text: Some file systems are used on local data storage devices; others provide file access via a network protocol (for example, NFS, SMB, or 9P clients). Some file systems are "virtual", meaning that the supplied "files" (called virtual files) are computed on request (such as procfs and sysfs) or are merely a mapping into a different file system used as a backing store. The file system manages access to both the content of files and the metadata about those files. It is responsible for arranging storage space; reliability, efficiency, and tuning with regard to the physical storage medium are important design considerations.


title: File system

text: Before the advent of computers the term "file system" was used to describe a method of storing and retrieving paper documents. By 1961, the term was being applied to computerized filing alongside the original meaning. By 1964, it was in general use.


title: File system

text: A file system consists of two or three layers. Sometimes the layers are explicitly separated, and sometimes the functions are combined.


title: File system

text: The "logical file system" is responsible for interaction with the user application. It provides the application program interface (API) for file operations — codice_1, codice_2, codice_3, etc., and passes the requested operation to the layer below it for processing. The logical file system "manage[s] open file table entries and per-process file descriptors". This layer provides "file access, directory operations, [and] security and protection".


title: File system

text: The second optional layer is the "virtual file system". "This interface allows support for multiple concurrent instances of physical file systems, each of which is called a file system implementation".


title: File system

text: The third layer is the "physical file system". This layer is concerned with the physical operation of the storage device (e.g. disk). It processes physical blocks being read or written. It handles buffering and memory management and is responsible for the physical placement of blocks in specific locations on the storage medium. The physical file system interacts with the device drivers or with the channel to drive the storage device.


title: File system

text: File systems allocate space in a granular manner, usually multiple physical units on the device. The file system is responsible for organizing files and directories, and keeping track of which areas of the media belong to which file and which are not being used. For example, in Apple DOS of the early 1980s, 256-byte sectors on 140 kilobyte floppy disk used a "track/sector map".


title: File system

text: This results in unused space when a file is not an exact multiple of the allocation unit, sometimes referred to as "slack space". For a 512-byte allocation, the average unused space is 256 bytes. For 64 KB clusters, the average unused space is 32 KB. The size of the allocation unit is chosen when the file system is created. Choosing the allocation size based on the average size of the files expected to be in the file system can minimize the amount of unusable space. Frequently the default allocation may provide reasonable usage. Choosing an allocation size that is too small results in excessive overhead if the file system will contain mostly very large files.


title: File system

text: File system fragmentation occurs when unused space or single files are not contiguous. As a file system is used, files are created, modified and deleted. When a file is created, the file system allocates space for the data. Some file systems permit or require specifying an initial space allocation and subsequent incremental allocations as the file grows. As files are deleted, the space they were allocated eventually is considered available for use by other files. This creates alternating used and unused areas of various sizes. This is free space fragmentation. When a file is created and there is not an area of contiguous space available for its initial allocation, the space must be assigned in fragments. When a file is modified such that it becomes larger, it may exceed the space initially allocated to it, another allocation must be assigned elsewhere and the file becomes fragmented.


title: File system

text: In some operating systems, a system administrator may use disk quotas to limit the allocation of disk space.


title: File system

text: A filename (or file name) is used to identify a storage location in the file system. Most file systems have restrictions on the length of filenames. In some file systems, filenames are not case sensitive (i.e., the names codice_4 and codice_5 refer to the same file in a directory); in others, filenames are case sensitive (i.e., the names codice_4, codice_7, and codice_5 refer to three separate files that are in the same directory).


title: File system

text: Most modern file systems allow filenames to contain a wide range of characters from the Unicode character set. However, they may have restrictions on the use of certain special characters, disallowing them within filenames; those characters might be used to indicate a device, device type, directory prefix, file path separator, or file type.


title: File system

text: File systems typically have directories (also called folders) which allow the user to group files into separate collections. This may be implemented by associating the file name with an index in a table of contents or an inode in a Unix-like file system. Directory structures may be flat (i.e. linear), or allow hierarchies where directories may contain subdirectories. The first file system to support arbitrary hierarchies of directories was used in the Multics operating system. The native file systems of Unix-like systems also support arbitrary directory hierarchies, as do, for example, Apple's Hierarchical File System, and its successor HFS+ in classic Mac OS, the FAT file system in MS-DOS 2.0 and later versions of MS-DOS and in Microsoft Windows, the NTFS file system in the Windows NT family of operating systems, and the ODS-2 (On-Disk Structure-2) and higher levels of the Files-11 file system in OpenVMS.


title: File system

text: Other bookkeeping information is typically associated with each file within a file system. The length of the data contained in a file may be stored as the number of blocks allocated for the file or as a byte count. The time that the file was last modified may be stored as the file's timestamp. File systems might store the file creation time, the time it was last accessed, the time the file's metadata was changed, or the time the file was last backed up. Other information can include the file's device type (e.g. block, character, socket, subdirectory, etc.), its owner user ID and group ID, its access permissions and other file attributes (e.g. whether the file is read-only, executable, etc.).


title: File system

text: A file system stores all the metadata associated with the file—including the file name, the length of the contents of a file, and the location of the file in the folder hierarchy—separate from the contents of the file.


title: File system

text: Most file systems store the names of all the files in one directory in one place—the directory table for that directory—which is often stored like any other file.


title: File system

text: Many file systems put only some of the metadata for a file in the directory table, and the rest of the metadata for that file in a completely separate structure, such as the inode.


title: File system

text: Such metadata includes information about unused regions—free space bitmap, block availability map—and information about bad sectors.


title: File system

text: Additional attributes can be associated on file systems, such as NTFS, XFS, ext2, ext3, some versions of UFS, and HFS+, using extended file attributes. Some file systems provide for user defined attributes such as the author of the document, the character encoding of a document or the size of an image.


title: File system

text: Some file systems allow for different data collections to be associated with one file name. These separate collections may be referred to as "streams" or "forks". Apple has long used a forked file system on the Macintosh, and Microsoft supports streams in NTFS. Some file systems maintain multiple past revisions of a file under a single file name; the filename by itself retrieves the most recent version, while prior saved version can be accessed using a special naming convention such as "filename;4" or "filename(-4)" to access the version four saves ago.


title: File system

text: See comparison of file systems#Metadata for details on which file systems support which kinds of metadata.


title: File system

text: In some cases, a file system may not make use of a storage device but can be used to organize and represent access to any data, whether it is stored or dynamically generated (e.g. procfs).


title: File system

text: File systems include utilities to initialize, alter parameters of and remove an instance of the file system. Some include the ability to extend or truncate the space allocated to the file system.


title: File system

text: Directory utilities may be used to create, rename and delete "directory entries", which are also known as "dentries" (singular: "dentry"), and to alter metadata associated with a directory. Directory utilities may also include capabilities to create additional links to a directory (hard links in Unix), to rename parent links (".." in Unix-like operating systems), and to create bidirectional links to files.


title: File system

text: File utilities create, list, copy, move and delete files, and alter metadata. They may be able to truncate data, truncate or extend space allocation, append to, move, and modify files in-place. Depending on the underlying structure of the file system, they may provide a mechanism to prepend to or truncate from the beginning of a file, insert entries into the middle of a file, or delete entries from a file. Utilities to free space for deleted files, if the file system provides an undelete function, also belong to this category.


title: File system

text: Some file systems defer operations such as reorganization of free space, secure erasing of free space, and rebuilding of hierarchical structures by providing utilities to perform these functions at times of minimal activity. An example is the file system defragmentation utilities.


title: File system

text: Some of the most important features of file system utilities are supervisory activities which may involve bypassing ownership or direct access to the underlying device. These include high-performance backup and recovery, data replication, and reorganization of various data structures and allocation tables within the file system.


title: File system

text: There are several mechanisms used by file systems to control access to data. Usually the intent is to prevent reading or modifying files by a user or group of users. Another reason is to ensure data is modified in a controlled way so access may be restricted to a specific program. Examples include passwords stored in the metadata of the file or elsewhere and file permissions in the form of permission bits, access control lists, or capabilities. The need for file system utilities to be able to access the data at the media level to reorganize the structures and provide efficient backup usually means that these are only effective for polite users but are not effective against intruders.


title: File system

text: Methods for encrypting file data are sometimes included in the file system. This is very effective since there is no need for file system utilities to know the encryption seed to effectively manage the data. The risks of relying on encryption include the fact that an attacker can copy the data and use brute force to decrypt the data. Additionally, losing the seed means losing the data.


title: File system

text: One significant responsibility of a file system is to ensure that the file system structures in secondary storage remain consistent, regardless of the actions by programs accessing the file system. This includes actions taken if a program modifying the file system terminates abnormally or neglects to inform the file system that it has completed its activities. This may include updating the metadata, the directory entry and handling any data that was buffered but not yet updated on the physical storage media.


title: File system

text: Other failures which the file system must deal with include media failures or loss of connection to remote systems.


title: File system

text: In the event of an operating system failure or "soft" power failure, special routines in the file system must be invoked similar to when an individual program fails.


title: File system

text: The file system must also be able to correct damaged structures. These may occur as a result of an operating system failure for which the OS was unable to notify the file system, a power failure, or a reset.


title: File system

text: The file system must also record events to allow analysis of systemic issues as well as problems with specific files or directories.


title: File system

text: The most important purpose of a file system is to manage user data. This includes storing, retrieving and updating data.


title: File system

text: Some file systems accept data for storage as a stream of bytes which are collected and stored in a manner efficient for the media. When a program retrieves the data, it specifies the size of a memory buffer and the file system transfers data from the media to the buffer. A runtime library routine may sometimes allow the user program to define a "record" based on a library call specifying a length. When the user program reads the data, the library retrieves data via the file system and returns a "record".


title: File system

text: Some file systems allow the specification of a fixed record length which is used for all writes and reads. This facilitates locating the n record as well as updating records.


title: File system

text: An identification for each record, also known as a key, makes for a more sophisticated file system. The user program can read, write and update records without regard to their location. This requires complicated management of blocks of media usually separating key blocks and data blocks. Very efficient algorithms can be developed with pyramid structures for locating records.


title: File system

text: Utilities, language specific run-time libraries and user programs use file system APIs to make requests of the file system. These include data transfer, positioning, updating metadata, managing directories, managing access specifications, and removal.


title: File system

text: Frequently, retail systems are configured with a single file system occupying the entire storage device.


title: File system

text: Another approach is to partition the disk so that several file systems with different attributes can be used. One file system, for use as browser cache or email storage, might be configured with a small allocation size. This keeps the activity of creating and deleting files typical of browser activity in a narrow area of the disk where it will not interfere with other file allocations. Another partition might be created for the storage of audio or video files with a relatively large block size. Yet another may normally be set "read-only" and only periodically be set writable.


title: File system

text: A third approach, which is mostly used in cloud systems, is to use "disk images" to house additional file systems, with the same attributes or not, within another (host) file system as a file. A common example is virtualization: one user can run an experimental Linux distribution (using the ext4 file system) in a virtual machine under his/her production Windows environment (using NTFS). The ext4 file system resides in a disk image, which is treated as a file (or multiple files, depending on the hypervisor and settings) in the NTFS host file system.


title: File system

text: Having multiple file systems on a single system has the additional benefit that in the event of a corruption of a single partition, the remaining file systems will frequently still be intact. This includes virus destruction of the "system" partition or even a system that will not boot. File system utilities which require dedicated access can be effectively completed piecemeal. In addition, defragmentation may be more effective. Several system maintenance utilities, such as virus scans and backups, can also be processed in segments. For example, it is not necessary to backup the file system containing videos along with all the other files if none have been added since the last backup. As for the image files, one can easily "spin off" differential images which contain only "new" data written to the master (original) image. Differential images can be used for both safety concerns (as a "disposable" system - can be quickly restored if destroyed or contaminated by a virus, as the old image can be removed and a new image can be created in matter of seconds, even without automated procedures) and quick virtual machine deployment (since the differential images can be quickly spawned using a script in batches).


title: File system

text: All file systems have some functional limit that defines the maximum storable data capacity within that system. These functional limits are a best-guess effort by the designer based on how large the storage systems are right now and how large storage systems are likely to become in the future. Disk storage has continued to increase at near exponential rates (see Moore's law), so after a few years, file systems have kept reaching design limitations that require computer users to repeatedly move to a newer system with ever-greater capacity.


title: File system

text: File system complexity typically varies proportionally with the available storage capacity. The file systems of early 1980s home computers with 50 KB to 512 KB of storage would not be a reasonable choice for modern storage systems with hundreds of gigabytes of capacity. Likewise, modern file systems would not be a reasonable choice for these early systems, since the complexity of modern file system structures would quickly consume or even exceed the very limited capacity of the early storage systems.


title: File system

text: File system types can be classified into disk/tape file systems, network file systems and special-purpose file systems.


title: File system

text: A "disk file system" takes advantages of the ability of disk storage media to randomly address data in a short amount of time. Additional considerations include the speed of accessing data following that initially requested and the anticipation that the following data may also be requested. This permits multiple users (or processes) access to various data on the disk without regard to the sequential location of the data. Examples include FAT (FAT12, FAT16, FAT32), exFAT, NTFS, HFS and HFS+, HPFS, APFS, UFS, ext2, ext3, ext4, XFS, btrfs, Files-11, Veritas File System, VMFS, ZFS, ReiserFS and ScoutFS. Some disk file systems are journaling file systems or versioning file systems.


title: File system

text: ISO 9660 and Universal Disk Format (UDF) are two common formats that target Compact Discs, DVDs and Blu-ray discs. Mount Rainier is an extension to UDF supported since 2.6 series of the Linux kernel and since Windows Vista that facilitates rewriting to DVDs.


title: File system

text: A "flash file system" considers the special abilities, performance and restrictions of flash memory devices. Frequently a disk file system can use a flash memory device as the underlying storage media, but it is much better to use a file system specifically designed for a flash device.


title: File system

text: A "tape file system" is a file system and tape format designed to store files on tape. Magnetic tapes are sequential storage media with significantly longer random data access times than disks, posing challenges to the creation and efficient management of a general-purpose file system.


title: File system

text: In a disk file system there is typically a master file directory, and a map of used and free data regions. Any file additions, changes, or removals require updating the directory and the used/free maps. Random access to data regions is measured in milliseconds so this system works well for disks.


title: File system

text: Tape requires linear motion to wind and unwind potentially very long reels of media. This tape motion may take several seconds to several minutes to move the read/write head from one end of the tape to the other.


title: File system

text: Consequently, a master file directory and usage map can be extremely slow and inefficient with tape. Writing typically involves reading the block usage map to find free blocks for writing, updating the usage map and directory to add the data, and then advancing the tape to write the data in the correct spot. Each additional file write requires updating the map and directory and writing the data, which may take several seconds to occur for each file.


title: File system

text: Tape file systems instead typically allow for the file directory to be spread across the tape intermixed with the data, referred to as "streaming", so that time-consuming and repeated tape motions are not required to write new data.


title: File system

text: However, a side effect of this design is that reading the file directory of a tape usually requires scanning the entire tape to read all the scattered directory entries. Most data archiving software that works with tape storage will store a local copy of the tape catalog on a disk file system, so that adding files to a tape can be done quickly without having to rescan the tape media. The local tape catalog copy is usually discarded if not used for a specified period of time, at which point the tape must be re-scanned if it is to be used in the future.


title: File system

text: IBM has developed a file system for tape called the Linear Tape File System. The IBM implementation of this file system has been released as the open-source IBM Linear Tape File System — Single Drive Edition (LTFS-SDE) product. The Linear Tape File System uses a separate partition on the tape to record the index meta-data, thereby avoiding the problems associated with scattering directory entries across the entire tape.


title: File system

text: Writing data to a tape, erasing, or formatting a tape is often a significantly time-consuming process and can take several hours on large tapes. With many data tape technologies it is not necessary to format the tape before over-writing new data to the tape. This is due to the inherently destructive nature of overwriting data on sequential media.


title: File system

text: Because of the time it can take to format a tape, typically tapes are pre-formatted so that the tape user does not need to spend time preparing each new tape for use. All that is usually necessary is to write an identifying media label to the tape before use, and even this can be automatically written by software when a new tape is used for the first time.


title: File system

text: Another concept for file management is the idea of a database-based file system. Instead of, or in addition to, hierarchical structured management, files are identified by their characteristics, like type of file, topic, author, or similar rich metadata.


title: File system

text: IBM DB2 for i (formerly known as DB2/400 and DB2 for i5/OS) is a database file system as part of the object based IBM i operating system (formerly known as OS/400 and i5/OS), incorporating a single level store and running on IBM Power Systems (formerly known as AS/400 and iSeries), designed by Frank G. Soltis IBM's former chief scientist for IBM i. Around 1978 to 1988 Frank G. Soltis and his team at IBM Rochester have successfully designed and applied technologies like the database file system where others like Microsoft later failed to accomplish. These technologies are informally known as 'Fortress Rochester' and were in few basic aspects extended from early Mainframe technologies but in many ways more advanced from a technological perspective.


title: File system

text: Some other projects that aren't "pure" database file systems but that use some aspects of a database file system:


title: File system

text: Some programs need to either make multiple file system changes, or, if one or more of the changes fail for any reason, make none of the changes. For example, a program which is installing or updating software may write executables, libraries, and/or configuration files. If some of the writing fails and the software is left partially installed or updated, the software may be broken or unusable. An incomplete update of a key system utility, such as the command shell, may leave the entire system in an unusable state.


title: File system

text: Transaction processing introduces the atomicity guarantee, ensuring that operations inside of a transaction are either all committed or the transaction can be aborted and the system discards all of its partial results. This means that if there is a crash or power failure, after recovery, the stored state will be consistent. Either the software will be completely installed or the failed installation will be completely rolled back, but an unusable partial install will not be left on the system. Transactions also provide the isolation guarantee, meaning that operations within a transaction are hidden from other threads on the system until the transaction commits, and that interfering operations on the system will be properly serialized with the transaction.


title: File system

text: Windows, beginning with Vista, added transaction support to NTFS, in a feature called Transactional NTFS, but its use is now discouraged. There are a number of research prototypes of transactional file systems for UNIX systems, including the Valor file system, Amino, LFS, and a transactional ext3 file system on the TxOS kernel, as well as transactional file systems targeting embedded systems, such as TFFS.


title: File system

text: Ensuring consistency across multiple file system operations is difficult, if not impossible, without file system transactions. File locking can be used as a concurrency control mechanism for individual files, but it typically does not protect the directory structure or file metadata. For instance, file locking cannot prevent TOCTTOU race conditions on symbolic links.


title: File system

text: File locking also cannot automatically roll back a failed operation, such as a software upgrade; this requires atomicity.


title: File system

text: Journaling file systems is one technique used to introduce transaction-level consistency to file system structures. Journal transactions are not exposed to programs as part of the OS API; they are only used internally to ensure consistency at the granularity of a single system call.


title: File system

text: Data backup systems typically do not provide support for direct backup of data stored in a transactional manner, which makes the recovery of reliable and consistent data sets difficult. Most backup software simply notes what files have changed since a certain time, regardless of the transactional state shared across multiple files in the overall dataset. As a workaround, some database systems simply produce an archived state file containing all data up to that point, and the backup software only backs that up and does not interact directly with the active transactional databases at all. Recovery requires separate recreation of the database from the state file after the file has been restored by the backup software.


title: File system

text: A "network file system" is a file system that acts as a client for a remote file access protocol, providing access to files on a server. Programs using local interfaces can transparently create, manage and access hierarchical directories and files in remote network-connected computers. Examples of network file systems include clients for the NFS, AFS, SMB protocols, and file-system-like clients for FTP and WebDAV.


title: File system

text: A "shared disk file system" is one in which a number of machines (usually servers) all have access to the same external disk subsystem (usually a storage area network). The file system arbitrates access to that subsystem, preventing write collisions. Examples include GFS2 from Red Hat, GPFS, now known as Spectrum Scale, from IBM, SFS from DataPlow, CXFS from SGI, StorNext from Quantum Corporation and ScoutFS from Versity.


title: File system

text: A "special file system" presents non-file elements of an operating system as files so they can be acted on using file system APIs. This is most commonly done in Unix-like operating systems, but devices are given file names in some non-Unix-like operating systems as well.


title: File system

text: A "device file system" represents I/O devices and pseudo-devices as files, called device files. Examples in Unix-like systems include devfs and, in Linux 2.6 systems, udev. In non-Unix-like systems, such as TOPS-10 and other operating systems influenced by it, where the full filename or pathname of a file can include a device prefix, devices other than those containing file systems are referred to by a device prefix specifying the device, without anything following it.


title: File system

text: In the 1970s disk and digital tape devices were too expensive for some early microcomputer users. An inexpensive basic data storage system was devised that used common audio cassette tape.


title: File system

text: When the system needed to write data, the user was notified to press "RECORD" on the cassette recorder, then press "RETURN" on the keyboard to notify the system that the cassette recorder was recording. The system wrote a sound to provide time synchronization, then modulated sounds that encoded a prefix, the data, a checksum and a suffix. When the system needed to read data, the user was instructed to press "PLAY" on the cassette recorder. The system would "listen" to the sounds on the tape waiting until a burst of sound could be recognized as the synchronization. The system would then interpret subsequent sounds as data. When the data read was complete, the system would notify the user to press "STOP" on the cassette recorder. It was primitive, but it (mostly) worked. Data was stored sequentially, usually in an unnamed format, although some systems (such as the Commodore PET series of computers) did allow the files to be named. Multiple sets of data could be written and located by fast-forwarding the tape and observing at the tape counter to find the approximate start of the next data region on the tape. The user might have to listen to the sounds to find the right spot to begin playing the next data region. Some implementations even included audible sounds interspersed with the data.


title: File system

text: In a flat file system, there are no subdirectories; directory entries for all files are stored in a single directory.


title: File system

text: When floppy disk media was first available this type of file system was adequate due to the relatively small amount of data space available. CP/M machines featured a flat file system, where files could be assigned to one of 16 "user areas" and generic file operations narrowed to work on one instead of defaulting to work on all of them. These user areas were no more than special attributes associated with the files; that is, it was not necessary to define specific quota for each of these areas and files could be added to groups for as long as there was still free storage space on the disk. The early Apple Macintosh also featured a flat file system, the Macintosh File System. It was unusual in that the file management program (Macintosh Finder) created the illusion of a partially hierarchical filing system on top of EMFS. This structure required every file to have a unique name, even if it appeared to be in a separate folder. IBM DOS/360 and OS/360 store entries for all files on a disk pack ("volume") in a directory on the pack called a "Volume Table of Contents" (VTOC).


title: File system

text: While simple, flat file systems become awkward as the number of files grows and makes it difficult to organize data into related groups of files.


title: File system

text: A recent addition to the flat file system family is Amazon's S3, a remote storage service, which is intentionally simplistic to allow users the ability to customize how their data is stored. The only constructs are buckets (imagine a disk drive of unlimited size) and objects (similar, but not identical to the standard concept of a file). Advanced file management is allowed by being able to use nearly any character (including '/') in the object's name, and the ability to select subsets of the bucket's content based on identical prefixes.


title: File system

text: Many operating systems include support for more than one file system. Sometimes the OS and the file system are so tightly interwoven that it is difficult to separate out file system functions.


title: File system

text: There needs to be an interface provided by the operating system software between the user and the file system. This interface can be textual (such as provided by a command line interface, such as the Unix shell, or OpenVMS DCL) or graphical (such as provided by a graphical user interface, such as file browsers). If graphical, the metaphor of the "folder", containing documents, other files, and nested folders is often used (see also: directory and folder).


title: File system

text: Unix-like operating systems create a virtual file system, which makes all the files on all the devices appear to exist in a single hierarchy. This means, in those systems, there is one root directory, and every file existing on the system is located under it somewhere. Unix-like systems can use a RAM disk or network shared resource as its root directory.


title: File system

text: Unix-like systems assign a device name to each device, but this is not how the files on that device are accessed. Instead, to gain access to files on another device, the operating system must first be informed where in the directory tree those files should appear. This process is called mounting a file system. For example, to access the files on a CD-ROM, one must tell the operating system "Take the file system from this CD-ROM and make it appear under such-and-such directory." The directory given to the operating system is called the "mount point" – it might, for example, be . The directory exists on many Unix systems (as specified in the Filesystem Hierarchy Standard) and is intended specifically for use as a mount point for removable media such as CDs, DVDs, USB drives or floppy disks. It may be empty, or it may contain subdirectories for mounting individual devices. Generally, only the administrator (i.e. root user) may authorize the mounting of file systems.


title: File system

text: Unix-like operating systems often include software and tools that assist in the mounting process and provide it new functionality. Some of these strategies have been coined "auto-mounting" as a reflection of their purpose.


title: File system

text: Linux supports numerous file systems, but common choices for the system disk on a block device include the ext* family (ext2, ext3 and ext4), XFS, JFS, and btrfs. For raw flash without a flash translation layer (FTL) or Memory Technology Device (MTD), there are UBIFS, JFFS2 and YAFFS, among others. SquashFS is a common compressed read-only file system.


title: File system

text: Solaris in earlier releases defaulted to (non-journaled or non-logging) UFS for bootable and supplementary file systems. Solaris defaulted to, supported, and extended UFS.


title: File system

text: Support for other file systems and significant enhancements were added over time, including Veritas Software Corp. (journaling) VxFS, Sun Microsystems (clustering) QFS, Sun Microsystems (journaling) UFS, and Sun Microsystems (open source, poolable, 128 bit compressible, and error-correcting) ZFS.


title: File system

text: Kernel extensions were added to Solaris to allow for bootable Veritas VxFS operation. Logging or journaling was added to UFS in Sun's Solaris 7. Releases of Solaris 10, Solaris Express, OpenSolaris, and other open source variants of the Solaris operating system later supported bootable ZFS.


title: File system

text: Logical Volume Management allows for spanning a file system across multiple devices for the purpose of adding redundancy, capacity, and/or throughput. Legacy environments in Solaris may use Solaris Volume Manager (formerly known as Solstice DiskSuite). Multiple operating systems (including Solaris) may use Veritas Volume Manager. Modern Solaris based operating systems eclipse the need for volume management through leveraging virtual storage pools in ZFS.


title: File system

text: macOS (formerly Mac OS X) uses the Apple File System (APFS), which in 2017 replaced a file system inherited from classic Mac OS called HFS Plus (HFS+). Apple also uses the term "Mac OS Extended" for HFS+. HFS Plus is a metadata-rich and case-preserving but (usually) case-insensitive file system. Due to the Unix roots of macOS, Unix permissions were added to HFS Plus. Later versions of HFS Plus added journaling to prevent corruption of the file system structure and introduced a number of optimizations to the allocation algorithms in an attempt to defragment files automatically without requiring an external defragmenter.


title: File system

text: Filenames can be up to 255 characters. HFS Plus uses Unicode to store filenames. On macOS, the filetype can come from the type code, stored in file's metadata, or the filename extension.


title: File system

text: HFS Plus has three kinds of links: Unix-style hard links, Unix-style symbolic links, and aliases. Aliases are designed to maintain a link to their original file even if they are moved or renamed; they are not interpreted by the file system itself, but by the File Manager code in userland.


title: File system

text: macOS 10.13 High Sierra, which was announced on June 5, 2017 at Apple's WWDC event, uses the Apple File System on solid-state drives.


title: File system

text: macOS also supported the UFS file system, derived from the BSD Unix Fast File System via NeXTSTEP. However, as of Mac OS X Leopard, macOS could no longer be installed on a UFS volume, nor can a pre-Leopard system installed on a UFS volume be upgraded to Leopard. As of Mac OS X Lion UFS support was completely dropped.


title: File system

text: Newer versions of macOS are capable of reading and writing to the legacy FAT file systems (16 and 32) common on Windows. They are also capable of "reading" the newer NTFS file systems for Windows. In order to "write" to NTFS file systems on macOS versions prior to Mac OS X Snow Leopard third party software is necessary. Mac OS X 10.6 (Snow Leopard) and later allow writing to NTFS file systems, but only after a non-trivial system setting change (third party software exists that automates this).


title: File system

text: Finally, macOS supports reading and writing of the exFAT file system since Mac OS X Snow Leopard, starting from version 10.6.5.


title: File system

text: OS/2 1.2 introduced the High Performance File System (HPFS). HPFS supports mixed case file names in different code pages, long file names (255 characters), more efficient use of disk space, an architecture that keeps related items close to each other on the disk volume, less fragmentation of data, extent-based space allocation, a B+ tree structure for directories, and the root directory located at the midpoint of the disk, for faster average access. A journaled filesystem (JFS) was shipped in 1999.


title: File system

text: PC-BSD is a desktop version of FreeBSD, which inherits FreeBSD's ZFS support, similarly to FreeNAS. The new graphical installer of PC-BSD can handle "/ (root) on ZFS" and RAID-Z pool installs and disk encryption using Geli right from the start in an easy convenient (GUI) way. The current PC-BSD 9.0+ 'Isotope Edition' has ZFS filesystem version 5 and ZFS storage pool version 28.


title: File system

text: Plan 9 from Bell Labs treats everything as a file and accesses all objects as a file would be accessed (i.e., there is no ioctl or mmap): networking, graphics, debugging, authentication, capabilities, encryption, and other services are accessed via I/O operations on file descriptors. The 9P protocol removes the difference between local and remote files. File systems in Plan 9 are organized with the help of private, per-process namespaces, allowing each process to have a different view of the many file systems that provide resources in a distributed system.


title: File system

text: Windows makes use of the FAT, NTFS, exFAT, Live File System and ReFS file systems (the last of these is only supported and usable in Windows Server 2012, Windows Server 2016, Windows 8, Windows 8.1, and Windows 10; Windows cannot boot from it).


title: File system

text: Windows uses a "drive letter" abstraction at the user level to distinguish one disk or partition from another. For example, the path represents a directory on the partition represented by the letter C. Drive C: is most commonly used for the primary hard disk drive partition, on which Windows is usually installed and from which it boots. This "tradition" has become so firmly ingrained that bugs exist in many applications which make assumptions that the drive that the operating system is installed on is C. The use of drive letters, and the tradition of using "C" as the drive letter for the primary hard disk drive partition, can be traced to MS-DOS, where the letters A and B were reserved for up to two floppy disk drives. This in turn derived from CP/M in the 1970s, and ultimately from IBM's CP/CMS of 1967.


title: File system

text: The family of FAT file systems is supported by almost all operating systems for personal computers, including all versions of Windows and MS-DOS/PC DOS, OS/2, and DR-DOS. (PC DOS is an OEM version of MS-DOS, MS-DOS was originally based on SCP's 86-DOS. DR-DOS was based on Digital Research's Concurrent DOS, a successor of CP/M-86.) The FAT file systems are therefore well-suited as a universal exchange format between computers and devices of most any type and age.


title: File system

text: The FAT file system traces its roots back to an (incompatible) 8-bit FAT precursor in Standalone Disk BASIC and the short-lived MDOS/MIDAS project.


title: File system

text: Over the years, the file system has been expanded from FAT12 to FAT16 and FAT32. Various features have been added to the file system including subdirectories, codepage support, extended attributes, and long filenames. Third parties such as Digital Research have incorporated optional support for deletion tracking, and volume/directory/file-based multi-user security schemes to support file and directory passwords and permissions such as read/write/execute/delete access rights. Most of these extensions are not supported by Windows.


title: File system

text: The FAT12 and FAT16 file systems had a limit on the number of entries in the root directory of the file system and had restrictions on the maximum size of FAT-formatted disks or partitions.


title: File system

text: FAT32 addresses the limitations in FAT12 and FAT16, except for the file size limit of close to 4 GB, but it remains limited compared to NTFS.


title: File system

text: FAT12, FAT16 and FAT32 also have a limit of eight characters for the file name, and three characters for the extension (such as .exe). This is commonly referred to as the 8.3 filename limit. VFAT, an optional extension to FAT12, FAT16 and FAT32, introduced in Windows 95 and Windows NT 3.5, allowed long file names (LFN) to be stored in the FAT file system in a backwards compatible fashion.


title: File system

text: NTFS, introduced with the Windows NT operating system in 1993, allowed ACL-based permission control. Other features also supported by NTFS include hard links, multiple file streams, attribute indexing, quota tracking, sparse files, encryption, compression, and reparse points (directories working as mount-points for other file systems, symlinks, junctions, remote storage links).


title: File system

text: exFAT is not backward compatible with FAT file systems such as FAT12, FAT16 or FAT32. The file system is supported with newer Windows systems, such as Windows XP, Windows Server 2003, Windows Vista, Windows 2008, Windows 7, Windows 8, Windows 8.1, Windows 10 and Windows 11.


title: File system

text: exFAT is supported in macOS starting with version 10.6.5 (Snow Leopard). Support in other operating systems is sparse since implementing support for exFAT requires a license. exFAT is the only file system that is fully supported on both macOS and Windows that can hold files larger than 4 GB.


title: File system

text: Prior to the introduction of VSAM, OS/360 systems implemented a hybrid file system. The system was designed to easily support removable disk packs, so the information relating to all files on one disk ("volume" in IBM terminology) is stored on that disk in a flat system file called the "Volume Table of Contents" (VTOC). The VTOC stores all metadata for the file. Later a hierarchical directory structure was imposed with the introduction of the "System Catalog", which can optionally catalog files (datasets) on resident and removable volumes. The catalog only contains information to relate a dataset to a specific volume. If the user requests access to a dataset on an offline volume, and they have suitable privileges, the system will attempt to mount the required volume. Cataloged and non-cataloged datasets can still be accessed using information in the VTOC, bypassing the catalog, if the required volume id is provided to the OPEN request. Still later the VTOC was indexed to speed up access.


title: File system

text: The IBM Conversational Monitor System (CMS) component of VM/370 uses a separate flat file system for each virtual disk ("minidisk"). File data and control information are scattered and intermixed. The anchor is a record called the "Master File Directory" (MFD), always located in the fourth block on the disk. Originally CMS used fixed-length 800-byte blocks, but later versions used larger size blocks up to 4K. Access to a data record requires two levels of indirection, where the file's directory entry (called a "File Status Table" (FST) entry) points to blocks containing a list of addresses of the individual records.


title: File system

text: Data on the AS/400 and its successors consists of system objects mapped into the system virtual address space in a single-level store. Many types of objects are defined including the directories and files found in other file systems. File objects, along with other types of objects, form the basis of the AS/400's support for an integrated relational database.


title: File system

text: It may be advantageous or necessary to have files in a different file system than they currently exist. Reasons include the need for an increase in the space requirements beyond the limits of the current file system. The depth of path may need to be increased beyond the restrictions of the file system. There may be performance or reliability considerations. Providing access to another operating system which does not support the existing file system is another reason.


title: File system

text: In some cases conversion can be done in-place, although migrating the file system is more conservative, as it involves a creating a copy of the data and is recommended. On Windows, FAT and FAT32 file systems can be converted to NTFS via the convert.exe utility, but not the reverse. On Linux, ext2 can be converted to ext3 (and converted back), and ext3 can be converted to ext4 (but not back), and both ext3 and ext4 can be converted to btrfs, and converted back until the undo information is deleted. These conversions are possible due to using the same format for the file data itself, and relocating the metadata into empty space, in some cases using sparse file support.


title: File system

text: Migration has the disadvantage of requiring additional space although it may be faster. The best case is if there is unused space on media which will contain the final file system.


title: File system

text: For example, to migrate a FAT32 file system to an ext2 file system. First create a new ext2 file system, then copy the data to the file system, then delete the FAT32 file system.


title: File system

text: An alternative, when there is not sufficient space to retain the original file system until the new one is created, is to use a work area (such as a removable media). This takes longer but a backup of the data is a nice side effect.


title: File system

text: In hierarchical file systems, files are accessed by means of a "path" that is a branching list of directories containing the file. Different file systems have different limits on the depth of the path. File systems also have a limit on the length of an individual filename.


title: File system

text: Copying files with long names or located in paths of significant depth from one file system to another may cause undesirable results. This depends on how the utility doing the copying handles the discrepancy.


title: MMR vaccine

text: The MMR vaccine is a vaccine against measles, mumps, and rubella (German measles), abbreviated as "MMR". The first dose is generally given to children around 9 months to 15 months of age, with a second dose at 15 months to 6 years of age, with at least four weeks between the doses. After two doses, 97% of people are protected against measles, 88% against mumps, and at least 97% against rubella. The vaccine is also recommended for those who do not have evidence of immunity, those with well-controlled HIV/AIDS, and within 72 hours of exposure to measles among those who are incompletely immunized. It is given by injection.


title: MMR vaccine

text: The MMR vaccine is widely used around the world. Worldwide over 500 million doses were administered between 1999 and 2004, and 575 million doses have been administered since the vaccine's introduction worldwide. Measles resulted in 2.6 million deaths per year before immunization became common. This has decreased to 122,000 deaths per year , mostly in low-income countries. Through vaccination, , rates of measles in North and South America are very low. Rates of disease have been seen to increase in populations that go unvaccinated. Between 2000 and 2018, vaccination decreased measles deaths by 73%.


title: MMR vaccine

text: Side effects of immunization are generally mild and resolve without any specific treatment. These may include fever, as well as pain or redness at the injection site. Severe allergic reactions occur in about one in a million people. Because it contains live viruses, the MMR vaccine is not recommended during pregnancy but may be given while breastfeeding. The vaccine is safe to give at the same time as other vaccines. Being recently immunized does not increase the risk of passing measles, mumps, or rubella on to others. There is no evidence of an association between MMR immunisation and autistic spectrum disorders. The MMR vaccine is a mixture of live weakened viruses of the three diseases.


title: MMR vaccine

text: The MMR vaccine was developed by Maurice Hilleman. It was licensed for use in USA by Merck in 1971. Stand-alone measles, mumps, and rubella vaccines had been previously licensed in 1963, 1967, and 1969, respectively. Recommendations for a second dose were introduced in 1989. The MMRV vaccine, which also covers chickenpox, may be used instead. An MR vaccine, without coverage for mumps, is also occasionally used.


title: MMR vaccine

text: Cochrane concluded that the "Existing evidence on the safety and effectiveness of MMR and MMRV vaccine supports current policies of mass immunisation aimed at global measles eradication in order to reduce morbidity and mortality associated with measles mumps rubella and varicella."


title: MMR vaccine

text: The combined MMR vaccine induces immunity less painfully than three separate injections at the same time, and sooner and more efficiently than three injections given on different dates. Public Health England reports that providing a single combined vaccine as of 1988, rather than giving the option to have them also done separately, increased uptake of the vaccine.


title: MMR vaccine

text: Before the widespread use of a vaccine against measles, rates of disease were so high that infection was felt to be "as inevitable as death and taxes." Reported cases of measles in the United States fell from hundreds of thousands to tens of thousands per year following introduction of the vaccine in 1963. Increasing uptake of the vaccine following outbreaks in 1971, and 1977, brought this down to thousands of cases per year in the 1980s. An outbreak of almost 30,000 cases in 1990 led to a renewed push for vaccination and the addition of a second vaccine to the recommended schedule. Fewer than 200 cases have been reported in the US each year between 1997 and 2013, and the disease is no longer considered endemic there.


title: MMR vaccine

text: The benefit of measles vaccination in preventing illness, disability, and death has been well documented. The first 20 years of licensed measles vaccination in the US prevented an estimated 52 million cases of the disease, 17,400 cases of intellectual disability, and 5,200 deaths. During 1999–2004, a strategy led by the World Health Organization and UNICEF led to improvements in measles vaccination coverage that averted an estimated 1.4 million measles deaths worldwide. Between 2000 and 2018, measles vaccination resulted in a 73% decrease in deaths from the disease.


title: MMR vaccine

text: Measles is common in many areas of the world. Although it was declared eliminated from the US in 2000, high rates of vaccination and good communication with people who refuse vaccination are needed to prevent outbreaks and sustain the elimination of measles in the US. Of the 66 cases of measles reported in the US in 2005, slightly over half were attributable to one unvaccinated individual who acquired measles during a visit to Romania. This individual returned to a community with many unvaccinated children. The resulting outbreak infected 34 people, mostly children and virtually all unvaccinated; 9% were hospitalized, and the cost of containing the outbreak was estimated at $167,685. A major epidemic was averted due to high rates of vaccination in the surrounding communities.


title: MMR vaccine

text: In 2017, an outbreak of measles occurred among the Somali-American community in Minnesota, where MMR vaccination rates had declined due to the misconception that the vaccine could cause autism. The US Centers for Disease Control and Prevention recorded 65 affected children in the outbreak by April 2017.


title: MMR vaccine

text: Rubella, also known as German measles, was also very common before widespread vaccination. The major risk of rubella is during pregnancy when the baby may contract congenital rubella, which can cause significant congenital defects.


title: MMR vaccine

text: Mumps is another viral disease that was once very common, especially during childhood. If mumps is acquired by a male who is past puberty, a possible complication is bilateral orchitis, which can in some cases lead to sterility.


title: MMR vaccine

text: The MMR vaccine is administered by a subcutaneous injection, the first dose typically at twelve months of age. The second dose may be given as early as one month after the first dose. The second dose is a dose to produce immunity in the small number of persons (2–5%) who fail to develop measles immunity after the first dose. In the US it is done before entry to kindergarten because that is a convenient time. Areas where measles is common typically recommend the first dose at nine months of age and the second dose at fifteen months of age.


title: MMR vaccine

text: Adverse reactions, rarely serious, may occur from each component of the MMR vaccine. Ten percent of children develop fever, malaise, and a rash 5–21 days after the first vaccination; and 3% develop joint pain lasting 18 days on average. Older women appear to be more at risk of joint pain, acute arthritis, and even (rarely) chronic arthritis. Anaphylaxis is an extremely rare but serious allergic reaction to the vaccine. One cause can be egg allergy. In 2014, the FDA approved two additional possible adverse events on the vaccination label: acute disseminated encephalomyelitis (ADEM), and transverse myelitis, with permission to also add "difficulty walking" to the package inserts. A 2012 IOM report found that the measles component of the MMR vaccine can cause measles inclusion body encephalitis in immunocompromised individuals. This report also rejected any connection between the MMR vaccine and autism. Some versions of the vaccine contain the antibiotic neomycin and therefore should not be used in people allergic to this antibiotic.


title: MMR vaccine

text: The number of reports on neurological disorders is very small, other than evidence for an association between a form of the MMR vaccine containing the Urabe mumps strain and rare adverse events of aseptic meningitis, a form of viral meningitis. The UK National Health Service stopped using the Urabe mumps strain in the early 1990s due to cases of transient mild viral meningitis, and switched to a form using the Jeryl Lynn mumps strain instead. The Urabe strain remains in use in a number of countries; MMR with the Urabe strain is much cheaper to manufacture than with the Jeryl Lynn strain, and a strain with higher efficacy along with a somewhat higher rate of mild side effects may still have the advantage of reduced incidence of overall adverse events.


title: MMR vaccine

text: A Cochrane review found that, compared with placebo, MMR vaccine was associated with fewer upper respiratory tract infections, more irritability, and a similar number of other adverse effects.


title: MMR vaccine

text: Naturally acquired measles often occurs with immune thrombocytopenic purpura (ITP, a purpuric rash and an increased tendency to bleed that resolves within two months in children), occurring in 1 to 20,000 cases. Approximately 1 in 40,000 children are thought to acquire ITP in the six weeks following an MMR vaccination. ITP below the age of six years is generally a mild disease, rarely having long-term consequences.


title: MMR vaccine

text: In 1998 Andrew Wakefield "et al." published a fraudulent paper about twelve children, reportedly with bowel symptoms and autism or other disorders acquired soon after administration of MMR vaccine, while supporting a competing vaccine. In 2010, Wakefield's research was found by the General Medical Council to have been "dishonest", and "The Lancet" fully retracted the paper. Three months following "The Lancet's" retraction, Wakefield was struck off the UK medical register, with a statement identifying deliberate falsification in the research published in "The Lancet", and was barred from practising medicine in the UK. The research was declared fraudulent in 2011 by the "British Medical Journal".


title: MMR vaccine

text: Since Wakefield's publication, multiple peer-reviewed studies have failed to show any association between the vaccine and autism. The US Centers for Disease Control and Prevention, the Institute of Medicine of the US National Academy of Sciences, the UK National Health Service and the Cochrane Library review have all concluded that there is no evidence of a link.


title: MMR vaccine

text: Administering the vaccines in three separate doses does not reduce the chance of adverse effects, and it increases the opportunity for infection by the two diseases not immunized against first. Health experts have criticized media reporting of the MMR-autism controversy for triggering a decline in vaccination rates. Before publication of Wakefield's article, the inoculation rate for MMR in the UK was 92%; after publication, the rate dropped to below 80%. In 1998, there were 56 measles cases in the UK; by 2008, there were 1348 cases, with two confirmed deaths.


title: MMR vaccine

text: In Japan, the MMR triplet is not used. Immunity is achieved by a combination vaccine for measles and rubella, followed up later with a mumps only vaccine. This has had no effect on autism rates in the country, further disproving the MMR autism hypothesis.


title: MMR vaccine

text: The component viral strains of MMR vaccine were developed by propagation in animal and human cells as all viruses require a living host cell to replicate.


title: MMR vaccine

text: For example, in the case of mumps and measles viruses, the virus strains were grown in embryonated chicken eggs. This produced strains of virus which were adapted for chicken cells and less well-suited for human cells. These strains are therefore called "attenuated strains". They are sometimes referred to as "neuroattenuated" because these strains are less virulent to human neurons than the wild strains.


title: MMR vaccine

text: The Rubella component, Meruvax, was developed in 1967, through propagation using the human embryonic lung cell line WI-38 (named for the Wistar Institute) that was derived six years earlier in 1961.


title: MMR vaccine

text: The term "MPR vaccine" is also used to refer to this vaccine, whereas "P" refer to Parotitis which is caused by mumps.


title: MMR vaccine

text: Merck MMR II is supplied freeze-dried (lyophilized) and contains live viruses. Before injection it is reconstituted with the solvent provided.


title: MMR vaccine

text: According to a review published in 2018, the GlaxoSmithKline (GSK) MMR vaccine known as Pluserix "contains the Schwarz measles virus, the Jeryl Lynn–like mumps strain, and RA27/3 rubella virus".


title: MMR vaccine

text: Pluserix was introduced in Hungary in 1999. Enders' Edmonston strain has been used since 1999 in Hungary in Merck MMR II product. GSK Priorix vaccine, which uses attenuated Schwarz Measles, was introduced in Hungary in 2003.


title: MMR vaccine

text: The MMRV vaccine, a combined measles, mumps, rubella and varicella (chickenpox) vaccine, has been proposed as a replacement for the MMR vaccine to simplify administration of the vaccines. Preliminary data indicate a rate of febrile seizures of 9 per 10,000 vaccinations with MMRV, as opposed to 4 per 10,000 for separate MMR and varicella shots; US health officials therefore do not express a preference for use of MMRV vaccine over separate injections.


title: MMR vaccine

text: In a 2012 study pediatricians and family doctors were sent a survey to gauge their awareness of the increased risk of febrile seizures (fever fits) in the MMRV. 74% of family doctors and 29% of pediatricians were unaware of the increased risk of febrile seizures. After reading an informational statement only 7% of family doctors and 20% of pediatricians would recommend the MMRV for a healthy 12- to 15-month-old child. The factor that was reported as the "most important" deciding factor in recommending the MMRV over the MMR+V was ACIP/AAFP/AAP recommendations (pediatricians, 77%; family physicians, 73%).


title: MMR vaccine

text: This is a vaccine that covers measles and rubella but not mumps. As of 2014, it was used in a "few (unidentified) countries".


title: MMR vaccine

text: Some brands of the vaccine use gelatin, derived from pigs, as a stabilizer. This has caused reduced take-up among some communities, despite the fact that alternative vaccines without pig derivatives are approved and available.


title: Alice Springs

text: Alice Springs () is the third-largest town in the Northern Territory of Australia. Known as Stuart until 31 August 1933, the name Alice Springs was given by surveyor William Whitfield Mills after Alice, Lady Todd ("née" Alice Gillam Bell), wife of the telegraph pioneer Sir Charles Todd. Known colloquially as 'The Alice' or simply 'Alice', the town is situated roughly in Australia's geographic centre. It is nearly equidistant from Adelaide and Darwin.


title: Alice Springs

text: The area is also known locally as Mparntwe to its original inhabitants, the Arrernte, who have lived in the Central Australian desert in and around what is now Alice Springs for tens of thousands of years.


title: Alice Springs

text: Alice Springs had an urban population of 26,534 in June 2018, having declined an average of 1.16% per year the preceding five years. The town's population accounts for approximately 10 per cent of the population of the Northern Territory.


title: Alice Springs

text: The town straddles the usually dry Todd River on the northern side of the MacDonnell Ranges. The surrounding region is known as Central Australia, or the Red Centre, an arid environment consisting of several deserts. Temperatures in Alice Springs can vary, with an average maximum in summer of and an average minimum in winter of .


title: Alice Springs

text: The Arrernte people are the traditional owners of the Alice Springs area and surrounding MacDonnell Ranges. They have lived in the area for at least 30,000 years. The traditional name for the township area is "Mparntwe".


title: Alice Springs

text: Their name has been spelt in various forms, including Aranda, Arrarnta, and Arunta. There are five dialects of the Arrernte language: South-eastern, Central, Northern, Eastern and North-eastern.


title: Alice Springs

text: Arrernte country is rich with mountain ranges, waterholes and gorges, which create a variety of natural habitats. According to Arrernte traditional histories, the landscape was shaped by the Yeperenye, Ntyarlke, Utnerrengatye caterpillars and Akngwelye or wild dogs.


title: Alice Springs

text: The numerous sites of traditional importance in and around Alice Springs include Anthwerrke (Emily Gap), Akeyulerre (Billy Goat Hill), Ntaripe (Heavitree Gap), Atnelkentyarliweke (ANZAC Hill) and Alhekulyele (Mt Gillen).


title: Alice Springs

text: In 1861–62, John McDouall Stuart led an expedition through Central Australia, to the west of what later became Alice Springs, thereby establishing a route from the south of the continent to the north.


title: Alice Springs

text: A settlement named after Stuart was necessitated ten years later with the construction of a repeater station on the Australian Overland Telegraph Line (OTL), which linked Adelaide to Darwin and Great Britain. The OTL was completed in 1872. It traced Stuart's route and opened up the interior for permanent settlement. The Alice Springs Telegraph Station was sited near what was thought to be a permanent waterhole in the normally dry Todd River, named Alice Springs by W.W. Mills after the wife of the Superintendent of Telegraphs and Postmaster General of South Australia, Sir Charles Todd, who was the driving force for constructing the OTL. The nearby settlement of Stuart was renamed as Alice Springs on 31 August 1933. The Todd River and its tributary the Charles River, which meet near the telegraph station, were named after Sir Charles.


title: Alice Springs

text: It was not until alluvial gold was discovered at Arltunga, east of the present Alice Springs, in 1887 that any significant European settlement occurred. The town's first substantial building was the Stuart Town Gaol in Parson's Street; this was built in 1909, when the town had a European population of fewer than 20 people. Many of the gaol's first prisoners were first-contact Aboriginal men incarcerated for killing cattle. The first aircraft, piloted by Francis Stewart Briggs landed in 1921. Central Australia's first hospital, Adelaide House, was built in 1926 when the European population of the town was about 40. It was not until 1929, when the train line to Alice was built, that the town's European population began to grow. Aboriginal Centralians outnumbered European Centralians until the mid-1930s. From 1926 to 1931, Alice Springs was the seat of government for the now-defunct Territory of Central Australia. Until 31 August 1933, the town was officially known as Stuart.


title: Alice Springs

text: The original mode of British-Australian transportation in the outback were camel trains, operated by immigrants from Pathan tribes in the North-West Frontier of then-British India (present-day Pakistan), known locally as Afghan cameleers based at Hergott Springs, or Marree as it is now known. Many cameleers moved to Alice Springs in 1929 when the railway finally reached the town. They lived on the block where the town council is now, transporting goods from the rail head to stations and settlements to the north. A gold rush in Tennant Creek in 1932 kept the wheels of the Alice Springs economy turning until the outbreak of World War II.


title: Alice Springs

text: Alice Springs was connected to Darwin by rail on 4 February 2004, when the first passenger train arrived in Darwin from Adelaide.


title: Alice Springs

text: World War II brought significant changes to Alice Springs. Prior to the war, Alice Springs was an extremely isolated settlement of fewer than 500 people. During the war, however, the town was an extremely active staging base, known as No. 9 Australian Staging Camp, and a depot base for the long four-day trip to Darwin. The railway hub in Alice Springs was taken over by military operations and the number of soldiers posted in Alice Springs grew rapidly, as did the number of personnel passing through on their way to and from Darwin. When Darwin was threatened by Japanese forces, the sea routes—the Northern Territory capital's primary means of transportation and resupply—were cut off. The evacuation of Darwin first brought a large number of civilians including elected officials and many of the territory government's records. Alice Springs became the war-time civilian capital of the Northern Territory. When Darwin was bombed by Japanese air forces, a large number of military personnel and their heavy equipment were rapidly moved south to Alice Springs.


title: Alice Springs

text: The number of soldiers posted in Alice Springs peaked at around 8,000 and the number of personnel passing through totalled close to 200,000. Once the war ended, the military camps and the evacuees departed, and Alice Springs' population declined rapidly. After being visited by nearly 200,000 people, including the American General Douglas MacArthur, Alice Springs gained considerable fame. The war years also left behind many structures. The historically listed Totem Theatre, created for the entertainment of this camp, still exists today. The Australian Army set up the 109th Australian General Hospital at Alice Springs. Seven Mile Aerodrome was constructed by the Royal Australian Air Force. War-related operations necessitated the first sealing of the road between Alice Springs and Larrimah, expansion and improvement of Alice Springs' water supply, and improving the rail head. The war-related operations left behind thousands of pieces of excess military equipment and vehicles, and a marked increase in Alice Springs' population.


title: Alice Springs

text: During World War II, Alice Springs was the location of RAAF No. 24 Inland Aircraft Fuel Depot (IAFD), completed on 20 May 1942 and closed in November 1944. Each usually consisting of four tanks, 31 fuel depots were built across Australia for the storage and supply of aircraft fuel for the RAAF and the US Army Air Forces, at a total cost of £900,000 ($1,800,000).


title: Alice Springs

text: During the 1960s Alice Springs became an important defence location with the development of the US/Australian Pine Gap joint defence satellite monitoring base, home to about 700 workers from both countries.


title: Alice Springs

text: By far the major industry in recent times is tourism. Almost in the exact centre of the continent, Alice Springs is some from the nearest ocean and from the nearest major cities, Darwin and Adelaide. Alice Springs is at the midpoint of the Adelaide–Darwin Railway.


title: Alice Springs

text: The modern town of Alice Springs has both European and Aboriginal influences. The town's focal point, the Todd Mall, hosts a number of Aboriginal art galleries and community events. Alice Springs' desert lifestyle has inspired several unique events, such as the Camel Cup, the Henley-on-Todd Regatta, Beanie Festival and the Tatts Finke Desert Race.


title: Alice Springs

text: Alice Springs has many historic buildings, including the Overland Telegraph Station, the Old Courthouse and Residency and the Hartley Street School. Adelaide House, a beautiful stone building in the middle of the Mall, Central Australia's first hospital, was designed and built by the Rev. John Flynn, founder of the world's first flying doctor service, in 1926. It was also the site of the world's first successful portable wireless radio experiment conducted by Alf Traeger. Today it is a museum, one of several significant tourist attractions which form part of 'The Flynn Trail' a self-guided urban heritage trail.


title: Alice Springs

text: Today, the town is an important tourist hub and service centre for the surrounding area. It is a well-appointed town for its size, with several large hotels, a world-class convention centre, and a good range of visitor attractions, restaurants, and other services.


title: Alice Springs

text: The region around Alice Springs is part of the Central Ranges xeric scrub area of dry scrubby grassland and includes the MacDonnell Ranges which run east and west of the town and contain a number of hiking trails and swimming holes such as Ormiston Gorge, Ormiston Gorge Creek, Red Bank Gorge and Glen Helen Gorge. The Larapinta Trail follows the West MacDonnell Ranges and is considered among the world's great walking experiences.


title: Alice Springs

text: The Simpson Desert, southeast of Alice Springs is one of Australia's great wilderness areas containing giant, red sand dunes and rock formations such as Chambers Pillar and Rainbow Valley.


title: Alice Springs

text: Under the Köppen climate classification, Alice Springs has a subtropical hot desert climate ("BWh"), featuring extremely hot, dry summers and short, mild winters. Located just south of the Tropic of Capricorn, the town of Alice Springs straddles the usually dry Todd River on the northern side of the MacDonnell Ranges. Alice Springs is located in Central Australia, also called the Red Centre, an arid environment consisting of several different deserts. The annual average rainfall is which would make it a semi-arid climate except that its high evapotranspiration, or its aridity, makes it a desert climate.


title: Alice Springs

text: Annual precipitation is erratic, varying year to year in Alice Springs. In 2001 fell and in 2002 only fell. The highest daily rainfall is , recorded on 31 March 1988.


title: Alice Springs

text: Temperatures in Alice Springs vary widely, and rainfall can vary quite dramatically from year to year. In summer, the average maximum temperature is in the mid-30s, whereas in winter the average minimum temperature can be , with an average of 12.4 nights below freezing every year, providing frost. The elevation of the town is about , which contributes to the cool nights in winter. The highest temperature on record is first recorded on 24 December 1891, whilst the record low is , recorded on 17 July 1976. This is also the lowest temperature recorded in the Northern Territory.


title: Alice Springs

text: According to the 2016 census of population, there were 23,726 people in the Alice Springs Urban Area.


title: Alice Springs

text: As Alice Springs is the regional hub of Central Australia, it attracts Aboriginal people from all over that region and well beyond. Many Aboriginal people visit regularly to use the town's services. Aboriginal residents usually live in the suburbs, on special purpose leases (or town camps), or further out at Amoonguna to the south and on the small family outstation communities on Aboriginal lands in surrounding areas.


title: Alice Springs

text: The traditional owners of the Alice Springs area are the Central Arrernte people. As it is the largest town in central Australia, there are also speakers of Warlpiri, Warumungu, Kaytetye, Alyawarre, Luritja, Pintupi, Pitjantjatjara, Yankunytjatjara, Ngaanyatjarra, Pertame, Eastern, and Western Arrernte among others.


title: Alice Springs

text: Americans have lived in Alice Springs continuously since the establishment of the United States Air Force Detachment 421, in 1954. Currently located on Schwarz Crescent, it is part of a joint American–Australian project called the Joint Geological and Geographical Research Station (JGGRS). The unit is locally known as "Det 421" or "The Det" and has sponsored as many as 25 American families to live as temporary residents of the Alice Springs district.


title: Alice Springs

text: To mark the longstanding friendship with the community, on 1 July 1995, the Alice Springs Town Council granted Detachment 421 honorary Freedom of Entry to Alice Springs. Since the early 1970s, the majority of the American population in Alice Springs has been associated with proximity to Pine Gap, a joint Australian-US satellite tracking station, located south-west of Alice Springs, that employs about 700 Americans and Australians.


title: Alice Springs

text: Currently, 2,000 residents of the Alice Springs district hold American citizenship. Many of these, joined by some Australians, celebrate major American public holidays, including the 4th of July and Thanksgiving. Americans in Alice Springs are also known to participate in a variety of associations and sporting teams, including baseball, basketball and soccer competitions.


title: Alice Springs

text: Several small immigrant communities of other foreign cultures have found a home in Alice Springs, including Vietnamese, Chinese, Thai, Sudanese and Indian ethnic groups. The most obvious impact of their presence in such a small and isolated town has been the opening of various restaurants serving their traditional cuisines.


title: Alice Springs

text: Alice Springs has a large itinerant population. This population is generally composed of foreign and Australian tourists, Aboriginal Australians visiting from nearby Central Australian communities, and Australian or international workers on short-term contracts (colloquially referred to as "blow-ins"). The major sources of work that recruit workers into town are the stations, mines, healthcare and law enforcement. Foreign tourists usually pass through on their way to Uluru-Kata Tjuta National Park, whilst Australian tourists usually come through as a part of an event such as the Masters Games and the Finke Desert Race. These events can cause the population of the town to fluctuate by several thousand within a matter of days.


title: Alice Springs

text: The Alice Springs Town Council governs the Alice Springs area, which takes in the town centre, its suburbs and some rural area. The Alice Springs Town Council has governed Alice Springs since 1971. The Alice Springs council consists of nine members: the mayor and eight aldermen. The town is not divided up into wards. The current mayor of Alice Springs is Matt Paterson. Council Meetings are held on the last Monday of each month. The Alice Springs Region is governed by the newly created MacDonnell Region local government area, for which Alice Springs serves as council seat.


title: Alice Springs

text: Alice Springs and the surrounding region have four elected members to the Northern Territory Legislative Assembly. Araluen and Braitling are entirely within Alice Springs, while the mostly rural seats of Gwoja (known as Stuart before 2020) and Namatjira spill into the town. Historically, Alice Springs has tilted conservative. It was a stronghold for the Country Liberal Party for many years; only the northeast (part of which is in Stuart) leans Labor. However, these trends were dramatically altered at the 2016 election. Former Chief Minister and Alice Springs resident Adam Giles lost Braitling to Labor, Araluen was retained by CLP-turned-independent Robyn Lambley, and Namatjira and Stuart fell to Labor. As a result, the CLP was completely shut out of Alice Springs for the first time ever. The CLP regained Braitling and Namatjira in 2020, while Lambley retained Araluen for her party at the time, the Territory Alliance.


title: Alice Springs

text: In the Australian House of Representatives, Alice Springs is part of the Division of Lingiari, which includes all of the Territory outside the Darwin/Palmerston area. Lingiari is currently held by Labor member Marion Scrymgour.


title: Alice Springs

text: Alice Springs began as a service town to the pastoral industry that first came to the region. The introduction of the rail line increased its economy. Today the town services a region of and a regional population of 38,749. The region includes a number of mining and pastoral communities, the Joint Defence Space Research Facility at Pine Gap and tourist attractions at Uluru-Kata Tjuta National Park, Watarrka National Park and the MacDonnell Ranges.


title: Alice Springs

text: The largest employer in Alice Springs is the Northern Territory Government, with 8% of employed people working in government administration, 7% in school education, and 4% in the Alice Springs Hospital. The economy of Alice Springs is somewhat reliant on domestic and international tourism, with 4% of its workforce employed providing accommodation.


title: Alice Springs

text: As well as Territory Discoveries, all major tour companies have a base in Alice Springs, including AAT Kings & APT, as well as numerous local operators, including Emu Run Tours, Anganu Waai! tours, Alice Wanderer and Wayoutback Desert Safaris, the only locally based Advanced Ecotourism Accredited operator.


title: Alice Springs

text: Alice Springs is home to numerous hotels, from the -star Lasseters Hotel Casino, to backpacker hostels. There are also caravan parks.


title: Alice Springs

text: Education is overseen territory-wide by the Department of Education and Training (DET). It works to continually improve education outcomes for all students, with a focus on Indigenous students.


title: Alice Springs

text: Alice Springs is served by a number of public and private schools that cater to local and overseas students.


title: Alice Springs

text: There are 10 private schools. Yirara College is a co-educational secondary boarding school catering for around 200 Aboriginal students run by the Finke River Mission. It has another campus in Kintore (Walungurru), which has four rooms and caters for around 30 students.


title: Alice Springs

text: The Alice Springs Campus of Charles Darwin University offers courses in TAFE and higher education. The Centre for Appropriate Technology was established in 1980 and provides a range of services to encourage and help Aboriginal people enhance their quality of life in remote communities.


title: Alice Springs

text: The town's focal point, the Todd Mall, hosts a number of Aboriginal art galleries and community events. Alice Springs' desert lifestyle has inspired several unique events, such as the Alice Desert Festival, the Red Centre NATS, Blacken Open Air music festival, Parrtjima, the Camel Cup, the Henley-on-Todd Regatta, the Beanie Festival and the Finke Desert Race. The Finke Desert Race is a 'there and back' challenge from Alice Springs to Aputula (Finke) Community, covering a round trip.


title: Alice Springs

text: Alice Springs is known as the Aboriginal Art capital of Central Australia, home to many local and Aboriginal art galleries. Indigenous Australian art is the more dominant, and galleries showcase the rich culture and native traditions that abound in Central Australia. Trade in Aboriginal art soared after the painting movement began at Papunya, a Central Australian Aboriginal settlement, and swept other indigenous communities. Central Australia is the home of some of the most prominent names in Aboriginal art, including Emily Kngwarreye, Minnie Pwerle, Clifford Possum Tjapaltjarri, Albert Namatjira and Wenten Rubuntja.


title: Alice Springs

text: The Museum of Central Australia / Stehlow Research Centre features some of the most important natural history and archival materials tied to the history and culture of the region. The Strehlow Archives also contain materials linked to the Arrernte people of Central Australia. The Araluen Centre for Arts and Entertainment presents world-class ballets and orchestras, as well as local performances. The Women's Museum of Australia (formerly National Pioneer Women's Hall of Fame) is located in the grounds of Old Alice Springs Gaol in the Heritage Precinct. Here women's stories from across Australia are presented with the lives of outback women as well as stories from the Old Gaol and Labour Prison. Objects include a large "Signature" quilt with signatures of over 300 women first in their field and a 4.2 m long Aviatrix tapestry celebrating the high flying lives of Australia's aviatrixes.


title: Alice Springs

text: The town has some excellent small museums. The extensive collection at the Old Timer's Traeger Museum on the North Stuart Highway includes artefacts from the town's early Afghan and German residents, traditional Aboriginal artefacts and objects which show the early fusion of European and Aboriginal cultures, such as a spinifex-handled glass-bladed knife. Included in the collection are soapstone carvings by Arrernte artist Erlikilyika.


title: Alice Springs

text: Alice Springs is home to the Alice Springs Public Library, also known as the Nevil Shute Memorial Library. The library, in addition to its general borrowable collections (including e-resources), is also home to two special, not-for-loan, collections. These are the Alice Springs Collection and the Akaltye Atheme Collection, both of which specifically collect Central Australian content, including Aboriginal language resources (from around 16 local languages) and cultural heritage information. The Alice Springs Collection also holds a significant digital collection, including PDF copies of the "Centralian Advocate" from 1947  to  2015, and over 6000 images, primarily from the Central Australian Historical Images Collection.


title: Alice Springs

text: Library & Archives NT also has offices in Alice Springs, located at Minerals House on Hartley Street, which holds archival collections relating to Central Australia, including Tennant Creek. Collections held here include community collections and government archives.


title: Alice Springs

text: Leisure and entertainment activities include hiking in the nearby MacDonnell Ranges and driving the four-wheel-drive tracks at Finke Gorge National Park.


title: Alice Springs

text: The Alice Springs Desert Park was created to educate visitors about the many facets of the surrounding desert environment. The arid climate botanic garden, Olive Pink Botanic Garden, is a short distance from the town centre. They were named after anthropologist, naturalist and artist Olive Pink, who lived in the town for almost 30 years and died in 1975. She was well known locally and referred to by all as Miss Pink. The Alice Springs Reptile Centre is located in the town centre.


title: Alice Springs

text: Alice Springs has a high rate of participation in many different sports, including tennis, hockey, Australian rules football, basketball, baseball, golf, soccer, cricket, rugby and boxing.


title: Alice Springs

text: Australian rules football is a particularly popular sport in Alice Springs in terms of both participation and as a spectator sport. The Central Australian Football League formed in 1947 has several teams. The sport is particularly popular in Indigenous communities. The local stadium, Traeger Park, has a 10,000 seat capacity and was designed to host (pre-season) AFL and was the home to the Northern Territory Thunder until 2019. In 2004, an AFL pre-season Regional Challenge match between Collingwood Football Club and Port Adelaide Football Club attracted a capacity sell-out crowd.


title: Alice Springs

text: Both codes of Rugby are played in Alice Springs. Rugby Union, managed by the Central Australian Rugby Union Association (CARU) is played in conjunction with the Northern Territory Rugby Union calendar which runs during Darwins dry season. The Central Australian Rugby Union administers a four team competition based in Alice Springs with matches played between October and March at ANZAC Oval. The First Central Australian Club Competition commenced in 1986. There are four senior teams; Dingo Cubs Rugby Union, Kiwi Warriors Rugby Union, Eagles Rugby Union and Devils Rugby Union.


title: Alice Springs

text: Rugby league has been a part of the local sporting scene since 1963. The Australian Rugby League has held a number of pre-season games in Alice Springs, at ANZAC Oval. The local competition is the Central Australian Rugby Football League, and sanctions both Junior and Senior Rugby League matches. The season usually kicks off around March/April and runs through to Late August. There are four senior teams in Alice Springs: Wests, Memo, United and Vikings. Matches are held during the winter months at ANZAC oval on Saturday afternoons.


title: Alice Springs

text: Organized baseball has been played in Alice Springs since the mid-1950s. Currently under the national organisation of the Australian Baseball Federation, the Alice Springs Baseball Association organises baseball competitions for youth players aged 5 to 18 and an adult competition played at Jim McConville Park and on Lyel Kempster Field at Traeger Park. As part of the worldwide Little League network, Alice Springs players and compete in the Australian National Little League competitions.


title: Alice Springs

text: The Alice Springs Golf Course, an 18-hole championship layout golf course designed by the architects Thomson Wolveridge, was opened in 1985 by a challenge match between top professionals Greg Norman and Johnny Miller. The course record of 64 is held jointly by, amateur members, Leigh Shacklady and Kerryn Heaver, beating professional Stuart Appleby's 65. Adam Scott won the Australian Boys Amateur Championship held there in 1997.


title: Alice Springs

text: Cricket is a popular sport in Alice Springs and is primarily played at Traeger Park. The Imparja Cup Cricket Carnival first was played in 1994 and attracts Indigenous teams from all across Australia. The four main clubs are Federal Demons CC, Rovers CC, RSL Works CC and Wests CC.


title: Alice Springs

text: Soccer is popular among the younger community. A high number of children play it. Soccer is also played frequently by amateur adults in different divisions. There is also an all-African league for soccer in Alice Springs. The most successful Club in the town is the Vikings Football Club, located at Traeger Park.


title: Alice Springs

text: The Traeger Park sporting complex also hosts tennis, baseball, boxing, swimming, canoe polo, hockey, basketball, squash, badminton, gymnastics and skateboarding.


title: Alice Springs

text: A unique sporting event, held annually, is the Henley-on-Todd Regatta, also known as the Todd River Race. It is a sand river race with bottomless boats and it remains the only dry river regatta in the world. Another unusual sporting event is the Camel Cup. The annual Camel Cup is held in July at Blatherskite Park, part of the Central Australian Show Society grounds. It is a full day event featuring a series of races using camels instead of horses.


title: Alice Springs

text: Every year, on the Queen's Birthday long weekend, the annual Finke Desert Race is held. It is a gruelling off-road race that runs from Alice Springs to the Finke community, then back again the next day. The total length of the race is roughly . It attracts spectators, who camp along the whole length of the track, and roughly 500 competitors, buggies and bikes, every year, making it the biggest sporting event in the Alice Springs calendar.


title: Alice Springs

text: Drag racing is held at the Alice Springs Inland Dragway which in June 2013 hosted a round of the national Aeroflow Sportsman Drag Racing Championship. In September 2017 12 people were injured when burning fuel sprayed from a drag-racing car onto a crowd of spectators at the Red CentreNATS competition.


title: Alice Springs

text: Alice Springs is also home to the Arunga Park Speedway, a 402-metre dirt oval speedway. The speedway runs from August to March and caters to cars, solos and sidecars. Located just off the Stuart Highway on the northern edge of the town, Arunga Park hosted the Australian Sidecar Championship in 1985 and the Australian Solo Championship in 1991.


title: Alice Springs

text: Property crime and violent crime, including domestic violence, often linked to alcohol abuse, has been a significant social issue in Alice Springs in the 21st century, with most of the victims being residents of the town. Many approaches and programs have been tried over the years, with varying levels of success. there has been a downward trend in most categories of crime.


title: Alice Springs

text: Alice Springs is served by both local and national radio and television services. The government-owned ABC provides five broadcast radio stations; local radio ABC Alice Springs and the national networks ABC Radio National, ABC News Radio, ABC Classic and Triple J. The national Christian radio network Vision Radio Network broadcasts on 88.0 FM.


title: Alice Springs

text: Commercial radio stations are 8HA 900 kHz, Sun 96.9 MHz and Gold 98.7 MHz. Community radio is provided by 8CCC 102.1 and Indigenous broadcaster CAAMA Radio 100.5