- It refers to computing systems capable of at least one exaFLOPS, or a billion billion calculations per second.
- Such capacity represents a thousandfold increase over the first petascale computer that came into operation in 2008.
- (One exaflops is a thousand petaflops or a quintillion, 1018, floating point operations per second.)
- At a supercomputing conference in 2009, Computerworld projected exascale implementation by 2018.
- Exascale computing would be considered as a significant achievement in computer engineering, for it is believed to be the order of processing power of the human brain at neural level (functional might be lower).
- It is, for instance, the target power of the Human Brain Project.
- They are fully halogenated paraffin hydrocarbons that contain only carbon, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane.
- They are also commonly known by the DuPont brand name Freon.
- The most common representative is dichlorodifluoromethane (R-12 or Freon-12).
- Many CFCs have been widely used as refrigerants, propellants (in aerosol applications), and solvents.
- Because CFCs contribute to ozone depletion in the upper atmosphere, the manufacture of such compounds has been phased out under the Montreal Protocol, and they are being replaced with other products such as hydrofluorocarbons (HFCs)
- Hot Jupiters are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital period(P<10 days).
- The close proximity to their stars and high surface-atmosphere temperatures resulted in the moniker “hot Jupiters”.
- Hot Jupiters are the easiest extrasolar planets to detect via the radial-velocity method, because the oscillations they induce in their parent stars’ motion are relatively large and rapid compared to those of other known types of planets.
- One of the best-known hot Jupiters is 51 Pegasi b. Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like star. 51 Pegasi b has an orbital period of about 4 days.
Great Indian Hornbill
- The Great Hornbill, Buceros bicornis, is a near threatened species, and is on the IUCN red list.
- A Great Indian Hornbill (Buceros Bicornis)
- The magnificent birds which were a common sight in the evergreen rain forests of the Western Ghats are now forced, due to deforestation, to adapt themselves to hollows in silver oak trees which form part of thick coffee plantations.
Birds that call their names
- Many of us will have seen an Asian Koel, a well known brood parasite of crows.
- There are many more birds that get their names based on their calls and songs. These names are called onomatopoeic names .If you listen to a Common Cuckoo (which is a migratory bird from Europe) you will know why this bird is called what it’s called.
- Not only in English, but also in several of our Indian languages, bird names are based on their vocalizations. In Hindi, crows are called Kauwa, resembling their call Kaww…kaww…kaww and Grey Francolin is Teetar since they give out a loud and repetitive call Ka-tee-tar….tee-tar… In Telugu, Red-wattled Lapwings are called Uththuthhi which sounds like their call. In Tamil, Common Hawk-Cuckoo is called Akka Kuyil since their repetitive call sounds like Akka..Akka..Akka….Akka means elder sister in Tamil while Kuyil refers to cuckoos in general.
- Not only do individual species get their names from their calls and songs, but several groups of birds are also named in this way. Some examples are babblers, laughingthrushes, warblers, whistling ducks and chats.
- The Common Hawk-Cuckoo is also called Brainfever bird as its ceaseless call sounds very much like saying Brain Fever…Brain Fever. Indian Cuckoo calls are sometimes written as one more bottle…one more bottle.
- Onomatopoeic names: Words that resemble the source of the sound that they describe are called onomatopoeias (eg. Hiccup, flip-flop, tick-tock). The names based on these sounds are onomatopoeic names.
- Brood parasitism: Animals that lay their eggs in the nests of other animals are called brood parasites. They rely on the host parents to raise their young ones. Cuckoos are well-known brood parasites.
- American experimental psychologist Edward Tolman was the first to propose, as early as 1948, a concept of a map-like representation of a place in the brain. However, he did not propose where these functions were located in the brain and how they functioned.
- O’Keefe was not the first to propose that the hippocampus was responsible for spatial navigation, it was received with scepticism. It soon came to be accepted that the hippocampus contains the mental map or inner map. The discovery of place cells and the demonstration that they represented a mental map, together with the proposal that the hippocampus containing the neural cells provides the inner map that store information of the environment were seminal.
- The entorhinal cortex, which lies on the dorsal side of the hippocampus, provided a major input to the hippocampus.
- A large part of the output from the entorhinal cortex projects to the dentate gurus in hippocampus, which in turn connect to the region in the hippocampus called CA3, and further to CA1 in the dorsal hippocampus.” The place cells are found in the CA1.
- The gird cells together with the place map provide the inner map. If the place cells provide the spatial map, the grid cells provide the navigation or path integration system.
- A single grid cell fires when an animal reaches particular locations in an arena. These locations are arranged in a hexagonal pattern. They also showed that the grid formation did not arise out of a simple transformation of sensory or motor signals, but out of complex network activity.
- They concluded that the grid cells were part of a navigation or path integration system. The grid system provided a solution to measuring movement distances and added a metric to the spatial maps in the hippocampus,
- All the three cells — the grid cells, the head-direction cells and border cells — projected to the hippocampus place cells.
- Though the presence of place cells and grid cells were identified experimentally in rats, such a system is found in other animals too, including humans.
- The hippocampal-entorhinal structure is found in all mammals and a hippocampal-like structure is found in non-mammals with navigational capacity. This suggests that the functional and robust grid-place cells system in vertebrates must have been conserved.
- The existence of place-like cells in the hippocampus and grid-like cells in the entorhinal cortex has been identified in the human brains of patients with epilepsy.
- Results from functional imaging (fMRI) studies on human brains have provided support for the existence of place cells and grid cells in humans. Also, studies of patients undergoing neurosurgery have strengthened the evidence of place cells and grid cells in humans.
- The discovery of place cells and grid cells and their role in spatial mapping and navigation have great implications in medicine.
- The reason why patients with Alzheimer’s disease often lose their way and cannot recognise the environment becomes clear as the hippocampus and entorhinal cortex, where the place cells and grid cells are located, are frequently affected at an early stage.
- Scientists using data from NASA’s Interstellar Boundary Explorer (IBEX) have pinned down an interstellar magnetic field which lies at the very edge of the giant magnetic bubble surrounding our solar system called the heliosphere.
- Immediately after its 2008 launch, IBEX spotted a curiosity in a thin slice of space: More particles streamed in through a long, skinny swath in the sky than anywhere else.
- The origin of the so-called “IBEX ribbon” was unknown — but its very existence opened doors to observing what lies outside our solar system.
- The theory says that some solar wind protons are sent flying back towards the sun as neutral atoms after a complex series of charge exchanges, creating the IBEX ribbon.
- With the second detection of gravitational waves by the LIGO detector, the space for experimental research on black holes using gravitational waves is expanding. Couple this with the success of the LISA Pathfinder experiment and you have the right mix that can boost the prospects of the evolved Laser Interferometer Space Antenna (eLISA) project.
- eLISA is a spectacular plan of setting into space three spacecraft, a mother and two daughter spacecraft, which will fly in a triangular formation, trailing the earth in its orbit around the sun at a distance of over 50 million km.
- eLISA aims to measure gravitational waves in the frequency range from 0.1mHz to about 100 mHz.
- The LISA Path Finder, a space experiment mean to set the path of the eLISA, recently relayed the first set of its observations on the force between two “freely-falling” test masses in space. The results, showing a better degree of accuracy than anticipated, augur well for the performance of eLISA.
- Indian teams have worked on the theoretical aspects of eLISA:in the theoretical aspects of measurement of cosmological parameters; using eLISA to set constraints on dark energy equation of state; developing techniques for time delay interferometry, and so on.