Signs and symptoms.

People with HPD are usually high-functioning, both socially and professionally. They usually have good social skills, despite tending to use them to manipulate others into making them the center of attention. HPD may also affect a person's social and romantic relationships, as well as their ability to cope with losses or failures. They may seek treatment for clinical depression when romantic (or other close personal) relationships end.  Individuals with HPD often fail to see their own personal situation realistically, instead dramatizing and exaggerating their difficulties. They may go through frequent job changes, as they become easily bored and may prefer withdrawing from frustration (instead of facing it). Because they tend to crave novelty and excitement, they may place themselves in risky situations. All of these factors may lead to greater risk of developing clinical depression.  Additional characteristics may include:  Some people with histrionic traits or personality disorder change their seduction technique into a more maternal or paternal style as they age.

Mnemonic.

A mnemonic that can be used to remember the characteristics of histrionic personality disorder is shortened as "PRAISE ME":

Causes.

Little research has been done to find evidence of what causes histrionic personality disorder and from where it stems. Although direct causes are inconclusive, there are a few theories and studies conducted that suggests there are multiple possible causes. There are neurochemical, genetic, psychoanalytical, and environmental causes contributing to histrionic personality disorder. Traits such as extravagance, vanity, and seductiveness of hysteria have similar qualities to women diagnosed with HPD. HPD symptoms do not fully develop until the age of 15 with treatment only beginning at approximately 40 years of age.

Neurochemical/physiological.

Studies have shown that there is a strong correlation between the function of neurotransmitters and the Cluster B personality disorders such as HPD. Individuals diagnosed with HPD have highly responsive noradrenergic systems which is responsible for the synthesis, storage, and release of the neurotransmitter, norepinephrine. High levels of norepinephrine leads to anxiety-proneness, dependency, and high sociability.

Genetic.

Twin studies have aided in breaking down the genetic vs. environment debate. A twin study conducted by the Department of Psychology at Oslo University attempted to establish a correlation between genetic and Cluster B personality disorders. With a test sample of 221 twins, 92 monozygotic and 129 dizygotic, researchers interviewed the subjects using the Structured Clinical Interview for DSM-III-R Personality Disorders (SCID-II) and concluded that there was a correlation of 0.67 that histrionic personality disorder is hereditary.

Psychoanalytic theory.

Though criticised as being unsupported by scientific evidence, psychoanalytic theories incriminate authoritarian or distant attitudes by one (mainly the mother) or both parents, along with conditional love based on expectations the child can never fully meet. Using psychoanalysis, Freud believed that lustfulness was a projection of the patient's lack of ability to love unconditionally and develop cognitively to maturity, and that such patients were overall emotionally shallow. He believed the reason for being unable to love could have resulted from a traumatic experience, such as the death of a close relative during childhood or divorce of one's parents, which gave the wrong impression of committed relationships. Exposure to one or multiple traumatic occurrences of a close friend or family member's leaving (via abandonment or mortality) would make the person unable to form true and affectionate attachments towards other people.

HPD and antisocial personality disorder.

Another theory suggests a possible relationship between histrionic personality disorder and antisocial personality disorder. Research has found 2/3 of patients diagnosed with histrionic personality disorder also meet criteria similar to those of the antisocial personality disorder, which suggests both disorders based towards sex-type expressions may have the same underlying cause. Women are hypersexualized in the media consistently, ingraining thoughts that the only way women are to get attention is by exploiting themselves, and when seductiveness isn't enough, theatricals are the next step in achieving attention. Men can just as well be flirtatious towards multiple women yet feel no empathy or sense of compassion towards them. They may also become the center of attention by exhibiting the "Don Juan" macho figure as a role-play.  Some family history studies have found that histrionic personality disorder, as well as borderline and antisocial personality disorders, tend to run in families, but it is unclear if this is due to genetic or environmental factors. Both examples suggest that predisposition could be a factor as to why certain people are diagnosed with histrionic personality disorder, however little is known about whether or not the disorder is influenced by any biological compound or is genetically inheritable. Little research has been conducted to determine the biological sources, if any, of this disorder.

Diagnosis.

The person's appearance, behavior and history, along with a psychological evaluation, are usually sufficient to establish a diagnosis. There is no test to confirm this diagnosis. Because the criteria are subjective, some people may be wrongly diagnosed.

DSM 5.

The current edition of the Diagnostic and Statistical Manual of Mental Disorders, DSM 5, defines histrionic personality disorder (in Cluster B) as: The DSM 5 requires that a diagnosis for any specific personality disorder also satisfies a set of general personality disorder criteria.

ICD-10.

The World Health Organization's ICD-10 lists histrionic personality disorder as:  It is a requirement of ICD-10 that a diagnosis of any specific personality disorder also satisfies a set of general personality disorder criteria.

Comorbidity.

Most histrionics also have other mental disorders. Comorbid conditions include: antisocial, dependent, borderline, and narcissistic personality disorders, as well as depression, anxiety disorders, panic disorder, somatoform disorders, anorexia nervosa, substance use disorder and attachment disorders, including reactive attachment disorder.

Millon's subtypes.

Theodore Millon identified six subtypes of histrionic personality disorder. Any individual histrionic may exhibit none or one of the following:

Treatment.

Treatment is often prompted by depression associated with dissolved romantic relationships. Medication does little to affect the personality disorder, but may be helpful with symptoms such as depression. The only successful method studied and proven to succeed is to fully break contact with their lovers in order to gain a sense of stability and independence once again. Treatment for HPD itself involves psychotherapy, including cognitive therapy.

Interviews and self-report methods.

In general clinical practice with assessment of personality disorders, one form of interview is the most popular; an unstructured interview. The actual preferred method is a semi-structured interview but there is reluctance to use this type of interview because they can seem impractical or superficial. The reason that a semi-structured interview is preferred over an unstructured interview is that semi-structured interviews tend to be more objective, systematic, replicable, and comprehensive. Unstructured interviews, despite their popularity, tend to have problems with unreliability and are susceptible to errors leading to false assumptions of the client.  One of the single most successful methods for assessing personality disorders by researchers of normal personality functioning is the self-report inventory following up with a semi-structured interview. There are some disadvantages with the self-report inventory method that with histrionic personality disorder there is a distortion in character, self-presentation, and self-image. This cannot be assessed simply by asking most clients if they match the criteria for the disorder. Most projective testing depend less on the ability or willingness of the person to provide an accurate description of the self, but there is currently limited empirical evidence on projective testing to assess histrionic personality disorder.

Functional analytic psychotherapy.

Another way to treat histrionic personality disorder after identification is through functional analytic psychotherapy. The job of a Functional Analytic Psychotherapist is to identify the interpersonal problems with the patient as they happen in session or out of session. Initial goals of functional analytic psychotherapy are set by the therapist and include behaviors that fit the client's needs for improvement. Functional analytic psychotherapy differs from the traditional psychotherapy due to the fact that the therapist directly addresses the patterns of behavior as they occur in-session.  The in-session behaviors of the patient or client are considered to be examples of their patterns of poor interpersonal communication and to adjust their neurotic defenses. To do this, the therapist must act on the client's behavior as it happens in real time and give feedback on how the client's behavior is affecting their relationship during therapy. The therapist also helps the client with histrionic personality disorder by denoting behaviors that happen outside of treatment; these behaviors are termed "Outside Problems" and "Outside Improvements". This allows the therapist to assist in problems and improvements outside of session and to verbally support the client and condition optimal patterns of behavior". This then can reflect on how they are advancing in-session and outside of session by generalizing their behaviors over time for changes or improvement".

Coding client and therapist behaviors.

This is called "coding client and therapist behavior". In these sessions there is a certain set of dialogue or script that can be forced by the therapist for the client to give insight on their behaviors and reasoning". Here is an example from" the conversation is hypothetical. T = therapist C = Client This coded dialogue can be transcribed as:

Functional ideographic assessment template.

Another example of treatment besides coding is functional ideographic assessment template. The functional ideographic assessment template, also known as FIAT, was used as a way to generalize the clinical processes of functional analytic psychotherapy. The template was made by a combined effort of therapists and can be used to represent the behaviors that are a focus for this treatment. Using the FIAT therapists can create a common language to get stable and accurate communication results through functional analytic psychotherapy at the ease of the client; as well as the therapist.

Epidemiology.

The survey data from the National epidemiological survey from 2001–2002 suggests a prevalence of HPD of 1.84 percent. Major character traits may be inherited, while other traits may be due to a combination of genetics and environment, including childhood experiences. This personality is seen more often in women than in men. Approximately 65% of HPD diagnoses are women while 35% are men. In Marcie Kaplan's "A Women's View of DSM-III", she argues that women are overdiagnosed due to potential biases and expresses that even healthy women are often automatically diagnosed with HPD.  Many symptoms representing HPD in the DSM are exaggerations of traditional feminine behaviors. In a peer and self-review study, it showed that femininity was correlated with histrionic, dependent and narcissistic personality disorders. Although two thirds of HPD diagnoses are female, there have been a few exceptions. Whether or not the rate will be significantly higher than the rate of women within a particular clinical setting depends upon many factors that are mostly independent of the differential sex prevalence for HPD. Those with HPD are more likely to look for multiple people for attention, which leads to marital problems due to jealousy and lack of trust from the other party. This makes them more likely to become divorced or separated once married. With few studies done to find direct causations between HPD and culture, cultural and social aspects play a role in inhibiting and exhibiting HPD behaviors.

History.

Although it is said that the history of histrionic personality disorder stems from the word hysteria, actually it comes from Etruscan histrio which means an actor. Hysteria can be described as an exaggerated or uncontrollable emotion that people, especially in groups, experience. Beliefs about hysteria have varied throughout time. It wasn’t until Sigmund Freud who studied histrionic personality disorder in a psychological manner. “The roots of histrionic personality can be traced to cases of hysterical neurosis described by Freud.” He developed the psychoanalytic theory in the late 19th century and the results from his development led to split concepts of hysteria. One concept labeled as hysterical neurosis (also known as conversion disorder) and the other concept labeled as hysterical character (currently known as histrionic personality disorder). These two concepts must not be confused with each other, as they are two separate and different ideas.  Histrionic personality disorder is also known as hysterical personality. Hysterical personality has evolved in the past 400 years and it first appeared in the DSM II (Diagnostic and Statistical Manual of Mental Disorders, 2nd edition) under the name hysterical personality disorder. The name we know today as histrionic personality disorder is due to the name change in DSM III, third edition. Renaming hysterical personality to histrionic personality disorder is believed to be because of possible negative connotations to the roots of hysteria, such as intense sexual expressions, demon possessions, etc.  Histrionic personality disorder has gone through many changes. From hysteria, to hysterical character, to hysterical personality disorder, to what it is listed as in the most current DSM, DSM-5. "Hysteria is one of the oldest documented medical disorders.” Hysteria dates back to both ancient Greek and Egyptian writings. Most of the writings related hysteria and women together, similar to today where the epidemiology of histrionic personality disorder is generally more prevalent in women and also frequently diagnosed in women.

Social implications.

The prevalence of histrionic personality disorder in women is apparent and urges a re-evaluation of cultural notions of normal emotional behaviour. The diagnostic approach classifies histrionic personality disorder behaviour as “excessive”, considering it in reference to a social understanding of normal emotionality.

Histrionic personality disorder (HPD) is defined by the American Psychiatric Association as a personality disorder characterized by a pattern of excessive attention-seeking behaviors, usually beginning in early adulthood, including inappropriate seduction and an excessive need for approval. People diagnosed with the disorder are said to be lively, dramatic, vivacious, enthusiastic, and flirtatious. HPD is diagnosed four times as frequently in women as men. It affects 2–3% of the general population and 10–15% in inpatient and outpatient mental health institutions.

戏剧化人格违常是人格违常的一种,又称表演型人格障碍。患者常显得、情绪不稳,具有强烈的自我意识和个人表现欲。他们富敏感而夸张的情感,追求感官刺激,喜欢成为被关注的中心。夸张、情绪爆发、甚至自虐倾向是戏剧人格的几大特点。往往很难用正常方式与他们沟通,因为戏剧人格者对真实有许多歪曲的体验。他们极度重视他人的赞同和保证,却又善于玩弄异性、威胁别人。


History.

The term "BRIC" is believed to be coined in 2001 by then-chairman of Goldman Sachs Asset Management, Jim O'Neill, in his publication "Building Better Global Economic BRICs".. But, it was actually coined by Roopa Purushothaman who was a Research Assistant in the original report. The foreign ministers of the initial four BRIC General states (Brazil, Russia, India, and China) met in New York City in September 2006 at the margins of the General Debate of the UN Assembly, beginning a series of high-level meetings. A full-scale diplomatic meeting was held in Yekaterinburg, Russia, on 16 June 2009.

First BRIC summit.

The BRIC grouping's first formal summit, also held in Yekaterinburg, commenced on 16 June 2009, with Luiz Inácio Lula da Silva, Dmitry Medvedev, Manmohan Singh, and Hu Jintao, the respective leaders of Brazil, Russia, India and China, all attending. The summit's focus was on means of improving the global economic situation and reforming financial institutions, and discussed how the four countries could better co-operate in the future. There was further discussion of ways that developing countries, such as 3/4 of the BRIC members, could become more involved in global affairs.  In the aftermath of the Yekaterinburg summit, the BRIC nations announced the need for a new global reserve currency, which would have to be "diverse, stable and predictable". Although the statement that was released did not directly criticise the perceived "dominance" of the US dollar – something that Russia had criticised in the past – it did spark a fall in the value of the dollar against other major currencies.

Entry of South Africa.

In 2010, South Africa began efforts to join the BRIC grouping, and the process for its formal admission began in August of that year. South Africa officially became a member nation on 24 December 2010, after being formally invited by China to join and subsequently accepted by other BRIC countries. The group was renamed BRICS – with the "S" standing for South Africa – to reflect the group's expanded membership. In April 2011, the President of South Africa, Jacob Zuma, attended the 2011 BRICS summit in Sanya, China, as a full member.

Developments.

The BRICS Forum, an independent international organisation encouraging commercial, political and cultural cooperation between the BRICS nations, was formed in 2011. In June 2012, the BRICS nations pledged $75 billion to boost the lending power of the International Monetary Fund (IMF). However, this loan was conditional on IMF voting reforms. In late March 2013, during the fifth BRICS summit in Durban, South Africa, the member countries agreed to create a global financial institution which they intended to rival the western-dominated IMF and World Bank. After the summit, the BRICS stated that they planned to finalise the arrangements for this New Development Bank by 2014. However, disputes relating to burden sharing and location slowed down the agreements.  At the BRICS leaders meeting in St Petersburg in September 2013, China committed $41 billion towards the pool; Brazil, India and Russia $18 billion each; and South Africa $5 billion. China, holder of the world's largest foreign exchange reserves and who is to contribute the bulk of the currency pool, wants a greater managing role, said one BRICS official. China also wants to be the location of the reserve. "Brazil and India want the initial capital to be shared equally. We know that China wants more," said a Brazilian official. "However, we are still negotiating, there are no tensions arising yet." On 11 October 2013, Russia's Finance Minister Anton Siluanov said that a decision on creating a $100 billion fund designated to steady currency markets would be taken in early 2014. The Brazilian finance minister, Guido Mantega stated that the fund would be created by March 2014. However, by April 2014, the currency reserve pool and development bank had yet to be set up, and the date was rescheduled to 2015. One driver for the BRICS development bank is that the existing institutions primarily benefit extra-BRICS corporations, and the political significance is notable because it allows BRICS member states "to promote their interests abroad... and can highlight the strengthening positions of countries whose opinion is frequently ignored by their developed American and European colleagues."  In March 2014, at a meeting on the margins of the Nuclear Security Summit in The Hague, the BRICS Foreign Ministers issued a communique that "noted with concern, the recent media statement on the forthcoming G20 Summit to be held in Brisbane in November 2014. The custodianship of the G20 belongs to all Member States equally and no one Member State can unilaterally determine its nature and character." In light of the tensions surrounding the 2014 Crimean crisis, the Ministers remarked that "The escalation of hostile language, sanctions and counter-sanctions, and force does not contribute to a sustainable and peaceful solution, according to international law, including the principles and purposes of the United Nations Charter." This was in response to the statement of Australian Foreign Minister Julie Bishop, who had said earlier that Russian President Vladimir Putin might be barred from attending the G20 Summit in Brisbane.  In July 2014, the Governor of the Russian Central Bank, Elvira Nabiullina, claimed that the "BRICS partners the establishment of a system of multilateral swaps that will allow to transfer resources to one or another country, if needed" in an article which concluded that "If the current trend continues, soon the dollar will be abandoned by most of the significant global economies and it will be kicked out of the global trade finance."  Over the weekend of 13 July 2014, when the final game of the FIFA World Cup was held, and in advance of the BRICS Fortaleza summit, Putin met fellow leader Dilma Rousseff to discuss the BRICS development bank, and sign some other bilateral accords on air defence, gas and education. Rouseff said that the BRICS countries "are among the largest in the world and cannot content themselves in the middle of the 21st century with any kind of dependency." The Fortaleza summit was followed by a BRICS meeting with the Union of South American Nations president's in Brasilia, where the development bank and the monetary fund were introduced. The development bank will have capital of US$50 billion with each country contributing US$10 billion, while the monetary fund will have US$100 billion at its disposal.  On 15 July, the first day of the BRICS 6th summit in Fortaleza, Brazil, the group of emerging economies signed the long-anticipated document to create the US$100 billion New Development Bank (formerly known as the "BRICS Development Bank") and a reserve currency pool worth over another US$100 billion. Documents on cooperation between BRICS export credit agencies and an agreement of cooperation on innovation were also inked.  At the end of October 2014, Brazil trimmed down its US government holdings to US$261.7 billion; India, US$77.5 billion; China, US$1.25 trillion; South Africa, US$10.3 billion.  In March 2015, Morgan Stanley stated that India and Indonesia had escaped from the 'fragile five' (the five major emerging markets with the most fragile currencies) by instituting economic reforms. Previously, in August 2013, Morgan Stanley rated India and Indonesia, together with Brazil, Turkey and South Africa, as the 'fragile five' due to their vulnerable currencies. But since then, India and Indonesia have reformed their economies, completing 85% and 65% of the necessary adjustments respectively, while Brazil had only achieved 15%, Turkey only 10%, and South Africa even less.  After the 2015 summit, the respective communications ministers, under a Russian proposal, had a first summit for their ministries in Moscow in October where the host minister, Nikolai Nikiforov, proposed an initiative to further tighten their information technology sectors and challenge the monopoly of the United States in the sector.  Since 2012, the BRICS group of countries have been planning an optical fibre submarine communications cable system to carry telecommunications between the BRICS countries, known as the BRICS Cable. Part of the motivation for the project was the spying of the National Security Agency on all telecommunications that flowed across the US.  In August 2019, the communications ministers of the BRICS countries signed a letter of intent to cooperate in the Information and Communication Technology sector. This agreement was signed in the fifth edition of meeting of communication ministers of countries member of the group. The agreement was signed at the fifth meeting of BRICS communications minister held in Brasilia.

Geography.

The BRICS is an association formed by countries in four continents: Brazil in South America, Russia in Europe, India and China in Asia and South Africa in Africa. Its member states cover an area of over 39,000,000 square kilometers, which is approximately 27% of the world's land surface.

Summits.

The grouping has held annual summits since 2009, with member countries taking turns to host. Prior to South Africa's admission, two BRIC summits were held, in 2009 and 2010. The first five-member BRICS summit was held in 2011. The most recent BRICS summit took place in Brazil from 13 to 14 November 2019.

Member countries.

Potential additional members=Afghanistan Argentina, Indonesia, Mexico and Turkey have expressed strong interest in full membership of the BRICS, while Egypt, Iran, Nigeria, Sudan, Syria and most recently Pakistan, Bangladesh and Greece have also expressed interest in joining BRICS.

Financial architecture.

Currently, there are two components that make up the financial architecture of BRICS, namely, the New Development Bank (NDB) or sometimes referred to as the BRICS Development Bank and the Contingent Reserve Arrangement (CRA). Both of these components were signed into treaty in 2014 and became active in 2015.

New Development Bank.

The New Development Bank (NDB), formerly referred to as the BRICS Development Bank, is a multilateral development bank operated by the BRICS states. The bank's primary focus of lending will be infrastructure projects with authorized lending of up to $34 billion annually. South Africa will be the African Headquarters of the Bank named the "New Development Bank Africa Regional Centre". The bank will have starting capital of $50 billion, with capital increased to $100 billion over time. Brazil, Russia, India, China and South Africa will initially contribute $10 billion each to bring the total to $50 billion.

BRICS CRA.

The BRICS Contingent Reserve Arrangement (CRA) is a framework for providing protection against global liquidity pressures. This includes currency issues where members' national currencies are being adversely affected by global financial pressures. It is found that emerging economies that experienced rapid economic liberalization went through increased economic volatility, bringing uncertain macroeconomic environment. The CRA is generally seen as a competitor to the International Monetary Fund (IMF) and along with the New Development Bank is viewed as an example of increasing South-South cooperation. It was established in 2015 by the BRICS countries. The legal basis is formed by the "Treaty for the Establishment of a BRICS Contingent Reserve Arrangement", signed at Fortaleza, Brazil on 15 July 2014. With its inaugural meetings of the BRICS CRA Governing Council and Standing Committee, held on September 4, 2015, in Ankara, Turkey it entered into force upon ratification by all BRICS states, announced at the 7th BRICS summit in July 2015.

BRICS payment system.

At the 2015 BRICS summit in Russia, ministers from BRICS nations, initiated consultations for a payment system that would be an alternative to the SWIFT system. Russian Deputy Foreign Minister Sergey Ryabkov stated in an interview, "The finance ministers and executives of the BRICS central banks are negotiating... setting up payment systems and moving on to settlements in national currencies. SWIFT or not, in any case we’re talking about... a transnational multilateral payment system that would provide greater independence, would create a definite guarantee for BRICS."  The Central Bank of Russia (CBR) also started consultations with BRICS nations for a payment system that would be an alternative to the SWIFT system. The main benefits highlighted were backup and redundancy in case there were disruptions to the SWIFT system. The Deputy Governor of the Central Bank of the Russia, Olga Skorobogatova stated in an interview, "The only topic that may be of interest to all of us within BRICS is to consider and talk over the possibility of setting up a system that would apply to the BRICS countries, used as a backup."  China has also initiated development of their own payment system called CIPS that would be an alternative to the SWIFT system. The Cross-Border Inter-Bank Payments System (CIPS) is a planned alternative payments system to SWIFT which would provide a network that enables financial institutions worldwide to send and receive information about financial transactions in a secure, standardized and reliable environment.

Reception.

In 2012, Hu Jintao, the then President of China and Paramount leader, described the BRICS countries as defenders and promoters of developing countries and a force for world peace. Western analysts have highlighted potential divisions and weaknesses in the grouping, including significant economic instabilities, disagreements between the members over UN Security Council reform, and India and China's disputes over territorial issues.  In June 2015, Jim Rogers said that he does not see any current alternative to the US dollar and that "The world needs something to compete with the US-dominated institutions, some of them - the World Bank and the IMF. So, if BRICS offer any new structures that can compete with these long-standing...institutions, it will be very good."  On 9 April 2013, Isobel Coleman from the Council on Foreign Relations, director of CFR's Civil Society, Markets and Democracy Program said that members of BRICS share a lack of consensus. They uphold drastically different political systems, from active democracy in Brazil to entrenched oligarchy in Russia, and their economies are little integrated and are different in size by orders of magnitude. Also she states that the great difference in GDP, influences the reserves, for China taking up of over 41% of the contribution, which in turn leads to bigger political say within the association.  Vijay Prashad, author and the Edward Said Chair at the American University of Beirut has shed lights on the limits of the BRICS as a political and economic 'locomotive of the South', for the states concerned, according to Prashad, follow neoliberal policies. They have established neither new counter-balancing institutions nor come up with an alternative ideology. Furthermore, the BRICS project, argues Prashad, has no ability to challenge the primacy of the United States and NATO.

BRICS Pro Tempore Presidency.

The group at each summit elects one of the heads of state of the component countries to serve as President Pro Tempore of the BRICS. In 2019, the pro tempore presidency is held by the president of Brazil.  The theme of the 11th BRICS summit was "BRICS: economic growth for an innovative future", and the priorities of the Brazilian Pro Tempore Presidency for 2019 are the following: Strengthening of the cooperation in Science, technology and innovation; Enhancement of the cooperation on digital economy; Invigoration of the cooperation on the fight against transnational crime, especially against organized crime, money laundering and drug trafficking; Encouragement to the rapprochement between the New Development Bank (NDB) and the BRICS Business Council.

BRICS is the acronym coined for an association of five major emerging national economies: Brazil, Russia, India, China and South Africa. Originally the first four were grouped as "BRIC" (or "the BRICs"), before the induction of South Africa in 2010. The BRICS members are known for their significant influence on regional affairs; all are members of G20. Since 2009, the BRICS nations have met annually at formal summits. China hosted the 9th BRICS summit in Xiamen on September 2017, while Brazil hosted the most recent 11th BRICS summit on 13-14 November 2019.

金砖国家,原指金砖四国(),现指金砖五国(),是指五个主要的新兴市场国家,分别为巴西、俄罗斯、印度、中国、南非。“金砖五国”国土面积占世界领土总面积的26%,人口占世界总人口的42%。根据国际货币基金组织的统计,2006年至2008年,四国经济平价增产率为10.7%。随着四国经济快速增长,其国际影响力与日俱增。


History.

Early history.

The area which became East Harlem was rural for most of the 19th century, but residential settlements northeast of Third Avenue and East 110th Street had developed by the 1860s. The construction of the elevated transit line to Harlem in 1879 and 1880, and the building of the Lexington Avenue subway in 1919, urbanized the area, precipitating the construction of apartment buildings and brownstones. The extension of cable cars up Lexington Avenue into East Harlem was stymied by the incline created by Duffy's Hill at 103rd Street, one of the steepest grades in Manhattan. East Harlem was first populated by poor German, Irish, Scandinavian, and Eastern European Jewish immigrants, with the Jewish population standing at 90,000 around 1917. In the 1870s, Italian immigrants joined the mix after a contractor building trolley tracks on First Avenue imported Italian laborers as strikebreakers. The workers' shantytown along the East River at 106th Street was the beginning of an Italian neighborhood, with 4,000 having arrived by the mid-1880s. As more immigrants arrived, it expanded north to East 115th Street and west to Third Avenue.  East Harlem consisted of pockets of ethnically-sorted settlements – Italian, German, Irish, and Jewish – which were beginning to press up against each other, with the spaces still between them occupied by "gasworks, stockyards and tar and garbage dumps". In 1895, Union Settlement Association, one of the oldest settlement houses in New York City, began providing services in the area, offering the immigrant and low-income residents a range of community-based programs, including boys and girls clubs, a sewing school and adult education classes.

Italian Harlem.

Southern Italians and Sicilians, with a moderate number of Northern Italians, soon predominated, especially in the area east of Lexington Avenue between 96th and 116th Streets and east of Madison Avenue between 116th and 125th Streets, with each street featuring people from different regions of Italy. The neighborhood became known as "Italian Harlem", the Italian American hub of Manhattan; it was the first part of Manhattan to be referred to as "Little Italy". The first Italians arrived in East Harlem in 1878, from Polla in the province of Salerno, and settled in the vicinity of 115th Street.  There were many crime syndicates in Italian Harlem from the early Black Hand to the bigger and more organized Italian gangs that formed the Italian-American Mafia. It was the founding location of the Genovese crime family, one of the Five Families that dominated organized crime in New York City. This includes the current 116th Street Crew of the Genovese family. During the 1970s, Italian East Harlem was also home to the Italian-American drug gang and murder-for-hire crew known as the East Harlem Purple Gang.  In the 1920s and early 1930s, Italian Harlem was represented in Congress by future Mayor Fiorello H. La Guardia, and later, in the 1940s, by Italian-American civil rights lawyer, activist, and socialist Vito Marcantonio. The Italian neighborhood approached its peak in the 1930s, with over 110,000 Italian-Americans living in its crowded, run-down apartment buildings. The 1930 census showed that 81 percent of the population of Italian Harlem consisted of first- or second-generation Italian Americans, somewhat less than the concentration of Italian Americans in the Lower East Side's Little Italy with 88 percent; Italian Harlem's total population, however, was three times that of Little Italy.  The Italian community in East Harlem remained strong into the 1980s, but it has slowly diminished since then. However, Italian inhabitants and vestiges of the old Italian neighborhood remain. The annual Feast of Our Lady of Mount Carmel and the "Dancing of the Giglio", the first Italian feast in New York City, is still celebrated there every year on the second weekend of August by the Giglio Society of East Harlem. Italian retail establishments still exist, such as Rao's restaurant, started in 1896, and the original Patsy's Pizzeria which opened in the 1933. In May 2011, one of the last remaining Italian retail businesses in the neighborhood, a barbershop owned by Claudio Caponigro on 116th Street, was threatened with closure by a rent increase.

Spanish Harlem.

Puerto Rican and Latin American migration after the First World War established an enclave at the western portion of East Harlem – around 110th Street and Lexington Avenue – which became known as "Spanish Harlem". The area slowly grew to encompass all of East Harlem, including Italian Harlem, as Italians moved out – to the Bronx, Brooklyn, upstate New York and New Jersey – and Latinos moved in during another wave of immigration in the 1940s and 1950s. Although in certain areas, particularly around Pleasant Avenue, Italian Harlem lasted through the 1970s, today most of the former Italian population is gone. Most of these predominantly older residents are clustered around Our Lady of Mount Carmel Church, mainly from 114th to 118th Streets. According to the 2000 Census, there were only 1,130 Italian-Americans still living in this area.  The newly dominant Puerto Rican population, which reached 63,000 in 1950, continued to define the neighborhood according to its needs, establishing bodegas and botánicas as it expanded; by the 1930s there was already an enclosed street market underneath the Park Avenue railroad viaduct between 111th and 116th Streets, called "La Marqueta" ("The Market"). Catholic and evangelistic Protestant churches appeared in storefronts. Although "Spanish Harlem" had been in use since at least the 1930s to describe the Latino enclave – along with "Italian Harlem" and "Negro Harlem" – the name began to be used to describe the entire East Harlem neighborhood by the 1950s. Later, the name "El Barrio" ("The Neighborhood") began to be used, especially by residents of the area.

Decline.

In the 1950s and 1960s, large sections of East Harlem were leveled for urban renewal projects, and the neighborhood was one of the hardest hit areas in the 1960s and 1970s as New York City struggled with deficits, race riots, urban flight, gang warfare, drug abuse, crime and poverty. Tenements were crowded, poorly maintained, and frequent targets for arson. In 1969 and 1970, a regional chapter of the Young Lords which were reorganized from a neighborhood street gang in Chicago by Jose (Cha-Cha) Jimenez, ran several programs including a Free Breakfast for Children and a Free Health Clinic to help Latino and poor families. The Young Lords came together with the Black Panthers and called for Puerto Rican independence and neighborhood empowerment. Still, as of the early 2000s, the Latin Kings gang remained prevalent in East Harlem.

Recent history.

By the beginning of the 21st century, East Harlem was a racially diverse neighborhood, with about a third of the population being Puerto Rican. As it has been throughout its history, it is predominantly a working-class neighborhood.  Until 2006, property values in East Harlem climbed along with those in the rest of New York City. With increased market-rate housing, including luxury condos and co-ops – most built on formerly vacant lots – there has been some decline of affordable housing in the community. A number of young professionals have settled into these recently constructed buildings. This influx of "yuppies" has caused rents to rise, more buildings in the area to get gut renovations, and changes to area demographics.  On March 12, 2014 at 9:00 EDT, a large explosion and fire at 1644–1646 Park Avenue killed eight people and injured more than 70.  The "New York Post" listed one part of the neighborhood – the block of Lexington Avenue between East 123rd and 124th Streets – as one of "the most dangerous blocks in the city" because police crime statistics for 2015 showed that 19 assaults had taken place there, more than for any other city block. The "Post" also reported that there were, according to the Harlem Neighborhood Block Association, "22 drug-treatment programs, four homeless-services providers and four transitional-living facilities" in East Harlem.  East Harlem has begun to feel the effects of gentrification. In February 2016, an article in "The New York Times" about "New York's Next Hot Neighborhoods" featured East Harlem as one of four such areas. A real-estate broker described it as "one of the few remaining areas in New York City where you can secure a good deal". The article mentioned new luxury developments, access to transportation, the opening of new retail stores, bars and restaurants, and national-brand stores beginning to appear on the outskirts of the neighborhood. Primarily, though, it was the cost of housing in comparison to the rest of Manhattan, which the article noted as the major factor. Beginning in 2016, the New York City government was seeking to rezone East Harlem "to facilitate new residential, commercial, community facility, and manufacturing development". The residents of the neighborhood generated a suggested zoning plan, the "East Harlem Neighborhood Plan", which was offered to the city in February 2017, but in August 2017 residents and the Manhattan Borough President, Gale Brewer, complained that the city had ignored their plan almost entirely.  In 2019, the oldest portion of the neighborhood, the blocks of East 111th through 120th Streets between Park and Pleasant Avenues, was listed on the National Register of Historic Places as the East Harlem Historic District.

Demographics.

The New York City Department of City Planning classifies East Harlem into two neighborhood tabulation areas: East Harlem North and East Harlem South, divided along 115th Street. The two areas had a combined population of 115,921, an increase of 1,874 (1.4%) from the combined 114,047 in the 2000 Census.  Based on data from the 2010 United States Census, the population of East Harlem North was 58,019, an increase of 871 (1.5%) from the 57,148 counted in 2000. Covering an area of, the neighborhood had a population density of. The racial makeup of the neighborhood was 6.8% (3,936) White, 35.5% (20,625) African American, 0.2% (128) Native American, 3.0% (1,766) Asian, 0.0% (9) Pacific Islander, 0.3% (185) from other races, and 1.3% (769) from two or more races. Hispanic or Latino of any race were 52.7% (30,601) of the population.  Based on data from the 2010 Census, the population of East Harlem South was 57,902, an increase of 1,003 (1.8%) from the 56,899 counted in 2000. Covering an area of, the neighborhood had a population density of. The racial makeup of the neighborhood was 17.4% (10,072) White, 24.6% (14,227) African American, 0.2% (96) Native American, 8.3% (4,802) Asian, 0.1% (55) Pacific Islander, 0.4% (218) from other races, and 1.6% (933) from two or more races. Hispanic or Latino of any race were 47.5% (27,499) of the population.  The most significant changes in the racial composition of East Harlem between 2000 and 2010 were the Asian population's increase by 109% (3,427), the White population's increase by 68% (5,689), and the Black population's decrease by 12% (4,625). Although more of the influx of Asian and White residents was in East Harlem South, the greatest percentage growth was in East Harlem North, while the Black population's decrease was evenly split. The Hispanic / Latino population also decreased by 4% (2,485), a decrease almost entirely concentrated in East Harlem South, where it fell from being the majority group to the plurality group. The small population of other races experienced a slight increase of 5% (132).  The entirety of Manhattan Community District 11, which consists of East Harlem, Randall's Island, and Ward's Island, had 124,323 inhabitants as of NYC Health's 2018 Community Health Profile, with an average life expectancy of 77.3 years. This is 3.9 years lower than the median life expectancy of 81.2 for all New York City neighborhoods. Most residents are children and middle-aged adults: 21% are between the ages of 0–17, while 33% are between 25–44, and 23% are between 45–64. The ratio of college-aged and elderly residents was lower, at 10% and 13% respectively.  As of 2017, the median household income in Community District 11 was $36,770. In 2018, an estimated 23% of Community District 11 residents lived in poverty, compared to 14% in all of Manhattan and 20% in all of New York City. One in nine residents (11%) were unemployed, compared to 7% in Manhattan and 9% in New York City. Rent burden, or the percentage of residents who have difficulty paying their rent, is 48% in Community District 11, compared to the boroughwide and citywide rates of 45% and 51% respectively. Based on this calculation,, Community District 11 is considered to be gentrifying: according to the Community Health Profile, the district was low-income in 1990 and has seen above-median rent growth up to 2010.

Ethnic groups.

Community District 11 is a mostly low to middle income area. It is made up of first and second generation Puerto Ricans, African-Americans, Italian-Americans, Asian-Americans, West Indian Americans (especially Dominican Americans and Cuban Americans), and a growing population of Mexican Americans and Salvadoran Americans and other Central American immigrants. It has one of the highest concentrations of Puerto Ricans in all of New York City. As of 2010, the Puerto Rican population was 27.7% in zip code 10029, and 23.4% in 10035. 10035 also has a large Mexican population, at 10.7%.  As noted before, the number of Asians in East Harlem more than doubled between 2000 and 2010, largely due to Chinese people moving to East Harlem. Increasing rents in Lower Manhattan's Chinatown have driven many into public and subsidized housing developments in the neighborhood. Advocates have been calling for Chinese language services to be available in the community centers to accommodate the growing number of Chinese residents in the area. In 2000, the Chinese population in the northern portion was less than one percent, but by 2010, it has gone up to being three percent in the area. In the southern part, it rose from 4.6% to 8.4%.

Social issues.

Social problems, including poverty, crime, and drug addiction, have long plagued the area. Although crime rates have dropped from the historically high numbers of the past, East Harlem suffers from a relatively high violent crime rate, especially in the 25th Precinct above 115th Street. In 2019, the 25th Precinct had the third-highest rate of felony assault, the sixth-highest rates of rape and robbery, the tenth-highest rate of burglary, and the fourteenth-highest rate of murder out of the New York Police Department's 77 precincts.  East Harlem has the highest concentration of shelters and facilities in Manhattan, with eight homeless shelters, 36 drug and alcohol treatment facilities and 37 mental health treatment facilities. It also has the highest jobless rate in the entire city, as well as the city's second highest cumulative AIDS rate. The asthma rate is also 5 times larger than national levels. The neighborhood also suffers from a high poverty rate. Union Settlement Association is one of the neighborhood's largest social service agencies, reaching more than 13,000 people annually at 17 locations throughout East Harlem, through a range of programs, including early childhood education, youth development, senior services, job training, the arts, adult education, nutrition, counseling, a farmers' market, community development, and neighborhood cultural events.

Housing.

East Harlem is dominated by public housing complexes of various types, with a high concentration of older tenement buildings between these developments. The neighborhood contains the second-highest concentration of public housing in the United States, behind Brownsville, Brooklyn. The total land area is.  After a wave of arson ravaged the low income communities of New York City throughout the 1970s, many of the residential structures in East Harlem were left seriously damaged or destroyed. By the late 1970s, the city began to rehabilitate many abandoned tenement style buildings and designate them as low income housing. Despite recent gentrification of the neighborhood, large numbers of apartment buildings have been deliberately kept vacant by their owners. Although the businesses on the ground floor are retained, landlords do not want to have the trouble involved in residential tenants. In some cases, landlords are waiting for a revived economy, warehousing the apartments so that they can rent them later at a higher rent.  In 2007, a survey of Manhattan's buildings found that 1,723 were significantly vacant, three-quarters of them north of 96th Street. A 1998 survey found that one-quarter of low-rise residential buildings on avenues or major cross streets in East Harlem had sealed-up residential floors, despite having commercial businesses on the ground floor.

Public housing projects.

There are twenty-four New York City Housing Authority developments located in East Harlem. As of 2013, 93.6% of all housing units were renter-occupied, and over 25% of the population resided in public housing units managed by the NYCHA.

Other residential developments.

Other subsidized housing includes:

Economy.

The neighborhood is home to one of the few major television studios north of midtown, Metropolis at 106th Street and Park Avenue, where shows such as BET's "106 & Park" and "Chappelle's Show" have been produced. PRdream.com, a web site on the history and culture of Puerto Ricans, founded a media gallery and digital film studio called MediaNoche in 2003. It presents technology-based art on Park Avenue and 102nd Street, providing exhibition space and residencies for artists and filmmakers, and webcasting events.

Police and crime.

East Harlem is served by two precincts of the NYPD. The area north of 116th Street is served by the 25th Precinct, located at 120 East 119th Street, while the area south of 116th Street is served by the 23rd Precinct, located at 164 East 102nd Street.  The 25th Precinct has a lower crime rate than in the 1990s, with crimes across all categories having decreased by 65.5% between 1990 and 2019. The precinct reported 3 murders, 23 rapes, 172 robberies, 329 felony assaults, 108 burglaries, 461 grand larcenies, and 21 grand larcenies auto in 2019. Of the five major violent felonies (murder, rape, felony assault, robbery, and burglary), the 25th Precinct had a rate of 1,340 crimes per 100,000 residents in 2019, compared to the boroughwide average of 632 crimes per 100,000 and the citywide average of 572 crimes per 100,000.  The 23rd Precinct also has a lower crime rate than in the 1990s, with crimes across all categories having decreased by 75.5% between 1990 and 2019. The precinct reported 2 murders, 20 rapes, 168 robberies, 330 felony assaults, 79 burglaries, 296 grand larcenies, and 21 grand larcenies auto in 2019. Of the five major violent felonies (murder, rape, felony assault, robbery, and burglary), the 23rd Precinct had a rate of 819 crimes per 100,000 residents in 2019, compared to the boroughwide average of 632 crimes per 100,000 and the citywide average of 572 crimes per 100,000. , Community District 11 has a non-fatal assault hospitalization rate of 130 per 100,000 people, compared to the boroughwide rate of 49 per 100,000 and the citywide rate of 59 per 100,000. Its incarceration rate is 1,291 per 100,000 people, compared to the boroughwide rate of 407 per 100,000 and the citywide rate of 425 per 100,000.  In 2019, the highest concentration of felony assaults in East Harlem was around the intersection of 125th Street and Lexington Avenue, where there were 39 felony assaults. This location is well-known as an open-air drug market and hotspot of other crimes. The highest concentration of robberies, on the other hand, was around the intersection of 116th Street and Third Avenue, where there were 21 robberies.

Fire safety.

East Harlem is served by four New York City Fire Department (FDNY) fire stations:

Health.

Preterm and teenage births in East Harlem are higher than the city average. In East Harlem, there were 108 preterm births per 1,000 live births (compared to 87 per 1,000 citywide), and 10.8 teenage births per 1,000 live births (compared to 19.3 per 1,000 citywide), though the teenage birth rate was based on a small sample size. East Harlem has a low population of residents who are uninsured. In 2018, this population of uninsured residents was estimated to be 3%, slightly less than the citywide rate of 12%, though this was based on a small sample size.  The concentration of fine particulate matter, the deadliest type of air pollutant, in East Harlem is, more than the city average. Eighteen percent of East Harlem residents are smokers, which is more than the city average of 14% of residents being smokers. In East Harlem, 28% of residents are obese, 17% are diabetic, and 34% have high blood pressure—compared to the citywide averages of 24%, 11%, and 28% respectively. In addition, 23% of children are obese, compared to the citywide average of 20%.  Eighty-four percent of residents eat some fruits and vegetables every day, which is lower than the city's average of 87%. In 2018, 76% of residents described their health as "good," "very good," or "excellent," less than the city's average of 78%. For every supermarket in East Harlem, there are 17 bodegas.  Metropolitan Hospital Center and Mount Sinai Hospital are both located in southern East Harlem. North General Hospital, which formerly served the area as well, is now closed. In addition, FDNY EMS Station 10 is located close to Metropolitan Hospital Center.

Fresh food.

A lack of access to healthy food causes serious hardships to citizens of East Harlem, a neighborhood which is considered to be a food desert. According to an April 2008 report prepared by the New York City Department of City Planning, East Harlem is an area of the city with the highest levels of diet-related diseases due to limited opportunities for citizens to purchase fresh foods.  With a high population density and a lack of nearby supermarkets, the neighborhood has little access to fresh fruit and vegetables and a low consumption of fresh foods. Citizens of East Harlem are likely to buy food from grocery stores that have a limited supply of fruits and vegetables, which are often of poor quality and generally more expensive than the same products sold at supermarkets. Compared to the Upper East Side, supermarkets in Harlem are 30% less common. Without access to affordable produce and meats, East Harlem residents have difficulty eating a healthy diet, which contributes to high rates of obesity and diabetes.  In 2011, Manhattan Borough President Scott Stringer announced a program which would send Veggie Vans to East Harlem senior centers and housing projects. In 2012, Whole Foods announced two uptown locations, one being on 125th Street and Lenox Avenue, the other in the Upper East Side. In 2010, Aldi's Grocery opened at the East River Plaza located at E. 117th St. and the FDR Drive, providing access to affordable food for East Harlem's residents. In 2013, a new Super FI Emperior Grocery store opened up in East Harlem on 103rd Street and Lexington Avenue.

Post offices and ZIP Codes.

East Harlem is located in two primary ZIP Codes. The area south of 116th Street is part of 10029 and the area north of 116th Street is part of 10035. The extreme northwestern portion of East Harlem is also located in 10037. The United States Postal Service operates two post offices near East Harlem:

Education.

East Harlem generally has a lower rate of college-educated residents than the rest of the city. While 38% have a college education or higher, 25% have less than a high school education and 37% are high school graduates or have some college education. By contrast, 64% of Manhattan residents and 43% of city residents have a college education or higher. The percentage of East Harlem students excelling in math rose from 25% in 2000 to 51% in 2011, and reading achievement increased from 33% to 39% during the same time period.  East Harlem's rate of elementary school student absenteeism is higher than the rest of New York City. In East Harlem, 30% of elementary school students missed twenty or more days per school year, more than the citywide average of 20%. Additionally, 67% of high school students in East Harlem graduate on time, less than the citywide average of 75%.  The schools in East Harlem are generally characterized by low test scores and high drop-out and truancy rates. As in other parts of the city, some schools require students pass through metal detectors and swipe ID cards to enter school buildings.

Schools.

The New York City Department of Education operates public schools in East Harlem as part of Community School District 2. The following public elementary schools are located in East Harlem:  The following public middle schools are located in East Harlem:  The following public high schools are located in East Harlem:  The public charter schools in East Harlem include:  St. Cecilia's School in East Harlem was closed by the Roman Catholic Archdiocese of New York – which operates Catholic schools in Manhattan and the Bronx – in 1991.

Libraries.

The New York Public Library (NYPL) operates two branches in East Harlem:  Two additional NYPL branches are located nearby. The 96th Street branch is located at 112 East 96th Street, at the border with the Upper East Side, while the Harlem branch is located at 9 West 124th Street, near the border with Harlem.

Transportation.

The Harlem River separates the Bronx and Manhattan, necessitating several spans between the two New York City boroughs. Three free bridges connect East Harlem and the Bronx: the Willis Avenue Bridge (for northbound traffic only), Third Avenue Bridge (for southbound traffic only), and Madison Avenue Bridge. In East Harlem, the Wards Island Bridge, also known as the 103rd Street Footbridge, connects Manhattan with Wards Island. The Triborough Bridge (officially the Robert F. Kennedy Bridge) is a complex of three separate bridges that offers connections between Queens, East Harlem, and the Bronx.  Public transportation service is provided by the Metropolitan Transportation Authority. The New York City Subway's IRT Lexington Avenue Line runs through East Harlem, with an express station at 125th Street (served by the ) as well as local stations at the 116th Street, 110th Street, 103rd Street, and 96th Street (served by the ). There is also a Second Avenue Subway station at 96th Street on the. MTA Regional Bus Operations and bus routes serve East Harlem as well. Metro-North Railroad has a commuter rail station at Harlem–125th Street, serving trains to the Lower Hudson Valley and Connecticut.

In popular culture.

Music  Literature  Film  Music videos

East Harlem, also known as Spanish Harlem or, is a neighborhood of Upper Manhattan, New York City, roughly encompassing the area north of the Upper East Side and bounded by 96th Street to the south, Fifth Avenue to the west, and the East and Harlem Rivers to the east and north. Despite its name, it is generally not considered to be a part of Harlem.

东哈林(英语:East Harlem),也称为东哈-{}-莱姆,又称为西班牙哈莱姆(英语:Spanish Harlem)或El Barrio,是纽约曼哈顿区的一部分。该地区为纽约最大的拉丁族裔社区之一,居民主要为波多黎各裔,也包括其他拉丁族裔和黑人。东哈莱姆曾经拥有庞大的意大利裔社区。


Geography.

Sigtuna is situated at the bay Skarven, stretching around Upplands-Bro and a part of Lake Mälaren.

History.

Sigtuna was founded on what was then the shore of Lake Mälaren just over 1,000 years ago. It took its name from an ancient royal estate (see Uppsala öd) several kilometers to the west (see Fornsigtuna). Various sources claim King Eric the Victorious as founder while others claim King Olof Skötkonung.  It operated as a royal and commercial centre for some 250 years, and was one of the most important cities of Sweden. During a brief period at the end of the 10th and beginning of the 11th century, Sweden's first coins were minted here. St. Mary's Church, built in the 13th century by the Dominican order as a monastery church, still remains largely intact. The Dominican monastery played an important role in the Swedish Middle Ages and produced many important Church officials. Among them, many Swedish archbishops. Many church and monastery ruins still stand, including St. Pers Church ("S:t Pers kyrkoruin") dating the 1100s, St. Olof Church ("S:t Olofs kyrkoruin") dated from around the middle of the 11th century and St. Lars Church ("S:t Lars kyrkoruin") dating from the middle of the 13th century.  In 1187 Sigtuna was attacked and pillaged by raiders from across the Baltic Sea, possibly Karelians, Curonian and/or Estonian (Oeselian) raiders. Archaeological excavations have not verified the traditions of destruction of the town. Normal life in Sigtuna continued until town started to slowly lose its importance during 13th century due to navigability problems caused by post-glacial rebound.  The current coat of arms can be traced to the town's first known seal, dating from 1311. According to a legend (possibly inspired by the town arms) Sigtuna was once the Royal seat, but this can not be confirmed. The crown may also symbolize the large royal mint which was located in the town. Since 1971 the coat of arms has been valid for the much larger Sigtuna Municipality.  In the late 19th century, it still only hosted about 600 people, and was the smallest town in Sweden. The town remained insignificant until the second half of the 20th century. Much of the population growth can be related to Stockholm Arlanda Airport (IATA: ARN) situated some 10 km from Sigtuna.

Sigtuna () is a locality situated in Sigtuna Municipality, Stockholm County, Sweden with 8,444 inhabitants in 2010. It is the namesake of the municipality even though the seat is in Märsta. Sigtuna is, despite its small population, for historical reasons often still referred to as a "stad". Statistics Sweden, however, only counts localities with more than 10,000 inhabitants as stads (a designation that encompasses both towns and cities). Modern-day Sigtuna developed approximately 4 kilometres east of Old Sigtuna, a harbor town that was established around 980 (and, according to tradition, was previously the home of Odin).

锡格蒂纳(),又译作西格图纳,是瑞典斯德哥尔摩省的一个自治市。在历史上它属于乌普兰。它位于斯德哥尔摩西北约50千米,面积328平方公里,有36,711名居民(2005年)。


Background.

The Japanese occupied Micronesia, including the Caroline Islands, in 1914, and established Truk as a base as early as 1939. The lagoon was first built up to house the IJN's 4th Fleet, its "South Seas Force". After the outbreak of war with the United States, the 4th Fleet was put under the command of the Combined Fleet, which continued to use Truk as a forward operating base into 1944. In addition to anchorages for warships, and port facilities for shipping between the home islands and the Southern Resources Area, five airfields and a seaplane base were constructed at Truk, making it the only major Japanese airfield within flying range of the Marshall Islands.  Despite the impressions of U.S. Navy leaders and the American public concerning Truk's projected fortifications, the base was never significantly reinforced or protected against land attack. In fact, the development of Truk only began in earnest and in hurried fashion in late 1943, when the airfields were extended, shore batteries were erected, and other defensive measures taken against a U.S. invasion.  Because aircraft stationed at Truk could potentially interfere with the upcoming invasion of Eniwetok, and because Truk had recently served as a ferry point for the resupply of aircraft to Rabaul, Admiral Raymond Spruance ordered Vice Admiral Marc A. Mitscher's Fast Carrier Task Force, designated TF 58, to carry out air raids against Truk. Three of TF 58's four carrier task groups (TGs) were committed to the operation. Their total strength consisted of five fleet carriers (the,,, and and four light carriers (the,, and ), carrying a total of 500+ warplanes. Supporting these aircraft carriers was a task force of seven battleships, and numerous heavy cruisers, light cruisers, destroyers, and submarines.  The Japanese, meanwhile, understood the weakness of their position at Truk. The IJN had begun withdrawing fleet units from its anchorages as early as October 1943. The effective abandonment of Truk as a forward operating base accelerated during the first week of February 1944, following Japanese sightings of U.S. Marine Corps PB4Y-1 Liberator reconnaissance planes sent to reconnoiter the area.

Attack.

The three carrier task groups committed to "Hailstone" moved into position and began launching their first fighter sweep 90 minutes before daybreak on 17 February 1944. No Japanese air patrol was active at the time as the IJN's 22nd and 26th Air Flotillas were enjoying shore leave after weeks on high alert following the Liberator sightings. Similarly problematic for the Japanese, radar on Truk was not capable of detecting low-flying planes — a weakness probably known and exploited by Allied intelligence organizations. Because of these factors, U.S. carrier aircraft achieved total surprise.  Japanese pilots scrambled into their cockpits just minutes before TF 58 planes arrived over Eten, Param, Moen and Dublon islands. Though there were more than 300 Imperial Japanese Navy Air Service (IJNAS) and Imperial Japanese Army Air Service (IJAAS) planes present at Truk on the first day of attacks, only about half of them were operational compared with over 500 operational aircraft among the carriers of TF 58. U.S. Navy fighter pilots in their Grumman F6F Hellcats, with the advantages of speed, altitude and surprise, achieved a one–sided victory against IJNAF pilots flying the inferior Mitsubishi A6M Zero. As many as 30 of the 80 Zeros sent up in response to the fighter sweep were shot down, compared with four Hellcats reported lost. Only token aerial resistance was encountered for the rest of the morning; almost no Japanese aircraft were present by the afternoon.  Due to the lack of air cover or warning, many merchant ships were caught at anchor with only the islands' anti-aircraft guns for defense against the U.S. carrier planes. Some vessels outside the lagoon already steaming towards Japan were attacked by U.S. submarines and sunk before they could make their escape. Still others, attempting to flee via the atoll's North Pass, were bottled up by aerial attack and by Admiral Spruance's surface force, Task Group 50.9, which circumnavigated Truk bombarding shore positions and engaging enemy ships.  Torpedo bomber and dive bomber squadrons from the carrier air groups (CAGs) were responsible for the bulk of the damage inflicted on Japanese ground facilities. Early on the first day of "Hailstone", Grumman TBF Avenger torpedo bomber squadrons from "Enterprise"s Air Group 10 (CAG-10) and "Intrepid"s CAG-6 dropped fragmentation and incendiary bombs on runways at Eten Island as well as the seaplane base on Moen Island. Dozens of aircraft were damaged or destroyed, further blunting any possible response by the Japanese to the strikes. Subsequent joint attacks by dive bombers and Avenger torpedo bombers cratered runways and destroyed hangar facilities.  Morning strikes were also launched against shipping targets in the lagoon. Lieutenant Commander (later Rear Admiral) James D. Ramage, commanding officer of Dive Bombing Squadron 10 (VB-10), is credited with sinking the previously damaged merchant tanker "Hoyo Maru". Lieutenant James E. Bridges and his crew in one of "Intrepid"s Torpedo Squadron 6 (VT-6) Avengers scored a direct hit on the ammunition ship. The bomb blast set off a tremendous explosion, which immediately sank the ship and apparently engulfed the plane as well, killing all three men inside.By the second and third anti-shipping strikes of the day, carrier air group action reports listed the apparent enemy mission as "escape". Those ships able to make for open sea steamed for the North Pass exit from the lagoon while weathering repeated aerial attacks. One particular group of warships—cruiser "Katori", auxiliary cruiser "Akagi Maru", destroyers "Maikaze", "Nowaki" and minesweeper "Shonan Maru"—was given special attention by carrier bombers. Multiple air groups attacked these ships, inflicting serious damage. "Yorktown"s dive and torpedo bombing squadrons claimed two hits on "Katori" and hits on another cruiser and multiple destroyers; "Essex" bombers claimed five hits on a as well, stating that the ship was stopped dead in the water after the attack.  At this point reports reached Admiral Spruance concerning the group of warships fleeing through North Pass. The admiral put himself in tactical command of Task Group 50.9, made up of four destroyers, two heavy cruisers and the battleships and, which he personally led in a surface engagement against the previously damaged Japanese ships. Spruance was so adamant on engaging in ship-to-ship combat that his carrier commander, Admiral Mitscher, ordered his air groups to stop attacking "Katori" and her companions.  The battered Japanese ships did not stand much of a chance against Task Group 50.9, though members of his staff saw Spruance's decision to engage in surface action when aircraft likely could have achieved similar results as needlessly reckless. Indeed, the Japanese destroyer "Maikaze" managed to fire torpedoes at the battleship "New Jersey" during the engagement. Fortunately for Spruance, the torpedoes missed, and the "battle" ended with predictably one–sided results. The U.S. Navy surface combatants incurred virtually no damage. The IJN lost "Maikaze", "Shonan Maru", "Katori" and "Akagi Maru". Destroyer "Nowaki" was the only Japanese ship from this group to escape.  Retaliation for the day's strikes arrived late at night in the form of small groups of Japanese bombers probing the task groups' defenses. From roughly 21:00, on 17 February, to just minutes past midnight on 18 February, at least five groups of between one and three enemy planes attempted to sneak past screening ships to strike at the fleet carriers. One such plane, a Nakajima B5N2 "Kate" bomber, managed to evade night fighter planes protecting the U.S. task force and dropped its torpedo on Task Group 58.2. The torpedo struck "Intrepid" on the starboard quarter of the ship, damaging steering control and killing 11 sailors. "Intrepid" was forced to retire to the U.S. for repairs and did not return to combat until August 1944.

Aftermath.

Truk, like so many other Japanese bases, was left to itself without hope of resupply or reinforcement. Army forces which had arrived at the atoll before the U.S. attacks put increasing strain on available foodstuffs and medical supplies. Dwindling ammunition even limited the ability of shore batteries to fend off intermittent attacks by Allied forces, including experimental raids by Boeing B-29 Superfortresses and attacks by Allied carrier aircraft.  Losses at Truk were severe. Some 17,000 tons of stored fuel were destroyed by the strikes. Shipping losses totaled almost 200,000 tons including precious resources in fleet oilers. This represents almost one tenth of total Japanese shipping losses between 1 November 1943 and 30 June 1944. Moreover, the isolation of this whole area of operations by submarine and air attack began the effective severance of Japanese shipping lanes between empire waters and critical fuel supplies to the south. The ultimate effect of such a disconnect was later seen during the Battle of Leyte Gulf, when IJN forces had to sortie separately from Japan and Lingga Roads due to fuel constraints. The neutralization of Truk, and the seizure of Eniwetok, paved the way for the upcoming invasion of Saipan, which for the first time put U.S. land-based heavy bombers within range of the Japanese home islands.  Truk is renowned today as a tourist destination for divers interested in seeing the many shipwrecks left in the lagoon, many of which were caused by the Operation Hailstone strikes.

List of warships in Truk at the time of attack.

List derived from Jeffery's "War Graves, Munition Dumps and Pleasure Grounds" (2007)

Warships sunk.

CL "Katori" (香取) 5,800 tons CL "Naka" (那珂) 5,195 tons  DD "Maikaze" (舞風) 陽炎型 2,000 tons DD "Fumizuki" (文月) 睦月型 1,320 tons DD "Oite" (追風) 神風型 1,270 tons DD "Tachikaze" (太刀風) 峯風型 1,215 tons  Submarine chaser "CH-29", 440 tons Submarine chaser "CH-24", 440 tons  Auxiliary submarine chaser "Shonan Maru" #15 (第15昭南丸), 355 tons  Motor torpedo boat #10, 85 tons

Warships damaged.

Repair ship "Akashi" (明石) 10,500 tons  Seaplane tender "Akitsushima" (秋津洲) 4,650 tons  DD "Matsukaze" (松風) 神風型 1,400 tons DD "Shigure" (時雨) 白露型 1,685 tons  Submarine "I-10" (伊10), 2,919 tons Submarine "RO-42", 1,115 tons  Submarine chaser "CHa-20"  Target ship "Hakachi" (波勝) 1,641 tons

List of merchant ships in Truk at the time of attack.

Merchant ships sunk.

Auxiliary cruiser "Aikoku Maru" (爱国丸) 10,348 tons Auxiliary cruiser "Akagi Maru" (赤城丸) 7,367 tons Auxiliary cruiser "Kiyosumi Maru" (清澄丸) 6,983 tons  Navy transport "Hoki Maru" (伯耆丸) 7,112 tons Navy transport "Yamagiri Maru" (山霧丸) 7,112 tons Navy transport "Fujikawa Maru" (富士川丸) 6,938 tons Navy transport/freighter "San Francisco Maru" (桑港丸) 5,831 tons Navy transport "Reiyo Maru" (麗洋丸) 5,446 tons Navy transport "Seiko Maru" (西江丸)? 5,385 tons Navy transport/passenger/cargo ship "Kensho Maru" (乾祥丸) 4,862 tons Navy transport/freighter "Hanakawa Maru" (花川丸) 4,739 tons Navy transport/passenger/cargo ship "Sankisan Maru" or "Yamakisan Maru" (山鬼山丸) 4,776 tons Navy transport/freighter "Hokuyo Maru" (北洋丸) 4,217 tons Navy transport/freighter "Momokawa Maru" (桃川丸) 3,829 tons Navy water carrier/passenger/cargo ship "Nippo Maru" (日豊丸) 3,764 tons Navy transport/freighter "Unkai Maru #6"(第六雲海丸) 3,220 tons Navy transport "Taiho Maru" (大邦丸) 2,827 tons Navy transport/freighter "Shotan Maru" (松丹丸) 1,999 tons Navy transport/freighter "Gosei Maru" (五星丸) 1,931 tons  Freighter "Taikichi Maru" or "Tachi Maru" (泰吉丸) 1,891 tons  Army transport "Gyoten Maru" (暁天丸) 6,854 tons Army transport/freighter "Nagano Maru" (長野丸) 3,824 tons Army transport "Yubae Maru" (夕映丸) 3,217 tons  Submarine tender "Heian Maru" (平安丸) 11,614 tons Submarine tender "Rio de Janeiro Maru" (リオデジャネイロ丸) 9,626 tons  Fleet oiler "Shinkoku Maru" (神国丸) 10,020 tons Oil tanker "Fujisan Maru" (富士山丸) 9,524 tons  Auxiliary oil tanker/whaler "Tonan Maru #3" (第三図南丸) 19,209 tons Auxiliary oil tanker "Houyou Maru" or "Hoyo Maru" (宝洋丸) 8,691 tons Auxiliary oil tanker/passenger/cargo ship "Amagisan Maru" (天城山丸) 7,620 tons

Merchant ships damaged.

Cargo ship "Sōya" (宗谷) 3,800 tons

Operation Hailstone (, lit. "the airstrike on Truk Island"), 17–18 February 1944, was a massive United States Navy air and surface attack on Truk Lagoon conducted as part of the American offensive drive against the Imperial Japanese Navy (IJN) through the Central Pacific Ocean during World War II.

冰雹行动()是美国海军于1944年2月17日至18日对日本海军位于中太平洋的军事要港特鲁克实施的一次大规模海空联合袭击行动,日方称“特鲁克岛空袭()”。特鲁克曾经是日本联合舰队最为重要的前线基地,也是维系日本本土与南太平洋的航空枢纽,有“太平洋上的直布罗陀”之称。


History.

Bexar County was created on December 20, 1836, and encompassed almost the entire western portion of the Republic of Texas. This included the disputed areas of western New Mexico northward to Wyoming. After statehood, 128 counties were carved out of its area.  The county was named for San Antonio de Béxar, one of the 23 Mexican municipalities (administrative divisions) of Texas at the time of its independence. San Antonio de Béxar—originally "Villa de San Fernando de Béxar"—was the first civil government established by the Spanish in the province of Texas. Specifically, the municipality was created in 1731 when 55 Canary Islanders settled near the system of missions that had been established around the source of the San Antonio River. The new settlement was named after the "Presidio" San Antonio de Béjar, the Spanish military outpost that protected the missions. The presidio, located at the San Pedro Springs, was founded in 1718 and named for Viceroy Balthasar Manuel de Zúñiga y Guzmán Sotomayor y Sarmiento, second son of the Duke of Béjar (a town in Spain). The modern city of San Antonio in the U.S. state of Texas also derived its name from San Antonio de Béjar.

Geography.

According to the U.S. Census Bureau, the county has a total area of, of which is land and (1.3%) is water. Bexar County is in south-central Texas, about 190 miles (305 km) west of Houston and from both the US-Mexican border to the southwest and the Gulf of Mexico to the southeast.  The Balcones Escarpment bisects the county from west to northeast; to the north of the escarpment are the rocky hills, springs and canyons of the Texas Hill Country. South of the escarpment are Blackland Prairie and the South Texas plains. The San Antonio River rises from springs north of Downtown San Antonio, and flows southward and southeastward through the county.

Major highways.

Bexar County has a comprehensive "wagon wheel" freeway system, with radial freeways and beltways that encircle Downtown San Antonio, allowing for simplified countywide freeway access, in a manner much like the freeways around Houston or Dallas. San Antonio is unique, however, in that unlike Houston or Dallas, none of these highways is currently tolled.

Demographics.

As of the 2010 United States Census, there were 1,714,773 people living in the county. Of those, 72.9% were White, 7.5% Black or African American, 2.4% Asian, 0.8% Native American, 0.1% Pacific Islander, 12.7% of some other race and 3.5% of two or more races. 58.7% were Hispanic or Latino (of any race).  As of the census of 2000, 1,392,931 people, 488,942 households, and 345,681 families were residing in the county. The population density was. There were 521,359 housing units at an average density of 418 per square mile (161/km2). The racial makeup of the county was 68.86% White, 7.18% Black or African American, 0.80% Native American, 1.61% Asian, 0.10% Pacific Islander, 17.80% from other races, and 3.64% from two or more races. About 54.35% of the population were Hispanic or Latino of any race.  Of 488,942 households, 36.60% had children under the age of 18 living with them, 50.50% were married couples living together, 15.50% had a female householder with no husband present, and 29.30% were not families. About 24.00% of all households were made up of individuals and 7.40% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.33.  A Williams Institute analysis of 2010 census data found there were about 6.2 same-sex couples per 1,000 households in the county.  In the county, the population was distributed as 28.50% under the age of 18, 10.70% from 18 to 24, 30.60% from 25 to 44, 19.90% from 45 to 64, and 10.40% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 94.70 males. For every 100 females age 18 and over, there were 91.20 males.  The median income for a household was $38,328, and for a family was $43,724. Males had a median income of $30,756 versus $24,920 for females. The per capita income for the county was $18,363. About 12.70% of families and 15.90% of the population were below the poverty line, including 22.40% of those under age 18 and 12.20% of those age 65 or over.

Corrections.

The Bexar County jail facilities are at 200 North Comal in downtown San Antonio, operated by the Bexar County Sheriff's Office (Javier Salazar, Sheriff). In late 2012, press reports noted an increase in the number of suicides at the facility. The issue was a topic of debate in the election for sheriff that year. The jail holds an average of about 3,800 prisoners in 2012, with a total capacity of 4,596, making it the fourth-largest in the state.  The Texas Department of Criminal Justice operates the Dominguez Unit, a state jail for men, in an unincorporated section of Bexar County.

Libraries.

On September 14, 2013, Bexar County opened BiblioTech - Bexar County's Digital Library, the nation's first bookless library.

Property taxes.

In 2016, for the third consecutive year, Bexar County increased the appraised value of businesses and residences. Most will hence find their property taxes will increase for the year, with higher payments for some beginning as early as November 1. The latest 7.5 percent increase in valuation follows an 11 percent rise in 2015, and a 7 percent jump in 2014. The 2016 total value for all property in the county is approximately $163 billion, or $13 billion more than in 2015. County residents express dismay to Mary Kieke, the deputy chief appraiser. "People are very upset. The tax system is absolutely broken," she said.

Politics.

Bexar County has generally voted for Democratic candidates in most presidential elections, though from 1932 to 2012 it was a nationwide bellwether, supporting the winner in every election except 1968. Democrats perform well within the Connally Loop, which contains heavily Hispanic neighborhoods on the south and west sides of San Antonio, and African Americans on the east side. In recent years, Democrats have made inroads on the Northwest Side toward the University of Texas at San Antonio, and the Northeast Side toward Kirby. Republicans' strength is concentrated around the military bases plus wealthier enclaves such as Alamo Heights, Terrell Hills, and the far northern section of the county.

Bexar County (, ) is a county in the U.S. state of Texas. As of the 2010 census, the population was 1,714,773, and a 2019 estimate put the population at 2,003,554. It is the 16th-most populous county in the nation and the fourth-most populated in Texas. Its county seat is San Antonio, the second-most populous city in Texas and the seventh-largest city in the United States.

比尔县(英语:Bexar County,)是位美国德克萨斯州中南部一个县。面积3,255平方公里。根据美国2000年人口普查,共有人口 1,392,931人。县治圣安东尼奥。


Compared to dihedral group.

The quaternion group Q has the same order as the dihedral group, but a different structure, as shown by their Cayley and cycle graphs:  The dihedral group D can be realized as a subset of the split-quaternions in the same way that Q can be viewed as a subset of the quaternions.

Cayley table.

The Cayley table (multiplication table) for Q is given by:

Properties.

The quaternion group has the unusual property of being Hamiltonian: every subgroup of Q is a normal subgroup, but the group is non-abelian. Every Hamiltonian group contains a copy of Q.  The quaternion group Q is one of the two smallest examples of a nilpotent non-abelian group, the other being the dihedral group D of order 8.  The quaternion group Q has five irreducible representations, and their dimensions are 1,1,1,1,2. The proof for this property is not difficult, since the number of irreducible characters of Q is equal to the number of its conjugacy classes, which is five ( { e }, { }, { i, }, { j, }, { k, } ).  These five representations are as follows:  Trivial representation  Sign representations with i,j,k-kernel: Q has three maximal normal subgroups: the cyclic subgroups generated by i, j, and k respectively. For each maximal normal subgroup, we obtain a one-dimensional representation with that subgroup as kernel. The representation sends elements inside the subgroup to 1, and elements outside the subgroup to -1.  2-dimensional representation: A representation :formula_2 is given below in the Matrix representations section.  So the character table of the quaternion group Q, which turns out to be the same as the character table of the dihedral group D, is: In abstract algebra, one can construct a real four-dimensional vector space as the quotient of the group ring R[Q] by the ideal defined by. The result is a skew field called the quaternions. Note that this is not quite the same as the group algebra on Q (which would be eight-dimensional). Conversely, one can start with the quaternions and "define" the quaternion group as the multiplicative subgroup consisting of the eight elements The complex four-dimensional vector space on the same basis is called the algebra of biquaternions.  Note that i, j, and k all have order four in Q and any two of them generate the entire group. Another presentation of Q demonstrating this is:  One may take, for instance, i = x, j = y and k = xy.  The center and the commutator subgroup of Q is the subgroup The factor group Q/{e,} is isomorphic to the Klein four-group V. The inner automorphism group of Q is isomorphic to Q modulo its center, and is therefore also isomorphic to the Klein four-group. The full automorphism group of Q is isomorphic to the symmetric group of degree 4, S, the symmetric group on four letters. The outer automorphism group of Q is then S/V which is isomorphic to S.

Matrix representations.

The quaternion group can be represented as a subgroup of the general linear group GL(C). A representation  is given by  Since all of the above matrices have unit determinant, this is a representation of Q in the special linear group SL(C). The standard identities for quaternion multiplication can be verified using the usual laws of matrix multiplication in GL(C). There is also an important action of Q on the eight nonzero elements of the 2-dimensional vector space over the finite field F. A representation  is given by  where are the three elements of F. Since all of the above matrices have unit determinant over F, this is a representation of Q in the special linear group. Indeed, the group SL(2, 3) has order 24, and Q is a normal subgroup of of index 3.

Galois group.

As Richard Dean showed in 1981, the quaternion group can be presented as the Galois group Gal("T"/Q) where Q is the field of rational numbers and "T" is the splitting field, over Q, of the polynomial The development uses the fundamental theorem of Galois theory in specifying four intermediate fields between Q and "T" and their Galois groups, as well as two theorems on cyclic extension of degree four over a field.

Generalized quaternion group.

A generalized quaternion group is sometimes defined to be a dicyclic group of order a power of 2, which admits the presentation and sometimes defined simply the same as a dicyclic group, with presentation for some integer. This group is denoted Q and has order 4"n". Coxeter labels these "dicyclic groups", being a special case of the binary polyhedral group and related to the polyhedral groups ("p","q","r"), and dihedral group (2,2,"n"). The usual quaternion group corresponds to the case. The generalized quaternion group can be realized as the subgroup of GL(C) generated by  where ω = "e". It can also be realized as the subgroup of unit quaternions generated by and.  The generalized quaternion groups have the property that every abelian subgroup is cyclic. It can be shown that a finite "p"-group with this property (every abelian subgroup is cyclic) is either cyclic or a generalized quaternion group as defined above. Another characterization is that a finite "p"-group in which there is a unique subgroup of order "p" is either cyclic or a 2-group isomorphic to generalized quaternion group. In particular, for a finite field "F" with odd characteristic, the 2-Sylow subgroup of SL("F") is non-abelian and has only one subgroup of order 2, so this 2-Sylow subgroup must be a generalized quaternion group,. Letting "p" be the size of "F", where "p" is prime, the size of the 2-Sylow subgroup of SL("F") is 2, where.  The Brauer–Suzuki theorem shows that groups whose Sylow 2-subgroups are generalized quaternion cannot be simple.

In group theory, the quaternion group Q (sometimes just denoted by Q) is a non-abelian group of order eight, isomorphic to a certain eight-element subset of the quaternions under multiplication. It is given by the group presentation

在群论里,四元群是指一个8目的不可换群。它常被标示为"Q",且被写成乘法的形式,以下列的8个元素 这里,1是单位元素,(−1) = 1且对每个"Q"内的"a",(−1)"a" = "a"(−1) = −"a"。剩下的乘法律能由下列的关系获得: "Q"的凯莱表如下: 需注意的是,此一群为非可换的;如"ij"=−"ji"。"Q"有着汉弥尔顿群较不常见的性质:每一个"Q"的子群都是其正规子群,但这个群不是可换的。每一个汉弥尔顿群都会含有一个或多个"Q"。