Lastly, cross-contamination of utensils and work spaces should be avoided when preparing food. Model organism in life science research
Because of its long history of laboratory culture and ease of manipulation, E. coli plays an important role in modern biological engineering and industrial microbiology. The work of Stanley Norman Cohen and Herbert Boyer in E. coli, using plasmids and restriction enzymes to create recombinant DNA, became a foundation of biotechnology.E. coli is a very versatile host for the production of heterologous proteins, and various protein expression systems have been developed which allow the production of recombinant proteins in E. coli. Researchers can introduce genes into the microbes using plasmids which permit high level expression of protein, and such protein may be mass-produced in industrial fermentation processes. One of the first useful applications of recombinant DNA technology was the manipulation of E. coli to produce human insulin.Many proteins previously thought difficult or impossible to be expressed in E. coli in folded form have been successfully expressed in E. coli. For example, proteins with multiple disulphide bonds may be produced in the periplasmic space or in the cytoplasm of mutants rendered sufficiently oxidizing to allow disulphide-bonds to form, while proteins requiring post-translational modification such as glycosylation for stability or function have been expressed using the N-linked glycosylation system of Campylobacter jejuni engineered into E. coli.Modified E. coli cells have been used in vaccine development, bioremediation, production of biofuels, lighting, and production of immobilised enzymes.Strain K-12 is a mutant form of E. coli that over-expresses the enzyme Alkaline Phosphatase (ALP).
Changes in sex hormone levels, specifically elevated levels of estrogen and relaxin in females during the menstrual cycle, have been hypothesized as causing predisposition of ACL ruptures. This is because they may increase joint laxity and extensibility of the soft tissues surrounding the knee joint. Ongoing research has observed a greater occurrence of ACL injuries in females during ovulation and fewer injuries during the follicular and luteal phases of the menstrual cycle.Study results have shown that female collegiate athletes with concentration levels of relaxin that are greater than 6.0 pg/mL are at four times higher risk of an ACL tear than those with lower concentrations.Additionally, female pelvises widen during puberty through the influence of sex hormones. This wider pelvis requires the femur to angle toward the knees. This angle towards the knee is referred to as the Q angle. The average Q angle for men is 14 degrees and the average for women is 17 degrees. Steps can be taken to reduce this Q angle, such as using orthotics. The relatively wider female hip and widened Q angle may lead to an increased likelihood of ACL tears in women. ACL, muscular stiffness, and strength
During puberty, sex hormones also affect the remodeled shape of soft tissues throughout the body. The tissue remodeling results in female ACLs that are smaller and will fail (i.e. tear) at lower loading forces, and differences in ligament and muscular stiffness between men and women. Womens knees are less stiff than mens during muscle activation.