Human Circulatory System

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Human Circulatory System
The System, which is primarily meant for the circulation of the nutritive products, disposal and excretion of waste material in the body is known as circulatory system. The two basic types of circulatory system have evolved in animals such as.

Open Circulatory system

It is the type in which blood is pumped by heart into an aorta, which branches off into a number of arteries that ultimately open into a series of spaces collectively called as haemocoel, e.g., most arthropods and some cephalopods.
It is the type in which blood is pumped by heart into an aorta, which branches off into a number of arteries that ultimately open into a series of spaces collectively called as haemocoel, e.g., most arthropods and some cephalopods.

Closed Circulatory System

It is the type in which blood stays in blood vessels. It does not come into direct contact with the body tissue. The only entry and exit to the system is through the walls of blood vessels e.g.. in annelids and chordates. This considered to be the most advantageous method as it supplies blood to the deepest tissues of the body.
Human circulatory system is of closed types and consists of blood vascular system and lymphatic system.

Blood vascular system

Human blood vascular system comprises blood, blood vesseles and heart

Blood

It is fluid connective tissue which forms 30-32% of total extracellular fluid. Volume of blood in an adult person is about 5-5.5L. Blood is a red coloured liquid which circulates in our body. It is red because it contains a red pigment called haemoglobin in its red blood cells. Components of Blood Blood is a fluid connective tissue comprising of fluid part called plasma and the cells known as blood corpuscles. These are described below Plasma It is a straw coloured, viscous fluid, slightly alkaline and aqueous solution. It forms about 55% of the blood. Compositions of Plasma. It is composed of many organic and inorganic substances, which includes 90-92% water and 6-8% solutes in it. The solutes found in plasma are various ions, glucose, tracces of other sugars, plasma proteins, amino acids, hormones, cholesterol, lipids, urea, other wastes and organic acids.
  • Serum: Factors for clotting or coagulation of blood are also present actively in the plasma. Plasma without the blood clotting factors is called serum.
  • Plasma Proteins: Proteins found in plasma are the important components. These are responsible for providing viscosity to the plasma. Over 70 different plasma proteins are found out of which the major proteins found in plasma are fibrinogen, globulins and albumins.
  • Minerals and inorganic salts: They occur in plasma in the form of ions i.e. potassium, magnesium, calcium, iron and manganese. Sodium and chloride are principle cation and anion of the plasma. Bicarbonate and phosphate also occur in smaller amounts.
  • Anticoagulant: A natural strong anticoagulant present in the plasma is heteropolysaccharide named anti prothrombin, or heparin, which checks clotting of blood in uninjured blood vessels by preventing conversion of prothrombin into thrombin. It is produced in the liver.
Functions of Plasma It performs various functions in the blood as follows
  1. Helps in transport and uniform distribution of heat all over the body
  2. Provides body immunity.
  3. Maintananc of blod pH.
  4. Provides prevention of blood loss.
  5. Fibrinogen helpsin blood clotting, globulin help in defense mechanism, albumin maintains osmotic balance

Formed Elements

The formed elements or blood corpuscles includ erythrocytes, leucocytes and platelets. These constitute about 45% of the blood. Functions of Blood Blood performs the following important functions
  1. Maintains body pH, water and ionic balance
  2. helps in healing of wounds
  3. Also helps in transportation of hormones from endocrine glands to target organs.
  4. Coagulation
  5. Helps in transportation of body wastes from different body parts to kidneys.
  6. Maintains normal body temperature
  7. Fight against infections by forming body immunity
  8. Helps in transportation of respiratory gases (i.e. Oxygen, carbon dioxide)
A woman has approximately 4.5 litres of blood in her body while man has 5.6 litres
Blood Groups Although blood of every human being appears to be similar in apperance but, it differ in certain aspects. The plasma membrane of RBCs contain certain glycoproteinaceous molecules known as antigen, which differ in different persons. Thus, providing them different blood groups. Two important common types of blood grouping found in human beings are 1. ABO Blood Grouping ABO blood grouping is based on the presence or absence of antigen A or Antigen B on the surface of RBCs (Chemicals that can induce immune response). Similarly, the plasma of different individuals contain two natural antibodies (which are proteins produced in response to antigens). 2. Rh Grouping Another antigen, known as Rh antigen (similar to the one present in Rhesus monkey) is also found on the RBCs surface in majority of humans (nearly about 80%). Individuals having Rh antigen are called Rh positive (Rh+) and those without the Rh antigen are called Rh negative (RH).
  • People with blood group O RH are called universal donors and people with blood group AB Rh+ are called universal receivers.
  • Rh+ blod can never be given to some with Rh- blood, but the other way around works. e.g. O Rh+ blood can not be given to someone with the blood type AB Rh.
Rh Incompatibility During Pregnancy This is special case of mismatching of Rh group or Rh incompatibility which has been observed between the RH- blood of a pregnant mother with RH+ blood of the foetus (born out of a marriage between RH- woman and a RH+ man). In such a case, mother becomes sensitive, while carrying a RH+ baby in her uterus. THis reason is that some of RBCs from the developing foetus enters into the blood stream of the mother during development. This causes the development of anti-Rh antibodies. This does not happen in her first pregnancy (because two remain separated by Placenta). But is case of her subsequent pregnancies (i.e., 2nd and 3rd) Rh+ foet uses get exposed to the anti-Rh antibodies, which will leak into the blood of the foetus (RH+) and destroy foetal RBCs. This could be fatal to the foetus or could cause severe anaemia and jaundice in the body. This is known as erythroblastrosis foetalis. The condition can be avoided by administering anti-Rh antibodies to the mother immediately after the delivery of the first child.

Lymph

It is a colourless flouid and its composition is same as that of tissue fluid, which in turn, is same as that of blood plasma. It contains very small amount of nutrients and oxygen but contains abundant carbon dioxide and other metabolic wastes. Amoeboid shaped white blood corpuscles are also present in lymph Formation of Lymph As the blood passes through the capiliaries of the arterial system into the tissues, some water along with many water soluble substances comes out in the spaces between the cells of tissues. But a very small amount of proteins come out from the capillary with the plasma (leaving the larger proteins and most of the formed elements in the blood vessel). The fluid thus, released out is called interstitial fluid (tissue fluid) or Extra Cellular Fluid (ECF). After entering the lymph vessel, the ECF becomes lymph. Functions of Lymph Lymph performs the following important functions
  1. It acts as an important carrier of nutrients, hormones, etc.
  2. Also, helps in the renewal of ECF.
  3. Absorption of fat also occurs through lymph in the lacteal present in the intestinal villi.
  4. Helps in keeping tissue cells moist.
  5. Maturation of lymphocytes i.e., B-cells and T-cells occur with the help of lymph nodes, releasing them into the lymph.

Heart (The Pumping Organ)

All vertebrates posses a muscular chambered heart Sepending upon the different types of circulation in theom heart is of following 3 types Four Chambered: Posses 2 atria and 2 ventricles; oxygenated and deoxygenated blood do not get mixed and pumped separately; double circulation e.g. birds and Mammanls Three Chambered: Posses w atria and 1 ventricle; left atrium receive oxygenated and right atrium receive de-oxygenated blood. which gets mixed in venticle, incomplete doouble circulation, e.g., amphibians and reptiles (except corocodile) Two Chambered: Posses atrium and 1 ventricle, heart always receive deoxygentaed blood which passes through it for once (single circulation) e.g., fishes

Human Heart

Human heart is muscluar organ of mesodermal origin, situated between the lungs of thoracic cavity. An average adult human heart is about 12cm. Its weight ranges from 280-340g (average 300 g) in males and 230-280 g (average 250 g) in females. The heart is surrounded by a protective covering called pericardium (two layered) which is filled with pericardial fluid. The heart is divided into four chambers in human beings; these chambers are
  1. Auricles or Atrium There are two auricles or atrium left and right separated by inter auricular septum and are superior in position. SA node (Sinoatrial Nod) is situated in the upper wall of right atrium.
  2. Ventricles: Two interior chambers of the heart are the right and left ventricle separated by inter-ventricular septum.
The walls of ventricle are thicker than that of atria because ventricles have to pump blood into various organs, while atria receives blood

Parts of the Human Heart and their Functions

  • Left Atrium It receives oxygenated blood from teh lungs via pulmonary vein
  • Left Ventricle It pumps blood to all parts of the body except the lungs via aorta
  • Right Atrium It receives deoxygenated blood coming from the body via vena cava
  • Right Ventricle It pumps blood to the lungs for oxygenation.
  • Valves It prevents backflow of blood. There are four typeso f valves i.e. two atrioventricular (AV) valve and two semilunar (SL) valve
  • Atrioventricular (AV) valves are present between the atria and the ventricles. It mainly prevent the back flow from the ventricles into the atrium during systole. It includes mitral valve and tricuspid valve
  • Semilunar valves are present in the arteries levving the hear
  • Aorta It caries oxygenated blood
  • Septum It prevents mixing of oxygenated and deoxygenated blood
  • Pulmonary Artery It caries deoxygenated blood to the lung
  • Pulmonary Vein It caries oxygenated blood from olung to the heart
  • Superior Vena Cava It returns deoxygenated blood from head and arms to the heart.
  • Inferior Vena Cava It returns deoxygenated blood from lower limbs and organs to the heart.

Aug 2, August 2 | Historical Events on August 2

Jagmit Singh Brar
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Aug 2, August 2 | Historical Events on August 2

Historical Events on 2 August or August 2

  • 338 BC Macedonian army led by Philip II defeats combined forces of Athens and Thebes in the Battle of Chaeronea, securing Macedonian hegemony in Greece and the Aegean
  • 216 BC Second Punic War: Battle of Cannae – Carthaginian army lead by Hannibal defeats numerically superior Roman army under command consuls Lucius Aemilius Paullus and Gaius Terentius Varro
  • 257 St Stephen I ends his reign as Catholic Pope
  • 1057 Frederik van Lotharingen elected as 1st Belgium Pope Stephen IX [X]
  • 1100 King William II of England (William Rufus) is killed by an arrow shot by Sir Walter Tyrell while hunting in the New Forest.
  • 1542 French troops leave Flanders
  • 1552 Treaty of Passau: Emperor Charles V accepts Lutheran religion
  • 1578 Battle of Rijmenam: Spanish Habsberg forces defeated by Dutch troops (Eighty Years’ War)
  • 1581 Leiden University names Snellius math professor
  • 1610 Henry Hudson enters bay later named after him, the Hudson Bay
  • 1665 French expedition against Barbarians in Tunis/Algiers
  • 1695 Daniel Quare receives a British patent for his portable barometer
  • 1701 Great Peace of Montreal signed between New France and North American Indian nations at urging of Huron chief Kondiaronk
  • 1704 Duke of Marlborough beats French & Bavarians at Blenheim
  • 1718 Austrian joins Triple Alliance
  • 1738 France offers emperor Karel VI mediation in war against Turkey
  • 1776 Formal signing of the US Declaration of Independence by 56 people (date most accepted by modern historians)
  • 1782 George Washington creates Honorary Badge of Distinction
  • 1786 Utrechtse Vroedschap flees
  • 1787 Horace the Saussure reaches top of Mont Blanc
  • 1790 1st US census conducted, the population was 3,939,214 including 697,624 slaves
  • 1791 Samuel Briggs & his son, patent nail-making machine
  • 1798 Battle of the Nile: British Royal Navy under Admiral Horatio Nelson further decimates the French fleet
  • 1802 Napoleon declared “Consul for Life”
  • 1819 1st parachute jump in US
  • 1830 Charles X of France abdicates in favour of his grandson the Duc de Bordeaux
  • 1831 Ten day campaign begins, Dutch army occupies Belgium
  • 1832 Battle of Bad Axe, Wisconsin: 1,300 Illinois militia defeat Sauk & Fox Native Americans ending the Black Hawk War in the US
  • 1858 1st mailboxes installed in Boston & NYC streets
  • 1858 Government of India transferred from East India Company to the British Crown
  • 1861 Skirmish at Dug Springs, MI

Historical Events on 2 August or August 2

  • 1864 2nd Saratoga Racetrack (NY) opens
  • 1865 Lewis Carroll publishes “Alice’s Adventures in Wonderland”
  • 1865 Trans Atlantic Cable being laid by SS Great Eastern snaps & is lost
  • 1870 Tower Subway, the world’s first underground tube railway, opens in London.
  • 1873 1st trial run of SF cable car, Clay Street between Kearny & Jones
  • 1875 1st roller skating rink opens (London)
  • 1877 SF Public Library opens with 5,000 volumes
  • 1880 British Parliament officially adopts Greenwich Mean Time (GMT)
  • 1884 Dutch Queen Emma appointed regent
  • 1887 Rowell Hodge patents barbed wire
  • 1892 Charles A Wheeler patents a prototype of the escalator
  • 1894 Death duties 1st introduced in Britain
  • 1894 Dutch Society for Women Suffrage gets royal charter
  • 1903 Unsuccessful uprising of Macedonians against Turkey
  • 1906 Chicago White Sox begin AL record 19 game win streak
  • 1907 Walter Johnson, 19, debuts with Washington & loses 3-2 to Detroit
  • 1909 1st Lincoln head pennies minted
  • 1909 Army Air Corps formed as Army takes 1st delivery from Wright Brothers
  • 1911 Haiti’s dictator Simon flees on US warship near Jamaica
  • 1912 18th US Golf Open: John McDermott shoots a 294 at CC of Buffalo NY
  • 1914 Belgian government receives German ultimatum
  • 1914 German press falsely reports that French bombed Nuremberg
  • 1914 German troops overthrows Luxembourg
  • 1914 Germany & Turkey sign secret treaty of alliance
  • 1914 Great Britain mobilizes
  • 1914 Postdam Conference ended
  • 1914 Russian troops invade Eastern Prussia
  • 1914 Sherlock Holmes Adventure “His Last Bow” takes place
  • 1916 World War I: Austrian sabotage causes the sinking of the Italian battleship Leonardo da Vinci in Taranto.
  • 1918 Japan announces that it is deploying troops to Siberia in the aftermath of World War I.
  • 1920 Marcus Garvey presents his “Back To Africa” program in NYC
  • 1921 Chicago jury brings in not guilty verdict against the Black Sox
  • 1922 China, hit by a typhoon; about 60,000 die
  • 1924 Joe Hauser sets record of 14 total bases in a game
  • 1928 Benito Mussolini signs peace treaty with Abyssinia (Ethiopia)
  • 1929 Phillies Don Hurst sets NL record of 6 consecutive games with a HR
  • 1931 Spanish Catalonia agrees (99+%) for autonomous status
  • 1932 Charlie Grimm replaces Roger Hornsby as manager of Chicago Cubs
  • 1932 Carl David Anderson discovers and photographs a positron, the first known antiparticle
  • 1934 1st airplane train, plane tows 3 mail gliders behind it
  • 1934 Adolf Hitler becomes commander-in-chief of German armed forces
  • 1934 William Franks twirls an indian club overhead 17,280 times in 1 hour
  • 1936 30th Tour de France won by Sylvere Maes of Belgium
  • 1937 Marihuana Tax Act of 1937 is passed in America, essentially rendering marijuana and all its by-products illegal
  • 1938 1st test of a yellow baseball (Dodgers vs Cardinals)
  • 1939 Hatch Act prohibits political activity by federal workers
  • 1940 Clermont-Ferrand sentences General Charles de Gaulle to death
  • 1940 KL-House of saxon & commandos focus on Gross Rosen, Silesia
  • 1941 German 11st Army surrounds 20 Soviet divisions at Oeman
  • 1941 Jews are expelled from Hungarian Ruthenia
  • 1942 250 Dutch Catholic Jews arrested, transported to Amersfoort camp
  • 1942 Col-Gen Hoth’ Panzer army reaches Kotelnikovo
  • 1943 Armed revolt breaks out in Treblinka
  • 1943 Lt John F. Kennedy’s PT-boat 109 sinks at Solomon islands
  • 1943 Sunderland seaplanes sinks U-706 & U-106
  • 1943 Uprising at Treblinka Concentration Camp (crematorium destroyed)
  • 1944 Amsterdam soccer team “The Volewijckers” plays in orange shirts
  • 1944 Jewish survivors of Kovono Ghetto emerge from their bunker
  • 1944 Turkey breaks diplomatic relationship with nazi-Germany
  • 1945 Potsdam Conference between Joseph Stalin, Harry Truman and Winston Churchill ends
  • 1953 Betty Jack Davis, singer (w/Skeeter Davis), killed in car crash
  • 1953 KCPQ TV channel 13 in Tacoma-Seattle, WA (IND) begins broadcasting
  • 1954 Tahar Ben Ammar appointed premier of Tunisia
  • 1955 USSR performs nuclear test
  • 1958 Jordan & Iraq disolve their Arab Federation, after 3 months
  • 1959 41st PGA Championship: Bob Rosburg shoots a 277 at Minneapolis GC
  • 1959 Milwaukee Brave Bill Bruton hits 2 bases loaded triples
  • 1959 SF Giants 1st baseman Willie McCovey hits 1st of his 521 HRs
  • 1961 Beatles 1st gig as house band of Liverpool’s Cavern Club
  • 1961 Cyrille Adula becomes premier of Congo
  • 1961 St Louis Cards (NFL) beat Toronto Argonauts (CFL) 36-7 in Toronto
  • 1963 30th NFL Chicago All-Star Game: All-Stars 20, Green Bay 17 (65,000)
  • 1964 Dutch government gives Indonesia export guarantees
  • 1964 Mickey Wright wins LPGA Milwaukee Jaycee Golf Open
  • 1964 North Vietnam fires on a US destroyer in the Gulf of Tonkin incident which would eventually escalate US involvement in the Vietnam War
  • 1964 Race riot in Jersey City NJ
  • 1965 Morley Safer’s sends 1st Vietnam report indicating the US is losing
  • 1966 Radio Vila (New Hebrides) begins transmitting
  • 1967 New Orleans Saints 1st pre-season game, they lose to LA Rams 16-77
  • 1967 US’s Lunar Orbiter 5 launched; enters lunar orbit Aug 5

Historical Events on 2 August or August 2

  • 1967 The second Blackwall Tunnel opens in Greenwich, London.
  • 1967 “In the Heat of the Night” directed by Norman Jewison and starring Sidney Poitier and Rod Steiger premieres in New York (Best Picture 1968)
  • 1968 35th NFL Chicago All-Star Game: Green Bay 34, All-Stars 17 (69,917)
  • 1969 Bob Dylan makes surprise appearance at Hibbing HS Minn 10th reunion
  • 1969 US President Richard Nixon visits Romania
  • 1970 Baltimore defeats KC 10-8, Orioles 23rd straight win over the Royals
  • 1970 France performs nuclear test at Fangataufa Island
  • 1970 Rubber bullets used for the first time in Northern Ireland during ‘The Troubles’
  • 1972 Gold hits record $70 an ounce in London
  •  1975 104°F (40°C) at Providence, Rhode Island (state record)
  • 1975 107°F (42°C) at Chester/New Bedford, Massachusetts (state record)
  • 1979 “Broadway Opry ’79” closes at St James Theater NYC after 6 performances
  • 1979 Gilda Radner Live From New York opens on Broadway
  • 1980 Fascist bomb attack on Bologna Italy train station, 86 killed
  • 1980 US swimmers set 3 world records at National championships
  • 1981 Australia set 151 to win, all out 121, Botham 5-11 in 14 overs
  • 1981 Donna Caponi Young wins LPGA Boston Five Golf Classic
  • 1982 Oakland’s Rickey Henderson steals his 100th base of the season
  • 1982 Roger Ebert’s “Movie News” premieres on ABC FM network
  • 1983 STS-8 vehicle moves to launch pad
  • 1983 US District Court begins trying Yonkers accused of race discrimination
  • 1984 US performs nuclear test at Nevada Test Site
  • 1985 5 die in a train crash in Westminster Colo
  • 1985 Delta Lockheed L-1011 crashes at Dallas-Fort Worth Airport, 137 die
  • 1986 Jackie Joyner-Kersee (US) sets record for heptathlon (7161 pts)
  • 1986 TODAY/PC born today
  • 1986 13th Commonwealth Games close in Edinburgh, Scotland
  • 1987 25th Tennis Fed Cup: Germany beats USA in Vancouver Canada (2-1)
  • 1987 Christa Johnson wins Columbia Savings LPGA National Golf Pro-Am
  • 1987 Cincinnati Red Eric Davis becomes 7th & earliest 30 HR 30 steal man
  • 1987 Don Brown sets flight record for handbow (1,336 yds 1’3″)
  • 1987 Eric Davis is 7th to hit 30 HRs & steal 30 bases in one season
  • 1987 Kevin Seitzer (KC Royals), gets 6 hits in one baseball game
  • 1987 Michael Andretti runs fastest Indy car race in history (171.49 MPH)
  • 1987 USSR performs nuclear test at Eastern Kazakh/Semipalitinsk USSR
  • 1988 Raymond Acevedo is retired from singing group Menudo
  • 1988 System Enhancement Association settles case with PKware (ARC vs PKARC)
  • 1989 NASA confirmed Voyager 2’s discovery of 3 more moons of Neptune designated temporarily 1989 N2, 1989 N3 & 1989 N24
  • 1990 Iraq invades & occupies Kuwait, Emir flees to Saudi Arabia
  • 1990 Yankees rookie Kevin Maas hits his 10th home run in just 77 at bats
  • 1990 23rd San Diego Comic-Con International opens at Holiday Inn
  • 1991 Hedy Lamaar is arrested for shoplifting in LA
  • 1991 Mike Jeffcoat is 1st AL pitcher to get an RBI since 1972
  • 1991 Space shuttle STS 43 (Atlantis 9) launched
  • 1991 Pan Am games open in Havana
  • 1992 “Death & the Maiden” closes at Brooks Atkinson NYC after 159 performances
  • 1992 Dottie Mochrie wins LPGA Welch’s Golf Classic
  • 1992 Tom Seaver, R Fingers, Hal Newhouser, & B McGowan enter Hall of Fame
  • 1993 NYC radio (WFAN) personality Don Imus’ lung collapes
  • 1993 Peter Angelos & William DeWitt purchase Orioles
  • 1993 Train crash in tunnel at Vega de Anzo Spain, 12 killed
  • 1993 Shamrock Broadcasting, a Disney company, officially takes ownership of Cleveland’s WMMS-FM/100.7 & WHK-AM/1420
  • 1994 Congressional hearings begin on White Water
  • 1994 Explosion in lead/zinc mine in Guangxi China, 120+ killed
  • 1994 NY Supreme Court refuses Howard Stern’s non financial disclosure
  • 1994 Noureddine Morceli runs world record 3000m (7:25.11)
  • 1995 Saudi Arabia’s King Fahd issues a decree replacing all members of the Council of Ministers who do not have blood ties so the royal Family
  • 1998 26th du Maurier Golf Classic: Brandie Burton
  • 1998 30th Curtis Cup: US wins 10-8 at The Minikahda Club (Minneapolis, Minnesota, US)
  • 1998 San Francisco Giants slugger Barry Bonds is hit by a pitch and charges the mound, causing a bench-clearing brawl
  • 1998 85th Tour de France won by Marco Pantani of Italy
  • 1999 “The Sixth Sense”, starring Bruce Willis, Toni Collette, and Haley Joel Osment, premieres
  • 2008 “Breaking Dawn”, 4th book in Stephenie Meyer’s “Twilight Saga” is published by Little Brown at midnight with a print run of 3.7 million copies
  • 2012 23 people are killed after two blasts in a fruit market in Lahore, Pakistan
  • 2013 40 people are killed after an ammunition depot explodes in Homs, Syria
  • 2013 Carl Icahn sues computer giant Dell in an attempt to derail a buyout bid by the CEO, Michael Dell

Bacteria | Bacterial Cells | Bacteria are useful and Harmful

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Bacteria | Bacterial Cells | Bacteria are useful and Harmful

Bacteria Definition

Bacteria, microscopic & unicellular organisms, are often coccus- (spherical) or rod-shaped and 0.5-5 µm in the longest dimension, although the wide diversity of bacteria can display a huge variety of morphologies. The study of bacteria is known as bacteriology, a branch of microbiology. Bacteria are ubiquitous in the environment, living in every possible habitat on the planet including soil, underwater, deep in the earth’s crust, and even such environments as sulfuric acid and nuclear waste. There are typically ten billion bacterial cells in a gram of soil, and one hundred thousand bacterial cells in a millilitre of sea water. Bacteria play an important role in the cycling of nutrients in the environment. They play many important steps in the nutrient cycle as catalysts, such as the fixation of nitrogen from the atmosphere. There are more bacterial cells on each of our bodies than there are cells of our own and bacteria are a natural component of the human body, particularly on the skin and in the mouth and intestinal tract. Bacteria are important to human health, as they are the causative agent of many infectious diseases, including cholera and tuberculosis. Historically, bacteria have been responsible for such diseases as bubonic plague and leprosy, but after the discovery of antibiotics many bacterial diseases are able to be controlled. Bacteria are also important to numerous industrial processes, such as wastewater treatment and more recently the industrial production of antibiotics and other chemicals. The first bacteria were observed by Anton van Leeuwenhoek in 1674 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 meaning “small stick”.

Cell Morphology and Arrangement of bacterial cells

Bacterial cells are typically 0.5-5 ìm in length, however some species, for example Thiomargarita namibiensis and Epulopiscium fishelsoni, may be up to 500 µm (0.5 mm) long and are visible to the unaided eye. Among the smallest bacteria are members of the genus Mycoplasma which measure just 0.2 µm; approximately the same size as the largest viruses. Most bacteria are either spherical, called coccus or rod-shaped, called bacillus (pl. baccili, from Latin baculus, stick) Some rod-shaped bacteria, called vibrio, are slightly curved or comma-shaped, while others, called spirilla, form twisted spirals. Many bacterial species exist simply as single cells, while others tend to associate in diploids / pairs (for example Neisseria), or chains (such as Streptococcus), while members of the genus Staphylococcus, form a “bunch of grapes” clusters. Bacteria can also be elongated to form filaments, for example the Actinomycetes. The bacterial cell is bound by a lipid membrane, or plasma membrane, which encompasses the contents of the cell, or cytoplasm, and acts as a barrier that holds nutrients, proteins and other essential molecules within the cell. Bacteria do not have membrane-bound organelles in the cytoplasm and thus contain few intracellular structures. They lack mitochondria, chloroplasts and the other organelles present in eukaryotic cells, such as the golgi apparatus and endoplasmic reticulum. Bacteria do not have a membrane-bound Bacteria do not have a membrane-bound nucleus and their genetic material is typically a single chromosome located in the cytoplasm as an irregularly-shaped body called the nucleoid. The nucleoid consists mainly of the chromosome but has also associated proteins and RNA. Like all living organisms bacteria contain ribosomes for the production of proteins. External to the cell membrane is the bacterial cell wall. Bacterial cell walls are composed of peptidoglycan, different from the cell walls of plants and fungi which have cell walls of cellulose and chitin, respectively. The cell wall is essential to the survival of bacteria; the antibiotic penicillin is able to effectively kill bacteria by inhibiting a step in the synthesis of peptidoglycan and stopping the production of the cell wall. Flagella are rigid protein structures, about 20 nm in diameter and up to 20 µm in length, that are used for motility. Some bacteria also produce nutrient storage granules, such as glycogen, polyphosphate, sulphur or polyhydro- xyalkanoates. These storage compounds enable bacteria to store compounds for later use. Certain bacterial species, such as the photosynthetic Cyanobacteria, produce internal gas vesicles which they use to regulate their buoyancy to regulate the optimal light intensity or nutrient levels. Bacteria serve as a link between plants and animals. They are now regarded as the simplest plants because of the following reasons:
  • They have a rigid cell wall made up of mucopolysacchrides.
  • Some of the bacteria like chlorobium are autotrophic, like green plants.
  • Some forms of bacteria are capable of sythesizing vitamins just like green plants.
  • Bacteria take in their nutrition in the form of solution only.
Bacteria differ from the eukaryotic cells of other plants in the following respects:
  • The mitochondria and endoplasmic reticulum are lacking in the cytoplasm.
  • The nuclear body does not divide by mitosis.
  • The photosynthetic lamellae when present are not organised into chloroplast.
  • No protoplasmic streaming movements seen.
  • Contains no vacuoles.

Respiration in Bacteria

Most bacteria make use of the free oxygen of the atmosphere or oxygen dissolved in the liquid environement, they are called aerobes or aerobic bactria. Free oxygen is necessary for their respiration. There are many bacteria which are able to live and multiply in the absence of free oxygen. They obtain oxygen from oxygen containing compounds such as sugar. They are called the anaerobes or anaerobic bacteria, but the amount of energy available from anaerobic respiration is much less than that from aerobic respiration, Syphilis and Tetanus bacteria are e.g. of obligate anaerobes. There are some bacteria which can live and grow whether oxygen is present or not. They are called facultative anaerobes.

Growth and Reproduction

All bacteria reproduce through asexual reproductio (one parent) binary fission, which results in cell division. Two identical clone daughter cells are produced. Some bacteria, while still reproducing asexually, form more complex reproductive structures that facilitate the dispersal of the newly-formed daughter cells. Bacteria, as asexual organisms, inherit an identical copy of their parent’s genes (i.e. are clonal). All bacteria, however, have the ability to evolve through selection on changes to their genetic material (DNA) which arise either through mutation or genetic recombination. Mutation occurs as a result of errors made during the replication of DNA. The most frequent genetic changes in bacterial genomes come from random mutation. Some bacteria can also undergo genetic recombination. This can occur when bacteria take-up exogenous environmental DNA from closely related genera in a process called transformation. In the process of transduction, a virus can alter the DNA of a bacterium by becoming lysogenic and introducing foreign DNA into the host chromosome, which can then be transcribed and replicated. Because of their ability to quickly grow, and the relative ease with which they can be manipulated, bacteria have historically been the workhorses for the fields of molecular biology, genetics and biochemistry. By making mutations in bacterial DNA and examining the resulting phenotypes, scientists have been able to determine the function of many different genes and enzymes.

Benefits and Dangers Bacteria are both harmful and useful to the environment

Bacteria are both harmful and useful to the environment and animals, including humans. Some bacteria act as pathogens and cause tetanus, typhoid fever, pneumonia, syphilis, cholera, food-borne illness, leprosy, and tuberculosis(TB). Sepsis, a systemic infectious syndrome characterized by shock and massive vasodilation, or localized infection, can be caused by bacteria such as Streptococcus, Staphylococcus bacteria. Some bacterial infections can spread throughout the host’s body and become systemic. In plants, bacteria cause leaf spot, fireblight, and wilts. The mode of infection includes contact, air, food, water, and insect-borne microorganisms. The hosts infected with the pathogens may be treated with antibiotics, which can be classified as bacteriocidal and bacteriostatic, which at concentrations that can be reached in bodily fluids either kill bacteria or hamper their growth, respectively. Antiseptic measures may be taken to prevent infection by bacteria, for example, by swabbing skin with alcohol prior to piercing the skin with the needle of a syringe. Sterilization of surgical and dental instruments is done to make them sterile or pathogen-free to prevent contamination and infection by bacteria. Sanitizers and disinfectants are used to kill bacteria or other pathogens to prevent contamination and risk of infection. In soil, microorganisms which reside in the rhizosphere (a zone that includes the root surface and the soil that adheres to the root after gentle shaking) help in the transformation of molecular dinitrogen gas as their source of nitrogen, converting it to nitrogenous compounds in a process known as nitrogen fixation. This serves to provide an easily absorbable form of nitrogen for many plants, which cannot fix nitrogen themselves. Many other bacteria are found as symbionts in humans and other organisms. For example, the presence of the gut flora in the large intestine can help prevent the growth of potentially harmful microbes. The ability of bacteria to degrade a variety of organic compounds is remarkable. Highly specialized groups of microorganisms play important roles in the mineralization of specific classes of organic compounds. For example, the decomposition of cellulose, which is one of the most abundant constituents of plant tissues, is mainly brought about by aerobic bacteria that belong to the genus Cytophaga. This ability has also been utilized by humans in industry, waste processing, and bioremediation. Bacteria capable of digesting the hydrocarbons in petroleum are often used to clean up oil spills. Bacteria, often in combination with yeasts and molds, are used in the preparation of fermented foods such as cheese, pickles, soya sauce, sauerkraut, vinegar, wine, and yogurt. Using biotechnology techniques, bacteria can be bioengineered for the production of therapeutic drugs, such as insulin, or for the bioremediation of toxic wastes. “Friendly bacteria” is a term used to refer to those bacteria that offer some benefit to human hosts, such as Lactobacillus species, which convert milk protein to lactic acid in the gut. The presence of such bacterial colonies also inhibits the growth of potentially pathogenic genic bacteria (usually through competitive exclusion). Other bacteria that are helpful inside the body are many strains of E. coli, which are harmless in healthy individuals and provide Vitamin K.  

Food Borne Disease caused by Bacteria | Intestinal tracts of animals

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Food Borne Disease caused by Bacteria | Intestinal tracts of animals

Bacteria That Cause Food-borne Disease

Food-borne disease often shows itself as flu-like symptoms such as nausea, vomiting, diarrhoea, or fever, so many people may not recognize the disease is caused by bacteria or other pathogens on food. They can grow in just about any food, but are fond of protein foods, such as meat, poultry, seafood, eggs, and dairy products in particular, as well as high-protein vegetables such as beans and grains. Bacteria multiply rapidly between 40° and 140° F. To keep food out of this “danger zone,” keep cold food cold and hot food hot. Store food in the refrigerator (40° F or below) or freezer (0° F or below); cook food to 160° F; maintain hot cooked food at 140° F; reheat cooked food to 165° F.

Botulism:

It is a rare but serious paralytic illness caused by a nerve toxin, botulin, that is produced by the bacterium Clostridium botulinum. Botulinic toxin is one of the most powerful known to man, with a lethal dose of a microgram. It acts blocking nerve function and leading to respiratory and musculoskeletal paralysis.
Clostridium Botulinum Food borne disease
Clostridium Botulinum
Some other bacteria cause more serious illness than others, but only a few are responsible for the majority of cases. Below is the information regarding nine prominent bacteria.

Campylobacter jejuni:

Found in intestinal tracts of animals and birds, raw milk, untreated water, and sewage sludge. Transmission through contaminated water, raw milk, and raw or under-cooked meat, poultry, or shellfish.
Campylobacter jejuni Food Borne disease Bacteria
Campylobacter jejuni

Clostridium botulinum:

It is widely distributed in nature: in soil and water, on plants, and in intestinal tracts of animals and fish. Bacteria produce a toxin that causes illness. Improperly canned foods, garlic in oil, and vacuum-packaged and tightly wrapped food can invite it.
Clostridium botulinum Food Borne Disease Bacteria
Clostridium botulinum

Clostridium perfringens:

Found in soil, dust, sewage, and intestinal tracts of animals and humans. It is called “the cafeteria germ” because many outbreaks result from food left for long periods in steam tables or at room temperature. Bacteria is destroyed by cooking, but some toxin-producing spores may survive.
Clostridium perfringens Food Borne Disease Bacteria
Clostridium perfringens

Escherichia coli O157:

Found in intestinal tracts of some mammals, raw milk, unchlorinated water; one of several strains of E. coli that can cause human illness. It is transmitted through contaminated water, raw milk, raw or rare ground beef, unpasteurized apple juice or cider, uncooked fruits and vegetables; person-to-person.
Escherichia coli O157 Food Borne Disease Bacteria
Escherichia coli O157

Salmonella:

Found in intestinal tract and feces of animals; Salmonella enteritidis in raw eggs. It transmits through raw or undercooked eggs, poultry, and meat; raw milk and dairy products; seafood.
Salmonella Bacterial food borne disease
Salmonella

Streptococcus A:

Found in noses, throats, pus, sputum, blood, and stools of humans. Transmission- people-to-food from poor hygiene, ill food handlers, or improper food handling; outbreaks from raw milk, ice cream, eggs, lobster, salads, custard, and pudding allowed to stand at room temperature for several hours between preparation and eating.
Streptococcus A Bacterial Food Borne Disease
Streptococcus A

Listeria monocytogenes:

Found in intestinal tracts of humans and animals, milk, soil, leaf vegetables, and processed foods; can grow slowly at refrigerator temperatures. Transmission- soft cheese, raw milk, improperly processed ice cream, raw leafy vegetables, meat, and poultry. Illness caused by bacteria that do not produce toxin.
Listeria monocytogenes Bacterial Food Borne Disease
Listeria monocytogenes

Shigella :

Found in human intestinal tract; rarely found in other animals. Transmission- person-to-person by fecal-oral route; fecal contamination of food and water. Most outbreaks result from food, especially salads, prepared and handled by workers using poor personal hygiene.

Staphylococcus aureus :

Found in on humans (skin, infected cuts, pimples, noses, and throats). Transmission – people-to-food through improper handling. Multiply rapidly at room temperature to produce a toxin that causes illness.
Staphylococcus aureus Bacterial food borne disease
Staphylococcus aureus

Biotechnology and Bacteria

Biochemistry is defined as the application of organisms such as bacteria, fungi and algae to the manufacturing and services industries. These include:
  • Fermentation processes, such as brewing, baking, cheese and butter manufacturing, chemical manufacturing such as ethanol, acetone, organic acid, enzymes, perfumes, etc.
  • Pharmaceuticals, such as antibiotics, vaccines and steroids.
  • Energy, in the form of biogas.
  • Food products, such as beverages, dairy products, amino acids and proteins.
  • Agriculture, such as animal feed, composting processes, pesticides, nitrogen fixation, plant cell and tissue culture.
  • Microbial mining, which is the bacteria and other microorganisms are cultured in container and then used to bring these processes e.g., copper extraction.

Genetic engineering and bacteria:

Genetic engineering is the manipulation of genes. It is also called recombinant DNA technology. In genetic engineering, pieces of DNA (genes) are introduced into a host by means of a carrier (vector) system. The foreign DNA becomes a permanent feature of the host, being replicated and passed on to daughter cells along with the rest of its DNA. Bacterial cells are transformed and used in production of commercially important products. The examples are production of human insulin (used against diabetes), human growth hormone (somatotrophin used to treat pituitary dwarfism), and infections which can be used to help fight viral diseases.

Fibre retting:

Bacterial populations, especially that of Clostridium butyclicum, are used to separate fibres of jute, hemp, flax, etc, the plants are immersed in water and when they swell, inoculated with bacteria which hydrolyze pectic substance of the cell walls and separate the fibres.These separated fibres are used t make ropes and sacks.

Digestion:

Some bacteria living in the gut of cattles, horses and other herbivores secrete enzyme cellulose that helps in digestion cellulose contents of cell wall. Cellulose in the major source of energy in these animals.

Vitamins synthesis:

Escherichia coli living in human colon synthesize vitamin B and release it for human use. Similarly, Clostridium butyclicum is used for commercial preparation of riboflavin, a vitamin B.

Waste disposal:

Aerobic and anaerobic bacteria are used to decompose sewage wastes. They break down organic matter to harmless, soluble sludge in settling tanks. The methane gas produced is used as energy source. Similarly toxic chemicals synthesized by living organisms and those present in the pesticides are disposed with the help of bacteria. Pseudomonas putida has been created by using genetic engineering techniques and can break down, xylene, and camphor.

Agents of disease:

Organisms which cause disease are called pathogens. Some bacteria are pathogens Some bacteria are pathogenic and cause diseases both in animals and plants. However, pathogenic bacteria more commonly affect animals than plants.

Food spoilage:

Saprotrophic bacteria attack and decompose organic matter. This characteristic has posed problem to mankind as food such as stored grains, meant, fish, vegetable and fruits are attacked by saprotrophic bacteria and spoiled. Similarly milk and products are easily contaminated by bacteria and spoiled.

Vaccine Manufacturing Bacteria:

Bacteria are used in a very large scale to produce antibiotic drugs. A bacterial vaccine is a preparation of dead or weakened bacteria. Vaccine of diptheria, pnenumonia, cough, cholera, tetanus, etc. is prepared using bacteria.

Classification of Plants with Examples and features

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Classification of Plants with Examples and features

Classification of Plants

Classification of Plants, according to longevity plants are annual, biennial and perennial. According to stature, height, growth & duration of stems, plants are herbs, shrubs, trees, creepers, twiners, climbers and lianas.

Classification of Plants on the basis of longevity

  • Annual plants complete their life cycle within one year, e.g., Buttercup, Pea.
  • Biennial plants complete their life cycle in two years – growing vegetatively and storing food in the first year; flowering and fruiting in the second year, eg., Henbane, Radish (in temperate areas).
  • Perennial plants survive for several years, e.g., Canna, Zizyphus, Mango, Agave, Bambusa, Eucalyptus, etc. Some perennial plants ars also monocarpic, e.g., Agave, Bambusa tulda, Melocanna bambusoides. They die after bearing fruits.

Classification of Plants on the basis of flower and fruit bearing cycle

  • Monocarpic plants flower and fruit only once in life. All annuals and biennials are monocarpic. Some perennial plants are also monocarpic, e.g., Agave, Bambusa tulda, Melocanna bambussodies. They die after bearing fruits.
  • Polycarpic are those perennial plants which bear fruits every year after attaining maturity, e.g., Mango, Artabotrys, Peepal.

Classification of Plants on the basis of Stem

Herb, shrubs, and tree
  • Herbs are small plants with soft and pliable stems. Herbs can be annual (e.g., Buttercup), biennial (e.g., Henbane) and perennial (e.g., Canna).
  • Shrubs are perennial plants with medium height woody stems but without any distinction of trunk. Shrubs often have several branches of equal height and are called bushes e.g., Capparis, Rose
  • Trees are tall perennial plants with a thick woody main stem or trunk. Trees are of three types:
  1. Caudex (Columnar): Unbranched trunk, e.g., Coconut Palm, Date Palm.
  2. Excurrent: Monopodial with one main stem or trunk from base to apex. Lateral branches giving a cone like appearance, e.g., Eucalyptus
  3. Deliquescent: The main stem or trunk is distinguishable only for some distance after it is replaced by a number of large branches which form a dome shaped crown., e.g., Mango, Dalbergia.

Classification of Plants on the basis of growth habit

  • Trailers: Plants which spread on the ground without interval, e.g., Strawberry.
  • Creepers plants spread on the ground, rooting at intervals, e.g., Strawberry.
  • Twiners are weak-stemmed plants where the stem coils or twines around an upright support, e.g., Ipomoea cairica (Railway Creeper), Quisquails (Rangoon Creeper).
  • Climbers plants climb up an upright support by special clinging or clasping structures like tendrils, roots and hooks.
  • Lianas (Lianes) are woody twiners and climbers are called lianas. They are found in tropical evergreen forests, e.g., Phenera (=Bauhinia) vahlii, Hiptage.
  • Epiphytes are plants which live on other plants for space only. They are, therefore, also called Space parasites. Angiospermic epiphytes commonly live on trees, e.g., vanda, Dendrobium. They often posses hanging roots with hygroscopic outer spongy tissue called velamen. The smallest angiosperm is Wolffia (a rootless aquatic). It has a diameter of 0.1 mm. The tallest plant is an angiosperm named Eucalyptus regnans. It reaches a height of 114 m or 375 ft. Sequoia sempervirens (a gymnosperm) is the second tallest tree with a height of 111m. Gymnosperm usually possess more taller trees as compared to angiosperms.
Also Read: Contributory factors for the abundance of insects

Coenzyme Q10 | CoQ10

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Coenzyme Q10 | CoQ10

What is Coenzyme Q10?

Coenzyme Q10 is also known as ubiquinone, Coenzyme Q10, CoQ10, trans 2, 3-dimethoxy-5-methyl-6-decaprenyl-1, 4-benzoquinone. Coenzyme Q is quinone derivative with a variable isoprenoid side chain THe mammalian tissues posses a quinone with 10 isoprenoid units which is known as coenzyme Q 10 (CoQ10).
Coenzyme Q10
Coenzyme Q10
The molecular formula of the Coenzyme Q10 is C59H90O4 Average Mass of the Coenzyme Q10 is 863.344 Da. There are three redox states of CoQ10
  1. fully oxidized (ubiquinone)
  2. semiquinone (ubisemiquinone)
  3. fully reduced (ubiquinol)
  Coenzyme Q is a lipophilic electron carrier. It can accept electrons from FMNH 2 produced in the ETC by NADH dehydrogenase or FADH 2 produced outside ETC (e.g. succinate dehydrogenase, acyl CoA dehydrogenase).

Found in all The living tissues

Coenzyme Q is not found in mycobacteria. Vitamin K performs the similar function as coenzyme Q in these organisms. Coenzyme Q has no known vitamin precursor in animals. It is directly synthesized in the body. Coenzyme is found almost in every cell of the body. It is not vitamin because it is produced by the eukaryotes body. Not need to feed externally. It presents in the respring eukaryotic cell, mainly in mitochondria.  It is a component of the electron transport chain and participates in aerobic cellular respiration, which generates energy in the form of ATP. Ninety-five percent of the human body’s energy is generated this way. It is a component of the electron transport chain and participates in aerobic cellular respiration, which generates energy in the form of ATP. Ninety-five percent of the human body’s energy is generated this way. Coenzyme Q10 is used to convert food to energy. It acts as an antioxidant to so, prevents cell from effects of aging. The cell which having higher energy requirement, have high concentration of Coq10 enzymes, like heart, liver.

Coenzyme Q10 or CoQ10 used as medicine

It is used for medicinal purpose. Antioxidants fight damaging particles in the body known as free radicals, which damage cell membranes, tamper with DNA, and even cause cell death. Scientists believe free radicals contribute to the aging process, as well as a number of health problems, including heart disease and cancer. Antioxidants, such as CoQ10, can neutralize free radicals and may reduce or even help prevent some of the damage they cause. Oil based CoQ10 supplements should be taken with meals

Spiky ferrofluid thrusters can move satellites

Jagmit Singh Brar
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Spiky ferrofluid thrusters can move satellites

Spiky ferrofluid thrusters can move satellites

Brandon Jackson, a doctoral candidate in mechanical engineering at Michigan Technological University, has created a new computational model of an electrospray thruster using ionic liquid ferrofluid — a promising technology for propelling small satellites through space. Specifically, Jackson looks at simulating the electrospray startup dynamics; in other words, what gives the ferrofluid its characteristic spikes. He is the lead author of a recent article in Physics of Fluids, “Ionic Liquid Ferrofluid Interface Deformation and Spray Onset Under Electric and Magnetic Stresses”. More than 1,300 active satellites orbit the Earth. Some are the size of a school bus, and others are far smaller, the size of a shoebox or a smart phone. Small satellites can now perform the missions of much larger and more expensive spacecraft, due to advances in satellite computational and communications systems. However, the tiny vehicles still need a more efficient way to maneuver in space. Scaled-down plasma thrusters, like those deployed on larger-class satellites, do not work well. A more promising method of micropropulsion is electrospray. Electrospray involves microscopic, hollow needles that use electricity to spray thin jets of fluid, pushing the spacecraft in the opposite direction. But the needles have drawbacks. They are intricate, expensive and easily destroyed. To solve this problem, L. Brad King, Ron & Elaine Starr Professor in Space Systems at Michigan Tech, is creating a new kind of microthruster that assembles itself out of its own propellant when excited by a magnetic field. The tiny thruster requires no fragile needles and is essentially indestructible. “We’re working with a unique material called an ionic liquid ferrofluid,” King says, explaining that it’s both magnetic and ionic, a liquid salt. “When we put a magnet underneath a small pool of the ferrofluid, it turns into a beautiful hedgehog structure of aligned peaks. When we apply a strong electric field to that array of peaks, each one emits an individual micro-jet of ions.” The phenomenon is known as a Rosensweig instability. The peaks also heal themselves and re-grow if they are somehow damaged. King came up with the idea of using ferrofluids for thrusters in 2012. He was trying to make an ionic liquid that behaved like a ferrofluid when he learned about a research team at the University of Sydney led by Brian Hawkett and Nirmesh Jain. They had developed a ferrofluid from magnetic nanoparticles made by the life sciences company Sirtex. King’s early work with the ferrofluid sample was pure trial and error; the results were good, but the physics were poorly understood. That’s when the Air Force Office of Scientific Research (AFOSR) gave King a contract to research the fluid physics of ferrofluid. Enter Jackson, whose doctoral work is advised by King. “Typically among engineers, there are experimentalists who build and measure things, or there are modelers who simulate things,” King says. “Brandon excels at both.” Working in King’s Ion Space Propulsion Laboratory, Jackson conducted an experimental and computational study on the interfacial dynamics of the ferrofluid, and created a computational model of ionic liquid ferrofluid electrosprays. “We wanted to learn what led up to emission instability in one single peak of the ferrofluid microthruster,” Jackson says, who developed a model for a single peak and conducted rigorous testing to ensure the model was correct. The team gained a much better understanding of the relationships between magnetic, electric and surface tension stresses. Some of the data gathered through the model surprised them. “We learned that the magnetic field has a large effect in preconditioning the fluid electric stress,” Jackson says, explaining this discovery might lead to a better understanding of the unique behaviors of ferrofluid electrosprays. The AFOSR recently awarded King a second contract to continue researching the physics of ferrofluids, and he says, “Now we can take what we’ve learned, and instead of modeling a single peak, we’ll scale it up and model multiple peaks.” Their next set of experiments will be more like a thruster, though a working thruster is still several years away. Although making 100 peaks or more, all thrusting identically, will be much more challenging. “Often in the lab we’ll have one peak working and 99 others loafing. Brandon’s model will be a vital tool for the team going forward,” King says. “If we are successful, our thruster will enable small inexpensive satellites with their own propulsion to be mass produced. That could improve remote sensing for better climate modeling, or provide better internet connectivity, which three billion people in the world still do not have.” The team has also begun collaborating with Juan Fernandez de la Mora, a professor of mechanical engineering and materials science at Yale University, one of the world’s leading experts in electrospray. In addition to spacecraft propulsion, ferrofluid electrospray technology could be useful in spectrometry, pharmace

Botanists discover hundreds of species of fungi in deep coral ecosystems

Jagmit Singh Brar
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Botanists discover hundreds of species of fungi in deep coral ecosystems

New Fungi species in deep coral ecosystem

Researchers from the University of Hawai’i at Mānoa (UHM) Department of Botany have discovered hundreds of potentially new species of fungi in the deep coral ecosystem in the ‘Au’au channel off Maui, Hawai’i. Mesophotic coral ecosystems (MCE) are generally found at depths between 130 – 500 feet and possess abundant plant (algal) life as well as new fish species. The mysteries of these reefs are only recently being revealed through technological advances in closed circuit rebreather diving. Previously overlooked–being too precarious for conventional SCUBA and too shallow to justify the cost of frequent submersible dives–mesophotic reefs continuously disclose breathtaking levels of biodiversity with each dive, yielding species and behavioral interactions new to science. The UHM Hawai’i Undersea Research Laboratory (HURL) used the Pisces V submersible to collect native algae from the mesophotic reefs in the ‘Au’au channel. Using the DNA sequencing facility at the UHM Hawai’i Institute of Marine Biology, Benjamin Wainwright, lead author of the study and UHM Botany postdoctoral researcher, and colleagues determined which species of fungus were associated with the native algae.

Fungi found in almost all habitats on Earth

Fungi have been documented in almost all habitats on Earth, although marine fungi are less studied in comparison to their terrestrial counterparts. Scientists have found fungi in deep and shallow water corals, marine sponges and other invertebrates. The recently discovered fungi, however, were found living in association with algae. “To the best of our knowledge, this is the first documented evidence confirming fungi in MCEs,” said Wainwright. Also Read: Fungal toxins easily become airborne, creating potential indoor health risk

27% of Species in deep see environment also found in rainforest of Hawai

Additionally, the research team discovered that 27% of the species detected in these deep dark environments are also found on terrestrial rainforest plants in Hawai’i. “Finding such high overlap of fungal diversity on terrestrial plants was surprising. Mesophotic reefs are as dark as it gets where photosynthesis is still possible, so to find the same species of fungi on forest plants illustrates the remarkable ability of some fungi to tolerate, and thrive, in extremely different habitats,” said Anthony Amend, senior author of the study and UHM associate professor of botany. “This ecological breadth is something that seemingly sets fungi apart from other organisms.”

Benefits of Fungi

Plant-associated fungi provide many benefits to society. For example, Taxol, a chemotherapy medication used to treat cancers, is produced by a fungus found inside tree bark and leaves. Additionally, research has shown that fungi are useful in bioremediation efforts (for example, oil spill and industrial waste treatment) and capable of breaking down plastic waste.

About new Found Fungi Specie

It is currently not known whether the newly discovered fungal species are pathogens, helpful symbionts or unimportant to their algae hosts. “Further, we don’t currently know what metabolic capabilities they have that may prove to have medical or environmental applications,” said Wainwright. “We know other undiscovered species are present in these ecosystems. Unfortunately, if we do not look now we may miss our opportunity to benefit from them and conserve them.” Deep reefs, like those in the ‘Au’au channel, may act as a refuge as Earth’s climate changes, providing habitat for any marine creatures that can take advantage of this deeper habitat. If this is indeed the case, understanding how this habitat functions and how the corals, algae and fungi interact with one another will be vital to preserving the refuge in the deep.

Using treated graywater for irrigation is better for arid environments

Jagmit Singh Brar
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Using treated graywater for irrigation is better for arid environments

Reusing Graywater for irrigation in arid area

Reusing graywater in dry areas may require treatment for more efficient irrigation in arid, sandy soils, according to a new study published in Chemosphere by researchers at the Ben-Gurion University of the Negev (BGU) Zuckerberg Institute for Water Research. Graywater includes any wastewater generated in households or office buildings except from the toilet.
Graywater use has been proven safe for agriculture irrigation. “Most of the scientific research and legislation efforts have focused on graywater’s health risks, while less attention has been given to its environmental outcomes, including its effect on soil properties,” says Prof. Amit Gross, head of the Department of Environmental Hydrology and Microbiology in the Zuckerberg Institute.

Graywater may lead to erosion of Soil

Prof. Gross and his team found that graywater does not infiltrate through the soil as easily as fresh water and is slower to reach plant roots. It can also cause water runoff leading to erosion. “This condition, called ‘graywater-induced hydrophobicity,’ is likely temporary and disappears quickly following rainwater or freshwater irrigation events,” says Prof. Gross. “However, it is a more significant concern in arid lands with negligible rainfall as compared with wetter regions.”

Treatment of Graywater eliminate the problem

According to the researchers, treating the graywater using biofiltration to degrade the hydrophobic organic compounds will eliminate the problem. In the study, the researchers examined how graywater induces soil hydrophobicity, as well as its degree and persistence. They created three graywater models using raw, treated and highly treated graywater to irrigate fine-grained sand compared to a freshwater control. The result was that only the raw graywater irrigated soil showed hydrophobicity, which could be mitigated with both moderately and highly treated solutions. “Onsite reuse of graywater for irrigation is perceived as a low risk and economical way of reducing freshwater use and, as such, it is gaining in popularity in both developing and developed countries,” says Prof. Gross. “As many government authorities are establishing new guidelines, the results of this study reinforce the recommendations to treat graywater before reusing for irrigation, particularly in arid regions.”

Gold Remembers: ‘Shape Memory’ Effect Demonstrated in Gold Particles

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Gold Remembers: ‘Shape Memory’ Effect Demonstrated in Gold Particles

Gold Remembers

Researchers from the Technion-Israel Institute of Technology and Germany have demonstrated for the first time the phenomena of shape memory and self-healing in gold microparticles. Achieved through defects-mediated diffusion in the particle, the discovery could one day lead to development of micro- and nano-robots capable of self-repair; mechanically stable and damage-tolerant components and devices; and targeted drug delivery.

The study, published in the journal Advanced Science, was conducted by doctoral student Oleg Kovalenko and Dr. Leonid Klinger, led by Prof. Eugen Rabkin of the Technion Department of Materials Science and Engineering, together with Dr. Christian Brandl of Karlsruhe Institute of Technology (KIT).

Shape memory Material Characters

Shape-memory materials are characterized by the ability to repair the damage caused to them (such as plastic deformation) and to recover their original shape. These materials can exist in two stable crystalline forms, or phases: austenite, which is the more symmetrical primary form stable at elevated temperatures; and martensite, which is a phase characterized by lower symmetry, but also by greater strength. A well-known example of transition between the two phases is the quenching of steel. The transformation of the austenite phase to the martensite can be activated by applying mechanical load to the material, or by cooling it down. The low-symmetry structure of the martensite allows the material to absorb considerable plastic strain by re-orienting the distorted crystals of martensite according to the direction of the stress applied to it. Even after plastic deformation, the martensite crystals “remember” their parent austenite phase and are capable of restoring it in its original configuration. This will happen if the material is heated up, causing the reverse martensite-austenite phase transformation and transforming the thermal energy into mechanical energy that will restore the material to its original shape. Until now, this shape memory effect has only been observed in very few metal alloys such as Nitinol (Ni-Ti). These alloys are characterized by polymorphism — multiplicity of possible stable crystalline phases. This is the first time the phenomenon of shape memory has been demonstrated in sub-micrometer particles of gold. The researchers indented the gold particles with a sharp diamond tip controlled by an atomic force microscope (AFM). Annealing of the indented particles at a temperature of 600°C (about 65% of the absolute melting temperature of gold) resulted in full healing of the damage and recovery of the particles’ original shape prior to deformation. According to Prof. Rabkin, the discovery of the shape memory effect in these particles is surprising for two reasons: “First, the particles’ original shape was not perfect in terms of energy and thermodynamic equilibrium. Second, gold in its solid state is not characterized by polymorphism.” To understand the process in depth, the researchers investigated the atomic motion during indentation and heating, using atomistic molecular dynamic computer simulations. They demonstrated that the plastic deformation during the indentation process is mediated by nucleation and glide of dislocation half-loops (the dislocations are linear, one-dimensional defects in the crystal through which it undergoes plastic deformation). The loops which egress at the free surfaces form terraces and ledges on the flat facets of the particle, and these serve as “guide rails” directing the diffusion of gold atoms back to the indented site during high-temperature anneal. Thus the particle recovers its original shape.

Like coffee that returns to the cup all by itself

Both plastic deformation and capillary-driven diffusion are classical examples of thermodynamically irreversible processes. It is remarkable that a combination of two irreversible processes can lead to damage recovery and reversible restoration of a particle shape. To understand how surprising this process is, think of spilled coffee jumping back from the floor into the cup, or a car that recovers its original shape after being totaled in an accident. Prof. Rabkin says that the discovered self-healing and shape memory effect in metallic nano- and microparticles could be utilized for the design of mechanically stable and damage-tolerant components and devices at the sub-micrometer length scale. For example, one of the main reasons for the failure of mobile electronic devices (such as tablets and smartphones) is the mechanical wear of electrical contacts. Designing a contact geometry based on the discovered shape memory effect can solve this problem once and for all: electric current flowing through the damaged electrical contact will heat up the contact area, and heat will be utilized to repair the mechanical damage of the contact. Another possible use is the controlled drug delivery to the specific areas of the patient’s body. For this application, the particles capable of recovering their shape at lower temperatures should be designed. A drug can be injected into the cavity on the particle surface produced by indentation, and released after heating.
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