David Cohen (physicist)

David Cohen made many of the first pioneering measurements in the area of biomagnetism (magnetic fields produced by the body), although he was initially trained as a nuclear physicist.

Early life and education

Cohen was born of immigrant parents in Winnipeg, Canada. He was raised there and earned a B.A. degree at the University of Manitoba. Then, he attended graduate school at the University of California, Berkeley, where he gained a Ph.D. in experimental nuclear physics.

Career

Working in this area, and using large magnets, he became interested in the other extreme; this was the measurement of very weak magnetic fields, which for example might be produced by the weak natural currents in the human body. In 1963, he proposed a method using a magnetically shielded room to keep out external magnetic disturbances, as in radiation shielding in nuclear experiments. At that time others reported the first biomagnetic measurement, where the MCG (magnetocardiogram, the magnetic field due to heart currents) was measured; this was done without shielding, hence showed much external interference. Cohen then built a modest shielded room, and with somewhat clearer signals verified the heart’s magnetic field. He also made the first measurement of the MEG (magnetoencephalogram, the magnetic field of the brain.) However, all these early biomagnetic measurements were generally too noisy, both because of the use of insensitive detectors, and incomplete magnetic shielding.

David Cohen (entrepreneur)

David Cohen is a serial entrepreneur and the founder of Pinpoint Technologies, iContact.com, and Earfeeder. He is also an angel investor with a portfolio of more than 100 companies. Cohen is best known as the founder of Techstars, a mentorship-based startup accelerator.

Cohen delivered the keynote speech at RailsConf2012, a conference dedicated to Ruby on Rails, an open source web application framework for the Ruby programming language.

He and Brad Feld co-authored Do More Faster: Techstars Lessons to Accelerate Your Startup.

Early life and education

Cohen was born in 1968 in DeLand, FL.

Early career

He began working as a software engineer in 1991 when he became the Director of Development for Automated Dispatch Services, Inc., where he worked until 1994.

Cohen founded Pinpoint Technologies in 1993. He served as its CTO and vice president of research and development. The company developed public safety and EMS dispatch vehicle software. Zoll Medical Corporation acquired Pinpoint Technologies in 1999. Cohen stayed on with the company until 2004.

David of Bulgaria

David (Bulgarian: Давид) (died 976) was a Bulgarian noble, brother of Emperor Samuel and eldest son of komes Nicholas. After the disastrous invasion of Rus' armies and the fall of North-eastern Bulgaria under Byzantine occupation in 971, he and his three younger brothers took the lead of the defence of the country. They executed their power together and each of them governed and defended a separate region. He ruled the southern-most parts of the realm from Prespa and Kastoria and was responsible for the defence the dangerous borders with Thessalonica and Thessaly. In 976 he participated in the major assault against the Byzantine Empire but was killed by vagrant Vlachs between Prespa and Kostur.

Family tree

Another theory

However, there's also another version about David’s origin. David gains the title "comes" during his service in the Byzantine army which recruited many Armenians from the Eastern region of the empire. The 11th-century historian Stepanos Asoghik wrote that Samuel had one brother, and they were Armenians from the district Derjan. This version is supported by the historians Nicholas Adontz, Jordan Ivanov, and Samuil's Inscription where it’s said that Samuel’s brother is David. Also, the historians Yahya and Al Makin clearly distinguish the race of Samuel and David (the Comitopouli) from the one of Moses and Aaron (the royal race):

David, Chiriquí

David (Spanish pronunciation: [daˈβið]) officially San José de David is a city and corregimiento located in the west of Panama. It is the capital of the province of Chiriquí and has an estimated population of 144,858 inhabitants as confirmed in 2013. It is a relatively affluent city with a firmly established, dominant middle class and a very low unemployment and poverty index. The Pan-American Highway is a popular route to David.

The development of the banking sector, public construction works such as the expansion of the airport and the David-Boquete highway alongside the growth of commercial activity in the city have increased its prominence as one of the fastest growing regions in the country. The city is currently the economic center of the Chiriqui province and produces more than half the gross domestic product of the province, which totals 2.1 billion. It is known for being the third-largest city in the country both in population and by GDP and for being the largest city in Western Panama.

David (Bernini)

David is a life-size marble sculpture by Gian Lorenzo Bernini. The sculpture was one of many commissions to decorate the villa of Bernini's patron Cardinal Scipione Borghese – where it still resides today, as part of the Galleria Borghese It was completed in the course of seven months from 1623 to 1624.

The subject of the work is the biblical David, about to throw the stone that will bring down Goliath, which will allow David to behead him. Compared to earlier works on the same theme (notably the David of Michelangelo), the sculpture broke new ground in its implied movement and its psychological intensity.

Background

Between 1618 and 1625 Bernini was commissioned to undertake various sculptural work for the villa of one of his patrons, Cardinal Scipione Borghese. In 1623 – only yet 24 years old – he was working on the sculpture of Apollo and Daphne, when, for unknown reasons, he abandoned this project to start work on the David. According to records of payment, Bernini had started on the sculpture by mid–1623, and his contemporary biographer, Filippo Baldinucci, states that he finished it in seven months.