(1608 – 1647)

He was an Italian physicist and mathematician, best known for his invention of the barometer. Evangelista Torricelli was born in Faenza, then part of the Papal States. He was left fatherles at an early age and educated under the care of his uncle, a Camaldolese monk, who first entered young Torricelli into a Jesuit College in 1624 to study mathematics and philosophy until 1626, when he sent Torricelli to Rome in 1627 to study science under the Benedictine Benedetto Castelli, professor of mathematics at the Collegio della Sapienza. 

Aside from several letters, little is known of Torricelli’s activities in the years between 1632 and 1641, when Castelli sent Torricelli’s monograph of the path of projectiles to Galileo, then a prisoner in his villa at Arcetri. Although Galileo promptly invited Torricelli to visit, he did not accept until just three months before Galileo’s death. During his stay, however, he wrote out Galileo’s Discourse of the Fifth day. After Galileo’s death on January 8, 1642, Grand Duke Ferdinando II de’ Medici asked him to succeed Galileo as the grand-ducal mathematician and professor of mathematics in the University of Pisa. In this role he solved some of the great mathematical problems of the day, such as finding a cycloid’s area and center of gravity. He also designed and built a number of telescopes and simple microscopes; several large lenses, engraved with his name, are still preserved at Florence. In 1644, he famously wrote in a letter: “We live submerged at the bottom of an ocean of air.”

Torricelli died in Florence a few days after having contracted typhoid fever, and was buried in San Lorenzo. The asteroid 7437 Torricelli was named in his honor.

Torricelli’s chief invention was the mercurial barometer, which arose from solving an important practical problem. Pumpmakers of the Grand Duke of Tuscany attempted to raise water to a height of 12 meters or more, but found that 10 meters was the limit to which it would rise in the suction pump. Torricelli thought to employ mercury, fourteen times as heavy as water. In 1643 he created a tube c. 1 meter long, sealed at the top end, filled it with mercury, and set it vertically into a basin of mercury. The column of mercury fell to about 76cm, leaving a Torricellian vacuum above. As we now know, the column’s height fluctuated with changing atmospheric pressure; this was the first barometer. This discovery has perpetuated his fame, and the Torr, a unit of pressure commonly used in vacuum measurements, was named in his honor. 

Torricelli also discovered Torricelli’s Law, regarding the speed of a fluid flowing out of an opening, which was later shown to be a particular case of Bernoulli’s principle. 

Torricelli gave the first scientific description of the cause of wind: … winds are produced by differences of air temperature, and hence density, between two regions of the earth.

human pathogen worldwide

Campylobacter jejuni and C. coli are considered for the majority of human food-borne infections (www.hpa.org.uk ). Human food poisoning is acquired through the consumption of contaminated food. Poultry is a major food source of infection and infection can arises by consumption of under-cooked poultry meat or cross-contamination of other food products (www.food.gov.uk).

Other sources of infection include contaminated raw milk and water.

The general symptoms of the disease are a fever and general feeling of unwell-ness which is accompanied or followed by abdominal cramps, watery, diarrhoea.

The disease is generally self-limiting after 2-7 days. Antibiotic treatment may be required in elderly or immune-compromised patients.

investigations

for “environmental

excursions”

Environmental excursion investigations are complex and multidisciplinary and require the investigator to elicit information from multiple departments to aid in determining the true root cause.

Excursions investigations are aided by a robust environmental trending program that should evaluate data for individual sites, rooms, suites and the normal microbial flora of the facility.

Proper investigation encompasses manufacturing areas, classified areas and microbial testing laboratories.

Failure to properly investigate environmental excursion to true root cause will not allow for appropriate and effective corrective actions.

This leads to lack of environmental control of you manufacturing or laboratory operations.

Ultimately,this may lead to product failures and possible regulatory actions or worse patient interactions.

working with “sonicator”

Sonicators are high-frequency sound generators used to disrupt cells or shear nucleic acids. Laboratory personnel must be concerned about two of the major hazards associated with sonicators. The first hazard is hearing damage caused by high frequency sound. The second hazard is the generation of aerosols from the sonication process.

Sonicators generate sound waves in the 20,000 Hz range. These sonicator-generated sound waves are outside the normal range of hearing. Often the sound heard while using a sonicator is produced by cavitations of the liquid in the sample container or vibrations from loose equipment. Actions you can take to reduce the hazards include:

• Wear earphone-type sound mufflers to protect your hearing while sonicating
   
• If possible, have the sonicator located in a “sound-proof” cabinet while sonicating
   
• Do not sonicate in a room containing people not wearing ear protection
   
• Shut doors of the room where sonication is taking place

Blending, Grinding, Sonicating, Lyophilizing

The greatest hazard when using sonicating and other equipment to disrupt cells or shear nucleic acids is the creation of aerosols. These aerosols are generated by cavitations of the sonicator horn in the sample media and mechanical mixing.  The following guidelines should be followed.

• Blenders, grinders, sonicators, lyophilizers, etc. should be operated in a biosafety cabinet whenever possible.
   
• Safety blenders should be used. Safety blenders are designed to prevent leakage from the bottom of the blender jar and to withstand sterilization by autoclaving. They also provide a cooling jacket to avoid biological inactivation.
   
• Avoiding using a glass blender jar. If a glass jar must be used, it must be covered with a polypropylene jar to contain the glass in case of breakage.
   
• A towel moistened with disinfectant should be placed over the top of the blender while operating. This practice can be adapted to grinders and sonicators as well.
   
• Aerosols must be allowed to settle for five minutes before opening the blender jar (or grinder or sonicator container).
   
• Lyophilizer vacuum pump exhaust should be filtered through HEPA filters or vented into a biosafety cabinet.
   
• Polypropylene tubes should be used in place of glass ampoules for storing biohazardous material in liquid nitrogen. Glass ampoules can explode, causing eye injuries and exposure to the biohazardous material.

Source: University of Rochester

have impact on

the growing

of Listeria monocytogenes

Sanco. Guidance document on Listeria monocytogenes shelf-life studies for ready-to-eat foods (2008).

to use for Q.C.

of Campylobacter

blood agar

The Clinical and Laboratory Standards Institute (CLSI) lists which reference cultures to use for Q.C. of certain selective types of media n Document M22_A3 “Quality Control for Commercially prepared Microbiological Culture Media: Approves Standard – Third Edition”.

The micro-organisms needed for Q.C. of Campylobacter blood agar: Campylobacter jejuni subsp. jejuni  (Cat. n. 0481), and Escherichia coli (Cat.n. 0335), Campylobacter Agar Q.C. set.

specifically dedicated

to virology

“Wong’s Virology” is a web site full of information about viruses and provides excellent summaries of virus information in an easy to access fashion. Derek Wong, a medical virologist in Hong Kong, worked in the lab that discovered the first-ever human avian influenza infection (H5N1).

http://virology-online.com

human pathogen?

Campylobacter is a major human pathogen worldwide

Campylobacter jejuni and C. coli are considered for the majority of human food-borne infections (www.hpa.org.uk ). Human food poisoning is acquired through the consumption of contaminated food. Poultry is a major food source of infection and infection can arises by consumption of under-cooked poultry meat or cross-contamination of other food products (www.food.gov.uk).

Other sources of infection include contaminated raw milk and water.

The general symptoms of the disease are a fever and general feeling of unwell-ness which is accompanied or followed by abdominal cramps, watery, diarrhoea.

The disease is generally self-limiting after 2-7 days. Antibiotic treatment may be required in elderly or immune-compromised patients.

safety rules in dealing

with perchloric acid?

FACT SHEET

Perchloric Acid Use

Fire, like any other manmade tool or device, will serve man well only when it is controlled and used wisely.