Sciencedoze: Science, Education and Technology

ISO: Introduction, History and ISO 9000

2023-12-28T13:20:00.000+05:30

What is ISO?

ISO, short for the International Organization for Standardization, is an independent and non-governmental international organization that consists of 167 national standards bodies. Its purpose is to develop and publish standards that promote global consistency and quality in various industries and sectors.

Its primary role is to develop and publish a wide range of proprietary, industrial, and commercial standards. Currently, ISO has over 24,000 active technical standards that encompass diverse areas, including manufactured products, technology, food safety, agriculture, and healthcare.

History of ISO

The International Organization for Standardization (ISO) was founded in 1947 and is currently based in Geneva, Switzerland. Its roots can be traced back to 1920 when it originated as the International Federation of the National Standardizing Associations (ISA).

However, its operations were suspended during World War 2. After the war, United Nations Standards Coordinating Committee (UNSCC) proposed a new global body and thus ISO was formed.

In 1951, ISO published its first-ever standard called ISO/R1:1951 which is also known as the standard reference temperature for industrial length measurements. And from then to now ISO published over 24,000 standards covering various segments like healthcare, railway, jewelry, clothing, weapons, etc.

ISO plays a crucial role in facilitating global trade by establishing common standards across different countries. These standards aim to ensure the safety, reliability, and quality of products and services.

By promoting international harmonization, ISO contributes to the removal of trade barriers and enhances interoperability among nations, fostering a more efficient and sustainable global marketplace.

ISO 9000

ISO 9000 is a family of standards that focuses on quality management and quality assurance. This standard is used by companies to develop and maintain their quality systems.

ISO 9000 focuses on relationship management, customer focus, and leadership. This standard can be used by an organization including service providers such as hospitals, banks, and universities.

ISO 9000 helps to increase productivity and efficiency, thus lowering the costs of an organization. It also improves customer experience resulting in repeat business, increased sales, and additional income.

ISO 9000 standards can be purchased from ISO members in the country or through the ISO store.

Features of Humerus Bone

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The humerus is a long bone located in the upper limb, spanning from the shoulder to the elbow joint.

The greater tubercle is a bony prominence located on the lateral side of the humerus, below the anatomical neck.

The lesser tubercle is a smaller bony projection located on the anterior side of the humerus, near the anatomical neck.

The greater tubercle is a prominent bony projection located on the lateral side of the proximal humerus. It provides attachment points for various muscles and tendons of the shoulder.

The narrow intertubercular groove, also known as the sulcus, passes between the greater and lesser tubercles of the humerus. This groove provides a pathway for certain structures, such as tendons and blood vessels, to pass through and interact with the surrounding shoulder anatomy.

The roughened, U-shaped area located at the middle portion of the humeral shaft is known as the deltoid tuberosity. This prominence serves as an attachment site for the deltoid muscle, a major muscle of the shoulder that is involved in various arm movements.

The capitulum is a rounded knob located on the lateral aspect of the distal humerus. It forms part of the articulation with the radius bone of the forearm, specifically the radial head.

The radial fossa is an anterior depression located above the capitulum on the distal humerus. It is specifically situated on the medial side of the elbow joint. The radial fossa accommodates the radial head when the elbow is flexed, allowing for smooth movement and articulation between the humerus and the radius bone.

Tree Data Structure and its Applications

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What is Tree Data Structure?

A tree is a non-linear data structure as it stores data in a hierarchical manner that consists of nodes connected through edges.

It is the best alternative for the linear data structure like arrays, stacks, queues, etc as these linear data structures have high time and space complexity.

The data stored in nodes of the tree are easier to access thus reducing the time complexity.

Terms related to tree data structure

1. Node

A node is an entity that stores a data element and links to its child and parent nodes.

2. Edge

The link between any two nodes is called the edge.

3. Root

The root is the transparent node in a tree that is a root node doesn't have any parent node. Here no. 1 is the Root node.

4. Parent and Child Node

The node which contains sub-nodes is called the parent node. Here 1 is the parent node for 2 and 3 and 2 is the parent node for 4 and 5.

The node which is a descendant of any node is called a child node. Here 2 and 3 are child nodes and 1 and 4 and 5 are child nodes of 2.

5. Internal node

A node that has at least one child node is called an Internal node. Here 1 is an internal node whereas 3 is not an internal node.

6. Leaf node (external node)

A node that doesn't have a child node is called a leaf node. It is the bottom-most node of a tree. Leaf nodes are commonly referred to as external nodes.

7. Height of a node

The number of edges from the node to the deepest leaf (leaf node) is called the height of a node. Here eight are node 1 and node 2. The height of node 2 is 1.

8. Depth of a node

The no. of edges from the root to that node is called the depth of the node. Here the depth of node 2 is 1. The depth of node 5 is 2.

9. Height of a tree

The height of the tree is the height of the root node to the deepest leaf node. Here the height of the tree is 2.

10. Degree of node

The degree of a node is the total number of branches of that node. Here node 1 has 2 degrees. Node 3 has 0 degrees as no branches are there.

Application of a Tree

1. Trees are used to quickly check whether a data element is present in the set or not.

2. Heap tree is used to perform heap sort of elements.

3. A modified version of a tree, called tries, is utilized in modern routers for storing routing information.

4. Compilers use a syntax tree to validate the syntax of every program.

Binary Tree Data Structure and Its Types

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What is Binary Tree Data Structure?

A binary tree is a type of tree in which each parent node have at most two child nodes. Each node of a binary tree has three items.

1. Data item

2. Address if a left child

3. Address of the right child

Types of Binary tree

1. Full Binary tree

A full binary tree is a type of binary tree in which each parent node have either two or no child nodes. Here 1 has 2 and 3 child nodes. 3 don't have any child nodes.

2. Perfect Binary Tree

A perfect Binary tree is a type of binary tree in which each parent node have exactly two child nodes and all leaf nodes are present at some level. Here 1 has 2 and 3 child nodes and 4,5,6,7 leaf nodes are present at some level.

3. Complete Binary tree

In a complete binary tree, all the levels are filled.

All leaf elements must lean towards the left in a tree structure.

The last leaf element might not have the right sibling.

4. Balanced Binary Tree

A balanced binary tree is a type of binary tree in which the height of the left and right subtree for each node is balanced, meaning it is either 0 or 1. Here the height of the left subtree is 2 and the height of the right subtree is 1 and their difference is 1.

5. Degenerate or pathological tree

A degenerate or pathological tree is a tree in which each node has only one child, either on the left or right side.

6. Skewed Binary Tree

A skewed binary tree is a pathological or degenerate tree in which the tree is either dominated by the left nodes or right nodes. Thus, there are two types of skewed binary trees: left-skewed binary trees and right-skewed binary trees.

Relation between Module, Package, Library, Framework in Python

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1. Module

A module in Python is a collection of functions and global variables having a .py extension. Eg: Date time, Regex, Random, etc.

2. Package

A package in Python is a collection of various modules. The package also contains sub-packages inside it. Eg: NumPy, Pandas, etc.

3. Library

A library in Python is a collection of various packages which help to perform tasks without writing the code. It can be re-used and can be used just by importing it into the program. Eg: Matplotlib, Seaburn, etc.

4. Framework

A Python framework is a comprehensive collection of modules and packages designed to accelerate the development process.

Unlike libraries, frameworks are more intricate and provide a structured foundation and architectural guidelines for building applications.

Hemoglobin and its Types

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What is Hemoglobin?

Hemoglobin is an iron-containing globular protein present in red blood cells (RBCs). They impart a red color to the blood and help in transporting oxygen from the lungs to different parts of the body.

A healthy individual has about 12-20 g of hemoglobin in every 100 ml of blood. Hemoglobin is a tetrameric protein that contains the heme prosthetic group attached to each subunit. Lackness of Hemoglobin in the blood can cause anemia.

Hemoglobin is made up of four amino acid chains and each of these chains contains heme. This is the compound that contains iron. The heme molecule forms strong covalent bonds with a globular protein, primarily through the nitrogen atoms of the imidazole ring located beneath the porphyrin ring.

Types of Hemoglobin

After Birth

Hemoglobin A

It accounts for 95-98% of Hemoglobin in adults. It consists of two alpha and two beta polypeptide chains, which together form the complete structure.

Hemoglobin A2

It accounts for 2-3% of Hemoglobin present in adults. It is composed of two alpha and two delta polypeptide chains, which combine to form the complete structure.

Hemoglobin F

It is also known as fetal hemoglobin which accounts for 2-3% of Hemoglobin F present in adults. It is composed of two alpha and two gamma chains, which come together to form the complete structure.

Abnormal Hemoglobin

Hemoglobin S

It's a primary cause of sickle cell anemia. There is a point mutation in the beta-globin chain- 'GAG' get converted into 'GTG' leading to the replacement of glutamic acid by valine at 6th position.

Hemoglobin C

Heterozygotes for the gene are asymptomatic. Hemoglobin C disease is caused by homozygotes. It leads to mild hemolytic anemia and enlargement of the spleen.

Hemoglobin E

It is the beta-chain variant of normal hemoglobin. It is frequently found in individuals of Southeast Asian descent. It causes mild haemolytic anamia in homozygotes.

Examples of Computer Security Incidents

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1. AIIMS Cyberattack

A recent cyberattack on the servers of AIIMS, Delhi compromised the records of around 3-4 crore patients like their Names, medical, history, lab reports, contact information, etc.

The servers of AIIMS, Delhi were infected with ransomware like wanna cry, mimilatz (check), and trojan and demanded 300 crore money to retrieve the access of servers.

Hackers used two proton mail address to send the ransomware and these email address belongs to China and Hong Kong.

The cyberattack targeted e-hospital applications, stopping the functioning of OPD, emergency, and other patient services.

2 Iran nuclear Program attack

The Stuxnet worm developed jointly by the U.S. and Israel is used to target Iran's nuclear program in 2010.

This malware is injected into the system of the nuclear facility through U.S.B devices and it targets the machine used for the enrichment of nuclear material.

Due to this attack, till now Iran is not able to develop its nuclear weapon.

3. Uber data breach, 2016

In 2016, the confidential data of 57 million customers and drivers is leaked by hackers.

The data contain sensitive information like the driving license numbers of around 6 lakh Uber drivers and the hackers demanded $100000 to delete the information.

4. Adobe Cyberattack, 2013

In 2013, the confidential data of 38 million active users is leaked and the hacker accessed a large number of activated and deactivated accounts.

Hackers also steal the source code of the popular photo editing software Photoshop and Acrobat PDF editor.

Features of Femur Bone

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The femur is the longest bone in the skeleton.

The small depression on the femoral head is called the fovea capitis.

The head of the femur is spherical in shape and forms a ball-and-socket synovial joint with the acetabulum of the pelvis.

The neck of the femur serves as the connection between the femoral head and the femoral shaft (body).

The larger bony prominence located laterally is known as the greater trochanter.

The smaller bony prominence located medially and more posteriorly is known as the lesser trochanter.

Features of Ulna and Radius Bone

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1. Ulna

The ulna is situated on the inner (medial) side of the forearm and is longer in length compared to the radius.

At the proximal end of the ulna, there is a distinctive c-shaped indentation called the trochlear notch.

The coronoid process, a prominent bony projection, forms the lower boundary of the trochlear notch at the proximal end of the ulna.

On the anterior side of the ulna, just below the coronoid process, there is a roughened area known as the ulnar tuberosity.

To the lateral side and slightly inferior to the trochlear notch, there is a small and smooth area known as the radial notch.

At the proximal end of the ulna, there is the olecranon, which forms the prominence of the elbow.

2. Radius

The radius is the smaller of the two bones in the forearm and runs parallel to the ulna on the lateral side of the forearm.

The proximal end of the radius features a disc-shaped structure known as the head.

The neck of the radius is the region immediately below the expanded head where the bone narrows.

Inferior to this point on the medial side of the radius, there is a prominent bony projection called the radial tuberosity.

On the medial side of the distal end of the radius, there is a concave surface called the radial notch, which articulates with the head of the ulna.

The distal end of the radius features a pointed projection known as the styloid process of the radius, which provides stability and serves as an attachment point for ligaments in the wrist joint.

Blood and its Composition

2023-12-28T13:07:00.000+05:30

What is Blood?

Blood is a body fluid that is dark brown to red. It contains four components that are plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Blood is essential for life as it delivers essential substances like oxygen and nutrients to various body cells. It also helps to fight infection and also regulate the pH of the body.

An average human adult contains approx 5 liters of blood which contributes to 8% of the total body weight. The blood in the body contains 55% plasma and 45% blood cells.

Composition of Blood

1. Plasma

The liquid component of blood is called plasma. It is yellowish and made up of mainly water, but it also contains proteins, sugars, hormones, and salts. Plasma helps in the transportation of blood cells throughout the body with water and nutrients.

2. Red Blood Cells (RBCs)

Red blood cells (RBCs) account for approximately 40-45% of blood volume and appear bright red due to their hemoglobin content. Hemoglobin enables RBCs to transport oxygen from the lungs to the body and carry carbon dioxide back to the lungs.

RBCs have a disc-like shape with a flattened center, lack a nucleus, and possess the ability to change shape, facilitating their passage through diverse blood vessels. Bone marrow produces RBCs at an impressive rate of around 5 billion per hour, and they have an average lifespan of approximately 120 days.

3. White Blood Cells (WBCs)

White Blood Cells (WBCs) account for only 1% of blood but they perform a very important biological function. They are essential for good health and protect us from various illnesses and diseases.

They are also generated in our bone marrow and flow through the bloodstream to attack viruses and bacteria. Leukocytes and Neutrophils are two important examples of WBCs.

4. Platelets

Platelets are small fragments of cells that help in the blood clotting process by accumulating at the site of injury. Also, a higher-than-normal number of platelets can cause unnecessary clotting which can lead to strokes and heart attacks.

Fingerprint Bureau and its main Functions

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The Fingerprint Bureau of India, also known as Central Fingerprint Bureau (CFPB) was set up in Kolkata in 1955 under the administrative control of the Intelligence Bureau (IB).

But, In 1973, the administrative control was transferred to CBI and again in 1986, the administrative control was finally given to the newly formed National Crime Records Bureau (NCRB) located in R.K Puram, New Delhi.

Functions of Fingerprint Bureau of India

1. The main function of FPB is to maintain the fingerprint data of Indian and Foreign criminals. The record of foreign criminals is sent by the Interpol Division of CBI.

2. It also examines the questioned fingerprint impressions referred by central Govt. departments and other Govt. of India undertakings.

3. It also imparts training in fingerprint science to police and non-police personnel of the state govt. and personnel of foreign countries under the 'Technical Co-operation Scheme'.

4. It also conducts the All India Board examination every year to certify the FingerPrint experts.

5. It also publishes the 'Fingerprint in India' annual journal stating the performance and activities performed by various Fingerprint Bureaux of the country.

DNA Quantitation: Definition and Methods Involved

2023-12-28T13:02:00.000+05:30

What is DNA Quantitation?

DNA quantitation is a process in which the quantity of DNA extracted is estimated. It is important to know the quantity of DNA because it helps in DNA purifying and performing PCR. Aiding too little DNA will result in a profile that is difficult to analyze.

Methods of DNA Purification

1. Spectrophotometry

Spectrophotometry techniques like UV absorbance can be used in DNA quantitation.

DNA absorbs light maximally at 260 nm. This helps in estimating the amount of DNA by measuring the absorbance of light at wavelengths ranging from 220 nm to 300 nm.

In this method, the DNA sample is placed in a quartz cuvette and the absorbance is measured against the standard sample.

Moreover, fluorescent dyes (Ethidium Bromide) can also be used for DNA quantization using spectrometry. These dyes interact with double-standard DNA and produce fluorescence which is detected by spectrophotometer.

2. Agorose Gel electrophoresis

This method is used for the separation of DNA fragments as well as DNA quantitation.

In this method, Agarose gel (10 cm) long is submerged in electrophoresis buffer and the DNA is loaded into wells that are formed using a comb.

When an electric current is applied across the gel, the negatively charged DNA migrates toward the anode. This method is based on the fact that smaller DNA molecules move through gel more quickly than larger DNA molecules.

A dye named Ethidium Bromide is also added before this technique on the DNA fragments to be visualized.

Finally, these DNA fragments are matched with a DNA ladder that will tell us the concentration of each band.

3. Slot blot technique

This is a different method of quantitation of DNA which is based on the specific hybridization of a 40 bp probe that binds to the human alpha satellite locus D17Z1.

By this technique, DNA is quantified by Visual Comparison of sample band intensities with the band intensities of standards, produced from a known amount of DNA.

4. Real Time-PCR

This is the latest method for DNA quantitation first developed by Higuchi and his co-workers.

In this technique, a fluorescent dye ethidium bromide is intercalated into the DNA fragments and it accumulates during the PCR process. It produces fluorescences in UV light and can be detected using a suitable camera.

DNA quantitation can be done by targeting any specific sequence of template DNA. Some RT-PCR kits are HY Plexor by Promega and Quantifiler Systems by Applied Biosystems.

5. DNA IQ™ Systems

DNA IQ™ system by Promega corporation can also be used for DNA quantization. It first extracts the DNA from the sample and then DNA is eluted to know the maximum concentration.

It has the advantage of combining the extraction and quantification steps but has the disadvantage of not being human-specific.

DNA Purification: Definition and Methods Involved

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Whats is DNA Purification?

DNA purification is followed just after the DNA extraction as the DNA cell concentrate will also contain protein and RNA. The purification is done to remove these contaminants.

The highly purified DNA sample increases the efficiency of the experiment and the chances of a false positive result are also reduced. Further, the purified DNA can be amplified using the PCR technique.

Methods for DNA Purification

1. Treatment with Alcohol

Alcohols like Methanol, Ethanol, and isopropanol can be used in DNA purification as well as DNA precipitation.

Once the DNA is precipitated, it is washed with 1 ml of alcohol and then the mixture is vortexed gently until the clear DNA pellet is observed.

After this, the sample undergoes high-speed centrifugation. The centrifugal force resulted in the separation of debris and other contaminants from the DNA at this location.

2. Gel filtration

This is a type of chromatography technique that uses molecular sieving properties of porous gel particles.

A matrix with fixed pure size allows smaller molecules to enter the pores by diffusion whereas the bigger molecules are excluded from the pores.

Thus, molecules are eluted in order of decreasing molecular size.

3. Ion-Exchange Chromatography

This is a type of chromatography technique that uses electrostatic interaction between the target molecule and other contaminants.

Nucleic acids (DNA) have a high negative charge whereas the impurities don't have significant change.

So with the help of salt Buffers, the sample can be eluted from ion exchange columns.

4. Absorption Chromatography

In absorption chromatography, nucleic acids are absorbed selectively on the silica or glass in the presence of certain salts like chaotropic salts, while other biological molecules (Impurities) do not.

Finally, water or a low-salt Buffer can be used to elute the nucleic acids.

5. Automated DNA purification

This is a relatively new technology that is automated, rapid, and easy to perform. DNA purification using Automated machines is much more effective and accurate than manual methods.

Some examples of automated purification machines are the Kingfisher series by Thermofisher, MPure 12 by MP Biomedicals, Maxwell nucleic acid purification system by Promega, and QIAcube series from Qiagen.

DNA Extraction: Steps and Methods Involved

2023-12-28T12:56:00.001+05:30

What is DNA Extraction?

DNA Extraction is a process of taking out DNA from a cell by breaking the cell membrane and Nuclear membrane with the help of chemical, enzyme, and physical disruptions. The first DNA isolation was done in 1869 by Friedrich Miescher.

Common sources of DNA isolation are whole blood, hair, semen, saliva, buccal (cheek) swabs, urine, and other important biological fluids. DNA isolation helps a forensic expert to link a suspect from a crime scene.

Steps involved in DNA isolation

1. Cell and tissue disruption

Cell and tissue disruption is done using an enzyme known as Proteinase K. Tissues can also be disrupted using boiling and alkali agents. Bones and teeth are frozen in liquid nitrogen and then ground to a fine powder.

2. Lysis of membranes and other organelles

Detergents like Sodium dodecyl sulfate (SDS) and Sarkosyl are used for the lysis of membranes in which DNA is released from nuclei and mitochondria.

A buffer like Tris-HCl is used to maintain the pH for avoiding the actions of degrading enzymes.

Reducing agents like DTT are also used to prevent the oxidation process that can damage DNA.

3. Removal of Proteins and Cytoplasmic contaminants

Some constituents of cytoplasm can get dissociated from DNA due to the action of detergent and high salt concentration in lysis buffer. This can interfere with DNA isolation.

So, these dissolved proteins are then removed by one or more rounds of extraction with phenol or phenol-chloroform mixture followed by centrifugation.

4. Contamination

Target DNA isolated from the exhibits can get contaminated with exogenous DNA while handling and processing the samples.

To avoid contamination, the evidence samples are extracted and processed in different areas.

5. Storage of DNA Solutions

Extracted DNA is stored in TE Buffer at 4 ℃ or -20 ℃ for short and -80 ℃ for long periods. Frequent freezing and throwing are avoided to save the DNA strands from breaking.

Methods for DNA Extraction

1. Phenol-Chroloform DNA Extraction

First of all, Protein digestion is carried out using Proteinase K and then these proteins are removed using a mixture of phenol:chloroform: isoamyl alcohol (25:24:1).

This denatures the protein, then centrifugation of the extract is done in which the pellicle (protein ppt) is removed from the junction of the aqueous phase and phenol-chloroform phase.

This process is repeated 2-3 times until there is no visible pellicle and finally, DNA is filtered out.

2. Chelex 100 Resin DNA Extraction

In this method, DNA extraction is done in 3 steps that are washing, boiling, and centrifugation.

First of all in the washing step, contaminations and PCR inhibitors like Heme are removed from the blood.

Then the boiling is done by suspending the cells in Chelex-100 (chelating resin). This is done because Alkalinity and heating temperature breaks the cell membrane which denatures the cell proteins and releases the DNA.

Finally, the suspension is centrifuged to separate the resin and cellular debris from the supernatant containing DNA.

3. Salting out method for DNA Extraction

This method is developed by Miller et al in 1988 and it is a rapid, safe, and cheap method for extraction.

This method involves salting out cellular proteins by dehydrating and precipitation with a saturated NaCl solution.

First of all, the Buffy coat of nucleated cell is taken in an anti-coagulant (EDTA) then it is suspended in nuclei lysis buffer and the cell lysate is digested overnight at 37 ℃ with SDS and proteinase K solution.

Then, a Saturated solution of NaCl is added to digest the ppt of protein and then centrifugation is done.

Finally, the DNA is precipitated b adding absolute alcohol to the supernatant containing the DNA.

4. Silica Based DNA Extraction

This method is developed by MC Cormick in 1989 and it is commercially used.

First of all, the sample is incubated with cell lysis buffer which breaks the cell membrane and the nuclear envelope. The proteinase K digest all the protein.

Then, All other impurities are removed by centrifugation. Here, the DNA remains bound with silica, and other impurities are discarded.

Finally, the DNA is dissolved into TE Buffer.

5. FTA Paper DNA Extraction

First of all, samples from mainly buccal swabs and fresh blood samples are applied to FTA paper which is stable at room temperature for several years.

Then, a small part of the card, a generally 2 mm diameter circle is placed into a 1.5 ml tube and impurities are washed off, leaving only DNA on the card.

Then, a small circle of FTA paper is then added directly to PCR.

FTA paper extractions are very simple to perform and do not require multiple tube changes, thus reducing the possibility of sample mixing.

6. Magnetic Bead DNA Extraction

The Magnetic Bead method is the newest method of extracting DNA in which the Magnetic Beads coated with a Matrix of Silica capture the DNA.

First of all, the sample must be lysed using SDS or other reagents then several rounds of washing in the presence of a magnetic field separate the DNA captured on magnetic beads from other impurities.

Finally, a low salt buffer elutes the DNA from the beads.

Biological Warfare and it's Types

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What is Biological Warfare?

Biological warfare is the use of various biological agents like bacteria, viruses, insects, and fungi to kill or harm some humans. A biological attack can result in a large number of causalities and can disrupt the economy and infrastructure of the enemy country.

A famous example of biological warfare is the use of bioagents in world war 1 that causes anthrax and glanders infection.

To reduce the proliferation of biological warfare agents, the Biological Weapons Convention (BWC) was signed in 1972. This international treaty prohibits the development, production, acquisition, transfer, stockpiling, and use of biological weapons. Its aim is to ensure the peaceful use of biological sciences and prevent the misuse of biological agents for harmful purposes.

Categories of Biological agent

The CDC of the united states divided various biological agents that are used in biological warfare into the following categories:

1. Category A

These weapons can have devastating consequences, leading to significant loss of life and posing major risks to public health. The use of biological warfare agents can result in high mortality rates and cause widespread harm to populations.

Therefore, it is crucial to prevent their development, production, and use to safeguard public safety and minimize the potential for such catastrophic impacts. They can be easily transmitted from person to person. They may cause public panic and require special attention. Eg: Anthrax, Plague, Smallpox, etc.

2. Category B

These weapons can cause moderate levels of illness and relatively low rates of mortality. While they may not have as high a mortality rate as some other weapons, they can still result in significant morbidity, causing illness and health complications among affected populations. They are moderately easy to spread from one person to another. Examples: Q fever, ricin toxin. cholera, etc.

3. Category C

They can be easily spread from one person to another. They have high morbidity and mortality. Examples are the Nipah virus, Hantavirus, etc.

DNA Fingerprinting: Definition, Method and Application

2023-07-02T11:34:00.000+05:30

What is DNA fingerprinting?

DNA fingerprinting is a laboratory technique that is used to determine the identity of a person using a unique pattern in the minisatellites of the genome of an individual.

It was first invented in 1984 by Sir Akec Jeffreys after he realized that we can detect variations in human DNA based on these minisatellites. On average, about 99.9% of DNA between two individuals is the same, the remaining 0.1 % makes the person unique.

DNA profiling, DNA testing, DNA examination, Genetic profiling, and Genetic fingerprinting are branches of DNA fingerprinting. Following is the complete process of DNA fingerprinting:

RFLP (Restriction Fragment Length Polymorphism)

The first step of DNA fingerprinting is to extract DNA from the biological fluid of human-like blood, buccal swabs, etc.

Then molecular scissors, also called restriction enzymes are used to cut the DNA into thousand pieces of different lengths.

These pieces of DNA are now separated using gel electrophoresis in which the fragments of DNA are separated by applying an electric current across the agarose gel through larger pieces of DNA.

Once DNA fragments are separated, the DNA pieces are transferred to a robust piece of nylon membrane and then 'unzipped' to produce single strands of DNA.

Now, the nylon membrane is incubated with radioactive probes. These probes only attach to the pieces of DNA that are complementary to each other. In our case, they attach to these minisatellites in the genome.

The minisatellites that are probes have been attached now visualized by exposing the nylon membrane to X-ray film.

A pattern of 30 dark bands appeared in the film. This pattern is our DNA fingerprint.

Application of DNA fingerprinting

It helps to link a suspect with the scene of the crime by doing DNA fingerprinting on the biological samples like blood, semen, hair, etc found on the scene of the crime.
DNA fingerprinting help in paternity testing as the offspring get half DNA from the mother and half from the father.
It helps to identify victims of natural disasters and helps to bring separated families back together.
It helps biologists to protect endangered species.
In U.S. armed forces, a program is there to collect DNA fingerprints from all personnel and use them later in case they are needed to identify causalities or persons missing in action.
By studying DNA fingerprints we can have a history of some particular disease and disorder.

History of Fingerprint Science

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Prof. Jan Evangelista Purkinje

The history of fingerprint science dates back three 3000 years as it was first used in Chinato to sign legal documents. Then, In 1823 Prof. Jan Evangelista Purkinje published a thesis describing the friction ridge patterns and classifying fingerprints into Nine categories.

Sir William Herschel

In 1858, An English civil servant Sir William Herschel posted in Bengal, India, started the practice of recording handprints of native Indians to sign the contract. This, greatly prevented the cheating and impersonation among native Indians to sign the contract. But, William Herschel did not publish any of his findings.

Dr. Henry Fauld

In 1874, Dr. Henry Fauld, a Scottish physician working in a hospital in Tokyo, Japan, published his theory on the potential use of fingerprints for personal identification. In 1880, Dr. Fauld suggested that skin ridge patterns can be proved important for the identification of criminals. He also published his findings in Book 'Nature'.

Francis Galton

Later, extensive research on fingerprint science was done by Francis Galton. He developed a methodology for classifying fingerprints for filing purposes. In 1892, he published a book named "Fingerprints" which had good statistical proof stating the uniqueness of fingerprints in personal identification.

Edward Henry

Sir Edward Henry, an Inspector General of Police posted in Bengal, India developed an interest in the works of Sir William Herschel and Francis Galton and developed a more workable system of classification which was first adopted in India in 1897.

He was assisted by two Indian Bengal Police officers named Khan Bahadur Azizul and Rai Bahadur Hemchandra Bose in developing the classification system which is also known as Henry's ten-digit classification system.

Steps involved in Agarose Gel Electrophoresis

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Agarose Gel Electrophoresis

Agarose gel electrophoresis helps in the separation of DNA fragments based on their speed of movement in Agarose gel towards the anode.

In this technique, the DNA sample is poured into the wells on the Agarose gel which are made using a comb.

Also, a fluorescent dye called Ethidium is added to the sample DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells. The migration of the sample can be seen through the gel.

A DNA marker (Also called DNA ladder) is also loaded into the first well of the gel. The fragments in the markers are of known length which will be compared with the size of DNA fragments of sample DNA.

Now the electric current is turned on so that the negatively charged DNA molecules move toward the positively charged anode.

The shorter lengths of DNA will move faster than the longer lengths of DNA in the gel. The electric current is kept on till DNA fragments move far enough across the gel.

Once the DNA has migrated far enough in the gel, the electric current is switched off and the gel is removed from the electrophoresis tank.

To visualize DNA, it is placed under a UV transilluminator which will show the stained DNA bright bands.

Now, we can estimate the size of the DNA fragment of the sample by comparing it with the DNA fragments of the marker (DNA ladder).

Types of Fingerprint Patterns

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What are Different Types of Fingerprint Patterns?

1. Arches

Arches are found in approx 5% of the recorded fingerprints. In an Arch pattern, ridges enter from one side travel to the other side, and lift slightly at the center of the pattern (like a wave) finally exiting from the opposite side.

Based on the nature of Arches they are further divided into two types i.e. Plain Arch and Tented Arch.

(a) Plain Arches

Plain Arch is the simplest pattern among all fingerprint patterns. In a plain arch, the ridges enter from a side (say left) and flow to the opposite side (Right) by making a small rise at the center like a wave. They don't have any core deltas but they do have numerous ridge formations like ridge endings, bifurcations, dots, and islands.

(b) Tented Arches

In this type of Arch, most of the ridges enter from one side and flow towards the opposite side by making a definitive angle (90 degrees or less) or standing straight at the center of the pattern and finally exiting from the opposite side. They also don't have any core or deltas but they do have numerous ridge formations like ridge endings, bifurcations, dots, and islands.

2. Loops

Around 60-65% of the recorded fingerprints are loop which makes it the most common fingerprint pattern in the population. A loop is formed when one or more ridges enter from a side (either left or right), continuing up to the center of the pattern, recurving around the core forming a loop, and then flowing back and terminating/exiting from the same side of the pattern.

A loop always has one delta and a core and at least one ridge passes freely between the delta and the core. Based on the direction of opening and closing the loops, they are further subdivided into two types:

(a) Radial Loops

The loop is formed by the ridges entering from one side and flowing back from the same side after recurving around the core, to the same side with the opening of the loop pointing toward the radial bone or

(b) Ulnar Loop

This loop is also formed by ridges, which enter from one side and flow back, after recurving around the core, to the same side with the opening of the loop pointing towards the ulnar bone or the little finger of the same hand. To check whether the loop is radial or ulnar, we must know the hand from which the fingerprint originated.

3. Whorls

Whorl is found in the approx 30-35% of the recorded fingerprints of the population, making it the second most common fingerprint pattern after the loops. In a whorl, the ridge enters from a side making a complete spiral around the core of the fingerprint and terminate or tend to terminate at the core.

A whorl has 2 deltas and one core and the imaginary line drawn between two deltas must cross at least one recurving ridge to call the pattern a whorl. These types of whorls are known as plain whorls.

4. Composites

Composites are the 4th category of the fingerprint pattern. They are a mixture of Arches, loops, and Whorls. Around 1-2% of the population have these composites. Based on the nature of ridge movements, composites are classified into 4 types:

(a) Central Pocket Loops

A central Pocket loop is a combination of a loop and a whorl. In this fingerprint pattern, most of the ridges form loop, but one or more ridges recurve around the core, forming a pocket. If an imaginary line is drawn between two deltas then it should not intersect any of these recurving ridges.

(b) Double/ Twinned Loops

As the name suggests, a twinned loop contains a double-loop pattern. The two loops either overlap or surround each other and contain the point of the core exiting towards the different delta. The double loop pattern is sometimes referred to as the "Ying-Yang" symbol.

(c) Lateral Pocket Loops

A lateral pocket loop is also a double loop pattern that is formed by two loops overlapping or surrounding each other. In this fingerprint pattern, two different kinds of loops enter from the same end of the finger, recurve, and exit from the same end, one loop forms a covering-like pocket outside the other loop.

(d) Accidental

Accidental patterns are formed with the combination of two different fingerprint patterns except for plain arch. They have 2 or more deltas. They are too irregular to be placed under the above 3 categories.

Classification of Thermal Injuries

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A) Cold Injuries

1. General Effects

1. Hypothermia

Exposure of the body to cold, below temperature 35 ℃ (95 ℉) is called Hypothermia. When the temperature of the body falls below 32 ℃ to 24 ℃, there is disorientation, loss of consciousness, loss of reflex, and a fall in respiration heart rate, and blood pressure. Red patches and pallor of the skin, edema of the face, and stiffness of neck muscle may be seen.

Postmortem Findings

1. External

Patches of pink/brownish-pink discoloration on the skin. Edema on feet and blistering of skin can be seen. The extremities may be white (White deaths)

2. Internal

Lungs are congested and show hemorrhages. The heart shows dilation of the right atrium and ventricle. Wischnewslay spots may be seen in the stomach. Fatty changes in the liver and contracted spleen. Hemorrhages in core muscle. Ulceration of the colon.

2. Local Effects

1. Chilblain

These are red, itching, and skin lesions due to exposure to cold. They may be associated with edema and blistering.

2. Frostbite

This thermal injury happens due to freezing and the formation of ice crystals on the skin which obstructs the supply of blood to tissues. It occurs due to exposure to great extremes of cold (-2.5 ℃) Blue-black discoloration of fingers, toes and other body parts like nose, ears, and face is seen. Edema, blisters, necrosis, and gangrene may also appear.

3. Trench foot

Trench foot also known as immersion foot is a type of immersion syndrome injury resulting from the exposure of body parts to severe cold (< 10 ℃). It is seen in soldiers who live in trenches.

B) Heat Injuries

1. General Effects

1. Heat cramps

This thermal injury developed in workers who work in high temperatures when the sweating has been profuse. This causes rapid fluid and electrolyte depletion in the body. The person may report a flushed face, dilated pupils, dizziness, headache, etc.

2. Heat exhaustion

This thermal injury is developed due to inadequate water or salt intake in the body during a hot environment. This is followed by dehydration and fluid loss in the body. The person may report nausea, vomiting, and even heat stroke.

3. Heat stroke

Heat stroke is a life-threatening medical emergency resulting from the failure of the thermoregulatory mechanism. The victim shows cerebral dysfunction, impaired consciousness, high fever (> 41 ℃), and absence of sweating.

Postmortem Findings

Lungs are congested. The heart shows subendocardial hemorrhages. The brain is congested and edematous

4. Heat prostration

This thermal injury is developed due to salt depletion and dehydration due to excessive sweating. This condition is usually seen in the tropics and deserts.

2. Local effects

1. Burns

Burn is a thermal injury caused by heat or by a chemical or physical agent having an effect similar to heat.

Following are some common types of burns:

1. Contact Burns

These are developed due to physical contact between the body and a hot object like solid or molten metal.

2. Flame Burns

These are developed due to contact of the body with flame.

3. Scalds

They are caused by contact with hot liquids, most commonly water, and usually occur on exposed skin.

4. Chemical burns

They are caused by the application of acids, alkalis, etc.

5. Radiant heat burns

They are caused by heat waves which are a type of electromagnetic wave. There is no physical contact between the body and flame or hot surface.

Classification of burns

1. Wilson Classification

According to this, various burns injuries can be categorized into 3 types depending body layer involved.

1. Epidermal

These occur in reddening and blister formation. These are painful and heal without the formation of any scars.

2. Dermo-epidermal

These occur when the full thickness of the skin is involved in burns like hair follicles, sweat, and sebaceous glands. These are extremely painful and heal with the formation of scars.

3. Deep

These occur when deeper tissues below the skin that is subcutaneous tissues, muscles, and bones are involved. They are relatively less painful and heal with the formation of scars.

2. Dupytren's classification

According to the depth of tissue involved, he classified burn injuries into six categories:

1. First Degree

These occur when a low degree of heat is applied for a very short duration of time. It remains painful for a day or two and redness fades in a few hours or a day.

2. Second Degree

This occurs when the epidermis is affected completely due to the application of heat. Blisters formation takes place which is very painful. They usually heal within 7 days without scar formation.

3. Third degree

This occurs when the epidermis is completely destroyed with the involvement of the dermis. Blisters formation takes place with a red line. They heal with the formation of scars.

4. Fourth Degree

This occurs when the whole thickness of the skin is involved. These are not much painful owing to the destruction of nerve endings.

5. Fifth Degree

These occur when the depth of the lesion extends further and subcutaneous tissue is involved. These are less painful due to the total destruction of sensory nerve endings. They heal with deep scarring.

6. Sixth Degree

These occur with muscle and bone are involved. These occur charring of the limb and heal with much difficulty with contracture formation.

Postmortem Findings

1. External Findings

Clothing should be carefully removed and examined for the presence of kerosene, petrol, or any other inflammable substance.
Site, distribution, and extent of burning are recorded.
The face is usually distorted and swollen and the tip of the tongue is usually burnt.
Blisters either ruptured or filled with fluid may be seen.
Postmortem staining is cherry red in color due to the presence of carbon monoxide (CO), if the individual was alive and breathing during the fire.
Antemortem burn shows redness.
Hair may be singed, or partially/ completely burnt.

2. Internal Findings

Charring of the skull is seen due to intense heat.
The brain appears congested and swollen. Subdural hemorrhage may be present.
Hemorrhage in the root of the tongue and neck muscles.
The larynx, trachea, and bronchioles contain carbon and soot particles.
Heart chamber full of blood, cherry red in color due to inhalation of carbon monoxide.
The stomach and intestines may contain carbon particles.
The spleen is enlarged and softened.
Fatty liver and cloudy swelling in the liver.
Adrenals may be enlarged and congested.

2. Scalds

A scald is a thermal injury that results from the application of liquid at a temperature greater than 60 ℃ or steam. It damages the superficial layers of the skin. Following are the types of scalds.

1. Immersion burns

Accidental or deliberate immersion in hot liquid, usually water.

2. Splash or spill burns

Usually accidental.

3. Steam burns

They occur due to the application of superheated steam.

Presumptive and Confirmatory Tests for Blood

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(a) Presumptive Test

1. Phenolpthalein Test (Kastle Meyer Test)

Place a small portion of the suspected bloodstain, such as a cutting, swab, or extract, onto a piece of filter paper.

Two or three drops of ethanol are added to the stain.

Add two drops of the prepared phenolphthalein solution to the stain.

After ensuring that no color develops during this waiting period, 2-3 drops of 3% hydrogen peroxide are introduced to the stain.

The emergence of a vibrant pink color signifies a positive result for peroxide activity, indicating the presence of hemoglobin.

2. Leuomalachite Green Test (LMG)

A small curring, swab, or extract of the suspected bloodstream is placed on filter paper.

Add leucomalachite green solution to the stain.

If indicate green color appears then it gives a positive test for the presence of blood.

3. Alder Test (Benzidine Test)

It is the oldest method for the detection of blood which was developed by Alder in 1904.

It produces dark blue color in the reaction of blood with benzidine substrate in the presence of hydrogen peroxide.

Take a small amount of blood sample in a petri dish.

Add a small quantity of benzidine reagent to the sample, typically a few drops.

Add 3% Hydrogen peroxide to it.

Wait for 20 seconds, the appearance of dark blue color indicates a positive blood test.

4. Luminol Test

Take the suspected blood stain and add a few amounts of Luminol reagent.

The appearance of fluorescent color indicates a positive blood test.

(b) Confirmatory Test

1. Takayama Test

Position the specimen to be tested onto a microscope slide and cover it using a cover slip.

Apply a single drop of Takayama reagent onto the sample, enabling it to spread beneath the cover slip.

Warm slide gently on a hot plate at 65 ℃ for 10-20 seconds

Allow to cool and observe under a microscope at 100X.

The appearance of pink needle-shaped crystals of pyridine Haemochromogen is a positive reaction for heme and conforms to the presence of Hemoglobin.

2. Teichmann Test

Position the specimen onto a microscope slide and carefully cover it with a cover slip.

Let the reagent drop under the cover slip.

Warm the slide gently on a hot plate at 65 ℃ for 10-20 seconds.

Allow to cool and observe under the microscope at 100X.

The appearance of brown rhombohedron-shaped crystals of ferriprotoporphyrin chloride is a positive reaction for heme.

Diagnosis and Management of Poisoning Cases

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Diagnosis of Poisoning Cases

1. Diagnosis of poisoning in living

Following are the symptoms that suggest the poisoning in living:

The sudden onset of symptoms such as abdominal pain, nausea, vomiting, diarrhea, and collapse.
The sudden occurrence of coma accompanied by pupil constriction.
Unexplained coma, especially in children.
An adult with a known history of depressive illness experiencing a state of coma.
Rapid onset of neurological or GIT illness.
Sudden onset of convulsion.
Delirium with dilated pupils.
Paralysis, Jaundice, and hepato-cellular failure.

2. Diagnosis of poisoning in the dead (Postmortem Examination)

Internal Findings

1. Smell

To detect unusual odors in the brain, the first step is to open the skull.

2. Mouth and throat

Thoroughly examine for indications of inflammation, erosion, or staining. Necrosis of the pharynx will be seen in case of death caused by sulphonamide and barbiturates.

3. Respiratory System

Corrosive poisons show edema and congestion of the mucous membrane of the trachea and bronchi.

4. Esophagus

The mucous membrane experiences significant softening and desquamation when exposed to corrosive alkalis.

5. Heart

Poisoning with arsenic, antimony, barium, and mercury can lead to the occurrence of subendocardial hemorrhage (internal bleeding) in the left ventricle.

6. Stomach

Hypermia of muscous membrane.
Redness of mucosa in case of asphyxial deaths.
Ulceration caused by corrosives or irritants is typically observed at the greater curvature.
Perforation is observed when strong mineral acids especially H₂SO₄ have been taken.
Softening of the mucous membrane of the stomach caused by alkali corrosives.

7. Liver

Phosphorus, chloroform, TNT, and CCl₄ are known to cause liver necrosis. Fatty liver is caused by arsenic, CCl₄, and FeSO₄. Jaundice is caused by phosphorous and potassium chlorate.

8. Kidney

Metal and cantharidin poisoning can lead to the manifestation of parenchymatous degenerative changes.

Necrosis of Proximal Convoluted Tubules (PCT) is observed in mercuric chloride, phenol, Lysol, etc.

Management of Poisoning Cases

1. Removal of Unabsorbed Poison

(a) Inhaled Poisons

In case of poisoning by carbon monoxide, automobile exhaust, gas from the septic tank, etc the patient should be immediately removed to fresh air to remove the poisonous gas through the lungs.

(b) Injected Poisons

If the poison has been injected then some unabsorbed poison may be removed by multiple incisions and suction, similar to that commonly advised for snake bites.

(c) Contact Poisons

If the poison is applied to eyes, skin, wound, or inserted, the poison is removed by washing with plain warm water and administration of specific antidotes.

(d) Ingested Poisons

(i) Stomach Washing (Gastric lavage)

Stomach washing is most useful within 1 hr of ingestion of any poison. In this method, 5 ml fluid/Kg of body weight is administered with the help of a french orogastric tube through the mouth.

It is repeated, till the clear and odorless fluid comes out. If any bleeding occurs, the procedure is halted or abandoned.

(ii) Emetics (Early Vomiting)

Early vomiting (emesis) is more effective in preventing absorption than performing vigorous gastric lavage after a delay. Emetics is easier than gastric lavage and less traumatic for the patient.

Emesis should be avoided in corrosive poisoning as it may damage the esophagus and stomach.

Examples of household emetics are copious lukewarm water, and 15 g of mustard powder in 200 ml of water.

(iii) Demulcents and Bulky Foods

These are the substances that prevent the absorption of the poison by forming a coating on the mucous membrane of the stomach. Common demulcents include fats, oils, milk, and egg albumin.

Bulky foods like bananas can serve as a mechanical antidote to glass by trapping its particles and preventing its harmful effects.

4. Administration of Antidotes

Antidotes function by mechanically preventing the action of the poison, without directly destroying or inactivating its harmful effects.

They are also used because the poison may not have been completely removed by emesis or lavage or the poison is already absorbed or it has been administered by other routes than ingestion. Based on their mode of action, antidotes are classified into the following categories:

(i) Physical/ Mechanical Antidotes

Physical antidotes prevent the absorption of poisons in the body by their presence. Following are some physical antidotes:

Activated Charcoal

It is a high-temperature product resulting from the destructive distillation of wood pulp, appearing as a fine, black, and odorless powder.

It is given about 1g/kg of body weight, mixed with water to form a soup-like mixture, and given orally. It acts mechanically by absorbing and retaining the poison within its pores, especially alkaloid poisons.

(iii) Chemical Antidotes

Chemical antidotes work by either forming harmless or insoluble compounds with poisons or by oxidizing the poisons upon contact, thereby preventing their harmful actions. For eg: Potassium permanganate has oxidizing properties.

Its 1:5000 solution is used and the wash must be continued till the solution coming out of the stomach is pink in color. Other examples of chemical antidotes are tannic acid, milk of magnesia, common salt, tincture iodine, etc.

(iii) Physiological/ Pharmacological Antidotes

These agents produce effects that are opposite to that of poison. They are used after some poison is absorbed into circulation. However, the antagonism is usually not complete and the remedy may itself produce undesired results.

Nalorphine has proven to be an effective specific antidote against morphine and its related substances, offering significant value in treatment. Specific chelating agents are commonly employed as antidotes against specific heavy metals, forming stable non-ionized cyclic complexes (Chelates) with cations.

These compounds have the ability to create stable, soluble complexes with calcium and specific heavy metals, rendering them non-toxic. Eg, BAI, EDTA, etc.

Quality Management: Definition, Principle and Stages

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What is Quality Management?

Quality management is a process to make sure that a product or service made by the company meets the standard of excellence and satisfies the customer's needs. Quality management not only focuses on product quality but also tells us the ways of achieving it.

Components of Quality Management

There are four main components of quality management:

1. Quality Control (QC)

It is a process in which the quality is maintained and reviewed considering all factors involved in the production.'

2. Quality Assurance (QA)

It is a process of preventing mistakes and manufacturing defects in a product and assuring the customer that the product delivered to him will be of high quality.

3. Quality Improvement (QI)

It is a process of continuous improvement in the quality of products through time-to-time inspections, checks, and reviews. This helps to evolve the product and meet the customer's expectations.

4 Quality Planning (QP)

It is the process of identifying the quality standards relevant to the project and deciding how to meet them.

Example of Quality Management

A great example of the implementation of quality management is Toyota Corporation's Kanban system. It is an inventory control system that helps to create visibility for both suppliers and buyers and helps to regulate the wastage of inventory on the production line at any given point in time.

This helps Toyota to increase its efficiency and develop cars that are high quality and meets customer needs.

Stages of Quality Management

There are 4 stages of quality management

Stage 1

In this stage, the goals and targets of the company are identified and quality metrics are denied for the product.

Stage 2

In this stage, training, documentation, policies, workflows, and procedures are defined to support the steps of quality management.

Stage 3

In this stage, the manufacturing of the product is monitored and the results are reviewed and areas of improvement are identified.

Stage 4

In this stage, the outcome is reviewed and this whole process is ready to enter into the standard operating procedure domain of the company.

Principles of Quality Management

1. Customer Focus

Meeting and exceeding customer expectations is the primary focus of quality management.

2. Leadership

Effective leadership establishes unity of purpose and direction within an organization.

3. Engagement of People

Involving and empowering people at all levels promotes their contribution to achieving organizational goals.

4. Process Approach

Managing activities and resources as interconnected processes helps achieve desired outcomes.

5. Improvement

Continual improvement is essential for enhancing performance, efficiency, and effectiveness.

6. Evidence-based Decision Making

Making decisions based on analysis and evaluation of data and information leads to better outcomes.

7. Relationship Management

Developing and maintaining mutually beneficial relationships with suppliers and stakeholders contributes to overall success.

Advantages of Quality Management

It helps an organization to achieve greater consistency in tasks and activities that are involved in the production of products and services.

By enhancing operational efficiency, minimizing waste, and optimizing resource utilization, it leads to increased productivity and effective utilization of time and resources.

It helps to improve customer satisfaction.

It enables businesses to market their products efficiently and search for new markets.

It makes a business continuously improve its products, processes, and systems.

Types of Ballistics in Forensic Science

2023-06-22T23:26:00.002+05:30

What is Ballistics?

Ballistics is a branch of science that deals with the propulsion, flight, and impact of projectiles on the target. The term "Ballistics" finds its roots in the Greek word "Ballein," signifying "to throw" or "to project." It is Colonel Godard who first coined forensic ballistics. He used the systematic study of firearms and ammunition for investigation and justice.

Types of Ballistics

Ballistics is divided into three major types:

1. Internal Ballistics

Internal Ballistics is the branch of ballistics that deals with the study of the projectile inside the barrel of the firearm that is from when the firing pin hits the primer to the time the bullet exists the barrel from the muzzle end of the firearm.

It is also known as Initial or Interior Ballistics. Internal ballistics helps in linking the projectile with the firearm by studying scratch marks on the projectile, velocity of the projectile, defects in the barrel, Erratic behavior of projectiles, etc.

2. External Ballistics

External Ballistics is the branch of Ballistics that deals with the study of the projectile of the bullet when it leaves the barrel and when it is about to hit the target. Therefore, it studies the trajectory, velocity, range, time of flight, etc of the bullet. External Ballistics came into consideration when Internal Ballistics ended and Terminal Ballistics is about to start.

3. Terminal Ballistics

Terminal Ballistics is the branch of Ballistics that deals with the study of the behavior of a projectile/bullet when it hits the target. It is concerned with the study of penetration potential and wound ballistics. Terminal Ballistics start just after External ballistics get over.

Total Quality Management: Definition, Phases and Principles

2023-06-17T10:52:00.001+05:30

What is Total Quality Management?

Total Quality Management (TQM) is a process of continuous effort by the management as well as employees of the company to improve processes, products, and services for customer satisfaction.

By fostering a collective commitment among employees to enhance work culture, processes, services, systems, and more, it paves the way for sustained success in the long run.

Phases of Total Quality Management (TQM)

Total Quality Management (TQM) is divided into four phases that are Plan, Do, Check, and Act. It is also called PDCA Cycle.

1. Planning Phase

It is the first and most crucial phase in Total Quality Management (TQM). In this phase, employees come up with their problems and queries which need to be addressed. A proper plan or road map is prepared to find the solution to all the queries and problems.

2. Doing Phase

In this phase, employees develop a detailed solution to the problems that they identified in the Planning Phase. Different strategies are implemented at this stage to overcome the challenges faced by the employees.

3. Checking Phase

In this phase, an audit is done to see if our initiated plan worked. It helps to identify problematic parts of the current process and eliminate them in the future.

4. Acting Phase

It represents the final stage of the PDCA (Plan-Do-Check-Act) cycle. In this phase, the previously developed plan comes into the force and employees document their results and prepare themselves to address other problems.

Principles of Total Quality Management (TQM)

There are total 8 principles of Total Quality Management (TQM):

1. Customer Focused

This principle tells us that the customer determines the level of quality of the product. So, to meet customer expectations, the product's quality should be customer-centered.

2. Total employee involvement

This principle tells us that the quality of the product can only be improved if all the employees are involved quickly and work towards a common goal.

3. Process Centred

This principle tells us that employees should focus on process thinking. The steps required to carry out the process should be continuously monitored to detect even minor defects.

4. Integrated System

This principle tells us that different systems/departments should be integrated to improve work efficiency.

5. Strategic and Systematic approach

This principle tells us that strategic and systematic approaches should be employed in the system to achieve an organization's vision, mission, and goals.

6. Continous improvement

This principle tells us that to improve the quality of the product, continuous improvement in both analytical and creative ways is necessary.

7. Fact-based decision making

This principle tells us that to know how well an organization is performing, data on performance measures are necessary.

8. Communications

This principle tells us that effective communication plays a vital role in maintaining morale and in motivating employees at all levels. Communication involves strategies, methods, and timeliness.

Advantages of Total Quality Management (TQM)

It helps to minimize product defects which reduce product recalls and helps to build customer trust.
It helps in higher customer satisfaction which leads to increased market share, and revenue growth.
It helps to save costs in customer support, product replacements, field service, and the creation of product fixes.