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Sunday, July 24, 2022

Concentration of media ownership

Media graphic showing the concentration of media ownership in the United States

Concentration of media ownership (also known as media consolidation or media convergence) is a process whereby progressively fewer individuals or organizations control increasing shares of the mass media. Contemporary research demonstrates increasing levels of consolidation, with many media industries already highly concentrated and dominated by a very small number of firms.

Globally, large media conglomerates include Bertelsmann, National Amusements (Paramount Global), Sony Group Corporation, News Corp, Comcast, The Walt Disney Company, Warner Bros. Discovery, Fox Corporation, Hearst Communications, MGM Holdings Inc., Grupo Globo (South America), and Lagardère Group.

As of 2022, the largest media conglomerates in terms of revenue are Comcast, The Walt Disney Company, Warner Bros. Discovery, and Paramount Global.

Mergers

Media mergers occur when one media company buys another. The current landscape of corporate media ownership in the United States of America can be described as an oligopoly.

Risks for media integrity

Media integrity is at risk when small number of companies and individuals control the media market. Media integrity refers to the ability of a media outlet to serve the public interest and democratic process, making it resilient to institutional corruption within the media system, economy of influence, conflicting dependence and political clientelism.

Elimination of net neutrality

Net neutrality is also at stake when media mergers occur. Net neutrality involves a lack of restrictions on content on the internet, however, with big businesses supporting campaigns financially they tend to have influence over political issues, which can translate into their mediums. These big businesses that also have control over internet usage or the airwaves could possibly make the content available biased from their political stand point or they could restrict usage for conflicting political views, therefore eliminating net neutrality.

Issues

Concentration of media ownership is very frequently seen as a problem of contemporary media and society.

Freedom of the press and editorial independence

Johannes von Dohnanyi, in a 2003 report published by the Organization for Security and Co-operation in Europe (OSCE)'s Office of the Representative on Freedom of the Media, argued market concentration among media—whether driven by domestic or foreign investors—should be "closely monitored" because "Horizontal concentration may cause dangers to media pluralism and diversity, while vertical concentration may result in entry barriers for new competitors." Von Dohnanyi argues that to "safeguard free and independent print media and protect professional journalism as one of the cornerstones of constitutional democracy" there should be standards for editorial independence, better labor protections for professional journalists, and independent institutions "to monitor the implementation and observance of all laws and regulations regarding concentration processes, media pluralism, content diversity and journalistic freedoms."

Deregulation

Robert W. McChesney argues that the concentration of media ownership is caused by a shift to neoliberal deregulation policies, which is a market-driven approach. Deregulation effectively removes governmental barriers to allow for the commercial exploitation of media. Motivation for media firms to merge includes increased profit-margins, reduced risk and maintaining a competitive edge. In contrast to this, those who support deregulation have argued that cultural trade barriers and regulations harm consumers and domestic support in the form of subsidies hinders countries to develop their own strong media firms. The opening of borders is more beneficial to countries than maintaining protectionist regulations.

Critics of media deregulation and the resulting concentration of ownership fear that such trends will only continue to reduce the diversity of information provided, as well as to reduce the accountability of information providers to the public. The ultimate consequence of consolidation, critics argue, is a poorly informed public, restricted to a reduced array of media options that offer only information that does not harm the media oligopoly's growing range of interests.

For those critics, media deregulation is a dangerous trend, facilitating an increase in concentration of media ownership, and subsequently reducing the overall quality and diversity of information communicated through major media channels. Increased concentration of media ownership can lead to corporate censorship affecting a wide range of critical thought.

Media pluralism

The concentration of media ownership is commonly regarded as one of the crucial aspects reducing media pluralism. A high concentration of the media market increases the chances to reduce the plurality of political, cultural and social points of views. Even if ownership of the media is one of the main concerns when it comes to assessing media pluralism, the concept of media pluralism is broader as it touches many aspects, from merger control rules to editorial freedom, the status of public service broadcasters, the working conditions of journalists, the relationship between media and politics, representation of local and regional communities and the inclusion of minorities' voices. Also, it embraces all measures guaranteeing citizens' access to diversified sources so to allow the formation of a plurality of opinions in the public sphere without undue influence of dominant powers.

Furthermore, media pluralism has a two-fold dimension, or rather internal and external. Internal pluralism concerns pluralism within a specific media organisation: in this regard, many countries request public broadcast services to account for a variety of views and opinions, including those of minority groups. External pluralism applies instead to the overall media landscape, for instance in terms of the number of media outlets operating in a given country.

Media ownership can pose serious challenges to pluralism when owners interfere with journalists' independence and editorial line. However, in a free market economy, owners must have the capacity to decide the strategy of their company to remain competitive in the market. Also, pluralism does not mean neutrality and lack of opinion, as having an editorial line is an integral part of the role of editors provided that this line is transparent and explicit to both the staff and audience.

Determinants of media pluralism

Size and wealth of the market

"Within any free market economy, the level of resources available for the provision of media will be constrained principally by the size and wealth of that economy, and the propensity of its inhabitants to consume media." [Gillian Doyle; 2002:15] Those countries that have a relatively large market, like the United Kingdom, France or Spain have more financial background to support diversity of output and have the ability to keep more media companies in the market (as they are there to make profit). More diverse output and fragmented ownership will, obviously, support pluralism. In contrast, small markets like Ireland or Hungary suffer from the absence of the diversity of output given in countries with bigger markets. It means that "support for the media through direct payment" and "levels of consumers expenditure", furthermore "the availability of advertising support" [Gillian Doyle; 2002:15] are less in these countries, due to the low number of audience. Overall, the size and wealth of the market determine the diversity of both media output and media ownership.

Consolidation of resources

The consolidation of cost functions and cost-sharing. Cost-sharing is a common practice in monomedia and cross media. For example, "for multi-product television or radio broadcasters, the more homogeneity possible between different services held in common ownership (or the more elements within a programme schedule which can be shared between 'different' stations), the greater the opportunity to reap economies". Though the main concern of pluralism is that different organization under different ownership may buy the same e.g. news stories from the same news-supplier agency. In the UK, the biggest news-supplier is The Press Association (PA). Here is a quoted text from PA web site: "The Press Association supplies services to every national and regional daily newspaper, major broadcasters, online publishers and a wide range of commercial organisations." Overall, in a system where all different media organizations gather their stories from the same source, we can't really call that system pluralist. That is where diversity of output comes in.

Pluralism in media ownership

Media privatization and the lessening of state dominance over media content has continued since 2012. In the Arab region, the Arab States Broadcasting Union (ASBU) counted 1,230 television stations broadcasting via Arab and international satellites, of which 133 were state-owned and 1,097 private. According to the ASBU Report, these numbers serve as evidence of a decline in the percentage of state channels and a rise in national private and foreign public stations targeting the Arab region. The reduction of direct government ownership over the whole media sector is commonly registered as a positive trend, but this has paralleled by a growth in outlets with a sectarian agenda.

In Africa, some private media outlets have maintained close ties to governments or individual politicians, while media houses owned by politically non-aligned individuals have struggled to survive, often in the face of advertising boycotts by state agencies. In almost all regions, models of public service broadcasting have been struggling for funding. In Western, Central and Eastern Europe, funds directed to public service broadcasting have been stagnating or declining since 2012.

New types of cross-ownership have emerged in the past five years that have spurred new questions about where to draw the line between media and other industries. A notable case has been the acquisition of The Washington Post by the founder of online retailer Amazon. While the move initially raised concerns about the newspaper's independence, the newspaper has significantly increased its standing in the online media—and print—and introduced significant innovations.

The community-centred media ownership model continues to survive in some areas, especially in isolated, rural or disadvantaged areas, and mostly pertaining to radio. Through this model, not-for-profit media outlets are run and managed by the communities they serve.

In particular nations

Australia

Controls over media ownership in Australia are laid down in the Broadcasting Services Act 1992, administered by the Australian Communications and Media Authority (ACMA). Even with laws in place Australia has a high concentration of media ownership. Ownership of national and the newspapers of each capital city are dominated by two corporations, Rupert Murdoch's News Corp Australia, (which was founded in Adelaide as News Limited) and Nine Entertainment Co. These two corporations along with Seven West Media co-own Australian Associated Press which distributes the news and then sells it on to other outlets such as the Australian Broadcasting Corporation. Although much of the everyday mainstream news is drawn from the Australian Associated Press, all the privately owned media outlets still compete with each other for exclusive pop culture news. Rural and regional media is dominated by Australian Community Media, with significant holdings in all states and territories. Daily Mail and General Trust operate the DMG Radio Australia commercial radio networks in metropolitan and regional areas of Australia. Formed in 1996, it has since become one of the largest radio media companies in the country. The company currently own more than 60 radio stations across New South Wales, Victoria, South Australia, Queensland and Western Australia.

There are rules governing foreign ownership of Australian media and these rules were loosened by the former Howard Government.

Media Watch is an independent media watchdog televised on the public broadcaster Australian Broadcasting Corporation (ABC), which is one of two government-administered channels, the other being Special Broadcasting Service (SBS).

In late 2011, the Finkelstein Inquiry into media regulation was launched, and reported its findings back to the federal government in early 2012.

New Zealand

Independent Newspapers Limited (INL) formerly published the Wellington-based newspapers The Dominion and The Evening Post, in addition to purchasing a large shareholding in pay TV broadcaster Sky Media Limited in 1997. These two newspapers merged to form the Dominion Post in 2002, and in 2003, sold its entire print media division to Fairfax New Zealand. The remainder of the company officially merged with Sky Media Limited in 2005 to form Sky Network Television Limited.

When INL ceased publishing the Auckland Star in 1991, The New Zealand Herald became the Auckland region's sole daily newspaper. The New Zealand Herald and the New Zealand Listener, formerly privately held by the Wilson & Horton families, was sold to APN News & Media in 1996. The long-running news syndication agency NZPA announced that it would close down in 2011, with operations to be taken over by 3 separate agencies, APN's APNZ, Fairfax's FNZN and AAP's NZN, all owned by Australian parent companies. In 2014, APN's New Zealand division officially changed its name to NZME, in order to reflect the company's convergence with its radio division The Radio Network. As of early 2015, Fairfax New Zealand and NZME have a near duopoly on newspapers and magazines in New Zealand. In May 2016, NZME and Fairfax NZ announced merger talks, pending Commerce Commission approval.

Commercial radio stations are largely divided up between MediaWorks New Zealand and NZME, with MediaWorks also owning TV3 and C4 (now The Edge TV). Television New Zealand, although 100% state-owned, has been run on an almost entirely commercial basis since the late 1980s, in spite of previous attempts to steer it towards a more public service-oriented role. Its primary public-service outlet, TVNZ7, ceased broadcasting in 2012 due to non-renewal of funding, and the youth-oriented TVNZ6 was rebranded as the short-lived commercial channel TVNZ U. In addition, the TVNZ channels Kidzone (and formerly TVNZ Heartland) are only available through Sky Network Television and not on the Freeview platform.

Sky Network Television has had an effective monopoly on pay TV in New Zealand since its nearest rival Saturn Communications (later part of TelstraClear and now Vodafone New Zealand) began wholesaling Sky content in 2002. However, in 2011, TelstraClear CEO Allan Freeth warned it would review its wholesale agreement with Sky unless it allowed TelstraClear to purchase non-Sky content.

Canada

Canada has the biggest concentrated TV ownership out of all the G8 countries and it comes in second place for the most concentrated television viewers.

Broadcasting and telecommunications in Canada are regulated by the Canadian Radio-television and Telecommunications Commission (CRTC), an independent governing agency that aims to serve the needs and interests of citizens, industries, interest groups and the government. The CRTC does not regulate newspapers or magazines.

Apart from a relatively small number of community broadcasters, media in Canada are primarily owned by a small number of groups, including Bell Canada, the Shaw family (via Corus Entertainment and Shaw Communications), Rogers Communications, Quebecor, and the government-owned CBC/Radio-Canada. Each of these companies holds a diverse mix of television, specialty television, and radio operations. Bell, Rogers, Shaw, and Quebecor also engage in the telecommunications industry with their ownership of internet providers, television providers, and mobile carriers, while Rogers is also involved in publishing.

In 2007, CTVglobemedia, Rogers Media and Quebecor all expanded significantly through the acquisitions of CHUM Limited, CityTV and Osprey Media, respectively. In 2010, Canwest Global Communications, having filed for bankruptcy, sold its television assets to Shaw (through a new subsidiary, Shaw Media) and spun off its newspaper holdings into Postmedia Network, a new company founded by the National Post's CEO Paul Godfrey. Later that year, Bell also announced that it would acquire the remaining shares of CTVglobemedia (which was originally majority owned by Bell when it was formed in 2001; Bell had reduced its stake in the following years), forming Bell Media.

Between 1990 and 2005 there were a number of media corporate mergers and takeovers in Canada. For example, in 1990, 17.3% of daily newspapers were independently owned; whereas in 2005, 1% were. These changes, among others, caused the Senate Standing Committee on Transport and Communications to launch a study of Canadian news media in March 2003. (This topic had been examined twice in the past, by the Davey Commission (1970) and the Kent Commission (1981), both of which produced recommendations that were never implemented in any meaningful way.)

The Senate Committee's final report, released in June 2006, expressed concern about the effects of the current levels of news media ownership in Canada. Specifically, the committee discussed their concerns regarding the following trends: the potential of media ownership concentration to limit news diversity and reduce news quality; the CRTC and Competition Bureau's ineffectiveness at stopping media ownership concentration; the lack of federal funding for the CBC and the broadcaster's uncertain mandate and role; diminishing employment standards for journalists (including less job security, less journalistic freedom, and new contractual threats to intellectual property); a lack of Canadian training and research institutes; and difficulties with the federal government's support for print media and the absence of funding for the internet-based news media.

The Senate report expressed particular concern about the concentration of ownership in the province of New Brunswick, where the Irving business empire owns all the English-language daily newspapers and most of the weeklies. Senator Joan Fraser, author of the report, stated, "We didn't find anywhere else in the developed world a situation like the situation in New Brunswick."

The report provided 40 recommendations and 10 suggestions (for areas outside of federal government jurisdiction), including legislation amendments that would trigger automatic reviews of a proposed media merger if certain thresholds are reached, and CRTC regulation revisions to ensure that access to the broadcasting system is encouraged and that a diversity of news and information programming is available through these services.

Public inquires into the concentration of ownership and its impact upon democracy. The Canadian regulatory framework imposes requirements upon the protection and enhancement of Canadian culture (through regulation, subsidies and the operation of the CBC). Increasing acceptance of media/news as commercial enterprise in 1990s driven by: hegemony of new-liberalism, role of commodified information technology in economic growth, commitment to private sector "champions" of Canadian culture.

Brazil

In Brazil, the concentration of media ownership seems to have manifested itself very early. Dr. Venício A. de Lima noted in 2003:

in Brazil there is an environment very conducive to concentration. Sectorial legislation has been timid, by express intention of the legislator, by failing to include direct provisions that limit or control the concentration of ownership, which, incidentally, goes in the opposite direction of what happens in countries like France, Italy and the United Kingdom, which are concerned with the plurality and diversity in the new scenario of technological convergence.

— Lobato, Folha de S.Paulo, 10/14/2001

Lima points to other factors that would make media concentration easier, particularly in broadcasting: the failure of legal norms that limit the equity interest of the same economic group in various broadcasting organizations; a short period (five years) for resell broadcasting concessions, facilitating the concentration by the big media groups through the purchase of independent stations, and no restrictions to the formation of national broadcasting networks. He cites examples of horizontal, vertical, crossed and "in cross" concentration (a Brazilian peculiarity).

  • Horizontal concentration: oligopoly or monopoly produced within an area or industry; television (pay or free) is the Brazilian classical model. In 2002 the cable networks Sky and NET dominated 61% of the Brazilian market. In the same year, 58.37% of all advertising budgets were invested in TV – and in this aspect, TV Globo and its affiliates received 78% of the amount.
  • Vertical concentration: integration of the different phases of production and distribution, eliminating the work of independent producers. In Brazil, unlike the United States, it is common for a TV network to produce, advertise, market and distribute most of its programming. TV Globo is known for its soap operas exported to dozens of countries; it keeps under permanent contract the actors, authors, and the whole production staff. The final product is broadcast by a network of newspapers, magazines, radio stations and websites owned by Globo Organizations.
  • Cross ownership: ownership of different kinds of media (TV, newspapers, magazines, etc.) by the same group. Initially, the phenomenon occurred in radio, television and print media, with emphasis on the group of "Diários Associados." At a later stage appeared the RBS Group (affiliated to TV Globo), with operations in the markets of Rio Grande do Sul and Santa Catarina. Besides being the owner of radio and television stations, and of the main local newspapers, it has two Internet portals. The opinions of its commentators are thus replicated by a multimedia system that makes it extremely easy to spread the point of view advocated by the group.
  • Monopoly "in cross": reproduction into local level, of the particularities of cross ownership. Research carried out in the early 1990s, detected the presence of this singularity in 18 of the 26 Brazilian states. Manifests itself by the presence of a TV channel with a large audience, often linked to TV Globo and by the existence of two daily newspapers, in which the one with the largest circulation is linked to the major television channel and to a network of radio stations, that almost always reproduces articles and the editorial line of the newspaper "O Globo". In 2002, another survey (which did not include pay TV), found the presence of the "monopoly in cross" in 13 major markets in Brazil.

The UNESCO office in Brasília has expressed its concern over the existence of an outdated code of telecommunications (1962), which no longer meets the expectations generated by the Brazilian Constitution of 1988 in the political and social fields, and the inability of the Brazilian government to establish an independent regulatory agency to manage the media. Attempts in this direction have been pointed by the mainstream media as attacks on freedom of expression, the trend of the political left in the entire Latin American continent.

Europe

Council of Europe and European Union

Since the 1980, a significant debate has developed at the European level concerning the regulation of media ownership and the principles to be adopted to regulate media ownership concentration. Both the Council of Europe (CoE) and the European Union (EU) have tried to formulate a distinctive and comprehensive media policy, including on the issue of concentration. However, the emphasis of both the organisations was more on strengthening media diversity and pluralism than on limiting concentration, even though they have often expressed the need for common European media concentration regulations. However, the European Union enforces a common regulation for environmental protection, consumer protection and human rights, but it has none for media pluralism.

Although there is no specific media concentration legislation at the European level, a number of existing legal instruments such as the Amsterdam Protocol, the Audiovisual Media Services Directive and actions programs contribute directly and indirectly to curbing media concentration at EU level.

When it comes to regulating media concentration at the common European level, there is a conflict between Member states and the European Commission (EC). Even if Member states do not publicly challenge the need for common regulation on media concentration, they push to incorporate their own regulatory approach at the EU level and are reluctant to give the European Union their regulatory power on the issue of media concentration.

The Council of Europe's initiative promoting media pluralism and curbing media concentration dates back to the mid-1970s. Several resolutions, recommendations, declarations by the Council of Europe Committee of Ministers and studies by experts' groups have addressed the issue since then. The council's approach has been mainly addressed at defining and protecting media pluralism, defined in terms of pluralism of media content in order to allow a plurality of ideas and opinions.

Within the European Union, two main standpoints have emerged in the debate: on the one hand, the European Parliament has favoured the idea that, considering the crucial role that media play in the functioning of democratic systems, policies in this field should prevent excessive concentration in order to guarantee pluralism and diversity. On the other hand, the European Commission has privileged the understanding that the media sector should be regulated, as any other economic field, following the principles of market harmonization and liberalization.

Indeed, media concentration issues can be addressed both by general competition policies and by specific media sector rules. According to some scholars, given the vital importance of contemporary media, sector-specific competition rules in the media industries should be enhanced. Within the EU, the Council regulation 4064/89/EEC on the control of concentrations between undertakings as part of European competition legislation covered also media concentration cases. The need for sector-specific regulation has been widely supported by both media scholars and the European Parliament. In the 1980s, when preparing legislation on cross-border television many experts and MEPs argued for including provisions for media concentration in the EU directive but these efforts failed. In 1992, the Commission of the European Communities published a policy document named "Pluralism and Media Concentration in the internal Market – an assessment of the need for Community action" which outlined three options on the issue of media concentration regulation at the Community level, i.e. no specific action to be taken; action regulating transparency; and action to harmonize laws. Out of these options, the first one was chosen but the debate on this decision lasted for years. Council regulation as a tool for regulating media concentration was excluded and the two proposals on a media concentration directive advanced in the mid 1990s were not backed by the commission. As a consequence, efforts at legislating media concentration at Community level were phased out by the end of the 1990s.

Despite a wide consensus over the idea that the vital importance of contemporary media justifies to regulate media concentration through sector-specific concentration rules going beyond the general competition policy, the need for sector specific regulation has been challenged in recent years due to the peculiar evolution of the media industry in the digital environment and media convergence. In practice, sector-specific media concentration rules have been abolished in some European countries in recent years.

As a consequence, scholars Harcourt and Picard argue that "the trend has been to remove ownership rules and restrictions on media ownership within Europe in order that 'domestic champions' can bulk up to 'fend off' the US threat. This has been a key argument for the loosening of ownership rules within Europe."

In 2002, the European Parliament tried to revitalize the efforts on regulating media concentration at the European level and adopted a resolution on media concentration which called on the European Commission to launch a broad and comprehensive consultation on media pluralism and media concentration and to prepare a Green Paper on the issue by the end of 2003. The European Commission failed to meet this deadline. In the following years, during the process of amending the Televisions Without Frontiers directive, which was adopted by the EP and the Council in 2007, the issue of media concentration was discussed, but it did not represent the core of the debate. In 2003, the European Commission issued a policy document named "The future of European Regulatory Audiovisual Policy" which stressed that, in order to ensure media pluralism, measures should aim at limiting the level of media concentration by establishing "maximum holdings in media companies and prevent[ing] cumulative control or participation in several media companies at the same time".

In 2007, reacting to concerns on media concentration and its repercussion on pluralism and freedom of expression in the EU member states raised by the European Parliament and by NGOs, the European Commission launched a new three-phase plan on media pluralism.

In October 2009, a European Union Directive was proposed to set for all member states common and higher standards for media pluralism and freedom of expression. The proposal was put to a vote in the European Parliament and rejected by just three votes. The directive was supported by the liberal-centrists, the progressives and the greens, and was opposed by the European People's Party. Unexpectedly, the Irish liberals made an exception by voting against the directive, and later revealed that they had been pressured by the Irish right-wing government to do so.

Following this debate, the European Commission commissioned a large, in depth study published in 2009 aiming to identify the indicators to be adopted to assess media pluralism in Europe.

The "Independent Study on Indicators for Media Pluralism in the Member States – Towards a Risk-Based Approach" provided a prototype of indicators and country reports for 27 EU member states. After years of refining and preliminary testings, the study resulted in the Media Pluralism Monitor (MPM), a yearly monitoring carried out by the Centre for Media Pluralism and Freedom at the European University Institute in Florence on a variety of aspects affecting media pluralism, including also the concentration of media ownership is considered. To assess the risk that media ownership concentration in a given country may actually hinder media pluralism, the MPM takes into account three specific elements:

  • Horizontal concentration, that is concentration of media ownership within a given media sector (press, audio-visual, etc.);
  • Cross-media concentration across different media markets;
  • Transparency of media ownership.

In 2015, the MPM was carried out in 19 European countries. The results of the monitoring activity in the field of media market concentration identify five countries as facing a high risk: Finland, Luxembourg, Lithuania, Poland and Spain. There are nine countries facing a medium risk: Czech Republic, Germany, Ireland, Latvia, Netherlands, Portugal, Romania, Sweden. Finally, only five countries face a low risk: Croatia, Cyprus, Malta, Slovenia and Slovakia. In the monitoring carried out in 2014, 7 of 9 countries (Belgium, Bulgaria, Denmark, France, Hungary, Italy, the UK) scored a high risk in audience concentration.

Pan-European groups

A 2016 report based on data collected by MAVISE, a free online database on audiovisual services and companies in Europe, highlights the growing number of Pan-European media companies in the field of broadcasting and divides them into different categories: multi‐country media groups, controlling "channels that play an important role in various national markets (for example Modern Times Group, CEME, RTL, a Luxembourg-based media group operating in 10 countries, and Sanoma). These groups generally control a high market share in the countries in which they operate, and have gradually emerged through the acquisition of existing channels or by establishing new companies in countries in which they were not already present. The four groups RTL Group, CEME, Modern Times Group and Sanoma are major players (in the top 4 regarding audience share) in 19 European countries (RTL Group, CEME and Modern Times Group are major players in 17 countries). Pan‐European broadcasters operate with a unique identity and well recognized brands across Europe. Most of them are based in the United States and have progressively expanded their activities in the European market. In many cases, these groups evolved from being content creators to also deliver such contents through channels renamed after the original brands.

Examples of such pan-European groups include Warner Bros. Discovery, Paramount Global, and The Walt Disney Company, pan‐European distribution groups (cable and satellite operators), companies that operate at the European level in the distribution sector via cable, satellite or IPTV. The emergence of major actors operating in this field has been made possible mainly thanks to the process of digitalization and benefit of specific economies of scale.

EU Member States

Czech Republic

In the Czech Republic about 80% of the newspapers and magazines were owned by German and Swiss corporations in 2007, as the two main press groups Vltava Labe Media and Mafra were (completely or partly) controlled by the German group Rheinisch-Bergische Druckerei- und Verlagsgesellschaft (Mediengruppe Rheinische Post), but were both later purchased by Czech-owned conglomerates Penta Investments and Agrofert in 2015 and 2013 respectively. Several major media previously owned by Swiss company Ringier became Czech-owned through their acquisition by the Czech News Center in 2013.

  • Vltava Labe Media, a subsidiary of Penta Investments, that owns the tabloids ŠÍP and ŠÍP EXTRA, 73 regional dailies Deník and other 26 weeklies and that is major shareholder of publishing houses Astrosat and Melinor and 100% owner of Metropol and also partly controls the distribution of all the prints through PNS, a.s. which was previously part of the German Verlagsgruppe Passau [de] (that controls also the German Neue Presse Verlags, the Polish Polskapresse and the Slovak Petit Press).
  • Mafra, a subsidiary of Agrofert (that owns the centre-right dailies Dnes, Lidové noviny, the local edition of the freesheet Metro, the periodical 14dní, several monthly magazines, the TV music channel Óčko, the radio stations Expresradio and Rádio Classic FM, several web portals and partly controls, together with Vltava-Labe-Press, the distribution company PNS, a.s.) was previously owned by the German Rheinisch-Bergische Drückerei- und Verlagsgesellschaft, prior to its acquisition by Agrofert.
  • Czech News Center controls 16 Czech daily tabloids and weeklies (such as 24 hodin, Abc, Aha!, Blesk, Blesk TV Magazin, Blesk pro ženy, Blesk Hobby, Blesk Zdravi, Nedělní Blesk, Nedělní Sport, Reflex, Sport, Sport Magazin) as well as 7 web portals, reaching approximately 3.2 million readers.

Czech governments have defended foreign newspaper ownership as a manifestation of the principle of the free movement of capital.

The weekly Respekt is published by R-Presse, the majority of whose shares are owned by former Czech Minister of Foreign Affairs Karel Schwarzenberg. The national television market is dominated by four terrestrial stations, two public (Czech TV1 and Czech TV2) and two private (NOVA TV and Prima TV), which draw 95% of audience share. Concerning the diversity of output, this is limited by a series of factors: the average low level of professional education among Czech journalists is compensated by "informal professionalization", leading to a degree of conformity in approaches; political parties hold strong ties in Czech media, especially print, where more than 50% of Czech journalists identify with the Right, while only 16% express sympathy for the Left; and the process of commercialization and "tabloidization" has increased, lowering differentiation of content in Czech print media.

Germany

Axel Springer AG is one of the largest newspaper publishing companies in Europe, claiming to have over 150 newspapers and magazines in over 30 countries in Europe. In the 1960s and 1970s the company's media followed an aggressive conservative policy (see Springerpresse). It publishes Germany's only nationwide tabloid, Bild, and one of Germany's most important broadsheets, Die Welt. Axel Springer also owns a number of regional newspapers, especially in Saxony and in the Hamburg Metropolitan Region, giving the company a de facto monopoly in the latter case. An attempt to buy one of Germany's two major private TV Groups, ProSiebenSat.1, in 2006, was withdrawn due to large concerns by regulation authorities as well as by parts of the public. The company is also active in Hungary, where it is the biggest publisher of regional newspapers, and in Poland, where it owns the best-selling tabloid Fakt, one of the nation's most important broadsheets, Dziennik, and is one of the biggest shareholder in the second-ranked private TV company, Polsat.

Bertelsmann is one of the world's largest media companies. It owns RTL Group, which is one of the two major private TV companies in both Germany and the Netherlands and also owning assets in Belgium, France, UK, Spain, Czech and Hungary. Bertelsmann also owns Gruner + Jahr, Germany's biggest popular magazine publisher, including popular news magazine Stern and a 26% share in investigative news magazine Der Spiegel. Bertelsmann also owns Random House, a book publisher, ranked first in the English-speaking world and second in Germany.

Ireland

In Ireland, the company Independent News & Media owns many national newspapers: the Evening Herald, Irish Independent, Sunday Independent, Sunday World and Irish Daily Star. It also owns 29.9% of the Sunday Tribune. Broadcast media is divided between state owned RTÉ, which operates several radio stations and television channels and started digital radio and television services in the early 2010s, TG4, an Irish language broadcaster, and TV3, a commercial television operator. Denis O'Brien an Irish billionaire with a fortune partly accumulated through the Esat Digifone licence controversy, formed Communicorp Group Ltd in 1989, with the company currently owning 42 radio stations in 8 European countries, including Ireland's Newstalk, Today FM, Dublin's 98FM, SPIN 1038 and SPIN South West. In January 2006, O'Brien took a stake in Tony O'Reilly's Independent News & Media (IN&M). As of May 2012, he holds a 29.9% stake in the company, making him the largest shareholder; the O'Reilly family's stake is around 13%.

Italy

Silvio Berlusconi, the former Prime Minister of Italy, is the major shareholder of – by far – Italy's biggest (and de facto only) private free TV company, Mediaset; Italy's biggest publisher, Mondadori; and Italy's biggest advertising company, Publitalia [it]. One of Italy's nationwide dailies, Il Giornale, is owned by his brother, Paolo Berlusconi, and another, Il Foglio, by his former wife, Veronica Lario. Berlusconi has often been criticized for using the media assets he owns to advance his political career.

United Kingdom

In Britain and Ireland, Rupert Murdoch owns best-selling tabloid The Sun as well as the broadsheet The Times and Sunday Times, in addition having also owned 39% of satellite broadcasting network BSkyB. In March 2011, the United Kingdom provisionally approved Murdoch to buy the remaining 61% of BSkyB; however, subsequent events (News of the World hacking scandal and its closure in July 2011) leading to the Leveson Inquiry have halted this takeover. In 2019, despite the British government granting formal permission for a new take over of Sky (conditional on the divestiture of Sky News), Fox were outbid by American conglomerate Comcast.

Reach own five major national titles, the Daily Mirror, Sunday Mirror and The Sunday People, and the Scottish Sunday Mail and Daily Record as well as over 100 regional newspapers. They claim to have a monthly digital reach of 73 million people.

Daily Mail and General Trust (DMGT) own the Daily Mail and The Mail on Sunday, Ireland on Sunday, and free London daily Metro, and control a large proportion of regional media, including through subsidiary Northcliffe Media, in addition to large shares in ITN and GCap Media.

The Guardian is owned by Guardian Media Group.

Richard Desmond owns OK! magazine, the Daily Express, and the Daily Star. He used to own Channel 5; on 1 May 2014 the channel was acquired by Viacom for £450 million (US$759 million).

The Evening Standard and former print publication The Independent are both partly owned by British-Russian media boss Evgeny Lebedev.

BBC News produces news for its television channels and radio stations.

Independent Television News produces news for ITV, Channel 4 and Channel 5.

Independent Radio News, which has a contract with Sky News, produces news for the most popular commercial radio stations.

India

In India a few political parties also own media organizations, for example the proprietors of Kalaignar TV are close aides of Tamil Nadu's former Chief Minister M. Karunanidhi. So is also the case with Sun TV. SRM university owner Pachamuthu, a member of Parliament, has stakes in Pudhiyathalaimurai News Channel. AMMK General Secretary TTV Dinakaran, MLA's close aides run Jaya TV. Sakshi TV a Telugu channel in Andhra Pradesh is owned by ex-chief minister's son and family.

Israel

In Israel, Arnon Mozes owns the most widespread Hebrew newspaper, Yediot Aharonot, the most widespread Russian newspaper Vesty, the most popular Hebrew news website Ynet, and 17% of the cable TV firm HOT. Moreover, Mozes owns the Reshet TV firm, which is one of the two operators of the most popular channel in Israel, Channel 2.

Mexico

In Mexico there are only two national broadcast television service companies, Televisa and Azteca. These two broadcasters together administer 434 of the 461 total commercial television stations in the country (94.14%).

Though concern about the existence of a duopoly had been around for some time, a press uproar sparked in 2006, when a controversial reform to the Federal Radio and Television Law, seriously hampered the entry of new competitors, like Cadena Tres.

Televisa also owns subscription TV enterprises Cablevision (Mexico) [es] and SKY, a publishing company Editorial Televisa [es], and the Televisa Radio broadcast radio network, creating a de facto media monopoly in many regions of the country.

United States

Recent media mergers in the United States

An infographic created by Jason at Frugal Dad states that in 1983, 90% of US media was controlled by 50 companies, and that in 2011, 90% was controlled by just 6 companies. One of the companies listed, News Corporation, was split into two separate companies on June 28, 2013, with publishing assets and Australian media assets going to News Corp and broadcasting and media assets going to 21st Century Fox.

Film industry

In the United States, movie production has been dominated by major studios since the early 20th century; before that, there was a period in which Edison's Trust monopolized the industry. The music and television industries recently witnessed cases of media consolidation, with Sony Music Entertainment's parent company merging their music division with Bertelsmann AG's BMG to form Sony BMG and Tribune's The WB and CBS Corp.'s UPN merging to form The CW. In the case of Sony BMG, there existed a "Big Five" (now "Big Four") of major record companies, while The CW's creation was an attempt to consolidate ratings and stand up to the "Big Four" of American network (terrestrial) television (this despite the fact that the CW was, in fact, partially owned by one of the Big Four in CBS). In television, the vast majority of broadcast and basic cable networks, over a hundred in all, are controlled by seven corporations: Fox Corporation, The Walt Disney Company (which includes the ABC, ESPN, FX and Disney brands), National Amusements (which owns Paramount Global), Comcast (which owns NBCUniversal), Warner Bros. Discovery, E. W. Scripps Company, Cablevision (now known as Altice USA), or some combination thereof.

There may also be some large-scale owners in an industry that are not the causes of monopoly or oligopoly. iHeartMedia (formerly Clear Channel Communications), especially since the Telecommunications Act of 1996, acquired many radio stations across the United States, and came to own more than 1,200 stations. However, the radio broadcasting industry in the United States and elsewhere can be regarded as oligopolistic regardless of the existence of such a player. Because radio stations are local in reach, each licensing a specific part of spectrum from the FCC in a specific local area, any local market is served by a limited number of stations. In most countries, this system of licensing makes many markets local oligopolies. The similar market structure exists for television broadcasting, cable systems and newspaper industries, all of which are characterized by the existence of large-scale owners. Concentration of ownership is often found in these industries.

Effect of ownership on coverage

In a 2020 article, Herzog and Scerbinina argued that CNN's coverage in 2017 of a potential merger between its parent company Time Warner and AT&T was "self-centered, self-promoting, and self-legitimizing."

Venezuela

About 70% of Venezuelan TV and radio stations are privately owned, while only about 5% or less of these stations are currently state-owned. The remaining stations are mostly community owned. VTV was the only state TV channel in Venezuela only about a decade ago. For the last decade, through the present day, the Venezuelan government operates and owns five more stations.

Commercial outlets completely rule over the radio sector. However, the Venezuelan government funds a good number of radio shows and TV stations. The primary newspapers of Venezuela are private companies that are frequently condemning of their government. These newspapers being produced in Venezuela do not have a large following.

Skin cancer

From Wikipedia, the free encyclopedia

Skin cancer
Basal cell carcinoma.jpg
A basal-cell skin cancer. Note the pearly appearance and telangiectasia.

SpecialtyOncology and dermatology
SymptomsBasal-cell: painless raised area of skin that may be shiny with small blood vessel running over it or ulceration
Squamous-cell: hard lump with a scaly top
Melanoma: mole that has changed in size, shape, color, or has irregular edges
TypesBasal-cell skin cancer (BCC), squamous-cell skin cancer (SCC), melanoma
CausesUltraviolet radiation from the Sun or tanning beds
Risk factorsLight skin, poor immune function
Diagnostic methodTissue biopsy
PreventionDecreasing exposure to ultraviolet radiation, sunscreen
TreatmentSurgery, radiation therapy, fluorouracil
Frequency5.6 million (2015)
Deaths111,700 (2015)

Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types of skin cancers: basal-cell skin cancer (BCC), squamous-cell skin cancer (SCC) and melanoma. The first two, along with a number of less common skin cancers, are known as nonmelanoma skin cancer (NMSC). Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death. It often appears as a painless raised area of skin that may be shiny with small blood vessels running over it or may present as a raised area with an ulcer. Squamous-cell skin cancer is more likely to spread. It usually presents as a hard lump with a scaly top but may also form an ulcer. Melanomas are the most aggressive. Signs include a mole that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds.

More than 90% of cases are caused by exposure to ultraviolet radiation from the Sun. This exposure increases the risk of all three main types of skin cancer. Exposure has increased, partly due to a thinner ozone layer. Tanning beds are another common source of ultraviolet radiation. For melanomas and basal-cell cancers, exposure during childhood is particularly harmful. For squamous-cell skin cancers, total exposure, irrespective of when it occurs, is more important. Between 20% and 30% of melanomas develop from moles. People with lighter skin are at higher risk as are those with poor immune function such as from medications or HIV/AIDS. Diagnosis is by biopsy.

Decreasing exposure to ultraviolet radiation and the use of sunscreen appear to be effective methods of preventing melanoma and squamous-cell skin cancer. It is not clear if sunscreen affects the risk of basal-cell cancer. Nonmelanoma skin cancer is usually curable. Treatment is generally by surgical removal but may, less commonly, involve radiation therapy or topical medications such as fluorouracil. Treatment of melanoma may involve some combination of surgery, chemotherapy, radiation therapy and targeted therapy. In those people whose disease has spread to other areas of the body, palliative care may be used to improve quality of life. Melanoma has one of the higher survival rates among cancers, with over 86% of people in the UK and more than 90% in the United States surviving more than 5 years.

Skin cancer is the most common form of cancer, globally accounting for at least 40% of cancer cases. The most common type is nonmelanoma skin cancer, which occurs in at least 2–3 million people per year. This is a rough estimate, however, as good statistics are not kept. Of nonmelanoma skin cancers, about 80% are basal-cell cancers and 20% squamous-cell skin cancers. Basal-cell and squamous-cell skin cancers rarely result in death. In the United States, they were the cause of less than 0.1% of all cancer deaths. Globally in 2012, melanoma occurred in 232,000 people and resulted in 55,000 deaths. White people in Australia, New Zealand and South Africa have the highest rates of melanoma in the world. The three main types of skin cancer have become more common in the last 20 to 40 years, especially regions where the population is predominantly white.

Classification

There are three main types of skin cancer: basal-cell skin cancer (basal-cell carcinoma) (BCC), squamous-cell skin cancer (squamous-cell carcinoma) (SCC) and malignant melanoma.

Cancer Description Illustration
Basal-cell carcinoma Note the pearly translucency to fleshy color, tiny blood vessels on the surface, and sometimes ulceration which can be characteristics. The key term is translucency.
Basal cell carcinoma3.JPG
Squamous-cell skin carcinoma Commonly presents as a red, crusted, or scaly patch or bump. Often a very rapidly growing tumor.
Squamous Cell Carcinoma1.jpg
Malignant melanoma These are commonly asymmetrical in shape and/or pigment distribution, with an irregular border, color variation, and often greater than 6 mm diameter.
Melanoma.jpg

Basal-cell carcinomas are most commonly present on sun-exposed areas of the skin, especially the face. They rarely metastasize and rarely cause death. They are easily treated with surgery or radiation. Squamous-cell skin cancers are also common, but much less common than basal-cell cancers. They metastasize more frequently than BCCs. Even then, the metastasis rate is quite low, with the exception of SCC of the lip, ear, and in people who are immunosuppressed. Melanoma are the least frequent of the three common skin cancers. They frequently metastasize, and potentially cause death once they spread.

Less common skin cancers include: dermatofibrosarcoma protuberans, Merkel cell carcinoma, Kaposi's sarcoma, keratoacanthoma, spindle cell tumors, sebaceous carcinomas, microcystic adnexal carcinoma, Paget's disease of the breast, atypical fibroxanthoma, leiomyosarcoma, and angiosarcoma, and porocarcinoma.

BCC and SCC often carry a UV-signature mutation indicating that these cancers are caused by UVB radiation via direct DNA damage. However malignant melanoma is predominantly caused by UVA radiation via indirect DNA damage. The indirect DNA damage is caused by free radicals and reactive oxygen species. Research indicates that the absorption of three sunscreen ingredients into the skin, combined with a 60-minute exposure to UV, leads to an increase of free radicals in the skin, if applied in too little quantity and too infrequently. However, the researchers add that newer creams often do not contain these specific compounds, and that the combination of other ingredients tends to retain the compounds on the surface of the skin. They also add that frequent re-application reduces the risk of radical formation.

Signs and symptoms

There are a variety of different skin cancer symptoms. These include changes in the skin that do not heal, ulcering in the skin, discolored skin, and changes in existing moles, such as jagged edges to the mole, enlargement of the mole, changes in color, the way it feels or if it bleeds. Other common signs of skin cancer can be painful lesion that itches or burns and large brownish spot with darker speckles.

Basal-cell skin cancer

Basal-cell skin cancer (BCC) usually presents as a raised, smooth, pearly bump on the sun-exposed skin of the head, neck, torso or shoulders. Sometimes small blood vessels (called telangiectasia) can be seen within the tumor. Crusting and bleeding in the center of the tumor frequently develops. It is often mistaken for a sore that does not heal. This form of skin cancer is the least deadly, and with proper treatment can be eliminated, often without significant scarring.

Squamous-cell skin cancer

Squamous-cell skin cancer (SCC) is commonly a red, scaling, thickened patch on sun-exposed skin. Some are firm hard nodules and dome shaped like keratoacanthomas. Ulceration and bleeding may occur. When SCC is not treated, it may develop into a large mass. Squamous-cell is the second most common skin cancer. It is dangerous, but not nearly as dangerous as a melanoma.

Melanoma

Most melanoma consist of various colours from shades of brown to black. A small number of melanoma are pink, red or fleshy in colour; these are called amelanotic melanoma and tend to be more aggressive. Warning signs of malignant melanoma include change in the size, shape, color or elevation of a mole. Other signs are the appearance of a new mole during adulthood or pain, itching, ulceration, redness around the site, or bleeding at the site. An often-used mnemonic is "ABCDE", where A is for "asymmetrical", B for "borders" (irregular: "Coast of Maine sign"), C for "color" (variegated), D for "diameter" (larger than 6 mm – the size of a pencil eraser) and E for "evolving."

Other

Merkel cell carcinomas are most often rapidly growing, non-tender red, purple or skin colored bumps that are not painful or itchy. They may be mistaken for a cyst or another type of cancer.

Causes

Ultraviolet radiation from sun exposure is the primary environmental cause of skin cancer. This can occur in professions such as farming. Other risk factors that play a role include:

  • Light skin color 
  • Age 
  • Smoking tobacco
  • HPV infections increase the risk of squamous-cell skin cancer.
  • Some genetic syndromes including congenital melanocytic nevi syndrome which is characterized by the presence of nevi (birthmarks or moles) of varying size which are either present at birth, or appear within 6 months of birth. Nevi larger than 20 mm (3/4") in size are at higher risk for becoming cancerous.
  • Chronic non-healing wounds. These are called Marjolin's ulcers based on their appearance, and can develop into squamous-cell skin cancer.
  • Ionizing radiation such as X-rays, environmental carcinogens, and artificial UV radiation (e.g. tanning beds). It is believed that tanning beds are the cause of hundreds of thousands of basal and squamous-cell skin cancer. The World Health Organization now places people who use artificial tanning beds in its highest risk category for skin cancer. Alcohol consumption, specifically excessive drinking increase the risk of sunburns.
  • The use of many immunosuppressive medications increases the risk of skin cancer. Cyclosporin A, a calcineurin inhibitor for example increases the risk approximately 200 times, and azathioprine about 60 times.
  • Deliberate exposure of sensitive skin not normally exposed to sunlight during alternative wellness behaviors such as perineum sunning.

Pathophysiology

A malignant epithelial tumor that primarily originates in the epidermis, in squamous mucosa or in areas of squamous metaplasia is referred to as a squamous-cell carcinoma.

Macroscopically, the tumor is often elevated, fungating, or may be ulcerated with irregular borders. Microscopically, tumor cells destroy the basement membrane and form sheets or compact masses which invade the subjacent connective tissue (dermis). In well differentiated carcinomas, tumor cells are pleomorphic/atypical, but resembling normal keratinocytes from prickle layer (large, polygonal, with abundant eosinophilic (pink) cytoplasm and central nucleus).

Their disposal tends to be similar to that of normal epidermis: immature/basal cells at the periphery, becoming more mature to the centre of the tumor masses. Tumor cells transform into keratinized squamous cells and form round nodules with concentric, laminated layers, called "cell nests" or "epithelial/keratinous pearls". The surrounding stroma is reduced and contains inflammatory infiltrate (lymphocytes). Poorly differentiated squamous carcinomas contain more pleomorphic cells and no keratinization.

A molecular factor involved in the disease process is mutation in gene PTCH1 that plays an important role in the Sonic hedgehog signaling pathway.

Diagnosis

Diagnosis is by biopsy and histopathological examination.

Non-invasive skin cancer detection methods include photography, dermatoscopy, sonography, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis.

Dermatoscopy may be useful in diagnosing basal cell carcinoma in addition to skin inspection.

There is insufficient evidence that optical coherence tomography (OCT) is useful in diagnosing melanoma or squamous cell carcinoma. OCT may have a role in diagnosing basal cell carcinoma but more data is needed to support this.

Computer-assisted diagnosis devices have been developed that analyze images from a dermatoscope or spectroscopy and can be used by a diagnostician to aid in the detection of skin cancer. CAD systems have been found to be highly sensitive in the detection of melanoma, but have a high false-positive rate. There is not yet enough evidence to recommend CAD as compared to traditional diagnostic methods.

High-frequency ultrasound (HFUS) is of unclear usefulness in the diagnosis of skin cancer. There is insufficient evidence for reflectance confocal microscopy to diagnose basal cell or squamous cell carcinoma or any other skin cancers.

Prevention

Sunscreen is effective and thus recommended to prevent melanoma and squamous-cell carcinoma. There is little evidence that it is effective in preventing basal-cell carcinoma. Other advice to reduce rates of skin cancer includes avoiding sunburning, wearing protective clothing, sunglasses and hats, and attempting to avoid sun exposure or periods of peak exposure. The U.S. Preventive Services Task Force recommends that people between 9 and 25 years of age be advised to avoid ultraviolet light.

The risk of developing skin cancer can be reduced through a number of measures including decreasing indoor tanning and mid day sun exposure, increasing the use of sunscreen, and avoiding the use of tobacco products.

The reason it is important to limit sun exposure and to avoid tanning beds is because they both involve UV light. UV light is known to damage skin cells by mutating the DNA in it. The mutated DNA can cause tumors and other growths to form on the skin. Further, there are other risk factors beside just UV exposure. Fair skin, prolonged history of sunburns, moles, and family history of skin cancer are just a few.

There is insufficient evidence either for or against screening for skin cancers. Vitamin supplements and antioxidant supplements have not been found to have an effect in prevention. Evidence for reducing melanoma risk from dietary measures is tentative, with some supportive epidemiological evidence, but no clinical trials.

Zinc oxide and titanium oxide are often used in sun screen to provide broad protection from UVA and UVB ranges.

Eating certain foods may decrease the risk of sunburns but this is much less than the protection provided by sunscreen.

A meta-analysis of skin cancer prevention in high risk individuals found evidence that topical application of T4N5 liposome lotion reduced the rate of appearance of basal cell carcinomas in people with xeroderma pigmentosum, and that acitretin taken by mouth may have a skin protective benefit in people following kidney transplant.

A research published in January 2022 by the Oregon State University College of Pharmacy showed that a vaccine that stimulates production of a protein critical to the skin's antioxidant network could reinforce people's defenses against skin cancer.

Treatment

Treatment is dependent on the specific type of cancer, location of the cancer, age of the person, and whether the cancer is primary or a recurrence. For a small basal-cell cancer in a young person, the treatment with the best cure rate (Mohs surgery or CCPDMA) might be indicated. In the case of an elderly frail man with multiple complicating medical problems, a difficult to excise basal-cell cancer of the nose might warrant radiation therapy (slightly lower cure rate) or no treatment at all. Topical chemotherapy might be indicated for large superficial basal-cell carcinoma for good cosmetic outcome, whereas it might be inadequate for invasive nodular basal-cell carcinoma or invasive squamous-cell carcinoma. In general, melanoma is poorly responsive to radiation or chemotherapy.

For low-risk disease, radiation therapy (external beam radiotherapy or brachytherapy), topical chemotherapy (imiquimod or 5-fluorouracil) and cryotherapy (freezing the cancer off) can provide adequate control of the disease; all of them, however, may have lower overall cure rates than certain type of surgery. Other modalities of treatment such as photodynamic therapy, epidermal radioisotope therapy, topical chemotherapy, electrodesiccation and curettage can be found in the discussions of basal-cell carcinoma and squamous-cell carcinoma.

Mohs' micrographic surgery (Mohs surgery) is a technique used to remove the cancer with the least amount of surrounding tissue and the edges are checked immediately to see if tumor is found. This provides the opportunity to remove the least amount of tissue and provide the best cosmetically favorable results. This is especially important for areas where excess skin is limited, such as the face. Cure rates are equivalent to wide excision. Special training is required to perform this technique. An alternative method is CCPDMA and can be performed by a pathologist not familiar with Mohs surgery.

In the case of disease that has spread (metastasized), further surgical procedures or chemotherapy may be required.

Treatments for metastatic melanoma include biologic immunotherapy agents ipilimumab, pembrolizumab, nivolumab, cemiplimab; BRAF inhibitors, such as vemurafenib and dabrafenib; and a MEK inhibitor trametinib.

Reconstruction

Currently, surgical excision is the most common form of treatment for skin cancers. The goal of reconstructive surgery is restoration of normal appearance and function. The choice of technique in reconstruction is dictated by the size and location of the defect. Excision and reconstruction of facial skin cancers is generally more challenging due to presence of highly visible and functional anatomic structures in the face.

When skin defects are small in size, most can be repaired with simple repair where skin edges are approximated and closed with sutures. This will result in a linear scar. If the repair is made along a natural skin fold or wrinkle line, the scar will be hardly visible. Larger defects may require repair with a skin graft, local skin flap, pedicled skin flap, or a microvascular free flap. Skin grafts and local skin flaps are by far more common than the other listed choices.

Skin grafting is patching of a defect with skin that is removed from another site in the body. The skin graft is sutured to the edges of the defect, and a bolster dressing is placed atop the graft for seven to ten days, to immobilize the graft as it heals in place. There are two forms of skin grafting: split thickness and full thickness. In a split thickness skin graft, a shaver is used to shave a layer of skin from the abdomen or thigh. The donor site regenerates skin and heals over a period of two weeks. In a full thickness skin graft, a segment of skin is totally removed and the donor site needs to be sutured closed.

Split thickness grafts can be used to repair larger defects, but the grafts are inferior in their cosmetic appearance. Full thickness skin grafts are more acceptable cosmetically. However, full thickness grafts can only be used for small or moderate sized defects.

Local skin flaps are a method of closing defects with tissue that closely matches the defect in color and quality. Skin from the periphery of the defect site is mobilized and repositioned to fill the deficit. Various forms of local flaps can be designed to minimize disruption to surrounding tissues and maximize cosmetic outcome of the reconstruction. Pedicled skin flaps are a method of transferring skin with an intact blood supply from a nearby region of the body. An example of such reconstruction is a pedicled forehead flap for repair of a large nasal skin defect. Once the flap develops a source of blood supply form its new bed, the vascular pedicle can be detached.

Prognosis

The mortality rate of basal-cell and squamous-cell carcinoma is around 0.3%, causing 2000 deaths per year in the US. In comparison, the mortality rate of melanoma is 15–20% and it causes 6500 deaths per year. Even though it is much less common, malignant melanoma is responsible for 75% of all skin cancer-related deaths.

The survival rate for people with melanoma depends upon when they start treatment. The cure rate is very high when melanoma is detected in early stages, when it can easily be removed surgically. The prognosis is less favorable if the melanoma has spread to other parts of the body. As of 2003 the overall five-year cure rate with Mohs' micrographic surgery was around 95 percent for recurrent basal cell carcinoma.

Australia and New Zealand exhibit one of the highest rates of skin cancer incidence in the world, almost four times the rates registered in the United States, the UK and Canada. Around 434,000 people receive treatment for non-melanoma skin cancers and 10,300 are treated for melanoma. Melanoma is the most common type of cancer in people between 15 and 44 years in both countries. The incidence of skin cancer has been increasing. The incidence of melanoma among Auckland residents of European descent in 1995 was 77.7 cases per 100,000 people per year, and was predicted to increase in the 21st century because of "the effect of local stratospheric ozone depletion and the time lag from sun exposure to melanoma development."

Epidemiology

Age-standardized death from melanoma and other skin cancers per 100,000 inhabitants in 2004

Skin cancers result in 80,000 deaths a year as of 2010, 49,000 of which are due to melanoma and 31,000 of which are due to non-melanoma skin cancers. This is up from 51,000 in 1990.

More than 3.5 million cases of skin cancer are diagnosed annually in the United States, which makes it the most common form of cancer in that country. One in five Americans will develop skin cancer at some point of their lives. The most common form of skin cancer is basal-cell carcinoma, followed by squamous cell carcinoma. Unlike for other cancers, there exists no basal and squamous cell skin cancers registry in the United States.

Melanoma

In the US in 2008, 59,695 people were diagnosed with melanoma, and 8,623 people died from it. In Australia more than 12,500 new cases of melanoma are reported each year, out of which more than 1,500 die from the disease. Australia has the highest per capita incidence of melanoma in the world.

Although the rates of many cancers in the United States is falling, the incidence of melanoma keeps growing, with approximately 68,729 melanomas diagnosed in 2004 according to reports of the National Cancer Institute.

Melanoma is the fifth most common cancer in the UK (around 13,300 people were diagnosed with melanoma in 2011), and the disease accounts for 1% all cancer deaths (around 2,100 people died in 2012).

Non-melanoma

Approximately 2,000 people die from basal or squamous cell skin cancers (non-melanoma skin cancers) in the United States each year. The rate has dropped in recent years. Most of the deaths happen to people who are elderly and might not have seen a doctor until the cancer had spread; and people with immune system disorders.

Superconducting magnet

From Wikipedia, the free encyclopedia
 
Schematic of a 20-tesla superconducting magnet with vertical bore

A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation. In its superconducting state the wire has no electrical resistance and therefore can conduct much larger electric currents than ordinary wire, creating intense magnetic fields. Superconducting magnets can produce greater magnetic fields than all but the strongest non-superconducting electromagnets and can be cheaper to operate because no energy is dissipated as heat in the windings. They are used in MRI machines in hospitals, and in scientific equipment such as NMR spectrometers, mass spectrometers, fusion reactors and particle accelerators. They are also used for levitation, guidance and propulsion in a magnetic levitation (maglev) railway system being constructed in Japan.

Construction

Cooling

During operation, the magnet windings must be cooled below their critical temperature, the temperature at which the winding material changes from the normal resistive state and becomes a superconductor, which is far below room temperature in the cryogenic range. The windings are typically cooled to temperatures significantly below their critical temperature, because the lower the temperature, the better superconductive windings work—the higher the currents and magnetic fields they can stand without returning to their non-superconductive state. Two types of cooling systems are commonly used to maintain magnet windings at temperatures sufficient to maintain superconductivity:

Liquid cooled

Liquid helium is used as a coolant for many superconductive windings. It has a boiling point of 4.2 K, far below the critical temperature of most winding materials. The magnet and coolant are contained in a thermally insulated container (dewar) called a cryostat. To keep the helium from boiling away, the cryostat is usually constructed with an outer jacket containing (significantly cheaper) liquid nitrogen at 77 K. Alternatively, a thermal shield made of conductive material and maintained in 40 K-60 K temperature range, cooled by conductive connections to the cryocooler cold head, is placed around the helium-filled vessel to keep the heat input to the latter at acceptable level. One of the goals of the search for high temperature superconductors is to build magnets that can be cooled by liquid nitrogen alone. At temperatures above about 20 K cooling can be achieved without boiling off cryogenic liquids.

Mechanical cooling

Because of increasing cost and the dwindling availability of liquid helium, many superconducting systems are cooled using two stage mechanical refrigeration. In general two types of mechanical cryocoolers are employed which have sufficient cooling power to maintain magnets below their critical temperature. The Gifford-McMahon Cryocooler has been commercially available since the 1960s and has found widespread application. The G-M regenerator cycle in a cryocooler operates using a piston type displacer and heat exchanger. Alternatively, 1999 marked the first commercial application using a pulse tube cryocooler. This design of cryocooler has become increasingly common due to low vibration and long service interval as pulse tube designs utilize an acoustic process in lieu of mechanical displacement. In a typical two-stage refrigerator, the first stage will offer higher cooling capacity but at higher temperature (≈77 K) with the second stage reaching ≈4.2 K and <2.0 watts cooling power. In use, the first stage is used primarily for ancillary cooling of the cryostat with the second stage used primarily for cooling the magnet.

Coil winding materials

The maximal magnetic field achievable in a superconducting magnet is limited by the field at which the winding material ceases to be superconducting, its "critical field", Hc, which for type-II superconductors is its upper critical field. Another limiting factor is the "critical current", Ic, at which the winding material also ceases to be superconducting. Advances in magnets have focused on creating better winding materials.

The superconducting portions of most current magnets are composed of niobium-titanium. This material has critical temperature of 10 kelvins and can superconduct at up to about 15 teslas. More expensive magnets can be made of niobium-tin (Nb3Sn). These have a Tc of 18 K. When operating at 4.2 K they are able to withstand a much higher magnetic field intensity, up to 25 to 30 teslas. Unfortunately, it is far more difficult to make the required filaments from this material. This is why sometimes a combination of Nb3Sn for the high-field sections and NbTi for the lower-field sections is used. Vanadium-gallium is another material used for the high-field inserts.

High-temperature superconductors (e.g. BSCCO or YBCO) may be used for high-field inserts when required magnetic fields are higher than Nb3Sn can manage. BSCCO, YBCO or magnesium diboride may also be used for current leads, conducting high currents from room temperature into the cold magnet without an accompanying large heat leak from resistive leads.

Conductor structure

The coil windings of a superconducting magnet are made of wires or tapes of Type II superconductors (e.g.niobium-titanium or niobium-tin). The wire or tape itself may be made of tiny filaments (about 20 micrometers thick) of superconductor in a copper matrix. The copper is needed to add mechanical stability, and to provide a low resistance path for the large currents in case the temperature rises above Tc or the current rises above Ic and superconductivity is lost. These filaments need to be this small because in this type of superconductor the current only flows in a surface layer whose thickness is limited to the London penetration depth. (See Skin effect) The coil must be carefully designed to withstand (or counteract) magnetic pressure and Lorentz forces that could otherwise cause wire fracture or crushing of insulation between adjacent turns.

Operation

7 T horizontal bore superconducting magnet, part of a mass spectrometer. The magnet itself is inside the cylindrical cryostat.

Power supply

The current to the coil windings is provided by a high current, very low voltage DC power supply, since in steady state the only voltage across the magnet is due to the resistance of the feeder wires. Any change to the current through the magnet must be done very slowly, first because electrically the magnet is a large inductor and an abrupt current change will result in a large voltage spike across the windings, and more importantly because fast changes in current can cause eddy currents and mechanical stresses in the windings that can precipitate a quench (see below). So the power supply is usually microprocessor-controlled, programmed to accomplish current changes gradually, in gentle ramps. It usually takes several minutes to energize or de-energize a laboratory-sized magnet.

Persistent mode

An alternate operating mode used by most superconducting magnets is to short-circuit the windings with a piece of superconductor once the magnet has been energized. The windings become a closed superconducting loop, the power supply can be turned off, and persistent currents will flow for months, preserving the magnetic field. The advantage of this persistent mode is that stability of the magnetic field is better than is achievable with the best power supplies, and no energy is needed to power the windings. The short circuit is made by a 'persistent switch', a piece of superconductor inside the magnet connected across the winding ends, attached to a small heater. When the magnet is first turned on, the switch wire is heated above its transition temperature, so it is resistive. Since the winding itself has no resistance, no current flows through the switch wire. To go to persistent mode, the supply current is adjusted until the desired magnetic field is obtained, then the heater is turned off. The persistent switch cools to its superconducting temperature, short-circuiting the windings. Then the power supply can be turned off. The winding current, and the magnetic field, will not actually persist forever, but will decay slowly according to a normal inductive (L/R) time constant:

where is a small residual resistance in the superconducting windings due to joints or a phenomenon called flux motion resistance. Nearly all commercial superconducting magnets are equipped with persistent switches.

Magnet quench

A quench is an abnormal termination of magnet operation that occurs when part of the superconducting coil enters the normal (resistive) state. This can occur because the field inside the magnet is too large, the rate of change of field is too large (causing eddy currents and resultant heating in the copper support matrix), or a combination of the two. More rarely a defect in the magnet can cause a quench. When this happens, that particular spot is subject to rapid Joule heating from the enormous current, which raises the temperature of the surrounding regions. This pushes those regions into the normal state as well, which leads to more heating in a chain reaction. The entire magnet rapidly becomes normal (this can take several seconds, depending on the size of the superconducting coil). This is accompanied by a loud bang as the energy in the magnetic field is converted to heat, and rapid boil-off of the cryogenic fluid. The abrupt decrease of current can result in kilovolt inductive voltage spikes and arcing. Permanent damage to the magnet is rare, but components can be damaged by localized heating, high voltages, or large mechanical forces. In practice, magnets usually have safety devices to stop or limit the current when the beginning of a quench is detected. If a large magnet undergoes a quench, the inert vapor formed by the evaporating cryogenic fluid can present a significant asphyxiation hazard to operators by displacing breathable air.

A large section of the superconducting magnets in CERN's Large Hadron Collider unexpectedly quenched during start-up operations in 2008, necessitating the replacement of a number of magnets. In order to mitigate against potentially destructive quenches, the superconducting magnets that form the LHC are equipped with fast-ramping heaters which are activated once a quench event is detected by the complex quench protection system. As the dipole bending magnets are connected in series, each power circuit includes 154 individual magnets, and should a quench event occur, the entire combined stored energy of these magnets must be dumped at once. This energy is transferred into dumps that are massive blocks of metal which heat up to several hundreds of degrees Celsius due to the resistive heating in a matter of seconds. Although undesirable, a magnet quench is a "fairly routine event" during the operation of a particle accelerator.

Magnet "training"

In certain cases, superconducting magnets designed for very high currents require extensive bedding in, to enable the magnets to function at their full planned currents and fields. This is known as "training" the magnet, and involves a type of material memory effect. One situation this is required in is the case of particle colliders such as CERN's Large Hadron Collider. The magnets of the LHC were planned to run at 8 TeV (2×4 TeV) on its first run and 14 TeV (2×7 TeV) on its second run, but were initially operated at a lower energy of 3.5 TeV and 6.5 TeV per beam respectively. Because of initial crystallographic defects in the material, they will initially lose their superconducting ability ("quench") at a lower level than their design current. CERN states that this is due to electromagnetic forces causing tiny movements in the magnets, which in turn cause superconductivity to be lost when operating at the high precisions needed for their planned current. By repeatedly running the magnets at a lower current and then slightly increasing the current until they quench under control, the magnet will gradually both gain the required ability to withstand the higher currents of its design specification without quenches occurring, and have any such issues "shaken" out of them, until they are eventually able to operate reliably at their full planned current without experiencing quenches.

History

Although the idea of making electromagnets with superconducting wire was proposed by Heike Kamerlingh Onnes shortly after he discovered superconductivity in 1911, a practical superconducting electromagnet had to await the discovery of superconducting materials that could support large critical supercurrent densities in high magnetic fields. The first successful superconducting magnet was built by G.B. Yntema in 1955 using niobium wire and achieved a field of 0.7 T at 4.2 K. Then, in 1961, J.E. Kunzler, E. Buehler, F.S.L. Hsu, and J.H. Wernick made the discovery that a compound of niobium and tin could support critical-supercurrent densities greater than 100,000 amperes per square centimeter in magnetic fields of 8.8 teslas. Despite its brittle nature, niobium-tin has since proved extremely useful in supermagnets generating magnetic fields up to 20 teslas.

The persistent switch was invented in 1960 by Dwight Adams while a postdoctoral associate at Stanford University. The second persistent switch was constructed at the University of Florida by M.S. student R.D. Lichti in 1963. It has been preserved in a showcase in the UF Physics Building.

In 1962, T.G. Berlincourt and R.R. Hake discovered the high-critical-magnetic-field, high-critical-supercurrent-density properties of niobium-titanium alloys. Although niobium-titanium alloys possess less spectacular superconducting properties than niobium-tin, they are highly ductile, easily fabricated, and economical. Useful in supermagnets generating magnetic fields up to 10 teslas, niobium-titanium alloys are the most widely used supermagnet materials.

In 1986, the discovery of high temperature superconductors by Georg Bednorz and Karl Müller energized the field, raising the possibility of magnets that could be cooled by liquid nitrogen instead of the more difficult-to-work-with helium.

In 2007, a magnet with windings of YBCO achieved a world record field of 26.8 teslas. The US National Research Council has a goal of creating a 30-tesla superconducting magnet.

In 2017, a YBCO magnet created by the National High Magnetic Field Laboratory (NHMFL) broke the previous world record with a strength of 32 T. This is an all superconducting user magnet, designed to last for many decades. They hold the current record as of March 2018.

In 2019 the NHMFL also developed a non-insulated YBCO test coil which broke the lab's own world record for highest continuous magnetic field for any configuration of magnet at 45.5 T. 

Uses

An MRI machine that uses a superconducting magnet. The magnet is inside the doughnut-shaped housing and can create a 3-tesla field inside the central hole.

Superconducting magnets have a number of advantages over resistive electromagnets. They can generate magnetic fields that are up to ten times stronger than those generated by ordinary ferromagnetic-core electromagnets, which are limited to fields of around 2 T. The field is generally more stable, resulting in less noisy measurements. They can be smaller, and the area at the center of the magnet where the field is created is empty rather than being occupied by an iron core. Most importantly, for large magnets they can consume much less power. In the persistent state (above), the only power the magnet consumes is that needed for any refrigeration equipment to preserve the cryogenic temperature. Higher fields, however can be achieved with special cooled resistive electromagnets, as superconducting coils will enter the normal (non-superconducting) state (see quench, above) at high fields. Steady fields of over 40 T can now be achieved by many institutions around the world usually by combining a Bitter electromagnet with a superconducting magnet (often as an insert).

Superconducting magnets are widely used in MRI machines, NMR equipment, mass spectrometers, magnetic separation processes, and particle accelerators.

In Japan, after decades of research and development into superconducting maglev by Japanese National Railways and later Central Japan Railway Company (JR Central), the Japanese government gave permission to JR Central to build the Chūō Shinkansen, linking Tokyo to Nagoya and later to Osaka.

One of the most challenging use of SC magnets is in the LHC particle accelerator. The niobium-titanium (Nb-Ti) magnets operate at 1.9 K to allow them to run safely at 8.3 T. Each magnet stores 7 MJ. In total the magnets store 10.4 gigajoules (2.5 tons of TNT). Once or twice a day, as the protons are accelerated from 450 GeV to 7 TeV, the field of the superconducting bending magnets will be increased from 0.54 T to 8.3 T.

The central solenoid and toroidal field superconducting magnets designed for the ITER fusion reactor use niobium-tin (Nb3Sn) as a superconductor. The Central Solenoid coil will carry 46 kA and produce a field of 13.5 teslas. The 18 Toroidal Field coils at max field of 11.8 T will store 41 GJ (total?). They have been tested at a record 80 kA. Other lower field ITER magnets (PF and CC) will use niobium-titanium. Most of the ITER magnets will have their field varied many times per hour.

One high-resolution mass spectrometer is planned to use a 21-tesla SC magnet.

Globally in 2014, about five billion euros worth of economic activity resulted from which superconductivity is indispensable. MRI systems, most of which employ niobium-titanium, accounted for about 80% of that total.

Essay

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Essay Essays of Michel de Monta...