Consider the program: var s: int:= 1, i: int co i:= 1 to 2 rightarrow do true rightarrow (await s > 0 rightarrow s: = s - 1) (s:= s + 1) Above, S_i is a statement list that is assumed not to modify shared variable s. Develop complete proof outlines for the two processes. Demonstrate that the proofs of the processes are interference-free. Then use the proof outlines and the method of Exclusion of Configurations (2.25) to show that S_1 and S_2 cannot execute at the same time and that the program is deadlock-free. What scheduling policy is required to ensure that a process delayed at its first await statement will eventually be able to proceed? Explain. Solution int i=1 do(i=1 to 2) { wait(s>0){ s=s-1 Si } s=s+1 } to prove that it should be deadlock free it should support mutual exclusion,progress,bounded waiting. mutual exclusion:- p1: int i=1 do(i=1 to 2) //entry section { wait(s>0){ //critical section s=s-1 Si } s=s+1 } //exit section so while p1 is exexcuting p2 while s enters into critical section as we don\'t update any values so mutual exclusion is possible and can be formed. progress:- when p1 is in non-critical section p2can execute in critical section.program gurantees progress. bounded-waiting :- suitable for ony countable no of procedures and processes. as it satisfies all properties ....so it\'s deadlock free..

1. Describe the steps in Sanger DNA sequencing. Provide a high level description of an algorithm,
including a cost function, for sequence alignment. Do you know of any other approaches to DNA
sequencing?
Solution
Dideoxy sequencing:
1. Sanger sequencing or dideoxysequencing uses dideoxy nucleotides (ddNTPs).
2. Dideoxyribonucleic acid (dideoxynucleotides, ddNTP's) structure is similar to
deoxyribonucleic acid (DNA), but it is lack of one oxygen atom present next to nucleotide
pairing. Dideoxyribonucleic acids are used as inhibitors of chain-elongation by DNA polymerase
3. A series of DNA fragments of different sizes are produced by this process, the size of these
fragments is measured by electrophoresis.
4. In each fragment, the base present at its end is known as its dideoxy nucleotide, which was
used to terminate the reaction.
5. By arranging these fragments in order based on their size, the DNA sequence can be framed
out.
6. This technique is used to determine the DNA sequence, and it gives specific results
The larger pieces of DNA can be broken down into differential sizes so that it can be done as per
cost function, sequence alignment to denote overlapping fragments. Therefore, assembling all
these contiguous sequence fragments using computer algorithms is essential for comparison of
nucleotide sequences from different clones based on overlaps
Other approaches of DNA sequencing:
Shotgun seqeuncing
Whole exome DNA sequencing
Whole Exome Sequencing of DNA Trios of both parents and an affected child to diagnose the
molecular cause of a disease, they may initially find hundreds of candidate variants. 1. The major
criteria they may use to help narrow the list to the most likely mutation as patients are often
chosen from consanguineous families. These are either sporadic or multiplex & analyzed the
whole exome sequencing for filtered variants based on “criteria of mutation” are either on
dominant or recessive inheritance models
For example:
It has illustrated that several genes are meticulously liable for many diseases and disorders such
as metabolic and neurodevelopemental, inherited, cancer. These genes can be identified with
high reliability and accuracy through whole –genome (exome sequencing) along with Sanger
sequencing compared to the micro array analysis & comparative genomic hybridization (CGH).

2. For example, MLL2 gene is responsible for Kabuki syndrome, this gene can be identified and
sequenced with highest possible accuracy finally this methodology is useful to unravel any
mutated genes in the coding exons. For example, CGH is only useful for to detect copy number
variation of color ratio using patient's single stranded DNA represented in “red” and isolated
DNA from a reference human as “green” as these two traits are going to compete for
hybridization. Microarray is not useful to detect the disease causing genes with highest possible
accuracy, as it is useful for detecting single nucleotide polymorphism.