THE NOBLE PRIZE
The Noble Prize is considered the most prestigious prize in the world .It is awarded annually to people or institutions for outstanding contribution in a variety of fields for the good of humanity.
The prize is named after Alfred Nobel, who in his will directed that the interest from the funds be set aside and used to give one annual prize in each of the five fields of Physics, Chemistry, medicine and literature and the ‘most effective work in the interest of International peace’. The prizes were first presented in 1901. A sixth prize the Nobel Memorial prize in economic science was instituted in 1968, by the national bank of Sweden.
These six Nobel prizes are awarded every year on December 10th the death anniversary of Alfred Nobel. Each recipient is presented a gold medal, a certificate baring the awards name and field of achievement, and a cash prize. The abverse side of each metal has a burst of Alfred Nobel. The reverse side of each medal, other than those of Physics and Chemistry, which had identical reverse sides, is different. The rize-giving ceremony is held in Stockholm, Sweden. The peace prize, however, is awarded in Oslo, Norway.
The Prize-winners are chosen by different committee whose members are selected by the Swedish Academics and institution and the Norwegian Parliament. The candidates are chosen from among the names recommended by eminent scholars, former Nobel Prize winners and distinguished scientist. The candidate does not apply for the prize directly. Sometimes two or more winners share the prize and sometimes no candidate is found suitable for a particular prize in that year.
In his will, Alfred Nobel had mentioned: “,…It is my express wish that in awarding the prizes no consideration whatever shall be given to nationality of the candidates, but that the most worthy shall receive the prize whether he be a Scandinavian or not.”
Sunday, March 29, 2009
The Luminous life of Alfred Nobel
The Luminous life of Alfred Nobel
On October 21, 1833 a bailey boy to a family in Stockholm, Sweden his father was Immanuel Nobel and his mother was Andretti Ahlell Noble.
He learnt a great deal of his own, which included learning French, by translating Voltaire first into Swedish and then back into French and checking it again the original. Alfred Noble’s expanding capacity that his revolutionary inventions the blasting cap and dynamite, patented in 1863and 1867 respectively famed the basis for operations at Vinterviken. Dynamite and detonating caps became much demanded in the construction of industry. Alfred set up factories in ninety different places. He also experimented hundred and fifty five patients in his name. He had been suffering from chronic cold and symptoms of scurry for some time and the balmy, mild climate of the Mediterranean was a welcome relief after the cold and humidity of Paris. The property that Alfred Nobel brought of the Rivera Di Puente, in 1891, had a large villa, whose exterior canned influences of the kind of architecture more widespread in the orient. He was familiar with Volaire and Rousseau the philosophers of enlightenment. He had also set out the draft of a longer novel called” Systrana” (the sisters), where he discusses faith and knowledge with free thinker called Oswald and questions the divinity of Christ .His last wish expressed that in awarding the prizes to no, the candidates but that the most worthy shall receive the prize, whether he be Scandinavian or not. He died in 1896 in his home in Sanrem, lately on December 10, 1896.
On October 21, 1833 a bailey boy to a family in Stockholm, Sweden his father was Immanuel Nobel and his mother was Andretti Ahlell Noble.
He learnt a great deal of his own, which included learning French, by translating Voltaire first into Swedish and then back into French and checking it again the original. Alfred Noble’s expanding capacity that his revolutionary inventions the blasting cap and dynamite, patented in 1863and 1867 respectively famed the basis for operations at Vinterviken. Dynamite and detonating caps became much demanded in the construction of industry. Alfred set up factories in ninety different places. He also experimented hundred and fifty five patients in his name. He had been suffering from chronic cold and symptoms of scurry for some time and the balmy, mild climate of the Mediterranean was a welcome relief after the cold and humidity of Paris. The property that Alfred Nobel brought of the Rivera Di Puente, in 1891, had a large villa, whose exterior canned influences of the kind of architecture more widespread in the orient. He was familiar with Volaire and Rousseau the philosophers of enlightenment. He had also set out the draft of a longer novel called” Systrana” (the sisters), where he discusses faith and knowledge with free thinker called Oswald and questions the divinity of Christ .His last wish expressed that in awarding the prizes to no, the candidates but that the most worthy shall receive the prize, whether he be Scandinavian or not. He died in 1896 in his home in Sanrem, lately on December 10, 1896.
Thursday, March 26, 2009
The father of Microsoft
The father of Microsoft
There are many great personalities in this would some achieve because of these character and some achieve greatness because of their intelligence these is one such great personality “Bill Gates” when richest man of the world and because of his hard work and intelligence he can be called the father of Microsoft.
Bill Gates is the chairman and chief software architect of Microsoft Corporation and the worldwide leader in software, services and Internet technologies for personal and business computing. Microsoft had revenues of US $32.19 billion for the fiscal year ending June 2003 and employees more than 54,000 people in 85 countries.
On October 28th, 1955 shortly after 9:00 pm Bill Gates was born. His father was a prominent lawyer and his mother Mary Gates was a school teacher in the University of Washington Regent and chairwoman united way International. His grandfather was a Vice President of a national bank. Thus Bill Gates was born to a family with a rich history in Business politics and community service. Bill Gates started programming at the age of 13. As a school boy he and his friend Paul in 1968 hacked into a security system of a firm computer and were then asked to look for its weakness. It was here that Gates and Ales really began to develop the talents that would lead to the formation of Microsoft seven years later.
In December of 1974, Alen was on his way to visit Gates when along the way he stopped to browse the current magazines. What he saw changed Bill Gates lives forever. On the cover of Popular Electronics was a picture of the altar 8080 and the headline world’s first Micro computer kit to Rival models. He bought the issue and rushed over to Gates dorm room. They both recognized it as a big opportunity the two knew that home computer market was about to explode and that someone would need to make the software for the machines within a few days Gates has called MITS (Micro Instrumentation and Telemetry System) makers of the Altair he told the company that he and Allen had developed a BASIC that could be used on the Altair. This was a lie. They have not written a line of code. They had neither a Altar nor the chip that man the computer.
The MITS Company did not know this was very interesting in seeing their BASIC so Gates and Allen began working feverishly on the BASIC they had promised. The code for the program was left mostly upto Bill Gates while Paul Allen began working on a way to simulate the Altair with the school PDP-10. Eight weeks two felt that their program was ready Allen was to fly MITS and show of their creation. The day after Allen arrived at MITS it was time to test their BASIC. Entering the programming into the company Altair was the first time Allen had ever touched one. If Alter simulation he designed of Gates codes was faulty the demonstration would mostly likely have ended in failure this was not the case and the program worked perfectly the first time MITS arranged a deal with Gates and Allen to buy their rights to their BASIC. Within a year Bill Gates had dropped out of Hardware to form Microsoft with Paul Allen in 1975.
Bill Gates and Paul had a vision of computers as a useful tool for everyone their big break was a contract with IBM for an Operating System for IBM’s new personal computer. In the 1980’s and 1990’s Microsoft developed and made a huge success of its Windows GUI. But its business practices brought accusation monopoly tactics.
Under Gates leadership Microsoft mission has been to continually advance and improve software technology and to make it easier more cost –effective and more enjoyable for people to sue computers. The company is committed to a long term view reflected in its investment of more than $6.8 billion on research and development in the current fiscal year.
There are many great personalities in this would some achieve because of these character and some achieve greatness because of their intelligence these is one such great personality “Bill Gates” when richest man of the world and because of his hard work and intelligence he can be called the father of Microsoft.
Bill Gates is the chairman and chief software architect of Microsoft Corporation and the worldwide leader in software, services and Internet technologies for personal and business computing. Microsoft had revenues of US $32.19 billion for the fiscal year ending June 2003 and employees more than 54,000 people in 85 countries.
On October 28th, 1955 shortly after 9:00 pm Bill Gates was born. His father was a prominent lawyer and his mother Mary Gates was a school teacher in the University of Washington Regent and chairwoman united way International. His grandfather was a Vice President of a national bank. Thus Bill Gates was born to a family with a rich history in Business politics and community service. Bill Gates started programming at the age of 13. As a school boy he and his friend Paul in 1968 hacked into a security system of a firm computer and were then asked to look for its weakness. It was here that Gates and Ales really began to develop the talents that would lead to the formation of Microsoft seven years later.
In December of 1974, Alen was on his way to visit Gates when along the way he stopped to browse the current magazines. What he saw changed Bill Gates lives forever. On the cover of Popular Electronics was a picture of the altar 8080 and the headline world’s first Micro computer kit to Rival models. He bought the issue and rushed over to Gates dorm room. They both recognized it as a big opportunity the two knew that home computer market was about to explode and that someone would need to make the software for the machines within a few days Gates has called MITS (Micro Instrumentation and Telemetry System) makers of the Altair he told the company that he and Allen had developed a BASIC that could be used on the Altair. This was a lie. They have not written a line of code. They had neither a Altar nor the chip that man the computer.
The MITS Company did not know this was very interesting in seeing their BASIC so Gates and Allen began working feverishly on the BASIC they had promised. The code for the program was left mostly upto Bill Gates while Paul Allen began working on a way to simulate the Altair with the school PDP-10. Eight weeks two felt that their program was ready Allen was to fly MITS and show of their creation. The day after Allen arrived at MITS it was time to test their BASIC. Entering the programming into the company Altair was the first time Allen had ever touched one. If Alter simulation he designed of Gates codes was faulty the demonstration would mostly likely have ended in failure this was not the case and the program worked perfectly the first time MITS arranged a deal with Gates and Allen to buy their rights to their BASIC. Within a year Bill Gates had dropped out of Hardware to form Microsoft with Paul Allen in 1975.
Bill Gates and Paul had a vision of computers as a useful tool for everyone their big break was a contract with IBM for an Operating System for IBM’s new personal computer. In the 1980’s and 1990’s Microsoft developed and made a huge success of its Windows GUI. But its business practices brought accusation monopoly tactics.
Under Gates leadership Microsoft mission has been to continually advance and improve software technology and to make it easier more cost –effective and more enjoyable for people to sue computers. The company is committed to a long term view reflected in its investment of more than $6.8 billion on research and development in the current fiscal year.
RIBOSOMES
RIBOSOMES
The ribosome is the main site for protein synthesis. It is spheroidal particle consisting of a large and a small subunit. In prokaryotes (E. coli), the intact particle has a sedimentation coefficient of 70S (S = Svedberg unit) where the small subunit is 30S and the large subunit is 50S. Each 30S subunit contains one 16S ribosomal RNA (rRNA) molecule and 21 different proteins. Each 50S subunit contains one 5S rRNA molecule, one 23S rRNA molecule and 32 different proteins. In eukaryotes, in intact particle is 80S and dissociates to give 40S small subunit and 60S large subunit. Each 40S subunit contains one 18S rRNA and 30 proteins. Each 60S subunit contains 28S rRNA, 5.8S rRNA and 40 proteins. Each subunit contains two transfer-RNA-binding sites—A-site (aminoacyl site) and P-site (peptidyl site). During proteins synthesis more ribosomes attach to a single messenger RNA molecule and form a polysome. It also protects the mRNA during protein synthesis.
The ribosome is the main site for protein synthesis. It is spheroidal particle consisting of a large and a small subunit. In prokaryotes (E. coli), the intact particle has a sedimentation coefficient of 70S (S = Svedberg unit) where the small subunit is 30S and the large subunit is 50S. Each 30S subunit contains one 16S ribosomal RNA (rRNA) molecule and 21 different proteins. Each 50S subunit contains one 5S rRNA molecule, one 23S rRNA molecule and 32 different proteins. In eukaryotes, in intact particle is 80S and dissociates to give 40S small subunit and 60S large subunit. Each 40S subunit contains one 18S rRNA and 30 proteins. Each 60S subunit contains 28S rRNA, 5.8S rRNA and 40 proteins. Each subunit contains two transfer-RNA-binding sites—A-site (aminoacyl site) and P-site (peptidyl site). During proteins synthesis more ribosomes attach to a single messenger RNA molecule and form a polysome. It also protects the mRNA during protein synthesis.
Sunday, March 22, 2009
RETROVIRUSES
RETROVIRUSES
Retroviruses have single-stranded RNA genomes, which are replicated through a double-stranded DNA intermediate. The life cycle of these viruses involves an obligatory stage in which the double stranded DNA inserted into the host genome by transposition-like event, which produces short direct repeats of 4, 5 or 6 bp in the target DNA. Each retrovirus particle contains two copies of the RNA genome, and becomes surrounded by a segment of the membrane of its host cell during its release. During infection, the membrane surrounding the virus particle fuses with plasma lemma of the new host cell and the virus particle is thereby released into the cytoplasm.
The virus particle carries along with its genome the enzyme reverse transcriptase, which converts the RNA genome into linear DNA duplex. The DNA duplex migrates into the cell nucleus, becomes inserted into the host genome in one or more copies, and is transcribed by the host machinery to yield RNA copies to itself, this RNA may function either as mRNA or as viral genome. The integration reaction is catalyzed by a single enzyme called integrase that is carried within the virus particle. The virus particle also carries an uncharged host tRNA molecule that serves as primer during reverse transcription of the viral genome.
Retroviruses have single-stranded RNA genomes, which are replicated through a double-stranded DNA intermediate. The life cycle of these viruses involves an obligatory stage in which the double stranded DNA inserted into the host genome by transposition-like event, which produces short direct repeats of 4, 5 or 6 bp in the target DNA. Each retrovirus particle contains two copies of the RNA genome, and becomes surrounded by a segment of the membrane of its host cell during its release. During infection, the membrane surrounding the virus particle fuses with plasma lemma of the new host cell and the virus particle is thereby released into the cytoplasm.
The virus particle carries along with its genome the enzyme reverse transcriptase, which converts the RNA genome into linear DNA duplex. The DNA duplex migrates into the cell nucleus, becomes inserted into the host genome in one or more copies, and is transcribed by the host machinery to yield RNA copies to itself, this RNA may function either as mRNA or as viral genome. The integration reaction is catalyzed by a single enzyme called integrase that is carried within the virus particle. The virus particle also carries an uncharged host tRNA molecule that serves as primer during reverse transcription of the viral genome.
NUCLEUS
NUCLEUS
Brown in 1831 first discovered the nucleus. The presence of definite nucleus is the main feature which differentiates the eukaryotic cell from prokaryotic cell. Nucleus is present in almost all eukaryotic cells expect mature erythrocytes and platelets. Nucleus contains most of the hereditary units of the cell, called genes, which are coiled as chromatin fibers. During cell division, chromatin fibers condense and packed into compact structure known as chromosomes. DNA replication, transcription and RNA processing takes place within the nucleus. The nuclear envelope provides the structural framework of the nucleus and acts as a separates the contents of the nucleus from the cytoplasm. The nuclear envelop consist of two nuclear membranes, (inner and outer nuclear membrane), nuclear lamina and nuclear pore complexes. The inner membrane carries unique proteins that are specific to the nucleus and the outer membrane is continuous with the endoplasmic reticulum. Underlying the inner nuclear membrane is the nuclear lamina, a fibrous meshwork that provides structural support to the nucleus. The nuclear lamina is composed of proteins called lamins. They exist in diametric form and associate with each other to the filaments that make up lamina. The nuclear pores complexes allow selective traffic of ions, proteins and RNAs. Nucleolus is the most prominent substructure within the nucleus. Nucleolus is the site of rRNA transcription and processing.
Brown in 1831 first discovered the nucleus. The presence of definite nucleus is the main feature which differentiates the eukaryotic cell from prokaryotic cell. Nucleus is present in almost all eukaryotic cells expect mature erythrocytes and platelets. Nucleus contains most of the hereditary units of the cell, called genes, which are coiled as chromatin fibers. During cell division, chromatin fibers condense and packed into compact structure known as chromosomes. DNA replication, transcription and RNA processing takes place within the nucleus. The nuclear envelope provides the structural framework of the nucleus and acts as a separates the contents of the nucleus from the cytoplasm. The nuclear envelop consist of two nuclear membranes, (inner and outer nuclear membrane), nuclear lamina and nuclear pore complexes. The inner membrane carries unique proteins that are specific to the nucleus and the outer membrane is continuous with the endoplasmic reticulum. Underlying the inner nuclear membrane is the nuclear lamina, a fibrous meshwork that provides structural support to the nucleus. The nuclear lamina is composed of proteins called lamins. They exist in diametric form and associate with each other to the filaments that make up lamina. The nuclear pores complexes allow selective traffic of ions, proteins and RNAs. Nucleolus is the most prominent substructure within the nucleus. Nucleolus is the site of rRNA transcription and processing.
Thursday, March 19, 2009
NATURAL SELECTION
NATURAL SELECTION
The chief contribution of Darwin was the identification of natural selection as the force directing organic evolution. Natural selection is the differential reproduction of various genotypes of a natural population in response to the natural environment in which the population exists. Clearly this concept of natural selection differs from the original Darwinian concept, which assumed the natural selection to weed out unfit genotype from populations, most likely by causing their death. But the modern day concept of natural selection perceives it as reducing the rates of reproduction of unfit genotypes rather than causing their elimination by death. It may also be emphasized that selection does not act on genes or alleles themselves; it act on the phenotypes produced by them. Similarly, selection seldom operates on individuals genes; it does not soon gene combinations present in the different individuals of a population. In other words, selection generally acts on the total phenotype of individuals not on the phenotype produced by the individual genes. In addition, a gene may be detrimental in one genetic background, while it may be beneficial in another one. In other words, the selective values of gene changes with environment.
The chief contribution of Darwin was the identification of natural selection as the force directing organic evolution. Natural selection is the differential reproduction of various genotypes of a natural population in response to the natural environment in which the population exists. Clearly this concept of natural selection differs from the original Darwinian concept, which assumed the natural selection to weed out unfit genotype from populations, most likely by causing their death. But the modern day concept of natural selection perceives it as reducing the rates of reproduction of unfit genotypes rather than causing their elimination by death. It may also be emphasized that selection does not act on genes or alleles themselves; it act on the phenotypes produced by them. Similarly, selection seldom operates on individuals genes; it does not soon gene combinations present in the different individuals of a population. In other words, selection generally acts on the total phenotype of individuals not on the phenotype produced by the individual genes. In addition, a gene may be detrimental in one genetic background, while it may be beneficial in another one. In other words, the selective values of gene changes with environment.
MUTATION
MUTATION
The term mutation is defined as a physico – chemical change in the gene, larger or small but not due to Mendelian segregation or recombination, leading to change in expression of gene, in the form of remarkable deviation from the normal parental gene expression. Mutation may be larger and conspicuous macro mutations. Small and inconspicuous – micro mutation; the latter is more common and is the main raw material constitutes evolutionary changes in plants and animals. Mutation occurs naturally in all animals and plants but can induced artificially by exposing them to X- rays and chemically known as mutagens. Mutant is the term to denote the resulting modified gene after mutation.
CLASSIFICATION
Mutation can be classified in various ways but broadly into
· Gene mutation
· Chromosomal mutation
· Genomatic mutation or Heteroploidy
The term mutation is defined as a physico – chemical change in the gene, larger or small but not due to Mendelian segregation or recombination, leading to change in expression of gene, in the form of remarkable deviation from the normal parental gene expression. Mutation may be larger and conspicuous macro mutations. Small and inconspicuous – micro mutation; the latter is more common and is the main raw material constitutes evolutionary changes in plants and animals. Mutation occurs naturally in all animals and plants but can induced artificially by exposing them to X- rays and chemically known as mutagens. Mutant is the term to denote the resulting modified gene after mutation.
CLASSIFICATION
Mutation can be classified in various ways but broadly into
· Gene mutation
· Chromosomal mutation
· Genomatic mutation or Heteroploidy
Monday, March 16, 2009
MASS OF EVIDENCE
MASS OF EVIDENCE
Hi! I am Geetika I want to tell you about Einstein’s special theory of relativity which is now a law .As we know Einstein gave a special theory of relativity in 1905, the famous E=mc2 formula
According to conventional model of particle physics, subatomic particle like protons and neutrons which are usually bound in the nucleus of atom comprise even more elementary particles known as quarks, which in turn are held too gather by gluons .The problem is that the mass of gluons is zero while that of quarks accounts for only 5 percent .So where the rest of 95 percent? The missing percent of the mass from the energy resulting from the interactions and movements of quarks and gluons .Gluons, in fact, are constantly popping into existence and disappearing again and energy of these so called vacuum fluctuations has to be included in the total mass. The new study crunched the numbers and found it matched the equation.
Does this make the theory of special relativity a “law” now? Actually nobody in scientific community. Ever needed to make this pointless distinction _especially since it had been experimentally tested over several decades to an extremely high degree of accuracy and was accepted by physicists the world over .The atomic bombs dropped on Hiroshima and Nagasaki were, unfortunately the direct result of an application of the same theory .
But there is a lesson to be learnt here for advocates of intelligent Design who rail against Darwin by saying that his, too ,is only a “theory” of evolution and , therefore ,should be treated on par with creationism which states that earth is just few thousand years old and humans were create by divine intervention .They forget that evolution is a powerful explanatory and predictive theory which has been verified experimentally .. So often that it is become the central organizing principle of modern biology today. Meaning, it is no longer requires the additional stamp of some ultimate confirmation to be considered a law.
Hi! I am Geetika I want to tell you about Einstein’s special theory of relativity which is now a law .As we know Einstein gave a special theory of relativity in 1905, the famous E=mc2 formula
According to conventional model of particle physics, subatomic particle like protons and neutrons which are usually bound in the nucleus of atom comprise even more elementary particles known as quarks, which in turn are held too gather by gluons .The problem is that the mass of gluons is zero while that of quarks accounts for only 5 percent .So where the rest of 95 percent? The missing percent of the mass from the energy resulting from the interactions and movements of quarks and gluons .Gluons, in fact, are constantly popping into existence and disappearing again and energy of these so called vacuum fluctuations has to be included in the total mass. The new study crunched the numbers and found it matched the equation.
Does this make the theory of special relativity a “law” now? Actually nobody in scientific community. Ever needed to make this pointless distinction _especially since it had been experimentally tested over several decades to an extremely high degree of accuracy and was accepted by physicists the world over .The atomic bombs dropped on Hiroshima and Nagasaki were, unfortunately the direct result of an application of the same theory .
But there is a lesson to be learnt here for advocates of intelligent Design who rail against Darwin by saying that his, too ,is only a “theory” of evolution and , therefore ,should be treated on par with creationism which states that earth is just few thousand years old and humans were create by divine intervention .They forget that evolution is a powerful explanatory and predictive theory which has been verified experimentally .. So often that it is become the central organizing principle of modern biology today. Meaning, it is no longer requires the additional stamp of some ultimate confirmation to be considered a law.
IMMUNITY
IMMUNITY
Immunity is the defence mechanism that protects an individual (host) from infectious diseases. They are of two types, viz. innate immunity and acquired immunity. Innate immunity is the inherited immunity. It acts as a first line of defence against infectious agents and does not exhibit any specificity. Innate Immunity may be considered at the level of species, race or individual.
The resistance that an individual acquires during life is known as acquired immunity. This type of immunity exhibits specificity. A particular infectious agent induces lymphocytes to proliferate, mature, secrete and “remember” that particular agent (primary immune response). Subsequent infection by the same parasite produces increased resistance and is called secondary immune response.
Acquired immunity has four essential features. They are as follows:
· An Induction phase,
· Recognition,
· Specificity and
· Immunological memory.
Acquired immunity is meditated by two interrelated and interdependent mechanisms – humeral immunity and cell meditated immunity. In humoral immunity the active proteins component, immunoglobulin’s (antibodies), are present in cell- free portion of the blood (plasma or serum). These immunoglobulins are specific for the infectious agents (antigens). They are derived from bone marrow lymphocytes or B-cells. Thymus-derived T-lymphocytes or T-cells reside in the peripheral blood and lymphoid tissues, which comprise the cellular component of the immune system. The infectious agents or their products stimulate the proliferations and differentiations of the T-cells and its progeny for the defence action.
Immunity is the defence mechanism that protects an individual (host) from infectious diseases. They are of two types, viz. innate immunity and acquired immunity. Innate immunity is the inherited immunity. It acts as a first line of defence against infectious agents and does not exhibit any specificity. Innate Immunity may be considered at the level of species, race or individual.
The resistance that an individual acquires during life is known as acquired immunity. This type of immunity exhibits specificity. A particular infectious agent induces lymphocytes to proliferate, mature, secrete and “remember” that particular agent (primary immune response). Subsequent infection by the same parasite produces increased resistance and is called secondary immune response.
Acquired immunity has four essential features. They are as follows:
· An Induction phase,
· Recognition,
· Specificity and
· Immunological memory.
Acquired immunity is meditated by two interrelated and interdependent mechanisms – humeral immunity and cell meditated immunity. In humoral immunity the active proteins component, immunoglobulin’s (antibodies), are present in cell- free portion of the blood (plasma or serum). These immunoglobulins are specific for the infectious agents (antigens). They are derived from bone marrow lymphocytes or B-cells. Thymus-derived T-lymphocytes or T-cells reside in the peripheral blood and lymphoid tissues, which comprise the cellular component of the immune system. The infectious agents or their products stimulate the proliferations and differentiations of the T-cells and its progeny for the defence action.
Friday, March 13, 2009
FUNCTIONS OF LIPIDS
FUNCTIONS OF LIPIDS
Lipid has three major roles in cells. It
· Provides an important form of energy storage.
· Forms the major component of cell membrane.
· Plays crucial role in cell signaling.
The simplest lipids are fatty acids, which consist of long hydrocarbon chains, consisting 16 or 18 carbon atoms, while carboxyl group ( coo- ) at one end. Unsaturated fatty acids contain one or more double bond between carbon atoms whereas in saturated fatty acids the carbon atoms are mostly bonded to hydrogen atoms. The long hydrocarbon chain of fatty acids contains more C-H bonds, which are non polar and hydrophobic in nature and which are responsible for the formation of biological membranes. Fatty acids are store in form of triacylglycerols. Triacylglycerols are insoluble in water. They accumulate as fat droplets in cytoplasm of cells of the adipose tissue. During emergency conditions, these fat droplets can be broken down for yielding energy.
Lipid has three major roles in cells. It
· Provides an important form of energy storage.
· Forms the major component of cell membrane.
· Plays crucial role in cell signaling.
The simplest lipids are fatty acids, which consist of long hydrocarbon chains, consisting 16 or 18 carbon atoms, while carboxyl group ( coo- ) at one end. Unsaturated fatty acids contain one or more double bond between carbon atoms whereas in saturated fatty acids the carbon atoms are mostly bonded to hydrogen atoms. The long hydrocarbon chain of fatty acids contains more C-H bonds, which are non polar and hydrophobic in nature and which are responsible for the formation of biological membranes. Fatty acids are store in form of triacylglycerols. Triacylglycerols are insoluble in water. They accumulate as fat droplets in cytoplasm of cells of the adipose tissue. During emergency conditions, these fat droplets can be broken down for yielding energy.
EXPLANATION OF MEIOSIS
EXPLANATION OF MEIOSIS
This type of cell division takes place in gonads during gametogenesis only. It consists of two successive divisions called first meiotic and second meiotic divisions. It is during the interphase of first meiotic division that the DNA is replicated in the usual manner leading to tetraploid amount of DNA in diploid
Number of chromosomes and during first meiotic division only the amount of DNA is reduced to diploid amount in each chromosome and chromosome number is also halved to haploid. In meiosis II the DNA in each new daughter cell is reduced to haploid, the chromosome number remaining haploid.
Both the first and the second meiotic divisions can be further subdivided into the same four stages- prophase, metaphase, anaphase, telophase each with few differences in the behavior of chromosomes and duration of phase.
First Meiotic Division
· Interphase: The DNA content of chromosome is doubled i.e. it is tetraploid.
· Prophase: This phase is of longer duration and complex and differs distinctly from mitotic prophase. It can be divided into following 5 stages.
(a)Leptotene stage
(b)Zygotene stage
(c) Pachytene stage
(d)Diplotene stage
(e)Diakinesis stage
· Metaphase I: It is similar to the metaphase of mitosis, the difference being only that it is homologous pair of chromosomes which lie parallel on the equator of spindle of microtubules with one member on the either side of the equator.
· Anaphase I: it differs from anaphase of mitosis in that the centromere does not split. So that one whole chromosome of homologous pair moves apart to reach the opposite poles of cell. This results in haploid number of chromosomes in each daughter cell i.e. 23 chromosomes consisting of two chromatids.
· Telophase: As there is random positioning of maternal and paternal bivalent chromosomes there is random assortment of maternal and paternal chromosomes in each daughter cell produced by cytoplasmic division during telophase.
This type of cell division takes place in gonads during gametogenesis only. It consists of two successive divisions called first meiotic and second meiotic divisions. It is during the interphase of first meiotic division that the DNA is replicated in the usual manner leading to tetraploid amount of DNA in diploid
Number of chromosomes and during first meiotic division only the amount of DNA is reduced to diploid amount in each chromosome and chromosome number is also halved to haploid. In meiosis II the DNA in each new daughter cell is reduced to haploid, the chromosome number remaining haploid.
Both the first and the second meiotic divisions can be further subdivided into the same four stages- prophase, metaphase, anaphase, telophase each with few differences in the behavior of chromosomes and duration of phase.
First Meiotic Division
· Interphase: The DNA content of chromosome is doubled i.e. it is tetraploid.
· Prophase: This phase is of longer duration and complex and differs distinctly from mitotic prophase. It can be divided into following 5 stages.
(a)Leptotene stage
(b)Zygotene stage
(c) Pachytene stage
(d)Diplotene stage
(e)Diakinesis stage
· Metaphase I: It is similar to the metaphase of mitosis, the difference being only that it is homologous pair of chromosomes which lie parallel on the equator of spindle of microtubules with one member on the either side of the equator.
· Anaphase I: it differs from anaphase of mitosis in that the centromere does not split. So that one whole chromosome of homologous pair moves apart to reach the opposite poles of cell. This results in haploid number of chromosomes in each daughter cell i.e. 23 chromosomes consisting of two chromatids.
· Telophase: As there is random positioning of maternal and paternal bivalent chromosomes there is random assortment of maternal and paternal chromosomes in each daughter cell produced by cytoplasmic division during telophase.
Tuesday, March 10, 2009
DNA (De-oxyribonucleic acid)
DNA (De-oxyribonucleic acid)
The DNA can be found at two sites in a cell, in large amount in nucleus as a part of chromosomes and a very small amount in cytoplasm as a part of mitochondria. Both these forms of DNA differ from each other in certain details, like the DNA thread is in the form of ring. The nitrogenous bases differ and they are mainly of maternal in origin. In mitochondrial DNA while the chromosomal DNA is in the form of double helix with complementary strands running in opposite direction for quick Fidel application. There is 10 nucleotide pair per complete turn of the double chain.
The replication is making a copy of DNA. This takes place during ‘S’ phase of interphase taking about 7 hours before the onset of mitosis or meiosis. Thus during replication
· Two strands of DNA helix separates out.
· Each strand act as a template.
· Each template forms complementary strand.
· One template with its complementary strand forms anew DNA molecule.
The DNA can be found at two sites in a cell, in large amount in nucleus as a part of chromosomes and a very small amount in cytoplasm as a part of mitochondria. Both these forms of DNA differ from each other in certain details, like the DNA thread is in the form of ring. The nitrogenous bases differ and they are mainly of maternal in origin. In mitochondrial DNA while the chromosomal DNA is in the form of double helix with complementary strands running in opposite direction for quick Fidel application. There is 10 nucleotide pair per complete turn of the double chain.
The replication is making a copy of DNA. This takes place during ‘S’ phase of interphase taking about 7 hours before the onset of mitosis or meiosis. Thus during replication
· Two strands of DNA helix separates out.
· Each strand act as a template.
· Each template forms complementary strand.
· One template with its complementary strand forms anew DNA molecule.
Friday, March 6, 2009
Different Methods of body composition
Different Methods of body composition
1. Surface Anthropometry
A. Matiegka’s Method:
Jindrich Matiegka (1921) felt the need of developing a method to determine the physical efficiency of a given subject just as psychologists test the mental faculties of a person.
The physical efficiency of a person depends on various factors such as quantities or amounts of various tissues (bone, muscle and subcutaneous fat), the physiological qualities of various organs like the reaction time, fatigue, and the state of health. Matiegke concentrated on body measurements of extremities and thought that these represent the whole of the body well, just as the brain is a representative of the mentality of a person. The method which he developed is called somatotechnique by which quantitative analysis of various compartments of the body is made. His method of finding the amount of various body masses is given below:
W=O+D+M+R
Where
W= Body Weight
O= Weight of Bones
D= Weight of Derma or Fat
M= Weight of Skeletal Muscles
R= Remainder Weight
The above components masses can be calculated by using the following equations:
1. Weight of bones or Ossa
Ossa=O2xLxK1
Where L is height of the subject
K1=1.2 (Constant)
O= (o1+o2-o3+o4)/4
o1 is the maximum diameter of humerus bicondylar (cm)
o2 is the maximum diameter of femur bicondylar (cm)
o3 is the maximum diameter of wrist (cm)
o4 is the maximum diameter of Ankle (cm)
2. D or Derma
D=dxSxk2
d=1/2 (d1+d2+d3+d4+d5+d6) (mm)
Where
d1= skin fold at the biceps muscles
d2= skin fold of forearm, at maximum development, over the plantar side.
d3= skin fold of thigh over quadriceps muscles in the middle of inguinal and knee.
d4= skin fold over the calf muscle
d5= skin fold over the thorax in the middle of the mammary gland and umbilicus
d6= skin fold over the abdomen, in the middle of the naval and the anterior superior iliac spine
The science of anthropometry was in infancy in the time of Matiegke and there was no instrument for measuring skin fold thickness. So, the skin fold measurements were taken with a sliding caliper by picking up the fat fold with mild pressure. The readers can make out how inaccurate the measurements can be if there is no way of checking the pressure with which to measure the skinfold of thickness.
S= surface area in cm2
=Wt0.425 x Ht0.725 x 71.84
Weight in kg and height in cm should be taken.
K2=0.13 (Constant)
3. M or skeletal muscle
M=r2 L x k3
r= (r1 + r2 + r3 + r4)/4
where L = height (cm)
r1= corrected radius of upper arm (flexed)
r2= corrected radius of upper arm (maximum)
r3= corrected radius of thigh between trochanter and lateral epicondyle.
r4= corrected radius of calf
k3= 6.5 (constant)
The correct radii can be calculated as following assuming the limb as a cylindrical entity:
Circumference= 2 x (22/7) x r
Or r=c/2 (22/7)
Corrected r=[c/2 (22/7) – ½ skinfold]
The unit of skin folds is the same as for circumference or radius while subtracting it.
4. R or remainder mass
R= W—(O +D +M)
In the process of development of this method, Matiegka studied the corpses of 12 boys of 16-17 years of age, all in good health. The constants were calculated, however, he felt that these constants must be finely tuned by conducting further studies on large groups of cadavers.
Concerning the physical efficiency, he found a good co-relation between the amount of muscles and the dynamometric strengths of persons; however, the correlation was not complete.
Further improvements in the method can help forming basis for comparison of various subjects from which it may be easily determined whether a person having an average skeleton has feeble, medium or bulky muscles and insufficient, normal or excessive quantity of fat.
Metiegka suggested that the constants for the above equations be carefully calculated which can be age, sex and height specific, on the basis of controls and cadavers. The qualities of different tissues and the results of physiological test must be carefully studied. Mental influence on muscular work also needs to be studied. Muscular work also depends on the state of mental health. Other things like test of strength, influence of exercise, training, experience and mental tone, all should be determined for a better understanding of a person’s physical efficiency. A deeper understanding of a person’s physical and mental faculties and efficiencies can be highly useful in the choice of a suitable profession. A person can feel happy and will be more satisfied if he finds a profession to which he is mentally and physically most suitable.
Example:
Height = 150 cm
Weight = 50 kg
Humerus bicondylar breadth = 6.8 cm
Femur bicondylar breadth = 8.5 cm
Wrist Breadth = 6.0 cm
Ankle Breadth = 6.5 cm
Biceps Skinfold = 5 mm
Forearm Skinfold = 6 mm
Thigh Skinfold = 10 mm
Calf Skinfold = 8 mm
Thoracic = 12 mm
Abdominal = 11 mm
Upper arm girth (Flexed) = 27.0 cm
Forearm girth = 25.0 cm
Thigh girth = 45.0 cm
Calf girth = 32 cm
A. Weight of Bones
Ossa=O2 x L x K1
= (6.95)2 x 150.0 x1.2
= 8694 grams
= 8.694 kg
B. Weight of derma or adipose tissue
D= d x S x k2
d= ½ [(5+6+10+8+12+11)/6]
= 4.33 mm
S= 500.425 x 1500.725 x 71.84 cm2
= 14320 cm2
D = 4.33 x 14320 x 0.13
= 8060.7 grams
= 8.061 kg
C. Weight of skeletal muscles
r1= corrected radius of upper arm
= [Circumference of upper arm/2 (22/7)—1/2 Skinfold]
= [27/2 (22/7) –0.25]
= 4.045 cm
r2= 3.677
r3= 6.659
r4= 4.691
Mean radius or r=(r1 + r2 +r3 +r4)/4
= (4.045 +3.677 +6.659 + 4.691)/4
= 4.768 cm
M= r2 x L x k3
= (4.768)2 150.0 x 6.5
= 22165 grams
= 22.165 kg
D. Remainder mass
R = Body weight – (O + M + D)
= 50 – (8.6940 + 8.061 + 22.1650)
= 50.0 – 38.920
= 11.080 kg
Fat mass calculation
z(triceps) =1/4.47[10(170.18/150.0)-15.4] = -0.907
z(subscapular) = 1/5.07[12(170.18/150)-17.2] = -0.707
z(suprailiac) =1/4.47[12(170.18/150.0)- 15.4] = -0.399
z(abdominal) = 1/7.78[20(170.18/150.0)- 25.4] = -0.348
z(thigh) =1/8.33[20(170.18/150.0)- 27.0] = -0.507
z(calf) = ¼.67 = [15(170.18/150.0)- 16.0] = -0.218
Mean z- value = -0.4433
The subject fat mass is 0.4433 SD less than that of the phantom’s fat mass of 12.13 kg. A z – value of 0.4433 for fat mass corresponds to a value of 1.4407 kg (0.4433x phantom SD for fat mass which is 3.25 = 1.4407), so, the subject fat mass = 12.13 – 1.4407 kg =10.6893 kg.
The above fat mass of the subject is so when his height is 170.18 cm. It is necessary to rescale this fat to its actual size which is 150.0 cm which can be done in the following manner:
Actual fat mass = Obtained fat mass/[170.18/height]3
=10.6893/[170.18/150.0]3
=7.3198 kg
Utilizing the mean score, the fractional masses can be directly calculated with the following formula:
M = [(z x s) + p]/170.18/h)3
Where M is the fractional mass
z is mean phantom z-values for the subset off the variables
p is the phantom value for the given fractional mass
s is the standard deviation
h is the subject’s height
d is the dimensional constant
The fat mass of the subject can be calculated with the above formula.
Fat mass =[(-0.4433 x 3.25) + 12.13]/(170.18/150.0)3
= 7.3198 kg
Skeletal mass
z(humerus) – 1/0.35[6.0(170.18/150.0) – 6.48] =0.9349
z(femur) = 1/0.48[8.9(170.18/150.0) – 9.52] = 1.2028
z(wrist) = 1/0.72[15.0(170.18/150.0) – 16.35] = 0.9278
z(ankle) = 1/1.33[20.2(170.18/150.0) – 21.71] = 0.9079
The mean z – value = 0.9934
M = [(0.9934 x 1.57) + 10.49]/(170.18/150.0)3
= 8.2513 kg
So, the skeletal mass = 8.2513 kg
Muscle mass
For the calculation of the muscle mass, four body girths, viz, upper arm (relaxed), chest, thigh and calf are necessary. All these girths must be corrected for the subcutaneous tissue overlying the body, in the following manner:
Corrected arm girth = Arm girth – [(22/7) x triceps skinfold]/10 = 22.0 – [(22/7) x 10]/10 = 18.86 cm
Corrected chest girth = Chest girth –[(22/7) x subscapular skinfold]/10 = 75.0 – [(22/7) x 12]/10 = 71.29 cm
Corrected thigh girth = Thigh girth – [(22/7) x front thigh skin fold]/10 = 40.0 – [(22/7) x 20]/10 = 33.71 cm
Corrected calf girth = Calf girth – [(22/7) medical calf skin fold]/10 =28.0 – [(22/7) x 15]/10 = 23.29 cm
These corrected body girths are utilized for the calculation of z – values. Since the body girths are taken in the centimeters and the skin fold in the millimeters, so, while making the above corrections, the entire skin fold must be divided by a factor of 10 so as to convert them into centimeters, as has been done in the above calculations.
z (arm) = 1/1.91 [18.86(170.18/150.0) – 22.05] = -0.3417
z (chest) = 1/4.86[71.29(170.18/150.0) - 82.46] = -0.3249
z (thigh) = 1/3.59 =[33.71(170.18/150.0) – 47.34] = - 2.5334
z (calf) = 1/1.97 =[23.29(170.18/150.0) – 30.22] = - 1.9273
Mean z – value= -1.2818
Muscle mass = [(-1.2818 x 2.99) + 25.55]/170.18/150.0)3
1. Surface Anthropometry
A. Matiegka’s Method:
Jindrich Matiegka (1921) felt the need of developing a method to determine the physical efficiency of a given subject just as psychologists test the mental faculties of a person.
The physical efficiency of a person depends on various factors such as quantities or amounts of various tissues (bone, muscle and subcutaneous fat), the physiological qualities of various organs like the reaction time, fatigue, and the state of health. Matiegke concentrated on body measurements of extremities and thought that these represent the whole of the body well, just as the brain is a representative of the mentality of a person. The method which he developed is called somatotechnique by which quantitative analysis of various compartments of the body is made. His method of finding the amount of various body masses is given below:
W=O+D+M+R
Where
W= Body Weight
O= Weight of Bones
D= Weight of Derma or Fat
M= Weight of Skeletal Muscles
R= Remainder Weight
The above components masses can be calculated by using the following equations:
1. Weight of bones or Ossa
Ossa=O2xLxK1
Where L is height of the subject
K1=1.2 (Constant)
O= (o1+o2-o3+o4)/4
o1 is the maximum diameter of humerus bicondylar (cm)
o2 is the maximum diameter of femur bicondylar (cm)
o3 is the maximum diameter of wrist (cm)
o4 is the maximum diameter of Ankle (cm)
2. D or Derma
D=dxSxk2
d=1/2 (d1+d2+d3+d4+d5+d6) (mm)
Where
d1= skin fold at the biceps muscles
d2= skin fold of forearm, at maximum development, over the plantar side.
d3= skin fold of thigh over quadriceps muscles in the middle of inguinal and knee.
d4= skin fold over the calf muscle
d5= skin fold over the thorax in the middle of the mammary gland and umbilicus
d6= skin fold over the abdomen, in the middle of the naval and the anterior superior iliac spine
The science of anthropometry was in infancy in the time of Matiegke and there was no instrument for measuring skin fold thickness. So, the skin fold measurements were taken with a sliding caliper by picking up the fat fold with mild pressure. The readers can make out how inaccurate the measurements can be if there is no way of checking the pressure with which to measure the skinfold of thickness.
S= surface area in cm2
=Wt0.425 x Ht0.725 x 71.84
Weight in kg and height in cm should be taken.
K2=0.13 (Constant)
3. M or skeletal muscle
M=r2 L x k3
r= (r1 + r2 + r3 + r4)/4
where L = height (cm)
r1= corrected radius of upper arm (flexed)
r2= corrected radius of upper arm (maximum)
r3= corrected radius of thigh between trochanter and lateral epicondyle.
r4= corrected radius of calf
k3= 6.5 (constant)
The correct radii can be calculated as following assuming the limb as a cylindrical entity:
Circumference= 2 x (22/7) x r
Or r=c/2 (22/7)
Corrected r=[c/2 (22/7) – ½ skinfold]
The unit of skin folds is the same as for circumference or radius while subtracting it.
4. R or remainder mass
R= W—(O +D +M)
In the process of development of this method, Matiegka studied the corpses of 12 boys of 16-17 years of age, all in good health. The constants were calculated, however, he felt that these constants must be finely tuned by conducting further studies on large groups of cadavers.
Concerning the physical efficiency, he found a good co-relation between the amount of muscles and the dynamometric strengths of persons; however, the correlation was not complete.
Further improvements in the method can help forming basis for comparison of various subjects from which it may be easily determined whether a person having an average skeleton has feeble, medium or bulky muscles and insufficient, normal or excessive quantity of fat.
Metiegka suggested that the constants for the above equations be carefully calculated which can be age, sex and height specific, on the basis of controls and cadavers. The qualities of different tissues and the results of physiological test must be carefully studied. Mental influence on muscular work also needs to be studied. Muscular work also depends on the state of mental health. Other things like test of strength, influence of exercise, training, experience and mental tone, all should be determined for a better understanding of a person’s physical efficiency. A deeper understanding of a person’s physical and mental faculties and efficiencies can be highly useful in the choice of a suitable profession. A person can feel happy and will be more satisfied if he finds a profession to which he is mentally and physically most suitable.
Example:
Height = 150 cm
Weight = 50 kg
Humerus bicondylar breadth = 6.8 cm
Femur bicondylar breadth = 8.5 cm
Wrist Breadth = 6.0 cm
Ankle Breadth = 6.5 cm
Biceps Skinfold = 5 mm
Forearm Skinfold = 6 mm
Thigh Skinfold = 10 mm
Calf Skinfold = 8 mm
Thoracic = 12 mm
Abdominal = 11 mm
Upper arm girth (Flexed) = 27.0 cm
Forearm girth = 25.0 cm
Thigh girth = 45.0 cm
Calf girth = 32 cm
A. Weight of Bones
Ossa=O2 x L x K1
= (6.95)2 x 150.0 x1.2
= 8694 grams
= 8.694 kg
B. Weight of derma or adipose tissue
D= d x S x k2
d= ½ [(5+6+10+8+12+11)/6]
= 4.33 mm
S= 500.425 x 1500.725 x 71.84 cm2
= 14320 cm2
D = 4.33 x 14320 x 0.13
= 8060.7 grams
= 8.061 kg
C. Weight of skeletal muscles
r1= corrected radius of upper arm
= [Circumference of upper arm/2 (22/7)—1/2 Skinfold]
= [27/2 (22/7) –0.25]
= 4.045 cm
r2= 3.677
r3= 6.659
r4= 4.691
Mean radius or r=(r1 + r2 +r3 +r4)/4
= (4.045 +3.677 +6.659 + 4.691)/4
= 4.768 cm
M= r2 x L x k3
= (4.768)2 150.0 x 6.5
= 22165 grams
= 22.165 kg
D. Remainder mass
R = Body weight – (O + M + D)
= 50 – (8.6940 + 8.061 + 22.1650)
= 50.0 – 38.920
= 11.080 kg
Fat mass calculation
z(triceps) =1/4.47[10(170.18/150.0)-15.4] = -0.907
z(subscapular) = 1/5.07[12(170.18/150)-17.2] = -0.707
z(suprailiac) =1/4.47[12(170.18/150.0)- 15.4] = -0.399
z(abdominal) = 1/7.78[20(170.18/150.0)- 25.4] = -0.348
z(thigh) =1/8.33[20(170.18/150.0)- 27.0] = -0.507
z(calf) = ¼.67 = [15(170.18/150.0)- 16.0] = -0.218
Mean z- value = -0.4433
The subject fat mass is 0.4433 SD less than that of the phantom’s fat mass of 12.13 kg. A z – value of 0.4433 for fat mass corresponds to a value of 1.4407 kg (0.4433x phantom SD for fat mass which is 3.25 = 1.4407), so, the subject fat mass = 12.13 – 1.4407 kg =10.6893 kg.
The above fat mass of the subject is so when his height is 170.18 cm. It is necessary to rescale this fat to its actual size which is 150.0 cm which can be done in the following manner:
Actual fat mass = Obtained fat mass/[170.18/height]3
=10.6893/[170.18/150.0]3
=7.3198 kg
Utilizing the mean score, the fractional masses can be directly calculated with the following formula:
M = [(z x s) + p]/170.18/h)3
Where M is the fractional mass
z is mean phantom z-values for the subset off the variables
p is the phantom value for the given fractional mass
s is the standard deviation
h is the subject’s height
d is the dimensional constant
The fat mass of the subject can be calculated with the above formula.
Fat mass =[(-0.4433 x 3.25) + 12.13]/(170.18/150.0)3
= 7.3198 kg
Skeletal mass
z(humerus) – 1/0.35[6.0(170.18/150.0) – 6.48] =0.9349
z(femur) = 1/0.48[8.9(170.18/150.0) – 9.52] = 1.2028
z(wrist) = 1/0.72[15.0(170.18/150.0) – 16.35] = 0.9278
z(ankle) = 1/1.33[20.2(170.18/150.0) – 21.71] = 0.9079
The mean z – value = 0.9934
M = [(0.9934 x 1.57) + 10.49]/(170.18/150.0)3
= 8.2513 kg
So, the skeletal mass = 8.2513 kg
Muscle mass
For the calculation of the muscle mass, four body girths, viz, upper arm (relaxed), chest, thigh and calf are necessary. All these girths must be corrected for the subcutaneous tissue overlying the body, in the following manner:
Corrected arm girth = Arm girth – [(22/7) x triceps skinfold]/10 = 22.0 – [(22/7) x 10]/10 = 18.86 cm
Corrected chest girth = Chest girth –[(22/7) x subscapular skinfold]/10 = 75.0 – [(22/7) x 12]/10 = 71.29 cm
Corrected thigh girth = Thigh girth – [(22/7) x front thigh skin fold]/10 = 40.0 – [(22/7) x 20]/10 = 33.71 cm
Corrected calf girth = Calf girth – [(22/7) medical calf skin fold]/10 =28.0 – [(22/7) x 15]/10 = 23.29 cm
These corrected body girths are utilized for the calculation of z – values. Since the body girths are taken in the centimeters and the skin fold in the millimeters, so, while making the above corrections, the entire skin fold must be divided by a factor of 10 so as to convert them into centimeters, as has been done in the above calculations.
z (arm) = 1/1.91 [18.86(170.18/150.0) – 22.05] = -0.3417
z (chest) = 1/4.86[71.29(170.18/150.0) - 82.46] = -0.3249
z (thigh) = 1/3.59 =[33.71(170.18/150.0) – 47.34] = - 2.5334
z (calf) = 1/1.97 =[23.29(170.18/150.0) – 30.22] = - 1.9273
Mean z – value= -1.2818
Muscle mass = [(-1.2818 x 2.99) + 25.55]/170.18/150.0)3
Monday, March 2, 2009
DEFINATION OF SYNDROME
DEFINATION OF SYNDROME
A syndrome represents a pattern of symptoms and signs common to a set of abnormal individuals. Clinical diagnosis of a chromosomal is in many instances difficult. It is based on features which, when taken alone, have no particular diagnostic value. Some of the symptoms like short stature, Low IQ, Mental retardation or aggressiveness may be commonly present in the population. Hence chromosomal disorder must not be suspected when a single such sign such observed, but only when several of them occurred together.
Among the autosomally transmitted diseases, the most common ones is Down syndrome and cri-du-chat syndrome, while most common sex chromosome abnormalities are turner syndrome and klinefelter syndrome. Other commonly reported syndromes are Edwards (trisomy 18), Patau’s (trisomy 13), Wolf-Hrischhorn (deletion of 4p), refractory anemia (deletion of 5q), Prader-Willi (depletion/translocation 15q), Angel man (deletion of 15q), Di George (Translocation 22q11).
A syndrome represents a pattern of symptoms and signs common to a set of abnormal individuals. Clinical diagnosis of a chromosomal is in many instances difficult. It is based on features which, when taken alone, have no particular diagnostic value. Some of the symptoms like short stature, Low IQ, Mental retardation or aggressiveness may be commonly present in the population. Hence chromosomal disorder must not be suspected when a single such sign such observed, but only when several of them occurred together.
Among the autosomally transmitted diseases, the most common ones is Down syndrome and cri-du-chat syndrome, while most common sex chromosome abnormalities are turner syndrome and klinefelter syndrome. Other commonly reported syndromes are Edwards (trisomy 18), Patau’s (trisomy 13), Wolf-Hrischhorn (deletion of 4p), refractory anemia (deletion of 5q), Prader-Willi (depletion/translocation 15q), Angel man (deletion of 15q), Di George (Translocation 22q11).
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