RC circuit A resistor–capacitor circuit (RC circuit), or RC filter or RC network, is an electric circuit composed of resistors and capacitors driven by a voltage or current source. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit. RC circuits can be used to filter a signal by blocking certain frequencies and passing others. The two most common RC filters are the high-pass filters and low-pass filters; band-pass filters and band-stop filters usually require RLC filters, though crude ones can be made with RC filters. Introduction There are three basic, linear passive lumped analog circuit components: the resistor (R), the capacitor (C), and the inductor (L). This article relies on knowledge of the complex impedance representation of capacitors and on knowledge of the frequency domain representation of signals. Natural response The simplest RC circuit is a capacitor and a resistor in series. Complex impedance where and As or . per
The pioneers | Spectrum California became the first U.S. state to legalize medical marijuana, mainly for adults with severe chronic illness such as cancer or AIDS. Since California’s decision in 1996, 24 states and the District of Columbia (Washington, D.C.) have followed, and since 2012, four states and Washington, D.C., have legalized recreational use of the drug. So far, only Pennsylvania specifically permits medical marijuana use for autism, but in the past few years, parents of children with epilepsy across the nation have adopted this approach. Much of this enthusiasm stemmed from the widespread media coverage in 2013 of Charlotte’s Web, a marijuana strain with high levels of CBD. Around that time, Karlee was at her wits’ end. Giving her son marijuana was not an easy decision for Karlee. With her prescription in hand, Karlee was able to visit a for-profit medical dispensary that sells marijuana oils and tinctures — marijuana extracts steeped in alcohol.
Kirchhoff's circuit laws Both of Kirchhoff's laws can be understood as corollaries of the Maxwell equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits. Kirchhoff's current law (KCL) The current entering any junction is equal to the current leaving that junction. i2 + i3 = i1 + i4 This law is also called Kirchhoff's first law, Kirchhoff's point rule, or Kirchhoff's junction rule (or nodal rule). The principle of conservation of electric charge implies that: The algebraic sum of currents in a network of conductors meeting at a point is zero. Recalling that current is a signed (positive or negative) quantity reflecting direction towards or away from a node, this principle can be stated as: n is the total number of branches with currents flowing towards or away from the node. This formula is valid for complex currents: Uses Kirchhoff's voltage law (KVL) Assuming
Role for Fatty Acid Metabolism in Preclinical AD? Action Points Note that this observational study found an association between higher levels of docosahexaenoic acid and lower levels of cerebral amyloidosis.Be aware that the study was focused on individuals with significant vascular risk factors and may not be generalizable to the population at large. Limited seafood intake may increase the risk of brain amyloid deposition and Alzheimer's disease (AD), according to new research. Greater levels of the essential fatty acid docosahexaenoic (DHA) were associated with less cerebral amyloidosis, larger brain volumes, and better cognitive measures in cognitively healthy patients, Hussein N. In 61 older participants enrolled in the Aging Brain Study, serum DHA levels (the percentage of total fatty acids) were 23% lower in those with significantly more cerebral amyloidosis than in those without (0.97 versus 1.25). In an accompanying editorial, Joseph F. So what's a clinician to do? Reviewed by F.
Ohm's law V, I, and R, the parameters of Ohm's law. where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current. The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. In physics, the term Ohm's law is also used to refer to various generalizations of the law originally formulated by Ohm. where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ is a material dependent parameter called the conductivity. History Ohm's law was probably the most important of the early quantitative descriptions of the physics of electricity. Scope
The New Drug That Could Treat Alzheimer's - Introducing NTRX-07 In Brief Five million people, in the US alone, could be significantly helped by a new drug to treat Alzheimer's Disease. There have been many recent breakthroughs in the study and treatment of nuerodegenerative disorders. From medication to gene therapy, new solutions are continually popping up to instill greater hope. Targeting Inflammation New developments and research into treating Alzheimer’s disease are always welcome. “This drug may reduce inflammation in the brain, which is linked to Alzheimer’s disease,” says lead researcher Mohamed Naguib of Cleveland Clinic. “NTRX-07 uses a different mechanism than many other Alzheimer’s drugs currently available, as it targets the cause of the disease, not just the symptoms,” Naguib explains. Restoring Memory and Lives During tests on mice bred to show neurodegenerative issues similar to Alzheimer’s, NTRX-07 showed memory-restoring abilities.
Mind-controlled quadcopter takes to the air (Screenshot by Michelle Starr/CNET Australia) Researchers at the University of Minnesota have designed an interface that allows humans to control a robot using only their thoughts. How close are we getting to actual brain control? It's starting to seem not far off at all. On the more silly end of the spectrum, we've seen robotic ears and tails that respond to brainwaves; but we've also seen more recently a Chilean company that has created a brain interface for designing printable objects, a mind-controlled exoskeleton for helping people walk, even mind-to-mind communication. A team of researchers at the University of Minnesota has just added another exciting new technology to the list: a quadcopter that can perform feats of aerial agility, controlled entirely by the pilot's thoughts. Using electroencephalography (EEG), a non-invasive cap fitted with 64 electrodes reads the electrical impulses of the brain to control the copter. Check out how the quadcopter flies in the video below.
Sugar Harms Your Brain Health, Drives Alzheimer’s Epidemic By Dr. Joseph Mercola Guest Writer for Wake Up World Alzheimer’s disease, a severe form of dementia, affects an estimated 5.2 million Americans, according to 2013 statistics. One in nine seniors over the age of 65 has Alzheimer’s, and the disease is now thought to be the third leading cause of death in the US, right behind heart disease and cancer. A growing body of research suggests there’s a powerful connection between your diet and your risk of developing Alzheimer’s disease, via similar pathways that cause type 2 diabetes. Contrary to popular belief, your brain does not require glucose, and actually functions better burning alternative fuels, especially ketones, which your body makes in response to digesting healthy fats. According to some experts, such as Dr. Sugar Damages Brain Structure and Function In your brain, insulin helps with neuron glucose-uptake and the regulation of neurotransmitters, such as acetylcholine, which are crucial for memory and learning. Neurologist Dr.
Green Fluorescent Protein - Cool Uses - Brainbow Brainbow Never before has a brain been so beautiful. Jeff Lichtman and Joshua Sanes, researchers at the Harvard Brain Center, have created transgenic mice with fluorescent multicolored neurons. The mice created by a genetic strategy termed "brainbow" will have a similar effect on neuroscience as Google Earth had on cartography. In the Brainbow mice, the Harvard researchers have introduced genetic machinery that randomly mixes green, cyan and yellow fluorescent proteins in individual neurons thereby creating a palette of ninety distinctive hues and colors. I can't wait for a three dimensional multicolored atlas of the brain or a Google Brain site that is as beautiful as it is useful. This is a photograph of the cerebral cortex. Another image of the cerebral cortex, which plays an important role in memory, perceptual awareness, thought and language.
'Mental Flossing' May Cut Cognitive Risk in Elderly Action Points Engaging in mentally stimulating activities even in late life may be protective against new-onset mild cognitive impairment (MCI), according to a prospective observational study.Note that the associations of mentally stimulating activities with risk of MCI may vary according to carrier status of APOE ε4, a genotype that is a well-known risk factor for MCI and Alzheimer Disease. Mentally stimulating activities may diminish the risk of mild cognitive impairment (MCI) in older people -- even in apolipoprotein E ε4 (APOE4) carriers, researchers found. In the population-based Mayo Clinic Study of Aging, several activities -- playing games, doing crafts, using the computer, and socializing -- were each associated with a significantly decreased risk of MCI in cognitively normal people age 70 and up over a median follow-up of 4 years, Yonas Geda, MD, of the Mayo Clinic in Scottsdale, Ariz., and colleagues reported online in JAMA Neurology. Reviewed by Henry A.
Human Connectome Project | Mapping the human brain connectivity Study: Opioid Abuse Rates Lower In Medical Marijuana States By Paul Armentano, NORML Deputy Director Rates of prescription opioid abuse are significantly lower in jurisdictions that permit medical marijuana access, according to data reported by Castlight Health, an employee health benefits platform provider. Investigators assessed anonymous prescription reporting data from over one million employees between the years 2011 and 2015. In states that did not permit medical marijuana access, 5.4 percent of individuals with an opioid prescription qualified as abusers of the drug. The findings are similar to those reported by the RAND Corporation in 2015, which determined, “[S]tates permitting medical marijuana dispensaries experience a relative decrease in both opioid addictions and opioid overdose deaths compared to states that do not.” Full text of the new study, “The opioid crisis in America’s workforce,” appears online here. Source: NORML - make a donation
Connectome: How the Brain's Wiring Makes Us Who We Are: Sebastian Seung: 9780547678597: Amazon.com