Microbiology is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms. This includes eukaryotes such as fungi and protists, and prokaryotes such as bacteria and certain algaes. Viruses, though not strictly classed as living organisms, are also studied.[1] Microbiology is a broad term which includes many branches like bacteriology, virology, mycology, parasitology and others. A person who specializes in the area of microbiology is called a microbiologist.
Although much is now known in the field of microbiology, advances are being made regularly. The most common estimates suggest that we have studied only about 1% of all of the microbes in any given environment. Thus, despite the fact that over three hundred years have passed since the discovery of microbes, the field of microbiology is clearly in its infancy relative to other biological disciplines such as zoology, botany and entomology.Bacteria were first observed by Anton van Leeuwenhoek in 1676 using a single-lens microscope of his own design. The name "bacterium" was introduced much later, by Ehrenberg in 1828, derived from the Greek word βακτηριον meaning "small stick". While Antony van Leeuwenhoek is often cited as the first microbiologist, the first recorded microbiological observation, that of the fruiting bodies of molds, was made earlier in 1665 by Robert Hooke.
The field of bacteriology (later a subdiscipline of microbiology) is generally considered to have been founded by Ferdinand Cohn (1828–1898), a botanist whose studies on algae and photosynthetic bacteria led him to describe several bacteria including Bacillus and Beggiatoa. Ferdinand Cohn was also the first to formulate a scheme for the taxonomic classification of bacteria.
Louis Pasteur (1822–1895) and Robert Koch (1843–1910) were contemporaries of Cohn’s and are often considered to be the founders of medical microbiology. Pasteur is most famous for his series of experiments designed to disprove the then widely held theory of spontaneous generation, thereby solidifying microbiology’s identity as a biological science. Pasteur also designed methods for food preservation (pasteurization) and vaccines against several diseases such as anthrax, fowl cholera and rabies. Robert Koch is best known for his contributions to the germ theory of disease, proving that specific diseases were caused by specific pathogenic microorganisms. He developed a series of criteria that have become known as the Koch's postulates. Koch was one of the first scientists to focus on the isolation of bacteria in pure culture resulting in his description of several novel bacteria including Mycobacterium tuberculosis, the causative agent of tuberculosis.
While Louis Pasteur and Robert Koch are often considered the founders of microbiology, their work did not accurately reflect the true diversity of the microbial world because of their exclusive focus on microorganisms having medical relevance. It was not until the work of Martinus Beijerinck (1851–1931) and Sergei Winogradsky (1856–1953), the founders of general microbiology (an older term encompassing aspects of microbial physiology, diversity and ecology), that the true breadth of microbiology was revealed. Martinus Beijerinck made two major contributions to microbiology: the discovery of viruses and the development of enrichment culture techniques. While his work on the Tobacco Mosaic Virus established the basic principles of virology, it was his development of enrichment culturing that had the most immediate impact on microbiology by allowing for the cultivation of a wide range of microbes with wildly different physiologies. Sergei Winogradsky was the first to develop the concept of chemolithotrophy and to thereby reveal the essential role played by microorganisms in geochemical processes. He was responsible for the first isolation and description of both nitrifying and nitrogen-fixing bacteriaThe field of microbiology can be generally divided into several subdisciplines:
Microbial physiology: The study of how the microbial cell functions biochemically. Includes the study of microbial growth, microbial metabolism and microbial cell structure.
Microbial genetics: The study of how genes are organised and regulated in microbes in relation to their cellular functions. Closely related to the field of molecular biology.
Medical microbiology: The study of the role of microbes in human illness. Includes the study of microbial pathogenesis and epidemiology and is related to the study of disease pathology and immunology.
Veterinary microbiology: The study of the role in microbes in veterinary medicine or animal taxonomy.
Environmental microbiology: The study of the function and diversity of microbes in their natural environments. Includes the study of microbial ecology, microbially-mediated nutrient cycling, geomicrobiology, microbial diversity and bioremediation. Characterisation of key bacterial habitats such as the rhizosphere and phyllosphere.
Evolutionary microbiology: The study of the evolution of microbes. Includes the study of bacterial systematics and taxonomy.
Industrial microbiology: The exploitation of microbes for use in industrial processes. Examples include industrial fermentation and wastewater treatment. Closely linked to the biotechnology industry. This field also includes brewing, an important application of microbiology.
Aeromicrobiology: The study of airborne microorganisms.
Food Microbiology: The study of microorganisms causing food spoilage.
Pharmaceutical microbiology: the study of microorganisms causing pharmaceutical contamination and spoillage
Saturday, July 7, 2007
Paus
पाऊस आलाय….भिजून घ्याथोडा मातीचा गंध घ्याथोडा मोराचा छंद घ्याउरात भरून आनंद घ्या..आलाय पाऊस…..भिजून घ्याबघा समुद्र उसळतोयवारा ढगांना घुसळतोयतुम्हीही त्यांच्यात मिसळून घ्या..आलाय पाऊस…..भिजून घ्याऑफ़ीस रोजच गाठत असतंकाम नेहमीच साठत असतंमनातून भिजावंसं वाटत असतंमनाची हौस पुरवून घ्या..आलाय पाऊस…..भिजून घ्यासर्दी पडसे रोजचेच..त्याला औषध तेच तेच..प्यायचेच आहेत नंतर काढे ,आधी अमृत पिऊन घ्या..आलाय पाऊस…..भिजून घ्याबघा निसर्ग बहरलायगारव्याने देहही शहारलायमनही थोडं मोहरून घ्या..आलाय पाऊस…..भिजून घ्या...............................
poem marathi
आयुष्य असचं जगायचं असतंजे घडेल ते सहन करायचे असतं, बदलत्या जगाबरोबर बदलायचं असतंआयुष्य असचं जगायचं असतंकुठून सुरु झालं हे माहीत नसलं तरी, कुठतरी थांबायचं असतं,आयुष्य असचं जगायचं असतंकुणासाठी काहीतरी निस्वार्थपणे करायचं असतं, स्वत:च्या सुखापेक्षा इतरांना सुखवायचे असतंआयुष्य असचं जगायचं असतंदु:ख आणि अश्रुंना मनात कोडुन ठेवायचं असतं, हसता नाही आलं तरी हसवायचं असतं,आयुष्य असचं जगायचं असतंपंखामध्ये बळ आल्यावर घरटं सोडायचं असतं, आकाशात झेपावुनही धरतीला विसरायचं नसतं,आयुष्य असचं जगायचं असतंमरणानं समोर येउन जीव जरी मागितला तरी मागुन मागुन काय मागितलसं असचं म्हणायचं असतं,आयुष्य असचं जगायचं असतंइच्छा असो वा नसो जन्मभर वाकायचं असतं, पणं जग सोडताना मात्र समाधानानं जायचं असतं,आयुष्य असचं जगायचं असतं .
Astro Physics
Astronomy (also frequently referred to as astrophysics) is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the cosmic background radiation). It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the formation and development of the universe.
Astronomy is one of the oldest sciences. Astronomers of early civilizations performed methodical observations of the night sky, and astronomical artifacts have been found from much earlier periods. However, the invention of the telescope was required before astronomy was able to develop into a modern science.
Since the 20th century, the field of professional astronomy split into observational and theoretical branches. Observational astronomy is focused on acquiring and analyzing data, mainly using basic principles of physics. Theoretical astronomy is oriented towards the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain the observational results, and observations being used to confirm theoretical results.
Historically, amateur astronomers have contributed to many important astronomical discoveries, and astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and observation of transient phenomena.
Modern astronomy is not to be confused with astrology, the belief system that claims that human affairs are correlated with the positions of celestial objects. Although the two fields share a common origin, most thinkers in both fields believe they are now distinct.
Astronomy is one of the oldest sciences. Astronomers of early civilizations performed methodical observations of the night sky, and astronomical artifacts have been found from much earlier periods. However, the invention of the telescope was required before astronomy was able to develop into a modern science.
Since the 20th century, the field of professional astronomy split into observational and theoretical branches. Observational astronomy is focused on acquiring and analyzing data, mainly using basic principles of physics. Theoretical astronomy is oriented towards the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain the observational results, and observations being used to confirm theoretical results.
Historically, amateur astronomers have contributed to many important astronomical discoveries, and astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and observation of transient phenomena.
Modern astronomy is not to be confused with astrology, the belief system that claims that human affairs are correlated with the positions of celestial objects. Although the two fields share a common origin, most thinkers in both fields believe they are now distinct.
Quantam Theory
In atomic physics, the Bohr model depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus — similar in structure to the solar system, but with electrostatic forces providing attraction, rather than gravity. This was an improvement on the earlier plum-pudding model (1904), the Saturnian model (1904), and the Rutherford model (1911). Since the Bohr model is a quantum-physics based modification of the Rutherford model, many sources combine the two, referring to the Rutherford-Bohr model.
Introduced by Niels Bohr in 1913, the model's key success lay in explaining the Rydberg formula for the spectral emission lines of atomic hydrogen; while the Rydberg formula had been known experimentally, it did not gain a theoretical underpinning until the Bohr model was introduced. Not only did the Bohr model explain the reason for the structure of the Rydberg formula, but it provided a justification for its empirical results in terms of fundamental physical constants.
The Bohr model is a primitive model of the hydrogen atom. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics, and thus may be considered to be an obsolete scientific theory. However, because of its simplicity, and its correct results for selected systems (see below for application), the Bohr model is still commonly taught to introduce students to quantum mechanics, before moving on to the more accurate but more complex valence shell atom. A related model was originally proposed by Arthur Erich Haas in 1910.
Introduced by Niels Bohr in 1913, the model's key success lay in explaining the Rydberg formula for the spectral emission lines of atomic hydrogen; while the Rydberg formula had been known experimentally, it did not gain a theoretical underpinning until the Bohr model was introduced. Not only did the Bohr model explain the reason for the structure of the Rydberg formula, but it provided a justification for its empirical results in terms of fundamental physical constants.
The Bohr model is a primitive model of the hydrogen atom. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics, and thus may be considered to be an obsolete scientific theory. However, because of its simplicity, and its correct results for selected systems (see below for application), the Bohr model is still commonly taught to introduce students to quantum mechanics, before moving on to the more accurate but more complex valence shell atom. A related model was originally proposed by Arthur Erich Haas in 1910.
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