SUMMARY / RELATED TOPICS

Immune system

The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, distinguish them from the organism's own healthy tissue. In many species, there are two major subsystems of the immune system: the innate immune system and the adaptive immune system. Both subsystems use humoral immunity and cell-mediated immunity to perform their functions. In humans, the blood–brain barrier, blood–cerebrospinal fluid barrier, similar fluid–brain barriers separate the peripheral immune system from the neuroimmune system, which protects the brain. Pathogens can evolve and adapt, thereby avoid detection and neutralization by the immune system. Simple unicellular organisms such as bacteria possess a rudimentary immune system in the form of enzymes that protect against bacteriophage infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and invertebrates.

These mechanisms include phagocytosis, antimicrobial peptides called defensins, the complement system. Jawed vertebrates, including humans, have more sophisticated defense mechanisms, including the ability to adapt over time to recognize specific pathogens more efficiently. Adaptive immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen; this process of acquired immunity is the basis of vaccination. Disorders of the immune system can result in autoimmune diseases, inflammatory diseases and cancer. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. In humans, immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency, acquired conditions such as HIV/AIDS, or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms.

Common autoimmune diseases include Hashimoto's thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, systemic lupus erythematosus. Immunology covers the study of all aspects of the immune system; the immune system protects organisms from infection with layered defenses of increasing specificity. In simple terms, physical barriers prevent pathogens such as bacteria and viruses from entering the organism. If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. Innate immune systems are found in all plants and animals. If pathogens evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, activated by the innate response. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen; this improved response is retained after the pathogen has been eliminated, in the form of an immunological memory, allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered.

Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules. In immunology, self molecules are those components of an organism's body that can be distinguished from foreign substances by the immune system. Conversely, non-self molecules are those recognized as foreign molecules. One class of non-self molecules are called antigens and are defined as substances that bind to specific immune receptors and elicit an immune response. Newborn infants have no prior exposure to microbes and are vulnerable to infection. Several layers of passive protection are provided by the mother. During pregnancy, a particular type of antibody, called IgG, is transported from mother to baby directly through the placenta, so human babies have high levels of antibodies at birth, with the same range of antigen specificities as their mother. Breast milk or colostrum contains antibodies that are transferred to the gut of the infant and protect against bacterial infections until the newborn can synthesize its own antibodies.

This is passive immunity because the fetus does not make any memory cells or antibodies—it only borrows them. This passive immunity is short-term, lasting from a few days up to several months. In medicine, protective passive immunity can be transferred artificially from one individual to another via antibody-rich serum. Microorganisms or toxins that enter an organism encounter the cells and mechanisms of the innate immune system; the innate response is triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms, or when damaged, injured or stressed cells send out alarm signals, many of which are recognized by the same receptors as those that recognize pathogens. Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way; this system does not confer long-lasting immunity against a pathogen. The innate immune system is the dominant system of host defense in most organisms.

Cells in the innate immune system use pattern recognition receptors to recognize molecular structures that are produced by microbial pathogens. PRRs are germline-encoded host sensors, which detect molecules typical for the pathogens, they are proteins expressed by cells of the innate immune system, such as dendrit

1999–2000 Charlotte Hornets season

The 1999–2000 NBA season was the 12th season for the Charlotte Hornets in the National Basketball Association. Despite finishing the previous season with a 26–24 record, the Hornets had the third pick in the 1999 NBA draft, selected UCLA point guard Baron Davis; the Hornets were competitive through the first half of the season finishing with a respectable 27–20 record heading into the All-Star break. However, tragedy struck on January 12, 2000 when guard Bobby Phills was killed in an automobile accident while racing with teammate David Wesley, who had a suspended license at the time. Despite the loss of Phills, a 7-game losing streak in January, the Hornets finished the first half of the season strong as Eddie Jones was selected for the 2000 NBA All-Star Game. At midseason, the team acquired Dale Ellis from the Milwaukee Bucks; the Hornets won their final seven games finishing second in the Central Division with a 49–33 record, qualified for their fifth playoff appearance. They faced the 5th-seeded Philadelphia 76ers in the first round, but were eliminated three games to one.

The Hornets finished eleventh in the NBA in attendance for the season. Following the season, Anthony Mason and second-year guard Ricky Davis were all traded to the Miami Heat, second-year center Brad Miller signed as a free agent with the Chicago Bulls. Ellis, involved in a trade with the Heat was released, retired Guard Bobby Phills died in a car accident on January 12. Charlotte Hornets vs. Philadelphia 76ers Last Playoff Meeting: Not available Eddie Jones, All-NBA Third Team Eddie Jones, NBA All-Defensive Second Team August 17, 1999Signed Eddie Robinson as a free agent. August 18, 1999Signed Todd Fuller as a free agent. October 4, 1999Signed Derek Hood as a free agent. Signed Jason Miskiri as a free agent. November 8, 1999Waived Jason Miskiri. November 9, 1999Signed Michael Hawkins as a free agent. November 23, 1999Waived Derek Hood. January 18, 2000Traded a 2000 2nd round draft pick and a 2002 2nd round draft pick to the Milwaukee Bucks for Dale Ellis. February 8, 2000Signed Chucky Brown as a free agent

List of ambassadors of the United States to Burkina Faso

This is a list of ambassadors of the United States to Burkina Faso. Until 1960 Upper Volta was a French possession as a part of French West Africa. In 1958 Upper Volta became an autonomous republic in the French Community, achieved independence as the Republic of Upper Volta on August 5, 1960; the United States recognized Upper Volta and assigned its first envoy on the nation's independence day, August 5. The envoy, Donald R. Norland, had presented his credentials as Chargé d'Affaires ad interim on the previous day, August 4, to take effect on the day of independence. Norland was the Chargé d'Affaires a.i. to the newly independent nations: Ivory Coast and Niger while resident in Abidjan. The first ranking ambassador, R. Borden Reams, was appointed October 17, 1960, he was the ambassador to the aforementioned countries while resident in Abidjan. On December 31, 1960, an embassy was established in Ouagadougou with a resident Chargé d'affaires. On May 29, 1961, the first ambassador accredited to Upper Volta was appointed.

On August 4, 1984, the nation's name was changed to Burkina Faso. The United States Embassy in Burkina Faso is located in Ouagadougou. R. Borden Reams– Career FSO Title: Ambassador Extraordinary and Plenipotentiary Appointed: October 17, 1960 Presented credentials: December 6, 1960 Terminated mission: superseded by new resident ambassador June 26, 1961 Thomas S. Estes – Career FSO Title: Ambassador Extraordinary and Plenipotentiary Appointed: May 29, 1961 Presented credentials: June 26, 1961 Terminated mission: left post July 13, 1966 Elliott P. Skinner – political appointee Title: Ambassador Extraordinary and Plenipotentiary Appointed: May 27, 1966 Presented credentials: September 14, 1966 Terminated mission: left post July 16, 1969 William E. Schaufele, Jr. – Career FSO Title: Ambassador Extraordinary and Plenipotentiary Appointed: September 29, 1969 Presented credentials: October 16, 1969 Terminated mission: Left post July 10, 1971 Donald B. Easum – Career FSO Title: Ambassador Extraordinary and Plenipotentiary Appointed: November 5, 1971 Presented credentials: December 8, 1971 Terminated mission: Left post January 19, 1974 Pierre R. Graham – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: June 20, 1974 Presented credentials: July 30, 1974 Terminated mission: left post June 13, 1978 Thomas D. Boyatt – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: July 18, 1978 Presented credentials: September 21, 1978 Terminated mission: left post October 23, 1980 Note: Larry C.

Grahl served as chargé d'affaires ad interim, October 1980–November 1981. Julius Waring Walker, Jr. – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: July 18, 1981 Presented credentials: November 18, 1981 Terminated mission: Left post July 5, 1984 Leonardo Neher – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: June 28, 1984 Presented credentials: September 21, 1984 Terminated mission: left post August 1, 1987 David H. Shinn – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: November 6, 1987 Presented credentials: November 28, 1987 Terminated mission: left post August 6, 1990 Edward P. Brynn – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: October 22, 1990 Presented credentials: January 14, 1991 Terminated mission: left post April 17, 1993 Donald J. McConnell – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: August 9, 1993 Presented credentials: November 22, 1993 Terminated mission: left post June 4, 1996 Sharon P. Wilkinson – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: July 11, 1996 Presented credentials: October 24, 1996 Terminated mission: left post July 12, 1999 Jimmy J. Kolker – Career FSO Title: Ambassador Extraordinary and Plenipotentiary Appointed: November 16, 1999 Presented credentials: January 11, 2000 Terminated mission: left post August 2, 2002 J. Anthony Holmes – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: October 3, 2002 Presented credentials: December 23, 2002 Terminated mission: left post July 9, 2005 Jeanine E. Jackson – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: February 21, 2006 Presented credentials: March 24, 2006 Terminated mission: unknown Gayleatha B. Brown – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: August 4, 2009 Presented credentials: unknown Terminated mission: unknown Thomas Dougherty – career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: May 27, 2010 Presented credentials: August 5, 2010 Terminated mission: September 30, 2013 Tulinabo S. Mushingi - career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: July 9, 2013 Presented credentials: August 5, 2013 Terminated mission: November 7, 2016 Andrew Robert Young - career foreign service officer Title: Ambassador Extraordinary and Plenipotentiary Appointed: September 28, 2016 Presented credentials: unknown Terminated mission: Incumbent Ambassadors to Burkina Faso Burkina Faso – United States relations Foreign relations of Burkina Faso Ambassadors of the United States United States Department of State: Background notes on Burkina Faso This article incorporates public domain material from the United States Department of State website https://www.state.gov/countries-areas/.

United States Department of State: Chiefs of Mission for Burkina Faso United States Department of State: Burkin