Question: What did Mariana Kovacevic use to treat the injury of Asamoah Gyan, a Ghanaian professional footballer for a suprising fast recovery time?

full_context: Document 1: Gordana Vunjak-Novakovic: Gordana Vunjak-Novakovic is a Serbian American biomedical engineer. She is University Professor and The Mikati Foundation Professor of Biomedical Engineering and Medical Sciences at Columbia University, where she directs the Laboratory for Stem Cells and Tissue Engineering. She is also a faculty in the Irving Comprehensive Cancer Center and in the Center for Human Development at Columbia University, an honorary professor at the Faculty of Technology and Metallurgy at the University of Belgrade, honorary professor at the University of Novi Sad, and an adjunct professor at the Department of Biomedical Engineering at Tufts University.
Document 2: Asamoah Gyan: Asamoah Gyan ( , , born 22 November 1985 in Accra) is a Ghanaian professional footballer who plays as a striker for Kayserispor and captains the Ghanaian national team.
Document 3: Joetex Asamoah Frimpong: Kwabena Joseph "Joetex" Asamoah Frimpong (born 17 April 1982 in Mampong ) is a retired Ghanaian professional football striker
Document 4: Derek Asamoah: Derek Asamoah (born 1 May 1981) is a Ghanaian professional footballer. He has previously played for clubs in England, France, Scotland, Bulgaria and South Korea.
Document 5: Michael Essien: Michael Kojo Essien (born 3 December 1982) is a Ghanaian footballer who currently plays for Indonesian club Persib Bandung. He has also played for the Ghana national team more than 50 times. He is a physically strong midfielder who has often been touted as a box-to-box midfielder for his ability to exert energy in supporting offensive and defensive play and for his powerful and tough tackling playing style which has earned him the nickname "The Bison". Essien can also play as a defender, both on the right of defence and in the centre.
Document 6: Martin Clawson: Martin Clawson is the Head Strength and Conditioning Coach at the club. He is himself a former player with Bradford Northern and comes from a famous Rugby League family. He has a background in sports fitness and was formerly a masseur at the club before assuming his present role. He is a former body building competitor and his personality makes him the ideal person for his job at the Bulls. Martin was employed as a business consultant for corporate communications giants Wish Communications with Garry Schofield OBE and John Stankevitch but has since taken up the role of Strength and Conditioning Coach at Wakefield Trinity Wildcats in the Super League.
Document 7: Emmanuel Adebayor: Sheyi Emmanuel Adebayor (] ; born 26 February 1984) is a Togolese professional footballer who plays as a striker for Turkish club İstanbul Başakşehir. He previously played for English clubs Arsenal, Manchester City, Tottenham Hotspur and Crystal Palace, as well as French sides Metz and Monaco and Spanish team Real Madrid. He was voted African Footballer of the Year for 2008 while playing at Arsenal.
Document 8: Ali Ashfaq: Ali Ashfaq (born 6 September 1985), nicknamed ""Dhagandey"," is a Maldivian professional footballer who plays for Maldivian club New Radiant and the Maldives national team. He is a forward and serves as captain for Maldives. He is widely regarded as one of the best players in south Asia region along with Sunil Chhetri and Bhaichung Bhutia. He is noted for his strength, amazing dribbling skills and the capability of beating any sort of defenders, according to many coaches. He is a free-kick specialist and a clinical finisher. His trademark style of scoring is beating couple of defenders and rounding off the keeper to score. He is considered as the best Maldivian footballer ever most notably when he was named as the "World's 2nd Best Top Goal Scorer" in 2013 by IFFHS. He was also named as South Asia's Best Player in 2014 by eultimategoal.com. In March 2016, Ashfaq completed his 50th goal mark for Maldives national team.
Document 9: Footbonaut: The Footbonaut is a football training machine which fires balls at different speeds and trajectories at players, who must control and pass the ball into a highlighted square. Footbonaut was invented by Christian Güttler in Berlin, Germany. The machine is also described as a robotic cage. Mario Götze's winning goal of the 2014 FIFA World Cup Final has been credited to his years of practice using Footbonaut. The Footbonaut is also credited for the success of Borussia Dortmund, who first used the machine. There are several undisclosed clubs in Germany currently using Footbonaut in their trainings.
Document 10: Kwadwo Asamoah: Kwadwo "Kojo" Asamoah , ; born 9 December 1988 in Accra) is a Ghanaian professional footballer, who plays as a left midfielder, left wing-back or as an offensive central midfielder for Italian club Juventus and the Ghana national football team.
Document 11: Addis Ababa Fistula Hospital: Addis Ababa Fistula Hospital (also known as "Hamlin Fistula Hospital") and its regional Hamlin Fistula Centres provide comprehensive care for women who suffer from incontinence, physical impairment, shame and marginalisation as a result of an obstetric fistula. The hospital was created by the Australian obstetrician and gynaecologists Catherine Hamlin and her husband Reginald Hamlin to care for women with childbirth injuries and has been in operation since 1974. It is in Addis Ababa, the capital of Ethiopia. It is the only hospital of its kind in the world dedicated exclusively to women with obstetric fistula (a condition common in the developing world where the maternal health provisions are poor), and it treats all patients free of charge. Patients undergo surgical repair by Ethiopian and expatriate surgeons trained at the hospital's main facility in Addis Ababa. Around 93% of these patients are repaired successfully.
Document 12: Mariana Kovacevic: Mariana Kovacevic is a Serbian traditional healer who has specialized in the use of horse placenta treatment to heal athletes. During the duration of the 2012 African Cup of Nations in Gabon and Equatorial Guinea she used the horse placenta treatment to heal Ghana's Asamoah Gyan, who had been injured and was supposed to be off football for four weeks. She is reported to have nursed him back to health in four hours. She was also reportedly enlisted by the Serbia during the world of 2010 in south Africa. Other footballers who are reported to have been treated by Mariana include Pablo Zabaleta, Vincent Kompany, Nigel de Jong and Robin Van Persie of Manchester United. There has been some doubt as to whether Mariana's therapies work. But more footballers are turning to her for help.
Document 13: Sister Lauras Food Supplement: In the early 1900s Sister Laura Marian Smith, a nurse at the Glasgow Royal Maternity Hospital, noted the high levels of malnutrition in children at the time, and is credited with promoting the use of a Casein inhibitor to make cows milk more beneficial to those who had extreme difficulty in digesting it. By creating a powder formulae to mix with milk, it enabled it to become an effective aid to patient recovery. Although named after Sister Laura - this was a marketing strategy as the powder is said to have been developed by Dr Leonard Findlay, at the time a noted expert of infant dietary disorders at Rottenrow. Although Sister Laura was one of the original shareholders when the company when it was established in 1911, by 1920 she had sold her interests in the company, though it continued to expand, opening a purpose-built factory at Emerson Road West, Bishopbriggs.
Document 14: Miljan Radović: Miljan Radović (Cyrillic: Миљан Радовић) was a Montenegrin footballer who last played for Pelita Bandung Raya in the Indonesia Super League. He is famous because of his accurate set pieces that often led to beautiful goals. He is also nicknamed 'The Professor' because of his well- timed and smart passes and also his entertaining skills.
Document 15: Vincenzo Tota: Dr. Vincenzo Tota (born in Florence, Italy) is a medical doctor specializing in sports medicine. He received his degree in Medicine and Surgery in 1982 from University of Siena, in Siena, Italy. For most of the past two decades, Dr. Tota has managed the medical care of numerous race car teams, including fitness training and nutrition for race drivers, in Formula One, off-road and sports car racing. A former off-road and offshore powerboat racer himself, Dr. Tota understands the physical toll of sports competition.
ground_truth: horse placenta