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Transcranial magnetic stimulation

Transcranial magnetic stimulation
Background[edit] Early attempts at stimulation of the brain using a magnetic field included those, in 1910, of Silvanus P. Thompson in London.[2] The principle of inductive brain stimulation with eddy currents has been noted since the 20th century. The first successful TMS study was performed in 1985 by Anthony Barker and his colleagues at the Royal Hallamshire Hospital in Sheffield, England.[3] Its earliest application demonstrated conduction of nerve impulses from the motor cortex to the spinal cord, stimulating muscle contractions in the hand. Theory[edit] From the Biot–Savart law it has been shown that a current through a wire generates a magnetic field around that wire. This electric field causes a change in the transmembrane current of the neuron, which leads to the depolarization or hyperpolarization of the neuron and the firing of an action potential.[5] Effects on the brain[edit] The exact details of how TMS functions are still being explored. Risks[edit] Clinical uses[edit]

Magnetobiology Magnetobiology is the study of biological effects of mainly weak static and low-frequency magnetic fields, which do not cause heating of tissues. Magnetobiological effects have unique features that obviously distinguish them from thermal effects; often they are observed for alternating magnetic fields just in separate frequency and amplitude intervals. Also, they are dependent of simultaneously present static magnetic or electric fields and their polarization. Magnetobiology is a subset of bioelectromagnetics. An example of magnetobiological effects is the magnetic navigation by migrant animals. Reproducibility[edit] The results of magnetobiological experiments are poorly reproducible. 10–20% of publications report failed attempts to observe magnetobiological effects. Safety standards[edit] Safe levels of the EM exposures developed by different national and international institutions. Medical approach[edit] Possible causes of the effects[edit] Profile scientific journals[edit] See also[edit]

Swarm reveals Earth's changing magnetism ( —The first set of high-resolution results from ESA's three-satellite Swarm constellation reveals the most recent changes in the magnetic field that protects our planet. Launched in November 2013, Swarm is providing unprecedented insights into the complex workings of Earth's magnetic field, which safeguards us from the bombarding cosmic radiation and charged particles. Measurements made over the past six months confirm the general trend of the field's weakening, with the most dramatic declines over the Western Hemisphere. But in other areas, such as the southern Indian Ocean, the magnetic field has strengthened since January. The latest measurements also confirm the movement of magnetic North towards Siberia. These changes are based on the magnetic signals stemming from Earth's core. This will provide new insight into many natural processes, from those occurring deep inside our planet to space weather triggered by solar activity. Explore further: Swarm's precise sense of magnetism

Magnetoencephalography Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, and SERF being investigated for future machines. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neurofeedback. This can be applied in a clinical setting to find locations of abnormalities as well as experimental setting to simply measure brain activity[1] History of MEG[edit] At first, a single SQUID detector was used to successively measure the magnetic field at a number of points around the subject’s head. The basis of the MEG signal[edit] Origin of the brain's magnetic field. Fetal MEG[edit]

How Vital Is a Planet's Magnetic Field? New Debate | Earth & Magnetic Field, Space Weather | Mars, Venus, Solar Wind Our nearest planetary neighbors, Mars and Venus, have no oceans or lakes or rivers. Some researchers have speculated that they were blown dry by the solar wind, and that our Earth escaped this fate because its strong magnetic field deflects the wind. However, a debate has arisen over whether a magnetic field is any kind of shield at all. The controversy stems from recent observations that show Mars and Venus are losing oxygen ions from their atmospheres into space at about the same rate as Earth. "My opinion is that the magnetic shield hypothesis is unproven," said Robert Strangeway from UCLA. Each of the three planets is losing roughly a ton of atmosphere to space every hour. "The problem is in taking today's rates and trying to guess what was happening billions of years ago," explained Janet Luhmann of the University of California, Berkeley. "People aren't putting all the cards on the table," Luhmann said. The Earth's magnetosphere deflects some of the solar wind. Solar variability

Magnetocardiography Magnetocardiography (MCG) is a technique to measure the magnetic fields produced by electrical activity in the heart using extremely sensitive devices such as the Superconducting Quantum Interference Device (SQUIDs). If the magnetic field is measured using a multichannel device, a map of the magnetic field is obtained over the chest; from such a map, using mathematical algorithms that take into account the conductivity structure of the torso, it is possible to locate the source of the activity. For example, sources of abnormal rhythms or arrhythmia, may be located using MCG. History[edit] The first MCG measurements were made by Baule and McFee[1] using two large coils placed over the chest, connected in opposition to cancel out the relatively large magnetic background. Magnetocardiography is now used in various laboratories and clinics around the world, both for research on the normal human heart, and for clinical diagnosis.[5] Clinical Implementation[edit] See also[edit] References[edit]

Introducing the Vacuum Transistor: A Device Made of Nothing In September 1976, in the midst of the Cold War, Victor Ivanovich Belenko, a disgruntled Soviet pilot, veered off course from a training flight over Siberia in his MiG-25 Foxbat, flew low and fast across the Sea of Japan, and landed the plane at a civilian airport in Hokkaido with just 30 seconds of fuel remaining. His dramatic defection was a boon for U.S. military analysts, who for the first time had an opportunity to examine up close this high-speed Soviet fighter, which they had thought to be one of the world’s most capable aircraft. What they discovered astonished them. For one thing, the airframe was more crudely built than those of contemporary U.S. fighters, being made mostly of steel rather than titanium. After all, in the United States vacuum tubes had given way to smaller and less power-hungry solid-state devices two decades earlier, not long after William Shockley, John Bardeen, and Walter Brattain cobbled together the first transistor at Bell Laboratories in 1947.

Magnetoception The homing pigeon can quickly return to its home, using its ability to sense the Earth's magnetic field and other cues to orient itself Magnetoception (or magnetoreception as it was first referred to in 1972[1]) is a sense which allows an organism to detect a magnetic field to perceive direction, altitude or location. This sense has been proposed to explain animal navigation in vertebrates and insects, and as a method for animals to develop regional maps. Magnetoception has been observed in bacteria, in invertebrates such as fruit flies, lobsters and honeybees. Proposed mechanisms[edit] An unequivocal demonstration of the use of magnetic fields for orientation within an organism has been in a class of bacteria known as magnetotactic bacteria. The second proposed model for magnetoreception relies on Fe3O4, also referred to as iron (II, III) oxide or magnetite, a natural oxide with strong magnetism. In invertebrates[edit] In homing pigeons[edit] In domestic hens[edit] In mammals[edit]

Human Genetic Engineering Pros And Cons Human Genetic Engineering Pros And Cons 4.17/5 (83.45%) 493 votes Many human genetic engineering pros and cons are there that have stayed the same since its introduction to humanity. When the humans started harnessing the atomic powers, then just few years later they also start recognizing the effects of human genetic engineering on mankind. Many scientists have a belief that gene therapy can be a mainstream for saving lives of many people. A lot of human genetic engineering pros and cons have been involved since the evolution of genetic engineering. Mentioned below are some important advantages or pros of genetic engineering: With the help of gene therapy our scientists can easily detect the humans or other resources that have greater chances of getting stuck into hereditary or deadly diseases.A lot of diseases are there that have no cure, so the invention of genetic engineering in medical sciences can result as a cure to several deadly diseases.

SQUID Sensing element of the SQUID A SQUID (for superconducting quantum interference device) is a very sensitive magnetometer used to measure extremely subtle magnetic fields, based on superconducting loops containing Josephson junctions. History and design[edit] There are two main types of SQUID: direct current (DC) and radio frequency (RF). DC SQUID[edit] Diagram of a DC SQUID. enters and splits into the two paths, each with currents and . represents the magnetic flux threading the DC SQUID loop. Electrical schematic of a SQUID where Ib is the bias current, I0 is the critical current of the SQUID, is the flux threading the SQUID and is the voltage response to that flux. Left: Plot of current vs. voltage for a SQUID. The DC SQUID was invented in 1964 by Robert Jaklevic, John J. splits into the two branches equally. , begins circulating in the loop that generates a magnetic field canceling the applied external flux. in one of the branches of the superconducting loop, and is opposite to in the other.

Pesticide exposure in pregnancy linked to autism risk in kids Pregnant women who live within a mile of spaces where commercial pesticides are applied appear to have an increased risk of having a child with autism, a new study suggests. The risk that a child would develop autism appeared to be highest for women who lived near farms, golf courses and other public spaces that were treated with pesticides during the last three months of their pregnancies. "Many of these compounds work on neurons. When they work on the insect, they're dealing with the nervous system of the insect and basically incapacitating it," said study author Irva Hertz-Picciotto, an environmental epidemiologist at the MIND Institute at University of California, Davis. In adults, the brain is protected from many chemical exposures thanks to special filters that prevent many substances from crossing from the blood into the brain. Because the study looked back in time, researchers weren't able to collect blood or urine samples to directly measure pesticide exposures.

SERF A spin exchange relaxation-free (SERF) magnetometer is a type of magnetometer developed at Princeton University in the early 2000s. SERF magnetometers measure magnetic fields by using lasers to detect the interaction between alkali metal atoms in a vapor and the magnetic field. The name for the technique comes from the fact that spin exchange relaxation, a mechanism which usually scrambles the orientation of atomic spins, is avoided in these magnetometers. This is done by using a high (1014 cm−3) density of Potassium atoms and a very low magnetic field. A spin-exchange relaxation-free (SERF) magnetometer achieves very high magnetic field sensitivity by monitoring a high density vapor of alkali metal atoms precessing in a near-zero magnetic field.[2] The sensitivity of SERF magnetometers improves upon traditional atomic magnetometers by eliminating the dominant cause of atomic spin decoherence caused by spin-exchange collisions among the alkali metal atoms. Spin-exchange relaxation[edit]

The Toxins of William B. Coley and the Treatment of Bone and Soft-Tissue Sarcomas Magnetometer Helium Vector Magnetometer (HVM) of the Pioneer 10 and 11 spacecraft Magnetometers are measurement instruments used for two general purposes: to measure the magnetization of a magnetic material like a ferromagnet, or to measure the strength and, in some cases, the direction of the magnetic field at a point in space. The first magnetometer was invented by Carl Friedrich Gauss in 1833 and notable developments in the 19th century included the Hall Effect which is still widely used. Magnetometers are widely used for measuring the Earth's magnetic field and in geophysical surveys to detect magnetic anomalies of various types. Magnetometers can be used as metal detectors: they can detect only magnetic (ferrous) metals, but can detect such metals at a much larger depth than conventional metal detectors; they are capable of detecting large objects, such as cars, at tens of metres, while a metal detector's range is rarely more than 2 metres. Introduction[edit] Magnetic fields[edit]

Huge Medical Marijuana Study Reference List (700+) | Youngstown Cannabis News What we have come across has got to be one of the biggest list of studies for cannabis ever. This PDF contains links to over 700 studies varied by disease. It is simply massive. Well, here I am again, staring at this blank screen, trying to figure out what to say so you will share the information I have gathered.