text: second period report about those detained under the Mental Health Act 1983. CCPR/C/58/Add.6 page 28 Persons subject to immigration control 120. The detention of persons subject to immigration control is governed by the provisions of the Immigration Act 1971. The power to detain is used as a last resort, when there are clear and positive grounds for believing that the person will abscond if left at liberty, and after all the known circumstances of the person concerned have been taken into account. The cases of those detained are given the highest priority and the need for continued detention is regularly reviewed. 121. In the circumstances described below, a person detained under the provisions of the Immigration Act 1971 may apply to the independent immigration appellate authorities for bail. The appellate authorities were established in 1970 under the Immigration Appeals Act 1969; their function is to hear appeals against decisions of the Secretary of State or an immigration officer, and applications for bail under the provisions of the 1971 Immigration Act (as amended by the Immigration Act 1988). They may allow an appeal if they consider that the decision against which the appeal was brought was not in accordance with the law or, in cases which are not subject to a restriction on the right of appeal (see arts. 12 and 13 below), if they consider that, where the decision involved the exercise of discretion, that discretion should have been exercised differently. The appellate authorities may require sureties to be provided before deciding to release a person on bail and may refuse to release on bail a person who has previously failed to comply with the conditions of bail or is likely to commit an offence if released. There are two tiers of appellate authority, namely, adjudicators, who hear nearly all appeals at first instance, and the 
analysis: The text appears to be discussing the legal framework and procedures for detaining individuals under the Mental Health Act 1983 and the Immigration Act 1971. The language used is formal and technical, suggesting a focus on legal and administrative processes rather than economic, environmental, or social development. The text does not mention specific industries, transportation, or communication systems, and it does not discuss humanitarian aid or relief. While it does touch on the concept of "persons subject to immigration control," it is not directly related to international trade or cultural issues.