mismatch repair

Examples of mismatch repair in the following topics:

• DNA Repair

  • Some errors are not corrected during replication, but are instead corrected after replication is completed; this type of repair is known as mismatch repair .
  • How do mismatch repair enzymes recognize which of the two bases is the incorrect one?
  • In mismatch repair, the incorrectly-added base is detected after replication.
  • The mismatch-repair proteins detect this base and remove it from the newly-synthesized strand by nuclease action.
  • Nucleotide excision repairs thymine dimers.

• Mutation

  • The mutants may also be counter-selected due to presence of a mismatch repair system which favors the methylated template DNA.

• Dead Space: V/Q Mismatch

  • Dead space is a broken down or blocked region of the lung that produces a mismatch of air and blood in the lungs (V/Q mismatch).
  • This is referred to as ventilation/perfusion (V/Q) mismatch.
  • There are two types of V/Q mismatch that produce dead space.
  • The lung has the capability to compensate for mismatches in ventilation and perfusion.
  • Compare and contrast anatomical and physiological dead space and their role in V/Q mismatch

• Operations management provides competitive advantage!

  • Toshiba needs to provide a repair service to its laptop computer customers.
  • The old approach of providing this service was cumbersome and time-consuming: (1) Customers had pick up their computers, (2) delivered the computers to Toshiba, (3) Toshiba repaired the computers, (4) picked up the repaired computers and delivered them back to the customers.
  • United Parcel Service hired, trained, and certified its own employees to repair Toshiba laptop computers.
  • The new repair process is much more efficient: (1) picks up computers from Toshiba owners, (2) repairs the computers, (3) delivers the computers back to their owners.
  • The total time to get a computer repaired is now about two days.

• Supporting and Conflicting Substituent Effects

  • In reaction B the β-polar substituent of the aldehyde is mismatched in this respect, but has little effect on the overall diastereoselectivity.
  • In reaction C the α-substituent of the aldehyde is mismatched, leading to dominance of the anti-Felkin-Ahn product.
  • Finally, reaction D shows the results of a fully mismatched combination, which even produces a small amount of syn-aldol product (not shown).
  • Reactions B and C are the partially mismatched cases, and D shows a mixture of products from the fully mismatched combination.
  • The remarkable influence of a β-polar substituent on the aldehyde is again shown in reaction C, where a strong shift to Felkin-Ahn addition occurs, despite the mismatched β-methyl substituent.

• Reporting Contingencies

  • For example, to accrue a provision for product warranty costs, assume that minor repairs cost 5% of the total product sales and an estimated 5% of products may require minor repairs within 1 year of sale.
  • Major repairs cost 20% and 1% of products may require major repairs in 3 years.
  • The provision is calculated by multiplying 5% of total product cost by 5% of products needing minor repair and then adding 20% of cost for major repair, multiplied by 1% of products needing major repair.
  • The amount for repairs occurring in year one is reported in the current liability section of the balance sheet; the portion relating to major repairs in three years is disclosed as long-term liability.
  • As the warranty claims are made, the liability account is debited and cash is credited for the cost of the repair.

• Types of Unemployment: Frictional, Structural, Cyclical

  • There is a mismatch between the skills of the unemployed workers and the skills needed for the jobs that are available.
  • It occurs when there is a mismatch between the workers and jobs.
  • The mismatch can be related to skills, payment, work time, location, seasonal industries, attitude, taste, and other factors.

• Reasons for Unemployment

  • Frictional unemployment exists because both jobs and workers are heterogenous, and a mismatch can result between the characteristics of supply and demand.
  • Such a mismatch can be related to skills, payment, work-time, location, seasonal industries, attitude, taste, and a multitude of other factors.
  • Structural unemployment is a form of unemployment where, at a given wage, the quantity of labor supplied exceeds the quantity of labor demanded, because there is a fundamental mismatch between the number of people who want to work and the number of jobs that are available.

• Valuing Repairs, Maintenance, and Additions

  • Such expenditures cancel a part of the existing accumulated depreciation; firms often call them extraordinary repairs.
  • Assume now that USD 6,000 in repairs expense is incurred for a plant asset that originally cost USD 40,000 and had a useful life of four years and no estimated salvage value.
  • The company capitalized the USD 6,000 that should have been charged to repairs expense in 2010.
  • The failure to perform needed repairs could lead to asset deterioration and, ultimately, asset impairment.
  • Therefore, asset repairs and maintenance are expensed on the income statement at the market value paid for the services rendered.

• Bone Remodeling and Repair

  • Bone is remodeled through the continual replacement of old bone tissue, as well as repaired when fractured.
  • The repair tissue between the broken bone ends, the fibrocartilaginous callus, is composed of both hyaline and fibrocartilage .