Antibiotics are used to treat a wide variety of bacterial infections and have saved millions of lives since they were first introduced in the 1940s and 1950s. However, due to both overuse and misuse, many are no longer effective and The World Health Organisation (WHO) considers the emergence of new antibiotic-resistant bacteria to be a serious threat to global public health.
According to their mechanism of action, antibiotics can be divided into three main groups, those inhibiting cell wall synthesis, those inhibiting protein synthesis and those that inhibit nucleic acid synthesis. For example, penicillin and its related compounds prevent susceptible bacteria from creating a cell wall. They do this by binding to and inactivating an enzyme (transpeptidase) necessary for the cross-linking of peptidoglycan in the wall, thus stopping its formation. Resistance to this antibiotic is due to the bacteria producing its own enzyme called beta-lactamase which breaks the ring structure of the penicillin and prevents its ability to bind to the bacterial transpeptidase.
As with all proteins, beta-lactamase is encoded by a section of DNA – but how does that DNA and the ability to produce a new protein transfer from one population of bacteria that have resistance to another population that don’t?
Other than direct transfer from parent to daughter cell, horizontal transmission of DNA between different genomes also occurs. Horizontal gene transfer is made possible by the existence of mobile genetic elements, such as plasmids (extrachromosomal genetic material), transposons (“jumping genes”) and bacteria-infecting viruses (bacteriophages). These elements are transferred between organisms through different mechanisms, which in prokaryotes include transformation, conjugation, and transduction.
In: Biology
Which charging method for objects involves touching a neutral object with a charged object and results in both objects sharing the same charge?
Select one:
a. zap charging
b. Inductive charging
c. Contact charging
d. Frictional charging
Which charging method for objects involves bringing a neutral conductor near but not touching a charged object and then grounding one side of the conductor and removing the ground then the charged object resulting in the conductor having a net charge?
Select one:
a. Frictional charging
b. Contact charging
c. Inductive charging
d. aura charging
The spacing between electric field lines is an indication of ____________.
Select one:
a. the direction of the electric field
b. the strength of the electric field in that region
c. the voltage times the electric field
d. the spacing doesn't mean anything
In: Physics
Write a short response of approximately 200 words on the following topic:
Ways to Improve the Standard of Living of the Shuswap Nation
The Shuswap Nation is one of the distinct societies of Indigenous Peoples located near Kamloops, BC, which is located on the traditional and unceded land of the Secwepemc. This First Nations community has its own distinct government and economy. Assume that the Shuswap Nation grows cherry fruits (in thousand kilograms) and produces crafts (in thousand units) by using all resources efficiently given the technology. Draw a production possibilities frontier (PPF) for the Shuswap Nation. The Shuswap Nation needs its economy to grow by shifting its PPF upward in order to increase the standard of living. List all possible ways that the Shuswap Nation can shift its PPF upward.
In: Economics
An American company sells merchandise on account to a Swiss company for CHF 50,000 on 1/12/2019 when the rate was 1 CHF = 0.9 USD. On 31/12/2019 the rate was 1 CHF = 0.96 USD. On 25/1/2020 the Swiss company pays its obligation to the US company (the rate was 1 CHF = 1.01 USD), which keeps the foreign cash it and converts the amount to US dollars on 10/2/2020, when the rate was 1 CHF = 0.99 USD. Required: Provide the journal entries on each of the above mentioned dates (Note: CHF means Swiss franc). NOTE: IF YOU CANNOT CLEARLY WRITE THE JOURNAL ENTRIES LIKE YOU WOULD ON A PAPER EXAM, PLEASE MENTION dr OR cr NEAR EACH ACCOUNT IN THE JOURNAL ENTRY AS APPROPRIATE.
In: Accounting
An American company sells merchandise on account to a Swiss company for CHF 50,000 on 1/12/2019 when the rate was 1 CHF = 0.9 USD. On 31/12/2019 the rate was 1 CHF = 0.96 USD. On 25/1/2020 the Swiss company pays its obligation to the US company (the rate was 1 CHF = 1.01 USD), which keeps the foreign cash it and converts the amount to US dollars on 10/2/2020, when the rate was 1 CHF = 0.99 USD. Required: Provide the journal entries on each of the above mentioned dates (Note: CHF means Swiss franc). NOTE: IF YOU CANNOT CLEARLY WRITE THE JOURNAL ENTRIES LIKE YOU WOULD ON A PAPER EXAM, PLEASE MENTION dr OR cr NEAR EACH ACCOUNT IN THE JOURNAL ENTRY AS APPROPRIATE.
In: Accounting
Carrie Ann thinks she has identified a hot opportunity. She has watched the demand for tattoos and body art increase over the last several years. Carrie Ann believes that this trend is now leveling off and that in the near future many people who have gotten tattoos will want them removed. In anticipation, she has developed a nonsurgical approach to tattoo removal that consists of a cream applied to the tattoo. The area is then covered with gauze, and the cream must be reapplied every day for two weeks. At the end of two weeks, the tattoo is gone. A tube of Carrie Ann's cream will retail for about $50.
Carrie Ann's business could become a fast-growth player as described in this chapter. What would she need to do to become a fast-growth company?
In: Accounting
A string of length 1.0m has a mass/length of 2.4 g/m and is under 460N of
tension. It is vibrating in its third harmonic (n = 3).
1. What is the frequency of the standing wave?
The vibrating string produces a sound wave and sits near a half-open tube of length L. The
speed of sound is 343m/s.
2. For what minimum value of L does the sound wave produced by the vibrating
string resonate with the tube (i.e., coincide with one of the allowed frequencies for standing
waves in the tube)?
3. If the tube were replaced by another tube of length 0.80L, how fast and in
what direction (towards or away from the tube) must the vibrating string be moving in order
for the sound wave it produces to resonate with the new tube? Hint: Consider the Doppler
effect.
In: Physics
Please, answer for following questions:
Thank you so much!
In: Accounting
I have several data sets or whatever they are called/data in 60 piece segments. 1-60 number of restaurants, and then that many monthly profit total figures, monthly advertising expenses monthly, and student population near each store. I need to make two accurate and effective bar charts to display the correlation of profit/advertising expense per month on one and profit/student population on the other. How do I do this?
I have to make the frequency or something? I tried and Excel frequency function did not work for me. I need to make bins and separate data or something so can have the rght info to make the bar charts? I know the basics if can explain it please. thank you!
In: Statistics and Probability
Modern Physics: Solid State and Nuclear Physics
You want to use the Hall Effect to determine if a particular sample of a semiconductor is n or p doped.
a. Sketch the following configuration: the sample is placed flat on the page. The applied voltage source is attached such that the positive lead is nearest to the top of the page, and the negative near the bottom. The magnetic field goes into the page. Identify on your drawing the direction of the current through the sample, assuming the usual convention of the current which is the movement of positive charges.
b. When you hook up a voltmeter to the sample with the negative lead on the left side, and positive on the right side, you find that a positive voltage is measured. Based on this, determine the sign of your charge carriers.
c. Is the sample n-doped or p-doped? If the sample is silicon, suggest a possible identity of the doping species.
In: Physics