Oophorectomy is the surgical removal of the ovaries of a female animal. In the case of non-human animals, this is also called spaying. It is a form of sterilization.

The removal of the ovaries together with the Fallopian tubes is called salpingo-oophorectomy. Oophorectomy and salpingo-oophorectomy are not common forms of birth control in humans; more usual is tubal ligation, in which the Fallopian tubes are blocked but the ovaries remain intact.

In humans, oophorectomy is most usually performed together with a hysterectomy - the removal of the uterus. Its use in a hysterectomy when there are no other health problems is somewhat controversial.

In animals, spaying involves an invasive removal of the ovaries, but rarely has major complications; the superstition that it causes weight gain is not based on fact. Spaying is especially important for certain animals that require the ovum to be released at a certain interval (called estrus or "heat"), such as cats and dogs. If the cell is not released during these animal's heat, it can cause severe medical problems that can be averted by spaying or partnering the animal with a male.

Oophorectomy is sometimes referred to as castration, but that term is most often used to mean the removal of a male animal's testicles.

See also

• tubal ligation & birth control
• circumcision
• genital mutilation & female circumcision

The Thompson submachine gun, also known as the Tommy gun, was an American submachine gun that became infamous during the prohibition era. It was a common sight in gangster films of the time; real-life gangsters referred to the tommy gun as the "Chicago type writer" and enjoyed its compact size and high volume of automatic fire, automatic weapons being legal for civilian possession at the time.

Contents

1 Design 2 Service 3 Variants 3.1 M1921 3.2 M1928 3.3 M1928A1 3.4 M1 3.5 M1A1 4 External links

Design

Designed during World War I by General John T. Thompson, the Tommy gun was available in the caliber .45 ACP (Automatic Colt Pistol) cartridge, and was used by the U.S. Army and British Commandos through World War II. The means of operation is direct blow-back, although early models made use of the Blish lock, turning the mechanism into a delayed blow-back system. After WWII it saw limited service in Korea, and was carried unofficially by a smattering of soldiers in Vietnam.

The Thompson went through numerous changes while in military service during WWII, almost all directed at reducing its high cost and lengthy manufacturing time. It was eventually replaced mid-war with the M3 "Grease Gun".

Service

In the United States, it was used by law enforcement, most prominently the FBI, until 1976 when it was declared obsolete. All Thompsons in government possession were destroyed, except for a few token museum pieces and training models. Owing to its gangster and WWII connections, Thompsons are highly sought after collector's items. An original 1928 gun in working condition can easily fetch $15,000. Semi-auto replicas are currently produced by the Auto-Ordnance Company, which is operated as a division of Kahr firearms.

Approx. 1,700,000 of these weapons were produced, 1,387,134 of them being part of the M1 series.

Variants

M1921

The original design, it is fashioned more like a sporting weapon. It was quite expensive with high quality wood and finely made parts.

M1928

The M1928 only differed slightly from the M1921, having a lower rate of fire due to its use of heavy actuaters and less powerful recoil springs.

M1928A1

The model available during the early years of WWII, the M1928A1 was faster and cheaper to manufacture than the M1928. The most visible difference between the two models is the removal of the vertical grip in favour of the horizontal one. Though the weapon could use both the 50 round drum as well as the 20 or 30 round magazines, it was found that the drums were more prone to jamming.

M1

A result of further simplification to cut costs, the most notable difference between the M1 and the M1928A1 is the inability of the M1 to utilize the ammunition drum. The 30 round magazine was made at this time to compensate. It also has a permanently attached buttstock and was first issued in 1943.

Caliber: .45 ACP
Mass, empty: 4.78 kg
Barrel Length: 267 mm
Rate of Fire: 700 RPM
Capacity: 20/30 rounds box magazine

M1A1

A very slight difference from the M1, the M1A1 had the firing pin machined into the face of the bolt.

External links

• Official Tommygun Home Page http://www.auto-ordnance.com/
• The Unofficial Tommy Gun Page http://www.nfatoys.com/tsmg/default.htm
• Nase noviny http://www.geocities.com/nasenoviny/ThompsonEN.html
• Second Amendment Foundation http://www.saf.org/LawReviews/PSharpe1.html