query: which stage of sleep is represented by delta waves

pos: Slow-wave sleep Slow-wave sleep Slow-wave sleep (SWS), often referred to as deep sleep, consists of stage three (combined stages 3 and 4) of non-rapid eye movement sleep. Initially, SWS consisted of both Stage 3, which has 20-50 percent delta wave activity, and Stage 4, which has more than 50 percent delta wave activity. However, as of 2008, the American Academy of Sleep Medicine (AASM) has discontinued the use of Stage four as a separate stage. Thus, the two stages are now combined as "Stage three" or N3. An epoch (30 seconds of sleep) which consists of 20% or more slow-wave (delta) sleep

pos: Slow-wave sleep Slow-wave sleep Slow-wave sleep (SWS), often referred to as deep sleep, consists of stage three (combined stages 3 and 4) of non-rapid eye movement sleep. Initially, SWS consisted of both Stage 3, which has 20-50 percent delta wave activity, and Stage 4, which has more than 50 percent delta wave activity. However, as of 2008, the American Academy of Sleep Medicine (AASM) has discontinued the use of Stage four as a separate stage. Thus, the two stages are now combined as "Stage three" or N3. An epoch (30 seconds of sleep) which consists of 20% or more slow-wave (delta) sleep

pos: Sleep brain uses less energy. REM sleep, also known as paradoxical sleep, represents a smaller portion of total sleep time. It is the main occasion for dreams (or nightmares), and is associated with desynchronized and fast brain waves, eye movements, loss of muscle tone, and suspension of homeostasis. The sleep cycle of alternate NREM and REM sleep takes an average of 90 minutes, occurring 4–6 times in a good night's sleep. The American Academy of Sleep Medicine (AASM) divides NREM into three stages: N1, N2, and N3, the last of which is also called delta sleep or slow-wave sleep. The whole

pos: Slow-wave sleep investigated further. Some of the brain regions implicated in the induction of slow-wave sleep include: The chemical gamma-hydroxybutyric acid (GHB) has been studied to increase SWS. In the United States, the Food and Drug Administration (FDA) permits the use of GHB under the trade name Xyrem to reduce cataplexy attacks and excessive daytime sleepiness in patients with narcolepsy. Notes Further reading Slow-wave sleep Slow-wave sleep (SWS), often referred to as deep sleep, consists of stage three (combined stages 3 and 4) of non-rapid eye movement sleep. Initially, SWS consisted of both Stage 3, which has 20-50 percent delta wave activity,

pos: Slow-wave sleep is now considered to be stage three. This period of sleep is called slow-wave sleep because the EEG activity is synchronized, producing slow waves with a frequency range of 0.5-2 Hz and peak-to-peak amplitude greater than 75µV. The first section of the wave signifies a "down state," which is an inhibition or hyperpolarizing phase in which the neurons in the neocortex are silent. This is the period when the neocortical neurons are able to rest. The second section of the wave signifies an "up state," which is an excitation or depolarizing phase in which the neurons fire briefly at a

pos: Sleep sex sexual behaviors may be unwanted by the partner, which could lead to the incident being defined as sexual assault. Non Rapid Eye Movement sleep, or NREM, consists of three stages. Stage 1 is described as "drowsy sleep" or "somnolence" and is characterized by breathing rates becoming increasingly more consistent, the beginning of a decrease in muscle activity, and a decrease in heart rate. The typical duration of Stage 1 is around 10 minutes and accounts for approximately 5% of an individual's total sleep. Stage 2 is characterized by further decline in muscle activity accompanied by a fading sense of consciousness

pos: Delta C Delta C The Delta C, or Thor-Delta C was an American expendable launch system used for thirteen orbital launches between 1963 and 1969. It was a member of the Delta family of rockets. The first stage was a Thor missile in the DSV-2A configuration, and the second stage was the Delta D, which was derived from the earlier Delta. The baseline Delta C used an Altair-2 third stage, whilst the Delta C1 had an FW-4D third stage, which provided a higher payload capacity than the Altair. It is unclear whether two or three launches were made using the C1 configuration.

neg: Delta wave by electroencephalography (EEG). Delta waves were originally defined as having a frequency between 1-4 Hz, although more recent classifications put the boundaries at between 0.5 and 2 Hz. They are the slowest and highest amplitude classically described brainwaves, although recent studies have described slower (<0.1 Hz) oscillations Delta waves begin to appear in stage 3 sleep, but by stage 4 nearly all spectral activity is dominated by delta waves. Stage 3 sleep is defined as having less than 50% delta wave activity, while stage 4 sleep has more than 50% delta wave activity. These stages have recently been combined and

neg: Delta wave Delta wave A delta wave is a high amplitude brain wave with a frequency of oscillation between 0.5–4 hertz. Delta waves, like other brain waves, are recorded with an electroencephalogram (EEG) and are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and aid in characterizing the depth of sleep. "Delta waves" were first described in the 1930s by W. Grey Walter, who improved upon Hans Berger's electroencephalograph machine (EEG) to detect alpha and delta waves. Delta waves can be quantified using quantitative electroencephalography. Delta waves, like all brain waves, can be detected

neg: Neuroscience of sleep to 4 Hz, but sleep standards in both the original R&K model (Allan Rechtschaffen and Anthony Kales in the "R&K sleep scoring manual."), as well as the new 2007 AASM guidelines have a range of 0.5–2 Hz.) This is the stage in which parasomnias such as night terrors, nocturnal enuresis, sleepwalking, and somniloquy occur. Many illustrations and descriptions still show a stage N3 with 20–50% delta waves and a stage N4 with greater than 50% delta waves; these have been combined as stage N3. REM Stage (REM Sleep – 20–25% of total sleep in adults): REM sleep is where most

neg: Neuroscience of sleep sleep (SWS) or deep sleep. SWS is initiated in the preoptic area and consists of delta activity, high amplitude waves at less than 3.5 Hz. The sleeper is less responsive to the environment; many environmental stimuli no longer produce any reactions. Slow-wave sleep is thought to be the most restful form of sleep, the phase which most relieves subjective feelings of sleepiness and restores the body. This stage is characterized by the presence of a minimum of 20% delta waves ranging from 0.5–2 Hz and having a peak-to-peak amplitude >75 μV. (EEG standards define delta waves to be from 0

neg: Delta wave are now collectively referred to as stage N3 slow-wave sleep. During N3 SWS, delta waves account for 20% or more of the EEG record during this stage. Delta waves occur in all mammals, and potentially all animals as well. Delta waves are often associated with another EEG phenomenon, the K-complex. K-Complexes have been shown to immediately precede delta waves in slow wave sleep. Delta waves have also been classified according to the location of the activity into frontal (FIRDA), temporal (TIRDA), and occipital (OIRDA) intermittent delta activity. Women have been shown to have more delta wave activity, and this is

neg: Slow-wave sleep metabolism in the brain increases as a result of tasks that demand mental activity. Another function affected by slow-wave sleep is the secretion of growth hormone, which is always greatest during this stage. It is also thought to be responsible for a decrease in sympathetic and increase in parasympathetic neural activity. Large 75-microvolt (0.5–2.0 Hz) delta waves predominate the electroencephalogram (EEG). Stage N3 is defined by the presence of 20% delta waves in any given 30-second epoch of the EEG during sleep, by the current 2007 AASM guidelines. Longer periods of SWS occur in the first part of the night,

neg: Neuroscience of sleep of Stage 1 NREM sleep. This frequency further decreases progressively through the higher stages of NREM and REM sleep. On the other hand, the amplitude of sleep waves is lowest during wakefulness (10–30μV) and shows a progressive increase through the various stages of sleep. Stage 2 is characterized by sleep spindles (intermittent clusters of waves at sigma frequency i.e. 12–14 Hz) and K complexes (sharp upward deflection followed by slower downward deflection). Stage 3 sleep has more sleep spindles. Stages 3 and 4 have very high amplitude delta waves (0–4 Hz) and are known as slow wave sleep. REM sleep

neg: Delta wave 75, stage four sleep and delta waves may be entirely absent. In addition to a decrease in the incidence of delta waves during slow-wave sleep in the elderly, the incidence of temporal delta wave activity is commonly seen in older adults, and incidences also increase with age. Regional delta wave activity not associated with NREM sleep was first described by W. Grey Walter, who studied cerebral hemisphere tumors. Disruptions in delta wave activity and slow wave sleep are seen in a wide array of disorders. In some cases there may be increases or decreases in delta wave activity, while others

neg: Delta wave so by stimulating sleep onset, or disrupting REM sleep, a number of chemicals and drugs have been shown to alter delta wave activity. Diets very low in carbohydrates, such as a ketogenic diet, have been shown to increase the amount of delta activity and slow wave sleep in healthy individuals. Delta wave A delta wave is a high amplitude brain wave with a frequency of oscillation between 0.5–4 hertz. Delta waves, like other brain waves, are recorded with an electroencephalogram (EEG) and are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and

neg: Sleep sex of surroundings. Brain waves during Stage 2 are seen in the theta range. Stage 2 accounts for approximately 45-50% of an individual's total sleep. Stage 3 is the final stage of NREM sleep and the most common for parasomnias to occur. Also known as slow wave sleep (SWS), Stage 3 is characterized by brain temperature, respiratory rate, heart rate, and blood pressure being measured at their lowest. Representing approximately 15-20% of an individual's total sleep, brain waves during this stage are seen in the delta range. When an individual awakes during this stage, they are likely to exhibit grogginess and

neg: Delta wave induced musculoskeletal pain and fatigue. Alcoholism has been shown to produce sleep with less slow wave sleep and less delta power, while increasing stage 1 and REM incidence in both men and women. In long-term alcohol abuse, the influences of alcohol on sleep architecture and reductions in delta activity have been shown to persist even after long periods of abstinence. Slow waves, including delta waves, are associated with seizure-like activity within the brain. W. Grey Walter was the first person to use delta waves from an EEG to locate brain tumors and lesions causing temporal lobe epilepsy. Neurofeedback has been

neg: Neural oscillation functions, including episodic memory. Tight coordination of single-neuron spikes with local theta oscillations is linked to successful memory formation in humans, as more stereotyped spiking predicts better memory. Sleep is a naturally recurring state characterized by reduced or absent consciousness and proceeds in cycles of rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Sleep stages are characterized by spectral content of EEG: for instance, stage N1 refers to the transition of the brain from alpha waves (common in the awake state) to theta waves, whereas stage N3 (deep or slow-wave sleep) is characterized by the presence of delta

neg: Neuroscience of sleep REM sleep was discovered as distinct, and thus William C. Dement and Nathaniel Kleitman reclassified sleep into four NREM stages and REM. The staging criteria were standardized in 1968 by Allan Rechtschaffen and Anthony Kales in the "R&K sleep scoring manual." In the R&K standard, NREM sleep was divided into four stages, with slow-wave sleep comprising stages 3 and 4. In stage 3, delta waves made up less than 50% of the total wave patterns, while they made up more than 50% in stage 4. Furthermore, REM sleep was sometimes referred to as stage 5. In 2004, the AASM commissioned

neg: Delta wave due to disruptions in the growth hormone secreted by the pituitary. In addition, hypoglycemia occurring during sleep may also disrupt delta-wave activity. Low-voltage irregular delta waves, have also been found in the left temporal lobe of diabetic patients, at a rate of 56% (compared to 14% in healthy controls). Patients suffering from fibromyalgia often report unrefreshing sleep. A study conducted in 1975 by Moldovsky "et al." showed that the delta wave activity of these patients in stages 3 and 4 sleep were often interrupted by alpha waves. They later showed that depriving the body of delta wave sleep activity also

neg: Delta wave a category of sleep disorders, are often associated with disruptions in slow wave sleep. Sleep walking and sleep talking most often occur during periods of high delta wave activity. Sleep walkers have also been shown to have more hypersynchronous delta activity (HSD) compared to total time spent in stages 2, 3, and 4 sleep relative to healthy controls. HSD refers to the presence of continuous, high-voltage (> 150 µV) delta waves seen in sleep EEGs. Parasomnias which occur deep in NREM sleep also include sleep terrors and confusional arousals. Total sleep deprivation has been shown to increase delta wave activity

neg: Delta wave during sleep. Delta waves have been shown to be mediated in part by T-type calcium channels. During delta wave sleep, neurons are globally inhibited by gamma-aminobutyric acid (GABA). Delta activity stimulates the release of several hormones, including growth hormone releasing hormone GHRH and prolactin (PRL). GHRH is released from the hypothalamus, which in turn stimulates release of growth hormone (GH) from the pituitary. The secretion of (PRL), which is closely related to (GH), is also regulated by the pituitary. The release of thyroid stimulating hormone (TSH), is decreased in response to delta-wave signaling. Infants have been shown to spend a

neg: Reticular formation desynchronization ensues. There are distinct differences in the brain's electrical activity during periods of wakefulness and sleep: Low voltage fast burst brain waves (EEG desynchronization) are associated with wakefulness and REM sleep (which are electrophysiologically similar); high voltage slow waves are found during non-REM sleep. Generally speaking, when thalamic relay neurons are in burst mode the EEG is synchronized and when they are in tonic mode it is desynchronized. Stimulation of the ARAS produces EEG desynchronization by suppressing slow cortical waves (0.3–1 Hz), delta waves (1–4 Hz), and spindle wave oscillations (11–14 Hz) and by promoting gamma band (20 –

neg: Delta wave great deal of time in slow-wave sleep, and thus have more delta wave activity. In fact, delta-waves are the predominant wave forms of infants. Analysis of the waking EEG of a newborn infant indicates that delta wave activity is predominant in that age, and still appears in a waking EEG of five-year-olds. Delta wave activity during slow-wave sleep declines during adolescence, with a drop of around 25% reported between the ages of 11 and 14 years. Delta waves have been shown to decrease across the lifespan, with most of the decline seen in the mid-forties. By the age of about

neg: Flunitrazepam insomnia, and anxiety. Rebound insomnia, worse than baseline insomnia, typically occurs after discontinuation of flunitrazepam even after short-term single nightly dose therapy. Flunitrazepam produces a decrease in delta wave activity. The effect of benzodiazepine drugs on delta waves, however, may not be mediated via benzodiazepine receptors. Delta activity is an indicator of depth of sleep within non-REM sleep; increased levels of delta sleep reflects better quality of sleep. Thus, flunitrazepam and other benzodiazepines cause a deterioration in sleep quality. Cyproheptadine may be superior to benzodiazepines in the treatment of insomnia as it enhances sleep quality based on EEG studies. Flunitrazepam

neg: Delta wave during sleep recovery, and has also been shown to increase hypersynchronous delta activity. Sleep disturbances, as well as dementia, are common features of Parkinson's disease, and patients with this disease show disrupted brain wave activity. The drug Rotigotine, developed for the treatment of Parkinson's disease, has been shown to increase delta power and slow-wave sleep. Delta-wave inducing peptide injected into the substantia nigra of the rat model has been shown to increase Parkinsonian symptoms. People suffering schizophrenia have shown disrupted EEG patterns, and there is a close association of reduced delta waves during deep sleep and negative symptoms associated with

neg: Somnology they may work well in treating insomnia, have a risk of abuse which is why these treatments are not the first resort. Some sleep disorders such as narcolepsy do require pharmacological treatment. Somnology Somnology is the scientific study of sleep. It includes clinical study and treatment of sleep disorders and irregularities. Sleep medicine is a subset of somnology. After the invention of the EEG, the stages of sleep were determined in 1936 by Harvey and Loomis, the first descriptions of delta and theta waves were made by Walter and Dovey, and REM sleep was discovered in 1953. Sleep apnea was

neg: Zopiclone to a significant increased risk of accidents in zopiclone users. Zopiclone induces impairment of psychomotor function. Driving or operating machinery should be avoided after taking zopiclone as effects can carry over to the next day, including impaired hand eye coordination. Similarly to other sedative hypnotic drugs, zopiclone causes a decrease in the core body temperature and is effective in decreasing sleep latency. It causes similar alterations on EEG readings and sleep architecture as benzodiazepines and causes disturbances in sleep architecture on withdrawal as part of its rebound effect. Zopiclone reduces both delta waves and the number of high-amplitude delta waves

neg: Sharp waves and ripples interneurons. Sparse firing of CA1 pyramidal cells and in-phase inhibition from the activated interneurons, give rise to high frequency (200 Hz) network oscillations, which are the ripples. CA1 population bursts lead to highly synchronized activity in the target population of parahippocampal structures. In spite of the self-emergent nature of the SWRs, their activity could be altered by inputs from the neocortex via the trisynaptic loop to the hippocampus. Activity of the neocortex during slow wave sleep is deterministic of inputs to the hippocampus; thalamocortical sleep spindles and delta waves are the sleep patterns of the neocortex. These inputs contribute to

neg: Sleep onset of inhibition. They appear to be the precursor of delta waves, also known as slow wave sleep, which appear during the deepest levels of sleep. Both these stages are classified as non-REM sleep. Sleep onset is finally induced by sleep-promoting neurons, located in the ventrolateral preoptic nucleus (VLPO). The sleep-promoting neurons are believed to project GABA type A and galanin, two known inhibitory neurotransmitters, to arousal-promoting neurons, such as histaminergic, serotonergic, orexinergic, noradrenergic, and cholinergic neurons (neurons mentioned above). Levels of acetylcholine, norepinepherine, serotonin, and histamine decrease with the onset of sleep, for they are all wakefulness promoting neurotransmitters. Therefore,

neg: K-complex They are created by the occurrence in widespread cortical areas of outward dendritic currents from the middle (III) to the upper (I) layers of the cerebral cortex. This is accompanied by a decrease in broadband EEG power including gamma wave activity. This produces "down-states" of neuronal silence in which neural network activity is reduced. The activity of K-complexes is transferred to the thalamus where it synchronizes the thalamocortical network during sleep, producing sleep oscillations such as spindles and delta waves. It has been observed that they are indeed identical in the "laminar distributions of transmembrane currents" to the slow waves

neg: Delta wave suggested as a treatment for temporal lobe epilepsy, and theoretically acts to reduce inappropriate delta wave intrusion, although there has been limited clinical research in this area. Other disorders frequently associated with disrupted delta-wave activity include: Initially, dreaming was thought to only occur in rapid eye movement sleep, though it is now known that dreaming may also occur during slow-wave sleep. Delta waves and delta wave activity are marked, in most people, by an apparently unconscious state, and the loss of physical awareness as well as the "iteration of information". Nevertheless, some people who practice a type of deep meditation

neg: Delta wave schizophrenia. During slow wave sleep (stages 3 and 4), schizophrenics have been shown to have reduced delta wave activity, although delta waves have also been shown to be increased during waking hours in more severe forms of schizophrenia. A recent study has shown that the right frontal and central delta wave dominance, seen in healthy individuals, is absent in patients with schizophrenia. In addition, the negative correlation between delta wave activity and age is also not observed in those with schizophrenia. Disruptions in slow wave (delta) sleep have been shown to increase risk for development of Type II diabetes, potentially

neg: Neuroscience of sleep (N2 – 45–55% of total sleep in adults): In this stage, theta activity is observed and sleepers become gradually harder to awaken; the alpha waves of the previous stage are interrupted by abrupt activity called sleep spindles (or thalamocortical spindles) and K-complexes. Sleep spindles range from 11 to 16 Hz (most commonly 12–14 Hz). During this stage, muscular activity as measured by EMG decreases, and conscious awareness of the external environment disappears. NREM Stage 3 (N3 – deep sleep, slow-wave sleep – 15–25% of total sleep in adults): Formerly divided into stages 3 and 4, this stage is called slow-wave

neg: Metaplasticity and thus favors LTP. There are several different stages of sleep, but only two separate types, REM (or rapid-eye movement) and NREM (non-rapid eye movement). NREM sleep is characterized by slow-wave neuronal activity known as theta waves, or delta waves. These slow-wave oscillations occur at very low frequencies, between 0.5 and 4.5 Hz. A recent hypothesis has come to the surface, integrating sleep and something known as synaptic homeostasis. The hypothesis comes in four parts: Wakefulness is associated with synaptic potentiation: Potentiation is happening all the time: through the many hours we spend reading useless information, or encountering something longer

neg: Somnology Somnology Somnology is the scientific study of sleep. It includes clinical study and treatment of sleep disorders and irregularities. Sleep medicine is a subset of somnology. After the invention of the EEG, the stages of sleep were determined in 1936 by Harvey and Loomis, the first descriptions of delta and theta waves were made by Walter and Dovey, and REM sleep was discovered in 1953. Sleep apnea was identified in 1965. In 1970, the first clinical sleep laboratory was developed at Stanford. The first actigraphy device was made in 1978 by Krupke, and continuous positive airway pressure therapy and uvulopalatopharyngoplasty

neg: Alpha wave where subjects report non-refreshing sleep and have EEG records reporting high levels of alpha intrusion into sleep. This occurrence is known as alpha wave intrusion. However, it is possible that these explanations may be misleading, as they only focus on alpha waves being generated from the occipital lobe. Alpha wave intrusion occurs when alpha waves appear with non-REM sleep when delta activity is expected. It is hypothesized to be associated with fibromyalgia, although the study may be inadequate due to a small sampling size. Despite this, alpha wave intrusion has not been significantly linked to any major sleep disorder, including

neg: Hypnagogia occurring hypnagogic images, on the one hand, and those of both REM sleep and relaxed wakefulness, on the other. To identify more precisely the nature of the EEG state which accompanies imagery in the transition from wakefulness to sleep, Hori et al. proposed a scheme of 9 EEG stages defined by varying proportions of alpha (stages 1–3), suppressed waves of less than 20μV (stage 4), theta ripples (stage 5), proportions of sawtooth waves (stages 6–7), and presence of spindles (stages 8–9). Germaine and Nielsen found spontaneous hypnagogic imagery to occur mainly during Hori sleep onset stages 4 (EEG flattening) and

neg: Rapid eye movement sleep tomography, and reports of dreamers upon waking, have all been used to study this phase of sleep. REM sleep is "paradoxical" because of its similarities to wakefulness. Although the body is paralyzed, the brain acts somewhat awake, with cerebral neurons firing with the same overall intensity as in wakefulness. Electroencephalography during REM deep sleep reveal fast, low amplitude, desynchronized neural oscillation (brainwaves) that resemble the pattern seen during wakefulness which differ from the slow δ (delta) waves pattern of NREM deep sleep. An important element of this contrast is the θ (theta) rhythm in the hippocampus that show 40–60 Hz

neg: Neuroscience of sleep as lesions in other parts of the brain do not affect them, but lesions in the cortex do. The delta waves have been shown to be generated by reciprocally connected thalamic and cortical neural circuits. During sleep, the thalamus stops relaying sensory information to the brain, however it continues to produce signals that are sent to its cortical projections. These waves are generated in the thalamus even in the absence of the cortex, but the cortical output seems to play a role in the simultaneous firing by large groups of neurons. The thalamic reticular nucleus is considered to be the

neg: Brain activity and meditation evaluate the running spontaneous activity of the cortex. This spontaneous activity is classified into four main classifications based on the frequency of the activity, ranging from low frequency delta waves (< 4 Hz) commonly found during sleep to beta waves (13–30 Hz) associated with an awake and alert brain. In between these two extremes are theta waves (4–8 Hz) and alpha waves (8–12 Hz). Many studies on mindfulness meditation, assessed in a review by Cahn and Polich in 2006, have linked lower frequency alpha waves, as well as theta waves, to meditation. Much older studies report more specific findings, such

neg: Cetacean intelligence In 2015, it was shown for the first time that a species of dolphin, the long-finned pilot whale, has more neocortical neurons than any mammal studied to date including humans. Unlike terrestrial mammals, dolphin brains contain a paralimbic lobe, which may possibly be used for sensory processing. The dolphin is a voluntary breather, even during sleep, with the result that veterinary anaesthesia of dolphins would result in asphyxiation. All sleeping mammals, including dolphins, experience a stage known as REM sleep. Ridgway reports that EEGs show alternating hemispheric asymmetry in slow waves during sleep, with occasional sleep-like waves from both hemispheres.

neg: Neuroscience of sleep REM sleep. By the age of five or so, only slightly over two hours is spent in REM. The function of REM sleep is uncertain but a lack of it impairs the ability to learn complex tasks. Functional paralysis from muscular atonia in REM may be necessary to protect organisms from self-damage through physically acting out scenes from the often-vivid dreams that occur during this stage. In EEG recordings, REM sleep is characterized by high frequency, low amplitude activity and spontaneous occurrence of beta and gamma waves. The best candidates for generation of these fast frequency waves are fast rhythmic

neg: Electroencephalography I sleep (equivalent to drowsiness in some systems) appears on the EEG as drop-out of the posterior basic rhythm. There can be an increase in theta frequencies. Santamaria and Chiappa cataloged a number of the variety of patterns associated with drowsiness. Stage II sleep is characterized by sleep spindles – transient runs of rhythmic activity in the 12–14 Hz range (sometimes referred to as the "sigma" band) that have a frontal-central maximum. Most of the activity in Stage II is in the 3–6 Hz range. Stage III and IV sleep are defined by the presence of delta frequencies and are

neg: Neuroscience of sleep later on found to have been due to low resolution of PET studies and it was shown that there is some slow wave activity in the brainstem as well. However, other parts of the brain, including the precuneus, basal forebrain and basal ganglia are deactivated during sleep. Many areas of the cortex are also inactive, but to different levels. For example, the ventromedial prefrontal cortex is considered the least active area while the primary cortex, the least deactivated. NREM sleep is characterized by slow oscillations, spindles and delta waves. The slow oscillations have been shown to be from the cortex,

neg: Sleep deprivation sleep and a 75% reduction in the peak amplitude of delta waves during NREM sleep in adolescence. School schedules are often incompatible with a corresponding delay in sleep offset, leading to a less than optimal amount of sleep for the majority of adolescents. Study published in the Journal of Economic Behavior and Organisation found out that the broadband internet connection caused sleep deprivation. The study concluded that the people with a broadband connection tend to sleep 25 minutes less than those without the broadband connection, hence they are less likely to get the scientifically recommended 7-9 hours of sleep. Sleep

neg: Hippocampus in fact, reactivations of neural activity patterns that were memorized during behavior, driven by strengthening of synaptic connections within the hippocampus. This idea forms a key component of the "two-stage memory" theory, advocated by Buzsáki and others, which proposes that memories are stored within the hippocampus during behavior and then later transferred to the neocortex during sleep. Sharp waves in Hebbian theory are seen as persistently repeated stimulations by presynaptic cells, of postsynaptic cells that are suggested to drive synaptic changes in the cortical targets of hippocampal output pathways. Suppression of sharp waves and ripples in sleep or during immobility

neg: Insomnia of the night, with more than half having trouble falling back to sleep after a middle-of-the-night awakening. Early morning awakening is an awakening occurring earlier (more than 30 minutes) than desired with an inability to go back to sleep, and before total sleep time reaches 6.5 hours. Early morning awakening is often a characteristic of depression. Poor sleep quality can occur as a result of, for example, restless legs, sleep apnea or major depression. Poor sleep quality is defined as the individual not reaching stage 3 or delta sleep which has restorative properties. Major depression leads to alterations in the

neg: Rhythmic movement disorder sleep and, specifically, K Complexes . Additionally, there is a close association with Alpha waves that contain a mixture of K complexes and arousals, regardless of the NREM stage in which the RMD occurred. The occurrence of these two sequences of brain waves suggests that the disorder is linked to an “unstable vigilance level” throughout NREM sleep . It has been noted that there is a complete absence of any EEG signs during or immediately after an intense rhythmic movement . After the episode, normal EEG patterns return. Functional MRI scans have shown that the mesencephalon and pons may be

neg: Brain electric fields when it is active. When large numbers of neurons show synchronized activity, the electric fields that they generate can be large enough to detect outside the skull, using electroencephalography (EEG) or magnetoencephalography (MEG). EEG recordings, along with recordings made from electrodes implanted inside the brains of animals such as rats, show that the brain of a living animal is constantly active, even during sleep. Each part of the brain shows a mixture of rhythmic and nonrhythmic activity, which may vary according to behavioral state. In mammals, the cerebral cortex tends to show large slow delta waves during sleep,

neg: Slow-wave sleep to about 75 percent of the normal wakefulness level. The regions of the brain that are most active when awake have the highest level of delta waves during slow-wave sleep. This indicates rest is geographical. The “shutting down” of the brain accounts for the grogginess and confusion if someone is awakened during deep sleep since it takes the cerebral cortex time to resume its normal functions. According to J. Siegel (2005), sleep deprivation results in the build-up of free radicals and superoxides in the brain. Free radicals are oxidizing agents that have one unpaired electron, making them highly reactive. These

neg: Fraunhofer diffraction equation with the wavelength. The incident light is diffracted by the slits into uniform spherical waves. The waves travelling in a given direction from the two slits have differing phases. The phase of the waves from the upper and lower slits relative to the origin is given by and The complex amplitude of the summed waves is given by: The aperture can be represented by the function: where is the delta function. We have and giving This is the same expression as that derived above by integration. This gives the intensity of the combined waves as: The width of the slits,

neg: William Grey Walter years later, on May 6, 1977. As a young man, Walter was greatly influenced by the work of the Russian physiologist Ivan Pavlov. He visited the lab of Hans Berger, who invented the electroencephalograph, or EEG machine, for measuring electrical activity in the brain. Walter produced his own versions of Berger's machine with improved capabilities, which allowed it to detect a variety of brain wave types ranging from the high speed alpha waves to the slow delta waves observed during sleep. In the 1930s, Walter made a number of discoveries using his EEG machines at Burden Neurological Institute in Bristol.

neg: Narcolepsy is awake, brain waves show a regular rhythm. When a person first falls asleep, the brain waves become slower and less regular, which is called non-rapid eye movement (NREM) sleep. After about an hour and a half of NREM sleep, the brain waves begin to show a more active pattern again, called REM sleep (rapid eye movement sleep), when most remembered dreaming occurs. Associated with the EEG-observed waves during REM sleep, muscle atonia is present called REM atonia. In narcolepsy, the order and length of NREM and REM sleep periods are disturbed, with REM sleep occurring at sleep onset instead

neg: K-complex and at 900 ms a final negative peak. K-complexes occur roughly every 1.0–1.7 minutes and are often followed by bursts of sleep spindles. They occur spontaneously but also occur in response to external stimuli such as sounds, touches on the skin and internal ones such as inspiratory interruptions. They are generated in widespread cortical locations though they tend to predominate over the frontal parts of the brain. Both K-complex and delta wave activity in stage 2 sleep create slow-wave (0.8 Hz) and delta (1.6–4.0 Hz) oscillations. However, their topographical distribution is different, and the delta power of K-complexes is higher.

neg: Somniloquy Somniloquy Somniloquy or sleep-talking is a parasomnia that refers to talking aloud while asleep. It can be quite loud, ranging from simple mumbling sounds to loud shouts and long, frequently inarticulate speeches, and can occur many times during a sleep cycle. As with sleepwalking and night terrors, sleeptalking usually occurs during delta-wave NREM sleep stages or during temporary arousals therefrom. It can also occur during the REM sleep stage, at which time it represents what sleep therapists call a "motor breakthrough" (see sleep paralysis) of dream speech: words spoken in a dream are spoken out loud. Depending on its frequency,

neg: Sleep onset and K complexes. Sleep spindles are short bursts of waves of 12–14 Hz that occur between two and five times a minute during states 1-4 of sleep. They appear to play a role in memory consolidation, and increased number of sleep spindles are correlated with increased scores on tests of intelligence. K complexes are sudden, sharp waveforms, which, unlike sleep spindles, are usually found only during stage 2 of sleep. They spontaneously occur at the rate of approximately one per minute, but often can be triggered by unexpected noises. It has been found that K complexes consist of isolated periods

neg: Neuroscience of sleep wakefulness, and sometimes occurs between periods of deeper sleep and periods of REM. The muscles are active, and the eyes roll slowly, opening and closing moderately. The brain transitions from alpha waves having a frequency of 8–13 Hz (common in the awake state) to theta waves having a frequency of 4–7 Hz. Sudden twitches and hypnic jerks, also known as positive myoclonus, may be associated with the onset of sleep during N1. Some people may also experience hypnagogic hallucinations during this stage. During Non-REM1, humans lose some muscle tone and most conscious awareness of the external environment. NREM Stage 2

neg: Acadian orogeny of calcareous silty shales and carbonates. These deposits reflect small transgressive-regressive cycles in a delta-front and delta platform environments. The third stage is represented by regional uplift, which accompanied the collision of an Avalon terrane with a promontory, and subsequently, developed a regional disconformity. The fourth and final stage is represented by tectonic quiescence with a widespread carbonate deposition in a slowly transgressing sea. Acadian orogeny The Acadian orogeny is a long-lasting mountain building event which began in the Middle Devonian, reaching a climax in the early Late Devonian. It was active for approximately 50 million years, beginning roughly around

neg: Neuroscience of sleep muscles are paralyzed, and heart rate, breathing and body temperature become unregulated. REM sleep is turned on by acetylcholine secretion and is inhibited by neurons that secrete monoamines including serotonin. REM is also referred to as "paradoxical sleep" because the sleeper, although exhibiting high-frequency EEG waves similar to a waking state, is harder to arouse than at any other sleep stage. Vital signs indicate arousal and oxygen consumption by the brain is higher than when the sleeper is awake. REM sleep is characterized by high global cerebral blood flow, comparable to wakefulness. In fact, many areas in the cortex have

neg: Neural oscillation (7.5–12.5 Hz) that can be detected from the occipital lobe during relaxed wakefulness and which increases when the eyes are closed. Other frequency bands are: delta (1–4 Hz), theta (4–8 Hz), beta (13–30 Hz), low gamma (30–70 Hz), and high gamma (70–150 Hz) frequency bands, where faster rhythms such as gamma activity have been linked to cognitive processing. Indeed, EEG signals change dramatically during sleep and show a transition from faster frequencies to increasingly slower frequencies such as alpha waves. In fact, different sleep stages are commonly characterized by their spectral content. Consequently, neural oscillations have been linked to cognitive

neg: PGO waves of the neurons is during the N3 stage of NREM, also known as the slow-wave sleep cycle. These same neurons are also active during REM sleep, but at a greatly reduced amplitude than NREM sleep. The neuronal cells that allow for the transfer of PGO waves from the pons to the other parts of the brain reside on the rostral portion of the peribrachial area. This grouping of cells fire in precisely two modes. The first mode is burst firing through low-threshold Calcium (Ca) ion channels. The other mode is a repetitive tonic firing through Sodium (Na) dependent ion channels.

neg: Sleep cycle is drowsy or awake to falling asleep. Brain waves and muscle activity start to decrease at this stage. N2 is when the person experiences a light sleep. Eye movement has stopped by this time. Brain wave frequency and muscle tonus is decreased. The heart rate and body temperature goes down. N3 or even N4 are the most difficult stages to be awakened. Every part of the body is now relaxed, breathing, blood pressure and body temperature are reduced. The National Sleep Foundation discusses the different stages of NREM sleep and their importance. They describe REM sleep as "A unique state,

neg: Clinical neurochemistry is a common breathing disorder during sleep and is related to a disability in the central respiratory drive mechanisms. Parasomnias are a class represented by nightmares, sleep terrors, night terrors, schizophrenia, certain mood disorders, and other conditions which arise during Stage 4 of sleep. General anesthetics typically induce non-REM sleep characterized by amnesia, analgesia, immobility, and hypnosis by facilitating the inhibition of excitatory ion channels or the excitation of inhibitory ligand-gated channels. Schizophrenia is a psychological disorder in which a patient experiences symptoms including hallucinations, delusions, amotivation, social withdrawal, cognitive defects, and poor working memory. Heredity and gene inheritance is

neg: Delta wave called Yoga Nidra ("Sleep yoga") can remain conscious while in delta-sleep. Delta wave activity has also been purported to aid in the formation of declarative and explicit memory formation. In Advaita Vedanta, deep dreamless sleep coexists with wakefulness and dreaming in turiya, considered the background of the higher state of consciousness. If one can stay aware or conscious while in deepest dreamless sleep, a deep meditative state (known as "jagrat sushupti") is said to be achievable. This notion of paradoxical consciousness may be linked to high cortical activity which happens during the delta-sleep. While most drugs that affect sleep do

neg: PGO waves sleep. This has led some researchers to further theorize about the usefulness of PGO waves for dreaming. One key use of REM sleep is for the brain to process and store information from the previous day. In a sense, the brain is learning by establishing new neuronal connections for things that have been learned. Neurophysiological studies have indicated a relationship between increased P-wave density during post-training REM sleep and learning performance. Basically, the abundance of PGO waves translates into longer periods of REM sleep, which thereby allows the brain to have longer periods where neuronal connections are formed. The importance

neg: Sleep and memory a post-training REM sleep period to examine changes in P waves affecting reprocessing of recently acquired stimuli. It was found that not only were the P waves increased during post-training sleep but also the density of the waves. These findings may imply that P waves during REM sleep may help to activate critical forebrain and cortical structures dealing with memory consolidation. In a Hennevin et al. study, 1989, the mesencephalic reticular formation (MRF) was given light electrical stimulation, during REM sleep, which is known to have an advantageous effect for learning when applied after training. The rats in the experiment

neg: Delta sleep-inducing peptide use haven't been established in clinical research studies. Delta sleep-inducing peptide Delta sleep-inducing peptide, abbreviated DSIP, is a neuropeptide that when infused into the mesodiencephalic ventricle of recipient rabbits induces spindle and delta EEG activity and reduced motor activities. Its aminoacid sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. However, the gene is unknown, raising serious questions regarding the actual existence of this peptide in nature. Delta sleep-inducing peptide was first discovered in 1974 by the Swiss Schoenenberger-Monnier group who isolated it from the cerebral venous blood of rabbits in an induced state of sleep. It was primarily believed to be involved in sleep regulation

neg: Delta sleep-inducing peptide Delta sleep-inducing peptide Delta sleep-inducing peptide, abbreviated DSIP, is a neuropeptide that when infused into the mesodiencephalic ventricle of recipient rabbits induces spindle and delta EEG activity and reduced motor activities. Its aminoacid sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. However, the gene is unknown, raising serious questions regarding the actual existence of this peptide in nature. Delta sleep-inducing peptide was first discovered in 1974 by the Swiss Schoenenberger-Monnier group who isolated it from the cerebral venous blood of rabbits in an induced state of sleep. It was primarily believed to be involved in sleep regulation due to its apparent ability to induce slow-wave

neg: Sleep and learning a 12-hour wake session, but a significant increase in performance after each group slept. This study gives evidence that REM sleep is a significant factor in consolidating motor skill procedural memories, therefore sleep deprivation can impair performance on a motor learning task. This memory decrement results specifically from the loss of stage 2, REM sleep. Declarative memory has also been shown to benefit from sleep, but not in the same way as procedural memory. Declarative memories benefit from the slow-waves nREM sleep. A study was conducted where the subjects learned word pairs, and the results showed that sleep not only

neg: Sleep spindle Sleep spindle Sleep spindles are bursts of neural oscillatory activity that are generated by interplay of the thalamic reticular nucleus (TRN) and other thalamic nuclei during stage 2 NREM sleep in a frequency of ~10 –12 Hz for at least 0.5 seconds. After generation in the TRN, spindles are sustained and relayed to the cortex by a thalamo-thalamic and thalamo-cortical feedback loops regulated by both GABAergic and NMDA-receptor mediated glutamatergic neurotransmission. Sleep spindles have been found in all tested mammalian species and in vitro cells. Research supports that spindles (sometimes referred to as "sigma bands" or "sigma waves") play an

neg: Binge drinking waves that persisted into adulthood, including persisting disturbances in sleep EEG with a reduction in slow wave sleep. These EEG findings are similar to premature aging. According to one review of the literature, if the developmental stage of adolescence is similar to the developmental stage of the fetus with regard to sensitivity to the neurotoxic effects of alcohol, and if long-lasting or permanent damage to the brain occurs similar to what animal studies suggest, then this represents a major public health issue due to the high levels of alcohol use by adolescents. Indeed, alcohol can affect the remodeling and functional

neg: Long-term memory for long-term storage. Specifically new declarative memories are better remembered if recall follows Stage II non-rapid eye movement sleep. The reactivation of memories during sleep can lead to lasting synaptic changes within certain neural networks. It is the high spindle activity, low oscillation activity, and delta wave activity during NREM sleep that helps to contribute to declarative memory consolidation. In learning before sleep spindles are redistributed to neuronally active upstates within slow oscillations. Sleep spindles are thought to induce synaptic changes and thereby contribute to memory consolidation during sleep. Here, we examined the role of sleep in the object-place recognition

neg: Rapid eye movement sleep energy use in REM sleep, as measured by oxygen and glucose metabolism, equals or exceeds energy use in waking. The rate in non-REM sleep is 11 – 40% lower. Neural activity during REM sleep seems to originate in the brain stem, especially the pontine tegmentum and locus coeruleus. REM sleep is punctuated and immediately preceded by PGO (ponto-geniculo-occipital) waves, bursts of electrical activity originating in the brain stem. (PGO waves have long been measured directly in cats but not in humans because of constraints on experimentation; however comparable effects have been observed in humans during "phasic" events which occur during

neg: Non-rapid eye movement sleep cortices, and the superior temporal gyri. They have different lengths. There are slow spindles in the range of 11 – 13 Hz that are associated with increased activity in the superior frontal gyrus, and fast spindles in the range of 13 – 15 Hz that are associated with recruitment of sensorimotor processing cortical regions, as well as recruitment of the mesial frontal cortex and hippocampus. There is no clear answer as to what these sleep spindles mean, but ongoing research hopes to illuminate their function. K-complexes are single long delta waves that last for only a second. They are also

neg: Sleep and memory period while another group of rats were deprived sleep. When comparing the two groups the sleep deprived rats showed a significant deficit in learning from having not undergone REM sleep. In another rat group, the P wave generator was stimulated using a carbachol injection and the rats then underwent a sleep deprivation stage. When these rats were again tested on their learning it was shown that activation of the P wave generator during sleep deprivation resulted in normal learning being achieved. This would point to the fact that the activation of P waves, even without REM sleep, was enough to

neg: Zopiclone pharmacological profile as benzodiazepines, including anxiolytic properties. Its mechanism of action is by binding to the benzodiazepine site and acting as a full agonist, which in turn positively modulates benzodiazepine-sensitive GABA receptors and enhances GABA binding at the GABA receptors to produce zopiclone's pharmacological properties. In addition to zopiclone's benzodiazepine pharmacological properties, it also has some barbiturate-like properties. In EEG studies, zopiclone significantly increases the energy of the beta frequency band and shows characteristics of high-voltage slow waves, desynchronization of hippocampal theta waves, and an increase in the energy of the delta frequency band. Zopiclone increases both stage 2 and

neg: Delta wave may manifest as disruptions in delta wave activity, such as alpha waves presenting in the EEG spectrum. Delta wave disruptions may present as a result of physiological damage, changes in nutrient metabolism, chemical alteration, or may also be idiopathic. Disruptions in delta activity is seen in adults during states of intoxication or delirium and in those diagnosed with various neurological disorders such as dementia or schizophrenia. Temporal low-voltage irregular delta wave activity has been commonly detected in patients with ischemic brain diseases, particularly in association with small ischemic lesions and is seen to be indicative of early-stage cerebrovascular damage. Parasomnias,

neg: Hypnagogia those of their culture. Physiological studies have tended to concentrate on hypnagogia in the strict sense of spontaneous sleep onset experiences. Such experiences are associated especially with stage 1 of NREM sleep, but may also occur with pre-sleep alpha waves. Davis et al. found short flashes of dreamlike imagery at the onset of sleep to correlate with drop-offs in alpha EEG activity. Hori et al. regard sleep onset hypnagogia as a state distinct from both wakefulness and sleep with unique electrophysiological, behavioral and subjective characteristics, while Germaine et al. have demonstrated a resemblance between the EEG power spectra of spontaneously

neg: Sleep sex require up to thirty minutes to regain normal function and consciousness. Though it is not possible for a definitive diagnosis of sexsomnia, a series of factors are considered to determine the presence of the condition. Clinical tests may also be utilized for further study. Determining factors include but are not limited to: Electroencephalograms, or EEG, are tests used to depict electrical activity and waves produced by the brain. This test has the ability to detect abnormalities that are associated with disorders that affect brain activity. Episodes of sexsomnia occur most commonly during slow-wave-sleep, or SWS. During this stage of sleep,

neg: Night terror in which any type of nocturnal attack or nightmare may be confused with and reported as a night terror. Night terrors tend to happen during periods of arousal from delta sleep, also known as slow-wave sleep. Delta sleep occurs most often during the first half of a sleep cycle, which indicates that people with more delta sleep activity are more prone to night terrors. However, they can also occur during daytime naps. Night terrors can often be mistaken for confusional arousal. While nightmares (bad dreams that cause feelings of horror or fear) are relatively common during childhood, night terrors occur

neg: Psychology EEG on an unopened skull, quickly found that brains exhibit signature "brain waves": electric oscillations which correspond to different states of consciousness. Researchers subsequently refined statistical methods for synthesizing the electrode data, and identified unique brain wave patterns such as the delta wave observed during non-REM sleep. Newer functional neuroimaging techniques include functional magnetic resonance imaging and positron emission tomography, both of which track the flow of blood through the brain. These technologies provide more localized information about activity in the brain and create representations of the brain with widespread appeal. They also provide insight which avoids the classic problems

neg: PGO waves provide excitatory bouts of PGO wave generation when electrically stimulated. The neurons within the suprachiasmatic nuclei region of the brain help to regulate REM sleep. The REM sleep cycle length causes the frequency of PGO waves to be phase locked. The use of auditory stimulation has been shown to increase PGO waves during waking and sleeping cycles with neurons associated with transfers of auditory information. Even while the subject is awake and in total darkness, the amplitude of PGO waves increases by auditory stimulation. Another study also found that auditory stimulation increased the amplitude of PGO waves in slow-wave sleep

neg: Electroencephalography and neonatal EEG is quite different from the adult EEG. Fetuses in the third trimester and newborns display two common brain activity patterns: "discontinuous" and "trace alternant." "Discontinuous" electrical activity refers to sharp bursts of electrical activity followed by low frequency waves. "Trace alternant" electrical activity describes sharp bursts followed by short high amplitude intervals and usually indicates quiet sleep in newborns. The EEG in childhood generally has slower frequency oscillations than the adult EEG. The normal EEG also varies depending on state. The EEG is used along with other measurements (EOG, EMG) to define sleep stages in polysomnography. Stage

neg: PGO waves of PGO waves during REM sleep also aids the idea of PGO waves as a signal that a person is dreaming. Since dreaming occurs during REM sleep, the PGO waves are theorized to be the signals that make the brain start to recount the experiences from the previous day. This, in turn, allows us to "see" our dreams since our visual sense is quickly going through the information it has stored. For more information of the importance of PGO waves during REM sleep, please refer to Activation synthesis theory. The next big area to research regarding this topic is to

neg: River delta slope offshore, waves will make river deltas smoother. Waves can also be responsible for carrying sediments away from the river delta, causing the delta to retreat. For deltas that form further upriver in an estuary, there are complex yet quantifiable linkages between winds, tides, river discharge, and delta water levels. Erosion is also an important control in tide-dominated deltas, such as the Ganges Delta, which may be mainly submarine, with prominent sandbars and ridges. This tends to produce a "dendritic" structure. Tidal deltas behave differently from a river- and wave-dominated deltas, which tend to have a few main distributaries. Once

neg: Rapid eye movement sleep reinterpreted in relation to previous semantic representations or nodes." In the "ultradian sleep cycle" an organism alternates between deep sleep (slow, large, synchronized brain waves) and paradoxical sleep (faster, desynchronized waves). Sleep happens in the context of the larger circadian rhythm, which influences sleepiness and physiological factors based on timekeepers within the body. Sleep can be distributed throughout the day or clustered during one part of the rhythm: in nocturnal animals, during the day, and in diurnal animals, at night. The organism returns to homeostatic regulation almost immediately after REM sleep ends. During a night of sleep, humans usually experience

neg: PGO waves and subthalamic nucleus (or subthalamus). This latter, glutamatergic nucleus is reciprocally connected with the PGO-transferring nuclei of the pons. In humans, subthalamic PGO-like waves, that resemble the PGO waves typically recorded in cats, can be recorded during pre-REM and REM sleep. This suggests that the subthalamus may play an active role in an ascending activating network implicated in the rostral transmission of PGO waves during REM sleep in humans. PGO waves are an integral part of rapid eye movement (REM) sleep. As stated earlier, the density of the PGO waves coincides with the amount of eye movement measured in REM

neg: Oneirology this type of brain stimulation, the dreaming that occurs is a by-product of the process. During normal sleep cycles, humans alternate between normal, NREM sleep and REM sleep. The brain waves characteristic of dreaming that are observed during REM sleep are the most commonly studied in dream research because most dreaming occurs during REM sleep. In 1952, Eugene Aserinsky discovered REM sleep while working in the surgery of his PhD advisor. Aserinsky noticed that the sleepers' eyes fluttered beneath their closed eyelids, later using a polygraph machine to record their brain waves during these periods. In one session, he awakened

neg: Delta Cryogenic Second Stage Delta Cryogenic Second Stage The Delta Cryogenic Second Stage (DCSS) is a family of cryogenic rocket stages used on the Delta III & Delta IV rockets, and which is planned to be used on the Block I Space Launch System. The stage consists of a cylindrical LH2 tank structurally separated from an oblate spheroid LOX tank. The LH2 tank cylinder carries payload launch loads, while the LOX tank and engine are suspended below within the rocket's inter-stage. The stage is powered by a single Pratt & Whitney RL10B-2 engine, which features an extendable carbon-carbon nozzle to improve specific impulse. The

neg: Delta-K Delta-K The Delta-K is an American rocket stage, developed by McDonnell Douglas and Aerojet. It was first used on August 27, 1989 as the second stage for the Delta 4000 series. It has continued to serve as the second stage for subsequent variants of the Delta rocket. It is propelled by a single AJ10-118K rocket engine, fueled by Aerozine 50 and dinitrogen tetroxide, which are hypergolic. The Delta-K has a long heritage to the first Able stage used in Project Vanguard. The AJ-10 engine was first used in the Able second stage of the Vanguard rocket, as the AJ10-118 configuration.

neg: Rapid eye movement sleep a nearly complete absence of monoamine neurotransmitters histamine, serotonin, and norepinephrine. REM sleep is physiologically different from the other phases of sleep, which are collectively referred to as non-REM sleep (NREM sleep, NREMS, synchronized sleep). REM and non-REM sleep alternate within one sleep cycle, which lasts about 90 minutes in adult humans. As sleep cycles continue, they shift towards a higher proportion of REM sleep. The transition to REM sleep brings marked physical changes, beginning with electrical bursts called PGO waves originating in the brain stem. Organisms in REM sleep suspend central homeostasis, allowing large fluctuations in respiration, thermoregulation, and

neg: Rapid eye movement sleep REM sleep, and the existence of similar PGO waves is thus inferred.) These waves occur in clusters about every 6 seconds for 1–2 minutes during the transition from deep to paradoxical sleep. They exhibit their highest amplitude upon moving into the visual cortex and are a cause of the "rapid eye movements" in paradoxical sleep. Other muscles may also contract under the influence of these waves. Research in the 1990s using positron emission tomography (PET) confirmed the role of the brain stem and suggested that, within the forebrain, the limbic and paralimbic systems showed more activation than other areas. The

neg: Neuroscience of sleep REM sleep is also related to the firing of ponto-geniculo-occipital waves (also called phasic activity or PGO waves) and activity in the cholinergic ascending arousal system. The PGO waves have been recorded in the lateral geniculate nucleus and occipital cortex during the pre-REM period and are thought to represent dream content. The greater signal-to-noise ratio in the LG cortical channel suggests that visual imagery in dreams may appear before full development of REM sleep, but this has not yet been confirmed. PGO waves may also play a role in development and structural maturation of brain, as well as long term

neg: Sea Dance Festival soft sand. The key stages of the festival include the Main stage with its 30,000 attendee capacity, No Sleep Stage, Reggae Stage, Silent Dance, Latino Stage, Cinema, and CHILL Zone. Dance Paradise Stage was replaced with the No Sleep Stage in 2017. The first Sea Dance Festival was held from 15 to 17 July 2014 at the Jaz beach in Budva, and represented 3 days of music performances. The festival was part of the EXIT Adventure, representing an additional 3 days of EXIT Festival. First edition of the festival visited 80 thousand people, making it one of the most visited

neg: Pontine tegmentum sleep Pontine waves, (PGO waves) or P-waves, are brain waves generated in the pontine tegmentum. They can be observed in mammals to precede the onset of REM sleep, and continue throughout its course. After periods of memory training, P-wave density increases during subsequent sleep periods in rats. This may be an indication of a link between sleep and learning. The two respiratory areas – the pneumotaxic center and the apneustic center make up the pontine respiratory group that provide antagonistic control signals to the dorsal respiratory group (DRG) located in the medulla. Increased input from the pneumotaxic center decreases the

neg: Delta-K It was initially fueled by nitric acid and UDMH. An AJ10 engine was first fired in flight during the third Vanguard launch, on 17 March 1958, which successfully placed the Vanguard 1 satellite into orbit. As of 25 May 2008, 138 have been launched, and excluding one which was destroyed by the explosion of a lower stage, none have failed. The Delta-K was used as the second stage of the Delta II rocket from 1989 to 2018. This second stage was retired at conclusion of the ICESat-2 launch on 15 September, 2018. Delta-K The Delta-K is an American rocket stage,

neg: Delta-P Delta-P The Delta-P is an American rocket stage, developed by McDonnell Douglas and TRW, first used on November 10, 1972 as the second stage for the Delta 1000 series. It continued to serve as the second stage for subsequent Delta 2000 and Delta 3000 flights for 17 years, with its last usage on February 8, 1988. It is propelled by a single TRW TR-201 rocket engine, fueled by Aerozine 50 and dinitrogen tetroxide, which are hypergolic. The Delta-P traces its heritage to the Apollo Lunar Module's Descent Propulsion System. The TR-201 engine is the Descent Propulsion System modified to be

neg: Rapid eye movement sleep whilst weaker, transient, "noise" memory traces disintegrate. Memory consolidation during paradoxical sleep is specifically correlated with the periods of rapid eye movement, which do not occur continuously. One explanation for this correlation is that the PGO electrical waves, which precede the eye movements, also influence memory. REM sleep could provide a unique opportunity for “unlearning” to occur in the basic neural networks involved in homeostasis, which are protected from this “synaptic downscaling” effect during deep sleep. REM sleep prevails most after birth, and diminishes with age. According to the "ontogenetic hypothesis", REM (also known in neonates as "active sleep") aids

neg: PGO waves understand what processes PGO waves are beneficial for in both states of sleep as well as consciousness. Although PGO waves are noticeably present during NREM sleep, some scientists believe they are also present during waking cycles. There is a possibility that PGO waves are essential for image correction of the eyes, since PGO waves are signals on a pathway that allow the motor cortex of the brain to interface with the vision system. The other future interests in research of this topic are what PGO waves are precisely doing for us while we are dreaming. Some scientists theorize that PGO