Welcome to JAAN's science class!!

Big hi to all of you! I'm an undergraduate following a Bsc in bioscience. Trust me I know the feeling of surfing around the net for ages and getting nothing in return! Or getting something worthless for the time we spent surfing. So I started this blog adding the science stuff I have noted which I think might help someone in their home work. Ok then enjoy!

06 March 2011

Insect Orders

Order Orthoptera
Cricket
Grasshopper

 Order Isoptera

 Odontotermes sp.(Termites)

Order Dermaptera
 Forficula sp.(Ear wig)

 Order Hemiptera
Sub order Heteroptera

 Nezara sp.

Sub order Homoptera
Aphis sp.

Order Hymenoptera
Vespa sp.(Wasp)

Ants

Order Lepidoptera

Moth
Butterfly

 Order Coleoptera
Oryctus rhinoceros (Coconut Black Beetle)

Rhuncophorus sp.(Red Palm Weevil)

 Order Phasmatoidea
Carausius sp.(Stick insect)

Phyllium sp.(Leaf insect)

 Order Mantodea
Hierodula sp.(Mantis)

Order Odonata
Libellago sp.(Damselfly)

Macrogomphus sp.(Dragonfly)

Order Thysanoptera
Thrips sp.

Order Phthiraptera
Pediculus humanus(head louse)

 Order Siphonaptera
Ctenocephalides sp.(Flea)

Order Diptera
Musca domestica

Order Blattodea
Periplaneta americana(Cockroach)

Order Thysanura
Lepisma Sp.(Silver fish)





01 March 2011

UNSOLVED PROBLEMS IN PHYSICS

  1. Are all the (measurable) dimensionless parameters that characterize the physical universe calculable in principle or are some merely determined by historical or quantum mechanical accident and uncalculable?

  1.  Einstein put it more crisply: did God have a choice in creating the universe? Imagine the Old One sitting at his control console, preparing to set off the Big Bang. "How fast should I set the speed of light?" "How much charge should I give this little speck called an electron?" "What value should I give to Planck's constant, the parameter that determines the size of the tiny packets -- the quanta -- in which energy shall be parceled?" Was he randomly dashing off numbers to meet a deadline? Or do the values have to be what they are because of a deep, hidden logic? These kinds of questions come to a point with a conundrum involving a mysterious number called alpha. If you square the charge of the electron and then divide it by the speed of light times Planck's constant, all the dimensions (mass, time and distance) cancel out, yielding a so-called "pure number" -- alpha, which is just slightly over 1/137. But why is it not precisely 1/137 or some other value entirely? Physicists and even mystics have tried in vain to explain why.

  1. How can quantum gravity help explain the origin of the universe?
  1.  Two of the great theories of modern physics are the standard model, which uses quantum mechanics to describe the subatomic particles and the forces they obey, and general relativity, the theory of gravity. Physicists have long hoped that merging the two into a "theory of everything" -- quantum gravity -- would yield a deeper understanding of the universe, including how it spontaneously popped into existence with the Big Bang. The leading candidate for this merger is String theory, or M theory, as the latest, souped-up version is called (with the M standing for "magic," "mystery," or "mother of all theories").

  1. What is the lifetime of the proton and how do we understand it? 
  1. It used to be considered gospel that protons, unlike, say, neutrons, live forever, never decaying into smaller pieces. Then in the 1970's, theorists realized that their candidates for a grand unified theory, merging all the forces except gravity, implied that protons must be unstable. Wait long enough and, very occasionally, one should break down. The trick is to catch it in the act. Sitting in underground laboratories, shielded from cosmic rays and other disturbances, experimenters have whiled away the years watching large tanks of water, waiting for a proton inside one of the atoms to give up the ghost. So far the fatality rate is zero, meaning that either protons are perfectly stable or their lifetime is enormous -- an estimated billion trillion trillion years or more.

  1. Is nature supersymmetric, and if so, how is supersymmetry broken? 
  1. Many physicists believe that unifying all the forces, including gravity, into a single theory would require showing that two very different kinds of particles are actually intimately related, a phenomenon called supersymmetry. The first, fermions, are loosely described as the building blocks of matter, like protons, electrons and neutrons. They clump together to make stuff. The others, the bosons, are the particles that carry forces, like photons, conveyors of light. With supersymmetry, every fermion would have a boson twin, and vice versa. Physicists, with their compulsion for coining funny names, call the so-called superpartners "sparticles": For the electron, there would be the selectron; for the photon, the photino. But since the sparticles have not been observed in nature, physicists would also have to explain why, in the jargon, the symmetry is "broken": the mathematical perfection that existed at the moment of creation was knocked out of kilter as the universe cooled and congealed into its present lopsided state.

  1. Why does the universe appear to have one time and three space dimensions? 
  1. "Just because" is not considered an acceptable answer. And just because people can't imagine moving in extra directions, beyond up-and-down, left-and-right, and back-and-forth, doesn't mean that the universe had to be designed that way. According to superstring theory, in fact, there must be six more spatial dimensions, each one curled up too tiny to detect. If the theory is right, then why did only three of them unfurl, leaving us with this comparatively claustrophobic dominion?

  1. Why does the cosmological constant have the value that it has? Is it zero and is it really constant? Until recently cosmologists thought the universe was expanding at a steady clip. But recent observations indicate that the expansion may be getting faster and faster. This slight acceleration is described by a number called the cosmological constant. Whether the constant turns out to be zero, as earlier believed, or some very tiny number, physicists are at a loss to explain why. According to some fundamental calculations, it should be huge -- some 1010 to 10122 times as big as has been observed. The universe, in other words, should be ballooning in leaps and bounds. Since it is not, there must be some mechanism suppressing the effect. If the universe were perfectly supersymmetric, the cosmological constant would become canceled out entirely. But since the symmetry, if it exists at all, appears to be broken, the constant would still remain far too large. Things would get even more confusing if the constant turned out to vary over time.

  1. What are the fundamental degrees of freedom of M-theory (the theory whose low-energy limit is eleven-dimensional supergravity and that subsumes the five consistent superstring theories) and does the theory describe nature? For years, one big strike against superstring theory was that there were five versions. Which, if any, described the universe? The rivals have been recently reconciled into an overarching 11-dimensional framework called M theory, but only by introducing complications. Before M theory, all the subatomic particles were said to be made from tiny superstrings. M theory adds to the subatomic mix even weirder objects called "branes" -- like membranes but with as many as nine dimensions. The question now is, Which is more fundamental -- are strings made from branes or vice versa? Or is there something else even more basic that no one has thought of yet? Finally, is any of this real, or is M theory just a fascinating mind game?

  1. What is the resolution of the black hole information paradox? According to quantum theory, information -- whether it describes the velocity of a particle or the precise manner in which ink marks or pixels are arranged on a document -- cannot disappear from the universe. But the physicists Kip Thorne, John Preskill and Stephen Hawking have a standing bet: what would happen if you dropped a copy of the Encyclopaedia Britannica down a black hole? It does not matter whether there are other identical copies elsewhere in the cosmos. As defined in physics, information is not the same as meaning, but simply refers to the binary digits, or some other code, used to precisely describe an object or pattern. So it seems that the information in those particular books would be swallowed up and gone forever. And that is supposed to be impossible. Dr. Hawking and Dr. Thorne believe the information would indeed disappear and that quantum mechanics will just have to deal with it. Dr. Preskill speculates that the information doesn't really vanish: it may be displayed somehow on the surface of the black hole, as on a cosmic movie screen.

  1. Why is gravity so much weaker than the other forces, like electromagnetism? A magnet can pick up a paper clip even though the gravity of the whole earth is pulling back on the other end. According to one recent proposal, gravity is actually much stronger. It just seems weak because most of it is trapped in one of those extra dimensions. If its full force could be tapped using high-powered particle accelerators, it might be possible to create miniature black holes. Though seemingly of interest to the solid waste disposal industry, the black holes would probably evaporate almost as soon as they were formed.

  1. Can we quantitatively understand quark and gluon confinement in quantum chromodynamics and the existence of a mass gap? Quantum chromodynamics, or QCD, is the theory describing the strong nuclear force. Carried by gluons, it binds quarks into particles like protons and neutrons. According to the theory, the tiny subparticles are permanently confined. You can't pull a quark or a gluon from a proton because the strong force gets stronger with distance and snaps them right back inside. But physicists have yet to prove conclusively that quarks and gluons can never escape. When they try to do so, the calculations go haywire. And they cannot explain why all particles that feel the strong force must have at least a tiny amount of mass, why it cannot be zero. Some hope to find an answer in M theory, maybe one that would also throw more light on the nature of gravity.

Found on 
http://www.oglethorpe.edu/

Endocrine Glands



Found on: www.hormone.org


The following list of glands make up the endocrine system.
  • Pituitary Gland
  • Hypothalmus
  • Thymus
  • Pineal Gland
  • Testes
  • Ovaries
  • Thyroid
  • Adrenal Glands
  • Parathyroid
  • Pancreas
Pituitary Gland
The pituitary gland is sometimes called the "master gland" because of its great influence on the other body organs. Its function is complex and important for overall well-being.pituitary
The pituitary gland is divided into two parts, front (anterior) and back (posterior).
The anterior pituitary produces several types of hormones:

    1. Prolactin or PRL - PRL stimulates milk production from a woman's breasts after childbirth and can affect sex hormone levels from the ovaries in women and the testes in men.
    1. Growth hormone or GH - GH stimulates growth in childhood and is important for maintaining a healthy body composition. In adults it is also important for maintaining muscle mass and bone mass. It can affect fat distribution in the body. (For more information go to the Growth section on this site)
    1. Adrenocorticotropin or ACTH - ACTH stimulates production of cortisol by the adrenal glands. Cortisol, a so-called "stress hormone," is vital to survival. It helps maintain blood pressure and blood glucose levels.
    1. Thyroid-stimulating hormone or TSH - TSH stimulates the thyroid gland to make thyroid hormones, which, in turn, control (regulate) the body's metabolism, energy, growth and development, and nervous system activity.
    1. Luteinizing hormone or LH - LH regulates testosterone in men and estrogen in women.
    1. Follicle-stimulating hormone or FSH - FSH promotes sperm production in men and stimulates the ovaries to release eggs (ovulate) in women. LH and FSH work together to allow normal function of the ovaries or testes.

The posterior pituitary produces two hormones:

  1. Oxytocin - Oxytocin causes milk letdown in nursing mothers and contractions during childbirth.
  2. Antidiuretic hormone or ADH - ADH, also called vasopressin, is stored in the back part of the pituitary gland and regulates water balance. If this hormone is not secreted properly, this can lead to problems of sodium (salt) and water balance, and could also affect the kidneys so that they do not work as well.

In response to over- or underproduction of pituitary hormones, the target glands affected by these hormones can produce too many or too few hormones of their own, leading to hormone imbalance. For example, too much growth hormone can cause gigantism, or excessive growth (referred to as acromegaly in adults), while too little GH may cause dwarfism, or very short stature.

Hypothalamus
The hypothalamus is part of the brain that lies just above the pituitary gland. It releases hormones that start and stop the release of pituitary hormones. The hypothalamus controls hormone production in the pituitary gland through several "releasing" hormones. Some of these are growth hormone-releasing hormone, or (controls GH release); thyrotropin-releasing hormone, or TRH (controls TSH release); and corticoptropin-releasing hormone, or CRH (controls ACTH release). Gonadotropin-releasing hormone (GnRH) tells the pituitary gland to make luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are important for normal puberty.

Thymus
ThymusThe thymus is a gland needed early in life for normal immune function. It is very large just after a child is born and weighs its greatest when a child reaches puberty. Then its tissue is replaced by fat. The thymus gland secretes hormones called humoral factors. These hormones help to develop the lymphoid system, which is a system throughout the body that help it to reach a mature immune response in cells to protect them from invading bodies, like bacteria.

Pineal Gland
Pineal glandScientists are still learning how the pineal gland works. They have found one hormone so far that is produced by this gland: melatonin. Melatonin may stop the action of (inhibit) the hormones that produce gonadotropin, which causes the ovaries and testes to develop and function. It may also help to control sleep patterns.

Testes
TestesMales have twin reproductive glands, called testes, that produce the hormone testosterone. Testosterone helps a boy develop and then maintain his sexual traits. During puberty, testosterone helps to bring about the physical changes that turn a boy into an adult male, such as growth of the penis and testes, growth of facial and pubic hair, deepening of the voice, increase in muscle mass and strength, and increase in height. Throughout adult life, testosterone helps maintain sex drive, sperm production, male hair patterns, muscle mass, and bone mass. 

Testicular cancer, which is the most common form of cancer for males between ages 15 and 35, may need to be treated by surgical removal of one or both testicles. The resulting decrease or absence of testosterone may cause decreased sexual drive, impotence, altered body image, and other symptoms.

Ovaries
OvariesThe two most important hormones of a woman's twin reproductive glands, the ovaries, are estrogen and progesterone. These hormones are responsible for developing and maintaining female sexual traits, as well as maintaining a pregnancy. Along with the pituitary gonadotropins (luteinizing hormone or LH and follicle-stimulating hormone or FSH), they also control the menstrual cycle. The ovaries also produce inhibin, a protein that curbs (inhibits) the release of follicle-stimulating hormone from the anterior pituitary and helps control egg development.
The most common change in the ovarian hormones is caused by the start of menopause, part of the normal aging process. It also can occur when ovaries are removed surgically. Loss of ovarian function means loss of estrogen, which can lead to symptoms of menopause including hot flashes, thinning vaginal tissue, lack of menstrual periods, mood changes and bone loss, or osteoporosis.
A condition called polycystic ovary syndrome (PCOS) is caused by overproduction of male hormones in females. PCOS can affect menstrual cycles, fertility, and hormone levels, as well as cause acne, facial hair growth, and male pattern balding.

Thyroid
thyroidThe thyroid is a small gland inside the neck, located in front of your breathing airway (trachea) and below your Adam's apple. The thyroid hormones control your metabolism, which is the body's ability to break down food and store it as energy and the ability to break down food into waste products with a release of energy in the process. The thyroid produces two hormones, T3 (called tri-iodothyronine) and T4 (called thyroxine).

Thyroid disorders result from an underactive or overactive thyroid producing, respectively, too little or too much thyroid hormone. Symptoms of hypothyroidism (too little hormone) include decreased energy, slow heart rate, dry skin, constipation, and feeling cold all the time. In children, hypothyroidism most commonly leads to slowed growth. Infants born with hypothyroidism can have delayed development and mental retardation if not treated. In adults, this disorder often causes weight gain. An enlarged thyroid, or goiter, may develop.
Hyperthyroidism (too much hormone) may impact normal thyroid size and result in exophthalmic goiter, or Grave's disease. Symptoms of this thyroid disease include anxiety, fast heart rate, diarrhea, and weight loss. An enlarged thyroid gland (goiter) and swelling behind the eyes that causes the eyes to push forward, or bulge out, are common.


Adrenal Glands
undefinedEach adrenal gland is actually two endocrine organs. The outer portion is called the adrenal cortex. The inner portion is called the adrenal medulla. The hormones of the adrenal cortex are essential for life. The types of  hormones secreted by the adrenal medulla are not.

The adrenal cortex produces glucocorticoids (such as cortisol) that help the body control blood sugar, increase the burning of protein and fat, and respond to stressors like fever, major illness, and injury. The mineralcorticoids (such as aldosterone) control blood volume and help to regulate blood pressure by acting on the kidneys to help them hold onto enough sodium and water. The adrenal cortex also produces some sex hormones, which are important for some secondary sex characteristics in both men and women.

Two important disorders caused by problems with the adrenal cortex are Cushing's syndrome and Addison's disease. Cushing's syndrome is the result of too much cortisol, and Addison's disease occurs when there is too little cortisol.
The adrenal medulla produces epinephrine (adrenaline), which is secreted by nerve endings and increases the heart rate, opens airways to improve oxygen intake, and increases blood flow to muscles, usually when a person is scared, excited, or under stress.
Norepinephrine also is made by the adrenal medulla, but this hormone is more related to maintaining normal activities as opposed to emergency reactions. Too much norepinephrine can cause high blood pressure.

Parathyroid
Parathyroid glandLocated behind the thyroid gland are four tiny parathyroid glands. These make hormones that help control calcium and phosphorous levels in the body. The parathyroid glands are necessary for proper bone development. In response to too little calcium in the diet, the parathyroid glands make parathyroid hormone, or PTH, that takes calcium from bones so that it will be available in the blood for nerve conduction and muscle contraction.
If the parathyroids are removed during a thyroid operation, low blood calcium will result in symptoms such as irregular heartbeat, muscle spasms, tingling in the hands and feet, and possibly difficulty breathing. A tumor or chronic illness can cause too much secretion of PTH and lead to bone pain, kidney stones, increased urination, muscle weakness, and fatigue.


Pancreas
PancreasThe pancreas is a large gland behind your stomach that helps the body to maintain healthy blood sugar (glucose) levels. The pancreas secretes insulin, a hormone that helps glucose move from the blood into the cells where it is used for energy. The pancreas also secretes glucagon when the blood sugar is low. Glucagon tells the liver to release glucose, stored in the liver as glycogen, into the bloodstream. 
Diabetes, an imbalance of blood sugar levels, is the major disorder of the pancreas. There are two types of diabetes. Type I, and Type II diabetes. Type I diabetes occurs when the pancreas does not produce enough insulin. Type II diabetes occurs when the body is resistant to the insulin in the blood). Without enough insulin to keep glucose moving through the metabolic process, the blood glucose level rises too high.
In Type I diabetes, a patient must take insulin shots. In Type II diabetes, a patient may may not necessarily need insulin and can sometimes control blood sugar levels with exercise, diet and other medications.
A condition called hyperinsulinism (HI) is caused by too much insulin and leads to hypoglycemia (low blood sugar). The inherited form, called congenital HI, causes severe hypoglycemia in infancy. Sometimes it can be treated with medication but often requires surgical removal of part or all of the pancreas. An insulin-secreting tumor of the pancreas, or insulinoma, is a less common cause of hypoglycemia. Symptoms of low blood sugar include anxiety, sweating, increased heart rate, weakness, hunger, and light-headedness. Low blood sugar stimulates release of epinephrine, glucagon and growth hormone, which help to return the blood sugar to normal.