Blood Donation

by Vikram Singh ECE

A blood donation occurs when a person voluntarily has blood drawn and used for transfusions or made into medications by a process called fractionation.

In the developed world, most blood donors are unpaid volunteers who give blood for a community supply. In poorer countries, established supplies are limited and donors usually give blood when family or friends need a transfusion. Many donors donate as an act of charity, but some are paid and in some cases there are incentives other than money such as paid time off from work. A donor can also have blood drawn for their own future use. Donating is relatively safe, but some donors have bruising where the needle is inserted or may feel faint.

Potential donors are evaluated for anything that might make their blood unsafe to use. The screening includes testing for diseases that can be transmitted by a blood transfusion, including HIV and viral hepatitis. The donor must also answer questions about medical history and take a short physical examination to make sure the donation is not hazardous to his or her health. How often a donor can give varies from days to months based on what he or she donates and the laws of the country where the donation takes place. For example, in the United States donors must wait eight weeks (56 days) between whole blood donations but only three days between plateletphere donations

The amount of blood drawn and the methods vary. The collection can be done manually or with automated equipment that only takes specific portions of the blood. Most of the components of blood used for transfusions have a short shelf life, and maintaining a constant supply is a persistent problem

 

*Types of donation:

A blood collection bus (bloodmobile) from Children’s Hospital Boston at a manufacturing facility in Massachusetts. Blood banks sometimes use a modified bus or similar large vehicle to provide mobile facilities for donation.

Blood donations are divided into groups based on who will receive the collected blood An allogeneic (also called homologous) donation is when a donor gives blood for storage at a blood bank for transfusion to an unknown recipient. A directed donation is when a person, often a family member, donates blood for transfusion to a specific individual Directed donations are relatively rare when an established supply exists. A replacement donor donation is a hybrid of the two and is common in developing countries such as Ghana In this case, a friend or family member of the recipient donates blood to replace the stored blood used in a transfusion, ensuring a consistent supply. When a person has blood stored that will be transfused back to the donor at a later date, usually after surgery, that is called an  donation. Blood that is used to make medications can be made from allogeneic donations or from donations exclusively used for manufacturing.

Blood is sometimes collected using similar methods for therapeutic phlebotomy, similar to the ancient practice of bloodletting which is used to treat conditions such as hereditary hemochromatosis or polycythemia vera. This blood is sometimes treated as a blood donation, but may be immediately discarded if it cannot be used for transfusion or further manufacturing.

The actual process varies according to the laws of the country, and recommendations to donors vary according to the collecting organization. The World Health Organization gives recommendations for blood donation policies, but in developing countries many of these are not followed. For example, the recommended testing requires laboratory facilities, trained staff, and specialized reagents, all of which may not be available or too expensive in developing countries.

An event where donors come to give allogeneic blood is sometimes called a blood driVe or a blood donor session. These can occur at a blood bank but they are often set up at a location in the community such as a shopping center, workplace, school, or house of worship.

* Screening:

Donors are typically required to give consent for the process and this requirement means that minors cannot donate without permission from a parent or guardian In some countries, answers are associated with the donor's blood, but not name, to provide anonymity; in others, such as the United States, names are kept to create lists of ineligible donors. If a potential donor does not meet these criteria, they are deferred. This term is used because many donors who are ineligible may be allowed to donate later. Blood banks in the United States may be required to label the blood if it is from a therapeutic donor, so some do not accept donations from donors with any blood disease. Others, such as the Australian Red Cross Blood Service, accept blood from donors with hemochromatosis. It is a genetic disorder that does not affect the safety of the blood.

All blood donors are asked questions about their medical history.

The donor's race or ethnic background is sometimes important since certain blood types, especially rare ones, are more common in certain ethnic groups. Historically, donors were segregated or excluded on race, religion, or ethnicity, but this is no longer a standard practice.

* Recipient safety:

Donors are screened for health risks that could make the donation unsafe for the recipient. Some of these restrictions are controversial, such as restricting donations from men who have sex with men for HIV risk Autologous donors are not always screened for recipient safety problems since the donor is the only person who will receive the blood. Donors are also asked about medications such as dutasteride since they can be dangerous to a pregnant woman receiving the blood

Donors are examined for signs and symptoms of diseases that can be transmitted in a blood transfusion, such as HIV, malaria, and viral hepatitis. Screening may include questions about risk factors for various diseases, such as travel to countries at risk for malaria or variant Creutzfeldt-Jakob Disease (vCJD). These questions vary from country to country. For example, while blood centers in Québec, Poland, and many other places defer donors who lived in the United Kingdom for risk of vCJD donors in the United Kingdom are only restricted for vCJD risk if they have had a blood transfusion in the United Kingdom.

                                                                                                                           *Donor safety:

The donor is also examined and asked specific questions about their medical history to make sure that donating blood is not hazardous to their health. The donor's hematocrit or hemoglobin level is tested to make sure that the loss of blood will not make them anemic, and this check is the most common reason that a donor is ineligible. Pulse, bLood pressure, and body temperature are also evaluated. Elderly donors are sometimes also deferred on age alone because of health concerns.The safety of donating blood during pregnancy has not been studied thoroughly, and pregnant women are usually deferred

*Blood testing:

The donor's blood typE must be determined if the blood will be used for transfusions. T he collecting agency usually identifies whether the blood is type A, B, AB, or O and the donor's RH (D)type and will screen for antibodies to less common antigens. More testing, including a crossmatch, is usually done before a transfusion. Group O is often cited as the "universal donor" but this only refers to red cell transfusions. For plasma transfusions the system is reversed and AB is the universal donor type.

Most blood is tested for diseases, including some STDs The tests used are high-sensitivity screening tests and no actual diagnosis is made. Some of the test results are later found to be false positives using more specific testing False negatives are rare, but donors are discouraged from using blood donation for the purpose of anonymous STD screening because a false negative could mean a contaminated unit. The blood is usually discarded if these tests are positive, but there are some exceptions, such as autologous donations. The donor is generally notified of the test result

Donated blood is tested by many methods, but the core tests recommended by the World Health Organization are these four:

                                                                                                                                                                                                                                                                                                                                                                                                                       (1) Hepatitis B Surface Antigen

(2) Antibody to Hepatitis C

(3) Antibody to HIV, usually subtypes 1 and 2

(4) Serologic test for Syphilis

The WHO reported in 2006 that 56 out of 124 countries surveyed did not use these basic tests on all blood donations.

A variety of other tests for transfusion transmitted infections are often used based on local requirements. Additional testing is expensive, and in some cases the tests are not implemented because of the cost. These additional tests include other infectious diseases such as West Nile Virus Sometimes multiple tests are used for a single disease to cover the limitations of each test. For example, the HIV antibody test will not detect a recently infected donor, so some blood banks use a p24 antigen or HIV nucleic acid test in addition to the basic antibody test to detect infected donors during that period. Cytomegalovirus is a special case in donor testing in that many donors will test positive for it. The virus is not a hazard to a healthy recipient, but it can harm infants and other recipients with weak immune systems.

Indian Economy

By Dhruv sharma CSE

Introduction:-

The Economy of India is the eleventh largest in the world by nominal GDP and the third largest by purchasing power parity(PPP).  The country is one of the G-20 major economies and a member of BRICS. In 2011, the country's per capita income stood at $3,694 IMF, 129^th in the world, thus making a lower-middle income economy.

After the independence-era Indian economy (before and a little after 1947) was inspired by the Soviet model of economic development, with a large public sector, high import duties combined with interventionist policies, leading to massive inefficiencies and widespread corruption.

India recorded the highest growth rates in the mid-2000s, and is one of the fastest-growing economies in the world. The growth was led primarily due to a huge increase in the size of the middle class consumer, a large labour force and considerable foreign investments. India is the nineteenth largest exporter and tenth largest importer in the world. Economic growth rates are projected at around 7% for the 2011-12.

History:-

The known Economic history of India begins with the Indus Valley civilization. The Indus civilization's economy appears to have depended significantly on trade, which was facilitated by advances in transport. Around 600 BC, the Mahajanapadas minted punch-marked silver coins. The period was marked by intensive trade activity and urban development. By 300 B.C., the Maurya Empire united most of the Indian subcontinent. The political unity and military security allowed for a common economic system and enhanced trade and commerce, with increased agricultural productivity.

For the next 1500 years, India produced its classical civilizations such as the Rashtrakutas, Hoysalas and Western Gangas. During this period India is estimated to have had the largest economy of the ancient and medieval world between the 1st and 17th centuries AD, controlling between one third and one fourth of the world's wealth up to the time of the Marathas, from whence it rapidly declined during European rule.

History is divided into four periods:-

Ø Pre-colonial period (up to 1773):-

The citizens of the Indus Valley civilisation, a permanent settlement that flourished between 2800 BC and 1800 BC, practiced agriculture, domesticated animals, used uniform weights and measures, made tools and weapons, and traded with other cities. Evidence of well-planned streets, a drainage system and water supply reveals their knowledge of urban, which included the world's first urban sanitation systems and the existence of a form of municipal government.

Ø Colonial period (1773–1947):-

Company rule in India brought a major change in the taxation and agricultural policies, which tended to promote commercialisation of agriculture with a focus on trade, resulting in decreased production of food crops, mass impoverishment and destitution of farmers, and in the short term, led to numerous famines. The economic policies of the British Raj caused a severe decline in the handicrafts and handloom sectors, due to reduced demand and dipping employment. After the removal of international restrictions by the Charter of 1813, Indian trade expanded substantially and over the long term showed an upward trend. The result was a significant transfer of capital from India to England, which, due to the colonial policies of the British, led to a massive drain of revenue rather than any systematic effort at modernisation of the domestic economy.

Ø Pre-liberalisation period (1947–1991):-

Indian economic policy after independence was influenced by the colonial experience, which was seen by Indian leaders as exploitative, and by those leaders' exposure to British social democracy as well as the progress achieved by the planned economy of the Soviet Union. Domestic policy tended towards protectionism, with a strong emphasis on import substitution industrialisation, economic interventionism, a large public sector, business regulation, and central planning, while trade and foreign investment policies were relatively liberal. Five-Year Plans of India resembled central planning in the Soviet Union. Steel, mining, machine tools, telecommunications, insurance, and power plants, among other industries, were effectively nationalised in the mid-1950s.

Ø Post-liberalisation period (since 1991):-

In the late 1970s, the government led by Morarji Desai eased restrictions on capacity expansion for incumbent companies, removed price controls, reduced corporate taxes and promoted the creation of small scale industries in large numbers. He also raised the income tax levels at one point to a maximum of 97.5%, a record in the world for non-communist economies. However, the subsequent government policy of  Fabian socialism hampered the benefits of the economy, leading to high fiscal deficits and a worsening current account. The collapse of the Soviet Union, which was India's major trading partner, and the Gulf War, which caused a spike in oil prices, resulted in a major balance-of-payments crisis for India, which found itself facing the prospect of defaulting on its loans. India asked for a $1.8 billion bailout loan from the International Monetary Fund (IMF), which in return demanded reforms.

SECTORS OF THE INDIAN ECONOMY

·      Primary Sector

When the economic activity depends mainly on exploitation of natural resources then that activity comes under the primary sector. Agriculture and agriculture related activities are the primary sectors of economy.

Agriculture:-

India ranks second worldwide in farm output. Agriculture and allied sectors like forestry, logging and fishing accounted for 15.7% of the GDP in 2009–10, employed 52.1% of the total workforce, and despite a steady decline of its share in the GDP, is still the largest economic sector and a significant piece of the overall socio-economic development of India. Yields per unit area of all crops have grown since 1950, due to the special emphasis placed on agriculture in the five-year plans and steady improvements in irrigation, technology, application of modern agricultural practices and provision of agricultural credit and subsidies since the Green Revolution in India. However, international comparisons reveal the average yield in India is generally 30% to 50% of the highest average yield in the world. Indian states  Uttar Pradesh,  Punjab,  Haryana,  Madhya Pradesh,  Andhra Pradesh,  Bihar,  West Bengal and Maharashtra are key agricultural contributing states of India.

·      Secondary Sector

When the main activity involves manufacturing then it is the secondary sector. All Industrial production where physical goods are produced come under the secondary sector.

Industry and service:-

Industry accounts for 28% of the GDP and employ 14% of the total workforce. In absolute terms, India is 12th in the world in terms of nominal factory output. The Indian industrial sector underwent significant changes as a result of the economic reforms of 1991, which removed import restrictions, brought in foreign competition, led to privatisation of certain public sector industries, liberalised the FDI regime, improved infrastructure and led to an expansion in the production of fast moving consumer goods. Post-liberalisation, the Indian private sector was faced with increasing domestic as well as foreign competition, including the threat of cheaper Chinese imports. It has since handled the change by squeezing costs, revamping management, and relying on cheap labour and new technology. However, this has also reduced employment generation even by smaller manufacturers who earlier relied on relatively labour-intensive processes.

·      Tertiary Sector

When the activity involves providing intangible goods like services then this is part of the tertiary sector. Financial services, management consultancy, telephony and IT are good examples of service sector.

Banking and finance

The Indian money market is classified into the organised sector, comprising private, public and foreign owned commercial banks and cooperative banks, together known as scheduled banks, and the unorganised sector, which includes individual or family owned indigenous bankers or money lenders and non-banking financial companies. The unorganised sector and microcredit are still preferred over traditional banks in rural and sub-urban areas, especially for non-productive purposes, like ceremonies and short duration loans.

Information technology

The Information technology industry in India has gained a brand identity as a knowledge economy due to its IT and ITES sector. The IT–ITES industry has two major components: IT Services and business process outsourcing (BPO). The growth in the service sector in India has been led by the IT–ITES sector, contributing substantially to increase in GDP, employment, and exports. The sector has increased its contribution to India's GDP from 1.2% in FY1998 to 7.1% in FY2011. According to NASSCOM, the IT–BPO sector in India aggregated revenues of US$88.1 billion in FY2011, where export and domestic revenue stood at US$59 billion and US$29 billion respectively. The top seven cities that account for about 90% of this sectors exports are Bangalore, Chennai, Hyderabad, Mumbai, Pune, Delhi, Kolkata and Coimbatore.

Income and consumption:-

India's gross national income per capita had experienced astonishing growth rates since 2002. India's Per Capita Income has tripled from Rs.19,040 in 2002–03 to Rs.53,331 in 2010–11, averaging 13.7% growth over these eight years. It further grew by 14.3% to reach Rs.60,972 during 2011–12 fiscal. Indian official estimates of the extent of poverty have been subject to debate, with concerns being raised about the methodology for the determination of the poverty line. As of 2005, according to World Bank statistics, 75.6% of the population lived on less than $2 a day (PPP), while 27.5% of the population was living below the new international poverty line of $1.25 (PPP) per day. However, data released in 2009 by the Government of India estimated that 37% of the population lived below the poverty line.

Housing is modest. According to The Times of India, a majority of Indians had a per capita space equivalent to or less than a 100 square feet (9.3 m²) room for their basic living needs, and one-third of urban Indians lived in "homes too cramped to exceed even the minimum requirements of a prison cell in the US. The average is 103 sq ft (9.6 m²) per person in rural areas and 117 sq ft (10.9 m²) per person in urban areas. Around half of Indian children are malnourished. The proportion of underweight children is nearly double that of Sub-Saharan Africa. However, India has not had any major famines since Independence.

Employment:-

Agricultural and allied sectors accounted for about 52.1% of the total workforce in 2009–10. While agriculture has faced stagnation in growth, services have seen a steady growth. Of the total workforce, 7% is in the organised sector, two-thirds of which are in the public sector. The NSSO survey estimated that in 2004–05, 8.3% of the population was unemployed, an increase of 2.2% over 1993 levels, with unemployment uniformly higher in urban areas and among women. Growth of labour stagnated at around 2% for the decade between 1994–2005, about the same as that for the preceding decade. Avenues for employment generation have been identified in the IT and travel and tourism sectors, which have been experiencing high annual growth rates of above 9%.

Economic disparities:-

A critical problem facing India's economy is the sharp and growing regional variations among India's different states and territories in terms of poverty, availability of infrastructure and socio-economic development. Six low-income states – Bihar, Chhattisgarh, Jharkhand, Madhya Pradesh, Orissa and Uttar Pradesh – are home to more than one third of India's population. Severe disparities exist among states in terms of income, literacy rates, life expectancy and living conditions.

Law of variable proportions

By Sapna CSE

Introduction:

The law of variable proportions states that as the quantity of one factor is increased, keeping the other factors fixed, the marginal product of that factor will eventually decline. This means that upto the use of a certain amount of variable factor, marginal product of the factor may increase and after a certain stage it starts diminishing. When the variable factor becomes relatively abundant, the marginal product may become negative.

Assumptions: The law of variable proportions holds good under the following conditions:

1.       Constant State of Technology: First, the state of technology is assumed to be given and unchanged. If there is improvement in the technology, then the marginal product may rise instead of diminishing.

2.       Fixed Amount of Other Factors: Secondly, there must be some inputs whose quantity is kept fixed. It is only in this way that we can alter the factor proportions and know its effects on output. The law does not apply if all factors are proportionately varied.

3.       Possibility of Varying the Factor proportions: Thirdly, the law is based upon the possibility of varying the proportions in which the various factors can be combined to produce a product. The law does not apply if the factors must be used in fixed proportions to yield a product. 

4.        

Illustration of the Law: The law of variable proportion is illustrated in the following table and figure. Suppose there is a given amount of land in which more and more labour (variable factor) is used to produce wheat.

Units of Labour	Total Product	Marginal Product	Average Product
1	2	2	2
2	6	4	3
3	12	6	4
4	16	4	4
5	18	2	3.6
6	18	0	3
7	14	-4	2
8	8	-6	1

It can be seen from the table that upto the use of 3 units of labour, total product increases at an increasing rate and beyond the third unit total product increases at a diminishing rate. This fact is shown by the marginal product which  is the addition made to Total Product as a result of increasing the variable factor i.e. labour.

It can be seen from the table that the marginal product of labour initially rises and beyond the use of  three units of labour, it starts diminishing. The use of six units of labour does not add anything to the total production of wheat. Hence, the marginal product of labour has fallen to zero. Beyond the use of six units of labour, total product diminishes and therefore marginal product of labour becomes negative. Regarding the average product of labour, it rises up to the use of third unit of labour and beyond that it is falling throughout. 

Three Stages of the Law of Variable Proportions: These stages are illustrated in the following figure where labour is measured on the X-axis and output on the Y-axis.

Stage 1. Stage of Increasing Returns: In this stage, total product increases at an increasing rate up to a point. This is because the efficiency of the fixed factors increases as additional units of the variable factors are added to it. In the figure, from the origin to the point F, slope of the total product curve TP is increasing i.e. the curve TP is concave upwards upto the point F, which means that the marginal product MP of labour rises. The point F where the total product stops increasing at an increasing rate and starts increasing at a diminishing rate is called the point of inflection. Corresponding vertically to this point of inflection marginal product of labour is maximum, after which it diminishes. This stage is called the stage of increasing returns because the average product of the variable factor increases throughout this stage. This stage ends at the point where the average product curve reaches its highest point.

Stage 2. Stage of Diminishing Returns: In this stage, total product continues to increase but at a diminishing rate until it reaches its maximum point H where the second stage ends. In this stage both the marginal product and average product of labour are diminishing but are positive. This is because the fixed factor becomes inadequate relative to the quantity of the variable factor. At the end of the second stage, i.e., at point M marginal product of labour is zero which corresponds to the maximum point H of the total product curve TP. This stage is important because the firm will seek to produce in this range.

Stage 3. Stage of Negative Returns: In stage 3, total product declines and therefore the TP curve slopes downward. As a result, marginal product of labour is negative and the MP curve falls below the X-axis. In this stage the variable factor (labour) is too much relative to the fixed factor.

Importance and Applicability of the Law of Variable Proportion:

The Law of Variable Proportion has universal applicability in any branch of production. It forms the basis of a number of doctrines in economics. The Malthusian theory of population stems from the fact that food supply does not increase faster than the growth in population because of the operation of the law of diminishing returns in agriculture.

Ricardo also based his theory of rent on this principle. According to him rent arises because the operation of the law of diminishing return forces the application of additional doses of labour and capital on a piece of land. Similarly the law of diminishing marginal utility and that of diminishing marginal physical productivity in the theory of distribution are also based on this theory.

The law is of fundamental importance for understanding the problems of underdeveloped countries. In such agricultural economies the pressure of population on land increases with the increase in population. This leads to declining or even zero or negative marginal productivity of workers. This explains the operation of the law of diminishing returns in LDCs in its intensive form. Ragnar Nurkse have suggested ways to make use of these disguisedly unemployed labour by withdrawing them and putting them in those occupations where the marginal productivity is positive.